The Screening Of The Cell Penetrating Peptide Which Competively Inhibits The Interaction Of HuR-PARP1 And The Research Of Its Anti-inflammatory Effects

The regulation of gene expression in eukaryotes is complex.Post-transcriptional regulation plays an important role in the accurate and precise expression of genes.mRNA degradation determines the stability of mRNA,which in turn influences the expression of proteins.The 3’untranslated region of the mRNA contains the ARE element and the ARE element is an AU-rich sequence.The mRNA containing ARE elements is easily degraded.The stability of mRNA is regulated by RNA binding proteins.HuR is one of the few proteins that maintains mRNA stability and is therefore widespreadly attented HuR is involved in many biological events in the cell,such as mRNA precursor cleavage,mRNA maturation,mRNA transport out of the nucleus,as well as mRNA translation and stability maintenance.HuR as a nucleoplasmin,different protein modifications will change its function.In our laboratory’s previous work,it was found that HuR had a poly ADP ribosylation(PARylation)when cells were stimulated.The binding of HuR and ARE elements was increased,and the expression of inflammatory factors was upregulated when HuR had PARylation.After HuR had PARylation,the shuttling of HuR was also promoted.HuR-PARP1 interaction leads to up-regulation of inflammatory factors.If HuR-PARP1 interactions are specifically prevented under inflammatory conditions,the stability of target mRNA of HuR is decreased and the expression of inflammatory factors is inhibited and this is a treatment strategy for inflammatory diseases.In this study,we found the specific amino acid sequence(short peptide)HNS3 that inhibits the interaction of HuR-PARP1.Using the cell-penetrating peptide TAT as a carrier,this amino acid sequence(short peptide)is transported into cells.We found that the screened cell-penetrating peptide TAT-HNS3 not only inhibited HuR-PARP1 interaction but also inhibited PARylation of HuR.The cell osmotic peptide TAT-HNS3 can translocate efficiently and can be localized in both cytoplasm and nucleus.In addition,this cell-penetrating peptide has no effect on cell proliferation and survival,which provides a guarantee for drug development of cell-penetrating peptides.Based on these experimental phenomena,we also found that cell-penetrating peptides not only inhibit HuR’s nucleation,but also inhibit the expression of inflammatory factors,such as CXCL2,TNF-α,and IL-1β.Since the target mRNA of HuR contains ARE elements and is mostly an inflammatory gene and an oncogene.In addition,the localization of HuR in cells changes during the development and progression of inflammation and tumors.Therefore,we think that the cell-penetrating peptide TAT-HNS3 is expected to become a new method for treating inflammatory diseases and even tumors.