Effects of high glucose induced primary cardiomyocytes injury on necroptosis and the related mechanism / 中国应用生理学杂志

OBJECTIVE@#To observe whether necroptosis was happened in high glucose (HG) - induced primary cardiomyocytes injury and to investigate the likely mechanism.@*METHODS@#The primary cultured cardiomyocytes were divided into 4 groups (n=9): control group (the cardiomyocytes were incubated with 5.5 mmol/L glucose for 48 h), HG group (the cardiomyocytes were incubated with 30 mmol/L glucose for 48 h), HG + necrostatin-1 (Nec-1) group (the cardiomyocytes was co-incubated with necroptosis inhibitor Nec-1 at 100 μmol/L and HG for 48 h) and hypertonic pressure group (HPG, the cardiomyocytes was co-incubated with 5.5 mmol/L glucose and 24.5 mmol/L mannitol for 48 h). Cell viability was measured by MTT method, reactive oxygen species (ROS) generation was measured by DHE staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) were tested by ELISA method. The mRNA and protein expressions of necroptosis related genes receptor interacting serine/threonine protein kinase 1 (RIP1), RIP3, mixed lineage kinase domain-like protein (MLKL) were tested by quantitative real-time PCR and Western blot.@*RESULTS@#The results showed HG intervention decreased cardiomyocytes viability, increased ROS generation, up-regulated the levels of TNF-α, IL-6 and IL-1β, increased RIP1, RIP3, MLKL expressions at mRNA and protein levels. Nec-1 treatment attenuated HG-induced increased cardiomyocytes viability, reduced ROS generation, down-regulated the levels of TNF-α, IL-6 and IL-1β, decreased RIP1, RIP3, MLKL expressions at mRNA and protein levels.@*CONCLUSION@#Necroptosis was happened in high glucose-induced primary cardiomyocytes injury. Inhibition of necroptosis can reduce high glucose-induced cardiomyocytes damage, may be related to inhibition of oxidative stress and depression of inflammative factors releasing.

Effects of hydrogen sulfide on renal fibrosis in diabetic rats and its mechanism / 中国应用生理学杂志

OBJECTIVE@#To investigate the effects of hydrogen sulfide (HS) on renal fibrosis in diabetic rats and explore its mechanism.@*METHODS@#Male Sprague-Dawley rats were randomly divided into normal control (NC) group, a diabetic control (DC) group, diabetes mellitus (DM)+sodium hydrosulfide (NaHS) group and DM+DL-propargylglycine (PAG) group, with 8 rats in each group.Type 1 diabetes was induced in the respective groups by a single intraperitoneal (i.p.) injection of streptozotocin.From the fifth week, rats in the DM+NaHS and DM+PAG groups were injected (i.p.) with 56 μmol/kg NaHS and 40 mg/kg PAG once a day, respectively.After treatment for 4 weeks, the levels of fasting blood glucose (FBG), blood urea nitrogen (BUN) and serum creatinine (SCr) were detected.The deposition of renal collagen fibers was observed by Masson staining, and collagen volume fraction (CVF) was calculated.The ultrastructural change of renal tissue was observed by transmission electron microscopy.The levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and hydroxyproline (Hyp) in renal tissues were detected using the kits.The expression levels of TGF-β1, Smad3, phosphorylated (p)-Smad3 and collagen-IV (col-IV) in renal tissues were detected using Western blot.@*RESULTS@#Compared with the NC group, the levels of FBG, BUN, SCr, CVF, IL-1β, IL-6, TNF-α and Hyp were increased; the deposition of renal collagen fibers and the ultrastructural damage were aggravated; the levels of TGF-β1, Smad3, p-Smad3, p-Smad3/Smad3 and col-IV were increased in the DC group.Compared with the DC group, excluding FBG, the aforementioned indices were improved in the DM+NaHS group; the aforementioned indices were further aggravated in the DM+PAG group.@*CONCLUSIONS@#HS attenuated renal fibrosis in diabetic rats, and the mechanism might be associated with the reduction of the release of proinflammatory cytokines, downregulation of the TGF-β1/Smad3 pathway, and inhibition of excessive accumulation of col-IV.

Effect of hydrogen sulfide on oxidative stress and endoplasmic reticulum stress in diabetic cardiomyopathy / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of hydrogen sulfide (H₂S) on oxidative stress and endoplasmic reticulum stress (ERS) in a rat model of diabetic cardiomyopathy (DCM).</p><p><b>METHODS</b>Thirty male SD rats were randomly divided into control group, diabetes group and treatment group( n = 10). Intraperitoneal injection of streptozotocin was utilized to establish a rat model of DCM. The rats with DCM in treatment group were intraperitoneally injected with NaHS solution. After treated for 12 weeks, the hearts isolated from rats were perfused on a langendorff apparatus. The ventricular hemodynamic parameters were measured. The ultrastructures of myocardium were observed using electron microscopy. The content of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in myocardial tissue were determined by spectrophotometry. The expressions of C/EBP homologous protein( CHOP), glucose-regulated protein 78 (GRP78) and Caspase 12 at mRNA level in myocardium were detected using RT-PCR.</p><p><b>RESULTS</b>Compared with control group, the cardiac function and myocardial ultrastructure were damaged obviously in diabetic rats. In myocardial tissue, the content of MDA was increased, while the activities of SOD and GSH-Px were decreased. CHOP, GRP78 and Caspase 12 mRNA expressions were increased significantly. Compared with diabetes group, cardiac function and myocardial ultrastructure damage were improved in treatment group. The content of MDA was decreased, while the activities of SOD and GSH-Px were increased significantly. The mRNA levels of CHOP, GRP78 and Caspase 12 were increased.</p><p><b>CONCLUSION</b>H2S can protect myocardium in diabetic rats, maybe it is related to reduce oxidative stress damage and inhibition of the ERS-induced apoptosis pathway.</p>