工作空间

文章信息

王鹤霏, 刘东军. 2015
转基因技术:糖尿病的动物模型构建及治疗
生物技术通报,2015,31(10): 89-98

Wang Hefei, Liu Dongjun. 2015
Transgenic Technology: Establishment of Animal Models and Treatment of Diabetes Mellitus
Biotechnology Bulletin,2015,31(10): 89-98

文章历史

收稿日期:2014-09-15

转基因技术:糖尿病的动物模型构建及治疗
王鹤霏, 刘东军     
(内蒙古大学国家动物转基因技术研究中心,呼和浩特 010070)
摘要:糖尿病是严重危害人类健康的疾病,近年来,随着转基因理论及技术的发展,很多科学家都致力于应用转基因技术治疗糖尿病,并取得了显著成效。主要综述了目前在转基因糖尿病动物模型构建和糖尿病治疗方面取得的诸多成果,以及面临的挑战。提出了今后在建立高效的胰岛素基因转移体系、选择与β细胞生理特点相似又免受自身免疫系统攻击的靶细胞、基因表达的持续性和糖尿病易感基因的鉴定等方向的突破,可以加快糖尿病的基因治疗用于临床的步伐。
关键词转基因     糖尿病     动物模型     治疗    
Transgenic Technology: Establishment of Animal Models and Treatment of Diabetes Mellitus
Wang Hefei, Liu Dongjun     
(National Research Center for Animal Transgenic Bio-technology,Inner Mongolia University,Hohhot 010070)
Abstract: Diabetes mellitus endangers human health seriously. In recent years, with the development of transgenic theory and technology, many researchers are devoted to treat diabetes by applying transgenic technology. Therefore, some remarkable achievements have been achieved. This review describes the current achievements and challenges in the establishment of animal models and treatment of D. mellitus by transgenic technology. In future the breakthroughs from following aspects may accelerate the gene therapy of D. mellitus in clinical practice, such as the establishment of effective insulin gene transfer system, selection of target cells resembling physiological characteristics of β cells and preventing them from the attack of own immune system, sustainability of gene expression and identification of D. mellitus susceptible genes.
Key words: transgene     Diabetes mellitus      animal model      treatment    

糖尿病是一种代谢紊乱疾病,继心脑血管疾病、癌症之后成为人类第三大杀手[1]。国际糖尿病联盟(International Diabetes Federation,IDF)2011年的调查结果显示全世界糖尿病患者已达3.66亿,预计到2030年上升到5.52亿[2]。动物模型在糖尿病及其并发症发病机制的研究中发挥着重要的作用,随着糖尿病相关基因的克隆及转基因技术的发展,利用转基因手段构建糖尿病动物模型成为近年来研究的热点。同时,糖尿病基因治疗进展迅速,通过转基因技术对与糖尿病相关的基因进行插入、敲除和修饰,可望成为彻底治愈糖尿病的有效方法。本文对转基因技术构建糖尿病动物模型及治疗糖尿病进行分类和整理,为研究者寻找和使用更适宜的糖尿病动物模型以及治疗糖尿病方面提供依据。

1 糖尿病动物模型 1.1 传统糖尿病动物模型

研究发现通过注射链脲霉素(Streptozocin,STZ)[3]、四氧嘧啶(Alloxan)[4]、吡甲硝苯脲(Vacor)、二苯基硫代卡巴腙(Dithizone)和8-羟基喹啉(8-hydroxyquinolone)等化学毒素类物质可以破坏胰腺组织。链脲霉素通过葡萄糖转运体(GLUT2)[5]进入胰腺β细胞,选择性破坏这些细胞并产生DNA烷基化,导致迅速而不可逆的细胞坏死[6]。腹膜内多次低剂量或单次高剂量注射STZ,诱导多种实验动物患上糖尿病[7]

非肥胖型糖尿病(Non-obese diabetic,NOD)小鼠是常用的Ⅰ型糖尿病(T1DM)动物模型,免疫细胞激活导致胰腺产生胰岛素β细胞袭击并破坏[8]。BB(Biobreeding)大鼠与人类Ⅰ型糖尿病发病特征相似,包括起始阶段、胰岛炎、高血糖症、终身依赖外源胰岛素等[9, 10]。GK(Goto Kakizaki)大鼠是在Wistar大鼠近交选育中筛选出具有自发非胰岛素依赖的糖尿病模型[11]。KK-Ay小鼠,也称作Yellow KK obese小鼠,携带致死yellow obese(Ay)和糖尿病基因,在8周龄时出现严重的肥胖症、高血糖症、高胰岛素血症和葡萄糖耐受不良,因此被广泛应用于Ⅱ型糖尿病(T2DM)模型[12, 13]。NSY(Nagoya-Shibata-Yasuda)是从Jcl:ICR克隆小鼠中通过选择性饲养葡萄糖耐受不良筛选出来的先天自发Ⅱ型糖尿病动物模型,与人类Ⅱ型糖尿病特征相似,如年龄依赖性、适度肥胖、腹部脂肪积累、葡萄糖刺激胰岛素分泌损伤和胰岛素抵抗等[14, 15, 16]

1.2 转基因糖尿病动物模型 1.2.1 Ⅱ型糖尿病动物模型

利用组织特异性基因敲除技术敲除Ⅱ型糖尿病的候选基因,为研究Ⅱ型糖尿病发病的分子机制提供了重要手段。外周组织器官的胰岛素抵抗和β细胞分泌功能障碍是Ⅱ型糖尿病发病过程中的两个重要环节,而胰岛素信号转导缺陷是产生胰岛素抵抗的重要机制,同时也影响胰岛素的分泌,因而利用基因敲除技术观察候选基因在产生胰岛素抵抗和胰岛素分泌缺陷中的作用已成为该领域的研究热点[17]。胰岛素受体(Insulin receptor,IR)基因敲除鼠,其纯合子小鼠可出现严重糖尿病症状并于出生后一周内死亡,杂合子小鼠无明显的代谢异常,仅10%在成年时出现糖尿病症状[18, 19]。而胰岛β细胞特异性IR基因或肌肉特异性IR基因敲除鼠虽然呈现胰岛素抵抗和轻度代谢紊乱,但却不发展成Ⅱ型糖尿病[20, 21]。美国国立卫生研究院于2001年建立MKR(Mice overexpressing a dominant-negative IGF-IR specifically in skeletal musc-le)小鼠[22],这是一种胰岛素样生长因子(Insulin-like growth factor,IGF)和IR的双重功能缺失鼠,表现为显著的肌肉、肝脏、脂肪组织胰岛素抵抗,胰岛β细胞功能紊乱,脂代谢紊乱及高血糖等症状,可作为研究Ⅱ型糖尿病的经典动物模型[23, 24, 25, 26, 27]

