Role of protein kinase C/NF-kappa B signal pathway In activation of T lymphocytes In human exposed to coal-arsenic / 中国地方病学杂志

ABSTRACT

Objective To investigate the activation of T lymphocytes in human peripheral blood and the signaling molecules in protein kinase C/nuclear factor KB(PKC/NF-κB) pathway expressivity or activity changes in human peripheral blood mononuclear cells(PBMCs) exposed to coal-arsenic,to explore the role of PKC/NF-κB signal pathway in activation of T cells in human exposed to coal-arsenic. Methods Blood samples were collected from individuals who lived in arsenism area of coal-burning in Guizhou province, and were divided into asymptomatically exposed group (12),mild arsenism group (33),moderate arsenism group (34) and severe arscnism group (15) according to Diagnosis Standard for Endemic Arsenism (WS/T 211-2001). The individuals who lived in non-arsenism area were control group(27). The ratio of activated T ceils was analyzed by flow cytometry. DNA binding activity of NF-κB in PBMCs was evaluated by electrophoretic mobility shift assay(EMSA). The expression of PKCθ and phospho-PKCθ(pPKCθ) in PBMCs were detected with western blotting analysis. Results The ratio of activating T cells in asymptomatically exposed group[(21.76±15.31)%],mild arsenism group[(18.41±11.36)%],moderate arsenism group[(17.78±11.93)%]and severe arsenism group[(18.79±13.38)%]were all higher than that of control group[(3.19±2.12)%],the difference among all groups being statistically significant(F = 7.893,P < 0.05). DNA binding activity of PBMCs NF-κB in asymptomatically exposed group,mild arsenism group,moderate arsenism group and severe arsenism group(1.49±0.24,1.58±0.30,1.57±0.34,1.51±0.16) were higher than that of the control group(1.30±0.17),the difference being statistically sign/ficant(P < 0.05 or < 0.01). The expression of PBMCs pPKCθ in mild arsenism group,moderate arsenism group and severe arsenism group(0.64± 0.14,0.64±0.27,0.62±0.12) were all lower than that of the control group(0.93±0.20),the difference being statistically significant(P < 0.05). There were significant negative correlations between the expression of pPKCθ and the activity of NF-κB(r =-0.565,P < 0.01). There were significant positive correlations between the activity of NF-κB and the ratio of activating T cells(r = 0.546,P < 0.01). Conclusion Coal-arsenic enhances the DNA binding activity of NF-κB,reduces the expression of PBMCs pPKCθ in human PBMCs and up-regulates the activity of T cells. It suggests that the PKC/NF-κB signal might be one of transduction pathway via activating of T cells by coal-arsenic.