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Abudu YP, Kournoutis A, Brenne HB, Lamark T, Johansen T. MORG1 limits mTORC1 signaling by inhibiting Rag GTPases. Mol Cell 2024; 84:552-569.e11. [PMID: 38103557 DOI: 10.1016/j.molcel.2023.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 10/02/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Autophagy, an important quality control and recycling process vital for cellular homeostasis, is tightly regulated. The mTORC1 signaling pathway regulates autophagy under conditions of nutrient availability and scarcity. However, how mTORC1 activity is fine-tuned during nutrient availability to allow basal autophagy is unclear. Here, we report that the WD-domain repeat protein MORG1 facilitates basal constitutive autophagy by inhibiting mTORC1 signaling through Rag GTPases. Mechanistically, MORG1 interacts with active Rag GTPase complex inhibiting the Rag GTPase-mediated recruitment of mTORC1 to the lysosome. MORG1 depletion in HeLa cells increases mTORC1 activity and decreases autophagy. The autophagy receptor p62/SQSTM1 binds to MORG1, but MORG1 is not an autophagy substrate. However, p62/SQSTM1 binding to MORG1 upon re-addition of amino acids following amino acid's depletion precludes MORG1 from inhibiting the Rag GTPases, allowing mTORC1 activation. MORG1 depletion increases cell proliferation and migration. Low expression of MORG1 correlates with poor survival in several important cancers.
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Affiliation(s)
- Yakubu Princely Abudu
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway; Nanoscopy Group, Department of Physics and Technology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway.
| | - Athanasios Kournoutis
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Hanne Britt Brenne
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway.
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2
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Barth J, Loeffler I, Bondeva T, Liebisch M, Wolf G. The Role of Hypoxia on the Trimethylation of H3K27 in Podocytes. Biomedicines 2023; 11:2475. [PMID: 37760919 PMCID: PMC10525388 DOI: 10.3390/biomedicines11092475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/28/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Epigenetic alterations contribute to the pathogenesis of chronic diseases such as diabetes mellitus. Previous studies of our group showed that diabetic conditions reduce the trimethylation of H3K27 in podocytes in a NIPP1- (nuclear inhibitor of protein phosphatase 1) and EZH2- (enhancer of zeste homolog 2) dependent manner. It has been previously reported that in differentiated podocytes, hypoxia decreases the expression of slit diaphragm proteins and promotes foot process effacement, thereby contributing to the progression of renal disease. The exact mechanisms are, however, not completely understood. The aim of this study was to analyze the role of hypoxia and HIFs (hypoxia-inducible factor) on epigenetic changes in podocytes affecting NIPP1, EZH2 and H3K27me3, in vitro and in vivo. In vivo studies were performed with mice exposed to 10% systemic hypoxia for 3 days or injected with 3,4-DHB (dihydroxybenzoate), a PHD (prolyl hydroxylase) inhibitor, 24 h prior analyses. Immunodetection of H3K27me3, NIPP1 and EZH2 in glomerular podocytes revealed, to the best of our knowledge for the first time, that hypoxic conditions and pharmacological HIFs activation significantly reduce the expression of NIPP1 and EZH2 and diminish H3K27 trimethylation. These findings are also supported by in vitro studies using murine-differentiated podocytes.
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3
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Wang X, Wu J, Wang M, Lu C, Li W, Lu Q, Li Y, Lian B, Zhang B. Substance P&dimethyloxallyl glycine-loaded carboxymethyl chitosan/gelatin hydrogel for wound healing. J Biomed Mater Res A 2023; 111:404-414. [PMID: 36479810 DOI: 10.1002/jbm.a.37475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/18/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Recent efforts have focused on preparing drug-loaded hydrogel for wound healing. In order to obtain an ideal hydrogel dressing for skin wound repair, a carboxymethyl chitosan-gelatin hydrogel was prepared for co-delivery of SP (substance P) and DMOG (dimethyloxallyl glycine) by a chemical cross-linking method using genipin as the cross-linking agent. The synthesized hydrogels have good biocompatibility and physicochemical properties due to the low toxicity of the hydrogel material. The three-dimensional network structure of the hydrogels supports cell migration and proliferation, and the combination of SP and DMOG drugs exhibited strong effects on cell proliferation. Moreover, the co-loaded drug hydrogels could significantly promote wound healing in vivo, and provide a potential hydrogel for wound healing.
