Sertoli Cells: Architects of Male Reproductive Function and Clinical Impacts (original) (raw)
Related papers
50 years of spermatogenesis: Sertoli cells and their interactions with germ cells
Biology of Reproduction, 2018
The complex morphology of the Sertoli cells and their interactions with germ cells has been a focus of investigators since they were first described by Enrico Sertoli. In the past 50 years, information on Sertoli cells has transcended morphology alone to become increasingly more focused on molecular questions. The goal of investigators has been to understand the role of the Sertoli cells in spermatogenesis and to apply that information to problems relating to male fertility. Sertoli cells are unique in that they are a nondividing cell population that is active for the reproductive lifetime of the animal and cyclically change morphology and gene expression. The numerous and distinctive junctional complexes and membrane specializations made by Sertoli cells provide a scaffold and environment for germ cell development. The increased focus of investigators on the molecular components and putative functions of testicular cells has resulted primarily from procedures that isolate specific ...
Anatomy and Embryology, 2006
During puberty, normal somatic Sertoli cells undergo dramatic morphological changes due to the differentiation of immature pre-Sertoli cells in functionally active adult Sertoli cells. Sertoli cell maturation is accompanied with loss of their mitotic activity before onset of spermatogenesis and loss of pre-pubertal and occurrence of adult immunohistochemical Sertoli cell differentiation markers. Testes of infertile adult patients often exhibit numerous histological signs of testicular dysgenesis syndrome (TDS) such as microliths, Sertoli cell only (SCO) tubules, tubules containing carcinoma in situ and immature seminiferous tubules (Sertoli cell nodules). Sertoli cell tumours, however, are very rare neoplasms possibly due to the fact that the mechanism and temporal origin of neoplastic Sertoli cells underlying Sertoli cell tumourigenesis still remain unknown. To clarify the state of Sertoli cell differentiation in both immature seminiferous tubules of adult patients with TDS and Sertoli cell tumour, we compared the expression of the Sertoli cell differentiation markers vimentin, inhibin-a, anti-Muellerian-hormone, cytokeratin 18, M2A-antigen, androgen receptor and connexin43 with that of SCO tubules with hyperplasia. In addition, we demonstrated for the first time the existence of proliferating Sertoli cells by Ki67-and PCNA-immunostaining in Sertoli cell nodules of the adult human testis. Our data indicate that mitotically active Sertoli cells in Sertoli cell nodules will be arrested prior to puberty and, contrary to dogma, do not represent foetal or neonatal cells. Since all markers in Sertoli cell nodules revealed a staining pattern identical to that in neoplastic Sertoli cells, but different to that in Sertoli cells of SCO tubules with hyperplasia, it may be speculated that Sertoli cell tumours in adult men may originate from Sertoli cell nodules.
Reproduction, 2003
Disorders of testicular function may have their origins in fetal or early life as a result of abnormal development or proliferation of Sertoli cells. Failure of Sertoli cells to mature, with consequent inability to express functions capable of supporting spermatogenesis, is a prime example. In a similar way, failure of Sertoli cells to proliferate normally at the appropriate period in life will result in reduced production of spermatozoa in adulthood. This review focuses on the control of proliferation of Sertoli cells and functional maturation, and is motivated by concerns about 'testicular dysgenesis syndrome' in humans, a collection of common disorders (testicular germ-cell cancer, cryptorchidism, hypospadias and low sperm counts) which are hypothesized to have a common origin in fetal life and to reflect abnormal function of Sertoli (and Leydig) cells. The timing of proliferation of Sertoli cells in different species is reviewed, and the factors that govern the conversion of an immature, proliferating Sertoli cell to a mature, non-proliferating cell are discussed. Protein markers of maturity and immaturity of Sertoli cells in various species are reviewed and their usefulness in studies of human testicular pathology are discussed. These markers include anti-Mullerian hormone, aromatase, cytokeratin-18, GATA-1, laminin alpha5, M2A antigen, p27 kip1 , sulphated glycoprotein 2, androgen receptor and Wilms' tumour gene. A scheme is presented for characterization of Sertoli-cell only tubules in the adult testis according to whether or not there is inherent failure of maturation of Sertoli cells or in which the Sertoli cells have matured but there is absence, or acquired loss, of germ cells. Functional 'de-differentiation' of Sertoli cells is considered. It is concluded that there is considerable evidence to indicate that disorders of maturation of Sertoli cells may be a common underlying cause of human male reproductive disorders that manifest at various life stages. This recognition emphasizes the important role that animal models must play to enable identification of the mechanisms via which failure of proliferation and maturation of Sertoli cells can arise, as this failure probably occurs in fetal life.
