409 research outputs found
PPAR? Downregulation by TGF in Fibroblast and Impaired Expression and Function in Systemic Sclerosis: A Novel Mechanism for Progressive Fibrogenesis
The nuclear orphan receptor peroxisome proliferator-activated receptor-gamma (PPAR-Ξ³) is expressed in multiple cell types in addition to adipocytes. Upon its activation by natural ligands such as fatty acids and eicosanoids, or by synthetic agonists such as rosiglitazone, PPAR-Ξ³ regulates adipogenesis, glucose uptake and inflammatory responses. Recent studies establish a novel role for PPAR-Ξ³ signaling as an endogenous mechanism for regulating transforming growth factor-Γ (TGF-Γ)- dependent fibrogenesis. Here, we sought to characterize PPAR-Ξ³ function in the prototypic fibrosing disorder systemic sclerosis (SSc), and delineate the factors governing PPAR-Ξ³ expression. We report that PPAR-Ξ³ levels were markedly diminished in skin and lung biopsies from patients with SSc, and in fibroblasts explanted from the lesional skin. In normal fibroblasts, treatment with TGF-Γ resulted in a time- and dose-dependent down-regulation of PPAR-Ξ³ expression. Inhibition occurred at the transcriptional level and was mediated via canonical Smad signal transduction. Genome-wide expression profiling of SSc skin biopsies revealed a marked attenuation of PPAR-Ξ³ levels and transcriptional activity in a subset of patients with diffuse cutaneous SSc, which was correlated with the presence of a ''TGF-Γ responsive gene signature'' in these biopsies. Together, these results demonstrate that the expression and function of PPAR-Ξ³ are impaired in SSc, and reveal the existence of a reciprocal inhibitory cross-talk between TGF-Γ activation and PPAR-Ξ³ signaling in the context of fibrogenesis. In light of the potent anti-fibrotic effects attributed to PPAR-Ξ³, these observations lead us to propose that excessive TGF-Γ activity in SSc accounts for impaired PPAR-Ξ³ function, which in turn contributes to unchecked fibroblast activation and progressive fibrosis. Β© 2010 Wei et al
High throughput mutagenesis for identification of residues regulating human prostacyclin (hIP) receptor
The human prostacyclin receptor (hIP receptor) is a seven-transmembrane G protein-coupled receptor (GPCR) that plays a critical role in vascular smooth muscle relaxation and platelet aggregation. hIP receptor dysfunction has been implicated in numerous cardiovascular abnormalities, including myocardial infarction, hypertension, thrombosis and atherosclerosis. Genomic sequencing has discovered several genetic variations in the PTGIR gene coding for hIP receptor, however, its structure-function relationship has not been sufficiently explored. Here we set out to investigate the applicability of high throughput random mutagenesis to study the structure-function relationship of hIP receptor. While chemical mutagenesis was not suitable to generate a mutagenesis library with sufficient coverage, our data demonstrate error-prone PCR (epPCR) mediated mutagenesis as a valuable method for the unbiased screening of residues regulating hIP receptor function and expression. Here we describe the generation and functional characterization of an epPCR derived mutagenesis library compromising >4000 mutants of the hIP receptor. We introduce next generation sequencing as a useful tool to validate the quality of mutagenesis libraries by providing information about the coverage, mutation rate and mutational bias. We identified 18 mutants of the hIP receptor that were expressed at the cell surface, but demonstrated impaired receptor function. A total of 38 non-synonymous mutations were identified within the coding region of the hIP receptor, mapping to 36 distinct residues, including several mutations previously reported to affect the signaling of the hIP receptor. Thus, our data demonstrates epPCR mediated random mutagenesis as a valuable and practical method to study the structurefunction relationship of GPCRs. Β© 2014 Bill et al
Penerapan Metode Eksperimen untuk Meningkatkan Konsep Dasar Sains pada Anak Didik Kelompok A Tk Pkk Suruhwadang Kecamatan Kademangan Kabupaten Blitar
