吴茱萸次碱通过SIRT1通路干预氧化应激诱导血管平滑肌细胞增殖的作用

目的观察吴茱萸次碱通过沉默信息调节因子(SIRT)1通路干预氧化应激诱导大鼠血管平滑肌细胞(VSMCs)增殖作用。方法原代培养大鼠VSMCs,用叔丁基过氧化氢(t-BHp)诱导VSMCs增殖。缩胆囊素八肽(CCK-8)法检测各组细胞增殖率;分光光度计检测细胞内超氧化物歧化酶(SOD)及丙二醛(MDA)含量;荧光分光计检测活性氧(ROS)水平;RT-PCR法检测吴茱萸次碱对SIRT1 mRNA表达的影响;Western印迹法测SIRT1蛋白的表达量,并运用EX-527抑制SIRT1的表达。结果与空白组比较,t-BHp组SOD含量显著降低,MDA含量显著升高,SOD水平显著升高,SIRT1 mRNA与蛋白的表达显著下降(均P0.05);与tBHp组比较,吴茱萸次碱组SOD含量显著升高,MDA含量显著降低,SOD水平显著降低,SIRT1 mRNA与蛋白的表达显著上升(均P0.05);与吴茱萸次碱组比较,EX-527组SOD含量显著降低,MDA含量显著升高,SOD水平显著升高,SIRT1 mRNA与蛋白的表达显著下降(均P0.05)。结论吴茱萸次碱可通过上调SIRT1表达提高抗细胞增殖的能力,抑制t-BHp诱导细胞内ROS生成、提高抗氧化能力,发挥保护血管的生物效应。     

PI3K/Akt信号通路与神经保护

PI3K/Akt通路是由磷脂酰肌醇3-激酶(phosphatidylinositol 3-kinase,PI3K)始动的生物信号转导通路,在细胞增殖、细胞周期调控、凋亡启动、血管生成等方面发挥着关键作用.此外,PI3K/Akt通路还与中枢神经系统损伤的保护机制密切相关.深入研究PI3K/Akt、下游分子及其调控机制可能为脑损伤的治疗提供新的思路和方法.     

Celiprolol activates eNOS through the PI3K-Akt pathway and inhibits VCAM-1 Via NF-kappaB induced by oxidative stress

Vascular cell adhesion molecule-1 (VCAM-1) and reactive oxygen species play critical roles in early atherogenesis, and nitric oxide (NO) is an important regulator of the cardiovascular system. Although celiprolol, a specific beta1-antagonist with weak beta2-agonistic action, stimulates endothelial nitric oxide synthase (eNOS) production, the mechanisms remain to be determined. Because it was recently reported that phosphatidylinositol 3-kinase (PI3K) and its downstream effector Akt are implicated in the activation of eNOS and that regulation of VCAM-1 expression is mediated via nuclear factor-kappaB (NF-kappaB), we hypothesized that celiprolol activates phosphorylation of eNOS through the PI3K-Akt signaling pathway; that celiprolol modulates VCAM-1 expression, which is associated with inhibiting NF-kappaB phosphorylation; and that celiprolol suppresses NAD(P)H oxidase p22phox, p47phox, gp91phox, and nox1 expression in the left ventricle of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. eNOS and Akt phosphorylation upregulated by celiprolol alone were suppressed by treatment with celiprolol plus wortmannin. Increased expression of VCAM-1, p22phox, p47phox, gp91phox, nox1, activated p65 NF-kappaB, c-Src, p44/p42 extracellular signal-regulated kinases, and their downstream effector p90 ribosomal S6 kinase phosphorylation in DOCA rats was inhibited by celiprolol. Celiprolol administration resulted in a significant improvement in cardiovascular remodeling and suppression of transforming growth factor-beta1 gene expression. In conclusion, celiprolol suppresses VCAM-1 expression because of inhibition of oxidative stress, NF-kappaB, and signal transduction, while increasing eNOS via stimulation of the PI3K-Akt signaling pathway and improving cardiovascular remodeling.     

