Hydrogen Sulfide Donor Protects Porcine Oocytes against Aging and Improves the Developmental Potential of Aged Porcine Oocytes

Abstract

Porcine oocytes that have matured in in vitro conditions undergo the process of aging during prolonged cultivation, which is manifested by spontaneous parthenogenetic activation, lysis or fragmentation of aged oocytes. This study focused on the role of hydrogen sulfide (H2S) in the process of porcine oocyte aging. H2S is a gaseous signaling molecule and is produced endogenously by the enzymes cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (MPST). We demonstrated that H2S-producing enzymes are active in porcine oocytes and that a statistically significant decline in endogenous H2S production occurs during the first day of aging. Inhibition of these enzymes accelerates signs of aging in oocytes and significantly increases the ratio of fragmented oocytes. The presence of exogenous H2S from a donor (Na2S.9H2O) significantly suppressed the manifestations of aging, reversed the effects of inhibitors and resulted in the complete suppression of oocyte fragmentation. Cultivation of aging oocytes in the presence of H2S donor positively affected their subsequent embryonic development following parthenogenetic activation. Although no unambiguous effects of exogenous H2S on MPF and MAPK activities were detected and the intracellular mechanism underlying H2S activity remains unclear, our study clearly demonstrates the role of H2S in the regulation of porcine oocyte aging.

Pyrrole‐Based Macrocyclic Small‐Molecule Inhibitors That Target Oocyte Maturation

“…Oocytes that failed to reach the MII stage are defined as “MI Arrested”, whereas oocytes with extruded polar bodies are denoted as “MII”. Statistically significant differences ( p <0.05, ANOVA) in oocyte maturation rates are indicated by the letters a, b, and c at top . B) Failure of parthenogenic embryo development caused by microinjection of macrocyclic compounds: oocytes injected with macrocyclic compounds ( 3 or 4 ), control compound (AB103‐8), or non‐injected control reached the MII stage, and were then subjected to parthenogenetic activation; their development to blastocyst stages were monitored and plotted.…”

“…Statistically significant differences( p < 0.05, ANOVA)i n oocytematuration rates are indicated by the letters a, b, and ca tt op. [16] B) Failure of parthenogenic embryo development caused by microinjection of macrocyclic compounds:oocytes injectedw ith macrocyclic compounds (3 or 4), control compound (AB103-8), or non-injected control reached the MII stage, and were then subjected to parthenogenetic activation; their development to blastocyst stageswere monitored and plotted. Embryosthat developed to the blastocyst stage were counteda s" BL Development", and embryosthatdid not reach the blastocyst stage wereclassified as "Development Failure".…”

Hydrogen Sulfide Impairs Meiosis Resumption in Xenopus laevis Oocytes

“…The differences in the expression profiles between the two species offer a first insight into the difference of oocyte behaviors toward H 2 S modulation in vertebrates. Another difference lies in the fact that while the H 2 S donor offered protective effects towards aging in porcine oocytes [20], NaHS did not improve the survival rate of metaphase II-blocked Xenopus oocytes. However, such differences may also arise from the different nature of the H 2 S donor used [22].…”

“…For each untreated or NaHS treated condition, ten oocytes were lysed at 4 • C in 5 µL pyridoxal 5-phosphate (0.2 M), 50 µL L-cystein (10 mM), 445 µL deionized water, and 250 µL of zinc acetate (1%), as described [20]. The reaction was started at 37 • C for 1 h and stopped by the addition of 250 µL of 50% trichloroacetic acid for 1 h at 37 • C. Samples were completed by addition of 133 µL N,N dimethyl-p-phenylenediamine sulphate (20 mM in 7.2 M HCl) and 133 µL FeCl3 (30 mM in 1.2 M HCl) to form methylene blue.…”

“…Few studies have been performed on the direct impact of H 2 S on oocytes. Recently, aging in porcine oocytes was prevented by H 2 S donors [20]. Although CBS, CSE, and MPST were observed in porcine oocytes [21], CBS was not detected in mice oocytes [6].…”