Browsing by Author "Radonjić, Nevena V. (23390243000)"

[No abstract available]

Phencyclidine (PCP), a dissociative anesthetic often abused as a hallucinogen, can induce schizophrenia-like psychosis, including positive and negative symptoms and cognitive dysfunction. PCP is a noncompetitive antagonist of the N-methyl-. d-aspartate receptor (NMDAR). NMDAR hypofunction has been proposed to be a critical component of the pathophysiology of schizophrenia, promoting deficits in gamma-aminobutyric acid (GABA)ergic signaling. Perinatal PCP administration to rodents represents one of the actual animal models of schizophrenia. Here, we explore acute and long-term effects of perinatal PCP administration on the expression of neuregulin-1, a putative risk gene described in schizophrenia. Furthermore, the effects of perinatal PCP treatment on the density of different subclasses of GABAergic cortical interneurons, redox homeostasis, and susceptibility of cortical interneurons to harmful effects of free radicals are discussed. © 2016 Elsevier Inc. All rights reserved.

Background: The presentation of schizophrenia (SCH) symptoms differs between the sexes. Long-term treatment with antipsychotics is frequently associated with decreased bone mineral density, increased fracture risk and metabolic side effects. Perinatal phencyclidine (PCP) administration to rodents represents an animal model of SCH. The aim of this study was to assess the effects of chronic haloperidol and clozapine treatment on bone mass, body composition, corticosterone, IL-6 and TNF-α concentrations and metabolic parameters in male and female rats perinatally treated with PCP. Methods: Six groups of male and six groups of female rats (n = 6-12 per group) were subcutaneously treated on 2nd, 6th, 9th and 12th postnatal day (PN), with either PCP (10 mg/kg) or saline. At PN35, one NaCl and PCP group (NaCl-H and PCP-H) started receiving haloperidol (1 mg/kg/day) and one NaCl and PCP group (NaCl-C and PCP-C) started receiving clozapine (20 mg/kg/day) dissolved in drinking water. The remaining NaCl and PCP groups received water. Dual X-ray absorptiometry measurements were performed on PN60 and PN98. Animals were sacrificed on PN100. Femur was analysed by light microscopy. Concentrations of corticosterone, TNF-α and IL-6 were measured in serum samples using enzyme-linked immunosorbent assay (ELISA) commercially available kits. Glucose, cholesterol and triacylglycerol concentrations were measured in serum spectrophotometrically. Results: Our results showed that perinatal PCP administration causes a significant decrease in bone mass and deterioration in bone quality in male and female rats. Haloperidol had deleterious, while clozapine had protective effect on bones. The effects of haloperidol on bones were more pronounced in male rats. It seems that the observed changes are not the consequence of the alterations of corticosterone, IL-6 and TNF-α concentration since no change of these factors was observed. Clozapine induced increase of body weight and retroperitoneal fat in male rats regardless of perinatal treatment. Furthermore, clozapine treatment caused sex specific increase in pro-inflammatory cytokines. Conclusion: Taken together our findings confirm that antipsychotics have complex influence on bone and metabolism. Evaluation of potential markers for individual risk of antipsychotics induced adverse effects could be valuable for improvement of therapy of this life-long lasting disease. © 2017 The Author(s).

Background: The presentation of schizophrenia (SCH) symptoms differs between the sexes. Long-term treatment with antipsychotics is frequently associated with decreased bone mineral density, increased fracture risk and metabolic side effects. Perinatal phencyclidine (PCP) administration to rodents represents an animal model of SCH. The aim of this study was to assess the effects of chronic haloperidol and clozapine treatment on bone mass, body composition, corticosterone, IL-6 and TNF-α concentrations and metabolic parameters in male and female rats perinatally treated with PCP. Methods: Six groups of male and six groups of female rats (n = 6-12 per group) were subcutaneously treated on 2nd, 6th, 9th and 12th postnatal day (PN), with either PCP (10 mg/kg) or saline. At PN35, one NaCl and PCP group (NaCl-H and PCP-H) started receiving haloperidol (1 mg/kg/day) and one NaCl and PCP group (NaCl-C and PCP-C) started receiving clozapine (20 mg/kg/day) dissolved in drinking water. The remaining NaCl and PCP groups received water. Dual X-ray absorptiometry measurements were performed on PN60 and PN98. Animals were sacrificed on PN100. Femur was analysed by light microscopy. Concentrations of corticosterone, TNF-α and IL-6 were measured in serum samples using enzyme-linked immunosorbent assay (ELISA) commercially available kits. Glucose, cholesterol and triacylglycerol concentrations were measured in serum spectrophotometrically. Results: Our results showed that perinatal PCP administration causes a significant decrease in bone mass and deterioration in bone quality in male and female rats. Haloperidol had deleterious, while clozapine had protective effect on bones. The effects of haloperidol on bones were more pronounced in male rats. It seems that the observed changes are not the consequence of the alterations of corticosterone, IL-6 and TNF-α concentration since no change of these factors was observed. Clozapine induced increase of body weight and retroperitoneal fat in male rats regardless of perinatal treatment. Furthermore, clozapine treatment caused sex specific increase in pro-inflammatory cytokines. Conclusion: Taken together our findings confirm that antipsychotics have complex influence on bone and metabolism. Evaluation of potential markers for individual risk of antipsychotics induced adverse effects could be valuable for improvement of therapy of this life-long lasting disease. © 2017 The Author(s).

