Effect Of Nickel(Ⅱ) On The Growth Of Mouse Fibroblast Cells

Background and Objective:Nickel ranks as the24th element in order of abundance in the earth’s crust. Humans are exposed to this ubiquitous element inevitably and constantly. Major environmental contamination of release of nickel are the combustion of coal and heavy fuel oil. Emissions from refineries and from refinery products such as road tar contain nickel from the original crude oil. Other sources include emissions from mining, electroplating industry, municipal waste incineration, and windblown dust. Nickel is found naturally in soils, aquatic environments, and vegetation in small quantities. Exposure to nickel may cause health effects on body influence the biological and physiological processes. Researches show that chronically exposure to nickel may cause apoptosis and malignant transformation on BEAS-2B cell and normal epithelial cell. Nickel(Ⅱ) is major biomorphic synthesis.In prolonged and direct contact with skin and mucosa, nickel(Ⅱ) may cause inflammatory reaction and teratogenic effect. The prevalence of nickel sensitivity is5%to15%in women and0.5%to1%in men. The world health organization(WHO) has taken the nickel as a carcinogenic factor. The researches suggest that exposures to nickel compounds are associated with increased nasal and lung cancer incidence.Nickel alloy is an ubiquitous transition metal that is widely applied in dentistry such as PFM and RPD may release Ni2+into the oral environment. The effects of Nickel pollution on human health, especially the biological safety of the Nickel alloy has been taken seriously. Thus far, no established result be widely adopted. Clinical study findings suggest:The gingival tissues around the Nickel alloy which contain the main nickel precipitation were dyed, with surrounding hyperemia. Therefore, the researches to evaluate the biological effects of nickel on gingiva and normal oral epithelium are very necessary.Research Method:Mice fibroblast cell (PA317) were provided by Dr.Wang Xinhua, The First Affiliated Hospital of College of Medicine, Zhejiang University. PA317cells were exposed to different nickel chloride (NiCl2) concentrations (0-800μM) for various periods exposure. Cell Counting Kit-8(CCK8) assay was used to assess the cell proliferation. The cell cycle and apoptosis rate of cultured cells was estimated by flow cytometry using Annexin V-FITC and Propidium Iodide (PI). The nuclear transcription factor-icB (NF-κB), cyclooxygenase2(COX-2), p21were measured by Western Blot analysis.Results:The mice fibroblast cells PA317cells were treated with Ni2+for24h that involved a dose and concentration dependent decrease in cell viability, the cell size decreased, the cell connection disappeared, the suspension cells increased and the cytoplasm demonstrated vacuolation. The results of CCK8showed exposure to Ni2+caused a dose and concentration dependent inhibition of cell proliferation in PA317cell (p<0.05). FCM showed that the proportion of PA317cells at G2/M decreased with Ni2+concentration dependent manner. When the PA317cells were treated with200μM,400μM,600μM and800μM Ni2+for24h, the rate of apoptosis were5.9%,17.0%,20.7%and17.0%, indicating a quantitative relationship. Furthermore, the protein level of NF-κB, COX-2, p21were increased significantly in Ni2+-treated PA317cells.Conclusions:Our results indicate that high concentration of nickel(Ⅱ) appears to up-regulate NF-κB, COX-2and p21protein. The Ni2+inhibit the proliferation of the mice fibroblast cell, causing the cell vacuolar degeneration, apoptosis, and a positive correlation between dose and concentration/time.