NF-κΒ、COX-2在高糖培养的肾小管上皮细胞中的表达及意义

EXPRESSION OF COX-2 AND NF-κB IN THE RENAL PROXIMAL TUBULAR EPITHELIAL CELLS CULTURED IN HIGH GLUCOSE MEDIUM

目的探讨核因子κB(nuclear factor-kappa B,NF-κB)/环氧化酶-2(cyclooxygenase 2,COX-2)信号途径在高糖培养的肾小管上皮细胞增殖中的作用及意义。方法用正常糖和高糖培养基培养肾小管上皮细胞,24、487、2 h后收集细胞,采用免疫细胞化学检测肾小管上皮细胞增殖细胞核抗原(proliferating cell nuclear autigen,PCNA)和NF-κB蛋白的表达变化,流式细胞术检测肾小管上皮细胞中NF-κB和COX-2蛋白的表达情况。结果①与正常糖组比较,高糖组肾小管上皮细胞PCNA表达增强;②正常糖组,NF-κB主要表达在肾小管上皮细胞的细胞浆内,而高糖组NF-κB表达增强,阳性表达主要定位于肾小管上皮细胞的细胞核内;高糖能够上调肾小管上皮细胞NF-κB和COX-2蛋白的表达;③NF-κB和COX-2呈显著正相关;同时COX-2蛋白表达与PCNA阳性率呈显著正相关。结论活化NF-κB,上调COX-2蛋白表达从而引起肾小管上皮细胞增殖可能是糖尿病肾脏损伤的机制之一。

Objective To investigate the effect of nuclear factor-kappa B （NF-KB）/ cyclooxygenase 2（COX-2） signal pathway on the proliferation of human renal proximal tubular cells（HKCs） cultured in high glucose medium. Methods HKCs were cultured separately in normal or high glucose medium for 24,48,72 h. The expression of NF-KB and COX-2 protein was detected by flow cytometry（FCM） and the expression of proliferating cell nuclear autigen（PCNA） was detected by immunocytochemical staining. Results ①Compared with those in HKC cultured in the medium with normal level glucose, the stainings were strengthened for PCNA in HKCs exposed to high glucose from 24 h. ②Immunocytochemically, activated NF-kB were positively expressed in nu.cli of HKCs cultured in high glucose mediumi By FCM, the expression of NF-kB and COX-2 in HKC cultured in high glucose medium was higher than that in normal glucose medium ③The expression of NF-kB and PCNA was positively correlated with the expression of COX-2. Conclusion Activating NF-kB and elevating the expression of COX-2 play an important role in regulating HKCs proliferation, which may be one of the injury mechanisms of the renal cells during diabetic nephropathy.