单核细胞趋化蛋白-1在非肥胖糖尿病小鼠胰腺中的表达

目的 通过观察单核细胞趋化蛋白-1（Monocyte Chemoattractant Protein-1）在1型糖尿病动物模型NOD小鼠胰腺中的表达，探讨其在1型糖尿病胰岛炎发病机制中的作用。方法 应用免疫组化SABC法和免疫电镜评价MCP-1在NOD小鼠和BALB／C小鼠胰腺中的表达，应用H＆E染色光镜下评价胰岛免疫细胞浸润。结果 免疫组化结果表明：NOD小鼠胰腺中MCP-1呈阳性表达，而对照组无MCP-1表达。免疫电镜进一步显示：MCP-1由胰岛β细胞产生并存在于细胞质中。结论 MCP-1主要由胰岛β细胞产生。MCP-1通过招募单核／巨噬细胞浸润胰岛而在1型糖尿病发病机制中起重要作用。     

Monocyte chemoattractant protein-1 plays a key role in type 1 diabetes

Type 1 diabetes is an autoimmune disease resulting from the selective destruuction of β cells in file pancreatic islets.In both human and rodent models of type 1 diabetes, the clinical disease is preceded by a progressive mononuclear cell invasion of the pancreatic islets ( insulitis ). In the early stage of insulitis, the major components are monocyte/macrophages, and the recruitment of mononuclear cells is a critical step in the pathogenesis of the type 1 diabetes. Studies have revealed that Monocyte chemoattractant protein-1 (MCP-1 )specifically recruits monocytes/ macrophages into pancreas and plays an important role in the development of insulitis and diabetes,     

Somatostatin receptor expression and biological functions in endocrine pancreatic cells: review based on a doctoral thesis

Type 1 diabetes is resulting from the selective destruction of insulin-producing betacells within the pancreatic islets. Somatostatin acts as an inhibitor of hormone secretion through specific receptors (sst1-5). All ssts were expressed in normal rat and mouse pancreatic islets, although the expression intensity and the co-expression pattern varied between ssts as well as between species. This may reflect a difference in response to somatostatin in islet cells of the two species. The Non-Obese Diabetic (NOD) mouse model is an experimental model of type 1 diabetes, with insulitis accompanied by spontaneous hyperglycaemia. Pancreatic specimens from NOD mice at different age and stage of disease were stained for ssts. The islet cells of diabetic NOD mice showed increased islet expression of sst2-5 compared to normoglycemic NOD mice. The increase in sst2-5 expression in the islets cells may suggest either a contributing factor in the process leading to diabetes, or a defense response against ongoing beta-cell destruction. Somatostatin analogues were tested on a human endocrine pancreatic tumour cell line and cultured pancreatic islets. Somatostatin analogues had an effect on cAMP accumulation, chromogranin A secretion and MAP kinase activity in the cell line. Treatment of rat pancreatic islets with somatostatin analogues with selective receptor affinity was not sufficient to induce an inhibition of insulin and glucagon secretion. However, a combination of selective analogues or non-selective analogues via costimulation of receptors can cause inhibition of hormone production. For insulin and glucagon, combinations of sst2 + sst5 and sst1 + sst2, respectively, showed a biological effect. In summary, knowledge of islet cell ssts expression and the effect of somatostatin analogues with high affinity to ssts may be valuable in the future attempts to influence beta-cell function in type 1 diabetes mellitus, since down-regulation of beta-cell function may promote survival of these cells during the autoimmune attack.     

