Model Of Chronic Kidney Disease Research Articles

A molecular target of vascular calcification in chronic kidney disease.

Vascular calcification (VC) causes cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD), particularly those with end-stage kidney disease (ESKD) on maintenance dialysis treatment. Although many mechanisms have been proposed, their detailed effects remain incompletely understood. In this issue of the JCI, Li et al. examined the molecular mechanism of the protective role of SIRT6 in VC in patients with CKD. Using in vitro and animal models of CKD, the authors demonstrated that SIRT6 prevents VC by suppressing the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs). Mechanistically, SIRT6 bound and deacetylated the runt-related transcription factor 2 (Runx2), a key transcription factor for osteogenic differentiation, promoting its nuclear export for proteasome degradation. These studies provide a pathway in the pathogenesis of VC and justify investigating SIRT6 as a potential target in CKD.

POSC353 Quality of Life in Chronic Kidney Disease (CKD): Results from a Systematic Review of CKD Models for Type 2 Diabetes

Advanced stages of chronic kidney disease (CKD), particularly end-stage kidney disease (ESKD), are associated with substantial reductions in quality of life, which need to be captured in models of CKD. In the present study, we reviewed health state utility (HSU) values used in CKD models in type 2 diabetes (T2D) and assessed their consistency.

Smart Monitoring System for Chronic Kidney Disease Patients based on Fuzzy Logic and IoT

A Chronic Kidney Disease (CKD) monitoring system was proposed for early detection of cardiovascular disease (CVD) and anemia using Fuzzy Logic. To determine the heart rate and blood oxygen saturation, the proposed model was simulated using MATLAB and Simulink to handle ECG and PPG inputs. The Pan-Tompkins method was used to determine the heart rate, while the Takuo Aoyagi algorithm was used to assess blood oxygen saturation levels. The findings show that the ECG recorded using the CKD model has all of the characteristics of a typical ECG wave cycle, but with reduced signal degradation in the 0.8–1.3mV region. The heart rate signal processing yielded findings between 78 and 83 beats per minute is within the range of the supplied heart rate. Takuo Aoyagi's pulse oximeter simulation generated the same findings. For real-time verification, the proposed model was implemented in hardware using ESP8266 32-bit microcontroller with IoT integration via Wireless Fidelity for data storage and monitoring. In comparison with the Fuzzy Logic simulation done on MATLAB and Simulink, the CKD monitoring device has 100% accuracy in patient status detection. The CKD monitoring system has an overall accuracy of 99% in comparison with a commercial fingertip pulse oximeter.

POSB313 Predicting Chronic Kidney Disease in Type 2 Diabetes Using Patient-level Simulation: Outcomes, Markers, Risk Factors, and Sequelae Identified in a Systematic Review

Modeling chronic kidney disease (CKD) in type 2 diabetes (T2D) is complex owing to the interplay of numerous risk factors, biomarkers, outcomes, and competing risks. One approach to capturing this interplay is the use of flexible frameworks such patient-level simulation (PLS) based on multivariable regression. The flexibility afforded by regression-based PLS allows a diverse array of risk factors to be captured and modeled. The present study aimed to review the markers, outcomes, risk factors, and sequelae captured in PLS models of CKD in T2D.

Update on Existing Care Models for Chronic Kidney Disease in Low- and Middle-Income Countries: A Systematic Review.

