RESUMO
Our previous research has shown that melatonin (MLT) can reduce cryopreserved ovarian damage in mice. Yet, the molecular mechanism of MLT protection is still unclear. Some studies have shown that melatonin receptor 1 (MT1) is very important for animal reproductive system. To evaluate whether MLT exerts its protective effect on cryopreserved mice ovarian tissue via MT1, we added antagonist of MT1/MT2 (Luzindor) or antagonist of MT2 (4P-PDOT) to the freezing solution, followed by cryopreservation and thawing of ovarian tissue. The levels of total superoxide dismutase (T-SOD), catalase (CAT), nitric oxide (NO) and malondialdehyde (MDA) were detected. Besides, by using RT-PCR and Western blotting, the expression of Bcl-2, Bax and Nrf2/HO-1 signalling pathway-related proteins was detected. These findings demonstrated that compared with the melatonin group, the addition of Luzindor increased apoptosis, NO and MDA activities, decreased CAT and T-SOD activities and inhibited Nrf2/HO-1 signalling pathway. In conclusion, melatonin can play a protective role in cryopreserved ovarian tissue of mice through MT1 receptor.
Assuntos
Criopreservação , Melatonina , Fator 2 Relacionado a NF-E2 , Ovário , Estresse Oxidativo , Receptor MT1 de Melatonina , Transdução de Sinais , Animais , Feminino , Melatonina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Ovário/efeitos dos fármacos , Receptor MT1 de Melatonina/metabolismo , Receptor MT1 de Melatonina/genética , Transdução de Sinais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/genética , Camundongos , Criopreservação/veterinária , Triptaminas/farmacologia , Apoptose/efeitos dos fármacos , Heme Oxigenase (Desciclizante)/metabolismo , Heme Oxigenase (Desciclizante)/genética , Óxido Nítrico/metabolismo , Malondialdeído/metabolismo , Proteínas de Membrana , Heme Oxigenase-1RESUMO
Ovarian tissue cryopreservation is an effective fertility protective strategy for preadolescent female cancer patients, whose tumor treatment cannot be delayed. In the present study, the effects of sericin, as an antioxidant, on mice ovarian tissue freezing and thawing were investigated. Mice ovarian tissues were cryopreserved and thawed in medium containing 0.5% or 1%sericin (w/v), and 0.1 mM melatonin. Then, the follicular morphology was observed. The levels of antioxidant enzymes were determined, including glutathione (GSH), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and catalase (CAT). Moreover, the levels of nitric oxide (NO), malondialdehyde (MDA) and lactate dehydrogenase (LDH) were also tested. Besides, apoptosis-related proteins Bcl-2 and Bax were determined. Our results showed that 1% sericin maintained follicular morphology, inhibited apoptosis, decreased MDA and NO levels, and boosted endogenous antioxidant enzyme levels, while had no significant effect on LDH levels. Furthermore, these effects may be related with the activation of the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of Rapamycin (mTOR) signaling pathway, as demonstrated by increased PI3K, p-AKT and mTOR levels. These findings demonstrate that 1% sericin may reduce oxidative stress and protect ovarian tissues during freezing and thawing via PI3K/AKT/mTOR signaling pathway.