[Expression of high mobility group box chromosomal protein 1 in peripheral blood of patients with rheumatoid arthritis].
OBJECTIVE
To investigate the mRNA and protein expression of high mobility group box chromosomal protein 1 (HMGB1) in peripheral blood mononuclear cells (PBMCs) and serum.


METHODS
Levels of HMGB1mRNA were detected with reverse transcription polymerase chain reaction (RT-PCR) in PBMC and levels of HMGB1 protein in PBMC and plasm were measured with Western blot in 38 patients with active rheumatoid arthritis (RA), 24 with inactive RA and 20 healthy controls. Ficoll density gradient centrifugation was used to separate PBMCs from peripheral blood. The correlation between the levels of HMGB1 in serum and the index of disease activity in RA was analyzed.


RESULTS
There was no statistically significant difference of the mRNA expression of HMGB1 in PBMCs from active RA patients as compared with those from inactive RA group and healthy controls (F = 1.23, P > 0.05). The protein expression of HMGB1 was significantly lower in PBMCs from active RA patients (F = 70.91, P < 0.01), while the protein expression of HMGB1 was higher in plasma from active RA patients (P < 0.001) as compared with that from inactive RA patients and healthy controls. However, there was no statistically significant difference between inactive RA patients and healthy controls (P > 0.05). The level of HMGB1 protein in plasma of RA patients was correlated with erythrocyte sedimentation rate (ESR) (r(s) = 0.478, P < 0.001) and C- reactive protein (CRP) (r(s) = 0.574, P < 0.05). It was not correlated with age, the number of tender joints and swollen joints, radiographic scores and therapeutic effect.


CONCLUSIONS
The protein expression of HMGB1 was significantly decreased in PBMCs from active RA patients, while it was increased in serum from active RA patients. HMGB1 plays a pivotal role in the pathogenesis of RA and may be a target of therapy as a novel cytokine.
Zuo
Xiao-xia
XX
Department of Rheumatology and Clinical Immunology, Xiangya Hospital, Central South University, Changsha 410008, China. susanzuo@hotmail.com
Zhou
Ya-ou
YO
Gong
Yan-hui
YH
Wang
Yan-ping
YP
Tang
Dao-lin
DL
Xiao
Xian-zhong
XZ
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000473:pathology; D015153:Blotting, Western; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D024243:HMGB1 Protein / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D024243:HMGB1 Protein; D012333:RNA, Messenger; D002097:C-Reactive Protein