51
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High glucose-induced circHIPK3 downregulation mediates endothelial cell injury. Biochem Biophys Res Commun 2018; 507:362-368. [DOI: 10.1016/j.bbrc.2018.11.041] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Accepted: 11/06/2018] [Indexed: 01/02/2023]
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52
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Liu H, Feng Y, Xu M, Yang J, Wang Z, Di G. Four-octyl itaconate activates Keap1-Nrf2 signaling to protect neuronal cells from hydrogen peroxide. Cell Commun Signal 2018; 16:81. [PMID: 30442144 PMCID: PMC6238317 DOI: 10.1186/s12964-018-0294-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022] Open
Abstract
Background Four-octyl itaconate (OI), the itaconate’s cell-permeable derivative, can activate Nrf2 signaling via alkylation of Keap1 at its cysteine residues. The current study tested the potential neuroprotective function of OI in hydrogen peroxide (H2O2)-treated neuronal cells. Methods SH-SY5Y neuronal cells and epigenetically de-repressed (by TSA treatment) primary murine neurons were treated with OI and/or H2O2. Nrf2 pathway genes were examined by Western blotting assay and real-time quantitative PCR analysis. Neuronal cell death was tested by the LDH and trypan blue staining assays. Apoptosis was tested by TUNEL and Annexin V assays. Results In SH-SY5Y neuronal cells and primary murine neurons, OI activated Nrf2 signaling, causing Keap1-Nrf2 disassociation, Nrf2 protein stabilization and nuclear translocation, as well as expression of Nrf2-regulated genes (HO1, NQO1 and GCLC) and ninjurin2 (Ninj2). Functional studies showed that OI attenuated H2O2-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage as well as neuronal cell death and apoptosis. shRNA-mediated knockdown, or CRISPR/Cas9-induced knockout of Nrf2 almost abolished OI-induced neuroprotection against H2O2. Keap1 is the primary target of OI. Keap1 knockout by CRISPR/Cas9 method mimicked and abolished OI-induced actions in SH-SY5Y cells. Introduction of a Cys151S mutant Keap1 in SH-SY5Y cells reversed OI-induced Nrf2 activation and anti-H2O2 neuroprotection. Conclusions OI activates Keap1-Nrf2 signaling to protect SH-SY5Y cells and epigenetically de-repressed primary neurons from H2O2 in vitro. Electronic supplementary material The online version of this article (10.1186/s12964-018-0294-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hua Liu
- Department of Neurosurgery, The First People's Hospital of Kunshan, Jiangsu University, Suzhou, China
| | - Yu Feng
- Department of Endocrinology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Min Xu
- Department of Neurosurgery, Kunshan Hospital of Traditional Chinese Medicine, Kunshan Affiliated Hospital, Suzhou, China
| | - Jian Yang
- Department of Neurosurgery, The First People's Hospital of Kunshan, Jiangsu University, Suzhou, China
| | - Zhichun Wang
- Department of Neurosurgery, Yijishan Hospital, Wannan Medical College, Wuhu, China
| | - Guangfu Di
- Department of Neurosurgery, Yijishan Hospital, Wannan Medical College, Wuhu, China.
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53
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miR-1273g silences MAGEA3/6 to inhibit human colorectal cancer cell growth via activation of AMPK signaling. Cancer Lett 2018; 435:1-9. [DOI: 10.1016/j.canlet.2018.07.031] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 07/23/2018] [Accepted: 07/23/2018] [Indexed: 12/23/2022]
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54
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Breit A, Miek L, Schredelseker J, Geibel M, Merrow M, Gudermann T. Insulin-like growth factor-1 acts as a zeitgeber on hypothalamic circadian clock gene expression via glycogen synthase kinase-3β signaling. J Biol Chem 2018; 293:17278-17290. [PMID: 30217816 DOI: 10.1074/jbc.ra118.004429] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/22/2018] [Indexed: 12/12/2022] Open
Abstract
Brain and muscle ARNT-like protein-1 (BMAL-1) is an important component of the cellular circadian clock. Proteins such as epidermal (EGF) or nerve growth factor (NGF) affect the cellular clock via extracellular signal-regulated kinases-1/2 (ERK-1/2) in NIH3T3 or neuronal stem cells, but no such data are available for the insulin-like growth factor-1 (IGF-1). The hypothalamus expresses receptors for all three growth factors, acts as a central circadian pacemaker, and releases hormones in a circadian fashion. However, little is known about growth factor-induced modulation of clock gene activity in hypothalamic cells. Here, we investigated effects of IGF-1, EGF, or NGF on the Bmal-1 promoter in two hypothalamic cell lines. We found that only IGF-1 but not EGF or NGF enhanced activity of the Bmal-1 promoter. Inhibition of ERK-1/2 activity did not affect IGF-1-induced Bmal-1 promoter activation and all three growth factors similarly phosphorylated ERK-1/2, questioning a role for ERK-1/2 in controlling BMAL-1 promoter activity. Of note, only IGF-1 induced sustained phosphorylation of glycogen synthase kinase-3β (GSK-3β). Moreover, the GSK-3β inhibitor lithium or siRNA-mediated GSK-3β knockdown diminished the effects of IGF-1 on the Bmal-1 promoter. When IGF-1 was used in the context of temperature cycles entraining hypothalamic clock gene expression to a 24-h rhythm, it shifted the phase of Bmal-1 promoter activity, indicating that IGF-1 functions as a zeitgeber for cellular hypothalamic circadian clocks. Our results reveal that IGF-1 regulates clock gene expression and that GSK-3β but not ERK-1/2 is required for the IGF-1-mediated regulation of the Bmal-1 promoter in hypothalamic cells.
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Affiliation(s)
- Andreas Breit
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Laura Miek
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Johann Schredelseker
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
| | - Mirjam Geibel
- the Institute of Medical Psychology, Medical Faculty, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Martha Merrow
- the Institute of Medical Psychology, Medical Faculty, LMU Munich, Goethestrasse 31, 80336 Munich, Germany
| | - Thomas Gudermann
- From the Walther Straub Institute of Pharmacology and Toxicology, Medical Faculty, LMU Munich, Goethestrasse 33, 80336 Munich and
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55
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Sun J, Huang W, Yang SF, Zhang XP, Yu Q, Zhang ZQ, Yao J, Li KR, Jiang Q, Cao C. Gαi1 and Gαi3mediate VEGF-induced VEGFR2 endocytosis, signaling and angiogenesis. Theranostics 2018; 8:4695-4709. [PMID: 30279732 PMCID: PMC6160771 DOI: 10.7150/thno.26203] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/17/2018] [Indexed: 12/21/2022] Open
Abstract
VEGF binding to VEGFR2 leads to VEGFR2 endocytosis and downstream signaling activation to promote angiogenesis. Methods: Using genetic strategies, we tested the requirement of α subunits of heterotrimeric G proteins (Gαi1/3) in the process. Results: Gαi1/3 are located in the VEGFR2 endocytosis complex (VEGFR2-Ephrin-B2-Dab2-PAR-3), where they are required for VEGFR2 endocytosis and downstream signaling transduction. Gαi1/3 knockdown, knockout or dominant negative mutation inhibited VEGF-induced VEGFR2 endocytosis, and downstream Akt-mTOR and Erk-MAPK activation. Functional studies show that Gαi1/3 shRNA inhibited VEGF-induced proliferation, invasion, migration and vessel-like tube formation of HUVECs. In vivo, Gαi1/3 shRNA lentivirus inhibited alkali burn-induced neovascularization in mouse cornea. Further, oxygen-induced retinopathy (OIR)-induced retinal neovascularization was inhibited by intravitreal injection of Gαi1/3 shRNA lentivirus. Moreover, in vivo angiogenesis by alkali burn and OIR was significantly attenuated in Gαi1/3 double knockout mice. Significantly, Gαi1/3 proteins are upregulated in proliferative retinal tissues of proliferative diabetic retinopathy (PDR) patients. Conclusion: These results provide mechanistic insights into the critical role played by Gαi1/3 proteins in VEGF-induced VEGFR2 endocytosis, signaling and angiogenesis.
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56
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Shi X, Liu HY, Li SP, Xu HB. Keratinocyte growth factor protects endometrial cells from oxygen glucose deprivation/re-oxygenation via activating Nrf2 signaling. Biochem Biophys Res Commun 2018; 501:178-185. [DOI: 10.1016/j.bbrc.2018.04.208] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022]
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57
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Marshall J, Zhou XZ, Chen G, Yang SQ, Li Y, Wang Y, Zhang ZQ, Jiang Q, Birnbaumer L, Cao C. Antidepression action of BDNF requires and is mimicked by Gαi1/3 expression in the hippocampus. Proc Natl Acad Sci U S A 2018; 115:E3549-E3558. [PMID: 29507199 PMCID: PMC5899481 DOI: 10.1073/pnas.1722493115] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Stress-related alterations in brain-derived neurotrophic factor (BDNF) expression, a neurotrophin that plays a key role in synaptic plasticity, are believed to contribute to the pathophysiology of depression. Here, we show that in a chronic mild stress (CMS) model of depression the Gαi1 and Gαi3 subunits of heterotrimeric G proteins are down-regulated in the hippocampus, a key limbic structure associated with major depressive disorder. We provide evidence that Gαi1 and Gαi3 (Gαi1/3) are required for the activation of TrkB downstream signaling pathways. In mouse embryonic fibroblasts (MEFs) and CNS neurons, Gαi1/3 knockdown inhibited BDNF-induced tropomyosin-related kinase B (TrkB) endocytosis, adaptor protein activation, and Akt-mTORC1 and Erk-MAPK signaling. Functional studies show that Gαi1 and Gαi3 knockdown decreases the number of dendrites and dendritic spines in hippocampal neurons. In vivo, hippocampal Gαi1/3 knockdown after bilateral microinjection of lentiviral constructs containing Gαi1 and Gαi3 shRNA elicited depressive behaviors. Critically, exogenous expression of Gαi3 in the hippocampus reversed depressive behaviors in CMS mice. Similar results were observed in Gαi1/Gαi3 double-knockout mice, which exhibited severe depressive behaviors. These results demonstrate that heterotrimeric Gαi1 and Gαi3 proteins are essential for TrkB signaling and that disruption of Gαi1 or Gαi3 function could contribute to depressive behaviors.
