Study of anti-Müllerian hormone levels in patients with Myotonic Dystrophy Type 1. Preliminary results.

Myotonic dystrophy type 1 is a multisystemic disorder characterized by myotonia, muscle weakness and involvement of several organs and apparatus such as heart, lungs, eye, brain and endocrine system. Hypogonadism and reproductive abnormalities are frequently reported. A progressive testicular atrophy occurs in about 80% in the affected males leading to Leydig cell hyperproliferation and elevated basal follicle stimulating hormone (FSH) levels. Anti-Müllerian hormone (AMH) - a dimeric glycoprotein belonging to the super-family of transforming grow factor beta (TGF-beta) - is the earliest Sertoli cell hormone secreted in males and, together with inhibin B and FSH, is an important indicator of Sertoli cell function. AMH levels remain high during the whole prepubertal phase and are down-regulated in puberty by the increasing testosterone levels. Aims of the work were to assess the AMH levels in 50 patients with Myotonic Dystrophy type 1 aged less 50 years and to investigate whether it may contribute to the endocrine function impairment observed in these patients. The results confirmed a reduction of testosterone levels associated with an increase in Luteinizing Hormone (LH) and FSH compared to controls, suggesting a reduced function of the Sertoli cells. Conversely the average levels of AMH were significantly lower in patients compared with controls, and almost undetectable in about 60% of them. Further studies are necessary to better clarify these findings.

First Evidence of DAAM1 Localization During the Post-Natal Development of Rat Testis and in Mammalian Sperm.

Dishevelled-associated activator of morphogenesis 1 (DAAM1) is a formin-family protein involved in nucleation of unbranched actin filaments and in cytoskeletal organization through Wnt-Dishevelled PCP pathway, which participates in essential biological processes, such as cell polarity, movement, and adhesion during morphogenesis and organogenesis. While its role has been investigated during development and in somatic cells, its potential association with the germinal compartment and reproduction is still unexplored. In this work, we assessed the possible association of DAAM1 with the morphogenesis of rat testis. We studied its expression and profiled its localization versus actin and tubulin, during the first wave of spermatogenesis and in the adult gonad (from 7 to 60 dpp). We show that, in mitotic phases, DAAM1 shares its localization with actin in Sertoli cells, gonocytes, and spermatogonia. Later, during meiosis, both proteins are found in spermatocytes, while only actin is detectable at the forming blood-testis barrier. DAAM1, then, follows the development of the acrosome system throughout spermiogenesis, and it is finally retained inside the cytoplasmic droplet in mature gametes, as corroborated by additional immunolocalization data on both rat and human sperm. Unlike the DAAM1, actin keeps its localization in Sertoli cells, and tubulin is associated with their protruding cytoplasm during the process. Our data support, for the first time, the hypothesis of a role for DAAM1 in cytoskeletal organization during Mammalian testis morphogenesis and gamete progression, while also hinting at its possible investigation as a morphological marker of germ cell and sperm physiology. J. Cell. Physiol. 231: 2172-2184, 2016. © 2016 Wiley Periodicals, Inc.

Prothymosin alpha expression and localization during the spermatogenesis of Danio rerio.

Prothymosin α (PTMA) is a highly acidic, intrinsically disordered protein, which is widely expressed and conserved throughout evolution; its uncommon features are reflected by its involvement in a variety of processes, including chromatin remodelling, transcriptional regulation, cell proliferation and death, immunity. PTMA has also been implicated in spermatogenesis: during vertebrate germ cell progression in the testis the protein is expressed in meiotic and post-meiotic stages, and it is associated with the acrosome system of the differentiating spermatids in mammals. Then, it finally localizes on the inner acrosomal membrane of the mature spermatozoa, suggesting its possible role in both the maturation and function of the gametes. In the present work we studied PTMA expression during the spermatogenesis of the adult zebrafish, a species in which two paralogs have been described. Our data show that ptma transcripts are expressed in the testis, and localize in meiotic and post-meiotic germ cells, namely spermatocytes and spermatids. Consistently, the protein is expressed in spermatocytes, spermatids, and spermatozoa: its initial perinuclear distribution is extended to the chromatin region during cell division and, in haploid phases, to the cytoplasm of the developing and final gametes. The nuclear localization in the acrosome-lacking spermatozoa suggests a role for PTMA in chromatin remodelling during gamete differentiation. These data further provide a compelling starting point for the study of PTMA functions during vertebrate fertilization.

Prolyl Endopeptidase (PREP) is Associated With Male Reproductive Functions and Gamete Physiology in Mice.

Prolyl endopeptidase (PREP) is a serine protease which has been implicated in many biological processes, such as the maturation and degradation of peptide hormones and neuropeptides, learning and memory, cell proliferation and differentiation, and glucose metabolism. A small number of reports have also suggested PREP participation in both male and female reproduction-associated processes. In the present work, we examined PREP distribution in male germ cells and studied the effects of its knockdown (Prep(gt/gt)) on testis and sperm in adult mice. The protein is expressed and localized in elongating spermatids and luminal spermatozoa of wild type (wt) mice, as well as Sertoli, Leydig, and peritubular cells. PREP is also expressed in the head and midpiece of epididymal spermatozoa, whereas the remaining tail region shows a weaker signal. Furthermore, testis weight, histology of seminiferous tubules, and epididymal sperm parameters were assessed in wt and Prep(gt/gt) mice: wild type testes have larger average tubule and lumen diameter; in addition, lumenal composition of seminiferous tubules is dissimilar between wt and Prep(gt/gt), as the percentage of spermiated tubules is much higher in wt. Finally, total sperm count, sperm motility, and normal morphology are also higher in wt than in Prep(gt/gt). These results show for the first time that the expression of PREP could be necessary for a correct reproductive function, and suggest that the enzyme may play a role in mouse spermatogenesis and sperm physiology.