Tujuan penelitian ini adalah untuk memperoleh tentang kemampuan kognitif anak dalamhal konsep dasar sains dengan menggunakan metode eksperimen pada anak didik kelompokA TK PKK Suruhwadang sebelum dan sesudah dilakukan tindakan. Melakukan tindakanberupa penerapan metode eksperimen untuk meningkatkan kemampuan kognitif dalamkonsep dasar sains pada anak didik kelompok A TK PKK Suruhwadang. Mengetahui adatidaknya perbedaan kemampuan konsep dasar sains dengan menggunakan metodeeksperimen pada anak didik kelompok A TK PKK Suruhwadang antara sebelum dan setelahdilakukan tindakan. Rumusan masalah pada penitilian ini adalah apakah metode eksperimendapat meningkatkan kemampuan pemahaman konsep dasar sains pada anak didik kelompokA TK PKK Suruhwadang Kecamatan Kademangan Kabupaten Blitar. Untuk menjawabrumusan masalah digunakan jenis penelitian tindakan kelas (PTK) dengan model Kemmisdan Taggart melalui empat tahapan yaitu tahap perencanaan , pelaksanaan, observasi danrefleksiyang dilalui dengan dua siklus. Teknik pengumpulan data menggunakan teknikobservasi dan dokumentasi. Adapun instrumen yang digunakan adalah lembar observasikegiatan anak dan lembar observasi pembelajaran oleh guru.Hasil penelitian menunjukanbahwa kemampuan kognitif anak kelompok A pada konsep dasar sain pada pra penelitianmenunjukkan prosentase 56.25%. Setelah pelaksanaan siklus I tentang bidang kemampuankognitif pada konsep dasar sains menunjukkan 59% mengalami peningkatan .Setelahpelaksanaan siklus ke II naik menjadi 83%. Hal ini menunjukkan pelaksanaan siklus ke IItelah mencapai kriteria ketuntasan dan membuktikan bahwa dengan metode eksperimendapat meningkatkan kemampuan kognitif dalam konsep dasar sains
Evaluation of a robotic technique for transrectal MRI-guided prostate biopsies
Item does not contain fulltextOBJECTIVES: To evaluate the accuracy and speed of a novel robotic technique as an aid to perform magnetic resonance image (MRI)-guided prostate biopsies on patients with cancer suspicious regions. METHODS: A pneumatic controlled MR-compatible manipulator with 5 degrees of freedom was developed in-house to guide biopsies under real-time imaging. From 13 consecutive biopsy procedures, the targeting error, biopsy error and target displacement were calculated to evaluate the accuracy. The time was recorded to evaluate manipulation and procedure time. RESULTS: The robotic and manual techniques demonstrated comparable results regarding mean targeting error (5.7 vs 5.8 mm, respectively) and mean target displacement (6.6 vs 6.0 mm, respectively). The mean biopsy error was larger (6.5 vs 4.4 mm) when using the robotic technique, although not significant. Mean procedure and manipulation time were 76 min and 6 min, respectively using the robotic technique and 61 and 8 min with the manual technique. CONCLUSIONS: Although comparable results regarding accuracy and speed were found, the extended technical effort of the robotic technique make the manual technique - currently - more suitable to perform MRI-guided biopsies. Furthermore, this study provided a better insight in displacement of the target during in vivo biopsy procedures.01 februari 201
Decreased expression of haemoglobin beta (HBB) gene in anaplastic thyroid cancer and recovory of its expression inhibits cell growth
Anaplastic thyroid cancer (ATC) is one of the most fulminant and foetal diseases in human malignancies. However, the genetic alterations and carcinogenic mechanisms of ATC are still unclear. Recently, we investigated the gene expression profile of 11 anaplastic thyroid cancer cell lines (ACL) and significant decreased expression of haemoglobin beta (HBB) gene in ACL. Haemoglobin beta is located at 11p15.5, where loss of heterozygosity (LOH) was reported in various kinds of cancers, including ATC, and it has been suggested that novel tumour suppressor genes might exist in this region. In order to clarify the meaning of decreased expression of HBB in ATC, the expression status of HBB was investigated with ACL, ATC, papillary thyroid cancer (PTC) and normal human tissues. Haemoglobin beta showed significant decreased expression in ACLs and ATCs; however, in PTC, HBB expressed equal to the normal thyroid gland. In addition, HBB expressed in normal human tissues ubiquitously. To validate the tumour-suppressor function of HBB, cell growth assay was performed. Forced expression of HBB in KTA2 cell, which is a kind of ACL, significantly suppressed KTA2 growth. The mechanism of downregulation of HBB in ATC is still unclear; however, our results suggested the possibility of HBB as a novel tumour-suppressor gene
Molecular line mapping of the giant molecular cloud associated with RCW 106 - III. Multi-molecular line mapping
We present multi-molecular line maps obtained with the Mopra Telescope
towards the southern giant molecular cloud (GMC) complex G333, associated with
the HII region RCW 106. We have characterised the GMC by decomposing the 3D
data cubes with GAUSSCLUMPS, and investigated spatial correlations among
different molecules with principal component analysis (PCA). We find no
correlation between clump size and line width, but a strong correlation between
emission luminosity and line width. PCA classifies molecules into high and low
density tracers, and reveals that HCO+ and N2H+ are anti-correlated.Comment: 24 pages, 21 figures accepted by MNRA
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