-
Endocrinology Apr 2021Luteinizing hormone (LH) via protein kinase A (PKA) triggers ovulation and formation of the corpus luteum, which arises from the differentiation of follicular granulosa...
Luteinizing hormone (LH) via protein kinase A (PKA) triggers ovulation and formation of the corpus luteum, which arises from the differentiation of follicular granulosa and theca cells into large and small luteal cells, respectively. The small and large luteal cells produce progesterone, a steroid hormone required for establishment and maintenance of pregnancy. We recently reported on the importance of hormone-sensitive lipase (HSL, also known as LIPE) and lipid droplets for appropriate secretory function of the corpus luteum. These lipid-rich intracellular organelles store cholesteryl esters, which can be hydrolyzed by HSL to provide cholesterol, the main substrate necessary for progesterone synthesis. In the present study, we analyzed dynamic posttranslational modifications of HSL mediated by PKA and AMP-activated protein kinase (AMPK) as well as their effects on steroidogenesis in luteal cells. Our results revealed that AMPK acutely inhibits the stimulatory effects of LH/PKA on progesterone production without reducing levels of STAR, CYP11A1, and HSD3B proteins. Exogenous cholesterol reversed the negative effects of AMPK on LH-stimulated steroidogenesis, suggesting that AMPK regulates cholesterol availability in luteal cells. AMPK evoked inhibitory phosphorylation of HSL (Ser565). In contrast, LH/PKA decreased phosphorylation of AMPK at Thr172, a residue required for its activation. Additionally, LH/PKA increased phosphorylation of HSL at Ser563, which is crucial for enzyme activation, and decreased inhibitory phosphorylation of HSL at Ser565. The findings indicate that LH and AMPK exert opposite posttranslational modifications of HSL, presumptively regulating cholesterol availability for steroidogenesis.
Topics: AMP-Activated Protein Kinases; Amino Acid Motifs; Animals; Cattle; Cholesterol; Cyclic AMP-Dependent Protein Kinases; Enzyme Activation; Female; Luteal Cells; Luteinizing Hormone; Phosphorylation; Progesterone; Signal Transduction
PubMed: 33502468
DOI: 10.1210/endocr/bqab015 -
International Journal of Molecular... Sep 2021The corpus luteum is an endocrine gland that synthesizes the steroid hormone progesterone. luteinizing hormone (LH) is a key luteotropic hormone that stimulates... (Review)
Review
The corpus luteum is an endocrine gland that synthesizes the steroid hormone progesterone. luteinizing hormone (LH) is a key luteotropic hormone that stimulates ovulation, luteal development, progesterone biosynthesis, and maintenance of the corpus luteum. Luteotropic and luteolytic factors precisely regulate luteal structure and function; yet, despite recent scientific progress within the past few years, the exact mechanisms remain largely unknown. In the present review, we summarize the recent progress towards understanding cellular changes induced by LH in steroidogenic luteal cells. Herein, we will focus on the effects of LH on inter-organelle communication and steroid biosynthesis, and how LH regulates key protein kinases (i.e., AMPK and MTOR) responsible for controlling steroidogenesis and autophagy in luteal cells.
Topics: Animals; Autophagy; Corpus Luteum; Female; Humans; Luteal Cells; Luteinizing Hormone; Organelles; Signal Transduction
PubMed: 34576135
DOI: 10.3390/ijms22189972 -
Biology of Reproduction Oct 2019Transient receptor potential cation channel, mucolipin subfamily, member 1 (TRPML1) (MCOLN1/Mcoln1) is a lysosomal counter ion channel. Mutations in MCOLN1 cause...
Transient receptor potential cation channel, mucolipin subfamily, member 1 (TRPML1) (MCOLN1/Mcoln1) is a lysosomal counter ion channel. Mutations in MCOLN1 cause mucolipidosis type IV (MLIV), a progressive and severe lysosomal storage disorder with a slow onset. Mcoln1-/- mice recapitulate typical MLIV phenotypes but roles of TRPML1 in female reproduction are unknown. Despite normal mating activities, Mcoln1-/- female mice had reduced fertility at 2 months old and quickly became infertile at 5 months old. Progesterone deficiency was detected on 4.5 days post coitum/gestation day 4.5 (D4.5). Immunohistochemistry revealed TRPML1 expression in luteal cells of wild type corpus luteum (CL). Corpus luteum formation was not impaired in 5-6 months old Mcoln1-/- females indicated by comparable CL numbers in control and Mcoln1-/- ovaries on both D1.5 and D4.5. In the 5-6 months old Mcoln1-/- ovaries, histology revealed less defined corpus luteal cord formation, extensive luteal cell vacuolization and degeneration; immunofluorescence revealed disorganized staining of collagen IV, a basal lamina marker for endothelial cells; Nile Red staining detected lipid droplet accumulation, a typical phenotype of MLIV; immunofluorescence of heat shock protein 60 (HSP60, a mitochondrial marker) and in situ hybridization of steroidogenic acute regulatory protein (StAR, for the rate-limiting step of steroidogenesis) showed reduced expression of HSP60 and StAR, indicating impaired mitochondrial functions. Luteal cell degeneration and impaired mitochondrial functions can both contribute to progesterone deficiency in the Mcoln1-/- mice. This study demonstrates a novel function of TRPML1 in maintaining CL luteal cell integrity and function.