Maddux等[28]在Ⅱ型糖尿病患者中发现抑制胰岛素受体酪氨酸激酶活性的浆细胞抗原-1(Plasma cell antigen-1,PC-1)与胰岛素抵抗直接相关。说明糖尿病患者组织中PC-1含量的增高可能是造成胰岛素抵抗或糖尿病的原因[29, 30, 31, 32]。王毅等[33]构建稳定表达PC-1基因的转基因小鼠系,对PC-1转基因阳性小鼠鉴定发现该基因在相关组织中的高表达不足以触发胰岛素抵抗或Ⅱ型糖尿病的发生。由于转基因技术本身的缺陷性,即不同物种来源蛋白可能存在表达差异,所以PC-1基因和Ⅱ型糖尿病发生之间的关系有待进一步研究。

近年来,一些与Ⅱ型糖尿病相关因子的报道为转基因技术构建Ⅱ型糖尿病动物模型带来新的可能。过氧化物酶体增殖激活受体-γ辅激活蛋白(PGC-1α)是一种转录协同激活子,涉及适应性发热作用、骨骼肌代谢、脂肪酸氧化和糖异生,有研究报道PGC-1α的多态性与Ⅱ型糖尿病的发生相关[34, 35, 36, 37]。垂体腺苷酸环化酶-激活多肽(Pituitary adenylate cyclase-activating polypeptide,PACAP)是促胰岛素G-蛋白偶联受体的配体,在II型糖尿病小鼠模型中抑制β-细胞团扩张和胰岛密度[38]。人胰岛淀粉样多肽(Human islet amyloid polypeptide,hIAPP)与II型糖尿病β细胞凋亡增加和β细胞团减少有关。hIAPP转基因胰岛中,hIAPP诱导cJUN N-末端激酶(JNK)通路激活,导致氧化应激、β细胞凋亡[39]

1.2.2 Ⅰ型糖尿病动物模型

T1DM是胰岛β细胞渐进破坏引起胰岛素缺乏和高血糖症的自身免疫性疾病[40, 41]。何君等[42]研究表明系统表达人T细胞受体α(TCRα)基因小鼠腹腔注射STZ后2-8周可建立稳定Ⅰ型糖尿病小鼠模型。一些与T1DM发生相关基因多态性的研究,为转基因技术构建Ⅰ型糖尿病动物模型带来了启发。Toll样受体3(TLR3)基因多态性[43]、抗原肽转运蛋白1(TAP1)I333V基因多态性[44],以及维生素D受体(VDR)基因BsmI多态性[45]与T1DM的易感性相关。

1.2.3 导致糖尿病潜在的基因位点

IKK/NF-κB(Inhibitor of κB kinase/nuclear factor-κB)是炎症反应的主要调节剂。Salem等[46]构建依赖Pdx-1(Panc-reatic and duodenal homeobox 1)启动子表达人组成型激活突变IKK2基因——IKK2-CA(Pdx-1)的转基因小鼠模型,用以研究β-细胞中NF-κB潜在的致糖尿病效果。研究发现转基因小鼠自发发展为伴随胰岛炎、高血糖症和低胰岛素血症的成熟免疫介导糖尿病,表明β-细胞特异的IKK2/NF-κB激活是免疫介导糖尿病潜在的触发器。

Fas-FasL相互作用触发胰岛β-细胞凋亡,并与胰岛素抵抗和糖尿病相关[47, 48]。苗宏生等[49]证实hFasL转基因小鼠在胰岛组织中可表达FasL,通过血糖测定和胰岛组织免疫组化染色表明它们相对于普通同品系小鼠更易被低剂量的STZ诱导而患病,证明Fas和FasL在糖尿病发生过程中起着重要作用。

3B4天然自身抗体可以识别包括胰岛素等多种抗原,且对胰岛素有较高的亲和力。宋媛等[50]研究表明高表达3B4天然自身抗体的转基因小鼠,无论是否具有NOD背景,均表现糖耐量异常,甚至诱发糖尿病。

UBC9是SUMO化修饰的唯一E2结合酶,而蛋白SUMO化修饰是一种重要的转录后抵抗应激的调节机制。赖巧红[51]构建诱导型UBC9基因敲除小鼠模型,导致胰岛形态和功能异常、β细胞凋亡、早期糖耐量异常、晚期血糖自发升高,出现自发糖尿病。因此,UBC9基因的敲除导致了糖尿病发生。

朱金改[52]选择肥胖与正常人脂肪组织中的差异表达基因PID1(GenBank:AY317148)为目的基因,建立了PID1转基因小鼠,在高脂饮食诱导下,转基因小鼠出现肥胖、脂质代谢紊乱、胰岛素敏感性降低等症状,暗示PID1可能与糖尿病相关。

转录因子Pax6是发育调节剂,在眼、脑、嗅觉系统和内分泌胰腺的发育中起重要作用。Hart等[53]构建纯合子Pax6敲除小鼠模型,导致典型的糖尿病症状,并且胰岛素、胰高血糖素和生长抑素表达减少。表明Pax6基因敲除诱导糖尿病。

综上,导致糖尿病潜在的基因位点与炎症反应、β-细胞凋亡、胰岛素结合抗体、蛋白修饰、肥胖和胰腺发育等基因相关。

2 转基因治疗糖尿病 2.1 转基因治疗自身免疫型糖尿病

Prdm1基因编码B淋巴细胞诱导的成熟蛋白1(BLIMP-1)。Lin等[54]建立了T细胞过表达Blimp1的转基因NOD小鼠,使淋巴细胞的增殖和激活被抑制、调控T细胞(Regulatory T cells,Tregs)的功能增强、胰岛炎和糖尿病症状减弱。表明BLIMP-1通过影响淋巴细胞和Tregs功能,调控自身免疫T细胞特异性,为治疗自身免疫型糖尿病提供可能。

MHC II类分子多态性,尤其位于β链57位(β57)是多种自身免疫疾病的敏感性或抗性位点。MHC II类分子I-A(b)以β56-67调控的方式,促进自体反应CD4+T细胞分化为抑制疾病的自体调控T细胞,促成了糖尿病抗性[55]

