Systemic administration of high-molecular weight hyaluronan stimulates wound healing in genetically diabetic mice

Hyaluronic acid (HA), an essential component of the extracellular matrix, is an efficient space filler that maintains hydration, serves as a substrate for assembly of proteoglycans and is involved in wound healing. Although numerous pieces of evidence demonstrate beneficial effects in promoting wound healing in diabetes, a systemic approach has never been tested. We used an incisional wound healing model in genetically diabetic mice to test the effects of systemic injection of HA. Diabetic (n = 56) and normoglycemic (n = 56) mice were subjected to incision and randomized (8 groups of 7 animals each) to receive HA at different doses, 7.5, 15 and 30 mg/kg/i.p., or vehicle (0.9% NaCl solution) for 12 days. At the end of the experiment animals were sacrificed and skin wounds were excised for histological, biochemical and molecular analysis. Histology revealed that the most effective dose to improve wound repair and angiogenesis in diabetic mice was 30 mg/kg. Furthermore HA injection (30 mg/kg) improved the altered healing pattern in diabetic animals, increased skin remodeling proteins TGF-β and transglutaminase-II and restored the altered expression of cyclin B1/Cdc2 complex. Evaluation of skin from diabetic animals injected with HA revealed also an increase in HA content, suggesting that systemic injection may be able to restore the reduced intracellular HA pool of diabetic mice. Finally HA markedly improved skin mechanical properties. These promising results, if confirmed in a clinical setting, may improve the care and management of diabetic patients.     

普罗布考对糖尿病大鼠肾组织氧化应激的影响

目的研究普罗布考（Probucol）对糖尿病大鼠肾组织氧化应激的影响。方法采用腹腔注射链脲佐菌素（STZ）建立糖尿病大鼠模型。30只Wistar大鼠分为正常对照组（NC）、糖尿病组（DM）、糖尿病普罗布考治疗组（DP）。8周末称取体重、肾重、计算肾肥大指数（肾重/体重）,检测尿白蛋白排泄率（UAER）;测定各组生化指标包括血糖（BG）、胆固醇（TC）、三酰甘油（TG）、血清肌酐（SCr）、血尿素氮（BUN）;检测肾组织中丙二醛（MDA）的含量及超氧化物歧化酶（SOD）、过氧化氢酶（CAT）与谷胱甘肽过氧化物酶（GSH-Px）活性;肾组织切片行PAS染色分析肾小球面积及肾小球体积。结果 DM组大鼠肾重、肾重/体重、UAER、TC、TG、SCr、BUN、肾小球面积、肾小球体积较NC组均明显增加,DP组上述改变较DM组均明显减轻（P〈0.05）。DP组肾组织中MDA含量明显低于DM组,SOD、CAT、GSH-Px活性明显高于DM组（P〈0.05）。结论普罗布考可能部分通过减轻肾组织氧化应激反应实现对糖尿病大鼠肾脏的保护作用。     

波动性高糖对乳鼠心肌细胞肥大的影响

目的 探讨波动性糖环境对体外培养的乳鼠心肌细胞肥大的影响.方法 取出生后2天SD大鼠乳鼠心脏,采用胶原酶消化法获取心肌细胞,进行心肌细胞原代培养.常规培养心肌细胞72h,待细胞搏动良好,将其随机分为3组:①对照组:给予稳定的糖浓度(5.5mmol/L);②高糖组:给予稳定高糖浓度(25.5mmol/L);③波动性糖组:波动性糖浓度为5.5mmol/L和25.5mmol/L,每12h交替,其他培养条件保持一致.Bradford法检测各组细胞总蛋白质含量;计算机细胞图像分析系统测量单个细胞的体积;采用3H-亮氨酸掺入法,用液闪仪测定心肌细胞蛋白质合成速率.结果 1.高糖组和波动性糖组与对照组相比心肌细胞蛋白含量均增加,波动性糖组与高糖组相比二者增加的数值相近.2.高糖组和波动性糖组与对照组相比心肌细胞体积均有明显增加.3.高糖组与波动性糖组与对照组相比均有蛋白合成的增加.波动性糖组与高糖组相比没有显著性差异.结论 波动性糖有促进心肌细胞肥大的作用,其作用强度与单纯性高糖相仿.在糖尿病心肌病中,波动性糖也是引起心肌细胞肥大、心肌顺应性下降的原因之一.提示临床治疗糖尿病患者时,除了要控制血糖防止血糖过高,而且还要保持血糖的稳定,减少血糖波动所导致的心肌损害.     

