Use of retinoids during oocyte maturation diminishes apoptosis in caprine embryos

Zhang

Proc. Natl. Acad. Sci. U.S.A.

et al. 2018

127

SignificanceMTOR (mechanistic target of rapamycin), an integrator of pathways important for cellular metabolism, proliferation, and differentiation, is expressed at all stages of oocyte development. Primordial oocytes constitute a nonproliferating, nongrowing reserve of potential eggs maintained for the entire reproductive lifespan of mammalian females. Using conditional knockouts, we determined the role of MTOR in both primordial and growing oocytes. MTOR-dependent pathways in primordial oocytes are not needed to sustain the viability of the primordial oocyte pool or their recruitment into the cohort of growing oocytes but are essential later for maintenance of oocyte genomic integrity, sustaining ovarian follicular development, and fertility. In growing oocytes, MTOR-dependent pathways are required for processes that promote completion of meiosis and enable embryonic development.

Section: Resultsmentioning

confidence: 99%

Oocyte stage-specific effects of MTOR determine granulosa cell fate and oocyte quality in mice

Zhang

Proc. Natl. Acad. Sci. U.S.A.

et al. 2018

127

“…The natural metabolites of retinol (RT) such as all- trans retinoic acid (t-RA) and 9- cis RA are collectively known as retinoids and are considered as non-enzymatic antioxidants (Guerin et al , 2001). Recent protocols have used these compounds in the culture medium of embryos taking into account their deep effect upon cellular survival, proliferation, differentiation and embryonic morphogenesis (Noy, 2010; Rajesh et al , 2010; Rhinn & Dollé, 2012; Conceição et al , 2015; Conceição et al , 2016). It was found that the addition of retinoids to the culture medium enhances the subsequent preimplantation embryonic development in bovine embryos (Lima et al , 2004; Ahmed et al , 2016), and in goat embryos (Duque et al , 2002a,b; Lima et al , 2006; Chiamenti et al , 2010, 2012; Conceição et al , 2015).…”

Section: Introductionmentioning

confidence: 99%

Antioxidant and developmental capacity of retinol on thein vitroculture of rabbit embryos

Elomda¹,

Saad²,

Saeed³

et al. 2018

Zygote

SummaryOxidative stress is a major cause of defective embryo development during in vitro culture. Retinoids are recognized as non-enzymatic antioxidants and may have an important role in the regulation of cell differentiation and vertebrate development. However, there are not enough reports discussing the antioxidant and developmental capacity of retinoids, including retinol (RT), on the in vitro development of embryos recovered from livestock animals, particularly in rabbit species. Therefore, morula embryos obtained from nulliparous Red Baladi rabbit does were cultured for 48 h in TCM199 medium in the absence of RT (control group) or in the presence of RT at concentrations of 10, 100 and 1000 nM. The developmental capacity to the hatched blastocyst stage, the antioxidant biomarker assay and the expression of several selected genes were analyzed in each RT group. The data show that RT significantly (P<0.001) promoted the embryo hatchability rate at the concentration of 1000 nM to 69.44% versus 29.71% for the control. The activity of malondialdehyde (MDA) level was significantly (P<0.05) lower in the RT groups than in the control group, while the total antioxidant capacity (TAC), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were significantly (P<0.05) higher following treatment with RT. Furthermore, RT treatment considerably upregulated the relative expression of gap junction protein alpha 1 (GJA1), POU class 5 homeobox 1 (POU5F1) and superoxide dismutase 1 (SOD1) genes compared with the control group. The current study highlights the potential effects of RT as antioxidant in the culture medium on the in vitro development of rabbit embryos.

“…RNA-seq analysis of the mTOR depleted oocytes discovered differential expression of 979 transcripts. Gene-enrichment analysis revealed down-regulation of genes controlling key oogeneic processes, oocyte mRNA decay, epigenetic and transcriptional control, cell cycle, microtubule-related processes, oocyte–granulosa communication as well as those involved in the development and survival of oocytes companion GC [ 32 , 33 , 34 , 35 , 36 , 37 ]. Genes associated with mRNA decay that could dysregulate the transcript dosage of certain key factors for oocyte and follicle development were upregulated.…”

Section: Novel Regulators Of Fulliculogenesismentioning

confidence: 99%

Newly Identified Regulators of Ovarian Folliculogenesis and Ovulation

Gershon

Dekel

2020

IJMS

116

Each follicle represents the basic functional unit of the ovary. From its very initial stage of development, the follicle consists of an oocyte surrounded by somatic cells. The oocyte grows and matures to become fertilizable and the somatic cells proliferate and differentiate into the major suppliers of steroid sex hormones as well as generators of other local regulators. The process by which a follicle forms, proceeds through several growing stages, develops to eventually release the mature oocyte, and turns into a corpus luteum (CL) is known as “folliculogenesis”. The task of this review is to define the different stages of folliculogenesis culminating at ovulation and CL formation, and to summarize the most recent information regarding the newly identified factors that regulate the specific stages of this highly intricated process. This information comprises of either novel regulators involved in ovarian biology, such as Ube2i, Phoenixin/GPR73, C1QTNF, and α-SNAP, or recently identified members of signaling pathways previously reported in this context, namely PKB/Akt, HIPPO, and Notch.