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MESH Headings
- Animals
- Brain-Derived Neurotrophic Factor/metabolism
- Dendrites/metabolism
- Dendrites/pathology
- Dendritic Spines/metabolism
- Dendritic Spines/pathology
- Depression/metabolism
- Depression/pathology
- Depressive Disorder, Major/metabolism
- Depressive Disorder, Major/pathology
- Down-Regulation
- Female
- GTP-Binding Protein alpha Subunit, Gi2/biosynthesis
- GTP-Binding Protein alpha Subunit, Gi2/genetics
- GTP-Binding Protein alpha Subunit, Gi2/metabolism
- GTP-Binding Protein alpha Subunits, Gi-Go/biosynthesis
- GTP-Binding Protein alpha Subunits, Gi-Go/genetics
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Hippocampus/metabolism
- Mice
- Mice, Knockout
- Neurons/metabolism
- Neurons/pathology
- Signal Transduction/drug effects
- Stress, Physiological/physiology
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Affiliation(s)
- John Marshall
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912;
| | - Xiao-Zhong Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, 215004 Jiangsu, China
| | - Gang Chen
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, 215006 Jiangsu, China
| | - Su-Qing Yang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
| | - Ya Li
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
| | - Yin Wang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
| | - Zhi-Qing Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
| | - Qin Jiang
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, 210029 Nanjing, China
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709;
- School of Medical Sciences, Institute of Biomedical Research, Catholic University of Argentina, C1107AAZ Buenos Aires, Argentina
| | - Cong Cao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases Research, Soochow University, Suzhou 215000, China;
- Institute of Neuroscience, Soochow University, Suzhou 215000, China
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, 210029 Nanjing, China
- North District, The Municipal Hospital of Suzhou, Suzhou 215001, China
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58
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Liu YY, Chen MB, Cheng L, Zhang ZQ, Yu ZQ, Jiang Q, Chen G, Cao C. microRNA-200a downregulation in human glioma leads to Gαi1 over-expression, Akt activation, and cell proliferation. Oncogene 2018. [PMID: 29520106 DOI: 10.1038/s41388-018-0184-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We previously identified a pivotal role for G protein α inhibitory subunit 1 (Gαi1) in mediating PI3K-Akt signaling by receptor tyrosine kinases (RTKs). Here, we examined the expression and biological function of Gαi1 in human glioma. Gαi1 mRNA and protein expression were significantly upregulated in human glioma tissues, which correlated with downregulation of an anti-Gαi1 miRNA: microRNA-200a ("miR-200a"). Forced-expression of miR-200a in established (A172/U251MG lines) and primary (patient-derived) human glioma cells resulted in Gαi1 downregulation, Akt inactivation and proliferation inhibition. Reduction of Gαi1 expression by shRNA, dominant negative mutant interference, or complete Gαi1 depletion inhibited Akt activation and cell proliferation. Notably, miR-200a was unable to inhibit glioma cell proliferation when Gαi1 was silenced or mutated. Co-immunoprecipitation studies, in human glioma cells and tissues, show that Gαi1 forms a complex with multiple RTKs (EGFR, PDGFRα, and FGFR) and the adapter protein Gab1. In vivo, the growth of subcutaneous and orthotopic glioma xenografts in nude mice was largely inhibited by expression of Gαi1 shRNA or miRNA-200a. Collectively, miR-200a downregulation in human glioma leads to Gαi1 over-expression, Akt activation and glioma cell proliferation.
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Affiliation(s)
- Yuan-Yuan Liu
- Clinical Research and Lab Center, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Min-Bin Chen
- Department of Radiotherapy and Oncology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, China
| | - Long Cheng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China.,Department of Interventional Radiology, The Second Affiliated Hospital of Soochow University, Soochow University, Suzhou, China
| | - Zhi-Qing Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China
| | - Zheng-Quan Yu
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qin Jiang
- The Affiliated Eye Hospital of Nanjing Medical University, Nanjing, China.
| | - Gang Chen
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China.
| | - Cong Cao
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, China. .,The Affiliated Eye Hospital of Nanjing Medical University, Nanjing, China. .,North District, The Municipal Hospital of Suzhou, Suzhou, China.
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59
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Cai S, Li Y, Bai JY, Zhang ZQ, Wang Y, Qiao YB, Zhou XZ, Yang B, Tian Y, Cao C. Gαi3 nuclear translocation causes irradiation resistance in human glioma cells. Oncotarget 2018; 8:35061-35068. [PMID: 28456783 PMCID: PMC5471034 DOI: 10.18632/oncotarget.17043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 03/30/2017] [Indexed: 12/27/2022] Open
Abstract
We have previously shown that Gαi3 is elevated in human glioma, mediating Akt activation and cancer cell proliferation. Here, we imply that Gαi3 could also be important for irradiation resistance. In A172 human glioma cells, Gαi3 knockdown (by targeted shRNAs) or dominant-negative mutation significantly potentiated irradiation-induced cell apoptosis. Reversely, forced over-expression of wild-type or constitutively-active Gαi3 inhibited irradiation-induced A172 cell apoptosis. Irradiation in A172 cells induced Gαi3 translocation to cell nuclei and association with local protein DNA-dependent protein kinase (DNA-PK) catalytic subunit. This association was important for DNA damage repair. Gαi3 knockdown, depletion (using Gαi3 knockout MEFs) or dominant-negative mutation potentiated irradiation-induced DNA damages. On the other hand, expression of the constitutively-active Gαi3 in A172 cells inhibited DNA damage by irradiation. Together, these results indicate a novel function of Gαi3 in irradiation-resistance in human glioma cells.
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Affiliation(s)
- Shang Cai
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Ya Li
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Jin-Yu Bai
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhi-Qing Zhang
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yin Wang
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Yin-Biao Qiao
- Department of Surgery, The Third Hospital affiliated to Soochow University
| | - Xiao-Zhong Zhou
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Bo Yang
- Department of Surgery, The Third Hospital affiliated to Soochow University
| | - Ye Tian
- Department of Radiotherapy and Oncology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Cong Cao
- Institute of Neuroscience, Soochow University, Suzhou, China
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60
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Zhang XP, Li KR, Yu Q, Yao MD, Ge HM, Li XM, Jiang Q, Yao J, Cao C. Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization. FASEB J 2018; 32:3782-3791. [PMID: 29465315 DOI: 10.1096/fj.201701074rr] [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] [Indexed: 01/27/2023]
Abstract
VEGF-induced neovascularization plays a pivotal role in corneal neovascularization (CoNV). The current study investigated the potential effect of ginsenoside Rh2 (GRh2) on neovascularization. In HUVECs, pretreatment with GRh2 largely attenuated VEGF-induced cell proliferation, migration, and vessel-like tube formation in vitro. At the molecular level, GRh2 disrupted VEGF-induced VEGF receptor 2 (VEGFR2)-Grb-2-associated binder 1 (Gab1) association in HUVECs, causing inactivation of downstream AKT and ERK signaling. Gab1 knockdown (by targeted short hairpin RNA) similarly inhibited HUVEC proliferation and migration. Notably, GRh2 was ineffective against VEGF in Gab1-silenced HUVECs. In a mouse cornea alkali burn model, GRh2 eyedrops inhibited alkali-induced neovascularization and inflammatory cell infiltrations in the cornea. Furthermore, alkali-induced corneal expression of mRNAs/long noncoding RNAs in cornea were largely attenuated by GRh2. Overall, GRh2 inhibits VEGF-induced angiogenic effect via inhibiting VEGFR2-Gab1 signaling in vitro. It also alleviates angiogenic and inflammatory responses in alkali burn-treated mouse corneas.-Zhang, X.-P., Li, K.-R., Yu, Q., Yao, M.-D., Ge, H.-M., Li, X.-M., Jiang, Q., Yao, J., Cao, C. Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization.
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Affiliation(s)
- Xiao-Pei Zhang
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Ke-Ran Li
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Qing Yu
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Mu-Di Yao
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Hui-Min Ge
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Xiu-Miao Li
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Qin Jiang
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Jin Yao
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China
| | - Cong Cao
- The Fourth School of Clinical Medicine, The Affiliated Eye Hospital, Nanjing Medical University, Nanjing, China.,Jiangsu Key Laboratory of Neuropsychiatric Diseases Research and Institute of Neuroscience, Soochow University, Suzhou, China; and.,North District, The Municipal Hospital of Suzhou, Suzhou, China
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61
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Targeted reduction of the EGFR protein, but not inhibition of its kinase activity, induces mitophagy and death of cancer cells through activation of mTORC2 and Akt. Oncogenesis 2018; 7:5. [PMID: 29358623 PMCID: PMC5833766 DOI: 10.1038/s41389-017-0021-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 11/08/2017] [Indexed: 01/06/2023] Open
Abstract
The oncogenic epidermal growth factor receptor (EGFR) is commonly overexpressed in solid cancers. The tyrosine kinase activity of EGFR has been a major therapeutic target for cancer; however, the efficacy of EGFR tyrosine kinase inhibitors to treat cancers has been challenged by innate and acquired resistance at the clinic. Accumulating evidence suggests that EGFR possesses kinase-independent pro-survival functions, and that cancer cells are more vulnerable to reduction of EGFR protein than to inhibition of its kinase activity. The molecular mechanism underlying loss-of-EGFR-induced cell death remains largely unknown. In this study, we show that, unlike inhibiting EGFR kinase activity that is known to induce pro-survival non-selective autophagy, downregulating EGFR protein, either by siRNA, or by a synthetic EGFR-downregulating peptide (Herdegradin), kills prostate and ovarian cancer cells via selective mitophagy by activating the mTORC2/Akt axis. Furthermore, Herdegradin induced mitophagy and inhibited the growth of orthotopic ovarian cancers in mice. This study identifies anti-mitophagy as a kinase-independent function of EGFR, reveals a novel function of mTORC2/Akt axis in promoting mitophagy in cancer cells, and offers a novel approach for pharmacological downregulation of EGFR protein as a potential treatment for EGFR-positive cancers.
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62
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Hu H, Hao L, Tang C, Zhu Y, Jiang Q, Yao J. Activation of KGFR-Akt-mTOR-Nrf2 signaling protects human retinal pigment epithelium cells from Ultra-violet. Biochem Biophys Res Commun 2018; 495:2171-2177. [DOI: 10.1016/j.bbrc.2017.12.078] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 12/14/2017] [Indexed: 11/24/2022]
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63
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Xu YY, Chen FL, Ji F, Fei HD, Xie Y, Wang SG. Activation of AMP-activated protein kinase by compound 991 protects osteoblasts from dexamethasone. Biochem Biophys Res Commun 2017; 495:1014-1021. [PMID: 29175330 DOI: 10.1016/j.bbrc.2017.11.132] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 11/19/2017] [Indexed: 12/20/2022]
Abstract
Dexamethasone (Dex) induces direct cytotoxicity to cultured osteoblasts. The benzimidazole derivative compound 991 ("C991") is a novel and highly-efficient AMP-activated protein kinase (AMPK) activator. Here, in both MC3T3-E1 osteoblastic cells and primary murine osteoblasts, treatment with C991 activated AMPK signaling, and significantly attenuated Dex-induced apoptotic and non-apoptotic cell death. AMPKα1 knockdown (by shRNA), complete knockout (by CRISPR/Cas9 method) or dominant negative mutation (T172A) not only blocked C991-mediated AMPK activation, but also abolished its pro-survival effect against Dex in osteoblasts. Further studies showed that C991 boosted nicotinamide adenine dinucleotide phosphate (NADPH) activity and induced mRNA expression of NF-E2-related factor 2 (Nrf2)-regulated genes (heme oxygenase-1 and NADPH quinone oxidoreductase 1). Additionally, C991 alleviated Dex-induced reactive oxygen species (ROS) production in osteoblasts. Notably, genetic AMPK inhibition reversed the anti-oxidant actions by C991 in Dex-treated osteoblasts. Together, we conclude that C991 activates AMPK signaling to protect osteoblasts from Dex.
