Progesterone Synthesis Research Articles

Over-expression of TSPO in the hippocampal CA1 area alleviates cognitive dysfunction caused by lipopolysaccharide in mice

The translocator protein 18kDa (TSPO) is closely related to regulation of immune/inflammatory response. However, the putative role and signaling mechanisms of TSPO in regulation of neuroinflammation remain unclear. GV287 lentiviral vectors mediating TSPO over-expression were injected into bilateral hippocampal CA1 areas to test whether TSPO over-expression was neuroprotective in lipopolysaccharide (LPS)-induced mice model. Finasteride, a blocker of allopregnanolone production, was used to test whether the protective effects were related to steroideogenesis. The results demonstrated that TSPO over-expression increased progesterone and allopregnanolone synthesis. TSPO over-expression in CA1 area improved LPS-induced cognitive deficiency in mice and this cognitive improvement was reversed by finasteride administration. These data suggest that up-regulation of TSPO level during neuroinflammation may be an adaptive response mechanism, a way to provide more neurosteroids. We confer that TSPO could be an attractive drug target for controlling neuroinflammation in the future.

Prohibitin regulates the FSH signaling pathway in rat granulosa cell differentiation.

Published results from our laboratory identified prohibitin (PHB), a gene product expressed in granulosa cells (GCs) that progressively increases during follicle maturation. Our current in vitro studies demonstrate that follicle-stimulating hormone (FSH) stimulates Phb expression in rat primary GCs. The FSH-dependent expression of PHB was primarily localized within mitochondria, and positively correlates with the morphological changes in GCs organelles, and synthesis and secretions of estradiol (E2) and progesterone (P4). In order to confirm that PHB plays a regulatory role in rat GC differentiation, endogenous PHB-knockdown studies were carried out in undifferentiated GCs using adenoviral (Ad)-mediated RNA interference methodology. Knockdown of PHB in GCs resulted in the suppression of the key steroidogenic enzymes including steroidogenic acute regulatory protein (StAR), p450 cholesterol side-chain cleavage enzyme (p450scc), 3β-hydroxysteroid dehydrogenase (3β-HSD), and aromatase (Cyp19a1); and decreased E2 and P4 synthesis and secretions in the presence of FSH stimulation. Furthermore, these experimental studies also provided direct evidence that PHB within the mitochondrial fraction in GCs is phosphorylated at residues Y249, T258, and Y259 in response to FSH stimulation. The observed levels of phosphorylation of PHB at Y249, T258, and Y259 were significantly low in GCs in the absence of FSH stimulation. In addition, during GC differentiation FSH-induced expression of phospho-PHB (pPHB) requires the activation of MEK1-ERK1/2 signaling pathway. Taken together, these studies provide new evidence supporting FSH-dependent PHB/pPHB upregulation in GCs is required to sustain the differentiated state of GCs.

