Apoptosis and cell removal in the cryptorchid rat testis

Platelet-rich plasma effects on in vitro cells derived from pediatric patients with andrological diseases

Undescended testis and testicular torsion represent two frequent andrological diseases that affect the pediatric age. Despite these testicular disorders having different causes, they both negatively influence fertility in adulthood mainly due to the accumulation of reactive oxygen species (ROS), which represents the primary molecular damage underlying their long-term effects. The gold standard of treatment for both pathologies is surgery; however, it cannot guarantee an optimal fertility outcome in all clinical cases, underscoring the need to identify effective adjuvant therapies that may target the augmented ROS levels. For this aim, we investigated the pro-proliferative and anti-oxidant effects of PRP (platelet-rich plasma), a hemoderivative product used in regenerative medicine. We confirmed the increased oxidative status in testicular tissue by directly analyzing patients' biopsies with mass spectrometry and highlighting that three antioxidant proteins are significantly overexpressed compared to healthy testicles. Afterward, we in vitro treated cells derived from patients with cryptorchidism or testicular torsion with PRP, showing that it consistently decreases ROS levels and slightly induces cell proliferation. This study supports the potential use of PRP in patients with testis torsion or cryptorchidism, encouraging its future clinical application as adjuvant therapy to preserve the functionality of this organ by decreasing its ROS levels.

Sodium acetate prevents testicular damage in Wistar rats subjected to testicular ischaemia/reperfusion injury

AIMS

The aim of this study was to investigate the potential antioxidant, anti-inflammatory, and sperm function-preserving properties of sodium acetate (ACE), a histone deacetylase (HDAC) inhibitor, in a rat model of testicular torsion/detorsion (T/D).

MAIN METHODS

Littermate Wistar rats of identical weight were subjected to sham surgery or testicular T/D by rotating the left testis at 720° around its axis along the spermatic cord clockwise and fixing it in this position for two and a half hours. 1 h before detorsion, T/D + ACE-treated rats were treated with ACE (200 mg/kg/day, per os) while T/D rats were vehicle-treated by administering 0.5 mL of distilled water. After 72 h, animals were euthanized, and the left testes were harvested for bio-molecular and histological analysis.

KEY FINDINGS

Acetate administration attenuated T/D-induced rises in serum and testicular HDAC and testicular xanthine oxidase, uric acid, MDA, GSSG, MPO, TNF-α, IL-1β, IL-6, NFkB, HIF-1α, and VCAM-1. In addition, acetate treatment alleviated T/D-induced decline in sperm quality (count, motility, viability, and normal morphology) and testicular 3β-HSD, 17β-HSD, testosterone, GSH, GSH/GSSG, SOD, catalase, GPx, GST, Nrf2, and HO-1. Furthermore, acetate prevented T/D-distorted testicular histoarchitecture and spermatogenic germ cell loss.

SIGNIFICANCE

Sodium acetate during the post-ischaemic phase of testicular T/D may be beneficial in preventing I/R injury and maintaining fertility.

Hindlimb unloading-induced reproductive suppression via Downregulation of hypothalamic Kiss-1 expression in adult male rats

BACKGROUND

Spaceflights-induced microgravity can alter various physiological processes in human's body including the functional status of the reproductive system. Rodent model of tail-suspension hindlimb unloading is extensively used to stimulate the organs responses to the microgravity condition. This study explores the potential effects of hindlimb unloading on testicular functions and spermatogenesis in adult male rats and the underlying mechanism/s.

METHODS

Twenty Sprague-Dawley rats were allotted into two groups: normally loaded group (control; all arms were in touch with the grid floor) and hindlimb unloaded group (HU; only the forearms were in contact with the grid floor).

RESULTS

Following 30 days of exposure, the HU group saw a decline in body weight, testicular and epidydimal weights, and all semen parameters. The circulating concentrations of gonadotropin-releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone significantly decreased, while levels of kisspeptin, corticosterone, inhibin, prolactin and estradiol (E2) increased in the HU group. Intratesticular levels of 5α-reductase enzyme and dihydrotestosterone (DHT) were suppressed, while the levels of aromatase and kisspeptin were significantly elevated in the HU group. Hypothalamic kisspeptin (Kiss1) mRNA expression levels were downregulated while its receptors (Kiss1R) were upregulated in the HU group. On the contrary, the mRNA expression levels of testicular Kiss1 were upregulated while Kiss1R were downregulated. The pituitary mRNA expression levels of FSHβ and LHβ decreased in the HU group. The levels of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and nitric oxide (NO) concentrations, and total antioxidant capacity (TAC) were elevated while malondialdehyde (MDA) concentrations declined in the testes of HU group. The testes of the HU rats showed positive immunostaining of caspase-3, heat shock protein 70 (HSP70) and Bcl2.

