背景：腹股沟疝是外科常见疾病，近些年来其发病率逐渐增加，并且发病人群集中于老龄患者。导致腹股沟疝发生的原因包括腹腔压力增大以及腹壁强度减弱，而引起腹壁强度减弱的主要原因是胶原代谢紊乱所致的腹壁筋膜薄弱。腹股沟疝胶原代谢紊乱的机制中，早期的研究认为基质金属蛋白酶(MMPs)所产生酶解作用使腹股沟区筋膜中包括胶原蛋白在内的细胞外基质过度降解引起筋膜薄弱；而近些年有研究认为转化生长因子β1(TGF-β1)表达异常与腹股沟疝的发生存在密切联系，并且TGF-β1与MMPs之间存在相互联系。再者TGF-β1参与器官纤维化、创面愈合以及瘢痕形成等生理病理活动并发挥促细胞增殖，迁移及促进胶原蛋白合成及调控纤维化等作用。因此我们利用TGF-β1在细胞增殖及促进胶原蛋等细胞外基质合成的作用，采用过表达TGF-β1方法来干预薄弱筋膜胶原蛋白合成，从而探索其对薄弱筋膜的改善情况，并初步摸索TGF-β1在薄弱筋膜胶原蛋白合成的作用机制，为降低或延缓腹股沟疝发生及治疗提供理论依据。 目的：本研究目的在于探索过表达TGF-β1对薄弱筋膜胶原蛋白合成代谢的影响，以及对筋膜薄弱程度的改善情况。 方法：(1)首先通过提取正常、腹股沟直疝和斜疝人群腹横筋膜标本，利用HE染色和Masson染色观察分析各组标本中大体形态学特征，并分析胶原蛋白在各组标本中所占面积，从而了解腹股沟疝人群腹横筋膜形态学特征。其次，我们利用免疫组化染色检测各组标本中TGF-β1表达情况，分析TGF-β1与腹股沟疝相关性。然后通过Western blot检测初步了解TGF-β1、Smad、MMP及COL蛋白表达水平变化与腹股沟疝之间的关系。 (2)在体外实验中，以成纤维细胞为研究对象，构建携带过表达TGF-β1慢病毒并转染成纤维细胞，观察过表达TGF-β1对成纤维细胞生长及迁移情况影响。通过RT-PCR和Western-blot分析参与胶原合成代谢途径上Smad，MMPs以及Collagen基因水平及蛋白水平表达变化，初步探索相关作用机制。并通过免疫荧光检测I型和III型胶原蛋白表达信号情况。 (3)在体内实验中，选取SD大鼠，通过刮薄左右两侧腹股沟筋膜组织约二分之一厚度，分别给予注射携带TGF-β1慢病毒、空载病毒及PBS。利用RT-PCR和Western-blot检测Smad，MMPs以及Collagen基因水平及蛋白水平表达变化，另外通过通过免疫荧光检测I型和III型胶原蛋白表达信号情况分析胶原蛋白合成变化，最后通过力学性能检测筋膜抗断裂强度(抗张强度)从而了解TGF-β1对筋膜力学性能的影响。 结果：(1)第一部分实验结果显示在腹股沟疝人群腹横筋膜标本HE染色中，纤维排列疏松且无序，纤维间的间隔增大，而正常人群则排列整齐且有序。在免疫组化染色中，腹股沟疝人群TGF-β1较正常组表达信号降低，Western blot检测发现TGF-β1及其通路上Smad 2，3的蛋白表达水平降低，而MMP-2和9呈现表达增强，与正常组相比差异存在统计学意义(P<0.05)。 (2)体外实验结果显示TGF-β1对成纤维细胞的凋亡并没有造成影响，各组间细胞凋亡率并无统计学差异(P>0.05)，并且在一定程度上促进成纤维细胞迁移。另外，TGF-β1通过Smad2／3信号通路来实现对胶原合成调控，对MMP-9起抑制作用，其mRNA和蛋白表达水平减弱，差异具有统计学意义(P<0.05)。但MMP-2随着TGF-β1表达增强出现同方向增强(P<0.05)。在胶原蛋白合成方面COL-1和COL-3呈现不同程度表达增强，以COL-1为主(P<0.05)。通过免疫荧光发现COL-1和COL-3表达信号明显较对照组明显增强。 (3)在体内实验，成功构建了腹股沟区域薄弱动物模型。Wsetern及PCR检测发现各组中TGF-β1、Smad 2，3均有不同程度表达增强，注射携带TGF-β1病毒组中增强更明显(P<0.05)，同时该组中MMP-9表达减弱，而MMP-2在组间比较中无统计学差异。在COL表达检测结果中，实验组COL-1较空载和PBS组表达明显增强(P<0.05)，各组COL-3表达无统计学差异(P>0.05)。通过力学性能检测发现筋膜标本抗断裂强度为2.00±0.66MPa，相比于对照组明显增强(P<0.05)。 结论：本研究证实了TGF-β1与腹股沟疝的发生存在相关性，并且初步验证TGF-β1通过Smad信号通路对胶原合成代谢发挥相应调控作用，同时在一定程度上抑制基质金属蛋白酶降解作用，使胶原蛋白降解减少。利用TGF-β1促细胞增殖、迁移及胶原合成等作用增加了薄弱筋膜处胶原合成，同时可以增强其强度，从而改善筋膜薄弱状态。 关键词：腹股沟疝，转化生长因子β，胶原合成与代谢

 Background: Inguinal hernia is a common disease in surgery. With increasing incidence per year, and the population with inguinal hernia has a tendency for aging. The causes of inguinal hernia include increased abdominal pressure and weakened abdominal wall strength. Among them, the frail abdominal wall fascia which caused by collagen metabolism disorder, often lead abdominal wall strength decreasing. In the mechanism of collagen metabolism disorder in the inguinal hernia, some early studies have suggested that the enzymatic hydrolysis of matrix metalloproteinases (MMPs) causes excessive degradation of the extracellular matrix including collagen in the inguinal region fascia, resulting in weak fascia; In recent years, studies have shown that the abnormal expression of transforming growth factor β1 (TGF-β1) is closely related to the occurrence of inguinal hernia and even abdominal wall hernia. Moreover, there is a correlation between TGF-β1 and MMPs, and TGF-β1 is involved in physiological and pathological activities such as organ fibrosis, wound healing, and scar formation, and plays a role in promoting cell proliferation, migration, and promoting collagen synthesis and regulation of fibrosis. Therefore, we used these functions of TGF-β1, and explore the improvement of weak fascia, which promoted the increase of weak fascia fibrosis by overexpressed TGF-β1 and with the purpose of increasing abdominal wall strength. So we may explore a new research for reducing or delaying inguinal hernia. Objective: The aim of this study was to explore the effects of synthesis or metabolism of collagen in weak fascia, and the improvement of fascia weakness by overexpression of TGF-β1. Methods: (1) Firstly, the transversalis fascia specimens of normal, direct hernia and indirect hernia patients were obtained. The morphological features of transversalis fascia specimens in each group were analyzed by HE staining and Masson staining, and the collagen area was statistically analyzed. Secondly, Immunohistochemical staining was used to detect the positive expression of TGF-β1 in each group, and we could analysis the relationship between TGF-β1 and inguinal hernia qualitatively. For understanding