Evaluation of neurotrophic tyrosine receptor kinase 2 (NTRK2) as a positional candidate gene for variation in estimated glomerular filtration rate (eGFR) in Mexican American participants of San Antonio Family Heart study

Postoperative day 1 serum cystatin C level predicts postoperative delayed graft function after kidney transplantation

Background

Delayed graft function (DGF) commonly occurs after kidney transplantation, but no clinical predictors for guiding post-transplant management are available.

Materials and methods

Data including demographics, surgery, anesthesia, postoperative day 1 serum cystatin C (S-CysC) level, kidney functions, and postoperative complications in 603 kidney transplant recipients who met the enrollment criteria from January 2017 to December 2018 were collected and analyzed to form the Intention-To-Treat (ITT) set. All perioperative data were screened using the least absolute shrinkage and selection operator. The discrimination, calibration, and clinical effectiveness of the predictor were verified with area under curve (AUC), calibration plot, clinical decision curve, and impact curve. The predictor was trained in Per-Protocol set, validated in the ITT set, and its stability was further tested in the bootstrap resample data.

Result

Patients with DGF had significantly higher postoperative day 1 S-CysC level (4.2 ± 1.2 vs. 2.8 ± 0.9 mg/L; P < 0.001), serum creatinine level (821.1 ± 301.7 vs. 554.3 ± 223.2 μmol/L; P < 0.001) and dialysis postoperative (74 [82.2%] vs. 25 [5.9%]; P < 0.001) compared with patients without DGF. Among 41 potential predictors, S-CysC was the most effective in the parsimonious model, and its diagnostic cut-off value was 3.80 mg/L with the risk score (OR, 13.45; 95% CI, 8.02–22.57; P < 0.001). Its specificity and sensitivity indicated by AUC was 0.832 (95% CI, 0.779–0.884; P < 0.001) with well fit calibration. S-CysC yielded up to 50% of clinical benefit rate with 1:4 of cost/benefit ratio.

Conclusion

The postoperative day 1 S-CysC level predicts DGF and may be used as a predictor of DGF but warrants further study.

In silico prediction and validation of potential therapeutic genes in pancreatic β-cells associated with type 2 diabetes

Diabetes mellitus is becoming a major health burden worldwide. Pancreatic β-cell death is a characteristic of type 2 diabetes (T2D), but the underlying mechanisms of pancreatic β-cell death remain unknown. Therefore, the aim of the present study was to identify potential targets in the pancreatic islet of T2D. The GSE20966 dataset was obtained from the Gene Expression Omnibus (GEO) database, and differentially expressed genes (DEGs) were identified by using the GEO2R tool. The Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes Pathway enrichment analysis of DEGs were further assessed using the Database for Annotation, Visualization and Integrated Discovery. Furthermore, protein-protein interaction (PPI) networks were constructed for the up- and downregulated genes using STRING databases and were then visualized with Cytoscape. The body weight, fasting blood glucose (FBG), pancreatic index and biochemistry parameters were measured in db/db mice. Moreover, the morphology of the pancreas was detected by hematoxylin and eosin staining, and hub genes were assessed using reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis. In total, 570 DEGs were screened, including 376 upregulated and 194 downregulated genes, which were associated with 'complement activation, classical pathway', 'proteolysis', 'complement activation' and 'pancreatic secretion pathway'. It was found that the body weight, FBG, alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglycerides, blood urea nitrogen, creatinine, fasting serum insulin, glucagon and low-density lipoprotein cholesterol levels were significantly higher in db/db mice, while high-density lipoprotein cholesterol levels and the pancreatic index were significantly decreased. Furthermore, albumin, interleukin-8, CD44, C-C motif chemokine ligand 2, hepatocyte growth factor, cystic fibrosis transmembrane conductance regulator, histone cluster 1 H2B family member n, mitogen-activated protein kinase 11 and neurotrophic receptor tyrosine kinase 2 were identified as hub genes in PPI network. RT-qPCR and western blotting results demonstrated the same expression trend in hub genes as found by the bioinformatics analysis. Therefore, the present study identified a series of hub genes involved in the progression of pancreatic β-cell, which may help to develop effective therapeutic strategy for T2D.

Dietary fatty acids from pomegranate seeds (Punica granatum) inhibit adipogenesis and impact the expression of the obesity-associated mRNA transcripts in human adipose-derived mesenchymal stem cells

Obesity is a metabolic disorder that manifests into various forms. Recent studies have indicated that the pomegranate (Punica granatum) seed oil (PSO) has many biologically active components that help in controlling diet-induced obesity and insulin resistance. However, its impact on the adipogenic differentiation of human adipose-derived mesenchymal stem cells (HADMSC) remains unclear. Here we have attempted to study the anti-obesity potential of SHAMstat3pg, a fatty acid composite extracted from PSO. It is composed of three dietary fatty acids: punicic acid [(9Z,11E,13Z)-9,11,13-Octadecatrienoic acid], oleic acid [Cis-9-Octadecenoic acid], and linoleic acid [(9Z,12Z)-octadeca-9,12-dienoic acid]. In this study, we discuss the impact of the fatty acids on adipogenesis, inflammation, glucose uptake, and mitochondrial ATP production. The impact of SHAMstat3pg on the expression of various obesity-associated protein and mRNA transcripts in HADMSC was also analyzed. The results indicate that exposure to 10 µg/ml of SHAMstat3pg (24 hr) inhibited adipogenesis of HADMSC, ameliorated inflammation, attenuated ATP production, and glucose uptake. Also, the extract favorably regulated the mRNA expression of the studied obesity-associated gene transcripts. PRACTICAL APPLICATIONS: SHAMstat3pg has the potential to serve as a multi-targeted therapy for the management of obesity. This study demonstrated that the dietary fatty acids inhibited the differentiation of preadipocytes to adipocytes. SHAMstat3pg has also shown to have a favorable impact on the expression of the obesity-linked proteins and genes in HADMSC that are associated with adipogenesis, inflammation, satiety, energy intake/expenditure (central and peripheral signaling molecules). The study gives an overview of the vast number of genes impacted by the treatment with SHAMstat3pg paving the way for future studies to demonstrate the exact mode of action of how dietary fatty acids can help manage obesity, insulin resistance, and type 2 diabetes.

Effects of DNA Methylation on Progression to Interstitial Fibrosis and Tubular Atrophy in Renal Allograft Biopsies: A Multi-Omics Approach

Progressive fibrosis of the interstitium is the dominant final pathway in renal destruction in native and transplanted kidneys. Over time, the continuum of molecular events following immunological and nonimmunological insults lead to interstitial fibrosis and tubular atrophy and culminate in kidney failure. We hypothesize that these insults trigger changes in DNA methylation (DNAm) patterns, which in turn could exacerbate injury and slow down the regeneration processes, leading to fibrosis development and graft dysfunction. Herein, we analyzed biopsy samples from kidney allografts collected 24 months posttransplantation and used an integrative multi-omics approach to understand the underlying molecular mechanisms. The role of DNAm and microRNAs on the graft gene expression was evaluated. Enrichment analyses of differentially methylated CpG sites were performed using GenomeRunner. CpGs were strongly enriched in regions that were variably methylated among tissues, implying high tissue specificity in their regulatory impact. Corresponding to this methylation pattern, gene expression data were related to immune response (activated state) and nephrogenesis (inhibited state). Preimplantation biopsies showed similar DNAm patterns to normal allograft biopsies at 2 years posttransplantation. Our findings demonstrate for the first time a relationship among epigenetic modifications and development of interstitial fibrosis, graft function, and inter-individual variation on long-term outcomes.