糖尿病小鼠左肾被膜下胰岛细胞与胰腺外分泌细胞共同移植动物模型的建立

目的：建立糖尿病小鼠左肾被膜下同种异体胰岛细胞与胰腺外分泌细胞共同移植动物模型及探讨胰腺外分泌细胞对胰岛移植物的损伤作用.方法：（1）体内实验：采用胆总管内逆行灌注胶原酶联合淋巴细胞分离液的方法来分离纯化胰岛,人工挑取胰岛细胞并收集胰腺外分泌细胞.链脲佐菌素腹腔注射诱导BALB/C小鼠成为糖尿病小鼠.单纯移植组（n=10）每只小鼠于左肾被膜上极移植胰岛细胞250个,共同移植组（n =10）每只小鼠于左肾被膜上下极同时移植胰岛细胞250个和等体积的胰腺外分泌细胞,持续观测血糖及生命体征变化,1个月后切除左肾并继续检测血糖.（2）体外实验：利用双硫腙对胰岛进行特异性染色来计算胰岛产量及纯度,利用台盼蓝染色鉴定胰岛细胞的活性,以及用葡萄糖刺激胰岛素释放实验来检测胰岛功能.结果：（1）胰岛移植后,单纯移植组及共同移植组血糖均逐步降至正常,共同移植组较单纯移植组血糖恢复正常时间延迟,移植术后第2,3,4,5天,单纯移植组受鼠血糖低于共同移植组,差异有统计学意义（P＜0.05）.切除两组受鼠左肾3d后,两组受鼠血糖均＞21 mmol/L.（2）每只小鼠可获得150～200个高质量胰岛,纯度及活性均高于90％,葡萄糖刺激后胰岛素释放量明显增加（SI=2.90）.结论：（1）成功建立糖尿病小鼠左肾被膜下同种异体胰岛细胞与胰腺外分泌细胞共同移植动物模型.（2）胰腺外分泌细胞与胰岛细胞同时移植会延迟植入胰岛功能恢复正常的时间.     

皮下注射胰岛素抑制胰岛β细胞凋亡预防NOD鼠糖尿病

目的：观察皮下注射胰岛素免疫干预对非肥胖糖尿病（non-obese diabetic,NOD）鼠胰岛炎、B细胞凋亡和糖尿病的影响,并探讨其诱导免疫耐受的机制。方法：60只NOD雌鼠随机分为胰岛素处理组（n=34）和磷酸盐缓冲液（phosphate buffered saline,PBS）对照组（n=28）,分别于4周、12周、20周、28周皮下注射中效胰岛素优泌林N（Humulin N）6U（60μL）＋不完全弗氏佐剂（incomplete Freund＇s adjuvant,IFA）60μL,对照组予PBS（60μL）＋IFA（60μL）。于12周龄观察胰岛炎和胰岛B细胞凋亡;检测胰岛Fas和FasL的表达;测定血清IL-4和IFN-γ浓度,以及胰岛内I-Aβ^x7,IL-1β,IFN-γ,Fas,IL-4 mRNA的表达水平。结果：NOD鼠皮下注射胰岛素加IFA组30周龄和52周龄时发病率仅为21．4％和28．6％,而皮下PBS加IFA组为71．4％和85．7％（P〈0．05）。胰岛素组胰岛炎积分比对照组低,但差异无统计学意义（P〉0．05）。胰岛素组胰岛Fas抗原表达和B细胞凋亡率均比PBS对照组低（均P〈0．05）。胰岛素组胰岛内I-Aβ^x7,IFN-γ,IL-1β,FasmRNA表达较PBS对照组低（均P〈0．05）,而IL-4mRNA表达较对照组高（P〈0．05）;胰岛素组血清IL-4比PBS组高,IFN-γ比PBS组低（均P〈0．05）。结论：皮下注射胰岛素能诱导NOD鼠的免疫耐受而预防糖尿病的发生,但不能阻断胰岛炎的进展。皮下注射胰岛素能诱导调节性T细胞产生,使全身和胰岛局部T细胞由,Th1向Th2转型,从而抑制Fas介导的B细胞凋亡而预防糖尿病。     

