Dapagliflozin vs. metolazone in heart failure resistant to loop diuretics.

BACKGROUND AND AIMS: To examine the decongestive effect of the sodium-glucose cotransporter 2 inhibitor dapagliflozin compared to the thiazide-like diuretic metolazone in patients hospitalized for heart failure and resistant to treatment with intravenous furosemide. METHODS AND RESULTS: A multi-centre, open-label, randomized, and active-comparator trial. Patients were randomized to dapagliflozin 10 mg once daily or metolazone 5-10 mg once daily for a 3-day treatment period, with follow-up for primary and secondary endpoints until day 5 (96 h). The primary endpoint was a diuretic effect, assessed by change in weight (kg). Secondary endpoints included a change in pulmonary congestion (lung ultrasound), loop diuretic efficiency (weight change per 40 mg of furosemide), and a volume assessment score. 61 patients were randomized. The mean (±standard deviation) cumulative dose of furosemide at 96 h was 977 (±492) mg in the dapagliflozin group and 704 (±428) mg in patients assigned to metolazone. The mean (±standard deviation) decrease in weight at 96 h was 3.0 (2.5) kg with dapagliflozin compared to 3.6 (2.0) kg with metolazone [mean difference 0.65, 95% confidence interval (CI) -0.12,1.41 kg; P = 0.11]. Loop diuretic efficiency was less with dapagliflozin than with metolazone [mean 0.15 (0.12) vs. 0.25 (0.19); difference -0.08, 95% CI -0.17,0.01 kg; P = 0.10]. Changes in pulmonary congestion and volume assessment score were similar between treatments. Decreases in plasma sodium and potassium and increases in urea and creatinine were smaller with dapagliflozin than with metolazone. Serious adverse events were similar between treatments. CONCLUSION: In patients with heart failure and loop diuretic resistance, dapagliflozin was not more effective at relieving congestion than metolazone. Patients assigned to dapagliflozin received a larger cumulative dose of furosemide but experienced less biochemical upset than those assigned to metolazone. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04860011.

Data Mining Identifies CCN2 and THBS1 as Biomarker Candidates for Cardiac Hypertrophy.

Cardiac hypertrophy is a condition that may contribute to the development of heart failure. In this study, we compare the gene-expression patterns of our in vitro stem-cell-based cardiac hypertrophy model with the gene expression of biopsies collected from hypertrophic human hearts. Twenty-five differentially expressed genes (DEGs) from both groups were identified and the expression of selected corresponding secreted proteins were validated using ELISA and Western blot. Several biomarkers, including CCN2, THBS1, NPPA, and NPPB, were identified, which showed significant overexpressions in the hypertrophic samples in both the cardiac biopsies and in the endothelin-1-treated cells, both at gene and protein levels. The protein-interaction network analysis revealed CCN2 as a central node among the 25 overlapping DEGs, suggesting that this gene might play an important role in the development of cardiac hypertrophy. GO-enrichment analysis of the 25 DEGs revealed many biological processes associated with cardiac function and the development of cardiac hypertrophy. In conclusion, we identified important similarities between ET-1-stimulated human-stem-cell-derived cardiomyocytes and human hypertrophic cardiac tissue. Novel putative cardiac hypertrophy biomarkers were identified and validated on the protein level, lending support for further investigations to assess their potential for future clinical applications.

Multi-Omics Characterization of a Human Stem Cell-Based Model of Cardiac Hypertrophy.

