scholarly journals Ischemia/Reperfusion Injury Alters Sphingolipid Metabolism in the Gut

2016 ◽  
Vol 39 (4) ◽  
pp. 1262-1270 ◽  
Author(s):  
Richard S. Hoehn ◽  
Aaron P. Seitz ◽  
Peter L. Jernigan ◽  
Erich Gulbins ◽  
Michael J. Edwards

Background: Intestinal ischemia/reperfusion injury (I/R) is a significant cause of morbidity and mortality in surgical patients. Ceramide is a mediator of apoptosis and has been implicated as increasing bacterial infection susceptibility. The metabolite of ceramide, sphingosine, was recently shown to play an important role in the cell-autonomous, innate immune response of the upper respiratory tract by killing bacterial pathogens. The role of ceramide and/or sphingosine after mesenteric I/R is unknown. We investigated the specific effects of intestinal I/R on tissue ceramide and sphingosine concentration and resulting susceptibility to bacterial invasion. Methods: To simulate intestinal I/R, C57BL/6 mice underwent 30 minutes of vascular clamp-induced occlusion of the superior mesenteric artery followed by variable reperfusion times. Jejunum segments and intraluminal contents were analyzed for ceramide, sphingosine and bacteria using immunohistochemistry. Jejunum samples were also homogenized and cultured to quantify bacterial presence in the proximal intestine. Results: We hypothesized that I/R induces an increase of ceramide in the intestine resulting in increased permeability, while a concomitant decrease of sphingosine may permit bacterial overgrowth. Control mice had no measurable bacteria in their proximal jejunum as measured by tissue culture and immunohistochemistry. After I/R, bacterial counts in the jejunum increased in a time-dependent manner, reaching a peak at 12 hours after reperfusion. Immunohistochemical analysis revealed a marked increase in ceramide in the vasculature of jejunal villi. In contrast, while ceramide concentrations in the epithelial cells decreased after I/R, sphingosine levels appeared to remain unchanged. Surprisingly, bacteria present in the jejunal lumen following I/R contained a ceramide coat. Conclusion: These data indicate that intestinal I/R leads to small intestine bacterial overgrowth as well as ceramide formation in the jejunal vasculature, which may contribute to the gut permeability associated with this injury. Moreover, our novel finding of ceramide in bacterial membranes represents a new opportunity to investigate the dynamic pathogenicity of the gut microbiome. The hypothesis that a decrease of sphingosine after I/R permits bacterial overgrowth in the intestine was not confirmed.

2021 ◽  
Author(s):  
Hui Li ◽  
Shuaiwei Wang ◽  
Shuangshuang An ◽  
Biao Gao ◽  
Tieshan Teng ◽  
...  

Abstract Background Renal ischemia-reperfusion injury (IRI) is a major cause of acute kidney injury. Hydrogen sulfide (H2S) exerts a protective effect in renal IRI. The present study was carried out to investigate the effects of exogenous H2S on renal IRI by regulating autophagy in mice. Methods Mice were randomly assigned to control, IRI, and NaHS (28, 56 and 100 µmol/kg) groups. Renal IRI was induced by clamping the bilateral renal pedicles for with non-traumatic arterial clamp for 45 min and then reperfused for 24 h. Mice were administered intraperitoneally with NaHS 20 min prior to renal ischemia. Sham group mice underwent the same procedures without clamping. Serum and kidney tissues were harvested 24 h after reperfusion for functional, histological, oxidative stress, and autophagic determination. Results Compared with the control group, the concentrations of serum creatinine (Scr), blood urea nitrogen (BUN), and malondialdehyde (MDA), the protein levels of LC3II/I, Beclin-1, and P62, as well as the number of autophagosomes were significantly increased, but the activity of superoxide dismutase (SOD) was decreased after renal IRI. NaHS pretreatment dramatically attenuated renal IRI-induced renal dysfunction, histological changes, MDA concentration, and p62 expression in a dose-dependent manner. However, NaHS increased the SOD activity and the protein levels of LC3II/I and Beclin-1. Conclusions These results indicate that exogenous H2S protects the kidney from IRI through enhancement of autophagy and reduction of oxidative stress. Novel H2S donors could be developed in the treatment of renal IRI.