Background:Approximately 78% of chronic kidney disease (CKD) cases reside in low- and middle-income countries (LMICs). However, little is known about the care models for CKD in LMICs.Objective:Our objective was to update a prior systematic review on CKD care models in LMICs and summarize information on multidisciplinary care and management of CKD complications.Design:We searched MEDLINE, EMBASE, and Global Health databases in September 2020, for papers published between January 1, 2017, and September 14, 2020. We used a combination of search terms, which were different iterations of CKD, care models, and LMICs. The World Bank definition (2019) was used to identify LMICs.Setting:Our review included studies published in LMICs across 4 continents: Africa, Asia, North America (Mexico), and Europe (Ukraine). The study settings included tertiary hospitals (n = 6), multidisciplinary clinics (n = 1), primary health centers (n = 2), referral centers (n = 2), district hospitals (n = 1), teaching hospitals (n = 1), regional hospital (n = 1), and an urban medical center (n = 1).Patients:Eighteen studies met inclusion criteria, and encompassed 4679 patients, of which 4665 were adults. Only 9 studies reported mean eGFR which ranged from 7 to 45.90 ml/min/1.73 m2.Measurements:We retrieved the following details about CKD care: funding, urban or rural location, types of health care staff, and type of care provided, as defined by Kidney Disease Improving Global Outcomes (KDIGO) guidelines for CKD care.Methods:We included studies which met the following criteria: (1) population was largely adults, defined as age 18 years and older; (2) most of the study population had CKD, and not end-stage kidney disease (ESKD); (3) population resided in an LMIC as defined by the World Bank; (4) manuscript described in some detail a clinical care model for CKD; (5) manuscript was in either English or French. Animal studies, case reports, comments, and editorials were excluded.Results:Eighteen studies (24 care models with 4665 patients) met inclusion criteria. Out of 24 care models, 20 involved interdisciplinary health care teams. Twenty models incorporated international guidelines for CKD management. However, conservative kidney management (management of kidney failure without dialysis or renal transplant) was in a minority of models (11 of 24). Although there were similarities between all the clinical care models, there was variation in services provided and in funding arrangement; the latter ranged from comprehensive government funding (eg, Sri Lanka, Thailand), to out-of-pocket payments (eg, Benin, Togo).Limitations:These include (1) lack of detail on CKD care in many of the studies, (2) small number of included studies, (3) using a different definition of care model from the original Stanifer et al paper, and (4) using the KDIGO Guidelines as the standard for defining a CKD care model.Conclusions:Most of the CKD models of care include the key elements of CKD care. However, access to such care depends on the funding mechanism available. In addition, few models included conservative kidney management, which should be a priority for future investment.Trial registration:Not applicable.

Resveratrol Butyrate Ester Protects Adenine-Treated Rats against Hypertension and Kidney Disease by Regulating the Gut-Kidney Axis.

Despite recent advances in pharma-nutritional management, chronic kidney disease (CKD) remains an increasingly prevalent disorder. Resveratrol, a pleiotropic phytochemical, has been found to reduce the risk for several chronic diseases. Considering the low bioavailability of resveratrol, we recently synthesized resveratrol butyrate ester (RBE) via the esterification of resveratrol with butyrate. The aim of this study was to examine the effectiveness of RBE as regards protection from hypertension and kidney damage and explore the underlying mechanisms using a young rat adenine-induced CKD model. Three-week-old male Sprague Dawley rats received regular or 0.5% adenine chow for three weeks. Three groups of adenine-fed CKD rats (N = 8/group) received resveratrol (50 mg/L), or a low dose (25 mg/L) or high dose (50 mg/L) of RBE in drinking water from week 6 to week 12. As compared with the controls, adenine-treated rats had markedly increased creatinine levels and blood pressure, which was associated with renal hypertrophy and decreased creatinine clearance. Treatment with resveratrol or a low or high dose of RBE, similarly protected adenine-fed rats against hypertension and kidney damage. CKD-induced hypertension is associated with an altered gut microbiota profile, dysregulated renal short chain fatty acid (SCFA) receptor expression, activation of the aryl hydrocarbon receptor (AhR) signaling pathway, and reduced nitric oxide bioavailability. We found gut microbiota compositions were shaped differentially by resveratrol and RBE treatment in adenine-treated CKD rats. The beneficial effect of high-dose RBE was associated with reduced renal expression of SCFA G protein-coupled receptor 41 (GPR41) and olfactory receptor 78 (Olfr78), antagonizing the AhR signaling pathway, and increased abundance of beneficial bacteria such as genera Akkermansia, Blautia, and Enterococcus. Our study provided the first evidence documenting RBE as a novel phytochemical supplement targeting the gut–kidney axis to protect against adenine-induced kidney damage and hypertension.

Multiple Imputation by Chained Equations–K-Nearest Neighbors and Deep Neural Network Architecture for Kidney Disease Prediction

Chronic kidney disease (CKD) is a health concern that affects people all over the world. Kidney dysfunction or impaired kidney functions are the causes of CKD. The machine learning-based prediction models are used to determine the risk level of CKD and assist healthcare practitioners in delaying and preventing the disease’s progression. The researchers proposed many prediction models for determining the CKD risk level. Although these models performed well, their precision is limited since they do not handle missing values in the clinical dataset adequately. The missing values of a clinical dataset can degrade the training outcomes that leads to false predictions. Thus, imputing missing values increases the prediction model performance. This proposed work developed a novel imputation technique by combining Multiple Imputation by Chained Equations and [Formula: see text]-Nearest Neighbors (MICE–KNN) for imputing the missing values. The experimental results show that MICE–KNN accurately predicts the missing values, and the Deep Neural Network (DNN) improves the prediction performance of the CKD model. Various metrics like mean absolute error, accuracy, specificity, Matthews correlation coefficient, the area under the curve, [Formula: see text]-score, sensitivity, and precision have been used to evaluate the proposed CKD model performance. The performance analysis exhibits that MICE–KNN with deep learning outperforms other classifiers. According to our experimental study, the MICE–KNN imputation algorithm with DNN is more appropriate for predicting the kidney disease.

Chronic Hematuria Increases Chronic Kidney Injury and Epithelial-Mesenchymal Transition in 5/6 Nephrectomy Rats.

Chronic kidney disease (CKD) is a common outcome of many kidney diseases. Interstitial fibrosis and tubular atrophy (IFTA) is a histologic hallmark of CKD. Hematuria is a common symptom in many human kidney diseases. Free hemoglobin may affect tubular epithelial cells by generating reactive oxygen species (ROS). Epithelial–mesenchymal transition (EMT) of the tubular epithelial cells has been shown to play an important role in the IFTA development. The aim of this study was to determine the effects of chronic hematuria on the CKD progression in 5/6 nephrectomy (5/6NE) rat model of CKD. 5/6 NE rats were treated with oral warfarin (0.5 mg/kg/day) or vehicle (control). The animals were monitored for 26 weeks, while prothrombin time (PT), serum creatinine (SCr), and hematuria were measured weekly. Staining for iron, trichrome, and EMT (vimentin, E-cadherin, smooth muscle actin) markers was performed on the remnant kidneys. ROS were detected in the kidneys by protein carbonyl assay and immunohistochemistry for heme oxygenase 1 (HMOX1), at the end of the study. Apoptosis was detected by TUNEL assay. Warfarin treatment resulted in a PT increase 1.5–2.5 times from control and an increase in hematuria and SCr. Histologically, warfarin-treated animals had more iron-positive tubular epithelial cells and increased IFTA as compared to control (42.9 ± 17% vs. 18.3 ± 2.6%). ROS were increased in the kidney in warfarin-treated rats. The number of tubules that show evidence of EMT was significantly higher in warfarin-treated 5/6NE as compared to control 5/6NE rats. The number of apoptotic tubular epithelial cells was higher in warfarin-treated 5/6 NE rats. Chronic hematuria results in increased iron-positive tubular epithelial cells, EMT, apoptosis, and more prominent IFTA in CKD rats. Our data suggest an important role of chronic hematuria in the progression of CKD.

Comparison of Machine Learning With Logistic Regression for Prediction of Chronic Kidney Disease in the Thai Adult Population

Background: Chronic kidney disease (CKD) takes huge amounts of resources for treatments. Early detection of patients by risk prediction model should be useful in identifying risk patients and providing early treatments.
 Objective: To compare the performance of traditional logistic regression with machine learning (ML) in predicting the risk of CKD in Thai population.
 Methods: This study used Thai Screening and Early Evaluation of Kidney Disease (SEEK) data. Seventeen features were firstly considered in constructing prediction models using logistic regression and 4 MLs (Random Forest, Naïve Bayes, Decision Tree, and Neural Network). Data were split into train and test data with a ratio of 70:30. Performances of the model were assessed by estimating recall, C statistics, accuracy, F1, and precision.
 Results: Seven out of 17 features were included in the prediction models. A logistic regression model could well discriminate CKD from non-CKD patients with the C statistics of 0.79 and 0.78 in the train and test data. The Neural Network performed best among ML followed by a Random Forest, Naïve Bayes, and a Decision Tree with the corresponding C statistics of 0.82, 0.80, 0.78, and 0.77 in training data set. Performance of these corresponding models in testing data decreased about 5%, 3%, 1%, and 2% relative to the logistic model by 2%.
 Conclusions: Risk prediction model of CKD constructed by the logit equation may yield better discrimination and lower tendency to get overfitting relative to ML models including the Neural Network and Random Forest.

Analysis of bone in adenine-induced chronic kidney disease model rats

ObjectivesThe purpose of this study is to investigate the stage of chronic kidney disease (CKD) in adenine-induced CKD model rats by serum analyses, and to examine bone mineral density (BMD), bone strength, and microstructure of trabecular and cortical bone in these rats. MethodsEight-week-old, male Wistar rats (n = 42) were divided into 2 groups: those fed a 0.75% adenine diet for 4 weeks until 12 weeks of age to generate CKD model rats (CKD group); and sham rats. The CKD and sham groups were sacrificed at 12, 16, and 20 weeks of age (n = 7 in each group and at 12, 16, and 20 weeks), and various parameters were evaluated, including body weight, renal wet weight, muscle wet weight, renal histology, biochemical tests, BMD, biomechanical testing, and micro-computed tomography (CT). The parameters were compared between the 2 groups at the various time points. ResultsIn the CKD model rats, at 20 weeks of age, serum creatinine, phosphorus, and intact-PTH levels were elevated, and serum calcium levels were normal, indicating that the CKD was stage IV and associated with secondary hyperparathyroidism. Decreased BMDs of the whole body and the femur were observed as bone changes, and micro-CT analysis showed deterioration of bone microstructure of the cortical bone that resulted in decreased bone strength in the cortical and trabecular bone. ConclusionsThese CKD model rats showed stage IV CKD and appear appropriate for evaluating the effects of several treatments for CKD-related osteoporosis and mineral bone disorder.

Abstract 11305: Protective Effects of Homoarginine on Cardiovascular Function in a Mouse Model of Chronic Kidney Disease

Introduction: The level of homoarginine (hArg) in plasma correlates inversely with cardiovascular and renal disease. However, the cardioprotective mechanism of hArg in renal disease is currently unknown. In this study, we assessed hArg’s effects on cardiovascular function in mice with chronic kidney disease (CKD). Hypothesis: We have previously reported that hArg reduces fibrosis and helps preserve ejection fraction in a model of coronary artery disease. We now hypothesize that hArg supplementation will 1) decrease cardiac and renal fibrosis and inflammation in a model of CKD, 2) preserve cardiac geometry and function, 3) increase renal artery blood flow, and 4) increase survival. Methods: The mice used in this study had a mutation in the low density lipoprotein receptor on the C57BL/6 genetic background. Mice of both sexes (n=28) were fed a standard rodent diet supplemented with 0.1% (F) and 0.2% (M) adenine to induce CKD. Mice were randomly assigned to 14 μg/ml hArg (in drinking water) or placebo (PBO). Cardiac structure and function as well as renal blood flow were measured via high frequency ultrasound (Vevo 3100, VisualSonics). Results: LV geometry data of hArg treated male mice showed increased left ventricular (LV) mass (p<0.05) with normal LV internal diameter and increased LV wall thickness (p<0.01). In terms of cardiac function, ejection fraction (EF, p<0.05), fractional shortening (p<0.01), and cardiac output (p<0.01) were also increased in hArg treated male mice compared to placebo. No differences in renal blood flow were observed. Survival was not affected by hArg. Additionally, we observed decreased food consumption (p<0.01) and fecal output (p<0.001) in hArg treated mice with no difference in urine output compared with placebo. Conclusion: hArg treated male mice developed physiologic cardiac hypertrophy with preserved EF in the absence of LV dilation. Additionally, hArg affected the metabolic state of treated mice reflected in food consumption.

Abstract 13166: Paraoxonase-3 Regulation of Cardiotonic Steroids Mediates Renal Injury and Dysfunction in a Dahl Salt Sensitive Model of Chronic Kidney Disease

Background: Paraoxonases (Pons) belong to a family of hydrolytic enzymes with 3 distinct isoforms: Pon 1, 2, and 3. While the physiologic substrates for Pons are unclear, their lactonase activity is considered central to their native physiological role. We have previously demonstrated an association between diminished Pon lactonase activity and worse clinical outcomes in volume expanded states such as chronic kidney disease (CKD). Furthermore, we have identified a novel reno-protective role for Pon3 in hypertensive renal disease. However, the underlying mechanism(s) are unknown. Cardiotonic steroids (CTS) are natriuretic hormones that are increased in CKD and promote renal inflammation and fibrosis via binding of their 17β-lactone ring to the alpha-1 subunit of the Na + /K + -ATPase (NKA-α-1). Therefore, we tested the hypothesis that reduction of Pon3 lactonase activity would lead to increased renal injury and dysfunction in a CTS induced rat model of CKD. Methods/Results: Experiments were performed on Dahl salt-sensitive rats (SS rats) and Pon3 knock-out rats on the Dahl salt-sensitive background (SS- Pon3 KO). First, CTS levels in the urine of SS control and SS- Pon3 KO rats were quantified using mass spectrometry. We found that SS- Pon3 KO rats had 59 times greater increase in 24-hour urine CTS levels vs SS rats. Next, to examine the role of Pon3 in mediating CTS induced renal injury, ten-week-old, age-matched male SS control and SS- Pon3 KO rats were administered the CTS telocinobufagin (TCB, 100 μg/kg/day s.q) for four weeks followed by assessment of blood pressure (tail cuff plethysmography) and renal function. We found that SS- Pon3 KO rats following TCB administration had significantly increased 24-hour urinary protein excretion (UPE) (50.73 ± 3.59vs 25.29 ± 2.07, p<0.0001), as well as decreased FITC-Sinistrin monitored glomerular filtration rate (GFR) (0.80 ± 0.10 vs 1.16 ± 0.05, p<0.01) compared to SS control rats, despite similar degrees of hypertension. Conclusion: These findings suggest that Pon3 plays a critical role in regulating CTS mediated renal dysfunction in vivo.