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Affiliation(s)
- Yong-Yi Xu
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Feng-Li Chen
- Clinical Laboratory, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Feng Ji
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
| | - Hao-Dong Fei
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Yue Xie
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Shou-Guo Wang
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
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64
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Ginseng Rh2 protects endometrial cells from oxygen glucose deprivation/re-oxygenation. Oncotarget 2017; 8:105703-105713. [PMID: 29285285 PMCID: PMC5739672 DOI: 10.18632/oncotarget.22390] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 10/27/2017] [Indexed: 01/22/2023] Open
Abstract
In this study, oxygen glucose deprivation/re-oxygenation (OGDR) was applied to cultured endometrial cells to mimic ischemic-reperfusion injuries. We also tested the potential effect of Ginseng Rh2 (GRh2) against the process. In established T-HESC human endometrial cells and primary murine endometrial cells, GRh2 largely inhibited OGDR-induced viability reduction and cell death. Remarkably, OGDR induced programmed necrosis in the endometrial cells, evidenced by cyclophilin D-p53-adenine nucleotide translocator 1 (ANT-1) mitochondrial association, mitochondrial depolarization, reactive oxygen species production, and lactate dehydrogenase release. Notably, such effects by OGDR were largely attenuated with co-treatment of GRh2. Further, cyclophilin D inhibition or knockdown also protected endometrial cells from OGDR. On the other hand, forced over-expression of cyclophilin D facilitated OGDR-induced T-HESC cell necrosis, which was dramatically inhibited by GRh2. Together, GRh2 protects endometrial cells from OGDR possibly via inhibiting CypD-dependent programmed necrosis pathway.
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Zheng K, Zhang Q, Lin G, Li Y, Sheng Z, Wang J, Chen L, Lu HH. Activation of Akt by SC79 protects myocardiocytes from oxygen and glucose deprivation (OGD)/re-oxygenation. Oncotarget 2017; 8:14978-14987. [PMID: 28122357 PMCID: PMC5362459 DOI: 10.18632/oncotarget.14785] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 01/11/2017] [Indexed: 12/21/2022] Open
Abstract
SC79 is a novel Akt activator. The current study tested its potential effect against oxygen and glucose deprivation (OGD)/re-oxygenation-induced myocardial cell death. We showed that SC79 activated Akt and protected H9c2 myocardial cells and primary murine myocardiocytes from OGD/re-oxygenation. Reversely, Akt inhibitor MK-2206 or Akt1 shRNA knockdown almost completely abolished SC79-mediated myocardial cytoprotection. SC79 treatment in H9c2 cells inhibited OGD/re-oxygenation-induced programmed necrosis pathway, evidenced by mitochondrial depolarization and cyclophilin D-p53-ANT-1 (adenine nucleotide translocator 1) association. Further, SC79 activated Akt downstream NF-E2-related factor 2 (NRF2) signaling to suppress OGD/re-oxygenation-induced reactive oxygen species (ROS) production. Reversely, NRF2 shRNA knockdown in H9c2 cells largely attenuated SC79-induced ROS scavenging ability and cytoprotection against OGD/re-oxygenation. Together, we conclude that activation of Akt by SC79 protects myocardial cells from OGD/re-oxygenation.
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Affiliation(s)
- Koulong Zheng
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Qing Zhang
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Gang Lin
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Yefei Li
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Zhenqiang Sheng
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Jue Wang
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Liang Chen
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
| | - Hui-He Lu
- Department of Cardiology, The Second Affiliated Hospital of Nantong University, Nantong, China
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66
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Yang B, Xu QY, Guo CY, Huang JW, Wang SM, Li YM, Tu Y, He L, Bi ZG, Ji C, Cheng B. MHY1485 ameliorates UV-induced skin cell damages via activating mTOR-Nrf2 signaling. Oncotarget 2017; 8:12775-12783. [PMID: 28061443 PMCID: PMC5355053 DOI: 10.18632/oncotarget.14299] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/08/2016] [Indexed: 12/30/2022] Open
Abstract
Ultra Violet (UV)-caused skin cell damage is a main cause of skin cancer. Here, we studied the activity of MHY1485, a mTOR activator, in UV-treated skin cells. In primary human skin keratinocytes, HaCaT keratinocytes and human skin fibroblasts, MHY1485 ameliorated UV-induced cell death and apoptosis. mTOR activation is required for MHY1485-induced above cytoprotective actions. mTOR kinase inhibitors (OSI-027, AZD-8055 and AZD-2014) or mTOR shRNA knockdown almost abolished MHY1485-induced cytoprotection. Further, MHY1485 treatment in skin cells activated mTOR downstream NF-E2-related factor 2 (Nrf2) signaling, causing Nrf2 Ser-40 phosphorylation, stabilization/upregulation and nuclear translocation, as well as mRNA expression of Nrf2-dictated genes. Contrarily, Nrf2 knockdown or S40T mutation almost nullified MHY1485-induced cytoprotection. MHY1485 suppressed UV-induced reactive oxygen species production and DNA single strand breaks in skin keratinocytes and fibroblasts. Together, we conclude that MHY1485 inhibits UV-induced skin cell damages via activating mTOR-Nrf2 signaling.
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Affiliation(s)
- Bo Yang
- Department of Dermatology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Qiu-Yun Xu
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Chun-Yan Guo
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Jin-Wen Huang
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Shu-Mei Wang
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Yong-Mei Li
- Department of Dermatology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ying Tu
- Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Yunnan Provincial Institute of Dermatology, Kunming, China
| | - Li He
- Department of Dermatology, The First Affiliated Hospital of Kunming Medical University, Yunnan Provincial Institute of Dermatology, Kunming, China
| | - Zhi-Gang Bi
- Department of Dermatology, BenQ Medical Center, Nanjing Medical University, Nanjing, China
| | - Chao Ji
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Bo Cheng
- Department of Dermatology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
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Martin LJ, Smith SB, Khoutorsky A, Magnussen CA, Samoshkin A, Sorge RE, Cho C, Yosefpour N, Sivaselvachandran S, Tohyama S, Cole T, Khuong TM, Mir E, Gibson DG, Wieskopf JS, Sotocinal SG, Austin JS, Meloto CB, Gitt JH, Gkogkas C, Sonenberg N, Greenspan JD, Fillingim RB, Ohrbach R, Slade GD, Knott C, Dubner R, Nackley AG, Ribeiro-da-Silva A, Neely GG, Maixner W, Zaykin DV, Mogil JS, Diatchenko L. Epiregulin and EGFR interactions are involved in pain processing. J Clin Invest 2017; 127:3353-3366. [PMID: 28783046 DOI: 10.1172/jci87406] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/27/2017] [Indexed: 12/27/2022] Open
Abstract
The EGFR belongs to the well-studied ErbB family of receptor tyrosine kinases. EGFR is activated by numerous endogenous ligands that promote cellular growth, proliferation, and tissue regeneration. In the present study, we have demonstrated a role for EGFR and its natural ligand, epiregulin (EREG), in pain processing. We show that inhibition of EGFR with clinically available compounds strongly reduced nocifensive behavior in mouse models of inflammatory and chronic pain. EREG-mediated activation of EGFR enhanced nociception through a mechanism involving the PI3K/AKT/mTOR pathway and matrix metalloproteinase-9. Moreover, EREG application potentiated capsaicin-induced calcium influx in a subset of sensory neurons. Both the EGFR and EREG genes displayed a genetic association with the development of chronic pain in several clinical cohorts of temporomandibular disorder. Thus, EGFR and EREG may be suitable therapeutic targets for persistent pain conditions.
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Affiliation(s)
- Loren J Martin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada.,Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Shad B Smith
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Arkady Khoutorsky
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Claire A Magnussen
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Alexander Samoshkin
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Robert E Sorge
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Chulmin Cho
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Noosha Yosefpour
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | | | - Sarasa Tohyama
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Tiffany Cole
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Thang M Khuong
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Ellen Mir
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dustin G Gibson
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jeffrey S Wieskopf
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Susana G Sotocinal
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Jean Sebastien Austin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Carolina B Meloto
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Joseph H Gitt
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Christos Gkogkas
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Joel D Greenspan
- Department of Neural and Pain Sciences and Brotman Facial Pain Center, University of Maryland Dental School, Baltimore, Maryland, USA
| | - Roger B Fillingim
- Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, Florida, USA
| | - Richard Ohrbach
- Department of Oral Diagnostic Services, University at Buffalo, Buffalo, New York, USA
| | - Gary D Slade
- Department of Dental Ecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Charles Knott
- Battelle Memorial Institute, Durham, North Carolina, USA
| | - Ronald Dubner
- Department of Neural and Pain Sciences and Brotman Facial Pain Center, University of Maryland Dental School, Baltimore, Maryland, USA
| | - Andrea G Nackley
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Alfredo Ribeiro-da-Silva
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - G Gregory Neely
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - William Maixner
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dmitri V Zaykin
- National Institutes of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Jeffrey S Mogil
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Luda Diatchenko
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
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68
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Zou Y, Ge M, Wang X. Targeting PI3K-AKT-mTOR by LY3023414 inhibits human skin squamous cell carcinoma cell growth in vitro and in vivo. Biochem Biophys Res Commun 2017. [DOI: 10.1016/j.bbrc.2017.06.052] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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69
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Zhao S, Chen C, Wang S, Ji F, Xie Y. MHY1485 activates mTOR and protects osteoblasts from dexamethasone. Biochem Biophys Res Commun 2017; 481:212-218. [PMID: 27884298 DOI: 10.1016/j.bbrc.2016.10.104] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 10/25/2016] [Indexed: 12/20/2022]
Abstract
Dexamethasone (Dex) exerts cytotoxic effects to cultured osteoblasts. The potential effect of MHY1485, a small-molecular mammalian target of rapamycin (mTOR) activator, against the process was studied here. In both osteoblastic MC3T3-E1 cells and primary murine osteoblasts, treatment with MHY1485 significantly ameliorated Dex-induced cell death and apoptosis. mTOR inhibition, through mTOR kinase inhibitor OSI-027 or mTOR shRNAs, abolished MHY1485-mediated osteoblast cytoprotection against Dex. Intriguingly, activation of mTOR complex (mTORC1), but not mTORC2, is required for MHY1485's anti-Dex activity. mTORC1 inhibitors (rapamycin and RAD001) or Raptor knockdown almost reversed MHY1485-induced osteoblast cytoprotection. mTORC2 inhibition, via shRNA knockdown of Rictor, failed to affect MHY1485's activity in MC3T3-E1 cells. Further studies showed that MHY1485 treatment in MC3T3-E1 cells and primary murine osteoblasts significantly inhibited Dex-induced mitochondrial death pathway activation, the latter was tested by mitochondrial depolarization, cyclophilin D-ANT-1 association and cytochrome C cytosol release. Together, these results suggest that MHY1485 activates mTORC1 signaling to protect osteoblasts from Dex.
