Effect and mechanism of knockout RhoE on the protein expression profiles in cardiac tissues of diabetic rats based on 4D proteomics

Objective:To analyze the effect of RhoE gene expression change on protein expression profiles in the cardiac tissue of diabetic rats,and analyse the possible underlying regulatory mechanism.Methods:Six-week-old male RhoE gene knockout(KO)and wild-type(WT)Sprague Dawley rats were injected intraperitoneally with streptozotocin(70 mg/kg)to establish the type 1 diabetes model(T1DM),with injection of the same amount of sodium citrate saline as the control group.A week later,the fasting blood glucose of the rats was measured daily,and blood glucose concentration 16.7 mmol/L was regarded as a successful model.Two additional weeks later,the hearts of the rats in each group were removed and fourdimensional label-free quantitative proteomics technology(4D-LFQ)was used to analyze the changes of protein profiles in the heart tissue.The related functions,enrichment signals,and protein‑protein interaction network(PPI)of the differentially expressed proteins were analyzed.Results:T1DM rat models were successfully established.Taking a fold change>1.5 and P<0.05 as the threshold,a total of 2931 quantifiable proteins were identified.In the non-diabetic state,the KO group had 26 and 45 significantly up-and downregulated proteins,respectively,compared with the WT group;in the diabetic state,the KO group had 19 and 28 significantly up-and downregulated proteins,respectively,compared with the WT group.The GO annotation results showed that most of the differentially expressed proteins were located in the extracellular matrix,and their biological functions were mainly concentrated in the immune response and energy metabolism.KEGG analysis showed that the signaling pathways associated with the differentially expressed proteins in cardiac tissue after RhoE knockout were mainly related to ribosomes and fat digestion and absorption.Protein interaction network analysis showed that in the cardiac tissue of the KO group,there were more Col1α1-and Col1α2-interacting proteins among the upregulated proteins,and among the down-regulated proteins,related proteins involved in the ribosomal pathway interact more in the network.Conclusion:RhoE knockout significantly changes the protein expression profiles in diabetic cardiac tissue,affecting multiple signaling pathways closely related to diabetic cardiomyopathy.The results provide insights into the pathogenesis and therapeutic target screening of diabetic cardiomyopathy.