Browsing by Author "Macut, Jelica Bjekić (54400683700)"

Obesity is the best described risk factor for the development of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction associated steatotic liver disease (MASLD) and polycystic ovary syndrome (PCOS) while the major pathogenic mechanism linking these entities is insulin resistance (IR). IR is primarily caused by increased secretion of proinflammatory cytokines, adipokines, and lipids from visceral adipose tissue. Increased fatty acid mobilization results in ectopic fat deposition in the liver which causes endoplasmic reticulum stress, mitochondrial dysfunction, and oxidative stress resulting in increased cytokine production and subsequent inflammation. Similarly, IR with hyperinsulinemia cause hyperandrogenism, the hallmark of PCOS, and inflammation in the ovaries. Proinflammatory cytokines from both liver and ovaries aggravate IR thus providing a complex interaction between adipose tissue, liver, and ovaries in inducing metabolic abnormalities in obese subjects. Although many pathogenic mechanisms of IR, NAFLD/MASLD, and PCOS are known, there is still no effective therapy for these entities suggesting the need for further evaluation of their pathogenesis. Extracellular vesicles (EVs) represent a novel cross-talk mechanism between organs and include membrane-bound vesicles containing proteins, lipids, and nucleic acids that may change the phenotype and function of target cells. Adipose tissue releases EVs that promote IR, the development of all stages of NAFLD/MASLD and PCOS, while mesenchymal stem cell-derived AVs may alleviate metabolic abnormalities and may represent a novel therapeutic device in NAFLD/MASLD, and PCOS. The purpose of this review is to summarize the current knowledge on the role of adipose tissue-derived EVs in the pathogenesis of IR, NAFLD/MASLD, and PCOS. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

Obesity is the best described risk factor for the development of non-alcoholic fatty liver disease (NAFLD)/metabolic dysfunction associated steatotic liver disease (MASLD) and polycystic ovary syndrome (PCOS) while the major pathogenic mechanism linking these entities is insulin resistance (IR). IR is primarily caused by increased secretion of proinflammatory cytokines, adipokines, and lipids from visceral adipose tissue. Increased fatty acid mobilization results in ectopic fat deposition in the liver which causes endoplasmic reticulum stress, mitochondrial dysfunction, and oxidative stress resulting in increased cytokine production and subsequent inflammation. Similarly, IR with hyperinsulinemia cause hyperandrogenism, the hallmark of PCOS, and inflammation in the ovaries. Proinflammatory cytokines from both liver and ovaries aggravate IR thus providing a complex interaction between adipose tissue, liver, and ovaries in inducing metabolic abnormalities in obese subjects. Although many pathogenic mechanisms of IR, NAFLD/MASLD, and PCOS are known, there is still no effective therapy for these entities suggesting the need for further evaluation of their pathogenesis. Extracellular vesicles (EVs) represent a novel cross-talk mechanism between organs and include membrane-bound vesicles containing proteins, lipids, and nucleic acids that may change the phenotype and function of target cells. Adipose tissue releases EVs that promote IR, the development of all stages of NAFLD/MASLD and PCOS, while mesenchymal stem cell-derived AVs may alleviate metabolic abnormalities and may represent a novel therapeutic device in NAFLD/MASLD, and PCOS. The purpose of this review is to summarize the current knowledge on the role of adipose tissue-derived EVs in the pathogenesis of IR, NAFLD/MASLD, and PCOS. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

Polycystic ovary syndrome is a heterogeneous endocrine and metabolic disorder associated with abdominal obesity, dyslipidemia and insulin resistance. Since abdominal obesity is characterized by low-grade inflammation, the aim of the study was to investigate whether visceral adipose tissue inflammation linked to abdominal obesity and dyslipidemia could lead to impaired insulin sensitivity in the animal model of polycystic ovary syndrome. Female Wistar rats were treated with nonaromatizable 5α-dihydrotestosterone pellets in order to induce reproductive and metabolic characteristics of polycystic ovary syndrome. Glucose, triglycerides, non-esterified fatty acids and insulin were determined in blood plasma. Visceral adipose tissue inflammation was evaluated by the nuclear factor kappa B intracellular distribution, macrophage migration inhibitory factor protein level, as well as TNFα, IL6 and IL1β mRNA levels. Insulin sensitivity was assessed by intraperitoneal glucose tolerance test and homeostasis model assessment index, and through analysis of insulin signaling pathway in the visceral adipose tissue. Dihydrotestosterone treatment led to increased body weight, abdominal obesity and elevated triglycerides and non-esterified fatty acids, which were accompanied by the activation of nuclear factor kappa B and increase in macrophage migration inhibitory factor, IL6 and IL1β levels in the visceral adipose tissue. In parallel, insulin sensitivity was affected in 5α-dihydrotestosterone-treated animals only at the systemic and not at the level of visceral adipose tissue. The results showed that abdominal obesity and dyslipidemia in the animal model of polycystic ovary syndrome were accompanied with low-grade inflammation in the visceral adipose tissue. However, these metabolic disturbances did not result in decreased tissue insulin sensitivity.

