Association of urinary monocyte chemoattractant protein-1 (MCP-1) and kidney injury molecule-1 (KIM-1) with risk factors of diabetic kidney disease in type 2 diabetes patients

Longitudinal Trajectories of Biomarkers of Kidney Tubular Function in Type 1 Diabetes

Introduction

Tubular biomarkers may shed insight into progression of kidney tubulointerstitial pathology complementary to traditional measures of glomerular function and damage.

Methods

We examined trajectories of tubular biomarkers in the Diabetes Control and Complications Trial and the Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC Study) of type 1 diabetes (T1D). Biomarkers were measured in a subset of 220 participants across 7 time points over 26 years. Measurements included the following: kidney injury molecule 1 (KIM-1), soluble tumor necrosis factor 1 (sTNFR1) in serum or plasma, epidermal growth factor (EGF), monocyte chemoattractant protein-1 (MCP1) in timed urine, and a composite tubular secretion score. We described biomarker trajectories and examined how these were affected by intensive glucose-lowering therapy and glycemia.

Results

At baseline, participants had a mean age of 28 years, 45% were women, and 50% were assigned to intensive glucose-lowering therapy. The mean estimated glomerular filtration rate (eGFR) was 125 ml/min per 1.73 m2 and 90% of participants had a urinary albumin excretion rate (AER) <30 mg/24h. Mean changes in biomarkers over time (percent/decade) were: KIM-1: 27.3% (95% confidence interval [CI]: 21.4-33.5), sTNFR1: 16.9% (14.5-19.3), MCP1: 18.4% (8.9-28.8), EGF: -13.5% (-16.7 to -10.1), EGF-MCP1 ratio: -26.9% (-32.2 to -21.3), and tubular secretion score -0.9% (-1.8 to 0.0), versus -12.0% (CI: -12.9 to -11.1) for eGFR and 10.9% (2.5-20.1) for AER. Intensive versus conventional glucose-lowering therapy was associated with slower increase in sTNFR1 (relative difference in change: 0.94 [0.90-0.98]). Higher HbA1c was associated with faster increases in sTNFR1 (relative difference in change: 1.06 per 1% higher HbA1c [1.05-1.08]) and KIM-1 (1.09 [1.05-1.14]).

Conclusion

Among participants with T1D and normal eGFR at baseline, kidney tubular biomarkers changed significantly over long-term follow-up. Hyperglycemia was associated with larger increases in serum or plasma sTNFR1 and KIM-1, when followed-up longitudinally.

Clinical significance of urinary inflammatory biomarkers in patients with IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis, although the definitive markers are unknown. We aimed to investigate the clinical significance of urinary cytokines in patients with IgAN.

METHODS

From 2009 to 2018, the patients were divided into three groups: IgAN (n = 191), disease control (n = 53), and normal control (n = 76). We used a multiplex enzyme-linked immunosorbent assay to measure 16 selected urinary inflammatory cytokines, evaluated the correlation between clinical and pathological features following regression analysis on progression.

RESULTS

The IgAN group exhibited significantly different levels of urinary cytokines compared to the normal control and disease control groups. Urinary levels of B-cell-activating factor, vascular endothelial growth factor receptor-2, monocyte chemoattractant protein-1, C-X-C motif chemokine 10, C-X-C motif ligand 16, epidermal growth factor (EGF), endocan, endostatin, growth/differentiation factor-15 (GDF-15), interleukin-6 (IL-6), mannose-binding lectin, transferrin receptor, and kidney injury molecule-1 were significantly correlated with both the estimated glomerular filtration rate and urine protein-creatinine ratio. In a multivariate Cox regression analysis, urinary EGF (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.17-0.95, P = 0.04), GDF-15 (HR 2.45, 95% CI 1.01-5.94, P = 0.048), and IL-6 (HR 3.02, 95% CI 1.05-8.64, P = 0.04) were associated with progression in IgAN.

CONCLUSIONS

Urinary inflammatory biomarkers may serve as alternative predictive biomarkers in patients with IgAN. Further studies are needed to elucidate the physiological mechanisms and confirm the results.

Plasma MCP-1 and TGF-β1 Levels are Associated with Kidney Injury in Children with Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are primarily causal for end-stage renal disease and have significant implications for long-term survival. A total of 39 healthy controls and 94 children with chronic kidney disease (CKD) were enrolled (3-12 years old as children, 13-18 years old as adolescents), who were divided into CAKUT and Non-CAKUT according to the etiology of CKD. CKD group was further classified according to estimating glomerular filtration rate (eGFR). Circulating levels of inflammatory markers such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemokine-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) were analyzed. The relationship between these inflammatory markers with eGFR and the kidney injury parameter (urine protein) was investigated to assess their potential as early markers of disease progression. All circulating levels of these inflammatory cytokines were increased in CKD patients (including CAKUT and Non-CAKUT) compared with healthy subjects. The circulating levels of MCP-1 and TGF-β1 were increased in CAKUT adolescents compared with CAKUT children. In CAKUT children, levels of MCP-1 and TGF-β1 increased as CKD progressed, and MCP-1 and TGF-β1 were negatively and significantly correlated with eGFR and positively with urine protein. MCP-1 and TGF-β1 may contribute to the early detection of CKD and disease stage/progression in CAKUT children.

Cellular crosstalk of mesangial cells and tubular epithelial cells in diabetic kidney disease

Diabetic kidney disease (DKD) is a major cause of end-stage renal disease and imposes a heavy global economic burden; however, little is known about its complicated pathophysiology. Investigating the cellular crosstalk involved in DKD is a promising avenue for gaining a better understanding of its pathogenesis. Nonetheless, the cellular crosstalk of podocytes and endothelial cells in DKD is better understood than that of mesangial cells (MCs) and renal tubular epithelial cells (TECs). As the significance of MCs and TECs in DKD pathophysiology has recently become more apparent, we reviewed the existing literature on the cellular crosstalk of MCs and TECs in the context of DKD to acquire a comprehensive understanding of their cellular communication. Insights into the complicated mechanisms underlying the pathophysiology of DKD would improve its early detection, care, and prognosis. Video Abstract.

Serum Biomarkers of Renal Fibrosis: A Systematic Review

Chronic kidney disease (CKD) is a widely diffuse pathological condition which deeply impacts upon an affected patient's quality of life and its worldwide rate is predicted to further rise. The main biological mechanism underlying CKD is renal fibrosis, a non-reversible process representing, for the affected system, a point of no return of tissue damage and dysfunction, deeply reducing the possible therapeutic strategies at the disposal of physicians. The best tool clinicians can use to address the extent of renal fibrosis at any level (glomeruli, tubule-interstitium, vasculature) is kidney biopsy that, despite its overall safety, remains an invasive procedure showing some shortcomings. Thus, the identification of novel non-invasive renal fibrosis biomarkers would be of fundamental importance. Here, when systematically reviewing the available evidence on serological biomarkers associated with renal fibrosis evaluated in patients suffering from CKD in the last five years, we found that despite the presence of several promising biomarkers, the level of observed evidence is still very scattered. Probably, the use of multiple measures capable of addressing different aspects involved in this condition would be the most suitable way to capture the high complexity characterizing the renal fibrotic process, having consequently a great impact on clinical practice by maximizing prevention, diagnosis, and management.

Toll-like receptor inflammatory cascade and the development of diabetic kidney disease in children and adolescents with type 1 diabetes

AIM

This study aimed to evaluate the association of toll-like receptor (TLR) inflammatory cascade with the development of diabetic kidney disease (DKD) in children and adolescents with type 1 diabetes (T1D).

METHODS

A total of 49 T1D patients and 49 normoglycaemic (NG) subjects aged 5-20 years old were recruited. TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 mRNA expressions were measured in peripheral blood mononuclear cells by reverse transcription-quantitative polymerase chain reaction. Fasting glucose, glycated haemoglobin, serum urea, serum creatinine and urinary albumin-to-creatinine ratio (ACR) were determined.

RESULTS

The mRNA expressions of TLR2, TLR4, MYD88 and NFKB were significantly increased in the T1D group compared with the NG group. The mRNA expression levels of MCP1/CCL2 and IL18 were higher in 21 T1D patients (42.9%) (average of MCP1/CCL2: 6.6-fold and IL18: 5.8-fold) than in NG patients. Furthermore, ACR was increased in the T1D group compared with the NG group.