Cardiac hypertrophy is an important and independent risk factor for the development of cardiac myopathy that may lead to heart failure. The mechanisms underlying the development of cardiac hypertrophy are yet not well understood. To increase the knowledge about mechanisms and regulatory pathways involved in the progression of cardiac hypertrophy, we have developed a human induced pluripotent stem cell (hiPSC)-based in vitro model of cardiac hypertrophy and performed extensive characterization using a multi-omics approach. In a series of experiments, hiPSC-derived cardiomyocytes were stimulated with Endothelin-1 for 8, 24, 48, and 72 h, and their transcriptome and secreted proteome were analyzed. The transcriptomic data show many enriched canonical pathways related to cardiac hypertrophy already at the earliest time point, e.g., cardiac hypertrophy signaling. An integrated transcriptome-secretome analysis enabled the identification of multimodal biomarkers that may prove highly relevant for monitoring early cardiac hypertrophy progression. Taken together, the results from this study demonstrate that our in vitro model displays a hypertrophic response on both transcriptomic- and secreted-proteomic levels. The results also shed novel insights into the underlying mechanisms of cardiac hypertrophy, and novel putative early cardiac hypertrophy biomarkers have been identified that warrant further investigation to assess their potential clinical relevance.

Unraveling the Metabolic Derangements Occurring in Non-infarcted Areas of Pig Hearts With Chronic Heart Failure.

Objective: After myocardial infarction (MI), the non-infarcted left ventricle (LV) ensures appropriate contractile function of the heart. Metabolic disturbance in this region greatly exacerbates post-MI heart failure (HF) pathology. This study aimed to provide a comprehensive understanding of the metabolic derangements occurring in the non-infarcted LV that could trigger cardiovascular deterioration. Methods and Results: We used a pig model that progressed into chronic HF over 3 months following MI induction. Integrated gene and metabolite signatures revealed region-specific perturbations in amino acid- and lipid metabolism, insulin signaling and, oxidative stress response. Remote LV, in particular, showed impaired glutamine and arginine metabolism, altered synthesis of lipids, glucose metabolism disorder, and increased insulin resistance. LPIN1, PPP1R3C, PTPN1, CREM, and NR0B2 were identified as the main effectors in metabolism dysregulation in the remote zone and were found differentially expressed also in the myocardium of patients with ischemic and/or dilated cardiomyopathy. In addition, a simultaneous significant decrease in arginine levels and altered PRCP, PTPN1, and ARF6 expression suggest alterations in vascular function in remote area. Conclusions: This study unravels an array of dysregulated genes and metabolites putatively involved in maladaptive metabolic and vascular remodeling in the non-infarcted myocardium and may contribute to the development of more precise therapies to mitigate progression of chronic HF post-MI.

Data from a pooled post hoc analysis of 14 placebo-controlled, dapagliflozin treatment studies in patients with type 2 diabetes with and without anemia at baseline.

Dapagliflozin is a highly selective sodium-glucose cotransporter 2 inhibitor associated with stabilization of estimated glomerular filtration rate (eGFR); reductions in glycated hemoglobin (HbA1c), systolic blood pressure, body weight, and albuminuria; and a small and consistent increase in hematocrit [1], [2], [3], [4]. This data set is based on the associated article [5] analyzing data from 5325 patients with type 2 diabetes from 14 placebo-controlled, phase 3 (one phase 2/3), double-blind dapagliflozin treatment studies of 24-104 weeks' duration. Data on dapagliflozin's effects (vs. placebo) on hemoglobin (Hb), hematocrit, serum albumin, serum total protein concentrations, urine albumin/creatinine ratio, eGFR, heart rate, blood pressure, body weight, and safety in patients with type 2 diabetes with and without anemia were pooled and analyzed. Patients were divided into two groups according to baseline Hb levels: anemia (Hb <13 g/dL in men and <12 g/dL in women) and no anemia. Some biomarkers associated with erythropoiesis and the presence of anemia, such as iron, transferrin, ferritin, reticulocytes, and hepcidin, were not included in the original studies and therefore data for these biomarkers were not available. Descriptive statistics were used for baseline characteristics and safety data and a longitudinal repeated-measures mixed model for efficacy data. Changes in Hb concentrations were evaluated, and the proportion of patients with baseline anemia who were no longer anemic at week 24 was determined, as was the occurrence of polycythemia (Hb >16.5 g/dL in men and >16.0 g/dL in women). Because anemia commonly occurs in patients with diabetes and chronic kidney disease [6], the data can be of value to further analyze trends in relevant physiological and pathophysiological parameters.

