Periovarian Adipose Tissue Research Articles

Adipokines level in plasma, hypothalamus, ovaries, and adipose tissue of rat's polycystic ovary syndrome model

Research questionDo the levels of adipokines (adiponectin, apelin, chemerin and vaspin) in plasma, hypothalamus, ovaries, and periovarian adipose tissue differ during polycystic ovarian syndrome (PCOS)? DesignThe PCOS was induced in rats by oral administration of nonsteroidal aromatase inhibitor letrozole. To determine the plasma levels of adiponectin, apelin, chemerin, and vaspin we performed enzyme-linked immunosorbent assays. To assess the expression (gene and protein) and immunolocalization of these adipokines and their receptors, namely Adipor1 and Adipor2 for adiponectin; Aplnr for apelin; Ccrl2, Cmklr1, and Gpr1 for chemerin; and Grp78 for vaspin in the hypothalamus, ovaries, and periovarian adipose tissue we conducted by real-time PCR, Western blot and immunohistochemistry, respectively. ResultsWe noted that PCOS modulates the plasma levels of adipokines (decreased adiponectin, increased apelin, chemerin, and vaspin) and the expression of adipokines and their receptors in the hypothalamus, ovaries, and periovarian adipose tissue compared with healthy rats. ConclusionsThis study confirmed a strong relationship between PCOS and adipokines and suggest that adipokines may be a biomarker of PCOS.

Oxford Nanopore Technologies (ONT) Full-length Transcriptomics Shows Electroacupuncture ameliorates Lipid Metabolic Disorder through Suppressing Hepatic Pdia3/Perk/Qrich1 Expression in Rats.

The incidence of dyslipidemia increases after menopause. Electroacupuncture (EA) has been recommended for menopause-related disease. However, the positive effect on lipid metabolism disorders is still unclear. To investigate the underlying mechanism of EA treatment on lipid metabolism disorders through ONT full-length transcriptome sequencing Methods: Adult female SD rats were randomly divided into Ctrl, sham operation+high-fat feed(Sham+HFD), Ovariectomized+high-fat feed (OVX+HFD), Ovariectomized+high-fat feed + Atorvastatin (OVX+HFD+ATO) and OVX+HFD+EA groups. Periovarian adipose tissue around the bilateral ovaries of rats in the Sham+HFD group was resected. Rats in the OVX+HFD, OVX+HFD+ATO and OVX+HFD+EA groups were subjected to bilateral oophorectomy to prepare the ovariectomized rat model. Treatment was applied to rats in the OVX+HFD+EA group. ST36, PC6, SP6, BL18 and ST40 were the selected acupoints. Daily food intake and body weights of rats were recorded. The samples were collected 30 days after treatment. The serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein (HDL-C) were detected to assess the improvement of lipid metabolism disorders. HE and oil red O staining were used to stain the liver tissues. Total RNA was extracted from liver tissues, and its transcriptional changes were determined by high-throughput sequencing. Additionally, RTÁqPCR and immunofluorescence staining were used to verify the crucial signal pathway screened by the ONT fullÁlength transcriptome sequencing. EA treatment resulted in a lowered weight of perirenal fat and liver and a significant improvement in the color of the liver. In addition, EA could improve the lipid profile and hepatic steatosis in OVX+HFD rats. According to fullÁlength transcriptome sequencing, 2292 genes showed differential expression in the OVX+HFD group; of these, 1121 were upregulated and 1171 down-regulated. 609 DEGs were found in the OVX+HFD+EA group compared to the OVX+HFD group; 235 up-regulated and 374 down-regulated. We also found that 77 genes are significantly upregulated after EA intervention through Venn map analysis (including Agtr1a, Pdia3, etc.), which may be the targeted genes for EA treatment of lipid metabolism disorders. Finally, we verified the expression of Pdia3, Perk and Qrich1 levels in liver tissues. HFD feeding could increase the expression of Pdia3 and its downstream signal pathways molecular Perk and Qrich1. But these effects were reversed by EA treatment, the results demonstrated that the expression of pdia3, Perk, as well as Qrich1 of OVX+HFD rats had a decreasing trend after EA treatment. EA could ameliorate lipid metabolic disorder in OVX+HFD rats. The Pdia3/Perk/Qrich1 signal pathway may play crucial roles in the improvement of lipid metabolism disorder of OVX+HFD rats after EA treatment.

