Neurotrophin/Trk receptor signaling mediates C/EBPα, -β and NeuroD recruitment to immediate-early gene promoters in neuronal cells and requires C/EBPs to induce immediate-early gene transcription

BACKGROUND: Extracellular signaling through receptors for neurotrophins mediates diverse neuronal functions, including survival, migration and differentiation in the central nervous system, but the transcriptional targets and regulators that mediate these diverse neurotrophin functions are not well understood. RESULTS: We have identified the immediate-early (IE) genes Fos, Egr1 and Egr2 as transcriptional targets of brain derived neurotrophic factor (BDNF)/TrkB signaling in primary cortical neurons, and show that the Fos serum response element area responds to BDNF/TrkB in a manner dependent on a combined C/EBP-Ebox element. The Egr1 and Egr2 promoters contain homologous regulatory elements. We found that C/EBPα/β and NeuroD formed complexes in vitro and in vivo, and were recruited to all three homologous promoter regions. C/EBPα and NeuroD co-operatively activated the Fos promoter in transfection assays. Genetic depletion of Trk receptors led to impaired recruitment of C/EBPs and NeuroD in vivo, and elimination of Cebpa and Cebpb alleles reduced BDNF induction of Fos, Egr1 and Egr2 in primary neurons. Finally, defective differentiation of cortical dendrites, as measured by MAP2 staining, was observed in both compound Cebp and Ntrk knockout mice. CONCLUSION: We here identify three IE genes as targets for BDNF/TrkB signaling, show that C/EBPα and -β are recruited along with NeuroD to target promoters, and that C/EBPs are essential mediators of Trk signaling in cortical neurons. We show also that C/EBPs and Trks are required for cortical dendrite differentiation, consistent with Trks regulating dendritic differentiation via a C/EBP-dependent mechanism. Finally, this study indicates that BDNF induction of IE genes important for neuronal function depends on transcription factors (C/EBP, NeuroD) up-regulated during neuronal development, thereby coupling the functional competence of the neuronal cells to their differentiation

Usefulness of three-dimensional computed tomographic anatomy in endoscopic frontal recess surgery

The endoscopic bidimensional vision offered by the endoscope during endoscopic sinus surgery involves difficulty in visualizing surgical field depth which makes it difficult to learn this surgical technique and makes it necessary for the endoscopic surgeon to mentally create a three-dimensional (3D) picture of the paranasal sinuses anatomy. In particular, frontal recess surgery requires good knowledge of its anatomic position, also since it is necessary to use angled endoscopes, which distort the view, and angular instruments which are difficult to use. Purpose of this project is to offer to the endoscopic surgeon a detailed 3D model of the nose and paranasal sinuses with particular attention to the frontal recess

TrkB regulates neocortex formation through the Shc/PLCγ-mediated control of neuronal migration

The generation of complex neuronal structures, such as the neocortex, requires accurate positioning of neurons and glia within the structure, followed by differentiation, formation of neuronal connections, and myelination. To understand the importance of TrkB signaling during these events, we have used conditional and knockin mutagenesis of the TrkB neurotrophin receptor, and we now show that this tyrosine kinase receptor, through docking sites for the Shc/FRS2 adaptors and phospholipase Cγ (PLCγ), coordinates these events in the cerebral cortex by (1) controlling cortical stratification through the timing of neuronal migration during cortex formation, and (2) regulating both neuronal and oligodendrocyte differentiation. These results provide genetic evidence that TrkB regulates important functions throughout the formation of the cerebral cortex via recruitment of the Shc/FRS2 adaptors and PLCγ

Reactive oxygen species-mediated effects on vascular remodeling induced by human atrial natriuretic peptide T2238C molecular variant in endothelial cells in vitro

Objectives T2238C ANP (atrial natriuretic peptide) gene variant has been associated with increased cardiovascular risk in humans and with a significant pharmacogenomic effect on cardiovascular disease outcome in hypertensive patients. We investigated the impact of T2238C ANP gene variant on oxidative stress production, cell proliferation and migration, angiogenesis and vascular remodeling in human umbilical vein endothelial cells in vitro. Methods Differentially expressed genes in human umbilical vein endothelial cells exposed to either wild-type (TT2238) or mutant (CC2238) alpha-ANP were characterized by real time-PCR-macroarray analysis using human oxidative stress, angiogenesis and matrix arrays. Reactive oxygen species (ROS) production was determined by dihydroethidium and by evaluation of dichlorofluorescein content. NADPH oxidase gp91phox subunit was investigated by western blotting. Endothelial cell proliferation, migration and tube formation were characterized both in the presence and in the absence of NADPH oxidase inhibition. Results Compared with TT2238, CC2238 alpha-ANP altered the redox state balance of the cells in a more significant manner, favoring ROS production and reducing antioxidative stress response. Gene expression of molecules involved in atherogenesis and vascular remodeling was enhanced. In contrast to TT2238 peptide, CC2238 was unable to stimulate cell proliferation and it markedly inhibited endothelial cell tube formation. NADPH oxidase inhibition restored the cell proliferative properties under CC2238 peptide exposure. Conclusion CC2238 alpha-ANP led to ROS accumulation and increased expression of genes related to atherosclerosis and vascular remodeling in human umbilical vein endothelial cells. As a consequence of NADPH-derived ROS, blunted endothelial cell proliferation and impaired endothelial cell tube formation were observed. These in-vitro effects may link the T2238C alpha-ANP variant to enhanced susceptibility to vascular damage in vivo. J Hypertens 27:1804-1813 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

Determinants of N-terminal proatrial natriuretic peptide plasma levels in a survey of adult male population from Southern Italy

