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Li X, Wang J, Liao C, Yang X, Zhao Z, Liu Y, Xue Q, Luo Y, Liu X, Liu Z. The binding of PKCε and MEG2 to STAT3 regulates IL-6-mediated microglial hyperalgesia during inflammatory pain. FASEB J 2024; 38:e23590. [PMID: 38656553 DOI: 10.1096/fj.202300152rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/10/2024] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
Studies have suggested that microglial IL-6 modulates inflammatory pain; however, the exact mechanism of action remains unclear. We therefore hypothesized that PKCε and MEG2 competitively bind to STAT3 and contribute to IL-6-mediated microglial hyperalgesia during inflammatory pain. Freund's complete adjuvant (FCA) and lipopolysaccharide (LPS) were used to induce hyperalgesia model mice and microglial inflammation. Mechanical allodynia was evaluated using von Frey tests in vivo. The interaction among PKCε, MEG2, and STAT3 was determined using ELISA and immunoprecipitation assay in vitro. The PKCε, MEG2, t-STAT3, pSTAT3Tyr705, pSTAT3Ser727, IL-6, GLUT3, and TREM2 were assessed by Western blot. IL-6 promoter activity and IL-6 concentration were examined using dual luciferase assays and ELISA. Overexpression of PKCε and MEG2 promoted and attenuated inflammatory pain, accompanied by an increase and decrease in IL-6 expression, respectively. PKCε displayed a stronger binding ability to STAT3 when competing with MEG2. STAT3Ser727 phosphorylation increased STAT3 interaction with both PKCε and MEG2. Moreover, LPS increased PKCε, MEG2, pSTAT3Tyr705, pSTAT3Ser727, IL-6, and GLUT3 levels and decreased TREM2 during microglia inflammation. IL-6 promoter activity was enhanced or inhibited by PKCε or MEG2 in the presence of STAT3 and LPS stimulation, respectively. In microglia, overexpression of PKCε and/or MEG2 resulted in the elevation of tSTAT3, pSTAT3Tyr705, pSTAT3Ser727, IL-6, and TREM2, and the reduction of GLUT3. PKCε is more potent than MEG2 when competitively binding to STAT3, displaying dual modulatory effects of IL-6 production, thus regulating the GLUT3 and TREM2 in microglia during inflammatory pain sensation.
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Affiliation(s)
- Xiongjuan Li
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Junliang Wang
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Changjian Liao
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Xinping Yang
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Zhao Zhao
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Yuqiang Liu
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
| | - Qingsheng Xue
- Department of Anesthesiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Yan Luo
- Department of Anesthesiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Xuesheng Liu
- Department of Anesthesiology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zhiheng Liu
- Department of Anesthesiology, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen, China
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Dugan MP, Maiya R, Fleischer C, Bajo M, Snyder AE, Koduri A, Srinivasan S, Roberto M, Messing RO. Brain-specific serine/threonine-protein kinase 1 is a substrate of protein kinase C epsilon involved in sex-specific ethanol and anxiety phenotypes. Addict Biol 2024; 29:e13388. [PMID: 38497285 PMCID: PMC10950061 DOI: 10.1111/adb.13388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 03/19/2024]
Abstract
Protein kinase C epsilon (PKCε) regulates behavioural responses to ethanol and plays a role in anxiety-like behaviour, but knowledge is limited on downstream substrates of PKCε that contribute to these behaviours. We recently identified brain-specific serine/threonine-protein kinase 1 (BRSK1) as a substrate of PKCε. Here, we test the hypothesis that BRSK1 mediates responses to ethanol and anxiety-like behaviours that are also PKCε dependent. We used in vitro kinase assays to further validate BRSK1 as a substrate of PKCε and used Brsk1-/- mice to assess the role of BRSK1 in ethanol- and anxiety-related behaviours and in physiological responses to ethanol. We found that BRSK1 is phosphorylated by PKCε at a residue identified in a chemical genetic screen of PKCε substrates in mouse brain. Like Prkce-/- mice, male and female Brsk1-/- mice were more sensitive than wild-type to the acute sedative-hypnotic effect of alcohol. Unlike Prkce-/- mice, Brsk1-/- mice responded like wild-type to ataxic doses of ethanol. Although in Prkce-/- mice ethanol consumption and reward are reduced in both sexes, they were reduced only in female Brsk1-/- mice. Ex vivo slice electrophysiology revealed that ethanol-induced facilitation of GABA release in the central amygdala was absent in male Brsk1-/- mice similar to findings in male Prkce-/- mice. Collectively, these results indicate that BRSK1 is a target of PKCε that mediates some PKCε-dependent responses to ethanol in a sex-specific manner and plays a role distinct from PKCε in anxiety-like behaviour.
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Affiliation(s)
- Michael P. Dugan
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Rajani Maiya
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
| | - Caleb Fleischer
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Michal Bajo
- Departments of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Angela E. Snyder
- Departments of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Ashwin Koduri
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Sathvik Srinivasan
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Marisa Roberto
- Departments of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Robert O. Messing
- Waggoner Center for Alcohol and Addiction Research, Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
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Khan K, Zafar S, Badshah Y, Ashraf NM, Rafiq M, Danish L, Shabbir M, Trembley JH, Afsar T, Almajwal A, Razak S. Cross talk of tumor protein D52 (TPD52) with KLF9, PKCε, and MicroRNA 223 in ovarian cancer. J Ovarian Res 2023; 16:202. [PMID: 37833790 PMCID: PMC10571360 DOI: 10.1186/s13048-023-01292-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Gynecologic cancers comprise malignancies in the female reproductive organs. Ovarian cancer ranks sixth in terms of incidence rates while seventh in terms of mortality rates. The stage at which ovarian cancer is diagnosed mainly determines the survival outcomes of patients. Various screening approaches are presently employed for diagnosing ovarian cancer; however, these techniques have low accuracy and are non-specific, resulting in high mortality rates of patients due to this disease. Hence, it is crucial to identify improved screening and diagnostic markers to overcome this cancer. This study aimed to find new biomarkers to facilitate the prognosis and diagnosis of ovarian cancer. METHODS Bioinformatics approaches were used to predict the tertiary structure and cellular localization along with phylogenetic analysis of TPD52. Its molecular interactions were determined through KEGG analysis, and real-time PCR-based expression analysis was performed to assess its co-expression with another oncogenic cellular pathway (miR-223, KLF9, and PKCε) proteins in ovarian cancer. RESULTS Bioinformatics analysis depicted the cytoplasmic localization of TPD52 and the high conservation of its coiled-coil domains. Further study revealed that TPD52 mRNA and miRNA-223 expression was elevated, while the expression of KLF 9 and PKCε was reduced in the blood of ovarian cancer patients. Furthermore, TPD52 and miR-223 expression were upregulated in the early stages of cancer and non-metastatic cancers. CONCLUSION TPD52, miR-223, PKCε, and KLF9, can be used as a blood based markers for disease prognosis, metastasis, and treatment response. The study outcomes hold great potential to be translated at the clinical level after further validation on larger cohorts.
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Affiliation(s)
- Khushbukhat Khan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan
| | - Sameen Zafar
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan
| | - Yasmin Badshah
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan
| | - Naeem Mahmood Ashraf
- School of Biochemistry & Biotechnology, University of the Punjab, Lahore, Pakistan
| | - Mehak Rafiq
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences and Technology, Islamabad, 44000, Pakistan
| | - Lubna Danish
- Agricultural Research Institute, Tarnab, Peshawar, Pakistan
| | - Maria Shabbir
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan.
- Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
| | - Janeen H Trembley
- Research Service, Minneapolis VA Health Care System, Minneapolis, MN, USA
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Tayyaba Afsar
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ali Almajwal
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Suhail Razak
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
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Zafar S, Khan K, Badshah Y, Shahid K, Trembley JH, Hafeez A, Ashraf NM, Arslan H, Shabbir M, Afsar T, Almajwal A, Razak S. Exploring the prognostic significance of PKCε variants in cervical cancer. BMC Cancer 2023; 23:819. [PMID: 37667176 PMCID: PMC10476323 DOI: 10.1186/s12885-023-11236-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/29/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Protein Kinase C-epsilon (PKCε) is a member of the novel subfamily of PKCs (nPKCs) that plays a role in cancer development. Studies have revealed that its elevated expression levels are associated with cervical cancer. Previously, we identified pathogenic variations in its different domains through various bioinformatics tools and molecular dynamic simulation. In the present study, the aim was to find the association of its variants rs1553369874 and rs1345511001 with cervical cancer and to determine the influence of these variants on the protein-protein interactions of PKCε, which can lead towards cancer development and poor survival rates. METHODS The association of the variants with cervical cancer and its clinicopathological features was determined through genotyping analysis. Odds ratio and relative risk along with Fisher exact test were calculated to evaluate variants significance and disease risk. Protein-protein docking was performed and docked complexes were subjected to molecular dynamics simulation to gauge the variants impact on PKCε's molecular interactions. RESULTS This study revealed that genetic variants rs1553369874 and rs1345511001 were associated with cervical cancer. Smad3 interacts with PKCε and this interaction promotes cervical cancer angiogenesis; therefore, Smad3 was selected for protein-protein docking. The analysis revealed PKCε variants promoted aberrant interactions with Smad3 that might lead to the activation of oncogenic pathways. The data obtained from this study suggested the prognostic significance of PRKCE gene variants rs1553369874 and rs1345511001. CONCLUSION Through further in vitro and in vivo validation, these variants can be used at the clinical level as novel prognostic markers and therapeutic targets against cervical cancer.
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Affiliation(s)
- Sameen Zafar
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Khushbukhat Khan
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Yasmin Badshah
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
| | - Kanza Shahid
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Janeen H Trembley
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
- Minneapolis VA Health Care System Research Service, Minneapolis, MN, USA
| | - Amna Hafeez
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Naeem Mahmood Ashraf
- School of Biochemistry and Biotechnology, University of the Punjab, Lahore, Pakistan
| | - Hamid Arslan
- University of Bonn, LIMES Institute (AG-Netea), Carl-Troll-Str. 31, 53115, Bonn, Germany
| | - Maria Shabbir
- Department of Healthcare Biotechnology, Atta-Ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Tayyaba Afsar
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ali Almajwal
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Suhail Razak
- Department of Community Health Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
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La Cognata V, D’Amico AG, Maugeri G, Morello G, Guarnaccia M, Magrì B, Aronica E, Alkon DL, D’Agata V, Cavallaro S. The ε-Isozyme of Protein Kinase C (PKCε) Is Impaired in ALS Motor Cortex and Its Pulse Activation by Bryostatin-1 Produces Long Term Survival in Degenerating SOD1-G93A Motor Neuron-like Cells. Int J Mol Sci 2023; 24:12825. [PMID: 37629005 PMCID: PMC10454105 DOI: 10.3390/ijms241612825] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and ultimately fatal neurodegenerative disease, characterized by a progressive depletion of upper and lower motor neurons (MNs) in the brain and spinal cord. The aberrant regulation of several PKC-mediated signal transduction pathways in ALS has been characterized so far, describing either impaired expression or altered activity of single PKC isozymes (α, β, ζ and δ). Here, we detailed the distribution and cellular localization of the ε-isozyme of protein kinase C (PKCε) in human postmortem motor cortex specimens and reported a significant decrease in both PKCε mRNA (PRKCE) and protein immunoreactivity in a subset of sporadic ALS patients. We furthermore investigated the steady-state levels of both pan and phosphorylated PKCε in doxycycline-activated NSC-34 cell lines carrying the human wild-type (WT) or mutant G93A SOD1 and the biological long-term effect of its transient agonism by Bryostatin-1. The G93A-SOD1 cells showed a significant reduction of the phosphoPKCε/panPKCε ratio compared to the WT. Moreover, a brief pulse activation of PKCε by Bryostatin-1 produced long-term survival in activated G93A-SOD1 degenerating cells in two different cell death paradigms (serum starvation and chemokines-induced toxicity). Altogether, the data support the implication of PKCε in ALS pathophysiology and suggests its pharmacological modulation as a potential neuroprotective strategy, at least in a subgroup of sporadic ALS patients.
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Affiliation(s)
- Valentina La Cognata
- Institute for Biomedical Research and Innovation, National Research Council, 95126 Catania, Italy
| | - Agata Grazia D’Amico
- Section of Human Anatomy and Histology, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Grazia Maugeri
- Section of Human Anatomy and Histology, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Giovanna Morello
- Institute for Biomedical Research and Innovation, National Research Council, 95126 Catania, Italy
| | - Maria Guarnaccia
- Institute for Biomedical Research and Innovation, National Research Council, 95126 Catania, Italy
| | - Benedetta Magrì
- Section of Human Anatomy and Histology, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Meibergdreef 9, 1105 Amsterdam, The Netherlands
| | | | - Velia D’Agata
- Section of Human Anatomy and Histology, Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy
| | - Sebastiano Cavallaro
- Institute for Biomedical Research and Innovation, National Research Council, 95126 Catania, Italy
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Qin W, Weng J. Hepatocyte NLRP3 interacts with PKCε to drive hepatic insulin resistance and steatosis. Sci Bull (Beijing) 2023; 68:1413-1429. [PMID: 37336688 DOI: 10.1016/j.scib.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/17/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023]
Abstract
Hepatic insulin resistance (IR), as a downstream sequela of nonalcoholic fatty liver disease (NAFLD), is strongly associated with liver steatosis. Despite numerous mechanism advancements, the molecular underpinnings and pathogenesis of hepatic IR, especially regarding the pattern recognition receptors in hepatocytes, remain elusive. Here, we identified hepatocyte NLRP3 as a direct and previously-unresolved driver of hepatic IR to promote steatosis response. Under the model of NAFLD, we identified hepatocyte NLRP3 as a crucial inducer of hepatic IR by undertaking multilayer transcriptomic searches and further confirmed that its expression was increased in the liver tissues from NAFLD patients and mouse models (high-fat diet (HFD), leptin-receptor-deficient (db/db) mice), and in palmitic acid (PA)-induced hepatocytes. Loss- or gain-of-function of hepatocyte-specific NLRP3 in HFD-induced mice ameliorated or exacerbated hepatic IR and steatosis, respectively. Mechanistically, NLRP3 directly bound to and promoted protein kinase C epsilon (PKCε) activation to impair insulin signaling and increase liver steatosis, while inhibition of PKCε activation dampened the beneficial effects seen in HFD-induced NLRP3-deficient mice. Moreover, we performed screening and discovered that the transcription factor Yin Yang 1 (YY1) positively controlled NLRP3 expression. In translational potential, adeno-associated virus serotype 8 (AAV8)-mediated NLRP3 knockdown in the liver alleviated hepatic IR and steatosis in db/db mice, and pharmacological inhibition of NLRP3 markedly alleviated diet-induced metabolic disorders. This finding reveals a previously-unexpected regulatory axis from YY1 to PKCε via NLRP3 induction for metabolic diseases and establishes the YY1-NLRP3-PKCε axis as a potential therapeutic target for NAFLD.