the relationship between TGF-β1 and inguinal hernia. The protein expression level of TGF-β1, Smad, MMPs were detected by Western blot. (2)In vitro, fibroblasts as the research objects, constructing lentivirus carrying overexpressing TGF-β1, then transfecting into fibroblasts, observing the effect of TGF-β1 on the growth and migration of fibroblasts. The expression of Smad, MMPs and Collagen genes and protein levels in collagen anabolic pathways were analyzed by RT-PCR and Western blot. The expression signals of type I and type III collagen were detected by immunofluorescence. (3)In vivo, SD rats were selected and craping about one-half of the thickness of the left and right inguinal fascia tissues for constructing an animal model with weak fascia in the inguinal region. And injected with TGF-β1 lentivirus, no-load virus and PBS, respectively. To vertify the genes level and protein level expression changes of Smad, MMPs and Collagen which involved in in the collagen anabolic pathway with the vitro test by RT-PCR and Western-blot. For analysis the changes of collagen synthesis, we detected the expression signals of type I and type III collagen by immunofluorescence. Otherwise, to understand the effect of TGF-β1 on the mechanical properties of the fascia, we detected the rupture strength (tensile resistance strength) of the fascia was measured by mechanical properties. Results: (1) The results of first part indicated that the fibers were loosely arranged and disordered, and the spacing between the fibers increased, while the normal group was neatly arranged of the transverse fascia specimens with the inguinal hernia patients in the HE staining. In immunohistochemical staining, the expression of TGF-β1 in inguinal hernia was lower than that in normal group. There was significant lower protein expression of TGF-β1 and Smad 2, 3, and higher expression of MMP-2, 9 compared with normal group (P<0.05) in Western blot. (2) Among the vitro results, there was no relationship between TGF-β1 and apoptosis of fibroblasts, compared with the control group, the apoptotic rate was not statistically increased (P>0.05). And promotes the migration of fibroblasts in some extent. In addition, we found that TGF-β1 regulates collagen synthesis through Smad2/3 signaling pathway by upgrated of Smad 2 and 3, meanwhile inhibits MMP-9, and its mRNA and protein expression levels are decreased, the difference is statistically significant (P<0.05), but MMP-2 increased in the same direction as the expression of TGF-β1 increased (P<0.05). In terms of collagen synthesis, COL-1 and COL-3 showed different degrees of expression enhancement, mainly COL-1 (P<0.05). The expression signals of COL-1 and COL-3 were significantly enhanced in immunofluorescence compared with the control group. (3)In vivo experiments, a weak animal model of the inguinal region was successfully constructed. Wsetern and PCR detection showed that TGF-β1 and Smad 2, 3 were enhanced in different degrees in each group, and more obvious in the lentivirus carrying overexpressing TGF-β1 group. (P<0.05), while MMP-9 expression dereased. There was no statistical difference in MMP-2 between groups. Among the COL test results, the expression of COL-1 in the experimental group was significantly higher than that in the no-load and PBS groups (P<0.05). There was no significant difference in the expression of COL-3 between the two groups (P>0.05). The mechanical properties test showed that the rupture strength of fascia specimens was 2.00±0.66 MPa, which was significantly enhanced compared with the control group (P<0.05). Conclusion: This study confirmed the inevitable correlation between TGF-β1 and inguinal hernia inevitablity, and TGF-β1 plays a significant role in the regulation of collagen synthesis and metabolism through Smad signaling pathway, and reduce the degradation of collagen by inhibits the matrix metalloproteinase in some extent. The use of TGF-β1 to promote cell proliferation, migration and collagen synthesis increases the collagen synthesis at the weak fascia and enhances its strength. Keywords: inguinal hernia, transform growth factor β, collagen synthesis and metabolism