Polycystic ovary syndrome is a heterogeneous endocrine and metabolic disorder associated with abdominal obesity, dyslipidemia and insulin resistance. Since abdominal obesity is characterized by low-grade inflammation, the aim of the study was to investigate whether visceral adipose tissue inflammation linked to abdominal obesity and dyslipidemia could lead to impaired insulin sensitivity in the animal model of polycystic ovary syndrome. Female Wistar rats were treated with nonaromatizable 5α-dihydrotestosterone pellets in order to induce reproductive and metabolic characteristics of polycystic ovary syndrome. Glucose, triglycerides, non-esterified fatty acids and insulin were determined in blood plasma. Visceral adipose tissue inflammation was evaluated by the nuclear factor kappa B intracellular distribution, macrophage migration inhibitory factor protein level, as well as TNFα, IL6 and IL1β mRNA levels. Insulin sensitivity was assessed by intraperitoneal glucose tolerance test and homeostasis model assessment index, and through analysis of insulin signaling pathway in the visceral adipose tissue. Dihydrotestosterone treatment led to increased body weight, abdominal obesity and elevated triglycerides and non-esterified fatty acids, which were accompanied by the activation of nuclear factor kappa B and increase in macrophage migration inhibitory factor, IL6 and IL1β levels in the visceral adipose tissue. In parallel, insulin sensitivity was affected in 5α-dihydrotestosterone-treated animals only at the systemic and not at the level of visceral adipose tissue. The results showed that abdominal obesity and dyslipidemia in the animal model of polycystic ovary syndrome were accompanied with low-grade inflammation in the visceral adipose tissue. However, these metabolic disturbances did not result in decreased tissue insulin sensitivity.

Background: The polycystic ovary syndrome (PCOS) is a frequent endocrine disorder that affects women of reproductive age. As the syndrome is strongly associated with obesity, it is of interest to examine the gene expression differences that accompany its development and the associated metabolic disturbances. Real-time RT PCR is a standard method for studying changes in gene expression. However, to obtain accurate and reliable results, validation of reference genes is obligatory. The aim of this study was to identify a suitable reference for the normalization of gene expression in peripheral blood mononuclear cells (PBMCs) from obese and normal-weight women with PCOS. Mathods: The expression stability of four potential reference genes: hypoxanthine guanine phosphoribosyl transferase 1 (HPRT), β-actin (BA), β2-microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was assessed in PBMCs from healthy women, and from normal-weight and obese women with PCOS. The variability in the expression of potential reference genes was analyzed by the TaqMan real-time RT PCR method, using GeNorm and NormFinder software packages. Results: Direct comparison of cycle threshold (Ct) values showed inter-individual variations for all validated genes, the Ct values of HPRT being less variable than those of BA, GAPDH and B2M. Both software packages pointed to HPRT as the most steadily expressed gene in the PBMCs of women with PCOS and healthy controls. Conclusions: Cross-validation of the expression stability of four potential reference genes identified HPRT as the most stable reference, suitable for further investigations of gene expression in PBMCs from women with PCOS.

Background: The polycystic ovary syndrome (PCOS) is a frequent endocrine disorder that affects women of reproductive age. As the syndrome is strongly associated with obesity, it is of interest to examine the gene expression differences that accompany its development and the associated metabolic disturbances. Real-time RT PCR is a standard method for studying changes in gene expression. However, to obtain accurate and reliable results, validation of reference genes is obligatory. The aim of this study was to identify a suitable reference for the normalization of gene expression in peripheral blood mononuclear cells (PBMCs) from obese and normal-weight women with PCOS. Mathods: The expression stability of four potential reference genes: hypoxanthine guanine phosphoribosyl transferase 1 (HPRT), β-actin (BA), β2-microglobulin (B2M) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was assessed in PBMCs from healthy women, and from normal-weight and obese women with PCOS. The variability in the expression of potential reference genes was analyzed by the TaqMan real-time RT PCR method, using GeNorm and NormFinder software packages. Results: Direct comparison of cycle threshold (Ct) values showed inter-individual variations for all validated genes, the Ct values of HPRT being less variable than those of BA, GAPDH and B2M. Both software packages pointed to HPRT as the most steadily expressed gene in the PBMCs of women with PCOS and healthy controls. Conclusions: Cross-validation of the expression stability of four potential reference genes identified HPRT as the most stable reference, suitable for further investigations of gene expression in PBMCs from women with PCOS.

Objective: Most women with PCOS have increased adrenal androgen production, enhanced peripheral metabolism of cortisol and elevation in urinary excretion of its me-tabolites. Increased cortisol clearance in PCOS is followed by a compensatory overdrive of the hypothalamic-pituitary-adrenocortical (HPA) axis. We hypothesized that oral contraceptives containing ethinylestradiol and drospirenone (EE-DRSP) could modulate glucocorticoid receptor (GR) expression and function and thus affect HPA axis activity in PCOS patients. Design: We analyzed 12 women with PCOS (age 24.17±4.88 years; body mass index 22.05±3.97 kg/m 2) treated for 12 months with EE-DRSP and 20 BMI‑matched controls. In all subjects testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hor-mone‑binding globulin (SHBG), cortisol (basal and after dexamethasone), concentrations of GR protein, phospo-GR211 protein, number of GR per cell (B max) and its equilibrium dissociation constant (K D) were measured. Results: Before treatment, increased concentrations of testosterone and DHEAS (p<0.001, respectively), unaltered basal cortisol and an increased sensitivity (p<0.05) of the HPA axis to dexamethasone were observed in PCOS women in comparison to controls. After treatment, testosterone (p<0.01), DHEAS (p<0.05) and cortisol suppression after dexamethasone (p<0.01) were decreased in PCOS women. There were no changes in GR protein concentration, GR phosphorylation nor in the receptor functional parameters B max and K D in women with PCOS before and after the therapy, and in comparison to controls. Conclusions: Prolonged treatment with EE-DRSP in PCOS women decreased serum androgens and increased cortisol in the presence of decreased sensitivity of the HPA axis and did not exert changes in GR expression and function. © 2015, Hellenic Endocrine Society. All rights reserved.