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Affiliation(s)
- Xiaoxue Wang
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China.,School of Nursing, Weifang University of Science and Technology, Weifang, People's Republic of China
| | - Jingliang Wu
- School of Nursing, Weifang University of Science and Technology, Weifang, People's Republic of China
| | - Min Wang
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Chunbo Lu
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Wenfang Li
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Qiao Lu
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Yanying Li
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Bo Lian
- School of Life Science and Technology, Weifang Medical University, Weifang, People's Republic of China
| | - Bo Zhang
- School of Pharmacy, Weifang Medical University, Weifang, People's Republic of China
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Jankowski E, Wulf S, Ziller N, Wolf G, Loeffler I. MORG1—A Negative Modulator of Renal Lipid Metabolism in Murine Diabetes. Biomedicines 2021; 10:30. [PMID: 35052710 PMCID: PMC8772719 DOI: 10.3390/biomedicines10010030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/17/2021] [Accepted: 12/21/2021] [Indexed: 12/19/2022] Open
Abstract
Renal fatty acid (FA) metabolism is severely altered in type 1 and 2 diabetes mellitus (T1DM and T2DM). Increasing evidence suggests that altered lipid metabolism is linked to tubulointerstitial fibrosis (TIF). Our previous work has demonstrated that mice with reduced MORG1 expression, a scaffold protein in HIF and ERK signaling, are protected against TIF in the db/db mouse model. Renal TGF-ß1 expression and EMT-like changes were reduced in mice with single-allele deficiency of MORG1. Given the well-known role of HIF and ERK signaling in metabolic regulation, here we examined whether protection was also associated with a restoration of lipid metabolism. Despite similar features of TIF in T1DM and T2DM, diabetes-associated changes in renal lipid metabolism differ between both diseases. We found that de novo synthesis of FA/cholesterol and β-oxidation were more strongly disrupted in T1DM, whereas pathological fat uptake into tubular cells mediates lipotoxicity in T2DM. Thus, diminished MORG1 expression exerts renoprotection in the diabetic nephropathy by modulating important factors of TIF and lipid dysregulation to a variable extent in T1DM and T2DM. Prospectively, targeting MORG1 appears to be a promising strategy to reduce lipid metabolic alterations in diabetic nephropathy.
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Makhdoumi P, Abnous K, Mehri S, Etemad L, Imenshahidi M, Karimi G. Oral deferiprone administration ameliorates cisplatin-induced nephrotoxicity in rats. ACTA ACUST UNITED AC 2018; 70:1357-1368. [PMID: 30051477 DOI: 10.1111/jphp.12990] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 07/07/2018] [Indexed: 01/13/2023]
Abstract
OBJECTIVES Cisplatin is one of the widely used antitumour agents with major clinical side effect, nephrotoxicity. We showed the role of iron in cisplatin-induced nephrotoxicity that entrance to the cell via transferrin receptor (TfR) as a gatekeeper for iron uptake. We also examined the effect of iron chelator deferiprone against this toxicity. METHODS Thirty male Wistar rats were randomly divided into six groups. Group I (saline orally for 10 days); group II (saline orally for 10 days plus single injection of cisplatin 7 mg/kg, intraperitoneally on 5th day); groups III, IV and V (deferiprone 50, 100 and 200 mg/kg orally for 10 days, respectively, plus cisplatin on 5th day). Group VI (deferiprone, orally). RESULTS Deferiprone provided functional and significant histological-proven protection in group IV. Deferiprone attenuated the increased creatinine, BUN, malondialdehyde and iron concentrations in cisplatin-injected animals. The increased amounts of TfR and decreased levels of HIF-1α and related anti-apoptotic genes expression in cisplatin-treated animals were improved by deferiprone. CONCLUSIONS The results supported a role for iron in cisplatin-induced nephrotoxicity and TfR may serve as an important source of iron. Based on these findings, deferiprone pretreatment may play a role in preventing cisplatin-induced nephropathy in cancer patient.
