Gene expression pattern of adiponectin and adiponectin receptors in dominant and atretic follicles and oocytes screened based on brilliant cresyl blue staining

The impact of cumulus cell viability and pre-culture with the healthy cell mass on brilliant cresyl blue (BCB) staining assessment and meiotic competence of suboptimal porcine oocytes

Objectives of the present study were to investigate the characteristics including glucose-6-phosphate dehydrogenase activity, as determined by Brilliant Cresyl Blue (BCB) staining, of suboptimal porcine oocytes and to enhance the meiotic competence of those through pre-culture with cumulus cell masses (CCMs). Percentage of oocyte-cumulus complexes (OCCs) derived from small follicles (SF; <3 mm in diameter) containing the oocytes that were assessed as BCB-negative (BCB-) was significantly higher than those derived from medium follicles (MF; 3-6 mm in diameter). Degrees of dead cumulus cells were significantly higher in OCCs containing BCB- oocytes, regardless of the origin of OCCs (MF vs. SF), than those containing BCB-positive (BCB+) ones. Exposing OCCs containing BCB+ oocytes to the apoptosis inducer, carbonyl cyanide m-chlorophenylhydrazone, for 20 h significantly induced the transition to BCB- and meiotic progression of exposed OCCs were significantly reduced in both SF and MF derived ones. Transit of BCB- oocytes to BCB+ was induced when OCCs were pre-cultured with CCMs of MF derived OCCs containing BCB+ oocytes for 20 h before IVM. This pre-culture also significantly increased the meiotic competence of BCB- oocytes, particularly in SF derived ones. However, reactive oxygen species levels were significantly higher in BCB+ oocytes as compared with BCB- ones, regardless of pre-culture with CCMs, whereas no significant differences were found in the ATP contents among the treatment groups. In conclusion, the BCB result of oocytes could be regulated by the healthy status and content of surrounding cumulus cells and the meiotic competence of suboptimal BCB- porcine oocytes is improved by pre-culture with healthy CCMs.

Selection of Rattus norvegicus cumulus-oocyte complex for vitrification by brilliant cresyl blue

The influence of the method of evaluating developmentally competent oocytes on their viability after cryopreservation still needs to be better understood. The objective of this study was to determine the cleavage and embryo developmental rates after parthenogenetic activation of cumulus-oocyte complexes (COCs) selected by different concentrations of brilliant cresyl blue (BCB) and cryopreservation. In the first experiment, COCs were separated into groups and incubated for 1 h in medium containing BCB (13 μM, 16 μM, or 20 μM). The control group was not exposed to BCB staining. In the second experiment, COCs were divided into four groups: 13 μM BCB(+), 13 μM BCB(-), fresh control (selected by morphologic observation and immediately in vitro matured) and vitrified control (selected by morphologic evaluation, vitrified, and in vitro matured). In the first experiment, the 13 μM BCB group displayed greater development rates at the morula stage (65.45%, 36/55) when compared with the other groups. In the second experiment, cleavage (47.05%, 72/153) and morula development (33.55%, 51/153) of the control group of fresh COCs were increased compared with the other groups. However, when comparing morula rates between vitrified COC control and BCB(+) groups, the BCB(+) group had better results (19.23%, 5/26 and 64.7%, 11/17, respectively). Our best result in rat COC selection by BCB staining was obtained using a concentration of 13 μM. This selection could be a valuable tool to improve vitrification outcomes, as observed by the BCB(+) group that demonstrated better results compared with the vitrified COC control.

