Alpha 1-VIII collagen is expressed in the rat glomerulus and in resident glomerular cells

Am J Physiol. 1993 Jun;264(6 Pt 2):F1003-10. doi: 10.1152/ajprenal.1993.264.6.F1003.

Abstract

Current knowledge regarding the molecular composition of extracellular matrices in the glomerulus does not explain how these components interact to form stable three-dimensional structures. The recent recognition that short-chain collagens such as type VIII collagen function as molecular bridges in some nonrenal tissues has raised the possibility that such molecules may serve a similar function in the glomerulus. We have recently shown that cultured rat mesangial cells synthesize and secrete several short-chain collagenous proteins, one of which has properties similar to alpha 1-VIII collagen. In the present study we have isolated a rat mesangial cell alpha 1-VIII collagen cDNA clone, the sequence of which is 81% homologous to mouse alpha 1-VIII collagen. We used this cDNA to determine that alpha 1-VIII collagen mRNA is expressed in rat renal cortex and in cultured glomerular mesangial, epithelial, and endothelial cells. Additionally, we demonstrated that alpha 1-VIII collagen is secreted by cultured mesangial cells as an 80-kDa translation product. By immunocytochemistry, alpha 1-VIII collagen localized to the media of large intrarenal arteries and to the capillary loops and the mesangium of normal rat kidney. These results indicate that type VIII collagen is a normal constituent of the rat glomerulus as well as large intrarenal arteries. We speculate that type VIII collagen may function in part to determine the three-dimensional organization of the subendothelial and mesangial matrices.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Collagen / genetics
  • Collagen / metabolism*
  • Endothelium / cytology
  • Endothelium / metabolism
  • Epithelial Cells
  • Epithelium / metabolism
  • Female
  • Glomerular Mesangium / cytology
  • Glomerular Mesangium / metabolism
  • In Vitro Techniques
  • Kidney Cortex / metabolism
  • Kidney Glomerulus / cytology
  • Kidney Glomerulus / metabolism*
  • Molecular Sequence Data
  • Protein Biosynthesis
  • RNA, Messenger / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Transcription, Genetic

Substances

  • RNA, Messenger
  • Collagen

Associated data

  • GENBANK/L15428
  • GENBANK/L20160
  • GENBANK/L20161
  • GENBANK/L20162
  • GENBANK/L20163
  • GENBANK/L20164
  • GENBANK/L20165
  • GENBANK/L20166
  • GENBANK/S61949
  • GENBANK/S63458