信号传导蛋白和转录激活物(STAT)蛋白家族在细胞因子信号和免疫调控中扮演重要作用。Jin等[56]构建过表达Stat5b基因的NOD小鼠,相比于同窝对照组小鼠,Stat5b转基因NOD小鼠自发糖尿病的发病率显著降低、CD4+和CD8+T细胞增殖能力升高、多种细胞因子(IL-2,IL-10,IFN-γ,TNF-α和抗细胞凋亡基因Bcl-xl)表达上调。表明Stat5b过表达使NOD小鼠免于糖尿病。

2.2 转基因改善胰岛移植

基因工程修饰细胞包括功能基因序列的构建和插入,修饰可以是简单报告基因或复杂基因盒,有基因开关、细胞特异性激活子和多种基因。干细胞基因修饰可提高它们的生存能力,增强其在细胞治疗方面的功能。干细胞基因修饰后进行移植,可在不利的环境中免于细胞凋亡和免疫排斥[57]

肠K(Intestinal K)细胞是葡萄糖敏感的内分泌细胞,可通过转基因修饰分泌胰岛素。Mojibian等[58]将转入胰岛素(Insulin)基因的肠K细胞移植到NOD小鼠中。相比于对照组小鼠,转基因小鼠降低了血糖水平、糖尿病发生率、自身阳性胰岛素抗体、内源β细胞破坏和T细胞分泌的炎症细胞因子水平。

猪胰岛移植具有潜在的临床价值,虽然野生型猪胰岛在非人类的灵长类动物中成功逆转糖尿病,但存在瞬间血液介导的炎症反应(Immediately blood-mediated inflammatory reaction,IBMIR,即外源胰岛在血液中迅速消失)和T细胞介导的移植物排斥。通过基因修饰(靶向删除猪抗原、转基因表达人补体调节和聚沉调节蛋白)的猪胰岛移植,降低了IBMIR移植物损失和移植物排斥的免疫应答[59]

Wu等[60]构建了编码人X连锁细胞凋亡抑制剂(hXIAP)和肝细胞生长因子(hHGF)的RGD肽修饰腺病毒载体(RGD-Adv),并将转入RGD-Adv-hHGF-hXIAP的人胰岛移植到糖尿病NOD/SCID小鼠肾囊中,降低胰岛细胞死亡,促进胰岛血管重建,提高了胰岛移植效果。

锌指蛋白A20基因能抑制肿瘤坏死因子(Tumor necrosis factor,TNF)诱导的细胞凋亡、NF-κB的活化和核转移、IL-6和IL-8等炎性介质产生,从而阻止免疫排斥反应[61, 62, 63, 64]。支涤静[65]用携带lenti-A20的重组质粒转染小鼠胰岛细胞,并将其移植到T1D大鼠模型中,表现为受体鼠糖尿病症状明显改善、血糖下降、移植胰岛的存活期延长,为糖尿病的异种胰岛移植治疗研究提供了新途径。

2.3 转基因改善胰岛素敏感度

糖尿病中富含磷蛋白(Phosphoprotein enriched in diabetes,PED)通过与磷脂酶D1(phospholipase D1,PLD1)的D4结构域相互作用,引起胰岛素抵抗。Cassese等[66]将携带人D4 cDNA的重组腺病毒载体(Ad-D4)处理过表达PED的转基因小鼠,使得转基因小鼠胰岛素敏感度提高并分泌胰岛素。同时,给予Ad-D4也在高脂膳食处理的肥胖C57Bl/6小鼠中提高了胰岛素敏感度。表明干扰PED-PLD1相互作用可提高胰岛素敏感度。GLUT4能促进葡萄糖载体介导的胰岛素依赖性糖摄取。Atkinson等[67]构建表达人GLUT4基因的转基因小鼠,相比于对照组小鼠,转基因小鼠显示高脂肪膳食(High fat diet,HFD)喂养后保持高胰岛素敏感度。表明适度增加GLUT4表达可以治疗胰岛素抵抗。

脂连素(Adiponectin)及其受体在调控小鼠葡萄糖和脂类代谢中起重要作用,肥胖、II型糖尿病和心血管疾病与脂连素信号下调高度相关。Liu等[68]构建过表达猪Adipor1基因(pAdipor1)的转基因小鼠,阻止了饮食诱导的体重增加和胰岛素抵抗。

Baf60c(又称Smarcd3)是一种在快缩肌肉中丰富的转录辅因子,通过mTOR相互作用蛋白质(Deptor)的DEP结构域介导Akt激活,促进氧化肌纤维到糖酵解肌纤维的转换。而从氧化到糖酵解的转换与II型糖尿病中骨骼肌胰岛素抵抗有关。Meng等[69]等构建了Baf60c转基因小鼠,使其免于饮食诱导的胰岛素抵抗和葡萄糖耐受不良。表明骼肌中氧化-糖酵解代谢转换对糖尿病有益,Baf60c基因改善胰岛素敏感度。

2.4 转基因治疗糖尿病潜在的基因位点

腺相关病毒(Adeno-associated viral,AAV)载体由于具有较高的安全性和有效性,被用于体内基因治疗。临床前试验显示AAV介导的基因转移在大小型动物模型中长期表达[70]。最近,这些临床前数据已被成功应用到人类中[71, 72]。Callejas等[73]构建AAV载体Serotype 1编码的葡萄糖激酶(Glucokinase,Gck)和胰岛素(Insulin,Ins),单次肌肉注射到糖尿病狗中,引起禁食血糖降低、糖化血浆蛋白水平降低、体重恢复,并且在基因转移后的4年期间没有低血糖并发症出现。表明Gck和Ins基因协同作用,治疗糖尿病。

为了在糖尿病动物模型成体胰腺中获得原位胰岛再生,Chen等[74]用超声波靶向微气泡破坏(Ultrasound targeted microbubble destruction,UTMD)、piggyBac转座子基因传递系统的方法,传递胰岛转录因子基因Nkx2.2到STZ处理的大鼠胰腺,使Nkx2.2基因长期表达。结果显示Nkx2.2通过UTMD定位到胰腺,诱导成体胰腺祖细胞增殖和分化,使胰岛再生,治疗糖尿病。

Akt1/蛋白激酶B(Akt1/PKB)是PI3K激活的下游直接靶点,具有抗细胞凋亡和诱导增殖活性的作用。Bone等[75]用感染性增强的腺病毒载体Ad5RGDpK7传递大鼠胰岛素启动子(Rat insulin promoter,RIP)驱动的CA-Akt1到β细胞中,促进了胰岛细胞存活和体外β细胞增殖,抵抗了STZ诱导的糖尿病。显示胰岛内源Akt表达和激活,对治疗糖尿病有益。