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Affiliation(s)
- Pouran Makhdoumi
- Student Research Committee, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad, Iran.,Pharmaceutical Research Center, Mashhad, Iran
| | - Khalil Abnous
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Soghra Mehri
- Department of Pharmacodynamics and Toxicology, Pharmacy School, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Leila Etemad
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohsen Imenshahidi
- Department of Pharmacodynamics and Toxicology, Pharmacy School, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Gholamreza Karimi
- Department of Pharmacodynamics and Toxicology, Pharmacy School, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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Fischer C, Deininger N, Wolf G, Loeffler I. CERA Attenuates Kidney Fibrogenesis in the db/db Mouse by Influencing the Renal Myofibroblast Generation. J Clin Med 2018; 7:E15. [PMID: 29385703 DOI: 10.3390/jcm7020015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/24/2018] [Accepted: 01/24/2018] [Indexed: 12/24/2022] Open
Abstract
Tubulointerstitial fibrosis (TIF) is a pivotal pathophysiological process in patients with diabetic nephropathy (DN). Multiple profibrotic factors and cell types, including transforming growth factor beta 1 (TGF-β1) and interstitial myofibroblasts, respectively, are responsible for the accumulation of extracellular matrix in the kidney. Matrix-producing myofibroblasts can originate from different sources and different mechanisms are involved in the activation process of the myofibroblasts in the fibrotic kidney. In this study, 16-week-old db/db mice, a model for type 2 DN, were treated for two weeks with continuous erythropoietin receptor activator (CERA), a synthetic erythropoietin variant with possible non-hematopoietic, tissue-protective effects. Non-diabetic and diabetic mice treated with placebo were used as controls. The effects of CERA on tubulointerstitial fibrosis (TIF) as well as on the generation of the matrix-producing myofibroblasts were evaluated by morphological, immunohistochemical, and molecular biological methods. The placebo-treated diabetic mice showed significant signs of beginning renal TIF (shown by picrosirius red staining; increased connective tissue growth factor (CTGF), fibronectin and collagen I deposition; upregulated KIM1 expression) together with an increased number of interstitial myofibroblasts (shown by different mesenchymal markers), while kidneys from diabetic mice treated with CERA revealed less TIF and fewer myofibroblasts. The mechanisms, in which CERA acts as an anti-fibrotic agent/drug, seem to be multifaceted: first, CERA inhibits the generation of matrix-producing myofibroblasts and second, CERA increases the ability for tissue repair. Many of these CERA effects can be explained by the finding that CERA inhibits the renal expression of the cytokine TGF-β1.
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Jiao X, Xu X, Fang Y, Zhang H, Liang M, Teng J, Ding X. miR-21 contributes to renal protection by targeting prolyl hydroxylase domain protein 2 in delayed ischaemic preconditioning. Nephrology (Carlton) 2017; 22:366-373. [PMID: 27030384 DOI: 10.1111/nep.12787] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 03/16/2016] [Accepted: 03/23/2016] [Indexed: 01/07/2023]
Abstract
AIM Upregulation of miR-21 in renal ischaemic preconditioning (IPC) was associated with increased hypoxia inducible factor (HIF)-1α expression. Hypoxic induction of HIF-1α is mediated by inhibition of prolyl hydroxylase domain protein 2 (PHD2) .We hypothesized that miR-21 regulated HIF-1α by targeting PHD2 in the renal IPC. METHODS Luciferase reporter assay examined if miR-21 target the 3'-untranslated region of PHD2. In vitro, human proximal tubular cell line (HK-2) was incubated in hypoxia or hypoxia/ reoxygenation condition. Kidneys of Mice were respectively subjected to ischaemia/reperfusion injury (IRI) and IPC. Locked nucleic acid (LNA) modified anti-miR-21 was used to knockdown miR-21. Serum creatinine and histological changes estimated the renal injury. Levels of HIF-1α, PHD2, VEGF and miR-21 were examined by western blot or real-time PCR. RESULT miR-21 targeting of PHD2 was confirmed by 3'-untranslated region reporter assay. miR-21 was significantly upregulated by hypoxia/reoxygenation in HK-2 cell, while PHD2 protein level decreased significantly. LNA anti-miR-21 significantly repressed miR-21 levels and increased the abundance of PHD2. In vivo, IPC upregulated miR-21 expression 24 h after the second ischaemia, while PHD2 expression decreased significantly with upregulation of HIF-1α protein and VEGF mRNA. MiR-21 induced by delayed IPC was effectively inhibited by the LNA anti-miR-21. With downregulation of miR-21, the protection of delayed IPC was attenuated and PHD2 protein was increased. Furthermore, upregulation of HIF-1α and VEGF were abolished after the LNA anti-miR-21 treatment. CONCLUSION miR-21 could protect kidney against IRI via HIF-1α by inhibiting its target PHD2.The study suggested a new relationship between miR-21 and HIF-1α.