Expression and localization of the neuropeptide phoenixin-14 and its receptor GRP173 in the canine reproductive organs and periovarian adipose tissue

Phoenixin-14 (PNX-14) is a regulatory neuropeptide encoded by the SMIM20 gene, which has been implicated in the reproductive cycle by modulating the hypothalamic-pituitary-gonadal (HPG) axis. Recently, we showed that PNX-14 is downregulated in bitches with cystic endometrial hyperplasia and pyometra. The objective of this study was to determine the expression of Smim20, PNX-14, and its putative receptor GRP173 in the canine ovary (both healthy and those with ovarian cysts), periovarian adipose tissue (PAT) and in the endometrium during the oestrous cycle. The expression was analysed by RT-qPCR and Western blot. In tissue sections, peptides were localised by immunofluorescent assays, and blood plasma concentrations of PNX-14 were detected by EIA. The results demonstrated increased levels of PNX in bitches in the anestrus groups compared to diestrus animals. The expression of GPR173 increased in PAT during the diestrus phase and endometrial tissue in late diestrus bitches. In the ovary, strong signals of PNX-14 and GPR173 were detected in the luteal and follicular cells. Furthermore, bitches with cystic ovaries were characterised by elevated circulating PNX levels and a significantly higher expression of PNX and GPR173 in gonadal tissues, when compared with healthy animals. Moreover, a positive correlation between PNX and progesterone in the blood of healthy bitches was noted, which changed to a negative correlation in females affected by cystic ovaries. These studies expand the knowledge regarding the expression and localization of the PNX/GRP173 system in canine reproductive organs during physiological and pathological conditions.

Physical exercise alleviates oxidative stress in brown adipose tissue and causes changes in body composition and nutritional behavior in rats with polycystic ovary syndrome

AimPolycystic Ovary Syndrome (PCOS) is a very common endocrine disorder in women. We investigate the effect of physical exercise on body composition, nutritional parameters, and oxidative stress in rats with PCOS. MethodsFemale rats were into three groups: Control, PCOS, and PCOS + Exercise. PCOS was induced by letrozole (1 mg/kg via p.o.) for 21 days consecutively. Physical exercise was swimming, for 21 consecutive days, 1 h/day with 5 % load. In all groups, we assessed the nutritional and murinometric parameters, body composition, thermography, and oxidative stress in brown adipose tissue (BAT) and peri-ovarian adipose tissue (POAT). Key findingsIn PCOS we observed an increase (P < 0.05) in body weight vs. the Control group. But, the PCOS + Exercise group prevent this weight gain (P < 0.05). The temperature in BAT, decrease (P < 0.05) in the PCOS group vs. Control group. PCOS + Exercise prevented this reduction (P < 0.05) in BAT temperature vs. PCOS groups. We observed decreases (P < 0.05) in Lee Index and BMI in POS + Exercise vs. PCOS group. In PCOS rats, we observed an increase (P < 0.05) in murinometric (SRWG, EI, and FE) and body composition parameters (TWB, ECF, ICF, and FFM) vs. the Control group. The PCOS + Exercise prevents (P < 0.05) these changes in all groups, compared with PCOS. Regarding the BAT, we observe an increase (P < 0.05) in MPO and MDA levels in the PCOS vs. Control group. PCOS + Exercise prevents (P < 0.05) these increases vs. the PCOS group. SignificancePCOS modifies body composition, and nutritional parameters, and induces changes in oxidative stress in BAT. Physical exercise prevented these alterations.

Influence of maternal periuterine and periovarian fat on reproductive performance and fetal growth in rats.

