Vitamin C Protects Porcine Oocytes From Microcystin-LR Toxicity During Maturation

Abstract

Microcystin-leucine arginine (MC-LR) is the most toxic cyanotoxin found in water bodies. Microcystins are produced as secondary products of cyanobacteria metabolism. They have a stable structure, and can bioaccumulate in living organisms. Humans and livestock who drink fresh water containing MC-LR can be poisoned. However, few studies have reported the effects of MC-LR exposure on livestock or human reproduction. In this study, we used porcine oocytes as a model to explore the effects of MC-LR on oocyte maturation, and studied the impact of vitamin C (VC) administration on MC-LR-induced meiosis defects. Exposure to MC-LR significantly restricted cumulus cell expansion and decreased first polar body extrusion. Further studies showed that MC-LR exposure led to meiosis arrest by disturbing cytoskeleton dynamics with MC-LR exposed oocytes displaying aberrant spindle organization, low levels of acetylate α-tubulin, and disturbed actin polymerization. Additionally, MC-LR exposure impaired cytoplasmic maturation by inducing mitochondria dysfunction. Moreover, MC-LR also produced abnormal epigenetic modifications, and induced high levels of oxidative stress, caused DNA damage and early apoptosis. The administration of VC provided partial protection from all of the defects observed in oocytes exposed to MC-LR. These results demonstrate that MC-LR has a toxic effect on oocyte meiosis through mitochondrial dysfunction-induced ROS, DNA damage and early apoptosis. Supplementation of VC is able to protect against MC-LR-induced oocyte damage and represents a potential therapeutic strategy to improve the quality of MC-LR-exposed oocytes.

Beneficial Effect of Selenium Doped Carbon Quantum Dots Supplementation on the in vitro Development Competence of Ovine Oocytes

“…The epigenetic alterations induced by advanced maternal aging, mitochondrial dysfunctions, abnormal nutrition supply and abnormal expression levels of hormones trigger seriously meiotic defects of mammalian gametes, subsequently resulting in the incidence of aneuploidy after fertilization and embryonic development defects. 17 In consistent with our present study, these former literature have revealed that the promotion of epigenetic modifications via the amelioration of mitochondrial dysfunctions significantly improved the development potentials of mammalian oocytes, 16,17,[64][65][66] further addressing the future applications of Se/CDs as dietary supplementation in mammalian IVM via the promotion of epigenetic modifications. However, the specific regulation mechanism related to the effect of Se/CDs' supplementation in the epigenetic modifications of ovine MII oocytes and the potential effect of Se/CDs' supplementation on the epigenetic modifications of ovine zygote and/or blastocyst need more detailed investigations.…”

Tea polyphenols alleviate the adverse effects of diabetes on oocyte quality

“…Food & Function more ROS in oocytes because ROS is a byproduct of mitochondrial oxidative phosphorylation. [41][42][43] In this study, we found that the ROS concentration in diabetic oocytes was higher compared with the control. The excessive accumulation of ROS in diabetic oocytes is also demonstrated by other studies and the higher ROS level is deleterious to oocyte maturation, leading to DNA damage.…”

Mogroside V Protects Porcine Oocytes From Lipopolysaccharide-Induced Meiotic Defects

“…As expected, we observed that MV reduced ROS levels and increased the expression of antioxidant genes ( CAT and GPx1 ) in LPS-exposed oocytes. Excessive ROS accumulation originating from the external microenvironment and cellular metabolism may cause oxidative stress and further induce early apoptosis in oocytes ( Pandey et al, 2010 ; Jia et al, 2019 ; Zhang et al, 2020 ). Moreover, we found that MV reduced the occurrence of early apoptosis caused by LPS exposure.…”