目的 探讨血红素加氧酶1（HO-1）对白蛋白诱导肾小管上皮细胞凋亡的影响及其可能机制。 方法 体外培养大鼠肾小管上皮细胞（NRK-52E）为正常对照。白蛋白对照组加去脂的小牛血清白蛋白（BSA）30 g/L共同培养。干预组先加钴卟啉（Cobalt protoporphyrin IX，CoPP，血红素加氧酶1诱导剂）5 μmol/L，0.5 h后再加入BSA 30 g/L，作用24 h。四甲基偶氮唑盐（MTT）比色法检测CoPP对BSA抑制NRK-52E细胞增殖的影响。细胞免疫荧光染色检测细胞凋亡率。RT-PCR法检测凋亡相关蛋白Bcl-2、Bax mRNA表达情况。 结果 与正常对照组比较，BSA对细胞增殖具有抑制作用并诱导细胞凋亡，差异有统计学意义（P < 0.05），而CoPP对BSA引起的细胞毒性作用具有保护作用（P < 0.05）；BSA对照组HO-1 mRNA表达增加（0.44±0.06比0.39±0.05，P < 0.05)，差异有统计学意义（P < 0.05）。CoPP预处理后，HO-1 mRNA表达（0.50±0.06）较BSA对照组增加（P < 0.05）。BSA可上调Bax mRNA表达(0.87±0.04比0.67±0.03，P < 0.05）及下调Bcl-2 mRNA的表达（0.25±0.04比0.42±0.02，P < 0.05)，当加入CoPP预处理后可抑制上述改变（Bax mRNA：0.75±0.07，Bcl-2 mRNA：0.36±0.03，均P < 0.05）。 结论 BSA可显著增加细胞的凋亡率并直接调控凋亡相关蛋白mRNA的表达，CoPP可抑制上述BSA的作用。HO-1对BSA所致肾小管上皮细胞凋亡具有保护作用，可以抑制细胞凋亡。

Objective To investigate the influence of heme oxygenase-1 (HO-1) on rat renal tubular epithelial cell apoptosis induced by albumin and the possible mechanism. Methods The renal tubular epithelial cells(NRK-52E) were cultured in DMEM/F12 1:1 medium as normal control group; NRK-52E cells were cultured with 30 g/L fat-free bovine serum albumin(BSA) as the BSA control group; NRK-52E cells were cultured with CoPP (Cobalt protoporphyrin IX) 5 μmol/L for 24 hours as the treatment group． MTT assay was used to observe the effects of CoPP on growth inhibition induced by BSA in NRK-52E cells. The effect of CoPP was observed in BSA-induced apoptosis with the fluorescence microscope dyed by AnnexinV-FITC PI. The levels of HO-1, and expression of Bcl-2 and Bax mRNA were detected by reverse transcript polymerase chain reaction (RT-PCR). Results Compared with normal control group, BSA inhibited the growth of NRK-52E cells（P<0.05) and increased cell apoptosis rate（P<0.05). The CoPP pretreatment partially inhibited the BSA-induced apoptosis（P<0.05). Compared with normal control group, HO-1 mRNA expression increased（0.44±0.06 vs 0.39±0.05, P<0.05） in BSA control group. Compared with the BSA control group, the expression of HO-1 mRNA significantly increased after CoPP pretreatment（0.50±0.06 vs 0.44±0.06, P<0.05）. Meanwhile, BSA increased the expression of Bax mRNA （0.87±0.04 vs 0.67±0.03, P<0.05）and reduced the expression of Bcl-2 mRNA（0.25±0.04 vs 0.42±0.02, P<0.05）. CoPP could inhibit the effect of BSA （Bax mRNA: 0.75±0.07, Bcl-2 mRNA: 0.36±0.03, P<0.05, respectively）. Conclusions BSA can increase the apoptosis rate significantly and regulate the expression of apoptosis associated proteins in mRNA level directly. CoPP inhibits these changes, which provides evidence to support the essential role of HO-1 in cytoprotective function .