Understanding the nature of renal disease progression

The potential for improving cardio-renal outcomes in chronic kidney disease with the aldosterone synthase inhibitor vicadrostat (BI 690517): a rationale for the EASi-KIDNEY trial

Patients with chronic kidney disease (CKD) are at risk of progressive loss of kidney function, heart failure, and cardiovascular death despite current proven therapies, including renin-angiotensin system inhibitors (RASi), sodium glucose co-transporter-2 inhibitors (SGLT2i), and statin-based regimens. RASi and SGLT2i reduce risk of CKD progression irrespective of primary cause of kidney disease, suggesting they target final common pathways. Targeting aldosterone overactivity with a nonsteroidal mineralocorticoid receptor antagonist (MRA) also reduces cardiorenal risk in patients with albuminuric diabetic kidney disease already treated with RASi. Together, these observations provide the rationale for trials to assess effects of inhibiting the aldosterone pathway in a broader range of patients with CKD, including those with non-diabetic causes of CKD or low albuminuria. Aldosterone synthase inhibitors (ASi) have emerged as an alternative to MRAs for aldosterone pathway inhibition. Phase II data from 586 patients with albuminuric CKD have shown that 10 mg of an ASi, vicadrostat (BI 690517), reduced urine albumin-to-creatinine ratio by ∼40% compared with placebo, with or without concurrent empagliflozin treatment. MRA and ASi increase risk of hyperkalaemia. Combining their use with an SGLT2i may mitigate some of this risk, improving tolerability, and allowing a wider range of patients to be treated (including those with higher levels of blood potassium than in previous trials). The EASi-KIDNEY (NCT06531824) double-blind placebo-controlled trial will test this approach by assessing the safety and cardiorenal efficacy of vicadrostat in combination with empagliflozin in ∼11 000 patients with CKD. It will be sufficiently large to assess effects in patients with and without diabetes separately.

Nicotinamide n-methyltransferase inhibitor synergizes with sodium-glucose cotransporter 2 inhibitor to protect renal tubular epithelium in experimental models of type 2 diabetes mellitus

AIMS

We aim to explore the potential of nicotinamide n-methyltransferase (NNMT) as a sensitive marker of renal tubular injury and the possibility of an NNMT inhibitor to combine with sodium-glucose cotransporter 2 (SGLT2) inhibitor to protect proximal tubular epithelium in vivo and in vitro model of Type 2 diabetes mellitus (T2DM), respectively.

METHODS

In vivo, immunohistochemical staining, Masson's trichrome staining and Sirius red staining were used to observe the changes of NNMT expression, renal tubular injury and interstitial fibrosis in renal tissue from the db/db mice. Bioinformatic analysis was also conducted to broaden the range of data validation. In vitro, Western Blot and quantitative RT-PCR were used to measure the degree of damage of HK-2 cells.

RESULTS

Our in vivo data showed upregulation of NNMT expression paralleled renal tubular damage and interstitial fibrosis. Our in vitro data revealed both NNMT inhibitors and SGLT2 inhibitors can protect against the injury as assessed by extracellular matrix (ECM) synthesis and profibrotic phenotype transition of HK-2 cells, and the combination of these two agents can further reduce these injuries.

CONCLUSIONS

The present study is the first to show that NNMT is a promising marker of renal tubular injury in diabetic nephropathy (DN) and NNMT inhibitors can synergize with SGLT2 inhibitors to protect HK-2 better. Our findings will provide the insight and pave the way of developing novel therapeutic strategies for chronic renal tubular injury associated with T2DM.

Angiopoietin-like protein 4 dysregulation in kidney diseases: a promising biomarker and therapeutic target

The global burden of renal diseases is increasingly severe, underscoring the need for in-depth exploration of the molecular mechanisms underlying renal disease progression and the development of potential novel biomarkers or therapeutic targets. Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional cytokine involved in the regulation of key biological processes, such as glucose and lipid metabolism, inflammation, vascular permeability, and angiogenesis, all of which play crucial roles in the pathogenesis of kidney diseases. Over the past 2 decades, ANGPTL4 has been regarded as playing a pivotal role in the progression of various kidney diseases, prompting significant interest from the scientific community regarding its potential clinical utility in renal disorders. This review synthesizes the available literature, provides a concise overview of the molecular biological effects of ANGPTL4, and highlights its relationship with multiple renal diseases and recent research advancements. These findings underscore the important gaps that warrant further investigation to develop novel targets for the prediction or treatment of various renal diseases.

Expression of Angiopoetin-Like Protein-4 and Kidney Injury Molecule-1 as Preliminary Diagnostic Markers for Diabetes-Related Kidney Disease: A Single Center-Based Cross-Sectional Study

The purpose of the study was to examine the urinary levels of kidney injury molecule-1 (KIM-1) and angiopoietin-like protein-4 (ANGPTL-4) in individuals with diabetic kidney disease (DKD) and their association with established DKD diagnostic markers such as albuminuria and estimated glomerular filtration rate (eGFR). Levels of ANGPTL-4 and KIM-1 were estimated in urine samples. A total of 135 participants were recruited into three groups: 45 diabetes type 2 patients in the control group and 90 DKD patients in two disease groups. Concentrations of ANGPTL-4 and KIM-1 were conclusively related to the urinary albumin-creatinine ratio (UACR). Also, the levels of both ANGPTL-4 and KIM-1 were negatively associated with the eGFR. Multivariable Poisson regression analysis showed that urinary ANGPTL-4 (PR: 3.40; 95% CI: 2.32 to 4.98; p < 0.001) and KIM-1 (PR: 1.25; 95% CI: 1.14 to 1.38; p < 0.001) were prevalent in DKD patients. Receiver operating characteristic (ROC) analysis of urinary ANGPTL-4 and KIM-1 in the combined form resulted in an area under curve (AUC) of 0.967 (95%CI: 0.932-1.000; p < 0.0001) in the microalbuminuria group and 1 (95%CI: 1.000-1.000; p < 0.0001) in the macroalbuminuria group. The association of urinary levels of ANGPTL-4 and KIM-1 with UACR and eGFR and significant prevalence in the diabetic kidney disease population illustrates the diagnostic potential of these biomarkers.

Therapeutic Potential of Two Derivative Prescriptions of Rokumijiogan, Hachimijiogan and Bakumijiogan against Renal Damage in Nephrectomized Rats

Background: Hachimijiogan (HJG) and Bakumijiogan (BJG), two derivative prescriptions of Rokumijiogan (RJG), were selected to investigate their renoprotective potential in the 5/6 nephrectomized (5/6Nx) rat model. Methods: Rats were treated with HJG and BJG orally at 150 mg/kg body weight/day once daily for 10 weeks after resection of 5/6 of the renal volume, and their renoprotective effects were compared with 5/6Nx vehicle-treated and sham-operated control rats. Results: Improvements in renal lesions, glomerulosclerosis, tubulointerstitial injury, and arteriosclerotic lesions estimated by histologic scoring indices in the HJG-treated group were compared with those in the BJG-treated group. HJG- and BJG-treated groups ameliorated the renal function parameters. Elevated levels of renal oxidative stress-related biomarkers were reduced, while decreased antioxidant defence systems (superoxide dismutase and the glutathione/oxidized glutathione ratio) were increased in the HJG-treated group rather than the BJG-treated group. In contrast, BJG administration significantly reduced expression of the inflammatory response through oxidative stress. The HJG-treated group showed a decrease in inflammatory mediators through the JNK pathway. To gain a deeper understanding of their therapeutic action, the effects of the main components detected in HJG and BJG were evaluated using the LLC-PK₁ renal tubular epithelial cell line, which is the renal tissue most vulnerable to oxidative stress. Corni Fructus and Moutan Cortex-originated compositions afforded important protection against oxidative stress induced by peroxynitrite. Conclusions: From our described and discussed analyses, it can be concluded that RJG-containing prescriptions, HJG and BJG are an excellent medicine for chronic kidney disease. In the future, appropriately designed clinical studies in people with chronic kidney disease are necessary to evaluate the renoprotective activities of HJG and BJG.

Elevated serum uric acid is not an independent risk factor for the occurrence of Type 2 diabetic kidney disease in Chinese populations

Previous studies suggested that increased serum uric acid (SUA) level is an independent risk factor for albuminuria in Type 2 diabetes (T2D) patients. However, the association between SUA and onset of Type 2 DKD (T2DKD) remained to be clarified. This was a cross-sectional clinical study in which 1210 Chinese T2D patients were enrolled. According to the urine albumin-to-creatinine ratio (UACR), the cohort was divided into normal-albuminuria (UACR < 30 mg/g), micro-albuminuria (UACR 30-300 mg/g) and macro-albuminuria (UACR > 300 mg/g). The micro- and macro-albuminuria groups were combined into albuminuria category. Results showed that T2D patients with macro-albuminuria have significantly higher SUA than the other 2 groups (P < .001). In the binary logistic regression model, the subjects with SUA higher than 420 μmol/L were associated with a 2-fold increase in the odds of albuminuria (odds ratio = 2.024, 95% confidence interval: 1.232-3.325, P = .005), as compared with those with SUA lower than 300 μmol/L. Moreover, the multinomial regression analysis revealed that the subjects with SUA higher than 420 μmol/L had about 3-fold increase in the odds of macro-albuminuria (odds ratio = 3.758, 95% confidence interval: 2.051-6.885, P < .001), as compared with those with SUA lower than 300 μmol/L. However, SUA was not significantly associated with the presence of micro-albuminuria. Although the SUAwas not independently risk factor for micro-albuminuria, it was closely correlated with the development of macro-albuminuria in Chinese T2DKD patients. Elevated SUA may be useful for predicting the occurrence of macro-albuminuria but not onset of micro-albuminuria at the early stage of T2DKD.

