2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione,isolated from the root of Averrhoa carambola L., protects against diabetic kidney disease by inhibiting TLR4/TGFβ signaling pathway

ObjectiveDiabetic kidney disease (DKD) is the leading cause of death and disability of diabetes mellitus. However, there is still a lack of specific drugs for the treatment of DKD. The chief aim of this research is to investigate the role and mechanism of 2-Dodecyl-6-methoxycyclohexa-2,5-diene-1,4-dione (DMDD) for DKD.MethodsWild type and TLR4 knockout mice were induced to diabetes. After 4-week treatment with DMDD, blood sugar, renal function, blood lipid and pathological changes were assessed. Real-time PCR, western blotting, and immunohistochemistry were employed to detect the expressions of TLR4, TGFβ1 and Smad2/3 in the renal tissue.ResultsDMDD improved the serum lipid and decreased fasting blood glucose levels in diabetic mice. CysC and urinary albumin levels increased markedly in the diabetic group, and they were obviously decreased after 4 weeks of DMDD treatment. Compared with the WT diabetic mice, the urinary albumin and CysC in the TLR4^-/- mice were expressed at lower levels. HE and Masson’s staining revealed that DMDD clearly ameliorated pathological changes and renal fibrosis. When TLR4 gene was knock out, the pathological was improved. Mechanistically, TLR4, TGF-β1 and Smad2/3 were obvious up-regulation in the renal tissues of diabetic mice. The expressions of these proteins were significantly down-regulated after DMDD treatment (p < 0.05). In the TLR4^-/- mice, mRNA and protein levels of TGF-β1 and Smad2/3 were obviously lower than those in the WT mice. In addition, IHC revealed that a strong in situ expressions of TLR4, TGF-β1 and Smad2/3 were seen in the kidney tissues of diabetic mice, which were distinctly weakened in the DMDD-treated mice. In the TLR4^-/- mice, however, expressions of TGF-β1 and Smad2/3 were not remarkable increase in the diabetic mice compared with normal mice.ConclusionsThese results strongly indicate that TLR4 is essential for DMDD protection against renal dysfunction in diabetic mice. Its hypoglycemic and anti-fibrosis effects were likely mediated by the TLR4/TGFβ signaling pathway.     

Alterations of morphology and phosphorylated protein expression in the seminal vesicles of diabetic mice

Although many studies reported the detrimental effects of type 1 and 2 diabetes mellitus (T1DM and T2DM) on testis, reproductive parameter changes in DM seminal vesicles have never been documented. This study aimed to examine the morphology, biochemical levels and tyrosine phosphorylation in seminal vesicles of T1DM and T2DM mice. Fifty‐six male C57BL/6 mice were divided into four groups (n = 14/each): T1DM control, T1DM, T2DM control and T2DM. T1DM mice were daily injected of streptozotocin (STZ; 40 mg/kg BW) for 5 days. T2DM mice received high‐fat diet for 14 days prior to STZ injection at a single dose (85 mg/kg BW). At the end of experiments (days 36 and 72), magnesium (MG) and fructosamine (FRA) levels, and phosphorylated protein expression in seminal vesicle were examined. The results showed that seminal and prostate weights and MG and FRA levels of T1DM animals were significantly increased as compared to T2DM mice. Some seminal histopathologies and decreased epithelial height were observed in both DM groups. Significantly, a 72‐kDa phosphorylated protein expression was increased in DM seminal vesicle. We concluded that changes of biochemical components and phosphorylated proteins in seminal vesicle of T1DM and T2DM mice may be associated with low‐quality seminal plasma.     

Levosimendan suppresses oxidative injury,apoptotic signaling and mitochondrial degeneration in streptozotocin-induced diabetic cardiomyopathy

Diabetic cardiomyopathy plays a major role in morbidity and mortality among cardiovascular disorder-related complications. This study was designed to explore long-term benefits of Levosimendan (LEVO) along with Ramipril and Insulin. Diabetic cardiomyopathy was induced using streptozotocin (STZ) at the dose of 25?mg/kg/body weight/day for three consecutive days in Wistar rats. Rats were randomly divided into 10 groups and treatments were started after 2 weeks of STZ administration. A gradual but severe hyperglycemia (^§§§p?<?0.001) was observed in all STZ-treated groups except those received insulin (2 U/day). LEVO alone and in combination with Ramipril and Insulin normalized (**p?<?0.01) mean arterial pressure and heart rate, restored catalase, superoxide dismutase, malondialdehyde, glutathione level and also attenuated (***p?<?0.001) the raised serum levels of creatine kinase-heart type, lactate dehydrogenase, tumor necrosis factor-alpha, C-reactive protein, and caspase-3 level in heart tissue altered after STZ treatment. Myofibril degeneration, mitochondrial fibrosis and vacuolization occurred after STZ treatment, were also reversed by LEVO in combination with Ramipril and Insulin. The combination of LEVO with Ramipril and Insulin improved hemodynamic functions, maintained cardiac enzymes and ameliorated myofibril damage in diabetic cardiomyopathy.     