Abstract 9172: Feasibility and Efficacy of Targeted Cardiac NF-kB Inhibition in Experimental Diastolic Dysfunction Using Drug-Delivery Technology: A Proof-of-Concept Study

Introduction: Elastin-like polypeptides (ELP) are novel drug delivery vectors that can be fused to therapeutic agents and cell penetrating peptides (CPPs), slowing their plasma clearance and increasing uptake by target tissues. We developed a CPP-ELP fusion to a specific inhibitor of the p50 subunit of NF-kB (SynB1-ELP-p50i). We developed a swine model of chronic kidney disease (CKD) that also fosters hypertension, cardiac remodeling, and diastolic dysfunction, and observed that cardiac abnormalities associate with increased cardiac expression of NF-kB, a ubiquitous transcription factor that modulates cardiac inflammation, fibrosis, and vascular remodeling. Hypothesis: We aimed to define the feasibility and efficacy of intra-coronary (IC) SynB1-ELP-p50i administration to test whether a targeted inhibition of NF-kB can improve cardiac abnormalities in CKD. Methods: We first performed a biodistribution study (BDS) in 3 pigs, 4 hours after IC injection of fluorescently labeled SynB1-ELP-p50i (10 mg/kg). Then, CKD was induced in 6 pigs (bilateral renovascular disease and dyslipidemia), treated with a single IC SynB1-ELP-p50i or placebo at 6 weeks and observed for 8 more weeks. Cardiac morphology and function were quantified before/after treatment by echocardiography. After completion of the studies, pigs were euthanized and hearts excised for ex vivo studies. Results: Using IVIS technology, the BDS showed significant retention of SynB1-ELP-p50i in the heart. In the efficacy study, a single IC administration of IC SynB1-ELP-p50i reduced cardiac NF-kB expression, improved cardiac relaxation, and remodeling compared to untreated CKD (Figure). Conclusions: We show for the first time the feasibility of a targeted inhibition of cardiac NF-kB using ELP technology in a translational model of CKD and diastolic dysfunction. Our study may set the stage for a new therapeutic strategy using unique drug-delivery technology never tested before to protect the heart.

A systematic review and meta-analysis of murine models of uremic cardiomyopathy

Chronic kidney disease (CKD) triggers the risk of developing uremic cardiomyopathy as characterized by cardiac hypertrophy, fibrosis and functional impairment. Traditionally, animal studies are used to reveal the underlying pathological mechanism, although variable CKD models, mouse strains and readouts may reveal diverse results. Here, we systematically reviewed 88 studies and performed meta-analyses of 52 to support finding suitable animal models for future experimental studies on pathological kidney-heart crosstalk during uremic cardiomyopathy. We compared different mouse strains and the direct effect of CKD on cardiac hypertrophy, fibrosis and cardiac function in "single hit" strategies as well as cardiac effects of kidney injury combined with additional cardiovascular risk factors in "multifactorial hit" strategies. In C57BL/6 mice, CKD was associated with a mild increase in cardiac hypertrophy and fibrosis and marginal systolic dysfunction. Studies revealed high variability in results, especially regarding hypertrophy and systolic function. Cardiac hypertrophy in CKD was more consistently observed in 129/Sv mice, which express two instead of one renin gene and more consistently develop increased blood pressure upon CKD induction. Overall, "multifactorial hit" models more consistently induced cardiac hypertrophy and fibrosis compared to "single hit" kidney injury models. Thus, genetic factors and additional cardiovascular risk factors can "prime" for susceptibility to organ damage, with increased blood pressure, cardiac hypertrophy and early cardiac fibrosis more consistently observed in 129/Sv compared to C57BL/6 strains.

