RESUMO
Objective:To evaluate the clinical performance of anti-peptidylarginine deiminase 2 (PAD2) and anti-PAD4 antibodies combined testing in a Chinese rheumatoid arthritis (RA) cohort.Methods:A total of 148 RA inpatients and 35 patients with non-RA arthritis as controls (DC) were recruited from November, 2018 to November, 2019 in Peking University People′s Hospital. In addition, a total of 44 healthy controls (HC) who went to Peking University People′s Hospital for annual physical examination were collected from June 2019 to July 2019. The α-PAD2 and α-PAD4 level in clinical specimens were determined by ELISA. Statistical analysis was performed by the Mann-Whitney U test, the Kruskal-Wallis (KW) test, the χ 2 test or the Fisher′s Exact Test, as necessary. Correlation analysis were performed by logistic regression. Results:α-PAD2 and α-PAD4 were present in 26.4% (39/148) and 20.9% (31/148) patients with RA, 5.7% (2/35) and 5.7% DC (2/35) and 4.5% (2/44) and 2.3% HC (2/44), respectively. α-PAD4-positive RA patients displayed significantly longer disease duration compared to α-PAD4-negative RA patients (17.3±13.2 years vs 8.6±10.2 years, P<0.001). α-PAD4-positive RA patients showed a significantly higher incidence of interstitial lung disease (ILD) compared to those without α-PAD4 (54.8% vs 25.6%, P=0.002). No associations between α-PAD2 and ILD were found ( OR: 0.797, P=0.579). In contrast, significant associations between α-PAD4 and ILD were found ( OR: 3.521, P=0.002). In seropositive RA, α-PAD4 displayed a weak correlation with ILD ( OR: 2.324, P=0.046), but this association was greatly enhanced when combined with α-PAD2 [anti-PAD2 (-)] ( OR: 4.059, P=0.007). Conclusions:The findings delineate the clinical relevance of α-PAD2 and α-PAD4 in RA and suggest that the combined testing for α-PAD2 and α-PAD4 may provide additional diagnostic value to the current clinically available assays in RA, in particular in identifying patients at risk of RA-ILD.
RESUMO
Objective To study the transcriptional regulation of vp1667 by H-NS in Vibrio parahaemolyticus.Methods Total RNAs were extracted from Δhns and WT strains.Quantitative RT-PCR was carried out to calculate the transcriptional variation of vp1667 between Δhns and WT.Primer extension assay was also employed to detect the transcription start site and the promoter activity (i.e.the amount of primer extension products) of vp1667 in Δhns and that in WT.The promoter DNA region of vp1667 was amplified, purified, and cloned into the corresponding restriction endonuclease sites of pHRP309 that harbors a gentamicin resistance gene and a promoterless lacZ reporter gene.The recombinant pHRP309 plasmid was transformed into Δhns and WT, respectively, while β-galactosidase activity in cellular extracts was measured using a β-galactosidase enzyme assay system.The over-expressed His-H-NS was purified under native conditions with nickel loaded HiTrap Chelating Sepharose columns.The electrophoretic mobility shift assay (EMSA) and DNaseⅠ footprinting were then applied to analyze the DNA-binding activity of His-H-NS to vp1667 promoter region in vitro.Results and Conclusion The primer extension assay detected one transcription start site for vp1667, which was located at 28 bp upstream of vp1667, and its transcribed activity was under the negative control of the H-NS.The EMSA and DNaseⅠ footprinting assay results showed that His-H-NS was unable to bind to the promoter-proximal DNA region of vp1667, suggesting that H-NS indirectly inhibits the transcription of vp1667.