To Explore The Expression And Clinical Significance Of KLF4 In Diabetic Nephropathy Based On The Theory Of "essence Loss And Collateral Paralysis

Objective:Diabetic kidney disease(DKD)is the leading cause of end-stage renal disease(ESRD)worldwide,and it is also a growing public health challenge.At present,the early diagnosis of DKD is not yet adequate to meet clinical needs,which is also lack of clear and effective treatments.Therefore,it is urgent to further explore the risk factors for the development of DKD and find effective biomarkers for early diagnosis and treatment.According to Professor Liu Hongfang,the core pathogenesis of DKD is "Essence deficiency and collaterals arthralgia".The results of previous studies show that deficiency of kidney essence is the main type of deficiency in origin in patients with DKD.Recent studies have shown that Krüppel-like factor 4(KLF4)plays an important role in the development and maintenance of normal physiological function of the kidney,and may be an early diagnostic and therapeutic target for DKD.In particular,KLF4 plays a role in renal protection by protecting podocytes and reducing proteinuria,which is similar to the biological effect of "kidney essence" and preventing the leakage.However,the expression pattern of KLF4 in urine and the relationship between KLF4 and kidney essence deficiency syndrome of DKD remain to be elucidated.The purpose of this study is to investigate the expression and clinical significance of KLF4 in urine of patients with DKD,and to explore the relationship between KLF4 and kidney-essence deficiency syndrome of DKD,so as to provide an objective basis for the microscopic differentiation of kidney-essence deficiency syndrome of DKD.Methods:A cross-sectional survey was conducted to include healthy controls,and patients who met the diagnostic criteria with type 2 diabetes mellitus(T2DM)and stage Ⅲ-Ⅳ DKD,who attended Dongzhimen Hospital of Beijing University of Traditional Chinese Medicine between September 2021 and March 2023.The DKD patients were divided into kidney essence deficiency group and the non-kidney essence deficiency group according to the TCM syndrome element evaluation scale which was formed in the earlier research.General information,medical history,laboratory tests,TCM symptoms and other relevant clinical data were collected from the subjects.And the urinary KLF4 levels were measured by Elisa in all the urine samples in the morning of all subjects.The differences in clinical data and urinary KLF4 levels between the healthy control group,the T2DM group and the DKD group were compared to investigate the correlation between urinary KLF4 and laboratory indices and to analyze the expression and clinical significance of urinary KLF4 in DKD.Moreover,further comparing the clinical data and the levels of urinary KLF4 between the kidney essence deficiency group and the non-kidney essence deficiency group,exploring the relationship between KLF4 and the type of kidneyessence deficiency of DKD.To analyze the expression and clinical significance of KLF4 in kidney essence deficiency syndrome of DKD.Results:In this study,45 patients with stage Ⅲ-Ⅳ DKD,56 patients with T2DM and 44 healthy controls were included,and the DKD patients were divided into two groups:27 cases in the kidney-essence deficiency group and 18 cases in the non-kidney essence deficiency group.1.In general clinical data,there were no significant difference in sex,age and BMI among healthy control group,T2DM group and DKD group(P>0.05),but the systolic blood pressure level of the subjects increased between the three groups(P<0.05),and the proportion of coronary heart disease,hypertension,hyperlipidaemia,smoking and family history of diabetes were significantly different between the three groups(P<0.05).The course of disease in DKD group was longer than that in T2DM group(P<0.05).In the DKD group,the levels of K,PRO,Scr,BUN,CysC,ACR and 24h-UTP were higher than those in the T2DM group(P<0.05),while the levels of GLU,FPG,HbA1c,Ca,TP,ALB and eGFR were lower than those in the T2DM group(P<0.05).2.Urinary KLF4 expression level:The expression of KLF4 in urine of DKD group was lower than that of healthy control group and T2DM group(P<0.05).But there was no significant difference between healthy control group and T2DM group(P>0.05).3.The diagnostic efficacy of urinary KLF4:Compared to the healthy control group,the optimal cut-off value of urinary KLF4 for DKD