Impact of Early Proteinuria Reduction in Glomerular Disease and Decline of Kidney Function: A Retrospective Cohort

Background: In glomerular disease, the degree of proteinuria is closely related to the progression of chronic kidney disease, and its reduction is associated with a slower decline in the glomerular filtration rate (eGFR) and consequent improvement in the renal prognosis. The aim of this study was to evaluate the impact of proteinuria reduction on the decline of the eGFR in patients with glomerular disease, during the first year after the diagnosis. Methods: This was a retrospective analysis of patients with primary glomerular disease, followed at the Nephrology Department of Centro Hospitalar Universitário Lisboa Norte, during 2019. We analyzed demographic, clinical and laboratorial characteristics (creatinine, GFR, urine analysis and quantification of proteinuria determined by the proteinuria/creatinuria ratio, in the first morning urine or a 24 h urine sample). The outcome assessed was the decline in renal function, defined as a reduction in the GFR ≥ 25%, during the follow-up period. Results: We analyzed 197 patients with glomerular disease, with a mean age of 41.7 ± 19.7 years and follow-up time of 6.5 ± 5.3 years. At the time of the diagnosis, the eGFR was 81.5 ± 49.8 mL/min/1.73 m2 and proteinuria was 3.5 g/24 h (IQR 5.8). At one-year follow-up, median proteinuria was 0.9 g/24 h (IQR 2.4). At the end of the follow-up, mean eGFR was 72.1 ± 43.3 mL/min/1.73 m2. Proteinuria (p = 0.435) and the eGFR (p = 0.880) at the time of diagnosis did not correlate with long-term decline in the eGFR. Proteinuria < 1 g/24 h (HR 0.45 (95% CI 0.25−0.83) p = 0.011) after the first year was protective against long-term decline in the eGFR. It maintained this association with the long-term eGFR decline, independently of the duration of the follow-up (HR 0.30 (95% CI 0.17−0.52) p < 0.001). Conclusions: Proteinuria reduction to lower than 1 g/24 h, during the first year after diagnosis, was a protective factor for the long-term decline of kidney function, having a more important role than proteinuria or the GFR at the time of the diagnosis.

Can SGLT2 inhibitors answer unmet therapeutic needs in chronic kidney disease?

Chronic kidney disease (CKD) is a global health problem, affecting more than 850 million people worldwide. The number of patients receiving renal replacement therapy (dialysis or renal transplantation) has increased over the years, and it has been estimated that the number of people receiving renal replacement therapy will more than double from 2.618 million in 2010 to 5.439 million in 2030, with wide differences among countries. The main focus of CKD treatment has now become preserving renal function rather than replacing it. This is possible, at least to some extent, through the optimal use of multifactorial therapy aimed at preventing end-stage kidney disease and cardiovascular events. Sodium/glucose cotransporter 2 inhibitors (SGLT2i) reduce glomerular hypertension and albuminuria with beneficial effects on progression of renal damage in both diabetic and non-diabetic CKD. SGLT2 inhibitors also show great benefits in cardiovascular protection, irrespective of diabetes. Therefore, the use of these drugs will likely be extended to the whole CKD population as a new standard of care.

Identification of 27 Novel Variants in Genes COL4A3, COL4A4, and COL4A5 in Lithuanian Families With Alport Syndrome

Introduction:

Alport syndrome (AS) is an inherited disorder characterized by hematuria, proteinuria, and kidney function impairment, and frequently associated with extrarenal manifestations. Pathogenic variants in COL4A5 usually cause X-linked Alport syndrome (XLAS), whereas those in the COL4A3 or COL4A4 genes are associated with autosomal dominant (AD) or recessive (AR) inheritance. To date, more than 3000 different disease-causing variants in COL4A5, COL4A3, and COL4A4 have been identified. The aim of this study was to evaluate the clinical and genetic spectrum of individuals with novel, pathogenic or likely pathogenic variants in the COL4A3-A5 genes in a previously unstudied cohort.

Methods

In this study molecular analysis by next generation sequencing (NGS) was performed on individuals from a Lithuanian cohort, with suspected AS. The presence of AS was assessed by reviewing clinical evidence of hematuria, proteinuria, chronic kidney disease (CKD), kidney failure (KF), a family history of AS or persistent hematuria, and specific histological lesions in the kidney biopsy such as thinning or lamellation of the glomerular basement membrane (GBM). Clinical, genetic, laboratory, and pathology data were reviewed. The novelty of the COL4A3-A5 variants was confirmed in the genetic variant databases (Centogene, Franklin, ClinVar, Varsome, InterVar). Only undescribed variants were included in this study.

Results

Molecular testing of 171 suspected individuals led to the detection of 99 individuals with 44 disease causing variants including 27, previously undescribed changes, with the frequency of 9/27 (33,3%) in genes COL4A5, COL4A3 and COL4A4 equally. Three individuals were determined as having digenic AS causing variants: one in COL4A3 and COL4A4, two in COL4A4 and COL4A5. The most prevalent alterations in genes COL4A3-5 were missense variants (n = 19), while splice site, frameshift, unknown variant and stop codon changes were detected more in genes COL4A4 and COL4A5 and accounted for 3, 3, 1 and 1 of all novel variants, respectively.

Conclusion

Genotype-phenotype correlation analysis suggested that some variants demonstrated intra-familial phenotypic variability. These novel variants represented more than half of all the variants found in a cohort of 171 individuals from 109 unrelated families who underwent testing. Our study expands the knowledge of the genetic and phenotypic spectrum for AS.

Cardiometabolic and Kidney Protection in Kidney Transplant Recipients With Diabetes: Mechanisms, Clinical Applications, and Summary of Clinical Trials

Kidney transplantation is the therapy of choice for patients with end-stage renal disease. Preexisting diabetes is highly prevalent in kidney transplant recipients (KTR), and the development of posttransplant diabetes is common because of a number of transplant-specific risk factors such as the use of diabetogenic immunosuppressive medications and posttransplant weight gain. The presence of pretransplant and posttransplant diabetes in KTR significantly and variably affect the risk of graft failure, cardiovascular disease (CVD), and death. Among the many available therapies for diabetes, there are little data to determine the glucose-lowering agent(s) of choice in KTR. Furthermore, despite the high burden of graft loss and CVD among KTR with diabetes, evidence for strategies offering cardiovascular and kidney protection is lacking. Recent accumulating evidence convincingly shows glucose-independent cardiorenal protective effects in non-KTR with glucose-lowering agents, such as sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists. Therefore, our aim was to review cardiorenal protective strategies, including the evidence, mechanisms, and rationale for the use of these glucose-lowering agents in KTR with diabetes.

Systematic Scoring of Tubular Injury Patterns Reveals Interplay between Distinct Tubular and Glomerular Lesions in ANCA-Associated Glomerulonephritis

Background: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small vessel vasculitis, most frequently presenting as microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA). Acute tubular injury with the presence of tubulitis was previously reported to be of prognostic value in ANCA glomerulonephritis (GN). In particular, distinct tubular injury lesions were associated with the deterioration of kidney function at AAV disease onset, as well as renal resistance to treatment, and higher risk of progression to composite outcome in patients with AAV. To expand our knowledge regarding distinct tubular lesions in AAV, we aimed to describe acute tubular injury patterns in association with glomerular lesions in ANCA GN by systematic histological scoring. Methods: A total number of 48 renal biopsies with confirmed renal involvement of AAV admitted to the University Medical Center Göttingen from 2015 to 2020 were retrospectively examined. By systematic scoring of tubular injury lesions, the association between clinical parameters, laboratory markers, and histopathological findings was explored. Results: We have shown that cellular casts in renal biopsies were frequently observed in the majority of cases with ANCA GN. Furthermore, we showed that tubular epithelial simplification with dilatation correlated with MPA and MPO subtypes, C3c hypocomplementemia, severe renal involvement, and uACR. Red blood cell (RBC) casts were associated with increased levels of C-reactive protein (CRP), leukocyturia, and hematuria. Finally, we found that hyaline casts were associated with an increased fraction of glomeruli with global glomerular sclerosis. Conclusions: Acute tubular injury patterns were correlated with active ANCA GN, whereas tubular injury lesions reflecting the later stages of kidney disease correlated with chronic glomerular lesions. These results suggest an interplay between different renal compartments.

Iron Metabolism: An Under Investigated Driver of Renal Pathology in Lupus Nephritis

Nephritis is a common manifestation of systemic lupus erythematosus, a condition associated with inflammation and iron imbalance. Renal tubules are the work horse of the nephron. They contain a large number of mitochondria that require iron for oxidative phosphorylation, and a tight control of intracellular iron prevents excessive generation of reactive oxygen species. Iron supply to the kidney is dependent on systemic iron availability, which is regulated by the hepcidin-ferroportin axis. Most of the filtered plasma iron is reabsorbed in proximal tubules, a process that is controlled in part by iron regulatory proteins. This review summarizes tubulointerstitial injury in lupus nephritis and current understanding of how renal tubular cells regulate intracellular iron levels, highlighting the role of iron imbalance in the proximal tubules as a driver of tubulointerstitial injury in lupus nephritis. We propose a model based on the dynamic ability of iron to catalyze reactive oxygen species, which can lead to an accumulation of lipid hydroperoxides in proximal tubular epithelial cells. These iron-catalyzed oxidative species can also accentuate protein and autoantibody-induced inflammatory transcription factors leading to matrix, cytokine/chemokine production and immune cell infiltration. This could potentially explain the interplay between increased glomerular permeability and the ensuing tubular injury, tubulointerstitial inflammation and progression to renal failure in LN, and open new avenues of research to develop novel therapies targeting iron metabolism.

Prevalence of chronic kidney disease and associated factors in the Spanish population attended in primary care: Results of the IBERICAN study

OBJECTIVES

To determine the prevalence of chronic kidney disease (CKD) and the factors associated with impaired renal function in the population attended in primary care (PC).

