Summary Numerous studies indicate an inflammatory link between obesity and type 2 diabetes. The inflammatory kinases IKKε and TBK1 are elevated in obesity; their inhibition in obese mice reduces weight, insulin resistance, fatty liver and inflammation. Here we studied amlexanox, an inhibitor of IKKε/TBK1, in a proof-of-concept randomized, double blind, placebo-controlled study of 42 obese patients with type 2 diabetes and nonalcoholic fatty liver disease. Treatment of patients with amlexanox produced a statistically significant reduction in Hemoglobin A1c and fructosamine. Interestingly, a subset of drug responders also exhibited improvements in insulin sensitivity and hepatic steatosis. This subgroup was characterized by a distinct inflammatory gene expression signature from biopsied subcutaneous fat at baseline. They also exhibited a unique pattern of gene expression changes in response to amlexanox, consistent with increased energy expenditure. Together, these data suggest that IKKε/TBK1 inhibitors may be effective therapies for metabolic disease in an identifiable subset of patients.

Diabetes mellitus is a growing health care problem, resulting in significant cardiovascular morbidity and mortality. Diabetes also increases the risk for heart failure (HF) and decreased cardiac myocyte function, which are linked to changes in cardiac mitochondrial energy metabolism. The free mitochondrial calcium level ([Ca] ) is fundamental in activating the mitochondrial respiratory chain complexes and ATP production and is also known toregulate pyruvate dehydrogenase complex (PDC) activity. The mitochondrial calcium uniporter (MCU) complex (MCUC) plays a major role in mediating mitochondrial Ca import, and its expression and function therefore have a marked impact on cardiac myocyte metabolism and function. Here, we investigated MCU's role in mitochondrial Ca handling, mitochondrial function, glucose oxidation, and cardiac function in the heart of diabetic mice. We found that diabetic mouse hearts exhibit altered expression of MCU and MCUC members and a resulting decrease in [Ca] , mitochondrial Ca uptake, mitochondrial energetic function, and cardiac function. Adeno-associated virus-based normalization of MCU levels in these hearts restored mitochondrial Ca handling, reduced PDC phosphorylation levels, and increased PDC activity. These changes were associated with cardiac metabolic reprogramming toward normal physiological glucose oxidation. This reprogramming likely contributed to the restoration of both cardiac myocyte and heart function to nondiabetic levels without any observed detrimental effects. These findings support the hypothesis that abnormal mitochondrial Ca handling and its negative consequences can be ameliorated in diabetes by restoring MCU levels via adeno-associated virus-based MCU transgene expression.

SummaryNon-human primates (NHPs) can serve as a human-like model to study cell therapy using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). However, whether the efficacy of NHP and human iPSC-CMs is mechanistically similar remains unknown. To examine this, RNU rats received intramyocardial injection of 1 × 107 NHP or human iPSC-CMs or the same number of respective fibroblasts or PBS control (n = 9–14/group) at 4 days after 60-min coronary artery occlusion-reperfusion. Cardiac function and left ventricular remodeling were similarly improved in both iPSC-CM-treated groups. To mimic the ischemic environment in the infarcted heart, both cultured NHP and human iPSC-CMs underwent 24-hr hypoxia in vitro. Both cells and media were collected, and similarities in transcriptomic as well as metabolomic profiles were noted between both groups. In conclusion, both NHP and human iPSC-CMs confer similar cardioprotection in a rodent myocardial infarction model through relatively similar mechanisms via promotion of cell survival, angiogenesis, and inhibition of hypertrophy and fibrosis.

Untargeted liquid-chromatography–mass spectrometry (LC-MS)-based metabolomics analysis of human biospecimens has become among the most promising strategies for probing the underpinnings of human health and disease. Analysis of spectral data across population scale cohorts, however, is precluded by day-to-day nonlinear signal drifts in LC retention time or batch effects that complicate comparison of thousands of untargeted peaks. To date, there exists no efficient means of visualization and quantitative assessment of signal drift, correction of drift when present, and automated filtering of unstable spectral features, particularly across thousands of data files in population scale experiments. Herein, we report the development of a set of R-based scripts that allow for pre- and postprocessing of raw LC-MS data. These methods can be integrated with existing data analysis workflows by providing initial preprocessing bulk nonlinear retention time correction at the raw data level. Further, this approach provides postprocessing visualization and quantification of peak alignment accuracy, as well as peak-reliability-based parsing of processed data through hierarchical clustering of signal profiles. In a metabolomics data set derived from ~3000 human plasma samples, we find that application of our alignment tools resulted in substantial improvement in peak alignment accuracy, automated data filtering, and ultimately statistical power for detection of metabolite correlates of clinical measures. These tools will enable metabolomics studies of population scale cohorts.

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