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Antioxidants (Basel, Switzerland) Mar 2023Aging has a major detrimental effect on the optimal function of the ovary with changes in this organ preceding the age-related deterioration in other tissues, with the... (Review)
Review
Aging has a major detrimental effect on the optimal function of the ovary with changes in this organ preceding the age-related deterioration in other tissues, with the middle-aged shutdown leading to infertility. Reduced fertility and consequent inability to conceive by women in present-day societies who choose to have children later in life leads to increased frustration. Melatonin is known to have anti-aging properties related to its antioxidant and anti-inflammatory actions. Its higher follicular fluid levels relative to blood concentrations and its likely synthesis in the oocyte, granulosa, and luteal cells suggest that it is optimally positioned to interfere with age-associated deterioration of the ovary. Additionally, the end of the female reproductive span coincides with a significant reduction in endogenous melatonin levels. Thus, the aims are to review the literature indicating melatonin production in mitochondria of oocytes, granulosa cells, and luteal cells, identify the multiple processes underlying changes in the ovary, especially late in the cessation of the reproductive life span, summarize the physiological and molecular actions of melatonin in the maintenance of normal ovaries and in the aging ovaries, and integrate the acquired information into an explanation for considering melatonin in the treatment of age-related infertility. Use of supplemental melatonin may help preserve fertility later in life and alleviate frustration in women delaying childbearing age, reduce the necessity of in vitro fertilization-embryo transfer (IVF-ET) procedures, and help solve the progressively increasing problem of non-aging-related infertility in women throughout their reproductive life span. While additional research is needed to fully understand the effects of melatonin supplementation on potentially enhancing fertility, studies published to date suggest it may be a promising option for those struggling with infertility.
PubMed: 36978942
DOI: 10.3390/antiox12030695 -
Frontiers in Physiology 2023The corpus luteum is a transient ovarian endocrine gland that produces the progesterone necessary for the establishment and maintenance of pregnancy. The formation and... (Review)
Review
The corpus luteum is a transient ovarian endocrine gland that produces the progesterone necessary for the establishment and maintenance of pregnancy. The formation and function of this gland involves angiogenesis, establishing the tissue with a robust blood flow and vast microvasculature required to support production of progesterone. Every steroidogenic cell within the corpus luteum is in direct contact with a capillary, and disruption of angiogenesis impairs luteal development and function. At the end of a reproductive cycle, the corpus luteum ceases progesterone production and undergoes rapid structural regression into a nonfunctional corpus albicans in a process initiated and exacerbated by the luteolysin prostaglandin F2α (PGF2α). Structural regression is accompanied by complete regression of the luteal microvasculature in which endothelial cells die and are sloughed off into capillaries and lymphatic vessels. During luteal regression, changes in nitric oxide transiently increase blood flow, followed by a reduction in blood flow and progesterone secretion. Early luteal regression is marked by an increased production of cytokines and chemokines and influx of immune cells. Microvascular endothelial cells are sensitive to released factors during luteolysis, including thrombospondin, endothelin, and cytokines like tumor necrosis factor alpha (TNF) and transforming growth factor β 1 (TGFB1). Although PGF2α is known to be a vasoconstrictor, endothelial cells do not express receptors for PGF2α, therefore it is believed that the angioregression occurring during luteolysis is mediated by factors downstream of PGF2α signaling. Yet, the exact mechanisms responsible for angioregression in the corpus luteum remain unknown. This review describes the current knowledge on angioregression of the corpus luteum and the roles of vasoactive factors released during luteolysis on luteal vasculature and endothelial cells of the microvasculature.
PubMed: 37841308
DOI: 10.3389/fphys.2023.1254943 -
Cell Proliferation Dec 2023Normal ovarian development is necessary for the production of healthy oocytes. However, the characteristics of oocytes development at different stages and the regulatory...
Normal ovarian development is necessary for the production of healthy oocytes. However, the characteristics of oocytes development at different stages and the regulatory relationship between oocytes and somatic cells remain to be fully explained. Here, we combined scRNA-seq and spatial transcriptomic sequencing to profile the transcriptomic atlas of developing ovarian of the rat. We identified four components from developing granulosa cells including cumulus, primitive, mural, and luteal cells, and constructed their differential transcriptional regulatory networks. Several novel growth signals from oocytes to cumulus cells were identified, such as JAG1-NOTCH2 and FGF9-FGFR2. Moreover, we observed three cumulus sequential phases during follicle development determined by the key transcriptional factors in each cumulus phase (Bckaf1, Gata6, Cebpb, etc.), as well as the potential pinpointed roles of macrophages in luteal regression. Altogether, the single-cell spatial transcriptomic profile of the ovary provides not only a new research dimension for temporal and spatial analysis of ovary development, but also valuable data resources and a research basis for in-depth excavation of the mechanisms of mammalian ovary development.
