脂联素受体1基因多态性与2型糖尿病相关性研究

目的研究西安地区汉族人群中脂联素受体1（AdipoR1）的两个单核苷酸多态性（SNP）位点与2型糖尿病（T2DM）的关系。方法采用突变特异性扩增系统（ARMS）结合测序方法对西安地区100例T2DM患者（T2DM组）及84名正常对照者（NC组）AdipoRl基因的两个SNP位点进行分析。结果（1）AdipoR1基因SNP-106A／G、SNP 5843A／G在DM组与NC组间基因型频率及等位基因频率差异无统计学意义。（2）AdipoR1基因5843G／G型T2DM患者的诊断年龄明显早于A／A型＋A／G型。结论在西安地区的汉族人群中，AdipoR1基因-106A／G、5843A／G的单个核苷酸多态性可能与T2DM的发病无关。携带5843G／G基因型的T2DM患者发病年龄较早。     

ATP结合盒转运子A1R219K基因多态性与2型糖尿病合并冠心病的相关性研究

目的探讨ATP结合盒转运子A1（ABCA1）R219K基因多态性与2型糖尿病（T2DM）合并冠心病（CHD）的关系。方法采用多聚酶链反应-限制性片段长度多态性法检测83例健康对照者（NC组）、72例单纯T2DM患者（CHD-组）、71例T2DM合并CHD患者（CHD＋组）ABCA1219位点的多态基因型。结果在NC组、CHD-组、CHD＋组中，KK基因型分布为19．3％、16．7％、4．2％；CHD＋组与NC组、CHD-组KK基因型频率差异有统计学意义（P〈0.05）。K等位基因频率分别为42．2％、38．9％、31．7％，三组间差异无统计学意义。在糖尿病患者中，KK基因型携带者的血浆HDL-C水平显著高于RR型，其差异有统计学意义（P〈0.05）。结论ABCA1R219K基因多态性可能相关于T2DM并发的CHD。     

抵抗素基因+299G/A多态性与T2DM并高血压病的相关性

目的研究抵抗素基因＋299G／A多态性与中国北方地区汉族人群2型糖尿病（T2DM）并高血压病的关系。方法采用聚合酶链式反应-限制性片段长度多态性技术检测北方地区汉族人群261例T2DM患者的抵抗素基因内含子2区299G／A突变。结果T2DM组GG、GA、AA基因型及G／A等位基因频率与非T2DM组比较有显著统计学差异（P〈0．01）；T2DM组GG基因型携带者空腹血糖明显高于AA基因型携带者（P〈0．05）。多元线性逐步回归分析显示，抵抗素基因＋299G／A与收缩压、舒张压无明显相关性。结论抵抗素基因＋299G／A多态性与T2DM有关．与高血压病元明显相关性。     

我国西部人群脂联素基因+45位点多态性与肥胖、胰岛素抵抗及2型糖尿病的相关性

目的探讨宁夏汉族人群脂联素基因＋45位核苷酸T／G多态性与肥胖、胰岛素抵抗（IR）及2型糖尿病（T2DM）的相关性。方法采用聚合酶链式反应-限制性内切酶长度多态性技术，对100例T2DM患者和101例正常对照（NC）者脂联素基因＋45位点进行基因分型；并计算BMI和HOMA-IR。结果（1）T2DM组GG基因型频率明显高于NC组（P〈0．01），G等位基因频率明显高于NC组（P〈0．01）。（2）在T2DM组中，GG＋TG基因型的BMI、HOMA-IR大于TT基因型（P〈0．01）。在NC组中，各基因型间BMI、HOMA-IR的差异无统计学意义。在T2DM组中，而BMII〉25组的GG＋TG基因型频率高于BMI〈25组（P〈0．01），G等位基因频率也高于BMI〈25组（P〈0．01）。结论脂联素基因＋45位核苷酸T／G多态性与肥胖、IR及T2DM相关。     