Expression of Locally Produced Adipokines and Their Receptors during Different Physiological and Reproductive Stages in the Bovine Corpus Luteum

This study aimed to determine the gene expression of different local novel adipokines, such as vaspin, adiponectin, visfatin, and resistin, and their known receptors, namely, heat shock 70 protein 5, adiponectin receptor 1, and adiponectin receptor 2, in the bovine corpus luteum (CL) during different phases of the estrous cycle (on days 1-2, 3-4, 5-7, 8-12, 13-18, >18) and pregnancy (at months 1-2, 3-4, 5-7, >7). The mRNA expression was measured by reverse transcription polymerase chain reaction (RT-qPCR). The mRNA expression levels were normalized to the geometric mean of all three constantly expressed reference genes (cyclophilin A, ubiquitin, ubiquitin C). Our findings suggest that adipokines are expressed and present in all investigated groups, and are specifically up- or downregulated during the estrus cycle and during pregnancy. Vaspin and adiponectin levels were upregulated in the middle and late cycle stages. Resistin was abundant during the CL regression stage and in the first months of pregnancy. The specific expression of adipokine receptors indicates their involvement in the local mechanisms that regulate CL function. Further investigations are required to elucidate the regulative mechanisms underlying the different local effects of adipokines on the ovarian physiology of cows.

Dimethyl itaconic acid improves viability and steroidogenesis and suppresses cytokine production in LPS-treated bovine ovarian granulosa cells by regulating TLR4/nfkβ, NLRP3, JNK signaling pathways

The stimulation of pro-inflammatory pathways by lipopolysaccharide (LPS) endotoxins is a key player in the pathological mechanisms involved in the development of ovarian dysfunctions in dairy cows. Dimethyl itaconate acid (DMIA) is a novel immunometabolite that has recently emerged as a regulator of inflammatory responses in mammals. The present study was undertaken to determine the anti-inflammatory effects of DMIA on bovine granulosa cells (GCs) and to explore its possible molecular mechanisms. The ovarian GCs were obtained from small follicles of dairy cows. The GCs were stimulated with 1 μg/mL LPS for 4 h and then treated with 250 μM DMIA for 12 h. The viability, production of pro-inflammatory cytokines, activation of inflammatory signaling pathways and synthesis of steroid hormones were evaluated in treated GCs. Our results showed that DMIA reduced the inflammatory responses in LPS stimulated GCs by down-regulating the expression of nod-like receptor family pyrin domain containing 3 inflammasome, and toll-like receptor 4 and by suppressing the phosphorylation of nuclear factor kappa B and c-Jun N-terminal kinase proteins. DMIA also attenuated the increased production of pro inflammatory cytokines (interleukin 6, tumor necrosis factor α and interleukin 1 beta (p < 0.01) in LPS stimulated GCs. Exposure of LPS stimulated GCs to DMIA improved the impaired steroidogenesis by up-regulation of steroid synthesis genes including 3-beta-hydroxysteroid dehydrogenase, follicle stimulating hormone receptor and cytochrome P450 aromatase. The results of the present study highlight the potential role of itaconic acid for the improvement of GCs inflammation in dairy cows with ovarian dysfunctions.

Silver nanoparticles induce oxidative stress, apoptosis and impaired steroidogenesis in ovarian granulosa cells of cattle

There have been increased effects of silver nanoparticle (Ag-NPs) on livestock during the past decade, but data related to adverse effects of Ag-NPs on reproductive tissues are limited. In the present study, the possible cytotoxic effects of Ag-NPs on oxidant/antioxidant balance, apoptosis and steroid hormone production in ovarian granulosa cells of cattle were studied.Cultured granulosa cells were treated with 10 nm Ag-NPs at various concentrations (1-100 µg/ml) for 24 h, and cell toxicity, oxidant/antioxidant markers, reactive oxygen species (ROS) production, abundances of apoptotic/antiapoptotic and steroidogenesis related mRNA transcripts were determined. The amount of DNA fragmentation was also determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Results indicated treatment of granulosa cells with Ag-NPs induced an increase of reactive oxygen species production concomitant with increased malondialdehyde concentrations and decreased antioxidant enzyme activities. There was a maximal percentage of TUNEL⁺ cells (46.6%) after treatment with 50 and 100 µg/ml of Ag-NPs. The Ag-NPs could induce apoptosis in granulosa cells as indicated by the increase in caspase-3 activity, and larger abundance of BCL2 associated X (BAX) and lesser abundance of B-cell lymphoma 2 (BCL2) mRNA transcripts. The abundance of steroidogenic enzyme mRNA transcripts decreased concomitant with suppression of steroid hormone synthesis from Ag-NP-treated cells. Findings indicate silver nanoparticles (SNP) induce apoptosis and oxidative stress and change the pattern of steroid hormone synthesis in granulosa cells of cattle. The results indicate Ag-NPs may inhibit the function and viability of ovarian cells.

