Isocitrate dehydrogenase 1 upregulation in urinary extracellular vesicles from proximal tubules of type 2 diabetic rats.

Diabetic nephropathy (DN) is a major cause of chronic kidney disease. Microalbuminuria is currently the most common non-invasive biomarker for the early diagnosis of DN. However, renal structural damage may have advanced when albuminuria is detected. In this study, we sought biomarkers for early DN diagnosis through proteomic analysis of urinary extracellular vesicles (uEVs) from type 2 diabetic model rats and normal controls. Isocitrate dehydrogenase 1 (IDH1) was significantly increased in uEVs from diabetic model rats at the early stage despite minimal differences in albuminuria between the groups. Calorie restriction significantly suppressed the increase in IDH1 in uEVs and 24-hour urinary albumin excretion, suggesting that the increase in IDH1 in uEVs was associated with the progression of DN. Additionally, we investigated the origin of IDH1-containing uEVs based on their surface sugar chains. Lectin affinity enrichment and immunohistochemical staining showed that IDH1-containing uEVs were derived from proximal tubules. These findings suggest that the increase in IDH1 in uEVs reflects pathophysiological alterations in the proximal tubules and that IDH1 in uEVs may serve as a potential biomarker of DN in the proximal tubules.

Ultrasensitive CCL2 Detection in Urine for Diabetic Nephropathy Diagnosis Using a WS2-Based Plasmonic Biosensor.

The accurate diagnosis of diabetic nephropathy relies on achieving ultrasensitive biosensing for biomarker detection. However, existing biosensors face challenges such as poor sensitivity, complexity, time-consuming procedures, and high assay costs. To address these limitations, we report a WS2-based plasmonic biosensor for the ultrasensitive detection of biomarker candidates in clinical human urine samples associated with diabetic nephropathy. Leveraging plasmonic-based electrochemical impedance microscopy (P-EIM) imaging, we observed a remarkable charge sensitivity in monolayer WS2 single crystals. Our biosensor exhibits an exceptionally low detection limit (0.201 ag/mL) and remarkable selectivity in detecting CC chemokine ligand 2 (CCL2) protein biomarkers, outperforming conventional techniques such as ELISA. This work represents a breakthrough in traditional protein sensors, providing a direction and materials foundation for developing ultrasensitive sensors tailored to clinical applications for biomarker sensing.

Urine Albumin-Creatinine Ratio Variability in People With Type 2 Diabetes: Clinical and Research Implications.

RATIONALE & OBJECTIVE: Evidence has demonstrated that albuminuria is a key diagnostic and prognostic marker of diabetic chronic kidney disease, but the impact of its day-to-day variability has not been adequately considered. This study quantified within-individual variability of albuminuria in people with type 2 diabetes to inform clinical albuminuria monitoring. STUDY DESIGN: Descriptive cross-sectional analysis. SETTING & PARTICIPANTS: People with type 2 diabetes (n=826, 67.1 [IQR, 60.3-72.4] years, 64.9% male) participating in the Progression of Diabetic Complications (PREDICT) cohort study. EXPOSURE: Four spot urine collections for measurement of urinary albumin-creatinine ratio (UACR) within 4 weeks. OUTCOME: Variability of UACR. ANALYTICAL APPROACH: We characterized within-individual variability (coefficient of variation [CV], 95% limits of random variation, intraclass correlation coefficient), developed a calculator displaying probabilities that any observed difference between a pair of UACR values truly exceeded a 30% difference, and estimated the ranges of diagnostic uncertainty to inform a need for additional UACR collections to exclude or confirm albuminuria. Multiple linear regression examined factors influencing UACR variability. RESULTS: We observed high within-individual variability (CV 48.8%; 95% limits of random variation showed a repeated UACR to be as high/low as 3.78/0.26 times the first). If a single-collection UACR increased from 2 to 5mg/mmol, the probability that UACR actually increased by at least 30% was only 50%, rising to 97% when 2 collections were obtained at each time point. The ranges of diagnostic uncertainty were 2.0-4.0mg/mmol after an initial UACR test, narrowing to 2.4-3.2 and 2.7-2.9mg/mmol for the mean of 2 and 3 collections, respectively. Some factors correlated with higher (female sex; moderately increased albuminuria) or lower (reduced estimated glomerular filtration rate and sodium-glucose cotransporter 2 inhibitor/angiotensin-converting enzyme inhibitor/angiotensin receptor blocker treatment) within-individual UACR variability. LIMITATIONS: Reliance on the mean of 4 UACR collections as the reference standard for albuminuria. CONCLUSIONS: UACR demonstrates a high degree of within-individual variability among individuals with type 2 diabetes. Multiple urine collections for UACR may improve capacity to monitor changes over time in clinical and research settings but may not be necessary for the diagnosis of albuminuria. PLAIN-LANGUAGE SUMMARY: Albuminuria (albumin in urine) is a diagnostic and prognostic marker of diabetic chronic kidney disease. However, albuminuria can vary within an individual from day to day. We compared 4 random spot urinary albumin-creatinine ratio (UACR) samples from 826 participants. We found that a second UACR collection may be as small as a fourth or as large as almost 4 times the first sample's UACR level. This high degree of variability presents a challenge to our ability to interpret changes in albuminuria. Multiple collections have been suggested as a solution. We have constructed tools that may aid clinicians in deciding how many urine collections are required to monitor and diagnose albuminuria. Multiple urine collections may be required for individual monitoring but not necessarily for diagnosis.