Fas-FasL在NOD小鼠胰岛炎中的作用

目的分析Fas-FasL在NOD小鼠胰岛炎中的作用。方法取32只分属不同周龄的雌性NOD小鼠,观察其血糖、胰岛HE染色、免疫组织化学染色———检测胰岛素、CD8、Fas、FasL的表达。在分析NOD小鼠胰岛炎中以胰岛或相关细胞为研究单位,从而减少了混杂因素的影响。结果雌性NOD小鼠自6周龄起出现胰岛炎,其评分逐渐增加(P<0.0005),14周龄出现糖尿病。随着胰岛炎的加重:胰岛素阳性细胞减少(P<0.0005),与胰岛炎评分呈负相关(P<0.05);Fas 胰岛细胞增加(P<0.0005),与评分呈正相关(P<0.01);FasL 胰岛细胞出现并逐渐增加(P<0.0005),与评分呈正相关(P<0.01);浸润细胞表达FasL、CD8,均逐渐增加(P<0.0005)。胰岛细胞的Fas与胰岛素表达之间呈负相关、胰岛素与FasL呈负相关、Fas与FasL呈正相关,浸润细胞的CD8与FasL表达呈正相关,P值均小于0.01。结论在NOD小鼠胰岛炎中,Fas-FasL可能参与β细胞损伤及自身免疫负调节。     

口服胰岛素抑制胰岛β细胞凋亡预防NOD鼠糖尿病

目的: 观察口服胰岛素免疫干预对非肥胖糖尿病(non-obese diabetic, NOD)鼠胰岛炎、β细胞凋亡和糖尿病的影响,并探讨其诱导免疫耐受的机制.方法: 86只NOD雌鼠随机分为胰岛素处理组(n=43)和磷酸盐缓冲液(phosphate buffered saline, PBS)对照组(n=43),从4周龄始每周灌胃人普通胰岛素1mg(70μL)2次,12周后改为每周灌胃1次至30周,对照组予等体积的PBS;于12周龄观察胰岛炎和胰岛β细胞凋亡;检测胰岛Fas和FasL的表达;测定血清IL-4和IFN-γ浓度,以及胰岛内I-Aβg7,IL-1β,IFN-γ,Fas,IL-4,TGF-β mRNA和小肠PP(Peyer's Patch)淋巴结IL-4,IFN-γ,TGF-β mRNA的表达水平.结果: NOD鼠口服胰岛素组30周龄和52周龄时发病率为55.6%和70.4%,分别比PBS对照组(85.7%和96.4%)低(P＜0.05).胰岛素组胰岛炎积分比对照组低,但差异无统计学意义(P＞0.05).胰岛素组胰岛Fas抗原表达和β细胞凋亡率均比PBS对照组低(均P＜0.05).胰岛素组胰岛内I-Aβg7,IFN-γ,IL-1β,Fas mRNA和PP淋巴结IFN-γ mRNA表达均较PBS对照组低(均P＜0.05),而IL-4,TGF-β mRNA表达较对照组高(均P＜0.05);胰岛素组血清IL-4比PBS组高,IFN-γ比PBS组低(均P＜0.05).结论:口服胰岛素能诱导NOD鼠的免疫耐受而预防糖尿病的发生,但不能阻断胰岛炎的进展.口服胰岛素能诱导调节性T细胞产生,使全身和胰岛局部T细胞由Th1向Th2转型,从而抑制Fas介导的β细胞凋亡而预防糖尿病.     

Oral administration of insulin to female nonobese diabetic mice inhibited diabetes and induced Fas ligand expression on islets of Langerhans

Objective To detect oral administration of recombinant human insulin to nonobese diabetic (NOD) mice for preventing them from diabetes and insulitis and to detect the effects of oral administration of insulin on Fas and Fas ligand expression on islet of Langerhans. Methods Sixty-four female NOD mice were divided into two groups.One group (34) was orally administered recombination human insulin 1 mg in 500 μl PBS and the other (30) 500 μl PBS only at age of 5 weeks old, twice a week for the first week, then weekly until 30 weeks of age. Results Oral administration of insulin to female NOD mice can significantly suppress diabetes and insulitis.The insulitis was less severe in the group fed with insulin than that in the control group (score of insulitis: 1.25±0.45 vs 3.0±0.76 at 16 weeks of age, P&lt;0.01).We examined Fas ligand and Fas expression on islets of Langerhans in both groups of NOD mice by using immunohistochemical techniques.We find that Fas only expressed on islets when the mice suffered the diabetes, whereas Fas ligand expressed on islets of the mice fed with insulin at 16 and 20 week of ages.We did not find Fas ligand positive staining on the islet feeding with PBS. Conclusion We speculated that oral insulin may induce Fas ligand expression on the islets and plays a role in protecting the pancreatic β-cell from autoimmune destruction.These results show that oral insulin affected autoimmune diabetes and insulitis in NOD mice.The immune mechanism of oral tolerance is closely related to the change of Fas ligand and Fas system.     

