Mutational screening of the INSL3 gene in azoospermic males with a history of cryptorchidism

Revisiting the gonadotropic regulation of mammalian spermatogenesis: evolving lessons during the past decade

Spermatogenesis is a multi-step process of male germ cell (Gc) division and differentiation which occurs in the seminiferous tubules of the testes under the regulation of gonadotropins - Follicle Stimulating Hormone (FSH) and Luteinising hormone (LH). It is a highly coordinated event regulated by the surrounding somatic testicular cells such as the Sertoli cells (Sc), Leydig cells (Lc), and Peritubular myoid cells (PTc). FSH targets Sc and supports the expansion and differentiation of pre-meiotic Gc, whereas, LH operates via Lc to produce Testosterone (T), the testicular androgen. T acts on all somatic cells e.g.- Lc, PTc and Sc, and promotes the blood-testis barrier (BTB) formation, completion of Gc meiosis, and spermiation. Studies with hypophysectomised or chemically ablated animal models and hypogonadal (hpg) mice supplemented with gonadotropins to genetically manipulated mouse models have revealed the selective and synergistic role(s) of hormones in regulating male fertility. We here have briefly summarized the present concept of hormonal control of spermatogenesis in rodents and primates. We also have highlighted some of the key critical questions yet to be answered in the field of male reproductive health which might have potential implications for infertility and contraceptive research in the future.

Congenital bilateral cryptorchidism in an infant conceived after maternal breast cancer treatment: A case report

BACKGROUND

The incidence of breast cancer among women of reproductive age is increasing, as well as the desire for children at late childbearing age. Identifying factors that may be associated with fetal malformation and maternal and fetal prognosis has gained importance. We describe a 32-year-old woman with breast cancer who gave birth to a son with congenital bilateral cryptorchidism after treatment, with a literature review performed.

CASE SUMMARY

A 32-year-old woman with breast cancer who had been treated by surgery and radiotherapy experienced recurrence and underwent a second surgery, adjuvant chemotherapy, and targeted therapy. Her tumor cells were negative for estrogen receptor (ER) α, progesterone receptor (PR), and p53; positive for ERβ, human epidermal growth factor receptor-2 (HER2), epidermal growth factor receptor (EGFR), and Ki67. She had pathogenic BRCA gene mutations. She became pregnant within 2 years and delivered a boy with congenital bilateral cryptorchidism. The boy underwent bilateral orchidopexy. As of this writing, the woman and her son are both healthy.

CONCLUSION

HER2 overexpression, positivity for EGFR, Ki67, and ER, and PR negativity are associated with a poor prognosis in breast cancer. While no link has been established statistically between treatment for breast cancer and cryptorchidism in a subsequent pregnancy, this case suggests the possibility that ERβ and gene mutations may be contributing factors.

The G178A polymorphic variant of INSL3 may be linked to cryptorchidism among Egyptian pediatric cohort

Cryptorchidism (CO) is a genital disorder of multifactorial etiology, with serious remote complications. Mutations in insulin-like 3 hormones (INSL3) G/A variant remain a matter of inquiry. We aimed to investigate the association between G178A-INSL3 polymorphism and undescended testis in a cohort of Egyptian children. In this study, a total of 160 children, including 80 cases with primary non-syndromic undescended testes and 80 healthy children with normal external genitalia as controls, both, were analyzed after detailed history, physical examination and imaging for mutations of G178A polymorphism of INSL3 gene by restriction fragment length polymorphism (RFLP) technique. We found most of the undescended testes were inside the inguinal canal mainly on the left side. Genetic analysis revealed that the mutant A allele of G178A INSL3 variant was significantly detected in the patient group with a frequency of 26.2% against 12.5% for control subjects, especially among cases with an evident family history of similar cases as shown by p value = 0.001 and odd's ratio (CI95%) of 0.13 (0.04-0.723). In conclusion, G178A-INSL3 gene polymorphism could be a susceptibility factor for testicular maldescent in Egyptian children. Also, family history of similar cases was considered as significant predictive risk for cryptorchidism, added to the shared genetic links to consanguinity in our locality.

Genetic analysis of the human insulin-like 3 gene in pediatric patients with testicular torsion

PURPOSE

Testicular torsion (TT) mainly affects boys under 18 years old. To avoid orchiectomy, TT requires an immediate operative management. The etiology of TT is still controversial. Observed familiar recurrence suggests the presence of a genetic involvement. The INSL3 gene consists of two exons, and it is specifically expressed in fetal and adult Leydig cells. In transgenic mice, deletion of this gene was observed an increased testicular mobility and testicular torsion. We have hypothesized the possible involvement of the INSL3 gene as a predisposing factor of human TT.

METHODS

We performed genetic analysis in 25 pediatric patients with unilateral and intravaginal TT (left, n = 13, 56%; right, n = 12, 48%). The age of the patients ranged from 1 to 16 years (median age n = 10.4 ± 5.46 years). In this study, we included two first male cousins affected by TT. Venous peripheral blood samples was obtained after parental written informed consent.

RESULTS

The Thr60Ala polymorphism was detected in exon 1 of INSL3 gene and other 2 rarer variants (rs1047233 and rs1003887) were identified in the 3' untranslated region. These variants are prevalent in patients with TT instead of healthy subjects.

CONCLUSIONS

Additional studies in a larger population are needed to better understand the clinical consequence of the INSL 3 variations founded. This would allow in the future to identify the patients at risk of TT to improve clinical management.

Relaxin-like peptides in male reproduction - a human perspective

The relaxin family of peptide hormones and their cognate GPCRs are becoming physiologically well-characterized in the cardiovascular system and particularly in female reproductive processes. Much less is known about the physiology and pharmacology of these peptides in male reproduction, particularly as regards humans. H2-relaxin is involved in prostate function and growth, while insulin-like peptide 3 (INSL3) is a major product of the testicular Leydig cells and, in the adult, appears to modulate steroidogenesis and germ cell survival. In the fetus, INSL3 is a key hormone expressed shortly after sex determination and is responsible for the first transabdominal phase of testicular descent. Importantly, INSL3 is becoming a very useful constitutive biomarker reflecting both fetal and post-natal development. Nothing is known about roles for INSL4 in male reproduction and only very little about relaxin-3, which is mostly considered as a brain peptide, or INSL5. The former is expressed at very low levels in the testes, but has no known physiology there, whereas the INSL5 knockout mouse does exhibit a testicular phenotype with mild effects on spermatogenesis, probably due to a disruption of glucose homeostasis. INSL6 is a major product of male germ cells, although it is relatively unexplored with regard to its physiology or pharmacology, except that in mice disruption of the INSL6 gene leads to a disruption of spermatogenesis. Clinically, relaxin analogues may be useful in the control of prostate cancer, and both relaxin and INSL3 have been considered as sperm adjuvants for in vitro fertilization.

LINKED ARTICLES

This article is part of a themed section on Recent Progress in the Understanding of Relaxin Family Peptides and their Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.10/issuetoc.