Paraquat inhibits progesterone synthesis in human placental mitochondria

IntroductionHuman placenta mitochondria produces huge amounts of progesterone necessary for maintaining the pregnancy. Lipid peroxidation in human placental mitochondria inhibits progesterone synthesis and that inhibition can be reversed by superoxide dismutase and other antioxidants. Paraquat (PQ) a highly toxic herbicide generates superoxide radical inside cells and induces lipid peroxidation. Hence, it is supposed to stimulate lipid peroxidation in human placental mitochondria and in consequence to inhibit a placental mitochondrial steroidogenesis. MethodsPlacentas were obtained from normal pregnancies. All experiments were done using isolated human placental mitochondria. Mitochondrial lipid peroxidation was determined as tiobarbituric acid reactive substances (TBARS). A conversion of cholesterol to pregnenolone or pregnenolone to progesterone was measured using radiolabeled steroids and thin layer chromatography. ResultsPQ enhanced the iron-dependent lipid peroxidation as also PQ heightened the inhibitory action of this process on progesterone synthesis in isolated human placental mitochondria. Paradoxically, a superoxide dismutase (SOD) reversed the inhibition of progesterone synthesis only minimally although it strongly inhibited PQ stimulated iron-dependent lipid peroxidation. When iron was absent, PQ stimulated only negligible lipid peroxidation but strongly inhibited progesterone synthesis. SOD had no effect on inhibition of progesterone synthesis by PQ. PQ strongly inhibited of the conversion of cholesterol to pregnenolone but had not got any influence on the enzymatic activity of mitochondrial 3β-hydroxysteroid dehydrogenase. PQ strongly decreased the efficiency of NADPH-dependent cytochrome P450 reduction as well as it promoted the rapid oxidation of the pre-reduced mitochondrial cytochrome P450. However PQ has not inhibited combined activity of adrenodoxin reductase and adrenodoxin. DiscussionWe conclude that the most important reason of the inhibition of progesterone synthesis by PQ is the escape of electrons from cytochrome P450scc to that compound what leads to cytochrome oxidation and, in consequence the inhibition of the reaction catalyzed by it. The action of PQ described here should be considered as potentially harmful for pregnancy and fetal development.

Does BPA alter steroid hormone synthesis in human granulosa cells in vitro?

Does Bisphenol A (BPA) impair steroid hormone production in human luteinized granulosa cells in vitro? At supra-physiological concentrations, BPA alters progesterone and estradiol synthesis in vitro and significantly reduces the mRNA and protein expression levels of three genes encoding steroidogenesis enzymes. In IVF patients, the effects of BPA exposure on cycle outcome are controversial. Previous animal studies have shown that granulosa cell steroid hormone synthesis is compromised after BPA exposure, but their findings have been difficult to replicate in humans due, in part, to the low availability of discarded biological material. Luteinized granulosa cells obtained from 44 fertile and infertile patients undergoing in vitro fertilization were cultured for 48 h with different concentrations of BPA (0, 0.2, 0.02, 2.0, 20 µg/ml). Culture medium and total RNA extracted from the luteinized granulosa cells were examined for estradiol and progesterone levels as well as mRNA and protein expression of steroidogenesis enzymes, using enzyme immunoassays, real-time PCR and western blots. Treatment of granulosa cells with 2 or 20 µg/ml BPA for 48 h resulted in significantly lower progesterone biosynthesis (P < 0.005 and <0.001, respectively). Estradiol production was significantly altered only after incubation with 20 µg/ml of BPA (P < 0.001). These concentrations also significantly reduced the mRNA levels of 3β-hydroxysteroid dehydrogenase (3β-HSD), CYP11A1 and CYP19A1 without affecting StAR and 17β-hydroxysteroid dehydrogenase mRNA expression. Similarly, 3β-HSD, CYP11A1 and CYP19A1 protein levels were reduced after administration of 20 µg/ml BPA. Lower BPA concentrations similar to, and up to 100 times, the concentrations measured in human follicular fluid, serum and urine did not alter steroidogenesis in primary granulosa cell cultures. This was an in vitro study investigating the effects of acute exposure (48 h) of BPA on discarded material. As such, the model may not accurately reflect the effect of BPA on the physiological events of follicular steroid hormone synthesis in vivo. Our results show that in vitro exposure to BPA at low doses does not affect granulosa cells steroidogenesis. Combined with recent in vivo studies, these data can be reassuring but further studies are needed to assess the effects of chronic exposure to BPA on ovarian steroidogenesis. This study was supported by grant number 1936/12 from the Israeli Science Foundation (ISF). The authors have no conflict of interest.