2021 ◽  
Vol 11 ◽  
Author(s):  
Cheng-Yin Liu ◽  
Yi Zhou ◽  
Tao Chen ◽  
Jing-Chao Lei ◽  
Xue-Jun Jiang

Arctigenin, one of the active ingredients extracted from Great Burdock (Arctium lappa) Achene, has been found to relieve myocardial infarction injury. However, the specific mechanism of Arctigenin against myocardial infarction remains largely unknown. Here, both acute myocardial ischemia-reperfusion injury (AMI/R) rat model and oxygen glucose deprivation (OGD)-induced myocardial cell injury model were constructed to explore the underlying role of AMPK/SIRT1 pathway in Arctigenin-mediated effects. The experimental data in our study demonstrated that Arctigenin ameliorated OGD-mediated cardiomyocytes apoptosis, inflammation and oxidative stress in a dose-dependent manner. Besides, Arctigenin activated AMPK/SIRT1 pathway and downregulated NF-κB phosphorylation in OGD-treated cardiomyocytes, while inhibiting AMPK or SIRT1 by the Compound C (an AMPK inhibitor) or SIRT1-IN-1 (a SIRT1 inhibitor) significantly attenuated Arctigenin-exerted protective effects on cardiomyocytes. In the animal experiments, Arctigenin improved the heart functions and decreased infarct size of the AMI/R-rats, accompanied with downregulated oxidative stress, inflammation and apoptotic levels in the heart tissues. What’s more, Arctigenin enhanced the AMPK/SIRT1 pathway and repressed NF-κB pathway activation. Taken together, our data indicated that Arctigenin reduced cardiomyocytes apoptosis against AMI/R-induced oxidative stress and inflammation at least via AMPK/SIRT1 pathway.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Yoshinori Katsumata ◽  
Motoaki Sano ◽  
Tomohiro Matsuhashi ◽  
Atsushi Anzai ◽  
Cardex Yan ◽  
...  

Background: Lipocalin-type prostaglandin D synthase (L-PGDS) is abundantly expressed on cardiomyocytes. We recently demonstrated that dexamethasone stimulates PGD 2 -dominated activation of prostanoid biosynthesis, thereby protecting hearts against ischemia/reperfusion injury. Here, we examined the downstream signaling responsible for cardioprotection mediated through PGD 2 -dominated activation. Methods and Results: (1) In cultured neonatal rat cardiomyocytes, PGD 2 strongly activates ERK in a dose-dependent manner, although canonical PGD 2 receptors, including DP (PGD 2 receptor) and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells) receptors, are hardly expressed on cardiomyocytes. (2) Interestingly, PGD 2 bounds to FP receptor (the canonical PGF 2 α receptor) with an affinity comparable to that for the DP receptor, and the FP receptor is abundantly expressed on cardiomyocytes. (3) PGD 2 -induced ERK activation is completely blocked by FP antagonist or siRNA-mediated knockdown of the FP, but not by DP and CRTH2 antagonist and siRNA-mediated knockdown of DP and CRTH2. (4) PGD 2 activates ERK in Langendorff perfused DP-knock out (KO) and CRTH2-KO mice hearts to comparable levels as those observed for wild-type hearts, while cannot activate it in FP-KO hearts. (5) Consistently, the cardioprotective effect of PGD 2 -dominated activation by dexamethasone was blunted in FP KO hearts. (6) Furtermore, genomewide gene expression profiles by microarray analysis and quantitative real-time RT-PCR analysis identified that Nrf-2 was the downstream target of L-PGDS-mediated PGD 2 biosynthesis. (7) In cultured cardiomyocytes, FP agonist stimulated Nrf2 nuclear translocation and consequently induced Nrf2-target genes expression in an ERK-dependent manner. (8) Finally, The cardioprotective effect by dexamethasone was completely abolished in Nrf-2 KO hearts. Conclusion: FP serves as a functionally relevant PGD 2 receptor in the hearts and PGD 2 -FP signaling plays a substantial role in the improvement of functional recovery after ischemia-reperfusion injury in the heart. Nrf-2 is a major effector molecule responsible for the cardioprotecton elicited by L-PGDS-derived PGD 2 .


2013 ◽  
Vol 304 (9) ◽  
pp. H1215-H1224 ◽  
Author(s):  
Bridgette F. Peake ◽  
Chad K. Nicholson ◽  
Jonathan P. Lambert ◽  
Rebecca L. Hood ◽  
Hena Amin ◽  
...  

