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Zaczek A, Lewiński A, Karbownik-Lewińska M, Lehoczki A, Gesing A. Impact of visceral adipose tissue on longevity and metabolic health: a comparative study of gene expression in perirenal and epididymal fat of Ames dwarf mice. GeroScience 2024:10.1007/s11357-024-01131-1. [PMID: 38517641 DOI: 10.1007/s11357-024-01131-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 03/09/2024] [Indexed: 03/24/2024] Open
Abstract
Emerging research underscores the pivotal role of adipose tissue in regulating systemic aging processes, particularly when viewed through the lens of the endocrine hypotheses of aging. This study delves into the unique adipose characteristics in an important animal model of aging - the long-lived Ames dwarf (df/df) mice. Characterized by a Prop1df gene mutation, these mice exhibit a deficiency in growth hormone (GH), prolactin, and TSH, alongside extremely low circulating IGF-1 levels. Intriguingly, while surgical removal of visceral fat (VFR) enhances insulin sensitivity in normal mice, it paradoxically increases insulin resistance in Ames dwarfs. This suggests an altered profile of factors produced in visceral fat in the absence of GH, indicating a unique interplay between adipose tissue function and hormonal influences in these models. Our aim was to analyze the gene expression related to lipid and glucose metabolism, insulin pathways, inflammation, thermoregulation, mitochondrial biogenesis, and epigenetic regulation in the visceral (perirenal and epididymal) adipose tissue of Ames dwarf and normal mice. Our findings reveal an upregulation in the expression of key genes such as Lpl, Adrβ3, Rstn, Foxo1, Foxo3a, Irs1, Cfd, Aldh2, Il6, Tnfα, Pgc1α, Ucp2, and Ezh2 in perirenal and Akt1, Foxo3a, PI3k, Ir, Acly, Il6, Ring1a, and Ring 1b in epididymal fat in df/df mice. These results suggest that the longevity phenotype in Ames dwarfs, which is determined by peripubertal GH/IGF-1 levels, may also involve epigenetic reprogramming of adipose tissue influenced by hormonal changes. The increased expression of genes involved in metabolic regulation, tumor suppression, mitochondrial biogenesis, and insulin pathways in Ames dwarf mice highlights potentially beneficial aspects of this model, opening new avenues for understanding the molecular underpinnings of longevity and aging.
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Affiliation(s)
- Agnieszka Zaczek
- Department of Endocrinology of Ageing, Medical University of Lodz, Lodz, Poland
| | - Andrzej Lewiński
- Department of Paediatric Endocrinology, Medical University of Lodz, Lodz, Poland
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland
| | - Małgorzata Karbownik-Lewińska
- Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland
| | - Andrea Lehoczki
- Department of Public Health, Semmelweis University, Budapest, Hungary
- Doctoral School, Health Sciences Program, Semmelweis University, Budapest, Hungary
- Department of Haematology and Stem Cell Transplantation, National Institute for Haematology and Infectious Diseases, South Pest Central Hospital, 1097, Budapest, Hungary
| | - Adam Gesing
- Department of Endocrinology of Ageing, Medical University of Lodz, Lodz, Poland.
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Arvanitakis K, Koufakis T, Kalopitas G, Papadakos SP, Kotsa K, Germanidis G. Management of type 2 diabetes in patients with compensated liver cirrhosis: Short of evidence, plenty of potential. Diabetes Metab Syndr 2024; 18:102935. [PMID: 38163417 DOI: 10.1016/j.dsx.2023.102935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 12/16/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND AND AIMS Treatment of type 2 diabetes (T2D) in patients with compensated cirrhosis is challenging due to hypoglycemic risk, altered pharmacokinetics, and the lack of robust evidence on the risk/benefit ratio of various drugs. Suboptimal glycemic control accelerates the progression of cirrhosis, while the frequent coexistence of nonalcoholic fatty liver disease (NAFLD) with T2D highlights the need for a multifactorial therapeutic approach. METHODS A literature search was performed in Medline, Google Scholar and Scopus databases till July 2023, using relevant keywords to extract studies regarding the management of T2D in patients with compensated cirrhosis. RESULTS Metformin, sodium-glucose co-transporter-2 inhibitors (SGLT2i), and glucagon-like peptide-1 receptor agonists (GLP-1 RA) are promising treatment options for patients with T2D and compensated liver cirrhosis, offering good glycemic control with minimal risk of hypoglycemia, while their pleiotropic actions confer benefits on NAFLD and body weight, and decrease cardiorenal risk. Sulfonylureas cause hypoglycemia, thus should be avoided, while in specific studies, dipeptidyl peptidase-4 inhibitors have been correlated with increased risk of decompensation and variceal bleeding. Despite the benefits of thiazolidinediones in nonalcoholic steatohepatitis, concerns about edema and weight gain limit their use in compensated cirrhosis. Insulin does not exert hepatotoxic effects and can be administered safely in combination with other drugs; however, the risk of hypoglycemia should be considered. CONCLUSIONS The introduction of new hepatoprotective diabetes drugs into clinical practice, including tirzepatide, SGLT2i, and GLP-1 RA, sets the stage for future trials to investigate the ideal therapeutic regimen for people with T2D and compensated cirrhosis.
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Affiliation(s)
- Konstantinos Arvanitakis
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece; Basic and Translational Research Unit, Special Unit for Biomedical Research and Education, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece
| | - Theocharis Koufakis
- Second Propedeutic Department of Internal Medicine, Hippokration General Hospital, Aristotle University of Thessaloniki, 54642, Thessaloniki, Greece
| | - Georgios Kalopitas
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece; Basic and Translational Research Unit, Special Unit for Biomedical Research and Education, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece
| | - Stavros P Papadakos
- First Department of Pathology, Medical School, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Kalliopi Kotsa
- Division of Endocrinology and Metabolism and Diabetes Centre, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA University Hospital, 54636, Thessaloniki, Greece
| | - Georgios Germanidis
- Division of Gastroenterology and Hepatology, First Department of Internal Medicine, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece; Basic and Translational Research Unit, Special Unit for Biomedical Research and Education, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54636, Thessaloniki, Greece.