Topics: Animals; Corpus Luteum; Disease Models, Animal; Female; Infertility; Luteal Cells; Lysosomal Storage Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mucolipidoses; Progesterone; Transient Receptor Potential Channels
PubMed: 31317194
DOI: 10.1093/biolre/ioz126 -
Animal : An International Journal of... May 2023This manuscript reviews the mechanisms that maintain the corpus luteum (CL) of pregnancy in ruminants. In mammals, ovulation and luteinization of the remaining cells in... (Review)
Review
This manuscript reviews the mechanisms that maintain the corpus luteum (CL) of pregnancy in ruminants. In mammals, ovulation and luteinization of the remaining cells in the CL are due to a surge in Luteinizing Hormone (LH). In cattle, continued secretion of pulses of LH is essential for full development and function of the CL during the estrous cycle (LH pulses), however, the few studies on the CL after d20 of pregnancy do not indicate that LH is essential for maintaining the CL of pregnancy. The first essential step in maintaining the CL of pregnancy in ruminants is overcoming the mechanisms that cause regression of the CL in non-pregnant ruminants (d18-25 in cattle; d13-21 in sheep). These mechanisms have a uterine component involving oxytocin-induced prostaglandin F2α (PGF2A) pulses and a luteal component involving decreased progesterone production and luteal cell death. There is a critical role for embryonic interferon-tau (IFNT) in suppressing the uterine secretion of PGF2A during early pregnancy (d13-21 in sheep; d16-25 in cattle) and preventing luteolysis. There are also effects of IFNT on the expression of interferon-stimulated genes in other tissues including the CL but the physiologic role of these interferon-stimulated genes is not yet clear. After the IFNT period, there is another mechanism that maintains the CL of pregnancy in ruminants since embryonic IFNT is inhibited as attachment occurs and trophoblastic binucleate/giant cells begin secretion of pregnancy-associated glycoproteins. The second mechanism for luteal maintenance has not yet been defined but acts in a local manner (ipsilateral to pregnancy), and remains functional from d25 until just before parturition. The most likely mechanisms mediating later maintenance of the CL of pregnancy are increased uterine blood flow or decreased prostaglandin transporter expression in the utero-ovarian vasculature, preventing PGF2A reaching the CL. Finally, implications of these ideas on pregnancy loss in cattle are explored, highlighting the importance of inappropriate regression of the CL of pregnancy as a mechanism for pregnancy loss in cattle.
Topics: Pregnancy; Female; Cattle; Sheep; Animals; Corpus Luteum; Ruminants; Progesterone; Luteolysis; Ovary; Luteinizing Hormone; Dinoprost
PubMed: 37567676
DOI: 10.1016/j.animal.2023.100827 -
The Journal of Clinical Endocrinology... Jul 2017Inadequate progesterone production from the corpus luteum is associated with pregnancy loss. Data available in model species suggest important roles of microRNAs...
CONTEXT
Inadequate progesterone production from the corpus luteum is associated with pregnancy loss. Data available in model species suggest important roles of microRNAs (miRNAs) in luteal development and maintenance.
OBJECTIVE
To comprehensively investigate the involvement of miRNAs during the ovarian follicle-luteal transition.
DESIGN
The effects of specific miRNAs on survival and steroid production by human luteinized granulosa cells (hLGCs) were tested using specific miRNA inhibitors. Candidate miRNAs were identified through microarray analyses of follicular and luteal tissues in a bovine model.
SETTING
An academic institution in the United Kingdom associated with a teaching hospital. hLGCs were obtained by standard transvaginal follicular-fluid aspiration from 35 women undergoing assisted conception.
