Endothelial cell-selective adhesion molecule in diabetic nephropathy

Quantitative urinary proteome analysis reveals potential biomarkers for disease activity of Behcet's disease uveitis

PURPOSE

Behçet's disease-associated uveitis (BDU) is a severe, recurrent inflammatory condition affecting the eye and is part of a systemic vasculitis with unknown etiology, making biomarker discovery essential for disease management. In this study, we intend to investigate potential urinary biomarkers to monitor the disease activity of BDU.

METHODS

Firstly, label-free data-dependent acquisition (DDA) and tandem mass tag (TMT)-labeled quantitative proteomics methods were used to profile the proteomes of urine from active and quiescent BDU patients, respectively. For further exploration, the remaining fifty urine samples were analyzed by a data-independent acquisition (DIA) quantitative proteomics method.

RESULTS

Twenty-nine and 21 differential proteins were identified in the same urine from BDU patients by label-free DDA and TMT-labeled analyses, respectively. Seventy-nine differentially expressed proteins (DEPs) were significantly changed in other active BDU urine samples compared to those in quiescent BDU urine samples by IDA analysis. Gene Ontology (GO) and protein-protein interaction (PPI) analyses revealed that the DEPs were associated with multiple functions, including the immune and neutrophil activation responses. Finally, seven proteins were identified as candidate biomarkers for BDU monitoring and recurrence prediction, namely, CD38, KCRB, DPP4, FUCA2, MTPN, S100A8 and S100A9.

CONCLUSIONS

Our results showed that urine can be a good source of biomarkers for BDU. These dysregulated proteins provide potential urinary biomarkers for BDU activity monitoring and provide valuable clues for the analysis of the pathogenic mechanisms of BDU.

Association of vascular endothelial growth factor (VEGF) protein levels and gene polymorphism with the risk of chronic kidney disease

Vascular endothelial growth factor (VEGF) is a heparin-specific growth factor specific for vascular endothelial cells and induces angiogenesis via binding to vascular endothelial growth factor receptor (VEGFR). Chronic kidney disease (CKD), accompanied by microvascular disease, is recognized as an irreversible reduction of renal function. The effects of VEGF on CKD risk were evaluated in this study. 121 CKD patients and 50 healthy volunteers were evaluated in the current study. Data mining using the China Biological Medicine (CBM) and NCBI/PubMed databases, was performed and applicable investigations were pursued. Pooled mean differences (MD) and pooled odds ratios (OR), with corresponding confidence intervals (CIs), were calculated by meta-analysis. The levels of Scr, BUN and VEGF in the CKD group were significantly higher, when compared with the control group (P < 0.01). For the meta-analysis, thirteen articles and our current study were evaluated. VEGF levels was found to be associated with CKD risk (P < 0.00001). In the sub-group meta-analysis, we found that the pooled MD of VEGF levels was related to the early CKD group, although the difference was not notable. However, the meta-analysis itself indicated that the pooled MD of VEGF levels were in accordance with severe CKD group (P < 0.00001). Furthermore, VEGF +936C/T T allele was not associated with CKD risk (P = 0.69). VEGF levels are apparently associated with CKD risk, especially in more severe CKD. Gene polymorphism analysis indicates that the VEGF +936C/T T allele is not associated with CKD risk.

Exhaled biomarkers in adults with non-productive cough

BACKGROUND

Chronic cough is a common condition but disease mechanisms are not fully understood. Our aim was to study respiratory biomarkers from the small airways in individuals with non-productive cough.

METHODS

A cohort of 107 participants answered detailed questionnaires, performed spirometry, exhaled NO measurement, impulse oscillometry, gave blood samples and particles in exhaled air (PEx) samples. Current smokers (N = 38) were excluded. A total of 14 participants reported non-productive cough (cases). A total of 55 participants reported no cough (control group). PEx samples, containing exhaled particles derived from small airways, were collected and analysed with the SOMAscan proteomics platform.

RESULTS

Participants with non-productive cough had similar age, sex, BMI, and inflammation markers in blood tests, as participants without cough. The proteomics analysis found 75 proteins significantly altered among participants with chronic cough compared to controls, after adjusting for sex and investigator performing the PExA measurement (all with p-value < 0.05 and q-value ≤ 0.13, thereof 21 proteins with a q-value < 0.05). These proteins were mostly involved in immune and inflammatory responses, complement and coagulation system, but also tight junction proteins and proteins involved in neuroinflammatory responses.

