The study of the effects of occupational aluminum exposure on TNFR1 expression and cognitive function

Objective To analyze the relationship between cognitive function and tumor necrosis factor receptor 1 (TNFR1) expression of occupational exposed workers to aluminum and provide the basis for the diagnosis of cognitive impairment. Methods 140 cases Shanxi aluminum plant workers were collected in 2016 as the research object, including 70 potroom workers for exposure group, 70 non-electrolytic aluminum plant workers in the control group, respectively. Using mini mental status examination (MMSE), digit span test (DST), fuld object memory examination(FOME) and simple reaction time test(SRTT) evaluate the cognitive function of objects. Using graphite furnace atomic absorption method for the determination of plasma aluminum levels as an indicator of aluminum contact exposure of workers. Using RT-PCR method for detection of tumor necrosis factor receptor 1 (TNFR1) mRNA expression levels. And comparison group differences in cognitive and TNFR1 mRNA expression levels. Results The plasma aluminum content of exposed group (77.12±27.18) μg/L higher than the control group (55.6±28.69)μg/L (P=0.000); Compared to control group, FOME and MMSE score was significantly increased in the exposed group (P=0.000, P=0.000), SRTT scores significantly higher in the exposed group (P=0.001), DST no significant difference in the control group (P=0.893). Compared to control group, The mRNA expression of TNFR1 was significantly higher in the exposed group(P=0.002); Compared to control group, The protein expression of TNFR1 was significantly higher in the exposed group (P=0.002). By correlation analysis in exposure group, plasma aluminum content was negatively correlated with MMSE and the DST (r=-0.284, r=-0.331, P<0.05) and positively correlated with the SRTT, TNFR1 (mRNA) and TNFR1(protein)(r=0.255, r=0.333, r=0.987, P<0.01), MMSE was negatively related to TNFR1 (mRNA) and TNFR1 (protein) (r=-0.268, r=-0.255, P<0.05); DST was negatively correlated with the SRTT and TNFR1 (protein)(r=-0.267, r=-0.330, P<0.05); SRTT was positively correlated with TNFR1 (protein)(r=0.243, P<0.05); TNFR1 (mRNA) was positively correlated with TNFR1 (protein)(r= 0.340, P<0.01). Conclusion Cognitive function change of occupational exposed workers to aluminum was related to the increase of TNFR1 expression. Key words: Aluminum; Occupational exposure; Receptor; tumor necrosis factor; Cognition