To study the relationship between abnormal Sertoli cell differentiation and spermatogenic impairment, we examined the expression of Sertoli cell markers normally lost at puberty, cytokeratin 18 (CK18), anti-Mü llerian hormone (AMH) and M2A antigen, in three children (aged 1–2 years), 50 adults (aged 19–45 years) with obstructive or non-obstructive azoospermia or oligozoospermia, and six patients (aged 1–18 years) with 5α-reductase deficiency. There was CK18 and/or AMH expression, but never M2A antigen expression, associated with spermatogonial arrest or Sertoli cell-only (SCO) syndrome in infertile men. Loss of M2A antigen suggests the transition of Sertoli cells to an adult phenotype, while CK18 and/or AMH expression may be a manifestation of de-differentiation of Sertoli cells. In 5α-reductase deficiency, there was a sequential loss of CK18, M2A antigen and AMH around puberty, associated with partial spermatogenesis. The persistence of immature Sertoli cells expressing M2A antigen was associated with prepubertal seminiferous cords and SCO syndrome. Therefore , 5α-reductase deficiency may prevent the maturation of Sertoli cells, resulting in impairment of spermatogenesis, and loss of M2A antigen expression coincides with a critical step in the Sertoli cell maturation. High follicle stimulating hormone concentrations due to failure of normal Sertoli cell differentiation indicate a normal development pattern of the hypothalamic–pituitary–gonadal axis. Keywords: anti-Müllerian hormone/cytokeratin/male infertil-ity/M2A antigen/5α-reductase deficiency Introduction The maturation of Sertoli cells at puberty is critical for the initiation and maintenance of spermatogenesis. Intriguingly,
The Sertoli cell: Novel clinical potentiality
HORMONES, 2015
The Sertoli cell is important for endocrine and paracrine control of spermatogenesis. Functions attributed to Sertoli cells are: (1) supportive and trophic functions for the cells of the seminiferous epithelium, (2) transport of mature spermatids towards the lumen of seminiferous tubules, (3) secretion of androgen binding protein, (4) production of substances with endocrine or paracrine action for spermatogenesis control and (5) interaction with intertubular endocrine Leydig cells. Inhibin B and anti-Müllerian hormone (AMH) are glycoproteins belonging to the transforming growth factor β (TGF-β) superfamily; they are produced almost exclusively by the Sertoli cells and have been proposed as direct markers of their function and indirect markers of spermatogenesis. Serum inhibin B and AMH concentrations seem to constitute additional diagnostic parameters in male subfertility as they reflect Sertoli cell function. Stimulated concentrations of serum inhibin B and AMH do not add clinically relevant information in subfertile men compared to basal concentrations of these hormones. Serum inhibin B and AMH concentrations correlate with testicular histology/cytology but are not superior to FSH as predictors of the presence of sperm in testicular sperm extraction (TESE)/fine needle aspiration (FNA) biopsy in men with azoospermia.
Elevated expression of the Sertoli cell androgen receptor disrupts male fertility
American journal of physiology. Endocrinology and metabolism, 2016
We recently created a unique gain-of-function mouse model with Sertoli cell-specific transgenic androgen receptor expression (TgSCAR) that showed SCAR activity controls the synchronized postnatal development of somatic Sertoli and Leydig cells, and meiotic-postmeiotic germ cells. Moderate TgSCAR (TgSCAR(m)) expression reduced testis size but had no effect on male fertility. Here, we reveal that higher TgSCAR expression (TgSCAR(H)) causes male infertility. Higher SCAR activity, shown by upregulated AR-dependent transcripts (Rhox5, Spinw1), resulted in smaller adult TgSCAR(H) testes (50% of normal), despite normal or elevated circulating and intratesticular testosterone levels. Unlike fertile TgSCAR(m) males, testes of adult TgSCAR(H) males exhibited focal regions of interstitial hypertrophy featuring immature adult Leydig cells, and higher intratesticular dihydrotestosterone and 5α-androstane 3α, 17β-diol levels which are normally associated with pubertal development. Mature TgSCAR(H...