CONCLUSIONS

Altogether, these results revealed an inhibitory effect of hindlimb unloading on kisspeptin signaling in the hypothalamic-pituitary-testicular axis with impaired spermatogenesis and steroidogenesis.

Identification of the Bisphenol A (BPA) and the Two Analogues BPS and BPF in Cryptorchidism

OBJECTIVE

to explore the association of plasma concentrations of bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) with unilateral cryptorchidism. In addition, to analyze selected demographic and intraoperative characteristics.

DESIGN

Retrospective analysis to determine plasma concentrations of total BPA, BPS and BPF using gas chromatography - mass spectrometry (GC-MS) among prepubertal boys with cryptorchidism and prebupertal male control subjects. During operation, the size, turgor and location of the cryptorchid testes were assessed.

MAIN OUTCOME MEASURE

Plasma concentrations of total BPA, BPS and BPF.

RESULTS

In children with cryptorchidism, plasma levels of BPA, BPS and BPF were significantly higher compared to the control subjects. For BPA, it was: median value: 9.95 ng/mL vs. 5.54 ng/mL, p<0.05. For BPS, it was: median value: 3.93 ng/mL vs. 1.45 ng/mL, p<0.001. For BPF, it was: median value: 3.56 ng/mL vs. 1.83 ng/mL, p<0.05. In cryptorchid group, BPA was detected in 61.4% samples, BPS in 19.3% and BPF in 19.3%. All the three bisphenols were detected in plasma samples of both the healthy subjects and the study cohort. In the latter group, we found significant higher levels of BPA in boys from urban areas. We found a weak positive correlation between the levels of BPS and BPF and reduced turgor of the testes. Furthermore, results showed weak positive correlations between BPA and BPS levels and the age of the children as well as between BPS and BPF concentrations and the place of residence.

CONCLUSIONS

Results provide a first characterization of prepubertal boys suffering from cryptorchidism and exposed to different kind of bisphenols. Our study suggests that cryptorchid boys are widely exposed to BPA and, to a lesser extent, also to its alternatives, such as BPS and BPF.

Rubus apetalus (Rosaceae) improves spermatozoa characteristics, antioxidant enzymes and fertility potential in unilateral cryptorchid rats

BACKGROUND

Cryptorchidism (CPT) is an important cause of male infertility. Rubus apetalus is a medicinal plant with a powerful antioxidant potential. We investigated the effects of aqueous and methanolic extracts of R. apetalus on spermatozoa parameters, antioxidant enzymes and fertility potential of rats with experimental unilateral CPT.

METHOD

Normal (n = 15), sham-operated (n = 15) and cryptorchid rats (n = 80; distributed into 16 groups of 5 rats/group) were treated for 2, 4 or 8 weeks with either distilled water (10 ml/kg/day), vitamin E (75 mg/kg/day), aqueous or methanolic extract of R. apetalus (12 and 60 mg/kg). Sex organ weights, spermatozoa parameters, testicular proteins, sex hormones, fertility potential, morphometric characteristics of testis and oxidative stress markers were measured.

RESULTS

CPT significantly (p < 0.05-0.001) decreased testicular and epididymal weights, spermatozoa density, spermatozoa motility, spermatozoa normality, testicular proteins, LH, FSH and testosterone concentrations. In cryptorchid rats, peri-vascular fibrosis significantly increased (p < 0.001), while diameter of the seminiferous tube, germ cell thickness, gestation index and fertility index decreased when compared to control. Additionally, CPT induced oxidative stress by increasing lipid peroxidation and by reducing superoxide dismutase and catalase activities. These alterations were corrected by R. apetalus. For instance, a significantly increase (p < 0.05-0.001) in spermatozoa motility, normality, viability and density after 2, 4 and 8 weeks of treatment was noticed. R. apetalus also increased (p < 0.05-0.001) testicular proteins, gestation index (90-100%) and fertility index (90-100%), compared to the untreated cryptorchid rats.

CONCLUSION

R. apetalus boosts fertility potential in cryptorchid rats and could be considered as a promising alternative agent for the management of infertility associated with CPT.

Surgery-induced cryptorchidism induces apoptosis and autophagy of spermatogenic cells in mice

Cryptorchidism, characterized by the presence of one (unilateral) or both (bilateral) undescended testes, is a common male urogenital defect. Cryptorchidism can lead to male infertility, testicular cancer being the most extreme clinical symptom, as well as psychological issues of the inflicted individual. Despite this, both knowledge about the aetiology of cryptorchidism and the mechanism for cryptorchidism-induced male infertility remain limited. In this present study, by using an artificial cryptorchid mouse model, we investigated the effects of surgery-induced cryptorchidism on spermatogenic cells and seminiferous epithelial cycles. We found that surgery-induced cryptorchidism led to a reduced testicular weight, aberrant seminiferous epithelial cycles and impaired spermatogenesis characterized by degenerating spermatogenic cells. We also observed multinucleated giant cells after surgery-induced cryptorchidism. Transmission electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) and western blot assays demonstrated cryptorchidism-induced apoptosis of spermatogenic cells. Moreover, we identified the occurrence of autophagy in germ cells after surgery-induced cryptorchidism. Interestingly, apoptosis and autophagy were synchronous, suggestive of their synergetic roles in promoting germ cell death. Our results provide novel insights into the cryptorchidism-induced male infertility, thereby contributing to the development of male contraceptive strategies as well as treatment options for male infertility caused by cryptorchidism.

