实验恒河猴糖尿病动物模型建立及视网膜并发症的研究

[目的]糖尿病是由于多种因素和遗传因素导致体内胰岛素相对或绝对分泌不足,而引起的代谢性内分泌疾病,它以血糖、尿糖升高为特点,起病隐蔽,通过并发症使人致残致死,是继心血管、癌症之后的第三大致死性疾病,很可能成为21世纪人类的“第一杀手”(1,2)。本文采用人工诱导的方法,建立恒河猴糖尿病动物模型,研究糖尿病疾病的发展和及其并发症的发生、发展规律和防治措施,同时对于治疗糖尿病新药的安全性评价和药物疗效的观察具有广阔的运用前景。[方法]选用成熟的、健康的、雄性恒河猴9只,随机分成三个组,其中高剂量组(60mg/kg)1只,中剂量组(45m…     

Profiling of vitreous proteomes from proliferative diabetic retinopathy and nondiabetic patients

Diabetes can lead to serious microvascular complications like proliferative diabetic retinopathy (PDR), which is the leading cause of blindness in adults. The proteomic changes that occur during PDR cannot be measured in the human retina for ethical reasons, but could be reflected by proteomic changes in vitreous humor. Thus, we considered that comparisons between the proteome profiles of the vitreous humors of PDR and nondiabetic controls could lead to the discovery of novel pathogenic proteins and clinical biomarkers. In this study, the authors used several proteomic methods to comprehensively examine vitreous humor proteomes of PDR patients and nondiabetic controls. These methods included immunoaffinity subtraction (IS)/2-DE/MALDI-MS, nano-LC-MALDI-MS/MS, and nano-LC-ESI-MS/MS. The identified proteins were subjected to the Trans-Proteomic Pipeline validation process. Resultantly, 531 proteins were identified, i.e., 415 and 346 proteins were identified in PDR and nondiabetic control vitreous humor samples, respectively, and of these 531 proteins, 240 were identified for the first time in this study. The PDR vitreous proteome was also found to contain many proteins possibly involved in the pathogenesis of PDR. The proteins described provide the most comprehensive proteome listing in the vitreous humor samples of PDR and nondiabetic control patients.     

Proteome map of normal rat retina and comparison with the proteome of diabetic rat retina: new insight in the pathogenesis of diabetic retinopathy

We have employed proteomics to establish a proteome map of the normal rat retina. This baseline map was then used for comparison with the early diabetic rat retinal proteome. Diabetic rat retinae were obtained from Dark Agouti rats after 10 wk of streptozotocin-induced hyperglycaemia. Extracted proteins from normal and diabetic rat retinae were separated and compared using 2-DE. A total of 145 protein spots were identified in the normal rat retina using MALDI-MS and database matching. LC-coupled ESI-MS increased the repertoire of identified proteins by 23 from 145 to 168. Comparison with early diabetic rat retinae revealed 24 proteins unique to the diabetic gels, and 37 proteins absent from diabetic gels. Uniquely expressed proteins identified included the HSPs 70.1A and 8, and platelet activating factor. There were eight spots with increased expression and 27 with decreased expression on diabetic gels. Beta catenin, phosducin and aldehyde reductase were increased in expression in diabetes whilst succinyl coA ligase and dihydropyrimidase-related protein were decreased. Identification of such changes in protein expression has given new insights and a more comprehensive understanding of the pathogenesis of diabetic retinopathy, widening the scope of potential avenues for new therapies for this common cause of blindness.     

糖尿病视网膜病变的基因治疗

糖尿病视网膜病变（diabetic retinopathy,DR）是糖尿病的主要并发症之一,大量的研究表明DR早期表现为视网膜神经细胞退化性改变,晚期出现新生血管及增殖膜,目前尚没有有效的治疗方法,严重危害患者视力。基因治疗为探索DR的治疗方法提供了新的手段,本文就目前DR的基因治疗研究现状和进展作一综述。     