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Affiliation(s)
- Sai Zhao
- Department of Paediatrics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Caiyun Chen
- Clinical Laboratory, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Shouguo Wang
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China.
| | - Feng Ji
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
| | - Yue Xie
- Department of Orthopedics, Huai'an First People's Hospital, Nanjing Medical University, Huai'an, China
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70
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Lv Y, Si M, Chen N, Li Y, Ma X, Yang H, Zhang L, Zhu H, Xu GY, Wu GP, Cao C. TBX2 over-expression promotes nasopharyngeal cancer cell proliferation and invasion. Oncotarget 2017; 8:52699-52707. [PMID: 28881763 PMCID: PMC5581062 DOI: 10.18632/oncotarget.17084] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/12/2017] [Indexed: 12/31/2022] Open
Abstract
TBX2 is a member of the T box transcription factor family. Its expression and potential biological functions in nasopharyngeal cancer (NPC) cells are studied here. We showed that TBX2 mRNA and protein expression was significantly elevated in multiple human NPC tissues, as compared with that in adjacent normal tissues. Knockdown of TBX2 by targeted-siRNA significantly inhibited proliferation and invasion of NPC cells (CNE-1 and HONE-1 lines). Meanwhile, TBX2 knockdown also induced G1-phase cell cycle arrest. At the molecular level, we discovered that expressions of several tumor suppressor genes, including p21, p27, phosphatase with tensin homology (PTEN) and E-Cadherin, were increased dramatically after TBX2 knockdown in above NPC cells. Collectively, our results imply that TBX2 over-expression promotes NPC cell proliferation and invasion, possibly via silencing several key tumor suppressor genes.
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Affiliation(s)
- Yan Lv
- Center of Translational Medicine, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - Meng Si
- Department of Neurology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Nannan Chen
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Ya Li
- Institute of Neuroscience, Soochow University, Suzhou, China
| | - Xingkai Ma
- Department of Otolaryngology, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - Huijun Yang
- Department of Otolaryngology, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - Ling Zhang
- Center of Translational Medicine, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - Hongyan Zhu
- Center of Translational Medicine, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - Guang-Yin Xu
- Center of Translational Medicine, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China.,Institute of Neuroscience, Soochow University, Suzhou, China
| | - Ge-Ping Wu
- Center of Translational Medicine, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China.,Department of Otolaryngology, The First People Hospital of Zhangjiagang City, Soochow University, Suzhou, China
| | - C Cao
- Institute of Neuroscience, Soochow University, Suzhou, China
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71
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Jia P, Li F, Gu W, Zhang W, Cai Y. Gab3 overexpression in human glioma mediates Akt activation and tumor cell proliferation. PLoS One 2017; 12:e0173473. [PMID: 28291820 PMCID: PMC5349442 DOI: 10.1371/journal.pone.0173473] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 02/22/2017] [Indexed: 11/18/2022] Open
Abstract
This current study tested expression and potential biological functions of Gab3 in human glioma. Gab3 mRNA and protein expression was significantly elevated in human glioma tissues and glioma cells. Its level was however low in normal brain tissues and primary human astrocytes. In both established (U251MG cell line) and primary human glioma cells, Gab3 knockdown by shRNA/siRNA significantly inhibited Akt activation and cell proliferation. Reversely, forced Gab3 overexpression in U251MG cells promoted Akt activation and cell proliferation. In vivo, the growth of U251MG tumors in nude mice was inhibited following expressing Gab3 shRNA. Akt activation in cancer tissues was also suppressed by Gab3 shRNA. Together, we conclude that Gab3 overexpression in human glioma mediates Akt activation and cancer cell proliferation.
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Affiliation(s)
- Pifeng Jia
- Department of Neurosurgery, RuiJin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Feng Li
- Department of Neurosurgery, RuiJin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weiting Gu
- Department of Neurosurgery, RuiJin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Weifeng Zhang
- Department of Neurosurgery, RuiJin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yu Cai
- Department of Neurosurgery, RuiJin Hospital North, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- * E-mail:
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72
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Wan J, Lin F, Zhang W, Xu A, DeGiorgis J, Lu H, Wan Y. Novel approaches to vitiligo treatment via modulation of mTOR and NF-κB pathways in human skin melanocytes. Int J Biol Sci 2017; 13:391-400. [PMID: 28367103 PMCID: PMC5370446 DOI: 10.7150/ijbs.17318] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/09/2017] [Indexed: 01/18/2023] Open
Abstract
Vitiligo is a skin depigmentation disorder with an increasing prevalence. Among recognized mechanisms is the oxidative stress that affects melanocytes which are responsible for skin pigmentation. Studies have shown that high concentration of hydrogen peroxide, or H2O2, induces apoptotic activities. Few studies have been done with lower doses of H2O2. Using human skin melanocytes, we investigated the effect of moderate concentration of H2O2 on melanocyte dendrites. Confocal data show that H2O2 at 250 µM induces loss of dendrites, as indicated by cytoskeletal proteins. α-melanocyte stimulating hormone or α-MSH pretreatment protects against H2O2-induced loss of dendrites, while α-MSH alone enhances dendrites. PI3K/AKT inhibitor LY294002 and mTORC1 inhibitor Rapamycin inhibit α-MSH-induced dendrites. In this study, we also investigated the effect of TNFα on cultured human skin melanocytes, since TNFα plays important roles in vitiligo. Confocal data demonstrate that TNFα induces NFκB activation. Western blot analysis shows that TNFα induces IκB phosphorylation and degradation. Interestingly, α-MSH does not have any effect of TNFα-induced IκB degradation and NF-κB activation. α-MSH, however, activates mTORC1 pathway. TNFα induces p38 but not AMPKα activation. Collectively, our data suggest that modulation of mTOR and NF-κB pathways may be a novel approach for better clinical management of vitiligo.
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Affiliation(s)
- Jerry Wan
- Department of Biology, Providence College, Providence, RI 02918, USA
| | - Fuquan Lin
- Department of Dermatology, the 3 rd Hospital of Hangzhou, Hangzhou 310000, Zhejiang Province, China
| | - Wei Zhang
- Department of Dermatology, Guiyang Medical University, Guizhou 550004, China
| | - Aie Xu
- Department of Dermatology, the 3 rd Hospital of Hangzhou, Hangzhou 310000, Zhejiang Province, China
| | - Joseph DeGiorgis
- Department of Biology, Providence College, Providence, RI 02918, USA
| | - Hongguang Lu
- Department of Dermatology, Guiyang Medical University, Guizhou 550004, China
| | - Yinsheng Wan
- Department of Biology, Providence College, Providence, RI 02918, USA
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73
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Xie J, Li Q, Ding X, Gao Y. GSK1059615 kills head and neck squamous cell carcinoma cells possibly via activating mitochondrial programmed necrosis pathway. Oncotarget 2017; 8:50814-50823. [PMID: 28881606 PMCID: PMC5584207 DOI: 10.18632/oncotarget.15135] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 01/11/2017] [Indexed: 12/12/2022] Open
Abstract
This study tested the anti-head and neck squamous cell carcinoma (HNSCC) cell activity by GSK1059615, a novel PI3K and mTOR dual inhibitor. GSK1059615 inhibited survival and proliferation of established (SCC-9, SQ20B and A253 lines) and primary human HNSCC cells. GSK1059615 blocked PI3K-AKT-mTOR activation in HNSCC cells. Intriguingly, GSK1059615 treatment in HNSCC cells failed to provoke apoptosis, but induced programmed necrosis. The latter was tested by mitochondria depolarization, ANT-1-cyclophilin-D mitochondrial association and lactate dehydrogenase (LDH) release. Reversely, mPTP blockers (sanglifehrin A, cyclosporin A and bongkrekic acid) or cyclophilin-D shRNA dramatically alleviated GSK1059615-induced SCC-9 cell death. Further studies demonstrated that GSK1059615 i.p. injection suppressed SCC-9 tumor growth in nude mice, which was compromised with co-administration with cyclosporin A. Thus, targeting PI3K-AKT-mTOR pathway by GSK1059615 possibly provokes programmed necrosis pathway to kill HNSCC cells.
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Affiliation(s)
- Jing Xie
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Quan Li
- Center of Stomatology, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Xi Ding
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yunyun Gao
- Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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74
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Ma J, Hui P, Meng W, Wang N, Xiang S. Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis. Biochem Biophys Res Commun 2017; 484:746-752. [PMID: 28153717 DOI: 10.1016/j.bbrc.2017.01.146] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 01/26/2017] [Indexed: 11/28/2022]
Abstract
The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificated when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells.
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Affiliation(s)
- Jiali Ma
- Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Pingping Hui
- Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Wenying Meng
- Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Na Wang
- Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China
| | - Shihao Xiang
- Department of Gastroenterology, Shanghai Tongren Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200336, China.
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75
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Gab3 is required for human colorectal cancer cell proliferation. Biochem Biophys Res Commun 2017; 484:719-725. [PMID: 28115166 DOI: 10.1016/j.bbrc.2017.01.095] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 11/21/2022]
Abstract
Here, we focused on the potential function of Gab3, an uncommon Gab family protein, in human colorectal cancer (CRC) cells. We found that Gab3 was only expressed in human colon cancer tissues as well as in established (HCT-116 and HT-29 lines) and primary human CRC cells. It was however absent in normal human colon cancer tissues and in FHC colon epithelial cells. Knockdown of Gab3 by targeted-shRNAs inhibited proliferation of the CRC cells. Reversely, exogenous over-expression of Gab3 promoted CRC cell proliferation. At the signaling level, Gab3 co-precipitated with p85 and SHP2 in CRC cells, which was required for subsequent Akt and Erk activation. Gab3 shRNA knockdown inhibited Akt and Erk activation, yet Gab3 over-expression augmented it. In vivo, HCT-116 xenograft tumor growth in severe combined immune deficient (SCID) mice was suppressed following expressing Gab3 shRNAs. Meanwhile, Akt and Erk activation in Gab3 shRNA-expressing tumors was also largely inhibited. Together, our results suggest that Gab3 expression in CRC cells is important for Akt-Erk activation and cell proliferation.
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Parag-Sharma K, Leyme A, DiGiacomo V, Marivin A, Broselid S, Garcia-Marcos M. Membrane Recruitment of the Non-receptor Protein GIV/Girdin (Gα-interacting, Vesicle-associated Protein/Girdin) Is Sufficient for Activating Heterotrimeric G Protein Signaling. J Biol Chem 2016; 291:27098-27111. [PMID: 27864364 DOI: 10.1074/jbc.m116.764431] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/17/2016] [Indexed: 11/06/2022] Open
Abstract
GIV (aka Girdin) is a guanine nucleotide exchange factor that activates heterotrimeric G protein signaling downstream of RTKs and integrins, thereby serving as a platform for signaling cascade cross-talk. GIV is recruited to the cytoplasmic tail of receptors upon stimulation, but the mechanism of activation of its G protein regulatory function is not well understood. Here we used assays in humanized yeast models and G protein activity biosensors in mammalian cells to investigate the role of GIV subcellular compartmentalization in regulating its ability to promote G protein signaling. We found that in unstimulated cells GIV does not co-fractionate with its substrate G protein Gαi3 on cell membranes and that constitutive membrane anchoring of GIV in yeast cells or rapid membrane translocation in mammalian cells via chemically induced dimerization leads to robust G protein activation. We show that membrane recruitment of the GIV "Gα binding and activating" motif alone is sufficient for G protein activation and that it does not require phosphomodification. Furthermore, we engineered a synthetic protein to show that recruitment of the GIV "Gα binding and activating" motif to membranes via association with active RTKs, instead of via chemically induced dimerization, is also sufficient for G protein activation. These results reveal that recruitment of GIV to membranes in close proximity to its substrate G protein is a major mechanism responsible for the activation of its G protein regulatory function.