CONCLUSION

The increased mRNA expression of TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 favours the development of an inflammatory process that may lead to a decline in renal function and consequently DKD in children and adolescents with T1D. This suggests that these genes are early mediators of onset DKD since the beginning of the lives of the paediatric T1D patients.

Yishen Capsule Alleviated Symptoms of Diabetic Nephropathy via NOD-like Receptor Signaling Pathway

PURPOSE

To explore the mechanism of Yishen capsule against diabetic nephropathy (DN) based on the analysis of transcriptomics.

MATERIAL AND METHODS

SD rats (Male, SPF grade) were randomly divided into four groups, the normal group, the DN group, the Yishen capsule group and the resveratrol group. Urine and renal tissue samples were collected after feeding with physiological saline and above drugs for 8 weeks. 24-hour urine microalbumin protein was detected by ELISA. HE staining and PAS staining were performed on renal tissues. Differential gene expression in renal tissues was analyzed by transcriptome sequencing. The differentially expressed genes were analyzed by GO enrichment and KEGG enrichment, and verified by RT-PCR and immunohistochemistry staining.

RESULTS

The level of 24-hour urinary microalbumin in DN group was increased, while Yishen capsule treatment reversed the increasement of urinary microalbumin. Mesangial cell proliferation, matrix accumulation, edema and vacuolar degeneration of renal tubular epithelial cells and glycogen accumulation were observed in DN group. However, pathological phenotypes mentioned above were alleviated after Yisen capsule administration. This result indicates that Yishen capsule reversed pathological phenotypes of DN in rats. The expression of 261 genes were changed in Yishen capsule group compared with DN group. GO enrichment analysis and KEGG pathway analysis showed that these genes were implicated in pathways, including mineral absorption, adipocytokine signaling pathway, fatty acid biosynthesis, thyroid hormone synthesis, renin-angiotensin system, and NOD-like receptor signaling pathway. Based on previous reported study, the expression of key factors in NOD-like receptor signaling pathway was verified. RT-PCR and immunohistochemistry staining showed that the expression of NLRP3, Caspase-1 and IL-1β in renal tissues of DN group were increased (P < 0.05), which were decreased in Yishen capsule group (P < 0.05).

CONCLUSION

Yishen capsule reduced microalbuminuria and alleviated pathological changes in DN rats, which may be achieved by regulating NOD-like receptor signaling pathway.

Urinary NGAL is a Potential Biomarker for Early Renal Injury in Insulin Resistant Obese Non-diabetic Children

OBJECTIVE

Neutrophil gelatinase-associated lipocalin (NGAL) is one of the new biomarkers for detecting acute renal injury. There are studies showing the relationship between NGAL and renal injury in obese children. The aim of this study was to investigate whether urinary levels of NGAL, kidney injury molecule-1, and serum cystatin C are increased in insulin resistance (IR) patients before the development of diabetes.

METHODS

Cross-sectional, case-controlled study that included non-diabetic obese children and adolescent patients with IR and a non-diabetic obese control group with no IR, who attended a tertiary center pediatric endocrinology outpatient clinic between 2016-2018. Those with diabetes mellitus and/or known renal disease were excluded. NGAL and creatinine (Cr) levels were evaluated in the morning spot urine from all participants. Serum renal function was evaluated.

RESULTS

Thirty-six control and 63 IR patients were included in the study, of whom 68 (68.7%) were girls. The mean age of all participants was 13.12±2.64 years and no statistically significant difference was found between the two groups in terms of age or gender distribution. Median (range) spot urinary NGAL (u-NGAL) values in the IR group were significantly higher at 26.35 (7.01-108.7) ng/mL than in the control group at 19.5 (3.45-88.14) ng/mL (p=0.018). NGAL/Cr ratio was also significantly higher in the IR group compared to the control group (p=0.018).

CONCLUSION

Obese pediatric patients with IR were shown to have elevated levels of u-NGAL, a marker of renal injury. u-NGAL examination may show early renal injury before development of diabetes.