CONCLUSIONS

This exploratory study on proteomics of exhaled particles among individuals with chronic cough found alterations in relative abundance of 75 proteins. The proteins identified are implicated in both pathways known to be implicated in cough, but also potentially new pathways. Further studies are needed to explore the importance of these findings.

Results of untargeted analysis using the SOMAscan proteomics platform indicates novel associations of circulating proteins with risk of progression to kidney failure in diabetes

This study applies a large proteomics panel to search for new circulating biomarkers associated with progression to kidney failure in individuals with diabetic kidney disease. Four independent cohorts encompassing 754 individuals with type 1 and type 2 diabetes and early and late diabetic kidney disease were followed to ascertain progression to kidney failure. During ten years of follow-up, 227 of 754 individuals progressed to kidney failure. Using the SOMAscan proteomics platform, we measured baseline concentration of 1129 circulating proteins. In our previous publications, we analyzed 334 of these proteins that were members of specific candidate pathways involved in diabetic kidney disease and found 35 proteins strongly associated with risk of progression to kidney failure. Here, we examined the remaining 795 proteins using an untargeted approach. Of these remaining proteins, 11 were significantly associated with progression to kidney failure. Biological processes previously reported for these proteins were related to neuron development (DLL1, MATN2, NRX1B, KLK8, RTN4R and ROR1) and were implicated in the development of kidney fibrosis (LAYN, DLL1, MAPK11, MATN2, endostatin, and ROR1) in cellular and animal studies. Specific mechanisms that underlie involvement of these proteins in progression of diabetic kidney disease must be further investigated to assess their value as targets for kidney-protective therapies. Using multivariable LASSO regression analysis, five proteins (LAYN, ESAM, DLL1, MAPK11 and endostatin) were found independently associated with risk of progression to kidney failure. Thus, our study identified proteins that may be considered as new candidate prognostic biomarkers to predict risk of progression to kidney failure in diabetic kidney disease. Furthermore, three of these proteins (DLL1, ESAM, and MAPK11) were selected as candidate biomarkers when all SOMAscan results were evaluated.

Cell junction proteins: Crossing the glomerular filtration barrier in diabetic nephropathy

Diabetic nephropathy as a deleterious complication of diabetes mellitus and an important cause of end-stage renal failure is characterized by changes in the molecular and cellular levels. Cell-cell communication via the gap and tight junctions are involved in the pathogenesis of diseases such as diabetes and kidney failure. Studying cell junctions including gap junctions, tight junctions, and anchoring junctions within the nephron can be used as an early sign of diabetic nephropathy. Furthermore, cell junctions may be an upcoming target by pharmacological methods to improve treatments of diabetic nephropathy and pave the way to introduce promising therapeutic strategies based on cell-cell communications effects and its translation into clinical studies for the treatment of diabetic nephropathy.

Toxicological and chemical studies of wastewater from hydraulic fracture and conventional shale gas wells

New technology has enabled recovery of inaccessible natural gas shale deposits; however, the potential impacts to human health from the migration of brines into drinking water or surface spills are unknown. To provide information that can inform these potential impacts, chemical characterization and in vitro toxicologic testing were conducted using pre- and postinjection waters from conventional and unconventional oil and gas wells. Wastewater concentrations may be diluted or reduced by fate and transport processes when released into the environment by unknown amounts, and laboratory studies only imply potential effects. In acute cytotoxicity and wound healing assays, there was dose-dependent toxicity in human and rat cells with growth promotion at low concentrations. Lethality was measured in time studies up to 10 d postinjection. Produced water samples from both well types were equally toxic to human cells and were corrosive at high concentrations. Measurement of protein and gene expression identified metabolic pathways responding to both well types as NADPH quinone oxidoreductase oxidative stress-responsive enzyme and tight junction protein genes. A KCl sample of matched ionic strength showed a different toxicity profile from produced waters, indicating that salts alone were not the cause of toxicity. Organic chemicals and branched alkanes were present in hydraulic fracture wells, and mainly branched alkanes were present in conventional wells. One organic substance was still present after 240 d. The known properties of these chemicals include potential toxicity to multiple human organs, sensitization, irritation, developmental effects, and tumor promotion, depending on the concentrations and synergistic effects of chemicals during exposure. Environ Toxicol Chem 2018;37:2098-2111. © 2018 SETAC.