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Affiliation(s)
- Weiwei Qin
- Department of Endocrinology, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Clinical Research Hospital of Chinese Academy of Sciences (Hefei), University of Science and Technology of China, Hefei 230027, China
| | - Jianping Weng
- Department of Endocrinology, Institute of Endocrine and Metabolic Diseases, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Clinical Research Hospital of Chinese Academy of Sciences (Hefei), University of Science and Technology of China, Hefei 230027, China.
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Hanim A, Mohamed IN, Mohamed RMP, Mokhtar MH, Makpol S, Naomi R, Bahari H, Kamal H, Kumar J. Alcohol Dependence Modulates Amygdalar mTORC2 and PKCε Expression in a Rodent Model. Nutrients 2023; 15:3036. [PMID: 37447362 PMCID: PMC10346598 DOI: 10.3390/nu15133036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/24/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
Multiple alcohol use disorder (AUD)-related behavioral alterations are governed by protein kinase C epsilon (PKCε), particularly in the amygdala. Protein kinase C (PKC) is readily phosphorylated at Ser729 before activation by the mTORC2 protein complex. In keeping with this, the current study was conducted to assess the variations in mTORC2 and PKCε during different ethanol exposure stages. The following groups of rats were employed: control, acute, chronic, ethanol withdrawal (EW), and EW + ethanol (EtOH). Ethanol-containing and non-ethanol-containing modified liquid diets (MLDs) were administered for 27 days. On day 28, either saline or ethanol (2.5 g/kg, 20% v/v) was intraperitoneally administered, followed by bilateral amygdala extraction. PKCε mRNA levels were noticeably increased in the amygdala of the EW + EtOH and EW groups. Following chronic ethanol consumption, the stress-activated map kinase-interacting protein 1 (Sin1) gene expression was markedly decreased. In the EW, EW + EtOH, and chronic ethanol groups, there was a profound increase in the protein expression of mTOR, Sin1, PKCε, and phosphorylated PKCε (Ser729). The PKCε gene and protein expressions showed a statistically significant moderate association, according to a correlation analysis. Our results suggest that an elevated PKCε protein expression in the amygdala during EW and EW + EtOH occurred at the transcriptional level. However, an elevation in the PKCε protein expression, but not its mRNA, after chronic ethanol intake warrants further investigation to fully understand the signaling pathways during different episodes of AUD.
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Affiliation(s)
- Athirah Hanim
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Isa N. Mohamed
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Rashidi M. P. Mohamed
- Department of Family Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Mohd Helmy Mokhtar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Suzana Makpol
- Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia;
| | - Ruth Naomi
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (R.N.); (H.B.)
| | - Hasnah Bahari
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (R.N.); (H.B.)
| | - Haziq Kamal
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur 56000, Malaysia; (A.H.); (M.H.M.); (H.K.)
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Dugan MP, Ferguson LB, Hertz NT, Chalkley RJ, Burlingame AL, Shokat KM, Parker PJ, Messing RO. Chemical Genetic Identification of PKC Epsilon Substrates in Mouse Brain. Mol Cell Proteomics 2023; 22:100522. [PMID: 36863607 PMCID: PMC10105488 DOI: 10.1016/j.mcpro.2023.100522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/25/2023] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
PKC epsilon (PKCε) plays important roles in behavioral responses to alcohol and in anxiety-like behavior in rodents, making it a potential drug target for reducing alcohol consumption and anxiety. Identifying signals downstream of PKCε could reveal additional targets and strategies for interfering with PKCε signaling. We used a chemical genetic screen combined with mass spectrometry to identify direct substrates of PKCε in mouse brain and validated findings for 39 of them using peptide arrays and in vitro kinase assays. Prioritizing substrates with several public databases such as LINCS-L1000, STRING, GeneFriends, and GeneMAINA predicted interactions between these putative substrates and PKCε and identified substrates associated with alcohol-related behaviors, actions of benzodiazepines, and chronic stress. The 39 substrates could be broadly classified in three functional categories: cytoskeletal regulation, morphogenesis, and synaptic function. These results provide a list of brain PKCε substrates, many of which are novel, for future investigation to determine the role of PKCε signaling in alcohol responses, anxiety, responses to stress, and other related behaviors.
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Affiliation(s)
- Michael P Dugan
- Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Laura B Ferguson
- Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA
| | - Nicholas T Hertz
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute at the University of California San Francisco, San Francisco, California, USA; Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Robert J Chalkley
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute at the University of California San Francisco, San Francisco, California, USA
| | - Peter J Parker
- The Francis Crick Institute, London, United Kingdom; School of Cancer and Pharmaceutical Sciences, King's College London, London, United Kingdom
| | - Robert O Messing
- Department of Neuroscience, The University of Texas at Austin, Austin, Texas, USA.
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Gada KD, Chang M, Chandrashekar A, Plant LD, Noujaim SF, Logothetis DE. Mechanism of PKCε regulation of cardiac GIRK channel gating. Proc Natl Acad Sci U S A 2023; 120:e2212325120. [PMID: 36584301 PMCID: PMC9910474 DOI: 10.1073/pnas.2212325120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/09/2022] [Indexed: 12/31/2022] Open
Abstract
G-protein-gated inwardly rectifying potassium (GIRK) channel activity is regulated by the membrane phospholipid, phosphatidylinositol-4,5-bisphosphate (PI 4,5P2). Constitutive activity of cardiac GIRK channels in atrial myocytes, that is implicated in atrial fibrillation (AF), is mediated via a protein kinase C-ε (PKCε)-dependent mechanism. The novel PKC isoform, PKCε, is reported to enhance the activity of cardiac GIRK channels. Here, we report that PKCε stimulation leads to activation of GIRK channels in mouse atria and in human stem cell-derived atrial cardiomyocytes (iPSCs). We identified residue GIRK4(S418) which when mutated to Ala abolished, or to Glu, mimicked the effects of PKCε on GIRK currents. PKCε strengthened the interactions of the cardiac GIRK isoforms, GIRK4 and GIRK1/4 with PIP2, an effect that was reversed in the GIRK4(S418A) mutant. This mechanistic insight into the PKCε-mediated increase in channel activity because of GIRK4(S418) phosphorylation, provides a precise druggable target to reverse AF-related pathologies due to GIRK overactivity.
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Affiliation(s)
- Kirin D. Gada
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
| | - Mengmeng Chang
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL33602
| | - Aishwarya Chandrashekar
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
| | - Leigh D. Plant
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
- Center for Drug Discovery, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
| | - Sami F. Noujaim
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL33602
| | - Diomedes E. Logothetis
- Department of Pharmaceutical Sciences, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
- Center for Drug Discovery, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
- Department of Chemistry and Chemical Biology, Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA02115
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Chen L, Wang H, Xing J, Shi X, Huang H, Huang J, Xu C. Silencing P2X7R Alleviates Diabetic Neuropathic Pain Involving TRPV1 via PKCε/P38MAPK/NF-κB Signaling Pathway in Rats. Int J Mol Sci 2022; 23:ijms232214141. [PMID: 36430617 PMCID: PMC9696864 DOI: 10.3390/ijms232214141] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/09/2022] [Accepted: 11/12/2022] [Indexed: 11/19/2022] Open
Abstract
Transient receptor potential vanillic acid 1 (TRPV1) is an ion channel activated by heat and inflammatory factors involved in the development of various types of pain. The P2X7 receptor is in the P2X family and is associated with pain mediated by satellite glial cells. There might be some connection between the P2X7 receptor and TRPV1 in neuropathic pain in diabetic rats. A type 2 diabetic neuropathic pain rat model was induced using high glucose and high-fat diet for 4 weeks and low-dose streptozocin (35 mg/kg) intraperitoneal injection to destroy islet B cells. Male Sprague Dawley rats were administrated by intrathecal injection of P2X7 shRNA and p38 inhibitor, and we recorded abnormal mechanical and thermal pain and nociceptive hyperalgesia. One week later, the dorsal root ganglia from the L4-L6 segment of the spinal cord were harvested for subsequent experiments. We measured pro-inflammatory cytokines, examined the relationship between TRPV1 on neurons and P2X7 receptor on satellite glial cells by measuring protein and transcription levels of P2X7 receptor and TRPV1, and measured protein expression in the PKCε/P38 MAPK/NF-κB signaling pathway after intrathecal injection. P2X7 shRNA and p38 inhibitor relieved hyperalgesia in diabetic neuropathic pain rats and modulated inflammatory factors in vivo. P2X7 shRNA and P38 inhibitors significantly reduced TRPV1 expression by downregulating the PKCε/P38 MAPK/NF-κB signaling pathway and inflammatory factors in dorsal root ganglia. Intrathecal injection of P2X7 shRNA alleviates nociceptive reactions in rats with diabetic neuropathic pain involving TRPV1 via PKCε/P38 MAPK/NF-κB signaling pathway.
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Affiliation(s)
- Lisha Chen
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Hongji Wang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Juping Xing
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Xiangchao Shi
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Huan Huang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Jiabao Huang
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
| | - Changshui Xu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang 330006, China
- Jiangxi Provincial Key Laboratory of Autonomic Nervous Function and Disease, Nanchang 330006, China
- The Clinical Medical School, Jiangxi Medical College, Shangrao 334000, China
- The First Affiliated Hospital, Jiangxi Medical College, Shangrao 334000, China
- Correspondence: ; Tel.: +86-791-86360556
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Barbagallo D, Palermo CI, Barbagallo C, Battaglia R, Caponnetto A, Spina V, Ragusa M, Di Pietro C, Scalia G, Purrello M. Competing endogenous RNA network mediated by circ_3205 in SARS-CoV-2 infected cells. Cell Mol Life Sci 2022; 79:75. [PMID: 35039944 PMCID: PMC8763136 DOI: 10.1007/s00018-021-04119-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 12/19/2022]
Abstract
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new member of the Betacoronaviridae family, responsible for the recent pandemic outbreak of COVID-19. To start exploring the molecular events that follow host cell infection, we queried VirusCircBase and identified a circular RNA (circRNA) predicted to be synthesized by SARS-CoV-2, circ_3205, which we used to probe: (i) a training cohort comprised of two pools of cells from three nasopharyngeal swabs of SARS-CoV-2 infected (positive) or uninfected (negative, UCs) individuals; (ii) a validation cohort made up of 12 positive and 3 negative samples. The expression of circRNAs, miRNAs and miRNA targets was assayed through real-time PCR. CircRNA-miRNA interactions were predicted by TarpMiR, Analysis of Common Targets for circular RNAs (ACT), and STarMir tools. Enrichment of the biological processes and the list of predicted miRNA targets were retrieved from DIANA miRPath v3.0. Our results showed that the predicted SARS-CoV-2 circ_3205 was expressed only in positive samples and its amount positively correlated with that of SARS-CoV-2 Spike (S) mRNA and the viral load (r values = 0.80952 and 0.84867, Spearman's correlation test, respectively). Human (hsa) miR-298 was predicted to interact with circ_3205 by all three predictive tools. KCNMB4 and PRKCE were predicted as hsa-miR-298 targets. Interestingly, the function of both is correlated with blood coagulation and immune response. KCNMB4 and PRKCE mRNAs were upregulated in positive samples as compared to UCs (6 and 8.1-fold, p values = 0.049 and 0.02, Student's t test, respectively) and their expression positively correlated with that of circ_3205 (r values = 0.6 and 0.25, Spearman's correlation test, respectively). We propose that our results convincingly suggest that circ_3205 is a circRNA synthesized by SARS-CoV-2 upon host cell infection and that it may behave as a competitive endogenous RNA (ceRNA), sponging hsa-miR-298 and contributing to the upregulation of KCNMB4 and PRKCE mRNAs.
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Affiliation(s)
- Davide Barbagallo
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy.
| | - Concetta Ilenia Palermo
- U.O.C. Laboratory Analysis Unit, A.O.U. Policlinico‑Vittorio Emanuele, 95123, Catania, Italy
| | - Cristina Barbagallo
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
| | - Rosalia Battaglia
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
| | - Angela Caponnetto
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
| | - Vittoria Spina
- Department of Biomedical and Biotechnological Sciences, Section of Medical Biochemistry, University of Catania, 95123, Catania, Italy
| | - Marco Ragusa
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
| | - Cinzia Di Pietro
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
| | - Guido Scalia
- Department of Biomedical and Biotechnological Sciences, Section of Microbiology, University of Catania, 95123, Catania, Italy
| | - Michele Purrello
- Department of Biomedical and Biotechnological Sciences, Section of Biology and Genetics Giovanni Sichel, University of Catania, 95123, Catania, Italy
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12
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Wu N, Liu W, Wang J, Han Y, Ye Y, Liu X, Yu Y, Chen Q, Bao Y, Liu C. Berberine ameliorates neuronal AD-like change via activating Pi3k/PGCε pathway. Biofactors 2021; 47:587-599. [PMID: 33740285 DOI: 10.1002/biof.1725] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/24/2021] [Indexed: 12/11/2022]
Abstract
IR (insulin resistance) in diabetic brain gave rise to the generation of toxic factor Aβ42 and axon collapse which were the marker of AD (Alzheimer's disease)-like lesions in the circumstance of diabetes mellitus. But the underling molecular mechanism was not clear. Chronic HGHI (high glucose and high insulin) exposure accelerates IR has been reported in type II diabetes models. Berberine has been shown to promising effect for IR in vitro and in vivo. This study demonstrates the protective effect and the underlying mechanism of berberine on HGHI-induced IR. HGHI-induced cells were used to mimic the hyperinsulinemia resulting in IR. Berberine was used to uncover the mechanisms for the treatment of hyperinsulinemia in IR model. Morris water maze (MWM), PET imaging, CCK8 assay, ELISA assay, glucose kits, microscopy, and western blot analysis were performed to evaluate the protective effects of berberine. Berberine-improved HGHI-induced IR was correlated with the increase of glucose application in neurons. Meanwhile, the expressions of Pi3K, as well as GLUT3, PKCε, and APP were downregulated in the model, while p-IRS Ser307 was upregulated compared with Normal group. Fortunately, these scenes were reversed by berberine administration. Furthermore, berberine decreased GSK3β Y216 expressions, inhibited the production of oligomer Aβ42 and extended neuronal axon. The monomeric berberine treatment improves IR that may be involved in glucose effective application, rectifying the related proteins of the aberrant insulin pathway. Additionally, it suppressed the generation of Aβ42 and ameliorated neuron axon damage. Finally, berberine improves DM (diabetes mellitus)-induced cognitive impairment.
