细胞自噬在去势后大鼠前列腺萎缩中的作用及其机制

The role of autophagy in castration-induced prostate atrophy

目的探讨细胞自噬在去势后大鼠前列腺萎缩中的作用及其机制。方法将SD大鼠72只随机均分为假切组、去势组、羟氯喹组。各组大鼠分别于术后第1、3、7、10、14、21天随机抽取4只取出前列腺组织。苏木素-伊红（HE）染色观察前列腺组织形态学变化，电镜下观察前列腺细胞自噬小体的变化，免疫组织化学链菌素抗生物素蛋白一过氧化物酶（sP）法检测Becfinl、P62、B淋巴细胞／白血病．2（bcl-2）、bax蛋白在前列腺组织中的表达：逆转录一聚合酶链反应（1it—PCR）检测微管相关蛋白轻链3（LC3）、自噬相关基因5（Atg5）mRNA在前列腺组织中的表达。结果去势后光镜下大鼠前列腺组织随时间变化逐渐萎缩，电镜下前列腺细胞出现大量空泡状双层膜样结构的自噬小体。去势后Beclinl表达增强（0．0665±0．0137），P62表达减弱（0．0103±0．0042），bcl-2表达减弱（0．0340±0．0048），bax表达增强（0．0456±0．0122）。加用羟氯喹处理后Beclinl表达减弱（0．0103±0．0042），P62表达增强（0．0526±0．0096），bcl-2表达进一步减弱（0．0090±0．0032），bax表达进一步增强（0．0828±0．0098）。RT-PCR检测去势后自噬相关基因LC3、Atg5mRNA表达较假切组增强，用羟氯喹处理后表达减弱。结论去势后大鼠前列腺细胞自噬增加，羟氯喹可通过阻断自噬促进细胞凋亡，自噬可能通过抑制凋亡而在去势后大鼠前列腺萎缩中起保护作用。

Objective To investigate the role of autophagy in castration-induced proatate atrophy. Methods Seventy-two healthy male SD rats were randomly divided into 3 groups： sham operation group, castration group and hydroxyehloroquine group. At 24 h, 72 h, 7 days, 10 days, 14 days and 21 days after operation, we took out four rats randomly from each group and the protaste tissues were removed. The mor- phological changes of the prostates were observed under a light microscope and the changes of cytolysosomes and apoptotic bodies in the prostates were observed under the electron microscopy. The protein expression of BediM, P62, B lymphocytes/leukemia-2 （bel-2） and bax was detected by detected by using immuno- histochemistry. The mRNA expression of microtubule-associated protein 1 light chain 3 （ LC3 ）, and auto- phagy related gene 5 （Atg5） was detected by using reverse transcription-polymerase chain reaction （RT- PCR）. Results The prostate tissues shranked remarkably in the castrated rats. Cytolysosomes were ob- served under the electron microscopy. The expressoin of Beclinl （0. 0665 _＋0. 0137） and bax （0. 0456 ＋ O. 0122） was increased, and that of P62 （0. 0103 _＋0. 0042） and bcl-2 （0. 0340 ＋0. 0048） was reduced. Af- ter treatment with hydroxychloroquine, the expressoin of Beclinl （0. 0103 ：~ 0.0042） and bel-2 （0. 0090 _＋ 0. 0032） was reduced, and that of P62 （0. 0526 ＋0. 0096）, and Bax （0. 0828 ＋0. 0098） was increased. RT-PCR revealed that the mRNA expression of LC3 and Atg5 was enhanced. After treatment with hydroxy- ehIoroquine, the mRNA expression of LC3, and Atg5 was weakened. Conclusion The expression of auto- phagy was increased in prostates after castration. After treatment with hydroxychloroquine, the expression of autophagy was decreased, but apoptosis increased, which suggested that the autophagy can protect the prostates to shinking.