We aimed to evaluate how high-fat diet consumption can interfere with rat reproductive performance and fetal development. High-fat diet (HFD) was initiated in 30-day-old rats, distributed into two groups (n=7 animals/group): Rats receiving a standard diet and rats receiving HFD. At adulthood, the rats were mated, and on day 21 of pregnancy, the females were anesthetized, decapitated, and submitted to laparotomy to obtain visceral and periovarian adipose tissue. The uterine horns were exposed for analysis of maternal reproductive performance. The fetuses and placentas were weighed and analyzed. Pearson's correlation test was used, and p<0.05 was considered significant. There was a significant positive correlation (HFD consumption x increased periovarian fat) and a negative correlation with the implantation, live fetus numbers and lower litter weight. Furthermore, the increased relative weight of periuterine fat was related to the lower number of live fetuses and litter weight. Regarding the fetal weight classification, there was a negative correlation between the relative weight of periovarian fat and the percentage of fetuses appropriate for gestational age and large for gestational age. Therefore, our findings show that HFD maternal intake negatively influenced on reproductive performance and fetal growth.

Effect of Desmodium renifolium on ovariectomized rat model of osteoporosis via BMP-2/Smads signaling pathway

This study aimed to investigate the effect of Desmodium renifolium(Linn.) Schindl on ovariectomized rat model of osteoporosis and explore the underlying mechanism. Rats were randomized into a sham group, a model group, a Xianlin Gubao group, and low-, medium-, and high-dose D. renifolium groups. Bilateral oophorectomy was performed in other groups except sham group(removal of bilateral peri-ovarian adipose tissue). The sham group and model group were administrated with equal volume of 0.5% CMC-Na, Xianlin Gubao group with Xianlin Gubao, and D. renifolium groups with different concentrations of alcoholic extract of D. renifolium once a day for 14 weeks. The body weight of rats were recorded during the experiment. The levels of estradiol(E_2), 1,25-dihydroxyvitamin D_3 [1,25(OH)_2D_3], calcium(Ca), and phosphorus(P) in serum were determined after the administration. The femur microstructure was analyzed via micro-CT. RT-PCR and Western blot were employed to respectively determine the mRNA and protein levels of bone morphogenetic protein 2(BMP-2), Runt-related transcription factor 2(Runx2), and osterix(OSX) in the tibia of rats. The results indicated that D. renifolium significantly inhibited the weight growth, improved the uterus appearance, elevated the levels of E_2, Ca, P, and 1,25(OH)_2D_3 in serum, increased the number and reduced the fracture of bone trabeculae, ameliorated the bone microstructure parameters, and up-regulated the mRNA and protein levels of BMP-2, Runx2, and OSX. All the results demonstrated that D. renifolium had significant protective effect on the ovariectomized rat model of osteoporosis by regulating the BMP-2/Smads signaling pathway.

Exposure to maternal hyperglycemia and high-fat diet consumption after weaning in rats: repercussions on periovarian adipose tissue.

Clinical and epidemiological studies show that maternal hyperglycemia can change the programming of offspring leading to transgenerational effects. These changes may be related to environmental factors, such as high-fat diet (HFD) consumption, and contribute to the comorbidity onset at the adulthood of the offspring. The objective of this study was to evaluate the hyperglycemic intrauterine environment, associated or not with an HFD administered from weaning to adult life on the periovarian adipose tissue of rat offspring Maternal diabetes was chemically induced by Streptozotocin. Female offsprings were randomly distributed into four experimental groups (n = 5 animals/group): Female offspring from control or diabetic mothers and fed an HFD or standard diet. HFD was prepared with lard enrichment and given from weaning to adulthood. On day 120 of life, the rats were anesthetized and sacrificed to obtain adipose tissue samples. Then, the hyperglycemic intrauterine environment and HFD fed after weaning caused a higher body weight, total fat, and periovarian fat in adult offspring, which could compromise the future reproductive function of these females. These rats showed higher adiposity index and adipocyte area, contributing to hypertrophied adipose tissue. Therefore, maternal diabetes itself causes intergenerational changes and, in association with the HFD consumption after weaning, exacerbated the changes in the adipose tissue of adult female offspring.