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Karkache IY, Molstad DHH, Vu E, Jensen ED, Bradley EW. Phlpp1 Expression in Osteoblasts Plays a Modest Role in Bone Homeostasis. JBMR Plus 2023; 7:e10806. [PMID: 38130760 PMCID: PMC10731110 DOI: 10.1002/jbm4.10806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/27/2023] [Accepted: 08/02/2023] [Indexed: 12/23/2023] Open
Abstract
Prior work demonstrated that Phlpp1 deficiency alters limb length and bone mass, but the cell types involved and requirement of Phlpp1 for this effect were unclear. To understand the function of Phlpp1 within bone-forming osteoblasts, we crossed Phlpp1 floxed mice with mice harboring type 1 collagen (Col1a12.3kb)-Cre. Mineralization of bone marrow stromal cell cultures derived from Phlpp1 cKOCol1a1 was unchanged, but levels of inflammatory genes (eg, Ifng, Il6, Ccl8) and receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratios were enhanced by either Phlpp1 ablation or chemical inhibition. Micro-computed tomography of the distal femur and L5 vertebral body of 12-week-old mice revealed no alteration in bone volume per total volume, but compromised femoral bone microarchitecture within Phlpp1 cKOCol1a1 conditional knockout females. Bone histomorphometry of the proximal tibia documented no changes in osteoblast or osteoclast number per bone surface but slight reductions in osteoclast surface per bone surface. Overall, our data show that deletion of Phlpp1 in type 1 collagen-expressing cells does not significantly alter attainment of peak bone mass of either males or females, but may enhance inflammatory gene expression and the ratio of RANKL/OPG. Future studies examining the role of Phlpp1 within models of advanced age, inflammation, or osteocytes, as well as functional redundancy with the related Phlpp2 isoform are warranted. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Ismael Y Karkache
- Department of OrthopedicsUniversity of MinnesotaMinneapolisMNUSA
- College of Veterinary SciencesUniversity of MinnesotaMinneapolisMNUSA
| | - David HH Molstad
- Department of OrthopedicsUniversity of MinnesotaMinneapolisMNUSA
| | - Elizabeth Vu
- Department of OrthopedicsUniversity of MinnesotaMinneapolisMNUSA
| | | | - Elizabeth W Bradley
- Department of OrthopedicsUniversity of MinnesotaMinneapolisMNUSA
- College of Veterinary SciencesUniversity of MinnesotaMinneapolisMNUSA
- Department of Orthopedic SurgeryStem Cell Institute, University of MinnesotaMinneapolisMNUSA
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Qin X, Fu Y, Fan J, Liu B, Liu P, Zhang Y, Jiang T, Zheng Q. Melatonin increases susceptibility to atrial fibrillation in obesity via Akt signaling impairment in response to lipid overload. J Pineal Res 2023; 74:e12851. [PMID: 36639364 DOI: 10.1111/jpi.12851] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 12/22/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
Melatonin has been proven to have antiarrhythmic potential; however, several studies have recently challenged this view. Herein, using a mouse model of obesity-induced atrial fibrillation (AF), we tentatively explored whether exogenous melatonin supplementation could increase AF susceptibility in the context of obesity. We observed that an 8-week drinking administration of melatonin (60 µg/ml in water) induced a greater susceptibility to AF in obese mice, although obesity-induced structural remodeling was alleviated. An investigation of systemic insulin sensitivity showed that melatonin treatment improved insulin sensitivity in obese mice, whereas it inhibited glucose-stimulated insulin secretion. Notably, melatonin treatment inhibited protein kinase B (Akt) signaling in the atria of obese mice and palmitate-treated neonatal rat cardiomyocytes, thereby providing an AF substrate. Melatonin increased lipid stress in obesity, as evidenced by elevated lipid accumulation and lipolysis-related gene expression, thus contributing to the impairment in atrial Akt signaling. Taken together, our results demonstrated that melatonin could increase AF susceptibility in obesity, probably due to increased lipid stress and resultant impairment of atrial Akt signaling. Our findings suggest that special precautions should be taken when administering melatonin to obese subjects.
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Affiliation(s)
- Xinghua Qin
- Xi'an Key Laboratory of Special Medicine and Health Engineering, School of Life Sciences, Northwestern Polytechnical University, Beilin District, Xi'an, Shaanxi, China
| | - Yuping Fu
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xincheng District, Xi'an, Shaanxi, China
| | - Jiali Fan
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xincheng District, Xi'an, Shaanxi, China
| | - Binghua Liu
- Xi'an Key Laboratory of Special Medicine and Health Engineering, School of Life Sciences, Northwestern Polytechnical University, Beilin District, Xi'an, Shaanxi, China
| | - Peng Liu
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xincheng District, Xi'an, Shaanxi, China
| | - Yudi Zhang
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xincheng District, Xi'an, Shaanxi, China
| | - Tiannan Jiang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Qiangsun Zheng
- Department of Cardiology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xincheng District, Xi'an, Shaanxi, China
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Liu X, Liu Y, Chen L, Zhang Z, Cui L, Wei T. Loss of pleckstrin homology domain and leucine-rich repeat protein phosphatase 2 has protective effects on high glucose-injured retinal ganglion cells via the effect on the Akt-GSK-3β-Nrf2 pathway. Inflamm Res 2023; 72:373-385. [PMID: 36562794 DOI: 10.1007/s00011-022-01680-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/12/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE Pleckstrin homology domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) is linked to various pathological states. However, whether PHLPP2 mediates diabetic retinopathy is unaddressed. This work explored the biological function of PHLPP2 in modulating high glucose (HG)-elicited damage of retinal ganglion cells (RGCs), an in vitro model for studying diabetic retinopathy. METHODS Mouse RGCs were treated with HG to establish a cell model. PHLPP2 was silenced by transfecting specific shRNAs targeting PHLPP2. RT-qPCR, immunoblotting, CCK-8 assay, flow cytometry, TUNEL assay, and ELISA were carried out. RESULTS Significant increases in PHLPP2 levels were observed in cultured RGCs exposed to HG. The severe damages evoked by HG to RGCs were remarkably weakened in PHLPP2-silenced RGCs, including improved cell survival, attenuated cell apoptosis, repressed oxidative stress, and prohibited proinflammatory response. The silencing of PHLPP2 strengthened the activation of Nrf2 in HG-treated RGCs via modulation of the Akt-GSK-3β axis. Interruption of the Akt-GSK-3β axis reversed PHLPP2-silencing-elicited Nrf2 activation. The protective effects of PHLPP2 silencing on HG-induced injury of RGCs were diminished by Nrf2 inhibition. CONCLUSIONS The loss of PHLPP2 was beneficial for HG-injured RGCs through the effect on the Akt-GSK-3β-Nrf2 pathway. This work suggests a possible role of PHLPP2 in diabetic retinopathy.
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Affiliation(s)
- Xuan Liu
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277 Yanta West Road, Xi'an, 710061, Shaanxi, China.
| | - Yong Liu
- The Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, No. 76 Yanta Road, Xi'an, 710061, Shaanxi, China.