Urinary sphingolipids in adolescents and young adults with youth-onset diabetes.

BACKGROUND: This study evaluated urinary sphingolipids as a marker of diabetic kidney disease (DKD) in adolescents and young adults with youth-onset type 1 and type 2 diabetes. METHODS: A comprehensive panel of urinary sphingolipids, including sphingomyelin (SM), glucosylceramide (GC), ceramide (Cer), and lactosylceramide (LC) species, was performed in patients with youth-onset diabetes from the SEARCH for Diabetes in Youth cohort. Sphingolipid levels, normalized to urine creatinine, were compared in 57 adolescents and young adults with type 1 diabetes, 59 with type 2 diabetes, and 44 healthy controls. The association of sphingolipids with albumin-to-creatinine (ACR) ratio and estimated glomerular filtration rate (eGFR) was evaluated. RESULTS: The median age (interquartile range [IQR]) of participants was 23.1 years (20.9, 24.9) and the median duration of diabetes was 9.3 (8.5, 10.2) years. Urinary sphingolipid concentrations in patients with and without DKD (ACR ≥ 30 mg/g) were significantly elevated compared to healthy controls. There were no significant differences in sphingolipid levels between participants with type 1 and type 2 diabetes. In multivariable analysis, many sphingolipid species were positively correlated with ACR. Most significant associations were evident for the following species: C18 SM, C24:1 SM, C24:1 GC, and C24:1 Cer (all p < 0.001). Sphingolipid levels were not associated with eGFR. However, several interaction terms (diabetes type*sphingolipid) were significant, indicating diabetes type may modify the association of sphingolipids with eGFR. CONCLUSION: Urinary sphingolipids are elevated in adolescents and young adults with youth-onset diabetes and correlate with ACR. Urinary sphingolipids may therefore represent an early biomarker of DKD.

Study of Neutrophil Gelatinase Associated Lipocalin and Kidney Injury Molecule-1 in Patients with Type 2 Diabetes Mellitus Nephropathy.