EGF受体(EGFR)信号对于β细胞正常发育和出生后β细胞增殖是必需的。Hakonen等[76]构建胰岛素启动子驱动的CA-EGFR转基因小鼠,表现为胰岛中EGFR和Akt的磷酸化水平增高,新生小鼠在胰腺发育期间β细胞增殖,但在成年小鼠中CA-EGFR表达没有影响β细胞团数量,转基因小鼠显著抑制STZ诱导的β细胞凋亡。表明EGFR基因保护β细胞并抵抗STZ诱导的糖尿病。

胰高血糖素样肽1(GLP1)是胰高血糖素原(Proglucagon)基因翻译后加工修饰的L细胞分泌的一种肠降血糖素,能够诱导胰岛β细胞增殖和分化,促进葡萄糖依赖的胰岛素分泌,抑制胰高血糖素分泌,减缓胃肠蠕动和饥饿感,减少饮食,从而降低血糖水平[77, 78]。由于GLP-1半衰期非常短,应用于临床治疗还存在问题。一种改进的方式是GLP1基因传递,使GLP-1在体内产生。Choi等[79]构建了SV40启动子/增强子驱动的GLP1(7-37)cDNA,将其注射到DIO(Diet Induced Obesity)小鼠中,显示维持2周以上的胰岛素分泌增加和血糖水平降低。表明GLP1基因治疗糖尿病具有一定的潜力。

2.5 转基因治疗糖尿病肾病

糖尿病患者长期血糖增高,导致血管受损并危及心、脑、肾、周围神经、眼睛、足等产生糖尿病并发症,其中糖尿病肾病是糖尿病患者最常见的并发症。炎症在糖尿病肾病发展中起关键作用。Mohamed等[80]构建肾小管特异的抗炎症分子netrin-1转基因小鼠。相比于对照组小鼠,netrin-1转基因小鼠经STZ处理后,降低了中性粒细胞和巨噬细胞浸润、趋化因子表达,以及肾脏管状上皮细胞凋亡。表明netrin-1基因在糖尿病肾病中起炎症和细胞凋亡调节剂的作用,有望用于治疗糖尿病肾病。

3 结语

虽然大量的动物实验及临床前期实验表明,利用转基因技术治疗糖尿病具有很大的可行性及有效性,但在其真正进入临床应用之前,仍有很多问题需要进一步研究和解决,如高效的胰岛素基因转移体系、选择与β细胞生理特点相似又免受自身免疫系统攻击的靶细胞、基因表达的持续性和糖尿病易感基因的鉴定等。

在构建高效的基因转移体系方面,Wiechert等[81]修饰Langendorff灌注系统心脏模型,响应β-肾上腺素能刺激进行基因转移。脂质体载体靶向胰腺β细胞,即胰腺β细胞的β-MEND(Multifunctional envelope-type nano device)能传递寡核苷酸到MIN6(胰腺β细胞系)细胞质中,靶向microRNA敲除并促进胰岛素分泌上调[82]。β-MEND是否成为高效靶向传递核酸到MIN6中用于治疗糖尿病需深入研究。Tomita等[83]发明了一种无毒而有效的体内直接基因转移方法,即外源基因和核蛋白被包入相同脂质体中,然后用灭活的HVJ(Sendai virus)处理使得外源基因通过膜融合直接导入细胞质中,核蛋白迅速运输人胰岛素功能基因到细胞核中,并观察到基因在血浆中表达同时降低血糖。Takahashi等[84]动脉传递结合四环素诱导的病毒颗粒(包含甘油激酶cDNA)到原位胰岛中,产生有效和受控的转基因表达,使小鼠胰岛中产生甘油刺激的胰岛素分泌。腺病毒(Adv)基因传递可用来修饰移植前胰岛以增强存活,修饰包括转移细胞保护分子确保移植后胰岛存活、抑制免疫系统的分子阻止慢性胰岛移植排斥,同时泛宿主性的巨细胞病毒启动子能有效诱导胰岛中荧光素酶高表达[85]。因此,Adv基因传递修饰和巨细胞病毒启动子结合,有望进行高效胰岛素基因转移。He等[86]将胰岛素cDNA插入到CMV启动子质粒载体并通过快速尾静脉注射转移到STZ诱导糖尿病小鼠肝脏中,改善高血糖,同时血浆胰岛素显著增加,即应用流体力学为基础的基因转移简单而有效。同时,转座子系统Sleeping Beauty可用于延长肝脏中胰岛素表达。Lentiviral基因转移体系是一个有效而稳定的基因转移载体,过表达A20和血红素氧合酶-1(Heme oxygenase-1,HO-1)蛋白通过lentivirus传递保持大鼠胰岛功能,并与CHX和TNF-α诱导的细胞凋亡相抗衡[87]。用有效病毒载体(Adenoviral或lentiviral载体)靶向iNOS激活的基因转移策略,能保护β细胞存活[88]

在选择β细胞替代物方面也取得一些进展。干细胞有潜能产生无限供应可移植的胰岛素产生细胞(Insulin-producing cells,IPCs)用于治疗糖尿病,同时伴随免疫调节功能来克服T1DM产生的缺陷,但依赖于离体培养方法冗长,未来应寻求获得安全和有效的β细胞替代物[89, 90]。iPS细胞用一系列胰腺生长因子可直接分化为IPCs并分泌胰岛素,在糖尿病免疫缺陷小鼠中降低血糖,所以iPS细胞是否成为治疗T1DM的新选择有待进一步研究[91]。MSCs(Mesenchymal stem cells)是多能非造血祖细胞,具有体外转分化成IPCs的潜能,已有报道MSCs治疗T1DM实验动物模型[92]。源于不同细胞系的胚胎或成体干细胞能分化成β-样细胞元素,可能修复最初胰岛素分泌模式并干扰β-细胞定向的自身免疫破坏[93]。Kong等[94]研究UMSC(Umbilical cord mesenchymal stem cell)能有效降低T2DM病人的血糖,增加C-肽水平。CD4CD25调控T细胞(Treg)共聚物和胰岛细胞能降低STZ诱导糖尿病小鼠血糖,同时Treg细胞使得异体移植胰岛细胞在肝脏中长期存活,没有全身免疫抑制[95]