The Radio-Sensitizing Effect of Pharmacological Concentration of Ascorbic Acid on Human Pancreatic Cancer Cells

BACKGROUND

Previous studies reported the inevitable destructive effects of radiotherapy on normal adjacent cells. Ascorbic Acid (AA) has been proposed as an effective anti-cancer agent with no obvious effects on normal cells.

OBJECTIVE

The effects of Ascorbic acid in combination with radiotherapy on human pancreatic carcinoma cell line were studied.

METHODS

The human pancreatic cancer cells were cultured and divided into four groups: control group (A) without any treatment, group B that received 2Gy radiotherapy alone, group C that was treated with 4mM AA alone, and group D that was co-treated with AA and radiotherapy. Cell viability, DNA fragmentation, expression of apoptotic genes, and Reactive Oxygen Species (ROS) production were determined in treated cells.

RESULTS

There was a noticeable decrease in cell viability after treatment with AA (and/or) radiotherapy. All treated groups showed elevated ROS production, Bax/Bcl2 expression, DNA fragmentation, and cytotoxycity compared with the control group. Cells under combination therapy showed the most cytotoxicity.

CONCLUSION

The results suggest that AA at a dose of 4mmol/l may be used as an effective radio-sensitizing agent in pancreatic cancer cell line.

Role of cardiac hypoxia in the pathogenesis of sudden death syndrome in broiler chickens - A metabolic and molecular study

Sudden death syndrome (SDS) is an economically important disorder in broiler chickens with unknown aetiology. The aim of the present study was to evaluate the metabolic and molecular alterations related to hypoxia in the myocardium of broiler chickens with SDS. Samples from the cardiac muscle of internal control broiler chickens (ICs) (n = 36) and chickens having died of SDS (n = 36) were obtained during the rearing period. The activities of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) and the concentration of lactate were measured in the cardiac tissue using available commercial kits. The expression of hypoxia-inducing factor 1α (HIF1α), glucose transporter 1 (GLUT1), pyruvate dehydrogenase kinase 4 (PDHK4) and monocarboxylate transporter 4 (MCT4) genes was determined in the myocardium by real-time PCR analysis. The results showed the elevation of lactate level and activities of LDH and CPK in the cardiac muscle of SDS-affected chickens compared with the IC birds (P < 0.05). The cardiac muscle expression of HIF1α, MCT4 and GLUT1 genes was increased, while the PDHK4 mRNA level was decreased in the SDS-affected group compared to those in the IC chickens (P < 0.05). Our results showed that metabolic remodelling associated with hypoxia in the cardiac tissues may have an important role in the pathogenesis of cardiac insufficiency and SDS in broiler chickens.