胱抑素C基因多态性与2型糖尿病患者轻度认知功能障碍的相关性研究

目的：研究老年2型糖尿病（T2DM）患者的胱抑素C基因（CST3）多态性与其发生轻度认知功能障碍（MCI）的关系,探讨发生MCI的相关危险因素。方法选取156例老年T2DM患者,分为MCI组和认知功能正常组（NC）,均使用简易智力状态量表、蒙特利尔认知评估量表、焦虑自评量表、流行病学调查用抑郁自评量表、帕金森病筛查量表、日常生活能力量表、全面衰退量表等进行测验,聚合酶链反应-限制性片段长度多态性分析（PCR-RFLP）CST3基因多态性。结果 A等位基因频率在MCI组与NC组分别为80.4%和90.9%,B等位基因频率在MCI组与NC组分别为19.6%和9.1%,两组比较c2＝7.005,P＝0.008,差异均有统计学意义。在0.05检验水准下,携带B等位基因（OR：2.279,95% CI：1.064～4.882,P＝0.034）与T2DM发生MCI危险性的关联差异有统计学意义。结论携带B等位基因是老年T2DM患者发生MCI的危险因素。检测CST3多态性有利于老年T2DM患者认知障碍的早期诊断。     

乙酰辅酶A羧化酶β基因多态性与2型糖尿病易感性关系的初步研究

目的 研究上海地区汉族人群中乙酰辅酶A羧化酶B（ACC-β）的2个单核苷酸多态性（SNP）位点与2型糖尿病（T2DM）易感性的关系。方法 采用等位基因专一性实时PCR的方法对上海地区438例T2DM患者及328名正常对照者（NC）ACC-β基因的2个SNP位点进行分析。结果 （1）ACC-β基因16号内含子区存在SNP位点116／73C＞T，T2DM组和NC组两组间基因型频率比较，差异有统计学意义（P=0．031）。且CC型＋CT型与TT型的分组比较在两组间的差异也有统计学意义（P=0．027）。（2）ACC-B基因16号内含子区还存在另-SNP位点：116／288A〉G，T2DM组G等位基因的频率高于NC组，但无统计学意义。结论 在上海地区的汉族人群中，ACC-β基因可能是T2DM的易感基因之一，其16号内含子区的116／73C＞T多态性（rs2268393）可能与T2DM的发病相关。     

维生素D受体基因FokⅠ多态性与2型糖尿病及其合并动脉粥样硬化的相关性

目的探讨维生素D受体（VDR）基因FokⅠ的多态性与T2DM及其合并动脉粥样硬化（AS）之间的相关性。方法通过提取全血DNA,PCR扩增VDR基因,FokⅠ酶切扩增产物,检测大连地区T2DM合并AS者（AS组）,DM非AS者（non-AS组）及健康对照者（NC组）的基因型。应用单因素非条件logistic回归分析研究VDR基因变异对T2DM及合并AS的影响。结果（1）VDR基因FokⅠ酶切位点各基因型在T2DM组和NC组中分布具有统计学差异（P〈0．01）。（2）AS组和non-AS组VDR基因FokⅠ酶切各基因型分布无统计学差异（P〉0．05）。（3）VDR等位基因f与T2DM呈显著正相关,等位基因F与T2DM呈显著负相关。结论在大连地区的汉族人群中,VDR基因FokⅠ的多态性与T2DM相关,而与T2DM合并AS无关。等位基因f是T2DM的易感基因,而等位基因F对T2DM具有保护作用。     

核因子kappaB基因多态性与2型糖尿病易感性相关的研究

目的探讨核因子kappaB基因多态性与2型糖尿病（T2DM）易感性的相关性。方法PCR荧光法分析T2DM组（160例）和正常健康对照组（Con,82例）NF-κB的（CA）重复序列的多态性。结果A4（124bp）等位基因的频率在Con组中明显高于T2DM组;A8（132bp）等位基因频率在T2DM组中明显高于Con组。结论NF-κB1基因在T2DM易感性上可能起到重要作用：等位基因A8携带者比A4携带者更容易患T2DM。     