PATIENTS AND METHOD

Cross-sectional and multicentre study carried out in the baseline patients of the IBERICAN study (Identificación de la poBlación Española de RIesgo CArdiovascular y reNal). CKD was considered with an estimated glomerular filtration (eGF) <60ml/min/1.73 m2 or elevated albuminuria (≥ 30mg/g). According to the eGF, the CKD was classified in six stages (1, 2, 3a, 3b, 4 and 5) and according to albuminuria in three stages (A1 or normal / slightly increased, A2 or moderately increased and A3 or severely increased). The clinical characteristics and the relationship of CKD with the main cardiovascular risk factors (CVRF) and other variables of interest were analysed using unconditional logistic regression.

RESULTS

7,895 patients were included (mean age 57.9±14.8 years; 54.5% women). 14.4% (95% CI: 13.6-15.1) had CKD; 16.1% (95% CI: 14.9-17.3) in men and 12.9% (95% CI: 11.9-14.0) in women. A continuous increase of the prevalence was observed with age (24.8% in≥65 years) and with CVFR aggregation. The variables that were most associated with the probability of suffering CKD were left ventricular hypertrophy (OR: 1.95; p <.001), diabetes (OR: 1.58; P<.001) and hypertension (OR: 1.56; P<.001).

CONCLUSIONS

Fourteen out of every 100 patients included in the IBERICAN study have CKD. The prevalence of CKD affects a quarter of patients ≥ 65 years and increases exponentially with the aggregation of FRCV.

Urinary Extracellular Vesicles as a Source of NGAL for Diabetic Kidney Disease Evaluation in Children and Adolescents With Type 1 Diabetes Mellitus

BACKGROUND

Tubular damage has a role in Diabetic Kidney Disease (DKD). We evaluated the early tubulointerstitial damage biomarkers in type-1 Diabetes Mellitus (T1DM) pediatric participants and studied the correlation with classical DKD parameters.

METHODS

Thirty-four T1DM and fifteen healthy participants were enrolled. Clinical and biochemical parameters [Glomerular filtration Rate (GFR), microalbuminuria (MAU), albumin/creatinine ratio (ACR), and glycated hemoglobin A1c (HbA1c)] were evaluated. Neutrophil gelatinase-associated lipocalin (NGAL), Hypoxia-inducible Factor-1α (HIF-1α), and Nuclear Factor of Activated T-cells-5 (NFAT5) levels were studied in the supernatant (S) and the exosome-like extracellular vesicles (E) fraction from urine samples.

RESULTS

In the T1DM, 12% had MAU >20 mg/L, 6% ACR >30 mg/g, and 88% had eGFR >140 ml/min/1.72 m². NGAL in the S (NGAL-S) or E (NGAL-E) fraction was not detectable in the control. The NGAL-E was more frequent (p = 0.040) and higher (p = 0.002) than NGAL-S in T1DM. The T1DM participants with positive NGAL had higher age (p = 0.03), T1DM evolution (p = 0.03), and serum creatinine (p = 0.003) than negative NGAL. The NGAL-E correlated positively with tanner stage (p = 0.0036), the median levels of HbA1c before enrollment (p = 0.045) and was independent of ACR, MAU, and HbA1c at the enrollment. NFAT5 and HIF-1α levels were not detectable in T1DM or control.

CONCLUSION

Urinary exosome-like extracellular vesicles could be a new source of early detection of tubular injury biomarkers of DKD in T1DM patients.

Tripterygium wilfordii Hook F Treatment for Stage IV Diabetic Nephropathy: Protocol for a Prospective, Randomized Controlled Trial

BACKGROUND

Diabetic nephropathy (DN) is a major cause of chronic kidney disease (CKD). There are no effective treatments to prevent or reverse the progression of DN. A preliminary study showed that Tripterygium glycosides from Tripterygium wilfordii Hook F (TwHF) with valsartan decrease proteinuria in patients with DN.

OBJECTIVES

The objective of the present study is to investigate the efficacy and safety of Tripterygium glycosides from TwHF, a traditional Chinese medicine, for the treatment of DN. Methods and Analysis. This is a prospective, single-center randomized controlled trial. Seventy participants diagnosed with DN were recruited and randomized 1 : 1 to two groups: (1) angiotensin receptor blocker (ARB) combined with TwHF and (2) ARB-only. The treatment period is 48 weeks. The primary endpoint is 24 h proteinuria decreased level (reduction of 30% vs. baseline) after 48 weeks of treatment. The secondary endpoints are (1) all-cause and cardiovascular-related mortality, (2) development of ESRD (serum creatinine > 530.4 μmol/L or estimated glomerular filtration rate (eGFR) < 15 mL/min/1.73 m2), (3) the need for renal replacement therapy, and (4) increased serum creatinine (2-fold higher than the baseline value or ≥442 μmol/L, with confirmation of the initial results after 4 weeks). A health economics analysis will be carried out. Discussion. A meta-analysis of RCTs carried out in patients with stage 4 (Mogensen classification) diabetic CKD showed that TwHF combined with an ARB was more effective than an ARB alone when considering 24 h proteinuria and serum albumin, but with an increase in adverse event (AE) frequency of 8%. This is a prospective clinical trial that may provide information on a safe and effective novel method for the treatment of DN, especially for patients with macroproteinuria. Ethics and Dissemination. The protocol is approved by the ethics committee of Beijing Hospital (2016BJYYEC-059-02). The results will be disseminated through peer-reviewed publications and international conferences. This trial is registered with ChiCTR-IOR-17010623.

High Dietary Protein Does Not Alter Renal Prostanoids and Other Oxylipins in Normal Mice or in Those with Inherited Kidney Disease

BACKGROUND

Ex vivo studies suggest that increased renal prostanoids can mediate effects of high-protein (HP) compared with low-protein (LP) diets on normal and diseased kidneys. However, a short-term HP feeding study in normal male rats failed to demonstrate higher renal prostanoids in vivo.

OBJECTIVES

The aim of the present study was to investigate whether long-term HP feeding alters renal prostanoids in male and female mice, with and without kidney disease.

METHODS

Weanling normal mice (CD1) and mice with kidney disease (CD1-pcy/pcy mice) were fed standard diets with normal protein [NP, 20% of energy (%E)] or HP (35%E) for 13 wk. Renal disease was assessed by histomorphometric analysis of cysts and fibrosis, and measurement of serum urea nitrogen (SUN) and creatinine concentrations. Targeted analysis of renal oxylipins was performed by HPLC-MS/MS.

RESULTS

The HP diet increased kidney size and water content of normal kidneys, and worsened disease in CD1-pcy/pcy mice as indicated by higher (P < 0.05) kidney weights (8-31%), water content (8-10%), cyst volume (36-60%), fibrous volume (44-53%), and SUN (47-55%). Diseased compared with normal kidneys had higher (P < 0.05) concentrations of 6 of 11 prostanoids and lower (P < 0.05) concentrations of 33 of 54 other oxylipins. This is consistent with previously known effects of dietary HP and disease effects on the kidney. However, the HP diet did not alter renal prostanoids and other renal oxylipins in either normal or diseased kidneys (P < 0.05), despite having the expected physiological effects on normal and diseased kidneys. This study also showed that females have higher concentrations of renal prostanoids [9 of 11 prostanoids higher (P < 0.05) in females], but lower concentrations of other oxylipins [28 of 54 other oxylipins lower (P < 0.05) in females].

CONCLUSIONS

The effects of HP diets on normal and diseased kidneys in CD1 and CD1-pcy/pcy mice are independent of renal oxylipin alterations.

Pharmacotherapy of hypertension in patients with pre-dialysis chronic kidney disease

INTRODUCTION

Hypertension is the most common co-morbidity in patients with chronic kidney disease (CKD), with prevalence gradually increasing across CKD Stages to the extent that about 90% of end-stage renal disease (ESRD) patients are hypertensives. Several factors contribute to blood pressure (BP) elevation and guide the therapeutic interventions that should be employed in these patients.

AREAS COVERED

This review summarizes the existing data for the management of hypertension, regarding optimal BP targets and the use of major antihypertensive classes in patients with CKD.

EXPERT OPINION

Management of hypertension in CKD requires both lowering BP levels and reducing proteinuria to minimize the risk of both CKD progression and cardiovascular disease. In this respect, aggressive control of office BP to levels <130/80 mmHg has long been proposed for patients with proteinuric nephropathies. Following evidence from recent studies that confirmed significant reductions in renal and cardiovascular outcomes with strict BP control, most, but not all, of international guidelines, suggest such BP goals for all hypertensive patients, including those with CKD. Use of renin-angiotensin system (RAS) blockers is the treatment of choice for patients with proteinuric nephropathies, while, in most patients with CKD, combination treatment with two, three, or more antihypertensive agents is often required to control BP.

Evaluation of the efficacy and safety of TWHF in diabetic nephropathy patients with overt proteinuria and normal eGFR

BACKGROUND/PURPOSE

The aim of this study was to evaluate the efficacy and safety of Tripterygium Wilfordii Hook F (TWHF) in DN patients with overt proteinuria and normal eGFR.

METHODS

124 eligible DN patients were randomly assigned into two groups to receive either valsartan 160 mg/d treatment (control group) or TWHF 60 mg/d plus valsartan 160 mg/d treatments (TWHF group) for 24 weeks. The changes of clinical, biochemical data and adverse events during observation period were all analyzed. The primary endpoint was a reduction in 24-h urine protein excretion between baseline and the end of study, the secondary endpoint was to observe the change in estimated glomerular filtration rate (eGFR) between two groups.

