Identification of murine phosphodiesterase 5A isoforms and their functional characterization in HL-1 cardiac cell line

Phosphodiesterase 5A (PDE5A) specifically degrades the ubiquitous second messenger cGMP and experimental and clinical data highlight its important role in cardiac diseases. To address PDE5A role in cardiac physiology, three splice variants of the PDE5A were cloned for the first time from mouse cDNA library (mPde5a1, mPde5a2 and mPde5a3). The predicted amino acidic sequences of the three murine isoforms are different in the N-terminal regulatory domain. mPDE5A isoforms were transfected in HEK293T cells and they showed high affinity for cGMP and similar sensitivity to sildenafil inhibition. RT-PCR analysis showed that mPde5a1, mPde5a2 and mPde5a3 had differential tissue distribution. In the adult heart, mPde5a1 and mPde5a2 were expressed at different levels whereas mPde5a3 was undetectable. Overexpression of mPDE5As induced an increase of HL-1 number cells which progress into cell cycle. mPDE5A1 and mPDE5A3 overexpression increased the number of polyploid and binucleated cells, mPDE5A3 widened HL-1 areas and modulated hypertrophic markers more efficiently respect to the other mPDE5A isoforms. Moreover, mPDE5A isoforms had differential subcellular localization: mPDE5A1 was mainly localized in the cytoplasm, mPDE5A2 and mPDE5A3 were also nuclear localized. These results demonstrate for the first time the existence of three PDE5A isoforms in mouse and highlight their potential role in the induction of hypertrophy. This article is protected by copyright. All rights reserved

Characterization of c-Kit receptor function in cardiac regeneration by using transgenic mouse models

Background. Cardiac stem cells expressing the tyrosine kinase receptor c-kit have been recently used in in vivo and in vitro cardiac regenerative studies. However, it remains to be clarified whether the c-kit receptor itself plays a critical role in the process of cardiac regeneration. In order to clarify this point, we will explore whether c-Kit receptor affects cardiac stem cells proliferation, survival, migration and differentiation after heart injury. Methods and Results. We have generated transgenic mice in which an activatory point mutation (c-KitD814Y mice) has been introduced in the kinase domain of the c-kit gene. Initially, we have analyzed c-kit expression in tissues and organs at different stages of embryonal and post-natal development through immunohystochemical and biochemical analyses. We have found that in two transgenic lines the receptor is highly expressed and activated in heart, testis and cerebellum, compared to wild type mice. In order to follow the fate of the c-Kit transgenic stem cells we crossed c-KitD814Y mice with mice expressing GFP under c-Kit regulative sequences control. By cytofluorimetric and fluorescence microscopy analyses, we observed a 2 fold of increase in the number of c-kit positive cells on heart samples from double transgenic mice at different ages. To verify the c-kit role in cardiac regeneration we performed a necrotic heart damage in vivo and monitored cardiac repair in transgenic mice versus wild-type mice. After 9 days the wounded hearts of transgenic mice presented a larger connectival tissue area compared to wild-type mice. On the contrary, after 45 days a consistent reduction of fibrotic area was observed in transgenic mice. These preliminary results suggest a faster repair of damaged heart area that contain stem cells with an activated c-kit receptor. Further in vitro and in vivo experiments will be performed to assess whether transgenic c-kit cells directly transdifferentiate into cardiomyocytes or whether they act in a paracrine manner. In summary, the generation of transgenic mice carrying a constitutively activated c-kit in cardiac stem cells, will allow to investigate the role of the receptor and to highlight the molecular mechanism underlying heart regeneration

Dietary cholesterol supplementation and inhibitory factor 1 serum levels in two dizygotic Smith-Lemli-Opitz syndrome twins: a case report

Smith-Lemli-Opitz syndrome (SLOS) is a rare genetic neurodevelopmental disorder caused by the defect in the 7-dehydrocholesterol reductase. This defect leads to the deficiency of cholesterol biosynthesis with accumulation of 7-dehydrocholesterol. Inhibitory factor 1 (IF1) is a well-known mitochondrial protein. Recently, it has been discovered in the human serum where it is reported to be involved in the HDL-cholesterol intake. Here we report the IF1 presence in the serum of two paediatric SLOS dizygotic twins treated with dietary cholesterol supplementation

Role of magnetic resonance imaging in the preoperative staging and work-up of patients affected by invasive lobular carcinoma or invasive ductolobular carcinoma

Purpose. The prevalence of invasive lobular carcinoma (ILC), the second most common type of breast cancer, accounts for 5%–15% of all invasive breast cancer cases. Its histological feature to spread in rows of single cell layers explains why it often fails to form a palpable lesion and the lack of sensitivity of mammography and ultrasound (US) to detect it. It also has a higher incidence of multifocal, multicentric, and contralateral disease when compared to the other histological subtypes. The clinicopathologic features and outcomes of Invasive Ductolobular Carcinoma (IDLC) are very similar to the ILC. The purpose of our study is to assess the importance of MRI in the preoperative management and staging of patients affected by ILC or IDLC. Materials and Methods. We identified women diagnosed with ILC or IDLC. We selected the patients who had preoperative breast MRI. For each patient we identified the areas of multifocal, multicentric, or contralateral disease not visible to standard exams and detected by preoperative MRI. We analyzed the potential correlation between additional cancer areas and histological cancer markers. Results. Of the 155 women who met our inclusion criteria, 93 (60%) had additional cancer areas detected by MRI. In 61 women, 39,4% of the overall population, the additional cancer areas were confirmed by US/tomosynthesis second look and biopsy. Presurgical MRI staging changed surgical management in the 37,4% of the patients. Only six patients of the overall population needed a reoperation after the initial surgery. No statistically significant correlation was found between MRI overestimation and the presence of histological peritumoral vascular/linfatic invasion. No statistically significant correlation was found between additional cancer areas and histological cancer markers. Conclusions. Our study suggests that MRI is an important tool in the preoperative management and staging of patients affected by lobular or ductolobular invasive carcinoma