ESAM predicts cardiovascular mortality in diabetic hemodialysis patients

AIM

To assess endothelial cell selective adhesion molecule (ESAM) as predictor of cardiovascular mortality in diabetic dialysis patients (DDPs).

METHODS

ESAM, clinical and laboratory parameters were assessed in 73 DDP. Cardiovascular mortality was recorded in a 2 years' prospective observational study.

RESULTS

Baseline ESAM was 17.1 (10.05-24.8) ng/ml and was correlated to phosphate (r = -0.42, p = 0.008), parathormone (r = -0.36, p = 0.048), albumin (r = -0.24, p = 0.048). ESAM significantly predicted cardiovascular death in univariate [HR = 1.03, 95% CI (1.006-1.054), p = 0.01] and multivariate [HR = 1.034, 95% CI (1.003-1.066), p = 0.03] Cox analysis. Time to cardiovascular death was shorter for patients with ESAM >12.44 ng/ml, p = 0.0045.

CONCLUSION

ESAM is an independent predictor of cardiovascular mortality in DDP.

Increases in insulin sensitivity among obese youth are associated with gene expression changes in whole blood

OBJECTIVE

Lifestyle intervention can improve insulin sensitivity in obese youth, yet few studies have examined the molecular signatures associated with these improvements. Therefore, the purpose of this study was to explore gene expression changes in whole blood that are associated with intervention-induced improvements in insulin sensitivity.

METHODS

Fifteen (7M/8F) overweight/obese (BMI percentile = 96.3 ± 1.1) Latino adolescents (15.0 ± 0.9 years) completed a 12-week lifestyle intervention that included weekly nutrition education and 180 minutes of moderate-vigorous exercise per week. Insulin sensitivity was estimated by an oral glucose tolerance test and the Matsuda Index. Global microarray analysis profiling from whole blood was performed to examine changes in gene expression and to explore biological pathways that were significantly changed in response to the intervention.

RESULTS

A total of 1,459 probes corresponding to mRNA transcripts (717 up, 742 down) were differentially expressed with a fold change ≥1.2. These genes were mapped within eight significant pathways identified, including insulin signaling, type 1 diabetes, and glycerophospholipid metabolism. Participants with increased insulin sensitivity exhibited five times the number of significant genes altered compared with nonresponders (1,144 vs. 230).

CONCLUSIONS

These findings suggest that molecular signatures from whole blood are associated with lifestyle-induced health improvements among high-risk Latino youth.

Low serum endothelial cell-selective adhesion molecule predicts increase in albuminuria in type 2 diabetes patients

PURPOSE

The newly discovered endothelial cell-selective adhesion molecule (ESAM) stabilizes the interendothelial tight junction; it circulates in serum as a soluble fraction. In experimental diabetes, reduced ESAM expression in the kidney is associated with albuminuria. We investigated, for the first time, serum ESAM as a predictor of progression of kidney disease in type 2 diabetes (T2D).

METHODS

T2D non-nephrotic patients with glomerular filtration rate (GFR) > 30 ml/min were included. History, medication and laboratory evaluation were assessed at inclusion and the end of study; ESAM was determined at baseline.

RESULTS

Eighty-eight patients--mean age 63 ± 10.84 years, 49 (55.68 %) males--were prospectively followed up for 20 months. Baseline GFR was 76.37 ± 29.56 ml/min, and urinary albumin/creatinine ratio (UACR) 21.63(7.08-94.52) mg/g; ESAM was 12.85(6.13-19.83) ng/ml. Difference (Δ) in UACR between end of study and baseline was inversely related to serum albumin (r = -0.27, p = 0.017) and ESAM (r = -0.21, p = 0.047); ΔGFR correlated to glycated hemoglobin (r = 0.22, p = 0.05). In multiple regression, introducing variables susceptible to influence progression of kidney disease, ΔUACR was significantly related to log ESAM (p = 0.005) and ΔGFR to glycated hemoglobin (p = 0.016).

CONCLUSION

Serum ESAM is a predictor of worsening of albuminuria in T2D patients without advanced kidney disease.