Hydrogen sulfide (H2S) therapy protects nondiabetic animals in various models of myocardial injury, including acute myocardial infarction and heart failure. Here, we sought to examine whether H2S therapy provides cardioprotection in the setting of type 2 diabetes. H2S therapy in the form of sodium sulfide (Na2S) beginning 24 h or 7 days before myocardial ischemia significantly decreased myocardial injury in db/db diabetic mice (12 wk of age). In an effort to evaluate the signaling mechanism responsible for the observed cardioprotection, we focused on the role of nuclear factor E2-related factor (Nrf2) signaling. Our results indicate that diabetes does not alter the ability of H2S to increase the nuclear localization of Nrf2, but does impair aspects of Nrf2 signaling. Specifically, the expression of NADPH quinine oxidoreductase 1 was increased after the acute treatment, whereas the expression of heme-oxygenase-1 (HO-1) was only increased after 7 days of treatment. This discrepancy was found to be the result of an increased nuclear expression of Bach1, a known repressor of HO-1 transcription, which blocked the binding of Nrf2 to the HO-1 promoter. Further analysis revealed that 7 days of Na2S treatment overcame this impairment by removing Bach1 from the nucleus in an Erk1/2-dependent manner. Our findings demonstrate for the first time that exogenous administration of Na2S attenuates myocardial ischemia-reperfusion injury in db/db mice, suggesting the potential therapeutic effects of H2S in treating a heart attack in the setting of type 2 diabetes.


2013 ◽  
Vol 119 (3) ◽  
pp. 687-697 ◽  
Author(s):  
Marie-Christine Ross-Huot ◽  
André Laferrière ◽  
Mina Khorashadi ◽  
Terence J. Coderre

Abstract Background: Ischemia–reperfusion injury causes chronic postischemia pain (CPIP), and rats with higher glycemia during ischemia–reperfusion injury exhibit increased allodynia. Glycemia-induced elevation of nuclear factor κB (NFκB) may contribute to increased allodynia. Methods: Glycemia during a 3-h ischemia–reperfusion injury was manipulated by: normal feeding; or normal feeding with administration of insulin; dextrose; or insulin/dextrose. In these groups, NFκB was measured in ipsilateral hind paw muscle and spinal dorsal horn by enzyme-linked immunosorbent assay (ELISA), and SN50, an NFκB inhibitor, was administered to determine its differential antiallodynic effects depending on glycemia. Results: CPIP fed/insulin rats (12.03 ± 4.9 g, N = 6) had less allodynia than fed, fed/insulin/dextrose, and fed/dextrose rats (6.29 ± 3.37 g, N = 7; 4.57 ± 3.03 g, N = 6; 2.95 ± 1.10 g, N = 9), respectively. Compared with fed rats (0.209 ± 0.022 AU, N = 7), NFκB in ipsilateral plantar muscles was significantly lower for fed/insulin rats, and significantly higher for fed/dextrose rats (0.152 ± 0.053 AU, N = 6; 0.240 ± 0.057 AU, N = 7, respectively). Furthermore, NFκB in the dorsal horn of fed, fed/insulin/dextrose, and fed/dextrose rats (0.293 ± 0.049 AU; 0.267 ± 0.037 AU; 0.315 ± 0.015 AU, respectively, N = 6 for each) was significantly higher than in fed/insulin animals (0.267 ± 0.037 AU, N = 6). The antiallodynic SN50 dose–response curves of CPIP rats in the fed/insulin/dextrose, fed/dextrose, and fed conditions exhibited a rightward shift compared with the fed/insulin group. The threshold SN50 dose of CPIP fed/dextrose, fed/insulin/dextrose, and fed rats (328.94 ± 92.4 ng, 77.80 ± 44.50 ng, and 24.89 ± 17.20 ng, respectively) was higher than that for fed/insulin rats (4.06 ± 7.04 ng). Conclusions: NFκB was activated in a glycemia-dependent manner in CPIP rats. Hypoglycemic rats were more sensitive to SN50 than rats with higher glycemia. The finding that SN50 reduces mechanical allodynia suggests that NFκB inhibitors might be useful for treating postischemia pain.


PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e115984 ◽  
Author(s):  
Felix Ulbrich ◽  
Nils Schallner ◽  
Mark Coburn ◽  
Torsten Loop ◽  
Wolf Alexander Lagrèze ◽  
...  

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