Pleiotrophin Deficiency Induces Browning of Periovarian Adipose Tissue and Protects against High-Fat Diet-Induced Hepatic Steatosis.

(1) Background: Pleiotrophin preserves insulin sensitivity, regulates adipose tissue lipid turnover and plasticity, energy metabolism and thermogenesis. The aim of this study was to determine the role of pleiotrophin in hepatic lipid metabolism and in the metabolic crosstalk between the liver and brown and white adipose tissue (AT) in a high-fat diet-induced (HFD) obesity mice model. (2) Methods: We analyzed circulating variables, lipid metabolism (hepatic lipid content and mRNA expression), brown AT thermogenesis (UCP-1 expression) and periovarian AT browning (brown adipocyte markers mRNA and immunodetection) in Ptn−/− mice either fed with standard-chow diet or with HFD and in their corresponding Ptn+/+ counterparts. (3) Results: HFD-Ptn−/− mice are protected against the development of HFD-induced insulin resistance, had lower liver lipid content and lower expression of the key enzymes involved in triacylglycerides and fatty acid synthesis in liver. HFD-Ptn−/− mice showed higher UCP-1 expression in brown AT. Moreover, Ptn deletion increased the expression of specific markers of brown/beige adipocytes and was associated with the immunodetection of UCP-1 enriched multilocular adipocytes in periovarian AT. (4) Conclusions: Ptn deletion protects against the development of HFD-induced insulin resistance and liver steatosis, by increasing UCP-1 expression in brown AT and promoting periovarian AT browning.

Long-term intermittent cold exposure affects peri-ovarian adipose tissue and ovarian microenvironment in rats

Long-term intermittent cold exposure affects peri-ovarian adipose tissue and ovarian microenvironment in rats

Increased pro-inflammatory cytokines in ovary and effect of γ-linolenic acid on adipose tissue inflammation in a polycystic ovary syndrome model

Polycystic Ovary Syndrome (PCOS), a major endocrine disorder, affects the reproductive function of a woman, along with an association with metabolic conditions like insulin resistance and inflammation. The inflammatory nature of PCOS is much debated over, owing to numerous cases of elevation in cytokine levels. Studies have shown the beneficiary effect of Gamma-Linolenic acid (GLA) in reducing inflammation related to many conditions such as atopic dermatitis, rheumatoid arthritis, arterial disease, obesity, and even PCOS. The study aims at assessing the expression of inflammatory cytokines in the ovary and Peri-ovarian adipose tissue (POAT) of the Dehydroepiandrosterone (DHEA) induced PCOS rat model. Further, this study also evaluates the effect of γ-linolenic Acid (GLA) on these cytokines in POAT. Female Wistar rats were subcutaneously injected with 60 mg/kg DHEA daily for 28 days. These PCOS-induced rats were then orally administered with 50 mg/kg GLA for 14 days. The gene expression of cytokines was assessed by Real Time-PCR. The study showed an increase in the expression of cytokines in the ovary and POAT of the DHEA group. This suggests the role of ovarian adipose in adding to the pro-inflammatory state of PCOS. Moreover, the administration of GLA to the PCOS-induced rats resulted in a reduction of cytokine expression from the POAT, indicating that the compound was successful in reducing the associated inflammation. The study throws light on the possibility of using GLA as a supplementary or naturalistic alternative in ameliorating ovarian adipose-associated inflammation that accompanies PCOS.

Tissue Harvesting Site Effect on the Canine Adipose Stromal Vascular Fraction Quantity and Quality.

