title: Knockdown of the pericellular matrix molecule perlecan lowers in situ cell and matrix stiffness in developing cartilage.
abstract: The pericellular matrix (PCM) is a component of the extracellular matrix that is found immediately surrounding individual chondrocytes in developing and adult cartilage, and is rich in the proteoglycan perlecan. Mutations in perlecan are the basis of several developmental disorders, which are thought to arise from disruptions in the mechanical stability of the PCM. We tested the hypothesis that defects in PCM organization will reduce the stiffness of chondrocytes in developing cartilage by combining a murine model of Schwartz-Jampel syndrome, in which perlecan is knocked down, with our novel atomic force microscopy technique that can measure the stiffness of living cells and surrounding matrix in embryonic and postnatal tissues in situ. Perlecan knockdown altered matrix organization and significantly decreased the stiffness of both chondrocytes and interstitial matrix as a function of age and genotype. Our results demonstrate that the knockdown of a spatially restricted matrix molecule can have a profound influence on cell and tissue stiffness, implicating a role for outside-in mechanical signals from the PCM in regulating the intracellular mechanisms required for the overall development of cartilage.
authors: Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Drive, Boulder, CO 80309, United States.
authors: Xin
authors: X
authors: Xu
authors: Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States.
authors: Zhiyu
authors: Z
authors: Li
authors: Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States.
authors: Yue
authors: Y
authors: Leng
authors: Department of Mechanical Engineering, University of Colorado Boulder, 1111 Engineering Drive, Boulder, CO 80309, United States. Electronic address: cpneu@colorado.edu.
authors: Corey P
authors: CP
authors: Neu
authors: Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN 47907, United States. Electronic address: scalve@purdue.edu.
authors: Sarah
authors: S
authors: Calve
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000254:growth & development / Q000473:pathology / Q000503:physiopathology*; D019902:Chondrocytes / Q000473:pathology / Q000502:physiology; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000473:pathology / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D005260:Female; D055785:Gene Knockdown Techniques; D019812:Heparan Sulfate Proteoglycans / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D018345:Mice, Knockout; D018625:Microscopy, Atomic Force; D010009:Osteochondrodysplasias / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D011247:Pregnancy
chemical_list: D016326:Extracellular Matrix Proteins; D019812:Heparan Sulfate Proteoglycans; C071927:perlecan
keywords: Atomic force microscopy; Chondrocyte; Mechanobiology; Pericellular matrix