GLP-1R agonists therapy for type 2 diabetes

Glucagon-like peptide-1 receptor （GLP-1R） agonists are widely used for treating type 2 diabetes mellitus （T2DM） be- cause of their glucose-lowering and weight-losing effects, and low risk of hypoglycemia. Hence, there is considerable interest in understanding the mechanism underlying the beneficial effects of GLP-I and developing stable and effective GLP-1R agonists. Here, we summarize the presently known mechanism of GLP-I actions, which are mainly through regulating cAMP-PKA signaling pathway; the latest developments in novel clinical GLP-1R agonists are also introduced, which are characterized with multiple properties, such as extended half-life, reduced side-effects, lower production costs and more convenient drug dosing mode. The potential risk of GLP-I-based therapeutics, an often-ignored fact, is also discussed.     

A genome-wide association study identifies KIAA0350 as a type 1 diabetes gene

Type 1 diabetes (T1D) in children results from autoimmune destruction of pancreatic beta cells, leading to insufficient production of insulin. A number of genetic determinants of T1D have already been established through candidate gene studies, primarily within the major histocompatibility complex but also within other loci. To identify new genetic factors that increase the risk of T1D, we performed a genome-wide association study in a large paediatric cohort of European descent. In addition to confirming previously identified loci, we found that T1D was significantly associated with variation within a 233-kb linkage disequilibrium block on chromosome 16p13. This region contains KIAA0350, the gene product of which is predicted to be a sugar-binding, C-type lectin. Three common non-coding variants of the gene (rs2903692, rs725613 and rs17673553) in strong linkage disequilibrium reached genome-wide significance for association with T1D. A subsequent transmission disequilibrium test replication study in an independent cohort confirmed the association. These results indicate that KIAA0350 might be involved in the pathogenesis of T1D and demonstrate the utility of the genome-wide association approach in the identification of previously unsuspected genetic determinants of complex traits.     

2型糖尿病胰岛素抵抗研究进展

胰岛素抵抗和B细胞功能障碍是2型糖尿病发病机制的两个主要环节,而胰岛素抵抗是2型糖尿病发生的始动因素.研究发现,信号蛋白异常和炎症因子与胰岛素抵抗的发生密切相关,探讨其相关关系为治疗糖尿病、防治或延缓其并发症的发生提供重要的科学依据.     

Prime role for an insulin epitope in the development of type 1 diabetes in NOD mice

A fundamental question about the pathogenesis of spontaneous autoimmune diabetes is whether there are primary autoantigens. For type 1 diabetes it is clear that multiple islet molecules are the target of autoimmunity in man and animal models. It is not clear whether any of the target molecules are essential for the destruction of islet beta cells. Here we show that the proinsulin/insulin molecules have a sequence that is a primary target of the autoimmunity that causes diabetes of the non-obese diabetic (NOD) mouse. We created insulin 1 and insulin 2 gene knockouts combined with a mutated proinsulin transgene (in which residue 16 on the B chain was changed to alanine) in NOD mice. This mutation abrogated the T-cell stimulation of a series of the major insulin autoreactive NOD T-cell clones. Female mice with only the altered insulin did not develop insulin autoantibodies, insulitis or autoimmune diabetes, in contrast with mice containing at least one copy of the native insulin gene. We suggest that proinsulin is a primary autoantigen of the NOD mouse, and speculate that organ-restricted autoimmune disorders with marked major histocompatibility complex (MHC) restriction of disease are likely to have specific primary autoantigens.     

人类巨细胞病毒感染致1型糖尿病机制的初步探讨

目的通过对1型糖尿病患者的HCMV感染标志物、空腹血糖、空腹C肽、胰岛素自身抗体及抗胰岛细胞抗体的研究,初步探讨HCMV致1型糖尿病的机制。方法检测1型糖尿病患者的HCMV感染标志物（包括HCMV—IgG及其相对含量、HCMV—IgM及HCMV—pp65）、空腹血糖、C肽、抗胰岛素自身抗体及抗胰岛细胞抗体并进行统计学分析。结果HCMV感染与1型糖尿病患者抗胰岛素自身抗体之间无明显相关性,但与1型糖尿病患者空腹血糖、空腹C肽、抗胰岛细胞抗体存在明显的相关性,HCMV—pp65阳性的1型糖尿病患者中其空腹血糖明显高于该指标阴性者;抗HCMV—IgG阳性的1型糖尿病患者空腹血糖水平、抗胰岛细胞抗体均显著高于抗HCMV—IgG阴性者,而空腹C肽水平则明显低于抗HCMV—IgG阴性者,且抗HCMV—IgG抗体指数在4．1以上者,其抗胰岛细胞抗体阳性率显著高于抗HCMV—IgG抗体指数在4．0以下者。结论HCMV感染可能通过直接损伤胰岛免疫病理反应损伤胰岛细胞最终导致1型糖尿病的发生。     

