AIM:The objective of this study is to examine the expression of profilin 1(PFN1)in mice with di-abetic nephropathy and determine its association with immune cell infiltration.METHODS:This study presents an analy-sis of PFN1 expression and immune cell infiltration in patients with diabetic nephropathy,utilizing transcriptome expres-sion data from kidney tissue microarray.Additionally,the findings were validated in a diabetic nephropathy mouse model.Sixteen C57BL/6 mice were randomly assigned into two groups,namely the normal group and the model group,in an equal manner.The model group underwent the establishment of the diabetic nephropathy model through intraperitoneal injection of streptozotocin.Subsequently,the expression levels of CD11b,F4/80,CC chemokine receptor 4(CCR4),interleukin-1 receptor type I(IL-1R1),B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax)and caspase-3 in kidney tissue were assessed upon successful establishment of the diabetic nephropathy model.Furthermore,the overexpression of PFN1 was observed in a cellular model of diabetic nephropathy,and the protein expression levels of monocyte chemotactic pro-tein-1(MCP-1)and caspase-3 were assessed.RESULTS:The expression of PFN1 was found to be significantly in-creased in the GSE30122 dataset of transcriptome expression in kidney tissues affected by diabetic nephropathy(P＜0.01).This increase in PFN1 expression was found to be correlated with the presence of macrophages and T cells.Fur-thermore,the renal tissue of the diabetic nephropathy model group exhibited significant pathological changes.In this mod-el group,the expression levels of PFN1,CD11b,F4/80,CCR4,IL-1R1,Bax,Bcl-2,and caspase-3 were all significant-ly increased(P＜0.01).Overexpression of PFN1 could enhance the expression of MCP-1 and caspase-3 proteins.CON-CLUSION:Macrophages and Th17 cells were identified within the renal tissue of mice with diabetic nephropathy,con-comitant with an up-regulation in the expression of PFN1.This up-regulation was observed to facilitate the induction of apoptosis in the context of diabetic nephropathy.