Identification of the Source of Secreted Proteins in the Kidney by Brefeldin A Injection.

Chronic kidney disease (CKD) is one of the top ten leading causes of death in the USA. Acute kidney injury (AKI), while often recoverable, predisposes patients to CKD later in life. Kidney epithelial cells have been identified as key signaling nodes in both AKI and CKD, whereby the cells can determine the course of the disease through the secretion of cytokines and other proteins. In CKD especially, several lines of evidence have demonstrated that maladaptively repaired tubular cells drive disease progression through the secretion of transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), and other profibrotic cytokines. However, identifying the source and the relative number of secreted proteins from different cell types in vivo remains challenging. This paper describes a technique using brefeldin A (BFA) to prevent the secretion of cytokines, enabling the staining of cytokines in kidney tissue using standard immunofluorescent techniques. BFA inhibits endoplasmic reticulum (ER)-to-Golgi apparatus transport, which is necessary for the secretion of cytokines and other proteins. Injection of BFA 6 h before sacrifice leads to a build-up of TGF-β, PDGF, and CTGF inside the proximal tubule cells (PTCs) in a mouse cisplatin model of AKI and TGF-β ina mouse aristolochic acid (AA) model of CKD. Analysis revealed that BFA + cisplatin or BFA + AA increased TGF-β-positive signal significantly compared to BFA + saline, cisplatin, or AA alone. These data suggest that BFA can be used to identify the cell type producing specific cytokines and quantify the relative amounts and/or different types of cytokines produced.

A Monoclonal Antibody Targeting ALK2 As a Potential Therapeutic Agent for Anemia of Inflammation

Background: Iron homeostasis is primarily regulated by hepcidin, a hormone predominantly expressed in the liver. Hepcidin activates the degradation of the transmembrane iron exporter ferroportin, thereby downregulating the release of iron from cells. Hepcidin expression is, at least partly, regulated in response to signaling of the type I TGF-β receptor ALK2, via SMAD2/3 phosphorylation. IL-6, which is commonly elevated in chronic kidney disease (CKD) and other inflammatory conditions, upregulates hepcidin expression and reduces serum iron bioavailability. As a result, chronic inflammatory conditions are often accompanied by secondary anemia of inflammation (AI).We have previously demonstrated that ALK2 inhibition suppressed hepcidin expression in rodents, monkeys and healthy humans. We further described that administration of a selective small molecule ALK2 kinase inhibitor (KTI-2338) reversed changes in hepcidin and iron in a mouse model of CKD, supporting the potential benefit of ALK2 inhibition in AI. Another approach to targeting ALK2 signaling is use of a neutralizing antibody. KTI-018 is a neutralizing ALK2 antibody with high affinity and selectivity for ALK2. This biologic has been demonstrated to reduce serum hepcidin and increase serum iron in healthy non-human primates.Aims: To further elucidate the specific contribution of ALK2 signaling as a driver in AI, and to determine the therapeutic potential of the antibody in this type of anemia, we assessed the effect of KTI-018 in the CKD mouse model.Methods: The study was conducted with 6-week-old male C57Bl/6 mice. Mice in the CKD cohort (CKD) were treated with once daily oral administration of adenine, a compound that metabolizes to 2,8-dihydroxyadenine, forming crystals in the proximal tubular epithelia and causing inflammation and fibrosis in the kidneys. Mice in the control cohort (healthy) received once daily oral administration of vehicle.Upon confirmation of disease, the CKD cohort was subdivided into two groups. The treatment group received twice weekly intraperitoneal treatment with KTI-018 (CKD-KTI-018), and the control group received tris-buffered saline (CKD-TBS). Healthy mice received TBS only. All mice were maintained on their assigned daily adenine or vehicle regimen. At day 53, the study was terminated and hematologic parameters, serum hepcidin, iron, and IL-6 levels were assessed.Results: After 42 days of adenine or vehicle administration, serum hepcidin, serum iron, and hematologic parameters were assessed in representative cohorts of CKD-TBS and healthy mice. The CKD-TBS cohort experienced changes associated with anemia of inflammation as compared to the healthy mice, including increased hepcidin, decreased serum iron, and decreased hematologic parameters. The differences between the healthy and CKD-TBS groups were maintained through the duration of the study.At study termination, CKD-TBS mice had increased serum IL-6 levels (218%), elevated serum hepcidin (149%), and reduced serum iron (-30%) as compared to the healthy mice. Laboratory findings characteristic of anemia were present in the CKD-TBS group, including decreased red blood cells (-6.1%), hemoglobin (-13.2%), and reticulocyte hemoglobin content (-9.3%) as compared to healthy mice.In contrast, CKD-KTI-018 mice had decreased serum hepcidin (-25%) and increased serum iron (59%) as compared to CKD-TBS mice. This restoration of serum iron corresponded to improvements in red blood cells, hemoglobin, and reticulocyte hemoglobin content, which were increased by 7.6%, 9.6%, and 6.7%, respectively, in the CKD-KTI-018 mice as compared to the CKD-TBS mice. These results demonstrate that, by decreasing serum hepcidin, KTI-018 increased the bioavailability of iron, which led to the restoration of hematologic parameters and appeared to reverse AI in mice.Discussion: In this study, a neutralizing ALK2 antibody decreased serum hepcidin, increased serum iron and consequently reversed AI in a mouse model of CKD. These results support the role of ALK2 signaling in AI and suggest that inhibition of ALK2 may be a potential treatment approach for anemia resulting from CKD and other chronic inflammatory diseases. Future studies will explore if ALK2 inhibition may prevent or treat progression of CKD itself, and the role that ALK2 inhibition may play in other chronic inflammatory conditions associated with elevated hepcidin. DisclosuresMedeiros: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company. Backus: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company. Materna: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company. Fisher: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company. Lachey: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Seehra: Keros Therapeutics: Current Employment, Current equity holder in publicly-traded company.

