STUDY QUESTION What are the consequences of ageing on human Leydig cell number and hormonal function? SUMMARY ANSWER Leydig cell number significantly decreases in parallel with INSL3 expression and Sertoli cell number in aged men, yet the in vitro Leydig cell androgenic potential does not appear to be compromised by advancing age. WHAT IS KNOWN ALREADY There is extensive evidence that ageing is accompanied by decline in serum testosterone levels, a general involution of testis morphology and reduced spermatogenic function. A few studies have previously addressed single features of the human aged testis phenotype one at a time, but mostly in tissue from patients with prostate cancer. STUDY DESIGN, SIZE, DURATION This comprehensive study examined testis morphology, Leydig cell and Sertoli cell number, steroidogenic enzyme expression, INSL3 expression and androgen secretion by testicular fragments in vitro. The majority of these endpoints were concomitantly evaluated in the same individuals that all displayed complete spermatogenesis. PARTICIPANTS/MATERIALS, SETTING, METHODS Testis biopsies were obtained from 15 heart beating organ donors (age range: 19–85 years) and 24 patients (age range: 19–45 years) with complete spermatogenesis. Leydig cells and Sertoli cells were counted following identification by immunohistochemical staining of specific cell markers. Gene expression analysis of INSL3 and steroidogenic enzymes was carried out by qRT-PCR. Secretion of 17-OH-progesterone, dehydroepiandrosterone, androstenedione and testosterone by in vitro cultured testis fragments was measured by LC-MS/MS. All endpoints were analysed in relation to age. MAIN RESULTS AND THE ROLE OF CHANCE Increasing age was negatively associated with Leydig cell number (R = −0.49; P < 0.01) and concomitantly with the Sertoli cell population size (R= −0.55; P < 0.001). A positive correlation (R = 0.57; P < 0.001) between Sertoli cell and Leydig cell numbers was detected at all ages, indicating that somatic cell attrition is a relevant cellular manifestation of human testis status during ageing. INSL3 mRNA expression (R= −0.52; P < 0.05) changed in parallel with Leydig cell number and age. Importantly, steroidogenic capacity of Leydig cells in cultured testis tissue fragments from young and old donors did not differ. Consistently, age did not influence the mRNA expression of steroidogenic enzymes. The described changes in Leydig cell phenotype with ageing are strengthened by the fact that the different age-related effects were mostly evaluated in tissue from the same men. LIMITATIONS, REASONS FOR CAUTION In vitro androgen production analysis could not be correlated with in vivo hormone values of the organ donors. In addition, the number of samples was relatively small and there was scarce information about the concomitant presence of potential confounding variables. WIDER IMPLICATIONS OF THE FINDINGS This study provides a novel insight into the effects of ageing on human Leydig cell status. The correlation between Leydig cell number and Sertoli cell number at any age implies a connection between these two cell types, which may be of particular relevance in understanding male reproductive disorders in the elderly. However aged Leydig cells do not lose their in vitro ability to produce androgens. Our data have implications in the understanding of the physiological role and regulation of intratesticular sex steroid levels during the complex process of ageing in humans. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by grants from Prin 2010 and 2017. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.
Mineralocorticoid receptor antagonists (MRAs) are recommended for the treatment of heart failure and hypertension, mainly due to their natriuretic and anti‐fibrotic mode of action. Rodent studies have shown that MRAs can prevent adverse metabolic consequences of obesity but an elucidation of underlying molecular mechanisms is missing. Here, we investigated metabolic effects of the novel non‐steroidal MRA finerenone (FIN) in a mouse model of high‐fat diet (HFD)‐induced obesity and the signaling pathways activated by MR antagonism at level of interscapular brown adipose tissue (iBAT). C57BL/6J male mice were fed a normal diet or a HFD (with60% kcal from fat) containing or not FIN for 3 months. Metabolic parameters, adipose tissue morphology, gene and protein expression analysis were assessed. We also used brown adipocyte cultures (T37i cells) to investigate the effects of FIN‐mediated MR antagonism upon lipid and mitochondrial metabolism. HFD + FIN‐treated mice showed improved glucose tolerance together with increased multilocularity and higher expression of thermogenic markers at the level of iBAT, without differences in white adipose depots, suggesting an iBAT‐specific effect of FIN. Mechanistically, FIN increased activation of AMP‐activated protein kinase which, in turn, stimulated adipose triglyceride lipase activation, with subsequent increased expression of uncoupling protein‐1 in brown adipocytes.
Background The incretin hormone glucagon‐like peptide‐l (GLP‐1) is an important regulator of post‐prandial insulin secretion, acting through a G protein‐coupled cell surface receptor (GLP‐1R). In addition to its expression in pancreatic β‐cells, several studies suggested that GLP‐1R is located in extra‐pancreatic tissues. Objectives In this study, we examined for the first time the testicular distribution of the GLP‐1R, both in normal human and neoplastic testicular tissues as well as in rodent testis and rodent testicular cell lines. Methods and Methods The GLP‐1R distribution in testicular section has been evaluated by immunohistochemistry, the specificity of IHC was validated by demonstrating a positive staining for GLP‐1RmRNA by RISH technology. While GLP‐1R expression in terms of protein was detected by western blot analysis, Moreover, mRNA levels were determined in human testis, in rodent Leydig, and Sertoli cell lines. Results Using immunohistochemistrya specific staining for GLP‐1R was detected in Leydig cells. The specificity of IHC was validated by demonstrating a positive staining for GLP‐1RmRNA only in these cell types. Species differences in the GLP‐1R expression between humans and rodents were observed. Interestingly, a decreased expression of the receptor in rodent tumor Leydig cell line and an absence in human Leydig tumor samples was detected. Discussion It may be hypothesized that GLP‐1R acts like an oncosuppressor in Leydig tumors. A role in regulation of hormone secretion by GLP‐1 has been shown in other endocrine cells, therefore we hypothesized that GLP‐1R is able to modulate somehow the Leydig cell function. Conclusion In our findings, a careful evaluation of human testicular tissues and rodent testis revealed Leydig cells as a potential target for GLP‐1. Collectively, an effect of GLP‐1R in Leydig cell function may be presumed although future studies are needed to ascertain the GLP‐1R’s role both in normal and tumor Leydig cells.
The molecular mechanisms leading to the transformation of anaplastic lymphoma kinase negative (ALK − ) anaplastic large cell lymphoma (ALCL) have been only in part elucidated. To identify new culprits which promote and drive ALCL, we performed a total transcriptome sequencing and discovered 1208 previously unknown intergenic long noncoding RNAs (lncRNAs), including 18 lncRNAs preferentially expressed in ALCL. We selected an unknown lncRNA, BlackMamba, with an ALK − ALCL preferential expression, for molecular and functional studies. BlackMamba is a chromatin-associated lncRNA regulated by STAT3 via a canonical transcriptional signaling pathway. Knockdown experiments demonstrated that BlackMamba contributes to the pathogenesis of ALCL regulating cell growth and cell morphology. Mechanistically, BlackMamba interacts with the DNA helicase HELLS controlling its recruitment to the promoter regions of cell-architecturerelated genes, fostering their expression. Collectively, these findings provide evidence of a previously unknown tumorigenic role of STAT3 via a lncRNA-DNA helicase axis and reveal an undiscovered role for lncRNA in the maintenance of the neoplastic phenotype of ALK − ALCL.
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