Puberty is a pivotal biological process that completes sexual maturation to achieve full reproductive capability. It is a major transformational period of life, whose timing is strongly affected by genetic makeup of the individual, along with various internal and external factors. Although the exact mechanism for initiation of the cascade of molecular events that culminate in puberty is not yet known, the process of pubertal onset involves interaction of numerous complex signaling pathways of hypothalamo-pituitary-testicular (HPT) axis. We developed a classification of the mechanisms involved in male puberty that allowed placing many genes into physiological context. These include (i) hypothalamic development during embryogenesis, (ii) synaptogenesis where gonadotropin releasing hormone (GnRH) neurons form neuronal connections with suprahypothalamic neurons, (iii) maintenance of neuron homeostasis, (iv) regulation of synthesis and secretion of GnRH, (v) appropriate receptors/proteins on neurons governing GnRH production and release, (vi) signaling molecules activated by the receptors, (vii) the synthesis and release of GnRH, (viii) the production and release of gonadotropins, (ix) testicular development, (x) synthesis and release of steroid hormones from testes, and (xi)the action of steroid hormones in downstream effector tissues. Defects in components of this system during embryonic development, childhood/adolescence, or adulthood may disrupt/nullify puberty, leading to long-term male infertility and/or hypogonadism. This review provides a list of 598 genes involved in the development of HPT axis and classified according to this schema. Furthermore, this review identifies a subset of 75 genes for which genetic mutations are reported to delay or disrupt male puberty.
Adolescent ; Male ; Humans ; Adult ; Child ; Gonadotropin-Releasing Hormone ; Gonadotropins/metabolism* ; Hypogonadism ; Testis/metabolism* ; Puberty/physiology* ; Sexual Maturation

Objective: This research was performed to evaluate the effect of tebuconazole (TBZ) on reproductive organs of male rats and to assess the protective role of combined essential trace elements in alleviating the detrimental effect of TBZ on male reproductive function. Methods: For this purpose, 48 rats were exposed to 100 mg/kg TBZ, TBZ supplemented with zinc (Zn), selenium (Se), copper (Cu), and iron (Fe), TBZ + (Se + Zn); TBZ + Cu; or TBZ + Fe. The experiment was conducted for 30 consecutive days. Results: TBZ caused a significant perturbation in mineral levels and reduction in reproductive organs weights, plasma testosterone level, and testicular antioxidant enzyme activities. The TBZ-treated group also showed a significant increase in sperm abnormalities (count, motility, and viability percent), plasma follicle-stimulating hormone and luteinizing hormone concentrations, lipid peroxidation, protein oxidation, and severe DNA degradation in comparison with the controls. Histopathologically, TBZ caused testis impairments. Conversely, treatment with trace elements, in combination or alone, improved the reproductive organ weights, sperm characteristics, TBZ-induced toxicity, and histopathological modifications in testis. Conclusion TBZ exerts significant harmful effects on male reproductive system. The concurrent administration of trace elements reduces testis dysfunction, fertility, and toxicity induced by TBZ.
Animal Feed/analysis* ; Animals ; Antioxidants/metabolism* ; Diet ; Dietary Supplements/analysis* ; Fungicides, Industrial/adverse effects* ; Male ; Minerals/metabolism* ; Mutagenicity Tests ; Rats ; Rats, Wistar ; Spermatozoa/physiology* ; Testis/physiology* ; Trace Elements/metabolism* ; Triazoles/adverse effects*

