Moderate-intensity exercise allows enhanced protection against oxidative stress-induced cardiac dysfunction in spontaneously hypertensive rats

The progression of myocardial injury secondary to hypertension is a complex process related to a series of physiological and molecular factors including oxidative stress. This study aimed to investigate whether moderate-intensity exercise (MIE) could improve cardiac function and oxidative stress in spontaneously hypertensive rats (SHRs). Eight-week-old male SHRs and age-matched male Wistar-Kyoto rats were randomly assigned to exercise training (treadmill running at a speed of 20 m/min for 1 h continuously) or kept sedentary for 16 weeks. Cardiac function was monitored by polygraph; cardiac mitochondrial structure was observed by scanning electron microscope; tissue free radical production was measured using dihydroethidium staining. Expression levels of SIRT3 and SOD2 protein were measured by western blot, and cardiac antioxidants were assessed by assay kits. MIE improved the cardiac function of SHRs by decreasing left ventricular systolic pressure (LVSP), and first derivation of LVP (+LVdP/dtmax and −LVdP/dtmax). In addition, exercise-induced beneficial effects in SHRs were mediated by decreasing damage to myocardial mitochondrial morphology, decreasing production of reactive oxygen species, increasing glutathione level, decreasing oxidized glutathione level, increasing expression of SIRT3/SOD2, and increasing activity of superoxide dismutase. Exercise training in SHRs improved cardiac function by inhibiting hypertension-induced myocardial mitochondrial damage and attenuating oxidative stresses, offering new insights into prevention and treatment of hypertension.

Influence of cyanide p-trifluoromethoxyphenyl-hydrazone on insulin sensitivity and mitochondrial function in 3T3-L1 adipocytes / 中华实用儿科临床杂志

Objective To observe the effect of uncoupler of mitochondrial oxidative phosphorylation——Cyanide p-trifluoromethoxyphenyl-hydrazone (FCCP) on mitochondrial function and insulin sensitivity in mature adipocytes.Me-thods 3T3-L1 pre-adipocytes were differentiated into mature adipocytes and then induced and maintained in medium that contained the chemical uncoupler 7.5 μmol/L FCCP.Glucose uptake was determined in the adipocytes by measu-ring 2-deoxy-D-[3H] glucose uptake.Western blot was used to detect the translocation of insulin-sensitive glucose transporter 4 (GLUT4) and measure the phosphorylation and total protein contents of insulin signaling proteins such as insulin receptor substrate(IRS)-1,Akt.The mitochondrial morphology was performed by transmission electron microscope.The mitochondrial DNA (mtDNA) copy number was evaluated by real time PCR.Luciferase-based luminescence assay was used to determine cellular ATP production.The mitochondrial membrane potential(△Ψm) and reactive oxygen species(ROS) were detected by flow cytometry.Results (1) Exposure of mature adipocytes to FCCP basal glucose uptake was similar to mature adipocytes without FCCP(t =-0.07,P ＞ 0.05) ; however,the insulin-stimulated glucose uptake was significantly decreased in FCCP group (t =5.87,P ＜ 0.01).(2)FCCP decreased insulin-stimulated GLUT4 translocation to the plasmalemma and inhibition of insulin-induced phosphorylation of IRS-1 and Akt in 3T3-L1 adipocytes.(3)The size of mitochondria in FCCP-treated adipocytes was smaller than that in 3T3-L1 adipocytes without FCCP,and the morphology was condensed and abnormal.(4) mtDNA copy number in FCCP-treated adipocytes was significantly lower than that in adipocytes without FCCP(t =-1.73,P ＜ 0.001).(5) Exposure of 3T3-L1 adipocytes to FCCP significantly decreased △Ψm (t =4.83,P ＜ 0.01) and total cellular ATP production compared with cells without FCCP (t =6.08,P ＜ 0.0001),as well as the increased intracellular ROS levels (t =-6.82,P ＜ 0.01).Conclusions FCCP may impair mitochondrial morphology and mitochondrion dysfunction,and inhibited the activation of insulin-induced phosphorylation of IRS-1 and Akt in 3T3-L1 adipocytes,which suggests that FCCP-induced insulin resistance may be correlated with the FCCP induced generation of ROS in 3T3-L1 adipocytes.