单核细胞趋化蛋白1基因A2518G多态性与2型糖尿病肾病的关系

目的 探讨单核细胞趋化蛋白（MCP-1）基因调节区A2518G多态性与湖南汉族人2型糖尿病（T2DM）合并肾病之间的关系。方法 运用聚合酶链反应限制性片段长度多态性技术（PCR-RFLP），结合DNA测序技术，检测了单纯糖尿病（DM）组86例，糖尿病肾病（DN）组94例；正常对照（NC）102例，282例湖南汉族人的MCP-1基因调节区A2518G多态性。结果 DN组MCP-1G／G基因型频率和G等位基因频率高于DM组、NC组，但差异无统计学意义（P〉0．05）。结论 （1）糖代谢紊乱和脂代谢紊乱是DN发生发展的危险因素；（2）MCP-1A2518G多态性与DN发病无相关性。     

昆明汉族2型糖尿病肾病与ATIR基因A1166C多态性关系

运用限制性片段长度多态性聚合酶链反应（PCR—RFLP）检测184例T2DM患者，其中110例为DN者[DN（＋）组]、74例为无肾病者[DN（-）组]及56例正常对照组（NC组）的AT1R基因多态性。结果（1）昆明汉族正常人群中AT1R基因型AA型86％，AC型14％，CC型未检出；A等位基因频率93％，C等位基因频率7％。（2）T2DM组与NC组A1R基因T的A1166C多态基因型频率和等位基因频率分布均无差异（P〉0．05）。（3）DN（＋）与DN（-）中AT1R基因的A1166C多态基因型频率和等位基因频率分布均无差异（P〉0．05）。结论（1）昆明地区汉族正常人群AT1R基因多态性频率分布具有一定的地区特征。（2）昆明汉族T2DM及2型DN与AT1R基因A1166C多态性无关。     

Tsc1 regulates tight junction independent of mTORC1

Tuberous sclerosis complex 1 (Tsc1) is a tumor suppressor that functions together with Tsc2 to negatively regulate the mechanistic target of rapamycin complex 1 (mTORC1) activity. Here, we show that Tsc1 has a critical role in the tight junction (TJ) formation of epithelium, independent of its role in Tsc2 and mTORC1 regulation. When an epithelial cell establishes contact with neighboring cells, Tsc1, but not Tsc2, migrates from the cytoplasm to junctional membranes, in which it binds myosin 6 to anchor the perijunctional actin cytoskeleton to β-catenin and ZO-1. In its absence, perijunctional actin cytoskeleton fails to form. In mice, intestine-specific or inducible, whole-body Tsc1 ablation disrupts adherens junction/TJ structures in intestine or skin epithelia, respectively, causing Crohn’s disease–like symptoms in the intestine or psoriasis-like phenotypes on the skin. In patients with Crohn’s disease or psoriasis, junctional Tsc1 levels in epithelial tissues are markedly reduced, concomitant with the TJ structure impairment, suggesting that Tsc1 deficiency may underlie TJ-related diseases. These findings establish an essential role of Tsc1 in the formation of cell junctions and underpin its association with TJ-related human diseases.