RESULTS

After treatment, there was a more significant decrease in proteinuria in patients who received TWHF treatment (from 4.95 ± 1.27 g/24 h to 3.36 ± 0.83 g/24 h) compared to valsartan monotherapy (from 5.21 ± 1.59 g/24 h to 4.52 ± 1.06 g/24 h). The percentage change in urine protein excretion was -32.12% in TWHF group and -13.24% in valsartan group. Patients' plasma albumin in TWHF group (from 32.53 ± 5.24 g/L to 36.91 ± 4.42 g/L) was higher than that in control group (from 33.18 ± 4.87 g/L to 34.67 ± 4.75 g/L). No significant change in blood pressure, blood glucose, eGFR, and serum potassium was observed. But the adverse events in TWHF group were higher than those in control group.

CONCLUSION

TWHF is more effective than valsartan monotherapy in reduction of proteinuria in DN patients with overt proteinuria and normal eGFR, but with more adverse effects.

Defining Disease Progression and Drug Durability in Type 2 Diabetes Mellitus

This communication shares insights into the definition of disease progression and drug durability in type 2 diabetes. Disease progression may be defined as gradual worsening of beta-cell function, clinically observed as an increase in drug dosage, drug frequency or number of glucose lowering drugs needed to maintain HbA1c control; and/or a ≥0.5% rise in HbA1c, unexplained by acute, modifiable factors, while using the same drug regimen; and/or as the occurrence or worsening of cardiovascular or microvascular complications, in spite of standard care, over a pre-specified time period. Durability of a drug or a drug combination may be defined as its ability to postpone or delay progression of disease, in a safe and well tolerated manner. Thus, all drugs that are able to prevent disease progression (i.e., postpone loss of glycaemic control, need for intensification of therapy or onset or worsening of complications) may be termed ‘durable’.

Clinical Efficacy and Safety of Jinshuibao Combined With ACEI/ARB in the Treatment of Diabetic Kidney Disease: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The present study aims to compare the relative efficacy and safety of jinshuibao (JSB) combined with angiotensinconverting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs) in the treatment of diabetic kidney disease.

METHODS

We searched EMBASE, MEDLINE, PubMed, China National Knowledge Internet, the Chinese Biomedical Database, and Wanfang database for articles from the building of the database to September 2018.

RESULTS

Fifty-one randomized controlled trials with 3,955 participants were included. The meta-analysis indicated that compared with the controls, JSB combined with ACEI/ARB group could remarkably improve the overall response rate (odds ratio 4.91; 95% confidence interval [CI] 3.32-7.25) and reduce 24 h proteinuria (mean difference [MD] -0.16; 95% CI -0.19 to -0.13), urine albumin excretion ratio (MD -28.20; 95% CI -36.30 to -20.11), serum creatinine (MD -13.84; 95% CI -18.01 to -9.68), blood urea nitrogen (MD -1.00; 95% CI -1.36 to -0.63), systolic blood pressure (MD -4.57; 95% CI -6.78 to -2.37), diastolic blood pressure (MD -3.96; 95% CI -5.73 to -2.19), fasting blood glucose (MD -0.85; 95% CI -1.45 to -0.24), hemoglobin A1c (MD -0.52; 95% CI -0.83 to -0.21), serum total cholesterol (MD -0.53; 95% CI -0.86 to -0.20), and triglyceride (MD -0.53; 95% CI -0.55 to -0.51).

CONCLUSIONS

JSB combined with ACEI/ARB in the treatment of diabetic kidney disease is superior to the single application of ACEI/ARB.

Meta-Analysis of Diagnostic Accuracy of Retinopathy for the Detection of Diabetic Kidney Disease in Adults With Type 2 Diabetes

OBJECTIVES

The study aimed to explore whether diabetic retinopathy (DR) could distinguish diabetic kidney disease (DKD) from nondiabetic renal diseases (NDRDs) in patients with type 2 diabetes mellitus and renal disease.

METHODS

We searched PubMed, Embase, Cochrane, MEDLINE and China National Knowledge Internet for articles that enrolled patients with DKD and NDRD. The results were summarized as sensitivity, specificity and the area under the curve of summary receiver operating characteristic curve with their 95% confidence intervals (CIs).

RESULTS

A total of 51 studies that included 4,990 participants were collected for evaluation. The overall pooled sensitivity, specificity and area under the curve with their 95% CIs were 0.67 (95% CI 0.61, 0.73), 0.77 (95% CI 0.72, 0.81) and 0.78 (95% CI 0.75 to 0.82), respectively. If the test for DR is negative, the probability of DKD would decrease to 10%, but if the test for DR is positive, the probability would increase only to 42%. In addition, although the mean specificity of proliferative DR for detection of DKD was 0.98 (95% CI 0.92 to 1.00), the mean sensitivity was 0.25 (95% CI 0.16, 0.35).

CONCLUSIONS

DR may lack adequate evidence either to verify DKD or to exclude NDRD, and the severity of DR may not parallel the presence of DKD.

The relationships between markers of tubular injury and intrarenal haemodynamic function in adults with and without type 1 diabetes: Results from the Canadian Study of Longevity in Type 1 Diabetes

OBJECTIVE

Our aim was to define the relationships between plasma biomarkers of kidney injury and intrarenal haemodynamic function (glomerular filtration rate [GFR], effective renal plasma flow [ERPF], renal vascular resistance [RVR]) in adults with type 1 diabetes (T1D).

METHODS

The study sample comprised patients with longstanding T1D (duration ≥50 years), among whom 44 were diabetic kidney disease (DKD) resistors (eGFR >60 mL/min/1.73 m² and <30 mg/d urine albumin excretion) and 22 had DKD, in addition to 73 control participants. GFR_INULIN and ERPF_PAH were measured, RVR was calculated, and afferent (R_A )/efferent (R_E ) areteriolar resistances were derived from Gomez equations. Plasma neutrophil gelatinase-associated lipocalin (NGAL), β2 microglobulin (B2M), osteopontin (OPN) and uromodulin (UMOD) were measured using immunoassay kits from Meso Scale Discovery.

RESULTS

Plasma NGAL, B2M and OPN were higher and UMOD was lower in DKD patients vs DKD resistors and non-diabetic controls. In participants with T1D, plasma NGAL inversely correlated with GFR (r = -0.33; P = 0.006) and ERPF (r = -0.34; P = 0.006), and correlated positively with R_A (r = 0.26; P = 0.03) and RVR (r = 0.31; P = 0.01). In participants without T1D, NGAL and B2M inversely correlated with GFR (NGAL r = -0.18; P = 0.13 and B2M r = -0.49; P < 0.0001) and with ERPF (NGAL r = -0.19; P = 0.1 and B2M r = -0.42; P = 0.0003), and correlated positively with R_A (NGAL r = 0.19; P = 0.10 and B2M r = 0.3; P = 0.01) and with RVR (NGAL r = 0.20; P = 0.09 and B2M r = 0.34; P = 0.003). Differences were significant after adjusting for age, sex, HbA1c, SBP and LDL. There were statistical interactions between T1D status, B2M and intrarenal haemodynamic function (P < 0.05).

CONCLUSIONS

Elevated NGAL relates to intrarenal haemodynamic dysfunction in T1D, whereas elevated NGAL and B2M relate to intrarenal haemodynamic dysfunction in adults without T1D. These data may define a diabetes-specific interplay between tubular injury and intrarenal haemodynamic dysfunction.

Clinical efficacy and safety of Tripterygium wilfordii Hook in the treatment of diabetic kidney disease stage IV: A meta-analysis of randomized controlled trials

BACKGROUND

The present study aims to evaluate the clinical efficacy and safety of Tripterygium wilfordii Hook (TwH) combined with angiotensin receptor blockers/ACE inhibitors (ARB/ACEI) in the treatment of diabetic kidney disease (DKD) stage IV.

METHODS

We searched China National Knowledge Internet (CNKI), the Chinese Biomedical Database, Embase and PubMed for articles about TwH combined with ARB/ACEI in treating DKD stage IV and set the study inclusion and elimination standards.

RESULTS

A total of 22 randomized controlled trials (RCTs) with 1414 participants were collected for detailed evaluation. The meta-analysis results suggested that compared with the controls, the combined group showed significant effects in reducing 24-h urinary protein [mean difference (MD) = -0.87, 95% confidence interval (CI) = (-1.03, -0.71)], raising serum albumin [MD = 4.14, 95% CI (3.43, 4.85)] and the total efficiency [odds ratio (OR) = 4.84, 95% CI (3.33, 7.03)], with no statistical difference in serum creatinine between both groups [MD = -3.02, 95% CI (-6.40, 0.37), P > .05]. However, the risk of adverse reactions increased by 8% [Risk Difference (RD) = 0.08, 95% CI (0.05, 0.11)] in the combination.

CONCLUSIONS

TwH combined with ARB/ACEI in the treatment of DKD stage IV is superior to the monotherapy of ARB/ACEI.

Insulin resistance and chronic kidney disease progression, cardiovascular events, and death: findings from the chronic renal insufficiency cohort study

BACKGROUND

Insulin resistance contributes to the metabolic syndrome, which is associated with the development of kidney disease. However, it is unclear if insulin resistance independently contributes to an increased risk of chronic kidney disease (CKD) progression or CKD complications. Additionally, predisposing factors responsible for insulin resistance in the absence of diabetes in CKD are not well described. This study aimed to describe factors associated with insulin resistance and characterize the relationship of insulin resistance to CKD progression, cardiovascular events and death among a cohort of non-diabetics with CKD.

METHODS

Data was utilized from Chronic Renal Insufficiency Cohort Study participants without diabetes (N = 1883). Linear regression was used to assess associations with insulin resistance, defined using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). The relationship of HOMA-IR, fasting glucose, hemoglobin A1c (HbA1c), and C-peptide with CKD progression, cardiovascular events, and all-cause mortality was examined with Cox proportional hazards models.

RESULTS

Novel positive associations with HOMA-IR included serum albumin, uric acid, and hemoglobin A1c. After adjustment, HOMA-IR was not associated with CKD progression, cardiovascular events, or all-cause mortality. There was a notable positive association of one standard deviation increase in HbA1c with the cardiovascular endpoint (HR 1.16, 95% CI: 1.00-1.34).

CONCLUSION

We describe potential determinants of HOMA-IR among a cohort of non-diabetics with mild-moderate CKD. HOMA-IR was not associated with renal or cardiovascular events, or all-cause mortality, which adds to the growing literature describing an inconsistent relationship of insulin resistance with CKD-related outcomes.

Secondary hypertension in patients with saccular intracranial aneurysm disease: A population based study

Background

Secondary hypertension is a serious form of hypertension, involving 5% to 10% of all hypertension patients. Hypertension is a risk factor of the saccular intracranial aneurysm (sIA) disease and subarachnoid hemorrhage from ruptured sIA (aSAH), but the impact of secondary hypertension on sIA disease is poorly known. In a defined Eastern Finnish sIA population we studied the prevalence of secondary hypertension and its impact on sIA disease phenotype.

Methods

We included 2704 consecutive sIA patients first admitted to Kuopio University Hospital from 1995 to 2014. Their clinical data from Kuopio Intracranial Aneurysm patient and Family Database was fused with prescription drug usage data, hospital diagnoses and causes of death, retrieved from nationwide registries. Medical records of hypertensive sIA patients were reviewed to confirm or exclude secondary hypertension. Prevalence of secondary hypertension and associated diagnoses were calculated. Logistic regression was used to identify clinical characteristics of sIA disease that associated with secondary hypertension.

Results

We identified 2029 (75%) sIA patients with hypertension and 208 (10%) of them had secondary hypertension. Most frequent conditions associated with secondary hypertension were kidney and renovascular diseases (45%), sleep apnea (27%) and hypothyroidism (19%); 46 (22%) of the 208 patients had more than one such condition. In multivariate logistic regression analyses of 1561 aSAH patients, secondary hypertension significantly associated with the number of sIAs (p = 0.003; OR 1.32; 95% CI 1.10–1.58) and male gender (p = 0.034; OR 1.59; 95% CI 1.04–2.43).

Conclusions

Secodary hypertension was relatively common (10%) among hypertensive sIA patients. Secondary causes for hypertension should be taken into account in hypertensive sIA patients, especially in aSAH patients with multiple intracranial aneurysms. Further research is indicated to evaluate the impact of secondary hypertension on the long-term rupture risk of unruptured sIA carriers and long-term outcome after aSAH.

Hospital admissions for severe infections in people with chronic kidney disease in relation to renal disease severity and diabetes status

BACKGROUND

Immunosuppressive agents are being investigated for the treatment of chronic kidney disease (CKD) but may increase risk of infection. This was a retrospective observational study intended to evaluate the risk of hospitalized infection in patients with CKD, by estimated glomerular filtration rate (eGFR) and proteinuria status, aiming to identify the most appropriate disease stage for immunosuppressive intervention.

METHODS

Routine UK primary-care and linked secondary-care data were extracted from the Clinical Practice Research Datalink. Patients with a record of CKD were identified and grouped into type 2, type 1 and nondiabetes cohorts. Time-dependent, Cox proportional hazard models were used to determine the likelihood of hospitalized infection.

RESULTS

We identified 97 839 patients with a record of CKD, of these 11 719 (12%) had type 2 diabetes. In these latter patients, the adjusted hazard ratios (aHR) were 1.00 (95% CI: 0.80-1.25), 1.00, 1.03 (95% CI: 0.92-1.15), 1.36 (95% CI: 0.20-1.54), 1.82 (95% CI: 1.54-2.15) and 2.41 (95% CI: 1.60-3.63) at eGFR stages G1, G2 (reference), G3a, G3b, G4 and G5, respectively; and 1.00, 1.45 (95% CI: 1.29-1.63) and 1.91 (95% CI: 1.67-2.20) at proteinuria stages A1 (reference), A2 and A3, respectively. All aHRs (except G1 and G3a) were significant, with similar patterns observed within the non-DM and overall cohorts.

CONCLUSIONS

eGFR and degree of albuminuria were independent markers of hospitalized infection in both patients with and without diabetes. The same patterns of hazard ratios of eGFR and proteinuria were seen in CKD patients regardless of diabetes status, with the risk of each outcome increasing with a decreasing eGFR and increasing proteinuria. Infection risk increased significantly from eGFR stage G3b and proteinuria stage A2 in type 2 diabetes. Treating type 2 DM patients with CKD at eGFR stages G1-G3a with immunosuppressive therapy may therefore provide a favourable risk-benefit ratio (G1-G3a in type 2 diabetes; G1-G2 in nondiabetes and overall cohorts) although the degree of proteinuria needs to be considered.

Role of melatonin receptor 1A and pituitary homeobox-1 coexpression in protecting tubular epithelial cells in membranous nephropathy

Membranous nephropathy (MN), a type of glomerular nephritis, is one of the most common causes of nephrotic syndrome in adults. Although it is known that melatonin plays a protective role in MN, the role of melatonin receptors in the pathophysiology of MN is unclear. Using an experimental MN model and clinical MN specimens, we studied melatonin receptor expression and found that melatonin receptor 1A (MTNR1A) expression was significantly downregulated in renal tubular epithelial cells. Molecular studies showed that the transcription factor pituitary homeobox-1 (PITX1) promoted MTNR1A expression via direct binding to its promoter. Treatment of a human tubular cell line with albumin to induce injury resulted in the stable reduction in MTNR1A and PITX1 expression. PITX1 levels were significantly downregulated in tubular epithelial cells from mice MN kidneys and MN renal specimens. Knockdown of MTNR1A, PITX1, or cyclic adenosine monophosphate-responsive element-binding protein (CREB) decreased E-cadherin (CDH1) expression, but upregulated Per2 and α-smooth muscle actin (αSMA) expression. Blockade of the MTNR1A receptor with luzindole in MN mice further impaired renal function; this was accompanied by CDH1 downregulation and Per2 and αSMA upregulation. Together, our results suggest that in injured tissue, decreased PITX1 expression at the MTNR1A promoter regions leads to decreased levels of MTNR1A in renal tubular epithelial cells, which increases the future risk of MN.

Role of (pro)renin receptor in albumin overload-induced nephropathy in rats

Proteinuria is not only a common feature of chronic kidney diseases (CKD) but also an independent risk factor promoting CKD progression to end-stage renal failure. However, the underlying molecular mechanisms for protein overload-induced renal injury remain elusive. The present study examined the role of (pro)renin receptor (PRR) in pathogenesis of albumin overload (AO)-induced nephropathy and activation of the intrarenal renin-angiotensin system (RAS) in rats. Wistar rats underwent unilateral nephrectomy and were treated for 7 wk with vehicle, bovine serum albumin (5 g·kg^-1·day^-1 via a single ip injection), alone or in conjunction with the PRR decoy inhibitor PRO20 (500 μg·kg^-1·day^-1 via 3 sc injections). The AO rat model exhibited severe proteinuria, tubular necrosis, and interstitial fibrosis, oxidative stress, and inflammation, accompanied by elevated urinary N-acetyl-β-d-glucosaminidase activity and urinary β₂-microglobulin secretion, all of which were significantly attenuated by PRO20. Urinary and renal levels of renin, angiotensinogen, and ANG II were elevated by AO and suppressed by PRO20, contrasting to largely unaltered plasma levels of the RAS parameters. The AO model also showed increased renal expression of full-length PRR and soluble PRR (sPRR) and urinary excretion of sPRR. Taken together, we conclude that PRR antagonism with PRO20 alleviates AO-induced nephropathy via inhibition of intrarenal RAS.

Thymosin β4 Deficiency Exacerbates Renal and Cardiac Injury in Angiotensin-II-Induced Hypertension

Thymosin β4 (Tβ4), a ubiquitous peptide, regulates several cellular processes that include cell morphology, wound healing, and inflammatory response. Administration of exogenous Tβ4 is protective in diabetic nephropathy and in a unilateral ureteral obstruction model. However, the role of endogenous Tβ4 in health and disease conditions remains unclear. To elucidate the pathophysiological role of endogenous Tβ4 in hypertension, we examined angiotensin-II (Ang-II)-induced renal and cardiac damage in Tβ4 knockout (Tβ4 KO) mice. Tβ4 KO and wild-type C57BL/6 mice were infused continuously for 6 weeks with either vehicle or Ang-II (980 ng/kg per minute). At baseline, Tβ4 deficiency did not affect renal and cardiac function. Systolic blood pressure in the Ang-II group was similar in wild-type and Tβ4 KO mice (wild-type Ang-II, 179.25±10.11 mm Hg; Tβ4 KO Ang-II, 169.81±6.54 mm Hg). Despite the similar systolic blood pressure after Ang-II infusion, Tβ4-deficient mice had dramatically increased albuminuria and decreased nephrin expression in the kidney (P<0.005). In the heart of Tβ4 KO mice, Ang-II reduced ejection fraction and shortening fraction (ejection fraction: wild-type Ang-II 77.95%±1.03%; Tβ4 KO Ang-II 62.58%±3.25%; P<0.005), which was accompanied by cardiac hypertrophy and left ventricular dilatation. In addition, renal and cardiac infiltration of CD68 macrophages, intercellular adhesion molecule-1, and total collagen content were increased after Ang-II infusion in Tβ4 KO mice (P<0.005). Overall, our data indicate that endogenous Tβ4 is crucial in preventing tissue injury from Ang-II-induced hypertension. This study gives new insights into the protective role of endogenous Tβ4 in hypertensive end-organ damage.

