小鼠胰腺再生模型的建立与分析

发布时间：2018-06-24 03:37

本文选题：胰腺再生 + 胰管标记　；参考：《汕头大学》2008年硕士论文

【摘要】：胰腺再生现象的研究有可能为糖尿病治疗提供一条新的途径,因而受到了广泛的关注,但是胰腺再生的机理还不是很清楚。本课题中,我们研究了三种模型的小鼠胰腺再生情况,即部分胰腺切除(Partial pancreatectomy, Ppx)、链脲霉素(Streptozotocin,STZ)注射、和部分胰管结扎(Partial Duct Ligation, PDL)。结果发现,在PDL模型的胰腺中出现了明显的管状复合体结构(Tubular Complexes, TC),并且在TC结构和正常的大胰管上都发现了胰岛素(Insulin, Ins)阳性的细胞。在90% Ppx模型中虽然也发现了TC结构富集的新生小叶(New Lobe),但是因为创伤过大,小鼠死亡率很高。在50% Ppx,70% Ppx以及STZ模型中则极少发现TC结构,并且在胰岛的数量以及胰岛素原、PDX-1、Ngn3、Ki67等基因的转录水平也没有体现出明显的增加。因此,PDL较Ppx和STZ是一个更为理想的胰腺再生模型。为研究胰腺再生的机理,我们建立了胆总管逆向注射腺病毒(adenovirus,Ad)技术,胰管细胞可被病毒携带的增强型绿色荧光蛋白(Enhanced Green Fluorescence Protein, EGFP)标记。研究结果表明,在12天龄幼鼠及两个月龄成年鼠中,胆总管注射1.5天后,约有15%的胰管细胞和腺泡细胞被EGFP标记。然而,胰岛内部有EGFP阳性细胞的现象只在12天龄幼鼠出现。并且,EGFP标记的胰岛数量在术后第7天比术后第3天有明显的增加。同时,5-溴脱氧尿嘧啶核苷(5-bromo-2-deoxyuridine,BrdU)标记实验发现,EGFP阳性胰岛内BrdU阳性细胞的比例较EGFP阴性的胰岛高,暗示了这些胰岛可能是从胰管新长出来的,因而具有更强的分裂能力。这一推论得到了如下实验的支持,EGFP阳性胰岛比EGFP阴性胰岛有更强的Ki67表达和更长的端粒。将胰管标记运用于90% Ppx模型,初步的实验结果提示,再生模型中没有从胰管新生的胰岛,说明其再生机理和胚胎中胰岛的发育不一样。我们推测胰管上胰岛素阳性的细胞最终可能都会凋亡,再生的胰岛可能来自于胰岛内祖细胞的分裂。
[Abstract]:The study of pancreatic regeneration may provide a new way for the treatment of diabetes, so it has received extensive attention, but the mechanism of pancreatic regeneration is not clear. In this study, we studied three models of pancreatic regeneration in mice: partial pancreatic excision (PPX), streptozotocin (STZ) injection, and partial ductal ligation (PDL). The results showed that there were obvious tubular complexes (TC) in the pancreas of PDL model, and Insulin (ins) positive cells were found in both TC structure and normal large pancreatic duct. In 90% Ppx model, the new lobule with rich TC structure was also found, but the death rate of mice was very high because of the high trauma. TC structures were rarely found in 50% PpxX 70% Ppx and STZ models, and no significant increase was found in the number of islets and the transcription level of proinsulin PDX-1Ngn3PX Ki67 genes. Therefore PDL is a more ideal pancreatic regeneration model than PpX and STZ. In order to study the mechanism of pancreatic regeneration, we developed a technique for retrograde injection of adenovirusAd (Ad) into the common bile duct. Pancreatic duct cells can be labeled with enhanced Green fluorescence protein (EGFP) carried by the virus. The results showed that about 15% of pancreatic duct cells and acinar cells were labeled by EGFP in 12 day old young rats and 2 months old adult rats 1.5 days after choledochus injection. However, the presence of EGFP-positive cells in the islet was found only in 12-day-old young rats. The number of islets labeled with EGFP was significantly increased on the 7th day after operation than on the third day after operation. At the same time, 5-bromo-2-deoxyuridineuridine (BrdU) labeling assay showed that the proportion of BrdU positive cells in EGFP positive islets was higher than that in EGFP negative islets, suggesting that these islets may be newly grown from the pancreatic duct and thus have stronger cleavage ability. The following results suggest that the EGFP positive islets have stronger Ki67 expression and longer telomere than EGFP negative islets. The pancreatic duct marker was applied to 90% PPX model. The preliminary experimental results showed that no islets were regenerated from the pancreatic duct in the regenerative model, which indicated that the regeneration mechanism was different from the development of pancreatic islets in embryos. We speculate that the insulin-positive cells in the pancreatic duct may eventually apoptosis, and the regenerated islets may come from the division of the progenitor cells in the islets.
【学位授予单位】：汕头大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：R-332;R657.51

【共引文献】