[Effect of "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture on reproductive function in mice with asthenozoospermia based on mitochondrial apoptosis].

Objective: To observe the effects of the "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture on key regulatory factors during mitochondrial apoptosis of testicular tissue in asthenozoospermia mice, and explore the potential mechanism of the protective effect of acupuncture on reproductive function.

Methods: Thirty C57BL/6 male mice were randomly divided into a blank group, a model group and an acupuncture group, 10 mice in each group. In the model and the acupuncture groups, the intraperitoneal injection of cyclophosphamide (30 mg•kg•d) was delivered for 7 days to prepare the asthenozoospermia model. After the success of modeling, the modeled mice in the acupuncture group were intervened with "Zhibian" (BL54)-toward-"Shuidao" (ST28) acupuncture, once daily and the needles were retained for 20 min. The duration of the intervention was 2 weeks. The general condition of each mouse was observed, and the body mass was recorded before modeling, after modeling and after intervention completion. After intervention, the testicular mass was recorded and the weight coefficient was calculated, and the mouse sperm quality was examined; the serum contents of testosterone (T), follicle stimulating hormone (FSH) and luteinizing hormone (LH) were detected using ELISA, the morphology of testicular tissue was observed using HE, the mitochondrial ultra-microstructure of testicular tissue was observed under transmission electrone microscopy, the mitochondrial membrane potential level of testicular tissue was detected using JC-1 staining, the positive rate of apoptosis cell of testicular tissue was observed using TUNEL; and the mRNA and protein expression of b-cell lymphocytoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), cytochrome c (Cyt C), apoptotic protease-activating factor1 (Apaf-1), Caspase-9 and Caspase-3 of testicular tissue was detected using real-time quantitative fluorescence PCR and Western blot methods separately; and the positive expression of Cleaved Caspase-3 of the testicular tissue was detected using immunohistochemistry.

Results: Compared with the blank group, the mice were in listless spirits, had shaggy hairs, the reduced appetite and movement, and weight loss in the model group (<0.01); the testicular mass and the weight coefficient decreased (<0.01); the total number of sperms, sperm motility, and sperm viability were declined (<0.01); while the levels of serum T, FSH, and LH were dropped (<0.01). The morphology of seminiferous tubules in testicular tissue was abnormal, the number of spermatogenic cells and the number of mitochondria decreased, the inner mitochondrial crest was fractured and lost, and vacuoles appeared. The level of mitochondrial membrane potential was reduced (<0.01); and the positive rate of apoptosis cell in testicular tissue increased (<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was elevated (<0.01, <0.05), the mRNA and protein expression of Bcl-2 was dropped (<0.01), and the average absorbance value of Cleaved Caspase-3 increased (<0.01). When compared with the model group, in the acupuncture group, the general condition of mice was improved, the testicular mass and the weight coefficient elevated (<0.01); the total number of sperms, sperm motility, and sperm viability increased (<0.01); while the levels of serum T, FSH, and LH rose (<0.01). The pathological morphology of testicular tissue and the inner mitochondrial ultra-microstructure were ameliorated, the level of mitochondrial membrane potential was elevated (<0.01); the positive rate of apoptosis cell was reduced (<0.01). The mRNA and protein expression of Bax, Cyt C, Apaf-1, Caspase-9 and Caspase-3 was dropped (<0.01, <0.05), the mRNA and protein expression of Bcl-2 elevated (<0.05), and the average absorbance value of Cleaved Caspase-3 declined (<0.01).

Conclusion: "Zhibian" (BL54)-toward- "Shuidao" (ST28) acupuncture may ameliorate mouse reproductive function by inhibiting mitochondrial apoptosis pathway, alleviating testicular tissue damage in the asthenospermia mice induced by cyclophosphamide.