| | - Li Chen
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Zhichao Zhang
- The Institute of Neurobiology, Xi'an Jiaotong University Health Science Center, No. 76 Yanta Road, Xi'an, 710061, Shaanxi, China
| | - Lijun Cui
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
| | - Ting Wei
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277 Yanta West Road, Xi'an, 710061, Shaanxi, China
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Zhang C, Joseph KM, Khan NM, Diaz‐Hernandez ME, Drissi H, Illien‐Junger S. PHLPP1 deficiency protects against age-related intervertebral disc degeneration. JOR Spine 2022; 5:e1224. [PMID: 36601379 PMCID: PMC9799085 DOI: 10.1002/jsp2.1224] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/21/2022] [Accepted: 09/07/2022] [Indexed: 01/07/2023] Open
Abstract
Background Intervertebral disc (IVD) degeneration is strongly associated with low back pain and is highly prevalent in the elderly population. Hallmarks of IVD degeneration include cell loss and extracellular matrix degradation. The PH domain leucine-rich-repeats protein phosphatase (PHLPP1) is highly expressed in diseased cartilaginous tissues where it is linked to extracellular matrix degradation. This study explored the ability of PHLPP1 deficiency to protect against age-related spontaneous IVD degeneration. Methods Lumbar IVDs of global Phlpp1 knockout (KO) and wildtype (WT) mice were collected at 5 months (young) and 20 months (aged). Picrosirius red-alcian blue staining (PR-AB) was performed to examine IVD structure and histological score. The expression of aggrecan, ADAMTS5, KRT19, FOXO1 and FOXO3 was analyzed through immunohistochemistry. Cell apoptosis was assessed by TUNEL assay. Human nucleus pulposus (NP) samples were obtained from patients diagnosed with IVD degeneration. PHLPP1 knockdown in human degenerated NP cells was conducted using small interfering RNA (siRNA) transfection. The expression of PHLPP1 regulated downstream targets was analyzed via immunoblot and real time quantitative PCR. Results Histological analysis showed that Phlpp1 KO decreased the prevalence and severity of age-related IVD degeneration. The deficiency of PHLPP1 promoted the increased expression of NP phenotypic marker KRT19, aggrecan and FOXO1, and decreased levels of ADMATS5 and cell apoptosis in the NP of aged mice. In degenerated human NP cells, PHLPP1 knockdown induced FOXO1 protein levels while FOXO1 inhibition offset the beneficial effects of PHLPP1 knockdown on KRT19 gene and protein expression. Conclusions Our findings indicate that Phlpp1 deficiency protected against NP phenotypic changes, extracellular matrix degradation, and cell apoptosis in the process of IVD degeneration, probably through FOXO1 activation, making PHLPP1 a promising therapeutic target for treating IVD degeneration.
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Affiliation(s)
- Changli Zhang
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Katherine M. Joseph
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | - Nazir M. Khan
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
| | | | - Hicham Drissi
- Department of OrthopaedicsEmory University School of MedicineAtlantaGeorgiaUSA
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Balamurugan K, Chandra K, Sai Latha S, Swathi M, Joshi MB, Misra P, Parsa KVL. PHLPPs: Emerging players in metabolic disorders. Drug Discov Today 2022; 27:103317. [PMID: 35835313 DOI: 10.1016/j.drudis.2022.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/21/2022] [Accepted: 07/07/2022] [Indexed: 12/15/2022]
Abstract
That reversible protein phosphorylation by kinases and phosphatases occurs in metabolic disorders is well known. Various studies have revealed that a multi-faceted and tightly regulated phosphatase, pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP)-1/2 displays robust effects in cardioprotection, ischaemia/reperfusion (I/R), and vascular remodelling. PHLPP1 promotes foamy macrophage development through ChREBP/AMPK-dependent pathways. Adipocyte-specific loss of PHLPP2 reduces adiposity, improves glucose tolerance,and attenuates fatty liver via the PHLPP2-HSL-PPARα axis. Discoveries of PHLPP1-mediated insulin resistance and pancreatic β cell death via the PHLPP1/2-Mst1-mTORC1 triangular loop have shed light on its significance in diabetology. PHLPP1 downregulation attenuates diabetic cardiomyopathy (DCM) by restoring PI3K-Akt-mTOR signalling. In this review, we summarise the functional role of, and cellular signalling mediated by, PHLPPs in metabolic tissues and discuss their potential as therapeutic targets.
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Affiliation(s)
- Keerthana Balamurugan
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Kanika Chandra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - S Sai Latha
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - M Swathi
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Manjunath B Joshi
- Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Parimal Misra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Kishore V L Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India.
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Balamurugan K, Medishetti R, Kotha J, Behera P, Chandra K, Mavuduru VA, Joshi MB, Samineni R, Katika MR, Ball WB, Thondamal M, Challa A, Chatti K, Parsa KV. PHLPP1 promotes neutral lipid accumulation through AMPK/ChREBP-dependent lipid uptake and fatty acid synthesis pathways. iScience 2022; 25:103766. [PMID: 35141506 PMCID: PMC8810408 DOI: 10.1016/j.isci.2022.103766] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/25/2021] [Accepted: 01/11/2022] [Indexed: 01/26/2023] Open
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Abstract
Over the last decades, research has focused on the role of pleckstrin homology (PH) domain leucine-rich repeat protein phosphatases (PHLPPs) in regulating cellular signaling via PI3K/Akt inhibition. The PKB/Akt signaling imbalances are associated with a variety of illnesses, including various types of cancer, inflammatory response, insulin resistance, and diabetes, demonstrating the relevance of PHLPPs in the prevention of diseases. Furthermore, identification of novel substrates of PHLPPs unveils their role as a critical mediator in various cellular processes. Recently, researchers have explored the increasing complexity of signaling networks involving PHLPPs whereby relevant information of PHLPPs in metabolic diseases was obtained. In this review, we discuss the current knowledge of PHLPPs on the well-known substrates and metabolic regulation, especially in liver, pancreatic beta cell, adipose tissue, and skeletal muscle in relation with the stated diseases. Understanding the context-dependent functions of PHLPPs can lead to a promising treatment strategy for several kinds of metabolic diseases.
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Affiliation(s)
- Jong-Ho Cha
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
| | - Yelin Jeong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Ah-Reum Oh
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Sang Bae Lee
- Division of Life Sciences, Jeonbuk National University; Sarcopenia Total Solution Center, Jeonju 54896, Korea
| | - Soon-Sun Hong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - KyeongJin Kim
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
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Is insulin the preferred treatment in persons with type 2 diabetes and liver cirrhosis? BMC Gastroenterol 2021; 21:263. [PMID: 34118892 PMCID: PMC8199810 DOI: 10.1186/s12876-021-01773-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/22/2021] [Indexed: 12/30/2022] Open
Abstract
Background Insulin is highly recommended for diabetes management in persons with liver cirrhosis. However, few studies have evaluated its long-term effects in these persons. We conducted this study to compare the risks of mortality, liver-related complications, and cardiovascular events in persons with type 2 diabetes mellitus (T2DM) and compensated liver cirrhosis. Methods From January 1, 2000, to December 31, 2012, we selected 2047 insulin users and 4094 propensity score-matched nonusers from Taiwan’s National Health Insurance Research Database. Cox proportional hazard models were used to assess the risks of outcomes. Results The mean follow-up time was 5.84 years. The death rate during the follow-up period was 5.28 and 4.07 per 100 person-years for insulin users and nonusers, respectively. In insulin users, the hazard ratios and 95% confidence intervals (CIs) of all-cause mortality, hepatocellular carcinoma, decompensated cirrhosis, hepatic failure, major cardiovascular events, and hypoglycemia were 1.31 (1.18–1.45), 1.18 (1.05–1.34), 1.53 (1.35–1.72), 1.26 (1.42–1.86), 1.41 (1.23–1.62), and 3.33 (2.45–4.53), respectively. Conclusions This retrospective cohort study indicated that among persons with T2DM and compensated liver cirrhosis, insulin users were associated with higher risks of death, liver-related complications, cardiovascular events, and hypoglycemia compared with insulin nonusers.
