scholarly journals Uremic cardiomyopathy is characterized by loss of the cardioprotective effects of insulin

2012 ◽  
Vol 303 (9) ◽  
pp. F1275-F1286 ◽  
Author(s):  
David J. Semple ◽  
Sunil Bhandari ◽  
Anne-Marie L. Seymour
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Rate Pressure Product ◽  
Sprague Dawley ◽  
Uremic Cardiomyopathy ◽  
Reperfusion Injury Salvage Kinase ◽  
Cardioprotective Effects ◽  
Kinase Pathway

Chronic kidney disease is associated with a unique cardiomyopathy, characterized by a combination of structural and cellular remodeling, and an enhanced susceptibility to ischemia-reperfusion injury. This may represent dysfunction of the reperfusion injury salvage kinase pathway due to insulin resistance. The susceptibility of the uremic heart to ischemia-reperfusion injury and the cardioprotective effects of insulin and rosiglitazone were investigated. Uremia was induced in Sprague-Dawley rats by subtotal nephrectomy. Functional recovery from ischemia was investigated in vitro in control and uremic hearts ± insulin ± rosiglitazone. The response of myocardial oxidative metabolism to insulin was determined by13C-NMR spectroscopy. Activation of reperfusion injury salvage kinase pathway intermediates (Akt and GSK3β) were assessed by SDS-PAGE and immunoprecipitation. Insulin improved postischemic rate pressure product in control but not uremic hearts, [recovered rate pressure product (%), control 59.6 ± 10.7 vs. 88.9 ± 8.5, P < 0.05; uremic 19.3 ± 4.6 vs. 28.5 ± 10.4, P = ns]. Rosiglitazone resensitized uremic hearts to insulin-mediated cardioprotection [recovered rate pressure product (%) 12.7 ± 7.0 vs. 61.8 ± 15.9, P < 0.05]. Myocardial carbohydrate metabolism remained responsive to insulin in uremic hearts. Uremia was associated with increased phosphorylation of Akt (1.00 ± 0.08 vs. 1.31 ± 0.11, P < 0.05) in normoxia, but no change in postischemic phosphorylation of Akt or GSK3β. Akt2 isoform expression was decreased postischemia in uremic hearts ( P < 0.05). Uremia is associated with enhanced susceptibility to ischemia-reperfusion injury and a loss of insulin-mediated cardioprotection, which can be restored by administration of rosiglitazone. Altered Akt2 expression in uremic hearts post-ischemia-reperfusion and impaired activation of the reperfusion injury salvage kinase pathway may underlie these findings.

scholarly journals Polyethylene Glycol Preconditioning: An Effective Strategy to Prevent Liver Ischemia Reperfusion Injury

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mohamed Bejaoui ◽  
Eirini Pantazi ◽  
Maria Calvo ◽  
Emma Folch-Puy ◽  
Anna Serafín ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Rat Liver ◽  
Ischemia Reperfusion Injury ◽  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Water Soluble ◽  
Effective Strategy ◽  
Sprague Dawley ◽  
Hepatic Ischemia

Hepatic ischemia reperfusion injury (IRI) is an inevitable clinical problem for liver surgery. Polyethylene glycols (PEGs) are water soluble nontoxic polymers that have proven their effectiveness in variousin vivoandin vitromodels of tissue injury. The present study aims to investigate whether the intravenous administration of a high molecular weight PEG of 35 kDa (PEG 35) could be an effective strategy for rat liver preconditioning against IRI. PEG 35 was intravenously administered at 2 and 10 mg/kg to male Sprague Dawley rats. Then, rats were subjected to one hour of partial ischemia (70%) followed by two hours of reperfusion. The results demonstrated that PEG 35 injected intravenously at 10 mg/kg protected efficiently rat liver against the deleterious effects of IRI. This was evidenced by the significant decrease in transaminases levels and the better preservation of mitochondrial membrane polarization. Also, PEG 35 preserved hepatocyte morphology as reflected by an increased F-actin/G-actin ratio and confocal microscopy findings. In addition, PEG 35 protective mechanisms were correlated with the activation of the prosurvival kinase Akt and the cytoprotective factor AMPK and the inhibition of apoptosis. Thus, PEG may become a suitable agent to attempt pharmacological preconditioning against hepatic IRI.

scholarly journals N6-methyladenosine demethylase FTO impairs hepatic ischemia–reperfusion injury via inhibiting Drp1-mediated mitochondrial fragmentation

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fragmentation ◽  
Hepatic Ischemia ◽  
Adeno Associated Virus ◽  
Downstream Target ◽  
Hepatic Ischemia Reperfusion

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.

scholarly journals The Sodium-Glucose Cotransporter-2 Inhibitor Canagliflozin Alleviates Endothelial Dysfunction Following In Vitro Vascular Ischemia/Reperfusion Injury in Rats

2021 ◽  
Vol 22 (15) ◽  
pp. 7774
Author(s):  
Sevil Korkmaz-Icöz ◽  
Cenk Kocer ◽  
Alex A. Sayour ◽  
Patricia Kraft ◽  
Mona I. Benker ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Reperfusion Injury ◽  
Vascular Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Artery Bypass ◽  
Diabetic Rats ◽  
Organ Bath ◽  
Sodium Glucose Cotransporter