1型糖尿病与自身免疫机制研究的新进展

1型糖尿病(T1DM)是由多种因素引起胰岛β细胞损伤与凋亡,导致胰岛素分泌量绝对不足,出现能量代谢紊乱为主要特征的自身免疫疾病。T1DM发病机制复杂,其中涉及特异性细胞免疫、固有免疫细胞、基因易患性、病毒感染及胰岛细胞自身抗体等多方面。该文就近年来对上述因素与T1DM的相关性研究进展予以综述,以加深对T1DM发病机制的理解,为临床防治T1DM提供新的思路与方案。     

小鼠胰岛α细胞的缺失对移植胰岛功能的影响

目的　探讨胰岛α细胞的丢失对胰岛素分泌功能的影响。方法　在人胰岛分离过程中 ,经胶原酶的过度消化造成胰岛周边α细胞缺失 ,用免疫组化及胰岛素 /胰高糖素含量分析予以证实。在体外 ,检测葡萄糖刺激引起的实验性糖尿病小鼠胰岛素的分泌 ;在体内 ,评价胰岛移植后对糖尿病小鼠血糖的调节 ,并研究胰高糖素对α细胞缺失胰岛功能的影响。结果　胶原酶的过度消化引起胰岛周边的α细胞丢失 ,使分离胰岛内胰岛素 /胰高糖素比值明显升高。与正常胰岛相比 ,α细胞缺失胰岛对葡萄糖刺激产生的胰岛素明显降低 ,胰岛素释放在正常胰岛和α细胞缺失胰岛分别为2 2 2 7uU/ml± 32 1uU/ml和 12 4 6uU/ml± 12 6uU/ml(P <0 0 1)。在体内 ,移植α细胞缺失的胰岛到糖尿病的C5 7/BL小鼠后不能有效地纠正动物的高血糖 ,胰岛移植后的平均血糖浓度在正常胰岛组和α细胞缺失胰岛组分别为 :8 9mmol/L± 1 98mmol/L和 2 1 3mmol/L± 2 2mmol/L(P <0 0 1) ,而给予外源性的胰高糖素可以在体外及体内明显改善α细胞缺失胰岛的胰岛素分泌功能。结论　胰岛α细胞的缺失明显降低胰岛的胰岛素分泌功能 ,用外源性的胰高糖素可以改善α细胞缺失胰岛的胰岛素分泌功能。     

胰岛细胞多肽激素分泌颗粒释放形式及其转运意义的透射电镜观察

目的观察胰岛的超微结构特点,探讨胰岛细胞多肽激素分泌颗粒的释放形式和转运途径及其功能意义。方法对小鼠胰组织超薄切片,进行透射电镜观察。结果小鼠胰岛散在分布于胰腺小叶之间,主要由A、B两类内分泌细胞组成。胰岛内部和周围存在丰富的有孔型（50nm）毛细血管;毛细淋巴管内皮为开放连接型（0．5～1．5μm）,只存在于胰岛周围。胰岛细胞内含大量电子致密的分泌颗粒（200～500nm）,常见许多分泌颗粒靠近细胞膜或突出于细胞表面。在胰岛细胞周围的组织间隙内,也常见到与胰岛细胞内相似的分泌颗粒。结论小鼠胰岛细胞多肽激素分泌颗粒连同颗粒被膜整体释放;释放入胰组织液中的多肽激素或分泌颗粒,更易通过淋巴管随淋巴转运,间接进入血液循环而发挥作用。     

