The role of nitric oxide synthase isoforms in aged porcine oocytes

Abstract

ABSTRACT:In the sphere of reproductive biotechnologies, the demand for sufficient numbers of high-quality oocytes is still increasing. In some cases, this obstacle is overcome by in vitro prolonged cultivation. However, a prolonged oocyte culture is accompanied by changes called ageing. Ageing is manifested by spontaneous parthenogenetic activation, programmed cell death or lysis. Various substances, such as caffeine or dithiothreitol, have been tested for ageing suppression. In this respect, research into gasotransmitters (hydrogen sulphide, carbon monoxide, and nitric oxide) has currently been intensified. The objectives of the present study were to localize nitric oxide synthases (NOS) and to evaluate NOS inhibition of aged porcine oocytes. We demonstrated the presence of NOS isoforms in oocyte cultivation prolonged by 24, 48, and 72 h. After 72 h of prolonged cultivation, NOS inhibition by the non-specific inhibitor L-NAME or the specific inhibitor aminoguanidine caused suppression both of programmed cell death and lysis. Although NOS amount rapidly decreased after the 72-h cultivation, changes induced by NOS inhibition were statistically significant. We can presume that NOS play an important physiological role in porcine oocyte ageing.

From Nitric Oxide Toward S-Nitrosylation: Expanding Roles in Gametes and Embryos

“…Furthermore, they reported that intracellular NO level may induce apoptosis in aged rat oocytes cultured in vitro. Similarly, Nevoral et al [77] described the suppression of apoptosis and lysis after prolonged cultivation of porcine oocytes in media supplemented by the NOS nonspecific inhibitor l-NAME. The decrease of intracellular levels of NO interrupts intracellular signal transduction pathways, especially Ca 2+ -mediated pathways [75].…”

Involvement of K+ATP and Ca2+ channels in hydrogen sulfide-suppressed ageing of porcine oocytes

“…Cumulus-oocyte complexes were collected from 3 to 5 mm follicles by aspiration using a syringe and 20G needle. Fully grown immature oocytes with intact ooplasm and compact layers of cumulus cells were selected for in vitro maturation in modified M199 culture medium for 48 h at 39 °C and 5% CO 2 [ 6 ]. Matured MII oocytes were denuded and subjected to further in vitro cultivation in modified M199 under standard conditions for 72 h [ 3 ].…”

“…Accordingly, age-related signalling has been extensively studied, and various substances with oocyte protective effects have been tested [ 3 , 4 ]. Gasotransmitters, particularly hydrogen sulfide, represent potent signalling molecules involved in the regulation of oocyte maturation and ageing [ 3 , 5 , 6 ]. Accordingly, a hydrogen sulfide treatment suppresses the negative effects of oocyte ageing, such as parthenogenetic activation and oocyte/embryo death, in a dose-dependent manner [ 3 ].…”

Interactions between Bisphenol S or Dibutyl Phthalates and Reproductive System

“…The studies on cell cultures showed that BPS affects cells mutagenically, genotoxically, and cytotoxically [20,21]. BPS exposure also disrupts the signaling pathway of apoptosis, so it may cause gametes cascades leading toward cell death and altered cell cycle [22,23].…”