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Effects of Ginsenoside Rg1 on the Biological Behavior of Human Amnion-Derived Mesenchymal Stem/Stromal Cells (hAD-MSCs). Stem Cells Int 2023; 2023:7074703. [PMID: 36845966 PMCID: PMC9946746 DOI: 10.1155/2023/7074703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/22/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
Ginsenoside Rg1 (Rg1) is purified from ginseng with various pharmacological effects, which might facilitate the biological behavior of human amnion-derived mesenchymal stem/stromal cells (hAD-MSCs). This study is aimed at investigating the effects of Rg1 on the biological behavior, such as viability, proliferation, apoptosis, senescence, migration, and paracrine, of hAD-MSCs. hAD-MSCs were isolated from human amnions. The effects of Rg1 on the viability, proliferation, apoptosis, senescence, migration, and paracrine of hAD-MSCs were detected by CCK-8, EdU, flow cytometry, SA-β-Gal staining, wound healing, and ELISA assays, respectively. The protein expression levels were detected by western blot. Cell cycle distribution was evaluated using flow cytometry. We found that Rg1 promoted hAD-MSC cycle progression from G0/G1 to S and G2/M phases and significantly increased hAD-MSC proliferation rate. Rg1 activated PI3K/AKT signaling pathway and significantly upregulated the expressions of cyclin D, cyclin E, CDK4, and CDK2 in hAD-MSCs. Inhibition of PI3K/AKT signaling significantly downregulated the expressions of cyclin D, cyclin E, CDK4, and CDK2, prevented cell cycle progression, and reduced hAD-MSC proliferation induced by Rg1. hAD-MSC senescence rate was significantly increased by D-galactose, while the elevated hAD-MSC senescence rate induced by D-galactose was significantly decreased by Rg1 treatment. D-galactose significantly induced the expressions of senescence markers, p16INK4a, p14ARF, p21CIP1, and p53 in hAD-MSCs, while Rg1 significantly reduced the expressions of those markers induced by D-galactose in hAD-MSCs. Rg1 significantly promoted the secretion of IGF-I in hAD-MSCs. Rg1 reduced the hAD-MSC apoptosis rate. However, the difference was not significant. Rg1 had no influence on hAD-MSC migration. Altogether, our results demonstrate that Rg1 can promote the viability, proliferation, and paracrine and relieve the senescence of hAD-MSCs. PI3K/AKT signaling pathway is involved in the promotive effect of Rg1 on hAD-MSC proliferation. The protective effect of Rg1 on hAD-MSC senescence may be achieved via the downregulation of p16INK4A and p53/p21CIP1 pathway.
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Tian H, Liu L, Wu Y, Wang R, Jiang Y, Hu R, Zhu L, Li L, Fang Y, Yang C, Ji L, Liu G, Dai A. Resistin-like molecule β acts as a mitogenic factor in hypoxic pulmonary hypertension via the Ca 2+-dependent PI3K/Akt/mTOR and PKC/MAPK signaling pathways. Respir Res 2021; 22:8. [PMID: 33407472 PMCID: PMC7789700 DOI: 10.1186/s12931-020-01598-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/09/2020] [Indexed: 12/28/2022] Open
Abstract
Background Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule β (RELM-β) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-β has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-β in HPH remain unclear. Methods We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-β in a rat HPH model and in hPASMCs. Results Overexpression of RELM-β caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-β partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-β gene overexpression or silencing, respectively. Recombinant RELM-β protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-β on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor. Conclusions Our findings suggest that RELM-β acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-β are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.
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Affiliation(s)
- Heshen Tian
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China.,State Key Lab of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510120, Guangdong, People's Republic of China
| | - Lei Liu
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Ying Wu
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Ruiwen Wang
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Yongliang Jiang
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Ruicheng Hu
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Liming Zhu
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Linwei Li
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Yanyan Fang
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Chulan Yang
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Lianzhi Ji
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Guoyu Liu
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China
| | - Aiguo Dai
- Department of Respiratory Medicine & Department of Geriatric, Hunan Provincial People's Hospital/The First Affiliated Hospital of Hunan Normal University, Changsha, 410016, Hunan, People's Republic of China. .,Department of Respiratory Diseases, Medical School, Hunan University of Chinese Medicine, Changsha, 410208, Hunan, People's Republic of China.