Morphology and vascularization of the corpus luteum of peccaries (Pecari tajacu, Linnaeus, 1758) throughout the estrous cycle

The current paper characterizes the changes in morphology and vascularization of the corpus luteum of collared peccaries during the estrous cycle and correlates progesterone synthesis (P4). Twenty females were subjected to a treatment for estrus synchronization; an ear implant containing 1.5 mg of norgestomet was implanted on D0, whereas on D9 the peccaries received an IM injection of eCG 200UI and 50g of PGF2a. The animals were divided into four groups (G1, G2, G3 and G4) and euthanized on post-ovulation days 3, 12, 18 and 22. The ovaries were collected and the corpora lutea were measured and processed for histological and vascular density (Dv). Blood was collected for dosage of P4 serum. The morphology of the ovaries, the corpora lutea and P4 varied significantly during the estrous cycle (P&lt;0.001). There was a significant co-relationship between weight and length of the ovaries and CL (r = 0.66, r = 0.52, P&lt;0.05, respectively) and between weight, length and width of the CL and P4 (r = 0.51, r = 0.54 and r = 0.68, P&lt;0.05, respectively). The luteal Dv was highly influenced by the estrous cycle phase (P&lt;0.0001). The P4 and luteal Dv concentrations were higher in G2 and evidenced maximum secretory activity, with a highly significant correlation (P&lt;0.0001). Assessed lutein parameters may estimate the phase of the estrous cycle in peccaries and the functional activity of the corpus luteum.

N-3 polyunsaturated fatty acid DHA during IVM affected oocyte developmental competence in cattle

The positive effect of n-3 polyunsaturated fatty acids (FAs) on fertility in ruminants seems to be partly mediated through direct effects on the oocyte developmental potential. We aimed to investigate whether supplementation with physiological levels of docosahexaenoic acid (DHA, C22:6 n-3 polyunsaturated fatty acids) during IVM has an effect on oocyte maturation and in vitro embryo development in cattle. We reported that DHA (0, 1, 10, or 100 μM) had no effect on oocyte viability or maturation rate after 22-hour IVM. Incubation of oocyte-cumulus complexes with 1-μM DHA during IVM significantly increased (P < 0.05) oocyte cleavage rate as compared with control (86.1% vs. 78.8%, respectively) and the greater than 4-cell embryo rate at Day 2 after parthenogenetic activation (39.1% vs. 29.7%, respectively). Supplementation with 1 μM DHA during IVM also induced a significant increase in the blastocyst rate at Day 7 after IVF as compared with control (30.6% vs. 17.6%, respectively) and tended to increase the number of cells in the blastocysts (97.1 ± 4.9 vs. 81.2 ± 5.3, respectively; P = 0.08). On the contrary, 10-μM DHA had no effects, whereas 100-μM DHA significantly decreased the cleavage rate compared with control (69.5% vs.78.8%, respectively) and the greater than 4-cell embryo rate at Day 2 after parthenogenetic activation (19.5% vs. 29.7%). As was shown by real-time polymerase chain reaction, negative effects of 100-μM DHA were associated with significant increase of progesterone synthesis by oocyte-cumulus complexes, a three-fold increase in expression level of FA transporter CD36 and a two-fold decrease of FA synthase FASN genes in cumulus cells (CCs) of corresponding oocytes. Docosahexaenoic acid at 1 and 10 μM had no effect on expression of those and other key lipid metabolism-related genes in CC. In conclusion, administration of a low physiological dose of DHA (1 μM) during IVM may have beneficial effects on oocyte developmental competence in vitro without affecting lipid metabolism gene expression in surrounding CCs, contrarily to 100 μM DHA which diminished oocyte quality associated with perturbation of lipid and steroid metabolism in CC.

Advanced Running Performance by Genetic Predisposition in Male Dummerstorf Marathon Mice (DUhTP) Reveals Higher Sterol Regulatory Element-Binding Protein (SREBP) Related mRNA Expression in the Liver and Higher Serum Levels of Progesterone.