鸢尾素通过抑制氧化应激减轻高糖/高脂诱导的人脐静脉内皮细胞损伤

目的 研究鸢尾素（irisin）是否通过抑制氧化应激减轻高糖/高脂所致心肌细胞损伤。方法 将培养的人脐静脉内皮细胞（Human umbilical vein endothelial cells,HUVECs）分为3组:正常对照组、高糖/高脂组及高糖/高脂+irisin组。各组培养24 h后检测细胞存活率、凋亡率、ROS产量、NADPH氧化酶gp91phox表达水平。结果 与正常对照组相比,高糖/高脂组细胞存活率显著下降,ROS产量、NADPH氧化酶gp91phox表达水平、细胞凋亡率显著升高(均P<0.05),irisin处理可以逆转上述改变（均P<0.05）。结论 高糖/高脂能够增加人脐静脉内皮细胞氧化应激,促进细胞凋亡;irisin可通过减轻氧化应激而发挥内皮保护作用。     

IGF-1 defends against chronic-stress induced depression in rat models of chronic unpredictable mild stress through the PI3K/Akt/FoxO3a pathway

This study aims to investigate the role of IGF-1 in chronic-stress induced depression through the PI3K/Akt/FoxO3a pathway. A rat model of chronic unpredictable mild stress (CUMS) was established. In total, 48 rats were randomized into control (normal rats), CUMS (CUMS modeled rats) and CUMS + IGF-1 (injection of IGF-1 before CUMS modeling) groups. Body weight, horizontal (number of horizontal crossing) and vertical activity (rearing times), and sucrose consumption were identified one day before and after the open-field test. The mRNA and protein expression of PI3K, Akt, FoxO3a and Bim in the hippocampus was measured by RT-qPCR and Western blotting, respectively. Compared with the control group, a lower body weight, a decreased number of horizontal crossings, reduced rearing times and lower sucrose consumption were observed in the CUMS and CUMS + IGF-1 groups after the test. However, a higher body weight, number of horizontal crossings, rearing times and sucrose consumption were found in the CUMS + IGF-1 group than those in the CUMS group. Compared with the control group, mRNA and protein expression of PI3K, Akt and FoxO3a was decreased, and Bim mRNA and protein expression was increased in the CUMS + IGF-1 and CUMS groups. Meanwhile, in comparison to the CUMS group, mRNA and protein expression of PI3K, Akt and FoxO3a was elevated, and Bim mRNA and protein expression was reduced in the CUMS + IGF-1 group. The results suggested that IGF-1 exerted an antidepressant-like effect on chronic-stress induced depression through the PI3K/Akt/FoxO3a pathway.     

Melatonin protects against thoracic aortic aneurysm and dissection through SIRT1-dependent regulation of oxidative stress and vascular smooth muscle cell loss

Melatonin functions as an endogenous protective molecule in multiple vascular diseases, whereas its effects on thoracic aortic aneurysm and dissection (TAAD) and underlying mechanisms have not been reported. In this study, TAAD mouse model was successfully induced by β-aminopropionitrile fumarate (BAPN). We found that melatonin treatment remarkably prevented the deterioration of TAAD, evidenced by decreased incidence, ameliorated aneurysmal dilation and vascular stiffness, improved aortic morphology, and inhibited elastin degradation, macrophage infiltration, and matrix metalloproteinase expression. Moreover, melatonin blunted oxidative stress damage and vascular smooth muscle cell (VSMC) loss. Notably, BAPN induced a decrease in SIRT1 expression and activity of mouse aorta, whereas melatonin treatment reversed it. Further mechanistic study demonstrated that blocking SIRT1 signaling partially inhibited these beneficial effects of melatonin on TAAD. Additionally, the melatonin receptor was involved in this phenomenon. Our study is the first to report that melatonin exerts therapeutic effects against TAAD by reducing oxidative stress and VSMC loss via activation of SIRT1 signaling in a receptor-dependent manner, thus suggesting a novel therapeutic strategy for TAAD.     

Melatonin protects against diabetic cardiomyopathy through Mst1/Sirt3 signaling

This study investigated the effects of melatonin on diabetic cardiomyopathy (DCM) and determined the underlying mechanisms. Echocardiography indicated that melatonin notably mitigated the adverse left ventricle remodeling and alleviated cardiac dysfunction in DCM. The mechanisms were attributed to increased autophagy, reduced apoptosis, and alleviated mitochondrial dysfunction. Furthermore, melatonin inhibited Mst1 phosphorylation and promoted Sirt3 expression in DCM. These results indicated that melatonin may exert its effects through Mst1/Sirt3 signaling. To verify this hypothesis, a DCM model using Mst1 transgenic (Mst1 Tg) and Mst1 knockout (Mst1^?/?) mice was constructed. As expected, melatonin increased autophagy, reduced apoptosis and improved mitochondrial biogenesis in Mst1 Tg mice subjected to DCM injury, while it had no effects on Mst1^?/? mice. In addition, cultured neonatal mouse cardiomyocytes were subjected to simulated diabetes to probe the mechanisms involved. Melatonin administration promoted autophagic flux as demonstrated by elevated LC3‐II and lowered p62 expression in the presence of bafilomycin A1. The results suggest that melatonin alleviates cardiac remodeling and dysfunction in DCM by upregulating autophagy, limiting apoptosis, and modulating mitochondrial integrity and biogenesis. The mechanisms are associated with Mst1/Sirt3 signaling.     