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Affiliation(s)
- Ninghua Wu
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
- Basic Medical College, Hubei University of Science and Technology, Xianning, China
| | - Wu Liu
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Jiawen Wang
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Yanqi Han
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Yu Ye
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Xiufen Liu
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Yuandong Yu
- Department of Oncology, Renmin Hospital, Hubei University of Medicine, Shiyan, China
| | - Qingjie Chen
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
| | - Yongfen Bao
- Basic Medical College, Hubei University of Science and Technology, Xianning, China
| | - Chao Liu
- Hubei Key Laboratory of Diabetes and Angiopathy, Hubei University of Science and Technology, Xianning, China
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Li H, Shi H, Zhang F, Xue H, Wang L, Tian J, Xu J, Han Q. LncRNA Tincr regulates PKCɛ expression in a miR-31-5p-dependent manner in cardiomyocyte hypertrophy. Naunyn Schmiedebergs Arch Pharmacol 2020; 393:2495-2506. [PMID: 32157348 DOI: 10.1007/s00210-020-01847-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 02/28/2020] [Indexed: 12/16/2022]
Abstract
Cardiomyocyte hypertrophy is a fatal factor in heart disease resulting in heart failure and even mortality. Although many studies have been focusing on the pathogenesis of cardiomyocyte hypertrophy, the exact molecular mechanisms are still unexclusive. In this study, we first found that the expression level of lncRNA Tincr was significantly decreased in the myocardial tissues of TAC mouse models of cardiomyocyte hypertrophy, and this result was further confirmed in H9C2 cells, a widely used rat myoblast cell lines. More intriguingly, we demonstrated that the aberration of Tincr is essential to the pathogenesis of cardiomyocyte hypertrophy, indicated by the re-induction of Tincr improving the heart functions of hypertrophic mice. In mechanism, we identified miR-31-5p as a direct target of Tincr using a widely used online bioinformatics tool StarBase, and this result was further experimentally validated using dual-luciferase reporter assay and real-time PCR. Also, we identified PRKCE as a direct target of miR-31-5p, and loss function of miR-31-5p significantly blocks the positive regulatory effect of Tincr on PRKCE expression in H9C2 cells. The knockdown of Tincr resulted in increased cardiomyocyte size, and, however, inhibition of miR-31-5p or overexpression of PRKCE significantly reversed the increased cardiomyocyte size. Taken together, our study showed that a novel Tincr-miR-31-5p axis targeting PRKCE was involved in cardiomyocyte hypertrophy, indicating that it may provide potential therapy in cardiomyocyte hypertrophy.
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Affiliation(s)
- Hao Li
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Hongtao Shi
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Fan Zhang
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Honghong Xue
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Lei Wang
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- The Affiliated Cardiovascular Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Jing Tian
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Jianrong Xu
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China
| | - Qinghua Han
- The First Clinical Medical School, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan, 030001, Shanxi, People's Republic of China.
- Department of Cardiology, The First Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, People's Republic of China.
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Wang M, Liu S, Wang H, Tang R, Chen Z. Morphine post-conditioning-induced up-regulation of lncRNA TINCR protects cardiomyocytes from ischemia-reperfusion injury via inhibiting degradation and ubiquitination of FGF1. QJM 2020; 113:859-869. [PMID: 32176291 DOI: 10.1093/qjmed/hcaa088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 02/24/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Our previous study has demonstrated that morphine post-conditioning (MpostC) protects cardiomyocytes from ischemia/reperfusion (I/R) injury partly through activating protein kinase-epsilon (PKCε) signaling pathway and subsequently inhibiting mitochondrial permeability transition pore (mPTP) opening. AIM In this study, we aim to investigate the relationship between long non-coding RNA TINCR and PKCε in cardiomyocytes under MpostC-treated I/R injury. DESIGN The myocardial I/R rat model was established by the ligation of lower anterior descending coronary artery for 45 min followed by the reperfusion for 1 h, and MpostC was performed before the reperfusion. METHOD H/R and MpostC were performed in the rat cardiomyocyte cell line (H9C2), and the Cytochrome-c release in cytosol and mPTP opening were determined. Cell viability was detected by using Cell Counting Kit-8, and cell apoptosis was determined by using flow cytometry or TUNEL assay. RESULTS The results indicated that MpostC restored the expression of TINCR in I/R rat myocardial tissues. In cardiomyocytes, the therapeutic effect of MpostC, including reduced mPTP opening, reduced Cytochrome-c expression, increased cell viability and reduced cell apoptosis, was dramatically negated by interfering TINCR. The expression of fibroblast growth factor 1 (FGF1), a protein that activates PKCε signaling pathway, was positively correlated with TINCR. The RNA immunoprecipitation and RNA pull-down assay further confirmed the binding between FGF1 and TINCR. Furthermore, TINCR was demonstrated to inhibit the degradation and ubiquitination of FGF1 in cardiomyocytes using the cycloheximide experiment and the ubiquitination assay. The TINCR/FGF1/PKCε axis was revealed to mediate the protective effect of MpostC against hypoxia/reoxygenation injury both in vitro and in vivo. CONCLUSION In conclusion, our findings demonstrated that MpostC-induced up-regulation of TINCR protects cardiomyocytes from I/R injury via inhibiting degradation and ubiquitination of FGF1, and subsequently activating PKCε signaling pathway, which provides a novel insight in the mechanism of TINCR and PKCε during MpostC treatment of I/R injury.
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Affiliation(s)
- M Wang
- Department of Anesthesiology, Qingdao Women and Children's Hospital, Shandong University, Qingdao, Shandong 266034, China
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261053, China
| | - S Liu
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - H Wang
- Department of Anesthesiology, Qingdao Women and Children's Hospital, Shandong University, Qingdao, Shandong 266034, China
| | - R Tang
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266003, China
| | - Z Chen
- Department of Anesthesiology, Qingdao Women and Children's Hospital, Shandong University, Qingdao, Shandong 266034, China
- Department of Anesthesiology, Qingdao Binhai University Affiliated Hospital, Qingdao, Shandong 266404, China
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Islam ABMMK, Mohammad E, Khan MAAK. Aberration of the modulatory functions of intronic microRNA hsa-miR-933 on its host gene ATF2 results in type II diabetes mellitus and neurodegenerative disease development. Hum Genomics 2020; 14:34. [PMID: 32993798 PMCID: PMC7526404 DOI: 10.1186/s40246-020-00285-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 09/01/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND MicroRNAs are ~ 22-nucleotide-long biological modifiers that act as the post-transcriptional modulator of gene expression. Some of them are identified to be embedded within the introns of protein-coding genes, these miRNAs are called the intronic miRNAs. Previous findings state that these intronic miRNAs are co-expressed with their host genes. This co-expression is necessary to maintain the robustness of the biological system. Till to date, only a few experiments are performed discretely to elucidate the functional relationship between few co-expressed intronic miRNAs and their associated host genes. RESULTS In this study, we have interpreted the underlying modulatory mechanisms of intronic miRNA hsa-miR-933 on its target host gene ATF2 and found that aberration can lead to several disease conditions. A protein-protein interaction network-based approach was adopted, and functional enrichment analysis was performed to elucidate the significantly over-represented biological functions and pathways of the common targets. Our approach delineated that hsa-miR-933 might control the hyperglycemic condition and hyperinsulinism by regulating ATF2 target genes MAP4K4, PRKCE, PEA15, BDNF, PRKACB, and GNAS which can otherwise lead to the development of type II diabetes mellitus. Moreover, we showed that hsa-miR-933 can regulate a target of ATF2, brain-derived neurotrophic factor (BDNF), to modulate the optimal expression of ATF2 in neuron cells to render neuroprotection for the inhibition of neurodegenerative diseases. CONCLUSIONS Our in silico model provides interesting resources for experimentations in a model organism or cell line for further validation. These findings may extend the common perception of gene expression analysis with new regulatory functionality.
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Affiliation(s)
| | - Eusra Mohammad
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
- Current Affiliation: Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Md. Abdullah-Al-Kamran Khan
- Department of Genetic Engineering and Biotechnology, University of Dhaka, Dhaka, Bangladesh
- Current Affiliation: Department of Mathematics and Natural Sciences, BRAC University, Dhaka, Bangladesh
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Zuo G, Zhang T, Huang L, Araujo C, Peng J, Travis Z, Okada T, Ocak U, Zhang G, Tang J, Lu X, Zhang JH. Activation of TGR5 with INT-777 attenuates oxidative stress and neuronal apoptosis via cAMP/PKCε/ALDH2 pathway after subarachnoid hemorrhage in rats. Free Radic Biol Med 2019; 143:441-453. [PMID: 31493504 PMCID: PMC6848789 DOI: 10.1016/j.freeradbiomed.2019.09.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/27/2019] [Accepted: 09/03/2019] [Indexed: 12/14/2022]
Abstract
BACKGROUND Oxidative stress and neuronal apoptosis play important roles in the pathogenesis of early brain injury (EBI) after subarachnoid hemorrhage (SAH). The activation of TGR5, a novel membrane-bound bile acid receptor, possesses anti-oxidative stress and anti-apoptotic effects in hepatobiliary disease and kidney disease. The present study aimed to explore the neuroprotective effect of TGR5 activation against EBI after SAH and the potential underlying mechanisms. METHODS The endovascular perforation model of SAH was performed on 199 Sprague Dawley rats to investigate the beneficial effects of TGR5 activation after SAH. INT-777, a specific synthetic TGR5 agonist, was administered intranasally at 1 h after SAH induction. TGR5 CRISPR and ALDH2 CRISPR were administered intracerebroventricularly at 48 h before SAH to illuminate potential mechanisms. The SAH grade, short-term and long-term neurobehavioral tests, TUNEL staining, Fluoro-Jade C staining, Nissl staining, immunofluorescence staining, and western blots were performed at 24 h after SAH. RESULTS The expressions of endogenous TGR5 and ALDH2 gradually increased and peaked at 24 h after SAH. TGR5 was expressed primarily in neurons, as well as in astrocytes and microglia. The activation of TGR5 with INT-777 significantly improved the short-term and long-term neurological deficits, accompanied by reduced the oxidative stress and neuronal apoptosis at 24 h after SAH. Moreover, INT-777 treatment significantly increased the expressions of TGR5, cAMP, phosphorylated PKCε, ALDH2, HO-1, and Bcl-2, while downregulated the expressions of 4-HNE, Bax, and Cleaved Caspase-3. TGR5 CRISPR and ALDH2 CRISPR abolished the neuroprotective effects of TGR5 activation after SAH. CONCLUSIONS In summary, the activation of TGR5 with INT-777 attenuated oxidative stress and neuronal apoptosis via the cAMP/PKCε/ALDH2 signaling pathway after SAH in rats. Furthermore, TGR5 may serve as a novel therapeutic target to ameliorate EBI after SAH.
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Affiliation(s)
- Gang Zuo
- Department of Neurosurgery, The Affiliated Taicang Hospital, Soochow University, Taicang, Suzhou, Jiangsu, 215400, China; Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Tongyu Zhang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA; Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, 150001, China
| | - Lei Huang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA; Department of Neurosurgery, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Camila Araujo
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jun Peng
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Zachary Travis
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Takeshi Okada
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Umut Ocak
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Guangyu Zhang
- Mass Spectrometry Core Facility, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Jiping Tang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA
| | - Xiaojun Lu
- Department of Neurosurgery, The Affiliated Taicang Hospital, Soochow University, Taicang, Suzhou, Jiangsu, 215400, China.
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, 92350, USA; Department of Neurosurgery, Loma Linda University, Loma Linda, CA, 92350, USA; Department of Anesthesiology, Loma Linda University, Loma Linda, CA, 92350, USA.
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Cheng F, Han L, Xiao Y, Pan C, Li Y, Ge X, Zhang Y, Yan S, Wang M. d- chiro-Inositol Ameliorates High Fat Diet-Induced Hepatic Steatosis and Insulin Resistance via PKCε-PI3K/AKT Pathway. J Agric Food Chem 2019; 67:5957-5967. [PMID: 31066268 DOI: 10.1021/acs.jafc.9b01253] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
d- chiro-Inositol (DCI) is a biologically active component found in tartary buckwheat, which can reduce hyperglycemia and ameliorate insulin resistance. However, the mechanism underlying the antidiabetic effects of DCI remains largely unclear. This study investigated the effects and underlying molecular mechanisms of DCI on hepatic gluconeogenesis in mice fed a high fat diet and saturated palmitic acid-treated hepatocytes. DCI attenuated free fatty acid uptake by the liver via lipid trafficking inhibition, reduced diacylglycerol deposition, and hepatic PKCε translocation. Thus, DCI could improve insulin sensitivity by suppressing hepatic gluconeogenesis. Subsequent analyses revealed that DCI decreased hepatic glucose output and the expression levels of PEPCK and G6 Pase in insulin resistant mice through PKCε-IRS/PI3K/AKT signaling pathway. Likewise, such effects of DCI were confirmed in HepG2 cells with palmitate-induced insulin resistance. These findings indicate a novel pathway by which DCI prevents hepatic gluconeogenesis, reduces lipid deposition, and ameliorates insulin resistance via regulation of PKCε-PI3K/AKT axis.
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Affiliation(s)
- Feier Cheng
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Lin Han
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Yao Xiao
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Chuanying Pan
- College of Animal Science and Technology , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Yunlong Li
- Institute of Agricultural Products Processing , Shanxi Academy of Agriculture Sciences , Taiyuan 030031 , People's Republic of China
| | - Xinhui Ge
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Yao Zhang
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Shaoqing Yan
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
| | - Min Wang
- College of Food Science and Engineering , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
- Shaanxi Key Laboratory of Natural Products & Chemical Biology , Northwest A&F University , Yangling , Shaanxi 712100 , People's Republic of China
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18
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Dang YF, Qiu TX, Song DW, Liu L. PMA-triggered PKCε activity enhances Nrf2-mediated antiviral response on fish rhabdovirus infection. Fish Shellfish Immunol 2019; 87:871-878. [PMID: 30776542 DOI: 10.1016/j.fsi.2019.02.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Viral infection is often accompanied with alteration of intracellular redox state, especially an imbalance between reactive oxygen species (ROS) production and antioxidant cellular defenses. The previous studies showed that an antioxidant cellular defense system, the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), played an important role against spring viraemia of carp virus (SVCV) infection in fish. To further reveal the mediated mechanism that Nrf2 active state was affected by protein kinase C (PKC), here we evaluated SVCV replication in host cells by treated with a strong activator of PKC phorbol-12-myristate-13-acetate (PMA) and an inhibitor staurosporine. Our results showed that PMA significantly repressed SVCV replication and viral-induced apoptosis in Epithelioma papulosum cyprini (EPC) cell, suggesting that PKC may exhibit an anti-SVCV effect. Likewise, PMA resulted in a higher phosphorylation levels of PKCε rather than PKCα/β to participate in the activation of Nrf2, mainly involved in the activation of Nrf2 phosphorylation of Ser40 to favor Nrf2 translocation to nucleus. Furthermore, the data revealed that PMA up-regulated an antiviral response heme oxygenase-1 (HO1) gene expression that was confirmed as the key player against SVCV infection by HO1 specific siRNA. Overall, this study provided a new therapeutic target for the treatment of SVCV infection, and modulating PKC activity could be used for the prevention and treatment of SVCV.
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Affiliation(s)
- Yun-Fei Dang
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Tian-Xiu Qiu
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Da-Wei Song
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Lei Liu
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China.
