Computational analysis of a novel mutation in ETFDH gene highlights its long-range effects on the FAD-binding motif

<p>Abstract</p> <p>Background</p> <p>Multiple acyl-coenzyme A dehydrogenase deficiency (MADD) is an autosomal recessive disease caused by the defects in the mitochondrial electron transfer system and the metabolism of fatty acids. Recently, mutations in electron transfer flavoprotein dehydrogenase (<it>ETFDH</it>) gene, encoding electron transfer flavoprotein:ubiquinone oxidoreductase (ETF:QO) have been reported to be the major causes of riboflavin-responsive MADD. To date, no studies have been performed to explore the functional impact of these mutations or their mechanism of disrupting enzyme activity.</p> <p>Results</p> <p>High resolution melting (HRM) analysis and sequencing of the entire <it>ETFDH </it>gene revealed a novel mutation (p.Phe128Ser) and the hotspot mutation (p.Ala84Thr) from a patient with MADD. According to the predicted 3D structure of ETF:QO, the two mutations are located within the flavin adenine dinucleotide (FAD) binding domain; however, the two residues do not have direct interactions with the FAD ligand. Using molecular dynamics (MD) simulations and normal mode analysis (NMA), we found that the p.Ala84Thr and p.Phe128Ser mutations are most likely to alter the protein structure near the FAD binding site as well as disrupt the stability of the FAD binding required for the activation of ETF:QO. Intriguingly, NMA revealed that several reported disease-causing mutations in the ETF:QO protein show highly correlated motions with the FAD-binding site.</p> <p>Conclusions</p> <p>Based on the present findings, we conclude that the changes made to the amino acids in ETF:QO are likely to influence the FAD-binding stability.</p

Hypokalemia, Its Contributing Factors and Renal Outcomes in Patients with Chronic Kidney Disease

Background: In the chronic kidney disease (CKD) population, the impact of serum potassium (sK) on renal outcomes has been controversial. Moreover, the reasons for the potential prognostic value of hypokalemia have not been elucidated. Design, Participants & Measurements 2500 participants with CKD stage 1–4 in the Integrated CKD care program Kaohsiung for delaying Dialysis (ICKD) prospective observational study were analyzed and followed up for 2.7 years. Generalized additive model was fitted to determine the cutpoints and the U-shape association between sK and end-stage renal disease (ESRD). sK was classified into five groups with the cutpoints of 3.5, 4, 4.5 and 5 mEq/L. Cox proportional hazard regression models predicting the outcomes were used. Results: The mean age was 62.4 years, mean sK level was 4.2±0.5 mEq/L and average eGFR was 40.6 ml/min per 1.73 m2. Female vs male, diuretic use vs. non-use, hypertension, higher eGFR, bicarbonate, CRP and hemoglobin levels significantly correlated with hypokalemia. In patients with lower sK, nephrotic range proteinuria, and hypoalbuminemia were more prevalent but the use of RAS (renin-angiotensin system) inhibitors was less frequent. Hypokalemia was significantly associated with ESRD with hazard ratios (HRs) of 1.82 (95% CI, 1.03–3.22) in sK 5 mEq/L conferred 1.6-fold (95% CI,1.09–2.34) increased risk of ESRD compared with sK = 4.5–5 mEq/L. Hypokalemia was also associated with rapid decline of renal function defined as eGFR slope below 20% of the distribution range. Conclusion: In conclusion, both hypokalemia and hyperkalemia are associated with increased risk of ESRD in CKD population. Hypokalemia is related to increased use of diuretics, decreased use of RAS blockade and malnutrition, all of which may impose additive deleterious effects on renal outcomes

Stepwise Increases in Left Ventricular Mass Index and Decreases in Left Ventricular Ejection Fraction Correspond with the Stages of Chronic Kidney Disease in Diabetes Patients

Aims. Patients with diabetic nephropathy are reported to have a high prevalence of left ventricular structural and functional abnormalities. This study was designed to assess the determinants of left ventricular mass index (LVMI) and left ventricular ejection fraction (LVEF) in diabetic patients at various stages of chronic kidney disease (CKD). Methods. This cross-sectional study enrolled 285 diabetic patients with CKD stages 3 to 5 from our outpatient department of internal medicine. Clinical and echocardiographic parameters were compared and analyzed. Results. We found a significant stepwise increase in LVMI (P < 0.001), LVH (P < 0.001), and LVEF <55% (P = 0.013) and a stepwise decrease in LVEF (P = 0.038) corresponding to advance in CKD stages. Conclusions. Our findings suggest that increases in LVMI and decreases in LVEF coincide with advances in CKD stages in patients with diabetes

Fibroblast Growth Factor-10 Promotes Cardiomyocyte Differentiation from Embryonic and Induced Pluripotent Stem Cells