MiR-384对HFFA诱导的Hepa1-6细胞sirt3/FOXO1信号通路的影响*

目的 观察MiR-384对HFFA诱导的Hepa1-6细胞sirt3/FOXO1信号通路的影响。方法 取Hepa1-6细胞,加入OA和PA储存液,使两者终浓度分别为1 mmol/L和0.5 mmol/L,培养24 h,建立非酒精性脂肪性肝炎体外细胞模型。测定肝细胞内活性氧水平评估模型建立的情况。分别以miR-384模拟物、miR-ctrl、miR-384抑制剂、miR-384抑制剂-ctrl、沉默信息调节因子3（Sirt3）或si-ctrl转染细胞48 h。使用FCM测定各组细胞ROS水平,采用Western blot法检测各组细胞sirt3、FOXO1及抗氧化蛋白锰超氧化物歧化酶（MnSOD）和抗氧化蛋白过氧化氢酶（CAT）表达,采用专用试剂盒检测SOD和CAT活性。结果 与正常组（0.66±0.01）比,miR-384模拟物组和si-sirt3组细胞内活性氧（ROS）水平显著升高[分别为（37.3±1.13）和（10.4±0.36）,P<0.01];与HFFA组（29.4±0.98）比,HFFA/miR-384抑制剂组细胞 ROS水平显著降低[（12.8±0.41）,P<0.01];与正常组（0.75±0.04）Hepa1-6细胞sirt3蛋白表达水平比,HFFA组显著降低[（0.23±0.01）,P<0.01];与HFFA组比,HFFA/sirt3组显著增加[（0.83±0.03）,P<0.01];与HFFA/sirt3组比,HFFA/sirt3/miR-384组显著降低[（0.46±0.02）,P<0.01];与对照组比, miR-384模拟物组Hepa1-6细胞sirt3蛋白、Forkhead 转录因子O亚家族( FOXO)成员 FOXO1蛋白表达显著减少[分别为（0.2±0.01）和（0.3±0.01）,P<0.01],而CAT和MnSOD表达显著增加[分别为（2.3±0.05）和（2.4±0.06）,P<0.01];与HFFA组比,HFFA/ miR-384抑制剂组Hepa1-6细胞sirt3蛋白和FOXO1蛋白表达显著增加[分别为（0.5±0.02）和（0.7±0.01）,P <0.01],MnSOD和CAT表达水平显著降低[分别为（1.6±0.04）和（2.0±0.03）,P<0.01];与NAFLD组SOD（327±3.45）和CAT（386±4.03）活性比,正常组SOD和CAT[分别为（425±5.49）和（512±6.04）,P<0.01]和 miR-384抑制剂组SOD和CAT活性[分别为（406±4.79）和（447±5.38）,P<0.01]显著升高。结论 miR-384表达可导致HFFA诱导的Hepa1-6细胞氧化损伤加重,部分可能是通过抑制sirt3/FOXO1途径实现的。     

Attenuation of atrial remodeling by aliskiren via affecting oxidative stress,inflammation and PI3K/Akt signaling pathway

Cardiovascular Drugs and Therapy - Atrial fibrillation (AF) is the most common type of arrhythmia. Atrial remodeling is a major factor to the AF substrate. The purpose of the study is to explore...     

