Hepatic sinusoidal endothelium upregulates IL-1α, IFN-γ, and iNOS in response to discordant xenogeneic islets in an in vitro model of xenoislet transplantation

Michael Tan, Antonio Di Carlo, Shu Qing Liu, A. Joseph Tector, Jean I. Tchervenkov, Peter Metrakos

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Background. Data indicate that early islet graft failure is due to nonspecific inflammatory mechanisms that occur prior to T-cell-mediated rejection. The role of the host hepatic endothelium in mediating this immediate islet injury has not been elucidated. The endothelial cell may be important in this process because it is essentially the first cellular barrier encountered by intraportally introduced islets. We have characterized the initial response of hepatic endothelium to xenogeneic islets by measuring the expression of Il-1α, TNF-α, IFN-γ, and iNOS in an in vitro dog-to-pig model of xenoislet transplantation. Materials and methods. Dog islets (500 islet equivalents) were cocultured with either porcine hepatic endothelium or porcine aortic endothelium over a 24-h period in serum-free medium. RNA was extracted at eight time points (0, 1, 2, 4, 6, 8, 12, and 24 h). Reverse-transcriptase polymerase chain reaction was performed on each sample. Polymerase chain reaction was done on the cDNA in order to visualize Il-1α, TNF-α, IFN-γ, and iNOS expression. Bands were semi-quantitated by comparison to an external standard (GAPDH) using band densitometry. Results. Hepatic endothelium had early (1 h) expression of IL-1α, IFN-γ, and iNOS. IL-1α peaked at 2 h, IFN-γ at 12 h, and iNOS at 1 and 12 h. Aortic endothelium expressed low levels of IL-1α and TNF-α, but not IFN-γ or iNOS. Conclusions. We have demonstrated that xenogeneic islets are able to activate host endothelial cells without serum or immune cells. The observed endothelial response corresponds with known islet toxic substances. Furthermore, the response differs between hepatic and aortic endothelial cells, suggesting that these differences may be important in choosing suitable implantation sites for islets. Our findings suggest that host endothelium may play an important part in early injury of islet xenotransplants.

Original languageEnglish (US)
Pages (from-to)229-236
Number of pages8
JournalJournal of Surgical Research
Volume102
Issue number2
DOIs
StatePublished - 2002
Externally publishedYes

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Keywords

  • Aortic endothelium
  • Cytokines
  • Endothelial cell activation
  • Hepatic endothelium
  • iNOS
  • Xenoislet transplantation

ASJC Scopus subject areas

  • Surgery

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