Neuroprotective effects of quercetin in diabetic rat retina

Diabetic retinopathy (DR) is a severe complication of diabetes and the leading cause of blindness among working adults worldwide. DR is being widely recognized as a neurodegenerative disease of the retina, since, retinal neurons are damaged soon after diabetes onset. Diabetes-induced oxidative stress is considered as central factor that dysregulates neurotrophic factors and activates apoptosis, thereby damages neurons in the diabetic retina. Flavonoids being a powerful antioxidant have been considered to protect neurons in diabetic retina. The purpose of this study was to analyze the beneficial effects of flavonoid, quercetin to protect neurons in the diabetic rat retina. We quantitated the expression levels of BDNF, NGF, TrkB, synaptophysin, Akt, Bcl-2, cytochrome c and caspase-3 using Western blotting techniques in the diabetic retina with and without quercetin treatments and compared with non-diabetic rats. In addition, we employed ELISA techniques to determine the level of BDNF. Caspase-3 activity and the level of glutathione were analyzed by biochemical methods. Our results indicate that quercetin treatment to diabetic rats caused a significant increase in the level of neurotrophic factors and inhibited the level of cytochrome c and caspase-3 activity in the diabetic retina. Furthermore, the level of an anti-apoptotic protein Bcl-2 was augmented in quercetin treated diabetic retina. Thus, quercetin, may protect the neuronal damage in diabetic retina by ameliorating the levels of neurotrophic factors and also by inhibiting the apoptosis of neurons. Therefore, this study suggests that quercetin can be a suitable therapeutic agent to prevent neurodegeneration in diabetic retinopathy.     

Mechanisms involved in the development of diabetic retinopathy induced by oxidative stress

Background: Diabetic retinopathy (DR) is one of the main complications in patients with diabetes and has been the leading cause of visual loss since 1990. Oxidative stress is a biological process resulting from excessive production of reactive oxygen species (ROS). This process contributes to the development of many diseases and disease complications. ROS interact with various cellular components to induce cell injury. Fortunately, there is an antioxidan t system that protects organisms against ROS. Indeed, when ROS exceed antioxidant capacity, the resulting cell injury can cause diverse physiological and pathological changes that could lead to a disease like DR.

Objective: This paper reviews the possible mechanisms of common and novel biomarkers involved in the development of DR and explores how these biomarkers could be used to monitor the damage induced by oxidative stress in DR, which is a significant complication in people with diabetes.

Conclusion: The poor control of glucemy in pacients with DB has been shown contribute to the development of complications in eyes as DR.     

Comparison between liraglutide alone and liraglutide in combination with insulin on osteoporotic rats and their effect on bone mineral density

Objectives:To compare the therapeutic efficacy of liraglutide (LRG) single drug combined with insulin (Ins) on osteoporosis in rats and its effect on bone mineral density (BMD). A rat model of diabetes combined with osteoporosis was established.Methods:40 Sprague-Dawley rats were divided into four groups (blank, control, LRG and LRG+Ins). Serum levels of CrossLaps, procollagen type I N propeptide (PINP), alkaline phosphatase (AKP) and osteocalcin (BGP) were detected by ELISA. Blood glucose was measured by its reaction with glucose oxidase. Serum insulin was analyzed by radioimmunology. Bone calcium and phosphorus contents were also recorded. ELISA was used to detect inflammatory factors. Bone mineral density (BMD) measurement was also performed.Results:BMD of the control group was significantly lower than that of the other three groups (p<0.05) and BMD of the LRG + Ins group was significantly higher than that of the LRG group (p<0.05). The inflammatory factors of the control group were significantly higher than those in the other three groups (p<0.05). The inflammatory factors were negatively correlated with BMD (p<0.05).Conclusions:liraglutide in combination with insulin for the treatment of diabetes complicated with osteoporosis can reduce blood glucose in vivo, promote production of islet, effectively improve osteoporosis symptoms, increase BMD and reduce the levels of inflammatory factors in vivo.     

Targeting carbonic anhydrase to treat diabetic retinopathy: Emerging evidences and encouraging results

Diabetic retinopathy (DR) is the leading cause of vision loss among working-age populations in developed countries. Current treatment options are limited to tight glycemic, blood pressure control and destructive laser surgery. Carbonic anhydrases (CAs) are a group of enzymes involving in the rapid conversion of carbon dioxide to bicarbonate and protons. Emerging evidences reveal CA inhibitors hold the promise for the treatment of DR. This article summarizes encouraging results from clinical and animal studies, and reviews the possible mechanisms.     

