Damage Of Human Bronchial Epithelial(BEAS-2B)Cells Induced By Three Typical Heavy Metals And Toxicity Inhibition Of Polyphenols

Heavy metals are major environmental pollutants.Nickel?Ni?,chromium?Cr?and cadmium?Cd?are typical heavy metals in the environment.They can enter the human body through digestion,respiration or skin contact,and induce cell damage and diseases,especially pulmonary bronchial injury and lung diseases.Polyphenols have a variety of physiological functions,and their antioxidant,anti-inflammatory and immunological functions are the prerequisites for the prevention of diseases.At present,the mechanism and molecular mechanism of lung damage caused by nickel,chromium and cadmium have not been fully understood,and no suitable method has been found to prevent the damage of heavy metals.Therefore,it is of great significance to study the toxic effects of common heavy metal pollutants nickel,chromium and cadmium on lung related cells and to find natural active substances to prevent and mitigate the damage caused by nickel,chromium and cadmium.In this study,human bronchial epithelial?BEAS-2B?cells were used as the research object,and the cell survival rate was detected by MTT method,which reflected the cell viability.The level of reactive oxygen species?ROS?was detected by DCFH-DA fluorescence probe,which reflected the oxidative stress of the cells.Hoechst33258 assay was used to detect the fluorescence intensity of DNA in the nucleus and to reflect the apoptosis of cells.Rhodamine 123 staining was used to detect the changes of mitochondrial membrane potential and the occurrence of apoptosis.Real-time PCR was used to detect the mRNA transcription levels of intracellular inflammation-related factors?TNF-?,IL-6,IL-8,CRP?.Using Western blot method to detect cells p38 lightning MAPK,JNK,ERK signaling pathway protein phosphorylation expression level,the NF-?B signaling pathway proteins into the nucleus expression and NLRP3 inflammatory corpuscle assembly and mitochondrial pathways of apoptosis signaling pathways within related proteins Bax,Bcl-2,Cleaved caspase-3 expression,reaction cell oxidative stress,inflammation,injury and apoptosis.The results showed that NiCl2 at certain concentrations significantly inhibited the proliferation of BEAS-2B cells in a dose-dependent relationship.DCFH-DA fluorescence probe assay results showed that NiCl₂ treatment increased ROS levels in BEAS-2B cells,indicating increased intracellular oxidative stress.The fluorescence staining results of Hoechst33258 showed that NiCl2 could cause the condensation of nuclear DNA of BEAS-2B.Real-time PCR was used to detect up-regulated levels of TNF-?,an inflammatory non-specific inflammatory marker,and il-8 and 6 in the interleukin family of cytokines activated to participate in the inflammatory response after NiCl₂ treatment in BEAS-2B cells,indicating that NiCl₂ induced the production of inflammatory factors.Western blot results showed that NiCl2 up-regulated the levels of pro-apoptotic proteins Bax and Cleaved caspase-3,inhibited the expression of apoptotic proteins Bcl-2,induced increased phosphorylation of proteins in the p38MAPK,JNK,and ERK signaling pathways in BEAS-2B cells,induced the assembly of NLRP3 inflammatory corpuscle,increased the nucleated expression of NF-?B,and phosphorylation of I?B proteins.On the basis of the toxicity study,the above research methods were further adopted,and it was found that resveratrol could significantly inhibit the cell damage induced by NiCl₂ and reverse the toxic effect caused by NiCl₂.The results showed that K₂Cr₂O₇ in a certain concentration range could significantly inhibit the proliferation ability of BEAS-2B cells,increase the level of ROS and the condensation of nuclear DNA in a dose-dependent manner.Western blot showed that K₂Cr₂O₇ could up-regulate the ratio of Bax/Bcl-2 protein and the level of Cleaved caspase-3 protein,activate p38 MAPK,JNK and ERK signaling pathways in BEAS-2B cells,induce the assembly of NLRP3 inflammasomes and activation of NF-?B signaling pathway.On the basis of toxicity research,the above research methods were further adopted to explore the inhibitory effect and molecular mechanism of ferulic acid on K2Cr2O7-induced BEAS-2B cell damage.The results showed that CdCl₂ in a certain concentration range could significantly inhibit the proliferation of BEAS-2B cells in a dose-dependent manner,increase the level of intracellular ROS,and significantly induce apoptosis of BEAS-2B cells.Rhodamine 123 staining experiment showed that mitochondrial membrane potential decreased in BEAS-2B cells treated with CdCl2.Western blot showed that CdCl2 could up-regulate the ratio of Bax/Bcl-2 protein and the level of Cleaved caspase-3 protein,and activate p38 MAPK,JNK and ERK signaling pathways in BEAS-2B cells.On the basis of toxicity research,the above research methods were further adopted to explore the inhibitory effect and molecular mechanism of taxifolin on CdCl₂-induced BEAS-2B cell damage.In summary,nickel,chromium and cadmium can cause oxidative stress and inflammatory damage in BEAS-2B cells and lead to activation of related signal pathways,while polyphenol compounds resveratrol,ferulic acid and taxifolin can inhibit cell damage and activation of signal pathways caused by nickel,chromium and cadmium respectively.This study revealed the molecular mechanism of BEAS-2B cell damage caused by heavy metals,proposed methods to alleviate cell damage,and provided ideas for the prevention of related diseases.