Effects of Moringa oleifera Lam Extract (MOLE) in the heat shock protein 70 expression and germ cell apoptosis on experimentally induced cryptorchid testes of rats

Moringa oleifera (Moringaceae) is a plant known for having high antioxidant potency, anticancer, hepatoprotective, cardioprotective etc. and many more activities. Besides these, Moringaceae has the potential for attenuating the male sexual dysfunction. Reactive oxygen species/ROS were increased in cryptorchidism and therefore cause infertility by damaging sperm DNA and germ cell apoptosis. There was an increase in heat shock proteins (HSP) in cells, which is affected by heat shock. In the present study, the antioxidant effects of two different doses of M. oleifera Lam Extract (MOLE) on experimentally induced cryptorchid testes of rats was investigated. Forty two male rats (16 days old) were divided into four groups: a normal control group, a cryptorchidism-induced control group and two cryptorchidism-induced groups treated orally with either 400 or 800 mg/kg MOLE for 2 weeks. Our study showed that there were ruptures from interstitial spaces, separation of the germ cells from basal membrane, falling of the germ cells into the lumen, perivascular fibrosis, oedema, increased level of HSP70, apoptosis, malondialdehyde (MDA) and decrease in the level of superoxide dismutase (SOD) after the cryptorchidism. We found that pathological damages, oxidative stress, expression of the HSP70 and germ cell apoptosis were decreased in treated groups with MOLE. In brief, we can say that aqueous extract of M. oleifera reduces the oxidative stress in a unilateral cryptorchidism induced rats, and it might attenuate histopathological damages, HSP expression and germ cell apoptosis.

Protective effects of red grape (Vitis vinifera) juice through restoration of antioxidant defense, endocrine swing and Hsf1, Hsp72 levels in heat stress induced testicular dysregulation of Wister rat

Ability of red grape juice (RGJ), a known antioxidant, on testis of adult Wister rat to protect from oxidative stress induced damages by heat stress has been investigated in this study. Heat stress was induced maintaining body and testicular temperature at 43°C for 30min/day for 15 days using a hyperthermia induction chamber. Four groups of rats (n=6 per group) comprising of Group-I (control) -kept at 32°C, Group-II -exposed to heat stress alone, Group-III received RGJ (0.8ml/rat/day) alone and Group-IV -exposed to heat stress and received RGJ at same dose. Analysis of blood and testicular tissue exhibited significant reduction in serum testosterone, testicular superoxide dismutase, testicular catalase and testicular glutathione (all p < 0.001); whereas, significant rise in the level of serum corticosteroid, testicular lipid peroxidase and the apoptotic enzyme caspase-3 of testis (all p < 0.001) were observed along with substantial increase in testicular Hsp72 and Hsf-1, and decrease in 17β-HSD3 were noted in heat stressed rats compared to controls. In Group-IV rats, RGJ administration could restore these parameters to normal levels. The signs of retention were clear in Group-IV rats and found to be significantly different as compared to that of the Group-II rats. In testicular histology of rats exposed to heat stress alone revealed remarkable germ cell degeneration and tubular deformations which were prevented by RGJ treatment (Group-IV). The reduced number of sperm level in Group-II also restored in RGJ treatment (Group-IV). The above results indicate that consumption of RGJ may substantially protect testis from heat stress induce dysfunctions.

Sperm DNA damage measured by sperm chromatin structure assay in men with a history of undescended testes

The aim of this study was to compare sperm DNA damage between men with a history of congenital undescended testis (UDT) and men with a history of acquired UDT. A long-term follow-up study of men with previous UDT was performed. Fifty men with congenital UDT who had undergone orchiopexy at childhood age, 49 men with acquired UDT after a 'wait-and-see'-protocol (e.g. awaiting spontaneous descent until puberty and perform an orchiopexy in case of non-decent), and 22 healthy proven fertile men were included. The DNA fragmentation index (DFI) using sperm chromatin structure assay (SCSA) was used to express the level of sperm DNA damage. Decreased fertility potential was considered if DFI was above 30%. Sperm DNA damage was not statistically different between cases of congenital and acquired UDT. DFI was significantly more often >30% in the complete group of men with congenital UDT (9/50; 18%) and in the subgroup with bilateral congenital UDT (3/7; 43%) in comparison with the controls (none) (p-value 0.049 and 0.01, respectively). Age at orchiopexy in congenital UDT had no statistical effect on DNA damage. In men with acquired UDT, DFI did not statistically differ between those having undergone orchiopexy and those experiencing spontaneous descent. This study supports the hypothesis that UDT is a spectrum representing both congenital UDT and acquired UDT. Sperm DNA damage at adult age is not influenced by age at orchiopexy in congenital UDT cases and by orchiopexy or spontaneous descent in acquired UDT cases.

