Induction of CXCL1 by extracellular matrix and autocrine enhancement by interleukin-1 in rat pancreatic beta-cells

Endocrinology. 2007 Nov;148(11):5582-90. doi: 10.1210/en.2007-0325. Epub 2007 Aug 16.

Abstract

As we showed previously, the extracellular matrix (ECM) derived from rat bladder carcinoma cells (804G-ECM) has positive effects on rat primary beta-cell function and survival in vitro. The aim of this study was to define beta-cell genes induced by this ECM with a specific focus on cytokines. Analysis of differential gene expression by oligonucleotide microarrays, RT-PCR, and in situ hybridization was performed to identify cytokine mRNA induced by this matrix. Four cytokines were overexpressed on 804G-ECM compared with poly-L-lysine: C-X-C motif ligand 1 (CXCL1), CXCL2, interferon-inducible protein-10, and IL-1beta. A time-course experiment indicated that maximal induction by 804G-ECM of CXCL1/2 and interferon-inducible protein-10 occurred at 4 h. Stimulation of CXCL1 release by beta-cells on 804G-ECM was confirmed at the protein level. Moreover, secreted CXCL1 was shown to be functionally active by attracting rat granulocytes. Preventing the interaction of beta1 integrins and laminin-5 (a major component of 804G-ECM) with specific antibodies resulted in a 40-50% inhibition of CXCL1 expression. Using the nuclear factor-kappaB pathway inhibitor Bay 11-7082 it is demonstrated that CXCL1 expression and secretion are dependent on nuclear factor-kappaB activation. IL-1 secreted by beta-cells plated on 804G-ECM was found to be a key soluble mediator because treatment of cells with the IL-1 receptor antagonist significantly reduced both CXCL1 gene expression and secretion. It is concluded that ECM induces expression of cytokines including CXCL1 with amplification by IL-1 acting via a positive autocrine feedback loop.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autocrine Communication / drug effects*
  • Cell Movement / drug effects
  • Cells, Cultured
  • Chemokine CXCL1 / genetics*
  • Chemokine CXCL1 / metabolism
  • Chemokine CXCL1 / pharmacology
  • Culture Media, Conditioned / pharmacology
  • Cytokines / genetics
  • Extracellular Matrix / physiology*
  • Gene Expression Regulation / drug effects
  • Granulocytes / cytology
  • Granulocytes / drug effects
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism
  • Interleukin-1 / pharmacology*
  • Male
  • Models, Biological
  • Rats
  • Rats, Wistar

Substances

  • Chemokine CXCL1
  • Culture Media, Conditioned
  • Cxcl1 protein, rat
  • Cytokines
  • Interleukin-1