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Mathur A, Pandey VK, Khan MF, Kakkar P. PHLPP1/Nrf2-Mdm2 axis induces renal apoptosis via influencing nucleo-cytoplasmic shuttling of FoxO1 during diabetic nephropathy. Mol Cell Biochem 2021; 476:3681-3699. [PMID: 34057658 DOI: 10.1007/s11010-021-04177-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 05/12/2021] [Indexed: 11/30/2022]
Abstract
Impaired PI3K/Akt signaling (insulin resistance) and poor glycemic control (hyperglycemia) are the major risk factors involved in the progression of diabetic nephropathy (DN). This study was designed to identify factors influencing cell survival during DN. We found that high glucose exposure in renal proximal tubular cells (NRK52E) upregulated PHLPP1, an Akt phosphatase (Ser473), causing suppression in Akt and IGF1β phosphorylation leading to inhibition in insulin signaling pathway. Results demonstrate that sustained activation of PHLPP1 promoted nuclear retention of FoxO1 by preventing its ubiquitination via Mdm2, an Akt/ Nrf2-dependent E3 ligase. Thus, enhanced FoxO1 nuclear stability caused aberration in renal gluconeogenesis and activated apoptotic cascade. Conversely, gene silencing of PHLPP1-enhanced Nrf2 expression and attenuated FoxO1 regulated apoptosis compared to hyperglycemic cells. Mechanistic aspects of PHLPP1-Nrf2/FoxO1 signaling were further validated in STZ-nicotinamide-induced type 2 diabetic Wistar rats. Importantly, we observed via immunoblotting and dual immunocytochemical studies that treatment of Morin (2',3,4',5,7-Pentahydroxyflavone) during diabetes significantly augmented FoxO1 nuclear exclusion, resulting in its ubiquitination via Akt-Nrf2/Mdm2 pathway. Furthermore, lowering of PHLPP1 expression by Morin also prevented FoxO1/Mst1-mediated apoptotic signaling in vitro and in vivo. Morin treatment under the experimental conditions, effectively decreased blood glucose levels, ameliorated insulin resistance, alleviated oxidative stress and attenuated renal apoptosis in diabetic rats comparable to metformin thereby exhibiting tremendous potential against renal complications of diabetes. These novel results further acclaim that inhibition of PHLPP1/FoxO1-Mdm2 axis is critical in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Alpana Mathur
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
| | - Vivek Kumar Pandey
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India
| | - Mohammad Fareed Khan
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India
| | - Poonam Kakkar
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India. .,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India.
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Age-related expression of prominent regulatory elements in mouse brain: catastrophic decline of FOXO3a. GeroScience 2021; 43:1935-1946. [PMID: 33864227 DOI: 10.1007/s11357-021-00364-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 04/06/2021] [Indexed: 10/21/2022] Open
Abstract
Aging is associated with changes in regulation, particularly among diverse regulators in the brain. We assayed prominent regulatory elements in mouse brain to explore their relationship to one another, stress, and aging. Notably, unphosphorylated (activated) forkhead transcription factor 3a (uFOXO3a) expressed exponential decline congruent with increasing age-related mortality. Decline in uFOXO3a would impact homeostasis, aging rate, stress resistance, and mortality. We also examined other regulators associated with aging and FOXO3a: protein kinase B (PKB), the mechanistic target of rapamycin (mTOR), 70 kDa ribosomal S6 kinase (P70S6K), and 5' AMP-activated protein kinase (AMPK). It would require powerful regulatory distortion, conflicting tradeoffs and/or significant damage to inflict exponential decline of a transcription factor as crucial as FOXO3a. No other regulator examined expressed an exponential pattern congruent with aging. PKB was strongly associated with decreases in uFOXO3a, but the aging pattern of PKB did not support a causal linkage. Although mTOR expressed a trend for age-related increase, this was not significant. We considered that the mTOR downstream element, P70S6K, might suppress FOXO3a, but remarkably, it expressed a strong positive association. The age-related pattern of AMPK was also incompatible. Literature suggested the immunological regulator NFĸB (nuclear factor kappa-light-chain-enhancer of activated B cells) increases with age and suppresses FOXO3a. This would inhibit apoptosis, autophagy, mitophagy, proteostasis, detoxification, antioxidants, chaperones, and DNA repair, thus exacerbating aging. We conclude that a key aspect of aging involves distortion of key regulators in the brain.
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Diceglie C, Anelli GM, Martelli C, Serati A, Lo Dico A, Lisso F, Parisi F, Novielli C, Paleari R, Cetin I, Ottobrini L, Mandò C. Placental Antioxidant Defenses and Autophagy-Related Genes in Maternal Obesity and Gestational Diabetes Mellitus. Nutrients 2021; 13:nu13041303. [PMID: 33920886 PMCID: PMC8071310 DOI: 10.3390/nu13041303] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 01/07/2023] Open
Abstract
Maternal obesity and gestational diabetes mellitus (GDM) are increasing worldwide, representing risk factors for both mother and child short/long-term outcomes. Oxidative stress, lipotoxicity and altered autophagy have already been reported in obesity, but few studies have focused on obese pregnant women with GDM. Antioxidant and macro/chaperone-mediated autophagy (CMA)-related gene expressions were evaluated herein in obese and GDM placentas. A total of 47 women with singleton pregnancies delivered by elective cesarean section were enrolled: 16 normal weight (NW), 18 obese with no comorbidities (OB GDM(–)), 13 obese with GDM (OB GDM(+)). Placental gene expression was assessed by real-time PCR. Antioxidant gene expression (CAT, GPX1, GSS) decreased, the pro-autophagic ULK1 gene increased and the chaperone-mediated autophagy regulator PHLPP1 decreased in OB GDM(–) vs. NW. On the other hand, PHLPP1 expression increased in OB GDM(+) vs. OB GDM(–). When analyzing results in relation to fetal sex, we found sexual dimorphism for both antioxidant and CMA-related gene expressions. These preliminary results can pave the way for further analyses aimed at elucidating the placental autophagy role in metabolic pregnancy disorders and its potential targetability for the treatment of diabetes outcomes.
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Affiliation(s)
- Cecilia Diceglie
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
| | - Gaia Maria Anelli
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
| | - Cristina Martelli
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
| | - Anais Serati
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
| | - Alessia Lo Dico
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
| | - Fabrizia Lisso
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
| | - Francesca Parisi
- Department of Woman, Mother and Child, Luigi Sacco and Vittore Buzzi Children Hospital, ASST Fatebenefratelli-Sacco, Università degli Studi di Milano, 20154 Milano, Italy;
| | - Chiara Novielli
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
| | - Renata Paleari
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
| | - Irene Cetin
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
- Department of Woman, Mother and Child, Luigi Sacco and Vittore Buzzi Children Hospital, ASST Fatebenefratelli-Sacco, Università degli Studi di Milano, 20154 Milano, Italy;
| | - Luisa Ottobrini
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, 20054 Segrate, Italy; (C.D.); (C.M.); (A.S.); (A.L.D.); (R.P.)
- Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), 20054 Segrate, Italy
- Correspondence: (L.O.); (C.M.); Tel.: +39-02-503-30346 (L.O.); +39-02-503-19883 (C.M.)
| | - Chiara Mandò
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università degli Studi di Milano, 20157 Milano, Italy; (G.M.A.); (F.L.); (C.N.); (I.C.)
- Correspondence: (L.O.); (C.M.); Tel.: +39-02-503-30346 (L.O.); +39-02-503-19883 (C.M.)
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14
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Zhang X, Lu Y, He N, Wang F. Downregulation of PHLPP1 ameliorates high glucose-evoked injury in retinal ganglion cells by attenuating apoptosis and oxidative stress through enhancement of Nrf2 activation. Exp Cell Res 2020; 397:112344. [PMID: 33164862 DOI: 10.1016/j.yexcr.2020.112344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022]
Abstract
High glucose (HG)-induced oxidative stress contributes significantly to the pathogenesis of diabetic retinopathy. Pleckstrin homology domain and leucine rich repeat protein phosphatase 1 (PHLPP1) has emerged as a key regulator of oxidative stress implicated in various pathological processes. However, whether PHLPP1 participates in the regulation of HG-induced oxidative stress injury of retinal ganglion cells (RGCs) in diabetic retinopathy is undetermined. The purpose of this study was to explore the potential role and molecular mechanism of PHLPP1 in regulating HG-induced injury of RGCs. Our data showed that PHLPP1 expression was markedly elevated in RGCs from diabetic rats and HG-exposed RGCs. Our functional assay elucidated that knockdown of PHLPP1 improved cell viability and decreased cell apoptosis and reactive oxygen species (ROS) production in HG-exposed RGCs. Additionally, upregulation of PHLPP1 lowered cell viability and increased cell apoptosis and ROS production in HG-exposed RGCs. Mechanistically, knockdown of PHLPP1 resulted in an increase in nuclear factor erythroid-2 related factor 2 (Nrf2) nuclear expression and Nrf2/antioxidant response element (ARE)-mediated transcription associated with upregulation of glycogen synthase kinase-3β (GSK-3β) phosphorylation. Moreover, inhibition of GSK-3β significantly reversed the suppressive effect of PHLPP1 overexpression on Nrf2/ARE activation. Notably, the protective effect of PHLPP1 knockdown on HG-induced injury in RGCs was markedly abolished by Nrf2 inhibition. In conclusion, Our findings demonstrate that downregulation of PHLPP1 activates Nrf2/ARE signaling to protect RGCs from HG-induced apoptosis and oxidative stress. This study indicates a potential role of PHLPP1 in regulating HG-induced injury of RGCs during the development and progression of diabetic retinopathy.
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Affiliation(s)
- Xiaohui Zhang
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Ye Lu
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Na He
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Feng Wang
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China.
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15
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CXCL13 is a differentiation- and hypoxia-induced adipocytokine that exacerbates the inflammatory phenotype of adipocytes through PHLPP1 induction. Biochem J 2020; 476:3533-3548. [PMID: 31710352 DOI: 10.1042/bcj20190709] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/04/2019] [Accepted: 11/11/2019] [Indexed: 01/16/2023]
Abstract
Hypoxia in adipose tissue is regarded as a trigger that induces dysregulation of the secretory profile in adipocytes. Similarly, local dysregulation of adipocytokine secretion is an initial event in the deleterious effects of obesity on metabolism. We previously reported that CXCL13 is highly produced during adipogenesis, however little is known about the roles of CXCL13 in adipocytes. Here, we found that hypoxia, as modeled by 1% O2 or exposure to the hypoxia-mimetic reagent desferrioxamine (DFO) has strong inductive effects on the expression of CXCL13 and CXCR5, a CXCL13 receptor, in both undifferentiated and differentiated adipocytes and in organ-cultured white adipose tissue (WAT). CXCL13 was also highly expressed in WAT from high fat diet-fed mice. Hypoxic profile, typified by increased expression of interleukin-6 (IL-6) and plasminogen activator inhibitor-1 (PAI-1) and decreased expression of adiponectin, was significantly induced by CXCL13 treatment during adipogenic differentiation. Conversely, the treatment of adipocytes with a neutralizing-antibody against CXCL13 as well as CXCR5 knockdown by specific siRNA effectively inhibited DFO-induced inflammation. The phosphorylation of Akt2, a protective factor of adipose inflammation, was significantly inhibited by CXCL13 treatment during adipogenic differentiation. Mechanistically, CXCL13 induces the expression of PHLPP1, an Akt2 phosphatase, through focal adhesion kinase (FAK) signaling; and correspondingly we show that CXCL13 and DFO-induced IL-6 and PAI-1 expression was blocked by Phlpp1 knockdown. Furthermore, we revealed the functional binding sites of PPARγ2 and HIF1-α within the Cxcl13 promoter. Taken together, these results indicate that CXCL13 is an adipocytokine that facilitates hypoxia-induced inflammation in adipocytes through FAK-mediated induction of PHLPP1 in autocrine and/or paracrine manner.
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Wu J, Dong T, Chen T, Sun J, Luo J, He J, Wei L, Zeng B, Zhang H, Li W, Liu J, Chen X, Su M, Ni Y, Jiang Q, Zhang Y, Xi Q. Hepatic exosome-derived miR-130a-3p attenuates glucose intolerance via suppressing PHLPP2 gene in adipocyte. Metabolism 2020; 103:154006. [PMID: 31715176 DOI: 10.1016/j.metabol.2019.154006] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/17/2019] [Accepted: 09/24/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Glucose and lipid metabolism disorders are a major risk factor for type II diabetes and cardiovascular diseases. Evidence has indicated that the interplay between the liver and adipose tissue is crucial in maintaining energy homeostasis. Recently, the interaction between two distant endocrine organs mainly focuses on the regulation of hormones and receptors. However, as a novel carrier in the inter-tissue communication, exosomes plays a role in liver-fat crosstalk, but its effects on glucose and lipid metabolisms are still unclear. In this study, we sought to investigate the effects of hepatic exosome-derived miR-130a-3p in the regulation of glucose/lipid metabolism in adipose tissues. MEASURE In vivo, we constructed generalized miR-130a-3p knockout (130KO) and overexpressed (130OE) mice. Wild type (WT), 130KO and 130OE mice (n = 10) were assigned to a randomized controlled trial and were fed diets with either 10% (standard diet, SD) or 60% (high-fat diet, HFD) of total calories from fat (lard). Next, hepatic exosomes were extracted from WT-SD, 130KO-SD and 130OE-SD mice (WT-EXO, KO-EXO, OE-EXO), and 130KO mice were injected with 100 mg hepatic exosomes of different sources via tail-vein (once every 48 h) for 28 days, fed with HFD. In vitro, 3T3-L1 cells were treated with miR-130a-3p mimics, inhibitor and hepatic exosomes. Growth performance and glucose and lipid metabolic profiles were examined. RESULTS After feeding with HFD, the weights of 130KO mice were markedly higher than WT mice. Over-expression of miR-130a-3p in 130OE mice and intravenous injection of 130OE-EXO in 130KO mice contributed to a positive correlation with the recovery of insulin resistance. In addition, miR-130a-3p mimics and 130OE-EXO treatment of 3T3-L1 cells exhibited decreasing generations of lipid droplets and increasing glucose uptake. Conversely, inhibition of miR-130a-3p in vitro and in vivo resulted in opposite phenotype changes. Furthermore, PHLPP2 was identified as a direct target of miR-130a-3p, and the hepatic exosome-derived miR-130a-3p could improve glucose intolerance via suppressing PHLPP2 to activate AKT-AS160-GLUT4 signaling pathway in adipocytes. CONCLUSIONS We demonstrated that hepatic exosome-derived miR-130a regulated energy metabolism in adipose tissues, and elucidated a new molecular mechanism that hepatic exosome-derived miR-130a-3p is a crucial participant in organismic energy homeostasis through mediating crosstalk between the liver and adipose tissues.