Protective effect of neuroglobin on retinal ganglion cell in glaucoma mice model / 中华实验眼科杂志

Background Neuroglobin (Ngb) is a newly discovered member of globin superfamily.It is thought to regulate cell survival under hypoxia or oxidative stress condition.Ngb is expressed at a high level in retinal neuron,suggesting that retina may be one of important functional sites of Ngb.Objective The aim of this study was to investigate the protective role of endogenous Ngb on retina ganglion cells (RGCs) following chronic high intraocular pressure(IOP)in mice and the underlying mechanisms.Methods This study included the in vitro and in vivo experiment.RGCs derived from adult C57BL/6J wild type(WT) mice and Ngb-transgenic(Ngb-Tg) mice which cultivated by our laboratory were incubated with 5.0,7.5,10.0 mmol/L glutamic acid for 3 days.RGCs survival rate was calculated for the ration of dead and survival cells using a double labeling kit to evaluate the influence of Ngb on RGCs survival rate in the addition of glutamic acid.Chronic ocular hypertension models were established by injection of fluorescent microballon(MB) (10 μm)into the anterior chamber of WT mice and Ngb-Tg mice,The mice were divided into WT control group(n=18),Ngb-Tg control group(n=30),WT+MB single injection group(n=38),Ngb-Tg+MB single injection group (n =38),WT+MB twice injection group (n =6) and Ngb-Tg + twice injection group (n=6).In addition,WT+PBS injection group (n =6) and Ngb-Tg+ PBS injection group (n =6) were designed as negative controls to identify if it can affect IOP or not.The mice were sacrificed on 0 day(control group),3 days and 1,4,8 weeks followed the MB anterior chamber injection.Real-time PCR,Western blot and immunoytochemistry were used respectively for the analysis of the expressions of Ngb mRNA and protein in mouse retina,and the survival rates of RGCs were compared between the two types mice.Dihydroethidium (DHE) in retina was detected after cardiac perfusion and ATP level in mouse retina homogenate was analyzed.Results The RGCs survival rate was significantly higher in Ngb mice compared with WT mice in 5.0,7.5 and 10.0 mmol/L glutamic acid treatcd groups (t =2.810,3.020,3.110,P＜ 0.01).IOP of WT+ MB single injection group and Ngb-Tg+ MB single injection group were elevated in comparison with the WT control group and WT+PBS injection group and the high IOP remained for 4 weeks.Ngb level was raised in the WT+MB single injection group on the third day following injection,but the Ngb concentration remained a high level in the Ngb-Tg mice during the period of the experiment duration.The RGCs apoptosis rate was elevated both in the WT mice and Ngb-Tg mice 1,4,8 weeks after injection of MB,however,the cell apoptosis rate was higher in WT mice than that of Ngb-Tg mice(P＜0.05).DHE content in retina in the Ngb-Tg+MB single injection group was significantly lower than that in the WT+MB single injection group (t =3.212,P=0.008),and ATP content in retina was elevated in the Ngb-Tg+MB single injection group compared with WT+MB single injection group(t =2.864,P＜0.01).Conclusions It is suggested that Ngb might be a neuroprotective molecules against RGCs death by decreasing oxidative stress and improving mitochondria function.

The damaging effect of sulfur mustard on the mitochondria in rat lymphocytes in vitro / 第三军医大学学报

Objective To investigate the damaging effect of sulfur mustard on the mitochondria in rat lymphocytes in vitro.Methods Rat spleen lymphocytes were isolated by density gradient centrifugation and cultured with 100 ?mol/L sulfur mustard in vitro.DNA ladderring was used to detect the cell apoptosis.Cyt-c release was measured by Western blotting.The mitochondria function was detected by MTT method.Fluorescent probe labeled with Rhodamine 123 was used to study mitochondria potential.Results The mitochondria potential and cell viability decreased at 4 h after treated with 100 ?mol/L sulfur mustard.There was a liner correlation between the mitochondria potential and cell viability in lymphocytes.The content of Cyt-c increased significantly at 4 h as compared with control group in Western blotting.Conclusion Sulfur mustard could damage the rat lymphocyte mitochondria significantly,and mitochondria participates in cytotoxic effect induced by the sulfur mustard.

Antagonizing effects of GSH against rat lymphocytotoxicity induced by sulfur mustard / 第三军医大学学报

Objective To investigate the protective effects of GSH on the mitochondria in rat lymphocyte in vitro.Methods Rat spleen lymphocytes were isolated by density gradient centrifugation and cultured with sulfur mustard of 100,500,1000 ?mol/L in vitro.The mitochondria function was detected by MTT.The changes of GSH were detected by fluorescence spectrophotometry and DNA fragments were also detected.Results There was a positive line correlation between the changes of mitochondria function and the GSH content(P