甘露消渴胶囊通过JAK2/STAT3信号通路对糖尿病肾病大鼠的影响

[目的] 研究甘露消渴胶囊对糖尿病肾病的治疗作用。[方法] 从70只雄性SD大鼠中随机选取10只作为空白对照组,其余大鼠用高脂高糖饲料喂养4周后腹腔注射链脲佐菌素（STZ,11 mg/mL,5 mL/kg）,继续饲养4周,选取造模成功的42只大鼠随机分为4组,分别为模型组10只、甘露消渴胶囊低剂量组（0.93 g/kg生药）11只、甘露消渴胶囊高剂量组（1.86 g/kg生药）11只、二甲双胍合并缬沙坦组（180 mg/kg,14.4 mg/kg）10只。各给药组灌胃体积为10 mL/kg,空白对照组及模型组灌胃等体积的蒸馏水,治疗给药8周后测24 h尿蛋白,尾静脉采血测随机血糖,腹腔注射10%水合氯醛（3 mL/kg）麻醉,腹主动脉取血,检测血尿素氮（BUN）、血肌酐（Scr）,最后取肾脏福尔马林溶液固定,用于苏木精-伊红（HE）染色和免疫组化技术检测JAK2、STAT3在肾脏组织的表达。[结果] 甘露消渴胶囊可显著降低JAK2及STAT3在糖尿病肾病大鼠肾脏组织表达,减轻糖尿病引起的肾小球增大及基底膜增生,减少糖尿病肾病大鼠尿蛋白、Scr及BUN的含量,且以上药理作用均与甘露消渴胶囊降低血糖的作用呈正相关。[结论] 甘露消渴胶囊可通过降低糖尿病大鼠随机血糖以及调控蛋白质酪氨酸激酶JAK2抗体（JAK2）、信号转导和转录激活因子3单克隆抗体（STAT3）在肾脏组织的表达,减轻高血糖对肾脏组织的病理损伤,改善肾功能,起到对糖尿病肾病大鼠肾脏的保护作用的作用。     

Altered platelet calsequestrin abundance,Na/Ca exchange and Ca signaling responses with the progression of diabetes mellitus

Introduction

Downregulation of calsequestrin (CSQ), a major Ca^2 + storage protein, may contribute significantly to the hyperactivity of internal Ca^2 + ([Ca^2 +]_i) in diabetic platelets. Here, we investigated changes in CSQ-1 abundance, Ca^2 + signaling and aggregation responses to stimulation with the progression of diabetes, especially the mechanism(s) underlying the exaggerated Ca^2 + influx in diabetic platelets.

Materials and methods

Type 1 diabetes was induced by streptozotocin in rats. Platelet [Ca^2 +]_i and aggregation responses upon ADP stimulation were assessed by fluorescence spectrophotometry and aggregometry, respectively. CSQ-1 expression was evaluated using western blotting.

Results

During the 12-week course of diabetes, the abundance of CSQ-1, basal [Ca^2 +]_i and ADP-induced Ca^2 + release were progressively altered in diabetic platelets, while the elevated Ca^2 + influx and platelet aggregation were not correlated with diabetes development. 2-Aminoethoxydiphenyl borate, the store-operated Ca^2 + channel blocker, almost completely abolished ADP-induced Ca^2 + influx in normal and diabetic platelets, whereas nifedipine, an inhibitor of the nicotinic acid adenine dinucleotide phosphate receptor, showed no effect. Additionally, inhibition of Na⁺/Ca^2 + exchange induced much slower Ca^2 + extrusion and more Ca^2 + influx in normal platelets than in diabetic platelets. Furthermore, under the condition of Ca^2 +-ATPase inhibition, ionomycin caused greater Ca^2 + mobilization and Ca^2 + influx in diabetic platelets than in normal platelets.

