scholarly journals New perspectives in the diagnosis of pediatric male hypogonadism: the importance of AMH as a Sertoli cell marker

2011 ◽  
Vol 55 (8) ◽  
pp. 512-519 ◽  
Author(s):  
Romina P. Grinspon ◽  
Rodolfo A. Rey

Sertoli cells are the most active cell population in the testis during infancy and childhood. In these periods of life, hypogonadism can only be evidenced without stimulation tests, if Sertoli cell function is assessed. AMH is a useful marker of prepubertal Sertoli cell activity and number. Serum AMH is high from fetal life until mid-puberty. Testicular AMH production increases in response to FSH and is potently inhibited by androgens. Serum AMH is undetectable in anorchidic patients. In primary or central hypogonadism affecting the whole gonad and established in fetal life or childhood, serum AMH is low. Conversely, when hypogonadism affects only Leydig cells (e.g. LHβ mutations, LH/CG receptor or steroidogenic enzyme defects), serum AMH is normal or high. In pubertal males with central hypogonadism, AMH is low for Tanner stage (reflecting lack of FSH stimulus), but high for the age (indicating lack of testosterone inhibitory effect). Treatment with FSH provokes an increase in serum AMH, whereas hCG administration increases testosterone levels, which downregulate AMH. In conclusion, assessment of serum AMH is helpful to evaluate gonadal function, without the need for stimulation tests, and guides etiological diagnosis of pediatric male hypogonadism. Furthermore, serum AMH is an excellent marker of FSH and androgen action on the testis.

2009 ◽  
Vol 21 (9) ◽  
pp. 8
Author(s):  
M. P. Hedger ◽  
J. A. Muir ◽  
W. R. Winnall

There is increasing evidence that the Sertoli cell, in addition to modulating responses to direct antigenic challenges (eg. intratesticular allografts), is central to the response of the testis to inflammation and infection. Systemic inflammation exerts an inhibitory effect on spermatogenesis, which has been attributed to the effects of fever, vascular disturbances, or loss of androgenic support. However, recent studies point to more direct effects of inflammation on spermatogenesis. The discovery that Sertoli cells express Toll-like receptors (TLR), and react to TLR ligands by producing inflammatory cytokines and other mediators, provides a mechanism to account for this direct inhibition. Moreover, the pattern of cytokines produced by the Sertoli cell during inflammation is highly characteristic. For example, when stimulated with TLR ligands the Sertoli cell produces the pro-inflammatory cytokines, interleukin-1α (IL1α) and IL6, and the regulatory cytokine, activin A, but does not produce IL1β and tumour necrosis factor-α, which are major pro-inflammatory products of activated macrophages. The disruptive effects of inflammation on spermatogenesis may be attributed to the elevated production of these cytokines, all of which have stimulatory or inhibitory effects on germ cell mitosis, meiosis and apoptosis and Sertoli cell tight junction formation, In addition, activation of TLR/IL1 mediated inflammatory pathways in the Sertoli cell inhibits its ability to respond to its principal trophic hormone, follicle-stimulating hormone. Studies on the regulation of these interactions will further establish the role of the Sertoli cell in inflammation and infection. However, such studies also have important implications for normal Sertoli cell function, as TLRs can respond to endogenous ligands as well. Consequently, the Sertoli cell may be viewed as a sentinel cell, supporting and protecting spermatogenesis when conditions are optimal, but rapidly shutting down spermatogenesis in the presence of infection or illness. Intriguingly, these apparently disparate roles appear to involve common inflammation-related mechanisms.


Reproduction ◽  
2019 ◽  
Vol 158 (2) ◽  
pp. R67-R77 ◽  
Author(s):  
Katrine Harpelunde Poulsen ◽  
Anne Jørgensen

Testicular development from the initially bipotential gonad is a tightly regulated process involving a complex signalling cascade to ensure proper sequential expression of signalling factors and secretion of steroid hormones. Initially, Sertoli cell specification facilitates differentiation of the steroidogenic fetal Leydig cells and establishment of the somatic niche, which is critical in supporting the germ cell population. Impairment of the somatic niche during fetal life may lead to development of male reproductive disorders, including arrest of gonocyte differentiation, which is considered the first step in the testicular cancer pathogenesis. In this review, we will outline the signalling pathways involved in fetal testis development focusing on the Nodal pathway, which has recently been implicated in several aspects of testicular differentiation in both mouse and human studies. Nodal signalling plays important roles in germ cell development, including regulation of pluripotency factor expression, proliferation and survival. Moreover, the Nodal pathway is involved in establishment of the somatic niche, including formation of seminiferous cords, steroidogenesis and Sertoli cell function. In our outline of fetal testis development, important differences between human and mouse models will be highlighted to emphasise that information obtained from mouse studies cannot always be directly translated to humans. Finally, the implications of dysregulated Nodal signalling in development of the testicular cancer precursor, germ cell neoplasia in situ, and testicular dysgenesis will be discussed – none of which arise in rodents, emphasising the importance of human models in the effort to increase our understanding of origin and early development of these disorders.


