Propargylglycine Group Research Articles

Hydrogen Sulfide Protects Against Uremic Accelerated Atherosclerosis via nPKCδ/Akt Signal Pathway.

Background: Cardiovascular disease is the most common complication and leading cause of death in maintenance hemodialysis patients. Previous studies have found that disorders of cystathionine-gamma-lyase/hydrogen sulfide (CSE/H2S) system in maintenance hemodialysis patients are correlated with the risk of cardiovascular disease. Although the role of CSE/H2S system in UAAS has been preliminarily explored, the molecular mechanism of CSE/H2S is still not systematically elaborated, and the molecular mechanism of nPKCδ and its related signaling pathway in UAAS is still not thoroughly studied. Methods: Forty chronic kidney disease (CHD) patients were studied and the activation of nPKCδ in peripheral blood mononuclear cells (PBMCs) were detected. ApoE−/− mice aged 6 weeks were treated with 5/6 nephrectomy and high-fat diet to make UAAS model. They were divided into Sham group (Sham group), UAAS group (UAAS group), UAAS+L-cysteine group (UAAS+L-cys group), UAAS+sodium hydrosulfide group (UAAS+NaHS group) and UAAS+propargylglycine group (UAAS+PPG group). The UAAS+L-cys group, UAAS+NaHS group and UAAS+PPG group were respectively given L-cys, NaHS and PPG by intraperitoneal injection. The aorta was taken 6 weeks after surgery. Western blot was used to detect the activation of nPKCδ, the phosphorylation of Akt, and the expression of VCAM-1 in the aorta of mice. Results: The membrane translocation of nPKCδ in CHD patients with plaque was higher than that in CHD patients without plaque. The membrane translocation of nPKCδ and the expression of VCAM-1 in UAAS group was higher than sham group, L-cys or NaHS injection could suppress the membrane translocation of nPKCδ and the expression of VCAM-1, but PPG treatment resulted in more membrane translocation of nPKCδ and the expression of VCAM-1 (P<0.05, n=6 per group). Akt phosphorylation in UAAS group was lower than sham group, and L-cys or NaHS injection could suppress the degradation of Akt phosphorylation, but PPG treatment resulted in more decrease in the Akt phosphorylation (P<0.05, n=6 per group). Conclusion: Endogenous CSE/H2S system protected against the formation of UAAS via nPKCδ/Akt signal pathway. The imbalance of CSE/H2S system may participate in the formation of UAAS by affecting the expression of downstream molecule VCAM-1, which may be mediated by nPKCδ/Akt signaling pathway.

CSE/H2S system alleviates uremic accelerated atherosclerosis by regulating TGF-\u03b2/Smad3 pathway in 5/6 nephrectomy ApoE\u2212/\u2212 mice

BackgroundHydrogen sulfide (H2S) has been shown to inhibit the atherosclerosis development and progression. It is produced by cystathionine γ-lyase (CSE) in the cardiovascular system. In our previous study, it has been shown that CSE/H2S system plays a significant role in the changes of uremic accelerated atherosclerosis (UAAS), but the mechanism is not known clearly.MethodsIn this study, we explored the antagonism of CSE/H2S system in UAAS and identified its possible signaling molecules in ApoE−/− mice with 5/6 nephrectomy and fed with atherogenic diet. Mice were divided into sham operation group (sham group), UAAS group, sodium hydrosulfide group (UAAS+NaHS group) and propargylglycine group (UAAS+PPG group). Serum creatinine, urea nitrogen, lipid levels and lesion size of atherosclerotic plaque in the aortic roots were analyzed. Meanwhile, the expression of CSE, TGF-β and phosphorylation of Smad3 were detected.ResultsCompared with sham group, the aortic root of ApoE−/− mice in the UAAS group developed early atherosclerosis, the levels of total cholesterol, triglyceride, low-density lipoprotein-cholesterol, serum creatinine and urea nitrogen were also higher than that in the sham group. NaHS administration can inhibit the development of atherosclerosis, but PPG administration can accelerate the atherosclerosis development. Meanwhile, the protein expression levels of CSE and TGF-β and phosphorylation of Smad3 significantly decreased in the UAAS mice. Treatment of UAAS mice with NaHS inhibited TGF-β protein expression and Smad3 phosphorylation decrease, but PPG treatment had the opposite effect.ConclusionsThe CSE/H2S system is of great importance for treating atherosclerosis in patients with chronic kidney disease, and it may protect the vascular from atherosclerosis through the TGF-β/Smad pathway.

