Serotonin drives striatal synaptic plasticity in a sex-related manner.

Abstract Introduction Plasticity at corticostriatal synapses is a key substrate for a variety of brain functions – including motor control, learning and reward processing – and is often disrupted in disease conditions. Despite intense research pointing toward a dynamic interplay between glutamate, dopamine (DA), and serotonin (5-HT) neurotransmission, their precise circuit and synaptic mechanisms regulating their role in striatal plasticity are still unclear. Here, we analyze the role of serotonergic raphe-striatal innervation in the regulation of DA-dependent corticostriatal plasticity. Methods Mice (males and females, 2–6 months of age) were housed in standard plexiglass cages at constant temperature (22 ± 1 °C) and maintained on a 12/12 h light/dark cycle with food and demineralized water ad libitum. In the present study, we used a knock-in mouse line in which the green fluorescent protein reporter gene (GFP) replaced the I Tph2 exon (Tph2GFP mice), allowing selective expression of GFP in the whole 5-HT system, highlighting both somata and neuritis of serotonergic neurons. Heterozygous, Tph2+/GFP, mice were intercrossed to obtain experimental cohorts, which included Wild-type (Tph2+/+), Heterozygous (Tph2+/GFP), and Mutant serotonin-depleted (Tph2GFP/GFP) animals. Results Using male and female mice, carrying on different Tph2 gene dosages, we show that Tph2 gene modulation results in sex-specific corticostriatal abnormalities, encompassing the abnormal amplitude of spontaneous glutamatergic transmission and the loss of Long Term Potentiation (LTP) in Tph2GFP/GFP mice of both sexes, while this form of plasticity is normally expressed in control mice (Tph2+/+). Once LTP is induced, only the Tph2+/GFP female mice present a loss of synaptic depotentiation. Conclusion We showed a relevant role of the interaction between dopaminergic and serotonergic systems in controlling striatal synaptic plasticity. Overall, our data unveil that 5-HT plays a primary role in regulating DA-dependent corticostriatal plasticity in a sex-related manner and propose altered 5-HT levels as a critical determinant of disease-associated plasticity defects

pathogenesis of takotsubo syndrome

Takotsubo syndrome (TTS) is an enigmatic disease with a multifactorial and still unresolved pathogenesis. Postulated mechanisms include catecholamine excess, coronary artery spasm, and microvascular dysfunction, however catecholamines seem to play a central role in the pathophysiology of TTS. In facts catecholamines have relevant effects on the vasculature and myocardium. Toxic direct effects of catecholamine on myocardium are mediated by multiple pathway including functional hypoxia, metabolic changes and changes in membrane permeability leading to various electrolytic imbalances. Recently report of familial cases has suggested a genetic component. Further research is required to help clarify the proposed hypotheses and to increase our understanding of the cardiovascular responses to acute stress and the pathophysiology underpinning TTS

Search of somatic GATA4 and NKX2.5 gene mutations in sporadic septal heart defects

Q3Q1Reporte de caso306-309High prevalence of somatic mutations in the cardiac transcription factor genes NKX2.5 and GATA4 have been reported in the affected cardiovascular tissue of patients with isolated cardiac septal defects, suggesting a role of somatic mutations in the pathogenesis of these congenital heart defects (CHDs). However, all somatic mutations have been identified in DNA extracted from an archive of formalin-fixed cardiac tissues. In the present study, to address the hypothesis that somatic mutations are important in isolated CHDs, we analyzed the GATA4 and NKX2.5 genes in the fresh-frozen pathologic cardiac tissue specimen and corresponding non-diseased tissue obtained from a series of 62 CHD patients, including 35 patients with cardiac septal defects and 27 with other cardiac anomalies. We identified one variant and two common polymorphisms in the NKX2.5 gene, and six variants and two common polymorphisms in the GATA4 gene. All identified variants were seen in both the fresh-frozen pathologic cardiac tissue and the corresponding non-diseased tissue, which indicates that they all were constitutional variants. The present study has identified NKX2.5 and GATA4 constitutional variants in our CHD cohort, but was unable to replicate the previously published findings of high prevalence of somatically derived sequence mutations in patients with cardiac septal defects using fresh-frozen cardiac tissues rather than formalin-fixed tissues. (C) 2011 Elsevier Masson SAS. All rights reserved