BACKGROUND: There is a need for accurate and rapid biomarkers for the early diagnosis of diabetic nephropathy (DN). We aimed to study the accuracy of urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary kidney injury molecule-1 (uKIM-1), and blood NGAL (bNGAL) in type 2 diabetics as biomarkers for diagnosis of DN. METHODS: The study was a retrospective case-control study that included 30 control subjects, 40 diabetics with normo-albuminuria < 30 mg/g and eGFR > 60 mL/minute/1.73 m2, and 30 diabetics with albuminuria > 30mg/g and eGFR < 60mL/minute/1.73 m2. Blood and urine samples were obtained to determine levels of bNGAL, uNAGAL, and uKIM1. RESULTS: There was a significant increase in bNGAL, uNGAL, uKIM 1, uNGAL/creatinine and uKIM 1/creatinine among diabetics with albuminuria compared to diabetics with normoalbuminuria and normal control (p < 0.001 for all markers). For diagnosis of early DN, both bNGAL and uKIM 1 had sensitivity and specificity of 100% for each at cutoff values of 322.5 pg/mL and 74.25 ng/mL, respectively. uNGAL had a sensitivity of 97.5% and a spec-ificity of 100% at a cutoff point of 565 ng/mL. uKIM1/creatinine at a cutoff of 51.2 had a sensitivity of 100% and specificity of 100%. CONCLUSIONS: The present study highlights the accuracy of urinary KIM1 and NGAL and blood NGAL as biomarkers for the diagnosis of nephropathy in the early stage of diabetic nephropathy. There were positive correlations with kidney function tests creatinine, blood urea nitrogen, and the presence of albuminuria.

Screening candidate diagnostic biomarkers for diabetic kidney disease.

BACKGROUND: There are big differences in treatments and prognosis between diabetic kidney disease (DKD) and non-diabetic renal disease (NDRD). However, DKD patients couldn't be diagnosed early due to lack of special biomarkers. Urine is an ideal non-invasive sample for screening DKD biomarkers. This study aims to explore DKD special biomarkers by urinary proteomics. MATERIALS AND METHODS: According to the result of renal biopsy, 142 type 2 diabetes mellitus (T2DM) patients were divided into 2 groups: DKD (n = 83) and NDRD (n = 59). Ten patients were selected from each group to define urinary protein profiles by label-free quantitative proteomics. The candidate proteins were further verifyied by parallel reaction monitoring (PRM) methods (n = 40). Proteins which perform the same trend both in PRM and proteomics were verified by enzyme-linked immunosorbent assays (ELISA) with expanding the sample size (n = 82). The area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of diagnostic biomarkers. RESULTS: We identified 417 peptides in urinary proteins showing significant difference between DKD and NDRD. PRM verification identified C7, SERPINA4, IGHG1, SEMG2, PGLS, GGT1, CDH2, CDH1 was consistent with the proteomic results and p < 0.05. Three potential biomarkers for DKD, C7, SERPINA4, and gGT1, were verified by ELISA. The combinatied SERPINA4/Ucr and gGT1/Ucr (AUC = 0.758, p = 0.001) displayed higher diagnostic efficiency than C7/Ucr (AUC = 0.632, p = 0.048), SERPINA4/Ucr (AUC = 0.661, p = 0.032), and gGT1/Ucr (AUC = 0.661, p = 0.029) respectively. CONCLUSIONS: The combined index SERPINA4/Ucr and gGT1/Ucr can be considered as candidate biomarkers for diabetic nephropathy after adjusting by urine creatinine.

URINARY EXCRETION OF ALPHA-ACTININ-4 AND TIGHT JUNCTION PROTEIN 1 IN PATIENTS WITH TYPE 2 DIABETES AND DIFFERENT PATTERNS OF CHRONIC KIDNEY DISEASE.

Abnormalities of the cytoskeleton and the slit diaphragm of podocytes have been attributed to diabetic nephropathy. In this study, we assessed urinary excretion of alpha-actinin-4 (ACTN-4), a cytoskeleton protein and a component of the slit diaphragm, and tight junction protein 1 (TJP-1, or ZO-1), a peripheral membrane protein that forms molecular complexes with actin filaments, in patients with type 2 diabetes (T2D) and albuminuric or non-albuminuric chronic kidney disease (CKD). The study included 140 patients with long-term T2D (≥10 years) and 20 healthy subjects as control. Patterns of CKD were identified based on the estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR). Urinary ACTN-4 and TJP-1 were assessed by ELISA. Patients with T2D had increased urinary excretion of ACTN-4 (p=0.03) and TJP-1 (p=0.006). In logistic regression models, both ACTN-4 and TJP-1 demonstrated associations with albuminuric CKD (UACR ≥3.0 mg/mmol and eGFR <60 mL/min×1.73 m2) after adjusting to age, sex, diabetes duration, HbA1c, and smoking. In ROC-analysis, TJP-1 excretion ≥70 pg/mmol was associated with albuminuric CKD (OR 5.45, 95% CI 1.96-15.18, p=0.001). The results demonstrate that elevated urinary ACTN-4 and TJP-1 are associated specifically with albuminuric CKD, but not with non-albuminuric CKD, in T2D patients.