Vascular ischemia/reperfusion injury (IRI) contributes to graft failure and adverse clinical outcomes following coronary artery bypass grafting. Sodium-glucose-cotransporter (SGLT)-2-inhibitors have been shown to protect against myocardial IRI, irrespective of diabetes. We hypothesized that adding canagliflozin (CANA) (an SGLT-2-inhibitor) to saline protects vascular grafts from IRI. Aortic rings from non-diabetic rats were isolated and immediately mounted in organ bath chambers (control, n = 9–10 rats) or underwent cold ischemic preservation in saline, supplemented either with a DMSO vehicle (IR, n = 8–10 rats) or 50µM CANA (IR + CANA, n = 9–11 rats). Vascular function was measured, the expression of 88 genes using PCR-array was analyzed, and feature selection using machine learning was applied. Impaired maximal vasorelaxation to acetylcholine in the IR-group compared to controls was significantly ameliorated by CANA (IR 31.7 ± 3.2% vs. IR + CANA 51.9 ± 2.5%, p < 0.05). IR altered the expression of 17 genes. Ccl2, Ccl3, Ccl4, CxCr4, Fos, Icam1, Il10, Il1a and Il1b have been found to have the highest interaction. Compared to controls, IR significantly upregulated the mRNA expressions of Il1a and Il6, which were reduced by 1.5- and 1.75-fold with CANA, respectively. CANA significantly prevented the upregulation of Cd40, downregulated NoxO1 gene expression, decreased ICAM-1 and nitrotyrosine, and increased PECAM-1 immunoreactivity. CANA alleviates endothelial dysfunction following IRI.

scholarly journals Overexpression of SP1 restores autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chong Huang ◽  
Yan Chen ◽  
Bin Lai ◽  
Yan-Xia Chen ◽  
Cheng-Yun Xu ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Akt Pathway ◽  
Acute Renal Injury ◽  
Injury Model ◽  
Renal Ischemia Reperfusion Injury

Abstract Background Acute kidney injury (AKI) is a major kidney disease with poor clinical outcome. SP1, a well-known transcription factor, plays a critical role in AKI and subsequent kidney repair through the regulation of various cell biologic processes. However, the underlying mechanism of SP1 in these pathological processes remain largely unknown. Methods An in vitro HK-2 cells with anoxia-reoxygenation injury model (In vitro simulated ischemic injury disease) and an in vivo rat renal ischemia-reperfusion injury model were used in this study. The expression levels of SP1, miR-205 and PTEN were detected by RT-qPCR, and the protein expression levels of SP1, p62, PTEN, AKT, p-AKT, LC3II, LC3I and Beclin-1 were assayed by western blot. Cell proliferation was assessed by MTT assay, and the cell apoptosis was detected by flow cytometry. The secretions of IL-6 and TNF-α were detected by ELISA. The targeted relationship between miR-205 and PTEN was confirmed by dual luciferase report assay. The expression and positioning of LC-3 were observed by immunofluorescence staining. TUNEL staining was used to detect cell apoptosis and immunohistochemical analysis was used to evaluate the expression of SP1 in renal tissue after ischemia-reperfusion injury in rats. Results The expression of PTEN was upregulated while SP1 and miR-205 were downregulated in renal ischemia-reperfusion injury. Overexpression of SP1 protected renal tubule cell against injury induced by ischemia-reperfusion via miR-205/PTEN/Akt pathway mediated autophagy. Overexpression of SP1 attenuated renal ischemia-reperfusion injury in rats. Conclusions SP1 overexpression restored autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway.

In vivo and In vitro PPAR-y Activation Decreases M1-Macrophage Polarization and Improves Liver Ischemia Reperfusion Injury

2018 ◽  
Vol 102 ◽  
pp. S708
Author(s):  
Ivan Linares ◽  
Agata Bartczak ◽  
Kaveh Farrokhi ◽  
Dagmar Kollmann ◽  
Moritz Kaths ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Liver Ischemia ◽  
M1 Macrophage

scholarly journals Poly-IC Preconditioning Protects against Cerebral and Renal Ischemia-Reperfusion Injury

2011 ◽  
Vol 32 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Amy E B Packard ◽  
Jason C Hedges ◽  
Frances R Bahjat ◽  
Susan L Stevens ◽  
Michael J Conlin ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Cortical Cells ◽  
Polycytidylic Acid ◽  
Populations At Risk

Preconditioning induces ischemic tolerance, which confers robust protection against ischemic damage. We show marked protection with polyinosinic polycytidylic acid (poly-IC) preconditioning in three models of murine ischemia-reperfusion injury. Poly-IC preconditioning induced protection against ischemia modeled in vitro in brain cortical cells and in vivo in models of brain ischemia and renal ischemia. Further, unlike other Toll-like receptor (TLR) ligands, which generally induce significant inflammatory responses, poly-IC elicits only modest systemic inflammation. Results show that poly-IC is a new powerful prophylactic treatment that offers promise as a clinical therapeutic strategy to minimize damage in patient populations at risk of ischemic injury.

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