Cytokine Regulation by MAPK Activated Kinase 2 in Keratinocytes Exposed to Sulfur Mustard
Abstract
Uncontrolled inflammation contributes to cutaneous damage following exposure to the warfare agent bis(2-chloroethyl) sulfide (sulfur mustard, SM). Activation of the p38 mitogen activated protein kinase (MAPK) precedes SM-induced cytokine secretion in normal human epidermal keratinocytes (NHEKs). This study examined the role of p38-regulated MAPK activated kinase 2 (MK2) during this process. Time course analysis studies using NHEK cells exposed to 200 lM SM demonstrated rapid MK2 activation via phosphorylation that occurred within 15 min. p38 activation was necessary for MK2 phosphorylation as determined by studies using the p38 inhibitor SB203580. To compare the role of p38 and MK2 during SMinduced cytokine secretion, small interfering RNA (siRNA) targeting these proteins was utilized. TNF-alpha, IL-1beta, IL-6 and IL-8 secretion was evaluated 24 h postexposure, while mRNA changes were quantified after 8 h. TNF-alpha, IL-6 and IL-8 up regulation at the protein and mRNA level was observed following SM exposure. IL-1beta secretion was also elevated despite unchanged mRNA levels. p38 knockdown reduced SM-induced secretion of all the cytokines examined, whereas significant reduction in SM-induced cytokine secretion was only observed with TNF-alpha and IL-6 following MK2 knockdown. Our observations demonstrate potential activation of other p38 targets in addition to MK2 during SM-induced cytokine secretion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 10, 2013
- Accession Number
- ADA590111
Entities
People
- E. Chepchumba K.
- James F. Dillman Iii
Organizations
- United States Army Medical Research Institute of Chemical Defense