Finerenone in chronic kidney disease and type 2 diabetes: the known and the unknown.

The novel nonsteroidal mineralocorticoid receptor antagonist finerenone has been shown to reduce the risk of kidney and cardiovascular outcomes in patients with type 2 diabetes and chronic kidney disease. In this issue of Kidney International, Bakris et al. present new data on the kidney efficacy of finerenone across subgroups of estimated glomerular filtration rate and urinary albumin-to-creatinine ratio, as well as safety data. We attempt to place these results in context by discussing the benefits and risks of finerenone, as well as the generalizability of the study findings to routine care settings.

Albuminuria and cardiorenal risk.

PURPOSE OF REVIEW: This article explores the prognostic association of albuminuria with the risk of adverse health outcomes and also provides an overview of novel guideline-directed therapies that confer cardiorenal protection in chronic kidney disease (CKD) patients with or without type 2 diabetes. RECENT FINDINGS: Although the identification of CKD is based on the simultaneous assessment of estimated glomerular filtration rate and albuminuria, recent studies have shown that the regular screening rate for an increased urinary albumin-to-creatinine ratio is very low in daily clinical practice. Accordingly, a large proportion of high-risk patients with early-stage CKD remain unidentified, missing the opportunity to receive optimized treatment with novel agents that are effective in causing regression of albuminuria and in improving adverse cardiorenal outcomes. SUMMARY: The broader implementation of albuminuria assessment in daily clinical practice facilitates the identification of high-risk patients with early-stage CKD who are candidates for treatment with sodium-glucose co-transporter type 2 inhibitors, glucagon-like peptide-1 receptor agonists and the nonsteroidal mineralocorticoid receptor antagonist finerenone. These novel drug categories have modified the role of albuminuria from a powerful cardiorenal risk predictor to a modifiable target of therapy.

Designing stimuli-responsive upconversion nanoparticles based on a mimetic immunoassay for potential accurate diabetic nephropathy diagnosis.

Diabetic nephropathy (DN) is the most common microvascular complication associated with incurable diabetes. The gold standard diagnostic method for DN is based on the detection of proteinuria but it overlooks cases of non-proteinuria (NP-DN). To address this limitation, urinary sialic acid (SA) has been confirmed as an effective biomarker for various DNs. Herein, we constructed an ultrasensitive non-proteinuria assay platform to accurately diagnose DN within 20 min. This platform utilized the ninhydrin reaction between acidic ninhydrin and urinary sialic acid (SA) as an effective biomarker for various DNs. A compound with a maximum absorption peak at 470 nm was produced in this reaction and contributed to the fluorescence decrease of the blue-emission core-shell upconverting nanoparticles through the inner filter effect (IFE). By integrating the inner filter effect (IFE) with a mimetic immunoassay, the imperceptible color was converted into highly sensitive fluorescence signals. This protocol shows a stable and high sensitivity with a detection limit of 20 nmol L-1 and provides 100% positive prediction for urine samples, demonstrating its potential for clinical diagnosis and long-term monitoring of DN.

RISK FACTORS FOR DIABETIC NEPHROPATHY IN DIABETES MELLITUS TYPE 1.