Molecular mechanisms of hydrogen sulfide against uremic accelerated atherosclerosis through cPKC\u03b2II/Akt signal pathway

BackgroundCardiovascular disease is the most common complication and leading cause of death in maintenance hemodialysis patients. The protection mechanism of hydrogen sulfide (H2S) and the specific role of conventional protein kinase C βII (cPKCβII)/Akt signaling pathway in the formation of atherosclerosis is still controversial.Methods8-week-old male ApoE−/− mice were treated with 5/6 nephrectomy and high-fat diet to make uremia accelerated atherosclerosis (UAAS) model. Mice were divided into normal control group (control group), sham operation group (sham group), UAAS group, L-cysteine group (UAAS+L-cys group), sodium hydrosulfide group (UAAS+NaHS group), and propargylglycine group (UAAS+PPG group). Western blot was used to detect cPKCβII activation, Akt phosphorylation and endothelial nitric oxide synthase (eNOS) expression in mice aorta.ResultsThe membrane translocation of cPKCβII in UAAS group was higher than sham group, and L-cys or NaHS injection could suppress the membrane translocation, but PPG treatment resulted in more membrane translocation of cPKCβII (P < 0.05, n = 6 per group). Akt phosphorylation and the eNOS expression in UAAS group was lower than sham group, and L-cys or NaHS injection could suppress the degradation of Akt phosphorylation and the eNOS expression, but PPG treatment resulted in more decrease in the Akt phosphorylation and the eNOS expression (P < 0.05, n = 6 per group).ConclusionEndogenous cystathionine-γ-lyase (CSE)/H2S system protected against the formation of UAAS via cPKCβII/Akt signal pathway. The imbalance of CSE/H2S system may participate in the formation of UAAS by affecting the expression of downstream molecule eNOS, which may be mediated by cPKCβII/Akt signaling pathway.

Significance of hydrogen sulfide in sepsis-induced myocardial injury in rats.

Sepsis-induced myocardial injury is a detrimental disorder for intensive care medicine due to its high rates of morbidity and mortality. Data suggest that nuclear factor (NF)-κB serves a critical role in the pathogenesis of myocardial injury. Hydrogen sulfide (H2S) serves an important role in the physiology and pathophysiology of regulatory mechanisms, particularly during an inflammatory reaction. However, the relationship between NF-κB and H2S in sepsis-induced myocardial injury is not well understood, and the underlying mechanisms remain unclear. In the present study, 60 male Sprague Dawley rats were randomly divided into the following six groups: A sham group, cecal ligation and puncture (CLP) group, sham + propargylglycine (PAG) group, CLP + PAG group, sham + sodium hydrosulfide (NaHS) group and CLP + NaHS group, with 10 rats in each group. The rats in all groups were sacrificed 12 h after surgery for sample collection. Compared with the sham group, it was observed that the concentrations of Creatine Kinase-MB (CK-MB) and cardiac troponin I (cTnI) in the serum, and pathological scores of myocardial tissue were significantly increased in the CLP, CLP + NaHS and CLP + PAG groups (P<0.05). The pathological scores and concentrations of CK-MB and cTnI were significantly higher in the CLP + PAG group (P<0.05) and significantly lower in the CLP + NaHS group (P<0.05) when compared with the CLP group. The expression of cystathionine-γ-lyase (CSE) mRNA and content of interleukin (IL)-10 were significantly higher in the CLP group compared with the CLP + PAG group (P<0.05), while the expression of myocardial NF-κB and content of tumor necrosis factor (TNF)-α in the CLP group were significantly lowered compared with the CLP + PAG group (P<0.05). The expression of NF-κB and content of TNF-α were significantly increased in the CLP group when compared with the CLP + NaHS group (P<0.05), while the content of myocardial IL-10 in the CLP group was significantly lower than in the CLP + NaHS group (P<0.05). In conclusion, H2S acted as an anti-inflammatory cytokine and biomarker in sepsis-induced myocardial injury. Furthermore, H2S may downregulate the NF-κB subunit p65 to mediate inflammatory responses. The present data suggest that myocardial injury in sepsis may be relieved through the regulation of H2S expression, and provide an experimental basis for the treatment of sepsis patients presenting with myocardial injury. In addition, myocardial injury in sepsis may be identified by monitoring changes in the expression of H2S.

