The Impact Of Arsenic On Skin Apoptosis And Keratinocytes Related Gene Expression And Study Of Early Skin Damage

Objective:Investigating the effects of arsenic on skin cell apoptosis and on the demonstration of related keratin genes provides the basis for further elaboration of arsenic inducing skin injury in early stage. Methods:1 Using the MTT reduction assay cell growth; exposed to different concentrations of sodium arsenite HaCaT cells 24 h, detect inhibition rate, determine the LC50 and the exposure dose, exposure doses were LC50 1/50,1/20, 1/10.2.Detection of HaCaT cell apoptosis by flow cytometry. 3.30 healthy adult male rabbits of clean grade were randomly divided into 5 groups, 6 rabbits in each group, including control group(Ultra pure water) and sodium arsenite group. By the free way of drinking to execute the exposure, for 12 continuous weeks. Exposure doses were respectively 1/100, 1/50,1/20, 1/10 of LD50.4.12 weeks after the end of exposure, the same region of the rabbit skin are taken for pathological examination.5.Expression levels of Nrf2, K1 and K10 m RNA are detected from HaCaT cells and rabbit skin tissues by real-time fluorescence quantitative(Real-Time Quantitative PCR).Results:1.Sodium arsenite infected HaCaT cells for 24 h 65.00μmol/L of LC50, canister to dose is the 1/50 of LC50 for 1.30 μmol/L, 1/20 of LC50 for 3.25 μmol/L, that is 1/10 of the LC50 for 6.50 μmol/L, and the control group to 0μmol/L.2.1.30μmol/L sodium arsenite can promote HaCaT cell proliferation, 3.25μmol/L, sodium arsenite 6.25μmol/L with the growth of exposure time, inhibit the growth of HaCaT cells, and the difference was statistically significant(P <0.05), cell proliferation was time to change the trend, and the role of the time factor and the difference varies with the exposure dose was statistically significant(P <0.05). 3.1.30μmol/L sodium arsenite can inhibit apoptosis in HaCaT cells.3.25μmol/L, 6.25μmol/L sodium arsenite with the growth of exposure time,can HaCa T cell apoptosis rate increased and the difference was statistically significant(P <0.05), the apoptosis rate trends over time, and the role of the time factor and the difference varies with the exposure dose was statistically significant(P <0.05).4.1.30 μmol/L sodium arsenite exposure HaCaT cells can promote Nrf2, K1 and K10 mRNA upregulation of expression, 6.25 μmol/L exposure of sodium arsenite in HaCaT cells, Nrf2, K1, K10 mRNA expression and the difference was statistically significant(P <0.05).5.Sodium arsenite exposure rabbit LD50 is 13mg/kg.canister to dose is low 1/100 of the LD50 for 0.13mg/kg, 1/50 of the LD50 for 0.26mg/kg, 1/20 of the LD50 for 0.65mg/kg, 1/20 of the LD50 for 1.3mg/kg and the control group to 0 mg/kg.6.Compared with the control group, the quality of basic rabbits exposed groups showed an increasing trend, but the difference was not statistically significant(P> 0.05).7. Electron microscopy showed that the skin of rabbits exposed groups with different degrees of changes in the stratum corneum, skin keratosis of high dose group.8. 0.13 mg/kg, 0.26 mg/kg in rabbits exposed skin tissue can promote the expression of Nrf2, K1 and K10 mRNA of; 0.65 mg/kg, 1.30 mg/kg and the differences can inhibit the expression of skin tissue Nrf2,K1 and K10 mRNA there statistically significant(P <0.05).Conclusion:1.Sodium arsenite on HaCaT cell has two-way adjustment function, 1.30μmol/Lcan promote cell proliferation, inhibiting cell apoptosis, 6.25μmol/L can inhibit cell proliferation, promote cell apoptosis. 2. Sodium arsenite exposure make HaCaT cells Nrf2, K1, K10 mRNA expression changes, the low dose enables upregulated genes, exposure increase with exposure time, exposure dose increased gradually lowered to make the gene expression.3.Effects of toxicity of sodium arsenite on HaCaT cells is affected by time and interaction of concentration,and it may be speculated that arsenic exposure can make the amage to skin cells more serious with the extension of exposure time and the increase of exposure concentration.4.Long term water arsenic exposure will cause skin damageand skin pathological change, and 1.30mg/kg sodium arsenite after three months’ exposure will lead rabbits to skin keratosis.5.Long term water arsenic exposure can cause changes of Nrf2, K1 and K10 mRNA in skin tissue,and 0.13mg/kg arsenic can make the gene expression rise,1.30mg/kg arsenic can make the gene expression reduce.