在基因表达的持续性方面,有研究称通过控制质粒DNA中CpG基序的定位和数量,可延伸转基因表达持续时间。如减少IFN表达质粒载体的CpG含量,可增加IFN-γ转基因表达[96]

在糖尿病易感基因的鉴定及方法方面,目前一些学者进行了研究,如Tan等[97]确定小鼠4号染色体上的T1DM敏感位点Idd11。Qiu等[98]在全基因组关联研究(Genome-wide association study,GWAS)基础上进行复制研究、差异表达和功能注释聚类分析,鉴定T1DM易感基因包括非人类白细胞抗原基因(Human leukocyte antigen,HLA)——RASIP1、STRN4、BCAR1和MYL2。Bergholdt等[99]整合T1DM GWAS数据和蛋白质相互作用构建疾病相关生物网络,8种调节基因CD83、IFNGR1、IL17RD、TRAF3IP2、IL27RA、PLCG2、MYO1B和CXCR7与T1DM相关,并在胰岛素分泌的INS-1β-细胞中被证实。PWAS(Proteome-wide analysis of SNPs)基于定量质谱分析,快速筛选差别转录因子结合的SNPs,其中12 SNPs在IL2RA位点与T1DM高度相关,编码白细胞介素2受体CD25[100]。Shu等[101]在糖尿病亚洲联盟中进行多级GWAS,确定T2DM敏感性位点在13q31.1和新独立风险变体在10p13和15q22.2。Park等[102]全基因组关联系统研究表明,染色体4q34-35含2种T2DM相关基因——GPM6A和NEIL3。Babaya等[103]研究表明NSY小鼠染色体Chr11和Chr14上含有主要的T2DM易感基因,这2条染色体相互作用产生更严重的高血糖和肥胖症。此外,Raza等[104]证实MTHFR(rs180-1133)和PPARγ2(rs1801282)基因多态性与T2DM敏感性相关。

转基因技术的出现与发展为探明人类疾病的发病机理,建立人类疾病的动物模型,基因治疗,生产天然活性药物蛋白的动物生物反应器和人类器官代用品等方面极具开发潜力,转基因技术的成熟和推广将给人类带来无限光明。随着对胰岛素分泌调节机制的不断认识,以及对胰岛素基因上游序列区顺式作用和反式作用调节因子研究的不断深入,转基因治疗整体水平和基因调控技术的不断发展,相信糖尿病基因治疗用于临床终将实现。

