Abstract
BACKGROUND: Treatment with the TRPV1 agonist, capsaicin, was previously shown to protect against experimental colitis in the severe combined immunodeficiency (SCID) T-cell transfer model. Here, we investigate trpv1 gene expression in lymphoid organs and cells from SCID and BALB/c mice to identify a potential target for the anti-inflammatory effect of capsaicin.
METHODS: The trpv1 expression was studied by real-time PCR in lymphoid tissues and gut of untreated and capsaicin-treated colitic SCID mice. Effects of capsaicin and a TRPV1 antagonist on T cells were studied in vitro.
RESULTS: In contrast to BALB/c mice, spleen, lymph nodes, and rectum of colitic and noncolitic SCID mice express trpv1 mRNA. Capsaicin treatment in vivo attenuated T-cell transfer colitis and capsaicin in vitro also attenuated T-cell proliferation induced by enteroantigen, mitogen, and anti-CD3/CD28 beads in BALB/c, C57BL/6 mice, and B6.129X1-trpv1tm1Jul/J trpv1 knockout mice. Proliferation and cytokine secretion were fully comparable in mice with and without trpv1 expression. Likewise, enteroantigen- and mitogen-stimulated T cells from wild-type and trpv1 knockout mice were equally inhibited by capsaicin. Surprisingly, the TRPV1 antagonist BCTC also inhibited enteroantigen- and mitogen-induced T-cell proliferation.
CONCLUSIONS: The trpv1 mRNA expression in lymphoid organs and the rectum of SCID mice suggests that the TRPV1 signaling in these organs could play a role in capsaicin-mediated attenuation of colitis. In addition, capsaicin-induced inhibition of T-cell proliferation of wild-type T cells lacking trpv1 expression suggests that capsaicin inhibits colitogenic T cells in a TRPV1 receptor-independent way, which might be linked to its anti-inflammatory effect.
Original language | English |
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Journal | Inflammatory Bowel Diseases |
Volume | 20 |
Issue number | 6 |
Pages (from-to) | 1004-14 |
Number of pages | 11 |
ISSN | 1078-0998 |
DOIs | |
Publication status | Published - Jun 2014 |
Keywords
- Animals
- Antigens
- Antipruritics
- CD4-Positive T-Lymphocytes
- Capsaicin
- Cell Proliferation
- Colitis
- Cytokines
- Disease Models, Animal
- Ligands
- Lymphoid Tissue
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, SCID
- Pyrazines
- Pyridines
- Signal Transduction
- TRPV Cation Channels
- beta 2-Microglobulin