Open AccessIdentification of the HSPB4/TLR2/NF‐κB axis in macrophage as a therapeutic target for sterile inflammation of the cornea
Author(s) -
Oh Joo Youn,
Choi Hosoon,
Lee Ryang Hwa,
Roddy Gavin W.,
Ylöstalo Joni H.,
Wawrousek Eric,
Prockop Darwin J.
Publication year - 2012
Publication title -
embo molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.923
H-Index - 107
eISSN - 1757-4684
pISSN - 1757-4676
DOI - 10.1002/emmm.201200221
Subject(s) - inflammation , tlr2 , cornea , corneal inflammation , biology , immunology , macrophage , infiltration (hvac) , heat shock protein , chemistry , biochemistry , gene , materials science , in vitro , tlr4 , neuroscience , composite material
Sterile inflammation underlies many diseases of the cornea including serious chemical burns and the common dry eye syndrome. In search for therapeutic targets for corneal inflammation, we defined the kinetics of neutrophil infiltration in a model of sterile injury to the cornea and identified molecular and cellular mechanisms triggering inflammatory responses. Neutrophil infiltration occurred in two phases: a small initial phase (Phase I) that began within 15 min after injury, and a larger second phase (Phase II) that peaked at 24–48 h. Temporal analysis suggested that the neuropeptide secretoneurin initiated Phase I without involvement of resident macrophages. Phase II was initiated by the small heat shock protein HSPB4 that was released from injured keratocytes and that activated resident macrophages via the TLR2/NF‐κB pathway. The Phase II inflammation was responsible for vision‐threatening opacity and was markedly suppressed by different means of inhibition of the HSPB4/TLR2/NF‐κB axis: in mice lacking HSPB4 or TLR2, by antibodies to HSPB4 or by TNF‐α stimulated gene/protein 6 that CD44‐dependently inhibits the TLR2/NF‐κB pathway. Therefore, our data identified the HSPB4/TLR2/NF‐κB axis in macrophages as an effective target for therapy of corneal inflammation.