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Mitogen-activated protein kinases are involved in hepatocanalicular dysfunction and cholestasis induced by oxidative stress. Arch Toxicol 2016; 91:2391-2403. [PMID: 27913845 DOI: 10.1007/s00204-016-1898-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 11/24/2016] [Indexed: 12/22/2022]
Abstract
In previous studies, we showed that the pro-oxidant model agent tert-butyl hydroperoxide (tBuOOH) induces alterations in hepatocanalicular secretory function by activating Ca2+-dependent protein kinase C isoforms (cPKC), via F-actin disorganization followed by endocytic internalization of canalicular transporters relevant to bile formation (Mrp2, Bsep). Since mitogen-activated protein kinases (MAPKs) may be downstream effectors of cPKC, we investigated here the involvement of the MAPKs of the ERK1/2, JNK1/2, and p38MAPK types in these deleterious effects. tBuOOH (100 µM, 15 min) increased the proportion of the active, phosphorylated forms of ERK1/2, JNK1/2, and p38MAPK, and panspecific PKC inhibition with bisindolylmaleimide-1 (100 nM) or selective cPKC inhibition with Gö6976 (1 μM) prevented the latter two events. In isolated rat hepatocyte couplets, tBuOOH (100 µM, 15 min) decreased the canalicular vacuolar accumulation of the fluorescent Bsep and Mrp2 substrates, cholylglycylamido fluorescein, and glutathione-methylfluorescein, respectively, and selective inhibitors of ERK1/2 (PD098059), JNK1/2 (SP600125), and p38MAPK (SB203580) partially prevented these alterations. In in situ perfused rat livers, these three MAPK inhibitors prevented tBuOOH (75 µM)-induced impairment of bile flow and the decrease in the biliary output of the Bsep and Mrp2 substrates, taurocholate, and dinitrophenyl-S-glutathione, respectively. The changes in Bsep/Mrp2 and F-actin localization induced by tBuOOH, as assessed by (immuno)fluorescence staining followed by analysis of confocal images, were prevented total or partially by the MAPK inhibitors. We concluded that MAPKs of the ERK1/2, JNK1/2, and p38MAPK types are all involved in cholestasis induced by oxidative stress, by promoting F-actin rearrangement and further endocytic internalization of canalicular transporters critical for bile formation.
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Schonhoff CM, Park SW, Webster CR, Anwer MS. p38 MAPK α and β isoforms differentially regulate plasma membrane localization of MRP2. Am J Physiol Gastrointest Liver Physiol 2016; 310:G999-G1005. [PMID: 27012769 PMCID: PMC4935486 DOI: 10.1152/ajpgi.00005.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/14/2016] [Indexed: 01/31/2023]
Abstract
In hepatocytes, cAMP both activates p38 mitogen-activated protein kinase (MAPK) and increases the amount of multidrug resistance-associated protein-2 (MRP2) in the plasma membrane (PM-MRP2). Paradoxically, taurolithocholate (TLC) activates p38 MAPK but decreases PM-MRP2 in hepatocytes. These opposing effects of cAMP and TLC could be mediated via different p38 MAPK isoforms (α and β) that are activated differentially by upstream kinases (MKK3, MKK4, and MKK6). Thus we tested the hypothesis that p38α MAPK and p38β MAPK mediate increases and decreases in PM-MRP2 by cAMP and TLC, respectively. Studies were conducted in hepatocytes isolated from C57BL/6 wild-type (WT) and MKK3-knockout (MKK3(-/-)) mice and in a hepatoma cell line (HuH7) that overexpresses sodium-taurocholate cotransporting polypeptide (NTCP) (HuH-NTCP). Cyclic AMP activated MKK3, p38 MAPK, and p38α MAPK and increased PM-MRP2 in WT hepatocytes, but failed to activate p38α MAPK or increase PM-MRP2 in MKK3(-/-) hepatocytes. In contrast to cAMP, TLC activated total p38 MAPK but decreased PM-MRP2, and did not activate MKK3 or p38α MAPK in WT hepatocytes. In MKK3(-/-) hepatocytes, TLC still decreased PM-MRP2 and activated p38 MAPK, indicating that these effects are not MKK3-dependent. Additionally, TLC activated MKK6 in MKK3(-/-) hepatocytes, and small interfering RNA knockdown of p38β MAPK abrogated TLC-mediated decreases in PM-MRP2 in HuH-NTCP cells. Taken together, these results suggest that p38α MAPK facilitates plasma membrane insertion of MRP2 by cAMP, whereas p38β MAPK mediates retrieval of PM-MRP2 by TLC.