OBJECTIVE: The aim: To find the risk factors of microalbuminuria and estimated Glomerular Filtration Rate (eGFR) in patients with type 1 diabetes mellitus. PATIENTS AND METHODS: Materials and methods: One hundred ten patients of type 1 diabetes mellitus in this cross-sectional study at diabetic and endocrinology center in Al-Najaf during the period from September 2021 to March 2022. All patients were asked about sociodemographic characteristics (age, gender, smoking, duration of DM type1, family history of DM type1), measured (body mass index BMI, blood pressure) and laboratory investigations done to all patients (G.U.E, s. creatinine, lipid profile, HBA1C, calculated estimated Glomerular Filtration Rate (eGFR) and Spot Urine Albumin-Creatinine Ratio (ACR). RESULTS: Results: Out of 110 patients, 62 male and 48 female, the mean age was (22±12). The patients with microalbuminuria (ACR ≥ 30 mg/g) show statistically significant with increase HBA1C, duration of DM type 1, total cholesterol (T.C), low density lipoprotein (LDL), triglycerides (TG) and family history of DM type 1, while there were not statistically significant with age, gender, smoking, BMI, eGFR, high density lipoprotein (HDL) and hypertension. Patients with eGFR<90mL/min/1.73m2 show statistically significant with increase HBA1C, duration of DM type1, LDL, TG, T.C, while significantly decrease in HDL and there were not statistically significant with age, gender, smoking, family history of DM type 1, BMI and hypertension. CONCLUSION: Conclusions: The degree of glycemic control, duration of type1 (DM) and dyslipidemia were associated with increased microalbuminuria and reduced eGFR (nephropathy). Family history of DM type1 was risk factor for microalbuminuria.

Meta-Analysis of the Efficacy and Safety of Finerenone in Diabetic Kidney Disease.

BACKGROUND: The phase III clinical trial of the nonsteroidal mineralocorticoid receptor antagonist finerenone (BAY 94-8862) has been completed, aiming to investigate renal and cardiovascular outcomes in type 2 diabetes (T2D) with chronic kidney disease (CKD). However, the efficacy and safety of finerenone in renal function remain controversial. The purpose of this study was to explore the efficacy and safety of finerenone in treating the patients with diabetic kidney disease (DKD). METHODS: Databases of PubMed, Cochrane Library, Embase, and Web of Science were searched for randomized controlled trials (RCTs) on patients with DKD receiving finerenone treatment from inception to September 2021. Data including patient characteristics and interested outcomes were extracted, and the dichotomous data and continuous variables were evaluated using risk ratio (RR) with 95% confidence intervals (CIs) and mean differences (MD) with 95% CIs, respectively. RESULTS: A total of 4 RCTs involving 13,945 patients were included in this meta-analysis. Analysis results demonstrated that patients receiving finerenone showed a significant decrease in changing urinary albumin-to-creatinine ratio (UACR) from baseline (MD: -0.30; 95% CI [-0.33, -0.27], p = 0.46, I2 = 0%) (p < 0.05). The number of patients with ≥40% reduction in estimated glomerular filtration rate (eGFR) from baseline in the finerenone group was significantly smaller than that in the placebo group (RR: 0.85; 95% CI [0.78, 0.93], p = 0.60, I2 = 0%) (p < 0.05). No difference was found in adverse events between the finerenone and placebo groups (RR: 1.00; 95% CI [0.98, 1.01], p = 0.94, I2 = 0%) (p = 0.65). The incidence of hyperkalemia was higher in the finerenone group than that in the placebo group (RR: 2.03; 95% CI [1.83, 2.26], p = 0.95, I2 = 0%) (p < 0.05). CONCLUSION: Finerenone contributes to the reduction of UACR and can ameliorate the deterioration of renal function in patients with T2D and CKD. The higher risk of hyperkalemia was found in the finerenone group compared with placebo; however, there was no difference in the risk of overall adverse events.

Serum Trimethylamine N-oxide and the Diversity of the Intestinal Microbial Flora in Type 2 Diabetes Complicated by Diabetic Kidney Disease.