Melatonin ameliorates myocardial ischemia reperfusion injury through SIRT3‐dependent regulation of oxidative stress and apoptosis

Sirtuins are a family of highly evolutionarily conserved nicotinamide adenine nucleotide‐dependent histone deacetylases. Sirtuin‐3 (SIRT3) is a member of the sirtuin family that is localized primarily to the mitochondria and protects against oxidative stress‐related diseases, including myocardial ischemia/reperfusion (MI/R) injury. Melatonin has a favorable effect in ameliorating MI/R injury. We hypothesized that melatonin protects against MI/R injury by activating the SIRT3 signaling pathway. In this study, mice were pretreated with or without a selective SIRT3 inhibitor and then subjected to MI/R operation. Melatonin was administered intraperitoneally (20 mg/kg) 10 minutes before reperfusion. Melatonin treatment improved postischemic cardiac contractile function, decreased infarct size, diminished lactate dehydrogenase release, reduced the apoptotic index, and ameliorated oxidative damage. Notably, MI/R induced a significant decrease in myocardial SIRT3 expression and activity, whereas the melatonin treatment upregulated SIRT3 expression and activity, and thus decreased the acetylation of superoxide dismutase 2 (SOD2). In addition, melatonin increased Bcl‐2 expression and decreased Bax, Caspase‐3, and cleaved Caspase‐3 levels in response to MI/R. However, the cardioprotective effects of melatonin were largely abolished by the selective SIRT3 inhibitor 3‐(1H‐1,2,3‐triazol‐4‐yl)pyridine (3‐TYP), suggesting that SIRT3 plays an essential role in mediating the cardioprotective effects of melatonin. In vitro studies confirmed that melatonin also protected H9c2 cells against simulated ischemia/reperfusion injury (SIR) by attenuating oxidative stress and apoptosis, while SIRT3‐targeted siRNA diminished these effects. Taken together, our results demonstrate for the first time that melatonin treatment ameliorates MI/R injury by reducing oxidative stress and apoptosis via activating the SIRT3 signaling pathway.     

Trigonelline insulates against oxidative stress,proinflammatory cytokines and restores BDNF levels in lipopolysaccharide induced cognitive impairment in adult mice

Neuroinflammation is said to play a pivotal role in the pathogenesis of neurodegenerative disorders such as Alzheimer’s disease (AD). Trigonelline (TRG) is a naturally occurring alkaloid, commonly isolated from fenugreek and coffee beans. In the present study, we investigated whether TRG exerts neuroprotective action against LPS mediated cognitive impairment. Mice pretreated with TRG (50 and 100 mg/kg po) were administered with LPS (250 μg/kg ip) for 7 days. Memory was assessed in the Morris water maze (MWM) and Y maze. LPS administration caused poor memory retention in MWM and Y maze paradigms, and resulted in marked oxidative stress as evidenced by decrease in superoxide dismutase (SOD), reduced glutathione (GSH) levels and increased lipid peroxidation in the hippocampus and cortex. Cholinergic involvement during neuroinflammation was evaluated by measuring levels of acetylcholinesterase (AChE) enzyme. TRG treatment at both the doses reversed LPS induced behavioral and memory disturbances, significantly decreased the oxidative stress and AChE levels in both the hippocampus and cortex. LPS administration also elevated the tumour necrosis factor (TNF-α) and interleukin ?6 (IL-6) levels, whereas brain derived neurotrophic factor (BDNF) levels were significantly depleted. TRG pretreatment led to decreased TNF-α and IL-6 levels and caused a significant upregulation of BDNF levels. In conclusion, present study highlights the promising neuroprotective role of TRG against LPS mediated cognitive impairment which could be attributed to reduced oxidative stress, inhibition of proinflammatory cytokines and restoration of BDNF levels.     

7,8-Dihydroxyflavone protects retinal ganglion cells against chronic intermittent hypoxia-induced oxidative stress damage via activation of the BDNF/TrkB signaling pathway

Sleep and Breathing - Chronic intermittent hypoxia (CIH) plays a key role in the complications of obstructive sleep apnea (OSA), which is strongly associated with retinal and optic nerve diseases....     

杨梅素通过磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白信号通路诱导MTB感染巨噬细胞发生自噬的研究

目的对杨梅素通过磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/Akt/mTOR)信号通路诱导MTB感染的巨噬细胞发生自噬进行研究,从而探讨杨梅素抗结核作用的机理。方法用CCK8法检测杨梅素对细胞增殖的影响,确定安全的用药范围;以H37Ra菌株感染的小鼠巨噬细胞Raw 264.7为模型组,并设空白组和药物处理组。按感染复数(MOI,即细菌:细胞=10:1)加入模型组、药物处理组,共孵育4 h后,磷酸盐缓冲液(PBS)洗3次以弃掉未进入胞内的MTB。药物处理组分别用不同浓度(12.5、25、50、100μmol/L)的杨梅素作用24 h,Western blot法检测自噬相关蛋白即"微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)和p62"表达水平的变化,并以此筛选出杨梅素促进自噬的最佳作用浓度;100μmol/L杨梅素作用于感染细胞72 h后,0.1%聚乙二醇辛基苯基醚(Triton X-100)冰上裂解细胞10 min,菌落形成单位(CFU)法检测巨噬细胞胞内荷菌量;杨梅素作用感染细胞不同时间(30、60、180 min)后Western blot测定PI3K/Akt/mTO...     