Long-term-selected DUhTP mice represent a non-inbred model for inborn physical high-performance without previous training. Abundance of hepatic mRNA in 70-day male DUhTP and control mice was analyzed using the Affymetrix mouse array 430A 2.0. Differential expression analysis with PLIER corrected data was performed using AltAnalyze. Searching for over-representation in biochemical pathways revealed cholesterol metabolism being most prominently affected in DUhTP compared to unselected control mice. Furthermore, pathway analysis by AltAnalyze plus PathVisio indicated significant induction of glycolysis, fatty acid synthesis and cholesterol biosynthesis in the liver of DUhTP mice versus unselected control mice. In contrast, gluconeogenesis was partially inactivated as judged from the analysis of hepatic mRNA transcript abundance in DUhTP mice. Analysis of mRNA transcripts related to steroid hormone metabolism inferred elevated synthesis of progesterone and reduced levels of sex steroids. Abundance of steroid delta isomerase-5 mRNA (Hsd3b5, FC 4.97) was increased and steroid 17-alpha-monooxygenase mRNA (Cyp17a1, FC -11.6) was massively diminished in the liver of DUhTP mice. Assessment of steroid profiles by LC-MS revealed increased levels of progesterone and decreased levels of sex steroids in serum from DUhTP mice versus controls. Analysis of hepatic mRNA transcript abundance indicates that sterol regulatory element-binding protein-1 (SREBP-1) may play a major role in metabolic pathway activation in the marathon mouse model DUhTP. Thus, results from bioinformatics modeling of hepatic mRNA transcript abundance correlated with direct steroid analysis by mass spectrometry and further indicated functions of SREBP-1 and steroid hormones for endurance performance in DUhTP mice.

Polymorphisms in NR5A2, gene encoding liver receptor homolog-1 are associated with preterm birth.

Preterm birth (PTB) is a major cause of neonatal mortality and morbidity. There is strong evidence of genetic susceptibility. Objective of this study was to identify genetic variants contributing to PTB. Genotyping was performed for 24 single nucleotide polymorphisms (SNPs) in 4 candidate genes (NR5A2, FSHR, FOXP3, and SERPINH1). Genotyping was completed on 728 maternal triads (mother and maternal grandparents of a preterm infant). Data were analyzed with Family Based Association Test. For all maternal triads rs2737667 of NR5A2 showed significant association at P = 0.02. When stratifying by gestational age three SNPs in NR5A2 had P values <0.05 in the <32-wk gestational age group (rs12131233, P = 0.007; rs2737667, P = 0.04; rs2816949, P = 0.02). When preterm premature rupture of membranes cases were excluded rs2737667 of NR5A2 showed the strongest association with a P value <0.0002. This association remained significant after correction for multiple testing. This study suggests a potential association between intronic SNPs in the NR5A2 gene and PTB. NR5A2 gene encodes for the liver receptor homolog-1 protein, which plays a critical role in regulation of cholesterol metabolism, steroidogenesis, and progesterone synthesis. These findings suggest that NR5A2 may be important in the pathophysiology of PTB and exploring noncoding regulators of NR5A2 is warranted.

Effects of dbcAMP on progesterone synthesis by cultured goat luteal cell subpopulations isolated from early and late luteal stage corpora lutea

This research aimed to investigate the effects of dbcAMP on steroid accumulation by culturing two distinct luteal cell subpopulations isolated from early and late luteal stage corpora lutea. Cells were isolated from corpora lutea collected from eight Angora goats on either the 5th or 15th days of their estrous cycles. Cell isolation was performed by enzymatic digestion using collagenase and DNase. Isolated cells were separated into two distinct subpopulations enriched with small and large luteal cells by percoll density-gradient centrifugation. Isolated cells were stained in order to detect 3β-hydroxysteroid dehydrogenase (3β-HSD). Cells stained positively for 3β-HSD activity (5 x 104 cell⁄well) were incubated with dbcAMP in the absence or presence of 22(R)-hydroxycholesterol (22R-HC) for periods of up to 7 days. Large luteal cell enriched subpopulations produced more basal progesterone (P < 0.05) than did the small luteal cell enriched subpopulations. Treatment of cells with 22R-HC alone induced 4.00 to 11.60 times increase in steroid synthesis depending on type of cells incubated, luteal age and days of incubation. Incubation of cells with 1 mM dbcAMP in the absence or presence of 22R-HC induced in a significant increase (P < 0.01) in steroid accumulation in all treated groups. In contrast, when cells are treated with low dose dbcAMP (0.1 mM), treatment induced stimulation failed to reach significant level in most treated groups. In conclusion, although treatment of goat luteal cells with dbcAMP induces an increase in steroid accumulation, a high dose is necessary to reach significant levels. Stimulatory effect of dbcAMP on steroidogenesis maintains during long life culturing.

