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Obese women often have certain degree of reproductive dysfunction with infertility. Although the clinical impact of obesity on female infertility has been extensively studied, the effective and targeted treatment is still lacking. Melanocortin-4-receptor knock-out (MC4R KO) mouse is an over-eating obese model with hyperphagia, hyperinsulinemia, reduced growth hormone (GH), and insulin resistance. Dapagliflozin improved the metabolic and hormonal parameters in MC4R KO mice. MC4R KO female mice were treated with dapagliflozin for 14 weeks from 14-week age. Age-matched WT littermates and non-treated MC4R KO mice were used as control groups. Food intake was measured daily. Body weight was measured twice a week. Estrous cycles, GH, and luteinizing hormone (LH) profiles were measured. Selected tissues were collected at the end of experiments for gene expression profiles and hematoxylin–eosin staining. Regularity and mode of hormonal profiles were restored by the dapagliflozin treatment. Estrous cycle was partially normalized, number of CL was significantly increased, and the expression of Kiss1 and Gnrh1 in the hypothalamus and LH in the pituitary was markedly increased by the dapagliflozin treatment. It is conclsuded that dapagliflozin may recover LH and GH profiles partially through modification of relevant gene expression in the hypothalamus and pituitary, and result in an improved ovulation rate in obese mouse model. Dapagliflozin may therefore improve fertility in obese patients.

Early life microglia are essential for brain development, and developmental disruption in microglial activity may have long-term implications for the neuroendocrine control of reproduction. We and others have previously shown that early life immune activation compromises the long-term potential for reproductive function in females. However, the supportive role of microglia in female reproductive development is still unknown. Here, we examined the long-term programming effects of transient neonatal microglial and monocyte ablation on hypothalamic–pituitary–gonadal (HPG) axis function in female rats. We employed a Cx3cr1-Dtr transgenic Wistar rat model to acutely ablate microglia and monocytes, commencing on either postnatal day (P) 7 or 14, since the development of the HPG axis in female rodents primarily occurs during the first two to three postnatal weeks. After an acutely diminished expression of microglia and monocyte genes in the brain and ovaries, respectively, microglia had repopulated the brain by P21, albeit that cellular complexity was still reduced in both groups at this time. Removal of microglia and monocytes on P7, but not P14 reduced circulating luteinising hormone levels in adulthood and ovarian gonadotropin receptors mRNA. These changes were notably associated with fewer primary and antral follicles in these rats. These data suggest that transient ablation of microglia and monocytes at the start of the second but not the third postnatal week has long-term effects on ovarian health. The findings highlight the important developmental role of a healthy immune system for female potential reproductive capacity and the importance of critical developmental periods to adult ovarian health.

Estrogen deficiency causes metabolic disorders in humans and rodents, including in part due to changes in energy expenditure. We have shown previously that skeletal muscle mitochondrial function is compromised in ovariectomized (Ovx) rats. Since physical exercise is a powerful strategy to improve skeletal muscle mitochondrial content and function, we hypothesize that exercise training would counteract the deficiency-induced skeletal muscle mitochondrial dysfunction in Ovx rats. We report that exercised Ovx rats, at 60–65% of maximal exercise capacity for 8 weeks, exhibited less fat accumulation and body weight gain compared with sedentary controls. Treadmill exercise training decreased muscle lactate production, indicating a shift to mitochondrial oxidative metabolism. Furthermore, reduced soleus muscle mitochondrial oxygen consumption confirmed that estrogen deficiency is detrimental to mitochondrial function. However, exercise restored mitochondrial oxygen consumption in Ovx rats, achieving similar levels as in exercised control rats. Exercise-induced skeletal muscle peroxisome proliferator-activated receptor-γ coactivator-1α expression was similar in both groups. Therefore, the mechanisms by which exercise improves mitochondrial oxygen consumption appears to be different in Ovx-exercised and sham-exercised rats. While there was an increase in mitochondrial content in sham-exercised rats, demonstrated by a greater citrate synthase activity, no induction was observed in Ovx-exercised rats. Normalizing mitochondrial respiratory capacity by citrate synthase activity indicates a better oxidative phosphorylation efficiency in the Ovx-exercised group. In conclusion, physical exercise sustains mitochondrial function in ovarian hormone-deficient rats through a non-conventional mitochondrial content-independent manner.

