2026-06-27T10:27:13Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/1028322025-03-18T14:31:08Zcom_20.500.14352_14col_20.500.14352_15

Arias Álvarez, María García García, Rosa María Torres Rovira, L. González Bulnes, Antonio Rebollar, P.G. Lorenzo González, Pedro Luis 2024-04-08T13:29:08Z 2024-04-08T13:29:08Z 2010-03-01 1470–1626 10.1530/REP-09-0309 https://hdl.handle.net/20.500.14352/102832 1741-7899 https://rep.bioscientifica.com/view/journals/rep/139/3/523.xml Extreme body mass indexes may impair reproductive outcome in assisted reproductive technologies. Leptin reflects the amount of body fat and could act as a modulator of oocyte quality through activation of specific transcription factors. The aim of this work was to establish whether: 1) leptin influences meiotic and cytoplasmic oocyte maturation; 2) STAT3 and MAPK mediate the effects of leptin and 3) leptin modulates steroid secretion by cumulus-oocyte complexes (COC) during in vitro maturation (IVM). We confirmed immunolocalisation of leptin receptor in oocytes, cumulus/granulosa cells during the peri-ovulatory period. The confocal study showed that COC supplemented with 1, 10 and 100 ng/ml leptin had a significantly higher metaphase II (MII) percentage than those IVM without leptin (P < 0.05) and a similar MII index compared to the group supplemented with 10% FCS. Leptin did not increase the percentage of cytoplasmically matured oocytes in terms of cortical granule migration rate, whereas a significantly higher index was found in the FCS group (P < 0.001). Oestradiol concentrations in spent media were higher in the FCS group compared to other treatments (P < 0.001). Leptin-stimulated nuclear oocyte maturation was significantly impaired when leptin-induced JAK2/STAT3 and MEK 1/2 activation was suppressed by the inhibitors (P < 0.001). Steroid secretion of COC was not affected by leptin activation of JAK2/STAT3 or MEK 1/2 pathways. In conclusion, JAK2/STAT3 and MEK 1/2 pathways mediate the enhancement of nuclear oocyte maturation by leptin; however, neither cytoplasmic oocyte maturation nor steroidogenic response of COC were improved in the present rabbit model. eng http://creativecommons.org/licenses/by/4.0/ open access Attribution 4.0 International Influence of leptin on in vitro maturation and steroidogenic secretion of cumulus-oocyte complexes through JAK2/STAT3 and MEK 1/2 pathways in the rabbit model journal article