Endocrinology ◽  
2008 ◽  
Vol 149 (12) ◽  
pp. 6425-6432 ◽  
Author(s):  
Catherine L. Rivier

Corticotropin-releasing factor (CRF) has previously been reported in rat testes in which it inhibits Leydig cells activity. However, recent studies in our laboratory have suggested that some of the effects originally attributed to CRF were instead due to the related peptide Urocortin 1 (Ucn 1) and that this latter hormone, not CRF, was detectable in Leydig cells. We show here that Ucn 1 [a mixed CRF receptor (CRFR) type 1 and CRFR2 agonist] and the CRFR1-selective peptide Stressin 1, but not Ucn 2 or Ucn 3 (both considered selective CRFR2 ligands), significantly blunt the testosterone response to human chorionic gonadotropin. The effect of Ucn 1 is observed regardless of whether this peptide is injected iv or directly into the testes, and it is reversed by the mixed CRFR1/R2 antagonist Astressin B. Blockade of GnRH receptors with the antagonist Azalin B does not interfere with the influence of Ucn 1, thereby demonstrating that pituitary luteinizing hormone does not appear to be involved in this model. Collectively these results suggest that Ucn 1, not CRF, is present in the rat testes and interferes with Leydig cell activity. However, whereas we previously reported that alcohol up-regulated gonadal Ucn 1 gene expression, CRF receptor antagonists were unable to reverse the inhibitory effect exerted by alcohol on human chorionic gonadotropin-induced testosterone release. The functional role played by testicular Ucn 1 in stress models characterized by blunted androgen levels therefore needs to be further investigated.


1985 ◽  
Vol 248 (2) ◽  
pp. E176-E181
Author(s):  
M. Benahmed ◽  
J. Reventos ◽  
E. Tabone ◽  
J. M. Saez

To determine the precise role of Sertoli cells in the stimulating effects of follicle stimulating hormone (FSH) on Leydig cell activity, porcine purified Leydig and Sertoli cells were cultured separately or together in a chemically defined medium in the absence or presence of porcine, FSH 50 ng/ml. Leydig cell activity was evaluated using two parameters: human chorionic gonadotropin (hCG) binding sites; and hCG-stimulated cAMP production and testosterone secretion. First, it was found that FSH increases Leydig cell activity in crude Leydig cell preparations (40–60% of Leydig cells), whereas it exerts no effect on purified Leydig cells (greater than 90% of Leydig cells). Second, FSH stimulates the activity of Leydig cells cocultured with Sertoli cells, whereas it remains without effect on purified Leydig cells cultured alone. This stimulating effect of FSH on Leydig cell activity is dependent on the Sertoli cell number in the coculture. These data 1) show that the stimulating effect of FSH on Leydig cell function is mediated by Sertoli cells and 2) support the concept of local control of Leydig cell function originating from Sertoli cells.


2022 ◽  
Vol 12 (1) ◽  
pp. 81-89
Author(s):  
Sheng Li ◽  
Youhua Yang ◽  
Fang Liu ◽  
Qian Song

To explore the mechanism of miR-29b in gestational diabetes mellitus (GDM) and its effect on the function of trophoblast cell (TBC), the placenta tissues of 55 normal term pregnancies and 55 GDM patients were selected and rolled into control group and observation group. In the early stage, microRNA (miRNA) chips were utilized to screen the differentially expressed miRNAs in the placenta of observation group and control group. According to the microarray results of miRNAs, three differentially expressed miRNAs, namely let-7b, miR-1202, and miR-29b were selected. Then, the differences in the miR-29b level in the four groups were analyzed, namely the microRNA-29b (miR-29b minic), mini-control (minic control), microRNA-29b inhibitor (miR-29b inhibitor), and inhibitor control (inhibitor control). The results showed that miR-29b level in the placenta of observation group was substantially inferior to that of controls, with remarkable differences (P < 0.05). miR-29b level in miR-29b minic and minic control had significant changes (P < 0.01). The TBC activity of minic control was greatly superior to that of minic control, and there was considerable difference between the two (P < 0.05). The difference between miR-29b inhibitor and inhibitor control in TBC was not obvious, without considerable differences (P > 0.05). The invasion ability of miR-29b inhibitor TBC was notably superior to inhibitor control, and there were substantial differences (P < 0.05). To sum up, miR-29b had a significant inhibitory effect on the proliferation and cell activity of TBC, and can promote the apoptosis and death of TBC. Moreover, its inhibitory effect on cell migration and invasion was also suggested.


1998 ◽  
Vol 83 (2) ◽  
pp. 675-681 ◽  
Author(s):  
Anna-Maria Andersson ◽  
Jorma Toppari ◽  
Anne-Maarit Haavisto ◽  
Jørgen H. Petersen ◽  
Tuula Simell ◽  
...  

