EXPRESSION OF BCL-2 AND BAX IN RHESUS MONKEY TESTIS DURING GERM CELL APOPTOSIS INDUCED BY TESTOSTERONE UNDECANOATE

NMR-based metabolomics approach to study the effects of Wu-Zi-Yan-Zong-Wan on triptolide-induced oligospermia in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Wu-Zi-Yan-Zong-Wan (WZYZW) is a commonly used Chinese medicinal recipe for oligozoospermia. Oligozoospermia is a common disease that harms human fertility, there is no effective therapeutic medicine at present. However, the underlying pharmacological mechanism remains unclear.

METHODS

Oligozoospermia rats model induced by Tripterygium glycosides (TG) was established to inspect the efficiency of WZYZW in the treatment of oligozoospermia by traditional pharmacodynamics combined with NMR-based metabolomics. Multivariate statistics were used to extracted the underlying biomarkers and metabolic pathways of WZYZW in the treatment of oligozoospermia.

RESULTS

The results showed that TG disturbed many metabolites and metabolic pathways such as oxidative stress (choline, O-phosphocholine, betaine and ascorbate), energy metabolism in mitochondria (glucose, lactate, succinate, fumarate, 3-hydroxybutyrate and alanine), mitochondrial apoptosis markers (Bax and Bcl-2) and amino acids metabolisms (arginine, branched-chain amino acids, taurine and myo-inositol).

CONCLUSIONS

WZYZW could significantly reverse the disturbed metabolites to their normal status by their abilities of anti-oxidation, anti-apoptosis, balancing the osmotic pressure regulatory molecules and regulating the amino acids metabolism. This study provides pharmacological basis and guidance for the clinical usage of WZYZW.

The effects of hydroalcoholic extract of Vaccinium arctostaphylos L. on sperm parameters, oxidative injury and apoptotic changes in oxymetholone-induced testicular toxicity in mouse

Anabolic androgenic steroids (AAS) such as oxymetholone (OM) used for athletic enhancement, but increased free radicals damage and changes in hormonal levels, lead to serious and irreversible organ damage. Vaccinium arctostaphylos(V. arctostaphylos( has been demonstrated to have antioxidant and antiinflammatory effects. The aim of present study was to investigate V. arctostaphylos effect on OM-induced oxidative injury in mouse testis and sperm parameters. In this experimental study, 30 BALB/c mice were divided into five groups, including healthy, positive control(5 mg/kg OM) and three treatment groups (100, 200 and 400 mg/kg of V. arctostaphylos extract + 5 mg/kg OM). At the end of the study, serum luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone levels were measured. Testis stereological and sperm parameters were calculated. Antioxidant status was measured using nitric oxide (NO) and FRAP assay, and malondialdehyde (MDA) levels. Furthermore, the expression of p53, caspase-3, Bax and Bcl-2 was measured. V. arctostaphylos decreased the serum level of testosterone, increased the LH and FSH, and improved the stereological and sperm parameters and down-regulated the p53, caspase-3 and Bax and up-regulated Bcl-2 genes. Furthermore, this dose decreased serum levels of NO and increased testis FRAP and MDA levels in treated groups compared with OM group. V. arctostaphylos extract has protective effects against testicular toxicity caused by OM.

Interrelationships between apoptosis and fertility in bull sperm

Male fertility, the ability of sperm to fertilize and activate the egg and support early embryogenesis, is vital for mammalian reproduction. Despite producing adequate numbers of sperm with normal motility and morphology, some males suffer from low fertility whose molecular mechanisms are not known. The objective was to determine apoptosis in sperm from high and low fertility bulls and its relationship with male fertility. DNA damage, phosphatidylserine (PS) translocation, and expression of pro- and anti-apoptotic proteins (BAX and BCL-2) in the sperm were determined using TUNEL, Annexin V, and immunoblotting approaches, respectively. Amounts of apoptotic spermatozoa were 2.86 (± 1.31) and 3.00 (± 0.96) in high and low fertility bulls, respectively (P=0.548), and were not correlated with fertility. There was a negative correlation between early necrotic spermatozoa and viable spermatozoa (r = -0.99, P<0.0001). Fertility scores were correlated with live spermatozoa detected by eosin-nigrosin test and necrotic spermatozoa determined via flow cytometry (r = -0.49, P<0.006 and r = -0.266, P<0.0113, respectively). BAX level was higher in low fertile group than high fertile group; however, this difference was not statistically significant due to the variations of bull samples (Bull 1-3 vs. Bull 4-5) in low fertile group (P<0.283). BCL-2 was not detectable in any of the sperm samples. The results shed light onto molecular and cellular underpinnings of male fertility.

Alteration in expression of estrogen receptor isoforms alpha and beta, and aromatase in the testis and its relation with changes in nitric oxide during aging in mice

The aim of present study was to investigate the changes in the testicular expression of aromatase, ER alpha, ER beta and iNOS protein and correlate these with serum testosterone and nitric oxide levels, to elucidate the role of estrogen and nitric oxide in the testis during aging. This study showed localization of aromatase and ER alpha mainly in the Leydig cell and showed close correlation of testicular aromatase level with circulating testosterone level suggesting that estrogen may be modulating testicular steroidogenesis. Localization ER alpha mainly in the mitotically active germ cell suggest possible role of estrogen in germ cell proliferation. This study showed basal level of nitric oxide during reproductively active period, whereas increased serum nitric oxide coincides with decreased testicular activity in old age. This study showed inverse correlation between aromatase and NO level. Treatment with either SNP or L-NAME on testicular steroidogenic factor (3-beta HSD/ StAR) or germ cell survival factor (Bcl2) showed that increased NO causes decreased steroidogenesis and increased germ cell apoptosis. In conclusion this study suggest that estrogen modulate steroidogenesis and germ cell survival in reproductively active period whereas in old age decreased estrogen concentration causes increased nitric oxide which in turn decreases testicular steroidogenesis and germ cell apoptosis.