Nutrient excess and altered mitochondrial proteome and function contribute to neurodegeneration in diabetes

Diabetic neuropathy is a major complication of diabetes that results in the progressive deterioration of the sensory nervous system. Mitochondrial dysfunction has been proposed to play an important role in the pathogenesis of the neurodegeneration observed in diabetic neuropathy. Our recent work has shown that mitochondrial dysfunction occurs in dorsal root ganglia (DRG) sensory neurons in streptozotocin (STZ) induced diabetic rodents. In neurons, the nutrient excess associated with prolonged diabetes may trigger a switching off of AMP kinase (AMPK) and/or silent information regulator T1 (SIRT1) signaling leading to impaired peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α) expression/activity and diminished mitochondrial activity. This review briefly summarizes the alterations of mitochondrial function and proteome in sensory neurons of STZ-diabetic rodents. We also discuss the possible involvement of AMPK/SIRT/PGC-1α pathway in other diabetic models and different tissues affected by diabetes.     

In vitro alpha-amylase inhibition and in vivo antioxidant potential of Amaranthus spinosus in alloxan-induced oxidative stress in diabetic rats

Amaranthus spinosus Linn. (Amaranthaceae), commonly known as “Mulluharivesoppu” in Kannada, is used in the Indian traditional system of medicine for the treatment of diabetes. The present study deals with the scientific evaluation of alpha amylase and the antioxidant potential of methanol extract of A. spinosus (MEAS). The aim of this study was to investigate in vitro alpha-amylase enzyme inhibition by CNPG3 (2-chloro-4-nitrophenol α-d-maltotrioside) and in vivo antioxidant potential of malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and total thiols (TT) in alloxan-induced diabetic rats of a methanolic extract of A. spinosus. Blood sugar was also determined in MEAS-treated alloxan-induced diabetic rats. MEAS showed significant inhibition of alpha-amylase activity and IC₅₀ 46.02 μg/ml. Oral administration of MEAS (200 and 400 mg/kg) for 15 days showed significant reduction in the elevated blood glucose, MDA and restores GSH, CAT and TT levels as compared with a diabetic control. The present study provides evidence that the methanolic extract of A. spinosus has potent alpha amylase, anti-diabetic and antioxidant activities.     

糖尿病性膀胱病逼尿肌中SCFmRNA和SCF蛋白的表达

目的：检测DCP逼尿肌中SCF表达水平,探讨SCF基因表达与DCP关系及其发病机制。方法：按1：2病例对照研究,采用链脲佐菌素（STZ）及尿动力学检测成功建立DCP豚鼠20只为实验组,并以同质豚鼠40为对照组,应用RT-PCR和Western-blotting方法分别检测各组膀胱逼尿肌中SCF mRNA、SCF蛋白的表达。结果：DCP豚鼠组织中SCF mRNA表达与正常对照组比较无明显显著差异（P〉0.05）,DCP豚鼠组织中SCF蛋白表达明显低于正常对照组（P〈0.01）。结论：DCP组织中SCF蛋白表达减少与SCF基因翻译水平异常有关,因此高血糖环境下SCF基因表达异常可能是DCP的发病机制之一。     

