1,5-Anhydroglucitol as a marker of maternal glycaemic control and predictor of neonatal birthweight in pregnancies complicated by type 1 diabetes mellitus

AIMS/HYPOTHESIS: Most pregnant women with type 1 diabetes mellitus achieve HbA(1c) targets; however, macrosomia remains prevalent and better pregnancy glycaemic markers are therefore needed. 1,5-Anhydroglucitol (1,5-AG) is a short-term marker of glycaemia, reflecting a period of 1 to 2 weeks. Its excretion rate depends on the renal glucose threshold and thus it is unclear whether it may be used in pregnant type 1 diabetes women. We evaluated 1,5-AG as a glycaemic marker and birthweight predictor in pregnant women with type 1 diabetes, and compared its performance with HbA(1c). METHODS: 1,5-AG and HbA(1c) were measured in 82 pregnant women with type 1 diabetes. In addition, 58 continuous glucose monitoring system (CGMS) records were available. Macrosomia was defined as birthweight >90th centile. The data were analysed with Pearson’s correlations, and linear and logistic regression models. Receiver operating characteristic (ROC) analysis was used to evaluate third trimester 1,5-AG as a predictor of macrosomia. RESULTS: Unlike HbA(1c), 1,5-AG strongly correlated with CGMS indices: the AUC above 7.8 mmol/l (r = −0.66; p < 0.001), average maximum glucose (r = −0.58; p < 0.001) and mean glucose (r = −0.54; p < 0.001). In the third trimester, 1,5-AG was the strongest predictor of macrosomia, with ROC AUC 0.81 (95% CI 0.70, 0.89). In contrast, HbA(1c) in the third trimester had a ROC AUC of 0.69 (95% CI 0.58, 0.81). The best discrimination was achieved when both markers were used jointly, yielding a ROC AUC of 0.84 (95% CI 0.76, 0.93). CONCLUSIONS/INTERPRETATION: In pregnant women with type 1 diabetes, 1,5-AG is a better glycaemic marker than HbA(1c), as assessed by CGMS. A decreased third trimester 1,5-AG level, either singly or with HbA(1c), is a strong predictor of macrosomia

CRISPLD1: a novel conserved target in the transition to human heart failure

Heart failure is a major health problem worldwide with a significant morbidity and mortality rate. Although studied extensively in animal models, data from patients at the compensated disease stage are lacking. We sampled myocardium biopsies from aortic stenosis patients with compensated hypertrophy and moderate heart failure and used transcriptomics to study the transition to failure. Sequencing and comparative analysis of analogous samples of mice with transverse aortic constriction identified 25 candidate genes with similar regulation in response to pressure overload, reflecting highly conserved molecular processes. The gene cysteine-rich secretory protein LCCL domain containing 1 (CRISPLD1) is upregulated in the transition to failure in human and mouse and its function is unknown. Homology to ion channel regulatory toxins suggests a role in Ca(2+) cycling. CRISPR/Cas9-mediated loss-of-function leads to dysregulated Ca(2+) handling in human-induced pluripotent stem cell-derived cardiomyocytes. The downregulation of prohypertrophic, proapoptotic and Ca(2+)-signaling pathways upon CRISPLD1-KO and its upregulation in the transition to failure implicates a contribution to adverse remodeling. These findings provide new pathophysiological data on Ca(2+) regulation in the transition to failure and novel candidate genes with promising potential for therapeutic interventions

Proteomic mapping of atrial and ventricular heart tissue in patients with aortic valve stenosis

Aortic valve stenosis (AVS) is one of the most common valve diseases in the world. However, detailed biological understanding of the myocardial changes in AVS hearts on the proteome level is still lacking. Proteomic studies using high-resolution mass spectrometry of formalin-fixed and paraffin-embedded (FFPE) human myocardial tissue of AVS-patients are very rare due to methodical issues. To overcome these issues this study used high resolution mass spectrometry in combination with a stem cell- derived cardiac specific protein quantification-standard to profile the proteomes of 17 atrial and 29 left ventricular myocardial FFPE human myocardial tissue samples from AVS-patients. In our proteomic analysis we quantified a median of 1980 (range 1495–2281) proteins in every single sample and identified significant upregulation of 239 proteins in atrial and 54 proteins in ventricular myocardium. We compared the proteins with published data. Well studied proteins reflect disease-related changes in AVS, such as cardiac hypertrophy, development of fibrosis, impairment of mitochondria and downregulated blood supply. In summary, we provide both a workflow for quantitative proteomics of human FFPE heart tissue and a comprehensive proteomic resource for AVS induced changes in the human myocardium