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Affiliation(s)
- Christopher M. Schonhoff
- 1Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
| | - Se Won Park
- 1Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
| | - Cynthia R.L. Webster
- 2Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts
| | - M. Sawkat Anwer
- 1Department of Biomedical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, Massachusetts; and
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Wang Y, Yang J, Li H, Wang X, Zhu L, Fan M, Wang X. Hypoxia promotes dopaminergic differentiation of mesenchymal stem cells and shows benefits for transplantation in a rat model of Parkinson's disease. PLoS One 2013; 8:e54296. [PMID: 23342124 PMCID: PMC3546985 DOI: 10.1371/journal.pone.0054296] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 12/10/2012] [Indexed: 02/07/2023] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent cells capable of differentiating into dopaminergic (DAergic) neurons, which is one of the major cell types damaged in Parkinson’s disease (PD). For this reason, MSCs are considered a potential cell source for PD therapy. It has been proved that hypoxia is involved in the proliferation and differentiation of stem cells. In this study, we investigated the effect of hypoxia on MSC proliferation and DAergic neuronal differentiation. Our results demonstrate that 3% O2 treatment can enhance rat MSC proliferation by upregulation of phosphorylated p38 MAPK and subsequent nuclear translocation of hypoxia inducible factor (HIF)-1α. During neural differentiation, 3% O2 treatment increases the expression of HIF-1α, phosphorylated ERK and p38 MAPK. These changes are followed by promotion of neurosphere formation and further DAergic neuronal differentiation. Furthermore, we explored the physiological function of hypoxia-induced DAergic neurons from human fetal MSCs by transplanting them into parkinsonian rats. Grafts induced with hypoxia display more survival of DAergic neurons and greater amelioration of behavioral impairments. Altogether, these results suggest that hypoxia can promote MSC proliferation and DAergic neuronal differentiation, and benefit for intrastriatal transplantation. Therefore, this study may provide new perspectives in application of MSCs to clinical PD therapy.
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Affiliation(s)
- Yue Wang
- Neuroscience Research Institute, Peking University, Key Laboratory of Neuroscience (PKU), Ministry of Education, Peking University Health Science Center, Beijing, China
| | - Jian Yang
- Department of Physiology and Neurobiology, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Education Ministry, Youanmen, Beijing, China
- Beijing An Ding Hospital, Beijing, China
| | - Haisheng Li
- Department of Brain Protection, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xuan Wang
- Department of Physiology and Neurobiology, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Education Ministry, Youanmen, Beijing, China
| | - Lingling Zhu
- Department of Brain Protection, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Ming Fan
- Department of Brain Protection, Beijing Institute of Basic Medical Sciences, Beijing, China
- * E-mail: (XMW); (MF)
| | - Xiaomin Wang
- Department of Physiology and Neurobiology, Capital Medical University, Key Laboratory for Neurodegenerative Disease of Education Ministry, Youanmen, Beijing, China
- * E-mail: (XMW); (MF)
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Yang J, Yu H, Zhou X, Kolosov V, Perelman J. Study on TRPV1-mediated mechanism for the hypersecretion of mucus in respiratory inflammation. Mol Immunol 2013; 53:161-71. [DOI: 10.1016/j.molimm.2012.06.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/20/2012] [Accepted: 06/24/2012] [Indexed: 02/06/2023]
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Abstract
Low oxygen tension exerts a significant effect on the replication of several DNA and RNA viruses in cultured cells. In vitro propagation of hepatitis C virus (HCV) has thus far been studied under atmospheric oxygen levels despite the fact that the liver tissue microenvironment is hypoxic. In this study, we investigated the efficiency of HCV production in actively dividing or differentiating human hepatoma cells cultured under low or atmospheric oxygen tensions. By using both HCV replicons and infection-based assays, low oxygen was found to enhance HCV RNA replication whereas virus entry and RNA translation were not affected. Hypoxia signaling pathway-focused DNA microarray and real-time quantitative reverse transcription-PCR (qRT-PCR) analyses revealed an upregulation of genes related to hypoxic stress, glycolytic metabolism, cell growth, and proliferation when cells were kept under low (3% [vol/vol]) oxygen tension, likely reflecting cell adaptation to anaerobic conditions. Interestingly, hypoxia-mediated enhancement of HCV replication correlated directly with the increase in anaerobic glycolysis and creatine kinase B (CKB) activity that leads to elevated ATP production. Surprisingly, activation of hypoxia-inducible factor alpha (HIF-α) was not involved in the elevation of HCV replication. Instead, a number of oncogenes known to be associated with glycolysis were upregulated and evidence that these oncogenes contribute to hypoxia-mediated enhancement of HCV replication was obtained. Finally, in liver biopsy specimens of HCV-infected patients, the levels of hypoxia and anaerobic metabolism markers correlated with HCV RNA levels. These results provide new insights into the impact of oxygen tension on the intricate HCV-host cell interaction.
