Related Experiment Video
Updated: Dec 2, 2025
Proteolytically Degraded Alginate Hydrogels and Hydrophobic Microbioreactors for Porcine Oocyte Encapsulation
Published on: July 30, 2020
Vitamin C Protects Porcine Oocytes From Microcystin-LR Toxicity During Maturation
Xue Zhang1, Changyin Zhou1, Weijian Li1
1Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China.
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.
Insights
Microcystin-leucine arginine (MC-LR), a toxic cyanotoxin, impairs livestock and human reproduction by damaging oocytes. Vitamin C (VC) supplementation offers partial protection against MC-LR-induced reproductive defects.
Area of Science:
- Environmental Toxicology
- Reproductive Biology
- Cellular Biology
Background:
- Microcystin-leucine arginine (MC-LR) is a prevalent and highly toxic cyanotoxin in aquatic environments.
- MC-LR bioaccumulates and poses risks to human and livestock health, yet its reproductive effects remain understudied.
- Cyanobacteria produce microcystins as metabolic byproducts, with MC-LR being the most potent variant.
Purpose of the Study:
- To investigate the detrimental effects of MC-LR exposure on porcine oocyte maturation and meiosis.
- To evaluate the protective efficacy of vitamin C (VC) against MC-LR-induced oocyte damage.
- To elucidate the molecular mechanisms underlying MC-LR toxicity in oocytes.
Main Methods:
- Porcine oocytes were utilized as a model system to assess MC-LR toxicity.
- Analysis of oocyte maturation, including cumulus cell expansion and first polar body extrusion.
- Microscopic examination of cytoskeleton dynamics (spindle organization, tubulin acetylation, actin polymerization) and mitochondrial function.
Main Results:
- MC-LR exposure significantly inhibited cumulus cell expansion and first polar body extrusion, indicating impaired oocyte maturation.
- MC-LR disrupted oocyte meiosis by causing aberrant spindle organization, reduced acetylated α-tubulin, and disturbed actin polymerization.
- MC-LR induced mitochondrial dysfunction, elevated oxidative stress, DNA damage, and early apoptosis, leading to epigenetic abnormalities.
Conclusions:
- MC-LR exerts significant toxic effects on oocyte meiosis, primarily through mitochondrial dysfunction, oxidative stress, DNA damage, and apoptosis.
- Vitamin C (VC) administration partially mitigates MC-LR-induced oocyte damage, suggesting a potential therapeutic role.
- VC supplementation may represent a viable strategy to improve oocyte quality in MC-LR-exposed individuals.
