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Abstract Efficient generation of cardiomyocytes from human-induced pluripotent stem cells (hiPSCs) is important for their application in basic and translational studies. Space microgravity can significantly change cell activities and function. Previously, we reported upregulation of genes associated with cardiac proliferation in cardiac progenitors derived from hiPSCs that were exposed to space microgravity for 3 days. Here we investigated the effect of long-term exposure of hiPSC-cardiac progenitors to space microgravity on global gene expression. Cryopreserved 3D hiPSC-cardiac progenitors were sent to the International Space Station (ISS) and cultured for 3 weeks under ISS microgravity and ISS 1 G conditions. RNA-sequencing analyses revealed upregulation of genes associated with cardiac differentiation, proliferation, and cardiac structure/function and downregulation of genes associated with extracellular matrix regulation in the ISS microgravity cultures compared with the ISS 1 G cultures. Gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes mapping identified the upregulation of biological processes, molecular function, cellular components, and pathways associated with cell cycle, cardiac differentiation, and cardiac function. Taking together, these results suggest that space microgravity has a beneficial effect on the differentiation and growth of cardiac progenitors. 

Fluorescence microscopy is one of the most indispensable and informative driving forces for biological research, but the extent of observable biological phenomena is essentially determined by the content and quality of the acquired images. To address the different noise sources that can degrade these images, we introduce an algorithm for multiscale image restoration through optimally sparse representation (MIRO). MIRO is a deterministic framework that models the acquisition process and uses pixelwise noise correction to improve image quality. Our study demonstrates that this approach yields a remarkable restoration of the fluorescence signal for a wide range of microscopy systems, regardless of the detector used (e.g., electron-multiplying charge-coupled device, scientific complementary metal-oxide semiconductor, or photomultiplier tube). MIRO improves current imaging capabilities, enabling fast, low-light optical microscopy, accurate image analysis, and robust machine intelligence when integrated with deep neural networks. This expands the range of biological knowledge that can be obtained from fluorescence microscopy. 

Abstract BackgroundCardiac pathological outcome of metabolic remodeling is difficult to model using cardiomyocytes derived from human-induced pluripotent stem cells (hiPSC-CMs) due to low metabolic maturation. MethodshiPSC-CM spheres were treated with AMP-activated protein kinase (AMPK) activators and examined for hiPSC-CM maturation features, molecular changes and the response to pathological stimuli. ResultsTreatment of hiPSC-CMs with AMPK activators increased ATP content, mitochondrial membrane potential and content, mitochondrial DNA, mitochondrial function and fatty acid uptake, indicating increased metabolic maturation. Conversely, the knockdown of AMPK inhibited mitochondrial maturation of hiPSC-CMs. In addition, AMPK activator-treated hiPSC-CMs had improved structural development and functional features—including enhanced Ca²⁺transient kinetics and increased contraction. Transcriptomic, proteomic and metabolomic profiling identified differential levels of expression of genes, proteins and metabolites associated with a molecular signature of mature cardiomyocytes in AMPK activator-treated hiPSC-CMs. In response to pathological stimuli, AMPK activator-treated hiPSC-CMs had increased glycolysis, and other pathological outcomes compared to untreated cells. ConclusionAMPK activator-treated cardiac spheres could serve as a valuable model to gain novel insights into cardiac diseases. 

In fluorescence microscopy, the quality of the acquired images determines the extent of observable biological phenomena. To address the different noise sources degrading these images, we introduce a model-based framework compatible with several microscopy systems independently from the detector used. 

BackgroundAlcohol use in pregnancy increases the risk of abnormal cardiac development, and excessive alcohol consumption in adults can induce cardiomyopathy, contractile dysfunction, and arrhythmias. Understanding molecular mechanisms underlying alcohol‐induced cardiac toxicity could provide guidance in the development of therapeutic strategies. MethodsWe have performed proteomic and bioinformatic analysis to examine protein alterations globally and quantitatively in cardiomyocytes derived from human‐induced pluripotent stem cells (hiPSC‐CMs) treated with ethanol (EtOH). Proteins in both cell lysates and extracellular culture media were systematically quantitated. ResultsTreatment with EtOH caused severe detrimental effects on hiPSC‐CMs as indicated by significant cell death and deranged Ca²⁺handling. Treatment of hiPSC‐CMs with EtOH significantly affected proteins responsible for stress response (e.g., GPX1 and HSPs), ion channel‐related proteins (e.g. ATP1A2), myofibril structure proteins (e.g., MYL2/3), and those involved in focal adhesion and extracellular matrix (e.g., ILK and PXN). Proteins involved in the TNF receptor‐associated factor 2 signaling (e.g., CPNE1 and TNIK) were also affected by EtOH treatment. ConclusionsThe observed changes in protein expression highlight the involvement of oxidative stress and dysregulation of Ca²⁺handling and contraction while also implicating potential novel targets in alcohol‐induced cardiotoxicity. These findings facilitate further exploration of potential mechanisms, discovery of novel biomarkers, and development of targeted therapeutics against EtOH‐induced cardiotoxicity.