The cell death regulatory protein bak is expressed in endothelial cells in inflamed tissues and Is induced by IFN-gamma in vitro.
In the present report, we examined the endothelial expression of the anti- and pro-apoptotic proteins Bcl-2 and Bak in situ and in vitro. Endothelial cells (EC) in regular tissue of the bowel and the skin were essentially negative for both Bcl-2 and Bak. In contrast, EC within the walls of fistulas and abscesses in these organs stained distinctly for Bak, but remained Bcl-2-negative. In tissue culture both unstimulated human dermal microvascular endothelial cells (HDMEC) and human umbilical vein endothelial cells (HUVEC) expressed Bcl-2 and Bak constitutively. Exposure of EC to 200-1000 IU IFN-gamma downregulated Bcl-2 but upregulated Bak. This opposing regulation of Bcl-2 and Bak in vitro and the expression of Bak in EC adjacent to necrotic tissue areas suggests that this pro-apoptotic protein may play a decisive role in regulation of EC survival in vivo.
Pammer
J
J
Institute of Clinical Pathology, University of Vienna, Vienna, A-1090, Austria.
Weninger
W
W
Ban
J
J
Wojta
J
J
Tschachler
E
E
D017209:Apoptosis; D002478:Cells, Cultured; D003872:Dermatitis / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005402:Fistula / Q000378:metabolism; D005759:Gastroenteritis / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology*; D008565:Membrane Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D014471:Umbilical Veins / Q000378:metabolism / Q000473:pathology; D015854:Up-Regulation; D050998:bcl-2 Homologous Antagonist-Killer Protein
C494772:BAK1 protein, human; D008565:Membrane Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D050998:bcl-2 Homologous Antagonist-Killer Protein; D007371:Interferon-gamma