Plasma Protein Comparison between Dairy Cows with Inactive Ovaries and Estrus

To screen differentially expressed proteins in the blood dairy cows with inactive ovaries caused by a negative energy balance and to determine the roles of the identified proteins in the development of inactive ovaries.Holstein cows at 14 to 21 days postpartum in an intensive dairy farm were examined for their energy balance (EB) status by blood β-hydroxybutyrate (BHBA) and assigned to the inactive ovary (IO) group (n = 50) and the normal oestrus control (CON) group (n = 50) at 60 to 90 days postpartum by means of the oestrus manifestation, rectal examination and B-ultrasound examination. Fourteen differentially expressed proteins from 61 proteins in the plasma of dairy cows with IOs were identified by iTRAQ/LC-MS/MS and GO, KEGG, and PATHWAY analysis. Eleven expressed proteins were upregulated, and 3 expressed proteins were downregulated. Among the 10 differentially expressed proteins verified by Western blot or ELISA, the relative expression levels of ALDOB, IGFBP2, ITIH3 and LDHB in mixed samples and single samples were consistent with the proteomic protein results. PKM2, GPX3, ALDOB, RBP4 and AHSG were significantly different between the two groups (P < 0.05); APOA4 and SPAM1 were not significantly different (P > 0.05) but were still downregulated in the ovarian resting group. This study confirmed that 14 plasma differential proteins in the inactive ovaries of postpartum dairy cows were associated with follicular development, and these findings provide a foundation for further research on the mechanism and prevention of inactive ovaries in dairy cows.

MafA Overexpression: A New Efficient Protocol for In Vitro Differentiation of Adipose-Derived Mesenchymal Stem Cells into Functional Insulin-Producing Cells

Objective

We proposed a novel differentiation method for the efficient differentiation of adipose-derived mesenchymal stem cells (ADMSCs) into functional insulin-producing cells (IPCs) based on MafA overexpression.

Materials and Methods

In this experimental study, a eukaryotic expression vector containing MafA [MafA/pcDNA3.1(+)] was constructed and purified. ADMSCs were differentiated into IPCs. ADMSCs were assigned in two groups including control (C), and the MafA overexpressed (MafA+) groups. The ADMSCs were transfected by MafA/pcDNA 3.1(+) at day 10 of the differentiation. Differentiated cells were analyzed for the expression of multiple β cell specific genes (Nkx2.2, Ngn3, Isl-1, Pdx1, MafA, Nkx6.1, and Insulin) using real-time polymerase chain reaction (PCR). The insulin secretion potency of the differentiated cells in response to glucose exposure was also determined using an enzyme-linked immunosorbent assay (ELISA) method and Dithizone (DTZ) staining. The IPCs from the control manipulated group, and un-differentiated ADMSCs group were transplanted to streptozotocin (STZ)-diabetic rats. Rats were monitored for blood glucose and insulin concentration.

Results

The results revealed that ADMSCs were successfully differentiated into IPCs through the 14 day differentiation protocol. The expression of β-cell specific genes in MafA+ IPCs was higher than in control cells. Glucose-induced insulin secretion after the exposure of IPCs to glucose was higher in MafA+ group than the control group. The STZ- diabetic rats showed an ability to secrete insulin and apparent hyperglycemic condition adjustment after transplantation of the control IPCs. The mean insulin concentration of diabetic rats that were transplanted by manipulated IPCs was significantly higher than ADMSCs-transplanted rats; however, no effect was observed in the concentration of blood glucose.

Conclusion

The overexpression of MafA can be used as a novel promising approach for the efficient production of IPCs from ADMSCs in vitro. However, the future therapeutic use of the MafA+ IPCs in diabetic animals needs further investigations.

The combined effect of Pdx1 overexpression and Shh manipulation on the function of insulin-producing cells derived from adipose-tissue stem cells