The gonads are usually considered quiescent organs in infancy and childhood. However, during the first few postnatal months of life, levels of gonadotropins and sex hormones are elevated in humans. Recent epidemiological evidence suggests that environmental factors operating perinatally may influence male reproductive health in adulthood. The early postnatal activity of the Sertoli cell, a testicular cell type that is supposed to play a major role in sperm production in adulthood is largely unknown. Recently, the peptide hormone inhibin B was shown to be a marker of Sertoli cell function in the adult male. In the adult woman, inhibin B is secreted by the granulosa cells. Longitudinal serum levels of inhibin B were measured in healthy boys (n = 15) and girls (n = 15), in cord blood, and every third month during the first 2 yr of life. In addition, serum levels of FSH, LH, and testosterone (boys) were measured in the same group of children. In boys, inhibin B, FSH, LH, and testosterone levels were all elevated at 3 months of age. However, the peak of inhibin B was unexpectedly high, into the supraadult range (mean ± se, 378 ± 23 pg/mL) and persisted much longer than the elevation of FSH, LH, and testosterone. Thus, although levels of FSH, LH, and testosterone decreased into the range observed later in childhood by the age of 6–9 months, serum inhibin B levels remained elevated up to at least the age of 15 months. In girls, the hormonal pattern was generally more complex, with a high interindividual variation in levels of inhibin B, FSH, and LH within each age. In conclusion, the sustained elevation of inhibin B to supraadult levels in infant boys indicates that the neonatal period may be a developmental window important for Sertoli cell proliferation and maturation. Thus, the gonads may be potentially vulnerable to exogenous endocrine interference, e.g. from environmental factors during this period of life. Measurement of serum levels of inhibin B in infants may give clinical clues about developmental deficiencies in the gonads that otherwise only become apparent around puberty or later in life.


Reproduction ◽  
2008 ◽  
Vol 135 (6) ◽  
pp. 839-850 ◽  
Author(s):  
P J O'Shaughnessy ◽  
L Hu ◽  
P J Baker

It has been shown that testicular germ cell development is critically dependent upon somatic cell activity but, conversely, the extent to which germ cells normally regulate somatic cell function is less clear. This study was designed, therefore, to examine the effect of germ cell depletion on Sertoli cell and Leydig cell transcript levels. Mice were treated with busulphan to deplete the germ cell population and levels of mRNA transcripts encoding 26 Sertoli cell-specific proteins and 6 Leydig cell proteins were measured by real-time PCR up to 50 days after treatment. Spermatogonia were lost from the testis between 5 and 10 days after treatment, while spermatocytes were depleted after 10 days and spermatids after 20 days. By 30 days after treatment, most tubules were devoid of germ cells. Circulating FSH and intratesticular testosterone were not significantly affected by treatment. Of the 26 Sertoli cell markers tested, 13 showed no change in transcript levels after busulphan treatment, 2 showed decreased levels, 9 showed increased levels and 2 showed a biphasic response. In 60% of cases, changes in transcript levels occurred after the loss of the spermatids. Levels of mRNA transcripts encoding Leydig cell-specific products related to steroidogenesis were unaffected by treatment. Results indicate (1) that germ cells play a major and widespread role in the regulation of Sertoli cell activity, (2) most changes in transcript levels are associated with the loss of spermatids and (3) Leydig cell steroidogenesis is largely unaffected by germ cell ablation.


Endocrinology ◽  
2008 ◽  
Vol 149 (7) ◽  
pp. 3279-3285 ◽  
Author(s):  
M. H. Abel ◽  
P. J. Baker ◽  
H. M. Charlton ◽  
A. Monteiro ◽  
G. Verhoeven ◽  
...  

Spermatogenesis in the adult male depends on the action of FSH and androgen. Ablation of either hormone has deleterious effects on Sertoli cell function and the progression of germ cells through spermatogenesis. In this study we generated mice lacking both FSH receptors (FSHRKO) and androgen receptors on the Sertoli cell (SCARKO) to examine how FSH and androgen combine to regulate Sertoli cell function and spermatogenesis. Sertoli cell number in FSHRKO-SCARKO mice was reduced by about 50% but was not significantly different from FSHRKO mice. In contrast, total germ cell number in FSHRKO-SCARKO mice was reduced to 2% of control mice (and 20% of SCARKO mice) due to a failure to progress beyond early meiosis. Measurement of Sertoli cell-specific transcript levels showed that about a third were independent of hormonal action on the Sertoli cell, whereas others were predominantly androgen dependent or showed redundant control by FSH and androgen. Results show that FSH and androgen act through redundant, additive, and synergistic regulation of spermatogenesis and Sertoli cell activity. In addition, the Sertoli cell retains a significant capacity for activity, which is independent of direct hormonal regulation.


2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.


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