Simple SummaryAdipose stromal vascular fraction (SVF) cells are freshly isolated non-cultured mesenchymal stem cells, which have been recently applied in the treatment of several musculoskeletal inflammatory conditions in dogs. However, the best adipose tissue (AT) sampling site is still challenging. This study first addressed the ideal AT harvesting site in canines ranging between middle and old age, the most susceptible age to chronic musculoskeletal problems. Our results showed that the peri-ovarian region is the best AT harvesting site, which yields high amounts of SVF cells with enough adipose-derived stem cells. These data may help the further set-up of cell-based regenerative therapies at the preclinical and experimental level in canines.Mesenchymal stem cells (MSCs) constitute a great promise for regenerative therapy, but these cells are difficultly recovered in large amounts. A potent alternative is the stromal vascular fraction (SVF), non-cultured MSCs, separated from adipose tissue (AT). We aim to evaluate AT harvesting site effect on the SVF cells’ quantity and quality in dogs. Subcutaneous abdominal fat, falciform ligament and peri-ovarian fat were sampled. After SVF isolation, the trypan blue exclusion test and a hemocytometer were used to assess the cell viability and cellular yield. SVF cells were labeled for four surface antigenic markers, clusters of differentiation CD90, CD44, CD29, and CD45, and then examined by flow cytometry. Semi-quantitative RT-PCR was used to evaluate the gene expression of the former markers in addition to OCT-4 and CD34. SVF cells in the peri-ovarian AT recorded the highest viability% (99.63 ± 0.2%), as well as a significantly higher cellular yield (36.87 ± 19.6 × 106 viable cells/gm fat, p < 0.001) and a higher expression of adipose-derived mesenchymal stem cells AD-MSCs surface markers than that of other sites. SVF cells from the peri-ovarian site revealed a higher expression of MSC markers (CD90, CD44, and CD29) and OCT-4 compared to the other sites, with weak CD45 and CD34 expressions. The positive OCT-4 expression demonstrated the pluripotency of SVF cells isolated from different sites. To conclude, the harvesting site is a strong determinant of SVF cells’ quantity and quality, and the peri-ovarian site could be the best AT sampling site in dogs.

Altered vitamin D3 metabolism in the ovary and periovarian adipose tissue of rats with letrozole-induced PCOS

Vitamin D3 (VD3) plays an important role in the ovary and its deficiency is associated with ovarian pathologies, including polycystic ovary syndrome (PCOS). However, there is no data related to VD3 metabolism in the ovary during PCOS. Herein, we investigated differences in the expression of VD3 receptor (VDR) and key VD3 metabolic enzymes, 1α-hydroxylase (CYP27B1) and 24-hydroxylase (CYP24A1), in the ovary and periovarian adipose tissue (POAT) of control (proestrus and diestrus) and PCOS induced by letrozole rats. Vdr, Cyp27b1 and Cyp24a1 mRNA expression was determined, their protein abundance was examined and immunolocalized. Furthermore, VD3 metabolite concentrations in plasma (25OHD) and tissues (ovary and POAT; 1,25(OH)2D3), and plasma calcium level were determined. 25OHD concentration decreased markedly in letrozole-treated rats in comparison with controls, whereas calcium concentration did not vary among the examined groups. The amount of 1,25(OH)2D3 decreased in both ovary and POAT of PCOS rats. In the ovary, we found decreased Cyp27b1 and increased Vdr mRNA expression in letrozole-treated and diestrus control group. Corresponding protein abundances were down-regulated and up-regulated, respectively but only following letrozole treatment. In POAT, only Cyp27b1 transcript level and CYP27B1 protein abundance were decreased in letrozole-treated rats. VDR was immunolocalized in healthy and cystic follicles, while CYP27B1 and CYP24A1 were found exclusively in healthy ones. Concluding, our results provide the first evidence of disrupted VD3 metabolism in the ovary and POAT of PCOS rats. The reduced 1,25(OH)2D3 concentration in those tissues suggests their contribution to VD3 deficiency observed in PCOS and might implicate in PCOS pathogenesis.