Stress-Activated Kinase MKK7 Governs Epigenetics of Cardiac Repolarization for Arrhythmia Prevention

BACKGROUND: Ventricular arrhythmia is a leading cause of cardiac mortality. Most antiarrhythmics present paradoxical proarrhythmic side effects, culminating in a greater risk of sudden death. METHODS: We describe a new regulatory mechanism linking mitogen-activated kinase kinase-7 deficiency with increased arrhythmia vulnerability in hypertrophied and failing hearts using mouse models harboring mitogen-activated kinase kinase-7 knockout or overexpression. The human relevance of this arrhythmogenic mechanism is evaluated in human-induced pluripotent stem cell-derived cardiomyocytes. Therapeutic potentials by targeting this mechanism are explored in the mouse models and human-induced pluripotent stem cell-derived cardiomyocytes. RESULTS: Mechanistically, hypertrophic stress dampens expression and phosphorylation of mitogen-activated kinase kinase-7. Such mitogen-activated kinase kinase-7 deficiency leaves histone deacetylase-2 unphosphorylated and filamin-A accumulated in the nucleus to form a complex with Kruppel-like factor-4. This complex leads to Kruppel-like factor-4 disassociation from the promoter regions of multiple key potassium channel genes (Kv4.2, KChIP2, Kv1.5, ERG1, and Kir6.2) and reduction of their transcript levels. Consequent repolarization delays result in ventricular arrhythmias. Therapeutically, targeting the repressive function of the Kruppel-like factor-4/histone deacetylase-2/filamin-A complex with the histone deacetylase-2 inhibitor valproic acid restores K+ channel expression and alleviates ventricular arrhythmias in pathologically remodeled hearts. CONCLUSIONS: Our findings unveil this new gene regulatory avenue as a new antiarrhythmic target where repurposing of the antiepileptic drug valproic acid as an antiarrhythmic is supported.British Heart Foundation [PG/09/052/27833, PG/14/71/31063, PG/12/76/29852, FS/15/16/31477]; Medical Research Council [G1002082, MC_PC_13070]; American Heart Association National Scientist Development Grants [12SDG12070077]; National Basic Research Program of China [2012CB518000]SCI(E)ARTICLE7683-69913

Efficient generation of osteoclasts from human induced pluripotent stem cells and functional investigations of lethal CLCN7-related osteopetrosis

Human induced pluripotent stem cells (hiPSCs) hold great potential for modelling human diseases and the development of innovative therapeutic approaches. Here, we report on a novel, simplified differentiation method for forming functional osteoclasts from hiPSCs. The three-step protocol starts with embryoid body formation, followed by hematopoietic specification, and finally osteoclast differentiation. We observed continuous production of monocyte-like cells over a period of up to nine weeks, generating sufficient material for several osteoclast differentiations. The analysis of stage-specific gene and surface marker expression proved mesodermal priming, the presence of monocyte-like cells, and of terminally differentiated multinucleated osteoclasts, able to form resorption pits and trenches on bone and dentine in vitro. In comparison to peripheral blood mononuclear cell (PBMC)-derived osteoclasts hiPSC-derived osteoclasts were larger and contained a higher number of nuclei. Detailed functional studies on the resorption behaviour of hiPSC-osteoclasts indicated a trend towards forming more trenches than pits and an increase in pseudo-resorption. We used hiPSCs from an ARO patient (BIHi002-A, ARO hiPSCs) with compound heterozygous missense mutations p.(G292E) and p.(R403Q) in CLCN7, coding for the Cl(-)/H(+) -exchanger ClC-7, for functional investigations. The patient's leading clinical feature was a brain malformation due to defective neuronal migration. Mutant ClC-7 displayed residual expression and retained lysosomal co-localization with OSTM1, but only ClC-7 harboring the mutation p.(R403Q) gave strongly reduced ion currents. An increased autophagic flux in spite of unchanged lysosomal pH was evident in undifferentiated ARO hiPSCs. ARO hiPSC-derived osteoclasts showed an increased size compared to hiPSCs of healthy donors. They were not able to resorb bone, indicating a loss-of-function effect of the mutations. In summary, we developed a highly reproducible, straightforward hiPSC-osteoclast differentiation protocol. We demonstrated that osteoclasts differentiated from ARO-hiPSCs can be used as a disease model for ARO and potentially also other osteoclast-related diseases