Markers of early progressive renal decline in type 2 diabetes suggest different implications for etiological studies and prognostic tests development

To identify determinants of early progressive renal decline in type 2 diabetes a range of markers was studied in 1032 patients enrolled into the 2nd Joslin Kidney Study. eGFR slopes estimated from serial measurements of serum creatinine during 5-12 years of follow-up were used to define early renal decline. At enrollment, all patients had normal eGFR, 58% had normoalbuminuria and 42% had albuminuria. Early renal decline developed in 6% and in 18% patients, respectively. As determinants, we examined baseline values of clinical characteristics, circulating markers: TNFR1, KIM-1, and FGF23, and urinary markers: albumin, KIM-1, NGAL, MCP-1, EGF (all normalized to urinary creatinine) and the ratio of EGF to MCP-1. In univariate analysis, all plasma and urinary markers were significantly associated with risk of early renal decline. When analyzed together, systolic blood pressure, TNFR1, KIM-1, the albumin to creatinine ratio, and the EGF/MCP-1 ratio remained significant with the latter having the strongest effect. Integration of these markers into a multi-marker prognostic test resulted in a significant improvement of discriminatory performance of risk prediction of early renal decline, compared with the albumin to creatinine ratio and systolic blood pressure alone. However, the positive predictive value was only 50% in albuminuric patients. Thus, markers in plasma and urine indicate that the early progressive renal decline in Type 2 diabetes has multiple determinants with strong evidence for involvement of tubular damage. However, new, more informative markers are needed to develop a better prognostic test for such decline that can be used in a clinical setting.

Oligonephronia and Wolf-Hirschhorn syndrome: A further observation

Wolf-Hirschhorn syndrome (WHS) is a rare chromosomal disorder caused by a partial deletion of chromosome 4 (4p16.3p16.2). We describe a case of a male 9 years old children with WHS proteinuria and hypertension. Laboratory data showed creatinine 1.05 mg/dl, GFR 65.9 ml/min/1.73 m² , cholesterol 280 mg/dl, triglyceride 125 mg/dl with electrolytes in the normal range. Urine collection showed protein 2.72 g/L with a urine protein/creatinine ratio (U_P /U_Cr ratio) of 4.2 and diuresis of 1,100 ml. Renal ultrasound showed reduced kidney dimensions with diffusely hyperechogenic cortex and poorly visualized pyramids. Renal biopsy showed oligonephronia with focal segmental glomerulosclerosis associated with initial tubulointerstitial sclerotic atrophy. The child began therapy with Angiotensin-converting enzyme inhibitors (ACE-inhibitors) to reduce proteinuria and progression of chronic kidney disease. In the literature the anomalies of number of glomeruli oligonephronia and oligomeganephronia (OMN) are described in two forms, one without any associated anomalies, sporadic, and solitary and the other with one or more anomalies. Our review of the literature shows that the pathogenesis of this anomaly is unknown but the role of chromosome 4 is very relevant. Many cases of OMN are associated with anomalies on this chromosome, in the literature cases series we observed this association in 14/48 cases (29.2%) and in 7 of these 14 cases with WHS. Our case and the review of literature demonstrate how periodic urinalysis and renal ultrasound monitoring is recommended in patients affected by WHS and the renal biopsy must be performed when there is the onset of proteinuria.

A more tubulocentric view of diabetic kidney disease

Diabetic nephropathy (DN) is a common complication of Diabetes Mellitus (DM) Types 1 and 2, and prevention of end stage renal disease (ESRD) remains a major challenge. Despite its high prevalence, the pathogenesis of DN is still controversial. Initial glomerular disease manifested by hyperfiltration and loss of glomerular size and charge permselectivity may initiate a cascade of injuries, including tubulo-interstitial disease. Clinically, 'microalbuminuria' is still accepted as an early biomarker of glomerular damage, despite mounting evidence that its predictive value for DN is questionable, and findings that suggest the proximal tubule is an important link in the development of DN. The concept of 'diabetic tubulopathy' has emerged from recent studies, and its causative role in DN is supported by clinical and experimental evidence, as well as plausible pathogenetic mechanisms. This review explores the 'tubulocentric' view of DN. The recent finding that inhibition of proximal tubule (PT) glucose transport (via SGLT2) is nephro-protective in diabetic patients is discussed in relation to the tubule's potential role in DN. Studies with a tubulocentric view of DN have stimulated alternative clinical approaches to the early detection of diabetic kidney disease. There are tubular biomarkers considered as direct indicators of injury of the proximal tubule (PT), such as N-acetyl-β-D-glucosaminidase, Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1, and other functional PT biomarkers, such as Urine free Retinol-Binding Protein 4 and Cystatin C, which reflect impaired reabsorption of filtered proteins. The clinical application of these measurements to diabetic patients will be reviewed in the context of the need for better biomarkers for early DN.

[Membranous nephropathy in a Russian population]

AIM

To analyze the clinical and morphological manifestations of membranous nephropathy (MN) and to evaluate the efficiency of its therapy.

MATERIAL AND METHODS

MN cases in 2009 to 2016 were retrospectively detected with a subsequent analysis of patients with primary MN (PMN). The titer of IgG-autoantibodies to phospholipase A2 receptor (anti-PLA2R Ab) was determined by an indirect immunofluorescence assay. Treatment outcomes, such as the time course of changes in proteinuria, nephrotic syndrome (NS), and the development of complete and partial remissions (CR and PR), were assessed.

RESULTS

MN was detected in 201 cases; the secondary etiology of the disease was established in 24.9%. The prevalence of MN among morphologically confirmed glomerulopathies was 14%; that of PMN was 10.4%. The median period to diagnosis PMN was 8 (5; 19) months. 150 patients with PMN (66.7% were men; age was 50±15 years) were distributed according to the following morphological stages: Stages I (23.9%), II (48.5%), III (26.1%), and IV (1.5%). Elevated anti-PLA2R Ab levels were found in 51.6% of cases; NS in the presence of proteinuria was detected in 85.6% of patients. An estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 was seen in 25% of cases. Treatment outcomes were evaluated in 80 cases; the median follow-up period was 19 (8; 40) months. 68% of cases had CR (32%) or PR (36%) with a median follow-up of 26 (13; 44) months. Spontaneous CRs or PRs were observed in 7.5% of the patients. Multivariate analysis showed that the probability of CR or PR increased 3.2-fold in the use of cyclophosphamide and/or cyclosporine and decreased as eGFR dropped.

CONCLUSION

In Russia, PMN is a common type of glomerulopathy, the specific features of which should include the low rates of spontaneous remissions and detection of anti-PLA2R Abs. For renal protection, the majority of patients with PMN require timely diagnosis and treatment; individualization of the choice of treatment and its enhanced efficiency call for further investigations.

Clinical study on Yishen Qufeng Shengshi Recipe () for glomerular proteinuria patients: A randomized controlled trial

OBJECTIVE

To explore the therapeutic effect of Yishen Qufeng Shengshi Recipe (, YQSR) in patients with glomerular proteinuria METHODS: A total of 145 patients with glomerular proteinuria were selected and randomly assigned to the treatment group (108 cases) and the control group (37 cases) according to a random number table in a ratio of 3:1. All patients received conventional and symptomatic treatment. In addition, patients in the treatment and control groups were given YQSR (200 mL, twice per day, orally) and losartan (50 mg/d orally), respectively for 6 months. The 24-h urine protein quantity, blood urea nitrogen, and serum creatinine in the two groups were measured at multiple time points before and after treatment.

RESULTS

At the end of the study, 5 cases were lost to follow-up in the treatment group and 1 in the control group. Finally, the statistical data included 103 cases in the treatment group and 36 cases in the control group. The total effectiveness after 2, 4, and 6 months was 81.6% (84/103), 87.4% (90/103), and 92.2% (95/103), respectively, in the treatment group and 47.2% (17/36), 55.6% (20/36), and 61.1% (22/36), respectively, in the control group, with significant difference between the two groups (P<0.01 at all observation points). In the treatment group, the curative effect after 6 months was better than that after 2 months (P<0.05). The 24-h urine protein quantity was significantly lower in the treatment group at 3, 4, 5, and 6 months than that in the control group (P<0.05 or P<0.01, respectively) CONCLUSION: YQSR could significantly reduce the amount of glomerular proteinuria in the early stage.

HIV as a Cause of Immune Activation and Immunosenescence

Systemic immune activation has emerged as an essential component of the immunopathogenesis of HIV. It not only leads to faster disease progression, but also to accelerated decline of overall immune competence. HIV-associated immune activation is characterized by an increase in proinflammatory mediators, dysfunctional T regulatory cells, and a pattern of T-cell-senescent phenotypes similar to those seen in the elderly. These changes predispose HIV-infected persons to comorbid conditions that have been linked to immunosenescence and inflamm-ageing, such as atherosclerosis and cardiovascular disease, neurodegeneration, and cancer. In the antiretroviral treatment era, development of such non-AIDS-defining, age-related comorbidities is a major cause of morbidity and mortality. Treatment strategies aimed at curtailing persistent immune activation and inflammation may help prevent the development of these conditions. At present, the most effective strategy appears to be early antiretroviral treatment initiation. No other treatment interventions have been found effective in large-scale clinical trials, and no adjunctive treatment is currently recommended in international HIV treatment guidelines. This article reviews the role of systemic immune activation in the immunopathogenesis of HIV infection, its causes and the clinical implications linked to immunosenescence in adults, and the therapeutic interventions that have been investigated.

Abolishment of proximal tubule albumin endocytosis does not affect plasma albumin during nephrotic syndrome in mice

The megalin/cubilin receptor complex is required for proximal tubular endocytosis and degradation of filtered albumin. An additional high-capacity retrieval pathway of intact albumin for the recovery of large amounts of filtered albumin has been proposed, possibly involving cooperation between megalin/cubilin and the neonatal Fc receptor. To clarify the potential role of such a pathway, we examined the effects of megalin/cubilin gene inactivation on tubular albumin uptake and plasma albumin levels in nephrotic, podocin knockout mice. Immunofluorescence microscopy of megalin/cubilin/podocin knockout mouse kidneys demonstrated abolishment of proximal tubule albumin uptake, in contrast to the excessive albumin accumulation observed in podocin knockout mice compared to controls. Correspondingly, urinary albumin excretion was increased 1.4 fold in megalin/cubilin/podocin compared to podocin knockout mice (albumin/creatinine: 226 vs. 157 mg/mg). However, no difference in plasma albumin levels was observed between megalin/cubilin/podocin and podocin knockout mice, as both were reduced to approximately 40% of controls. There were no differences in liver albumin synthesis by mRNA levels and protein abundance. Thus, megalin/cubilin knockout efficiently blocks proximal tubular albumin uptake in nephrotic mice but plasma albumin levels did not differ as a result of megalin/cubilin-deficiency, suggesting no significance of the megalin/cubilin-pathway for albumin homeostasis by retrieval of intact albumin.