INTERVENTION(S)
Inhibition of candidate miRNAs in vitro.
MAIN OUTCOME MEASURE(S)
Levels of miRNAs, mRNAs, FOXO1 protein, apoptosis, and steroids were measured in tissues and/or cultured cells.
RESULTS
Two specific miRNA clusters, miR-183-96-182 and miR-212-132, were dramatically increased in luteal relative to follicular tissues. miR-96 and miR-132 were the most upregulated miRNAs within each cluster. Database analyses identified FOXO1 as a putative target of both these miRNAs. In cultured hLGCs, inhibition of miR-96 increased apoptosis and FOXO1 protein levels, and decreased progesterone production. These effects were prevented by small interfering RNA-mediated downregulation of FOXO1. In bovine luteal cells, miR-96 inhibition also led to increases in apoptosis and FOXO1 protein levels.
CONCLUSIONS
miR-96 targets FOXO1 to regulate luteal development through effects on cell survival and steroid production. The miR-183-96-182 cluster could provide a novel target for the manipulation of luteal function.
Topics: Animals; Apoptosis; Cattle; Cell Survival; Cells, Cultured; Female; Forkhead Box Protein O1; Gene Expression Profiling; Gene Expression Regulation; Granulosa Cells; Humans; Luteal Cells; MicroRNAs; Ovarian Follicle; Progesterone; Species Specificity; Up-Regulation
PubMed: 28368475
DOI: 10.1210/jc.2017-00259 -
Fertility and Sterility Nov 2010To evaluate estrogens (Es)--E2, estrone (E1), and estriol--and androgens--T and androstendione (A)-effect on P, prostaglandin (PG) F2α, PGE2, and vascular endothelial...
OBJECTIVE
To evaluate estrogens (Es)--E2, estrone (E1), and estriol--and androgens--T and androstendione (A)-effect on P, prostaglandin (PG) F2α, PGE2, and vascular endothelial growth factor (VEGF) release and on VEGF expression in human luteal cells. To elucidate whether androgens effects were direct or mediated by their conversion in Es, an aromatase inhibitor was used. Finally, the luteal effect of the non-aromatizable dihydrotestosterone was evaluated.
DESIGN
Prospective laboratory study.
SETTING
University hospital.
PATIENT(S)
Corpora lutea (CLs) were obtained from 36 normally menstruating patients in the midluteal phase of the menstrual cycle.
INTERVENTION(S)
The human luteal cells were isolated from CLs and primary cultures were established.
MAIN OUTCOME MEASURE(S)
P and PG release were assayed by enzyme immunoassay; VEGF secretion by ELISA; VEGF messenger RNA (mRNA) expression by real-time polymerase chain reaction (PCR).
RESULT(S)
P and PGF2α secretion were decreased by Es and androgens. The VEGF release was increased by Es and androgens, whereas VEGF mRNA expression was not. The aromatase inhibitor counteracted T and A luteal effects.
CONCLUSION(S)
Both Es and androgens could participate in the regulation of human luteal function. The effect of T and A seems to be mediated by their conversion to Es, whereas for dihydrotestosterone, both direct androgenic and indirect estrogenic luteal effects could coexist.
Topics: Adult; Androgens; Aromatase Inhibitors; Cells, Cultured; Dinoprost; Drug Evaluation, Preclinical; Estrogens; Female; Humans; Luteal Cells; Progesterone; Testosterone; Vascular Endothelial Growth Factor A
PubMed: 20307879
DOI: 10.1016/j.fertnstert.2010.02.009 -
Frontiers in Endocrinology 2019Although the corpus luteum (CL) contains high concentrations of lipid in the form of steroid hormone precursors and prostaglandins, little is known about the abundance...