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Affiliation(s)
- Xiaoyan Jiao
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Kidney Disease and Dialysis, Shanghai, China.,Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China
| | - Xialian Xu
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Kidney Disease and Dialysis, Shanghai, China.,Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China
| | - Yi Fang
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Hui Zhang
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Kidney Disease and Dialysis, Shanghai, China.,Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China
| | - Mingyu Liang
- Department of Physiology and Center of Systems Molecular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jie Teng
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiaoqiang Ding
- Division of Nephrology, Zhongshan Hospital, Fudan University, Shanghai, China.,Shanghai Institute of Kidney Disease and Dialysis, Shanghai, China.,Kidney and Blood Purification Laboratory of Shanghai, Shanghai, China
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8
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Bian S, Li X, Mainali H, Chen L, Dhaubhadel S. Genome-wide analysis of DWD proteins in soybean (Glycine max): Significance of Gm08DWD and GmMYB176 interaction in isoflavonoid biosynthesis. PLoS One 2017; 12:e0178947. [PMID: 28586359 PMCID: PMC5460815 DOI: 10.1371/journal.pone.0178947] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/22/2017] [Indexed: 01/26/2023] Open
Abstract
A subset of WD40 proteins with DWD motif has been proposed to serve as substrate receptor of DDB-CUL4-ROC1 complex, thereby getting involved in protein degradation via ubiquitination pathway. Here, we identified a total of 161 potential DWD proteins in soybean (Glycine max) by searching DWD motif against the genome-wide WD40 repeats, and classified them into 20 groups on the basis of their functional domains and annotations. These putative DWD genes in soybean displayed tissue-specific expression patterns, and their genome localization and analysis of evolutionary relationship identified 48 duplicated gene pairs within 161 GmDWDs. Among the 161 soybean DWD proteins, Gm08DWD was previously found to interact with an isoflavonoid regulator, GmMYB176. Therefore, Gm08DWD and its homologue Gm05DWD were further investigated. Expression profile of both genes in different soybean tissues revealed that Gm08DWD was expressed higher in embryo, while Gm05DWD exhibited maximum transcript accumulation in leaf. Our protein-protein interaction studies demonstrated that Gm08DWD interacts with GmMYB176. Although Gm08DWD was localized both in nucleus and cytoplasm, the resulting complex of Gm08DWD and GmMYB176 was mainly observed in the nucleus. This finding is consistent with the functional localization of CUL4-E3 ligase complex. In conclusion, the survey on soybean potential DWD protein is useful reference for the further functional investigation of their DDB1-binding ability. Based on the functional investigation of Gm08DWD, we speculate that protein-protein interaction between Gm08DWD and GmMYB176 may lead to the degradation of GmMYB176 through CUL4-DDB1complex.
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Affiliation(s)
- Shaomin Bian
- College of Plant Science, Jilin University, Changchun, Jilin, China
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada
| | - Xuyan Li
- College of Plant Science, Jilin University, Changchun, Jilin, China
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada
| | - Hemanta Mainali
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada
| | - Ling Chen
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada
| | - Sangeeta Dhaubhadel
- Agriculture and Agri-Food Canada, London Research and Development Centre, London, ON, Canada
- Department of Biology, Western University, London, ON, Canada
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Conde E, Giménez-Moyano S, Martín-Gómez L, Rodríguez M, Ramos ME, Aguado-Fraile E, Blanco-Sanchez I, Saiz A, García-Bermejo ML. HIF-1α induction during reperfusion avoids maladaptive repair after renal ischemia/reperfusion involving miR127-3p. Sci Rep 2017; 7:41099. [PMID: 28106131 DOI: 10.1038/srep41099] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 12/15/2016] [Indexed: 12/11/2022] Open
Abstract
Ischemia/reperfusion (I/R) leads to Acute Kidney Injury. HIF-1α is a key factor during organ response to I/R. We previously demonstrated that HIF-1α is induced during renal reperfusion, after ischemia. Here we investigate the role of HIF-1α and the HIF-1α dependent mechanisms in renal repair after ischemia. By interference of HIF-1α in a rat model of renal I/R, we observed loss of expression and mis-localization of e-cadherin and induction of α-SMA, MMP-13, TGFβ, and collagen I. Moreover, we demonstrate that HIF-1α inhibition promotes renal cell infiltrates by inducing IL-1β, TNF-α, MCP-1 and VCAM-1, through NFkB activity. In addition, HIF-1α inhibition induced proximal tubule cells proliferation but it did not induce compensatory apoptosis, both in vivo. In vitro, HIF-1α knockdown in HK2 cells subjected to hypoxia/reoxygenation (H/R) promote cell entry into S phase, correlating with in vivo data. HIF-1α interference leads to downregulation of miR-127-3p and induction of its target gene Bcl6 in vivo. Moreover, modulation of miR-127-3p in HK2 cells subjected to H/R results in EMT regulation: miR127-3p inhibition promote loss of e-cadherin and induction of α-SMA and collagen I. In conclusion, HIF-1α induction during reperfusion is a protector mechanism implicated in a normal renal tissue repair after I/R.
