摘要 目的：胃黏膜上皮的生长、更新和修复的过程是受到严格调控的，其修复能力可能与肽类物质的表达水平有关。该文探讨急性胃黏膜损伤修复中乳癌相关肽（pS2）、转化生长因子-α(TGF-α)及增殖细胞核抗原(PCNA) 的作用。方法：18日龄Wistar大鼠，随机分为实验组（LPS组）和对照组，分别腹腔注射内毒素（5 mg/kg）及生理盐水，每一时相点8只，注射后1.5, 3, 6, 24, 48, 72 h 观察胃黏膜损伤情况，苏木精-伊红染色观察形态学改变，免疫组化SP法检测胃黏膜pS2、TGF-α及PCNA蛋白表达变化。结果：LPS组6 h胃黏膜损伤最重，黏膜表面可见大片糜烂、出血、条索状坏死，与胃纵轴平行；光镜下黏膜表面上皮广泛脱落，黏膜内有出血，炎性细胞浸润，核碎裂、固缩，凋亡小体出现，腺体受损。LPS组的PCNA在3，6，24，48 h 胃黏膜组织细胞核表达较对照组明显减低（P<0.01）；pS2在1.5 h胃黏膜组织细胞浆表达低于对照组，3 h 恢复正常，6，24，48，72 h 明显高于对照组（P<0.01）；TGF-α在6，24，48 h 胃黏膜组织细胞浆表达较对照组明显增强（P<0.01）。结论：PCNA表达变化反映了胃黏膜损伤和修复过程中胃黏膜细胞的增殖活性；pS2表达上调，可能通过介导细胞增殖参与急性胃黏膜细胞保护作用；TGF-α表达增强，可能促进了胃黏膜上皮的代谢和生长，参与胃黏膜的修复。
Abstract：OBJECTIVE: Growth, regeneration and reparation of gastric mucosal epithelium may relate to the expression of peptides. This study aimed to investigate the effect of pS2, TGF-α and PCNA in endotoxin-induced acute gastric mucosal injury in young rats. METHODS: Eighteen-day-old Wistar rats were randomly injected intraperitoneally with lipopolysaccharide (LPS) (5 mg/kg) or normal saline (control). The gastric mucosal specimens were harvested 1.5, 3, 6, 24, 48, and 72 hrs after LPS or normal saline injection (n=8 each). The pathological changes of the gastric mucosa were observed by hematoxylin-eosin staining. The expression of pS2,TGF-α and PCNA was measured by immunohistochemistry SP method. RESULTS: Gastric mucosal injuries were the most serious 6 hrs after LPS injection, characterized by massive erosion, bleeding and cord necrosis of the gastric mucosa paralleling with gastric longitudinal axis. PCNA expression in the gastric mucosa in the LPS group 3, 6, 24 and 48 hrs after LPS injection was significantly lower than that in the control group (P<0.01). pS2 expression in the gastric mucosa weakened 1.5 hrs after LPS injection, recovered to the control level at 3 hrs and was significantly higher than the control at 6, 24, 48 and 72 hrs of LPS injection (P<0.01). TGF-α expression in the gastric mucosa in the LPS group increased significantly 6, 24 and 48 hrs after LPS injection when compared with the control group (P<0.01). CONCLUSIONS: PCNA expression may be associated with the proliferation activity of the gastric mucosa in the process of gastric mucosal injury/reparation. pS2 and TGF-α might participate in the defense and reparation of gastric mucosal cells through mediating cell proliferation following acute gastric mucosal injury.
LIU Chun-Ying,WANG Li-Jie,WANG Yan-Bin et al. Expression of pS2, TGF-α and PCNA in the gastric mucosa of young rats with endotoxemia[J]. CJCP, 2008, 10(2): 221-224.
