Journal of the Endocrine Society | 2021
Molecular Clues From Testis Involve NHLH2, a DNA Binding Transcription Factor That Controls the Onset of Mini-Puberty via Its Neuronal Activity, in Curative GnRH Treatment of Cryptorchidism Dependent Infertility
Abstract
\n Introduction: GnRHa treatment following surgery to correct cryptorchidism restores mini-puberty via endocrinological and transcriptional effects and prevents adult infertility in most cases. A large group of genes are important for central hypogonadotropic hypogonadism in mammals, including many that are transcribed both in brain and testis. However, the expression of these genes in prepubertal gonads has not been systematically studied and little is known about the effect of hormone therapy on their testicular and neuronal expression levels. Here, we interpret histological sections, data on hormone levels and RNA profiling data from adult normal testis in comparison to pre-pubertal low infertility risk (LIR) and high infertility risk (HIR) patients randomized for treatment with surgery in combination with GnRHa or only surgery. Major Results: We organize 31 target genes relevant for hypogonadotropic hypogonadism and cryptorchidism into five classes depending on their expression levels in HIR versus LIR samples and their response to GnRHa treatment. Only the mRNA encoding the DNA binding transcription factor NHLH2 is decreased in HIR as compared to LIR samples, increased after GnRHa treatment, and expressed in both brain and testis. GnRHa treatment of cryptorchidism that restores mini-puberty and rescues adult fertility increases NHLH2 mRNA levels in testis from HIR patients. Conclusion: This phenomenon may reflect a broader effect of hormone treatment on gene expression in both testicular and central nervous tissues, which could explain why the hypothalamus-pituitary-testicular axis is permanently restored by the administration of GnRHa.