Endothelial nitric oxide synthase genotype and haplotype are not associated with diabetic retinopathy in diabetes type 2 patients

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene have been associated with the development of diabetic retinopathy (DR) in patients with type 1 diabetes mellitus (T1DM), but not with T2DM. However, no previous study has analyzed combinations of genetic markers (haplotypes), which can be more informative. We studied three eNOS genetic polymorphisms: a single nucleotide polymorphism in the promoter region (T(-786)C), in exon 7 (Glu298Asp), and a variable number of tandem repeats in intron 4 (b/a) in 103 healthy controls, and in 170 patients with T2DM (without DR, N=114; with DR, N=56). We also examined the association of eNOS gene haplotypes with T2DM and with DR. No differences were found in the frequencies of genotypes and alleles of the three polymorphisms among the three groups of subjects. However, the "C-Glu-b" haplotype was more common in healthy controls (24%) than in T2DM patients (7%) (P=0.0001). Finally, no significant difference in the distribution of eNOS haplotypes frequencies was found when T2DM patients with or without DR were compared (P=0.7372). These findings suggest no association between DR and individual eNOS haplotypes in T2DM patients. The "C-Glu-b" haplotype, however, may have a protective effect against T2DM. Further studies should be conducted to address the molecular basis for such an effect.     

Periostin, discovered by nano-flow liquid chromatography and mass spectrometry, is a novel marker of diabetic retinopathy

Diabetes can lead to serious microvascular complications including proliferative diabetic retinopathy (PDR), the leading cause of blindness in adults. Recent studies using gene array technology have attempted to apply a hypothesis-generating approach to elucidate the pathogenesis of PDR, but these studies rely on mRNA differences, which may or may not be related to significant biological processes. To better understand the basic mechanisms of PDR and to identify potential new biomarkers, we performed shotgun liquid chromatography (LC)/tandem mass spectrometry (MS/MS) analysis on pooled protein extracts from neovascular membranes obtained from PDR specimens and compared the results with those from non-vascular epiretinal membrane (ERM) specimens. We detected 226 distinct proteins in neovascular membranes and 154 in ERM. Among these proteins, 102 were specific to neovascular membranes and 30 were specific to ERM. We identified a candidate marker, periostin, as well as several known PDR markers such as pigment epithelium-derived factor (PEDF). We then performed RT-PCR using these markers. The expression of periostin was significantly up-regulated in proliferative membrane specimens. Periostin induces cell attachment and spreading and plays a role in cell adhesion. Proteomic analysis by LC/MS/MS, which permits accurate quantitative comparison, was useful in identifying new candidates such as periostin potentially involved in the pathogenesis of PDR.     

The KL-VS polymorphism of KLOTHO gene is protective against retinopathy incidence in patients with type 1 diabetes

Background and aims

KLOTHO is an anti-ageing circulating hormone involved in insulin signaling, inflammation and vascular homeostasis through its protective effects on the endothelium and antioxidant actions. The common functional “KL-VS” variant of the KLOTHO gene is reproducibly associated with longevity in humans. Large number of studies have evaluated close relationship between KLOTHO protein and diabetes but the association between KL-VS variant and retinopathy in type 1 diabetes mellitus (T1D) is unknown. Therefore, in the present study we examined the association between the KL-VS polymorphism and the risk of diabetic retinopathy (DR) in patients with T1D.

Modulation of IL-1β and VEGF expression in rat diabetic retinopathy after PACAP administration

Diabetic retinopathy (DR) is a microvascular complication of diabetes. Hyperglycemic/hypoxic microenvironment concurs to aberrant angiogenesis characterizing the pathology and activates many downstream target genes including inflammatory cytokines and vasoactive peptides, such as interleukin-1β (IL-1β) and vascular endothelial growth factor (VEGF).It has been largely demonstrated that pituitary adenylate cyclase-activating peptide (PACAP) plays a protective effect in DR. In the present study, we investigated the role of PACAP to protect retinal tissue through IL-1β and VEGF expression. Diabetes was induced in rats by streptozotocin (STZ) injection, and one week later a single intravitreal injection of 100 μM PACAP was administrated. Analyses of IL-1β and VEGF levels were performed three weeks after diabetes induction.The results demonstrated that a single intraocular administration of PACAP significantly reduced the expression of IL-1β in diabetic animals. Moreover, it affects VEGF and its receptors (VEGFRs) levels and interferes with their retinal layers distribution as showed by confocal microscopy analysis. In particular, PACAP treatment downregulates VEGF and VEGFRs that are increasingly expressed in STZ-treated animals as compared to controls. These results indicate that PACAP plays an important role to attenuate the early phase of DR.     

