TNF-alpha decreases expression of somatostatin, somatostatin receptors, and cortistatin in human coronary endothelial cells

J Surg Res. 2005 Feb;123(2):294-301. doi: 10.1016/j.jss.2004.07.244.


Background: The objective of this study was to determine the expression of somatostatin (SST) and its receptors (SSTRs) and their regulation by TNF-alpha as well as cell proliferation in response to SST in human endothelial cells.

Materials and methods: Human coronary artery endothelial cells (HCAECs) were cultured without or with TNF-alpha (0.1, 1, or 10 ng/ml) for 24 h. The mRNA levels of SST, SSTR-1-5, as well as a housekeeping gene (beta-actin) were determined by real-time RT-PCR. Expression of SSTR-2 was also demonstrated by immunofluorescence staining. Cell proliferation in response to SST treatment (0.04, 0.2, or 1 ng/ml) was performed by [3H]thymidine incorporation.

Results: Without TNF-alpha treatment, HCAECs showed mRNA expression of SST, SSTR-1, SSTR-2, and SSTR-5. The mRNA of SSTR-2 was expressed at a higher level than that of SSTR-1 and SSTR-5. However, SSTR-3 and SSTR-4 were not expressed or were minimally expressed. After treatment with TNF-alpha, the mRNA levels of SST, SSTR-1, SSTR-2, and SSTR-5 were significantly reduced in a dose-dependent fashion. TNF-alpha (1 ng/ml) reduced SST, SSTR-1, SSTR-2, and SSTR-5 by 93, 51, 85, and 99%, respectively, compared to controls (P < 0.001, t test). The immunoreactivity of SSTR-2 was also reduced after TNF-alpha treatment. SST-treated cells showed a significant reduction in [3H]thymidine incorporation in a dose-dependent manner. TNF-alpha treatment decreased SST inhibitory potential in cell proliferation.

Conclusions: HCAECs express SST, SSTR-1, SSTR-2, and SSTR-5, which are all decreased by TNF-alpha treatment. Furthermore, treatment with exogenous SST significantly reduces cell proliferation, and this inhibitory effect is also decreased by TNF-alpha.

Publication types

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

MeSH terms

  • Cell Division / drug effects
  • Cells, Cultured
  • Coronary Vessels / cytology
  • Coronary Vessels / drug effects*
  • Coronary Vessels / physiology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Endothelium, Vascular / physiology
  • Gene Expression / drug effects
  • Humans
  • Neuropeptides / genetics*
  • Neuropeptides / metabolism
  • RNA, Messenger / analysis
  • Receptors, Somatostatin / genetics*
  • Receptors, Somatostatin / metabolism
  • Somatostatin / genetics*
  • Somatostatin / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology*


  • Neuropeptides
  • RNA, Messenger
  • Receptors, Somatostatin
  • Tumor Necrosis Factor-alpha
  • cortistatin
  • somatostatin receptor type 1
  • Somatostatin
  • somatostatin receptor 5
  • somatostatin receptor 2