Regulation of hydrogen sulfide on transporter protein Bsep and Mdr2 in acute liver failure

To observe the effect of hydrogen sulfide on Bsep and Mdr2 in acute liver failure induced by thioacetamide. Twenty-four male SD rats were randomly divided into thioacetamide (TAA) induced model group (n=6), control group (n=6), TAA+sodium hydrosulfide group (n=6), and TAA+ propargylglycine group (n=6). TAA was given to enterocoelia at the dose of 600 mg/kg for the model group, sodium hydrosulfide group and propargylglycine group rats.Sodium hydrosulfide with the dose of 0.15 mmol/kg and propargylglycine of 30 mg/kg was injected into enterocoelia one hour before the TAA used. All rats were sacrificed and serum specimen was collected to test hydrogen sulfide and hepatic function. The method of Western blot and Immunohistochemistry were used to measure the expression of Bsep and Mdr2 in the liver. The Liver function of TAA group rats was severely injured [ALT(524.0±32.0) vs (28.3±8.4) U/L]. It was worsen by application of sodium hydrosulfide [ALT(861.9±55.1) U/L] while recovered [ALT(59.5±10.2) U/L)] by propargylglycine. The level of bilirubin and bile acid was significantly higher in the TAA group rats than in the normal control group, and the application of sodium hydrosulfide caused bile acids increased further besides of bilirubin. On the contrary, the levels of bile acids and bilirubin were significantly decreased with PPG application. The level of hydrogen sulfide in the serum of the TAA group rats was higher than normal group rats'. That was elevated by sodium hydrosulfide and decreased by propargylglycine.Severely edema, necrosis and inflammatory cell infiltration were observed in TAA group rats, which worse by sodium hydrosulfide and released by propargylglycine. The expression of Bsep and Mdr2 down regulated in TAA and deteriorated by sodium hydrosulfide application and relieved by propargylglycine application. Hydrogen sulfide exacerbated the Bsep and Mdr2 loss in the liver failure and contributed to high serum concentration of bile acids.

Impact of endogenous hydrogen sulfide on toll-like receptor pathway in renal ischemia/reperfusion injury in rats

In this study, we investigated the impact of endogenous hydrogen sulfide (H2S) on toll-like receptors (TLRs)-mediated inflammatory response and apoptosis in renal ischemia–reperfusion injury (IRI). Twenty-four male Wistar rats were randomly divided into four groups: sham, IR, IR + propargylglycine (PAG) and IR + hydroxylamine (HA). After right nephrectomy, rats were given saline for the sham and IR group, PAG for the IR + PAG group and HA for the IR + HA group, through the left renal artery for 20 min. Five minutes after drug administration, all rats except sham underwent 45 min of left renal ischemia followed by 24 h of reperfusion. Kidneys were harvested for histological and biochemical evaluation. Levels of TLRs, downstream signaling molecules and pro-inflammatory cytokines were determined by Western blot or immunohistochemistry. Hematoxylin and eosin (H&E) stained renal sections were used for histological grading of renal injury. Apoptotic cells were detected by TUNEL assay. Compared to the sham group, rats in the IR group showed higher renal levels of TLR-2, TLR-4, nuclear NF-κB p65, phosphorylated ASK1, phosphorylated TRAF2, IL-1β, IL-6, IL-18 and TNF-α (p < 0.05), and exhibited acute kidney injury (p < 0.05) and apoptosis (p < 0.05). Compared to the IR group, rats receiving PAG or HA showed significantly higher levels of TLR-2, TLR-4, nuclear NF-κB p65, phosphorylated ASK1, phosphorylated TRAF2, IL-1β, IL-6, IL-18 and TNF-α (p < 0.01), more severe acute kidney injury (p < 0.05) and increased apoptosis (p < 0.01). Thus, inflammatory response and apoptosis mediated by TLRs are involved in renal IRI. Inhibition of endogenous H2S significantly activated inflammatory response and apoptosis, and thus promoted renal IRI.