MR 11. Autophagic deficiency may lead to steroidogenic decline in aged Leydig cells
Male Reproduction

MR 11. Autophagic deficiency may lead to steroidogenic decline in aged Leydig cells

Wei-Ren Li1, Lei Hou1, Zhi-Jie Chang2, Hua Xin3, Tao Liu3, Guang-Yong Li3, Feng Zhou3, Yan-Qing Gong3, Zhe-Zhu Gao3, Zhong-Cheng Xin3

1Beijing General Aerospace Hospital, Beijing 100076, China; 2Department of Biological Sciences and Biotechnology, School of Medicine, Tsinghua University, Beijing 100084, China; 3Andrology Center, Peking University First Hospital, Peking University, Beijing 100034, China

Objective: To explore the role of autophagy in steroidogenic decline of aged Leydig cells.

Methods: Ten young and ten aged male subjects were enrolled in this study. Aging Male's Symptoms (AMS) scale was used for symptom evaluation. The histological changes in testis and ultrastructure of Leydig cells were observed by H.E. staining and electron microscopy (EM) respectively. Steroidogenesis was assessed by of steroidogenic acute regulatory (StAR), protein expression by Western blotting, and serum testosterone detection with an ELISA kit. Autophagic changes were studied via autophagosome analysis in EM and LC3 protein expression analysis by western blot. Beclin 1 was knocked down with siRNA in TM3 mouse Leydig cells followed by StAR and LC3 protein detection and supernatant testosterone measurement. CM-H2DCF-DA, an accepted cell-permeant indicator of ROS, was used to assess the ROS level in Leydig cells.

Results: The scores of AMS in the aged group were s igni f i c ant ly higher than those in the young group (61.25±7.08 vs. 20.75±3.73, P<0.001) with decreased serum testosterone levels [(3.12±0.58) μg/L vs. (6.29±1.17) μg/ L, P<0.05]. HE staining showed degenerative changes in aged human testes. Many swollen mitochondria with mitochondrial cristae disappeared were found in aged human Leydig cells in EM. The expression of StAR protein and serum total testosterone level in aged group were significantly lower than those of young groups. The ratio of autophagic area in EM and LC3-II protein expression were decreased in aged human testes. Knockdown of Beclin 1 decreased LHstimulated StAR expression and testosterone production in TM3 mouse Leydig cells, which were associated with increased intracellular ROS level.

Conclusions: Ageing; autophagy; late onset hypogonadism; leydig cell; reactive oxygen species; testosterone

Key words

Annexin 5; ECT2; cell proliferation; leydig cells

DOI: 10.3978/j.issn.2223-4683.2012.s104

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