BACKGROUND: Trimethylamine N-oxide (TMAO) serves as a metabolite of intestinal bacteria as well as a urotoxin influencing the prognosis of chronic kidney disease (CKD), which has become a research hotspot in the field of kidney disease. This study preliminarily explored the alternations of the microbial flora and serum TMAO in patients with type 2 diabetes mellitus (T2DM) complicated with diabetic kidney disease (DKD). METHODS: Seventeen T2DM patients at the Affiliated Hospital of Zunyi Medical University between September 2018 and February 2019 were included. Among these patients, 8 patients had T2DM complicated with DKD. Eight healthy volunteers constituted the control group. Fresh stool was collected for Illumina sequencing. Based on the sequencing outcomes, the flora diversity and species differences were analyzed. Serum TMAO, cystatin C, urinary albumin/urine creatinine ratios (ACRs), and routine biochemical outcomes were also compared. RESULTS: The DKD group exhibited a significantly higher TMAO level than the remaining groups. The high-TMAO group had a significantly increased ACR level compared with the low-TMAO group. TMAO positively correlated with the ACR. Compared with the control group, the DKD group exhibited a decreased flora diversity. At the genus level, both the T2DM group and the DKD group showed decreased numbers of Alloprevotella and Megasphaera compared with the control group. The difference in Megasphaera between the DKD group and the control group was significant. CONCLUSIONS: The alternation of the intestinal microbial flora may participate in the development of DKD, and TMAO and chronic inflammation might be important factors for DKD development.

What can urinary exosomes tell us?

Exosomes are involved in a wide variety of biochemical processes in human body homeostasis. Exosomes also provide important information regarding communications among several organ systems. Additionally, they can serve as molecular vehicles to deliver drugs. Therefore, exosomes have received wide attention in current biomedical research for unraveling pathogenic mechanisms of diseases, searching for novel biomarkers, and discovering new drugs. This paper reviews and discusses the significance of urinary exosomes for a better understanding of human disease pathophysiology and their potential use as therapeutic targets. Isolation methods of exosomes and the latest technological advances are also discussed. Furthermore, novel urinary exosomal biomarkers are highlighted with special emphasis on their clinical applicability (particularly sensitivity, specificity, reliability, and other aspects). Finally, future trends for this field are analyzed and our perspectives are provided.

Management of hypertension and renin-angiotensin-aldosterone system blockade in adults with diabetic kidney disease: Association of British Clinical Diabetologists and the Renal Association UK guideline update 2021.

People with type 1 and type 2 diabetes are at risk of developing progressive chronic kidney disease (CKD) and end-stage kidney failure. Hypertension is a major, reversible risk factor in people with diabetes for development of albuminuria, impaired kidney function, end-stage kidney disease and cardiovascular disease. Blood pressure control has been shown to be beneficial in people with diabetes in slowing progression of kidney disease and reducing cardiovascular events. However, randomised controlled trial evidence differs in type 1 and type 2 diabetes and different stages of CKD in terms of target blood pressure. Activation of the renin-angiotensin-aldosterone system (RAAS) is an important mechanism for the development and progression of CKD and cardiovascular disease. Randomised trials demonstrate that RAAS blockade is effective in preventing/ slowing progression of CKD and reducing cardiovascular events in people with type 1 and type 2 diabetes, albeit differently according to the stage of CKD. Emerging therapy with sodium glucose cotransporter-2 (SGLT-2) inhibitors, non-steroidal selective mineralocorticoid antagonists and endothelin-A receptor antagonists have been shown in randomised trials to lower blood pressure and further reduce the risk of progression of CKD and cardiovascular disease in people with type 2 diabetes. This guideline reviews the current evidence and makes recommendations about blood pressure control and the use of RAAS-blocking agents in different stages of CKD in people with both type 1 and type 2 diabetes.

