908 research outputs found

    Identification of the Thyroid Transcription Factor-1 as a Target for Rat MST2 Kinase

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    Abstract Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor that is required for thyroid-specific expression of the thyroglobulin and thyroperoxidase genes as well as for lung-specific expression of the surfactant protein A, B, and C and the CC10 and the HNF-3α genes. TTF-1 is a phosphoprotein, and the phosphorylation of TTF-1 has been studied already. However, the kinase(s) that could be responsible for this phosphorylation have not been known. In this paper we report the identification by in-gel kinase assay of a 56-kDa serine/threonine kinase that is able to phosphorylate TTF-1 in thyroid cells. The cloning of this kinase revealed that we had identified the rat homolog of the human MST2 kinase. The pathway in which human MST2 functions is not known; however, it does not appear to involve either mitogen-activated protein kinases such as Erk1 and Erk2 nor the stress-activated protein kinases such as JNK and p38. We show that the activity responsible for TTF-1 phosphorylation is constitutive in thyroid cells. Furthermore, we demonstrate that TTF-1 is phosphorylatedin vivo by rMST2 at the same residues that had been identified previously as the major phosphorylation sites. Thus, TTF-1 represents the first identified target of this class of protein kinases

    Seismic retrofit of an existing reinforced concrete building with buckling-restrained braces

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    Background: The seismic retrofitting of frame structures using hysteretic dampers is a very effective strategy to mitigate earthquake-induced risks. However, its application in current practice is rather limited since simple and efficient design methods are still lacking, and the more accurate time-history analysis is time-consuming and computationally demanding. Aims: This paper develops and applies a seismic retrofit design method to a complex real case study: An eight-story reinforced concrete residential building equipped with buckling-restrained braces. Methods: The design method permits the peak seismic response to be predicted, as well as the dampers to be added in the structure to obtain a uniform distribution of the ductility demand. For that purpose, a pushover analysis with the first mode load pattern is carried out. The corresponding story pushover curves are first idealized using a degrading trilinear model and then used to define the SDOF (Single Degree-of-Freedom) system equivalent to the RC frame. The SDOF system, equivalent to the damped braces, is designed to meet performance criteria based on a target drift angle. An optimal damper distribution rule is used to distribute the damped braces along the elevation to maximize the use of all dampers and obtain a uniform distribution of the ductility demand. Results: The effectiveness of the seismic retrofit is finally demonstrated by non-linear time-history analysis using a set of earthquake ground motions with various hazard levels. Conclusion: The results proved the design procedure is feasible and effective since it achieves the performance objectives of damage control in structural members and uniform ductility demand in dampers

    The CRE-Like Element Inside the 5′-Upstream Region of the Rat Sodium/Iodide Symporter Gene Interacts with Diverse Classes of b-Zip Molecules that Regulate Transcriptional Activities through Strong Synergy with Pax-8

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    AbstractWe previously demonstrated that transcription of the rat sodium/iodide symporter (NIS) gene is regulated by NUE, an upstream enhancer located between nucleotides −2264 and −2495 of the 5′-flanking region. To elucidate the mechanism of TSH/cAMP-mediated regulation of NIS gene expression, we have characterized the putative cAMP response element (CRE)/activator protein (AP)-1 site (termed NUC) that is closely located between the two Pax-8 (paired box domain transcription factor-8) binding sites within NUE. In two different approaches using either gel supershift analyses or dominant-negative inhibitors of b-Zip molecules, we have shown that NUC can be recognized by several members of the AP-1 and CREB family transcription factors that modulate the transcriptional activity of NUE. Using tethered dimers of b-Zip molecules, we have also demonstrated that specific homo- or heterodimers of AP-1 can synergistically stimulate NUE activity in concert with Pax-8. To demonstrate further that NUC is a bona fide CRE, we made an artificial promoter with the five-time tandem repeat of this sequence (5xNUC). In comparison to the canonical CRE (5xCRE), 5xNUC manifested greater transcriptional activity and broader response to cAMP signaling. Hence, we postulate that the significance of this evolutionally conserved CRE-like site may lie in its broader cell type specificity

    Prevalence of obesity and obesity-associated muscle wasting in patients on peritoneal dialysis