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Affiliation(s)
- Jiahan Wu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Tao Dong
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Ting Chen
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Jiajie Sun
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Junyi Luo
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Jiajian He
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Limin Wei
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Bin Zeng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Haojie Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Weite Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Jie Liu
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Xingping Chen
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Mei Su
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Yuechun Ni
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Qingyan Jiang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China
| | - Yongliang Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China.
| | - Qianyun Xi
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, National Engineering Research Center For Breeding Swine Industry, Guangdong Province Research Center of Woody Forage Engineering and Technology, College of Animal Science, South China Agricultural University, 483 Wushan Road, Guangzhou 510642, China.
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Wang J, He Y, Yu D, Jin L, Gong X, Zhang B. Perilla oil regulates intestinal microbiota and alleviates insulin resistance through the PI3K/AKT signaling pathway in type-2 diabetic KKAy mice. Food Chem Toxicol 2020; 135:110965. [DOI: 10.1016/j.fct.2019.110965] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 01/10/2023]
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18
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Zhang C, Smith MP, Zhou GK, Lai A, Hoy RC, Mroz V, Torre OM, Laudier DM, Bradley EW, Westendorf JJ, Iatridis JC, Illien-Jünger S. Phlpp1 is associated with human intervertebral disc degeneration and its deficiency promotes healing after needle puncture injury in mice. Cell Death Dis 2019; 10:754. [PMID: 31582730 PMCID: PMC6776553 DOI: 10.1038/s41419-019-1985-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/20/2019] [Accepted: 09/12/2019] [Indexed: 12/22/2022]
Abstract
Back pain is a leading cause of global disability and is strongly associated with intervertebral disc (IVD) degeneration (IDD). Hallmarks of IDD include progressive cell loss and matrix degradation. The Akt signaling pathway regulates cellularity and matrix production in IVDs and its inactivation is known to contribute to a catabolic shift and increased cell loss via apoptosis. The PH domain leucine-rich repeat protein phosphatase (Phlpp1) directly regulates Akt signaling and therefore may play a role in regulating IDD, yet this has not been investigated. The aim of this study was to investigate if Phlpp1 has a role in Akt dysregulation during IDD. In human IVDs, Phlpp1 expression was positively correlated with IDD and the apoptosis marker cleaved Caspase-3, suggesting a key role of Phlpp1 in the progression of IDD. In mice, 3 days after IVD needle puncture injury, Phlpp1 knockout (KO) promoted Akt phosphorylation and cell proliferation, with less apoptosis. At 2 and 8 months after injury, Phlpp1 deficiency also had protective effects on IVD cellularity, matrix production, and collagen structure as measured with histological and immunohistochemical analyses. Specifically, Phlpp1-deletion resulted in enhanced nucleus pulposus matrix production and more chondrocytic cells at 2 months, and increased IVD height, nucleus pulposus cellularity, and extracellular matrix deposition 8 months after injury. In conclusion, Phlpp1 has a role in limiting cell survival and matrix degradation in IDD and research targeting its suppression could identify a potential therapeutic target for IDD.
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Affiliation(s)
- Changli Zhang
- Emory University School of Medicine, Atlanta, GA, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - George K Zhou
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alon Lai
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert C Hoy
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Victoria Mroz
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Olivia M Torre
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | | | | | | - Svenja Illien-Jünger
- Emory University School of Medicine, Atlanta, GA, USA.
- Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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19
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Wang H, Gu R, Tian F, Liu Y, Fan W, Xue G, Cai L, Xing Y. PHLPP2 as a novel metastatic and prognostic biomarker in non-small cell lung cancer patients. Thorac Cancer 2019; 10:2124-2132. [PMID: 31571378 PMCID: PMC6825916 DOI: 10.1111/1759-7714.13196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/27/2019] [Accepted: 08/27/2019] [Indexed: 12/24/2022] Open
Abstract
Background PH domain and leucine‐rich repeat protein phosphatase 2 (PHLPP2) has been reported to be a potent tumor suppressor in many human cancers. However, PHLPP2 has not been fully researched as a putative clinical prognostic biomarker of lung cancer. Methods The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases including data on 1383 non‐small cell lung cancer (NSCLC) patients were used to determine PHLPP2 expression. PHLPP2 expression was then examined by immunohistochemistry, and its clinical significance analyzed in 134 NSCLC patients, including 73 patients with adenocarcinoma and 81 with squamous cell carcinoma. Results We found PHLPP2 expression to be less pronounced in NSCLC tissue samples than that in nontumoral lung tissues according to data taken from TCGA and GEO datasets; this outcome was further validated by immunohistochemistry assay. The low PHLPP2 expression level was found to be associated with the presence of lymph node metastasis (P = 0.003). Importantly, PHLPP2 was found to be an independent indicator of prognosis for overall (hazard ratio [HR] = 0.520, 95% confidence interval [Cl] = 0.327–0.827; P = 0.006) and disease‐free survival (HR = 0.489, 95% Cl = 0.308–0.775; P = 0.002) in patients with surgically‐resected NSCLC by multivariate analysis. Conclusion Taken together, our findings show that PHLPP2 is a robust clinical marker for NSCLC survival and could serve as a potential therapeutic target.
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Affiliation(s)
- Hongmei Wang
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Ruixue Gu
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Fanglin Tian
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Yuechao Liu
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Weina Fan
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Guiqin Xue
- General Surgical Department, The Fifth Hospital of Daqing, Daqing, China
| | - Li Cai
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
| | - Ying Xing
- The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China
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20
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Gu L, Xie C, Peng Q, Zhang J, Li J, Tang Z. Arecoline suppresses epithelial cell viability through the Akt/mTOR signaling pathway via upregulation of PHLPP2. Toxicology 2019; 419:32-39. [PMID: 30910432 DOI: 10.1016/j.tox.2019.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/19/2019] [Accepted: 03/20/2019] [Indexed: 12/16/2022]
Abstract
Arecoline, the major active ingredient of the betel nut, is involved in the pathogenesis of oral submucous fibrosis. However, the underlying mechanism of this pathogenesis remains unclear. In this study, we found that arecoline suppresses the cell proliferation of the HaCaT epithelial cell and induces cell cycle arrest at the G1/S phase with an IC50 of 50 μg/mL. Furthermore, we found that arecoline reduces the protein level of cyclin D1, but it has no effect on its mRNA level and protein stability, implying that arecoline may modulate the translation of cyclin D1. We also observed the downregulation of the Akt/mTOR signaling pathway after treatment with arecoline, which may be related to the translation of cyclin D1. RNA-seq analysis identified that PHLPP2, the direct upstream target of Akt, is significantly upregulated after arecoline treatment. siRNA-mediated knockdown of PHLPP2 recovered the phosphorylation state of Akt, as well as attenuated the effect of arecoline on cell viability. Thus, our study revealed the crucial role of PHLPP2 in arecoline-induced cell viability suppression.
