Chronic kidney diseases (CKDs) are currently classified according to their clinical features, associated comorbidities and pattern of injury on biopsy. Even within a given classification, ...considerable variation exists in disease presentation, progression and response to therapy, highlighting heterogeneity in the underlying biological mechanisms. As a result, patients and clinicians experience uncertainty when considering optimal treatment approaches and risk projection. Technological advances now enable large-scale datasets, including DNA and RNA sequence data, proteomics and metabolomics data, to be captured from individuals and groups of patients along the genotype-phenotype continuum of CKD. The ability to combine these high-dimensional datasets, in which the number of variables exceeds the number of clinical outcome observations, using computational approaches such as machine learning, provides an opportunity to re-classify patients into molecularly defined subgroups that better reflect underlying disease mechanisms. Patients with CKD are uniquely poised to benefit from these integrative, multi-omics approaches since the kidney biopsy, blood and urine samples used to generate these different types of molecular data are frequently obtained during routine clinical care. The ultimate goal of developing an integrated molecular classification is to improve diagnostic classification, risk stratification and assignment of molecular, disease-specific therapies to improve the care of patients with CKD.
Chronic inflammation is postulated to be involved in the development of end-stage renal disease in diabetes, but which specific circulating inflammatory proteins contribute to this risk remain ...unknown. To study this, we examined 194 circulating inflammatory proteins in subjects from three independent cohorts with type 1 and type 2 diabetes. In each cohort, we identified an extremely robust kidney risk inflammatory signature (KRIS), consisting of 17 proteins enriched in tumor necrosis factor-receptor superfamily members, that was associated with a 10-year risk of end-stage renal disease. All these proteins had a systemic, non-kidney source. Our prospective study findings provide strong evidence that KRIS proteins contribute to the inflammatory process underlying end-stage renal disease development in both types of diabetes. These proteins point to new therapeutic targets and new prognostic tests to identify subjects at risk of end-stage renal disease, as well as biomarkers to measure responses to treatment of diabetic kidney disease.
The coronavirus disease 2019 (COVID-19) pandemic has infected >22.7 million and led to the deaths of 795,000 people worldwide. Patients with diabetes are highly susceptible to COVID-19-induced ...adverse outcomes and complications. The COVID-19 pandemic is superimposing on the preexisting diabetes pandemic to create large and significantly vulnerable populations of patients with COVID-19 and diabetes. This article provides an overview of the clinical evidence on the poorer clinical outcomes of COVID-19 infection in patients with diabetes versus patients without diabetes, including in specific patient populations, such as children, pregnant women, and racial and ethnic minorities. It also draws parallels between COVID-19 and diabetes pathology and suggests that preexisting complications or pathologies in patients with diabetes might aggravate infection course. Finally, this article outlines the prospects for long-term sequelae after COVID-19 for vulnerable populations of patients with diabetes.
Diabetic kidney disease (DKD) is the most common cause of kidney failure in many countries today, but treatments have not improved in the last 20 years. Recently, systems biology methods have allowed ...the elucidation of signalling pathways and networks involved in the progression of DKD that were not well appreciated previously. A prominent pathway found to be integrally associated with DKD progression is the Janus kinase–signal transducer and activator of transcription (JAK–STAT) pathway. Increased expression of JAK–STAT genes was found in multiple cells in the kidney, including glomerular podocytes, in both early and progressive DKD. Subsequent experiments in a mouse diabetic model showed that enhanced expression of JAK2 selectively in glomerular podocytes increased functional and pathological features of DKD. Finally, a yet unpublished Phase 2 multicentre, randomised, double-blind, placebo-controlled study of the efficacy of a selective JAK1 and JAK2 inhibitor has been conducted in type 2 diabetic participants with DKD. In this trial there was a reduction of albuminuria in participants who received the active inhibitor compared with those who received a placebo These results support the further study of JAK inhibitors as a new therapy for DKD. This review summarises a presentation given at the ‘Anti-inflammatory interventions in diabetes’ symposium at the 2015 annual meeting of the EASD. It is accompanied by an overview by the Session Chair, Hiddo Heerspink (DOI:
10.1007/s00125-016-4030-4
).