Removal of peri-ovarian adipose tissue affects follicular development and lipid metabolism†

The development and maturity of follicles are regulated by sex hormones and growth factors. It has been proven that peri-ovarian adipose tissue (POAT) plays an important role in folliculogenesis and fertility in the female ICR and KM mice. The aim of the present study was to further investigate whether the removal of bilateral POAT affected follicular development and lipid metabolism in the female C57BL/6J mice. Female C57BL/6J mice at 6-week old were sham-operated (Sham) or removed bilateral POAT (Surgery). After 2 weeks, the mice were subjected to the body composition analysis and indirect calorimetry measurement. Our results show that the Surgery mice exhibited abnormal follicular development, including increased follicular dysplasia and atresia, decreased serum sex hormone levels, and abnormal expression of follicular development-related genes. Correspondingly, the endometrial thickness of the Surgery mice was less than the Sham mice. In addition, the Surgery mice had abnormal lipid metabolism, including reduced fat mass, increased energy expenditure, and up-regulated gene and protein expression involved in lipolysis. These data confirmed the importance of POAT in the follicular development in the female reproduction and suggested the contribution of POAT to the whole-body lipid metabolism.

Levels of the neuropeptide phoenixin-14 and its receptor GRP173 in the hypothalamus, ovary and periovarian adipose tissue in rat model of polycystic ovary syndrome

Phoenixin (PNX) is a newly discovered peptide produced by proteolytic cleavage of a small integral membrane protein 20 (Smim20), which acts as an important regulator of energy homeostasis and reproduction. Since dysfunction of reproduction is characteristic in polycystic ovarian syndrome (PCOS), the role of PNX in pathogenesis of PCOS needs further investigation. The objective of this study was to determine expression of Smim20, PNX-14 and its receptor GRP173 in the hypothalamus, ovary and periovarian adipose tissue (PAT) of letrozole induced PCOS rats. Phosphorylation of extracellular signal-regulated kinase (ERK1/2), protein kinases A (PKA) and B (Akt) were also estimated. We observed that PCOS rats had high weight gain and a number of ovarian cyst, high levels of testosterone, luteinizing hormone and PNX-14, while low estradiol. Smim20 mRNA expression was higher in the ovary and PAT, while PNX-14 peptide production was higher only in the ovary of PCOS rat. Moreover, in PCOS rats Gpr173 level was lower in PAT but at the protein level increased only in the ovary. Depending on the tissues, kinases phosphorylation were significantly differ in PCOS rats. Our results showed higher levels of PNX-14 in PCOS rats and indicated some novel findings regarding the mechanisms of PCOS pathophysiology.

Histologic analysis and lipid profiling reveal reproductive age-associated changes in peri-ovarian adipose tissue

BackgroundReproductive aging is a robust phenotype that occurs in all females and is characterized by a significant reduction in gamete quantity and quality, which can have negative consequences on both endocrine function and fertility. Age-associated differences in the oocyte, follicle, and ovary have been well-documented, but how the broader environment changes with age is less well understood. Fat is one of the largest organs in the body, and peri-gonadal adipose tissue surrounds the rodent ovary and comprises a local ovarian environment. The goal of this study was to characterize how peri-ovarian adipose tissue changes with advanced reproductive age.MethodsWe isolated peri-gonadal adipose tissue from two cohorts of CB6F1 mice: reproductively young (6–12 weeks) and reproductively old (14–17 months). A comparative histological analysis was performed to evaluate adipocyte architecture. We then extracted lipids from the tissue and performed multiple reaction monitoring (MRM)-profiling, a mass spectrometry-based method of metabolite profiling, to compare the lipid profiles of peri-gonadal adipose tissue in these age cohorts.ResultsWe found that advanced reproductive age was associated with adipocyte hypertrophy and a corresponding decrease in the number of adipocytes per area. Of the 10 lipid classes examined, triacylglycerols (TAGs) had significantly different profiles between young and old cohorts, despite quantitative analysis revealing a decrease in the total amount of TAGs per weight of peri-gonadal adipose tissue with age.ConclusionsThese findings pinpoint age-associated physiological changes in peri-gonadal adipose tissue with respect to adipocyte morphology and lipid profiles and lay the foundation for future studies to examine how these alterations may influence both adipocyte and ovarian function.