Dynamic Changes in the Follicular Transcriptome and Promoter DNA Methylation Pattern of Steroidogenic Genes in Chicken Follicles throughout the Ovulation Cycle.

The molecular mechanisms associated with follicle maturation and ovulation are not well defined in avian species. In this study, we used RNA-seq to study the gene expression profiles of the chicken follicles from different developmental stages (pre-hierarchical, pre-ovulatory and post-ovulatory). Transcriptomic analysis revealed a total of 1,277 and 2,310 genes were differentially expressed when follicles progressed through the pre-hierarchical to hierarchical and pre-ovulatory to post-ovulatory transitions, respectively. The differentially expressed genes (DEG) were involved in signaling pathways such as adherens junction, apoptosis and steroid biosynthesis. We further investigated the transcriptional regulation of follicular steroidogenesis by examining the follicle-specific methylation profiles of Star (steroidogenic acute regulatory protein), Cyp11a1 (cytochrome P450, family 11, subfamily a, polypeptide 1) and Hsd3b (hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1), genes encoding the key enzymes for progesterone synthesis. The varied patterns of DNA methylation in proximal promoters of Star and Cyp11a1but not Hsd3b in different follicles could play a major role in controlling gene expression as well as follicular steroidogenic activity. Finally, the promoter-reporter analysis suggests that TGF-β could be involved in the regulation of Hsd3b expression during ovulation. Together, current data not only provide novel insights into the molecular mechanisms of follicular physiology in chicken follicles, but also present the first evidence of epigenetic regulation of ovarian steroidogenesis in avian species.

Steroid hormones, prostanoids, and angiogenic systems during rescue of the corpus luteum in pigs.

In order to characterize the transition of the corpora lutea (CL) from acquisition of luteolytic sensitivity to rescue of luteal function: i) the expression of 38 factors associated with steroids, prostanoids, and angiogenic systems and ii) concentrations of the main hormones responsible for maintenance of CL function in cyclic and pregnant pigs were examined. Additionally, the effect of prostaglandin (PG) E2 and F2 α on luteal function during the estrous cycle and pregnancy was evaluated in vitro. Significantly up-regulated gene expression was revealed in CL collected on day 14 of the estrous cycle (CYP19A1, ESR2, PTGS2, HIF1A, and EDN1) and on days 12-14 of pregnancy (SCARB1, PGRMC1, STAR, HSD3B1, NR5A1, PTGFR, PTGER4, and VEGFA). Elevated concentrations of estradiol-17β and PGE2 occurred in CL on days 12 and 14 of pregnancy respectively, while an increased intraluteal PGF2 α content was noted on day 14 of the estrous cycle. Both PGs increased the synthesis of progesterone by cultured luteal slices obtained on day 14 of pregnancy, in contrast to the action of PGF2 α on the corresponding day of the estrous cycle. PGE2 stimulated cAMP production via PTGER2 and PTGER4, while PGF2 α elevated the content of CREB in cultured luteal slices from CL of pregnant pigs. In silico analysis showed that infiltration of lymphocytes and apoptosis of microvascular endothelium were activated in CL on day 12 of the estrous cycle vs pregnancy. Summarizing, an abundance of E2 and PGE2 during pregnancy regulates specific pathways responsible for steroidogenesis, the prostanoid signaling system and angiogenesis during rescue from luteolysis in porcine CL.

Notch Signaling Pathway Regulates Progesterone Secretion in Murine Luteal Cells.

Notch signaling is an evolutionarily conserved pathway, which involves in various cell life activities. Other studies and our report showed that the Notch signaling plays very important role in follicle development in mammalian ovaries. In luteal cells, Notch ligand, delta-like ligand 4, is involved in normal luteal vasculature. In this study, murine luteal cells were cultured in vitro and treated with Notch signaling inhibitors, L-658,458 and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester (DAPT). We found that L-658,458 and DAPT treatment decrease basal and human chorionic gonadotropin (hCG)-stimulated progesterone secretion. On the contrary, overexpression of intracellular domain of Notch3 increased basal and hCG-stimulated progesterone secretion. Further studies demonstrated that Notch signaling regulated the expression of steroidogenic acute regulatory protein and CYP11A, 2 key enzymes for progesterone synthesis. In conclusion, Notch signaling plays important role in regulating progesterone secretion in murine luteal cells.

Adrenal insufficiency in the preterm infant

Cortisol production by the human fetal adrenal cortex has been shown to be not adequate at early gestation. This is due to an inefficient expression of 3β-hydroxysteroid dehydrogenase, the enzyme that catalyzes the synthesis of progesterone from pregnenolone, before about 23 weeks of gestation. Whereas, the fetal adrenal cortex it is able to produce dehydroepiandrosterone sulphate for placental estrogen synthesis and to convert placental progesterone to cortisol [1,2]. During the last trimester of pregnancy the fetal adrenal gland undergoes significant anatomical and functional maturation for adaptation to extra-uterine life and cortisol production increases greatly in the last two months of gestation. Cortisol increases synthesis of surfactant, enhances the reabsorption of lung fluid, promotes the conversion of T4 to T3, favors the closure of the ductus arteriosus and maturation of liver and intestinal enzymes [2]. Adrenal insufficiency can be caused by rare conditions such as adrenocortical hypoplasia or congenital enzymatic deficiencies of steroidogenesis, with clinical variables depending on the hormone involved. In preterm infants, the developmental immaturity, combined with increased demands in critical illness, may result in insufficient cortisol production to maintain homeostasis in the face of acute stress or illness, despite apparently normal cortisol levels. This condition is known as “transient or relative adrenal insufficiency” (TAI) [3,4]. TAI usually appears in the first week of life and normalizes in the second week. Infants with TAI can exhibit refractory hypotension (hypotension not responsive to volume expanders and inotropic drugs, but responsive to corticosteroids), respiratory distress, patent ductus arteriosus and bronchopulmonary dysplasia (BPD) [2,3]. Diagnosis of TAI is not easy because many other conditions can cause hypotension in VLBW infants: hypovolemia, myocardial dysfunction, deficient vascular tone, hyaline membrane disease, infection or a combinations of these factors. In addition, normal basal cortisol levels are extremely variable in preterms and to date there is no consensus on the diagnosis of adrenal insufficiency based on tests with adrenocorticotropic hormone (ACTH) [5-8]. Appropriate dose and duration of steroid therapy have not been established yet. On the other hand refractory and persistent hypotension is associated with intraventricular hemorrhage, periventricular leukomalacia, increased mortality and neurological disability [9]. Poor adrenal response has been shown to be associated with later development of BPD and with death [10,11]. For these reasons further studies are needed to evaluate the efficacy and safety of glucocorticoids in the treatment of cardiovascular failure due to TAI in ill preterm and term infants [12,13].

Hypoxia inducible factor-1α plays a role in hypoxia-increased progesterone synthesis during luteinization of granulosa cells

Hypoxia inducible factor-1α plays a role in hypoxia-increased progesterone synthesis during luteinization of granulosa cells

Gonadotropin stimulation alters the expression of local growth factors in the granulosa cells involved in paracrine communication, dominant follicle selection and luteinization

Recruitment of antral cohort for further growth and the selection of a single follicle to reach the ovulatory stage are achieved within the ovary by the actions of endogenously produced FSH in the natural cycle. Certain growth factors locally produced in the ovary interact with FSH in a paracrine manner and modulate FSH signaling in a way that promotes estradiol (E2) production (aromatization) while inhibiting progesterone synthesis (by limiting 3-β HSD activity), acting as a luteinization inhibitor during rapid growth of antral follicles.