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Affiliation(s)
- Kshitij Parag-Sharma
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Anthony Leyme
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Vincent DiGiacomo
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Arthur Marivin
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Stefan Broselid
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
| | - Mikel Garcia-Marcos
- From the Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118
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77
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Bissinger R, Lang E, Ghashghaeinia M, Singh Y, Zelenak C, Fehrenbacher B, Honisch S, Chen H, Fakhri H, Umbach AT, Liu G, Rexhepaj R, Liu G, Schaller M, Mack AF, Lupescu A, Birnbaumer L, Lang F, Qadri SM. Blunted apoptosis of erythrocytes in mice deficient in the heterotrimeric G-protein subunit Gαi2. Sci Rep 2016; 6:30925. [PMID: 27499046 PMCID: PMC4976336 DOI: 10.1038/srep30925] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 07/11/2016] [Indexed: 01/09/2023] Open
Abstract
Putative functions of the heterotrimeric G-protein subunit Gαi2-dependent signaling include ion channel regulation, cell differentiation, proliferation and apoptosis. Erythrocytes may, similar to apoptosis of nucleated cells, undergo eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine (PS) exposure. Eryptosis may be triggered by increased cytosolic Ca2+ activity and ceramide. In the present study, we show that Gαi2 is expressed in both murine and human erythrocytes and further examined the survival of erythrocytes drawn from Gαi2-deficient mice (Gαi2−/−) and corresponding wild-type mice (Gαi2+/+). Our data show that plasma erythropoietin levels, erythrocyte maturation markers, erythrocyte counts, hematocrit and hemoglobin concentration were similar in Gαi2−/− and Gαi2+/+ mice but the mean corpuscular volume was significantly larger in Gαi2−/− mice. Spontaneous PS exposure of circulating Gαi2−/− erythrocytes was significantly lower than that of circulating Gαi2+/+ erythrocytes. PS exposure was significantly lower in Gαi2−/− than in Gαi2+/+ erythrocytes following ex vivo exposure to hyperosmotic shock, bacterial sphingomyelinase or C6 ceramide. Erythrocyte Gαi2 deficiency further attenuated hyperosmotic shock-induced increase of cytosolic Ca2+ activity and cell shrinkage. Moreover, Gαi2−/− erythrocytes were more resistant to osmosensitive hemolysis as compared to Gαi2+/+ erythrocytes. In conclusion, Gαi2 deficiency in erythrocytes confers partial protection against suicidal cell death.
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Affiliation(s)
- Rosi Bissinger
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Elisabeth Lang
- Department of Gastroenterology, Hepatology and Infectious Diseases, University of Duesseldorf, Germany
| | - Mehrdad Ghashghaeinia
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Yogesh Singh
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Christine Zelenak
- Department of Internal Medicine, Charité Medical University, Berlin, Germany
| | | | - Sabina Honisch
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Hong Chen
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Hajar Fakhri
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Anja T Umbach
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Guilai Liu
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Rexhep Rexhepaj
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany.,Institute of Biochemistry and Molecular Biology, University of Bonn, Germany
| | - Guoxing Liu
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | | | | | - Adrian Lupescu
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, Durham, NC, USA
| | - Florian Lang
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany
| | - Syed M Qadri
- Institute of Cardiology, Vascular Medicine and Physiology, University of Tuebingen, Germany.,Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, Buenos Aires, Argentina.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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78
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C6 ceramide sensitizes the anti-hepatocellular carcinoma (HCC) activity by AZD-8055, a novel mTORC1/2 dual inhibitor. Tumour Biol 2016; 37:11039-48. [PMID: 26897748 DOI: 10.1007/s13277-015-4598-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022] Open
Abstract
Aberrant activation of mammalian target of rapamycin (mTOR) plays pivotal roles in promoting hepatocellular carcinoma (HCC) tumorigenesis and chemoresistance. Here, we tested the potential anti-HCC activity by a novel mTOR complex 1/2 (mTORC1/2) dual inhibitor AZD-8055 and, more importantly, the potential AZD-8055 sensitization effect by a cell-permeable short-chain ceramide (C6). We showed that AZD-8055 mainly exerted moderate cytotoxic effect against a panel of HCC cell lines (HepG2, Hep3B, and SMMC-7721). Co-treatment of C6 ceramide remarkably augmented AZD-8055-induced HCC cytotoxicity. Meanwhile, C6 ceramide dramatically potentiated AZD-8055-induced HCC cell apoptotic death. Further studies demonstrated that AZD-8055 and C6 ceramide synergistically induced anti-survival and pro-apoptotic activity in primary cultured human HCC cells, but not in the non-cancerous human hepatocytes. Signaling studies showed that AZD-8055 and C6 ceramide synergistically suppressed Akt-mTOR complex 1/2 cascade activation. In vivo, AZD-8055 oral administration suppressed HepG2 hepatoma xenograft growth in nude mice, while moderately improving mice survival. Its anti-tumor activity was dramatically potentiated with co-administration of a liposome-packed C6 ceramide. Together, these results demonstrate that concurrent targeting mTORC1/2 by AZD-8055 exerts anti-tumor ability in preclinical HCC models, and its activity is further sensitized with co-administration of C6 ceramide.
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79
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Aznar N, Kalogriopoulos N, Midde KK, Ghosh P. Heterotrimeric G protein signaling via GIV/Girdin: Breaking the rules of engagement, space, and time. Bioessays 2016; 38:379-93. [PMID: 26879989 DOI: 10.1002/bies.201500133] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Canonical signal transduction via heterotrimeric G proteins is spatially and temporally restricted, that is, triggered exclusively at the plasma membrane (PM), only by agonist activation of G protein-coupled receptors (GPCRs) via a process that completes within a few hundred milliseconds. Recently, a rapidly emerging paradigm has revealed a non-canonical pathway for activation of heterotrimeric G proteins by the non-receptor guanidine-nucleotide exchange factor (GEF), GIV/Girdin. This pathway has distinctive temporal and spatial features and an unusual profile of receptor engagement: diverse classes of receptors, not just GPCRs can engage with GIV to trigger such activation. Such activation is spatially and temporally unrestricted, that is, can occur both at the PM and on internal membranes discontinuous with the PM, and can continue for prolonged periods of time. Here, we provide the most complete up-to-date review of the molecular mechanisms that govern the unique spatiotemporal aspects of non-canonical G protein activation by GIV and the relevance of this new paradigm in health and disease.
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Affiliation(s)
- Nicolas Aznar
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | | | - Krishna K Midde
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Pradipta Ghosh
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA.,Department of Cell and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
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80
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Gab1 is essential for membrane translocation, activity and integrity of mTORCs after EGF stimulation in urothelial cell carcinoma. Oncotarget 2015; 6:1478-89. [PMID: 25596749 PMCID: PMC4359308 DOI: 10.18632/oncotarget.2756] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 11/16/2014] [Indexed: 11/30/2022] Open
Abstract
Urothelial carcinoma is the most common type of malignancy in long-term dialysis patients and kidney transplant recipients in Taiwan. mTORCs (mammalian target of rapamycin complexes) and EGF are important in urothelial carcinoma. To identify the regulation of mTORCs upon EGF stimulation is necessary. mTOR integrates signals from growth factors via mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2). The mechanism of mTORC1 action has been widely studied; however, the regulation of mTORC2 has not been well studied. Here, we demonstrate that Gab1 is an important upstream regulator in EGF-mediated activation of mTORCs. In our study, we confirm that mTORCs translocate from the cytoplasm to the plasma membrane via the PH domain of Gab1 upon EGF stimulation. Moreover, Gab1 associates with mTORCs. This association stabilizes the integrity of mTORCs and induces mTORC activity. Compared to normal bladder tissue, the expression of Gab1 and activity of mTORCs are elevated in urothelial carcinoma. Collectively, our results suggest that Gab1 is an essential regulator of the EGF-mediated mTORC pathways and may potentially be used as a biomarker for urothelial carcinoma to predict diagnosis and drug response.
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81
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Bakacak M, Bostanci MS, İnanc F, Yaylali A, Serin S, Attar R, Yildirim G, Yildirim OK. Protective Effect of Platelet Rich Plasma on Experimental Ischemia/Reperfusion Injury in Rat Ovary. Gynecol Obstet Invest 2015; 81:225-31. [PMID: 26496072 DOI: 10.1159/000440617] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 08/24/2015] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Ovarian torsion is a common cause of local ischemic damage, reduced follicular activity and infertility. Platelet-rich plasma (PRP) contains growth factors with demonstrated cytoprotective properties; so we evaluated PRP efficacy in a rat ischemia/reperfusion (I/R) model. METHODS Sixty adult female Sprague-Dawley albino rats were randomly assigned to 6 groups of 8 animals each: Sham, Ischemia, I/R, Sham + PRP, I + PRP and I/R + PRP; and the remaining 12 used to prepare PRP. Ischemia groups were subjected to bilateral adnexal torsion for 3 h, while I/R and I/R + PRP groups received subsequent detorsion for 3 h. Intraperitoneal PRP was administered 30 min prior to ischemia (Ischemia + PRP) or reperfusion (I/R + PRP). RESULTS Total oxidant status (TOS), oxidative stress index (OSI) and total ovarian histopathological scores were higher in Ischemia and I/R groups than in the Sham group (p < 0.05). PRP decreased mean TOS, OSI and histopathological scores in I + PRP and I/R + PRP groups compared to the corresponding Ischemia and I/R groups (p < 0.001). There was a strong correlation between total histopathological score and OSI (r = 0.877, p < 0.001). Peritoneal vascular endothelial growth factor was significantly higher in PRP-treated groups than corresponding untreated groups (p < 0.05). CONCLUSION PRP is effective for the prevention of ischemia and reperfusion damage in rat ovary.
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Affiliation(s)
- Murat Bakacak
- Department of Obstetrics and Gynecology, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey
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82
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Ha JH, Gomathinayagam R, Yan M, Jayaraman M, Ramesh R, Dhanasekaran DN. Determinant role for the gep oncogenes, Gα12/13, in ovarian cancer cell proliferation and xenograft tumor growth. Genes Cancer 2015; 6:356-364. [PMID: 26413218 PMCID: PMC4575922 DOI: 10.18632/genesandcancer.72] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 07/30/2015] [Indexed: 01/19/2023] Open
Abstract
Recent studies have shown that the gip2 and gep oncogenes defined by the α-subunits of Gi2 and G12 family of G proteins, namely Gαi2 and Gα12/13, stimulate oncogenic signaling pathways in cancer cells including those derived from ovarian cancer. However, the critical α-subunit involved in ovarian cancer growth and progression in vivo remains to be identified. Using SKOV3 cells in which the expressions of individual Gα-subunits were silenced, we demonstrate that the silencing of Gα12 and Gα13 drastically attenuated serum- or lysophosphatidic acid-stimulated proliferation. In contrast, the invasive migration of these cells were reduced only by the silencing of Gαi2 or Gα13. Analyses of the xenograft tumors derived from these Gα-silenced cells indicated that only the silencing of Gα13 drastically reduced xenograft tumor growth and prolonged the survival of the mice. Similar, but albeit reduced, effect was seen with the silencing of Gα12. On the contrary, the silencing of Gαi2 or Gαq failed to exert such effect. Thus, our studies establish for the first time that Gα12/13, the putative gep oncogenes, are the determinant α-subunits involved in ovarian cancer growth in vivo and their increased oncogenicity can be correlated with its ability to stimulate both proliferation and invasive migration.
