Electric cell-substrate impedance sensing in kidney research.

Electric cell-substrate impedance sensing (ECIS) is a quantitative, label-free, non-invasive analytical method allowing continuous monitoring of the behaviour of adherent cells by online recording of transcellular impedance. ECIS offers a wide range of practical applications to study cell proliferation, migration, differentiation, toxicity and monolayer barrier integrity. All of these applications are relevant for basic kidney research, e.g. on endothelial cells, tubular and glomerular epithelial cells. This review gives an overview on the fundamental principles of the ECIS technology. We name strengths and remaining hurdles for practical applications, present an ECIS array reuse protocol, and review its past, present and potential future contributions to preclinical kidney research.

Drug Testing for Residual Progression of Diabetic Kidney Disease in Mice Beyond Therapy with Metformin, Ramipril, and Empagliflozin.

BACKGROUND: Progression of CKD in type 2 diabetes, despite dual inhibition of sodium-glucose transporter-2 and the renin-angiotensin system, remains a concern. Bromoindirubin-3'-oxime (BIO), previously reported to promote podocyte survival and regeneration, is a candidate additional drug to elicit renoprotective effects beyond therapy with metformin, ramipril, and empagliflozin (MRE). Evaluating a drug with standard therapeutics more closely mimics the clinical setting than evaluating the drug alone. METHODS: Uninephrectomized BKS-Lepr-/- (db/db) mice treated with or without MRE served as a model of progressive CKD in type 2 diabetes. Mice on or off MRE were randomized to only 4 weeks of add-on BIO or vehicle. The primary end point was slope of GFR (ΔGFR). RESULTS: Four weeks of MRE treatment alone did not affect ΔGFR, but significantly attenuated hyperglycemia, albuminuria, and glomerulosclerosis and increased podocyte filtration slit density, as assessed by STED super-resolution microscopy upon tissue clearing. BIO alone improved albuminuria, podocyte density in superficial and juxtamedullary nephrons, and podocyte filtration slit density. MRE+BIO combination therapy had additive protective effects on ΔGFR, glomerulosclerosis, podocyte density in juxtamedullary nephrons, and filtration slit density. CONCLUSIONS: Add-on treatment with BIO for only 4 weeks attenuates progression of CKD beyond MRE therapy in mice with type 2 diabetes. Additional drug combinations may help to further delay ESKD in type 2 diabetes.

Drug Testing for Chronic Kidney Disease and Diabetes in Animals versus Humans: A Comparative Analysis of Study Designs and Reporting Qualities.

INTRODUCTION: Diabetes is a highly prevalent accelerator or even cause of chronic kidney disease imposing a large unmet medical need at the global scale. Massive research activities continue to be in search of a cure but the yield of the classical bench-to-bedside research approach has been low. We speculated that a significant mismatch in design and quality of animal and clinical studies in this domain is a hurdle for translation. METHODS: We performed a meta-analysis of matched pairs of animal and human studies that tested the efficacy of distinct drug interventions for diabetic kidney disease (DKD). We reviewed study designs and reporting quality of such studies over the last decade according to the standards listed in the CONSORT and ARRIVE recommendations, respectively. RESULTS: We noted a wide diversity in the study designs of animal studies in terms of diabetes induction. Major mismatches with the respective human studies referred to age and sex distribution, comorbidities, stage of the kidney disease, and selection of primary endpoints. Usually, treatment was initiated before onset of kidney disease without any standard of care as a background therapy. The reporting quality of animal studies was poor for randomization procedures, blinding, sample size calculation for a prespecified primary endpoint or the safety analysis. Reporting quality of clinical studies had deficits in trial design-, recruitment-, allocation-, and outcome-related aspects. CONCLUSION: Bench-to-bedside translation in the domain of DKD suffers from major deficits in the design of experimental studies in view of the projected clinical trials as well as from significant deficits in the reporting quality in preclinical and clinical studies.

Energy Homeostasis Gene Nucleotide Variants and Survival of Hemodialysis Patients-A Genetic Cohort Study.

BACKGROUND: Patients undergoing hemodialysis (HD) therapy have an increased risk of death compared to the general population. We investigated whether selected single nucleotide variants (SNVs) involved in glucose and lipid metabolism are associated with mortality risk in HD patients. METHODS: The study included 805 HD patients tested for 11 SNVs in FOXO3, IGFBP3, FABP1, PCSK9, ANGPTL6, and DOCK6 using HRM analysis and TaqMan assays. FOXO3, IGFBP3, L-FABP, PCSK9, ANGPTL6, and ANGPTL8 plasma concentrations were measured by ELISA in 86 individuals. The Kaplan-Meier method and Cox proportional hazards models were used for survival analyses. RESULTS: We found out that the carriers of a C allele in ANGPTL6 rs8112063 had an increased risk of all-cause, cardiovascular, and cardiac mortality. In addition, the C allele of DOCK6 rs737337 was associated with all-cause and cardiac mortality. The G allele of DOCK6 rs17699089 was correlated with the mortality risk of patients initiating HD therapy. The T allele of FOXO3 rs4946936 was negatively associated with cardiac and cardiovascular mortality in HD patients. We observed no association between the tested proteins' circulating levels and the survival of HD patients. CONCLUSIONS: The ANGPTL6 rs8112063, FOXO3 rs4946936, DOCK6 rs737337, and rs17699089 nucleotide variants are predictors of survival in patients undergoing HD.