骨钙素减轻糖尿病大鼠血- 视网膜屏障的损伤

目的:研究骨钙素(Osteocalcin)对链脲佐菌素诱导的糖尿病大鼠血-视网膜屏障的影响。方法:取健康SD大鼠24只,随机分为正常对照组、糖尿病1月(DM1)组、糖尿病骨钙素干预(DM1+OCGY)组。尾静脉注射STZ建立DM模型,成模后DM1+OCGY组腹腔注射骨钙素(2.57 mg.kg-.1d-1),DM1组腹腔注射等量生理盐水,1个月后处死动物。用伊文思蓝方法检测大鼠血-视网膜屏障的改变。结果:造模1月后大鼠视网膜血管渗透性显著增加,共聚焦显微镜显示红色荧光斑点主要分布在视网膜血管周围,给予骨钙素后,红色荧光斑点明显减少,进一步定量显示1M糖尿病大鼠视网膜伊文思蓝含量为57.4±8.7μg.g-1,骨钙素能够改变这种变化,DM1+OCGY组伊文思蓝含量为26.1±3.8μg.g-1。结论:骨钙素能抑制糖尿病视网膜病的血管渗漏,对糖尿病引起的血-视网膜屏障破坏有保护作用。     

神经节苷脂联合α-硫辛酸治疗糖尿病神经源性膀胱临床观察

目的:观察α-硫辛酸、神经节苷脂联合治疗糖尿病神经源性膀胱的临床疗效。方法:60例2型糖尿病神经源性膀胱患者,随机分为α-硫辛酸治疗对照组、神经节苷脂治疗对照组,联合治疗组,疗程30d,观察症状体征及治疗前后B超膀胱残余尿量症状的变化,比较不同方案的疗效。结果:α-硫辛酸治疗对照组有效率90%,神经节苷脂治疗对照组有效率90%,联合治疗组有效率95%两组间无统计学差异(P>0.05),但3组的治愈率分别为90.0%、50.0%、60.0%,治疗组的治愈率高于两个对照组,有统计学差异(P<0.05)。结论:α-硫辛酸和神经节苷脂联合治疗糖尿病神经源性膀胱有较好的临床疗效,值得临床推广。     

尿微量白蛋白检测在社区糖尿病患者管理中的临床意义

目的:观察尿微量白蛋白在糖尿病患者中的改变情况,探讨提高社区糖尿病肾病早期诊断检出率的方法。方法:选择社区2型糖尿病患者73例,根据空腹血糖控制情况及糖尿病病程时长分别分组,比较不同组间患者尿微量白蛋白水平及阳性病例检出率,同时进行相关性分析。结果:MAlb在不同血糖控制情况患者中,血糖水平与MAlb数值、阳性检出率具有正相关性(P<0.05);血糖控制良好患者与其他血糖控制情况患者相比,差异具有(高度)统计学意义(P<0.01;P<0.05);MAlb在不同病程患者中,病程时间与MAlb数值、阳性检出率具有正相关性(P<0.05);≤5年组患者与5～10年组和≥10年组相比,差异具有(高度)统计学意义(P<0.01;P<0.05)。结论:尿微量白蛋白(MAlb)可作为早期糖尿病肾病检测的重要指标,能够提示肾脏病变的发展,定期检查能够提高早期糖尿病肾病的检出率。     

CCN-2 is up-regulated by and mediates effects of matrix bound advanced glycated end-products in human renal mesangial cells

CCN-2, also known as connective tissue growth factor (CCN-2/CTGF) is a cysteine rich, extracellular matrix protein that acts as a pro-fibrotic cytokine in tissues in many diseases, including in diabetic nephropathy. We have published that soluble advanced glycation end products (AGEs), that are present in increased amounts in diabetes, induce CCN-2. However in vivo AGEs are known to be heavily tissue bound and whether matrix bound AGEs regulate CCN-2 has not been investigated. In this study we determined in human renal mesangial cells if CCN-2 is induced by matrix associated AGEs and if CCN-2 may then secondarily mediate effects of matrix AGEs on extracellular matrix expansion. Data generated show that CCN-2 mRNA and protein expression are induced by matrix bound AGEs, and in contrast, this was not the case for TGF-β1 mRNA regulation. Using CCN-2 adenoviral anti-sense it was found that CCN-2 mediated the up-regulation of fibronectin and the tissue inhibitor of matrix metalloproteinase, TIMP-1, that was caused by matrix bound AGEs. In conclusion, CCN-2 is induced by non-enzymatically glycated matrix and it mediates downstream fibronectin and TIMP-1 increases, thus through this mechanism potentially contributing to ECM accumulation in the renal glomerulus in diabetes.