Early changes in pituitary adenylate cyclase-activating peptide, vasoactive intestinal peptide and related receptors expression in retina of streptozotocin-induced diabetic rats

The retinal expression and distribution of pituitary adenylate cyclase-activating peptide (PACAP) and vasoactive intestinal peptide (VIP) and their receptors was investigated in early streptozotocin (STZ)-induced diabetic rats. Diabetes was induced in rats by STZ injection (60mg/kg i.p.). PACAP, VIP and their receptors in nondiabetic control and diabetic retinas were assayed by quantitative real-time PCR and Western blot 1 and 3 weeks after STZ injection. Effects of intravitreal treatment with PACAP38 on the expression of the two apoptotic-related genes Bcl-2 and p53 were also evaluated. PACAP and VIP, as well as VPAC1 and VPAC2 receptors, but not PAC1 mRNA levels, were transiently induced in retinas 1week following STZ. These findings were confirmed by immunoblot analyses. Three weeks after the induction of diabetes, significant decreases in the expression of peptides and their receptors were observed, Bcl-2 expression decreased and p53 expression increased. Intravitreal injection of PACAP38 restored STZ-induced changes in retinal Bcl-2 and p53 expression to nondiabetic levels. The initial upregulation of PACAP, VIP and related receptors and the subsequent downregulation in retina of diabetic rats along with the protective effects of PACAP38 treatment, suggest a role for both peptides in the pathogenesis of diabetic retinopathy.     

Catalogue of soluble proteins in the human vitreous humor: comparison between diabetic retinopathy and macular hole

Two-dimensional gel electrophoresis and mass spectrometry were used to make a catalogue of soluble proteins in the human vitreous humor (VH). Fifty-one different proteins were identified on silver-stained two-dimensional (2D) gel patterns with VH proteins obtained from diabetic retinopathy and macular hole. Thirty of these have not been listed in the reported 2D profiles of plasma. Immunoglobulin (Ig), alpha1-antitrypsin, alpha2-HS glycoprotein,and complement C(4) fragment showed stronger spots in VH with diabetic retinopathy patient samples than those with macular hole. Pigment epithelium-derived factor, a potent inhibitor of angiogenesis in the cornea and vitreous, was clearly detected in VH with diabetes. It is impressive that the inhibitor increases in the vitreous with proliferative angiogenesis.     

The antioxidant effect of ubiquinone and combined therapy on mitochondrial function in blood cells in non-proliferative diabetic retinopathy: A randomized,double-blind,phase IIa,placebo-controlled study

Objectives: To evaluate the effect of ubiquinone and combined antioxidant therapy on mitochondrial function in non-proliferative diabetic retinopathy (NPDR) in a randomized, double-blind, phase IIa, placebo-controlled, clinical trial. Three groups of 20 patients were formed: Group 1, ubiquinone; Group 2, combined therapy; and Group 3, placebo (one daily dose for 6 months).

Methods: Fluidity of the submitochondrial membrane in platelets was determined by examining intensity of fluorescence between the monomer (I_m) and excimer (I_e). Hydrolytic activity of the mitochondrial F₀F₁-ATPase was evaluated with the spectrophotometric method.