Background: Maternal deprivation (MD) in rodents is an important neurodevelopmental model for studying a variety of behavioral changes which closely resemble the symptoms of schizophrenia in humans. Subjects and methods: To determine whether early-life stress leads to changes in the limbic system structures: the amygdala and the nucleus accumbens, 9-day-old Wistar rats were exposed to 24 hour MD. On P60 the rats were sacrificed for morphometric analysis and their brains were compared to the control group. Results: Results show that MD affected important limbic system structures: the amygdala and the nucleus accumbens, whose volume was decreased (17 % of the control value for the amygdala and 9% of the control value for the nucleus accumbens ), as well as the number of neurons (41 % of the control value for the amygdala and 43% of the control value for the nucleus accumbens ) and the size of their cells soma (12% of the control value for the amygdala and 33% of the control value for the nucleus accumbens ). Conclusion: This study indicates that early stress in life leads to changes in the morphology of the limbic areas of the brain, most probably due to the loss of neurons during postnatal development, and it further contributes to our understanding of the effects of maternal deprivation on brain development. © 2016 Medicinska naklada - Zagreb, Croatia.

Objective The aim of this study was to estimate insulin sensitivity (IS) in nondiabetic patients with adrenal incidentalomas (AI): nonfunctional adrenal incidentalomas (NAI) and patients with AI and subclinical Cushing's syndrome (SCS). Methods Based on the inclusion criteria (normal fasting glucose levels, no previous history of impaired fasting glucose and/or diabetes, and no medications or concomitant relevant diseases) and the exclusion criteria (pheochromocytoma, overt hypercortisolism, hyperaldosteronism, adrenal carcinoma, metastasis of extra-adrenal tumors, extra-adrenal malignancies), 142 subjects were drawn from a series of patients with AI. The subjects were age-, sex- and body mass index (BMI)-matched: 70 with NAI (50 women and 20 men), 37 with AI and SCS (31 women and 6 men) and 35 healthy control (HC) subjects (30 women and 5 men). The oral glucose tolerance test (OGTT) and several indices of insulin sensitivity (IS) were used: homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI), triglycerides and glucose index (TyG), index of whole-body insulin sensitivity (ISI-composite) and glucose to insulin ratio (G/I). Results There was a significant difference in IS between subjects with NAI and HC (HOMA, p = 0.049; QUICKI, p = 0.036; TyG, p = 0.002; ISI-composite, p = 0.024) and subjects with SCS and HC (AUC insulin, p = 0.01; HOMA, p = 0.003; QUICKI, p = 0.042; TyG, p = 0.008; ISI-composite, p = 0.002). There was no difference in the tested indices of IS between subjects with NAI and SCS (p > 0.05). However, subjects with SCS had a significantly higher prevalence of impaired glucose tolerance and higher area under the curve for glucose than subjects with NAI (p = 0.0174). The linear regression analysis showed that 1 mg-DST cannot be used as a predictor of HOMA (R2 = 0.004, F = 0.407, p = 0.525). Significant relationship was found between 1 mg-DST and ISI-composite (R2 = 0.042, F = 4.981, p = 0.028) but this relationship was weak and standard error of estimate was high. The linear regression model also showed that ACTH cannot be used as a predictor of HOMA (R2 = 0.001, F = 0.005, p = 0.943) or ISI-composite (R2 = 0.015, F = 1.819, p = 0.187). Conclusions Insulin resistance is a major cardiovascular risk factor; therefore, the assessment of IS in patients with AI, even nonfunctional, has a valuable place in the endocrine workup of these patients. © 2013 Elsevier Inc.