SUR1基因多态性与磺脲类药物疗效的相关性

采用聚合酶链反应-限制性片段长度多态性技术检测了178例2型糖尿病和132例健康对照者磺脲类药物受体1(SURl)基因外显子16-3c／t多态性，并对其中112例糖尿病患者观察了磺脲类降糖药的疗效．与对照组相比，“t”等位基因频率和“tt”基因型(纯合子)在糖尿病组中的分布显著升高，“tt”基因型患者反映其胰岛素分泌功能的Homap指数较其他基因型(tc和cc)组显著降低，糖尿病中33例磺脲药治疗失效组t等位基因频率明显多于79例磺脲药治疗有效组．提示SURl基因变异可能导致2型糖尿病胰岛素分泌功能障碍，SUR1基因外显子16-3c／t多态性与磺脲类降糖药的疗效间存在连锁不平衡．     

Immunology: Insulin auto-antigenicity in type 1 diabetes

Spontaneous type 1 diabetes occurs when the autoimmune destruction of pancreatic beta-islet cells prevents production of the hormone insulin. This causes an inability to regulate glucose metabolism, which results in dangerously raised blood glucose concentrations. It is generally accepted that thymus-derived lymphocytes (T cells) are critically involved in the onset and progression of type 1 diabetes, but the antigens that initiate and drive this destructive process remain poorly characterized--although several candidates have been considered. Nakayama et al. and Kent et al. claim that insulin itself is the primary autoantigen that initiates spontaneous type 1 diabetes in mice and humans, respectively, a result that could have implications for more effective prevention and therapy. However, I believe that this proposed immunological role of insulin may be undermined by the atypical responses of T cells to the human insulin fragment that are described by Kent et al..     

运动对2型糖尿病胰岛素抵抗相关因子的影响研究

通过分析运动对2型糖尿病胰岛素抵抗的相关因子的影响,发现2型糖尿病主要是胰岛素抵抗和胰岛素分泌受损所导致.因此,只要了解胰腺β细胞的胰岛素抵抗程度,就可以加以弥补,使葡萄糖耐受性维持正常.     

Interleukin-1 beta as a potent hyperalgesic agent antagonized by a tripeptide analogue

Interleukin-1 (IL-1) describes two inflammatory proteins, IL-1 alpha and IL-1 beta, produced by activated macrophages and other cell types and encoded by two genes. Their amino acid sequences have only 26% similarity, but their biological activities are comparable, with a few exceptions; indeed, both molecules appear to act at the same receptor. As IL-1 release prostaglandins which sensitize nociceptors in man and in experimental animals, we tested IL-1 alpha and IL-1 beta in rats for hyperalgesic (nociceptive) activity. Our results show that IL-1 beta given systemically is an extremely potent hyperalgesic agent with a probable peripheral site of action; IL-1 alpha is approximately 3,000 times less active than IL-1 beta. We have delineated the region of IL-1 beta mediating the hyperalgesic effect and developed an analgesic tripeptide analogue of IL-1 beta which antagonizes hyperalgesia evoked by IL-1 beta and by the inflammatory agent carrageenan.     

T-cell clones from a type-1 diabetes patient respond to insulin secretory granule proteins

T LYMPHOCYTES reactive to pancreatic beta-cells are thought to have a central role in the autoimmune process leading to type 1 (insulin-dependent) diabetes, but the molecular targets of these T cells have not yet been defined. As identification of such antigens may enable measures to be developed to prevent the disease, we have characterized an antigen that is recognized by insulinoma membrane-reactive T-cell clones established from a newly diagnosed type-1 diabetes patient. Subcellular fractionation studies using rat insulinoma indicate that the antigenic determinant recognized by one of these clones is an integral membrane component of the insulin secretory granule. After a 5,000-fold purification, we have defined the antigen as a monomer of relative molecular mass 38,000. As granular membrane proteins are transiently exposed on the cell surface during exocytosis, their accessibility to components of the immune system may be a function of the secretory activity of beta-cells.     

Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes

In obesity and type 2 diabetes, expression of the GLUT4 glucose transporter is decreased selectively in adipocytes. Adipose-specific Glut4 (also known as Slc2a4) knockout (adipose-Glut4(-/-)) mice show insulin resistance secondarily in muscle and liver. Here we show, using DNA arrays, that expression of retinol binding protein-4 (RBP4) is elevated in adipose tissue of adipose-Glut4(-/-) mice. We show that serum RBP4 levels are elevated in insulin-resistant mice and humans with obesity and type 2 diabetes. RBP4 levels are normalized by rosiglitazone, an insulin-sensitizing drug. Transgenic overexpression of human RBP4 or injection of recombinant RBP4 in normal mice causes insulin resistance. Conversely, genetic deletion of Rbp4 enhances insulin sensitivity. Fenretinide, a synthetic retinoid that increases urinary excretion of RBP4, normalizes serum RBP4 levels and improves insulin resistance and glucose intolerance in mice with obesity induced by a high-fat diet. Increasing serum RBP4 induces hepatic expression of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) and impairs insulin signalling in muscle. Thus, RBP4 is an adipocyte-derived 'signal' that may contribute to the pathogenesis of type 2 diabetes. Lowering RBP4 could be a new strategy for treating type 2 diabetes.     

一种利用混合模型研究基因与疾病间关联的方法

给出了将多位点基因型信息作为混杂因子的协变量,利用混合模型讨论在病例一对照研究中,当被研究群体中存在着分层现象时,被研究基因与疾病之间关联的一种新的方法．在子群体内部满足Hardy-Weinberg平衡时,此方法充分地利用已知信息,用基因标识物将群体分层,并估计出被研究基因与疾病之间的关联性,同时还考虑了多位点基因型数据有缺失的情况．     

一种利用混合模型研究基因与疾病问关联的方法

给出了将多位点基因型信息作为混杂因子的协变量,利用混合模型讨论在病例一对照研究中,当被研究群体中存在着分层现象时,被研究基因与疾病之间关联的一种新的方法.在子群体内部满足Hardy-Weinberg平衡时,此方法充分地利用已知信息,用基因标识物将群体分层,并估计出被研究基因与疾病之间的关联性,同时还考虑了多位点基因型数据有缺失的情况.     

Genetic analysis of autoimmune type 1 diabetes mellitus in mice.

Two genes, Idd-3 and Idd-4, that influence the onset of autoimmune type 1 diabetes in the nonobese diabetic mouse have been located on chromosomes 3 and 11, outside the chromosome 17 major histocompatibility complex. A genetic map of the mouse genome, analysed using the polymerase chain reaction, has been assembled specifically for the study. On the basis of comparative maps of the mouse and human genomes, the homologue of Idd-3 may reside on human chromosomes 1 or 4 and Idd-4 on chromosome 17.     

使用病毒载体的罕见病基因疗法临床进展

 很大一部分的罕见病由遗传因素决定,难以用普通的小分子或大分子药物治愈,而基因治疗有望从根本上修正人体功能的缺失或异常,给罕见病患者带来改善生活质量的希望。目前许多基因疗法的临床试验正在开展,病毒载体是常用的基因递送方法,本文讨论了用于临床基因递送的多种病毒载体,包括腺相关病毒、逆转录病毒和慢病毒,重点列举了这些病毒在罕见病临床试验中的研究、应用和进展,评价了这些病毒的优缺点,并简述了基因疗法的研究方向及应用前景。     

The localization of type 2 diabetes susceptibility gene loci in northern Chinese Han families

We conducted a genome-wide scan, in which 358 well distributed fluorescent dye-labeled microsatellite marker sets were applied in 32 Chinese Han type 2 diabetes families from Northern China to search for the susceptibility gene loci. The data collected from screening all the chromosomes of genome were genotyped by using genescan and genotyping software, then, parametric and non-parametric multipoint test, and affected sib-pair analysis as well, were used to analyze the data. We identified some susceptibility gene loci residing in chromosomes 1, 12, 18, 20, respectively, or precisely, located around D1S214, D1S207, D1S218, D1S235, D12S336, D18S61 and D20S118. The comparison of this result with those from other regions and races reflected the complexity and heterogeneity of type 2 diabetes.     

应用STR基因座基因型频率对阿昌族及其他种族和民族的遗传距离进行比较

目的：对阿昌族和其他种族和民族的遗传进行距离比较,以对阿昌族的起源进行有益的分析。方法：复合扩增9个STR基因座,扩增产物进行基因扫描和基因分型。调查阿昌族9个STR基因座的基因频率分布。对阿昌族和其他种族和民族的遗传距离进行比较和聚类分析。结果：阿昌族与美国黑人、白人和我国其他几个民族遗传距离差异由小到大依次为：藏族(0．0433)→汉族(0．0532)→蒙古族(0．0670)→回族(0．0858)→维吾尔族(0．1075)→白种人(0．1571)→黑种人(0．2542)。结论：表示种族之间差异大于民族之间的差异。阿昌族与藏族、汉族的遗传距离较近而与维吾尔族较远。