Mouse Genetics and Proteomic Analyses Demonstrate a Critical Role for Complement in a Model of DHRD/ML, an Inherited Macular Degeneration Results demonstrate a critical role for the complement system in basal deposit formation, and suggest that complement-mediated recognition of abnormal extracellular matrix may participate in basal deposit formation in Doyne Honeycomb Retinal Dystrophy/Malattia Leventinese (DHRD/ML) and perhaps other macular degenerations. [Hum Mol Genet] Abstract | Press Release Regulation of PDGFC Signaling and Extracellular Matrix Composition by FREM1 Investigators showed that Fras1 related extracellular matrix protein 1 (FREM1) binds to PDGFC and that this interaction regulates signaling downstream of PDGFRα. Fibroblasts from Frem1-mutant mice respond to PDGFC stimulation, but with a shorter duration and amplitude than wild type cells. [Dis Model Mech] Abstract | Full Article Hyaluronic Acid Fragments Enhance the Inflammatory and Catabolic Response in Human Intervertebral Disc Cells through Modulation of Toll-Like Receptor 2 Signaling Pathways Human intervertebral disc cells isolated from patient biopsies were stimulated with hyaluronic acid fragments and their effect on cytokine and matrix degrading enzyme production was assessed using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. [Arthritis Res Ther] Abstract | Full Article Homotypic Versican G1 Domain Interactions Enhance Hyaluronan Incorporation into Fibrillin Microfibrils The authors clarified the role of Versican G1 domain-containing fragments (VG1Fs) in the extracellular macrocomplex, specifically in mediating the recruitment of hyaluronan (HA) to microfibrils. Sequential extraction studies suggested that the VG1Fs were not associated with dermal elements through HA binding properties alone. [J Biol Chem] Abstract | Full Article Laminin and Collagen Modulate Expression of the Small Leucine-Rich Proteoglycan Fibromodulin in Rat Anterior Pituitary Gland Scientists investigated whether fibromodulin expression is modulated by major anterior pituitary extracellular matrix components such as laminin and type I collagen. Using transgenic rats expressing green fluorescent protein (GFP) specifically in folliculostellate (FS) cells, they examined fibromodulin expression in GFP-positive FS cells and GFP-negative cells. [Cell Tissue Res] Abstract Thrombin Weakens the Amnion Extracellular Matrix (ECM) Directly Rather than through Protease Activated Receptors Researchers determined whether thrombin weakens the isolated amnion through thrombin receptor-protease activated receptors (PARs 1,2,3,4), activation of previously secreted ECM enzymes, or by direct action on the ECM. [Placenta] Abstract Age-Dependent Alterations of Decorin Glycosaminoglycans in Human Skin Investigators quantified transcripts of 20 known interstitial proteoglycans in human skin and found that decorin was the most highly expressed. Decorin was predominantly produced by dermal fibroblasts. Decorin was localized in dermal extracellular matrix with glycosaminoglycan bound to type I collagen fibrils. [Sci Rep] Full Article Evaluating Extracellular Matrix Influence on Adherent Cell Signaling by Cold Trypsin Phosphorylation-Specific Flow Cytometry Phosphorylation-specific flow cytometry necessitates trypsinization of adherent cells to accommodate flow cytometric analysis. To address this researchers developed a cold trypsin-phosphorylation-specific flow cytometry protocol, where adherent cells are prepared for flow cytometric analysis on ice, a temperature where trypsin retains activity but where intracellular kinases are inactive. [BMC Cell Biol] Full Article Influence of Cartilage Extracellular Matrix Molecules on Cell Phenotype and Neocartilage Formation The authors examined the influence of cartilage zone-specific extracellular matrix on neocartilage formation by human articular chondrocytes in 2D and 3D environments. [Tissue Eng Part A] Full Article |