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Affiliation(s)
- Liqun Gu
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
| | - Changqing Xie
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China
| | - Qian Peng
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China
| | - Jiaming Zhang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
| | - Jiada Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
| | - Zhangui Tang
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Department of Oral and Maxillofacial Surgery, Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China.
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21
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Pandey VK, Mathur A, Kakkar P. Emerging role of Unfolded Protein Response (UPR) mediated proteotoxic apoptosis in diabetes. Life Sci 2018; 216:246-258. [PMID: 30471281 DOI: 10.1016/j.lfs.2018.11.041] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/16/2018] [Accepted: 11/19/2018] [Indexed: 02/07/2023]
Abstract
Endoplasmic reticulum (ER) is a crucial single membrane organelle that acts as a quality control system for cellular proteins as it is intricately involved in their synthesis, folding and trafficking to the respective targets. Type 2 diabetes is characterized by enhanced blood glucose level that promotes insulin resistance and hampers cellular glucose metabolism. Hyperglycemia provokes mitochondrial ROS production and glycation of proteins which exert a tremendous load on ER for conventional refolding of misfolded/unfolded and nascent proteins that perturb ER homeostasis resulting in apoptotic cell death. Impairment in ER functions is suspected to be through specific ER membrane-bound proteins known as Unfolded Protein Response (UPR) sensor proteins. Conformational changes in these proteins induce oligomerization and cross-autophosphorylation which facilitate processes required for the restoration of ER homeostatic imbalance. Multiple studies have reported the involvement of UPR mediated autophagy and apoptotic pathways in the progression of metabolic disorders including diabetes, cardiac ischemia/reperfusion injury and hypoxia-mediated cell death. In this review, the involvement of UPR pathways in the progression of diabetes associated complications have been addressed, which underscores molecular crosstalks during neuropathy, nephropathy, hepatic injury and retinopathy. A better understanding of these molecular interventions may reveal advanced therapeutic approaches for preventing diabetic comorbidities. The article also highlights the importance of phytochemicals that are emerging as novel ER stress inhibitors and are being explored for targeted interaction in preventing cell death responses during diabetes.
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Affiliation(s)
- Vivek Kumar Pandey
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, M.G Marg, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India
| | - Alpana Mathur
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, M.G Marg, Lucknow 226001, Uttar Pradesh, India; Babu Banarasi Das University, Lucknow, Uttar Pradesh, India
| | - Poonam Kakkar
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan 31, M.G Marg, Lucknow 226001, Uttar Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Toxicology Research, Lucknow 226001, Uttar Pradesh, India.
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22
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MicroRNAs as Regulators of Insulin Signaling: Research Updates and Potential Therapeutic Perspectives in Type 2 Diabetes. Int J Mol Sci 2018; 19:ijms19123705. [PMID: 30469501 PMCID: PMC6321520 DOI: 10.3390/ijms19123705] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/08/2018] [Accepted: 11/17/2018] [Indexed: 12/21/2022] Open
Abstract
The insulin signaling pathway is composed of a large number of molecules that positively or negatively modulate insulin specific signal transduction following its binding to the cognate receptor. Given the importance of the final effects of insulin signal transduction, it is conceivable that many regulators are needed in order to tightly control the metabolic or proliferative functional outputs. MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively modulate gene expression through their specific binding within the 3′UTR sequence of messenger RNA (mRNA), thus causing mRNA decoy or translational inhibition. In the last decade, miRNAs have been addressed as pivotal cellular rheostats which control many fundamental signaling pathways, including insulin signal transduction. Several studies demonstrated that multiple alterations of miRNAs expression or function are relevant for the development of insulin resistance in type 2 diabetes (T2D); such alterations have been highlighted in multiple insulin target organs including liver, muscles, and adipose tissue. Indirectly, miRNAs have been identified as modulators of inflammation-derived insulin resistance, by controlling/tuning the activity of innate immune cells in insulin target tissues. Here, we review main findings on miRNA functions as modulators of insulin signaling in physiologic- or in T2D insulin resistance- status. Additionally, we report the latest hypotheses of prospective therapies involving miRNAs as potential targets for future drugs in T2D.
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23
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Huang X, Liu G, Guo J, Su Z. The PI3K/AKT pathway in obesity and type 2 diabetes. Int J Biol Sci 2018; 14:1483-1496. [PMID: 30263000 PMCID: PMC6158718 DOI: 10.7150/ijbs.27173] [Citation(s) in RCA: 835] [Impact Index Per Article: 139.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/10/2018] [Indexed: 02/06/2023] Open
Abstract
Obesity and type 2 diabetes mellitus are complicated metabolic diseases that affect multiple organs and are characterized by hyperglycaemia. Currently, stable and effective treatments for obesity and type 2 diabetes mellitus are not available. Therefore, the mechanisms leading to obesity and diabetes and more effective ways to treat obesity and diabetes should be identified. Based on accumulated evidences, the PI3K/AKT signalling pathway is required for normal metabolism due to its characteristics, and its imbalance leads to the development of obesity and type 2 diabetes mellitus. This review focuses on the role of PI3K/AKT signalling in the skeletal muscle, adipose tissue, liver, brain and pancreas, and discusses how this signalling pathway affects the development of the aforementioned diseases. We also summarize evidences for recently identified therapeutic targets of the PI3K/AKT pathway as treatments for obesity and type 2 diabetes mellitus. PI3K/AKT pathway damaged in various tissues of the body leads to obesity and type 2 diabetes as the result of insulin resistance, and in turn, insulin resistance exacerbates the PI3K/AKT pathway, forming a vicious circle.