G_S, the stimulatory heterotrimeric G protein, is an essential regulator of osteogenesis and bone turnover. To determine if increasing Gα_S in osteoblasts alters bone responses to hyperparathyroidism, we used a transgenic mouse line overexpressing Gα_S in osteoblasts (G_S-Tg mice). Primary osteoblasts from G_S-Tg mice showed increased basal and parathyroid hormone (PTH)-stimulated cAMP and greater responses to PTH than cells from WT mice. Skeletal responses to 2-week continuous PTH administration (cPTH) in female mice resulted in trabecular bone loss in WT mice but 74% and 34% increase in trabecular bone mass in long bones and vertebrae, respectively, in G_S-Tg mice. Vertebral biomechanical strength was compromised by cPTH treatment in WT mice but not in G_S-Tg. Increased peritrabecular fibrosis was greatly increased by cPTH in G_s-Tg compared to WT mice and corresponded with greater increases in Wnt pathway proteins in trabecular bone. Cortical bone responded negatively to cPTH in WT and G_s-Tg mice with large increases in porosity, decreased cortical thickness and compromised biomechanical properties. These results demonstrate that hyperparathyroidism can increase trabecular bone when G_S expression and cAMP stimulation in osteoblasts are increased but this is not the case in cortical bone where increased G_S expression exacerbates cortical bone loss.

Loss of LEPR function (LOF) in mammals leads to diverse phenotypes including morbid obesity and infertility while zebrafish show relatively minor phenotypes. This however allows the study of LEPR LOF in the absence of the detrimental effects of hyperglycemia or obesity. Here, we show evidence that leptin plays a role in the central as well as peripheral regulation of the hypothalamic–pituitary–gonadal (HPG) axis in zebrafish. Animals with a Lepr LOF show dysregulated pituitary HPG genes as well as evidence that oocytes mature slower and/or exhibit an increased rate of atresia. In culture, Lepr LOF attenuates the effect of 17α-20β-dihydroxy-4 pregnen-3-one in promoting germinal vesicle breakdown (GVBD) and increases the rate of GVBD as well as attenuates the rate of oocyte atresia.

The aim of this study was to evaluate the paternal programming of sex-dependent alterations in fetoplacental growth and placental lipid metabolism regulated by peroxisome proliferator-activated receptor (PPAR) target genes in F1 diabetic males born from F0 pregestational diabetic rats. F1 control and diabetic male rats were mated with control female rats. On day 21 of gestation, F2 male and female fetoplacental growth, placental lipid levels, and protein and mRNA levels of genes involved in lipid metabolism and transport were evaluated. Fetal but not placental weight was increased in the diabetic group. Triglyceride, cholesterol and free fatty acid levels were increased in placentas of male fetuses from the diabetic group. The mRNA levels of Pparα and Pparγ coactivator 1α (Pgc-1α) were increased only in placentas of male fetuses from the diabetic group. Protein levels of PPARα and PGC-1α were decreased only in placentas of male fetuses from the diabetic group. No differences were found in Pparγ mRNA and protein levels in placentas from the diabetic group. The mRNA levels of genes involved in lipid synthesis showed no differences between groups, whereas the mRNA levels of genes involved in lipid oxidation and transport were increased only in placentas of male fetuses from the diabetic group. In conclusion, paternal diabetes programs fetal overgrowth and sex-dependent effects on the regulation of lipid metabolism in the placenta, where only placentas of male fetuses show an increase in lipid accumulation and mRNA expression of enzymes involved in lipid oxidation and transport pathways.