间质干细胞移植治疗1型糖尿病

1型糖尿病是由胰岛β细胞的自身免疫性破坏所致。补充胰岛素是1型糖尿病最基本的治疗,胰岛移植是治愈的根本。然而胰岛移植受供体缺乏的限制。来源于间质母细胞(MSCs)的胰岛生成细胞(IPCs)则成为一种新的有吸引力的选择。一方面,在体外,来源于胰腺、骨髓、脂肪组织、脐带血及组织的MSCs通过基因修饰能够分化成为IPCs。另一方面,MSCs可以作为人类胰岛素基因表达的载体。此外,MSCs的血管生成作用也能被用于糖尿病的治疗。总之,应用MSCs治疗1型糖尿病具有广阔前景。     

NOD 小鼠胰岛的分离及其在体内外的生物学特性

目的 建立分离纯化非肥胖性糖尿病(NOD)小鼠胰岛的方法,并对其体内外生物学特性进行研究?方法 采用改良的胶原酶消化结合Ficoll 密度梯度离心方法,分离纯化NOD 小鼠胰岛?应用体外糖刺激实验检测分离纯化的胰岛功能,以及通过监测移植小鼠的血糖?体重变化及糖耐量实验对移植胰岛的体内生物学功能进行分析,并通过HE 染色和免疫荧光染色检测肾被膜下移植胰岛的存活情况?结果 胰岛产率为(116 ±12)个胰岛/胰腺,纯度>90%?体外糖刺激实验结果显示,NOD 小鼠胰岛的糖刺激胰岛素释放水平明显低于KM 小鼠胰岛?胰岛移植实验显示,移植胰岛能有效改善糖尿病小鼠的血糖?体重和糖耐量,但改善作用一般仅能维持2 周左右?HE 染色和免疫荧光染色结果显示,肾被膜下可见胰岛素阳性的胰岛细胞团,并且在残存的移植胰岛细胞团周围存在大量淋巴细胞浸润?结论 通过改良的小鼠胰岛分离方法可由NOD 小鼠分离得到大量较高纯度的胰岛,可用于今后探索如何阻断自身免疫损伤保护移植胰岛的研究?     

黄芪多糖对NOD小鼠1型糖尿病的预防作用

目的 探讨黄芪多糖对NOD小鼠1型糖尿病的预防作用。方法 比较APS预免疫组NOD小鼠和NS对照组NOD小鼠DM发病率、血清C-P和GAD-Ab水平、脾脏T细胞亚群比例、胰岛组织病理学和免疫组化。结果 APS组与NS组比较,DN发病率显著降低,血清C-P水平显著增高,胰岛炎症程度减轻,CD8T细胞亚群比例显著增高,CD4/CD8比值显著降低。结论 早期应用黄芪多糖预免疫可以预防或延缓NOD小鼠1型糖尿病的发病。     

激活素A及其结合蛋白在STZ损伤小鼠胰腺组织中的表达及意义

目的：探讨激活素A（Act A）及其结合蛋白follistatin(FS)在小鼠胰腺损伤过程中的表达,为胰腺损伤后组织修复与重建奠定基础。方法：雄性ICR小鼠21 只,随机分为对照组（n＝6）与实验组（n＝15）。应用一次性大剂量腹腔注射链脲菌素（STZ）制备小鼠胰岛损伤模型,免疫组织化学染色法检测Act A和 FS蛋白表达, 逆转录聚合酶链反应（RT-PCR）法检测Act A和FS mRNA相对转录水平。　结果：免疫组织化学染色显示,Act A主要分布在正常小鼠胰岛细胞,腺泡细胞也有表达;FS仅表达在小鼠胰岛细胞,在腺泡细胞不表达。RT-PCR检测结果显示,Act A和FS mRNA均在正常小鼠胰腺组织表达,与对照组比较,实验组小鼠Act mRNA表达随着诱导时间的延长表达量进行性减少（P<0.01）,而FS mRNA在诱导的第7天表达明显增加,第14和21天下降（P<0.01）。结论：Act A及FS主要表达在小鼠胰岛组织,在STZ诱导胰腺损伤过程中Act-FS系统表达失平衡,可能与糖尿病的发生、发展有关。     