Heart failure drug titration, discontinuation, mortality and heart failure hospitalization risk: a multinational observational study (US, UK and Sweden).

AIMS: Use and dosing of guideline-directed medical therapy (GDMT) in patients with heart failure (HF) have been shown to be suboptimal. Among new users of GDMT in HF, we followed the real-life patterns of dose titration and discontinuation of angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), beta-blockers, mineralocorticoid receptor antagonists (MRA) and angiotensin receptor-neprilysin inhibitors (ARNI). METHODS AND RESULTS: New users were identified in health care databases in Sweden, UK and US between 2016-2019. Inclusion criterion was a recent HF hospitalization (HHF) triggering the initiation of GDMT. Patients were grouped by GDMT, i.e. ACEi, ARB, beta-blocker, MRA and ARNI, and stratified by initial dose. Follow-up was 12 months, until death or study end. Outcomes were dose titration within each drug class, discontinuation and first HHF or death. Dose/discontinuation follow-up was assessed daily based on the coverage length of a filled prescription and reported on day 365. New users of ACEi (n = 8426), ARB (n = 2303), beta-blockers (n = 10 476), MRA (n = 17 421), and ARNI (n = 29 546) were identified. Over 12 months, target dose achievement was 15%, 10%, 12%, 30%, and discontinuation was 55%, 33%, 24% and 27% for ACEi, ARB, beta-blockers and ARNI, respectively. MRA was rarely titrated and discontinuation rates were high (40%). Event rates for HHF or death ranged from 40.0-86.9 per 100 patient-years across the treatment groups. CONCLUSION: Despite high risk of clinical events following HHF, new initiation of GDMT was followed by consistent patterns of low up-titration and early GDMT discontinuation in three countries with different health care and economies. Our data highlight the urgent need for moving away from long sequential approach when initiating HF treatment and for improving just-in-time decision support for patients and health care providers.

Multi-assignment clustering: Machine learning from a biological perspective.

A common approach for analyzing large-scale molecular data is to cluster objects sharing similar characteristics. This assumes that genes with highly similar expression profiles are likely participating in a common molecular process. Biological systems are extremely complex and challenging to understand, with proteins having multiple functions that sometimes need to be activated or expressed in a time-dependent manner. Thus, the strategies applied for clustering of these molecules into groups are of key importance for translation of data to biologically interpretable findings. Here we implemented a multi-assignment clustering (MAsC) approach that allows molecules to be assigned to multiple clusters, rather than single ones as in commonly used clustering techniques. When applied to high-throughput transcriptomics data, MAsC increased power of the downstream pathway analysis and allowed identification of pathways with high biological relevance to the experimental setting and the biological systems studied. Multi-assignment clustering also reduced noise in the clustering partition by excluding genes with a low correlation to all of the resulting clusters. Together, these findings suggest that our methodology facilitates translation of large-scale molecular data into biological knowledge. The method is made available as an R package on GitLab (https://gitlab.com/wolftower/masc).

Cardiac hypertrophy in a dish: a human stem cell based model.

Cardiac hypertrophy is an important and independent risk factor for the development of heart failure. To better understand the mechanisms and regulatory pathways involved in cardiac hypertrophy, there is a need for improved in vitro models. In this study, we investigated how hypertrophic stimulation affected human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs). The cells were stimulated with endothelin-1 (ET-1) for 8, 24, 48, 72, or 96 h. Parameters including cell size, ANP-, proBNP-, and lactate concentration were analyzed. Moreover, transcriptional profiling using RNA-sequencing was performed to identify differentially expressed genes following ET-1 stimulation. The results show that the CMs increase in size by approximately 13% when exposed to ET-1 in parallel to increases in ANP and proBNP protein and mRNA levels. Furthermore, the lactate concentration in the media was increased indicating that the CMs consume more glucose, a hallmark of cardiac hypertrophy. Using RNA-seq, a hypertrophic gene expression pattern was also observed in the stimulated CMs. Taken together, these results show that hiPSC-derived CMs stimulated with ET-1 display a hypertrophic response. The results from this study also provide new molecular insights about the underlying mechanisms of cardiac hypertrophy and may help accelerate the development of new drugs against this condition.

