Ucma--A novel secreted factor represents a highly specific marker for distal chondrocytes

Matrix Biol. 2008 Jan;27(1):3-11. doi: 10.1016/j.matbio.2007.07.004. Epub 2007 Jul 13.

Abstract

Growth and development of most parts of the vertebrate skeleton takes place by endochondral ossification, a process during which chondrocytes undergo distinct stages of differentiation resulting in a successive replacement of the cartilage anlagen by bone. In the context of an EST project we isolated a novel transcript from a human fetal growth plate cartilage cDNA library. The transcript which we called Ucma (unique cartilage matrix-associated protein) encodes a short protein of 138 amino acids. The protein sequence is evolutionary conserved throughout vertebrates and comprises a signal peptide, a coiled-coil domain, and a putative dibasic cleavage site for proprotein convertases. Using RNA in situ hybridization and immunohistochemistry with a polyclonal anti-Ucma antibody we found high expression of Ucma uniquely in distal (resting) chondrocytes in developing long bones of wildtype mice. This restricted expression could also be observed in Ihh(-/-), Ihh(-/-); Gli3(-/-), Gli3(-/-) mice, and in mice that overexpress Ihh under the control of the Col2a1 promoter indicating that expression of Ucma is regulated independent of hedgehog signaling. During insulin-induced differentiation of ATDC5 cells we found gradual increase of Ucma expression at day 21 with a maximum at day 24 and a decrease correlating with a simultaneous increase in the expression of cartilage link protein (Crtl1), a protein with maximum expression in column-forming proliferating chondrocytes. The present data strongly suggest an important function of Ucma in the early phase of chondrocyte differentiation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Biomarkers / metabolism*
  • Cartilage, Articular / cytology
  • Cartilage, Articular / physiology
  • Cell Differentiation / physiology
  • Cell Line
  • Chondrocytes / chemistry*
  • Chondrocytes / cytology
  • Chondrocytes / physiology*
  • Chondrogenesis / physiology
  • Extracellular Matrix Proteins
  • Extremities / anatomy & histology
  • Extremities / embryology
  • Extremities / physiology
  • Fetus / anatomy & histology
  • Growth Plate / cytology*
  • Hedgehog Proteins / genetics
  • Hedgehog Proteins / metabolism
  • Humans
  • In Situ Hybridization
  • Intercellular Signaling Peptides and Proteins
  • Intracellular Signaling Peptides and Proteins
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Mice
  • Mice, Knockout
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Proteins / genetics
  • Proteins / metabolism*
  • Sequence Alignment
  • Zinc Finger Protein Gli3

Substances

  • Biomarkers
  • Extracellular Matrix Proteins
  • Gli3 protein, mouse
  • Hedgehog Proteins
  • Intercellular Signaling Peptides and Proteins
  • Intracellular Signaling Peptides and Proteins
  • Kruppel-Like Transcription Factors
  • Nerve Tissue Proteins
  • Proteins
  • Ucma protein, human
  • Ucma protein, mouse
  • Zinc Finger Protein Gli3
  • ihh protein, mouse