The Role of Heat Shock Factors in Mammalian Spermatogenesis

Heat shock transcription factors (HSFs), as regulators of heat shock proteins (HSPs) expression, are well known for their cytoprotective functions during cellular stress. They also play important yet less recognized roles in gametogenesis. All HSF family members are expressed during mammalian spermatogenesis, mainly in spermatocytes and round spermatids which are characterized by extensive chromatin remodeling. Different HSFs could cooperate to maintain proper spermatogenesis. Cooperation of HSF1 and HSF2 is especially well established since their double knockout results in meiosis arrest, spermatocyte apoptosis, and male infertility. Both factors are also involved in the repackaging of the DNA during spermatid differentiation. They can form heterotrimers regulating the basal level of transcription of target genes. Moreover, HSF1/HSF2 interactions are lost in elevated temperatures which can impair the transcription of genes essential for spermatogenesis. In most mammals, spermatogenesis occurs a few degrees below the body temperature and spermatogenic cells are extremely heat-sensitive. Pro-survival pathways are not induced by heat stress (e.g., cryptorchidism) in meiotic and postmeiotic cells. Instead, male germ cells are actively eliminated by apoptosis, which prevents transition of the potentially damaged genetic material to the next generation. Such a response depends on the transcriptional activity of HSF1 which in contrary to most somatic cells, acts as a proapoptotic factor in spermatogenic cells. HSF1 activation could be the main trigger of impaired spermatogenesis related not only to elevated temperature but also to other stress conditions; therefore, HSF1 has been proposed to be the quality control factor in male germ cells.

Electroacupuncture enhances spermatogenesis in rats after scrotal heat treatment

Spermatogenesis is regulated by a cascade of steroid regulated genes in the testis. Recent studies suggested that acupuncture may improve fertility in men with abnormal semen parameters. Yet, the underlying mechanisms in which acupuncture enhances spermatogenesis remain largely unknown. Here we used a scrotal heat-treated rat model to study the effect of electroacupuncture (EA) on recovery of spermatogenesis. In this model, spermatogenesis was disrupted by 30 min scrotal heat treatment at 43°C. Ten sessions of EA were given at Baihui (GV20), Guanyuan (CV4), Zusanli (ST36) and Sanyinjiao (SP6) from day 9 to day 36 post-treatment. Sperm motility and production, morphology of the germinal epithelium by Johnsen’s scoring, germ cell apoptosis by TUNEL staining, proliferation by proliferating cell nuclear antigen (PCNA) staining, as well as serum testosterone and inhibin B levels by immunoassays were evaluated on day 0, 1, 9, 25, 37, 46, 56 and 79. When compared with the heat-treated (H) group, the heat-treated plus EA (H⁺EA) group showed a significant increase (p < 0.05) in PCNA-positive cells and inhibin B levels on days 37 and 46, and a higher Johnsen’s score till day 56. On day 79, motile spermatozoa could be found in the vas deferens of H⁺EA group only. Consistently, there was a trend of improved motility and increased number of motile epididymal spermatozoa in the H⁺EA group than the H group; while apoptosis of germ cells and serum testosterone levels were similar between the two groups. Taken together, EA enhanced germ cell proliferation through improvement of Sertoli cell functions. This may facilitate the recovery of spermatogenesis and may restore normal semen parameters in subfertile patients.

Possible role of ZPAC, zygote-specific proteasome assembly chaperone, during spermatogenesis in the mouse

