Investigation On The Remission Mechanisms Of Biochanin A Against PM₁₀-induced Acute Pulmonary Cell Injury Based On PI3K/AKT Signaling Pathway

Epidemiological studies have shown that the increase of PM₁₀concentration in the atmosphere is closely related to the increased risk of cardiopulmonary disease.PM₁₀carries a large number of toxic and harmful substances,which could easily enter the lung parenchyma through the physical barrier of the cilia and mucous membrane of the upper respiratory tract,deepen and deposit directly in the bronchi and alveoli,causing or aggravating various cardiopulmonary diseases,which seriously affects human health.As a kind of natural isoflavones in legumes,Biochanin A（BCA）has many bioactive functions,such as anti-inflammatory,anti-oxidation,anti-bacterial,etc.Therefore,its role in the intervention of PM₁₀induced acute pulmonary cell injury has attracted more and more attention,but its molecular mechanism is not completely clear.In this project,PM₁₀particles are taken as the research object.Through collecting the atmospheric PM₁₀particles in Tianjin,the comparative analysis of its particle size,composition and morphology shows that the equivalent diameter of PM₁₀particles in Tianjin is about 10μm,and the overall dynamic diameter is in the range of 0～100μm;PM₁₀comes from a wide range of sources,with complex biological and chemical composition,which mainly consists of soluble salt ions(F^-,Cl^-,NO^2-,SO₄^2-,NO^3-,PO^4-),metal elements（including heavy metals and radioactive elements）,organic compounds（including aromatic hydrocarbons and their oxygen-containing derivatives,branched/normal alkanes,silane derivatives,ketones and other organic compounds）,and biological components.By using the American animal research database（Toxref DB）,the high-throughput screening database in vitro（Toxcast DB）and comprehensive literature retrieval-bioinformatics analysis,the significant correlation between the chemical components of respiratory system damage in PM₁₀and the adverse consequences/potential key molecular targets of respiratory system damage was identified.And the study reveals the toxic chemical components in PM₁₀and their potential respiratory system hazards,and the signal pathways and molecular targets for the prevention and treatment of PM₁₀induced respiratory system damage:the main pathway of respiratory system injury caused by PM₁₀is the Calcium signaling pathway,MAPK signaling pathway,PI3K-AKT signaling pathway,and the core proteins in which are likely to be the molecular targets for the prevention and treatment of damage caused by PM₁₀.Taking BCA as the research object,based on human bronchial epithelial cells（BEAS-2B）,a cell model of PM₁₀in Tianjin exposure-BCA protection was established.The results showed that PM₁₀significantly reduced the level of intracellular CAT,induced LDH outflow and lipid peroxidation,significantly increased the gene expression and release of IL-6,IL-8 and TNF-α,and promoted the synthesis of NO and the transcription of i NOS;BCA（5,10,20,40μM）and LY294002（10μM）,a PI3K/AKT target protein inhibitor,could effectively intervene the above changes caused by PM₁₀in Tianjin,showing good anti-inflammatory and antioxidant activities.In addition,around the PI3K/AKT signaling pathway,Western Blot and q RT-PCR were used to explore the mechanism of BCA regulating the PI3K/Akt process in PM₁₀induced acute pulmonary cell injury.PM₁₀in Tianjin will significantly affect the normal operation of intracellular biomarker protein,PI3K/AKT signaling pathway and DNA base repair pathway,while BCA may intervene the regulation of PI3K/AKT signaling pathway by XRCC1 and PTEN protein through targeting the activation of PI3K protein in the cell membrane,which will interfere with the expression and phosphorylation of downstream AKT protein,and then regulate the downstream signal molecules to a certain extent to play an anti-acute pulmonary cell injury function.