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

AIM: This study aimed to evaluate the association of toll-like receptor (TLR) inflammatory cascade with the development of diabetic kidney disease (DKD) in children and adolescents with type 1 diabetes (T1D). METHODS: A total of 49 T1D patients and 49 normoglycaemic (NG) subjects aged 5-20 years old were recruited. TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 mRNA expressions were measured in peripheral blood mononuclear cells by reverse transcription-quantitative polymerase chain reaction. Fasting glucose, glycated haemoglobin, serum urea, serum creatinine and urinary albumin-to-creatinine ratio (ACR) were determined. RESULTS: The mRNA expressions of TLR2, TLR4, MYD88 and NFKB were significantly increased in the T1D group compared with the NG group. The mRNA expression levels of MCP1/CCL2 and IL18 were higher in 21 T1D patients (42.9%) (average of MCP1/CCL2: 6.6-fold and IL18: 5.8-fold) than in NG patients. Furthermore, ACR was increased in the T1D group compared with the NG group. CONCLUSION: The increased mRNA expression of TLR2, TLR4, MYD88, NFKB, MCP1/CCL2 and IL18 favours the development of an inflammatory process that may lead to a decline in renal function and consequently DKD in children and adolescents with T1D. This suggests that these genes are early mediators of onset DKD since the beginning of the lives of the paediatric T1D patients.

Early Response in Albuminuria and Long-Term Kidney Protection during Treatment with an Endothelin Receptor Antagonist: A Prespecified Analysis from the SONAR Trial.

BACKGROUND: Whether early reduction in albuminuria with atrasentan treatment predicts its long-term kidney-protective effect is unknown. METHODS: To assess the long-term effects on kidney outcomes of atrasentan versus placebo in the SONAR trial, we enrolled patients who had type 2 diabetes and CKD (stage 2-4) and a urinary albumin creatinine ratio (UACR) of 300-5000 mg/g; participants were receiving maximum tolerated renin-angiotensin system inhibition. After 6 weeks exposure to 0.75 mg/day atrasentan (enrichment period), participants were randomized (stratified by UACR response during enrichment, ranging from ≤60% to >0%) to continue atrasentan or transition to placebo. Primary kidney outcome was a composite of sustained serum creatinine doubling or ESKD. RESULTS: UACR response to atrasentan during enrichment persisted throughout the double-blind treatment phase and predicted the primary kidney outcome, whereas UACR levels with placebo remained below pre-enrichment values in the two highest UACR response strata, and exceeded pre-enrichment values in the two lowest strata. As a result, early UACR response to atrasentan during enrichment was also associated with the primary kidney outcome during placebo. Accordingly, the predictive effect of early albuminuria changes during atrasentan was eliminated after placebo correction, leading to a consistent relative risk reduction for the primary kidney outcome with atrasentan compared with placebo, irrespective of the initial UACR response. The difference between atrasentan and placebo in UACR during double-blind treatment was also consistent across UACR response strata. CONCLUSIONS: Our findings do not support UACR response as a causal predictor of atrasentan's treatment effect. However, the variable trajectory in UACR with placebo, aspects of the trial design, day-to-day variability in albuminuria, and potential long-lasting effects of atrasentan may have contributed.

Upregulation of miR145 and miR126 in EVs from Renal Cells Undergoing EMT and Urine of Diabetic Nephropathy Patients.

Diabetic nephropathy (DN) is a severe kidney-related complication of type 1 and type 2 diabetes and the most frequent cause of end-stage kidney disease. Extracellular vesicles (EVs) present in the urine mainly derive from the cells of the nephron, thus representing an interesting tool mirroring the kidney's physiological state. In search of the biomarkers of disease progression, we here assessed a panel of urinary EV miRNAs previously related to DN in type 2 diabetic patients stratified based on proteinuria levels. We found that during DN progression, miR145 and miR126 specifically increased in urinary EVs from diabetic patients together with albuminuria. In vitro, miRNA modulation was assessed in a model of TGF-ß1-induced glomerular damage within a three-dimensional perfusion system, as well as in a model of tubular damage induced by albumin and glucose overload. Both renal tubular cells and podocytes undergoing epithelial to mesenchymal transition released EVs containing increased miR145 and miR126 levels. At the same time, miR126 levels were reduced in EVs released by glomerular endothelial cells. This work highlights a modulation of miR126 and miR145 during the progression of kidney damage in diabetes as biomarkers of epithelial to mesenchymal transition.

[Association study of serum LncRNA MALAT1 and SAA with type 2 diabetic kidney disease].