Correction of anemia by dapagliflozin in patients with type 2 diabetes.

AIMS: Anemia is common in type 2 diabetes (T2D), particularly in patients with kidney impairment, and often goes unrecognized. Dapagliflozin treatment increases hemoglobin and serum erythropoietin levels. We investigated the effect of dapagliflozin 10-mg/day on hemoglobin in T2D patients with and without anemia. METHODS: Data from 5325 patients from 14 placebo-controlled, dapagliflozin-treatment studies of at least 24-weeks duration were pooled. Dapagliflozin's effects (vs. placebo) on hemoglobin, serum albumin, estimated glomerular filtration rate (eGFR), systolic blood pressure, body weight, and safety in patients with and without anemia were evaluated. RESULTS: At baseline, 13% of all T2D patients and 28% of those with chronic kidney disease (eGFR <60 mL/min/1.73 m2) had anemia. Hemoglobin increased continuously to at least week 8 and was sustained throughout 24-weeks follow-up in dapagliflozin-treated patients. Serum albumin increased in dapagliflozin-treated patients at week 4 and remained stable thereafter. Dapagliflozin was well tolerated and corrected anemia in 52% of patients with anemia at baseline (placebo: 26%). Incidences of new-onset anemia were lower in dapagliflozin-treated (2.3%) versus placebo-treated (6.5%) patients. CONCLUSIONS: Treatment with dapagliflozin can correct and prevent anemia in T2D patients. A gradual increase in hemoglobin beyond week 4 may indicate an erythropoiesis-stimulating effect of sodium-glucose cotransporter 2 inhibition.

Human Pluripotent Stem Cell-Derived Hepatocytes Show Higher Transcriptional Correlation with Adult Liver Tissue than with Fetal Liver Tissue.

Human pluripotent stem cell-derived hepatocytes (hPSC-HEP) display many properties of mature hepatocytes, including expression of important genes of the drug metabolizing machinery, glycogen storage, and production of multiple serum proteins. To this date, hPSC-HEP do not, however, fully recapitulate the complete functionality of in vivo mature hepatocytes. In this study, we applied versatile bioinformatic algorithms, including functional annotation and pathway enrichment analyses, transcription factor binding-site enrichment, and similarity and correlation analyses, to datasets collected from different stages during hPSC-HEP differentiation and compared these to developmental stages and tissues from fetal and adult human liver. Our results demonstrate a high level of similarity between the in vitro differentiation of hPSC-HEP and in vivo hepatogenesis. Importantly, the transcriptional correlation of hPSC-HEP with adult liver (AL) tissues was higher than with fetal liver (FL) tissues (0.83 and 0.70, respectively). Functional data revealed mature features of hPSC-HEP including cytochrome P450 enzymes activities and albumin secretion. Moreover, hPSC-HEP showed expression of many genes involved in drug absorption, distribution, metabolism, and excretion. Despite the high similarities observed, we identified differences of specific pathways and regulatory players by analyzing the gene expression between hPSC-HEP and AL. These findings will aid future intervention and improvement of in vitro hepatocyte differentiation protocol in order to generate hepatocytes displaying the complete functionality of mature hepatocytes. Finally, on the transcriptional level, our results show stronger correlation and higher similarity of hPSC-HEP to AL than to FL. In addition, potential targets for further functional improvement of hPSC-HEP were also identified.

The effects of dapagliflozin on cardio-renal risk factors in patients with type 2 diabetes with or without renin-angiotensin system inhibitor treatment: a post hoc analysis.