Topics: Female; Rats; Animals; Ovary; Oocytes; Granulosa Cells; Oogenesis; Transcriptome; Mammals
PubMed: 37309718
DOI: 10.1111/cpr.13516 -
Molecular and Cellular Endocrinology Jan 2022Glucose uptake increases in canine luteal cells under insulin treatment. We hypothesize that insulin also increases luteal cell steroidogenesis. Dogs underwent elective...
Glucose uptake increases in canine luteal cells under insulin treatment. We hypothesize that insulin also increases luteal cell steroidogenesis. Dogs underwent elective ovariohysterectomy from days 10-60 post ovulation and their corpora lutea (CL) and blood samples were collected. Deep RNA sequencing determined differentially expressed genes in CL; those related to insulin signaling and steroidogenesis were validated in vivo by qPCR and their respective proteins by Western blotting and immunofluorescence. Next, luteal cell cultures were stimulated with insulin with or without inhibition of MAPK14, MAP2K1 and PI3K. Studied proteins except P450 aromatase showed the same expression pattern of coding genes in vivo. The expression of HSD3B and CYP19A1 was higher in insulin-treated cells (P < 0.005). Following respective pathway blockades, the culture medium had decreased concentrations of progesterone (P4) and 17b-estradiol (E2) (P < 0.01). Our results indicate that insulin increases HSD3B and CYP19A1 expression via MAPK and PI3K, and contributes to the regulation of P4 and E2 production in canine luteal cells.
Topics: Animals; Cells, Cultured; Corpus Luteum; Dogs; Estradiol; Female; Glucose; Insulin; Luteal Cells; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Phosphatidylinositol 3-Kinases; Progesterone; Signal Transduction; Steroids
PubMed: 34808277
DOI: 10.1016/j.mce.2021.111518 -
Molecular Human Reproduction Jul 2023The corpus luteum is the major source of progesterone, the essential hormone for female reproductive function. While progesterone activity has been the subject of... (Review)
Review
The corpus luteum is the major source of progesterone, the essential hormone for female reproductive function. While progesterone activity has been the subject of extensive research for decades, characterization of non-canonical progesterone receptor/signaling pathways provided a new perspective for understanding the complex signal transduction mechanisms exploited by the progesterone hormone. Deciphering these mechanisms has significant implications in the management of luteal phase disorders and early pregnancy complications. The purpose of this review is to highlight the complex mechanisms through which progesterone-induced signaling mediates luteal granulosa cell activity in the corpus luteum. Here, we review the literature and discuss the up-to-date evidence on how paracrine and autocrine effects of progesterone regulate luteal steroidogenic activity. We also review the limitations of the published data and highlight future research priorities.
Topics: Female; Humans; Pregnancy; Corpus Luteum; Granulosa Cells; Hormones; Progesterone; Signal Transduction
PubMed: 37289566
DOI: 10.1093/molehr/gaad022 -
The Journal of Reproduction and... Dec 2022In mammals, the corpus luteum (CL) is a transient organ that secretes progesterone (P4). In the absence of pregnancy, the CL undergoes regression (luteolysis), which is...
In mammals, the corpus luteum (CL) is a transient organ that secretes progesterone (P4). In the absence of pregnancy, the CL undergoes regression (luteolysis), which is a crucial preparation step for the next estrous cycle. Luteolysis, initiated by uterine prostaglandin F (PGF) in cattle, is usually divided into two phases, namely functional luteolysis characterized by a decline in P4 concentration and structural luteolysis characterized by the elimination of luteal tissues from the ovary. Programmed cell death (PCD) of luteal cells, including luteal steroidogenic cells (LSCs) and luteal endothelial cells (LECs), plays a crucial role in structural luteolysis. The main types of PCD are caspase-dependent apoptosis (type 1), autophagic cell death (ACD) via the autophagy-related gene (ATG) family (type 2), and receptor-interacting protein kinase (RIPK)-dependent programmed necrosis (necroptosis, type 3). However, these PCD signaling pathways are not completely independent and interact with each other. Over the past several decades, most studies on luteolysis have focused on apoptosis as the principal mode of bovine luteal cell death. Recently, ATG family members were reported to be expressed in bovine CL, and their levels increased during luteolysis. Furthermore, the expression of RIPKs, which are crucial mediators of necroptosis, is reported to increase in bovine CL during luteolysis and is upregulated by pro-inflammatory cytokines in bovine LSCs and LECs. Therefore, apoptosis, ACD, and necroptosis may contribute to bovine CL regression. In this article, we present the recent findings regarding the mechanisms of the three main types of PCD and the contribution of these mechanisms to luteolysis.
Topics: Pregnancy; Female; Cattle; Animals; Luteolysis; Necroptosis; Autophagic Cell Death; Endothelial Cells; Dinoprost; Corpus Luteum; Apoptosis; Mammals
PubMed: 36384912
DOI: 10.1262/jrd.2022-097 -
PloS One 2022Reactivation of the hypothalamic-pituitary-ovarian (HPO) axis triggered by the decline in serum progesterone in mid-gestation is an uncommon trait that distinguishes the...
