C-Jun NH2 terminal kinase (JNK) is an essential mediator of Toll-like receptor 2-induced corneal inflammation.

Abstract

TLRs play an important role in the host inflammatory response to bacteria and bacterial products by activating a cascade of intracellular events leading to production of proinflammatory and chemotactic cytokines. To determine the role of MAPKs in TLR- induced corneal inflammation, we stimulated human corneal epithelial (HCE) cells with TLR2 ligands, tripalmitoyl-S-glycero-Cys-(Lys)4 (Pam3Cys) or inactivated Staphylococcus aureus, and examined the time course of expression of MAPKs and the effect of MAPK inhibition on IkBalpha degradation and CXC chemokine production. We found that S. aureus and Pam3Cys stimulate phosphorylation of JNK, p38 MAPK, and ERK within 4 h and that blockade of JNK, but not p38 or ERK phosphorylation, had an inhibitory effect on IkBalpha degradation and CXC chemokine production. To determine if JNK is also important in TLR2-induced corneal inflammation in vivo, we examined JNK1(-/-) mice and pharmacological inhibitors in a murine model of TLR2-induced corneal inflammation which is characterized by neutrophil recruitment to the corneal stroma and development of corneal haze. We found that corneal inflammation was significantly impaired in JNK1(-/-) mice compared with control mice, and in mice treated with the JNK inhibitor compared with vehicle control. Taken together with results from HCE cells, these findings demonstrate that JNK has an essential role in TLR2-induced corneal inflammation.

• Authors: Gautam Adhikary, Yan Sun, Eric Pearlman
• Journal: Journal of leukocyte biology (J Leukoc Biol) Vol. 83 Issue 4 Pg. 991-7 (Apr 2008) ISSN: 0741-5400 [Print] United States
• PMID: 18218857 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• TLR2 protein, human
• Toll-Like Receptor 2
• JNK Mitogen-Activated Protein Kinases
• Mitogen-Activated Protein Kinase 8

Topics

• Adult
• Aged
• Animals
• Cell Line
• Cornea (cytology)
• Corneal Diseases (microbiology, physiopathology)
• Disease Models, Animal
• Epithelial Cells (physiology)
• Humans
• Inflammation (physiopathology)
• JNK Mitogen-Activated Protein Kinases (metabolism)
• Keratinocytes (physiology)
• Keratitis (physiopathology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Middle Aged
• Mitogen-Activated Protein Kinase 8 (antagonists & inhibitors, deficiency)
• Staphylococcus aureus
• Tissue Donors
• Toll-Like Receptor 2 (physiology)