Mitochondria-dependent apoptosis of activated T lymphocytes induced by astin C, a plant cyclopeptide, for preventing murine experimental colitis.

State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, 22 Han Kou Road, Nanjing 210093, China.
Biochemical pharmacology (Impact Factor: 4.25). 05/2011; 82(3):260-8. DOI: 10.1016/j.bcp.2011.04.013
Source: PubMed

ABSTRACT Facilitating T-cell apoptosis is implicated as an effective therapeutic strategy for treatment of T cell-mediated disease, including inflammatory bowel disease. Here, we report that astin C, a plant cyclopeptide isolated from the roots of Aster tataricus (Compositae), induced apoptosis of activated T cells in a mitochondria-dependent but Fas-independent manner in that such activity was still observed in T cells from Fas-mutated MRLlpr/lpr mice. Although caspase 8 was not activated, astin C treatment led to the cleavage of caspase 9 and caspase 3, the upregulation of Bad protein expression as well as release of cytochrome c in activated T cells. Astin C did not induce the expression of GRP78 and GADD153, excluding involvement of endoplasmic reticulum stress-mediated pathway. Moreover, oral administration of astin C protected mice against TNBS-induced colonic inflammation, as assessed by a reduced colonic weight/length ratio and histological scoring. Administering astin C significantly decreased serum levels of TNF-α, IL-4 and IL-17, accompanied with the induction of apoptosis in activated T cells in vivo. The results demonstrate, for the first time, the ability of astin C to induce apoptosis in activated T cells and its potential use in the treatment of colonic inflammation.

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