Pancreatic and duodenal homeobox 1 (Pdx1) and Sonic hedgehog (Shh) are the key regulators of beta-cell function. In vitro experiments have shown that there is significant cooperation between Pdx1 and Shh with regard to the production and maintenance of insulin-producing cells (IPCs). In this study, the combined effect of Pdx1 overexpression and Shh manipulation on the function of adipose tissue-derived IPCs was determined. A eukaryotic expression vector (Pdx1- pCDNA3.1(+)) was constructed and transfected into a Chinese hamster ovary (CHO) cell line. Adipose tissue-derived mesenchymal stem cells (ADMSCs) obtained from rats were assigned to two groups [control (C) and manipulated (M)] and differentiated into IPCs. Manipulated cells were treated with a mixture of FGF-β and cyclopamine and recombinant Shh protein at days 3 and 11, respectively, and transfected with Pdx1- pCDNA3.1(+) at day 10. The expression of multiple genes related to function of beta cells was analyzed using real-time PCR. The functionality of IPCs in vitro was analyzed through dithizone (DTZ) staining and ELISA. IPCs were injected into the tail vein of diabetic rats, and blood glucose and insulin concentrations were measured. CHO cells transfected with Pdx1- pCDNA3.1(+) showed a significantly higher expression of Pdx1 compared with nontransfected cells. Manipulated IPCs exhibited a significantly higher expression of MafA, Nkx2.2, Nkx6.1, Ngn3, insulin, and Isl1 and a higher insulin secretion in response to glucose challenge in relation to control cells. Rats that received manipulated IPCs exhibited a higher ability to normalize blood glucose and insulin secretion when compared to controls. Our protocol might be used for more efficient cell therapy of patients with diabetes in the future.

Single-cell transcriptome sequencing reveals that cell division cycle 5-like protein is essential for porcine oocyte maturation

The brilliant cresyl blue (BCB) test is used in both basic biological research and assisted reproduction to identify oocytes likely to be developmentally competent. However, the underlying molecular mechanism targeted by the BCB test is still unclear. To explore this question, we first confirmed that BCB-positive porcine oocytes had higher rates of meiotic maturation, better rates of cleavage and development into blastocysts, and lower death rates. Subsequent single-cell transcriptome sequencing on porcine germinal vesicle (GV)-stage oocytes identified 155 genes that were significantly differentially expressed between BCB-negative and BCB-positive oocytes. These included genes such as cdc5l, ldha, spata22, rgs2, paip1, wee1b, and hsp27, which are enriched in functionally important signaling pathways including cell cycle regulation, oocyte meiosis, spliceosome formation, and nucleotide excision repair. In BCB-positive GV oocytes that additionally had a lower frequency of DNA double-strand breaks, the CDC5L protein was significantly more abundant. cdc5l/CDC5L inhibition by short interference (si)RNA or antibody microinjection significantly impaired porcine oocyte meiotic maturation and subsequent parthenote development. Taken together, our single-oocyte sequencing data point to a potential new role for CDC5L in porcine oocyte meiosis and early embryo development, and supports further analysis of this protein in the context of the BCB test.

Sonic hedgehog pathway suppression and reactivation accelerates differentiation of rat adipose-derived mesenchymal stromal cells toward insulin-producing cells

BACKGROUND AIMS

Sonic hedgehog (Shh) is an intercellular signaling molecule that regulates pancreas development in mammals. Manipulation of Shh signaling pathway can be used as reliable approach to improve the generation of functional insulin-producing cells (IPCs) from mesenchymal stromal cells (MSCs).

METHODS

In the present study, a novel differentiation protocol was used to produce IPCs from adipose tissue-derived MSCs (ATDMSCs) based on sequential inhibition and reactivation of Shh pathway. ATDMSCs were differentiated into IPCs via a 14-day basic protocol using 1% insulin transferrin selenium (ITS) and 1% nicotinamide in Dulbecco's Modified Eagle's Medium medium. A mixture of 0.25 µmol/L cyclopamine + 64 ng/mL basic fibroblast growth factor at day 3 of differentiation and 150 ng/mL recombinant Shh at day 11 of differentiation were used, respectively, to promote sequential inhibition and reactivation of Shh pathway. Insulin granule formation, glucose-stimulated insulin secretion and gene expression pattern related to the pancreatic endocrine development and function were analyzed in manipulated and unmanipulated IPCs.

RESULTS

IPCs obtained after Shh manipulation secreted higher amounts of insulin in vitro. This phenotype was accompanied by increased expression of both genes critical for β-cell function and transcription factors associated with their mature phenotype including Pdx1, MafA, Nkx2.2, Nkx6.1, Ngn3, Isl1 and insulin at day 14 of differentiation.

CONCLUSIONS

Our findings indicated that the early inhibition and late reactivation of Shh signaling pathway during the differentiation of ATDMSCs improved the functional properties of IPCs, a novel method that could be considered as an alternative approach for cell-based therapy for type 1 diabetes.

Adiponectin and resistin: potential metabolic signals affecting hypothalamo-pituitary gonadal axis in females and males of different species

Adipokines, including adiponectin and resistin, are cytokines produced mainly by the adipose tissue. They play a significant role in metabolic functions that regulate the insulin sensitivity and inflammation. Alterations in adiponectin and resistin plasma levels, or their expression in metabolic and gonadal tissues, are observed in some metabolic pathologies, such as obesity. Several studies have shown that these two hormones and the receptors for adiponectin, AdipoR1 and AdipoR2 are present in various reproductive tissues in both sexes of different species. Thus, these adipokines could be metabolic signals that partially explain infertility related to obesity, such as polycystic ovary syndrome (PCOS). Species and gender differences in plasma levels, tissue or cell distribution and hormonal regulation have been reported for resistin and adiponectin. Furthermore, until now, it has been unclear whether adiponectin and resistin act directly or indirectly on the hypothalamo–pituitary–gonadal axis. The objective of this review was to summarise the latest findings and particularly the species and gender differences of adiponectin and resistin on female and male reproduction known to date, based on the hypothalamo–pituitary–gonadal axis.

The impact of follicular fluid adiponectin and ghrelin levels based on BMI on IVF outcomes in PCOS

PURPOSE

This study aimed at evaluating the effects of polycystic ovary syndrome (PCOS) and body mass index (BMI) on follicular fluid (FF) adiponectin and ghrelin levels, and on in vitro fertilization outcomes in patients who underwent controlled ovarian hyperstimulation.

METHODS

This prospective cross-sectional study was performed with a total of 120 primary infertile women [group 1; non-PCOS = 60 (BMI <25 = 30, BMI ≥25 = 30) and group 2; PCOS = 60 (BMI <25 = 30, BMI ≥25 = 30)]. On the day of oocyte pickup, FF samples were collected.

RESULTS

The FF adiponectin levels were lower in the lean PCOS group than the lean non-PCOS group (p = 0.001), and these levels were lower in the overweight non-PCOS group compared to lean non-PCOS group (0.001). However, there was no difference in the FF ghrelin levels between the groups. Additionally, we could not find a relationship between clinical pregnancy and adiponectin and ghrelin levels.

CONCLUSION

The FF adiponectin and ghrelin levels have no effects on clinical pregnancy in PCOS. Therefore, further studies are needed to elucidate this issue.

Association of glucose-6-phosphate dehydrogenase activity with oocyte cytoplasmic lipid content, developmental competence, and expression of candidate genes in a sheep model

PURPOSE

To evaluate associations of glucose-6-phosphate dehydrogenase (G6PDH) activity in sheep oocytes with cytoplasmic lipid content, maturational competence, developmental competence to the blastocyst stage, and gene expression of certain molecular markers.

METHODS

Before brilliant cresyl blue (BCB) staining test, oocytes were classified as high, middle, and low cytoplasmic lipid content (HCLC, MCLC, and LCLC) and after the test as having low or high G6PDH-activity (BCB(+) and BCB(-), respectively). After maturation in vitro, a group of oocytes were subjected to IVF followed by in vitro embryo culture and another group was used for evaluation of expression of candidate genes.

RESULTS

The cleavage and blastosyst rates were lowest (P < 0.05) in LCLC group, intermediate (P < 0.05) in MCLC group and highest (P < 0.05) in HCLC group. More (P < 0.05) oocytes in HCLC group were BCB(+), and higher (P < 0.05) maturation, cleavage, and blastocyst rates were seen for BCB(+) oocytes than the BCB(-) oocytes. Our gene expression data indicated that mRNA transcript abundance of ITGB2, pZP3, BMP15, and GDF9 genes was similar between BCB oocytes groups. However, the expression of ATP1A1 was higher (P < 0.05) for BCB(+) oocytes compared to BCB(-) oocytes. In addition, BAX transcript abundance was similar (P > 0.05) among BCB(+), BCB(-), and control groups, before and after maturation in vitro.

CONCLUSION

Activity of G6PDH in sheep oocytes is highly associated with lipid content, and compared with the morphological parameters might be a more precise and objective predictor for subsequent developmental competence in vitro.

The effect of nutrition and metabolic status on the development of follicles, oocytes and embryos in ruminants

The impact of nutrition and energy reserves on the fertility of ruminants has been extensively described. However, the metabolic factors and the molecular mechanisms involved in the interactions between nutrition and ovarian function are still poorly understood. These factors could be hormonal (either reproductive and/or metabolic) and/or dietary and metabolic (glucose, amino acids and fatty acids). In this review, we briefly summarize the impact of those nutrients (fatty acids, glucose and amino acids) and metabolic hormones (insulin/IGF-I, growth hormone, T3/4, ghrelin, apelin and the adipokines (leptin, adiponectin and resistin)) implicated in the development of ovarian follicles, oocytes and embryos in ruminants. We then discuss the current hypotheses on the mechanisms of action of these factors on ovarian function. We particularly describe the role of some energy sensors including adenosine monophosphate-activated kinase and peroxisome proliferator-activated receptors in the ovarian cells.

Ovarian HMW adiponectin is associated with folliculogenesis in women with polycystic ovary syndrome

BACKGROUND

Adiponectin may regulate ovarian steroidogenesis, folliculogenesis and ovulation. The alterations in the distribution of adiponectin multimers in follicular fluid (FF) and the relationship between adiponectin multimers and folliculogenesis in women with polycystic ovary syndrome (PCOS) remain unclear. In this study, we aimed to investigate the association between the levels of total and high molecular weight (HMW) adiponectin in serum and FF and folliculogenesis in women undergoing in vitro fertilisation (IVF).

METHODS

This prospective study included ten Chinese women with PCOS and ten controls undergoing IVF. The levels of the total and HMW adiponectin in serum and FF were determined by ELISA. Insulin resistance (IR) was estimated using the homeostasis model assessment insulin resistance index (HOMA-IR).

RESULTS

After controlling for the body mass index (BMI), the levels of the total, and the HMW adiponectin in the serum and FF were significantly lower in the women with PCOS compared with the normovulatory women undergoing IVF (P < 0.05). The levels of the HMW adiponectin were significantly lower in the FF than in the serum (P < 0.01). No significant differences were found in the total adiponectin levels in the serum and in the FF (P > 0.05). Decreased HMW adiponectin in the FF was associated with an increased number of follicles and decreased follicular diameters in the normovulatory and PCOS women, and this association was independent of the overall adiposity. A strong positive linear correlation was observed between the number of the follicles and the IR estimated by HOMA-IR (r = 0.784, P < 0.0001). We found that the larger follicular diameters had a negative relationship with the IR estimated by HOMA-IR (r = -0.445, P < 0.05). A strong negative linear correlation was observed between HOMA-IR and the HMW adiponectin levels (r = -0.726, P < 0.001) and the total adiponectin levels (r = -0.759, P < 0.001) in the FF.

CONCLUSIONS

The levels of the total adiponectin and the HMW adiponectin in the FF and serum were decreased in the Chinese women with PCOS compared with the normovulatory women undergoing IVF, and the differences persisted after controlling for the BMI. Ovarian HMW adiponectin is negatively correlated to folliculogenesis.