参考文献
[1] 黄建萍, 陈大灵. 糖尿病的流行趋势及预防控制策略的研究进展[J]. 现代预防医学, 2008, 35(5):962-964.
[2] Alam U, Asghar O, Azmi S, et al. General aspects of diabetes mellitus[J]. Handb Clin Neurol, 2014, 126:211-222.
[3] Junod A, Lambert AE, Stauffacher W, et al. Diabetogenic action of streptozotocin:relationship of dose to metabolic response[J]. J Clin Invest, 1969, 48(11):2129-2139.
[4] Lenzen S, Patten U. Alloxan history and mechanism of action[J]. Diabetologia, 1988, 31(6):337-342.
[5] Schnedl WJ, Ferber S, Johnson JH, et al. STZ transport and cytotoxicity. Specific enhancement in GLUT2-expressing cells[J]. Diabetes, 1994, 43:1326-1333.
[6] de la Garza-Rodea AS, Kna?n-Shanzer S, den Hartigh JD, et al. Anomer-equilibrated streptozotocin solution for the induction of experimental diabetes in mice(Mus musculus)[J]. J Am Assoc Lab Anim Sci, 2010, 49(1):40-44.
[7] Rees DA, Alcolado JC. Animal models of diabetes mellitus[J]. Diabet Med, 2005, 22:359-370.
[8] King C, Sarvetnick N. The incidence of type-1 diabetes in NOD mice is modulated by restricted flora not germ-free conditions[J]. PLoS One, 2011, 6(2):e17049.
[9] Crisa L, Mordes JP, Rossini AA. Autoimmune diabetes mellitus in the BB rat[J]. Diabetes Metab Rev, 1992, 8:4-37.
[10] Scott J. The spontaneously diabetic BB rat:sites of the defects leading to autoimmunity and diabetes mellitus:a review[J]. Curr Top Microbiol Immunol, 1990, 156:1-14.
[11] Ghanaat-Pour H, Huang Z, Lehtihet M, et al. Global expression profiling of glucose-regulated genes in pancreatic islets of spontaneously diabetic Goto-Kakizaki rats[J]. J Mol Endocrinol, 2007, 39:135-150.
[12] Iwatsuka H, Shino A, Suzuoki Z. General survey of diabetic features of yellow KK mice[J]. Endocrinol Jpn, 1970, 17:23-35.
[13] Castle CK, Colca JR, Melchior GW. Lipoprotein profile characterization of the KKA(y)mouse, a rodent model of type II diabetes, before and after treatment with the insulin-sensitizing agent pioglitazone[J]. Arterioscler Thromb, 1993, 13:302-309.
[14] Ikegami H, Fujisawa T, Ogihara T. Mouse models of type 1 and type 2 diabetes derived from the same closed colony:genetic susceptibility shared between two types of diabetes[J]. ILAR J, 2004, 45:268-277.
[15] Ueda H, Ikegami H, Kawaguchi Y, et al. Age-dependent changes in phenotypes and candidate gene analysis in a polygenic animal model of Type II diabetes mellitus;NSY mouse[J]. Diabetologia, 2000, 43:932-938.
[16] Ueda H, Ikegami H, Yamato E, et al. The NSY mouse:a new animal model of spontaneous NIDDM with moderate obesity[J]. Diabetologia, 1995, 38:503-508.
[17] 吴勇军, 喻嵘, 胡伟, 等. 滋阴益气活血解毒组方对MKR转基因2型糖尿病小鼠糖代谢的影响[J]. 湖南中医药大学学报, 2007, 27(2):20-23.
[18] Accili D, Drago J, Lee EJ, et al. Early neonatal death in mice homozygous for a null allele of the insulin receptor gene[J]. Nat Genet, 1996, 12:106-109.
[19] Joshi RL, Lamothe B, Cordonnier N, et al. Targeted disruption of the insulin receptor gene in the mouse results in neonatal lethality[J]. EMBOJ, 1996, 15:1542-1547.
[20] Kulkarni RN, Bruning JC, Winnay JN, et al. Tissue-specific knockout of the insulin receptor in pancreatic beta cells creates an insulin secretory defect similar to that in type 2 diabetes[J]. Cell, 1999, 96:329-339.
[21] Bruning JC, Michael MD, Winnay JN, et al. A muscle-specific insulin receptor knockout exhibits features of the metabolic syndrome of NIDDM without altering glucose tolerance[J]. Mol Cell, 1998, 2:559-569.
[22] Fernandez AM, Kim JK, Yakar S, et al. Functional inactivation of the IGF-1 and insulin receptor in skeletal muscle causes type 2 diabetes[J]. Genes Dev, 2001, 15:1926-1934.
[23] Kim H, Haluzik M, Gavrilova O, et al. Thiazolidinediones improve insulin sensitivity in adipose tissue and reduce the hyperlipidaemia without affecting the hyperglycaemia in a transgenic model of type 2 diabetes[J]. Diabetologia, 2004, 47(12):2215-2225.
[24] Kim H, Pennisi P, Zhao H, et al. MKR mice are resistant to the metabolic actions of both insulin and adiponectin:discordance between insulin resistance and adiponectin responsiveness[J]. Am J Physiol Endocrinol Metab, 2006, 291(2):E298-E305.
[25] Patricia P, Oksana G, Jennifer SP, et al. Recombinant human insulin-like growth factor-1(rhIGF-1)treatment inhibits gluconeogenesis in a transgenic mouse model of type 2 diabetes mellitus(DM)[J]. Endocrinology, 2006, 147:2619- 2630.
[26] Kumar A, Harrelson T, Lewis NE, et al. Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice[J]. PLoS One, 2014, 9(7):e102319.
[27] Li X, Wu X, Camacho R, et al. Intracerebroventricular leptin infusion improves glucose homeostasis in lean type 2 diabetic MKR mice via hepatic vagal and non-vagal mechanisms[J]. PLoS One, 2011, 6(2):e17058.
[28] Maddux BA, Sbraccia P, Kumakura S, et al. Membrane glycoprotein PC-1 and insulin resistance in non-insulin-dependent diabetes mellitus[J]. Nature, 1995, 373:448-451.
[29] Kumakura S, Maddux BA, Sung CK. Overexpression of membrane glycoprotein PC-1 can influence insulin action at a post-receptor site[J]. J Cell Biochem, 1998, 68:366-377.
[30] Teno S, Kanno H, Oga S, et al. Increased activity of membrane glycoprotein PC-1 in the fibroblast from non-insulin-dependent diabetes mellitus patients with insulin resistance[J]. Diabet Res Clin Pract, 1999, 45:25-30.
[31] Menzaghi C, Di Paola R, Baj G, et al. Insulin modulates PC-1 processing and recruitment in cultured human cells[J]. Am J Physical Endocrinol Metab, 2003, 284:514-520.
[32] Frittitta L, Sbraccia P, Costanzo BV, et al. High insulin levels do not influence PC-1 gene expression and protein content in human muscle tissue and hepatoma cells[J]. Diabet Metab Res Rev, 2000, 16:26-32.
[33] 王毅, 骆惠均, 王芳, 等. PC-1转基因小鼠的建立及其与2型糖尿病发病的关系[J]. 中华内分泌代谢, 2005, 21:554-556.
[34] Jemaa Z, Kallel A, et al. The Gly482Ser polymorphism of the peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α)is associated with type 2 diabetes in Tunisian population[J]. Diabetes Metab Syndr, 2013, pii:S1871-4021(13)00101-X.
[35] Choi J, Ravipati A, Nimmagadda V, et al. Potential roles of PINK1 for increased PGC-1α-mediated mitochondrial fatty acid oxidation and their associations with Alzheimer disease and diabetes[J]. Mitochondrion, 2014, 18C:41-48.