Retrospective Comparison of Estimated GFR using 2006 MDRD, 2009 CKD-EPI and Cockcroft-Gault with 24 Hour Urine Creatinine Clearance

INTRODUCTION

The assessment of Glomerular Filtration Rate (GFR) is essential for clinical practice in assessing kidney function, drug dosing, detecting and estimating the prognosis of Chronic Kidney Disease (CKD). The most common practical method for assessing GFR is performed with a 24 hour/timed urine collection for creatinine clearance evaluation. The estimation of eGFR by creatinine based formulae is known to be a rapid and reliable means of approximation of creatinine clearance.

AIM

To compare eGFR using three commonly used Formulae {Modification of Diet in Renal Disease Study Equation (MDRD 2006), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI 2009) and Cockcroft-Gault Formula} with 24 hour creatinine clearance and to identify which amongst the 3 formulae for eGFR closely correlates with 24 hour creatinine clearance in a secondary care hospital.

MATERIALS AND METHODS

We retrospectively collected laboratory data requested for 24 hour creatinine clearance in the period from January 2014 to August 2016. Totally 91 laboratory request for 24 hour creatinine clearance data were obtained. The paired-t-test was used for comparison since all parameters used in the study were numerical, all patients came from same population and all had paired results.

RESULTS

The eGFR by MDRD formulae had a statistically insignificant p-value (p > 0.05) i.e., good approximation in the II^nd, III^rd, IV^th and V^th stages of CKD on comparison with 24 hour creatinine clearance. The eGFR by CKD-EPI formulae had a statistically insignificant p-value (p > 0.05) in the II^nd, IV^th and V^th stages of CKD. The eGFR by Cockcroft-Gault Formulae had a statistically insignificant p-value (p > 0.05) in the I^st, II^nd and V^th stages of CKD.

CONCLUSION

The Creatinine based GFR estimation provides a more accurate assessment of 24 hour creatinine clearance and kidney function than measuring serum creatinine alone but have certain limitations in few clinical circumstances. No single equation will be optimal for all populations. But the result of this study showed MDRD 2006 formulae to be more accurate than CKD-EPI 2009 and Cockcroft-Gault formulae in estimating GFR, detection of CKD, drug dosing and estimating prognosis.

Protective effect of 1α,25-dihydroxyvitamin D3 on effector CD4+ T cell induced injury in human renal proximal tubular epithelial cells

Background

The aim of this study was to investigate the protective effect of 1α,25-dihydroxyvitamin D3 [1,25(OH)₂D3] on effector CD4⁺ T cells or on inflammatory cytokine-induced injury in human renal proximal tubular epithelial cells (HRPTEpiC).

Methods

First, we investigated the effect of 1,25(OH)₂D3 on CD4⁺ T cell proliferation. Second, we examined the effect of 1,25(OH)₂D3 on inflammatory cytokine secretion or fibrosis in HRPTEpiC induced by inflammatory cytokines or activated CD4⁺ T cells using ELISA and real-time PCR. Lastly, we compared urine inflammatory-cytokine (IL-6, IL-8) or KIM-1 levels in kidney transplant recipients low serum 25-hydroxyvitamin D (25(OH)D) group (< 20 ng/mL) (n = 40) and normal 25(OH)D group (n = 50).

Results

Pre-incubation with 1,25(OH)₂D3 significantly reduced the percentages of Th1 and Th17 cells compared to that of Th0 condition (P < 0.05 for each). In contrast, 1,25(OH)₂D3 increased the proportion of Th2 and Treg cells in a dose-dependent manner (P < 0.05 for each). Treatment of HRPTEpiC with inflammatory cytokines (TNF-α, IL-17, and TGF-β) or effector CD4⁺ T cells resulted in increased production of IL-6, IL-8, or KIM-1 from HRPTEpiC in a dose-dependent manner. However, treatment with 1,25(OH)₂D3 significantly reduced the level of these cytokines (P < 0.05 for all). Western blot analysis demonstrated that the mTOR/STAT3/ERK pathway was downregulated by 1,25(OH)₂D3 in HRPTEpiC. Furthermore, the concentrations of urine IL-6/creatinine (P < 0.05) and Kim-1/creatinine (P < 0.05) were higher in the low 25(OH)D group than in the normal 25(OH)D group in kidney transplant recipients.

Conclusion

The results of this study suggests that vitamin D may have a significant role in the regulation of inflammation in allograft tissue in kidney transplant recipients.

Trial registration

All participants provided written informed consent in accordance with the Declaration of Helsinki. This study was approved by the Institutional Review Board of Seoul St. Mary’s Hospital (KC13TNMI0701).

Glycosuria and Renal Outcomes in Patients with Nondiabetic Advanced Chronic Kidney Disease

Sodium glucose cotransporter 2 inhibitors have shown a potential for renoprotection beyond blood glucose lowering. Glycosuria in nondiabetic patients with chronic kidney disease (CKD) is sometimes noted. Whether glycosuria in CKD implies a channelopathy or proximal tubulopathy is not known. The consequence of glycosuria in CKD is also not studied. We performed a cross-sectional study for the association between glycosuria and urine electrolyte excretion in 208 nondiabetic patients. Fractional excretion (FE) of glucose >4% was 3.4%, 6.3% and 62.5% in CKD stage 3, 4 and 5, respectively. These patients with glycosuria had higher FE sodium, FE potassium, FE uric acid, UPCR, and urine NGAL-creatinine ratio. We conducted a longitudinal study for the consequence of glycosuria, defined by dipstick, in 769 nondiabetic patients with stage 4-5 CKD. Glycosuria was associated with a decreased risk for end-stage renal disease (adjusted hazard ratio: 0.77; CI = 0.62-0.97; p = 0.024) and for rapid renal function decline (adjusted odds ratio: 0.63; CI = 0.43-0.95; p = 0.032); but glycosuria was not associated with all-cause mortality or cardiovascular events. The results were consistent in the propensity-score matched cohort. Glycosuria is associated with increased fractional excretion of electrolytes and is related to favorable renal outcomes in nondiabetic patients with stage 5 CKD.

Relative antihypertensive and glomeruloprotective efficacies of enalapril and candesartan cilexetil in the remnant kidney model

The present studies were performed to investigate whether the differences described between the two modalities for interruption of the renin-angiotensin-aldosterone system (RAAS), angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin AT 1receptor antagonists (AIIA) result in differences in renoprotective efficacy in the rat remnant kidney model. Male Sprague-Dawley rats with an initial body weight of 225—300 g, underwent 5/6 renal ablation and had radiotransmitters installed for radiotelemetric blood pressure (BP) measurements, owing to the known limitations of periodic tail-cuff BP measurements to adequately reflect ambient BP profiles. After renal ablation surgery, the rats received no treatment (n=10); enalapril (n=11) or candesartan (n=9) after the first week, both administered initially at a dose of 50 mg/l of drinking water (~10 mg/kg). However, the dose of candesartan had to be reduced to 10—25 mg/l in 4/9 rats to avoid excessive hypotension. Both enalapril and candesartan produced significant reductions in average systolic BP during the subsequent approximately six weeks of observations as compared with untreated rats (187±4 mmHg, p<0.001), but candesartan was significantly more effective at these relative doses (121±3 vs. 133±4 mmHg, p<0.05). At approximately seven weeks, serum creatinine and proteinuria were measured before sacrifice for morphologic assessment of percentage glomerulosclerosis (GS). Despite the described differences between ACE-I and AIIA after acute administration, the percentage GS was reduced similarly by enalapril (down to 6.8±2.8%) and candesartan (down to 2.9±1.5%) as compared with untreated rats (37.2±4.3%). Moreover, GS in individual animals paralleled the BP reductions achieved. Proteinuria was reduced in parallel to the decrease in % GS. These data indicate that, at least in the 5/6 renal ablation model, RAAS blockade by either ACE-I or AIIA provides protection by BPdependent rather than BP-independent mechanisms. This may reflect the primarily hypertensive pathogenesis of GS in this model, and the fact that hypertension is also very angiotensin II-dependent in this model. Thus, these data suggest that models other than the 5/6 ablation model may be more appropriate to demonstrate the BP-independent protective effects of RAAS blockade.

HIV infection-induced transcriptional program in renal tubular epithelial cells activates a CXCR2-driven CD4+ T-cell chemotactic response

OBJECTIVE

Viral replication and interstitial inflammation play important roles in the pathogenesis of HIV-associated nephropathy. Cell-cell interactions between renal tubule epithelial cells (RTECs) and HIV-infected T cells can trigger efficient virus internalization and viral gene expression by RTEC. To understand how HIV replication initiates HIV-associated nephropathy, we studied the cellular response of RTECs to HIV, examining the transcriptional profiles of primary RTECs exposed to cell-free HIV or HIV-infected T cells.

METHODS

HIV-induced gene expression in hRTECs was examined in vitro by Illumina RNA deep sequencing and revealed an innate response to HIV, which was subclassified by gene ontology biological process terms. Chemokine responses were examined by CD4 T-cell chemotaxis assays.