While it is known that spermatogonial stem cells (SSCs) initiate the production of male germ cells, the mechanisms of SSC self-renewal, proliferation, and differentiation remain poorly understood. We have previously identified Strawberry Notch 1 (SBNO1), a vertebrate strawberry notch family protein, in the proteome profile for mouse SSC maturation and differentiation, revealing SBNO1 is associated with neonatal testicular development. To explore further the location and function of SBNO1 in the testes, we performed Sbno1 gene knockdown in mice to study the effects of SBNO1 on neonatal testicular and SSC development. Our results revealed that SBNO1 is required for neonatal testicular and SSC development in mice. Particularly, in vitro Sbno1 gene knockdown with morpholino oligonucleotides caused a reduction of SSCs and inactivation of the noncanonical Wnt pathway, through Jun N-terminal kinases. Our study suggests SBNO1 maintains SSCs by promoting the noncanonical Wnt pathway.
Adult Germline Stem Cells/metabolism* ; Animals ; Cell Proliferation/physiology* ; Gene Knockdown Techniques ; Male ; Mice ; Proteome ; Repressor Proteins/metabolism* ; Testis/metabolism* ; Wnt Signaling Pathway/physiology*

Varicocele is a common finding in men. Varicocele correction has been advocated for young patients with testicular hypotrophy, but there is a lack of morphofunctional follow-up data. We assessed whether percutaneous treatment of left varicocele is associated with testicular "catch-up growth" in the following 12 months by retrospectively reviewing data from an electronic database of 10 656 patients followed up in our clinic between 2006 and 2016. We selected all young adults (<35 years) with left varicocele who underwent percutaneous treatment, had a minimum of 12 months' ultrasound imaging follow-up, and had no other conditions affecting testicular volume. One hundred and fourteen men (mean±standard deviation [s.d.] of age: 22.8 ± 5.4 years) met the inclusion and exclusion criteria. Left testicular hypotrophy (LTH), defined as a ≥20% difference between left and right testicular volume at baseline, was observed in 26 (22.8%) men. Participants with LTH (mean±s.d.: 14.5 ± 2.7 ml) had lower baseline testicular volume compared to those without LTH (mean±s.d.: 15.7 ± 3.8 ml; P = 0.032). Repeated measures mixed models showed a significant interaction between LTH and time posttreatment when correcting for baseline left testicular volume (β = 0.114, 95% confidence interval [CI]: 0.018-0.210, P = 0.020), resulting in a catch-up growth of up to 1.37 ml per year (95% CI: 0.221-2.516). Age at intervention was also associated with reduced testicular volume (-0.072 ml per year, 95% CI: -0.135--0.009; P = 0.024). Percutaneous treatment of left varicocele in young adults with LTH can result in catch-up growth over 1 year of follow-up. The reproductive and psychological implications of these findings need to be confirmed in longer and larger prospective studies.
Adolescent ; Adult ; Follow-Up Studies ; Humans ; Male ; Organ Size/physiology* ; Retrospective Studies ; Testis/surgery* ; Treatment Outcome ; Ultrasonography ; Varicocele/surgery* ; Young Adult

During spermatogenesis, developing germ cells that lack the cellular ultrastructures of filopodia and lamellipodia generally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These include the transport of preleptotene spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell-cell and Sertoli-germ cell interface also undergo rapid remodeling, involving disassembly and reassembly of cell junctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the involving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protein S6 (rpS6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mTORC1/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubule-based cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.
Actins/metabolism* ; Animals ; Blood-Testis Barrier/metabolism* ; Cells, Cultured ; Male ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Permeability ; Rats ; Ribosomal Protein S6/metabolism* ; Seminiferous Epithelium/metabolism* ; Sertoli Cells/metabolism* ; Signal Transduction/physiology*

