Effect of spermidine on ameliorating spermatogenic disorders in diabetic mice via regulating glycolysis pathway.

Diabetes mellitus (DM), a high incidence metabolic disease, is related to the impairment of male spermatogenic function. Spermidine (SPM), one of the biogenic amines, was identified from human seminal plasma and believed to have multiple pharmacological functions. However, there exists little evidence that reported SPM's effects on moderating diabetic male spermatogenic function. Thus, the objective of this study was to investigate the SPM's protective effects on testicular spermatogenic function in streptozotocin (STZ)-induced type 1 diabetic mice. Therefore, 40 mature male C57BL/6 J mice were divided into four main groups: the control group (n = 10), the diabetic group (n = 10), the 2.5 mg/kg SPM-treated diabetic group (n = 10) and the 5 mg/kg SPM-treated diabetic group (n = 10), which was given intraperitoneally for 8 weeks. The type 1 diabetic mice model was established by a single intraperitoneal injection of STZ 120 mg/kg. The results showed that, compare to the control group, the body and testis weight, as well the number of sperm were decreased, while the rate of sperm malformation was significantly increased in STZ-induced diabetic mice. Then the testicular morphology was observed, which showed that seminiferous tubule of testis were arranged in mess, the area and diameter of which was decreased, along with downregulated anti-apoptotic factor (Bcl-2) expression, and upregulated pro-apoptotic factor (Bax) expression in the testes. Furthermore, testicular genetic expression levels of Sertoli cells (SCs) markers (WT1, GATA4 and Vimentin) detected that the pathological changes aggravated observably, such as the severity of tubule degeneration increased. Compared to the saline-treated DM mice, SPM treatment markedly improved testicular function, with an increment in the body and testis weight as well as sperm count. Pro-apoptotic factor (Bax) was down-regulated expression with the up-regulated expression of Bcl-2 and suppression of apoptosis in the testes. What's more, expression of WT1, GATA4, Vimentin and the expressions of glycolytic rate-limiting enzyme genes (HK2, PKM2, LDHA) in diabetic testes were also upregulated by SPM supplement. The evidence derived from this study indicated that the SMP's positive effect on moderating spermatogenic disorder in T1DM mice's testis. This positive effect is delivered via promoting spermatogenic cell proliferation and participating in the glycolytic pathway's activation.

[Effect of SUMO Modification on the Chromosomal Aneuploidy in Oocytes].

The chromosomal aneuploidy in oocytes is one of main causes of abortion and neonatal birth defects.It is mainly due to the premature separation of sister chromatid caused by the loss of Cohesin protein complex and the non-disjunction sister chromatids caused by abnormal microtubule dynamics aneuploidy.As a pathway of protein post-translational modification,SUMO modification(or SUMOylation)involves many physiological regulation processes including cell proliferation,differentiation,apoptosis,and cycle regulation.In the oocytes,SUMOylation can regulate the localization of Cohesin protein complex on the chromosome to affect the chromosomal aneuploidy in oocytes caused by premature separation of sister chromatid.On the other hand,SUMOylation can regulate the microtubule dynamics to affect the chromosomal aneuploidy in oocytes caused by non-disjunction sister chromatids.Therefore,SUMOylation plays an important role in regulating the chromosomal aneuploidy of oocytes;the exact mechanisms via which the SUMOylated substrates affect aneuploidy in oocytes remain unclear.This articles reviews the roles of SUMOylation in premature separation and non-isolated chromatid aneuploidy in oocyte from the effects of SUMOylationon Cohesin protein complex and microtubule dynamics.

[Energy Demand and Its Regulatory Mechanism during Folliculogenesis].

The growth and development of follicles are regulated by genes,hormones and growth factors autocrined and paracrined from granulosa cells,theca cells,and oocytes.Products of glycolysis from granulosa cells such as pyruvate and lactate are one of the main energy sources,which play an important role during folliculogenesis and follicle maturity.Studies on the changes of the products and rate-limiting enzymes during granulosa cells' glycolysis help to clarify the molecular mechanism of energy demand in folliculogenesis and guide the clinical treatment of infertility due to abnormal follicular development.This article reviews recent research advances in the energy demand and regulatory mechanism in different states of folliculogenesis.

[Role and regulatory mechanism of glycometabolism of Sertoli cells in spermatogenesis].

Testis has been reported to be a naturally oxygen-deprived organ. Lactate produced by glycolysis of Sertoli cells is an important source of energy in spermatogenic cells, which quickly provides adenosine triphosphate to meet the needs of rapidly proliferating spermatogenic cells for energy and substances. Wide attention has been drawn to the studies of energy metabolism and its regulatory mechanisms in normal spermatogenesis. It is essential to illuminate the regulation of glucose transport by glucose transporters in Sertoli cells, the catalysis of pyruvate to lactic acid by lactate dehydrogenase and the transport process of the single carboxylate transporter to lactic acid under the influence of different factors or diseases, which play important roles in ensuring the normal spermatogenesis and male reproductive function. This review summarizes the changes of energy metabolism in spermatogenesis and the mechanisms of endocrine factors, signaling pathways, miRNAs and protein acetylation regulating cell glycolysis, aiming to provide some important reference for the elucidation of the molecular metabolism of spermatogenesis and clinical treatment of relevant diseases.

[Estradiol benzoate induces abnormal proliferation of spermatogenic cells in the testis of infertile male mice].

OBJECTIVE: To explore the change in the proliferation of spermatogenic cells in the male mouse with infertility induced by exogenous estradiol benzoate (EB). METHODS: Sixty male mice aged 4 weeks were randomly divided into a control, a low-dose EB, and a high-dose EB group to be injected intramuscularly with corn oil at 150 µl or EB at 5 or 10 mg/kg, respectively, every other day for 4 weeks. Then, we obtained the weight and indexes of the testis, performed HE staining of the paraffin sections of the testis tissue and epididymal cauda, counted the spermatozoa in the epididymal sperm suspension, and determined the expression of the proliferating cell nuclear antigen (PCNA), the mRNA expressions of CyclinA1, CyclinB1, VASA and p53, and the protein expressions of p53 and phosphorylated p53 in the testis by immunohistochemistry, qRT-PCR and Western blot, respectively. RESULTS: In comparison with the controls, the mice treated with EB showed significantly decreased testicular indexes (P <0.05), no sperm in the sperm suspension or epididymal tubes, remarkably reduced numbers of spermatogonia, primary spermatocytes and Sertoli cells (P <0.05), down-regulated expression of PCNA (P <0.05) and mRNA expressions of CyclinA1, CyclinB1, PCNA and VASA in the seminiferous tubules (P <0.05), but a dose-dependent increase of the p53 level (P <0.05). Western blot revealed markedly higher levels of p53 protein expression and phosphorylation in the EB than in the control group (P <0.05) and even higher in the 10 mg/kg than in the 5 mg/kg EB group (P <0.05). CONCLUSIONS: EB inhibited the proliferation of spermatogenic cells by down-regulating the expressions of cell cycle-related factors in a dose-dependent manner, which might contribute to abnormal proliferation of spermatogenic cells in the testis of infertile male mice.