ABSTRACT
Objective To investigate the relation of synovial anti-citrullinated epitope peptide(CCP)expression and peptidyl arginine deiminase 4 (PADI4)gene in the rheumatoid arthritis patient.Methods From February 2013 to 2015 in Dongfeng General Hospital Affiliated to Hubei University,selected 110 patients with rheumatoid arthritis as the observation group, and selected 110 healthy people at the same period in this hospital for medical examination as the control group,both groups were given the synovial CCP expression positive rate and PADI4 gene expression detecting and correlation analysis.Results The synovial anti-CCP expression positive rates in the observation group and the control group were 70.9% and 9.1% re-spectively,and the observation group were significantly higher than the control group (P<0.05).The PADI4-104 genotype expression frequency compared between the observation group and control group,the difference were statistically significant (P<0.05).The G/G expression was more in the observation group,while the control group was more wit the C/G expres-sion.Pearson correlation analysis showed that in the observation group,synovial CCP positive expression were significant correlated to the expression of genotype PADI4-104 (r=0.344,P<0.05).Logistic regression analysis showed PADI4-104 genotype frequency were the main factors for the synovial CCP epitope expression (P<0.05).Conclusion The rheumatoid arthritis was more with synovial anti-CCP positive expression.There were also PADI4 polymorphism disorder expression, and clear correlation between the two.Thus impact the incidence of rheumatoid arthritis.
ABSTRACT
Objective To explore the probable function of peptidyl arginine deiminase 4 (PAD4) in rheumatoid arthritis(RA).Methods Real-time quantitative polymerase chain reaction (PCR) was used to determine the expression of PAD4 mRNA in peripheral blood mononucleated cells (PBMCs) from 60 RA patients and 40 healthy individuals.Asymmetric di-methylation of histone H3R17,symmetric di-methylation and mono-methylation of H4R3 were semi-quantified by Western blotting in 12 patients with osteoarthritis (OA),26 patients with RA and 10 healthy controls.Results PAD4 mRNA in RA was significantly higher than that in healthy controls [34.6 (16.7,70.8) vs 20.6 (11.1,51.8),P ＜ 0.05].The level of histone H3R17 asymmetric di-methylation in RA was significantly higher than that of OA or control groups(71.34 ±25.65 vs 37.18 ± 18.62 vs 50.67 ± 13.99,P ＜0.01),which was positively related to Tender joint count and Swollen joint count in 28 joints (r =0.418,P =0.034 ; r =0.402,P =0.042).The level of histone H4R3 symmetric di-methylation was similar in RA,OA and control groups (75.02 ± 20.35 vs 57.92 ± 22.77 vs 68.37 ± 17.57,P ＞ 0.05).The level of histone H4R3 mono-methylation in RA patients was significantly lower than that of OA patients and healthy individuals (11.24 ±7.81 vs 32.77 ±30.77 vs 51.20 ±47.14,P ＜ 0.05).The level of histone H4R3 mono-methylation in RA patients was negatively correlated to PAD4 (r =-0.643,P ＜ 0.01).The level of histone H3R17 asymmetric di-methylation and H4R3 symmetric di-methylation was not associated with PAD4 level in RA group (r =-0.185,P =0.377; r =0.198,P =0.344).Conclusions The level of histone H3R17 asymmetric di-methylation is significantly higher and the level of histone H4R3 mono-methylation is significantly lower in RA patients comparing with OA and control groups.Abnormality of histone methylation may be one of the mechanisms for the development of RA.PAD4 probably plays an important role in rheumatoid arthritis by influencing histone methylation.