title: Inflammation-induced up-regulation of ionotropic glutamate receptor expression in human skin.
abstract: BACKGROUND
  N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methylisoxazolone-4-propionic acid (AMPA), and kainate (KA) receptors are members of the ionotropic glutamate receptor (iGluR) family and are increased in inflamed rat skin. These receptors contribute to inflammatory pain. In this study, we have examined whether there is a similar increase in iGluRs in inflamed human skin in the presence of inflammatory pain.
  
  
  METHODS
  Normal and inflamed-skin biopsies were obtained from eight patients undergoing elective wound-debridement surgery. Real-time-polymerase chain reaction (PCR) and western blot analysis were used for quantitation of iGluR mRNA and protein in normal and inflamed human skin.
  
  
  RESULTS
  A significant increase in mRNA and protein for NMDA, AMPA, and KA receptor subunits was detected in inflamed compared with normal skin. The amounts of NMDA (NR1 subunit), AMPA (GluR2 subunit), and KA (GluR6 subunit) mRNA in inflamed skin were mean 6 (SD 1.6-fold), 2.5 (0.6-fold), and 3.8 (0.9-fold) (P<0.05), respectively, greater than that measured in normal skin. The ratio of NR1, GluR2, and GluR6 protein in inflamed compared with normal skin was 5.7 (1.2), 2.4 (0.5), and 3.6 (0.9) (P<0.05), respectively.
  
  
  CONCLUSIONS
  These results, in human tissue, demonstrate that iGluR mRNA and protein expression are increased during persistent inflammation and that this increased activity may be involved in mediating clinical inflammatory pain in human skin.
authors.affiliation: Department of Anesthesiology, E-DA Hospital, I-Shou University, 1, Yi-Da Road, Yuan-Chou Shiang, Kaohsiung County, Taiwan, Republic of China. tanphphd@hotmail.com
authors.forename: P-H
authors.initials: PH
authors.lastname: Tan
authors.forename: L-C
authors.initials: LC
authors.lastname: Yang
authors.forename: P-T
authors.initials: PT
authors.lastname: Chiang
authors.forename: J S-C
authors.initials: JS
authors.lastname: Jang
authors.forename: H-C
authors.initials: HC
authors.lastname: Chung
authors.forename: C-H
authors.initials: CH
authors.lastname: Kuo
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western / Q000379:methods; D003872:Dermatitis / Q000378:metabolism*; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D012333:RNA, Messenger / Q000235:genetics; D018091:Receptors, AMPA / Q000235:genetics / Q000378:metabolism; D017470:Receptors, Glutamate / Q000235:genetics / Q000378:metabolism*; D018092:Kainic Acid Receptors / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012867:Skin / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D012333:RNA, Messenger; D018091:Receptors, AMPA; D017470:Receptors, Glutamate; D018092:Kainic Acid Receptors; D016194:Receptors, N-Methyl-D-Aspartate