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    Background and aims: A progressive decrease in muscle mass until full-blown sarcopenia may occur in patients on peritoneal dialysis (PD) and worsen their life quality and expectancy. Here we investigate the prevalence of obesity and obesity-associated muscle wasting in PD patients. Patients and methods: The study design was observational, cross sectional. Body composition was assessed with BIA and BIVA in 88 PD patients (53.4 ± 13.1 years; 67% male). Patients with obesity and/or with reduced muscle mass were identified using FMI and SM/BW cutoff values, respectively. Inflammatory status was assessed by measuring CRP and fibrinogen blood levels. Results: A total of 44.3% of the patients showed a reduced muscle mass (37.5% moderate and 6.8% severe). The prevalence of obesity was 6.1%, 81.8%, and 100% in patients with normal, moderately, and severely reduced muscle mass, respectively (p < 0.05). Of the total, 15.2% of the patients with normal muscle mass, 18.4% of those with moderately reduced muscle mass, and 66.7% of those with severely reduced muscle mass had diabetes. The prevalence of severe muscle mass loss was higher in those with diabetes than in those without diabetes (22.2% vs. 2.8%, p < 0.05). Patients with obesity-associated muscle wasting showed higher fibrinogen (613.9 ± 155.1 vs. 512.9 ± 159.5 mg/dL, p < 0.05) and CPR (1.4 ± 1.3 vs. 0.6 ± 0.8 mg/dL, p < 0.05) blood concentrations than those with normal body composition. Conclusion: Obesity and diabetes were strongly associated with muscle mass loss in our PD patients. It remains to be established whether prevention of obesity with nutritional interventions can halt the occurrence of muscle mass loss in patients on PD

    Redundant domains contribute to the transcriptional activity of the thyroid transcription factor 1.

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    The thyroid transcription factor 1 (TTF-1) is a homeodomain-containing protein implicated in the activation of thyroid-specific gene expression. Here we report that TTF-1 is capable of activating transcription from thyroglobulin and, to a lesser extent, thyroperoxidase gene promoters in nonthyroid cells. Full transcriptional activation of the thyroglobulin promoter by TTF-1 requires the presence of at least two TTF-1 binding sites. TTF-1 activates transcription via two functionally redundant transcriptional activation domains that as suggested by competition experiments, could use a common intermediary factor

    MicroRNA deregulation in thyroid cancer

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    In cancer microRNAs are often dysregulated with their expression patterns being correlated with clinically relevant tumor characteristics. Recently, microRNAs were shown to be directly involved in cancer initiation and progression. Despite the large amount of data showing strong correlations between cancer phenotype and microRNAs aberrant expression, very little is known about the molecular mechanisms inducing such deregulation. Thyroid carcinomas comprise a heterogeneous group of neoplasms with distinctive clinical and pathological characteristics. Activating mutations in Ras genes are frequently found in poorly differentiated and in anaplastic thyroid carcinomas. We have recently shown that oncogenic activation of Ras is able to change the expression of several microRNAs in thyroid epithelial cells. One of the top aberrantly expressed ones is miR-21, a microRNA prevoiusly reported overexpressed in a wide variety of cancers and causally linked to cellular proliferation, survival and migration. By using an inducible Ras oncogene we demonstrated that constitutively active Ras induce overexpression of miR-21 at very early times after its activation, and that such overexpression is maintained at later times as well as in chronically Ras-transformed cells. Analysis of a panel of thyroid tumors with different hystotypes revealed that miR-21 is overexpressed mainly in anaplastic carcinomas, thus correlating with the most aggressive phenotype. Interestingly, this induction seems to be cell-type specific, since the inducible Ras oncogene is unable to increase miR-21 levels in cultured fibroblasts. Moreover, our data show that at least two different Ras downstream pathways are necessary to induce miR-21 expression. We then asked if the ability of Ras in inducing miR-21 overexpression is verified in vivo. To answer this question we analyzed the expression of this microRNA in a mouse model of Ras-induced lung tumorigenesis, showing that Ras constitutive activation is able to increase miR-21 levels in normal lung and that the Ras-initiated lung cancer progression is accompained by a further increase in miR-21 expression. Taken together, our data strongly suggest that the oncogenic activation of Ras could be responsible for the increased expression of miR-21 frequently observed in human cancers

    The IkB kinase inhibitor nuclear factor-kB essential modulator–binding domain peptide for inhibition of balloon injury-induced neointimal formation