In the mammalian testis, the ubiquitin-proteasome system plays important roles in the process that promotes the formation of mature sperm. We recently identified zygote-specific proteasome assembly chaperone (ZPAC), which is specifically expressed in the mouse gonads and zygote. ZPAC mediates a unique proteasome assembly pathway in the zygote, but the expression profile and function of ZPAC in the testis is not fully understood. In this study, we investigated the possible role of ZPAC during mouse spermatogenesis. First, we analyzed the expression of ZPAC and 20S proteasome subunit α4/PSMA7 in the adult mouse testis. ZPAC and α4 were expressed in spermatogonia, spermatocytes, and round spermatids. In elongating spermatids, ZPAC was expressed until step 10, whereas expression of α4 persisted until step 12. We then examined the expression profile of ZPAC and α4 in a mouse model of experimental unilateral cryptorchidism. Consistent with appearance of morphologically impaired germ cells following cryptorchidism, the ZPAC protein level was significantly decreased at 4 days post induction of experimental cryptorchidism (D4) compared with the intact testis, although the amount of α4 protein persisted at least until D10. Moreover, intense ZPAC staining was co-localized with staining of annexin V, an early indicator of apoptosis in mammalian cells, in germ cells of cryptorchid testis, but ZPAC was also expressed in germ cells showing no detectable expression of annexin V. These results suggest that ZPAC plays a role during spermatogenesis and raises the possibility that 20S proteasome mediated by ZPAC may be involved in the regulation of germ cell survival during spermatogenesis.

Effects of methanolic extract of Moringa oleifera leaves on semen and biochemical parameters in cryptorchid rats

While anti-oxidant effects of Moringa oleifera in much oxidative stress related diseases have been well reported, cryptorchidism on the other hand has been shown to cause oxidative stress. However, study is scanty on the likely role of Moringa oleifera in reducing cryptorchidism-induced oxidative stress in rats has not been studied. The present study looked into the effects of methanolic extract of Moringa oleifera leaves (MEMO) on semen and biochemical parameters in cryptorchid rats. Twenty male albino rats (200-250 g) were randomly divided into 4 groups (n=5 each). Groups A and B were sham-operated and treated with corn-oil and 200 mg/kg of MEMO respectively, while groups C and D were rendered cryptorchid and also treated with corn-oil and 200 mg/kg of MEMO respectively. Cryptorchid rats had lower testicular weight, sperm count, germ cell count, testicular superoxide dismutase (SOD) concentration, testicular total protein and higher testicular malondialdehyde (MDA) concentration compared to sham-operated rats. MEMO had no significant effect on testicular weight and MDA concentration, while it significantly increased sperm count, germ cell count, testicular SOD and total protein in the cryptorchid rats. The present study suggests that MEMO ameliorates cryptorchidism associated germ cell loss and oxidative stress.

Rats with metabolic syndrome resist the protective effects of N-acetyl l-cystein against impaired spermatogenesis induced by high-phosphorus/zinc-free diet

Consumption of relatively high amounts of processed food can result in abnormal nutritional status, such as zinc deficiency or phosphorus excess. Moreover, hyperphosphatemia and hypozincemia are found in some patients with diabetic nephropathy and metabolic syndrome. The present study investigated the effects of high-phosphorus/zinc-free diet on the reproductive function of spontaneously hypertensive rats/NDmcr-cp (SHR/cp), a model of the metabolic syndrome. We also investigated the effects of antioxidant, N-acetyl-l-cysteine (NAC), on testicular dysfunction under such conditions. Male SHR/cp and control rats (Wistar Kyoto rats, WKY) were divided into three groups; rats fed control diet (P 0.3%, w/w; Zn 0.2%, w/w), high-phosphorus and zinc-deficient diet (P 1.2%, w/w; Zn 0.0%, w/w) with vehicle, or high-phosphorus and zinc-deficient diet with NAC (1.5mg/g/day) for 12 weeks (n=6 or 8 rats/group). The weights of testis and epididymis were significantly reduced by high-phosphate/zinc-free diet in both SHR/cp and WKY. The same diet significantly reduced caudal epididymal sperm count and motility and induced histopathological changes in the testis in both strains. Treatment with NAC provided significant protection against the toxic effects of the diet on testicular function in WKY, but not in SHR/cp. The lack of the protective effects of NAC on impaired spermatogenesis in SHR/cp could be due to the more pronounced state of oxidative stress observed in these rats compared with WKY.

Vitamins e and C alleviate the germ cell loss and oxidative stress in cryptorchidism when administered separately but not when combined in rats

The antioxidant effects of vitamins C and E on cryptorchidism-induced oxidative stress were investigated in male Sprague-Dawley rats. Forty rats (200-250 g) were randomly divided in a blinded fashion into five groups (n = 8). Group 1 was sham operated and treated with vehicle (corn-oil, 10 mL/kg). Groups 2, 3, 4, and 5 were rendered unilaterally cryptorchid and treated with vehicle (10 mL/kg), vitamin E solution (75 mg/kg), vitamin C solution (1.25 g/kg), and combination of vitamin E (75 mg/kg) and vitamin C (1.25 g/kg) solutions, respectively. Germ cell count, superoxide dismutase (SOD), total protein (TP), and testicular weight (TW) were lower, but malondialdhyde (MDA) was higher in the cryptorchid rats than the sham-operated rats. When administered separately, vitamins C and E increased germ cell count, SOD, TP, and TW but did not reduce MDA in the cryptorchid rats when compared to the vehicle-treated cryptorchid rats. However, there was no significant difference in these parameters between vehicle-treated and combined vitamins C- and E-treated rats. This suggests that vitamins E and C alleviate the germ cell loss and oxidative stress in cryptorchidism when administered separately but not when combined in rats.

