氯膦酸二钠脂质体对重症急性胰腺炎大鼠肠黏膜Akt、MAPK(ERK1/2)活性的影响

Liposomal clodronate reduces Akt and mitogen-activated protein kinase expression in the intestinal mucosa of rats with severe acute pancreatitis

目的:研究氯膦酸二钠脂质体(liposomal clodronate,LC)对重症急性胰腺炎(severe acute pancreatitis,SAP)大鼠肠黏膜蛋白激酶B(protein kinase B,Akt)和丝裂原活化蛋白激酶1/2[mitogen-activated protein kinase,MAPK(ERK1/2)]活性的影响,探讨LC治疗SAP肠黏膜损伤的保护作用.方法:利用薄膜法制备LC.SD大鼠48只,随机分为3组:对照组(C组)、SAP+空白脂质体治疗组(P组)、SAP+Clodronate脂质体治疗组(T组).P组和T组采用胰腺被膜下均匀注射5%牛磺胆酸钠制作SAP模型后,分别经尾静脉注射空白脂质体和Clodronate脂质体,C组仅注射等量生理盐水.制模后2、6 h分别取肠系膜上静脉血液,检测各组大鼠血清中淀粉酶(amylase,AMS)的含量,同时检测各组大鼠血清中白介素-6(interleukin-6,IL-6)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的含量,观察各组肠黏膜的病理学变化及病理评分,采用免疫组织化学方法检测肠黏膜巨噬细胞Akt和MAPK(ERK1/2)的表达情况.结果:P组大鼠在制模后2、6 h的血清AMS水平较C组明显升高(P<0.01).与P组比较,T大鼠各时相的血清AMS水平均显著降低(P<0.01).P组较C组2、6 h血清IL-6和TNF-α明显升高(P<0.01).T组各时相较P组血清IL-6和TNF-α显著降低(P<0.01).T组大鼠的肠黏膜病理变化均较P组明显减轻,病理学评分明显降低(P<0.01).T组肠黏膜Akt和MAPK(ERK1/2)的表达较P组明显减少.结论:巨噬细胞在SAP大鼠肠黏膜损伤中起重要作用,LC可选择性清除巨噬细胞,减少肠黏膜Akt、MAPK(ERK1/2)的表达,对肠黏膜损伤有一定的保护作用.

AIM： To study the effect of liposomal clodronate on the expression of protein kinase B （Akt） and mitogen-activated protein kinase [MAPK （ERK1/2）] in the intestinal mucosa of rats with severe acute pancreatitis （SAP）, and to investigate the mechanism behind the therapeutic effect of liposomal clodronate on SAP-associated intestinal mucosal injury. METHODS： Liposomal clodronate was prepared by means of thin film. Forty-eight SD rats were randomly divided into a model control group （C）, a liposome control group （P）, and a liposomal clodronate group （T）. SAP was induced in rats of groups P and T by injection of sodium taurocholate under the pancreatic capsule, while group C received equal volume of normal saline. Serum levels of interleukin-6 （IL-6）, tumor necrosis factor-α （TNF-α） and AMS were measured 2 and 6 h after SAP induction. Pathological alterations in the intestinal mucosa were observed. RESULTS： Serum levels of AMS, IL-6 and TNF-α were significantly elevated in group P compared to group C （all P 〈 0.01）. Compared with group P, serum levels of AMS, IL-6 and TNF-α were significantly decreased in group T （all P 〈 0.01）. Pathological alterations （scores） in the intestinal mucosa were significantly attenuated in group T compared to group P. The expression of Akt and MAPK （ERK1/2） was significantly decreased in group T compared to group P. CONCLUSION： Macrophages play an important role in the pathogenesis of intestinal mucosal injury in SAP. Macrophages can be depleted via phagocytosis of liposome encapsulated clodronate. Liposomal clodronate alleviates intestinal mucosal injury in SAP rats possibly by decreasing the expression of Akt and MAPK （ERK1/2）.