МЕТАБОЛІЧНИЙ ПРОФІЛЬ КРОВІ КОРІВ ЗА ЛІКУВАННЯ ГІПОФУНКЦІЇ ЯЄЧНИКІВ ГОРМОНАЛЬНИМИ ТА ФІТОПРЕПАРАТАМИ

&lt;p&gt;For the correction of reproductive function of cows with ovarian hypofunction practices use a number of hormones. Recently, to stimulate reproductive function using herbal medicines that have gonadotropic effect or stimulate secretion of steroid hormones who try to use to increase fertility. Therefore, we carried out an attempt to develop a method of regulation of reproductive function of the ovaries of cows using combination therapies that can provide effective treatment by studying the biochemical parameters of animals.&lt;/p&gt; &lt;p&gt;The cows were divided depending on the treatment to control and two experimental groups of 5 animals in each group. Groups were formed by the following treatment regimens indicated pathology. Cows control group treated by next scheme: day 1 — intramuscular injection drug in vitro at a dose of 10 ml; day 2 —PMSG intramuscular administration of the drug at a dose of 500 IU; day 3 —intramuscular injection drug Surfahon at a dose of 50 mg. Cows from experimental group 1 was injected intramuscularly liposomal drug based on herbal (Rhodiola rosea, Salvia); Animals from second experimental group were injected intramuscularly liposomal drug based on phyto-substances (Rhodiola rosea, Salvia) with gonadotropin-releasing hormone (Surfahon).&lt;/p&gt; &lt;p&gt;Analysis of biochemical parameters of blood serum of cows with ovarian hypofunction found low concentrations of estradiol-17-β and progesterone. Between the control and experimental groups concentration of progesterone and estradiol-17-β differ within 10%, which indicates the same level of disease in all animals selected. Level carotene, ascorbic acid and cholesterol in all groups was within the physiological norm and differed slightly.&lt;/p&gt; &lt;p&gt;It was established that the treatment of cows with hypofunction ovaries in the experimental group 1 progesterone level 7 days after treatment was 11.5, and 2 - on 41,4% (p &amp;lt;0,01) higher than in the control group animals, indicating that the revitalization of the ovary as a result of treatment and efficacy of liposomal drug on the basis of phyto-substances with gonadotropin-releasing hormone.&lt;/p&gt; &lt;p&gt;The level of cholesterol on 7th day after treatment cows with ovarian hypofunction in the first experimental group was higher by 25,5% (p &amp;lt;0,05) and slightly exceeded the physiological value of this indicator in cows. In the second experimental group, it also exceed the physiological norm and exceeded the level in blood of cows in the control group at 18,6% (p &amp;lt;0,05), indicating the possibility of using cholesterol for the synthesis of progesterone.&lt;/p&gt; &lt;p&gt;All the cows in the period from 30 to 60 days after the treatment have sign of oestrus and were artificially inseminated.&lt;/p&gt;

Alternativa terapéutica en gestantes con el diagnóstico de insuficiencia lútea.

La insuficiencia lútea es una causa conocida de infertilidad (abortos tempranos). El objetivo del presente trabajo es ofrecer una alternativa terapéutica a pacientes gestantes portadoras de insuficiencia lútea. El tratamiento ideal debería de ser a base de progesterona químicamente pura, de la cual carecemos en nuestro medio. Los progestágenos, que constituirían la alternativa terapéutica, son conocidos actualmente de tener efectos luteolíticos. La función del cuerpo lúteo en el humano puede ser definida en términos de cantidad y duración de la síntesis esteroidogénica de progesterona y estrógenos. Estas dos hormonas reflejan la actividad de diferentes tipos celulares a nivel del cuerpo lúteo y se ha observado que ellos pueden variar independientemente durante la fase lútea.

