RUNX2 mutations in Taiwanese patients with cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is an autosomal dominant human skeletal disorder comprising hypoplastic clavicles, wide cranial sutures, supernumerary teeth, short stature, and other skeletal abnormalities. It is known that mutations in the human RUNX2 gene mapped at 6p21 are responsible for CCD. We analyzed the mutation patterns of the RUNX2 gene by direct sequencing in six Taiwanese index cases with typical CCD. One of the patients was a familial case and the others were sporadic cases. Sequencing identified four mutations. Three were caused by single nucleotide substitutions, which created a nonsense (p.R391X), two were missense mutations (p.R190W, p.R225Q), and the forth was a novel mutation (c.1119delC), a one-base deletion. Real time quantitative PCR adapted to determine copy numbers of the promoter, all exons and the 3’UTR region of the RUNX2 gene detected the deletion of a single allele in a sporadic case. The results extend the spectrum of RUNX2 mutations in CCD patients and indicate that complete deletions of the RUNX2 gene should be considered in those CCD patients lacking a point mutation detected by direct sequencing

Overexpression of cathepsin K during silica-induced lung fibrosis and control by TGF-β

BACKGROUND: Lung fibrosis is characterized by tissue remodeling resulting from an imbalance between synthesis and degradation of extracellular organic matrices. To examine whether cathepsin(s) (Cat) are important in the development of pulmonary fibrosis, we assessed the expression of four Cat known for their collagenolytic activity in a model of silica-induced lung fibrosis. METHODS: Different strains of mice were transorally instilled with 2.5 mg crystalline silica or other particles. Cat expression (Cat K, S, L and B) was quantified in lung tissue and isolated pulmonary cells by quantitative RT-PCR. In vitro, we assessed the effect of different cytokines, involved in lung inflammatory and fibrotic responses, on the expression of Cat K by alveolar macrophages and fibroblasts. RESULTS: In lung tissue, Cat K transcript was the most strongly upregulated in response to silica, and this upregulation was intimately related to the fibrotic process. In mouse strains known for their differential response to silica, we showed that the level of Cat K expression following silica treatment was inversely related to the level of TGF-β expression and the susceptibility of these strains to develop fibrosis. Pulmonary macrophages and fibroblasts were identified as Cat K overproducing cells in the lung of silicotic mice. In vitro, Cat K was downregulated in mouse and human lung fibroblasts by the profibrotic growth factor TGF-β1. CONCLUSION: Altogether, these data suggest that while Cat K may contribute to control lung fibrosis, TGF-β appears to limit its overexpression in response to silica particles

Importance of lysosomal cysteine proteases in lung disease

The human lysosomal cysteine proteases are a family of 11 proteases whose members include cathepsins B, C, H, L, and S. The biology of these proteases was largely ignored for decades because of their lysosomal location and the belief that their function was limited to the terminal degradation of proteins. In the past 10 years, this view has changed as these proteases have been found to have specific functions within cells. This review highlights some of these functions, specifically their roles in matrix remodeling and in regulating the immune response, and their relationship to lung diseases

The Influence of Radiographic Phenotype and Smoking Status on Peripheral Blood Biomarker Patterns in Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease (COPD) is characterized by both airway remodeling and parenchymal destruction. The identification of unique biomarker patterns associated with airway dominant versus parenchymal dominant patterns would support the existence of unique phenotypes representing independent biologic processes. A cross-sectional study was performed to examine the association of serum biomarkers with radiographic airway and parenchymal phenotypes of COPD. Methodology/Principal Findings: Serum from 234 subjects enrolled in a CT screening cohort was analyzed for 33 cytokines and growth factors using a multiplex protein array. The association of serum markers with forced expiratory volume in one second percent predicted (FEV1%) and quantitative CT measurements of airway thickening and emphysema was assessed with and without stratification for current smoking status. Significant associations were found with several serum inflammatory proteins and measurements of FEV1%, airway thickening, and parenchymal emphysema independent of smoking status. The association of select analytes with airway thickening and emphysema was independent of FEV1%. Furthermore, the relationship between other inflammatory markers and measurements of physiologic obstruction or airway thickening was dependent on current smoking status. Conclusions/Significance: Airway and parenchymal phenotypes of COPD are associated with unique systemic serum biomarker profiles. Serum biomarker patterns may provide a more precise classification of the COPD syndrome, provide insights into disease pathogenesis and identify targets for novel patient-specific biological therapies. © 2009 Bon et al

Screening of protein kinase inhibitors identifies PKC inhibitors as inhibitors of osteoclastic acid secretion and bone resorption

<p>Abstract</p> <p>Background</p> <p>Bone resorption is initiated by osteoclastic acidification of the resorption lacunae. This process is mediated by secretion of protons through the V-ATPase and chloride through the chloride antiporter ClC-7. To shed light on the intracellular signalling controlling extracellular acidification, we screened a protein kinase inhibitor library in human osteoclasts.</p> <p>Methods</p> <p>Human osteoclasts were generated from CD14+ monocytes. The effect of different kinase inhibitors on lysosomal acidification in human osteoclasts was investigated using acridine orange for different incubation times (45 minutes, 4 and 24 hours). The inhibitors were tested in an acid influx assay using microsomes isolated from human osteoclasts. Bone resorption by human osteoclasts on bone slices was measured by calcium release. Cell viability was measured using AlamarBlue.</p> <p>Results</p> <p>Of the 51 compounds investigated only few inhibitors were positive in both acidification and resorption assays. Rottlerin, GF109203X, Hypericin and Ro31-8220 inhibited acid influx in microsomes and bone resorption, while Sphingosine and Palmitoyl-DL-carnitine-Cl showed low levels of inhibition. Rottlerin inhibited lysosomal acidification in human osteoclasts potently.</p> <p>Conclusions</p> <p>In conclusion, a group of inhibitors all indicated to inhibit PKC reduced acidification in human osteoclasts, and thereby bone resorption, indicating that acid secretion by osteoclasts may be specifically regulated by PKC in osteoclasts.</p

Cell Cycle- and Cancer-Associated Gene Networks Activated by Dsg2: Evidence of Cystatin A Deregulation and a Potential Role in Cell-Cell Adhesion

This work was supported by grants from the National Institutes of Health (Mahoney, R01AR056067; Riobo, RO1 GM088256). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript