Recent Advances and Future Directions in the Mechanisms and Therapeutic Strategies Targeting the Complement System in Diabetic Nephropathy

Experimental Models of Type-2 Diabetic Nephropathy

In order to elucidate the epigenetic mechanism and explore new biomarkers for diabetes and diabetic nephropathy, circulating lncRNA and mRNA expression profiles of normal control, diabetes mellitus, and diabetic nephropathy patients were analyzed. Serum samples from diabetic nephropathy patients (DN), diabetes mellitus patients without microalbuminuria (DM), and healthy controls (N) were collected. Arraystar Human LncRNA/mRNA V3.0 expression spectrum biochips were used for serum lncRNA and mRNA expression profile analysis. The urinary microalbumin/creatinine ratio and serum creatinine level were higher in diabetic nephropathy patients, and the estimated glomerular filtration rate (eGFR) was significantly decreased compared to that in diabetic patients and healthy controls (<0.05). Compared with healthy controls, 245 upregulated and 680 downregulated lncRNAs were identified in the serum of diabetic patients, and 45 and 813 lncRNAs were up- and downregulated in the serum of diabetic nephropathy patients compared with diabetic patients. Levels of lncRNA-ARAP1-AS2 gradually increased during the progression of diabetes and diabetic nephropathy (2.82 times in DM/N and 2.47 times in DN/DM), whereas those of lncRNA-ARAP1-AS1 gradually decreased (2.24 times in DM/N, 4.79 times in DN/DM). Additionally, mRNA levels of their target gene ARAP1 (ArfGAP with RhoGAP domain, ankyrin repeat, and PH domain 1) gradually increased (2.25 times in DM/N and 2.45 times in DN/DM). lncRNA-ARAP1-AS1 and ARAP1-AS2 enhanced ARAP1 mRNA expression and may be involved in the pathogenesis of diabetes and DN. Circulating lncRNA-ARAP1-AS1, ARAP1-AS2, and ARAP1 may serve as new biomarkers for diabetes and diabetic nephropathy.

Background: Diabetic nephropathy (DN) is a microvascular complication of Diabetes Mellitus (DM) and the prevalence of which is increasing in every year. Monitoring of Vitamin D status in diabetic nephropathy patients is important, as the deficiency of vitamin D appears as a risk factor for the development of diabetic nephropathy. Studies evaluating the role of vitamin D in DN are few. Conflicting data is available on the correlation between vitamin D and Diabetic Nephropathy. Studies revealed the sample population is Vitamin D deficient. Therefore, it is important to understand the correlation of Vitamin D with severity of Diabetic nephropathy and its role in fibrogenesis. The aim of this study is to analyse vitamin D status in different stages of type 2 diabetic nephropathy and its correlation with transforming growth factor beta-1.&#x0D; Methods: A 1.5-year cross-sectional study of 120 diabetic patients, 60 with nephropathy and 60 without nephropathy patients enrolled to MES Medical College. Patients with heart, liver, or thyroid disease, as well as those on dialysis, were excluded from the study. The VITROS 5600 integrated system were used to measure fasting blood sugar (FBS), HbA1c, creatinine and vitamin D. Transforming Growth Factor Beta-1 (TGF-β1) is measured using ELISA technique. According to HbA1c and estimated glomerular filtration rate (eGFR) values, the study population is divided into two groups. The statistical package for the social sciences (SPSS) software was used to conduct the analysis. The level of significance was calculated at 95%.&#x0D; Results: The level of vitamin D in diabetic patients with nephropathy is much lower than in diabetic patients without nephropathy. In diabetic nephropathy patients, serum creatinine, urea, HbA1c and TGF-β1 exhibited a highly significant negative correlation with vitamin D status, but eGFR showed a highly significant positive correlation.&#x0D; Conclusion: Vitamin D status has been found to be poor in all diabetic patients, with a greater drop in diabetic nephropathy patients. In diabetic nephropathy patients, serum creatinine, urea, HbA1c and TGF-β1 exhibited a highly significant negative association with vitamin D status, but eGFR showed a highly significant positive link. Deficiency of vitamin D have role in the development and severity of DN, and showed a highly significant correlation with the regulator of fibrosis, TGF-β1. This finding indicates that vitamin D couldbe an important factor for development and progression of Diabetic nephropathy. So supplementation of vitamin D may slow down progression of DN.

Background: Diabetic Nephropathy (DN) is a common cause of abnormal lipoprotein metabolism and can be influenced by impairment of renal function and metabolic controls in diabetes. Aim: The aim of this study is to determine the level of Haptoglobin and Lipid Profile in Diabetic Nephropathy Patients. Subjects and Method: A prospective case-controlled study was carried out among Diabetic Nephropathy Patients and Control with a total number of 50 DN Patients and 50 Non-Diabetics control subjects respectively. Serum Glucose estimation was analyzed using Glucose Oxidase Peroxidase (GOD) method, Serum Haptoglobin was determined using a Nephelometric method while the Lipid Profile (Total cholesterol, Triglycerides, and HDL-cholesterol) was assayed using an enzymatic method of estimation, while LDL-cholesterol was calculated by Friedewald equation. Body Mass Index (BMI, kgm-2) was calculated from height and weight which were obtained from a questionnaire used to record the demographic features of all the participants/subjects. Result: The results obtained show that serum glucose was significantly increased in Diabetic Nephropathy Patients (8.62 ± 1.34, p&lt;0.05) when compared with control subjects (3.02 ± 0.88, p&lt;0.05). There was also a significant increase (p&lt;0.05) in mean Serum Haptoglobin (38.25 ± 6.67) in Diabetics when compared with control subjects (19.40 ± 3.92). A significant increase was also observed in Triglycerides in DN Patients with a mean of (0.77 ± 0.53, p&lt;0.05) when compared to control subjects (0.63 ± 0.26). However, there were no significant increases in Total Cholesterol and LDL-Cholesterol, with their mean value of (4.15 ± 1.27 and 1.95 ± 0.72) when compared to control subjects (3.59 ± 1.04 and 3.59 ± 1.04) respectively. While an insignificant decrease was observed in DN Patient’s HDL-cholesterol mean value (0.81 ± 0.34) when compared to control subjects (1.18 ± 0.19). In this study, a strong statistically significant positive correlation was observed in Haptoglobin and Total cholesterol (R= 0.939, P= 0.015), HDL-C (R= 0.897, P= 0.025). Conclusion: This study showed increased levels of Fasting Blood Glucose, Serum Haptoglobin, and Triglycerides increased Diabetic Nephropathy in Ilorin. Lipid control appears to be important in the prevention and treatment of Diabetic Nephropathy. This study suggests that serum Hp levels may be used as a potential biomarker for the early diagnosis of Diabetic Kidney Diseases in Diabetes Patients.

Rationale and Strategies for Early Detection and Management of Diabetic Kidney Disease

Introduction: Diabetic nephropathy is an important complication of diabetes mellitus leading to significant morbidity and mortality. Objectives: To study the awareness of diabetic nephropathy in patients with type 2 diabetes mellitus (T2DM) and the factors influencing patient awareness of diabetic nephropathy. Patients and Methods: Four hundred subjects, aged above 18 years with T2DM as per American Diabetes Association (ADA) criteria, were selected. Patient awareness regarding diabetic nephropathy was assessed as per a prefixed questionnaire. Results: Awareness of basic information concerning diabetes was present in more than 60% of patients. No significant differences were seen between awareness scores of male and female (P = 0.385), rural and urban (P = 0.120) and literate and illiterate (P = 0.567) diabetic patients. Awareness scores were higher in diabetic patients exceeding 50 years of age (P = 0.004) and patients having diabetes for more than10 years (P &lt; 0.0001), controlled diabetes (P = 0.026) and diabetic nephropathy (P &lt; 0.0001). Awareness of diabetic nephropathy was independently associated with duration of diabetes (P = 0.010) and diabetic nephropathy (P = 0.011) but not with age (P = 0.754) and control of diabetes (P = 0.229). Conclusion: A substantial proportion of diabetic patients are still unaware of the basic facts about diabetes and diabetic nephropathy. Awareness of diabetic nephropathy depended upon duration of diabetes and presence of diabetic nephropathy and requires promotion during early stages of diabetes to improve control of diabetes and prevent diabetic nephropathy.