Relationship Between Risk Factors and Mortality in Type 1 Diabetic Patients in Europe: The EURODIAB Prospective Complications Study (PCS)

OBJECTIVE—The purpose of this study was to examine risk factors for mortality in patients with type 1 diabetes

Plasma levels of matrix metalloproteinase-2, -3, -10, and tissue inhibitor of metalloproteinase-1 are associated with vascular complications in patients with type 1 diabetes: The EURODIAB Prospective Complications Study

Impaired regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in patients with type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1, and cardiovascular disease (CVD) or microvascular complications in type 1 diabetic patients. We also evaluated to which extent these associations could be explained by low-grade inflammation (LGI) or endothelial dysfunction (ED). Methods: 493 type 1 diabetes patients (39.5 ± 9.9 years old, 51% men) from the EURODIAB Prospective Complications Study were included. Linear regression analysis was applied to investigate differences in plasma levels of MMP-1, -2, -3, -9, -10, and TIMP-1 between patients with and without CVD, albuminuria or retinopathy. All analyses were adjusted for age, sex, duration of diabetes, Hba1c and additionally for other cardiovascular risk factors including LGI and ED. Results: Patients with CVD (n = 118) showed significantly higher levels of TIMP-1 [β = 0.32 SD (95%CI: 0.12; 0.52)], but not of MMPs, than patients without CVD (n = 375). Higher plasma levels of MMP-2, MMP-3, MMP-10 and TIMP-1 were associated with higher levels of albuminuria (p-trends were 0.028, 0.004, 0.005 and 0.001, respectively). Severity of retinopathy was significantly associated with higher levels of MMP-2 (p-trend = 0.017). These associations remained significant after further adjustment for markers of LGI and ED. Conclusions: These data support the hypothesis that impaired regulation of matrix remodeling by actions of MMP-2, -3 and-10 and TIMP-1 contributes to the pathogenesis of vascular complications in type 1 diabetes

The seventh international RASopathies symposium: Pathways to a cure-expanding knowledge, enhancing research, and therapeutic discovery.

RASopathies are a group of genetic disorders that are caused by genes that affect the canonical Ras/mitogen-activated protein kinase (MAPK) signaling pathway. Despite tremendous progress in understanding the molecular consequences of these genetic anomalies, little movement has been made in translating these findings to the clinic. This year, the seventh International RASopathies Symposium focused on expanding the research knowledge that we have gained over the years to enhance new discoveries in the field, ones that we hope can lead to effective therapeutic treatments. Indeed, for the first time, research efforts are finally being translated to the clinic, with compassionate use of Ras/MAPK pathway inhibitors for the treatment of RASopathies. This biannual meeting, organized by the RASopathies Network, brought together basic scientists, clinicians, clinician scientists, patients, advocates, and their families, as well as representatives from pharmaceutical companies and the National Institutes of Health. A history of RASopathy gene discovery, identification of new disease genes, and the latest research, both at the bench and in the clinic, were discussed

Instance reduction for one-class classification

Instance reduction techniques are data preprocessing methods originally developed to enhance the nearest neighbor rule for standard classification. They reduce the training data by selecting or generating representative examples of a given problem. These algorithms have been designed and widely analyzed in multi-class problems providing very competitive results. However, this issue was rarely addressed in the context of one-class classification. In this specific domain a reduction of the training set may not only decrease the classification time and classifier’s complexity, but also allows us to handle internal noisy data and simplify the data description boundary. We propose two methods for achieving this goal. The first one is a flexible framework that adjusts any instance reduction method to one-class scenario by introduction of meaningful artificial outliers. The second one is a novel modification of evolutionary instance reduction technique that is based on differential evolution and uses consistency measure for model evaluation in filter or wrapper modes. It is a powerful native one-class solution that does not require an access to counterexamples. Both of the proposed algorithms can be applied to any type of one-class classifier. On the basis of extensive computational experiments, we show that the proposed methods are highly efficient techniques to reduce the complexity and improve the classification performance in one-class scenarios