Differential expression and significance of Foxp3, TGF-β1 and IL-2 in peripheral blood of patients with coal-burning arsenic poisoning / 中华地方病学杂志

ABSTRACT

Objective To investigate the expression of transcription factor forkhead/winged helix transcription factor 3 (Foxp3),immune factor transforming growth factor-beta 1 (TGF-β1),and T-lymphocyte activation related factor interleukin-2 (IL-2) in peripheral blood of patients with coal-burning arsenic poisoning,and to analyze the effects of arsenic exposure on immune function.Methods A case-control study was conducted to investigate 149 cases [94 males and 55 females,(50.69 ± 6.14) years old] of arsenic poisoning in Yuzhang coalburning arsenic poisoning area,southwestern Guizhou Province,and the cases were diagnosed based on the "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015) and confirmed by clinical review.According to skin damage,the patients were divided into mild arsenic poisoning group (39 cases),moderate arsenic poisoning group (54 cases) and severe arsenic poisoning group (56 cases);and 41 cases [12 males and 29 females,(45.76 ± 7.88) years old] of non-arsenic exposed residents from 12 km of Yuzhang coal-burning area were selected as control group.Morning urine and peripheral blood samples were collected with informed consent.Urine arsenic content was measured by inductively coupled plasma mass spectrometry (ICP-MS).Urine arsenic was corrected by creatinine (Cr).Detection of regulatory T cell (Treg)-specific transcription factor Foxp3 gene expression in human peripheral blood was done by real-time fluorescence quantitative PCR,and the levels of Treg-related immune factor TGF-β1 and IL-2 in serum were detected by enzyme linked immunosorbent assay (ELISA).Results The urinary arsenic contents [median (quartile)29.13 (19.75-54.50),31.81 (17.52-53.31),30.51 (18.35-45.76) μg/g Cr] in each arsenic poisoning group were higher than that in the control group [21.62 (17.65-28.44) μg/g Cr,P ＜ 0.05].The expression levels of Foxp3 mRNA in peripheral blood of each arsenic poisoning group [median (quartile)0.58 (0.17-1.27),0.32 (0.17-0.61),0.33 (0.13-0.62)] were significantly lower than that in the control group [0.87 (0.64-1.50),P ＜ 0.05];compared with mild arsenic poisoning group,the expression of Foxp3 mRNA in peripheral blood of moderate and severe arsenic poisoning groups decreased (P ＜ 0.05).The contents of serum TGF-β1 [(13.14 ± 5.19),(12.85 ± 5.51),(12.78 ± 4.95) μg/L] in each arsenic poisoning group were significantly higher than that in the control group [(3.90 ± 1.53) μg/L,P ＜ 0.05].The levels of IL-2 in serum of each arsenic poisoning group [(9.85 ± 5.38),(11.64 ± 6.40),(12.27 ± 6.19) ng/L] were lower than that in the control group [(34.30 ± 4.84) ng/L,P ＜ 0.05];the serum level of IL-2 in severe arsenic poisoning group was higher than that in mild arsenic poisoning group (P ＜ 0.05).Conclusions Arsenic exposure can cause abnormal changes of Treg-specific transcription factor Foxp3 and related immune factors TGF-β1 and IL-2 in peripheral blood of patients.It is suggested that Treg dysfunction may be related to arsenic poisoning.