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Khaksari M, Mehrjerdi FZ, Rezvani ME, Safari F, Mirgalili A, Niknazar S. The role of erythropoietin in remote renal preconditioning on hippocampus ischemia/reperfusion injury. J Physiol Sci 2017; 67:163-171. [PMID: 27099131 PMCID: PMC10717085 DOI: 10.1007/s12576-016-0451-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 04/11/2016] [Indexed: 11/24/2022]
Abstract
Remote ischemic preconditioning (RIPC) is an intriguing approach which exposes a remote organ/tissue to a non-lethal transient ischemia/reperfusion (I/R) in order to potentiate the resistance of the desired organ/tissue against the next unwanted I/R. It has been suggested that RIPC exerts its effect through neuronal and hormonal pathways. The underlying mechanisms of RIPC are obscure and should be elucidated. In this study, we induced RIPC in mice using 3 cycles of 5 min ischemia alternating with 5 min reperfusion of the left renal artery. Renal failure was induced in mice by intra-peritoneal (i.p.) injection of 200 mg/kg body weight of gentamicin twice per day for 4 consecutive days. Global hippocampal ischemia reperfusion (I/R) was performed by bilateral carotid artery occlusion for 20 min followed by reperfusion for 72 h. Moreover, the retention trial of passive avoidance test was determined 72 h after global ischemia. Histopathological changes of hippocampus neurons were observed using Nissl staining to detect neuronal loss. Finally, terminal deoxynucleotidyl transferase mediated dUTP nick end-labeling (TUNEL) was performed to assess the status of apoptotic cells in the hippocampus. The results of this study suggest that renal ischemic preconditioning is a good candidate for prevention of I/R-induced hippocampal injury. However, RRPC (remote renal preconditioning) failed to exert a neuroprotective effect in mice with renal failure (RF), indicating the probable role of a humoral factor which is released from kidneys in response to ischemia. In agreement with this hypothesis, treatment of mice with rhEPO (5000 IU/kg intraperitoneal) before induction of RRPC restored the neuroprotective effects of RRPC in RF mice. Accordingly, it is plausible to expect that erythropoietin is released from kidneys to act as a mediator for RRPC-induced neuroprotective effects. Renal ischemic preconditioning prevents I/R-induced hippocampal injury. In contrast, renal failure hampers protective effects of RRPC, while exogenous administration of erythropoietin (EPO) significantly prevents the inhibiting effects of renal failure.
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Affiliation(s)
- Mehdi Khaksari
- Addiction Research Center, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Fatemeh Zare Mehrjerdi
- Neurobiomedical Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
| | | | - Fatemeh Safari
- Neurobiomedical Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Aghdas Mirgalili
- Department of Anatomy, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Somayeh Niknazar
- Hearing Disorders Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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11
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Ma R, Zhang J, Liu X, Yue S, Zhao Q, Xu Y. 7,8-DHF Treatment Induces Cyr61 Expression to Suppress Hypoxia Induced ER Stress in HK-2 Cells. Biomed Res Int 2016; 2016:5029797. [PMID: 28116298 DOI: 10.1155/2016/5029797] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/21/2016] [Indexed: 02/06/2023]
Abstract
Acute kidney injury (AKI) is a common syndrome which is strongly linked to high morbidity and mortality. Hypoxia is the leading cause of AKI and the proximal renal tubular cells are the most damaged part in the kidney during this period. It has been observed that 7,8-dihydroxyflavone (7,8-DHF) plays a protective role by acting on antiapoptosis and antioxidative stress. In this study we explored functions of 7,8-DHF in protecting human proximal tubular cell line HK-2 from hypoxia insults. We observed that treatment of 7,8-DHF could improve the viability of ischemic cell. Mechanistically, we found that 7,8-DHF could elevate the expression of cysteine-rich protein 61 (Cyr61), a protective immediate early gene in AKI. In addition, treatment of 7,8-DHF decreased CCAAT/enhancer-binding protein homologous protein (CHOP) expression, which is a marker protein during endoplasmic reticulum (ER) stress activation. Intriguingly, overexpression of Cyr61 significantly reduced CHOP expression. Taken together, our results provide novel insights into the possible protective role of 7,8-DHF by activating Cyr61 signaling and suppressing ER stress in hypoxic HK-2 cells which have potential clinical implications for the treatment of AKI.