Lysosomes are involved in induction of steroidogenic acute regulatory protein (StAR) gene expression and progesterone synthesis through low-density lipoprotein in cultured bovine granulosa cells

Progesterone is an important steroid hormone in the regulation of the bovine estrous cycle. The steroidogenic acute regulatory protein (StAR) is an indispensable component for transporting cholesterol to the inner mitochondrial membrane, which is one of the rate-limiting steps for progesterone synthesis. Low-density lipoprotein (LDL) supplies cholesterol precursors for progesterone formation, and the lysosomal degradation pathway of LDL is essential for progesterone biosynthesis in granulosa cells after ovulation. However, it is currently unknown how LDL and lysosomes coordinate the expression of the StAR gene and progesterone production in bovine granulosa cells. Here, we investigated the role of lysosomes in LDL-treated bovine granulosa cells. Our results reported that LDL induced expression of StAR messenger RNA and protein as well as expression of cholesterol side-chain cleavage cytochrome P-450 (CYP11A1) messenger RNA and progesterone production in cultured bovine granulosa cells. The number of lysosomes in the granulosa cells was also significantly increased by LDL; whereas the lysosomal inhibitor, chloroquine, strikingly abolished these LDL-induced effects. Our results indicate that LDL promotes StAR expression, synthesis of progesterone, and formation of lysosomes in bovine granulosa cells, and lysosomes participate in the process by releasing free cholesterol from hydrolyzed LDL.

Cytotoxic mechanism related to dihydrolipoamide dehydrogenase in Leydig cells exposed to heavy metals

Heavy metals are common environmental toxicants with adverse effects on steroid biosynthesis. The importance of mitochondria has been recognized in cytotoxic mechanism of heavy metals on Leydig cells these years. But it is still poorly known. Our previous study reported that dihydrolipoamide dehydrogenase (DLD) located on the mitochondria was significantly decreased in Leydig cells exposed to cadmium, which suggested that DLD might be involved in the cytotoxic effects. Therefore, the altered expression of DLD was validated in rats and R2C cells exposed to cadmium, manganese and lead, and the role of DLD in the steroid synthesis pathway cAMP/PKA-ERK1/2 was investigated in this study. With a low expression of DLD, heavy metals dramatically reduced the levels of steroid hormone by inhibiting the activation of cAMP/PKA, PKC signaling pathway and the steroidogenic enzymes StAR, CYP11A1 and 3β-HSD. After knockdown of DLD in R2C cells, progesterone synthesis was reduced by 40%, and the intracellular concentration of cAMP, protein expression of StAR, 3β-HSD, PKA, and the phosphorylation of ERK1/2 were also decreased. These results highlight that DLD is down-regulation and related to steroid biosynthesis in Leyig cells exposed to heavy metals; cAMP/PKA act as downstream effector molecules of DLD, which activate phosphorylation of ERK1/2 to initiate the steroidogenesis.

Multiple roles of hypoxia in ovarian function: roles of hypoxia-inducible factor-related and -unrelated signals during the luteal phase.

There is increasing interest in the role of oxygen conditions in the microenvironment of organs because of the discovery of a hypoxia-specific transcription factor, namely hypoxia-inducible factor (HIF) 1. Ovarian function has several phases that change day by day, including ovulation, follicular growth and corpus luteum formation and regression. These phases are regulated by many factors, including pituitary hormones and local hormones, such as steroids, peptides and cytokines, as well as oxygen conditions. Hypoxia strongly induces angiogenesis because transcription of the potent angiogenic factor vascular endothelial growth factor (VEGF) is regulated by HIF1. Follicular development and luteal formation are accompanied by a marked increase in angiogenesis assisted by HIF1-VEGF signalling. Hypoxia is also one of the factors that induces luteolysis by suppressing progesterone synthesis and by promoting apoptosis of luteal cells. The present review focuses on recent studies of hypoxic conditions, as well as HIF1-regulated genes and proteins, in the regulation of ovarian function.