MECHANISMS INVOLVED IN LEPTIN ANTIAPOPTOTIC EFFECT AFTER HIF-1α STABILIZATION

NATALY DE DIOS; RODRIGO RIEDEL; MALENA SCHANTON; ANTONIO PÉREZ PÉREZ; SEBASTIÁN SALINAS; CASALE, ROBERTO; VÍCTOR SÁNCHEZ-MARGALET; JULIETA L. MAYMÓ; CECILIA L. VARONE

Virtual

Congreso; IX Simposio Latinoamericano de Placenta e Interacción Materno Fetal; 2022

SLIMP

MECHANISMS INVOLVED IN LEPTIN ANTIAPOPTOTIC EFFECT AFTER HIF-1α STABILIZATION de Dios N1, Riedel R1 ,Schanton M1, Pérez-Pérez A2, Salinas S1, Casale R3, Sánchez-Margalet V2, Maymó J2 and Varone C1 1. Departamento de Química Biológica FCEN-UBA, Instituto de Química Biológica IQUIBICEN, CONICET, Buenos Aires, Argentina 2 Departamento de Bioquímica Médica y Biología Molecular e Inmunología, Hospital Universitario Virgen Macarena, Facultad de Medicina, Universidad de Sevilla, Avenida Sánchez Pizjuán 4, 41009, Sevilla, España. 3 Hospital Nacional Profesor Alejandro Posadas, Buenos Aires, Argentina Leptin acts as a regulatory hormone in the maternal fetal interface. We demonstrated that leptin promotes proliferation and survival of trophoblastic cells. Moreover, leptin prevents cellular stress in trophoblastic cells. In this sense, leptin is incremented in different pregnancy pathologies such as preeclampsia. In this work we aimed to elucidate the mechanisms involved in leptin antiapoptotic effect on placental apoptosis induced by cobalt chloride (CoCl2). This agent stabilizes HIF-1α transcription factor. All procedures were approved by ethical review committee at the Alejandro Posadas National Hospital. We used Swan-71 cells, a cytotrophoblast human cell line and human term placental explants. Both cell models were treated with or without CoCl2 (50,100 or 250 μM) in the presence or absence of leptin (100 ng/ml). Leptin diminished Bax/Bcl-2 ratio (0.2 ± 0.1) in Swan-71 cells, under simil-hypoxic condition; determinated by qRT-PCR and WB. Leptin treatment decreased the proapoptotic proteíns t-Bid (0.5 ± 0.4); Bax (0.8 ±0.1), Bid (1.3 ± 0.09) and enhanced the antiapoptotic Bcl-2 (2.0± 0.3), Bcl-XL (2.3 ± 0.3) and MCL-1 (1.4 ± 0.2). Leptin also prevented CoCl2 apoptosis in placental explants determined by DNA ladder assay. Moreover, MAPK and PI3K signaling pathways were evaluated after CoCl2 treatment, using pharmacological inhibitors. The presence of 100 μM PD98059 or 50 nM wortmannin, completely reverted leptin antiapoptotic effect. All these results suggest that the stabilization of HIF-1α has negative effects on cell survival; and leptin protects trophoblastic cells from the hypoxic condition involving MAPK and PI3K pathways, which reinforces the importance of leptin in the regulation of placental health.Key words: Placenta, apoptosis, hypoxia, leptin, signaling pathwayLeptin acts as a regulatory hormone in the maternal fetal interface. We demonstrated previously that leptin promotes proliferation and survival of trophoblastic cells. Moreover, leptin prevents cellular stress in trophoblastic cells. In this sense, leptin is incremented in different pregnancy pathologies such as preeclampsia. In this work we aimed to elucidate the mechanisms involved in leptin antiapoptotic effect on placental apoptosis induced by cobalt chloride (CoCl2). This agent stabilizes HIF-1α transcription factor. All procedures were approved by ethical review committee at the Alejandro Posadas National Hospital. We used Swan-71 cells, a cytotrophoblast human cell line and human term placental explants. Both cell models were treated with or without CoCl2 (50,100 or 250 μM) in the presence or absence of leptin (100 ng/ml). Leptin treatment decreased the expression of the proapoptotic proteins t-Bid (0.5 ± 0.4); Bax (0.8 ±0.1), Bid (1.3 ± 0.09) and enhanced the expression of the antiapoptotic ones Bcl-2 (2.0± 0.3), Bcl-XL (2.3 ± 0.3) and MCL-1 (1.4 ± 0.2) in Swan-71 cells, under simil-hypoxic condition, determined by qRT-PCR and Western blot. In this way Bax/Bcl-2 ratio was diminished (0.2 ± 0.1) by leptin treatment. Leptin also prevented CoCl2 apoptosis in placental explants determined by DNA ladder assay. Moreover, MAPK and PI3K signaling pathways were evaluated after CoCl2 treatment, using pharmacological inhibitors. The presence of 100 μM PD98059 or 50 nM wortmannin completely reverted leptin antiapoptotic effect in placental explants. All these results suggest that the stabilization of HIF-1α has negative effects on cell survival; and leptin protects trophoblastic cells from the hypoxic condition involving MAPK and PI3K pathways; which reinforces the importance of leptin in the regulation of placental health.