Peri-ovarian adipose tissue contributes to intraovarian control during folliculogenesis in mice.

Peri-ovarian adipose tissue (POAT) is a kind of intra-abdominal white adipose tissue that is present surrounding the ovaries in rodents. Recent studies demonstrated that POAT-deficient mice displayed a phenotype of delayed antral follicular development, for which decreases in serum estrogen, serum FSH and FSHR levels were responsible. However, folliculogenesis is regulated by endocrine signals and also modulated by a number of locally produced intraovarian factors whose acts are both autocrine and paracrine. Here, we used a model of surgical removal of POAT unilaterally and contralateral ovaries as controls, as both were under the same endocrine control, to assess the paracrine effect of the POAT on folliculogenesis. Surgical removal of unilateral POAT resulted in delayed antral follicular development and the increased number of atretic follicles, accompanied by decreased levels of intraovarian adipokines and growth factors, lipid accumulation and steroidogenic enzyme expression. POAT-deficient ovaries displayed compensatory increased expressions of intraovarian genes, such as Vegf and Adpn for angiogenesis, Acc, Fasn, and Gapdh involved in lipogenesis and Fshr in response to FSH stimulation. Furthermore, we demonstrated that removal of POAT promoted follicular apoptosis, caused retention of cytoplasmic YAP and inhibited PTEN-AKT-mTOR activation. These alterations were observed only in the POAT-deficient ovaries but not in the contralateral ovaries (with POAT), which suggests that a paracrine interaction between POAT and ovaries is important for normal folliculogenesis.

Prohibitin-induced obesity leads to anovulation and polycystic ovary in mice

ABSTRACTPolycystic ovary syndrome (PCOS) is a prevalent endocrine disorder and the most common cause of female infertility. However, its etiology and underlying mechanisms remain unclear. Here we report that a transgenic obese mouse (Mito-Ob) developed by overexpressing prohibitin in adipocytes develops polycystic ovaries. Initially, the female Mito-Ob mice were equally fertile to their wild-type littermates. The Mito-Ob mice began to gain weight after puberty, became significantly obese between 3-6 months of age, and ∼25% of them had become infertile by 9 months of age. Despite obesity, female Mito-Ob mice maintained glucose homeostasis and insulin sensitivity similar to their wild-type littermates. Mito-Ob mice showed morphologically distinct polycystic ovaries and elevated estradiol, but normal testosterone and insulin levels. Histological analysis of the ovaries showed signs of impaired follicular dynamics, such as preantral follicular arrest and reduced number, or absence, of corpus luteum. The ovaries of the infertile Mito-Ob mice were closely surrounded by periovarian adipose tissue, suggesting a potential role in anovulation. Collectively, these data suggest that elevated estradiol and obesity per se might lead to anovulation and polycystic ovaries independent of hyperinsulinemia and hyperandrogenism. As obesity often coexists with other abnormalities known to be involved in the development of PCOS such as insulin resistance, compensatory hyperinsulinemia and hyperandrogenism, the precise role of these factors in PCOS remains unclear. Mito-Ob mice provide an opportunity to study the effects of obesity on anovulation and ovarian cyst formation independent of the major drivers of obesity-linked PCOS.

Proteomic study of periovarian adipose tissue in 17β-estradiol-treated and untreated ovariectomized rats.

