First Author | Koedel U | Year | 2007 |
Journal | Am J Pathol | Volume | 171 |
Issue | 1 | Pages | 200-13 |
PubMed ID | 17591966 | Mgi Jnum | J:122826 |
Mgi Id | MGI:3715573 | Doi | 10.2353/ajpath.2007.060821 |
Citation | Koedel U, et al. (2007) Acute brain injury triggers MyD88-dependent, TLR2/4-independent inflammatory responses. Am J Pathol 171(1):200-13 |
abstractText | Endogenous molecules released from disrupted cells and extracellular matrix degradation products activate Toll-like receptors (TLRs) and, thus, might contribute to immune activation after tissue injury. Here, we show that aseptic, cold-induced cortical injury triggered an acute immune response that involves increased production of multiple cytokines/chemokines accompanied by neutrophil recruitment to the lesion site. We observed selective reductions in injury-induced cytokine/chemokine expression as well as in neutrophil accumulation in mice lacking the common TLR signaling adaptor MyD88 compared with wild-type mice. Notably, attenuation of the immune response was paralleled by a reduction in lesion size. Neutrophil depletion of wild-type mice and transplantation of MyD88-deficient bone marrow into lethally irradiated wild-type recipients had no substantial impact on injury-induced expression of cytokines/chemokines and on lesion development. In contrast to MyD88 deficiency, double deficiency of TLR2 and TLR4 -- despite the two receptors being activated by specific endogenous molecules associated to danger and signal through MyD88 -- altered neither immune response nor extent of tissue lesion size on injury. Our data indicate modulation of the neuroinflammatory response and lesion development after aseptic cortical injury through MyD88-dependent but TLR2/4-independent signaling by central nervous system resident nonmyeloid cells. |