AIMS: Renin-angiotensin system inhibitors (RASi) are the most effective treatments for diabetic kidney disease but significant residual renal risk remains, possibly because of other mechanisms of kidney disease progression unrelated to RAS that may be present. Sodium-glucose co-transporter-2 inhibitors reduce albuminuria and may complement RASi by offering additional renal protection. This post hoc analysis investigated the effects of dapagliflozin on cardio-renal risk factors in patients with type 2 diabetes (T2D) with increased albuminuria treated with or without RASi at baseline. MATERIALS AND METHODS: We evaluated the effects of dapagliflozin 10 mg/day over 12-24 weeks across 13 placebo-controlled studies in patients with T2D with a urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g at baseline. Patients were divided into two subgroups based on treatment with or without RASi at baseline. RESULTS: Compared with patients with RASi at baseline (n = 957), patients without RASi (n = 302) were younger, had a shorter duration of diabetes (7 vs. 12 years), higher estimated glomerular filtration rate (eGFR) and lower UACR, serum uric acid (sUA), body weight and systolic blood pressure. Placebo-adjusted treatment effects of dapagliflozin on UACR, eGFR, glycated haemoglobin and haematocrit over 24 weeks were similar across groups. Mean reductions in body weight and sUA were more distinct in patients without RASi treatment at baseline. CONCLUSIONS: Treatment with dapagliflozin over 24 weeks provides similar clinically relevant improvements in metabolic and haemodynamic parameters, and similar reductions in UACR, in patients with T2D with elevated albuminuria treated with or without RASi at baseline.

Correction of hypomagnesemia by dapagliflozin in patients with type 2 diabetes: A post hoc analysis of 10 randomized, placebo-controlled trials.

AIMS: Hypomagnesemia (serum magnesium [Mg] <0.74 mmol/L [<1.8 mg/dL]) is commonly observed in patients with type 2 diabetes (T2D). This study investigated the effect of treatment with dapagliflozin 10 mg on Mg concentrations in patients with T2D. METHODS: In this post hoc analysis, we used pooled data from 10 placebo-controlled studies of dapagliflozin over 24 weeks of treatment in patients with T2D. We evaluated the change in Mg in patients receiving dapagliflozin vs. placebo overall, and in subgroups with baseline hypomagnesemia and normal/hypermagnesemia (≥0.74 mmol/L [≥1.8 mg/dL]). We determined the proportion of patients with baseline hypomagnesemia who achieved Mg ≥0.74 mmol/L (≥1.8 mg/dL). RESULTS: A total of 4398 patients with T2D were included. The mean change from baseline to week 24 in Mg was significantly larger with dapagliflozin vs. placebo; difference, 0.06 mmol/L (95% confidence interval [CI]: 0.05, 0.06). The proportion of patients with Mg within the population reference range after 24 weeks of treatment was significantly higher with dapagliflozin vs. placebo; difference, 47.8% (95% CI: 41.4, 53.9). The proportion of patients displaying hypermagnesemia did not increase with dapagliflozin treatment. CONCLUSIONS: Treatment with dapagliflozin 10 mg resulted in correction of Mg concentrations in patients with T2D and hypomagnesemia.

Diabetic Cardiomyopathy Modelling Using Induced Pluripotent Stem Cell Derived Cardiomyocytes: Recent Advances and Emerging Models.

The global burden of diabetes has drastically increased over the past decades and in 2017 approximately 4 million deaths were caused by diabetes and cardiovascular complications. Diabetic cardiomyopathy is a common complication of diabetes with early manifestations of diastolic dysfunction and left ventricular hypertrophy with subsequent progression to systolic dysfunction and ultimately heart failure. An in vitro model accurately recapitulating key processes of diabetic cardiomyopathy would provide a useful tool for investigations of underlying disease mechanisms to further our understanding of the disease and thereby potentially advance treatment strategies for patients. With their proliferative capacity and differentiation potential, human induced pluripotent stem cells (iPSCs) represent an appealing cell source for such a model system and cardiomyocytes derived from induced pluripotent stem cells have been used to establish other cardiovascular related disease models. Here we review recently made advances and discuss challenges still to be overcome with regard to diabetic cardiomyopathy models, with a special focus on iPSC-based systems. Recent publications as well as preliminary data presented here demonstrate the feasibility of generating cardiomyocytes with a diabetic phenotype, displaying insulin resistance, impaired calcium handling and hypertrophy. However, capturing the full metabolic- and functional phenotype of the diabetic cardiomyocyte remains to be accomplished.