Nanos2, a member of the Nanos2 gene family, is a specific gene in male germ cells and encodes an evolutionarily conserved RNA binding protein expressed in male primordial germ cells (PGCs) during the embryonic period as well as in the spermatogonial stem cells (SSCs) of the testis. In the embryonic period, Nanos2 promotes the development of male PGCs and inhibits them from meiosis. In the process of spermatogenesis, Nanos2 suppresses the differentiation of SSCs in the testis and maintains the stability of the SSC pool. The knockout of Nanos2 may cause the disappearance of germ cells and sterility in male mice while its overexpression in the testis may lead to accumulation of SSCs in seminiferous tubules. Besides, Nanos2 is involved in the degradation of specific RNAs and possibly associated with some diseases of the male reproductive system. This review focuses on the recent progress in the studies of Nanos2 in the male reproductive system.
Animals ; Cell Differentiation ; Gene Knockout Techniques ; Male ; Meiosis ; Mice ; RNA ; metabolism ; RNA-Binding Proteins ; genetics ; metabolism ; Spermatogenesis ; physiology ; Spermatogonia ; Spermatozoa ; Testis ; cytology

ObjectiveTo study the effect of Erxian Decoction (EXD) on oligospermia (OS) induced by cyclophosphamide in mice.

METHODSEighty 6-week-old male Kunming mice were randomly divided into five groups of equal number, normal control, OS model control, and low-, medium- and high-dose EXD, the former two groups treated intragastrically with normal saline and the latter three with EXD at 3, 6 and 12 g per kg of the body weight qd for 30 days. From the 21st day of administration, the mice of the normal control group were injected intraperitoneally with saline and those of the other four groups with cyclophosphamide at 80 mg per kg of the body weight qd for 5 consecutive days. At 24 hours after the last gavage, the bilateral epididymides of the mice were collected and sperm suspension prepared for determination of the sperm count and motility, and the bilateral testes were harvested for histomorphological observation and measurement of the concentrations of superoxide dismutase (SOD), malondialdehyde (MAD) and glutathione (GSH) in the testis tissue.

RESULTSCompared with the normal controls, the mice of the OS model control group showed significant decreases in epididymal sperm concentration (［9.31 ± 1.32］ vs ［3.32 ± 1.13］×107/ml, P <0.01) and motility (［44.75 ± 8.12］% vs ［25.95 ± 11.41］， P<0.01) and the concentrations of SOD (［37.27 ± 0.99］ vs ［14.23 ± 1.99］ U/mg prot, P <0.01) and GSH (［101.55 ± 8.74］ vs ［58.77 ± 8.93］ μmol/L, P <0.01) but an obvious increase in the MDA level (［2.21 ± 0.65］ vs ［2.61 ± 0.15］ nmol/mg prot, P <0.05) in the testis tissue. In comparison with the OS model controls, the mice treated with low-, medium- and high-dose EXD exhibited significantly increased epididymal sperm concentration (［8.34 ± 2.59］, ［8.59 ± 1.10］ and ［8.41 ± 1.47］×107/ml) (P <0.01) and motility (［36.04 ± 12.33］%, ［38.87 ± 13.13］% and ［41.90 ± 8.09］%) (P <0.01) and concentrations of SOD (［22.99 ± 1.11］, ［20.82 ± 1.81］ and ［21.33 ± 1.66］ U/mg prot) (P <0.01) and GSH (［104.74 ± 2.47］, ［98.61 ± 12.98］ and ［108.89 ± 5.85］ μmol/L) (P <0.01) but decreased level of MDA (P <0.05).

CONCLUSIONSErxian Decoction can improve cyclophosphamide-induced reduction of sperm concentration and motility, which might be associated with its abilities of resisting oxidation and reducing oxidative stress injury.

Animals ; Cyclophosphamide ; Drugs, Chinese Herbal ; pharmacology ; Epididymis ; Glutathione ; analysis ; Male ; Malondialdehyde ; analysis ; Mice ; Oligospermia ; chemically induced ; drug therapy ; Oxidative Stress ; Random Allocation ; Sperm Count ; Sperm Motility ; drug effects ; physiology ; Spermatozoa ; drug effects ; Superoxide Dismutase ; analysis ; Testis ; anatomy & histology ; chemistry ; drug effects

ObjectiveTo explore the antagonistic effect of vitamin E (VE) on male reproductive toxicity induced by di-2-ethylhexyl phthalate (DEHP) in pubertal SD rats and its underlying mechanisms.