Tissue Factor Is Induced by Resistin in Human Coronary Artery Endothelial Cells by the NF-?B-Dependent Pathway

Objective: Atherosclerosis is characterized by endothelial inflammation and dysfunction. Adipose tissue has increasingly been recognized as an active endocrine organ secreting so-called adipokines. Among these, resistin – recently described, but not yet extensively studied – has been defined as a novel inflammatory marker in atherosclerosis. The pathophysiology underlying this interplay, however, remains to be fully characterized. The aim of the study is to determine whether resistin might affect prothrombotic characteristics of human coronary artery endothelial cells (HCAECs). Methods and Results: Incubation of HCAECs with resistin caused upregulation of tissue factor (TF) expression as demonstrated by FACS analysis. Moreover, TF activity was induced in a dose-dependent manner, as shown by real-time PCR and colorimetric assay. Resistin-induced TF expression was mediated by oxygen free radicals through the activation of the transcription factor nuclear factor-ĸB (NF-ĸB), as demonstrated by electrophoretic mobility shift assay and by suppression of TF expression by superoxide dismutase, catalase, and the NF-ĸB inhibitors PDTC and BAY 11-7082. Conclusions: These data confirm the hypothesis that resistin may contribute to atherothrombosis, exerting direct effects on HCAECs by promoting TF expression; thus, it represents an effector molecule able to induce a prothrombotic phenotype in cells present in the vessel wall

Diastolic Pressure And Acr Are Modifiable Risk Factors Of Arterial Stiffness In T2DM Without Cardiovascular Disease

Aim: To evaluate early, before the onset of cardiovascular events and of chronic renal insufficiency, the association between CKD-mineral bone disorder biomarkers and vascular stiffness (Cardio Ankle Vascular Index, CAVI) in the course of type 2 diabetes (T2DM). Method: we evaluated 174 T2DM patients (median age 56 y; M/F = 100/74) with diabetes duration less than 10 years and without decreased glomerular filtration rate (eGFR ≥60 ml/min/1.73 m 2) or macrovascular complications. Thirty-four age matched healthy subjects (M/F: 13/21; age: 53.5[50.0-57.7] y.o; eGFR 107.5[97.0-119.7]) ml/ml/min1.73m2) served as local reference control for CAVI (pathological: ≥8) and the novel CKD-MBD biomarkers. Results: albumin-to-creatinine ratio (ACR) averaged 8.5 mg/g [5.6-17.2] with 12.6% of the patients showing pathologic values, indicative of incipient diabetic nephropathy (DN). Serum parathyroid hormone, Fibroblast Growth Factor 23 and Sclerostin were higher while 1,25-dihydroxyvitamin D and Klotho were lower than a control group. CAVI was normal (<8) in only 54% and correlated positively with age (p<.001), Hb1A1c (p=.036), systolic (p=.021) and diastolic blood pressure (DBP) (p=.001) and negatively with 25D (p=.046). In multivariate analysis, age, DBP, ACR, and s-Klotho were independent positive predictors of CAVI. Conclusion: in the absence of overt cardiovascular disease and of chronic renal insufficiency, CAVI is frequently pathologic in T2DM. DBP, and ACR are modifiable risk factors of vascular stiffness in T2DM thus warranting optimal assessment

Genetics of Takotsubo Syndrome

Takotsubo syndrome (TTS) is an enigmatic disease with a multifactorial and still unresolved pathogenesis. A genetic predisposition has been suggested based on the few familial TTS cases. Conflicting results have been published regarding the role of functional polymorphisms in relevant candidate genes, such as α1-, β1-, and β2-adrenergic receptors; G protein–coupled receptor kinase 5; and estrogen receptors. Further research is required to help clarify the role of genetic susceptibility in TTS