Epithelium is a thin tissue covering the body surface, lining alimentary spaces, and other structures inside the body. It is composed of a layer of attached epithelial cells, such that it blocks the paracellular diffusion of solutes and water, as well as preventing infectious microorganisms entering the body (1). This paracellular blockage is achieved by a tripartite apical junctional complex, which constitutes tight junctions (TJs), adherens junctions (AJs), and desmosomes arranged in sequential order, from the apical end to the basal end of the junction. In this arrangement, TJs establish barrier functions. Consequently, TJ dysfunction is associated with a myriad of human diseases, including Crohn’s disease, ulcerative colitis, celiac disease (leak-flux diarrhea), cystic fibrosis, atopic dermatitis (AD), and psoriasis (1–3).TJs are composed of networks of strands formed by transmembrane proteins. The extracellular domains of these membrane proteins are tethered together, and their cytoplasmic domains are anchored to the actin cytoskeleton via cytoplasmic scaffolding proteins. More than 40 different proteins have been found in TJs, including transmembrane proteins, claudins, junctional adhesion molecules, coxsackie adenovirus receptors, and TJ-associated marvel proteins, such as occludin, tricellulin, marvelD3 proteins, and cytoplasmic scaffolding proteins of the ZO family (4–7). While AJ and TJ structural components and organization are well studied, the mechanisms controlling their assembly and stability of established adhesive contacts remain unclear. Several studies have shown that AJ formation precedes TJ and is essential for TJ formation (8, 9). The attachment of the cadherin α-catenin–β-catenin adhesion complex to perijunctional cortex actin filaments establishes AJs (10, 11). The subsequent recruitment of ZO-1 to the α-catenin–β-catenin complex is believed to initiate TJ formation from the existing AJs (12).Tsc1 (hamartin) is a tumor suppressor protein encoded by TSC1, a causative gene for tuberous sclerosis complex (TSC) syndrome (13–16). Tsc1 functions with Tsc2, a GTPase-activating protein (GAP), to restrict Rheb activation, a Ras-like small GTPase and activator of mechanistic targets of rapamycin complex 1 (mTORC1). Tsc1 binds Tsc2 directly to stabilize the latter, preventing it from proteasomal degradation (17, 18). The GAP activity of Tsc2 leads to Rheb inactivation and subsequent mTORC1 inhibition (19, 20). mTORC1 is a central signaling hub controlling cell growth, metabolism, survival, and autophagy in response to nutrient availability and growth factors (21–25). Its abnormal activation in Tsc1- and Tsc2-deficient cells is believed to be the main pathogenic cause behind TSC syndrome (20, 26, 27).While studying the function of Tsc1 in intestinal epithelial cells, we serendipitously observed that intestinal, epithelial-specific Tsc1 ablation caused symptoms and histopathological alterations in mice, commonly associated with TJ defects (28, 29). This observation led us to investigate a previously unknown role of Tsc1 in TJs. Here, we show that Tsc1 is a key regulator of cell–cell adhesion that controls TJ formation independent of its role in mTORC1 regulation. Reduced Tsc1 levels at the junctional membrane are associated with TJ-related diseases in humans.     

Divalent metal transporter 1 (DMT1) regulation by Ndfip1 prevents metal toxicity in human neurons

The regulation of metal ion transport within neurons is critical for normal brain function. Of particular importance is the regulation of redox metals such as iron (Fe), where excess levels can contribute to oxidative stress and protein aggregation, leading to neuronal death. The divalent metal transporter 1 (DMT1) plays a central role in the regulation of Fe as well as other metals; hence, failure of DMT1 regulation is linked to human brain pathology. However, it remains unclear how DMT1 is regulated in the brain. Here, we show that DMT1 is regulated by Ndfip1 (Nedd4 family-interacting protein 1), an adaptor protein that recruits E3 ligases to ubiquitinate target proteins. Using human neurons we show the Ndfip1 is upregulated and binds to DMT1 in response to Fe and cobalt (Co) exposure. This interaction results in the ubiquitination and degradation of DMT1, resulting in reduced metal entry. Induction of Ndfip1 expression protects neurons from metal toxicity, and removal of Ndfip1 by shRNAi results in hypersensitivity to metals. We identify Nedd4–2 as an E3 ligase recruited by Ndfip1 for the ubiquitination of DMT1 within human neurons. Comparison of brains from Ndfip1^−/− with Ndfip1^+/+ mice exposed to Fe reveals that Ndfip1^−/− brains accumulate Fe within neurons. Together, this evidence suggests a critical role for Ndfip1 in regulating metal transport in human neurons.     

Distinct receptor-mediated activities in macrophages for natural ceramide-1-phosphate (C1P) and for phospho-ceramide analogue-1 (PCERA-1)

Ceramide-1-phosphate (C1P) is known as a second messenger regulating a multitude of processes including cell growth, apoptosis and inflammation. Exciting recent findings now suggest that C1P can stimulate macrophages migration in an extra-cellular manner via a G protein-coupled receptor (GPCR). Interestingly, a synthetic C1P analog, named phospho-ceramide analogue-1 (PCERA-1), was recently described as a potent in-vivo anti-inflammatory agent, and was suggested to act on macrophages in an extra-cellular manner via a GPCR. Here we summarize and compare the receptor-mediated as well as receptor-independent activities of natural C1P and its synthetic analog. We also provide experimental data in support of distinct C1P and PCERA-1 receptors.     

