ABSTRACT
Objective To assess the associations of anti-Smith antibodies with clinical manifestations and disease activity in children with systemic lupus erythematosus (SLE).Methods According to SLE disease activity index (SLEDAI) score,72 children with SLE were divided into the active group and inactive group.An immunoblotting method was used to detect serum anti-Smith antibodies in these subjects.Chi-square test was conducted to assess the associations of anti-Smith antibodies with clinical manifestations and disease activity in these patients.Results Of these patients,28 (38.9％) were assigned into the inactive group,and 44 (61.1％) to the active group.Anti-Smith antibodies were detected in 17 (23.6％) patients,but not in the other 55 (76.4％) patients.Elevated incidence rate of kidney injury was observed in anti-Smith antibody-positive patients compared with anti-Smith antibody-negative patients (70.6％ (12/17) vs.41.8％ (23/55),P ＜ 0.05).Meanwhile,the positivity rate of anti-Smith antibodies was 31.8％ (14/44) in the active group,significantly higher than that in the inactive group (10.7％,3/28,P ＜ 0.05).Conclusions Anti-Smith antibodies are not only an important indicator for the diagnosis of SLE,but also a risk factor for disease exacerbation and kidney injury in children with SLE.
ABSTRACT
Objective To investigate the mechanism underlying the WNK4 kinasemediated inhibitory effect on BK channel. Methods Cos-7 cells were cotransfected with BK in combination with either CD4 (control group) or wild type WNK4 (WNK4-WT).Immunostaining and confocal microscopy,chemiluminescence,Western blotting analysis were then employed to determine the BK localization in cells,BK surface expression and total protein level,respectively.To further investigate whether the reduction of BK protein expression is due to an increase in degradation through a lysosomal pathway,BK protein level was determined after treated with bafilomycin A1(Baf A1),a proton pump inhibitor affecting lysosomal degradation. Results Immunostaining and confocal microscopic study showed that BK was localized both in plasma membrane and cytosol in the control group.After cells transfected with WNK4-WT,BK expression was markedly reduced.Chemiluminescent assay found that BK surface expression level was 299.9±18.6 in the control group,whereas it was significantly reduced (148.4±13.7,P＜0.01) in the WNK4-WT group.Western blotting analysis showed that total BK protein level was markedly reduced in the presence of WNK4-WT compared to the control group.WNK4-WT was shown to significantly reduce the BK total protein level (42.3％±15.2％) compared to the control group (100％) (P＜0.01).When the cells was treated with Bafilomycin A1 (Baf A1,0.5 μmol/L),WNK4-mediated reduction in BK protein was reversed (82.2％±12.1％,P＜0.05). Conclusions WNK4 inhibits total and surface protein expression of BK in Cos-7 cells whick is likely due to an increase in BK degradation through a lysosomal pathway.