Digital Gene Expression Profiling Technological Analysis Of The Effect On Overexpressing HSP25 Gene In Chicken Cell

In the family of small heat shock proteins(s HSPs), mammals heat stress protein 25/27 k D(HSP25/27) gene high expression can dominate the aggregation depositio n, prevent irreversible combining between mis-folded proteins, then mitigate apoptosis caused by endoplasm stress. But the egg- laying animal embryo HSP25 sequence, structure and function in the organization are different from mammals HSP25/27. Under the condition of heat stress, if chicken HSP25 gene(cHSP25) high expression also play a protection role of cells is still not clear. Because in the process of cell apoptosis induced by heat stress cHSP25 involved in which signaling pathways are still no reports. So to explore the pathways of the material change and to clarify oviparous animals unique HSP25 genetic role in the apoptosis process are significative. In our study, chicken fibroblast cell line(DF-1) in 37℃ incubator was respectively processed interference and overexpression of cHSP25 gene. Through digital gene expression spectrum(DGE), we analysis related pathways involved in cell apoptosis and gene express ion. The condition of heat stress(45℃, 3 h) was processed in DF-1 cultivation. At last we detect apoptosis number and related gene expression level. The results showed that:In interference group, cHSP25 gene m RNA expression level relatively decreased 50%. In overexpression group, cHSP25 gene m RNA expression level raised 500 fold.The DGE sequencing analysis results revealed that comparing the interference group to the control group, there was only one down-regulation(with no comments) differentially expressed gene. Comparing the overexpression group to the control group, there were 95 differentially expressed genes, including 60 up-regulation genes, 35 down-regulation genes. Comparing the overexpression group to the interference group, there were 32 differentially expressed genes, including 19 up-regulation genes, 13 down-regulation genes. In the overexpression group, through KEGG pathway analysis we found that PPARG and LAMA2 enriched in pathways in cancer, etc. BDNF enriched in neurophin signaling pathway and classical MAP kinase pathway.After heat stress treatment in chicken DF-1, HSP27 and HSP70 gene expression were decreased significantly in overexpression group. The expressions of the differentially expressed genes of BDNF, LAMA2 and PPARG, and related downstream pathways genes of AKT and NFk B were significantly down-regulation. The number of S phase cells and the total apoptosis cel s were increased.Conclusion: under the condition of heat stress, continuous high cHSP25 gene expression in chicken DF-1 caused inhibitory effect on gene expression of HSP27 and HSP70, and make the BDNF, LAMA2 and PPARG, and downstream pathway gene AKT and NFk B level reduce, which involved in neurophin signaling pathway and classical MAP kinase pathway, leading to the stagnation of the cell cycle and the aggravation of cell apoptosis.