Taking into account the sexual dimorphism previously found in white adipose tissue (WAT) regarding mitochondrial function and biogenesis, as well as insulin sensitivity, the aim of this study was to go further into the role of sex hormones in this dimorphism. To achieve this objective, we used ovariectomized rats and performed a screening by means of proteomic analyses of the periovarian WAT, combined with a study of the protein levels of specific factors involved in mitochondrial function. Rats were ovariectomized at 5 weeks of age and subcutaneously injected every 48 h with corn-oil (OVX group) or with 17β-estradiol (E2, 10 μg/kg body mass; OVX + E2 group) for 4 weeks prior to sacrifice. Beside proteomic analysis, protein levels of Transcription Factor A, Mitochondrial (TFAM), cytochrome oxidase (COX)II, and COXIV were determined by Western blot, and mRNA levels of peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α, ERα, ERβ, lipoprotein lipase (LPL), peroxisome proliferator-activated receptor-γ (PPARγ), and adiponectin were quantified by real-time PCR. Our results show that ovariectomy leads to an increase in anabolic processes and inflammatory protein levels as well as to a decrease in some of the markers of mitochondrial function, which are restored, at least in part, by E2 supplementation. Indeed, this E2 supplementation seems to be counteracted by a decline in ERα and in the ERα to ERβ ratio values that could be directed to avoid an over-stimulation of the E2 signaling pathway, given the possibility of an activation of extra-gonadal steroid biosynthetic pathways.

Letrozole vs estradiol valerate induced PCOS in rats: glycemic, oxidative and inflammatory status assessment.

The objective of our study was to investigate glycemic, oxidative/antioxidative and inflammatory status in letrozole and estradiol valerate induced polycystic ovarian syndrome (PCOS) models. Sixty adult female Wistar rats were divided into four groups: L (0.2 mg letrozole/0.5 ml carboxymethyl cellulose (CMC), daily for 30 days), the control group CL, EV (one i.m. injection of 5 mg EV/0.5 ml sesame oil) and its corresponding control group CEV. After 30 days, ovarian morphology was assessed through ultrasound, serum free testosterone was determined, and an oral glucose tolerance test was performed. Blood, muscle, liver and periovarian adipose tissue (POAT) were collected for oxidative/antioxidative and inflammatory status evaluation. Free testosterone was increased only in the L group, while fasting glycemia was higher in the EV group. Both L and EV led to a significantly decreased level of muscle malondialehyde (MDA) and liver glutathione peroxidase (GPx) activity, while in POAT, MDA level diminished and GPx activity increased. The only difference between the two protocols was in muscle, where after L administration, GPx activity was significantly lower. Implementation of both protocols resulted in an increased expression of pNFKB in muscle, liver and POAT. The expression of monocyte chemoattractant protein 1 (MCP1) increased in liver and POAT after L administration, while in the EV group, MCP1 and STAT3 decreased in POAT. Our study shows that both protocols are characterized by an inflammatory environment in the usually insulin resistant tissues of human PCOS, without generating oxidative stress. In addition, EV has mild metabolic effects and unexpected interference with MCP1 expression in POAT, which require further investigation.

Progressive obesity alters ovarian folliculogenesis with impacts on pro-inflammatory and steroidogenic signaling in female mice.

Diet-induced obesity induces immune cell infiltration and inflammation in peri-ovarian adipose tissue and mRNA expression of inflammatory markers in ovarian tissue. Whether these changes are associated with obesity-related ovarian dysfunction remains unknown. In the present study, qRT-PCR and Western blotting techniques were used to compare mRNA and protein abundance of ovarian immune cell and inflammation markers, along with NF-kappaB and steroidogenic pathway members in normal wild-type non-agouti (a/a; lean) and lethal yellow mice (KK.CG-A(y/)J; obese) at 6, 12, 18, or 24 wk of age. Our data revealed that, beginning at 12 wk of age, NF-kappaB inflammatory signaling members were elevated (P < 0.05) in obese females. Interestingly obesity had opposing and temporal effects on the steroidogenic enzyme pathway. Obesity decreased (P < 0.05) STAR protein at 12, 18, and 24 wk of age. CYP11A1 and CYP19A1 proteins were increased (P < 0.05) at 12 wk but were decreased (P < 0.05) at 18 and 24 wk. Interestingly, CYP19A1 was increased in lethal yellow mouse ovaries at 6 wk of age, potentially indicating early puberty onset. These data demonstrate that obesity alters expression of ovarian inflammatory and steroidogenic pathway genes in ways which could adversely affect ovarian function.