High concentrations of triglycerides are associated with diabetic kidney disease in new-onset type 2 diabetes in China: Findings from the China Cardiometabolic Disease and Cancer Cohort (4C) Study

AIMS

The aims of this study were to evaluate the associations of metabolic abnormalities with incident diabetic kidney disease (DKD) and to explore whether dyslipidaemia, particularly high fasting triglyceride (TG), was associated with the development of DKD.

METHODS

In total, 11 142 patients with new-onset type 2 diabetes with baseline estimated glomerular filtration rates (eGFR) ≥60 mL/min/1.73 m² were followed up during 2011-2016. Incident DKD was defined as eGFR <60 mL/min/1.73 m² at follow-up. Multiple logistic regression analysis was conducted to explore the relationship of metabolic abnormalities at baseline and at follow-up with risks of DKD. High TG was defined by TG ≥1.70 mmol/L. Low high-density lipoprotein cholesterol (HDL-c) was defined by HDL-c <1.0 mmol/L for men or <1.3 mmol/L for women.

RESULTS

Participants who developed DKD had higher levels of waist circumference and systolic blood pressure, and lower levels of HDL-c at both baseline and follow-up visits. The DKD group also had higher levels of post-load plasma glucose and TG at follow-up. Multivariate logistic regression analysis revealed that both high TG at baseline [odds ratio (OR) = 1.37, p = .012) and high TG at follow-up (OR = 1.71, p < .001) were significantly associated with increased risks of DKD. Patients with high TG levels at both baseline and follow-up had higher risk of DKD compared with constantly normal TG (OR = 1.65, p < .001) after adjustment for covariates.

CONCLUSIONS

In a large population of patients with new-onset type 2 diabetes, a high TG level was an independent risk factor for the development of DKD. Tight TG control might delay the occurrence of DKD.

Novel Cardiovascular Risk Factors in Patients with Diabetic Kidney Disease

Patients with diabetic kidney disease (DKD) are at very high risk for cardiovascular events. Only part of this increased risk can be attributed to the presence of diabetes mellitus (DM) and to other DM-related comorbidities, including hypertension and obesity. The identification of novel risk factors that underpin the association between DKD and cardiovascular disease (CVD) is essential for risk stratification, for individualization of treatment and for identification of novel treatment targets.In the present review, we summarize the current knowledge regarding the role of emerging cardiovascular risk markers in patients with DKD. Among these biomarkers, fibroblast growth factor-23 and copeptin were studied more extensively and consistently predicted cardiovascular events in this population. Therefore, it might be useful to incorporate them in risk stratification strategies in patients with DKD to identify those who would possibly benefit from more aggressive management of cardiovascular risk factors.

Chronic treatment with the (iso-)glutaminyl cyclase inhibitor PQ529 is a novel and effective approach for glomerulonephritis in chronic kidney disease

Glomeruli and renal tubule injury in chronic kidney disease (CKD) is reported to involve induction of macrophage activation through the CCL2/CCR2 axis. The effects of inhibitors of the CCL2/CCR2 axis, such as anti-CCL2 antibody and CCR2 antagonist, on kidney function in animal models or humans with kidney dysfunction have been demonstrated. The N-terminal glutamine on immature CCL2 is replaced with pyroglutamate (pE) by glutaminyl cyclase (QC) and isoQC. pE-CCL2 is stable and resistant to peptidases. We hypothesized that inhibiting QC/isoQC activity would lead to the degradation of CCL2, thereby ameliorating CKD and reducing kidney inflammation. To test this hypothesis, we investigated the renoprotective properties of the QC/isoQC inhibitor PQ529 in anti-glomerular basement membrane (GBM) antibody-induced glomerulonephritis Wistar Kyoto (WKY) rats. Three-week repeated administration of PQ529 (30 and 100 mg/kg, twice daily) significantly reduced the serum and urine CCL2 and urinary protein excretion in a dose-dependent manner. Correlations between the urinary protein level and serum or urinary CCL2 levels were confirmed in tested animals. Repeated administration of PQ529 significantly reduced the expression of CD68, a macrophage marker, in the kidney cortex and mononuclear infiltration into the tubulointerstitium. In addition, decreased levels of urinary KIM-1, β2 microglobulin, and clusterin were detected, suggesting the inhibition of inflammation in both the proximal and distal tubules. These results suggest that PQ529 suppresses the progression of inflammation-induced renal dysfunction by inhibiting the CCL2/CCR2 axis. Inhibition of QC/isoQC may thus be a viable alternative therapeutic approach for treating glomerulonephritis and CKD patients.