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19
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Nishizaki T. PKCε Increases Extracellular Elastin and Fibulin-5/DANCE in Dermal Fibroblasts. Cell Physiol Biochem 2018; 46:291-302. [PMID: 29590645 DOI: 10.1159/000488430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 02/28/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS In the earlier study, the selective PKCε activator DCP-LA increased elastic fibres in the dermis of HR-1 hairless mice. As a process of elastic fibre formation, tropoelastin, an elastin monomer, is secreted into the extracellular space. Secreted tropoelastin is delivered to the microfibrils by fibulin-5/developmental arteries and neural crest epidermal growth factor-like (DANCE) and undergoes self-association. Then, tropoelastin assembles around the microfibrils, growing into elastin and elastic fibres by lysyl oxidase (LOX)- or LOX-like (LOXL)-mediated cross-linking. The present study was conducted to understand the mechanism underlying DCP-LA-induced increase in elastin/elastic fibre. METHODS Western blotting, immunocytochemistory, and real-time reverse transcription-polymerase chain reaction (RT-PCR) were carried out in cultured human dermal fibroblasts. PKCε, mammalian target of rapamycin complex (mTOR), and p70 S6 kinase (S6K) were knocked-down by transfecting each siRNA. RESULTS DCP-LA increased elastin and fibulin-5/DANCE in a treatment time (6-24 h)- and a bell-shaped concentration (1 nM-1 µM)-dependent manner in the culture medium of human dermal fibroblasts. DCP-LA markedly increased elastic fibres in the extracellular space of cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was abolished by a PKC inhibitor or knocking-down PKCε. DCP-LA did not affect expression of mRNAs for tropoelastin and fiblin-5/DANCE in cultured fibroblasts. DCP-LA-induced increase in extracellular elastin and fibulin-5/DANCE was not inhibited by the protein synthesis inhibitor cycloheximide or by knocking-down mTOR and S6K. DCP-LA never increased extracellular elastin in the presence of elastase, that breaks down elastin. An inhibitor of matrix metalloproteinase 9, that degrades multiple extracellular matrix components including elastin, had no effect on the basal levels and the DCP-LA-induced increase levels of extracellular elastin. CONCLUSION The results of the present study indicate that PKCε, activated by DCP-LA, increases elastin and fibulin-5/DANCE in the extracellular space of cultured fibroblasts by the mechanism independent of transcriptional and translational modulation or inhibition of elastolysis.
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20
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Sen A, Nelson TJ, Alkon DL, Hongpaisan J. Loss in PKC Epsilon Causes Downregulation of MnSOD and BDNF Expression in Neurons of Alzheimer's Disease Hippocampus. J Alzheimers Dis 2018; 63:1173-1189. [PMID: 29710707 DOI: 10.3233/jad-171008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Oxidative stress and amyloid-β (Aβ) oligomers have been implicated in Alzheimer's disease (AD). The growth and maintenance of neuronal networks are influenced by brain derived neurotrophic factor (BDNF) expression, which is promoted by protein kinase C epsilon (PKCɛ). We investigated the reciprocal interaction among oxidative stress, Aβ, and PKCɛ levels and subsequent PKCɛ-dependent MnSOD and BDNF expression in hippocampal pyramidal neurons. Reduced levels of PKCɛ, MnSOD, and BDNF and an increased level of Aβ were also found in hippocampal neurons from autopsy-confirmed AD patients. In cultured human primary hippocampal neurons, spherical aggregation of Aβ (amylospheroids) decreased PKCɛ and MnSOD. Treatment with t-butyl hydroperoxide (TBHP) increased superoxide, the oxidative DNA/RNA damage marker, 8-OHG, and Aβ levels, but reduced PKCɛ, MnSOD, BDNF, and cultured neuron density. These changes were reversed with the PKCɛ activators, bryostatin and DCPLA-ME. PKCɛ knockdown suppressed PKCɛ, MnSOD, and BDNF but increased Aβ. In cultured neurons, the increase in reactive oxygen species (ROS) associated with reduced PKCɛ during neurodegeneration was inhibited by the SOD mimetic MnTMPyP and the ROS scavenger NAc, indicating that strong oxidative stress suppresses PKCɛ level. Reduction of PKCɛ and MnSOD was prevented with the PKCɛ activator bryostatin in 5-6-month-old Tg2576 AD transgenic mice. In conclusion, oxidative stress and Aβ decrease PKCɛ expression. Reciprocally, a depression of PKCɛ reduces BDNF and MnSOD, resulting in oxidative stress. These changes can be prevented with the PKCɛ-specific activators.
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Affiliation(s)
- Abhik Sen
- Center for Neurodegenerative Diseases, Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, USA
| | - Thomas J Nelson
- Center for Neurodegenerative Diseases, Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, USA
| | | | - Jarin Hongpaisan
- Center for Neurodegenerative Diseases, Rockefeller Neurosciences Institute, West Virginia University, Morgantown, WV, USA
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Baek KI, Li R, Jen N, Choi H, Kaboodrangi A, Ping P, Liem D, Beebe T, Hsiai TK. Flow-Responsive Vascular Endothelial Growth Factor Receptor-Protein Kinase C Isoform Epsilon Signaling Mediates Glycolytic Metabolites for Vascular Repair. Antioxid Redox Signal 2018; 28:31-43. [PMID: 28762754 PMCID: PMC5695747 DOI: 10.1089/ars.2017.7044] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/31/2017] [Accepted: 07/31/2017] [Indexed: 12/19/2022]
Abstract
AIMS Hemodynamic shear stress participates in maintaining vascular redox status. Elucidating flow-mediated endothelial metabolites enables us to discover metabolic biomarkers and therapeutic targets. We posited that flow-responsive vascular endothelial growth factor receptor (VEGFR)-protein kinase C isoform epsilon (PKCɛ)-6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) signaling modulates glycolytic metabolites for vascular repair. RESULTS Bidirectional oscillatory flow (oscillatory shear stress [OSS]: 0.1 ± 3 dyne·cm-2 at 1 Hz) upregulated VEGFR-dependent PKCɛ expression to a greater degree than did unidirectional pulsatile flow (pulsatile shear stress [PSS]: 23 ± 8 dyne·cm-2 at 1 Hz) in human aortic endothelial cells (p < 0.05, n = 3). PSS and OSS further upregulated PKCɛ-dependent PFKFB3 expression for glycolysis (p < 0.05, n = 4). Constitutively active PKCɛ increased, whereas dominant-negative PKCɛ reduced both basal and maximal extracellular acidification rates for glycolytic flux (p < 0.01, n = 4). Metabolomic analysis demonstrated an increase in PKCɛ-dependent glycolytic metabolite, dihydroxyacetone (DHA), but a decrease in gluconeogenic metabolite, aspartic acid (p < 0.05 vs. control, n = 6). In a New Zealand White rabbit model, both PKCɛ and PFKFB3 immunostaining was prominent in the PSS- and OSS-exposed aortic arch and descending aorta. In a transgenic Tg(flk-1:EGFP) zebrafish model, GATA-1a morpholino oligonucleotide injection (to reduce viscosity-dependent shear stress) impaired vascular regeneration after tail amputation (p < 0.01, n = 20), which was restored with PKCɛ messenger RNA (mRNA) rescue (p < 0.05, n = 5). As a corollary, siPKCɛ inhibited tube formation and vascular repair, which were restored by DHA treatment in our Matrigel and zebrafish models. Innovation and Conclusion: Flow-sensitive VEGFR-PKCɛ-PFKFB3 signaling increases the glycolytic metabolite, dihydroxyacetone, to promote vascular repair. Antioxid. Redox Signal. 28, 31-43.
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Affiliation(s)
- Kyung In Baek
- 1 Department of Bioengineering, School of Engineering and Applied Science, University of California , Los Angeles, Los Angeles, California
| | - Rongsong Li
- 2 Division of Cardiology, Department of Medicine, University of California , Los Angeles, Los Angeles, California
| | - Nelson Jen
- 1 Department of Bioengineering, School of Engineering and Applied Science, University of California , Los Angeles, Los Angeles, California
| | - Howard Choi
- 2 Division of Cardiology, Department of Medicine, University of California , Los Angeles, Los Angeles, California
| | - Amir Kaboodrangi
- 1 Department of Bioengineering, School of Engineering and Applied Science, University of California , Los Angeles, Los Angeles, California
| | - Peipei Ping
- 2 Division of Cardiology, Department of Medicine, University of California , Los Angeles, Los Angeles, California
- 3 Department of Physiology, School of Medicine, University of California , Los Angeles, Los Angeles, California
| | - David Liem
- 2 Division of Cardiology, Department of Medicine, University of California , Los Angeles, Los Angeles, California
| | - Tyler Beebe
- 1 Department of Bioengineering, School of Engineering and Applied Science, University of California , Los Angeles, Los Angeles, California
| | - Tzung K Hsiai
- 1 Department of Bioengineering, School of Engineering and Applied Science, University of California , Los Angeles, Los Angeles, California
- 2 Division of Cardiology, Department of Medicine, University of California , Los Angeles, Los Angeles, California
- 3 Department of Physiology, School of Medicine, University of California , Los Angeles, Los Angeles, California
- 4 Greater Los Angeles VA Healthcare System , Los Angeles, California
- 5 Department of Medical Engineering, California Institute of Technology , Pasadena, California
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22
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Alcantara D, Elmslie F, Tetreault M, Bareke E, Hartley T, Majewski J, Boycott K, Innes AM, Dyment DA, O'Driscoll M. SHORT syndrome due to a novel de novo mutation in PRKCE (Protein Kinase Cɛ) impairing TORC2-dependent AKT activation. Hum Mol Genet 2017; 26:3713-3721. [PMID: 28934384 DOI: 10.1093/hmg/ddx256] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 06/29/2017] [Indexed: 02/11/2024] Open
Abstract
SHORT syndrome is a rare, recognizable syndrome resulting from heterozygous mutations in PIK3R1 encoding a regulatory subunit of phosphoinositide-3-kinase (PI3K). The condition is characterized by short stature, intrauterine growth restriction, lipoatrophy and a facial gestalt involving a triangular face, deep set eyes, low hanging columella and small chin. PIK3R1 mutations in SHORT syndrome result in reduced signaling through the PI3K-AKT-mTOR pathway. We performed whole exome sequencing for an individual with clinical features of SHORT syndrome but negative for PIK3R1 mutation and her parents. A rare de novo variant in PRKCE was identified. The gene encodes PKCε and, as such, the AKT-mTOR pathway function was assessed using phospho-specific antibodies with patient lymphoblasts and following ectopic expression of the mutant in HEK293 cells. Kinase analysis showed that the variant resulted in a partial loss-of-function. Whilst interaction with PDK1 and the mTORC2 complex component SIN1 was preserved in the mutant PKCε, it bound to SIN1 with a higher affinity than wild-type PKCε and the dynamics of mTORC2-dependent priming of mutant PKCε was altered. Further, mutant PKCε caused impaired mTORC2-dependent pAKT-S473 following rapamycin treatment. Reduced pFOXO1-S256 and pS6-S240/244 levels were also observed in the patient LCLs. To date, mutations in PIK3R1 causing impaired PI3K-dependent AKT activation are the only known cause of SHORT syndrome. We identify a SHORT syndrome child with a novel partial loss-of-function defect in PKCε. This variant causes impaired AKT activation via compromised mTORC2 complex function.
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Affiliation(s)
- Diana Alcantara
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK
| | - Frances Elmslie
- South West Thames Regional Genetics Service, St. George's, University of London, London SW17 0RE, UK
| | - Martine Tetreault
- McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Eric Bareke
- McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Taila Hartley
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
| | - Jacek Majewski
- McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Kym Boycott
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada
| | - A Micheil Innes
- Department of Medical Genetics, Alberta Children's Hospital Research Institute for Child and Maternal Health, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - David A Dyment
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, ON K1H 8L1, Canada
| | - Mark O'Driscoll
- Genome Damage and Stability Centre, University of Sussex, Brighton BN1 9RQ, UK
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23
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Wang Q, Wang J, Gao D, Li J. Inhibition of PAR2 and TRPA1 signals alleviates neuropathic pain evoked by chemotherapeutic bortezomib. J BIOL REG HOMEOS AG 2017; 31:977-983. [PMID: 29254302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bortezomib (BTZ) is generally used as a chemotherapeutic agent for the treatment of multiple myeloma; however, one of the significant limiting complications of BTZ is painful peripheral neuropathy observed during BTZ therapy. There is a lack of drugs which can prevent and/or treat the painful symptoms induced by BTZ, as the underlying molecular mechanism leading to neuropathic pain remains largely unclear. In the present study, we examined engagement of proteinase-activated receptor 2 (PAR2) and transient receptor potential ankyrin 1 (TRPA1) in neuropathic pain induced by BTZ in rats. Our results demonstrated that systemic injection of BTZ increased mechanical pain and cold sensitivity as compared with control animals (P less than 0.05 vs control rats). Our data further showed that blocking respective PAR2 and TRPA1 attenuated mechanical pain and cold sensitivity observed in control rats and BTZ rats (P less than 0.05 vs vehicle control). Notably, the attenuating effect of blocking PAR2 and TRPA1 on mechanical pain and cold sensitivity was significantly less in BTZ rats than that in control rats. In addition, protein expression of PAR2 and TRPA1 was upregulated in the lumbar dorsal root ganglion of BTZ rats, and inhibition of PAR2 decreased the levels of TRPA1 and attenuated its downstream pathways (namely, PKCɛ and PKA). Overall, we revealed specific signaling pathways leading to neuropathic pain induced by chemotherapeutic BTZ and that blocking PAR2 and TRPA1 in sensory nerves is beneficial to improve neuropathic pain during BTZ intervention.
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Affiliation(s)
- Q Wang
- Tumor Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - J Wang
- Tumor Center, The First Hospital of Jilin University, Changchun, Jilin, China
| | - D Gao
- Department of Oto¬rhinolaryngology, The First Hospital of Jilin University, Changchun, Jilin, China
| | - J Li
- Department of Radiology, The First Hospital of Jilin University, Changchun, Jilin, China
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24
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Chen X, Wu Q, Depeille P, Chen P, Thornton S, Kalirai H, Coupland SE, Roose JP, Bastian BC. RasGRP3 Mediates MAPK Pathway Activation in GNAQ Mutant Uveal Melanoma. Cancer Cell 2017; 31:685-696.e6. [PMID: 28486107 PMCID: PMC5499527 DOI: 10.1016/j.ccell.2017.04.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 12/07/2016] [Accepted: 04/05/2017] [Indexed: 01/14/2023]
Abstract
Constitutive activation of Gαq signaling by mutations in GNAQ or GNA11 occurs in over 80% of uveal melanomas (UMs) and activates MAPK. Protein kinase C (PKC) has been implicated as a link, but the mechanistic details remained unclear. We identified PKC δ and ɛ as required and sufficient to activate MAPK in GNAQ mutant melanomas. MAPK activation depends on Ras and is caused by RasGRP3, which is significantly and selectively overexpressed in response to GNAQ/11 mutation in UM. RasGRP3 activation occurs via PKC δ- and ɛ-dependent phosphorylation and PKC-independent, DAG-mediated membrane recruitment, possibly explaining the limited effect of PKC inhibitors to durably suppress MAPK in UM. The findings nominate RasGRP3 as a therapeutic target for cancers driven by oncogenic GNAQ/11.
