ACTIONS OF MELATONIN IN HAMSTER TESTICULAR PERITUBULAR CELLS

CIGORRAGA SB; MAYERHOFER A; RIVIERE E; PELLIZARI EH; ROSSI SP; MATZKIN ME; CALANDRA RS; FRUNGIERI MB

Buenos Aires

Jornada; XX Jornada Anual de la Sociedad Argentina de Biología; 2018

Sociedad Argentina de Biología

Peritubular cells, surrounding the seminiferous tubules of the testis, are well known for their implication on tubular contractility and sperm transport. Together with Sertoli cells, they form the cellular boundary of the spermatogonial stem cell (SSC) niche. However little is known about the contribution of peritubular cells to the SSCs and its niche, mainly as secretome cells.The objectives of this study were: i) to isolate and characterize immature hamster testicular peritubular cells (haTPCs), and ii) to investigate the potential actions of melatonin on the contractile and synthesis activities of haTPCs.haTPCs were isolated from testes of immature Syrian hamsters (21-23 days old) by successive enzymatic digestions (trypsin and collagenase) and subsequently characterized by immunocytochemistry. haTPCs showed positive staining for a peritubular cell marker (-smooth muscle actin, -SMA) but negative staining for Sertoli cell markers (SOX9 and anti-Müllerian hormone, AMH) and a germ cell marker (VASA).haTPCs express the melatonin receptors subtype MT1 and MT2. Incubation of haTPCs with 1M melatonin significantly increased mRNA and/or protein expression of the contractile markers -SMA and calponin. mRNA expression of the glial cell line-derived neurotrophic factor (GDNF), a factor involved in the maintenance of the SSCs self-renewal, was also upregulated by melatonin (P0.05).In addition, 1M melatonin increased mRNA and protein expression of cyclooxygenase 2 (COX2), key enzyme in prostaglandin (PG) synthesis, as well as the production of PGD2 (P0.05).haTPCs and hamster Sertoli cells express PGD2 receptors (DP receptors). Moreover, glucose uptake and lactate production in Sertoli cells purified from photoperiodically regressed adult hamsters showed a statistically significant increase in the presence of 1M PGD2.Therefore primary cultures of peritubular cells are an important tool for studying not only the structural role of these cells in the testis but also for understanding their function in the homeostasis of the testicular environment, i.e. regulation of the SSCs and its niche. In this study, we specially demonstrated a regulatory role exerted locally by melatonin in haTPCs.