To characterize the expression of Toll-like receptor 4 (TLR4) in monocytes of diabetic nephropathy (DN) patients and the response of TLR4 to lipopolysaccharide (LPS), and, further, to explore the potential effects of inflammatory immune response in DN. Thirty DN patients with uremia, ten early-type 2 DN patients, and twenty healthy volunteers were enrolled for the determination of TLR4 expression in monocytes by using peripheral blood flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated and subjected to 1 μg/mL LPS for 24 h. Monocytes were collected to assay NF-κB p65 and Notch1 expression by Western blot, with immuneofluorescence detection. Serum and supernatants were sampled for the determination of interleukin-6 (IL-6) concentration by using ELISA. Serum C-reactive protein (CRP) level was determined by using the immunoturbidimetry. Compared with the normal control, type 2 DN uremic patients had a significantly higher TLR4 fluorescence-blot intensities (FI), and serum CRP and IL-6 levels [TLR4 FI: DN uremia patients 2.8±0.9; early type 2 DN patients 3.4 ±0.7; healthy subjects 1.6±0.7. IL-6 concentration: DN uremia patients (84.8±20.7) pg/mL; early type 2 DN patients (63.20±14.4) pg/mL; healthy subjects (11.0±2.0) pg/mL. CRP concentraton: DN uremia patients (5.4±2.8) mg/L; early type 2 DN patients (3.7±1.7) mg/L; healthy subjects (1.7±0.7) mg/L. P<0.01 for any DN-group vs control]. In early type 2 DN patients, following exposure to LPS, PBMCs showed a significant upregulation in TLR4 and NF-κB p65 expression and a remarked increase in serum IL-6 level (all P<0.05), and NF-κB p65 transfer to the nucleus is enhanced. Notch1 protein expression was not significantly altered in any group. A disturbance in proinflammatory CD14(+)CD16(+) monocytes occurs in type 2 DN patients. Such immunological dysfunction may be related to activation in NF-κB/TLR4 signaling pathways, and have nothing to do with the Notch1 signaling pathway.

Diabetes and the Kidney

Clinical utility of serum beta-2-microglobulin as a predictor of diabetic complications in patients with type 2 diabetes without renal impairment

This study was to explore the causal effect of iron status on renal function and the risk of diabetic nephropathy in diabetic patients. The data on exposures including ferritin, serum iron, transferrin saturation (TSAT), and total iron-binding capacity (TIBC) were obtained from a genome-wide association study (GWAS). The outcomes were diabetic nephropathy, Type 1 diabetes mellitus (T1DM) with renal complications, Type 2 diabetes mellitus (T2DM) with renal complications, estimated glomerular filtration rate (creatinine) (eGFRcrea) in diabetes mellitus, and urinary albumin-to-creatinine ratio (UACR) in diabetes mellitus. The causal associations of exposures and outcomes were analyzed using MR analysis with the inverse variance-weighted (IVW) method as the primary analytical method. Leave-one-out analysis was utilized to find any individual SNP associated with exposures influencing outcomes. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated. The F values of all the SNPs were > 10, indicating a sufficient strength of the instrumental variables. The results from pleiotropy analysis indicated that most SNPs showed no horizontal pleiotropy (p > 0.05). The ferritin level had a causal effect on decreased eGFRcrea level in diabetes mellitus patients (OR = 0.937, 95% CI: 0.887–0.990) and increased risk of T1DM with renal complications (OR = 1.783, 95% CI: 1.005–3.162). TIBC level was causally associated with decreased risk of diabetic nephropathy (OR = 0.864, 95% CI: 0.771–0.968) and T1DM with renal complications (OR = 0.743, 95% CI: 0.603–0.916). Ferritin level had a causal effect on eGFRcrea level in diabetes mellitus patients and T1DM with renal complications. In conclusion, TIBC levels are causally linked to a lower risk of both diabetic nephropathy and T1DM with renal complications. The findings might provide a reference for using TIBC levels as a biomarker for prevention and treatment of diabetic nephropathy in the future. As the study was an MR analysis based on gene, the value of TIBC levels still should be validated in large prospective trials.

