Regulation of bFGF expression and ANG II secretion in cardiac myocytes and microvascular endothelial cells

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Thomas A. Fischer - , Harvard University, Johannes Gutenberg University Mainz (Author)
  • Dan Ungureanu-Longrois - , Harvard University, CHU de Nancy (Author)
  • Krishna Singh - , Harvard University (Author)
  • Juan De Zengotita - , Harvard University (Author)
  • Daniel DeUgarte - , Harvard University (Author)
  • Alborz Alali - , Harvard University (Author)
  • Albert P. Gadbut - , Harvard University (Author)
  • Min A.E. Lee - , Harvard University (Author)
  • Jean Lug Balligand - , Harvard University (Author)
  • Imre Kifor - , Harvard University (Author)
  • Thomas W. Smith - , Harvard University (Author)
  • Ralph A. Kelly - , Harvard University (Author)

Abstract

Basic fibroblast growth factor (bFGF; fibroblast growth factor-2) and angiotensin II (ANG II), among other peptide signaling autacoids (cytokines), are known to regulate the phenotypic adaptation of cardiac muscle to physiological stress. The cell type(s) in cardiac muscle responsible for ANG II synthesis and secretion and the role of endogenous cytokines in the regulation of bFGF induction remain unclear. With the use of confluent, serum-starved, low-passage cultures of cardiac microvascular endothelial cells (CMEC), ANG II could be detected in cellular lysates and in medium conditioned by these cells with the use of high-performance liquid chromatography followed by radioimmunoassay. The secretion of angiotensins by individual CMEC could be detected with a cell-blot assay technique. ANG II secretion was decreased by brefeldin A, an agent that interrupts constitutive and regulated secretory pathways for peptide autacoid/hormone synthesis, suggesting de novo synthesis, activation, and secretion of angiotensins by CMEC. In primary isolates of adult rat ventricular myocytes (ARVM) and CMEC, ANG II, acting at ANG II type 1 receptors in both cell types, was found to increase bFGF mRNA levels measured by ribonuclease protection assay. Endothelin-1 (ET-1), which is known to be synthesized by CMEC, and bFGF itself, which has been detected in both ARVM and CMEC, increased bFGF transcript levels in both cell types. Interleukin-β (IL-1β), which like ANG II and ET-1 is known to activate mitogen-activated protein kinases in both ARVM and CMEC, increased bFGF mRNA levels only in cardiac myocytes. Thus cytokines such as ANG II, ET-1, bFGF, and IL-1β locally generated by cellular constituents of cardiac muscle, including CMEC, regulate bFGF mRNA levels in a cell type-specific manner.

Details

Original languageEnglish
Pages (from-to)H958-H968
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume272
Issue number2 41-2
Publication statusPublished - Feb 1997
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 9124460

Keywords

Keywords

  • angiotensin I converting enzyme, endothelin, interleukin-1