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Affiliation(s)
- Xu Chen
- Departments of Dermatology and Pathology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Qiuxia Wu
- Departments of Dermatology and Pathology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Philippe Depeille
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Peirong Chen
- Departments of Dermatology and Pathology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sophie Thornton
- Department of Molecular and Clinical Cancer Medicine, Institute of Translational Mewdicine, University of Liverpool, Liverpool L7 8TX, UK
| | - Helen Kalirai
- Department of Molecular and Clinical Cancer Medicine, Institute of Translational Mewdicine, University of Liverpool, Liverpool L7 8TX, UK
| | - Sarah E Coupland
- Department of Molecular and Clinical Cancer Medicine, Institute of Translational Mewdicine, University of Liverpool, Liverpool L7 8TX, UK
| | - Jeroen P Roose
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Boris C Bastian
- Departments of Dermatology and Pathology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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25
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Shiota M, Yokomizo A, Takeuchi A, Kashiwagi E, Dejima T, Inokuchi J, Tatsugami K, Uchiumi T, Eto M. Protein kinase C regulates Twist1 expression via NF-κB in prostate cancer. Endocr Relat Cancer 2017; 24:171-180. [PMID: 28223364 DOI: 10.1530/erc-16-0384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 02/21/2017] [Indexed: 11/08/2022]
Abstract
The progression of prostate cancer to metastatic and castration-resistant disease represents a critical step. We previously showed that protein kinase C (PKC) activation followed by Twist1 and androgen receptor (AR) induction played a critical role in castration resistance, but the precise molecular mechanism remains unknown. This study aimed to elucidate the relevant molecular mechanism, focusing on NF-κB transcription factor. We examined the activity of NF-κB after PKC inhibition, and the expression of Twist1 and AR after inhibition of NF-κB in human prostate cancer cells. We also investigated the status of PKC/NF-κB after inhibition of AR signaling in cells resistant to hormonal therapy. As a result, inhibition of PKC signaling using knockdown and small-molecule inhibition of PKC suppressed RelA activity, while blocking NF-κB suppressed Twist1 and AR expression. Conversely, inhibition of AR signaling by androgen depletion and the novel antiandrogen enzalutamide induced PKC and RelA activation, resulting in Twist1/AR induction at the transcript level. Moreover, inhibition of NF-κB signaling prevented enzalutamide-induced Twist1 and AR induction. Finally, NF-κB was activated in both castration-resistant and enzalutamide-resistant cells. In conclusion, NF-κB signaling was responsible for Twist1 upregulation by PKC in response to AR inhibition, resulting in aberrant activation of AR. NF-κB signaling thus appears to play a critical role in promoting both castration resistance and enzalutamide resistance in PKC/Twist1 signaling in prostate cancer.
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Affiliation(s)
- Masaki Shiota
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Akira Yokomizo
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ario Takeuchi
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Eiji Kashiwagi
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takashi Dejima
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Junichi Inokuchi
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Katsunori Tatsugami
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Takeshi Uchiumi
- Department of Clinical Chemistry and Laboratory MedicineGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masatoshi Eto
- Department of UrologyGraduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Wang Y, He Y, Wang M, Lv P, Liu J, Wang J. Role of Protease-Activated Receptor 2 in Regulating Focal Segmental Glomerulosclerosis. Cell Physiol Biochem 2017; 41:1147-1155. [PMID: 28245472 DOI: 10.1159/000464121] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 01/03/2017] [Indexed: 11/19/2022] Open
Abstract
Background /Aims: The underlying mechanisms leading to focal segmental glomerulosclerosis (FSGS) are lacking. In this report, we examined the role of protease-activated receptors (PARs) subtype PAR2 and its downstream signals in regulating the pathophysiological process of FSGS. METHODS Nephropathy was induced by intravenous injections of adriamycin (ADR) in rats to study FSGS. Western Blot analysis and ELISA were employed to determine the protein expression levels of PAR2 and its downstream signal pathways as well as the levels of PICs. RESULTS In ADR rats, expression of PAR2, PKCε and PKA was amplified and this was accompanied with increases of pro-inflammatory cytokines (PICs) including IL-1β, IL-6 and TNF-α. Inhibition of PAR2 signal by systemic administration of FSLLRY-NH2 (FSL) attenuated amplification of PICs. Notably, FSL further influenced key molecular mediators during development of FSGS. i.e., it specifically restored the impaired nephrin and attenuated the exaggerated transforming growth factor beta 1 (TGF-β1), caspase-9 and desmin thereby improving worsened renal functions and glomerular injury. Consistent with this, in cultured podocytes FSL also largely restored downregulation of nephrin and attenuated amplifications of caspase-9 and desmin induced by TGF-β1. CONCLUSIONS Results of this study suggest that PAR2 plays an important role in mediating renal injury induced by glomerulosclerosis. Inhibition of PAR2 signal pathway has a protective effect on FSGS mainly via PIC and TGF-β1 mechanisms. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of FSGS observed in patients.
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Wang Z, Li Q, Xiang M, Zhang F, Wei D, Wen Z, Zhou Y. Astragaloside Alleviates Hepatic Fibrosis Function via PAR2 Signaling Pathway in Diabetic Rats. Cell Physiol Biochem 2017; 41:1156-1166. [PMID: 28245465 DOI: 10.1159/000464122] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/04/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Astragaloside (AGS) extracted from radix astragalin (Huangqi) has been considered to be beneficial to liver diseases. In this study, we examined the role played by AGS in alleviating hepatic fibrosis function via protease-activated receptor-2 (PAR2) mechanisms. We hypothesized that AGS affects PAR2 signaling pathway thereby improving hepatic function in rats with hepatic fibrosis induced by carbon tetrachloride (CCl4). We further hypothesized that AGS attenuates impaired hepatic function evoked by CCl4 to a greater degree in diabetic animals. METHODS ELISA and Western Blot analysis were used to examine PAR2 signaling pathway in diabetic CCl4-rats and non-diabetic CCl4-rats. RESULTS AGS inhibited the protein expression of PAR2 and its downstream pathway PKA and PKCɛ in CCl4-rats. Notably, the effects of AGS were greater in CCl4-rats with diabetes. AGS also significantly attenuated the CCl4-induced upregulations of pro-inflammatory cytokines, namely interleukin-1β, interleukin-6 and tumor necrosis factor-α accompanied with decreases of collagenic parameters such as hexadecenoic acid, laminin and hydroxyproline. Additionally, AGS improved the CCl4-induced exaggerations of liver index and functions including alanine aminotransferase, aspartate aminotransferase. Moreover, TGF-β1, a marker of hepatic fibrosis, was increased in CCl4-rats and AGS inhibited increases in TGF-β1 induced by CCl4. CONCLUSIONS AGS alleviates hepatic fibrosis by inhibiting PAR2 signaling expression and its effects are largely enhanced in diabetic animals. Targeting one or more of these signaling molecules may present new opportunities for treatment and management of hepatic fibrosis; and results of our study are likely to shed light on strategies for application of AGS because it has potentially greater therapeutic effectiveness for hepatic fibrosis in diabetes.
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Pike T, Brownlow N, Kjaer S, Carlton J, Parker PJ. PKCɛ switches Aurora B specificity to exit the abscission checkpoint. Nat Commun 2016; 7:13853. [PMID: 28004745 PMCID: PMC5192180 DOI: 10.1038/ncomms13853] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 11/03/2016] [Indexed: 01/21/2023] Open
Abstract
The 'NoCut', or Aurora B abscission checkpoint can be activated if DNA is retained in the cleavage furrow after completion of anaphase. Checkpoint failure leads to incomplete abscission and a binucleate outcome. These phenotypes are also observed after loss of PKCɛ in transformed cell models. Here we show that PKCɛ directly modulates the Aurora B-dependent abscission checkpoint by phosphorylating Aurora B at S227. This phosphorylation invokes a switch in Aurora B specificity, with increased phosphorylation of a subset of target substrates, including the CPC subunit Borealin. This switch is essential for abscission checkpoint exit. Preventing the phosphorylation of Borealin leads to abscission failure, as does expression of a non-phosphorylatable Aurora B S227A mutant. Further, depletion of the ESCRT-III component and Aurora B substrate CHMP4C enables abscission, bypassing the PKCɛ-Aurora B exit pathway. Thus, we demonstrate that PKCɛ signals through Aurora B to exit the abscission checkpoint and complete cell division.
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Affiliation(s)
- Tanya Pike
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Nicola Brownlow
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Svend Kjaer
- Protein Purification Facility, Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jeremy Carlton
- Division of Cancer Studies King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Peter J. Parker
- Protein Phosphorylation Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Division of Cancer Studies King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
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Petersen MC, Madiraju AK, Gassaway BM, Marcel M, Nasiri AR, Butrico G, Marcucci MJ, Zhang D, Abulizi A, Zhang XM, Philbrick W, Hubbard SR, Jurczak MJ, Samuel VT, Rinehart J, Shulman GI. Insulin receptor Thr1160 phosphorylation mediates lipid-induced hepatic insulin resistance. J Clin Invest 2016; 126:4361-4371. [PMID: 27760050 DOI: 10.1172/jci86013] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 09/08/2016] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a risk factor for type 2 diabetes (T2D), but whether NAFLD plays a causal role in the pathogenesis of T2D is uncertain. One proposed mechanism linking NAFLD to hepatic insulin resistance involves diacylglycerol-mediated (DAG-mediated) activation of protein kinase C-ε (PKCε) and the consequent inhibition of insulin receptor (INSR) kinase activity. However, the molecular mechanism underlying PKCε inhibition of INSR kinase activity is unknown. Here, we used mass spectrometry to identify the phosphorylation site Thr1160 as a PKCε substrate in the functionally critical INSR kinase activation loop. We hypothesized that Thr1160 phosphorylation impairs INSR kinase activity by destabilizing the active configuration of the INSR kinase, and our results confirmed this prediction by demonstrating severely impaired INSR kinase activity in phosphomimetic T1160E mutants. Conversely, the INSR T1160A mutant was not inhibited by PKCε in vitro. Furthermore, mice with a threonine-to-alanine mutation at the homologous residue Thr1150 (InsrT1150A mice) were protected from high fat diet-induced hepatic insulin resistance. InsrT1150A mice also displayed increased insulin signaling, suppression of hepatic glucose production, and increased hepatic glycogen synthesis compared with WT controls during hyperinsulinemic clamp studies. These data reveal a critical pathophysiological role for INSR Thr1160 phosphorylation and provide further mechanistic links between PKCε and INSR in mediating NAFLD-induced hepatic insulin resistance.
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Yu YH, Liao PR, Guo CJ, Chen CH, Mochly-Rosen D, Chuang LM. PKC-ALDH2 Pathway Plays a Novel Role in Adipocyte Differentiation. PLoS One 2016; 11:e0161993. [PMID: 27575855 PMCID: PMC5004862 DOI: 10.1371/journal.pone.0161993] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 08/16/2016] [Indexed: 01/13/2023] Open
Abstract
The ALDH2 gene encodes the mitochondrial aldehyde dehydrogenase 2 (ALDH2), a critical enzyme involved in ethanol clearance through acetaldehyde metabolism. ALDH2 also catalyzes the metabolism of other bioreactive aldehydes, including propionaldehyde, butyraldehyde, and 4-hydroxykenals (4-HNE). Increased levels of 4-HNE in adipose tissue positively correlate with obesity and insulin resistance. However, it remains unclear whether ALDH2 is involved in regulation of adipocyte differentiation. Here, we found that ALDH2 protein levels were lower in white adipose tissue of high-fat diet-fed mice and ob/ob mice relative to lean mice. Knockdown of ALDH2 expression in 3T3-L1 preadipocytes caused an increase in intracellular 4-HNE, thereby attenuated adipocyte differentiation. By contrast, an ALDH2 activator, Alda-1, significantly accelerated adipogenesis, which was accompanied by an increase in adipogenic gene expression. Consistently, adipogenesis was reduced when protein kinase C ε (PKCε), an ALDH2 phosphorylating activator, was silenced in 3T3-L1 preadipocytes, whereas treatment with a PKCε agonist in 3T3-L1 preadipocytes enhanced adipogenesis. Whole-genome microarray profiling of Alda-1-treated cells demonstrated several upregulated transcripts encoding proteins involved in metabolism and the majority of these transcripts are for proteins involved in PPAR signaling pathways. Furthermore, PKCε-ALDH2 interaction alleviates 4-HNE induced aberrant PPARγ regulation on adipogenesis. Taken together, these results demonstrate that ALDH2 activation enhances adipogenesis and signaling pathways involving PPARγ. Thus, activation of PKCε-ALDH2 regulatory axis may be a therapeutic target for treating obesity and type 2 diabetes.
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Affiliation(s)
- Yu-Hsiang Yu
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
| | - Pei-Ru Liao
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chien-Jung Guo
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Che-Hong Chen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, 94305, United States of America
| | - Daria Mochly-Rosen
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, 94305, United States of America
| | - Lee-Ming Chuang
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Pepin É, Al-Mass A, Attané C, Zhang K, Lamontagne J, Lussier R, Madiraju SRM, Joly E, Ruderman NB, Sladek R, Prentki M, Peyot ML. Pancreatic β-Cell Dysfunction in Diet-Induced Obese Mice: Roles of AMP-Kinase, Protein Kinase Cε, Mitochondrial and Cholesterol Metabolism, and Alterations in Gene Expression. PLoS One 2016; 11:e0153017. [PMID: 27043434 PMCID: PMC4820227 DOI: 10.1371/journal.pone.0153017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/22/2016] [Indexed: 12/27/2022] Open
Abstract
Diet induced obese (DIO) mice can be stratified according to their weight gain in response to high fat diet as low responders (LDR) and high responders (HDR). This allows the study of β-cell failure and the transitions to prediabetes (LDR) and early diabetes (HDR). C57BL/6N mice were fed for 8 weeks with a normal chow diet (ND) or a high fat diet and stratified as LDR and HDR. Freshly isolated islets from ND, LDR and HDR mice were studied ex-vivo for mitochondrial metabolism, AMPK activity and signalling, the expression and activity of key enzymes of energy metabolism, cholesterol synthesis, and mRNA profiling. Severely compromised glucose-induced insulin secretion in HDR islets, as compared to ND and LDR islets, was associated with suppressed AMP-kinase activity. HDR islets also showed reduced acetyl-CoA carboxylase activity and enhanced activity of 3-hydroxy-3-methylglutaryl-CoA reductase, which led respectively to elevated fatty acid oxidation and increased cholesterol biosynthesis. HDR islets also displayed mitochondrial membrane hyperpolarization and reduced ATP turnover in the presence of elevated glucose. Expression of protein kinase Cε, which reduces both lipolysis and production of signals for insulin secretion, was elevated in DIO islets. Genes whose expression increased or decreased by more than 1.2-fold were minor between LDR and ND islets (17 differentially expressed), but were prominent between HDR and ND islets (1508 differentially expressed). In HDR islets, particularly affected genes were related to cell cycle and proliferation, AMPK signaling, mitochondrial metabolism and cholesterol metabolism. In conclusion, chronically reduced AMPK activity, mitochondrial dysfunction, elevated cholesterol biosynthesis in islets, and substantial alterations in gene expression accompany β-cell failure in HDR islets. The β-cell compensation process in the prediabetic state (LDR) is largely independent of transcriptional adaptive changes, whereas the transition to early diabetes (HDR) is associated with major alterations in gene expression.
