PD39-03 LEPTIN SECRETED FROM TESTICULAR MICROENVIRONMENT MODULATES HEDGEHOG SIGNALLING TO AUGMENT THE ENDOGENOUS FUNCTION OF LEYDIG CELLS (2021)

You have accessJournal of UrologyInfertility: Basic Research & Pathophysiology (PD39)1 Sep 2021PD39-03 LEPTIN SECRETED FROM TESTICULAR MICROENVIRONMENT MODULATES HEDGEHOG SIGNALLING TO AUGMENT THE ENDOGENOUS FUNCTION OF LEYDIG CELLS Kajal Khodamoradi, Madhumita Parmar, Derek J Van Booven, Deepa Seetharam, Issa Isabelle Catherine, Joshua M. Hare, Ranjith Ramasamy, and Himanshu Arora Kajal KhodamoradiKajal Khodamoradi More articles by this author , Madhumita ParmarMadhumita Parmar More articles by this author , Derek J Van BoovenDerek J Van Booven More articles by this author , Deepa SeetharamDeepa Seetharam More articles by this author , Issa Isabelle CatherineIssa Isabelle Catherine More articles by this author , Joshua M. HareJoshua M. Hare More articles by this author , Ranjith RamasamyRanjith Ramasamy More articles by this author , and Himanshu AroraHimanshu Arora More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002049.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Although testosterone deficiency (TD) may be present in 1 out of 5 men 40 years or older, the factors responsible for TD remain largely unknown. Leydig stem cells (LSCs) differentiate into adult Leydig cells (ALC) and produce testosterone in the testes under the pulsatile control of luteinizing hormone (LH) from the pituitary gland. However, our recent studies have suggested that the testicular microenvironment (TME), which is comprised of Sertoli and peritubular myoid cells (PMC), plays an instrumental role in LSC differentiation and testosterone production under the regulation of the desert hedgehog signalling pathway (DHH). In the present study, we hypothesized that testicular TME releases paracrine factors that modulate LSC differentiation. METHODS: A total of 13 men with testicular failure underwent testis biopsies for sperm retrieval. Using an IRB approved protocol, about 10mg of testicular tissue from each of these men were processed for Leydig stem cell isolation, culture and characterized. Cytokine antibody array was performed to identify the paracrine factors released by TME. The cells were treated with hedgehog signalling agonist and antagonist in the presence or absence of identified paracrine factors from the conditioned media. GraphPad Prism (GraphPad Software) was used for statistical analysis. All data were presented as the means ± SEM. The statistical significance between two groups was estimated by unpaired two-tailed t-test. RESULTS: We successfully isolated and cultured up to 5 X 106million LSC’s / biopsy from all 13 human testis biopsies. These cells were characterized for the presence or absence of different cell types in testis such as adult Leydig cells, Leydig stem cells, Sertoli cells, peritublar myoid cells and germ cells. Results showed that, of the cells cultured, up to 70% of the cells were Leydig stem cells and 10% of them were Sertoli-cell in origin on day 14. IF and qPCR data showed as the majority of cell population was undifferentiated (PDGFR-α). Upon stimulation by LH, the expression of 3βHSD (mature Leydig cells) was increased and that of PDGFR-α was decreased. Furthermore, the results demonstrated that TME secretes leptin which induces LSC differentiation and increases T production. Leptin’s effects on LSC differentiation and T production, however, are inversely concentration-dependent: positive at low doses and negative at higher doses. Mechanistically, leptin acts on LSCs upstream of DHH; leptin-DHH regulation functions unidirectionally insofar as DHH gain or loss of function has no effects on leptin levels. CONCLUSIONS: Taken together, these findings identify leptin as a key paracrine factor released by cells within the TME that modulates LSC differentiation and testosterone release from mature Leydig cells, a finding with important clinical implications for TD. Further studies are ongoing to validate the implications of these Leptin in terms of its role in LSCs function, differentiation and survival. Source of Funding: Financial Support: Supported by the American Urological Association Research Scholar Award and Stanley Glaser Award to RR. J.M.H. is supported by NIH grants 1R01 HL137355, 1R01 HL107110, 1R01 HL134558, 5R01 CA136387, 5UM1 HL113460 and Soffer Family Foundation © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e668-e669 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kajal Khodamoradi More articles by this author Madhumita Parmar More articles by this author Derek J Van Booven More articles by this author Deepa Seetharam More articles by this author Issa Isabelle Catherine More articles by this author Joshua M. Hare More articles by this author Ranjith Ramasamy More articles by this author Himanshu Arora More articles by this author Expand All Advertisement Loading ...