Hypoxia-inducible factor-1 modulates upregulation of mutT homolog-1 in colorectal cancer

AIM: To investigate the roles and interactions of mutT homolog (MTH)-1 and hypoxia-inducible factor (HIF)-1α in human colorectal cancer (CRC).METHODS: The expression and distribution of HIF-1α and MTH-1 proteins were detected in human CRC tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). SW480 and HT-29 cells were exposed to normoxia or hypoxia. Protein and mRNA levels of HIF-1α and MTH-1 were analyzed by western blotting and qRT-PCR, respectively. In order to determine the effect of HIF-1α on the expression of MTH-1 and the amount of 8-oxo-deoxyguanosine triphosphate (dGTP) in SW480 and HT-29 cells, HIF-1α was silenced with small interfering RNA (siRNA). Growth studies were conducted on cells with HIF-1α inhibition using a xenograft tumor model. Finally, MTH-1 protein was detected by western blotting in vivo.RESULTS: High MTH-1 mRNA expression was detected in 64.2% of cases (54/84), and this was significantly correlated with tumor stage (P = 0.023) and size (P = 0.043). HIF-1α protein expression was correlated significantly with MTH-1 expression (R = 0.640; P < 0.01) in human CRC tissues. Hypoxic stress induced mRNA and protein expression of MTH-1 in SW480 and HT-29 cells. Inhibition of HIF-1α by siRNA decreased the expression of MTH-1 and led to the accumulation of 8-oxo-dGTP in SW480 and HT-29 cells. In the in vivo xenograft tumor model, expression of MTH-1 was decreased in the HIF-1α siRNA group, and the tumor volume was much smaller than that in the mock siRNA group.CONCLUSION: MTH-1 expression in CRC cells was upregulated via HIF-1α in response to hypoxic stress, emphasizing the crucial role of HIF-1α-induced MTH-1 in tumor growth.     

Arabidopsis MZT1 homologs GIP1 and GIP2 are essential for centromere architecture

Centromeres play a pivotal role in maintaining genome integrity by facilitating the recruitment of kinetochore and sister-chromatid cohesion proteins, both required for correct chromosome segregation. Centromeres are epigenetically specified by the presence of the histone H3 variant (CENH3). In this study, we investigate the role of the highly conserved γ-tubulin complex protein 3-interacting proteins (GIPs) in Arabidopsis centromere regulation. We show that GIPs form a complex with CENH3 in cycling cells. GIP depletion in the gip1gip2 knockdown mutant leads to a decreased CENH3 level at centromeres, despite a higher level of Mis18BP1/KNL2 present at both centromeric and ectopic sites. We thus postulate that GIPs are required to ensure CENH3 deposition and/or maintenance at centromeres. In addition, the recruitment at the centromere of other proteins such as the CENP-C kinetochore component and the cohesin subunit SMC3 is impaired in gip1gip2. These defects in centromere architecture result in aneuploidy due to severely altered centromeric cohesion. Altogether, we ascribe a central function to GIPs for the proper recruitment and/or stabilization of centromeric proteins essential in the specification of the centromere identity, as well as for centromeric cohesion in somatic cells.In eukaryotes, centromeres play a critical role in accurate chromosome segregation and in the maintenance of genome integrity through their regulated assembly and the maintenance of their cohesion until anaphase. Centromeres consist each of a central core (1) characterized epigenetically by the recruitment of the histone H3 variant CENH3 (CENP-A in animals). Extensive studies are still ongoing to identify the regulatory factors for loading and maintenance of CENH3 at centromeres. In yeast, suppressor of chromosome missegregation protein 3 was identified as a specific chaperone for CENP-A loading (2). In animals, the Mis18 complex, including the CENH3 assembly factor Kinetochore Null 2 (KNL2; also called Mis18BP1), recruits the cell cycle-dependent maintenance and deposition factor of CENP-A, HJURP (Holliday junction recognition protein), to centromeres (3). Recently, two Mis18-complex components, Eic1 and Eic2, were identified in fission yeast (4). Whereas Eic1 promotes CENH3 loading and maintenance, Eic2 is recruited at centromeres independently of its association with Mis18. Together with CENH3, the conserved kinetochore assembly protein CENP-C participates in pericentromeric cohesin recruitment (5). The CENH3 loading machinery changed rapidly during evolution, and a CENH3 chaperone has not been identified in plants thus far. Moreover, nothing is known about a possibly conserved interplay between CENH3 loading and sister chromatid cohesion at centromeres. Recently, the plant homolog of KNL2 was proposed as an upstream component for CENH3 deposition at centromeres (6). Finally, the regulation of centromeric complex positioning at the nuclear envelope environment is still elusive in plants.