was 2856.633 pg/ml,the sensitivity was 100.0%,the specificity was 55.6%,and the AUC was 0.772(95%CI:0.648-0.877,P=0.001).Compared to the T2DM group,the optimal cut-off value of urinary KLF4 for DKD was 2834.177 pg/ml,with a sensitivity of 92.3%,specificity of 48.9%,and AUC of 0.717(95%CI:0.590-0.829,P=0.002).4.Urinary KLF4 clinicopathological association:The level of KLF4 in urine of patients with renal proteinuria(24h-UTP>3.5 g/24h)was lower than that of patients with subrenal proteinuria(24h-UTP ≤3.5 g/24h)(P<0.05).In correlation analysis,urinary KLF4 was positively correlated with eGFR(r=0.378,P<0.05)and negatively correlated with Scr(R=0.358,P<0.05),CysC(R=-0.388,P<0.05)and 24h-UTP(R=-0.344,P<0.05).5.Possible causative factors for T2DM and DKD:Multiple logistic regression analysis showed that smoking history was positively correlated with the risk of developing T2DM(P<0.05,OR=13.533).While systolic blood pressure(P<0.05,OR=1.113),hypertension history(P<0.05,OR=14.416)and smoking history(P<0.05,OR=11.758)were positively correlated with the risk of developing DKD,there was a negative correlation between the level of urinary KLF4 and the risk of developing DKD(P<0.05,OR=0.993).6.There was no significant difference in sex,age,BMI and course of T2DM between the kidney essence deficiency group and the non-kidney essence deficiency group(P>0.05),the course and stage of DKD and the history of hypertension in the kidney essence deficiency group were higher than those in the non-kidney essence deficiency group(P<0.05).The levels of PRO,P,Scr,BUN,CysC,TG,24h-UTP in the kidney essence deficiency group were higher than those in the non-kidney essence deficiency group(P<0.05),while the levels of HGB,Ca,TP,ALB,eGFR were lower than those in the non-kidney essence deficiency group(P<0.05).7.Characteristics of Chinese medicine symptoms of DKD:The kidney essence deficiency group had higher scores of waist and knee soreness,tinnitus and deafness,loose teeth,urine foam and kidney-essence deficiency syndrome(P<0.05).In the kidney essence deficiency group,the syndrome of blood stasis(63.0%)>damp-heat syndrome(48.1%),phlegm-turbid syndrome(48.1%)>water-dampness syndrome(40.7%)>heat-excess syndrome(22.2%)>Qi stagnation syndrome(11.1%).The proportion of syndrome of kidney essence deficiency group combined with water-dampness and blood stasis was significantly higher than that of nonkidney essence deficiency group(P<0.01).The kidney essence deficiency group’s scores of syndrome of water-dampness,blood stasis and phlegm-turbid were higher than those of nonkidney essence deficiency group(P<0.05).On the other hand,the score of essence deficiency syndrome was positively correlated with 24h-UTP(r=0.362,P<0.05),negatively correlated with eGFR(r=-0.309.P<0.05).The score of water-dampness syndrome was positively correlated with Scr(r=0.460,P<0.05),negatively correlated with eGFR(r=-0.456,P<0.05).The scores of damp-heat syndrome was positively correlated with 24h-UTP(r=0.250,P<0.05).The scores of blood stasis syndrome were positively correlated with Scr(r=0.421,P<0.05)and BUN(r=0.446,P<0.05),negatively correlated with eGFR(r=-0.454,P<0.05).The scores of phlegm-turbid was positively correlated with Scr(r=0.350,P<0.05).8.The relationship between urinary KLF4 and kidney essence deficiency syndrome of DKD:The expression of KLF4 in urine of kidney essence deficiency group was lower than that of non-kidney essence deficiency group(P<0.05).In correlation analysis,the expression level of KLF4 in urine was negatively correlated with the score of kidney essence deficiency syndrome(r=-0.323,P<0.05),and negatively correlated with the score of blood stasis syndrome(r=-0.338,P<0.05).Conclusions:1.The abnormal low expression of KLF4 in urine of patients with DKD was negatively correlated with the levels of renal function and proteinuria,which may be an important factor in the development of DKD.2.The higher levels of Scr,BUN,CysC and 24h-UTP and lower levels of eGFR in DKD patients with kidney essence deficiency suggest that renal essence deficiency is a key factor of progression in DKD.3.The expression level of urinary KLF4 in DKD patients with kidney essence deficiency was decreased,and there was a negative correlation between the expression level of urinary KLF4 and the score of syndrome of kidney essence deficiency in DKD.Which indicates that KLF4 may participate in the pathogenesis of kidney essence deficiency syndrome of DKD.