Objective The aim of this study was to estimate insulin sensitivity (IS) in nondiabetic patients with adrenal incidentalomas (AI): nonfunctional adrenal incidentalomas (NAI) and patients with AI and subclinical Cushing's syndrome (SCS). Methods Based on the inclusion criteria (normal fasting glucose levels, no previous history of impaired fasting glucose and/or diabetes, and no medications or concomitant relevant diseases) and the exclusion criteria (pheochromocytoma, overt hypercortisolism, hyperaldosteronism, adrenal carcinoma, metastasis of extra-adrenal tumors, extra-adrenal malignancies), 142 subjects were drawn from a series of patients with AI. The subjects were age-, sex- and body mass index (BMI)-matched: 70 with NAI (50 women and 20 men), 37 with AI and SCS (31 women and 6 men) and 35 healthy control (HC) subjects (30 women and 5 men). The oral glucose tolerance test (OGTT) and several indices of insulin sensitivity (IS) were used: homeostasis model assessment (HOMA), quantitative insulin sensitivity check index (QUICKI), triglycerides and glucose index (TyG), index of whole-body insulin sensitivity (ISI-composite) and glucose to insulin ratio (G/I). Results There was a significant difference in IS between subjects with NAI and HC (HOMA, p = 0.049; QUICKI, p = 0.036; TyG, p = 0.002; ISI-composite, p = 0.024) and subjects with SCS and HC (AUC insulin, p = 0.01; HOMA, p = 0.003; QUICKI, p = 0.042; TyG, p = 0.008; ISI-composite, p = 0.002). There was no difference in the tested indices of IS between subjects with NAI and SCS (p > 0.05). However, subjects with SCS had a significantly higher prevalence of impaired glucose tolerance and higher area under the curve for glucose than subjects with NAI (p = 0.0174). The linear regression analysis showed that 1 mg-DST cannot be used as a predictor of HOMA (R2 = 0.004, F = 0.407, p = 0.525). Significant relationship was found between 1 mg-DST and ISI-composite (R2 = 0.042, F = 4.981, p = 0.028) but this relationship was weak and standard error of estimate was high. The linear regression model also showed that ACTH cannot be used as a predictor of HOMA (R2 = 0.001, F = 0.005, p = 0.943) or ISI-composite (R2 = 0.015, F = 1.819, p = 0.187). Conclusions Insulin resistance is a major cardiovascular risk factor; therefore, the assessment of IS in patients with AI, even nonfunctional, has a valuable place in the endocrine workup of these patients. © 2013 Elsevier Inc.

The complex structure and function of the cerebral cortex critically depend on the balance of excitation and inhibition provided by the pyramidal projection neurons and GABAergic interneurons, respectively.The calretinin-expressing (CalR+) cell is a subtype of GABAergic cortical interneurons that is more prevalent in humans than in rodents. In rodents, CalR+ interneurons originate in the caudal ganglionic eminence (CGE) from Gsx2+ progenitors, but in humans it has been suggested that a subpopulation of CalR+ cells can also be generated in the cortical ventricular/subventricular zone (VZ/SVZ). The progenitors for cortically generated CalR+ subpopulation in primates are not yet characterized. Hence, the aim of this study was to identify patterns of expression of the transcription factors (TFs) that commit cortical stem cells to the CalR fate, with a focus on Gsx2. First, we studied the expression of Gsx2 and its downstream effectors, Ascl1 and Sp8 in the cortical regions of the fetal human forebrain at midgestation. Next, we established that a subpopulation of cells expressing these TFs are proliferating in the cortical SVZ, and can be co-labeled with CalR. The presence and proliferation of Gsx2+ cells, not only in the ventral telencephalon (GE) as previously reported, but also in the cerebral cortex suggests cortical origin of a subpopulation of CalR+ neurons in humans. In vitro treatment of human cortical progenitors with Sonic hedgehog (Shh), an important morphogen in the specification of interneurons, decreased levels of Ascl1 and Sp8 proteins, but did not affect Gsx2 levels. Taken together, our ex-vivo and in vitro results on human fetal brain suggest complex endogenous and exogenous regulation of TFs implied in the specification of different subtypes of CalR+ cortical interneurons. © 2014 Radonjić, Ortega, Memi, Dionne, Jakovcevski and Zecevic.

The complex structure and function of the cerebral cortex critically depend on the balance of excitation and inhibition provided by the pyramidal projection neurons and GABAergic interneurons, respectively.The calretinin-expressing (CalR+) cell is a subtype of GABAergic cortical interneurons that is more prevalent in humans than in rodents. In rodents, CalR+ interneurons originate in the caudal ganglionic eminence (CGE) from Gsx2+ progenitors, but in humans it has been suggested that a subpopulation of CalR+ cells can also be generated in the cortical ventricular/subventricular zone (VZ/SVZ). The progenitors for cortically generated CalR+ subpopulation in primates are not yet characterized. Hence, the aim of this study was to identify patterns of expression of the transcription factors (TFs) that commit cortical stem cells to the CalR fate, with a focus on Gsx2. First, we studied the expression of Gsx2 and its downstream effectors, Ascl1 and Sp8 in the cortical regions of the fetal human forebrain at midgestation. Next, we established that a subpopulation of cells expressing these TFs are proliferating in the cortical SVZ, and can be co-labeled with CalR. The presence and proliferation of Gsx2+ cells, not only in the ventral telencephalon (GE) as previously reported, but also in the cerebral cortex suggests cortical origin of a subpopulation of CalR+ neurons in humans. In vitro treatment of human cortical progenitors with Sonic hedgehog (Shh), an important morphogen in the specification of interneurons, decreased levels of Ascl1 and Sp8 proteins, but did not affect Gsx2 levels. Taken together, our ex-vivo and in vitro results on human fetal brain suggest complex endogenous and exogenous regulation of TFs implied in the specification of different subtypes of CalR+ cortical interneurons. © 2014 Radonjić, Ortega, Memi, Dionne, Jakovcevski and Zecevic.