Effects of combined administration of low-dose gossypol with steroid hormones on the mitotic phase of spermatogenesis of rat

Our previous studies suggested that combined low-dose gossypol with steroid hormones possesses a reversible antifertility role on adult male rat. Spermatocyte apoptosis during the meiosis of spermatogenesis is the main reason for the antifertility. This study evaluates the effects of the regimen on the mitosis of spermatogenesis. Thirty-two adult male rats were divided into four groups randomly, Group GH: rats were fed orally with gossypol acetic acid (GA, 12.5 mg/kg d) and desogestrel (DSG, 0.125 mg/kg d)/ethinylestradiol (EE, 0.025 mg/kg d)/testosterone undecanoate (TU, 100 mg/kg d); Group G: a single dose of GA (12.5 mg/kg d); Group H: the same dosage of DSG/EE/TU as in Group GH; Group C: rats were treated with vehicle (1% methyl cellulose) as control. Testes were removed at the 8th week after treatment to assess the weight, volumes, diameter, and degenerated rate of seminiferous tubule, spermatogonia is quantitated by stereological assay. TUNEL assay and proliferating cell nuclear antigen immunohistochemistry were used to determine the germ cell apoptosis and proliferation. The changes of gene expression of glial cell line-derived neurotrophic factor (GDNF) and Ets variant gene 5 (Etv5) were analyzed. The results manifested that the spermatogenesis was suppressed, the type A and intermediate spermatogonia reduced, and spermatocyte and spermatid apoptosis increased both in Group GH and Group H. The expressions of GDNF protein in these two groups were downregulated, but no change was observed in Etv5 expression. However, the numbers of spermatogonia, germ cell apoptosis and proliferation, and the expressions of GDNF and Etv5 were unchanged in Group G compared with Group C. Above all, we concluded that the mitotic phase of spermatogenesis is suppressed by the combination regimen, it might be the steroid hormones in the regimen that caused the reduction of spermatogonia through the downregulation of GDNF.

Determination of nitric oxide synthase activity and apoptosis of germ cells in different obstruction models

We aimed to determine the changes of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) immunoreactivity and apoptosis after proximal and distal obstruction models on ipsilateral and contralateral testicular tissues. Male albino Wistar rats were randomly divided into three groups (n=30): a control group which underwent sham operations (n=10), a unilateral vasal ligation (n=10) and a unilateral epididymal ligation group (n=10). iNOS and eNOS distribution and apoptosis were studied in both ipsilateral and contralateral testes using quantitative immunohistochemistry. Nitric oxide synthase activity was significantly affected in ipsilateral and contralateral testes cells after vasal and epididymal ligation. eNOS immunoreactivity increased markedly after ipsilateral vasal ligation (ILVL). Degeneration-related changes were also associated with changes in apoptotic rate. Analysis using the terminal dUTP nick end-labeling TUNEL method revealed that apoptotic cell numbers significantly increased after ILVL. p53 and bcl-2 immunoreactivity increased in both experimental groups compared with the sham-operated group. Changes in iNOS and eNOS immunolocalisation were strongly associated with cell damage, because germ cell degeneration was more prominent in the ILVL group. Altered p53 immunolocalisation was also associated with cell degeneration, and a rise in bcl-2 immunoreactivity might be considered to reflect a protective mechanism in the testis. These cellular changes could enlighten understanding of the interaction between testicular functioning and damage.

Control of spermatogenesis in primate and prospect of male contraception

The present review is a summary of mechanisms of spermatogenesis in primates with emphasis on anti-spermatogenesis of testosterone (T), gossypol, and "testicular heat stress" for development of male contraception, Both FSH and testosterone stimulate all phases of spermatogenesis. FSH is capable of amplifying the population of the differential spermatogonia (B1, B2, B3 and B4) and controls the spermatogonia production rate, and, in synergy with testosterone, regulating spermatogenesis in adult monkeys. Pituitary FSH beta gene expression is governed by a feedback of Beta inhibin, which is a major component of the testicular negative feedback signals. Beta inhibin secreted by Sertoli cells is in turn inhibited by testosterone from Leydig cells under the control of LH. Disturbance of the normal interaction of pituitary FSH with Sertoli cell Beta inhibin is responsible for azoospermia or oligozoospermia induced by exogenous T. Three possible regimens of T, gossypol and "heat stress" have been suggested for male contraception. They act on different sites and stages of spermatogenesis in testis or sperm activity in epididymis. Apoptosis induced by testosterone occurs mainly at staged VII-VIII of spermatogenesis while that by testicular "heat stress" mostly occurs at stages I-IV and X-XII. Low dose of gossypol mainly influences the sperm activity in the epididymis although it also acts on testicular spermatids.