Scoring model to predict risk of chronic kidney disease in Chinese health screening examinees with type 2 diabetes

PurposeAs health screening continues to increase in China, there is an opportunity to integrate a large number of demographic as well as subjective and objective clinical data into risk prediction modeling. The aim of this study was to develop and validate a prediction model for chronic kidney disease (CKD) in Chinese health screening examinees with type 2 diabetes mellitus (T2DM).MethodsWe conducted a retrospective cohort study consisting of 2051 Chinese T2DM patients between 35 and 78 years old who were enrolled in the XY3CKD Follow-up Program between 2009 and 2010. All participants were randomly assigned into a derivation set or a validation set at a 2:1 ratio. Cox proportional hazards regression model was selected for the analysis of risk factors for the development of the proposed risk model of CKD. We established a prediction model with a scoring system following the steps proposed by the Framingham Heart Study.ResultsThe mean follow-up was 8.52 years, with a total of 315 (23.20%) and 189 (27.27%) incident CKD cases in the derivation set and validation set, respectively. We identified the following risk factors: age, gender, body mass index, duration of type 2 diabetes, variation of fasting blood glucose, stroke, and hypertension. The points were summed to obtain individual scores (from 0 to 15). The areas under the curve of 3-, 5- and 10-year CKD risks were 0.843, 0.799 and 0.780 in the derivation set and 0.871, 0.803 and 0.785 in the validation set, respectively.ConclusionsThe proposed scoring system is a promising tool for further application of assisting Chinese medical staff for early prevention of T2DM complications among health screening examinees.

TDAG51 induces renal interstitial fibrosis through modulation of TGF-\u03b2 receptor 1 in chronic kidney disease

Chronic kidney disease (CKD) is characterized by the gradual loss of renal function and is a major public health concern. Risk factors for CKD include hypertension and proteinuria, both of which are associated with endoplasmic reticulum (ER) stress. ER stress-induced TDAG51 protein expression is increased at an early time point in mice with CKD. Based on these findings, wild-type and TDAG51 knock-out (TDKO) mice were used in an angiotensin II/deoxycorticosterone acetate/salt model of CKD. Both wild-type and TDKO mice developed hypertension, increased proteinuria and albuminuria, glomerular injury, and tubular damage. However, TDKO mice were protected from apoptosis and renal interstitial fibrosis. Human proximal tubular cells were used to demonstrate that TDAG51 expression induces apoptosis through a CHOP-dependent mechanism. Further, a mouse model of intrinsic acute kidney injury demonstrated that CHOP is required for ER stress-mediated apoptosis. Renal fibroblasts were used to demonstrate that TGF-β induces collagen production through an IRE1-dependent mechanism; cells treated with a TGF-β receptor 1 inhibitor prevented XBP1 splicing, a downstream consequence of IRE1 activation. Interestingly, TDKO mice express significantly less TGF-β receptor 1, thus, preventing TGF-β-mediated XBP1 splicing. In conclusion, TDAG51 induces apoptosis in the kidney through a CHOP-dependent mechanism, while contributing to renal interstitial fibrosis through a TGF-β-IRE1-XBP1 pathway.

