Androgens are key for pubertal development of the mammalian testis, a phenomenon tightly linked to Sertoli cell maturation. In this review, we discuss how androgen signalling affects Sertoli cell function and morphology by concomitantly inhibiting some processes and promoting others that contribute jointly to the completion of spermatogenesis. We focus on the molecular mechanisms that underlie AMH inhibition by androgens at puberty, as well as on the role androgens have on Sertoli cell tight junction formation and maintenance and, consequently, on its effect on proper germ cell differentiation and meiotic onset during spermatogenesis.

The toxic effects of 4-octylphenol (4-OP) have been studied in species such as mouse and fish; however, the toxic effects of 4-OP in male specific niche cells has not been researched. In this study, we investigated the molecular mechanism of toxicity of 4-OP in mouse TM4 Sertoli cells. TM4 cells were treated with four concentrations (0, 10, 30, and 50 µM/mL) of 4-OP at time points 24, 48, and 72 h. Cell viability and apoptosis assay was conducted following exposure. 4-OP significantly decreased cell viability in a concentration- and time-dependent manner, and increased apoptosis. Quantitative PCR analysis showed that Bad, Bax, and Bak mRNA expression levels were higher in exposed cells than in the control, but Bcl-2 expression was decreased. Western blotting revealed that 4-OP induced activities of caspase-3 and phosphorylation of Bad in a concentration- and time-dependent manner. Additionally, cytochrome C protein did not colocalize with mitochondria marker dye by 24 h. Cytochrome c protein expression increased in a time-dependent manner with 50 µM/mL. These results suggest that 4-OP induces mitochondria-mediated apoptosis by regulation of Bcl-2 family proteins and caspase-3 activation in male Sertoli cells.

Background: DICER1, cancer predisposition syndrome (CPS), seems to escape timely diagnosis in pediatric patients. Case report 1: A 16-year-old female patient was referred to the endocrinology ward due to a large goiter. Her medical history indicated normal sexual maturation, with menarche occurring at 13.5 years. Over the past 2.5 years, she developed pronounced androgenic symptoms, including a deepened male voice, facial, back and neckline acne, hirsutism, and menstrual irregularities leading to secondary amenorrhoea. A thyroid ultrasound identified a multinodular goiter with cystic-solid lesions containing calcifi-cations. An abdominal ultrasound identified a 5.7x6.9 cm solid mass in the right adnexal region, displacing the uterus to the left. Histopathological examination confirmed a Sertoli-Leydig cell tumor. The patient was subjected to total thyroidectomy. Histopathology revealed benign follicular cell-derived neoplasms. Thyroid follicular nodular disease was diagnosed bilaterally. DNA analysis using NGS, confirmed by the Sanger method, revealed a pathogenic heterozygotic variant c.2953>T [p.Gln985*] in exon 18 of DICER1 gene. Case report 2: A 12-year-old male patient was admitted to the pediatric surgery unit due to a 33 ml goiter. A month prior to admission, the patient discovered a palpable nodule in his neck, accompanied by hoarseness. An ultrasound revealed a multinodular goiter. Molecular analysis revealed a pathogenic heterozygotic variant c.2782C>T [p.Gln928Ter] in exon 17 of DICER1 gene. Subsequently, a total thyroidectomy was performed, and histopathological examination revealed thyroid follicular nodu-lar disease bilaterally. Conclusion: Multinodular goiter, although rare in pediatric population, when accompanied by characteristic ultrasound and histopathological features, and by additional features such as androgen excess, warrants exclusion of DICER1 syndrome.

Environmental darkness signal is transferred from the retina to the pineal gland triggering melatonin secretion. Melatonin influences the synthesis and release of the hypothalamic GnRH and the adenohypophyseal gonadotropin hormones and therefore, regulates testicular function in photoperiodic species. Besides the brain, direct actions of melatonin at the testicular level have also been described. Melatonin released from the pineal gland to the circulation is taken up by peripheral tissues including testes. Testicular synthesis of melatonin has also been reported. The two key somatic cell types in the testis, Leydig and Sertoli cells, express melatonergic receptors. Melatonin acts as a local modulator of the endocrine activity in Leydig cells. In Sertoli cells, melatonin influences the oxidation state and the energy metabolism, and consequently may regulate spermatogenesis. Melatonergic receptors were also described in testicular macrophages and mast cells of infertile patients. Whereas melatonin exerts anti-proliferative and anti-inflammatory effects on testicular macrophages, it provides protective effects against oxidative stress in testicular mast cells. These data pinpoints melatonin as a key player in the regulation of testicular physiology (i.e. steroidogenesis, spermatogenesis) mostly in seasonal breeders. More importantly, melatonin is also involved in the modulation of testicular inflammatory and oxidant/anti-oxidant states in patients with idiopathic infertility.