Effects Of Permethrin On Intestinal Mucosal Barrier And Intestinal Flora In High-Fat Diet Mice

Objective: The purpose of this study was to investigate the changes in intestinal mucosal barrier function and intestinal microflora in C57BL/6J mice induced by long-term low-level permethrin exposure,and to identify new mechanisms by which permethrin affects the human gut so that the information obtained can be used to more fully assess the chronic health risks of permethrin exposure.Methods: The 6-week-old SPF grade C57BL/6J male mice were selected,and the C57BL/6J male mice were fed for one week,and 32 C57BL/6J male mice were randomly divided into control group(CON)and permethrin group(PERM).After 12 weeks,the mice were killed under anesthesia,and the body weight of the mice was recorded.The changes of intestinal mucosal permeability in mice were detected by vivo imaging and immunofluorescence staining.Serum levels of inflammatory cytokines IL-4,IL-6,IL-10,TNF-α and LPS were detected by ELISA.The morphological changes of intestinal mucosa were detected by H(5)E staining and Alcian blue staining.Changes in protein and gene levels of junction proteins(ZO-1,Claudin-1,Occludin,and E-cadherin)were evaluated by immunohistochemistry,Western blot,and qRT-PCR.Mouse feces were collected and 16 s DNA was used to analyze changes in intestinal flora composition.Human colorectal adenocarcinoma cells(SW480)and human normal colon epithelial cells(HCoEpiC)were cultured in vitro to detect the effects of permethrin on cell proliferation and migration by CCK-8method and scratch healing.Changes in protein and gene levels of connexin and HIF-1α were detected by Western blot and qRT-PCR.Results:(1)Long-term low permethrin intake significantly increased body weight,serum inflammatory factor levels and colonic mucosal permeability in mice.(2)Permethrin exposed damaged crypt structure,reduced mucous layer thickness and inhibited mucous secretion.(3)The protein expression level of junction proteins(ZO-1,Claudin-1,Occludin and E-cadherin)in colon mucosal epithelial cells decreased,and the mRNA level did not change significantly.(4)Permethrin may promote lipid accumulation by increasing the relative proportion of Firmicufiria,thereby damaging the intestinal mucosal barrier,reducing Muribaculum,uncultured＿Barnesiella＿sp.,Muribaculaceae＿unclassified and Akkermansia＿muciniphila abundations increased Lachnospiraceae＿unclassified,Unclassified Odoribacter＿unclassified and Stenotrophomonas＿maltophilia and Alistipes＿sp.(5)Permethrin may induce oxidative damage and intestinal inflammation by promoting the degradation of D-galactose and D-glucosidate,thereby damaging intestinal mucosal barrier and altering intestinal flora composition.(6)The cell viability of HCoEpiC and SW480 cells decreased in a dose-dependent manner under permethrin treatment.(7)Permethrin inhibited scratch repair of HCoEpiC and SW480 cells.(8)Permethrin inhibited the expression of connexin and HIF-1α in HCoEpiC and SW480 cells.Conclusions: Long-term low permethrin intake can damage colon tissue structure,increase mucosal barrier permeability,change intestinal symbiotic flora composition,and possibly inhibit HIF-1α transcription factor activity in high-fat diet mice.Inhibition of the expression of junction proteins(ZO-1,Claudin-1,Occludin and E-cadherin)is involved in intestinal mucosal injury in mice.