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    Objective—The activation of nuclear factor-kB (NF-kB) is a crucial step in the arterial wall’s response to injury. The identification and characterization of the NF-kB essential modulator– binding domain (NBD) peptide, which can block the activation of the IkB kinase complex, have provided an opportunity to selectively abrogate the inflammation-induced activation of NF-kB. The aim of the present study was to evaluate the effect of the NBD peptide on neointimal formation.&lt;br&gt;&lt;/br&gt; Methods and Results—In the rat carotid artery balloon angioplasty model, local treatment with the NBD peptide (300 microg/site) significantly reduced the number of proliferating cells at day 7 (by 40%; P&#60;0.01) and reduced injury-induced neointimal formation (by 50%; P&#60;0.001) at day 14. These effects were associated with a significant reduction of NF-kB activation and monocyte chemotactic protein-1 expression in the carotid arteries of rats treated with the peptide. In addition, the NBD peptide (0.01 to 1 micromol/L) reduced rat smooth muscle cell proliferation, migration, and invasion in vitro. Similar results were observed in apolipoprotein E-/-, mice in which the NBD peptide (150 microg/site) reduced wire-induced neointimal formation at day 28 (by 47%; P&#60;0.01).&lt;br&gt;&lt;/br&gt; Conclusion—The NBD peptide reduces neointimal formation and smooth muscle cell proliferation/migration, both effects associated with the inhibition of NF-kB activation

    Inhibition of in-stent stenosis by oral administration of bindarit in porcine coronary arteries

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    &lt;p&gt;&lt;b&gt;Objective:&lt;/b&gt; We have previously demonstrated that bindarit, a selective inhibitor of monocyte chemotactic proteins (MCPs), is effective in reducing neointimal formation in rodent models of vascular injury by reducing smooth muscle cell proliferation and migration and neointimal macrophage content, effects associated with the inhibition of MCP-1/CCL2 production. The aim of the current study was to evaluate the efficacy of bindarit on in-stent stenosis in the preclinical porcine coronary stent model.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods and Results:&lt;/b&gt; One or 2 bare metal stents (Multi-Link Vision, 3.5 mm) were deployed (1:1.2 oversize ratio) in the coronary arteries of 42 pigs (20 bindarit versus 22 controls). Bindarit (50 mg/kg per day) was administered orally from 2 days before stenting until the time of euthanasia at 7 and 28 days. Bindarit caused a significant reduction in neointimal area (39.4%, P&#60;0.001, n=9 group), neointimal thickness (51%, P&#60;0.001), stenosis area (37%, P&#60;0.001), and inflammatory score (40%, P&#60;0.001) compared with control animals, whereas there was no significant difference in the injury score between the 2 groups. Moreover, treatment with bindarit significantly reduced the number of proliferating cells (by 45%, P&#60;0.05; n=6 group) and monocyte/macrophage content (by 55%, P&#60;0.01; n=5–6 group) in stented arteries at day 7 and 28, respectively. These effects were associated with a significant (P&#60;0.05) reduction of MCP-1 plasma levels at day 28. In vitro data showed that bindarit (10–300 micromol/L) reduced tumor necrosis factor-alpha (50 ng/mL)–induced pig coronary artery smooth muscle cell proliferation and inhibited MCP-1 production.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; Our results show the efficacy of bindarit in the prevention of porcine in-stent stenosis and support further investigation for clinical application of this compound.&lt;/p&gt

    Effect of a moderately hypoenergetic Mediterranean diet and exercise program on body cell mass and cardiovascular risk factors in obese women

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    Objective: To assess the effects of a moderately hypoenergetic Mediterranean diet (MHMD) and exercise program on body cell mass (BCM) and cardiovascular disease risk factors in obese women. Subjects/Methods: Forty-seven obese women, 39.7 +/- 13.2 years of age, with a body mass index (BMI) 30.7 +/- 6.0 kg/m(2), completed the study. The following were measured at baseline, 2 and 4 months: BCM, BCM index (BCMI), body weight, BMI, fat-free mass (FFM), fat mass (FM), total body water (TBW), extracellular water (ECW) and intracellular water (ICW) using bioelectrical impedance analysis; fasting blood glucose (FBG), serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) concentrations; systolic (SBP) and diastolic (DBP) blood pressure. Results: Body weight, BMI, FM, TC and TG significantly decreased (P<0.001; P<0.002 (TG)) at 2 and 4 months. FFM, TBW, ECW, FBG and DBP significantly decreased at 2 months (P<0.05 (FFM); P<0.001). LDL-C significantly decreased (P<0.001), while HDL-C significantly increased (P<0.002) at 4 months. BCM, BCMI, ICW and SBP remained stable over time. Conclusion: BCM was preserved and cardiovascular disease risk factors improved in obese women placed on a MHMD and exercise program for 4 months

    Small bowel transplantation for diffuse intestinal angiomatosis

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    Intestinal angiomatosis is a very rare phenomenon producing lower gastrointestinal bleeding. Its most frequent causes are diverticula, congenital arteriovenous malformation, acquired angiodysplasia, ischemia, inflammation, ulceration, benign or malignant tumours and iatrogenic injury. In this paper, the case of a 48-year-old white man is reported
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