细粒棘球蚴抗原B对NOD小鼠1型糖尿病的预防作用

目的探讨细粒棘球蚴抗原B(抗原B)对非肥胖糖尿病(NOD)小鼠1型糖尿病免疫机制的影响。方法将造模成功的20只NOD小鼠依据随机数字表法分为抗原B处理组和生理盐水处理组,各10只。记录并比较两组小鼠初始/成模后/用药后1、2、3周的体质量和血糖变化值。运用酶联免疫吸附测定法检测小鼠血清中白细胞介素(IL)2/IL-10的水平;运用荧光定量聚合酶链反应(PCR)检测胰腺组织中两种细胞因子的表达量。结果在用药后3周各组小鼠之间体质量比较差异有统计学意义(P<0.05),生理盐水处理组体质量下降明显;生理盐水处理组血糖上升水平较抗原B处理组高(P<0.05)。酶联免疫吸附测定结果显示,抗原B处理组IL-2水平较生理盐水处理组低,血清IL-10水平高于生理盐水处理组(P<0.05)。荧光定量PCR结果:抗原B处理组IL-2 mRNA表达量较生理盐水处理组显著下调,IL-10显著上调(P<0.05)。结论细粒棘球蚴抗原B可以降低IL-2水平,升高IL-10水平,暂可认为使Th1/Th2细胞发生免疫偏移,向着有利于胰岛保护的方向,细粒棘球蚴抗原B可能有预防或治疗1型糖尿病的作用。     

Application of anti-CD103 immunotoxin for saving islet allograft in context of transplantation

Background Previous studies using knockout mice document a key role for the integrin CD103 in promoting organ allograft rejection and graft-versus-host disease. However, a determination of whether blockade of the CD103 pathway represents a viable therapeutic strategy for intervention in these processes has proven problematic due to the lack of reagents that efficiently deplete CD103＋ cells from wild type hosts. To circumvent this problem, in the present study, we invented an anti-CD103 immunotoxin （M290-SAP）. We investigated whether M290-SAP has capacity to eliminate CD103-expressing cells in vivo and protect transplanted islets from destroying by host immune cells.Methods Flow cytometry was used to analyze the efficacy of M290-SAP in depleting CD103-expressing cells in vivo.Then using allogenic islet transplantation models as well as NOD mice with recent onset type 1 diabetes, the therapeutic efficacy of CD103-expressing cell depletion was addressed.Results M290-SAP dramatically reduces the frequency and absolute numbers of CD103-expressing leukocytes in peripheral lymphatic tissues of treated mice. Balb/c islets transplanted into streptozotocin-induced diabetic C57BL/6 mice under single M290-SAP treatment showed an indefinite survival time compared with untreated mice, M290-treated mice and IgG-SAP treated mice （mean survival time, ＞100 days vs. ＜20 days）. C57BL/6 islets transplanted into hyperglycemic NOD mice under single M290-SAP treatment showed a pronounced delay in allograft rejection compared with untreated mice （mean survival time 12-13 days vs. ＜7 days）. Immunological analysis of mice with long-term islet allograft survival revealed an obvious atrophy thymus and severe downregulation of alloimmunity of CD8 subpopulation response to allogenic stimulation.Conclusion Regardless of the underlying mechanisms, these data document that depletion of CD103-expressing cells represents a viable strategy for therapeutic intervention in islet allograft rejection.     

小鼠实验性糖尿病免疫组织化学观察

用HRP-SPA免疫组织化学方法观察了四氧嘧啶所致小鼠实验性糖尿病胰岛A、B细胞的变化.结果表明,实验性糖尿病小鼠部分胰岛有改变.主要为胰岛形态不规则,边缘不整齐,胰岛细胞排列紊乱,胰岛内有较大空虚部分与胰岛细胞极明显的离散现象,有改变的胰岛中部分胰岛细胞境界不清、边缘不整齐与免疫反应颗粒缺失与消失等变化.