METHODSThirty 5-week-old male SD rats were randomly divided into five groups of equal number, corn oil control, low-dose (10 mg/kg/d), medium-dose (100 mg/kg/d) and high-dose DEHP exposure (500 mg/kg/d), and VE intervention (high-dose DEHP + VE ［100 mg/kg/d］), and treated respectively for 30 successive days. At 3 days after treatment, the testes of the animals were harvested for determination of the oxidative stress index, serum reproductive hormone levels, cauda epididymal sperm parameters, and expressions of cell apoptosis-related genes and proteins.

RESULTSCompared with the control group, the rats of the medium- and high-dose DEHP groups showed significant decreases in the levels of such serum reproductive hormones as follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T), sperm parameters as average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), straightness (STR), linearity (LIN) and wobble (WOB), and the activities of superoxide dismutase (SOD) and glutathione peroxide (GSH-Px), but significant increases were observed in the latter two groups in the content of malondialdehyde (MDA)(［3.32±0.87］ nmol/mg pro vs ［2.13±0.49］ nmol/ mg pro), mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio, and protein expressions of Cytochrome C and Caspase-3. In comparison with the high-dose DEHP group, the VE intervention group exhibited remarkably increased serum LH and T levels, sperm VAP, VSL, VCL, STR and WOB, and activities of SOD and GSH-Px, but markedly decreased mRNA expressions of Bad, Bax, Cytochrome C, Caspase-3 and the Bax/Bcl-2 ratio as well as the protein expressions of Cytochrome C and Caspase-3 in the testis tissue (P<0.05).

CONCLUSIONSExposure to DEHP induces androgen secretion disorders, causes oxidative damage to the testicular tissue, activates the mitochondrial apoptosis pathway in the testis, and ultimately reduces the quality of epididymal sperm, while VE can protect the rat testis from DEHP-induced reproductive toxicity.

Animals ; Antioxidants ; pharmacology ; Apoptosis ; genetics ; Autophagy-Related Protein 5 ; metabolism ; Caspase 3 ; metabolism ; Diethylhexyl Phthalate ; antagonists & inhibitors ; Epididymis ; Follicle Stimulating Hormone ; blood ; Luteinizing Hormone ; blood ; Male ; Malondialdehyde ; metabolism ; Mitochondria ; drug effects ; Oxidative Stress ; drug effects ; Oxidoreductases ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reproduction ; Spermatozoa ; drug effects ; physiology ; Superoxide Dismutase ; metabolism ; Testis ; drug effects ; Testosterone ; blood ; Vitamin E ; pharmacology