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Affiliation(s)
- Émilie Pepin
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Anfal Al-Mass
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Camille Attané
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Kezhuo Zhang
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Julien Lamontagne
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Roxane Lussier
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - S. R. Murthy Madiraju
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Erik Joly
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Neil B. Ruderman
- Departments of Medicine and Physiology and Biophysics, Boston University School of Medicine and Diabetes Unit, Boston Medical Center, Boston, MA, United States of America
| | - Robert Sladek
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Marc Prentki
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- Departments of Nutrition, Biochemistry and Molecular Medicine, Faculty of Medicine, University of Montréal, Montreal, Québec, Canada
- * E-mail: (MP); (MLP)
| | - Marie-Line Peyot
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- * E-mail: (MP); (MLP)
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Maiya R, McMahon T, Wang D, Kanter B, Gandhi D, Chapman HL, Miller J, Messing RO. Selective chemical genetic inhibition of protein kinase C epsilon reduces ethanol consumption in mice. Neuropharmacology 2016; 107:40-48. [PMID: 26947945 DOI: 10.1016/j.neuropharm.2016.02.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/18/2016] [Accepted: 02/27/2016] [Indexed: 11/19/2022]
Abstract
Reducing expression or inhibiting translocation of protein kinase C epsilon (PKCε) prolongs ethanol intoxication and decreases ethanol consumption in mice. However, we do not know if this phenotype is due to reduced PKCε kinase activity or to impairment of kinase-independent functions. In this study, we used a chemical-genetic strategy to determine whether a potent and highly selective inhibitor of PKCε catalytic activity reduces ethanol consumption. We generated ATP analog-specific PKCε (AS-PKCε) knock-in mice harboring a point mutation in the ATP binding site of PKCε that renders the mutant kinase highly sensitive to inhibition by 1-tert-butyl-3-naphthalen-1-ylpyrazolo[3,4-d]pyrimidin-4-amine (1-NA-PP1). Systemically administered 1-NA-PP1 readily crossed the blood brain barrier and inhibited PKCε-mediated phosphorylation. 1-NA-PP1 reversibly reduced ethanol consumption by AS-PKCε mice but not by wild type mice lacking the AS-PKCε mutation. These results support the development of inhibitors of PKCε catalytic activity as a strategy to reduce ethanol consumption, and they demonstrate that the AS- PKCε mouse is a useful tool to study the role of PKCε in behavior.
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Affiliation(s)
- Rajani Maiya
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 78712, USA
| | - Thomas McMahon
- The Ernest Gallo Clinic and Research Center, University of California San Francisco, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA
| | - Dan Wang
- The Ernest Gallo Clinic and Research Center, University of California San Francisco, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA
| | - Benjamin Kanter
- The Ernest Gallo Clinic and Research Center, University of California San Francisco, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA
| | - Dev Gandhi
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 78712, USA
| | - Holly L Chapman
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 78712, USA
| | - Jacklyn Miller
- The Ernest Gallo Clinic and Research Center, University of California San Francisco, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA
| | - Robert O Messing
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, 78712, USA; The Ernest Gallo Clinic and Research Center, University of California San Francisco, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA.
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Xia JY, Holland WL, Kusminski CM, Sun K, Sharma AX, Pearson MJ, Sifuentes AJ, McDonald JG, Gordillo R, Scherer PE. Targeted Induction of Ceramide Degradation Leads to Improved Systemic Metabolism and Reduced Hepatic Steatosis. Cell Metab 2015; 22:266-278. [PMID: 26190650 PMCID: PMC4527941 DOI: 10.1016/j.cmet.2015.06.007] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 04/16/2015] [Accepted: 06/10/2015] [Indexed: 12/13/2022]
Abstract
Sphingolipids have garnered attention for their role in insulin resistance and lipotoxic cell death. We have developed transgenic mice inducibly expressing acid ceramidase that display a reduction in ceramides in adult mouse tissues. Hepatic overexpression of acid ceramidase prevents hepatic steatosis and prompts improvements in insulin action in liver and adipose tissue upon exposure to high-fat diet. Conversely, overexpression of acid ceramidase within adipose tissue also prevents hepatic steatosis and systemic insulin resistance. Induction of ceramidase activity in either tissue promotes a lowering of hepatic ceramides and reduced activation of the ceramide-activated protein kinase C isoform PKCζ, though the induction of ceramidase activity in the adipocyte prompts more rapid resolution of hepatic steatosis than overexpression of the enzyme directly in the liver. Collectively, our observations suggest the existence of a rapidly acting "cross-talk" between liver and adipose tissue sphingolipids, critically regulating glucose metabolism and hepatic lipid uptake.
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Affiliation(s)
- Jonathan Y. Xia
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - William L. Holland
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Christine M. Kusminski
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Ankit X. Sharma
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Mackenzie J. Pearson
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Angelika J. Sifuentes
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Jeffrey G. McDonald
- Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Ruth Gordillo
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
| | - Philipp E. Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
- Department of Cell Biology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-8549
- Correspondence should be addressed to: Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX, 75390-8549, USA, , Tel: 214-648-8715. Fax: 214-648-8720
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Akie TE, Liu L, Nam M, Lei S, Cooper MP. OXPHOS-Mediated Induction of NAD+ Promotes Complete Oxidation of Fatty Acids and Interdicts Non-Alcoholic Fatty Liver Disease. PLoS One 2015; 10:e0125617. [PMID: 25933096 PMCID: PMC4416931 DOI: 10.1371/journal.pone.0125617] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 03/24/2015] [Indexed: 12/21/2022] Open
Abstract
OXPHOS is believed to play an important role in non-alcoholic fatty liver disease (NAFLD), however, precise mechanisms whereby OXPHOS influences lipid homeostasis are incompletely understood. We previously reported that ectopic expression of LRPPRC, a protein that increases cristae density and OXPHOS, promoted fatty acid oxidation in cultured primary hepatocytes. To determine the biological significance of that observation and define underlying mechanisms, we have ectopically expressed LRPPRC in mouse liver in the setting of NAFLD. Interestingly, ectopic expression of LRPPRC in mouse liver completely interdicted NAFLD, including inflammation. Consistent with mitigation of NAFLD, two markers of hepatic insulin resistance—ROS and PKCε activity—were both modestly reduced. As reported by others, improvement of NAFLD was associated with improved whole-body insulin sensitivity. Regarding hepatic lipid homeostasis, the ratio of NAD+ to NADH was dramatically increased in mouse liver replete with LRPPRC. Pharmacological activators and inhibitors of the cellular respiration respectively increased and decreased the [NAD+]/[NADH] ratio, indicating respiration-mediated control of the [NAD+]/[NADH] ratio. Supporting a prominent role for NAD+, increasing the concentration of NAD+ stimulated complete oxidation of fatty acids. Importantly, NAD+ rescued impaired fatty acid oxidation in hepatocytes deficient for either OXPHOS or SIRT3. These data are consistent with a model whereby augmented hepatic OXPHOS increases NAD+, which in turn promotes complete oxidation of fatty acids and protects against NAFLD.
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Affiliation(s)
- Thomas E. Akie
- Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States of America
| | - Lijun Liu
- Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States of America
| | - Minwoo Nam
- Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States of America
| | - Shi Lei
- Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States of America
| | - Marcus P. Cooper
- Division of Cardiovascular Medicine, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States of America
- * E-mail:
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Muscella A, Vetrugno C, Calabriso N, Cossa LG, De Pascali SA, Fanizzi FP, Marsigliante S. [Pt(O,O'-acac)(γ-acac)(DMS)] alters SH-SY5Y cell migration and invasion by the inhibition of Na+/H+ exchanger isoform 1 occurring through a PKC-ε/ERK/mTOR Pathway. PLoS One 2014; 9:e112186. [PMID: 25372487 PMCID: PMC4221608 DOI: 10.1371/journal.pone.0112186] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 10/13/2014] [Indexed: 11/19/2022] Open
Abstract
We previously showed that [Pt(O,O'-acac)(γ-acac)(DMS)] ([Pt(acac)2(DMS)]) exerted substantial cytotoxic effects in SH-SY5Y neuroblastoma cells, and decreased metalloproteases (MMPs) production and cells migration in MCF-7 breast cancer cells. The ubiquitously distributed sodium-hydrogen antiporter 1 (NHE1) is involved in motility and invasion of many solid tumours. The present study focuses on the effects of [Pt(acac)2(DMS)] in SH-SY5Y cell migration and also on the possibility that NHE1 may be involved in such effect. After sublethal [Pt(acac)2(DMS)] treatment cell migration was examined by wounding assay and cell invasion by transwell assay. NHE1 activity was measured in BCECF-loaded SH-SY5Y as the rate of Na+-dependent intracellular pH recovery in response to an acute acid pulse. Gelatin zymography for MMP-2/9 activities, Western blottings of MMPs, MAPKs, mTOR, S6 and PKCs and small interfering RNAs to PKC-ε/-δ mRNA were performed. Sublethal concentrations of [Pt(acac)2(DMS)] decreases NHE1 activity, inhibits cell migration and invasion and decreases expression and activity of MMP-2 and -9. [Pt(acac)2(DMS)] administered to SH-SY5Y cells provokes the increment of ROS, generated by NADPH oxidase, responsible for the PKC-ε and PKC-δ activation. Whilst PKC-δ activates p38/MAPK, responsible for the inhibition of MMP-2 and -9 secretion, PKC-ε activates a pathway made of ERK1/2, mTOR and S6K responsible for the inhibition of NHE1 activity and cell migration. In conclusion, we have shown a drastic impairment in tumour cell metastatization in response to inhibition of NHE1 and MMPs activities by [Pt(acac)2(DMS)] occurring through a novel mechanism mediated by PKC-δ/-ε activation.
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Affiliation(s)
- Antonella Muscella
- Cell Pathology Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
| | - Carla Vetrugno
- Neuropathology Unit, Istituto di Neurologia sperimentale e Divisione di Neuroscienze, Istituto Scientifico IRCCS San Raffaele (sezione di Lecce), Milano, Italy
| | - Nadia Calabriso
- Cell Physiology Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
| | - Luca Giulio Cossa
- Cell Physiology Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
| | - Sandra Angelica De Pascali
- General and Inorganic Chemistry Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
| | - Francesco Paolo Fanizzi
- General and Inorganic Chemistry Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
| | - Santo Marsigliante
- Cell Physiology Lab, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Salento University, Lecce, Italy
- * E-mail:
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Worthmann K, Leitges M, Teng B, Sestu M, Tossidou I, Samson T, Haller H, Huber TB, Schiffer M. Def-6, a novel regulator of small GTPases in podocytes, acts downstream of atypical protein kinase C (aPKC) λ/ι. Am J Pathol 2013; 183:1945-1959. [PMID: 24096077 PMCID: PMC5707189 DOI: 10.1016/j.ajpath.2013.08.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 08/21/2013] [Accepted: 08/26/2013] [Indexed: 11/23/2022]
Abstract
The atypical protein kinase C (aPKC) isotypes PKCλ/ι and PKCζ are both expressed in podocytes; however, little is known about differences in their function. Previous studies in mice have demonstrated that podocyte-specific loss of PKCλ/ι leads to a severe glomerular phenotype, whereas mice deficient in PKCζ develop no renal phenotype. We analyzed various effects caused by PKCλ/ι and PKCζ deficiency in cultured murine podocytes. In contrast to PKCζ-deficient podocytes, PKCλ/ι-deficient podocytes exhibited a severe actin cytoskeletal phenotype, reduced cell size, decreased number of focal adhesions, and increased activation of small GTPases. Comparative microarray analysis revealed that the guanine nucleotide exchange factor Def-6 was specifically up-regulated in PKCλ/ι-deficient podocytes. In vivo Def-6 expression is significantly increased in podocytes of PKCλ/ι-deficient mice. Cultured PKCλ/ι-deficient podocytes exhibited an enhanced membrane association of Def-6, indicating enhanced activation. Overexpression of aPKCλ/ι in PKCλ/ι-deficient podocytes could reduce the membrane-associated expression of Def-6 and rescue the actin phenotype. In the present study, PKCλ/ι was identified as an important factor for actin cytoskeletal regulation in podocytes and Def-6 as a specific downstream target of PKCλ/ι that regulates the activity of small GTPases and subsequently the actin cytoskeleton of podocytes.
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Affiliation(s)
- Kirstin Worthmann
- Division of Nephrology, Department of Medicine, Hannover Medical School, Hannover, Germany
| | - Michael Leitges
- Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Beina Teng
- Division of Nephrology, Department of Medicine, Hannover Medical School, Hannover, Germany
| | - Marcello Sestu
- Faculty of Medicine, Interdisciplinary Centre for Clinical Research (IZKF) Leipzig, University of Leipzig, Leipzig, Germany
| | - Irini Tossidou
- Division of Nephrology, Department of Medicine, Hannover Medical School, Hannover, Germany
| | - Thomas Samson
- Department of Cell and Developmental Biology, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina
| | - Hermann Haller
- Division of Nephrology, Department of Medicine, Hannover Medical School, Hannover, Germany
| | - Tobias B Huber
- Renal Division, University Hospital Freiburg, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, Albert-Ludwigs-University, Freiburg, Germany
| | - Mario Schiffer
- Division of Nephrology, Department of Medicine, Hannover Medical School, Hannover, Germany.
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Huang J, Guo J, Beigi F, Hodgkinson CP, Facundo HT, Zhang Z, Espinoza-Derout J, Zhou X, Pratt RE, Mirotsou M, Dzau VJ. HASF is a stem cell paracrine factor that activates PKC epsilon mediated cytoprotection. J Mol Cell Cardiol 2013; 66:157-64. [PMID: 24269490 DOI: 10.1016/j.yjmcc.2013.11.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 11/07/2013] [Accepted: 11/12/2013] [Indexed: 11/18/2022]
Abstract
Despite advances in the treatment of acute tissue ischemia significant challenges remain in effective cytoprotection from ischemic cell death. It has been documented that injected stem cells, such as mesenchymal stem cells (MSCs), can confer protection to ischemic tissue through the release of paracrine factors. The study of these factors is essential for understanding tissue repair and the development of new therapeutic approaches for regenerative medicine. We have recently shown that a novel factor secreted by MSCs, which we called HASF (Hypoxia and Akt induced Stem cell Factor), promotes cardiomyocyte proliferation. In this study we show that HASF has a cytoprotective effect on ischemia induced cardiomyocyte death. We assessed whether HASF could potentially be used as a therapeutic agent to prevent the damage associated with myocardial infarction. In vitro treatment of cardiomyocytes with HASF protein resulted in decreased apoptosis; TUNEL positive nuclei were fewer in number, and caspase activation and mitochondrial pore opening were inhibited. Purified HASF protein was injected into the heart immediately following myocardial infarction. Heart function was found to be comparable to sham operated animals one month following injury and fibrosis was significantly reduced. In vivo and in vitro HASF activated protein kinase C ε (PKCε). Inhibition of PKCε blocked the HASF effect on apoptosis. Furthermore, the beneficial effects of HASF were lost in mice lacking PKCε. Collectively these results identify HASF as a protein of significant therapeutic potential, acting in part through PKCε.
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Affiliation(s)
- Jing Huang
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Jian Guo
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Farideh Beigi
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Conrad P Hodgkinson
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Heberty T Facundo
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Zhiping Zhang
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Jorge Espinoza-Derout
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Xiyou Zhou
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Richard E Pratt
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Maria Mirotsou
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA
| | - Victor J Dzau
- Duke Cardiovascular Research Center, Duke University Medical Center, NC 27710, USA; Mandel Center for Hypertension and Atherosclerosis Research, Duke University Medical Center, NC 27710, USA.