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Affiliation(s)
- Ji Hee Ha
- Stephenson Cancer Center and the Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rohini Gomathinayagam
- Stephenson Cancer Center and the Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Mingda Yan
- Stephenson Cancer Center and the Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Muralidharan Jayaraman
- Stephenson Cancer Center and the Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Rajagopal Ramesh
- Stephenson Cancer Center and the Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Danny N Dhanasekaran
- Stephenson Cancer Center and the Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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83
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Gαi1 and Gαi3 regulate macrophage polarization by forming a complex containing CD14 and Gab1. Proc Natl Acad Sci U S A 2015; 112:4731-6. [PMID: 25825741 DOI: 10.1073/pnas.1503779112] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterotrimeric G proteins have been implicated in Toll-like receptor 4 (TLR4) signaling in macrophages and endothelial cells. However, whether guanine nucleotide-binding protein G(i) subunit alpha-1 and alpha-3 (Gαi1/3) are required for LPS responses remains unclear, and if so, the underlying mechanisms need to be studied. In this study, we demonstrated that, in response to LPS, Gαi1/3 form complexes containing the pattern recognition receptor (PRR) CD14 and growth factor receptor binding 2 (Grb2)-associated binding protein (Gab1), which are required for activation of PI3K-Akt signaling. Gαi1/3 deficiency decreased LPS-induced TLR4 endocytosis, which was associated with decreased phosphorylation of IFN regulatory factor 3 (IRF3). Gαi1/3 knockdown in bone marrow-derived macrophage cells (Gαi1/3 KD BMDMs) exhibited an M2-like phenotype with significantly suppressed production of TNF-α, IL-6, IL-12, and NO in response to LPS. The altered polarization coincided with decreased Akt activation. Further, Gαi1/3 deficiency caused LPS tolerance in mice. In vitro studies revealed that, in LPS-tolerant macrophages, Gαi1/3 were down-regulated partially by the proteasome pathway. Collectively, the present findings demonstrated that Gαi1/3 can interact with CD14/Gab1, which modulates macrophage polarization in vitro and in vivo.
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84
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Wei J, Qi X, Zhan Q, Zhou D, Yan Q, Wang Y, Mo L, Wan Y, Xie D, Xie J, Yang S. miR-20a mediates temozolomide-resistance in glioblastoma cells via negatively regulating LRIG1 expression. Biomed Pharmacother 2015; 71:112-8. [PMID: 25960225 DOI: 10.1016/j.biopha.2015.01.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 01/25/2015] [Indexed: 12/29/2022] Open
Abstract
AIMS Resistance to temozolomide (TMZ) is a major obstacle in the treatment of glioblastoma multiforme (GBM). MiRNAs is considered as an important modulator of drug resistance in many cancers. Here, we aimed to elucidate the relationship between miR-20a, its predicted target genes leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) and TMZ resistance in GBM. MAIN METHODS Real-time PCR or western blot was used to measure the levels of miR-20a and LRIG1. The cell viability was obtained to investigate the sensitivity of U251 cells and TMZ-resistant U251 (U251/TMZ) cells to TMZ. MiR-20a inhibitor or miR-20a mimic was used to down-regulate or up-regulate miR-20a expression. The interaction between miR-20a and its predicted target gene LRIG1 was confirmed by 3'-UTR dual-luciferase reporter assay. pcDNA-LRIG1 was used to overexpress LRIG1 [corrected]. A xenograft tumor model was used to investigate the in vivo antitumor activity. KEY FINDINGS MiR-20a was highly expressed and LRIG1 lowly expressed in U251/TMZ cells. Knockdown of miR-20a by treatment with miR-20a inhibitor restored sensitivity of U251/TM cells to TMZ in vivo and in vitro, whereas overexpression of miR-20a by treatment with miR-20a mimic resulted in increased TMZ resistance. The levels of LRIG1 were inversely related to miR-20a levels. And the luciferase reporter assays showed that miR-20a directly targeted the 3'UTR of LRIG1. In addition, functional knock-down of LRIG1 by gene specific siRNA reversed the effect of miR-20a inhibitor. SIGNIFICANCE MiR-20a mediated TMZ-resistance in glioblastoma cells through negatively regulating LRIG1 expression, which suggesting that miR-20a and LRIG1 would be potential therapeutic targets for glioma therapy.
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Affiliation(s)
- Junhua Wei
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Xuchen Qi
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Qitao Zhan
- Department of Reproductive Endocrinology, Women's Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310006, China
| | - Daoyang Zhou
- Department of Emergency, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Qingfeng Yan
- College of Life Science, Zhejiang University, Hangzhou 310058, China
| | - Yirong Wang
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Lianjie Mo
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Yingfeng Wan
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Dajiang Xie
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Jixi Xie
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China
| | - Shuxu Yang
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou 310016, China.
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Yang L, Zheng LY, Tian Y, Zhang ZQ, Dong WL, Wang XF, Zhang XY, Cao C. C6 ceramide dramatically enhances docetaxel-induced growth inhibition and apoptosis in cultured breast cancer cells: a mechanism study. Exp Cell Res 2015; 332:47-59. [PMID: 25576381 DOI: 10.1016/j.yexcr.2014.12.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/14/2014] [Accepted: 12/26/2014] [Indexed: 01/26/2023]
Abstract
Here we reported that co-administration of docetaxel and a cell-permeable short-chain ceramide (C6) resulted in a striking increase in growth inhibition and apoptosis in primary and transformed breast cells (MCF-7 and MDA-231), which were associated with mitochondrial permeability transition pore (mPTP) opening, a significant reactive oxygen species (ROS) production and the pro-apoptotic AMP-Protein Kinase (AMPK) as well as c-Jun N-terminal kinases (JNK) activations. Contrarily, the mPTP blocker sanglifehrin A (SfA) or the ROS scavenger N-acetyl-l-cysteine (NAC) largely inhibited co-administration-induced cytotoxicity. Further, cyclosporin A (CsA), the inhibitor of cyclophilin-D (Cyp-D, the key mPTP component), as well as Cyp-D RNA silencing also suppressed breast cancer cell death by the co-treatment, while cells overexpressing Cyp-D showed hypersensitivity to docetaxel. Meanwhile, JNK and AMPK inhibition alleviated cell death induced by the co-administration in cultured breast cancer cells. Significantly, C6 ceramide plus docetaxel caused dramatic human epidermal growth factor receptor (HER)-1/-2 degradation and downstream Akt/Erk inhibition in HER-2 expressing MDA-231 cells. These in vitro findings provide confidence in support of further development of C6 ceramide as an adjunct of docetaxel for the treatment of the metastatic breast cancer.
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Affiliation(s)
- Lan Yang
- Department of Breast Surgery, the Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Li-Yun Zheng
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, China
| | - Ye Tian
- Department of Radiotherapy and Oncology, the Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhi-Qing Zhang
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215021, China
| | - Wan-Li Dong
- Department of Neurology, the First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xu-Fen Wang
- Department of Breast Surgery, the Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China
| | - Xiao-Ying Zhang
- Department of Cardiothoracic Surgery, the Third Affiliated Hospital of Soochow University, Changzhou, China.
| | - Cong Cao
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215021, China.
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86
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Requirement of Gαi1/3–Gab1 Signaling Complex for Keratinocyte Growth Factor–Induced PI3K–AKT–mTORC1 Activation. J Invest Dermatol 2015; 135:181-191. [DOI: 10.1038/jid.2014.326] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2014] [Revised: 06/24/2014] [Accepted: 07/14/2014] [Indexed: 01/06/2023]
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87
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Squamosamide derivative FLZ protects retinal pigment epithelium cells from oxidative stress through activation of epidermal growth factor receptor (EGFR)-AKT signaling. Int J Mol Sci 2014; 15:18762-75. [PMID: 25329617 PMCID: PMC4227245 DOI: 10.3390/ijms151018762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/02/2014] [Accepted: 09/11/2014] [Indexed: 12/19/2022] Open
Abstract
Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is attributed to age-related macular degeneration (AMD) pathogenesis. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, Annona glabra, has displayed significant cyto-protective activity. In the current study, we explored the pro-survival effect of FLZ in oxidative stressed-RPE cells and studied the underlying signaling mechanisms. Our results showed that FLZ attenuated hydrogen peroxide (H2O2)-induced viability decrease and apoptosis in the RPE cell line (ARPE-19 cells) and in primary mouse RPE cells. Western blotting results showed that FLZ activated AKT signaling in RPE cells. The AKT-specific inhibitor, MK-2206, the phosphoinositide 3-kinase (PI3K)/AKT pan inhibitor, wortmannin, and AKT1-shRNA (short hairpin RNA) depletion almost abolished FLZ-mediated pro-survival/anti-apoptosis activity. We discovered that epidermal growth factor receptor (EGFR) trans-activation mediated FLZ-induced AKT activation and the pro-survival effect in RPE cells, and the anti-apoptosis effect of FLZ against H2O2 was inhibited by the EGFR inhibitor, PD153035, or by EGFR shRNA-knockdown. In conclusion, FLZ protects RPE cells from oxidative stress through activation of EGFR-AKT signaling, and our results suggest that FLZ might have therapeutic values for AMD.
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88
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Zhang A, Mao X, Li L, Tong Y, Huang Y, Lan Y, Jiang H. Necrostatin-1 inhibits Hmgb1-IL-23/IL-17 pathway and attenuates cardiac ischemia reperfusion injury. Transpl Int 2014; 27:1077-85. [PMID: 24810904 DOI: 10.1111/tri.12349] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/13/2014] [Accepted: 05/05/2014] [Indexed: 02/02/2023]
Abstract
Ischemia reperfusion (IR) injury is a major issue in cardiac transplantation and inflammatory processes play a major role in myocardial IR injury. Necrostatin-1 (Nec-1) is a small molecule capable of inhibiting RIP1 kinase activity and attenuates inflammation-mediated tissue injury. In our study, hearts of C57Bl/6 mice were flushed and stored in cold Bretschneider solution for 8 h and then transplanted into syngeneic recipients. We found that Nec-1 decreased cardiomyocyte necrosis and recruitment of neutrophils and macrophages. Troponin T (TnT) production on 24 h after myocardial IR injury was reduced by Nec-1 administration. Cardiac output at 60 mmHg of afterload pressure was significantly increased in hearts with Nec-1 administration and the cardiac allograft survival in Nec-1-treated animals was significantly prolonged (MST = 90 days in IR + Nec-1 group, P < 0.05 as compared with IR group, MST = 83.5 days). Nec-1 treatment attenuated ROS generation and increased expression of NOS2 and COX-2. The expression of Hmgb1, IL-23, and IL-17A were also decreased with Nec-1 administration. Furthermore, the decreased TnT expression induced by Nec-1 was abrogated with exogenous Hmgb1 administration. In conclusion, Nec-1 played a protective role in cardiomyocyte IR injury, and this was associated with inhibited Hmgb1-IL-23/IL-17 pathway.