BACKGROUND AND OBJECTIVES:One out of five Saudi diabetics develops end-stage renal disease (ESRD). Factors associated with progressive loss of renal function have not been extensively studied and reported in our community. We sought to evaluate the pattern and progression in glomerular filtration rate (GFR) and investigate the potential risk factors associated with progression to diabetic nephropathy (DN) among Saudi patients.DESIGN AND SETTING:Hospital-based retrospective analysis of type 2 diabetic patients seen between January 1989 and January 2004 at Security Forces Hospital and King Saud University in Riyadh, Saudi Arabia.PATIENTS AND METHODS:DN was defined as persistent proteinuria assessed by urine dipstick [at least twice for at least two consecutive years and/or serum creatinine >130 μmol/L; and/or GFR <60 mL/min/1.73m2].RESULTS:Of 1952 files reviewed, 621 (31.8%) met the criteria for DN, and 294 (47%) were males. The mean (SD) age of the patients at baseline was 66.9 (11.4) years, and mean duration of diabetes was 15.4 (7.5) years. GFR deteriorated from a baseline value of 78.3 (30.3) mL/min/1.73m2 to 45.1 (24.1) mL/min/1.73m2 at the last visit, with a mean rate of decline in GFR of 3.3 mL/min/year. Progression of nephropathy was observed in 455 (73.3%) patients, with 250 (40.3%) patients doubling their first–hospital-visit serum creatinine level in a mean of 10.0 (6.0) years. At the end of the study, 16.5% of the cohort developed ESRD and were dialyzed. GFR >90 mL/min/1.73m2 at the first hospital visit; duration of diabetes >10 years; persistent proteinuria; systolic blood pressure >130 mm Hg; and presence of retinopathy were significant markers associated with progression of nephropathy.CONCLUSION:Diabetic nephropathy tends to be progressive among Saudis, with GFR deteriorating at a rate of 3.3 mL/year and with a doubling of serum creatinine level in 40.3% of patients in 9.9 years.

Introduction

Glycosaminoglycans: use in treatment of diabetic nephropathy.

Introduction: Diabetic nephropathy (DN) is one of the diabetic complications, which leads to end-stage renal disease. This study aimed to assess the expression of the lipoic acid synthetase (LIAS) gene in type 2 diabetic patients and DN patients. Subjects and Methods: A case-control study conducted on 60 patients who had type 2 diabetes, 60 patients who had DN, and 60 healthy matched individuals. The peripheral blood expression of the LIAS gene was assessed by real-time qRT-PCR. Results: In diabetic and DN patients, the expressions of LIAS were significantly lower than controls (p < 0.001). The LIAS expression showed a reducing trend with the progress of DN (p < 0.001). The LIAS expression showed a sensitivity of 95 % and specificity of 88.3% in the differentiating between diabetic and DN patients and it can detect early DN with a sensitivity of 93.5 % and specificity of 90%. LIAS expression in DN patients had significant negative correlations with disease duration and albuminuria. LIAS gene expression can protect significantly from the DN. It had an odds ratio of 0.01 [95% confidence interval (CI): 0.001-0.03] (p < 0.001). LIAS gene expression can significantly predict disease severity. Conclusion: Peripheral blood expression of the LIAS gene was significantly lower in diabetic and DN patients in comparison to controls. The LIAS expression negatively correlated with the progress of DN. LIAS gene expression seems to be a promising marker for prediction and early detection of DN in type 2 diabetic patients.

Introduction: Diabetic nephropathy (DN) is one of the diabetic complications, which leads to end-stage renal disease. This study aimed to assess the expression of the lipoic acid synthetase (LIAS) gene in type 2 diabetic patients and DN patients. Subjects and Methods: A case-control study conducted on 60 patients who had type 2 diabetes, 60 patients who had DN, and 60 healthy matched individuals. The peripheral blood expression of the LIAS gene was assessed by real-time qRT-PCR. Results: In diabetic and DN patients, the expressions of LIAS were significantly lower than controls (p < 0.001). The LIAS expression showed a reducing trend with the progress of DN (p < 0.001). The LIAS expression showed a sensitivity of 95 % and specificity of 88.3% in the differentiating between diabetic and DN patients and it can detect early DN with a sensitivity of 93.5 % and specificity of 90%. LIAS expression in DN patients had significant negative correlations with disease duration and albuminuria. LIAS gene expression can protect significantly from the DN. It had an odds ratio of 0.01 [95% confidence interval (CI): 0.001-0.03] (p < 0.001). LIAS gene expression can significantly predict disease severity. Conclusion: Peripheral blood expression of the LIAS gene was significantly lower in diabetic and DN patients in comparison to controls. The LIAS expression negatively correlated with the progress of DN. LIAS gene expression seems to be a promising marker for prediction and early detection of DN in type 2 diabetic patients.