[36] Wu HH, Liu NJ, et al. Association and interaction analysis of PPA-RGC1A and serum uric acid on type 2 diabetes mellitus in Chinese Han population[J]. Diabetol Metab Syndr, 2014, 6:107.
[37] Shokouhi S, Haghani K, Borji P, et al. Association between PGC-1alpha gene polymorphisms and type 2 diabetes risk:a case-control study of an iranian population[J]. Can J Diabetes, 2014, pii:S1499-2671(14)00194-4.
[38] Inoue H, Shintani N, Sakurai Y, et al. PACAP inhibits β-cell mass expansion in a mouse model of type II diabetes:persistent suppressive effects on islet density[J]. Front Endocrinol(Lausanne), 2013, 4:27.
[39] Subramanian SL, Hull RL, Zraika S, et al. cJUN N-terminal kinase(JNK)activation mediates islet amyloid-induced beta cell apoptosis in cultured human islet amyloid polypeptide transgenic mouse islets[J]. Diabetologia, 2012, 55(1):166-174.
[40] Iancu AD, St?varu C. Double transgenic mice--a suitable model for studying oxidative stress in type 1 diabetes mellitus[J]. Roum Arch Microbiol Immunol, 2012, 71(4):201-220.
[41] Morgan MA, Muller PS, Mould A, et al. The nonconventional MHC class II molecule DM governs diabetes susceptibility in NOD mice[J]. PLoS One, 2013, 8(2):e56738.
[42] 何君, 韩瑞红, 邓巍, 等. 表达人TCRα转基因小鼠1型糖尿病模型的建立及其免疫机制的初步研究[J]. 中国实验动物学报, 2013, 21(5):82-85.
[43] Assmann TS, Brondani Lde A, Bauer AC, et al. Polymorphisms in the TLR3 gene are associated with risk for type 1 diabetes mellitus[J]. Eur J Endocrinol, 2014, 170(4):519-527.
[44] Li YY, Gao W, Pang SS, et al. TAP1 I333V gene polymorphism and type 1 diabetes mellitus:a meta-analysis of 2248 cases[J]. J Cell Mol Med, 2014, 18(5):929-937.
[45] Wang G, Zhang Q, Xu N, et al. Associations between two polymorphisms(FokI and BsmI)of vitamin D receptor gene and type 1 diabetes mellitus in Asian population:a meta-analysis[J]. PLoS One, 2014, 9(3):e89325.
[46] Salem HH, Trojanowski B, Fiedler K, et al. Long-term IKK2/NF-κB signaling in pancreatic β-cells induces immune-mediated diabetes[J]. Diabetes, 2014, 63(3):960-975.
[47] Feng ZC, Riopel M, Li J, et al. Downregulation of Fas activity rescues early onset of diabetes in c-Kit(Wv/+)mice[J]. Am J Physiol Endocrinol Metab, 2013, 304(6):E557-565.
[48] Blüher M, Kl?ting N, Wueest S, et al. Fas and FasL expression in human adipose tissue is related to obesity, insulin resistance, and type 2 diabetes[J]. J Clin Endocrinol Metab, 2014, 99:36-44.
[49] 苗宏生, 惠国桢. 小剂量链脲霉素(STZ)诱导hFasL转基因小鼠发生糖尿病的研究[J]. 实用临床医药杂志, 2004, 8(2):44-46.
[50] 宋媛, 徐少勇, 周洁, 等. 高表达胰岛素反应性天然自身抗体转基因小鼠糖耐量分析[J]. 现代生物医学进展, 2013, 13(9):1627-1630.
[51] 赖巧红. SUMO化修饰对胰岛β细胞凋亡的调控其机制研究[D]. 武汉:华中科技大学, 2013.
[52] 朱金改. PID1脂肪组织特异性转基因小鼠的构建及表型分析[D]. 南京:南京医科大学, 2012.
[53] Hart AW, Mella S, Mendrychowski J, et al. The developmental regulator Pax6 is essential for maintenance of islet cell function in the adult mouse pancreas[J]. PLoS One, 2013, 8(1):e54173.
[54] Lin MH, Chou FC, Yeh LT, et al. B lymphocyte-induced maturation protein 1(BLIMP-1)attenuates autoimmune diabetes in NOD mice by suppressing Th1 and Th17 cells[J]. Diabetologia, 2013, 56(1):136-146.
[55] Tsai S, Serra P, Clemente-Casares X, et al. Antidiabetogenic MHC class II promotes the differentiation of MHC-promiscuous autoreactive T cells into FOXP3+ regulatory T cells[J]. Proc Natl Acad Sci USA, 2013, 110(9):3471-3476.
[56] Jin Y, Purohit S, Chen X, et al. Over-expression of Stat5b confers protection against diabetes in the non-obese diabetic(NOD)mice via up-regulation of CD4+ CD25+ regulatory T cells[J]. Biochem Biophys Res Commun, 2012, 424(4):669-674.
[57] Phillips MI, Tang Y. Genetic modification of stem cells for cardiac, diabetic, and hemophilia transplantation therapies[J]. Prog Mol Biol Transl Sci, 2012, 111:285-304.
[58] Mojibian M, Lam AW, Fujita Y, et al. Insulin-producing intestinal K cells protect NOD mice from autoimmune diabetes[J]. Gastroenterology, 2014, pii:S0016-5085.
[59] Nagaraju S, Bottino R, Wijkstrom M, et al. Islet xenotransplantation from genetically engineered pigs[J]. Curr Opin Organ Transplant, 2013, 18(6):695-702.
[60] Wu H, Yoon AR, Li F, et al. RGD peptide-modified adenovirus expressing hepatocyte growth factor and X-linked inhibitor of apoptosis improves islet transplantation[J]. J Gene Med, 2011, 13(12):658-669.
[61] Codd JD, Salisbury JR, Packham G, et al. A20 RNA expression is associated with undifferentiated nasopharyngeal carcinoma and poorly differentiated head and neck squamous cell carcinoma[J]. J Pathol, 1999, 187:549-555.
[62] Lee EG, Boone DL, Chai S, et al. Failure to regulate TNF-induced NF-kappaB and cell death responses in A20-deficient mice[J]. Science, 2000, 289:2350-2354.
[63] Opipari AW Jr, Hu HM, Yabkowitz R, et al. The A20 zinc finger protein protects cells from tumor necrosis factor cytotoxicity[J]. J Biol Chem, 1992, 267:12424-12427.
[64] Janicke RU, Lee FH, Porter AG. Nuclear c-Myc plays an important role in the cytotoxicity of tumor necrosis factor a in tumor cells[J]. Mol Cell Biol, 1994, 14:5661-5670.
[65] 支涤静. A20转基因抑制胰岛移植排斥反应作用的初步探讨[D].上海:复旦大学, 2011.
[66] Cassese A, Raciti GA, Fiory F, et al. Adenoviral gene transfer of PLD1-D4 enhances insulin sensitivity in mice by disrupting phospholipase D1 interaction with PED/PEA-15[J]. PLoS One, 2013, 8(4):e60555.
[67] Atkinson BJ, Griesel BA, King CD, et al.Moderate GLUT4 overex-pression improves insulin sensitivity and fasting triglyceridemia in high-fat diet-fed transgenic mice[J]. Diabetes, 2013, 62(7):2249-2258.
[68] Liu BH, Lin YY, Wang YC, et al. Porcine adiponectin receptor 1 transgene resists high-fat/sucrose diet-induced weight gain, hepatosteatosis and insulin resistance in mice[J]. Exp Anim, 2013, 62(4):347-360.
[69] Meng ZX, Li S, Wang L, et al. Baf60c drives glycolytic metabolism in the muscle and improves systemic glucose homeostasis through Deptor-mediated Akt activation[J]. Nat Med, 2013, 19(5):640-645.
[70] Mingozzi F, High KA. Therapeutic in vivo gene transfer for genetic disease using AAV:progress and challenges[J]. Nat Rev Genet, 2011, 12:341-355.
[71] Maguire AM, High KA, Auricchio A, et al. Age-dependent effects of RPE65 gene therapy for Leber’s congenital amaurosis:a phase 1 dose-escalation trial[J]. Lancet, 2009, 374:1597-1605.