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Bao B, Azmi AS, Ali S, Ahmad A, Li Y, Banerjee S, Kong D, Sarkar FH. The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:272-96. [PMID: 22579961 PMCID: PMC3788359 DOI: 10.1016/j.bbcan.2012.04.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/25/2012] [Accepted: 04/28/2012] [Indexed: 12/13/2022]
Abstract
Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia.
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Affiliation(s)
- Bin Bao
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Asfar S. Azmi
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Shadan Ali
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Aamir Ahmad
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Yiwei Li
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Sanjeev Banerjee
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Dejuan Kong
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Fazlul H. Sarkar
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
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Boaglio AC, Zucchetti AE, Toledo FD, Barosso IR, Sánchez Pozzi EJ, Crocenzi FA, Roma MG. ERK1/2 and p38 MAPKs are complementarily involved in estradiol 17ß-D-glucuronide-induced cholestasis: crosstalk with cPKC and PI3K. PLoS One 2012; 7:e49255. [PMID: 23166621 PMCID: PMC3498151 DOI: 10.1371/journal.pone.0049255] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 10/04/2012] [Indexed: 12/17/2022] Open
Abstract
Objective The endogenous, cholestatic metabolite estradiol 17ß-d-glucuronide (E217G) induces endocytic internalization of the canalicular transporters relevant to bile formation, Bsep and Mrp2. We evaluated here whether MAPKs are involved in this effect. Design ERK1/2, JNK1/2, and p38 MAPK activation was assessed by the increase in their phosphorylation status. Hepatocanalicular function was evaluated in isolated rat hepatocyte couplets (IRHCs) by quantifying the apical secretion of fluorescent Bsep and Mrp2 substrates, and in isolated, perfused rat livers (IPRLs), using taurocholate and 2,4-dinitrophenyl-S-glutathione, respectively. Protein kinase participation in E217G-induced secretory failure was assessed by co-administering selective inhibitors. Internalization of Bsep/Mrp2 was assessed by confocal microscopy and image analysis. Results E217G activated all kinds of MAPKs. The PI3K inhibitor wortmannin prevented ERK1/2 activation, whereas the cPKC inhibitor Gö6976 prevented p38 activation, suggesting that ERK1/2 and p38 are downstream of PI3K and cPKC, respectively. The p38 inhibitor SB203580 and the ERK1/2 inhibitor PD98059, but not the JNK1/2 inhibitor SP600125, partially prevented E217G-induced changes in transporter activity and localization in IRHCs. p38 and ERK1/2 co-inhibition resulted in additive protection, suggesting complementary involvement of these MAPKs. In IPRLs, E217G induced endocytosis of canalicular transporters and a rapid and sustained decrease in bile flow and biliary excretion of Bsep/Mrp2 substrates. p38 inhibition prevented this initial decay, and the internalization of Bsep/Mrp2. Contrarily, ERK1/2 inhibition accelerated the recovery of biliary secretion and the canalicular reinsertion of Bsep/Mrp2. Conclusions cPKC/p38 MAPK and PI3K/ERK1/2 signalling pathways participate complementarily in E217G-induced cholestasis, through internalization and sustained intracellular retention of canalicular transporters, respectively.