To investigate the correlation of serum long noncoding RNA-metastasis associated lung adenocarcinoma transcript 1(LncRNA MALAT1) and serum amyloid A(SAA) with diabetic kidney disease. Retrospective research was used, and 40 patients with type 2 diabetes and 80 patients with type 2 diabetic kidney disease patients who were treated in Tianjin Medical University Chu Hsien-I Memorial Hospital from August 2021 to February 2022 were selected, and 40 healthy subjects were selected during the same period. Reverse transcription-polymerase chain reaction(RT-PCR) was used to detect serum LncRNA MALAT1. SAA were detected with enzyme linked immunosorbent assay (ELISA). Automatic biochemistry analyzer was used to detect serum creatinine (CREA) and low-density lipoprotein cholesterol(LDL-C),automatic blood glucose analyzer to detect serum fasting plasma glucose (FPG), automatic glycated hemoglobin analyzer to detect hemoglobin A1C (HbA1c), and automatic immunoassay analyzer to detect urinary albumin to creatinine ratio(UACR). Differences between groups were compared by t test and analysis of variance. Pearson analysis was used to analyze the correlation between MALAT1, SAA and other indicators. Receiver operating characteristic curve(ROC) was used to evaluate the auxiliary diagnostic value of MALAT1 and SAA for diabetic kidney disease. The results showed that MALAT1 and SAA in the diabetic kidney disease with mass albuminuria group were higher than those in the type 2 diabetes mellitus group (q=8.57, P<0.01; q=11.09, P<0.01) and the diabetic kidney disease with microalbuminuria group (q=3.96, P<0.05; q=7.85, P<0.01). MALAT1 had a high correlation with UACR, CREA, SAA, HbA1c and FPG (r value was 0.706, 0.643, 0.578, 0.553, and 0.524, all P<0.01), and SAA had a high correlation with UACR, HbA1c and FPG (r value was 0.664, 0.617, and 0.595, all P<0.01). ROC curve analysis of the diagnostic value of LncRNA MALAT1 and protein SAA for diabetic kidney disease showed that the areas under curve (AUC) were 0.741 and 0.744, respectively. The combined diagnostic value of the two was the greatest (AUC=0.801). In summary, MALAT1 and SAA were elevated in the serum of patients with type 2 diabetes. Their concentrations in the serum of group with diabetic kidney disease were higher than that in the type 2 diabetes group, and the serum concentrations of MALAT1 and SAA in group with mass albuminuria are higher than the group with microalbuminuria. MALAT1 and SAA were both closely related to UACR and HbA1c, and there is a correlation between them. Both of them may have ancillary diagnostic value for diabetic kidney disease.

Simultaneous analyses of urinary eicosanoids and related mediators identified tetranor-prostaglandin E metabolite as a novel biomarker of diabetic nephropathy.

Diabetic nephropathy is a major complication of diabetes mellitus, and thus novel biomarkers are desired to evaluate the presence and progression of diabetic nephropathy. In this study, we sought to identify possible metabolites related to diabetic nephropathy among urinary eicosanoids and related mediators. Using liquid chromatogram-tandem mass spectrometry, we optimized the lipid extraction from urine using the Monospin C18 as a solid-phase extraction cartridge and measured the urinary lipid mediators in 111 subjects with type 2 diabetes mellitus as well as 33 healthy subjects. We observed that 14 metabolites differed significantly among the clinical stages of nephropathy. Among them, levels of tetranor-prostaglandin E metabolite (tetranor-PGEM), an arachidonic acid metabolite, were significantly higher in subjects with stage 1 nephropathy than in healthy subjects and increased with the progression of nephropathy. We also observed that levels of maresin-1, a docosahexaenoic acid metabolite, and leukotriene B4-ethanolamide, an arachidonoyl ethanolamide metabolite, were significantly lower in subjects with stage 3-4 nephropathy than in healthy subjects and those with stage 1-2 nephropathy. Finally, using a comprehensive analysis of urinary eicosanoids and related mediators, we concluded that tetranor-PGEM was capable of discriminating clinical stages of nephropathy and thus useful as a novel biomarker for diabetic nephropathy.