Extended intervention time and evaluation of sperm suppression by dienogest plus testosterone undecanoate in male rat

BACKGROUND

The potential of using dienogest [DNG, 40 mg/kg body weight (bw)] plus testosterone undecanoate (TU, 25 mg/kg bw) in rats for development of a once-a-month male hormonal contraceptive has been reported earlier in our laboratories.

STUDY DESIGN

In the present study, we report a separate efficacy evaluation of the same combination, DNG (40 mg/kg bw) and TU (25 mg/kg bw) in which interval of drug administration has been extended further to 45 and 60 days instead of every 30 days.

RESULTS

Complete sperm suppression was observed in rats sacrificed either 60 or 90 days after DNG+TU administration, for two injections at 45-day interval. The neutral α-glucosidase activity in these treated rats remained in the normal range. Germ cell loss due to apoptosis was frequently observed both after 60 or 90 days of combination treatment. Significant decline in serum gonadotropin and testosterone, both serum and intratesticular levels, were observed in the treated rats. Following stoppage of treatment (given at 45-day interval) after two (0 and 45 days) or three injections (0, 45 and 90 days), complete restoration of spermatogenesis was observed by 120 and 165 days, respectively. The sperm suppression, however, could not be sustained when the period of combined drug administration was extended from every 45 to 60 days.

CONCLUSIONS

Dienogest plus testosterone undecanoate in the above doses retained contraceptive effectiveness when administered every 45 days but not 60 days. The spermatogenic arrest was completely reversible once drug treatment is stopped. The dose and the frequency of intervention can be extrapolated in future clinical trials.

Trials for development of once-a-month injectable, hormonal male contraceptive using dienogest plus testosterone undecanoate: dose standardization, efficacy and reversibility studies in rats

BACKGROUND

The study was conducted to test the potential of using dienogest (DNG) plus testosterone undecanoate (TU) in rats for development of a once-a-month injectable male hormonal contraceptive.

STUDY DESIGN

Dose selection studies were initiated with administration of DNG in three different doses of 20, 30 and 40 mg/kg body weight (bw) per week plus TU 25 mg/kg bw once in every 6 weeks. Status of spermatogenesis and sperm count in epididymis was evaluated. The frequency of DNG intervention was later extended to every 2- and 4-week intervals. Mating studies, toxicity and reversibility of spermatogenesis following stoppage of treatment were carried out with DNG 40 mg/kg bw at 4-week intervals.

RESULTS

Complete arrest of spermatogenesis was observed after 60 days of treatment at all doses of DNG (20, 30 and 40 mg/kg bw per week)+TU. However, weights of testis and accessory sex organs (epididymis, prostate and seminal vesicle) declined significantly 60 days post treatment compared to vehicle-treated controls. Epididymis in the treated animals was completely devoid of sperm. When the frequency of DNG injection (20 mg/kg bw) was extended to once every 15 days, a few immotile and decapitated sperm were observed in the epididymis. With TU treatment unchanged, animals receiving DNG (40 mg/kg bw) once either every 2- or 4-week intervals demonstrated good and uniform arrest of spermatogenesis. DNG 40 mg/kg per 4 weeks+TU also demonstrated a significant rise in germ cell apoptosis in the seminiferous epithelium. There was no significant increase in the serum high-density lipoprotein and low-density lipoprotein levels at the end of 120 days of treatment. Following withdrawal of treatment after 60 or 120 days, qualitative restoration of spermatogenesis was rapid in the former compared to the latter.

CONCLUSION

Dienogest plus TU has the potential for development as a monthly injectable showing reversible hormonal male contraception with good efficacy.

Effect of allopurinol on damage caused by free radicals to cryptorchid testes

Cryptorchidism causes apoptosis of germ cells. It has been suggested that the redox regulatory system is involved in this process. The free radicals produced are thought to be generated during the production of uric acid, a reaction catalyzed by xanthine oxidase. This enzyme is inhibited by allopurinol; however, the role of allopurinol in neonate rats with inguinal cryptorchidism has not been assessed yet. Sixty male Wistar rats were used and five groups were formed: a control, a sham, a sham group with allopurinol administration and two groups with surgical unilateral cryptorchidism, which either did not receive, or received, allopurinol. The rats were assessed at 40 days post-partum. Reactive oxygen species concentration and epithelial area were measured and the histopathological, apoptotic and cellular proliferation indexes were determined. We found a decrease in reactive oxygen species, histopathological and apoptotic indexes and an increase in proliferation index and epithelial area in rats with cryptorchidism treated with allopurinol in comparison with rats with untreated cryptorchidism. We suggest that the over-production of reactive oxygen species plays an important role in the damage of the cryptorchid testes. Allopurinol administration decreases reactive oxygen species concentrations as well as the damage to the germ epithelium.