BACKGROUND: The fibroblast growth factor (FGF) family is essential to normal heart development. Yet, its contribution to cardiomyocyte differentiation from stem cells has not been systemically studied. In this study, we examined the mechanisms and characters of cardiomyocyte differentiation from FGF family protein treated embryonic stem (ES) cells and induced pluripotent stem (iPS) cells. METHODOLOGY/PRINCIPAL FINDINGS: We used mouse ES cells stably transfected with a cardiac-specific α-myosin heavy chain (αMHC) promoter-driven enhanced green fluorescent protein (EGFP) and mouse iPS cells to investigate cardiomyocyte differentiation. During cardiomyocyte differentiation from mouse ES cells, FGF-3, -8, -10, -11, -13 and -15 showed an expression pattern similar to the mesodermal marker Brachyury and the cardiovascular progenitor marker Flk-1. Among them, FGF-10 induced cardiomyocyte differentiation in a time- and concentration-dependent manner. FGF-10 neutralizing antibody, small molecule FGF receptor antagonist PD173074 and FGF-10 and FGF receptor-2 short hairpin RNAs inhibited cardiomyocyte differentiation. FGF-10 also increased mouse iPS cell differentiation into cardiomyocyte lineage, and this effect was abolished by FGF-10 neutralizing antibody or PD173074. Following Gene Ontology analysis, microarray data indicated that genes involved in cardiac development were upregulated after FGF-10 treatment. In vivo, intramyocardial co-administration of FGF-10 and ES cells demonstrated that FGF-10 also promoted cardiomyocyte differentiation. CONCLUSION/SIGNIFICANCE: FGF-10 induced cardiomyocyte differentiation from ES cells and iPS cells, which may have potential for translation into clinical applications

Menelloides C and D, New Sesquiterpenoids from the Gorgonian Coral Menella sp

Two new metabolites, including a lindenane-type sesquiterpenoid, menelloide C (1), and a germacrane-type sesquiterpenoid, menelloide D (2), were isolated from a Formosan gorgonian coral identified as Menella sp. The structures of 1 and 2 were established by spectroscopic methods and 2 displayed a weak inhibitory effect on the release of elastase by human neutrophils

Effects of Extract from Solid-State Fermented Cordyceps sinensis on Type 2 Diabetes Mellitus

Diabetes mellitus is the most common chronic disease in the world, and a wide range of drugs, including Chinese herbs, have been evaluated for the treatment of associated metabolic disorders. This study investigated the potential hypoglycemic and renoprotective effects of an extract from the solid-state fermented mycelium of Cordyceps sinensis (CS). We employed the KK/HIJ diabetic mouse model, in which the mice were provided with a high-fat diet for 8 weeks to induce hyperglycemia, followed by the administration of CS or rosiglitazone for 4 consecutive weeks. Several parameters were evaluated, including changes in body weight, plasma lipid profiles, oral glucose tolerance tests, insulin tolerance tests, and plasma insulin concentrations. Our results show that the CS extract significantly elevated HDL/LDL ratios at 4 weeks and decreased body weight gain at 8 weeks. Interestingly, CS treatment did not lead to obvious improvements in hyperglycemia or resistance to insulin, while in vitro MTT assays indicated that CS protects pancreatic beta cells against the toxic effects of STZ. CS also enhanced renal NKA activity and reduced the accumulation of mesangial matrix and collagen deposition. In conclusion, CS extract can potentially preserve β-cell function and offer renoprotection, which may afford a promising therapy for DM

Prognostic Cardiovascular Markers in Chronic Kidney Disease

Chronic kidney disease (CKD), including end-stage renal disease (ESRD), is a public health issue worldwide, and is associated with high rates of morbidity and mortality. In addition, cardiovascular disease is a major cause of mortality in these patients. Both traditional and nontraditional risk factors associated with CKD can lead to remodeling of the myocardium and blood vessels, thereby resulting in cardiomyopathy, atherosclerosis and arterial stiffness. This can subsequently lead to ischemic heart disease, heart failure, cardiovascular death, rapid renal progression and progression to ESRD. Identifying these risk factors to allow for aggressive preventive and interventional strategies is important for the management of patients with CKD. This aim of this review was to survey the clinical outcomes of CKD using cardiac and vascular markers including echocardiographic parameters, systolic time intervals, electrocardiography, heart rate variability, ankle-brachial index, pulse wave velocity, differences between interarm and interankle blood pressure, and vascular calcification

Improved Image Quality for Static BLADE Magnetic Resonance Imaging Using the Total-Variation Regularized Least Absolute Deviation Solver.

In order to improve the image quality of BLADE magnetic resonance imaging (MRI) using the index tensor solvers and to evaluate MRI image quality in a clinical setting, we implemented BLADE MRI reconstructions using two tensor solvers (the least-squares solver and the L1 total-variation regularized least absolute deviation (L1TV-LAD) solver) on a graphics processing unit (GPU). The BLADE raw data were prospectively acquired and presented in random order before being assessed by two independent radiologists. Evaluation scores were examined for consistency and then by repeated measures analysis of variance (ANOVA) to identify the superior algorithm. The simulation showed the structural similarity index (SSIM) of various tensor solvers ranged between 0.995 and 0.999. Inter-reader reliability was high (Intraclass correlation coefficient (ICC) = 0.845, 95% confidence interval: 0.817, 0.87). The image score of L1TV-LAD was significantly higher than that of vendor-provided image and the least-squares method. The image score of the least-squares method was significantly lower than that of the vendor-provided image. No significance was identified in L1TV-LAD with a regularization strength of λ= 0.4-1.0. The L1TV-LAD with a regularization strength of λ= 0.4-0.7 was found consistently better than least-squares and vendor-provided reconstruction in BLADE MRI with a SENSitivity Encoding (SENSE) factor of 2. This warrants further development of the integrated computing system with the scanner

Excavatoids E and F: Discovery of Two New Briaranes from the Cultured Octocoral Briareum excavatum

Two new briarane-related diterpenoids, designated as excavatoids E (1) and F (2), were isolated from the cultured octocoral Briareum excavatum. The structures of compounds 1 and 2 were established on the basis of extensive spectral data analysis. Briaranes 1 and 2 were found to exhibit moderate inhibitory effects on elastase release by human neutrophils