Genistein attenuates neuroinflammation and oxidative stress and improves cognitive impairment in a rat model of sepsis-associated encephalopathy: potential role of the Nrf2 signaling pathway

Metabolic Brain Disease - Oxidative stress and inflammation seem to be the main factors responsible for cognitive impairment in sepsis. Genistein (GEN) is claimed to exert many beneficial effects...     

Epigallocatechin-3-O-gallate (EGCG) attenuates FFAs-induced peripheral insulin resistance through AMPK pathway and insulin signaling pathway in vivo

We aimed to investigate the effects and possible mechanisms of Epigallocatechin-3-O-gallate (EGCG) on free fatty acids (FFAs)-induced peripheral insulin resistance in vivo. Overnight-fasted Wistar rats were subjected to 48-h intravenous infusion of either saline or Intralipid plus heparin (IH) with or without different doses of EGCG co-injection. Hyperinsulinemic-euglycemic clamp was performed in awake rats to assess peripheral insulin sensitivity. Co-injection with EGCG significantly prevented FFAs-induced peripheral insulin resistance, decreased plasma markers of oxidative stress: malondialdehyde (MDA) and 8-isoprostaglandin, and increased antioxidant enzymes: superoxide dismutases (SOD) and Glutathione peroxidase (GPx). Furthermore, EGCG treatment reversed IH-induced: (1) decrease in Thr172 phosphorylation of AMP activated protein kinase (AMPK); (2) increase in protein kinase Cθ(PKCθ) membrane translocation and Ser307 phosphorylation of insulin receptor substrate-1 (IRS-1); (3) decrease in Ser473 phosphorylation of Akt and Glucose transporter 4 (GLUT4) translocation in skeletal muscle and adipose tissue. Our data suggest that EGCG treatment ameliorated FFAs-induced peripheral insulin resistance in vivo, and this might be through decreasing oxidative stress and PKCθ membrane translocation, activating the AMPK pathway and improving insulin signaling pathway in vivo. This study suggests the therapeutic value of EGCG in protecting from insulin resistance caused by elevated FFAs.     

丝胶蛋白对2型糖尿病大鼠肾脏氧化应激损伤和PI3K/Akt信号通路的影响

目的探讨丝胶蛋白(彩色蚕茧水提物)对2型糖尿病大鼠肾脏氧化应激损伤和磷脂酰肌醇-3-激酶(PI3K)/蛋白激酶B(Akt)信号通路的影响。方法 48只SD大鼠随机均分为四组各12只,正常对照组、2型糖尿病模型组、丝胶低剂量灌胃组、丝胶高剂量灌胃组。采用高脂高糖饲料饲养+链脲佐菌素(35 mg/kg,2次)腹腔注射的方法建模,成模标准是空腹血糖≥11.1 mmol/L。待建模成功后,丝胶低[1.8 g/(kg·d)]、高[2.4 g(kg·d)]剂量组大鼠分别给予不同剂量丝胶连续灌胃35 d。分别检测各组大鼠血糖,血尿素氮和肌酐水平;分别检测各组大鼠肾脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、总一氧化氮合酶(tNOS)、过氧化氢(H_2O_2)的水平;采用Real Time Q-PCR法分别检测各组大鼠肾脏PI3K、Akt mRNA的表达。结果丝胶低、高剂量组大鼠肾脏SOD、CAT水平及肾脏PI3K、Akt mRNA的表达明显高于模型组(P<0.01,P<0.05);血糖,血尿素氮和肌酐水平及肾脏tNOS、H_2O_2水平明显低于对照组(P<0.01)。并且,丝胶高剂量组大鼠肾脏CAT水平、PI3K mRNA的表达明显高于低剂量组,血尿素氮和肾脏H_2O_2水平明显低于低剂量组(P<0.01)。结论丝胶蛋白对2型糖尿病时肾脏损伤具有保护作用,其机制可能与丝胶蛋白能抑制肾脏氧化应激损伤和激活PI3K/Akt信号通路有关。