Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Apr 1;99(4):skab072.
doi: 10.1093/jas/skab072.

Glycine ameliorates mitochondrial dysfunction caused by ABT-199 in porcine oocytes

Sicong Yu  1 , Lepeng Gao  1 , Yang Song  1 , Xin Ma  1 , Shuang Liang  2 , Hainan Lan  1 , Xin Zheng  1 , Suo Li  1
Affiliations

Glycine ameliorates mitochondrial dysfunction caused by ABT-199 in porcine oocytes

Sicong Yu et al. J Anim Sci. .

Abstract

Mitochondria play an important role in controlling oocyte developmental competence. Our previous studies showed that glycine (Gly) can regulate mitochondrial function and improve oocyte maturation in vitro. However, the mechanisms by which Gly affects mitochondrial function during oocyte maturation in vitro have not been fully investigated. In this study, we induced a mitochondrial damage model in oocytes with the Bcl-2-specific antagonist ABT-199. We investigated whether Gly could reverse the mitochondrial dysfunction caused by ABT-199 exposure and whether it is related to calcium regulation. Our results showed that ABT-199 inhibited cumulus expansion, decreased the oocyte maturation rate and the intracellular glutathione (GSH) level, caused mitochondrial dysfunction, which was confirmed by decreased mitochondrial membrane potential (ΔΨm) and the expression of mitochondrial function-related genes PGC-1α, and increased reactiveoxygenspecies (ROS) levelsand the expression of apoptosis-associated genes Bax, Caspase-3, and Cyto C.More importantly, ABT-199-treated oocytes showed an increase in the intracellular free calcium concentration ([Ca2+]i) and had impaired cortical type 1 inositol 1,4,5-trisphosphate receptors (IP3R1) distribution. Nevertheless, treatment with Gly significantly ameliorated mitochondrial dysfunction, oxidative stress, and apoptosis, and Gly also regulated [Ca2+]i levels and IP3R1 cellular distribution, which further protects oocyte maturation in ABT-199-induced porcine oocytes.Taken together, our results indicate that Gly has a protective action against ABT-199-induced mitochondrial dysfunction in porcine oocytes.

Keywords: apoptosis; calcium; glycine; mitochondria; oocyte; oxidative stress.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Effectof Gly on cumulus expansion of porcine oocytes treated with ABT-199. Measurement of cumulus cell expansion in COCs after ABT-199 treatment or Gly supplementation. (A) The morphology of COCs matured in vitro. (B) The vertical and horizontal diameters of mature COC cumulus cells were measured in all groups and are presented as the mean ± SEM, n = 3 experimental replicates with more than 30 COCs per treatment group. Bar = 200 μm. Different letters (a, b) above bars show significant differences (P < 0.05).
Figure 2.
Figure 2.
Effect of Gly on GSH and ROS levels in porcine oocytes treated with ABT-199. (A) Immunofluorescent staining of GSH and ROS in MII porcine oocytes after ABT-199 treatment or Gly supplementation. Blue, GSH; green, ROS. Bar = 200 µm. (B-C) Fluorescence intensity analysis of the GSH and ROS signals by ImageJ software. Data are presented as mean ± SEM. Different letters (a–d) above bars show significant differences (P < 0.05).
Figure 3.
Figure 3.
Effect of Gly on mitochondrial ΔΨm inporcine oocytes treated with ABT-199. (A) MitoTracker Red CMXRos signals in MII porcine oocytes after ABT-199 treatment or Gly supplementation. Red, MitoTracker Red CMXRos; blue, DNA. Bar = 200 µm. (B) Fluorescence intensity analysis of the MitoTracker Red CMXRos signal by ImageJ software. Data are presented as mean ± SEM. Different letters (a and b) above bars show significant differences (P < 0.05).
Figure 4.
Figure 4.
Effect of Gly on Ca2+ levels in porcine oocytes treated with ABT-199. (A) The [Ca2+]i in MII porcine oocytes was detected by immunostaining with 5 μM Fluo-3/AM after ABT-199 treatment or Gly supplementation. (B) Fluorescence intensity analysis of the Fluo-3AM signal by ImageJ software. Data are presented as mean ± SEM. Different letters (a–c) above bars show significant differences (P < 0.05).
Figure 5.
Figure 5.
Effect of Gly on IP3R1 cellular distribution in porcine oocytes treated with ABT-199. IP3R1 cellular distribution pattern after ABT-199 treatment or Gly supplementation. IP3R1 (green), DNA (blue), and merged images in MII oocytes.
Figure 6.
Figure 6.
Effect of Gly on apoptosis in porcine oocytes treated with ABT-199. (A) The Caspase-3 activities and Annexin-V signals in MII porcine oocytes after ABT-199 treatment or Gly supplementation. Green, GreenNuc Caspase-3 substrate; Red, Annexin-V-mCherry. Bar = 20 µm. (B) Fluorescence intensity analysis of the Caspase-3 activities by ImageJ software. (C) Fluorescence intensity analysis of the Annexin-V signals by ImageJ software. Data are presented as mean ± SEM. Different letters (a and b) above bars show significant differences (P < 0.05).
Figure 7.
Figure 7.
Effect of Gly on mitochondrial function and apoptosis in porcine oocytes treated with ABT-199. (A) The relative mRNA expression of mitochondrial function-related genes after ABT-199 treatment or Gly supplementation. (B, C) The relative mRNA expression of apoptosis-related genes after ABT-199 treatment or Gly supplementation.
Figure 8.
Figure 8.
Schematic representation of ABT-199 exposure and Gly treatment on porcine oocytes maturation.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Antignani, A., and Youle R. J.. . 2006. How do Bax and Bak lead to permeabilization of the outer mitochondrial membrane? Curr. Opin. Cell Biol. 18:685–689. doi:10.1016/j.ceb.2006.10.004 - DOI - PubMed
    1. Bhatti, J. S., Bhatti G. K., and Reddy P. H.. . 2017. Mitochondrial dysfunction and oxidative stress in metabolic disorders – a step towards mitochondria based therapeutic strategies. Biochim. Biophys. Acta - Mol. Basis Dis. 1863(5). doi:10.1016/j.bbadis.2016.11.010 - DOI - PMC - PubMed
    1. Brevini, A. L. T., R. Vassena, C. Francisci, and F. Gandolfi. 2005. Role of adenosine triphosphate, active mitochondria, and microtubules in the acquisition of developmental competence of parthenogenetically activated pig oocytes. Biol. Reprod. 72:1218– 1223. doi:10.1095/biolreprod.104.038141 - DOI - PubMed
    1. Cao, X.-Y.,, et al. 2016. Glycine increases preimplantation development of mouse oocytes following vitrification at the germinal vesicle stage. Sci. Rep. 6:37262. doi:10.1038/srep37262 - DOI - PMC - PubMed
    1. Chen, R.,, et al. 2004. Bcl-2 functionally interacts with inositol 1,4,5-trisphosphate receptors to regulate calcium release from the ER in response to inositol 1,4,5-trisphosphate. J. Cell Biol. 2004;166(2):193–203. doi:10.1186/1742-4690-7-S1-P135 - DOI - PMC - PubMed