Mechanism Of Cell Toxicity Of Fumonisin B₁ To Sf9 Cells

Fumonisins is a kind of mycotoxin produced by Fusarium spp., mainly F.proliferatum and F.vertieilliodes, which be contaminated with crops all over the world. As a class of secondary metabolites, they have great potential hazards to the health of animals and human beings.So far, the toxicity and mechanism of action of fumonisins is ambiguity, and it is unclear that fumonisins have a toxicity to insect cells. Sf9 cell line is ovarian cells of Spodoptera frugperda.It also easy to cultivate and need not keep the cells in a CO2 incubator.It can provide the appropriate information at the cellular level and could be be regarded as useful and reliable for toxicity studies of pesticide. This article takes the Sf9 cells as the research object, aiming to study fumonisin B₁'s toxicity and its mechanism of action on Sf9 cells. The contents is as follows:1.The vitality of Sf9 cells was deteceted by Cell Counting Kit-8?CCK-8?. Sf9 cell lines was treated with different concentration of FB₁?0, 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L?400mg/L?.After 48 h of treatment, the proliferation inhibition rate was 10.5%±0.03, 20.3%, 30.9%,49.9% and 65.4% respectively.2. Under inverted phase microscope, for control, the growth of Sf9 cell was in a good condition, treatment for 25 mg/L, part of cells swelling appeared, treatment for 50 mg/L, the proportion of swelling cells increased, part of cells vacuole appeared, and cell proliferation was suppressed seriously when treated with 200 mg/L.3. After treatment with FB₁ for 48 h, which concentration was caused inhibition rate for10%, 30%, 50% towards Sf9 cell lines. The result found that FB₁ enhanced cell cycle arrest at the G2/M phase, caused membrane depolarization of Sf9 cells, caused apoptosis of Sf9 cells and the apoptosis rate of control and treatment group respectively were 6.18%, 16.65%, 16.89%,21.90%, induced Sf9 cells mitochondrial membrane potential hyperpolarization.4. The result of transcriptome sequencing as follows:?1? Detoxification metabolism genes and metabolism pathway: In our experiment, Sf9 cellsmainly start excessive expression of genes such as cytochrome P450, glutathione-S-transferases and UDP-glucuronosyl transferase in response to the toxic effects of FB₁.?2? Growth and development genes and metabolism pathway: In this study, FB₁ inhibit cell proliferation by affecting cell microtubule binding protein 1, cellular adhesive molecular protein, growth factor protein and break 20-hydroxyecdysone and juvenile hormone balance in insects' body and so on.?3? Immune system genes and metabolism pathway: The result found that Sf9 cells start toll-like receptors signaling pathways and phagosome signaling pathways fight the damage of FB₁ to cell.?4? Apoptosis gene and metabolism pathway: FB₁ induced Sf9 cells to start JNK and p38 MAPK signal transduction pathway, and then accelerated the process of cell apoptosis, resulted in apoptosis finally.?5? Other related genes and metabolic pathways: In addition to the above-mentioned metabolism, this research also involves sphingolipid metabolism, carbohydrate metabolism,pyrimidine, and purine metabolism and amino acid metabolism.