Reactivation of the hypothalamic-pituitary-ovarian (HPO) axis triggered by the decline in serum progesterone in mid-gestation is an uncommon trait that distinguishes the vizcacha from most mammals. Accessory corpora lutea (aCL) developed upon this event have been proposed as guarantors of the restoration of the progesterone levels necessary to mantain gestation. Therefore, the steroidogenic input of primary CL (pCL) vs aCL was evaluated before and after HPO axis-reactivation (BP and AP respectively) and in term pregnancy (TP). Nonpregnant-ovulated females (NP) were considered as the pCL-starting point group. In BP, the ovaries mainly showed pCL, whose LH receptor (LHR), StAR, 3β-HSD, 20α-HSD, and VEGF immunoexpressions were similar or lower than those of NP. In AP, luteal reactivity increased significantly compared to the previous stages, and the pool of aCL developed in this stage represented 20% of the ovarian structures, equaling the percentage of pCL. Both pCL and aCL luteal cells shared similar histological features consistent with secretory activity. Although pCL and aCL showed equivalent labeling intensity for the luteotropic markers, pCL were significantly larger than aCL. Towards TP, both showed structural disorganization and loss of secretory characteristics. No significant DNA fragmentation was detected in luteal cells throughout gestation. Our findings indicate that the LH surge derived from HPO axis-reactivation targets the pCL and boost luteal steroidogenesis and thus progesterone production. Because there are many LHR-expressing antral follicles in BP, they also respond to the LH stimuli and luteinize without extruding the oocyte. These aCL certainly contribute but it is the steroidogenic restart of the pCL that is the main force that restores progesterone levels, ensuring that gestation is carried to term. Most importantly, the results of this work propose luteal steroidogenesis reboot as a key event in the modulation of vizcacha pregnancy and depict yet another distinctive aspect of its reproductive endocrinology.
Topics: Animals; Corpus Luteum; Female; Luteal Cells; Luteinizing Hormone; Pregnancy; Progesterone; Receptors, LH; Rodentia
PubMed: 35802690
DOI: 10.1371/journal.pone.0271067 -
Fertility and Sterility Jun 2014MicroRNAs have recently begun to be explored in ovarian cells, uncovering their influence on fundamental ovarian features like steroidogenesis, ovulation, and curpos... (Review)
Review
MicroRNAs have recently begun to be explored in ovarian cells, uncovering their influence on fundamental ovarian features like steroidogenesis, ovulation, and curpos luteum development and function. We provide a review of the current knowledge on microRNAs, specifically relating to human ovarian cell function and microRNAs' role in the ovarian physiologic process and ovulation dysfunction. Because of microRNAs' known stability in body fluids, we enlighten also their potential use in the clinical setting as novel biomarkers for ovarian function. Future research of the role of microRNAs in physiologic and dysfunctional ovulation may offer new diagnostic and treatment strategies for infertility and other ovarian disorders.
Topics: Animals; Cumulus Cells; DEAD-box RNA Helicases; Female; Fertility; Gene Expression Regulation; Humans; Infertility, Female; Luteal Cells; MicroRNAs; Oocytes; Ovarian Diseases; Ovary; Ovulation; Pregnancy; Ribonuclease III; Signal Transduction
PubMed: 24882616
DOI: 10.1016/j.fertnstert.2014.04.024 -
Scientific Reports Jul 2021In mammalian ovaries, mitochondria are integral sites of energy production and steroidogenesis. While shifts in cellular activities and steroidogenesis are well...
In mammalian ovaries, mitochondria are integral sites of energy production and steroidogenesis. While shifts in cellular activities and steroidogenesis are well characterized during the differentiation of large luteal cells in folliculogenesis and luteal formation, mitochondrial dynamics during this process have not been previously evaluated. In this study, we collected ovaries containing primordial follicles, mature follicles, corpus hemorrhagicum, or corpus luteum from goats at specific times in the estrous cycle. Enzyme histochemistry, ultrastructural observations, and 3D structural analysis of serial sections of mitochondria revealed that branched mitochondrial networks were predominant in follicles, while spherical and tubular mitochondria were typical in large luteal cells. Furthermore, the average mitochondrial diameter and volume increased from folliculogenesis to luteal formation. In primordial follicles, the signals of cytochrome c oxidase and ATP synthase were undetectable in most cells, and the large luteal cells from the corpus hemorrhagicum also showed low enzyme signals and content when compared with granulosa cells in mature follicles or large luteal cells from the corpus luteum. Our findings suggest that the mitochondrial enlargement could be an event during folliculogenesis and luteal formation, while the modulation of mitochondrial morphology and respiratory enzyme expressions may be related to tissue remodeling during luteal formation.
Topics: Animals; Female; Goats; Lipogenesis; Luteal Cells; Mitochondrial Dynamics
PubMed: 34330986
DOI: 10.1038/s41598-021-95161-w