Reduction in albuminuria with dapagliflozin cannot be predicted by baseline clinical characteristics or changes in most other risk markers.

The sodium glucose co-transporter-2 inhibitor dapagliflozin has been shown to decrease urinary albumin-to-creatinine ratio (UACR). This effect, however, varies among individual patients. In this study, we assessed the baseline characteristics and concurrent changes in other cardiovascular risk markers that might be associated with UACR response to dapagliflozin. A pooled analysis of 11 phase 3 randomized, controlled clinical trials was performed. UACR change from baseline after 24 weeks treatment with dapagliflozin 10 mg/d in 531 patients with type 2 diabetes and UACR ≥30 mg/g at baseline was determined. UACR response was defined as >30% reduction from baseline at 24 weeks, whereas UACR non-response was defined as ≤30% reduction at 24 weeks. A total of 288 (54%) patients were classified as responders and 243 (46%) as non-responders. At 24 weeks, the UACR-adjusted mean change from baseline was -71.2% and 25.9% in responders and non-responders, respectively. Baseline characteristics were similar between both groups. Changes in HbA1c and body weight were comparable across groups. Responders showed a numerically larger reduction in estimated glomerular filtration rate and systolic blood pressure versus non-responders. UACR reduction to dapagliflozin is an individual characteristic that cannot be predicted by baseline clinical features or changes in metabolic variables. Whether UACR response would improve long-term renal and cardiovascular outcomes remains to be determined.

Efficacy and safety of dapagliflozin in patients with type 2 diabetes and moderate renal impairment (chronic kidney disease stage 3A): The DERIVE Study.

AIMS: Dapagliflozin is a selective inhibitor of sodium glucose co-transporter 2 (SGLT2). This study assessed the efficacy and safety of dapagliflozin 10 mg vs placebo in patients with type 2 diabetes (T2D) and moderate renal impairment (estimated glomerular filtration rate [eGFR], 45-59 mL/min/1.73 m2 ; chronic kidney disease [CKD] stage 3A). MATERIALS AND METHODS: In this double-blind, parallel group, Phase 3 study (NCT02413398, clinicaltrials.gov) patients with inadequately controlled T2D (HbA1c 7.0%-11.0%) were randomized (1:1) to dapagliflozin 10 mg once daily (N = 160) or matching placebo (N = 161) for 24 weeks. Randomization was stratified by pre-enrolment glucose-lowering therapy. The primary endpoint was change from baseline in HbA1c at Week 24. RESULTS: At Week 24, compared with placebo, dapagliflozin significantly decreased HbA1c (difference [95% CI], -0.34% [-0.53, -0.15]; P < 0.001), body weight (difference [95% CI], -1.25 kg [-1.90, -0.59]; P < 0.001), fasting plasma glucose (difference [95% CI], -0.9 mmol/L [-1.5, -0.4]; P = 0.001) and systolic blood pressure (difference [95% CI], -3.1 mm Hg [-6.3, 0.0]; P < 0.05). Decreases from baseline in eGFR were greater with dapagliflozin than placebo at Week 24 (-2.49 mL/min/1.73 m2 [-4.96, -0.02]), however, eGFR returned to baseline levels at Week 27 (3 weeks post-treatment) (0.61 mL/min/1.73 m2 [-1.59, 2.81]). No increase in adverse events (AEs; 41.9% vs 47.8%) or serious AEs (5.6% vs 8.7%) were reported with dapagliflozin versus placebo. No AEs of bone fractures, amputations or DKA were reported. CONCLUSIONS: The findings of this study (NCT02413398, clinicaltrials.gov) support the positive benefit/risk profile of dapagliflozin for the treatment of patients with T2D and CKD 3A.