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38
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Zhu H, Moriasi CM, Zhang M, Zhao Y, Zou MH. Phosphorylation of serine 399 in LKB1 protein short form by protein kinase Cζ is required for its nucleocytoplasmic transport and consequent AMP-activated protein kinase (AMPK) activation. J Biol Chem 2013; 288:16495-16505. [PMID: 23612973 PMCID: PMC3675585 DOI: 10.1074/jbc.m112.443580] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/21/2013] [Indexed: 11/06/2022] Open
Abstract
Two splice variants of LKB1 exist: LKB1 long form (LKB1(L)) and LKB1 short form (LKB1(S)). In a previous study, we demonstrated that phosphorylation of Ser-428/431 (in LKB1(L)) by protein kinase Cζ (PKCζ) was essential for LKB1-mediated activation of AMP-activated protein kinase (AMPK) in response to oxidants or metformin. Paradoxically, LKB1S also activates AMPK although it lacks Ser-428/431. Thus, we hypothesized that LKB1(S) contained additional phosphorylation sites important in AMPK activation. Truncation analysis and site-directed mutagenesis were used to identify putative PKCζ phosphorylation sites in LKB1(S). Substitution of Ser-399 to alanine did not alter the activity of LKB1(S), but abolished peroxynitrite- and metformin-induced activation of AMPK. Furthermore, the phosphomimetic mutation (S399D) increased the phosphorylation of AMPK and its downstream target phospho-acetyl-coenzyme A carboxylase (ACC). PKCζ-dependent phosphorylation of Ser-399 triggered nucleocytoplasmic translocation of LKB1(S) in response to metformin or peroxynitrite treatment. This effect was ablated by pharmacological and genetic inhibition of PKCζ, by inhibition of CRM1 activity and by substituting Ser-399 with alanine (S399A). Overexpression of PKCζ up-regulated metformin-mediated phosphorylation of both AMPK (Thr-172) and ACC (Ser-79), but the effect was ablated in the S399A mutant. We conclude that, similar to Ser-428/431 (in LKB1(L)), Ser-399 (in LKB1(S)) is a PKCζ-dependent phosphorylation site essential for nucleocytoplasmic export of LKB1(S) and consequent AMPK activation.
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Affiliation(s)
- Huaiping Zhu
- Section of Molecular Medicine, Department of Medicine, Oklahoma City, Oklahoma 73013
| | - Cate M Moriasi
- Section of Molecular Medicine, Department of Medicine, Oklahoma City, Oklahoma 73013
| | - Miao Zhang
- Section of Molecular Medicine, Department of Medicine, Oklahoma City, Oklahoma 73013
| | - Yu Zhao
- Section of Molecular Medicine, Department of Medicine, Oklahoma City, Oklahoma 73013
| | - Ming-Hui Zou
- Section of Molecular Medicine, Department of Medicine, Oklahoma City, Oklahoma 73013; Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73013.
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Varsano T, Lau E, Feng Y, Garrido M, Milan L, Heynen-Genel S, Hassig CA, Ronai ZA. Inhibition of melanoma growth by small molecules that promote the mitochondrial localization of ATF2. Clin Cancer Res 2013; 19:2710-22. [PMID: 23589174 DOI: 10.1158/1078-0432.ccr-12-2689] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Effective therapy for malignant melanoma, the leading cause of death from skin cancer, remains an area of significant unmet need in oncology. The elevated expression of PKCε in advanced metastatic melanoma results in the increased phosphorylation of the transcription factor ATF2 on threonine 52, which causes its nuclear localization and confers its oncogenic activities. The nuclear-to-mitochondrial translocation of ATF2 following genotoxic stress promotes apoptosis, a function that is largely lost in melanoma cells, due to its confined nuclear localization. Therefore, promoting the nuclear export of ATF2, which sensitizes melanoma cells to apoptosis, represents a novel therapeutic modality. EXPERIMENTAL DESIGN We conducted a pilot high-throughput screen of 3,800 compounds to identify small molecules that promote melanoma cell death by inducing the cytoplasmic localization of ATF2. The imaging-based ATF2 translocation assay was conducted using UACC903 melanoma cells that stably express doxycycline-inducible GFP-ATF2. RESULTS We identified two compounds (SBI-0089410 and SBI-0087702) that promoted the cytoplasmic localization of ATF2, reduced cell viability, inhibited colony formation, cell motility, and anchorage-free growth, and increased mitochondrial membrane permeability. SBI-0089410 inhibited the 12-O-tetradecanoylphorbol-l3-acetate (TPA)-induced membrane translocation of protein kinase C (PKC) isoforms, whereas both compounds decreased ATF2 phosphorylation by PKCε and ATF2 transcriptional activity. Overexpression of either constitutively active PKCε or phosphomimic mutant ATF2(T52E) attenuated the cellular effects of the compounds. CONCLUSION The imaging-based high-throughput screen provides a proof-of-concept for the identification of small molecules that block the oncogenic addiction to PKCε signaling by promoting ATF2 nuclear export, resulting in mitochondrial membrane leakage and melanoma cell death.
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Affiliation(s)
- Tal Varsano
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA
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40
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Körner C, Keklikoglou I, Bender C, Wörner A, Münstermann E, Wiemann S. MicroRNA-31 sensitizes human breast cells to apoptosis by direct targeting of protein kinase C epsilon (PKCepsilon). J Biol Chem 2013; 288:8750-8761. [PMID: 23364795 PMCID: PMC3605692 DOI: 10.1074/jbc.m112.414128] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 01/16/2013] [Indexed: 12/24/2022] Open
Abstract
MicroRNAs post-transcriptionally regulate gene expression and thereby contribute to the modulation of numerous complex and disease-relevant cellular phenotypes, including cell proliferation, cell motility, apoptosis, and stress response. In breast cancer cell systems, miR-31 has been shown to inhibit cell migration, invasion, and metastasis. Here, we link enhanced expression of miR-31 to the inhibition of the oncogenic NF-κB pathway, thus supporting the tumor-suppressive function of this microRNA. We identified protein kinase C epsilon (PKCε encoded by the PRKCE gene) as a novel direct target of miR-31 and show that down-regulation of PKCε results in impaired NF-κB signaling, enhanced apoptosis, and increased sensitivity of MCF10A breast epithelial and MDA-MB-231 triple-negative breast cancer cells toward ionizing radiation as well as treatment with chemotherapeutics. Mechanistically, we attribute this sensitization to anti-cancer treatments to the PRKCE-mediated down-regulation of the anti-apoptotic factor BCL2. In clinical breast cancer samples, high BCL2 expression was associated with poor prognosis. Furthermore, we found an inverse correlation between miR-31 and BCL2 expression, highlighting the functional relevance of the indirect down-regulation of BCL2 via direct targeting of PRKCE by miR-31.
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Affiliation(s)
- Cindy Körner
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ioanna Keklikoglou
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christian Bender
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Angelika Wörner
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ewald Münstermann
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefan Wiemann
- Division of Molecular Genome Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.
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41
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Pedersen DJ, Diakanastasis B, Stöckli J, Schmitz-Peiffer C. Protein kinase Cε modulates insulin receptor localization and trafficking in mouse embryonic fibroblasts. PLoS One 2013; 8:e58046. [PMID: 23469261 PMCID: PMC3585804 DOI: 10.1371/journal.pone.0058046] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 01/30/2013] [Indexed: 12/03/2022] Open
Abstract
We have previously shown that deletion of protein kinase C epsilon (PKCε) in mice results in protection against glucose intolerance caused by a high fat diet. This was in part due to reduced insulin uptake by hepatocytes and insulin clearance, which enhanced insulin availability. Here we employed mouse embryonic fibroblasts (MEFs) derived from wildtype (WT) and PKCε-deficient (PKCε−/−) mice to examine this mechanistically. PKCε−/− MEFs exhibited reduced insulin uptake which was associated with decreased insulin receptor phosphorylation, while downstream signalling through IRS-1 and Akt was unaffected. Cellular fractionation demonstrated that PKCε deletion changed the localization of the insulin receptor, a greater proportion of which co-fractionated with flotillin-1, a marker of membrane microdomains. Insulin stimulation resulted in redistribution of the receptor in WT cells, while this was markedly reduced in PKCε−/− cells. These alterations in insulin receptor trafficking were associated with reduced expression of CEACAM1, a receptor substrate previously shown to modulate insulin clearance. Virally-mediated reconstitution of PKCε in MEFs increased CEACAM1 expression and partly restored the sensitivity of the receptor to insulin-stimulated redistribution. These data indicate that PKCε can affect insulin uptake in MEFs through promotion of receptor-mediated endocytosis, and that this may be mediated by regulation of CEACAM1 expression.
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Affiliation(s)
- David J. Pedersen
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Barbara Diakanastasis
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Jacqueline Stöckli
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Carsten Schmitz-Peiffer
- Diabetes and Obesity Program, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- * E-mail:
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42
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Yang W, Xia Y, Cao Y, Zheng Y, Bu W, Zhang L, You MJ, Koh MY, Cote G, Aldape K, Li Y, Verma IM, Chiao PJ, Lu Z. EGFR-induced and PKCε monoubiquitylation-dependent NF-κB activation upregulates PKM2 expression and promotes tumorigenesis. Mol Cell 2012; 48:771-84. [PMID: 23123196 PMCID: PMC3526114 DOI: 10.1016/j.molcel.2012.09.028] [Citation(s) in RCA: 187] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 06/05/2012] [Accepted: 09/19/2012] [Indexed: 01/28/2023]
Abstract
Many types of human tumor cells have overexpressed pyruvate kinase M2 (PKM2). However, the mechanism underlying this increased PKM2 expression remains to be defined. We demonstrate here that EGFR activation induces PLCγ1-dependent PKCε monoubiquitylation at Lys321 mediated by RINCK1 ubiquitin ligase. Monoubiquitylated PKCε interacts with a ubiquitin-binding domain in NEMO zinc finger and recruits the cytosolic IKK complex to the plasma membrane, where PKCε phosphorylates IKKβ at Ser177 and activates IKKβ. Activated RelA interacts with HIF1α, which is required for RelA to bind the PKM promoter. PKCε- and NF-κB-dependent PKM2 upregulation is required for EGFR-promoted glycolysis and tumorigenesis. In addition, PKM2 expression correlates with EGFR and IKKβ activity in human glioblastoma specimens and with grade of glioma malignancy. These findings highlight the distinct regulation of NF-κB by EGF, in contrast to TNF-α, and the importance of the metabolic cooperation between the EGFR and NF-κB pathways in PKM2 upregulation and tumorigenesis.
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MESH Headings
- Animals
- Brain Neoplasms/enzymology
- Brain Neoplasms/genetics
- Brain Neoplasms/pathology
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Cell Line, Tumor
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Enzyme Activation
- Epidermal Growth Factor/metabolism
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- Female
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Neoplastic
- Genes, Reporter
- Glioblastoma/enzymology
- Glioblastoma/genetics
- Glioblastoma/pathology
- Glucose/metabolism
- Glycolysis
- HEK293 Cells
- Heterogeneous-Nuclear Ribonucleoproteins/metabolism
- Humans
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- I-kappa B Kinase/metabolism
- Lactic Acid/metabolism
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Nude
- Mutagenesis, Site-Directed
- Mutation
- NF-kappa B/genetics
- NF-kappa B/metabolism
- Neoplasm Grading
- Neoplasm Transplantation
- Phospholipase C gamma/metabolism
- Phosphorylation
- Polypyrimidine Tract-Binding Protein/metabolism
- Prognosis
- Promoter Regions, Genetic
- Protein Kinase C-epsilon/genetics
- Protein Kinase C-epsilon/metabolism
- RNA Interference
- Serine
- Signal Transduction
- Thyroid Hormones/genetics
- Thyroid Hormones/metabolism
- Transcription Factor RelA/metabolism
- Transfection
- Ubiquitination
- Up-Regulation
- Thyroid Hormone-Binding Proteins
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Affiliation(s)
- Weiwei Yang
- Brain Tumor Center and Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yan Xia
- Brain Tumor Center and Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yu Cao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yanhua Zheng
- Brain Tumor Center and Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Wen Bu
- Lester and Sue Smith Breast Center & Department of Molecular and Cell Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Lin Zhang
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030, USA
| | - M. James You
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Mei Yee Koh
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Gilbert Cote
- Department of Endocrine Neoplasia and Hormonal Disorders, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Kenneth Aldape
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Yi Li
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Inder M. Verma
- Laboratory of Genetics and Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Paul J Chiao
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
| | - Zhimin Lu
- Brain Tumor Center and Department of Neuro-Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030, USA
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Carubbi C, Mirandola P, Mattioli M, Galli D, Marziliano N, Merlini PA, Lina D, Notarangelo F, Cozzi MR, Gesi M, Ardissino D, De Marco L, Vitale M, Gobbi G. Protein kinase C ε expression in platelets from patients with acute myocardial infarction. PLoS One 2012; 7:e46409. [PMID: 23071564 PMCID: PMC3465320 DOI: 10.1371/journal.pone.0046409] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 08/29/2012] [Indexed: 01/16/2023] Open
Abstract
Objective Platelets play crucial roles in the pathophysiology of thrombosis and myocardial infarction. Protein kinase C ε (PKCε) is virtually absent in human platelets and its expression is precisely regulated during human megakaryocytic differentiation. On the basis of what is known on the role of platelet PKCε in other species, we hypothesized that platelets from myocardial infarction patients might ectopically express PKCε with a pathophysiological role in the disease. Methods and Results We therefore studied platelet PKCε expression from 24 patients with myocardial infarction, 24 patients with stable coronary artery disease and 24 healthy subjects. Indeed, platelets from myocardial infarction patients expressed PKCε with a significant frequency as compared to both stable coronary artery disease and healthy subjects. PKCε returned negative during patient follow-up. The forced expression of PKCε in normal donor platelets significantly increased their response to adenosine diphosphate-induced activation and adhesion to subendothelial collagen. Conclusions Our data suggest that platelet generations produced before the acute event retain PKCε-mRNA that is not down-regulated during terminal megakaryocyte differentiation. Results are discussed in the perspective of peri-infarctual megakaryocytopoiesis as a critical component of myocardial infarction pathophysiology.
