Experimental Study Of VGLL4 Mimic Peptide Inhibiting Renal Fibrosis Induced By UUO Model Via YAP/TEAD Pathway

Objective: The most typical manifestation of renal fiber is the proliferation of myofibroblasts and the increase of extracellular matrix.The most classical of these is the extracellular matrix(ECM)of the TGF-β/smad pathway involved in renal fibrosis,but previous studies have shown that it is not suitable for intervention as a target for renal fibrosis.Therefore,screening for fibrotic intervention targets,we sought a target for total fibrosis in pathways that may interact with the TGF-β pathway.The most promising target for intervention is the YAP/TAZ complex.The YAP/TAZ complex is the core component of the Hippo pathway.The hippo pathway is an evolutionarily highly conserved signaling pathway that regulates organ size and participates in important biological processes such as cell proliferation,differentiation,and apoptosis.Recent studies have shown that the YAP/TAZ complex participates in renal fibrosis by participating in processes such as renal fibroblast proliferation and myofibroblast cell formation.This study was to investigate the therapeutic effect of the peptide super-TDU,which mimics the structure of the VGLL4 protein domain,on renal fibrosis.It is also explored whether it is feasible to block the Hippo pathway by binding the effector protein YAP to TEAD as a new drug target for the treatment of renal fibrosis,and the mechanism of action of the mimetic polypeptide in blocking renal fibrosis.Research method: This experiment is a basic research.C57BL6 mice are used as the research object.Unilateral ureteral obstruction(UUO)is performed after anesthesia.After the suture of the muscle layer,an osmotic pump is embedded under the skin.50ug/kg,100ug/kg dose was continuously pumped into the super-TDU peptide,and the positive control group was filled with 200 uL of normal saline in the osmotic pressure pump.The mice were sacrificed after the eyeball was taken 7 days after surgery,leaving the left and right sides.Renal specimens were evaluated by Masson staining for interstitial fibrosis,and smoothing actin(α-SMA),N-cadherin(N-cadherin),Ecadherin(E-cadherin),waveform were detected by western-blot technique.Protein(Vimentin),YAP/TEAD transcription target gene,downstream gene of Wnt pathway.RESULTS: In the positive control group 7 days after UUO,the left renal pelvis was highly dilated and the renal cortex was thinned.HE staining of paraffin sections suggested that the tubules were extremely dilated,part of the renal medulla was compressed and deformed,and inflammatory cells infiltrated in the tubulointerstitial.Masson-stained kidneys suggest an increase in interstitial components in the tubules.Western-blot experiments suggest elevated levels of α-SMA,suggesting that renal fibrosis is successful.In the experimental group of super-TDU peptide,HE staining of the left kidney paraffin section showed that the tubules were dilated in different degrees,and the medulla was partially deformed by the medulla.The Masson-stained kidney showed no obvious tubulointerstitial hyperplasia,and the western-blot experiment suggested α.The level of SMA was lower than that of the positive control group(P<0.05),and there was no statistical difference between the sham operation group and the sham operation group.N-cadherin and vimentin were significantly lower in the kidney tissue than in the experimental group.In the control group,the YAP and TEAD levels were significantly higher in the experimental group than in the positive control group,but the level of YAP/TEAD transcriptional target gene was not significantly increased.The protein level of c-Myc and cylinD1 in the downstream gene detection of Wnt pathway was significantly higher than that of the control group.Conclusion: The peptide super-TDU,which mimics the structure of the VGLL4 protein domain,can attenuate renal fibrosis caused by unilateral ureteral obstruction.The mechanism may be to reduce renal fibrosis by inhibiting YAP/TEAD.