Objectives Natriuretic peptides control cardiovascular functions through diuretic, natriuretic, and vasodilatory properties. Several anthropometric, cardiac and renal variables were found to be independently correlated to their levels. Few studies, however, systematically investigated the independent determinants of natriuretic peptide levels in large populations. Design The present analysis was carried out in a large unselected sample of adult male population in Southern Italy (The Olivetti Heart Study, n = 806 men, mean age = 59.5, range 35-82 years). We examined the relationship of plasma natriuretic peptide-proatrial natriuretic peptide (NT-proANP) levels with relevant anthropometric, clinical and biochemical variables; the impact of age; and the association of NT-proANP levels with cardiovascular risk. Results NT-proANP was directly associated to age, pulse pressure (PP), renal sodium fractional excretion (FENa) (P<0.005), and inversely to diastolic blood pressure (DBP), heart rate (HR), creatinine clearance, body mass index (BMI), arm and leg circumferences (P<0.005). After adjustment for age, DBP, creatinine clearance, FENa and HR remained independent determinants of NT-proANP levels (all P<0.01, cumulative R(2) = 0.186). Upon stratification of our population by tertile of age, NT-proANP was significantly associated (P <= 0.01) to arm circumference in the lowest age tertile (mean age 53.8 years), and to FENa, DBP and creatinine clearance in the highest tertile (mean age 66.7 years). A direct significant association between NT-proANP levels and cardiovascular risk score, estimated by two independent algorithms, was observed (P<0.001). Conclusions Anthropometric, cardiovascular and renal factors exerted a different impact on NT-proANP levels at different ages in our study population. Higher NT-proANP levels were associated with increased cardiovascular risk. J Hypertens 28: 1638-1645 (c) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

A 68-year-old Caucasian man presenting with urinary bladder lymphoepithelioma: a case report

Introduction. Lymphoepithelioma is a very rare form of malignant tumor originating from epithelial line cells. Its occurrence has potential clinical, therapeutic and prognostic implications. In the present report we describe an unusual case of bladder cancer with two different histological varieties: transition cell carcinoma and lymphoepithelioma-like carcinoma. Lymphoepithelioma-like carcinoma of the bladder has only been rarely reported in the literature to date. Case presentation. We present the case of a 68-year-old Caucasian man who, after occurrence of hematuria, underwent transurethral resection of a bladder tumor. The results of a histological examination confirmed a high-grade non-muscle-invasive pT1 lymphoepithelioma-like carcinoma of the urinary bladder, associated with a concurrent high-grade transition cell carcinoma. After analyzing the histological features, our patient was subjected to treatment with intra-vesical instillations of bacillus Calmette- Guérin. Our work stresses that diagnosis and therapeutic approaches can be difficult and controversial, especially in the early stages of this rare carcinoma. Conclusions: This report emphasizes the importance of extending our knowledge and experiences regarding this uncommon carcinoma. Further studies are needed to better understand this rare disease and define more accurate diagnostic and therapeutic strategies. © 2013 Spinelli et al.; licensee BioMed Central Ltd

Neurotoxic Effect of Doxorubicin Treatment on Cardiac Sympathetic Neurons

Doxorubicin (DOXO) remains amongst the most commonly used anti-cancer agents for the treatment of solid tumors, lymphomas, and leukemias. However, its clinical use is hampered by cardiotoxicity, characterized by heart failure and arrhythmias, which may require chemotherapy interruption, with devastating consequences on patient survival and quality of life. Although the adverse cardiac effects of DOXO are consolidated, the underlying mechanisms are still incompletely understood. It was previously shown that DOXO leads to proteotoxic cardiomyocyte (CM) death and myocardial fibrosis, both mechanisms leading to mechanical and electrical dysfunction. While several works focused on CMs as the culprits of DOXO-induced arrhythmias and heart failure, recent studies suggest that DOXO may also affect cardiac sympathetic neurons (cSNs), which would thus represent additional cells targeted in DOXO-cardiotoxicity. Confocal immunofluorescence and morphometric analyses revealed alterations in SN innervation density and topology in hearts from DOXO-treated mice, which was consistent with the reduced cardiotropic effect of adrenergic neurons in vivo. Ex vivo analyses suggested that DOXO-induced denervation may be linked to reduced neurotrophic input, which we have shown to rely on nerve growth factor, released from innervated CMs. Notably, similar alterations were observed in explanted hearts from DOXO-treated patients. Our data demonstrate that chemotherapy cardiotoxicity includes alterations in cardiac innervation, unveiling a previously unrecognized effect of DOXO on cardiac autonomic regulation, which is involved in both cardiac physiology and pathology, including heart failure and arrhythmias

A rare genetic variant of BPIFB4 predisposes to high blood pressure via impairment of nitric oxide signaling

BPIFB4 is associated with exceptional longevity: four single-nucleotide polymorphisms distinguish the wild-type form from a longevity-associated variant conferring positive effects on blood pressure. The effect of a rare variant (RV; allele frequency, 4%) on blood pressure is unknown. Here, we show that overexpression of RV-BPIFB4 in ex-vivo mouse vessels impairs phosphorylation of endothelial nitric oxide synthase (eNOS), blunting acetylcholine-evoked vasorelaxation; in vivo, virally mediated overexpression of RV-BPIFB4 increases blood pressure, an action absent in eNOS-deficient mice. In humans, we found RV carriers to have increased diastolic blood pressure, a finding that was more marked in subjects on anti-hypertensive medication; moreover, recombinant RV-BPIFB4 protein impaired eNOS function in ex-vivo human vessels. Thus, RV-BPIFB4 acts directly on blood pressure homeostasis and may represent a novel biomarker of vascular dysfunction and hypertension