RESULTS

As compared with cell-free virus infection, exposure to HIV-infected T cells elicited a stronger upregulation of inflammatory and immune response genes. A major category of upregulated genes are chemokine/cytokine families involved in inflammation and immune response, including inflammatory cytokines CCL20, IL6 and IL8-related chemokines: IL8, CXCL1, CXCL2, CXCL3, CXCL5 and CXCL6. Supernatants from virus-exposed RTECs contained strong chemoattractant activity on primary CD4 T cells, which was potently blocked by a CXCR2 antagonist that antagonizes IL8-related chemokines. We observed a preferential migration of CXCR2-expressing, central memory CD4 T cells in response to HIV infection of RTECs.

CONCLUSION

Interactions between primary RTECs and HIV-infected T cells result in potent induction of inflammatory response genes and release of cytokines/chemokines from RTECs that can attract additional T cells. Activation of these genes reflects an innate response to HIV by nonimmune cells.

Effects of Genetic Polymorphisms of the Renin-Angiotensin System in Children with Nephrotic Syndrome

Background. The renin-angiotensin system (RAS) has been considered to be responsible for the pathogenesis or progression of many diseases which may or may not be related to kidney. Genetic polymorphisms of the various components of the RAS have been associated with differences in the clinical course of several disease states in adults and children.

Objectives. The purpose of our study was to investigate RAS gene polymorphisms in patients with steroid resistant primary focal segmental glomerulosclerosis (FSGS) and nephrotic syndrome responding to steroid therapy. Furthermore, we aimed to investigate whether there was an association between polymorphic alleles and responses to steroid therapy, the degree of renal dysfunction, and prevalence of end-stage renal disease (ESRD).

Material and methods. One hundred and fifty-eight children with the diagnosis of nephrotic syndrome were recruited from the Nephrology unit in the Department of Paediatrics of Ege University. Forty-nine of them were classified as renal biopsy-proven FSGS and 102 patients were considered to have response to steroid treatment. Renal functional impairment was detected in 19 subjects with FSGS and end-stage renal insufficiency in 13 patients. The control group consisted of 287 healthy adult subjects. Angiotensin-converting enzyme (ACE), angiotensin II type 1 receptor (AT1R) and angiotensinogen (AGT) gene polymorphisms were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. Statistical significance was regarded as p<0.05.

Results. There were no statistically significant differences for the C allele of AT1R or the T allele of AGT genes between the children with nephrotic syndrome and control group, but on the other hand statistically significant differences were detected for D allele of ACE gene. There was no significant relationship detected between the D allele of ACE, the C allele of AT1R or the T allele of AGT genes and response to steroid therapy, extent of renal dysfunction and the progression to ESRD. However, there was a significant relationship between T allele of AGT gene and resistance to steroid treatment (OR; 4,837, 95% CI; 1,723—13,577, p=0.01), renal dysfunction (OR; 3,189, 95% CI; 0,999—10,182, p=0.041) and progression to ESRD (OR; 3,852, 95% CI; 1,057—14,040, p=0.03).

Conclusion. In this study, the angiotensino gene -235T allele was found to be related with steroid resistance, renal dysfunction and progression of ESRD in nephrotic syndrome.

Protein Profiling of Urine from Dogs with Renal Disease Using ProteinChip Analysis

Measurement of total urinary proteins in individuals that tested positive by urinary dipstick is a typical method for assessing the presence of potentially serious renal disorders. In the absence of such overt proteinuria, however, measurement of specific urinary proteins may be useful in the diagnosis of nephropathies and may provide greater insight into the pathogenesis. The urine of 28 dogs (16 with renal disease and 12 healthy) was evaluated to determine whether specific low—molecular-weight proteins or the pattern of protein excretion could also be used as a marker of tubular dysfunction in dogs. Specific proteins were assessed by immunological methods, whereas protein profiles were determined by surface-enhanced laser desorption/ionization time–of-flight mass spectrometry (MS). In particular, changes in the excretion of retinol-binding protein (RBP) and Tamm-Horsfall protein (THP) appear to be of clinical relevance in the diagnosis of canine kidney diseases. The pattern of urinary protein and peptides revealed specific changes in abundance in dogs with renal disease at molecular masses (kD) of 11.58, 12.41, 12.60, 14.58, 20.95 (RBP), 27.85, and 65.69 (albumin). In conclusion, comparable proteins as in humans might be used as urinary markers for proximal (RBP) and distal (THP) tubular dysfunction in dogs. Surface-enhanced laser desorption/ionization time-of-flight MS is a promising tool for the study of kidney physiology and pathophysiology and might aid in the discovery of new biomarkers of renal disease.

Tacrolimus Modulates TGF-β Signaling to Induce Epithelial-Mesenchymal Transition in Human Renal Proximal Tubule Epithelial Cells

Epithelial-mesenchymal transition (EMT), a process which describes the trans-differentiation of epithelial cells into motile mesenchymal cells, is pivotal in stem cell behavior, development and wound healing, as well as contributing to disease processes including fibrosis and cancer progression. Maintenance immunosuppression with calcineurin inhibitors (CNIs) has become routine management for renal transplant patient, but unfortunately the nephrotoxicity of these drugs has been well documented. HK-2 cells were exposed to Tacrolimus (FK506) and EMT markers were assessed by RT PCR and western blot. FK506 effects on TGF-β mRNA were assessed by RT PCR and TGF-β secretion was measured by ELISA. The impact of increased TGF-β secretion on Smad signaling pathways was investigated. The impact of inhibition of TGF-β signaling on EMT processes was assessed by scratch-wound assay. The results presented in this study suggest that FK506 initiates EMT processes in the HK-2 cell line, with altered expression of epithelial and myofibroblast markers evident. Additionally, the study demonstrates that FK506 activation of the TGF-β/ SMAD pathways is an essential step in the EMT process. Overall the results demonstrate that EMT is heavily involved in renal fibrosis associated with CNI nephrotoxicity.

NFκBiz protein downregulation in acute kidney injury: Modulation of inflammation and survival in tubular cells

Acute kidney injury is characterized by decreased renal function, tubular cell death and interstitial inflammation. The transcription factor NF-κB is a key regulator of genes involved in cell survival and the inflammatory response. In order to better understand the regulation and role of NF-κB in acute kidney injury we explored the expression of NF-κB-related genes in experimental acute kidney injury induced by a folic acid overdose. NFκBiz, a member of the IκB family of NF-κB regulators encoding NFκBiz, was among the top up-regulated NF-κB-related genes at the mRNA level in experimental acute kidney injury. However, the NFκBiz protein was constitutively expressed by normal tubular cells but was down-regulated in experimental acute kidney injury. Kidney NFκBiz mRNA upregulation and protein downregulation was also observed in acute kidney injury induced by cisplatin or unilateral kidney injury resulting from ureteral obstruction. Thus, we studied the consequences of NFκBiz protein downregulation by specific siRNA in cultured tubular epithelial cells. NFκBiz mRNA and protein were up-regulated by inflammatory cytokines (IL-1β or TWEAK/TNFα/IFNγ) and by LPS in cultured tubular cells. However, TWEAK only induced a very mild and short lived NFκBiz upregulation. NFκBiz targeting increased chemokine production and dampened Klotho downregulation induced by TWEAK, without modulating cell proliferation. NFκBiz targeting also rendered cells more resistant to apoptosis induced by serum deprivation or inflammatory cytokines. In conclusion, NFκBiz differentially regulates NF-κB-mediated responses of tubular cells to inflammatory cytokines in a gene-specific manner, and may be of potential therapeutic interest to limit inflammation in kidney disease.

Standardized multilevel transition program: Does it affect renal transplant outcome?

The transfer of renal transplant patients from pediatric to adult care is a crucial step with a high risk of subsequent graft loss. Therefore, the transition should be a thoroughly planned, well-designed and multidisciplinary process focused on the individual patient. Our pediatric nephrology department introduced a structured step-by-step transition program supported by a multidisciplinary team of health professionals. The purpose of our study was to determine the effects of the transition program on eGFR and number of ARs in comparison to a group without a transition program at one and three yr after transfer. We conducted a single-center retrospective cohort study of renal transplant patients prior to and after the introduction of the transition program. Multiple regression analysis revealed a significantly lower decline of eGFR in the group with transition program (-11.3 ± 44 mL/min/1.73 m(2) ) compared to the group without transition program (-28.4 ± 33 mL/min/1.73 m(2) ) at three yr after transfer. The number of AR episodes significantly decreased from 34.6% in the group without transition program to 9.1% in the group with transition program. The standardized multilevel transition program seems to have significant positive effects on eGFR and number of AR episodes in renal transplant patients.

The renoprotective role of autophagy activation in proximal tubular epithelial cells in diabetic nephropathy

With intensive investigations recently, autophagy is hoped to be a potential therapeutic target to prevent or alleviate diabetic nephropathy (DN). Our previous study revealed that lipotoxicity participated in epithelial-to-mesenchymal transition (EMT) of proximal tubular epithelial cells (PTECs) under diabetic conditions. Based on evidences that autophagy and lipid metabolism are closely related, we investigated autophagy under diabetic conditions and how it contributed in the lipotoxicity and EMT. In high-glucose-cultured PTECs, we found that Beclin1 and LC3-II were elevated, while p62 was decreased. These results indicate that autophagy activity was elevated under diabetic conditions. Autophagy deficiency induced by autophagy inhibitors, chloroquine diphosphate (CQ) and 3-Methyladenine (3-MA), and by Atg5 siRNA transfection exacerbated lipid accumulation and EMT. This supports that the elevated autophagy activity acts as a renoprotective response under diabetic conditions. Treatment of rapamycin, which is a mammalian target of rapamycin (mTOR) receptor-specific inhibitor and a known autophagy activator, attenuated high-glucose-induced lipid accumulation and EMT. The Atg5 silence counteracted the protective effect of rapamycin. The present study deepens our understanding of the role of autophagy in DN, suggesting a complex interplay of autophagy, metabolic pathways, lipotoxicity and EMT.