Comparing the renoprotective effects of BM-MSCs versus BM-MSC-exosomes, when combined with an anti-fibrotic drug, in hypertensive mice

Fibrosis, a hallmark of chronic kidney disease (CKD), impairs the viability of human bone marrow derived-mesenchymal stromal cells (BM-MSCs) post-transplantation. To address this, we demonstrated that combining BM-MSCs with the anti-fibrotic drug, serelaxin (RLX), enhanced BM-MSC-induced renoprotection in preclinical CKD models. Given the increased interest and manufacturing advantages to using stem cell-derived exosomes (EXO) as therapeutics, this study determined whether RLX could enhance the therapeutic efficacy of BM-MSC-EXO, and compared the renoprotective effects of RLX and BM-MSC-EXO versus RLX and BM-MSCs in mice with hypertensive CKD. Adult male C57BL/6 mice were uninephrectomised, received deoxycorticosterone acetate and given saline to drink (1K/DOCA/salt) for 21 days. Control mice were uninephrectomised and given normal drinking water for the same time-period. Subgroups of 1K/DOCA/salt-hypertensive mice were then treated with either RLX (0.5 mg/kg/day) or BM-MSC-EXO (25 μg/mouse; equivalent to 1–2 × 106 BM-MSCs/mouse) alone; combinations of RLX and BM-MSC-EXO or BM-MSCs (1 × 106/mouse); or the mineralocorticoid receptor antagonist, spironolactone (20 mg/kg/day), from days 14–21. 1K/DOCA/salt-hypertensive mice developed kidney tubular damage, inflammation and fibrosis, and impaired kidney function 21 days post-injury. Whilst RLX alone attenuated the 1K/DOCA/salt-induced fibrosis, BM-MSC-EXO alone only diminished measures of tissue inflammation post-treatment. Comparatively, the combined effects of RLX and BM-MSC-EXO or BM-MSCs demonstrated similar anti-fibrotic efficacy, but RLX and BM-MSCs offered broader renoprotection over RLX and/or BM-MSC-EXO, and comparable effects to spironolactone. Only RLX and BM-MSCs, but not RLX and/or BM-MSC-EXO, also attenuated the 1K/DOCA/salt-induced hypertension. Hence, although RLX improved the renoprotective effects of BM-MSC-EXO, combining RLX with BM-MSCs provided a better therapeutic option for hypertensive CKD.

Hydrogen sulfide suppresses the proliferation of intestinal epithelial cells through cell cycle arrest

The pathogenesis of chronic kidney disease (CKD) is closely related to the changes in the intestinal microbiota and integrity. Our previous studies have shown the accumulation of hydrogen sulfide (H2S)-producing bacterial family, Desulfovibrionacea, in the colon of a murine model of CKD, suggesting that the increased H2S contributes to the impaired intestinal integrity in CKD. Here, we investigated the anti-proliferative effect of H2S in the intestinal epithelial cells. A slow- H2S releasing molecule GYY4137 ((p-methoxyphenyl)morpholino-phosphinodithioic acid) reduced the proliferation of Caco-2 and IEC-6 cells. Flow cytometric analysis demonstrated that GYY4137 accumulated Caco-2 cells in the S phase fraction, suggesting that H2S arrested the cell cycle at G2 and/or M phases. The RNA sequencing analysis demonstrated that GYY4137 modulated the mRNA expression of the genes involved in the G2/M and the spindle assembly checkpoints; increased mRNA levels of Cdkn1a, Gadd45a, and Sfn and decreased mRNA levels of Cdc20, Pttg1, and Ccnb1 were observed. These alterations were confirmed by quantitative reverse transcription-polymerase chain reaction and Western blot analyses. Besides, studies exploring the MEK inhibitor indicated that MEK activation is involved in the GYY4137-mediated increase in the Sfn expression. Altogether, our data showed that H2S reduced the proliferation of intestinal epithelial cells through transcriptional regulation in G2/M and the spindle assembly checkpoints. This may be one of the underlying mechanisms for the observed impaired intestinal integrity in CKD.