Table S1.

Gene accession numbers

From the Cover: Mutant superoxide dismutase 1-induced IL-1β accelerates ALS pathogenesis

ALS is a fatal motor neuron disease of adult onset. Neuroinflammation contributes to ALS disease progression; however, the inflammatory trigger remains unclear. We report that ALS–linked mutant superoxide dismutase 1 (SOD1) activates caspase-1 and IL-1β in microglia. Cytoplasmic accumulation of mutant SOD1 was sensed by an ASC containing inflammasome and antagonized by autophagy, limiting caspase-1–mediated inflammation. Notably, mutant SOD1 induced IL-1β correlated with amyloid-like misfolding and was independent of dismutase activity. Deficiency in caspase-1 or IL-1β or treatment with recombinant IL-1 receptor antagonist (IL-1RA) extended the lifespan of G93A-SOD1 transgenic mice and attenuated inflammatory pathology. These findings identify microglial IL-1β as a causative event of neuroinflammation and suggest IL-1 as a potential therapeutic target in ALS.     

Updates on HTLV-1 Uveitis

HTLV-1 uveitis (HU) is the third clinical entity to be designated as an HTLV-1-associated disease. Although HU is considered to be the second-most frequent HTLV-1-associated disease in Japan, information on HU is limited compared to that on adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy (HAM). Recent studies have addressed several long-standing uncertainties about HU. HTLV-1-related diseases are known to be caused mainly through vertical transmission (mother-to-child transmission), but emerging HTLV-1 infection by horizontal transmission (such as sexual transmission) has become a major problem in metropolitan areas, such as Tokyo, Japan. Investigation in Tokyo showed that horizontal transmission of HTLV-1 was responsible for HU with severe and persistent ocular inflammation. The development of ATL and HAM is known to be related to a high provirus load and hence involves a long latency period. On the other hand, factors contributing to the development of HU are poorly understood. Recent investigations revealed that severe HU occurs against a background of Graves’ disease despite a low provirus load and short latency period. This review highlights the recent knowledge on HU and provides an update on the topic of HU in consideration of a recent nationwide survey.     

Msc1 links dynamic Swi6/HP1 binding to cell fate determination

Eukaryotic genomes can be organized into distinct domains of heterochromatin or euchromatin. In the fission yeast Schizosaccharomyces pombe, assembly of heterochromatin at the silent mating-type region is critical for cell fate determination in the form of mating-type switching. Here, we report that the ubiquitin ligase, Msc1, is a critical factor required for proper cell fate determination in S. pombe. In the absence of Msc1, the in vivo mobility of Swi6 at heterochromatic foci is compromised, and centromere heterochromatin becomes hyperenriched with the heterochromatin binding protein Swi6/HP1. However, at the mating-type locus, Swi6 recruitment is defective in the absence of Msc1. Therefore, Msc1 links maintaining dynamic heterochromatin with proper heterochromatin assembly and cell fate determination. These findings have implications for understanding mechanisms of differentiation in other organisms.