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Affiliation(s)
- Cecilia Carubbi
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Prisco Mirandola
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Maria Mattioli
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Daniela Galli
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | | | | | - Daniela Lina
- Division of Cardiology, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | | | - Maria Rita Cozzi
- Department of Laboratory Medicine, CRO National Cancer Institute, Aviano, Italy
| | - Marco Gesi
- Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy
| | - Diego Ardissino
- Division of Cardiology, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
| | - Luigi De Marco
- Department of Laboratory Medicine, CRO National Cancer Institute, Aviano, Italy
| | - Marco Vitale
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
- * E-mail:
| | - Giuliana Gobbi
- Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
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44
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Raddatz K, Frangioudakis G, Diakanastasis B, Liao BM, Leitges M, Schmitz-Peiffer C. Deletion of protein kinase Cε in mice has limited effects on liver metabolite levels but alters fasting ketogenesis and gluconeogenesis. Diabetologia 2012; 55:2789-2793. [PMID: 22814763 DOI: 10.1007/s00125-012-2647-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 06/18/2012] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS Protein kinase Cε (PKCε) is emerging as a key mediator of lipid-induced insulin resistance in liver and hepatic lipid metabolism itself. We investigated whether PKCε plays a role in other metabolic processes, to further examine its suitability as a therapeutic target. METHODS We measured amino acid, organic acid and sugar levels by liquid and gas chromatography-mass spectrometry of liver extracts from chow and fat-fed wild-type (WT) and PKCε-deficient (Prkce(-/-)) mice. Fed and fasting glucose, ketone and fatty acid levels were measured in blood. Triacylglycerol levels and gluconeogenic and ketogenic enzyme expression were measured in liver. The effect of fasting on epididymal fat pad mass was also determined. RESULTS Metabolomic analysis indicated that the short-term high-fat diet affected over 20 compounds, including a 50% reduction in the glucogenic amino acid alanine. Prkce deletion resulted only in a reduction of 4-hydroxyproline and aspartate and an increase in glutamate. However, upon fasting, Prkce(-/-) mice were better able to maintain blood glucose levels and also exhibited lower levels of the ketone β-hydroxybutyrate compared with WT mice. Upon fasting, Prkce deletion also resulted in lower liver and plasma lipids and a smaller reduction in fat pad mass. CONCLUSIONS/INTERPRETATION Metabolomic analysis provided new insights into the effects of a high-fat diet on liver metabolite levels. Glucose homeostasis under fasting conditions is improved in Prkce(-/-) mice, which, in turn, may reduce the mobilisation of lipid from adipose tissue, reducing the availability of ketogenic substrate in the liver. Together with the protection against fat-diet-induced glucose intolerance previously observed in the fed state, these findings indicate PKCε as a unique therapeutic target for the improvement of glucose homeostasis.
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Affiliation(s)
- K Raddatz
- Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
- Competence Centre Functional Genomics-Pathoproteomics, University of Greifswald, Greifswald, Germany
| | - G Frangioudakis
- Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - B Diakanastasis
- Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - B M Liao
- Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - M Leitges
- Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - C Schmitz-Peiffer
- Diabetes and Obesity Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia.
- St Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
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45
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UNSWORTH AJ, FINNEY BA, NAVARRO-NUNEZ L, SEVERIN S, WATSON SP, PEARS CJ. Protein kinase Cε and protein kinase Cθ double-deficient mice have a bleeding diathesis. J Thromb Haemost 2012; 10:1887-94. [PMID: 22812584 PMCID: PMC3532618 DOI: 10.1111/j.1538-7836.2012.04857.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 07/10/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND In comparison to the classical isoforms of protein kinase C (PKC), the novel isoforms are thought to play minor or inhibitory roles in the regulation of platelet activation and thrombosis. OBJECTIVES To measure the levels of PKCθ and PKCε and to investigate the phenotype of mice deficient in both novel PKC isoforms. METHODS Tail bleeding and platelet activation assays were monitored in mice and platelets from mice deficient in both PKCθ and PKCε. RESULTS PKCε plays a minor role in supporting aggregation and secretion following stimulation of the collagen receptor GPVI in mouse platelets but has no apparent role in spreading on fibrinogen. PKCθ, in contrast, plays a minor role in supporting adhesion and filopodial generation on fibrinogen but has no apparent role in aggregation and secretion induced by GPVI despite being expressed at over 10 times the level of PKCε. Platelets deficient in both novel isoforms have a similar pattern of aggregation downstream of GPVI and spreading on fibrinogen as the single null mutants. Strikingly, a marked reduction in aggregation on collagen under arteriolar shear conditions is observed in blood from the double but not single-deficient mice along with a significant increase in tail bleeding. CONCLUSIONS These results reveal a greater than additive role for PKCθ and PKCε in supporting platelet activation under shear conditions and demonstrate that, in combination, the two novel PKCs support platelet activation.
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Affiliation(s)
- A J UNSWORTH
- Department of Biochemistry, University of OxfordOxford
| | - B A FINNEY
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - L NAVARRO-NUNEZ
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - S SEVERIN
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - S P WATSON
- Centre for Cardiovascular Sciences, Institute of Biomedical Research, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of BirminghamBirmingham, UK
| | - C J PEARS
- Department of Biochemistry, University of OxfordOxford
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García-Hoz C, Sánchez-Fernández G, García-Escudero R, Fernández-Velasco M, Palacios-García J, Ruiz-Meana M, Díaz-Meco MT, Leitges M, Moscat J, García-Dorado D, Boscá L, Mayor F, Ribas C. Protein kinase C (PKC)ζ-mediated Gαq stimulation of ERK5 protein pathway in cardiomyocytes and cardiac fibroblasts. J Biol Chem 2012; 287:7792-802. [PMID: 22232556 PMCID: PMC3293562 DOI: 10.1074/jbc.m111.282210] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Gq-coupled G protein-coupled receptors (GPCRs) mediate the actions of a variety of messengers that are key regulators of cardiovascular function. Enhanced Gα(q)-mediated signaling plays an important role in cardiac hypertrophy and in the transition to heart failure. We have recently described that Gα(q) acts as an adaptor protein that facilitates PKCζ-mediated activation of ERK5 in epithelial cells. Because the ERK5 cascade is known to be involved in cardiac hypertrophy, we have investigated the potential relevance of this pathway in cardiovascular Gq-dependent signaling using both cultured cardiac cell types and chronic administration of angiotensin II in mice. We find that PKCζ is required for the activation of the ERK5 pathway by Gq-coupled GPCR in neonatal and adult murine cardiomyocyte cultures and in cardiac fibroblasts. Stimulation of ERK5 by angiotensin II is blocked upon pharmacological inhibition or siRNA-mediated silencing of PKCζ in primary cultures of cardiac cells and in neonatal cardiomyocytes isolated from PKCζ-deficient mice. Moreover, upon chronic challenge with angiotensin II, these mice fail to promote the changes in the ERK5 pathway, in gene expression patterns, and in hypertrophic markers observed in wild-type animals. Taken together, our results show that PKCζ is essential for Gq-dependent ERK5 activation in cardiomyocytes and cardiac fibroblasts and indicate a key cardiac physiological role for the Gα(q)/PKCζ/ERK5 signaling axis.
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Affiliation(s)
- Carlota García-Hoz
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Universidad Autónoma de Madrid, Spain
- the Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
| | - Guzmán Sánchez-Fernández
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Universidad Autónoma de Madrid, Spain
- the Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
| | - Ramón García-Escudero
- the Molecular Oncology Unit, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, 28040 Madrid, Spain
| | | | - Julia Palacios-García
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Universidad Autónoma de Madrid, Spain
- the Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
| | - Marisol Ruiz-Meana
- the Vall d'Hebron University Hospital and Research Institute, Universitat Autonoma de Barcelona, 08035 Barcelona, Spain
| | - Maria Teresa Díaz-Meco
- the Tumor Microenvironment Program, Sanford-Burnham Medical Research Institute, La Jolla, California 92037
| | - Michael Leitges
- The Biotechnology Centre of Oslo, University of Oslo, 0317 Oslo, Norway, and
| | - Jorge Moscat
- the Tumor Microenvironment Program, Sanford-Burnham Medical Research Institute, La Jolla, California 92037
| | - David García-Dorado
- the Vall d'Hebron University Hospital and Research Institute, Universitat Autonoma de Barcelona, 08035 Barcelona, Spain
| | - Lisardo Boscá
- the Instituto de Investigaciones Biomédicas Alberto Sols, CSIC-UAM, 28029 Madrid, Spain
| | - Federico Mayor
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Universidad Autónoma de Madrid, Spain
- the Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
- To whom correspondence may be addressed: Centro de Biología Molecular “Severo Ochoa,” Universidad Autónoma de Madrid, 28049 Madrid, Spain. Tel.: 34-91-1964626; Fax: 34-91-1964420; E-mail:
| | - Catalina Ribas
- From the Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa,” Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), 28049 Madrid, Universidad Autónoma de Madrid, Spain
- the Instituto de Investigación Sanitaria La Princesa, 28006 Madrid, Spain
- To whom correspondence may be addressed: Centro de Biología Molecular “Severo Ochoa”, Universidad Autónoma de Madrid, 28049 Madrid, Spain. Tel.: 34-91-1964640; Fax: 34-91-1964420; E-mail:
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Toledo RA, Sekiya T, Horvath A, Faucz F, Fragoso MCBV, Longuini VC, Lourenço DM, Toledo SPA, Stratakis CA. Assessing the emerging oncogene protein kinase C epsilon as a candidate gene in families with Carney complex-2. Clin Endocrinol (Oxf) 2012; 76:147-8. [PMID: 21649687 DOI: 10.1111/j.1365-2265.2011.04144.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Campioli E, Batarseh A, Li J, Papadopoulos V. The endocrine disruptor mono-(2-ethylhexyl) phthalate affects the differentiation of human liposarcoma cells (SW 872). PLoS One 2011; 6:e28750. [PMID: 22205965 PMCID: PMC3244402 DOI: 10.1371/journal.pone.0028750] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/14/2011] [Indexed: 01/04/2023] Open
Abstract
Esters of phthalic acid (phthalates) are largely used in industrial plastics, medical devices, and pharmaceutical formulations. They are easily released from plastics into the environment and can be found in measurable levels in human fluids. Phthalates are agonists for peroxisome proliferator-activated receptors (PPARs), through which they regulate translocator protein (TSPO; 18 kDa) transcription in a tissue-specific manner. TSPO is a drug- and cholesterol-binding protein involved in mitochondrial respiration, steroid formation, and cell proliferation. TSPO has been shown to increase during differentiation and decrease during maturation in mouse adipocytes. The purpose of this study was to establish the effect of mono-(2-ethylhexyl) phthalate (MEHP) on the differentiation of human SW 872 preadipocyte cells, and examine the role of TSPO in the process. After 4 days of treatment with 10 µM MEHP, we observed changes in the transcription of acetyl-CoA carboxylase alpha, adenosine triphosphate citrate lyase, glucose transporters 1 and 4, and the S100 calcium binding protein B, all of which are markers of preadipocyte differentiation. These observed gene expression changes coincided with a decrease in cellular proliferation without affecting cellular triglyceride content. Taken together, these data suggest that MEHP exerts a differentiating effect on human preadipocytes. Interestingly, MEHP was able to temporarily increase TSPO mRNA levels through the PPAR-α and β/δ pathways. These results suggest that TSPO can be considered an important player in the differentiation process itself, or alternatively a factor whose presence is essential for adipocyte development.
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Affiliation(s)
- Enrico Campioli
- Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Amani Batarseh
- Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Jiehan Li
- Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Vassilios Papadopoulos
- Research Institute of the McGill University Health Center and the Departments of Medicine, Biochemistry, and Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
- * E-mail:
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49
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Alipour MR, Aliparasti MR, Keyhanmanesh R, Almasi S, Halimi M, Ansarin K, Feizi H. Effect of ghrelin on protein kinase C-ε and protein kinase C-δ gene expression in the pulmonary arterial smooth muscles of chronic hypoxic rats. J Endocrinol Invest 2011; 34:e369-73. [PMID: 22067223 DOI: 10.3275/8056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Protein kinase C (PKC), can be activated in pulmonary arterial smooth muscle cells during hypoxia, leading to hypoxic pulmonary vasoconstriction (HPV). Studies are going on to detect the strict PKC isoform involved in the phenomenon. It has been shown that ghrelin, a 28-amino-acid peptide, may protect lungs from HPV side effects, to some extent. The aim of study was to evaluate the effect of exogenous ghrelin on PKC-ε and PKC-δ gene expression during chronic hypoxia. MATERIAL AND METHODS Twenty-four adult male Wistar rats were divided randomly in 3 groups. Hypoxic rats with saline or ghrelin treatment were placed in a normobaric hypoxic chamber for 2 weeks. Controls remained in room air. PKC-ε and PKC-δ gene expression was measured by real-time RT-PCR. RESULTS Morphometric analysis showed that ghrelin reversed the hypoxia induced pulmonary artery wall thickness. In hypoxic animals, there was a 2- and 4-fold increment in PKC-ε and PKC- δ gene expression, respectively. Ghrelin treatment reduced the overexpression of PKC-ε and PKC-δ to control animals' value. CONCLUSION Ghrelin by decreasing the expression of PKC-ε and PKC-δ in hypoxic animals reduces the HPV. Although more studies are needed, it could be an honest deduction that ghrelin affects HPV in a multifunctional manner and might be used as a therapeutic agent in the future.
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Affiliation(s)
- M R Alipour
- Tuberculosis and Lung Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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50
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Raddatz K, Turner N, Frangioudakis G, Liao BM, Pedersen DJ, Cantley J, Wilks D, Preston E, Hegarty BD, Leitges M, Raftery MJ, Biden TJ, Schmitz-Peiffer C. Time-dependent effects of Prkce deletion on glucose homeostasis and hepatic lipid metabolism on dietary lipid oversupply in mice. Diabetologia 2011; 54:1447-56. [PMID: 21347625 DOI: 10.1007/s00125-011-2073-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 01/10/2011] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS We examined the time-dependent effects of deletion of the gene encoding protein kinase C epsilon (Prkce) on glucose homeostasis, insulin secretion and hepatic lipid metabolism in fat-fed mice. METHODS Prkce(-/-) and wild-type (WT) mice were fed a high-fat diet for 1 to 16 weeks and subjected to i.p. glucose tolerance tests (ipGTT) and indirect calorimetry. We also investigated gene expression and protein levels by RT-PCR, quantitative protein profiling (isobaric tag for relative and absolute quantification; iTRAQ) and immunoblotting. Lipid levels, mitochondrial oxidative capacity and lipid metabolism were assessed in liver and primary hepatocytes. RESULTS While fat-fed WT mice became glucose intolerant after 1 week, Prkce(-/-) mice exhibited normal glucose and insulin levels. iTRAQ suggested differences in lipid metabolism and oxidative phosphorylation between fat-fed WT and Prkce(-/-) animals. Liver triacylglycerols were increased in fat-fed Prkce(-/-) mice, resulting from altered lipid partitioning which promoted esterification of fatty acids in hepatocytes. In WT mice, fat feeding elevated oxygen consumption in vivo and in isolated liver mitochondria, but these increases were not seen in Prkce(-/-) mice. Prkce(-/-) hepatocytes also exhibited reduced production of reactive oxygen species (ROS) in the presence of palmitate. After 16 weeks of fat feeding, however, the improved glucose tolerance in fat-fed Prkce(-/-) mice was instead associated with increased insulin secretion during ipGTT, as we have previously reported. CONCLUSIONS/INTERPRETATION Prkce deletion ameliorates diet-induced glucose intolerance via two temporally distinct phenotypes. Protection against insulin resistance is associated with changes in hepatic lipid partitioning, which may reduce the acute inhibitory effects of fatty acid catabolism, such as ROS generation. In the longer term, enhancement of glucose-stimulated insulin secretion prevails.
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Affiliation(s)
- K Raddatz
- Garvan Institute of Medical Research, 384 Victoria Street, Sydney, NSW 2010, Australia.
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