Inflammation is hypothesized to play an important role in several diseases associated to the female genital tract and dihydrotestosterone (DHT) has shown immunomodulatory protective effects in experimental models of chronic inflammation. In the present study we aimed to evaluate the potential anti-inflammatory effects of DHT in a model of smooth muscle cells (hSMCs) isolated from human vagina biopsies and their potential role as APCs (Antigen Presenting Cells), crucial for the immune response. In addition we investigated the tissue expression of enzymes involved in steroidogenic machinery, to evaluate the potential role of the hormone on-site production. hSMCs were isolated by tissue samples obtained from laparoscopic patients and were characterized with the main smooth muscle markers α-smooth muscle actin (α-SMA) and myosin heavy chain 11 (MHC11). The cells were stimulated in vitro with the Toll-Like Receptors (TLRs) agonist lipopolysaccharide (LPS), with or without DHT (30 nM), for 24 h in order to analyze, by real time RT PCR, the expression of the main pro-inflammatory genes, such as IL-4, IL-6, IL-12, MCP1 and cyclooxygenase-2 (COX-2). In addition, immunofluorescence studies were performed to analyze the LPS-induced NF-kB translocation, with or without DHT (30 nM) co-treatment. In the flow cytometry studies, hSMC were stimulated with INFγ 1000 UI/ml, in absence or in presence of DHT (30 nM) for 48h. Finally, the mRNA expression of enzymes involved in the steroidogenesis pathway in human vagina tissues was evaluated by RT-PCR, taking the ovary as a control. Our data showed that LPS significantly increased the expression of several pro-inflammatory genes (IL-4, IL-6, MCP1 and COX2) and induced a consistent NF-kB nuclear translocation, while DHT treatment counteracted these effects. Moreover, DHT reverted the HLA-DR expression up-regulated by INFγ stimulation. Finally, the genes linked to the synthesis of androgenic precursors were expressed in vagina tissues. In particular, genes related to DHT synthesis (5α-reductase 1, 2 and 3; SRD5A1, SRD5A2, SRD5A3) were significantly higher expressed compared to ovary. In conclusion, the results of this study showed that in our experimental model, DHT has anti-inflammatory properties inhibiting the mRNA expression of several pro-inflammatory genes as well as LPS-induced NF-kB nuclear translocation. In addition, the counteracting effects of DHT on the INFγ-induced HLA-DR expression suggested an immunomodulatory profile similar to APC. Finally, the high expression of androgen synthesis-related genes in vagina tissues suggests an on-site production. Taken together, our data support the possible therapeutic role of androgens in genital trait disorders in women.
18 - 21 May 2019
European Society of Endocrinology