Conclusions

These data demonstrate that platelet hyperactivity in diabetes is caused by several integrated factors. Besides the downregulation of CSQ-1 that mainly disrupts basal Ca^2 + homeostasis, insufficient Na⁺/Ca^2 + exchange also contributes, at least in part, to the hyperactive Ca^2 + response to stimulation in diabetic platelets.     

Adrenal gland-dependent augmentation of plasminogen activator inhibitor-1 expression in streptozotocin-induced diabetic mice

BACKGROUND: Diabetes is associated with an excess risk of cardiac events, and one risk factor for infarction is an elevated level of plasminogen activator inhibitor-1 (PAI-1). OBJECTIVES AND METHODS: To evaluate whether the glucocorticoid hormones are involved in the diabetes-induced PAI-1 production, we examined expression profiles of PAI-1 mRNA in adrenalectomized (ADX) mice with streptozotocin (STZ)-induced diabetes. RESULTS: The diabetes-induced augmentation of plasma PAI-1 levels and PAI-1 mRNA expression in the heart and lungs was completely normalized in diabetic ADX mice. The glucocorticoid receptor antagonist RU486 significantly, but only partly suppressed PAI-1 induction in STZ-induced diabetic mice, suggesting that factors other than glucocorticoids are also involved in PAI-1 induction provoked by diabetes. CONCLUSION: Our results suggested that the adrenal gland plays a critical role in the progression of thrombosis in diabetic patients by inducing expression of the PAI-1 gene.     

Isogeneic or allogeneic transplantation of duct-ligated pancreas in streptozotocin diabetic mice.

Recovery from hyperglycaemia was observed in three different mouse hybrids that were made diabetic with streptozotocin, and then transplanted with pancreas from isogeneic donors whose pancreatic ducts were ligated over 8 weeks earlier. Recovery did not occur in recipients of allografts indicating that islets in ligated pancreas cannot be successfully transplanted across a major histocompatibility barrier. However, in lethally irradiated mice injected with allogeneic bone marrow (allogeneic radiation chimeras), subsequent transplantation of ligated pancreas from either isogeneic donors or allogeneic donors of the same strain as the bone marrow donor decreased blood glucose of diabetic recipients. Thus, irradiation and allogeneic bone marrow therapy allow subsequent allogeneic transplantation of functional islet tissue in diabetic mice. Observations on diabetic mice transplanted isogeneically with ligated pancreas suggest that recovery from hyperglycaemia was more consistent when grafts were placed subcutaneously rather than intraperitoneally and when hosts received ligated pancreas from three donors rather than one. Thus, the site and amount of tissue transplanted are important considerations in the transplantation of ligated pancreas. Persistence of endocrine beta-cells in ligated pancreas was required for recovery in grafted mice since diabetic hosts failed to recover when grafted with ligated pancreas obtained from alloxan or streptozotocin-treated, diabetic donors.     

Melatonin prevents deterioration of erectile function in streptozotocin-induced diabetic rats via sirtuin-1 expression

A review of the literature indicated that sirtuin-1 expression, a regulator of nitric oxide bioavailability in erectile dysfunction (ED) after melatonin therapy, has not yet been investigated. The objective of this study was to evaluate the protective effects of melatonin for erectile function with sirtuin-1 protein expression in type 1 diabetic rat models. Fifty male Sprague Dawley rats were placed into five groups. Except for those in the control group (C), each animal received a single dose (60 mg/kg) of streptozotocin to induce diabetes. The animals were placed into the diabetes (D) group, insulin (I) group (6 U/kg/day), melatonin (Mel) group (10 mg kg⁻¹ day⁻¹) and combined treatment (I + Mel) group. Ten weeks later, the serum testosterone levels, intracavernosal pressure (ICP), mean arterial pressure (MAP), malondialdehyde (MDA), cyclic guanosine monophosphate (c-GMP), 8-hydroxydeoxyguanosine (8-OHdG), nitric oxide synthase (NOS), caspase-3 activity, sirtuin-1 and endothelial nitric oxide synthase (eNOS) protein expression and histological findings were assessed. The mean ICP/MAP ratio for the D group was lower than the mean ratios for the other groups. The treatment groups, particularly the I + Mel group, exhibited lower 8-OHdG and MDA levels and caspase-3 activity than the D group. The sirtuin-1 and eNOS expression and cavernosal tissue (CT) histology seemed to have been preserved by the melatonin and/or insulin therapy. These results were indicative of a profound protective effect of melatonin by the activation of sirtuin-1 protein expression against hyperglycemia-induced oxidative CT injury.