A Deficiency in the Prostaglandin D-2 Receptor CRTH2 Exacerbates Adjuvant-Induced Joint Inflammation

作者：Tsubosaka Yoshiki; Nakamura Tatsuro; Hirai Hiroyuki; Hori Masatoshi; Nakamura Masataka; Ozaki Hiroshi; Murata Takahisa^*

来源：The Journal of Immunology, 2014, 193(12): 5835-5840.

DOI：10.4049/jimmunol.1303478

Although the cyclooxygenase metabolites PGs are known to be involved in the progression of arthritis, the role of PGD2 remains unclear. In this study, we evaluated the contribution of signaling mediated through a PGD(2) receptor, chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2), in the progression of adjuvant-induced joint inflammation. Injection of CFA into the ankle joint stimulated PGD(2) production and induced paw swelling in both CRTH2-naive (WT) and CRTH2(-/-) mice. CRTH2(-/-) mice presented more severe arthritic manifestations than did WT mice. Through bone marrow transplantation experiments between WT and CRTH2(-/-) mice, we showed that CRTH2 deficiency in bone marrow-derived immune cells is involved in disease progression. Morphological studies showed that CRTH2 deficiency accelerated the infiltration of macrophages into the inflamed paw. Consistent with this finding, we observed that treatment with the macrophage inactivator GdCl3 or the macrophage-depleting agent liposomal clodronate improved arthritis symptoms in CRTH2(-/-) mice. Adoptive transfer of CRTH2(-/-) macrophages exacerbated joint inflammation in WT mice. In addition, CRTH2 deficiency accelerated, whereas CRTH2 agonism inhibited, the expression of a macrophage-activating cytokine (GM-CSF) and a chemokine receptor (CXCR2) in CFA-treated peritoneal macrophages. Together, these observations demonstrate that PGD(2)-CRTH2 signaling plays a protective role in joint inflammation by attenuating the infiltration of macrophages.

• 出版日期2014-12-15