PDE5 inhibition counteracts β- adrenergic induction of cardiac hypertrophy

The b-adrenoreceptors play important roles in cardiovascular function regulation mediated by the sympathetic nervous system. It is known that sustained b-adrenergic stimulations promotes cardiac hypertrophy (Oleg et al., 2007). Recently an antihypertrophic role of sildenafil, that acts as a phosphodiesterase 5 (PDE5) inhibitor, has been demonstrated in mice where hypertrophy was mechanically induced (Takimoto et al., 2005). We report the results obtained on a cellular system of cardiac hypertrophy in vitro. By using three-dimensional cultures of mouse ventricular cardiomyocytes (Xiang et al., 2005) and isolated cardiomyocytes we show that: 1) these cells express levels of PDE5 comparable with the ones in normal heart, 2) treatment of the cultures with the b-adrenoreceptors agonist isoproterenol induces cell hypertrophy accompanied by an increment of the level of PDE5 expression and 3) sildenafil prevents the development of such hypertrophy through specific b-adrenoreceptors and signaling pathways 4) the inhibition of other members of PDE family might contribute to the prevention of hypertrophy following b-adrenergic stimulation. In summary, we present a test system that may contribute to clarify intracellular signaling pathways leading to cardiac hypertrophy and to identify molecular targets, like the ones involved in PDE5 activity, on which to steer the development of new drugs and to design new clinical therapies

IMAGING FINDINGS OF HEPATIC FOCAL NODULAR HYPERPLASIA IN GD-EOB-DTPA VS. GD-BOPTA-ENHANCED MRI

Focal nodular hyperplasia (FNH) is a benign focal lesion of the liver. Magnetic resonance imaging (MRI) plays a key role in the detection and characterization of focal hepatic lesions, thanks to the widespread availability of conventional contrast media, especially liver-specific media such as Gd-BOPTA (Multihance, or Gadobenate Dimeglumine) and GdEOB-DTPA (Primovist, or Gadoxetic Acid) that are selectively accumulated in hepatocytes and partially excreted by the biliary system. There are no significant differences in FNH enhancement, neither during the dynamic phase nor during the liver-specific phase of MRI, following the infusion with GD-BOPTA or GD-EOB-DTPA

Chemotherapy reduces para-aortic node recurrences in endometrial cancer with positive pelvic and unknown para-aortic nodes

The objective of this study was to evaluate how the administration of different adjuvant therapies influences the risk for developing recurrences in the para-aortic area in endometrial cancer (EC) with positive pelvic and unknown para-aortic nodes

PDE5 Inhibition Counteracts beta-Adrenergic Induction Of Cardiac Hypertrophy

The beta-adrenoreceptors play important roles in cardiovascular function regulation mediated by the sympathetic nervous system. It is known that sustained beta-adrenergic stimulations promotes cardiac hypertrophy. Recently, an anti-hypertrophic role of sildenafil, that acts as a specific phosphodiesterase 5 (PDE5) inhibitor, has been demonstrated in mice where hypertrophy was mechanically induced. We report the results obtained on an in vitro model of cardiac hypertrophy. By using three-dimensional cultures of mouse ventricular cardiomyocytes we show that: 1) these cells express levels of PDE5 comparable with the ones in normal heart, 2) treatment of the cultures with the beta-adrenoreceptors agonist isoproterenol induces cell hypertrophy accompanied by an increment of the level of PDE5 expression and 3) sildenafil prevents the development of such hypertrophy. In summary, we present a test system that may contribute to clarify intracellular signaling pathways leading to cardiac hypertrophy and to identify molecular targets, like the ones involved in PDE5 activity, on which to steer the development of new drugs and to design new clinical therapies

PDE5 inhibition counteracts beta- adrenergic induction of cardiac hypertrophy

The b-adrenoreceptors play important roles in cardiovascular function regulation mediated by the sympathetic nervous system. It is known that sustained b-adrenergic stimulations promotes cardiac hypertrophy (Oleg et al., 2007). Recently an antihypertrophic role of sildenafil, that acts as a phosphodiesterase 5 (PDE5) inhibitor, has been demonstrated in mice where hypertrophy was mechanically induced (Takimoto et al., 2005). We report the results obtained on a cellular system of cardiac hypertrophy in vitro. By using three-dimensional cultures of mouse ventricular cardiomyocytes (Xiang et al., 2005) and isolated cardiomyocytes we show that: 1) these cells express levels of PDE5 comparable with the ones in normal heart, 2) treatment of the cultures with the b-adrenoreceptors agonist isoproterenol induces cell hypertrophy accompanied by an increment of the level of PDE5 expression and 3) sildenafil prevents the development of such hypertrophy through specific b-adrenoreceptors and signaling pathways 4) the inhibition of other members of PDE family might contribute to the prevention of hypertrophy following b-adrenergic stimulation. In summary, we present a test system that may contribute to clarify intracellular signaling pathways leading to cardiac hypertrophy and to identify molecular targets, like the ones involved in PDE5 activity, on which to steer the development of new drugs and to design new clinical therapies

Evaluation of anxiety level in patients wating to undergo to diagnostic radiological exams

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