hCG treatment raises H2O2 levels and induces germ cell apoptosis in rat testis

The clinical significance of exogenous hCG treatment is to stimulate steroidogenesis and spermatogenesis in the testis. However, the pathogenesis of detrimental effects on the testis arising out of chronic hCG treatment is yet to be clearly ascertained. In the present study we have shown that hCG treatment (100 IU/day) to rats for 30 days raises testicular oxidative stress leading to germ cell apoptosis and impairment of spermatogenesis. The treatment raises testicular H(2)O(2) levels along with increase in lipid peroxidation and concomitant decrease in the enzymatic antioxidant activities like superoxide dismutase, catalase and glutathione-s-transferase. The rise in the number of apoptotic germ cells was associated with up regulation of Fas protein expression and caspase-3 activity in the testis. However, serum testosterone which was elevated by 15 days of hCG treatment declined to pretreatment levels by 30 days. No significant alteration in serum gonadotropins was observed. The above findings indicate that the pathogenesis of deleterious effects following chronic hCG treatment is due to increase in testicular oxidative stress with high H(2)O(2) availability leading to apoptosis among germ cells.

Heat shock transcription factor 1 down-regulates spermatocyte-specific 70 kDa heat shock protein expression prior to the induction of apoptosis in mouse testes

Expression of constitutively active heat shock transcription factor 1 (HSF1) in mouse spermatocytes induces apoptosis and leads to male infertility. We report here that prior to the onset of massive apoptosis caused by expression of active HSF1 in spermatocytes a marked reduction in spermatocyte-specific Hsp70.2 mRNA and protein levels occurs. In addition, HSP70.2 protein relocalizes from a predominant cytoplasmic to a nuclear position in developing spermatocytes that express active HSF1. Later in the developmental stages, cells undergoing HSF1-induced apoptosis essentially lack the HSP70.2 protein. The down-regulation of Hsp70.2 gene expression by HSF1 is paradoxical because HSF1 is the prototypical activator of HSP genes. Furthermore, HSF1-mediated repression neither involved a heat shock element (HSE)-like sequence adjacent to the Hsp70.2 gene nor were Hsp70.2 promoter sequences associated directly with HSF1. Interestingly, other spermatocyte- and spermatid-specific transcripts are also down-regulated in testes of transgenic mice expressing active HSF1, suggesting involvement of a putative HSF1-dependent block of development of spermatogenic cells. Importantly however, transcription of the Hsp70.2 gene is down-regulated in testes of wild-type mice subjected to a hyperthermia that induces transient activation of HSF1, indicating that the spermatocyte-specific activity of HSF1 might misdirect a network of transcription factors required for proper regulation of Hsp70.2.

Inducible 70 kDa heat shock protein does not protect spermatogenic cells from damage induced by cryptorchidism

Accumulation of inducible heat shock proteins (e.g. Hsp70i) during cellular stress confers thermotolerance, reduces the consequences of damage and facilitates cellular recovery, while abrogation of Hsp70i expression renders sensitivity to apoptosis. Testis translocation into abdominal cavity, which results in temperature elevation, does not induce expression of the Hsp70i proteins. Despite constitutive expression of testis-specific Hsp70 proteins, spermatocytes are very sensitive to damage at elevated temperatures. To test whether Hsp70i protein could protect testes from heat-induced damage, we have engineered transgenic mice that over-express this protein selectively in spermatocytes and spermatids. We demonstrate that the testes of cryptorchid transgenic mice, like those of wild-type mice, exhibit reduced weight and smaller sizes of their seminiferous tubules, disorganization of their germinal epithelium structures, appearance of multinucleated giant cells, and reduced populations of germ cells. The data show that constitutive expression of Hsp70i does not protect the seminiferous epithelium against cryptorchidism-induced damage.

Blockage of testicular connexins induced apoptosis in rat seminiferous epithelium