Objective: To investigate the expression of the G-protein coupled estrogen receptor (GPER) in the testis of the male mouse with kidney yin or kidney yang deficiency and its influence on the reproductive function of the mouse. METHODS: We randomized 30 six-week-old male Kunming mice into three groups of equal number: kidney yang deficiency, kidney yin deficiency, and normal control, and established the models of kidney yang deficiency and kidney yin deficiency by peritoneal injection of hydrocortisone at 50 mg/kg for 5 days and 25 mg/kg for 10 days, respectively. We observed the behavioral changes of the mice using the elevated plus-maze, exhaustive swimming and field experiment, examined the semen quality with the automatic sperm quality analyzer, calculated the average number of the offspring, measured the serum testosterone (T) and estradiol (E2) levels and T/E2 ratio by Roche electrochemiluminescence assay, and determined the localization and expression of GPER in the testis by immunohistochemistry and immunofluorescence staining. RESULTS: Compared with the mice with kidney yin deficiency, those with kidney yang deficiency showed remarkably fewer entries into the open arm and central area (P <0.05) and shorter time of exhaustive swimming (P <0.05), but no statistically significant difference in the time spent in the open arm or the central area (P >0.05); the latter group also exhibited significant decreases in the epididymal sperm count (［7.27 ± 1.30］ vs ［3.05 ± 1.06］ ×108/g, P <0.01), sperm motility (［54.15 ± 13.52］ vs ［51.57 ± 8.75］ %, P <0.01) and average number of the offspring (6.46 vs 4.33, P <0.05), a slight increase in the rate of morphologically abnormal sperm (［13.42 ± 2.32］ vs ［15.39 ± 2.48］ %, P >0.05), and markedly reduced serum T (［24.96 ± 6.18］ vs ［16.72 ± 5.92］ ng/dl,P <0.05), E2 (［19.81 ± 4.01］ vs ［15.24 ± 1.11］ pg/ml,P <0.05) and T/E2 ratio (1.41 vs 1.25, P <0.05). The expression of GPER was found in the cytoplasm of the Leydig cells, negative in the nuclei and cell membrane, significantly higher in the kidney yang than in the kidney yin deficiency group (P <0.05). CONCLUSIONS The numbers of sperm and offspring decreased while the percentage of morphologically abnormal sperm increased in both the kidney yang and kidney yin deficiency mice, even more significantly in the former, which might be associated with the up-regulated expression of GPER in the testis of the mouse with kidney yang deficiency and consequently the reduced serum T level and T/E2 ratio.
Animals ; Drugs, Chinese Herbal ; Kidney Diseases ; metabolism ; Male ; Mice ; Random Allocation ; Receptors, Estrogen ; metabolism ; Receptors, G-Protein-Coupled ; metabolism ; Reproduction ; physiology ; Semen Analysis ; Testis ; metabolism ; Yang Deficiency ; metabolism ; Yin Deficiency ; metabolism

Objective: To elucidate the possible role of human lysozyme-like protein 4 (LYZL4) in fertilization and characterize its enzymatic properties. METHODS: The localization of LYZL4 in human spermatozoa was investigated by immunofluorescence staining, the sources of LYZL4 on the sperm surface examined by RT-PCR, and the role of LYZL4 in fertilization assessed by the zona-free hamster egg penetration test. The recombinant plasmid pPIC9K-LYZL4 was constructed and its expression induced with methanol after transformed into competent Pichia pastoris GS115. The recombinant LYZL4 protein (rLYZL4) was purified from the fermentation supernatant and subsequently identified by Western blot. The hyaluronan binding ability of rLYZL4 was determined by ELISA and the muramidase activity, hyaluronidase activity, and free radical scavenging ability examined by spectrophotometric methods. RESULTS: Immunodetection with a specific antiserum localized LYZL4 on the acrosomal membrane of mature spermatozoa, which was exclusively secreted from the testis and epididymis as shown by RT-PCR. Immunoneutralization of LYZL4 significantly decreased the number of human spermatozoa bound to zona-free hamster eggs in a dose-dependent manner in vitro. The recombinant protein was expressed successfully by the P. pastoris strain GS115. Purified rLYZL4 exhibited a potent hyaluronan binding ability and a strong free radical scavenging ability but no muramidase or hyaluronidase activity. CONCLUSIONS LYZL4 secreted from the testis and epididymis is localized on the acrosomal membrane of mature spermatozoa and plays a role in sperm-egg binding as well as in binding hyaluronan and scavenging free radicals, which suggests that it might be a multi-functional molecule contributive to sperm protection and sperm-egg binding.
Acrosome ; enzymology ; Animals ; Blotting, Western ; Cricetinae ; Enzyme-Linked Immunosorbent Assay ; Epididymis ; Female ; Fertilization ; physiology ; Free Radical Scavengers ; metabolism ; Humans ; Hyaluronic Acid ; metabolism ; Male ; Muramidase ; analysis ; physiology ; Pichia ; Plasmids ; metabolism ; Recombinant Proteins ; analysis ; metabolism ; Sperm-Ovum Interactions ; physiology ; Spermatozoa ; enzymology ; Testis