Expression Profiling of Human Pluripotent Stem Cell-Derived Cardiomyocytes Exposed to Doxorubicin-Integration and Visualization of Multi-Omics Data.

Anthracyclines, such as doxorubicin, are highly efficient chemotherapeutic agents against a variety of cancers. However, anthracyclines are also among the most cardiotoxic therapeutic drugs presently on the market. Chemotherapeutic-induced cardiomyopathy is one of the leading causes of disease and mortality in cancer survivors. The exact mechanisms responsible for doxorubicin-induced cardiomyopathy are not completely known, but the fact that the cardiotoxicity is dose-dependent and that there is a variation in time-to-onset of toxicity, and gender- and age differences suggests that several mechanisms may be involved. In this study, we investigated doxorubicin-induced cardiotoxicity in human pluripotent stem cell-derived cardiomyocytes using proteomics. In addition, different sources of omics data (protein, mRNA, and microRNA) from the same experimental setup were further combined and analyzed using newly developed methods to identify differential expression in data of various origin and types. Subsequently, the results were integrated in order to generate a combined visualization of the findings. In our experimental model system, we exposed cardiomyocytes derived from human pluripotent stem cells to doxorubicin for up to 2 days, followed by a wash-out period of additionally 12 days. Besides an effect on the cell morphology and cardiomyocyte functionality, the data show a strong effect of doxorubicin on all molecular levels investigated. Differential expression patterns that show a linkage between the proteome, transcriptome, and the regulatory microRNA network, were identified. These findings help to increase the understanding of the mechanisms behind anthracycline-induced cardiotoxicity and suggest putative biomarkers for this condition.

Comparative transcriptomics of hepatic differentiation of human pluripotent stem cells and adult human liver tissue.

Hepatocytes derived from human pluripotent stem cells (hPSC-HEP) have the potential to replace presently used hepatocyte sources applied in liver disease treatment and models of drug discovery and development. Established hepatocyte differentiation protocols are effective and generate hepatocytes, which recapitulate some key features of their in vivo counterparts. However, generating mature hPSC-HEP remains a challenge. In this study, we applied transcriptomics to investigate the progress of in vitro hepatic differentiation of hPSCs at the developmental stages, definitive endoderm, hepatoblasts, early hPSC-HEP, and mature hPSC-HEP, to identify functional targets that enhance efficient hepatocyte differentiation. Using functional annotation, pathway and protein interaction network analyses, we observed the grouping of differentially expressed genes in specific clusters representing typical developmental stages of hepatic differentiation. In addition, we identified hub proteins and modules that were involved in the cell cycle process at early differentiation stages. We also identified hub proteins that differed in expression levels between hPSC-HEP and the liver tissue controls. Moreover, we identified a module of genes that were expressed at higher levels in the liver tissue samples than in the hPSC-HEP. Considering that hub proteins and modules generally are essential and have important roles in the protein-protein interactions, further investigation of these genes and their regulators may contribute to a better understanding of the differentiation process. This may suggest novel target pathways and molecules for improvement of hPSC-HEP functionality, having the potential to finally bring this technology to a wider use.

A data analysis framework for biomedical big data: Application on mesoderm differentiation of human pluripotent stem cells.

The development of high-throughput biomolecular technologies has resulted in generation of vast omics data at an unprecedented rate. This is transforming biomedical research into a big data discipline, where the main challenges relate to the analysis and interpretation of data into new biological knowledge. The aim of this study was to develop a framework for biomedical big data analytics, and apply it for analyzing transcriptomics time series data from early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. To this end, transcriptome profiling by microarray was performed on differentiating human pluripotent stem cells sampled at eleven consecutive days. The gene expression data was analyzed using the five-stage analysis framework proposed in this study, including data preparation, exploratory data analysis, confirmatory analysis, biological knowledge discovery, and visualization of the results. Clustering analysis revealed several distinct expression profiles during differentiation. Genes with an early transient response were strongly related to embryonic- and mesendoderm development, for example CER1 and NODAL. Pluripotency genes, such as NANOG and SOX2, exhibited substantial downregulation shortly after onset of differentiation. Rapid induction of genes related to metal ion response, cardiac tissue development, and muscle contraction were observed around day five and six. Several transcription factors were identified as potential regulators of these processes, e.g. POU1F1, TCF4 and TBP for muscle contraction genes. Pathway analysis revealed temporal activity of several signaling pathways, for example the inhibition of WNT signaling on day 2 and its reactivation on day 4. This study provides a comprehensive characterization of biological events and key regulators of the early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. The proposed analysis framework can be used to structure data analysis in future research, both in stem cell differentiation, and more generally, in biomedical big data analytics.