Activation of the LH receptor up regulates the type 2 adiponectin receptor in human granulosa cells

PURPOSE

Adiponectin is a predominantly adipocyte-derived hormone which influences insulin sensitivity and energy homeostasis through at least two receptors, AdipoR1 and AdipoR2. In animal models, adiponectin may regulate ovarian steroidogenesis, folliculogenesis, and ovulation. The receptors AdipoR1 and AdipoR2 are present in the human ovary, but their regulation is unknown. In these studies, we determined the effects of LH receptor activation on the expression and function of the two adiponectin receptors in human granulosa cells.

METHODS

Granulosa cells were obtained at the time of oocyte retrieval in women undergoing in vitro fertilization (IVF). Cells were isolated and cultured for 48 h in DMEM/F12 medium with 5 % FBS and 50 ug/ml gentamicin. Medium was changed to low serum for 12 h and cells were treated with hCG (100 ng/ml), forskolin (30 μMol/L), or FSH (1 IU/ml) for 24 h for mRNA experiments. mRNA was isolated and RT PCR was performed using Taqman assays and quantification with the delta delta CT method. For immunocytochemistry, cells were grown on chamber slides and treated with hCG for 1 to 24 h and fixed with acetone. ICC was performed with polyclonal rabbit primary antibodies followed by alexa fluor goat anti-rabbit antibody and imaging with a fluorescence microscope and Zeiss software analysis. 3β-hydroxysteroid dehydrogenase (3βHSD) enzyme activity was determined by measuring the progesterone produced when cells were provided with an excess of 22-hydroxy-cholesterol as substrate following an incubation with hCG (1 IU/ml) and/or adiponectin (10 ng/ml). Progesterone content in the media was determined by ELISA.

RESULTS

Messenger RNA for the two Adiponectin receptors is differentially regulated by activation of LHR with hCG treatment. AdipoR2 was increased nearly 4-fold (p < 0.05), whereas AdipoR1 expression was not changed by hCG treatment. Treatment with either FSH or forskolin (an activator of cAMP) had similar effects. Basal AdipoR2 protein was fairly low in granulosa cells in culture however treatment of cells with hCG resulted in a discernible increase in immunodetectable cytoplasmic protein as early as 6 h after treatment and was maintained for at least 24 h. The number of cells positive for AdipoR2 at 6 h increased from a basal of 20 % to almost 60 % (p < 0.05). Adiponectin treatment of hCG-primed cells resulted in increased 3βHSD activity by approximately 60 % over hCG alone and more than 3-fold over basal levels.

CONCLUSIONS

AdipoR2 is regulated by the LH receptor function via a cAMP dependant mechanism. Increased expression of adipoR2 prior to and following ovulation may contribute to enhanced 3βHSD activity and increased progesterone secretion by the corpus luteum of the ovary. Dysregulation of adiponectin that may occur with PCOS may impair normal progesterone production.

Adiponectin gene polymorphisms may not be associated with idiopathic premature ovarian failure

Premature ovarian failure (POF) is a syndrome characterized by loss of ovarian function before the age of 40 years. Adiponectin, a protein secreted by adipose tissue, exerts beneficial effects on glucose and lipid metabolism. Transcription of adiponectin and its receptor gene is correlated with follicular development. POF, as a type of pathological ovarian aging, is associated with an increase in fat mass and body weight, in which adiponectin may be involved. The present study aimed to investigate the relationship between adiponectin gene polymorphisms and idiopathic POF in Chinese women. We examined DNA samples of the variant SmaI (rs2241766) and BsmI (rs1501299) loci of the adiponectin gene in 120 POF patients and 104 controls. Polymerase chain reaction and restriction fragment length polymorphism were used to assess these genotype variants. Our results showed that the genotype distributions of the SmaI and BsmI polymorphisms did not significantly differ between the patients with idiopathic POF and the controls. Moreover, no significant difference was found between the controls and POF patients in the haplotype analysis. This suggests that the SmaI and BsmI polymorphisms of adiponectin gene might not be responsible for idiopathic POF, at least, in the Chinese population. More researches are required to determine whether these findings can be extrapolated to other populations.