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Affiliation(s)
- Anbin Zhang
- Department of Rheumatology and Immunology, Xiangyang Central Hospital, Hubei University of Arts and Science, Hubei, China
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89
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Jabbarzadeh Kaboli P, Rahmat A, Ismail P, Ling KH. Targets and mechanisms of berberine, a natural drug with potential to treat cancer with special focus on breast cancer. Eur J Pharmacol 2014; 740:584-95. [PMID: 24973693 DOI: 10.1016/j.ejphar.2014.06.025] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/10/2014] [Accepted: 06/17/2014] [Indexed: 01/02/2023]
Abstract
Breast cancer is the most common cancer among women worldwide and novel therapeutic agents are needed to treat this disease. The plant-based alkaloid berberine has potential therapeutic applications for breast cancer, although a better understanding of the genes and cellular pathways regulated by this compound is needed to define the mechanism of its action in cancer treatment. In this review, the molecular targets of berberine in various cancers, particularly breast cancer, are discussed. Berberine was shown to be effective in inhibiting cell proliferation and promoting apoptosis in various cancerous cells. Some signaling pathways affected by berberine, including the MAP (mitogen-activated protein) kinase and Wnt/β-catenin pathways, are critical for reducing cellular migration and sensitivity to various growth factors. This review will discuss recent studies and consider the application of new prospective approaches based on microRNAs and other crucial regulators for use in future studies to define the action of berberine in cancer. The effects of berberine on cancer cell survival and proliferation are also outlined.
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Affiliation(s)
- Parham Jabbarzadeh Kaboli
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia.
| | - Asmah Rahmat
- Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia.
| | - Patimah Ismail
- Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia.
| | - King-Hwa Ling
- Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia; Genetics and Regenerative Medicine Research Centre, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, UPM Serdang 43400, Selangor, Malaysia.
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90
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Lou HZ, Weng XC, Pan HM, Pan Q, Sun P, Liu LL, Chen B. The novel mTORC1/2 dual inhibitor INK-128 suppresses survival and proliferation of primary and transformed human pancreatic cancer cells. Biochem Biophys Res Commun 2014; 450:973-8. [PMID: 24971544 DOI: 10.1016/j.bbrc.2014.06.081] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 06/17/2014] [Indexed: 11/25/2022]
Abstract
Pancreatic cancer has one of worst prognosis among all human malignancies around the world, the development of novel and more efficient anti-cancer agents against this disease is urgent. In the current study, we tested the potential effect of INK-128, a novel mammalian target of rapamycin (mTOR) complex 1 and 2 (mTORC1/2) dual inhibitor, against pancreatic cancer cells in vitro. Our results demonstrated that INK-128 concentration- and time-dependently inhibited the survival and growth of pancreatic cancer cells (both primary cells and transformed cells). INK-128 induced pancreatic cancer cell apoptosis and necrosis simultaneously. Further, INK-128 dramatically inhibited phosphorylation of 4E-binding protein 1 (4E-BP1), ribosomal S6 kinase 1 (S6K1) and Akt at Ser 473 in pancreatic cancer cells. Meanwhile, it downregulated cyclin D1 expression and caused cell cycle arrest. Finally, we found that a low concentration of INK-128 significantly increased the sensitivity of pancreatic cancer cells to gemcitabine. Together, our in vitro results suggest that INK-128 might be further investigated as a novel anti-cancer agent or chemo-adjuvant for pancreatic cancer treatment.
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Affiliation(s)
- Hai-Zhou Lou
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Xiao-Chuan Weng
- Department of Anesthesiology, Hangzhou Xia-sha Hospital, Hangzhou 310018, China
| | - Hong-Ming Pan
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Qin Pan
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Peng Sun
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China
| | - Li-Li Liu
- Department of Medical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China
| | - Bin Chen
- Department of Hepatopancreatobiliary Surgery, First People's Hospital of Hangzhou, Hangzhou 310006, China.
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91
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Yu R, Zhang ZQ, Wang B, Jiang HX, Cheng L, Shen LM. Berberine-induced apoptotic and autophagic death of HepG2 cells requires AMPK activation. Cancer Cell Int 2014; 14:49. [PMID: 24991192 PMCID: PMC4079188 DOI: 10.1186/1475-2867-14-49] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 04/28/2014] [Indexed: 12/23/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC), the primary liver cancer, is one of the most malignant human tumors with extremely poor prognosis. The aim of this study was to investigate the anti-cancer effect of berberine in a human hepatocellular carcinoma cell line (HepG2), and to study the underlying mechanisms by focusing on the AMP-activated protein kinase (AMPK) signaling cascade. Results We found that berberine induced both apoptotic and autophagic death of HepG2 cells, which was associated with a significant activation of AMPK and an increased expression of the inactive form of acetyl-CoA carboxylase (ACC). Inhibition of AMPK by RNA interference (RNAi) or by its inhibitor compound C suppressed berberine-induced caspase-3 cleavage, apoptosis and autophagy in HepG2 cells, while AICAR, the AMPK activator, possessed strong cytotoxic effects. In HepG2 cells, mammalian target of rapamycin complex 1 (mTORC1) activation was important for cell survival, and berberine inhibited mTORC1 via AMPK activation. Conclusions Together, these results suggested that berberine-induced both apoptotic and autophagic death requires AMPK activation in HepG2 cells.
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Affiliation(s)
- Rong Yu
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China ; Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Zhi-Qing Zhang
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu 215123, China
| | - Bin Wang
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Hong-Xin Jiang
- Department of Oncology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Lei Cheng
- Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
| | - Li-Ming Shen
- Department of Interventional Radiology, Suzhou Municipal Hospital, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu 215000, China
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92
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Wang SL, Shi XH, Yang Z, Zhang YM, Shen LR, Lei ZY, Zhang ZQ, Cao C, Fan DL. Osteopontin (OPN) is an important protein to mediate improvements in the biocompatibility of C ion-implanted silicone rubber. PLoS One 2014; 9:e98320. [PMID: 24911051 PMCID: PMC4049582 DOI: 10.1371/journal.pone.0098320] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 05/01/2014] [Indexed: 01/15/2023] Open
Abstract
Medical device implants are drawing increasing amounts of interest from modern medical practitioners. However, this attention is not evenly spread across all such devices; most of these implantable devices can cause adverse reactions such as inflammation, fibrosis, thrombosis, and infection. In this work, the biocompatibility of silicone rubber (SR) was improved through carbon (C) ion implantation. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results confirmed that these newly generated carbon-implanted silicone rubbers (C-SRs) had large, irregular peaks and deep valleys on their surfaces. The water contact angle of the SR surface decreased significantly after C ion implantation. C ion implantation also changed the surface charge distribution, silicone oxygen rate, and chemical-element distribution of SR to favor cell attachment. The dermal fibroblasts cultured on the surface C-SR grew faster and showed more typical fibroblastic shapes. The expression levels of major adhesion proteins, including talin-1, zyxin, and vinculin, were significantly higher in dermal fibroblasts cultured on C-SR coated plates than in dermal fibroblasts cultured on SR. Those same dermal fibroblasts on C-SRs showed more pronounced adhesion and migration abilities. Osteopontin (OPN), a critical extracellular matrix (ECM) protein, was up-regulated and secreted from dermal fibroblasts cultured on C-SR. Matrix metalloproteinase-9 (MMP-9) activity was also increased. These cells were highly mobile and were able to adhere to surfaces, but these abilities were inhibited by the monoclonal antibody against OPN, or by shRNA-mediated MMP-9 knockdown. Together, these results suggest that C ion implantation significantly improves SR biocompatibility, and that OPN is important to promote cell adhesion to the C-SR surface.
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Affiliation(s)
- Shao-liang Wang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Xiao-hua Shi
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Zhi Yang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Yi-ming Zhang
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Li-ru Shen
- Southwestern Institute of Physics, Chengdu, Sichuan, People's Republic of China
| | - Ze-yuan Lei
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
| | - Zhi-qing Zhang
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, People's Republic of China
| | - Cong Cao
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, People's Republic of China
- * E-mail: (CC); (DF)
| | - Dong-li Fan
- Department of Plastic and Cosmetic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, People's Republic of China
- * E-mail: (CC); (DF)
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93
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Xu XD, Yang L, Zheng LY, Pan YY, Cao ZF, Zhang ZQ, Zhou QS, Yang B, Cao C. Suberoylanilide hydroxamic acid, an inhibitor of histone deacetylase, suppresses vasculogenic mimicry and proliferation of highly aggressive pancreatic cancer PaTu8988 cells. BMC Cancer 2014; 14:373. [PMID: 24886166 PMCID: PMC4047270 DOI: 10.1186/1471-2407-14-373] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 05/16/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Pancreatic cancer is one of the most aggressive human malignancies with a extremely low 5-year survival rate. Hence, the search for more effective anti-pancreatic cancer agents is urgent. METHODS PaTu8988 pancreatic cancer cells were treated with different concentrations of suberoylanilide hydroxamic acid (SAHA), cell survival, proliferation, migration and vasculogenic mimicry (VM) were analyzed. Associated signaling changes were also analyzed by RT-PCR and Western blots. RESULTS Here, we reported that SAHA, a histone deacetylase inhibitor (HDACi), exerted significant inhibitory efficiency against pancreatic cancer cell survival, proliferation, migration and VM. SAHA dose-dependently inhibited PaTu8988 pancreatic cancer cell growth with the IC-50 of 3.4 ± 0. 7 μM. Meanwhile, SAHA suppressed PaTu8988 cell cycle progression through inducing G2/M arrest, which was associated with cyclin-dependent kinase 1 (CDK-1)/cyclin-B1 degradation and p21/p27 upregulation. Further, SAHA induced both apoptotic and non-apoptotic death of PaTu8988 cells. Significantly, SAHA suppressed PaTu8988 cell in vitro migration and cell-dominant tube formation or VM, which was accompanied by semaphorin-4D (Sema-4D) and integrin-β5 down-regulation. Our evidences showed that Akt activation might be important for Sema-4D expression in PaTu8988 cells, and SAHA-induced Sema-4D down-regulation might be associated with Akt inhibition. CONCLUSIONS This study is among the first to report the VM formation in cultured human pancreatic cancer cells. And we provided strong evidence to suggest that SAHA executes significant anti-VM efficiency in the progressive pancreatic cancer cells. Thus, SAHA could be further investigated as a promising anti-pancreatic cancer agent.
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Affiliation(s)
| | | | | | | | | | | | | | - Bo Yang
- Department of General Surgery, the Third Hospital affiliated to Soochow University, Changzhou City 213003, Jiangsu, China.
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94
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Fan JB, Liu W, Yuan K, Zhu XH, Xu DW, Chen JJ, Cui ZM. EGFR trans-activation mediates pleiotrophin-induced activation of Akt and Erk in cultured osteoblasts. Biochem Biophys Res Commun 2014; 447:425-30. [PMID: 24727451 DOI: 10.1016/j.bbrc.2014.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 04/02/2014] [Indexed: 12/28/2022]
Abstract
Pleiotrophin (Ptn) plays an important role in bone growth through regulating osteoblasts' functions. The underlying signaling mechanisms are not fully understood. In the current study, we found that Ptn induced heparin-binding epidermal growth factor (HB-EGF) release to trans-activate EGF-receptor (EGFR) in both primary osteoblasts and osteoblast-like MC3T3-E1 cells. Meanwhile, Ptn activated Akt and Erk signalings in cultured osteoblasts. The EGFR inhibitor AG1478 as well as the monoclonal antibody against HB-EGF (anti-HB-EGF) significantly inhibited Ptn-induced EGFR activation and Akt and Erk phosphorylations in MC3T3-E1 cells and primary osteoblasts. Further, EGFR siRNA depletion or dominant negative mutation suppressed also Akt and Erk activation in MC3T3-E1 cells. Finally, we observed that Ptn increased alkaline phosphatase (ALP) activity and inhibited dexamethasone (Dex)-induced cell death in both MC3T3-E1 cells and primary osteoblasts, such effects were alleviated by AG1478 or anti-HB-EGF. Together, these results suggest that Ptn-induced Akt/Erk activation and some of its pleiotropic functions are mediated by EGFR trans-activation in cultured osteoblasts.