Although the corpus luteum (CL) contains high concentrations of lipid in the form of steroid hormone precursors and prostaglandins, little is known about the abundance or function of other luteal lipid mediators. To address this, 79 lipid mediators were measured in bovine CL, using ultra performance liquid chromatography-tandem mass spectrometry. CL from estrous cycle days 4, 11, and 18 were compared and, separately, CL from days 18 of the estrous cycle and pregnancy were compared. Twenty-three lipids increased as the estrous cycle progressed ( < 0.05), with nine increasing between days 4 and 11 and fourteen increasing between days 4 and 18. Overall, this indicated a general upregulation of lipid mediator synthesis as the estrous cycle progressed, including increases in oxylipins and endocannabinoids. Only 15-KETE was less abundant in the CL of early pregnancy ( < 0.05), with a tendency ( < 0.10) for four others to be less abundant. Notably, 15-KETE also increased between estrous cycle days 4 and 18. Ingenuity Pathway Analysis (IPA, Qiagen) indicated that functions associated with differentially abundant lipids during the estrous cycle included leukocyte activation, cell migration, and cell proliferation. To investigate changes in CL during maternal recognition of pregnancy, this lipid dataset was integrated with a published dataset from mRNA profiling during maternal recognition of pregnancy. This analysis indicated that lipids and mRNA that changed during maternal recognition of pregnancy may regulate some of the same functions, including immune cell chemotaxis and cell-cell communication. To assess effects of these lipid mediators, luteal cells were cultured with 5-KETE or 15-KETE. One ng/mL 5-KETE reduced luteal progesterone on day 1 of culture, only in the absence of luteinizing hormone (LH), while 1 ng/mL 15-KETE induced progesterone only in the presence of LH (10 ng/mL). On day 7 of culture, 0.1 ng/mL 15-KETE reduced prostaglandin (PG)F2A-induced inhibition of LH-stimulated progesterone production, while 1 ng/mL 15-KETE did not have this effect. Overall, these data suggest a role for lipid mediators during luteal development and early pregnancy, as regulators of steroidogenesis, immune cell activation and function, intracellular signaling, and cell survival and death.
PubMed: 31636603
DOI: 10.3389/fendo.2019.00662 -
Frontiers in Bioscience (Landmark... Jan 2012The steroidogenic acute regulatory protein, cytochrome P450 cholesterol side-chain cleavage enzyme and specific 3beta-hydroxysteroid dehydrogenase/delta5-delta4... (Review)
Review
The steroidogenic acute regulatory protein, cytochrome P450 cholesterol side-chain cleavage enzyme and specific 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerases initiate the essential process of steroidogenesis in the gonads. Testicular and ovarian expression of their respective genes, STARD1, CYP11A1 and gonadal HSD3B, is primarily controlled by gonadotropins with contributions by various growth factors. Gonadotropins through their receptors switch on cyclic AMP signaling pathways that recruit NR5A, GATA and often CREB, NR4A, or Sp1 transcription factors to regulatory regions of each gene's promoter to elicit transcription. The specific combination of transcription factors involved depends on the cellular context. In this review, we summarize current understanding of the factors that control transactivation of the STARD1, CYP11A1 and gonadal HSD3B genes in Leydig cells in the testis and the theca, differentiating granulosa and luteal cells in the ovary.
Topics: Animals; Cholesterol Side-Chain Cleavage Enzyme; Female; Granulosa Cells; Humans; Leydig Cells; Luteal Cells; Male; Multienzyme Complexes; Ovary; Phosphoproteins; Progesterone Reductase; Steroid Isomerases; Steroids; Testis; Transcriptional Activation
PubMed: 22201776
DOI: 10.2741/3959 -
Animals : An Open Access Journal From... Apr 2021Intermediate filaments (IFs) maintain cell-cell adhesions and are involved in diverse cellular processes such as cytokinesis, cell migration and the maintenance of cell...
Intermediate filaments (IFs) maintain cell-cell adhesions and are involved in diverse cellular processes such as cytokinesis, cell migration and the maintenance of cell structure. In this study, we investigated the influence of prostaglandin F2 alpha (PGF2α) on cytokeratin and vimentin IFs, Rho-associated protein kinase (ROCK), and cell-cell adhesion in bovine luteal theca cells (LTCs). The luteal cells were isolated from bovine corpus luteum (CL), and the LTCs were treated with 0, 0.01, 0.1 and 1.0 mM PGF2α. Cytokeratin, vimentin and desmoplakin proteins were disrupted and the ROCK protein was significantly increased in PGF2α-treated LTCs. In addition, cell-cell adhesion was significantly ( < 0.05) decreased in the PGF2α-induced LTCs compared to control group (0 mM PGF2α). In conclusion, PGF2α affected the adhesion of cell to cell via disruption of desmoplakin, cytokeratin and vimentin, additionally increasing ROCK in bovine LTCs. These results may provide a better understanding of the mechanism of bovine CL regression.
PubMed: 33918916
DOI: 10.3390/ani11041073 -
Frontiers in Endocrinology 2020
Topics: Animals; Cell Differentiation; Corpus Luteum; Corpus Luteum Maintenance; Female; Humans; Pregnancy
PubMed: 32390947
DOI: 10.3389/fendo.2020.00244