Results: Normal, baseline submitochondrial membrane fluidity, 0.24 ± 0.01 I_e/I_m, was significantly diminished in the three study groups vs. normal values (P < 0.0001); placebo, 0.14 ± 0.01 I_e/I_m; ubiquinone, 0.14 ± 0.01 I_e/I_m; and combined therapy, 0.13 ± 0.00 I_e/I_m. Afterward, it increased significantly (P < 0.0001), the ubiquinone group 0.22 ± 0.01 I_e/I_m, combined therapy group, 0.19 ± 0.01 I_e/I_m; with no changes the placebo group. Baseline hydrolytic activity of the F₀F₁-ATPase enzyme increased in the three study groups vs. normal values (184.50 ± 7.84 nmol PO₄), placebo, 304.12 ± 22.83 nmol PO₄ (P < 0.002); ubiquinone, 312.41 ± 25.63 nmol PO₄ (P < 0.009); and combined therapy, 371.28 ± 33.50 nmol PO₄ (P < 0.002). Afterward, a significant decrease the enzymatic activity: ubiquinone, 213.25 ± 14.19 nmol PO₄ (P < 0.001); and combined therapy, 225.55 ± 14.48 nmol PO₄ (P < 0.0001).

Discussion: Mitochondrial dysfunction significantly improved in groups of NPDR patients treated with antioxidants.     

Cancer inhibition mechanism of lung cancer mouse model based on dye trace method

To minimize the incidence and mortality of cancer, dye trace method was used to explore the mechanism of drug inhibition. 60 mice were selected as the research objects and randomly divided into five groups: model group, shikonin group, aconitine group, notoginsenoside R1 group, and compound group. When establishing the model, begin to administrate the medicine by gavage. The permeability of lung barrier was measured, and H.E staining, immunohistochemical staining, and Western blot test were carried out. The results showed that the mice in model group had decreased autonomic activity, increased permeability of the lung barrier, white nodules on the lung tissue, decreased protein expression related to cell proliferation and differentiation, and decreased protein expression associated with cell proliferation and differentiation, increased expression of related proteins in cancer stem cells, and low level of cell-linked communication. And the incidence of lung cancer in the model group mice was 100%. The histopathological changes in mice were improved to varying degrees after the intervention of the three drugs. Especially in the compound group, the incidence of lung cancer decreased to 8.3%. This study demonstrated that the combination of shikonin, aconitine and notoginsenoside R1 had a good anti-cancer effect, which provided a theoretical basis for clinical research.     

Animal models of diabetic retinopathy: doors to investigate pathogenesis and potential therapeutics

Effective and validated animal models are valuable to investigate the pathogenesis and potential therapeutics for human diseases. There is much concern for diabetic retinopathy (DR) in that it affects substantial number of working population all around the world, resulting in visual deterioration and social deprivation. In this review, we discuss animal models of DR based on different species of animals from zebrafish to monkeys and prerequisites for animal models. Despite criticisms on imprudent use of laboratory animals, we hope that animal models of DR will be appropriately utilized to deepen our understanding on the pathogenesis of DR and to support our struggle to find novel therapeutics against catastrophic visual loss from DR.     

红参粉末治疗糖尿病视网膜病变的临床观察

目的：观察红参粉末治疗糖尿病视网膜病变的临床效果。方法：随机选取2012年1月至2012年12月在我院接受治疗的2型糖尿病合并糖尿病视网膜病变（Diabetic Retinopathy,DR）患者103例。其中30例（57眼）仅采用常规方法治疗,即对照组;其余73例（125眼）在常规治疗的基础上加用红参粉末,即观察组。治疗180天后,观察并比较两组患者的视力、眼底镜、荧光血管造影等检查结果的变化情况。结果：在观察组中,患者经红参粉末治疗后的视力与治疗前相比有所提高,差异具有统计学意义（P〈0．05）;而对照组中,患者治疗前后的视力变化无统计学意义（P〉0．05）;观察组治疗有效率为76．7％,而对照组治疗有效率为46．7％,差异有显著意义（P〈0．05）。观察组中,男性DR患者治疗有效率为68．8％、女性为92．0％;早期DR治疗有效率为85．4％、晚期为65．1％;糖尿病病程不超过10年的DR患者治疗有效率为88．9％、超过10年的为64．9％,差异均具有统计学意义（P〈0．05）。结论：尽早的发现和及时的治疗可减少糖尿病患者视网膜病变的发生率,从而避免因视网膜病变而引起的严重的视力下降,甚至失明。红参粉末治疗糖尿病视网膜病变有显著的临床效果,特别是对早期糖尿病视网膜病变的疗效更佳,值得临床推广。