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Affiliation(s)
- Xingjun Huang
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou (510006), China.,Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
| | - Guihua Liu
- Shenzhen Center for Disease Control and Prevention, 8 Longyuan Road, Nanshan District, Shenzhen (518055), China
| | - Jiao Guo
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
| | - Zhengquan Su
- Guangdong Engineering Research Center of Natural Products and New Drugs, Guangdong Provincial University Engineering Technology Research Center of Natural Products and Drugs, Guangdong Pharmaceutical University, Guangzhou (510006), China.,Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangdong Pharmaceutical University, Guangzhou (510006), China
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24
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Sohrabipour S, Sharifi MR, Sharifi M, Talebi A, Soltani N. Effect of magnesium sulfate administration to improve insulin resistance in type 2 diabetes animal model: using the hyperinsulinemic-euglycemic clamp technique. Fundam Clin Pharmacol 2018; 32:603-616. [PMID: 29869808 DOI: 10.1111/fcp.12387] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 05/08/2018] [Accepted: 06/01/2018] [Indexed: 12/15/2022]
Abstract
This study attempted to elucidate the possible mechanism of magnesium sulfate (MgSO4 ) administration on reducing insulin resistance in type 2 diabetic rats. Fifty Wistar rats were divided into five groups: NDC was fed the normal diet, CD received high-fat diet with 35 mg/kg of streptozotocin, CD-Mg animals received MgSO4 via drinking water, CD-Ins1, and CD-Ins2 animals treated with low or high dose of insulin. Body weight and blood glucose levels were measured weekly. Intraperitoneal glucose tolerance test (IPGTT), insulin tolerance test, and metabolic cage assessment were performed monthly. After 12 weeks, the hyperinsulinemic-euglycemic clamp was performed for all animals and blood sample was taken to measure glycated hemoglobin (HbA1c), plasma insulin, glucagon, calcium, and magnesium levels. Liver and gastrocnemius muscle were isolated to measure glucagon receptor (GR), Glucose 6 phosphatase (G6Pase), Phosphoenolpyruvate carboxykinase (Pepck) and Glucose transporter 4 (Glut4) genes expression and GLUT4 protein translocation into the cell membrane. Consuming of high-fat diet generated insulin-resistant rats. Magnesium or insulin therapy altered insulin resistance, blood glucose, IPGTT, gluconeogenesis pathway, GR, body weight, the percentage of body fat, and HbA1C in diabetic rats. Administrations of MgSO4 or insulin in Type 2 diabetes mellitus animals increase GLUT4 gene and protein expression. Mg could improve glucose tolerance via stimulation of Glut4 gene expression and translocation and also suppression of the gluconeogenesis pathway and GR gene expression. Mg also increased glucose infusion rate and displayed beneficial effects in the treatment of glucose metabolism and improved insulin resistance.
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Affiliation(s)
- Shahla Sohrabipour
- Endocrinology and Metabolism Research Center, Hormozgan University of Medical Sciences, Bandar, Abbas, Iran
| | - Mohammad Reza Sharifi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammadreza Sharifi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ardeshir Talebi
- Department of Clinical Pathology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nepton Soltani
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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25
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Behera S, Kapadia B, Kain V, Alamuru-Yellapragada NP, Murunikkara V, Kumar ST, Babu PP, Seshadri S, Shivarudraiah P, Hiriyan J, Gangula NR, Maddika S, Misra P, Parsa KV. ERK1/2 activated PHLPP1 induces skeletal muscle ER stress through the inhibition of a novel substrate AMPK. Biochim Biophys Acta Mol Basis Dis 2018; 1864:1702-1716. [DOI: 10.1016/j.bbadis.2018.02.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/29/2018] [Accepted: 02/22/2018] [Indexed: 11/28/2022]
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26
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Yeh ST, Zambrano CM, Koch WJ, Purcell NH. PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) regulates G-protein-coupled receptor kinase 5 (GRK5)-induced cardiac hypertrophy in vitro. J Biol Chem 2018; 293:8056-8064. [PMID: 29628444 DOI: 10.1074/jbc.m117.809913] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 03/30/2018] [Indexed: 12/20/2022] Open
Abstract
PH domain leucine-rich repeat protein phosphatase (PHLPP) is a serine/threonine phosphatase that has been shown to regulate cell growth and survival through dephosphorylation of several members of the AGC family of kinases. G-protein-coupled receptor kinase 5 (GRK5) is an AGC kinase that regulates phenylephrine (PE)-induced cardiac hypertrophy through its noncanonical function of directly targeting proteins to the nucleus to regulate transcription. Here we investigated the possibility that the PHLPP2 isoform can regulate GRK5-induced cardiomyocyte hypertrophy in neonatal rat ventricular myocytes (NRVMs). We show that removal of PHLPP2 by siRNA induces hypertrophic growth of NRVMs as measured by cell size changes at baseline, potentiated PE-induced cell size changes, and re-expression of fetal genes atrial natriuretic factor and brain natriuretic peptide. Endogenous GRK5 and PHLPP2 were found to interact in NRVMs, and PE-induced nuclear accumulation of GRK5 was enhanced upon down-regulation of PHLPP2. Conversely, overexpression of PHLPP2 blocked PE-induced hypertrophic growth, re-expression of fetal genes, and nuclear accumulation of GRK5, which depended on its phosphatase activity. Finally, using siRNA against GRK5, we found that GRK5 was necessary for the hypertrophic response induced by PHLPP2 knockdown. Our findings demonstrate for the first time a novel regulation of GRK5 by the phosphatase PHLPP2, which modulates hypertrophic growth. Understanding the signaling pathways affected by PHLPP2 has potential for new therapeutic targets in the treatment of cardiac hypertrophy and failure.
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Affiliation(s)
- Szu-Tsen Yeh
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Cristina M Zambrano
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Walter J Koch
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Nicole H Purcell
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093.
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27
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miR-214-Dependent Increase of PHLPP2 Levels Mediates the Impairment of Insulin-Stimulated Akt Activation in Mouse Aortic Endothelial Cells Exposed to Methylglyoxal. Int J Mol Sci 2018; 19:ijms19020522. [PMID: 29425121 PMCID: PMC5855744 DOI: 10.3390/ijms19020522] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 02/06/2018] [Accepted: 02/06/2018] [Indexed: 01/08/2023] Open
Abstract
Evidence has been provided linking microRNAs (miRNAs) and diabetic complications, by the regulation of molecular pathways, including insulin-signaling, involved in the pathophysiology of vascular dysfunction. Methylglyoxal (MGO) accumulates in diabetes and is associated with cardiovascular complications. This study aims to analyze the contribution of miRNAs in the MGO-induced damaging effect on insulin responsiveness in mouse aortic endothelial cells (MAECs). miRNA modulation was performed by transfection of specific miRNA mimics and inhibitors in MAECs, treated or not with MGO. miRNA-target protein levels were evaluated by Western blot. PH domain leucine-rich repeat protein phosphatase 2 (PHLPP2) regulation by miR-214 was tested by luciferase assays and by the use of a target protector specific for miR-214 on PHLPP2-3′UTR. This study reveals a 4-fold increase of PHLPP2 in MGO-treated MAECs. PHLPP2 levels inversely correlate with miR-214 modulation. Moreover, miR-214 overexpression is able to reduce PHLPP2 levels in MGO-treated MAECs. Interestingly, a direct regulation of PHLPP2 is proved to be dependent by miR-214. Finally, the inhibition of miR-214 impairs the insulin-dependent Akt activation, while its overexpression rescues the insulin effect on Akt activation in MGO-treated MAECs. In conclusion, this study shows that PHLPP2 is a target of miR-214 in MAECs, and identifies miR-214 downregulation as a contributing factor to MGO-induced endothelial insulin-resistance.
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