[72] Nathwani AC, Tuddenham EG, Rangarajan S, et al. Adenovirus-associated virus vector-mediated gene transfer in hemophilia B[J]. N Engl J Med, 2011, 365:2357-2365.
[73] Callejas D, Mann CJ, Ayuso E, et al. Treatment of diabetes and long-term survival after insulin and glucokinase gene therapy[J]. Diabetes, 2013, 62(5):1718-1729.
[74] Chen S, Shimoda M, Chen J, et al. Ectopic transgenic expression of NKX2.2 induces differentiation of adult pancreatic progenitors and mediates islet regeneration[J]. Cell Cycle, 2012, 11:1544-1153.
[75] Bone RN, Icyuz M, Zhang Y, et al. Gene transfer of active Akt1 by an infectivity-enhanced adenovirus impacts β-cell survival and proliferation differentially in vitro and in vivo[J]. Islets, 2012, 4(6):366-378.
[76] Hakonen E, Ustinov J, Eizirik DL, et al. In vivo activation of the PI3K-Akt pathway in mouse beta cells by the EGFR mutation L858R protects against diabetes[J]. Diabetologia, 2014, 57:970-979.
[77] 姚艳丽, 冯凭. 胰高血糖素样肽-1与Ⅰ型糖尿病治疗[J]. 生命的化学, 2005, 25(4):316-317.
[78] Giorgino F, Laviola L, Leonardini A, et al. GLP-1:a new approach for type 2 diabetes therapy[J]. Diabetes Research and Clinical Practice, 2006, 74:S152-S155.
[79] Choi S, Oh S, Lee M, et al. Glucagon-like peptide-1 plasmid construction and delivery for the treatment of type 2 diabetes[J]. Mol Ther, 2005, 12(5):885-891.
[80] Mohamed R, Jayakumar C, Ranganathan PV, et al. Kidney proximal tubular epithelial-specific overexpression of netrin-1 suppresses inflammation and albuminuria through suppression of COX-2-mediated PGE2 production in streptozotocin-induced diabetic mice[J]. Am J Pathol, 2012, 181(6):1991-2002.
[81] Wiechert S, El-Armouche A, Rau T, et al. 24-h Langendorff-perfused neonatal rat heart used to study the impact of adenoviral gene transfer[J]. Am J Physiol Heart Circ Physiol, 2003, 285(2):H907- H914.
[82] Yamada Y, Tabata M, Yasuzaki Y, et al. A nanocarrier system for the delivery of nucleic acids targeted to a pancreatic beta cell line[J]. Biomaterials, 2014, 35(24):6430-6438.
[83] Tomita N, Higaki J, Ogihara T, et al. A novel gene-transfer technique mediated by HVJ(Sendai virus), nuclear protein, and liposomes[J]. Cancer Detect Prev, 1994, 18(6):485-491.
[84] Takahashi R, Ishihara H, Takahashi K, et al. Efficient and controlled gene expression in mouse pancreatic islets by arterial delivery of tetracycline-inducible adenoviral vectors[J]. J Mol Endocrinol, 2007, 38(1-2):127-136.
[85] Londrigan SL, Brady JL, Sutherland RM, et al. Evaluation of promoters for driving efficient transgene expression in neonatal porcine islets[J]. Xenotransplantation, 2007, 14(2):119-125.
[86] He CX, Shi D, Wu WJ, et al. Insulin expression in livers of diabetic mice mediated by hydrodynamics-based administration[J]. World J Gastroenterol, 2004, 10(4):567-572.
[87] Lu Z, Shen SX, Zhi DJ, et al. Protective effect of cotransfection of A20 and HO-1 gene against the apoptosis induced by TNF-α in rat islets in vitro[J]. Zhonghua Er Ke Za Zhi, 2013, 51:420-425.
[88] McCabe C, O’Brien T. The rational design of beta cell cytoprotective gene transfer strategies:targeting deleterious iNOS expression[J]. Mol Biotechnol, 2007, 37(1):38-47.
[89] Giannoukakis N, Trucco M. A 2015 reality check on cellular therapies based on stem cells and their insulin-producing surrogates[J]. Pediatr Diabetes, 2015, doi:10.1111/pedi.12259.
[90] Lin HP, Chan TM, Fu RH, et al. Applicability of adipose-derived stem cells in type 1 diabetes mellitus[J]. Cell Transplant, 2015, 24(3):521-532.
[91] Raikwar SP, Kim EM, et al. Human iPS cell-derived insulin produ-cing cells form vascularized organoids under the kidney capsules of diabetic mice[J]. PLoS One, 2015, 10(1):e0116582.
[92] Dave S. Mesenchymal stem cells derived in vitro transdifferentiated insulin-producing cells:A new approach to treat type 1 diabetes[J]. Adv Biomed Res, 2014, 3:266.
[93] Calafiore R, Montanucci P, Basta G. Stem cells for pancreatic β-cell replacement in diabetes mellitus:actual perspectives[J]. Curr Opin Organ Transplant, 2014, 19(2):162-168.
[94] Kong D, Zhuang X, Wang D, et al. Umbilical cord mesenchymal stem cell transfusion ameliorated hyperglycemia in patients with type 2 diabetes mellitus[J]. Clin Lab, 2014, 60:1969-1976.
[95] Takemoto N, Konagaya S, Kuwabara R, et al. Coaggregates of regulatory T cells and islet cells allow long-term graft survival in liver without immunosuppression[J]. Transplantation, 2015, 95(5):942-947.
[96] Mitsui M, Nishikawa M, Zang L, et al. Effect of the content of unmethylated CpG dinucleotides in plasmid DNA on the sustainability of transgene expression[J]. J Gene Med, 2009, 11(5):435-443.
[97] Tan IK, Mackin L, Wang N, et al. A recombination hotspot leads to sequence variability within a novel gene(AK005651)and contributes to type 1 diabetes susceptibility[J]. Genome Res, 2010, 20(12):1629-1638.
[98] Qiu YH, Deng FY, Li MJ, et al. Identification of novel risk genes associated with type 1 diabetes mellitus using a genome-wide gene-based association analysis[J]. J Diabetes Investig, 2014, 5(6):649-656.
[99] Bergholdt R, Brorsson C, Palleja A, et al. Identification of novel type 1 diabetes candidate genes by integrating genome-wide association data, protein-protein interactions, and human pancreatic islet gene expression[J]. Diabetes, 2012, 61(4):954-962.
[100] Butter F, Davison L, Viturawong T, et al. Proteome-wide analysis of disease-associated SNPs that show allele-specific transcription factor binding[J]. PLoS Genet, 2012, 8(9):e1002982.
[101] Shu XO, Long J, Cai Q, et al. Identification of new genetic risk variants for type 2 diabetes[J]. PLoS Genet, 2010, 6(9):e1001127.
[102] Park MH, Kwak SH, Kim KJ, et al. Identification of a genetic locus on chromosome 4q34-35 for type 2 diabetes with overweight[J]. Exp Mol Med, 2013, 45:e7.
[103] Babaya N, Fujisawa T, Nojima K, et al. Direct evidence for susceptibility genes for type 2 diabetes on mouse chromosomes 11 and 14[J]. Diabetologia, 2010, 53(7):1362-1371.
[104] Raza ST, Abbas S, Ahmed F, et al. Association of MTHFR and PPARγ2 gene polymorphisms in relation to type 2 diabetes mellitus cases among north Indian population[J]. Gene, 2012, 511(2):375-379.