Perspectives in systems nephrology Lindenmeyer, Maja T.; Alakwaa, Fadhl; Rose, Michael ...
Cell and tissue research,
08/2021, Letnik:
385, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Chronic kidney diseases (CKD) are a major health problem affecting approximately 10% of the world’s population and posing increasing challenges to the healthcare system. While CKD encompasses a broad ...spectrum of pathological processes and diverse etiologies, the classification of kidney disease is currently based on clinical findings or histopathological categorizations. This descriptive classification is agnostic towards the underlying disease mechanisms and has limited progress towards the ability to predict disease prognosis and treatment responses. To gain better insight into the complex and heterogeneous disease pathophysiology of CKD, a systems biology approach can be transformative. Rather than examining one factor or pathway at a time, as in the reductionist approach, with this strategy a broad spectrum of information is integrated, including comprehensive multi-omics data, clinical phenotypic information, and clinicopathological parameters. In recent years, rapid advances in mathematical, statistical, computational, and artificial intelligence methods enable the mapping of diverse big data sets. This holistic approach aims to identify the molecular basis of CKD subtypes as well as individual determinants of disease manifestation in a given patient. The emerging mechanism-based patient stratification and disease classification will lead to improved prognostic and predictive diagnostics and the discovery of novel molecular disease-specific therapies.
Organoids derived from human pluripotent stem cells are a potentially powerful tool for high-throughput screening (HTS), but the complexity of organoid cultures poses a significant challenge for ...miniaturization and automation. Here, we present a fully automated, HTS-compatible platform for enhanced differentiation and phenotyping of human kidney organoids. The entire 21-day protocol, from plating to differentiation to analysis, can be performed automatically by liquid-handling robots, or alternatively by manual pipetting. High-content imaging analysis reveals both dose-dependent and threshold effects during organoid differentiation. Immunofluorescence and single-cell RNA sequencing identify previously undetected parietal, interstitial, and partially differentiated compartments within organoids and define conditions that greatly expand the vascular endothelium. Chemical modulation of toxicity and disease phenotypes can be quantified for safety and efficacy prediction. Screening in gene-edited organoids in this system reveals an unexpected role for myosin in polycystic kidney disease. Organoids in HTS formats thus establish an attractive platform for multidimensional phenotypic screening.
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•Liquid-handling robots generate and analyze kidney organoids in microwell arrays•Single-cell RNA-seq reveals that organoid cell types recapitulate human kidney complexity•Growth factor addition greatly increases vascular endothelial cells in organoids•A phenotypic drug screen discovers a role for myosin in polycystic kidney disease
Organoids derived from human iPSCs have great potential for drug screening, but their complexity poses a challenge for miniaturization and automation. Freedman and colleagues establish a robotic pipeline to manufacture and analyze kidney organoids in microwell arrays. They apply this system to improve differentiation, measure toxicity, and comprehend disease.
The mammalian kidney develops through reciprocal interactions between the ureteric bud and the metanephric mesenchyme to give rise to the entire collecting system and the nephrons. Most of our ...knowledge of the developmental regulators driving this process arises from the study of gene expression and functional genetics in mice and other animal models. In order to shed light on human kidney development, we have used single-cell transcriptomics to characterize gene expression in different cell populations, and to study individual cell dynamics and lineage trajectories during development. Single-cell transcriptome analyses of 6414 cells from five individual specimens identified 11 initial clusters of specific renal cell types as defined by their gene expression profile. Further subclustering identifies progenitors, and mature and intermediate stages of differentiation for several renal lineages. Other lineages identified include mesangium, stroma, endothelial and immune cells. Novel markers for these cell types were revealed in the analysis, as were components of key signaling pathways driving renal development in animal models. Altogether, we provide a comprehensive and dynamic gene expression profile of the developing human kidney at the single-cell level.
Division of Nephrology, Department of Medicine, University
Hospital Freiburg, Freiburg; Institute of Anatomy and Cell Biology
I, University of Heidelberg, Heidelberg; and Medical Policlinic,
...University of Munich, Munich,
Germany
Pavenstädt, Hermann,
Wilhelm Kriz, and
Matthias Kretzler.