EC ENDOCRINOLOGY AND METABOLIC RESEARCH , 2017
Spermatogenesis is the biological process that generates male gametes for the transfer of the paternal chromosomes to the oo-cytes, at the time of fertilization. Neuroendocrine hormones work in tandem with testicular genes to bring about the maturation of the male gamete or spermatozoon. While some of the genes involved in the differentiation of spermatozoa are well known others are 'not so obvious'. The aim of this article is to conceptualize the molecular pathway(s) through which the 'not so obvious' Sertoli cell 'mediators' communicate with germ cells for their differentiation within the seminiferous tubules of the mammalian testes.
International Journal of Molecular Sciences
Sertoli cell-only syndrome (SCOS) affects about 26.3–57.8% of azoospermic men, with their seminiferous tubules containing only Sertoli cells. Recently, it was reported that testicular biopsies from nonobstructive azoospermic (NOA) patients contained germ cells, and that sperm could be found in the tubules of 20% of SCOS patients using testicular sperm extraction technology. Since the patients without sperm in their testicular biopsies do not have therapy to help them to father a biological child, in vitro maturation of spermatogonial stem cells (SSCs) isolated from their testis is a new approach for possible future infertility treatment. Recently, the induction of human and mice SSCs proliferation and differentiation was demonstrated using different culture systems. Our group reported the induction of spermatogonial cell proliferation and differentiation to meiotic and postmeiotic stages in mice, rhesus monkeys, and prepubertal boys with cancer using 3D agar and methylcellulose (MCS...
Temporal Role of Sertoli Cell Androgen Receptor Expression in Spermatogenic Development
Molecular Endocrinology
Sertoli cell (SC) androgen receptor (AR) activity is vital for spermatogenesis. We created a unique gain-of-function transgenic (Tg) mouse model to determine the temporal role of SCAR expression in testicular development. The SC-specific rat Abpa promoter directed human Tg AR [Tg SC-specific AR (TgSCAR)] expression, providing strong premature postnatal AR immunolocalized to SC nuclei. Independent Tg lines revealed that TgSCAR dose dependently reduced postnatal and mature testis size (to 60% normal), whereas androgen-dependent mature seminal vesicle weights and serum testosterone levels remained normal. Total SC numbers were reduced in developing and mature TgSCAR testes, despite normal or higher Fshr mRNA and circulating FSH levels. Postnatal TgSCAR testes exhibited elevated levels of AR-regulated Rhox5 and Spinlw1 transcripts, and precocious SC function was demonstrated by early seminiferous tubular lumen formation and up-regulated expression of crucial SC tight-junction (Cldn11 an...
2000
Testosterone acting through the androgen receptor (AR) maintains the arrest of spermatogonial differentiation in juvenile spermatogonial depletion (jsd mutation in the Utp14b gene) mutant adult male mice. It is not known which of the somatic cell types expressing AR mediates this inhibition. To determine if Sertoli cells are responsible, we selectively eliminated AR in Sertoli cells in jsd mice containing a floxed-Ar gene and an anti-Müllerian hormone-Cre transgene. In these Sertoli ARknockout (SCARKO)-jsd mice, spermatogonial differentiation did not recover. However, the normal organization of Sertoli cell nuclei was drastically disrupted in SCARKO-jsd mice, compared to SCARKO or jsd mice. In addition, the extent of ectoplasmic specializations was reduced, tight junctions were not found, vinculin, an anchoring protein found in ectoplasmic specializations, became uniformly distributed in the cytoplasm, and the adult Sertoli cells showed excess heterochromatin subjacent to their nuclear envelope. Despite the abnormalities in Sertoli cells in SCARKO-jsd mice, global suppression of testosterone action and levels was still effective in restoring the differentiated germ cells, and this was accompanied by an improved arrangement of Sertoli cell nuclei. We conclude that Sertoli cells are not targets for the testosterone-mediated inhibition of spermatogonial differentiation in jsd mice, and both AR in Sertoli cells and the presence of differentiated germ cells contribute to maintaining the organization of Sertoli cells within the seminiferous tubules.