Dapagliflozin in patients with type II diabetes mellitus, with and without elevated triglyceride and reduced high-density lipoprotein cholesterol levels.

BACKGROUND: Dapagliflozin is a selective sodium-glucose cotransporter 2 inhibitor that improves glycemic control in patients with type II diabetes mellitus (T2DM) by reducing renal glucose reabsorption. OBJECTIVE: The aim was to evaluate the lipid effects of dapagliflozin 10 mg or placebo in patients with T2DM with/without baseline elevated triglyceride and reduced high-density lipoprotein (HDL) cholesterol levels. METHODS: This was a post hoc analysis of 10 phase 3, placebo-controlled studies of dapagliflozin 10 mg (N = 2237) or placebo (N = 2164) administered for 24 weeks in patients with T2DM. Patients with elevated triglyceride (≥150 mg/dL [1.69 mmol/L]) and reduced HDL cholesterol levels (<40 mg/dL [1.04 mmol/L] in men; <50 mg/dL [1.29 mmol/L] in women) were included (group A). The reference group (group B) included patients who did not meet the defined lipid criteria. RESULTS: The effects of dapagliflozin on fasting lipid profiles were generally similar in the 2 lipid groups (ie, groups A and B) and, compared with placebo, were associated with minor increases in non-HDL cholesterol, low-density lipoprotein, and HDL cholesterol levels. The effects on triglyceride levels were inconsistent. The incidence of adverse events (AEs)/serious AEs, and AEs of genital infection, urinary tract infection, volume reduction, renal function, and hypoglycemia were similar in the 2 lipid groups. CONCLUSION: Patients with T2DM treated with dapagliflozin experienced minor changes in lipid levels; the changes were generally similar in the 2 lipid groups. The clinical significance of these changes in lipids is unclear, especially in view of the positive effects of dapagliflozin on other cardiovascular disease risk factors.

Comparative transcriptomic analysis identifies genes differentially expressed in human epicardial progenitors and hiPSC-derived cardiac progenitors.

Regenerative therapies hold great potential to change the treatment paradigm for cardiac diseases. Human cardiac progenitor cells can be used for drug discovery in this area and also provide a renewable source of cardiomyocytes. However, a better understanding of their characteristics is critical for interpreting data obtained from drug screening using these cells. In the present study, we performed global transcriptional analysis of two important sources of cardiac progenitors, i.e., patient epicardium-derived cells (EPDCs) and cardiac progenitor cells (CPCs) derived from human induced pluripotent stem cells. In addition, we also compared the gene expression profiles of these cells when they were cultured under normoxic and hypoxic conditions. We identified 3,289 mRNAs that were differentially expressed between EPDCs and CPCs. Gene ontology annotation and pathway enrichment analyses further revealed possible unique functions of these two cell populations. Notably, the impact of hypoxia vs normoxia on gene expression was modest and only a few genes (e.g., AK4, ALDOC, BNIP3P1, PGK1, and SLC2A1) were upregulated in EPDCs and CPCs after the cells were exposed to low oxygen for 24 h. Finally, we also performed a focused analysis of the gene expression patterns of a predefined set of 92 paracrine factors. We identified 30 of these genes as differentially expressed, and 29 were expressed at higher levels in EPDCs compared with CPCs. Taken together, the results of the present study advance our understanding of the transcriptional programs in EPDCs and CPCs and highlights important differences and similarities between these cell populations.