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Affiliation(s)
- Jian-Bo Fan
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Wei Liu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Kun Yuan
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Xin-Hui Zhu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Da-Wei Xu
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Jia-Jia Chen
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China
| | - Zhi-Ming Cui
- The Department of Orthopaedics, The Second Affiliated Hospital of Nantong University, North Hai-er-xiang Road 6, Nantong 226001, Jiangsu, People's Republic of China.
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95
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Zhang H, Liu YY, Jiang Q, Li KR, Zhao YX, Cao C, Yao J. Salvianolic acid A protects RPE cells against oxidative stress through activation of Nrf2/HO-1 signaling. Free Radic Biol Med 2014; 69:219-28. [PMID: 24486344 DOI: 10.1016/j.freeradbiomed.2014.01.025] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 01/03/2014] [Accepted: 01/20/2014] [Indexed: 12/22/2022]
Abstract
Reactive oxygen species (ROS) impair the physiological functions of retinal pigment epithelial (RPE) cells, which is known as one major cause of age-related macular degeneration. Salvianolic acid A (Sal A) is the main effective aqueous extract of Salvia miltiorrhiza. The aim of this study was to test the potential role of Sal A against oxidative stress in cultured RPE cells and to investigate the underlying mechanistic signaling pathways. We observed that Sal A significantly inhibited hydrogen peroxide (H2O2)-induced primary and transformed RPE cell death and apoptosis. H2O2-stimulated mitogen-activated protein kinase activation, ROS production, and subsequent proapoptotic AMP-activated protein kinase activation were largely inhibited by Sal A. Further, Sal A stimulation resulted in a fast and dramatic activation of Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling, followed by phosphorylation, accumulation, and nuclear translocation of the NF-E2-related factor 2 (Nrf2), along with increased expression of the antioxidant-response element-dependent gene heme oxygenase-1 (HO-1). Both Nrf2 and HO-1 were required for Sal A-mediated cytoprotective effect, as Nrf2/HO-1 inhibition abolished Sal A-induced beneficial effects against H2O2. Meanwhile, the PI3K/Akt/mTORC1 chemical inhibitors not only suppressed Sal A-induced Nrf2/HO-1 activation, but also eliminated its cytoprotective effect in RPE cells. These observations suggest that Sal A activates the Nrf2/HO-1 axis in RPE cells and protects against oxidative stress via activation of Akt/mTORC1 signaling.
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Affiliation(s)
- Hui Zhang
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Yuan-yuan Liu
- Institute of Neuroscience, Soochow University, Suzhou 215123, China
| | - Qin Jiang
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Ke-ran Li
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Yu-xia Zhao
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Cong Cao
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China; Institute of Neuroscience, Soochow University, Suzhou 215123, China.
| | - Jin Yao
- The Eye Hospital, Nanjing Medical University, Nanjing 210029, China.
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96
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Boularan C, Kehrl JH. Implications of non-canonical G-protein signaling for the immune system. Cell Signal 2014; 26:1269-82. [PMID: 24583286 DOI: 10.1016/j.cellsig.2014.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 02/22/2014] [Indexed: 01/13/2023]
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins), which consist of three subunits α, β, and γ, function as molecular switches to control downstream effector molecules activated by G protein-coupled receptors (GPCRs). The GTP/GDP binding status of Gα transmits information about the ligand binding state of the GPCR to intended signal transduction pathways. In immune cells heterotrimeric G proteins impact signal transduction pathways that directly, or indirectly, regulate cell migration, activation, survival, proliferation, and differentiation. The cells of the innate and adaptive immune system abundantly express chemoattractant receptors and lesser amounts of many other types of GPCRs. But heterotrimeric G-proteins not only function in classical GPCR signaling, but also in non-canonical signaling. In these pathways the guanine exchange factor (GEF) exerted by a GPCR in the canonical pathway is replaced or supplemented by another protein such as Ric-8A. In addition, other proteins such as AGS3-6 can compete with Gβγ for binding to GDP bound Gα. This competition can promote Gβγ signaling by freeing Gβγ from rapidly rebinding GDP bound Gα. The proteins that participate in these non-canonical signaling pathways will be briefly described and their role, or potential one, in cells of the immune system will be highlighted.
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Affiliation(s)
- Cédric Boularan
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States
| | - John H Kehrl
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, United States.
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97
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Wang Z, Dela Cruz R, Ji F, Guo S, Zhang J, Wang Y, Feng GS, Birnbaumer L, Jiang M, Chu WM. G(i)α proteins exhibit functional differences in the activation of ERK1/2, Akt and mTORC1 by growth factors in normal and breast cancer cells. Cell Commun Signal 2014; 12:10. [PMID: 24521094 PMCID: PMC3937014 DOI: 10.1186/1478-811x-12-10] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 02/01/2014] [Indexed: 12/29/2022] Open
Abstract
Background In a classic model, Giα proteins including Gi1α, Gi2α and Gi3α are important for transducing signals from Giα protein-coupled receptors (GiαPCRs) to their downstream cascades in response to hormones and neurotransmitters. Our previous study has suggested that Gi1α, Gi2α and Gi3α are also important for the activation of the PI3K/Akt/mTORC1 pathway by epidermal growth factor (EGF) and its family members. However, a genetic role of these Giα proteins in the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) by EGF is largely unknown. Further, it is not clear whether these Giα proteins are also engaged in the activation of both the Akt/mTORC1 and ERK1/2 pathways by other growth factor family members. Additionally, a role of these Giα proteins in breast cancer remains to be elucidated. Results We found that Gi1/3 deficient MEFs with the low expression level of Gi2α showed defective ERK1/2 activation by EGFs, IGF-1 and insulin, and Akt and mTORC1 activation by EGFs and FGFs. Gi1/2/3 knockdown breast cancer cells exhibited a similar defect in the activations and a defect in in vitro growth and invasion. The Giα proteins associated with RTKs, Gab1, FRS2 and Shp2 in breast cancer cells and their ablation impaired Gab1’s interactions with Shp2 in response to EGF and IGF-1, or with FRS2 and Grb2 in response to bFGF. Conclusions Giα proteins differentially regulate the activation of Akt, mTORC1 and ERK1/2 by different families of growth factors. Giα proteins are important for breast cancer cell growth and invasion.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Meisheng Jiang
- Cancer Biology Program, University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI 96813, USA.
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98
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Zhang L, Loh HH, Law PY. A novel noncanonical signaling pathway for the μ-opioid receptor. Mol Pharmacol 2013; 84:844-53. [PMID: 24061856 DOI: 10.1124/mol.113.088278] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The µ-opioid receptor (OPRM1) signals as a classic G protein-coupled receptor by activating heterotrimeric Gi/Go proteins resulting in adenylyl cyclase (AC) inhibition. Such AC inhibition is desensitized after prolonged agonist treatment. However, after receptor desensitization, the intracellular cAMP level remains regulated by OPRM1, as demonstrated by the intracellular cAMP level increase or AC superactivation upon removal of an agonist or addition of an antagonist. We now demonstrate that such intracellular cAMP regulation is mediated by a novel noncanonical signaling pathway resulting from OPRM1 being converted to a receptor tyrosine kinase (RTK)-like entity. This noncanonical OPRM1 signaling is initiated by the receptor recruiting and activating Src kinase within the receptor complex, leading to phosphorylation of the OPRM1 Tyr(336) residue. Phospho-Tyr(336) serves as the docking site for growth factor receptor-bound protein/son of sevenless, leading to the recruitment and activation of the Ras/Raf-1 and subsequent phosphorylation and activation of AC5/6 by Raf-1. Such sequence of events was established by the absence of Ras/Raf1 recruitment and activation by the OPRM1-Y336F mutant, by the presence of Src kinase inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2) or the absence of Src activity, by the presence of specific Raf-1 inhibitor GW5074 (5-iodo-3-[(3,5-dibromo-4-hydroxyphenyl) methylene]-2-indolinone) or the absence of Raf-1, or by the dominant negative RasN17 mutant. Src together with Ras activates Raf1 which was established by the inability of the Raf1-Tyr(340/341) mutant to activate AC. Hence, the phosphorylation of OPRM1 at Tyr(336) by Src serves as the trigger for the conversion of a classic Gi/Go-coupled receptor into an RTK-like entity, resulting in a noncanonical pathway even after the original Gi/Go signals are blunted.
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Affiliation(s)
- Lei Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota
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99
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Qi XC, Xie DJ, Yan QF, Wang YR, Zhu YX, Qian C, Yang SX. LRIG1 dictates the chemo-sensitivity of temozolomide (TMZ) in U251 glioblastoma cells via down-regulation of EGFR/topoisomerase-2/Bcl-2. Biochem Biophys Res Commun 2013; 437:565-72. [PMID: 23850692 DOI: 10.1016/j.bbrc.2013.06.116] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 06/29/2013] [Indexed: 01/08/2023]
Abstract
In the current study, we aimed to understand the potential role of leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) in TMZ-resistance of U251 glioma cells. We established TMZ-resistant U251 clones (U251/TMZ cells), which expressed low level of LRIG1, but high levels of epidermal growth factor receptor (EGFR), topoisomerase-2 (Topo-2) and Bcl-2. Depletion of LRIG1 by the targeted RNA interference (RNAi) upregulated EGFR/Topo-2/Bcl-2 in U251 cells, and the cells were resistant to TMZ. Reversely, over-expression of LRIG1 in U251 cells downregulated EGFR/Topo-2/Bcl-2 expressions, and cells were hyper-sensitive to TMZ. Our data suggested EGFR-dependent mammalian target of rapamycin (mTOR) activation was important for Topo-2 and Bcl-2 expressions in U251/TMZ cells. The EGFR inhibitor and the mTOR inhibitor downregulated Topo-2/Bcl-2 expressions, both inhibitors also restored TMZ sensitivity in U251/TMZ cells. Finally, inhibition of Topo-2 or Bcl-2 by targeted RNAi(s) knockdown or by the corresponding inhibitor re-sensitized U251/TMZ cells to TMZ, indicating that both Topo-2 and Bcl-2 were important for TMZ resistance in the resistant U251 cells. Based on these results, we concluded that LRIG1 inhibits EGFR expression and the downstream signaling activation, interferes with Bcl-2/Topo-2 expressions and eventually sensitizes glioma cells to TMZ.
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Affiliation(s)
- Xu-chen Qi
- Department of Neurosurgery, Sir Run Run Shaw Hospital, College of Medical Sciences, Zhejiang University, Hangzhou, China
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Gambogic acid induces EGFR degradation and Akt/mTORC1 inhibition through AMPK dependent-LRIG1 upregulation in cultured U87 glioma cells. Biochem Biophys Res Commun 2013; 435:397-402. [DOI: 10.1016/j.bbrc.2013.04.099] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 04/29/2013] [Indexed: 11/24/2022]
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