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12
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Ribeiro S, Garrido P, Fernandes J, Vala H, Rocha-Pereira P, Costa E, Belo L, Reis F, Santos-Silva A. Pathological and molecular mechanisms underlying resistance to recombinant human erythropoietin therapy in the remnant kidney rat model of chronic kidney disease associated anemia. Biochimie 2016; 125:150-62. [PMID: 27039028 DOI: 10.1016/j.biochi.2016.03.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/25/2016] [Indexed: 10/22/2022]
Abstract
Anemia of chronic kidney disease (CKD) can be corrected by treatment with recombinant human erythropoietin (rHuEPO); however, some patients become hyporesponsive. The molecular mechanisms underlying this resistance remain to be elucidated. Our aim was to study hyporesponsiveness to rHuEPO therapy using the remnant kidney rat model of anemia associated with CKD induced by 5/6 nephrectomy. At starting, male Wistar rats were divided in 3 groups, for a 3-week protocol: Sham, CRF (vehicle) and two rHuEPO (200 k/kg body weight [BW]/week) treated groups; at the end of protocol, the rHuEPO treated rats were subdivided in responders (CRF200) and non-responders (CRF200NR), according to their hematologic response; blood, cellular and tissue studies were performed. The CRF200 group achieved correction of anemia, while the CRF200NR group developed anemia, after an initial response (1st week) to rHuEPO therapy. CRF and CRF200NR groups presented a trend to higher serum CRP levels; CRF200NR showed also high levels of renal inflammatory markers, such as interleukin (IL)-6, IL-1β, nuclear factor kappa B, connective tissue growth factor (CTGF) and transforming growth factor beta 1 (TGF-β1); no changes were found in iron metabolism. Our data suggest that the development of anemia/rHuEPO hyporesponsiveness is associated with a higher systemic and renal inflammatory condition, favoring hypoxia and triggering an increase in renal expression of HIF-1α, TGF-β1 and CTGF that will further aggravate renal fibrosis, which will enhance the inflammatory response, creating a cycle that promotes disease progression. New therapeutic strategies to reduce inflammation in CKD patients could improve the response to rHuEPO therapy and reduce hyporesponsiveness.
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Affiliation(s)
- Sandra Ribeiro
- Research Unit on Applied Molecular Biosciences (UCIBIO), REQUIMTE, Department of Biological Sciences, Laboratory of Biochemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Patrícia Garrido
- Laboratory of Pharmacology & Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - João Fernandes
- Laboratory of Pharmacology & Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Center for Neuroscience and Cell Biology-Institute for Biomedical Imaging and Life Sciences (CNC.IBILI) Research Unit, University of Coimbra, Coimbra, Portugal
| | - Helena Vala
- Center for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB) and Center for Studies in Education, Technologies and Health (CI&DETS), Agrarian School of Viseu, Polytechnic Institute of Viseu, Viseu, Portugal
| | - Petronila Rocha-Pereira
- Health Sciences Research Centre, Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
| | - Elísio Costa
- Research Unit on Applied Molecular Biosciences (UCIBIO), REQUIMTE, Department of Biological Sciences, Laboratory of Biochemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Luís Belo
- Research Unit on Applied Molecular Biosciences (UCIBIO), REQUIMTE, Department of Biological Sciences, Laboratory of Biochemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Flávio Reis
- Laboratory of Pharmacology & Experimental Therapeutics, Institute for Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Center for Neuroscience and Cell Biology-Institute for Biomedical Imaging and Life Sciences (CNC.IBILI) Research Unit, University of Coimbra, Coimbra, Portugal
| | - Alice Santos-Silva
- Research Unit on Applied Molecular Biosciences (UCIBIO), REQUIMTE, Department of Biological Sciences, Laboratory of Biochemistry, Faculty of Pharmacy, University of Porto, Porto, Portugal.
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