The Role Of Neutrophil Extracellular Traps In Diabetic Nephropathy

Background: A new large sample study in China shows that Diabetic kidney disease(DKD)has become the first cause of chronic kidney disease.The mechanism of DKD has not been fully elucidated.It is currently believed that the occurrence of DKD is related to a series of metabolic disorders initiated by chronic hyperglycemia,but the existing DKD treatment methods have limited effects,so the role and mechanism of hyperglycemia-induced metabolic disorders in the occurrence of DKD are clarified It will provide evidence for finding new DKD treatment targets and has great clinical significance.Neutrophil extracelluar traps(NETs)are neutrophils that release nucleus and cytoplasmic substances to the outside of cells when faced with external stimuli.These substances attach MPO,NE,Cit-Histone3 and other proteins form a network that kills pathogenic microorganisms.Objective: To explore the role and mechanism of NETs on diabetic nephropathyMethods: A total of 228 diabetic patients were included in the cross-sectional study in the population study,and they were divided into 3groups(n = 76)according to UACR levels to detect serum MPO-DNA levels.In the prospective study,a total of 160 diabetic patients were included,and the baseline serum dsDNA levels were detected and followed up for 3 years to calculate the relationship between dsDNA and the progression of diabetic nephropathy.At the same time,in animal experiments,1)C57 mice were injected intraperitoneally with STZ to induce T1 DM 2)db/db background T2 DM mouse models were constructed.UACR levels were detected to observe changes in kidney function,PAS staining,and scanning electron microscopy to detect changes in kidney structure of mice.3)Constructed a model of diabetic nephropathy in PAD4 knockout mice,and explored whether the specific blockade of NETs can improve diabetic nephropathy.In Vitro,the effect of high glucose on human primary neutrophils was detected,and the high glucose-induced neutrophil extracellular traps was used to treat human primary glomerular vascular endothelial cells,and immunofluorescence was used to detect endothelial cells.Results: The results of a cross-sectional study of the population showed that serum MPO-DNA levels in the UACR> 300 mg / g group were significantly higher than those in the UACR <30 mg / g group and UACR30-300 mg / g.In a prospective study,patients with diabetic nephropathy were followed up for 3 consecutive years.After adjusting for multiple confounding factors,the risk of DKD progression increased by 2.4times for each standard deviation of dsDNA.In the T1 DM and T2 DM mouse models,DNaseI treatment could alleviate the increase of UACR,while the kidney glycogen deposition is reduced,podocyte and endothelial cell damage is reduced.In vitro experiments we found that high glucose could stimulate neutrophils to produce NETs,and then we use high-glucose induced NETs to treat glomerular vascular endothelial cells.NETs treatment could downregulate the expression of endothelial marker proteins.After NETs intervention,the albumin pass rate of glomerular vascular endothelial cells was decreased.Conclusion: Serum dsDNA is associated with diabetic nephropathy,and NETs may paly a role in predicting DKD progression.