Vitamin D derivatives induce apoptosis and downregulate ICAM-1 levels in peripheral blood mononuclear cells of inflammatory bowel disease patients.
BACKGROUND
Lymphocytes are crucial in the pathogenesis of inflammatory bowel disease (IBD) and are an important target for drug development. Our aim was to verify whether 2 vitamin D derivatives, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and EB 1089, could induce cell apoptosis and affect cell-cell interaction by regulating adhesion molecule levels.


METHODS
Peripheral blood mononuclear cell (PBMC) proliferation was studied by [3H]thymidine incorporation and apoptosis was determined using an enzyme-linked immunosorbent assay (ELISA) kit. (Poly(ADP-ribose)polymerase (PARP) cleavage, caspase-3, and ICAM-1 protein levels were determined by Western blot analysis.


RESULTS
Our results indicate that 1,25(OH)2D3 or EB 1089 or anti-TNF-alpha (infliximab) induce apoptosis in PBMC obtained from healthy subjects. In IBD patients apoptosis is induced by vitamin D derivatives and by anti-TNF-alpha only in CD patients. Caspase-3 activation and PARP cleavage are registered when PBMC were treated with vitamin D derivatives. ICAM-1 levels remarkably increase when PBMC was incubated with lipopolysaccharide (LPS) or TNF-alpha. The treatment with the vitamin D derivatives, alone or in combination with LPS or TNF-alpha, significantly decreases ICAM-1 levels both in healthy subjects and IBD patients. In HUVEC cocultured with PBMC, previously incubated with LPS or TNF-alpha associated with 1,25(OH)2D3, ICAM-1 levels decrease both in healthy subjects and IBD patients.


CONCLUSIONS
1,25(OH)2D3 and EB 1089 inhibit PBMC proliferation, induce apoptosis in PBMC of healthy subjects and IBD patients, and affect ICAM-1 expression on PBMC and on HUVEC cocultured with PBMC, suggesting that the ICAM-1 downregulation could provide a new target for controlling the recruitment of leukocytes at the sites of inflammation in IBD.
Martinesi
Maria
M
Department of Biochemical Sciences, University of Florence, Florence, Italy.
Treves
Cristina
C
d'Albasio
Giuseppe
G
Bagnoli
Siro
S
Bonanomi
Andrea G
AG
Stio
Maria
M
D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D015153:Blotting, Western; D002117:Calcitriol / Q000031:analogs & derivatives / Q000627:therapeutic use; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics*; D053938:DNA Fragmentation; D015536:Down-Regulation / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000188:drug therapy / Q000235:genetics*; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D014807:Vitamin D / Q000008:administration & dosage* / Q000819:agonists / Q000031:analogs & derivatives / Q000627:therapeutic use; D014815:Vitamins / Q000627:therapeutic use
D007166:Immunosuppressive Agents; D014815:Vitamins; D018799:Intercellular Adhesion Molecule-1; D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D; D004247:DNA; D002117:Calcitriol; C078903:seocalcitol