Primary chondrocytes resist hydrostatic pressure-induced stress while primary synovial cells and fibroblasts show modified Hsp70 response

K Kaarniranta, C I Holmberg, M J Lammi, J E Eriksson, L Sistonen, H J Helminen

Research output: Contribution to journalArticleScientificpeer-review

37 Citations (Scopus)

Abstract

OBJECTIVE: During joint loading, chondrocytes in the articular cartilage are subjected to gradients of high compressive hydrostatic pressure (HP). In response to diverse chemical or physical stresses, heat shock genes are induced to express heat shock proteins (Hsps). This study sought to examine the role of Hsps in baroresistance in primary bovine chondrocytes and synovial cells, as well as in primary human fibroblasts.

METHODS: Northern blotting was used to analyze the steady-state levels of hsp70 mRNA in the primary cells exposed to HP or heat stress. Hsp70 protein accumulation was analyzed by Western blotting, and the DNA-binding activity was examined by gel mobility shift assay.

RESULTS: Primary bovine chondrocytes which have been adapted to live under pressurized conditions showed negligible Hsp70 response upon HP loading, whereas primary bovine synovial cells and human fibroblasts accumulated hsp70 mRNA and protein when subjected to HP. The response was initiated without activation of the heat shock transcription factor 1. Interestingly, pre-conditioning of the barosensitive fibroblasts with HP or heat shock reduced the Hsp70 response, indicating induction of baroresistance.

CONCLUSION: This study suggests that Hsp70 can play an important role in the early stages of adaptation of cells to HP. Thus, the Hsp70 gene expression upon HP loading may serve as one indicator of the chondrocytic phenotype of the cells. This can be of use in the treatment of cartilage lesions.

Original languageEnglish
Pages (from-to)7-13
Number of pages7
JournalOsteoarthritis and Cartilage
Volume9
Issue number1
DOIs
Publication statusPublished - Jan 2001
MoE publication typeA1 Journal article-refereed

Keywords

  • Animals
  • Cartilage, Articular/physiology
  • Cattle
  • Chondrocytes/cytology
  • Fibroblasts/physiology
  • HSP70 Heat-Shock Proteins/metabolism
  • Heat-Shock Response/physiology
  • Humans
  • Hydrostatic Pressure/adverse effects
  • Stress, Mechanical
  • Synovial Membrane/physiology

Fingerprint

Dive into the research topics of 'Primary chondrocytes resist hydrostatic pressure-induced stress while primary synovial cells and fibroblasts show modified Hsp70 response'. Together they form a unique fingerprint.

Cite this