Melatonin Restores the Developmental Competence of Heat Stressed Porcine Oocytes, and Alters the Expression of Genes Related to Oocyte Maturation

Abstract

Melatonin enhances the quality and in vitro maturation (IVM) of oocytes under heat stress (HS), but the mechanism of melatonin in reducing HS injury on oocytes is not fully understood. In this study, porcine cumulus-oocyte complexes (COCs) were randomly divided into three groups. The COCs of the control group were cultured at 38.5 °C for 42 h, and the COCs of the HS group were cultured at 41.5 °C for 4 h, and then transferred into 38.5 °C for 38 h. The COCs of the HS + melatonin group were cultured with 10−9 M melatonin under the same conditions as the HS group. The survival rate, maturation rate, distribution of α-tubulin and F-actin of the oocytes were assessed. In addition, the expression profiles for genes related to the oocyte maturation, including heat shock protein 70 (HSP70), nuclear factor erythroid 2-related factor 2 (NRF2), cyclin-dependent kinase 1 (CDK1), growth differentiation factor 9 (GDF9) were analyzed by real-time quantitative PCR. The results showed that HS decreased the survival rate and maturation rate, distribution of α-tubulin and F-actin, but melatonin treatment could partly counteract these adverse effects. In addition, HS increased expression of HSP70 and NRF2 mRNA, and melatonin treatment had a similar effect on HSP70 expression, but had a contrary effect on NRF2 expression. Furthermore, HS inhibited expression of CDK1 and GDF9 mRNA, but melatonin treatment could weaken the effect on GDF9 expression induced by HS. In summary, melatonin treatment could attenuate the unfavorable effects induced by HS to enhance developmental competence of porcine oocytes during IVM.

NRF2 attenuation aggravates detrimental consequences of metabolic stress on cultured porcine parthenote embryos

“…It is well established that antioxidant supplementation improves porcine embryo development 22 , 50 . Melatonin was chosen as the antioxidant for this study due to its known effects in ameliorating oocyte maturation and embryo development 18 , 21 , 27 , 30 , mitigating the detrimental consequences of excess glucose on embryo development, improving glucose metabolism in adult mice by upregulating hepatic FBXL7 expression 20 , and its proposed role in alleviating oxidative stress through NRF2 28 – 30 . However, based on the concentration used in our study (100 nM), we were unable to observe a significant impact of melatonin on embryo development and embryo quality, or a clear link between melatonin and NRF2.…”

“…Melatonin has been suggested to mitigate fertility decline and reduce ovarian aging 25 . It has also been shown to improve the developmental competence of porcine oocytes and embryos 18 , 19 , 21 , 26 , 27 . Additionally, melatonin has been found to modulate histone acetylation levels 18 , and regulate lipid metabolism by influencing the expression of key genes involved in lipid metabolism, ATP content, and lipid droplet size 26 .…”

The effect of melatonin on the Bcl-2 and Bad proteins expression in ovarian corpus luteum cells after exposure to experimental hyperthermia

“…вает пагубное влияние на потенциал развития ооцитов у свиней, мышей, крупного рогатого скота, включая неблагоприятное воздействие на выживаемость, скорость созревания и мейотическую компетентность ооцитов, образование в них F-актина и α-тубулина, экспрессию генов NRF2, CDK1 и GDF9 [17]. МТ представляет собой плейотропную молекулу, которая регулирует различные процессы, включая беременность.…”

“…МТ представляет собой плейотропную молекулу, которая регулирует различные процессы, включая беременность. Применение МТ в условиях теплового стресса у свиней улучшает качество и скорость созревания ооцитов (частично за счёт восстановления распределения F-актина) [17], оказывает положительное влияние на продолжительность эстрального периода и выживаемость эмбрионов [18]. Использование МТ снижает выработку АФК в созревающих ооцитах крупного рогатого скота и повышает способность к развитию эмбрионов из ооцитов, подвергшихся тепловому шоку [17].…”

Melatonin and Pathological Cell Interactions: Mitochondrial Glucose Processing in Cancer Cells

“…The first experimental documentation of melatonin formation in mitochondria was reported by He et al [112]. This group isolated and purified mitochondria from mouse oocytes, a cell in which melatonin is essential for its maturation and one in which oxidative damage must be held to a minimum to ensure a normal fetus [113,114]. Oocyte mitochondria were incubated in the presence or absence of serotonin (5-hydroxytryptamine, 5-HT), a necessary substrate for the rate-limiting enzyme, arylalkylamine N-acetyltransferase (AANAT), in melatonin synthesis.…”