Circulating adhesion molecules and associations with HbA1c, hypertension, nephropathy, and retinopathy in the Treatment Options for type 2 Diabetes in Adolescent and Youth study

BACKGROUND

The Treatment Options for type 2 Diabetes in Adolescent and Youth study, a randomized clinical trial of three treatments for type 2 diabetes (T2DM) in youth, demonstrated treatment failure (defined as sustained HbA1c ≥8%, or inability to wean insulin after 3 months after acute metabolic decomposition) in over half of the participants. Given that binding of mononuclear cells to vascular endothelium, initiated by cellular adhesion molecules and chemokines, is an early step in vascular injury, we sought to evaluate (a) changes in cellular adhesion molecule levels during the trial; (b) effect of diabetes treatment; and (c) association of markers with HbA1c, hypertension, hypercholesterolemia, nephropathy, and retinopathy.

METHODS

Participants (n = 515 of 699) that had baseline assessment of adhesion molecules (monocyte chemoattractant protein-1 [MCP-1], vascular cell adhesion marker [VCAM], intercellular adhesion marker [ICAM], and E-Selectin) and at least one other assessment, measured at month 12, 24, or 36, were included.

RESULTS

Over 1 to 3 years, significant increases in MCP-1 and decreases in VCAM (both P < .0001) concentrations were found; however, no significant interactions were identified with treatment group for any molecule. For every 1% increase in HbA1c, ICAM increased by 1.8%, VCAM by 1.5%, and E-selectin by 6.8% (all P < .0001). E-selectin increased by 3.7% and 4.2% for every 10 mm Hg increase in systolic and diastolic blood pressure, respectively (both P < .0001). ICAM was 10.2% higher and E-selectin was 15.5% higher in participants with microalbuminuria (both P < .01). There was no significant association of adhesion molecule levels with retinopathy.

CONCLUSION

Concentrations of cellular adhesion molecules rise with increasing HbA1c in youth with T2DM, and are associated with blood pressure and microalbuminuria, markers of vascular injury.

Praliciguat inhibits progression of diabetic nephropathy in ZSF1 rats and suppresses inflammation and apoptosis in human renal proximal tubular cells

Praliciguat, a clinical-stage soluble guanylate cyclase (sGC) stimulator, increases cGMP via the nitric oxide-sGC pathway. Praliciguat has been shown to be renoprotective in rodent models of hypertensive nephropathy and renal fibrosis. In the present study, praliciguat alone and in combination with enalapril attenuated proteinuria in the obese ZSF1 rat model of diabetic nephropathy. Praliciguat monotherapy did not affect hemodynamics. In contrast, enalapril monotherapy lowered blood pressure but did not attenuate proteinuria. Renal expression of genes in pathways involved in inflammation, fibrosis, oxidative stress, and kidney injury was lower in praliciguat-treated obese ZSF1 rats than in obese control rats; fasting glucose and cholesterol were also lower with praliciguat treatment. To gain insight into how tubular mechanisms might contribute to its pharmacological effects on the kidneys, we studied the effects of praliciguat on pathological processes and signaling pathways in cultured human primary renal proximal tubular epithelial cells (RPTCs). Praliciguat inhibited the expression of proinflammatory cytokines and secretion of monocyte chemoattractant protein-1 in tumor necrosis factor-α-challenged RPTCs. Praliciguat treatment also attenuated transforming growth factor-β-mediated apoptosis, changes to a mesenchyme-like cellular phenotype, and phosphorylation of SMAD3 in RPTCs. In conclusion, praliciguat improved proteinuria in the ZSF1 rat model of diabetic nephropathy, and its actions in human RPTCs suggest that tubular effects may contribute to its renal benefits, building upon strong evidence for the role of cGMP signaling in renal health.