Cell Biology of the Glomerular Podocyte. Physiol. Rev. 83: 253-307, 2003. Glomerular
podocytes are highly specialized cells with a complex cytoarchitecture.
Their most prominent features are interdigitated foot processes with
filtration slits in between. These are bridged by the slit diaphragm,
which plays a major role in establishing the selective permeability of
the glomerular filtration barrier. Injury to podocytes leads to
proteinuria, a hallmark of most glomerular diseases. New technical
approaches have led to a considerable increase in our understanding of
podocyte biology including protein inventory, composition and
arrangement of the cytoskeleton, receptor equipment, and signaling
pathways involved in the control of ultrafiltration. Moreover,
disturbances of podocyte architecture resulting in the retraction of
foot processes and proteinuria appear to be a common theme in the
progression of acquired glomerular disease. In hereditary nephrotic
syndromes identified over the last 2 years, all mutated gene products
were localized in podocytes. This review integrates our recent
physiological and molecular understanding of the role of podocytes
during the maintenance and failure of the glomerular filtration barrier.
Inflammation signaled by Janus kinases (JAKs) promotes progression of diabetic kidney disease (DKD). Baricitinib is an oral, reversible, selective inhibitor of JAK1 and JAK2. This study tested the ...efficacy of baricitinib versus placebo on albuminuria in adults with Type 2 diabetes at high risk for progressive DKD.
In this Phase 2, double-blind, dose-ranging study, participants were randomized 1:1:1:1:1 to receive placebo or baricitinib (0.75 mg daily; 0.75 mg twice daily; 1.5 mg daily; or 4 mg daily), for 24 weeks followed by 4-8 weeks of washout.
Participants (N = 129) were 63±9.1 (mean±standard deviation) years of age, 27.1% (35/129) women and 11.6% (15/129) African-American race. Baseline hemoglobin A1c (HbA1c) was 7.3±1% and estimated glomerular filtration rate was 45.0±12.1 mL/min/1.73 m2 with first morning urine albumin-creatinine ratio (UACR) of 820 (407-1632) (median; interquartile range) mg/g. Baricitinib, 4 mg daily, decreased morning UACR by 41% at Week 24 compared with placebo (ratio to baseline 0.59, 95% confidence interval 0.38-0.93, P = 0.022). UACR was decreased at Weeks 12 and 24 and after 4-8 weeks of washout. Baricitinib 4 mg decreased inflammatory biomarkers over 24 weeks (urine C-X-C motif chemokine 10 and urine C-C motif ligand 2, plasma soluble tumor necrosis factor receptors 1 and 2, intercellular adhesion molecule 1 and serum amyloid A). The only adverse event rate that differed between groups was anemia at 32.0% (8/25) for baricitinib 4 mg daily versus 3.7% (1/27) for placebo.
Baricitinib decreased albuminuria in participants with Type 2 diabetes and DKD. Further research is required to determine if baricitinib reduces DKD progression.
An abnormal neutrophil subset has been identified in the PBMC fractions from lupus patients. We have proposed that these low-density granulocytes (LDGs) play an important role in lupus pathogenesis ...by damaging endothelial cells and synthesizing increased levels of proinflammatory cytokines and type I IFNs. To directly establish LDGs as a distinct neutrophil subset, their gene array profiles were compared with those of autologous normal-density neutrophils and control neutrophils. LDGs significantly overexpress mRNA of various immunostimulatory bactericidal proteins and alarmins, relative to lupus and control neutrophils. In contrast, gene profiles of lupus normal-density neutrophils do not differ from those of controls. LDGs have heightened capacity to synthesize neutrophils extracellular traps (NETs), which display increased externalization of bactericidal, immunostimulatory proteins, and autoantigens, including LL-37, IL-17, and dsDNA. Through NETosis, LDGs have increased capacity to kill endothelial cells and to stimulate IFN-α synthesis by plasmacytoid dendritic cells. Affected skin and kidneys from lupus patients are infiltrated by netting neutrophils, which expose LL-37 and dsDNA. Tissue NETosis is associated with increased anti-dsDNA in sera. These results expand the potential pathogenic roles of aberrant lupus neutrophils and suggest that dysregulation of NET formation and its subsequent responses may play a prominent deleterious role.
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