Proteins related to the functions of fibroblast-like synoviocytes identified by proteomic analysis.
OBJECTIVE
It is well known that the fibroblast-like synoviocytes (FLS) play a key role in pathogenesis of rheumatoid arthritis (RA). This study was performed to separate the differentially expressed proteins of FLS from the patients with RA or osteoarthritis (OA) by two-dimensional electrophoresis (2-DE), and found proteins associated with the functions of FLS by mass spectrometry (MS).


METHODS
Total proteins were extracted and quantified from the primary cultured FLS from patients of RA (n=8) or OA (n=6). Proteins were separated by high-resolution 2-DE, and identified the differentially expressed proteins by MS. Western blot analyses was used to validated the expression of candidate proteins. The mRNA of these proteins was detected by semi-quantitative fluorescent PCR.


RESULTS
There are 1147 protein spots from RA and 1324 protein spots from OA showed on 2-DE graphs, respectively. We have selected 84 protein spots for MS analysis, and 27 protein spots were successfully identified. We have found that protein isoaspartyl methyltransferase (PIMT) and pirin (iron-binding nuclear protein, PIR) with lower expression in RA, and thioredoxin 1(Trx-1) only expressed in RA may be associated with functions of FLS. Western Blot confirmed the expression of PIMT and pirin lower in RA, and Trx-1 expressed only in RA. The results of semi-quantitative fluorescent PCR are also consistent with 2-DE graphs.


CONCLUSIONS
PIMT, pirin and Trx-1 affect the functions of FLS in some style and can be the drug targets of RA.
Department of Clinical Laboratory, Shangai East Hospital, Tong Ji University, Shanghai, China.
Hui
H
Zhang
Lie Ying
LY
Fan
Ming
M
Zong
Li Shan
LS
Sun
Liu
L
Lu
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D049308:Dioxygenases; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000378:metabolism; D020370:Osteoarthritis, Knee / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D026601:Protein D-Aspartate-L-Isoaspartate Methyltransferase / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology; D053719:Tandem Mass Spectrometry; D013879:Thioredoxins / Q000378:metabolism
D002352:Carrier Proteins; D009687:Nuclear Proteins; D011506:Proteins; D012333:RNA, Messenger; C491203:TXN protein, human; D013879:Thioredoxins; D049308:Dioxygenases; C105340:PIR protein, human; C435725:PCMT1 protein, human; D026601:Protein D-Aspartate-L-Isoaspartate Methyltransferase