Spermatogenesis, a tightly regulated developmental process of male germ cells in testis, is associated with temporal and spatial expression of gap junction proteins, such as the connexin family members. Perturbation of their expressions may lead to spermatogenic arrest as manifested by disruption of cell-cell interaction. To explore the role(s) of connexins during spermatogenesis, we utilized the small peptide antagonistic approach to specifically deplete connexin 31, connexin 33, and pan-connexin. Three connexin peptides corresponding to the extracellular binding domain of connexin 31 and connexin 33 and to the extracellular conserved domain of connexins were designed and synthesized commercially. Peptides (at single dosage of 0.5, 1, or 2 mg per animal) were injected into rat testes and testes were collected on day 0, 1, 3, 5, 10, 15, and 30 after microinjection. In situ TUNEL assay demonstrated the induction of apoptosis in the testes after pan-connexin peptide treatment in a dose-dependent manner from day 3 and onward. Unlike the pan-connexin peptide, connexin 31 and connexin 33 peptides appeared to have little effect on inducing apoptosis and germ cell loss. CD45 staining also detected the occasional presence of infiltrating lymphocytes in the seminiferous tubules. Accompanied with the apoptotic events, two apoptotic markers, NF-kappaB and caspase 3, demonstrated a general up-regulation in their expressions. In adjacent testis sections, eliminations of connexin 31, 32, and 43 were observed. However, an induction of connexin 33 expression was detected. This suggests the versatility and functional diversity of connexins in the testis. The expression of ZO-1, the only known adaptor of connexins in the testis, was reduced and remained in a low level in the seminiferous epithelium. As such, the alterations of connexins in seminiferous epithelium may induce apoptotic signaling in the testis via the caspase 3 and the NF-kappaB pathway. This demonstrates the significant role of testicular connexins to maintain the survival of germ cells by regulating inter-cellular communications among germ cells and adjacent supporting cells during spermatogenesis. In addition, the inter-relationship between connexins and other junction proteins and associated signaling protein were investigated. After pan-connexin peptide treatment, a dys-localization of N-cadherin, an adherens junction protein, and diminution of occludin, a tight junction protein, level were detected. In addition, inductions of junction regulatory protein, cathepsin L, was observed during the course of peptide-mediated germ cell loss in the testes. In summary, pan-connexin peptide treatment triggered apoptosis and germ cell loss in the testes. This event influenced the localization and expression of different junction proteins and junction-associated protein in the testes.

Estradiol treatment induces testicular oxidative stress and germ cell apoptosis in rats

In order to understand the pathogenesis of estradiol induced effects in the seminiferous epithelium, studies were undertaken in adult rats with estradiol-3-benzoate administered for different durations. After 30 d of treatment, a significant rise in lipid peroxidation with concomitant fall in the activities of superoxide dismutase and catalase was observed. Both, serum and intra-testicular testosterone levels were found severely depleted. Seminiferous epithelium was devoid of elongated spermatids and spermatozoa by 30 d of treatment. Number of spermatocytes and round spermatids were significantly (p < 0.001) reduced. Flowcytometric analysis confirmed a drastic reduction of the haploid cell population (1c peak). Beginning from day 10 of treatment, there was a consistent rise in the number of pyknotic/apoptotic germ cells in the seminiferous epithelium. A gradual increase in Bax protein expression was observed with the duration of treatment. The shift in Bax immunostaining from the cytoplasm and nucleus of germ cells (at 10 d of treatment) to only nuclei of cells by 30 d of treatment was also noticed. By this time testicular tissue showed three-fold increase in caspase-8 enzyme activity. Viable testicular cells isolated in vitro decreased drastically subsequent to different periods of estradiol treatment. The above findings substantiate the fact that the testicular pathogenesis of estradiol benzoate treatment may be primarily because of altered reproductive hormone levels and high oxidative stress leading to germ cell apoptosis and subsequent germ cell loss in the seminiferous epithelium.

Effects of Experimental Cryptorchidism on Sperm Motility and Testicular Endocrinology in Adult Male Rats

The effect of induced cryptorchidism on testicular function and sperm motility was investigated. Bilateral cryptorchidism was created surgically in adult male rats (treated group), and sham-operated rats were used as a control group. Five rats from each group were sacrificed on days 1, 3, 5, and 7 after surgery. The percentage of motile spermatozoa began to decrease 1 day after the operation, followed by an abrupt decline 3 and 5 days later in cryptorchid rats. Furthermore, there were significant decreases in the other sperm motility parameters 5 days after inducement of cryptorchidism. In cryptorchid rats, plasma concentrations of LH, FSH, testosterone, and inhibin B were significantly lower than in the control group 1 day after the operation. Thereafter, plasma concentrations of LH, FSH, and testosterone gradually increased in the cryptorchid rats. On the other hand, plasma concentrations of inhibin B showed a further decline from day 3 after the operation onward. Concentrations of immunoreactive (ir)-inhibin, but not testosterone, in testicular interstitial fluid were remarkably increased until 3 days after surgery in the cryptorchid rats, and declined thereafter. Testicular response to human chorionic gonadotropin (hCG) for testosterone release was decreased in the cryptorchid rats compared with the control rats, indicating that heat stress to testes resulted in a reduction of the activity of Leydig cells and Sertoli cells. These results clearly indicate that heat stress to the testes resulted in a significant reduction of sperm activity within 3 days, and this was followed by changes in testicular endocrine function.