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Affiliation(s)
| | | | | | | | | | - Fernando A. Crocenzi
- Institute of Experimental Physiology, National Scientific and Technical Research Council/National University of Rosario, Rosario, Argentina
- * E-mail: (FAC); (MGR)
| | - Marcelo G. Roma
- Institute of Experimental Physiology, National Scientific and Technical Research Council/National University of Rosario, Rosario, Argentina
- * E-mail: (FAC); (MGR)
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Lu G, Ashraf M, Haider KH. Insulin-like growth factor-1 preconditioning accentuates intrinsic survival mechanism in stem cells to resist ischemic injury by orchestrating protein kinase cα-erk1/2 activation. Antioxid Redox Signal 2012; 16:217-27. [PMID: 21923556 PMCID: PMC3263485 DOI: 10.1089/ars.2011.4112] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS To test our hypothesis that the intrinsic molecular mechanism in stem cells for adaptation to ischemia is accentuated by preconditioning with insulin-like growth factor (IGF-1). RESULTS Bone marrow Sca-1(+) cells were exposed to oxygen and glucose deprivation (OGD) for up to 12 h. Erk1/2 was activated in Sca-1(+) cells under OGD which was blocked by MEK inhibitor (PD98059) and resulted in accelerated cell death. Moreover, elevated intracellular calcium with concomitant activation of protein kinase C (PKC) was observed under OGD. Pretreatment with nifedipine or dantrolene reduced cellular calcium, abrogated PKC and Erk1/2 activation, and increased cytotoxicity. Treatment with phorbol 12-myristate 13-acetate (PMA) for 30 min (short-term) activated Erk1/2, whereas 12 h (long-term) PMA treatment abrogated PKCα, reduced Erk1/2 activation and significantly increased cell death under OGD. These results were confirmed by loss-of-function studies using PKCα and Erk1/2 specific small interfering RNA. Gain-of-function studies with PKCα plasmid transfection improved cell survival under OGD. Preconditioning with 100 nM IGF-1 accentuated the intrinsic mechanism of resistance of the cells to ischemia via Erk1/2 activation and improved their survival under OGD as well as post-transplantation in an experimentally infarcted heart. INNOVATION Strategies to target intrinsic survival mechanism in stem cells by growth factor preconditioning to enhance their survival via activation of PKCα and Erk1/2 are innovative. CONCLUSIONS Intracellular calcium elevation under OGD activated PKCα and Erk1/2 as a part of the intrinsic prosurvival mechanism that was accentuated during preconditioning with IGF-1 to protect Sca-1(+) cells from ischemic injury.
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Affiliation(s)
- Gang Lu
- Department of Pathology, University of Cincinnati, Ohio, USA
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Hypoxia-induced sensitization of transient receptor potential vanilloid 1 involves activation of hypoxia-inducible factor-1 alpha and PKC. Pain 2011; 152:936-945. [DOI: 10.1016/j.pain.2011.02.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 12/26/2010] [Accepted: 02/07/2011] [Indexed: 02/01/2023]
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The hypoxia-inducible factor 1/NOR-1 axis regulates the survival response of endothelial cells to hypoxia. Mol Cell Biol 2009; 29:5828-42. [PMID: 19720740 DOI: 10.1128/mcb.00945-09] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Hypoxia induces apoptosis but also triggers adaptive mechanisms to ensure cell survival. Here we show that the prosurvival effects of hypoxia-inducible factor 1 (HIF-1) in endothelial cells are mediated by neuron-derived orphan receptor 1 (NOR-1). The overexpression of NOR-1 decreased the rate of endothelial cells undergoing apoptosis in cultures exposed to hypoxia, while the inhibition of NOR-1 increased cell apoptosis. Hypoxia upregulated NOR-1 mRNA levels in a time- and dose-dependent manner. Blocking antibodies against VEGF or SU5614 (a VEGF receptor 2 inhibitor) did not prevent hypoxia-induced NOR-1 expression, suggesting that NOR-1 is not induced by the autocrine secretion of VEGF in response to hypoxia. The reduction of HIF-1 alpha protein levels by small interfering RNAs, or by inhibitors of the phosphatidylinositol-3 kinase (PI3K)/Akt pathway or mTOR, significantly counteracted hypoxia-induced NOR-1 upregulation. Intracellular Ca(2+) was involved in hypoxia-induced PI3K/Akt activation and in the downstream NOR-1 upregulation. A hypoxia response element mediated the transcriptional activation of NOR-1 induced by hypoxia as we show by transient transfection and chromatin immunoprecipitation assays. Finally, the attenuation of NOR-1 expression reduced both basal and hypoxia-induced cIAP2 (cellular inhibitor of apoptosis protein 2) mRNA levels, while NOR-1 overexpression upregulated cIAP2. Therefore, NOR-1 is a downstream effector of HIF-1 signaling involved in the survival response of endothelial cells to hypoxia.
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