In this study, we identified that a conserved circular RNA (circRNA) DICAR, which was downregulated in diabetic mouse hearts. DICAR had an inhibitory effect on diabetic cardiomyopathy (DCM), as the spontaneous cardiac dysfunction, cardiac cell hypertrophy, and cardiac fibrosis occurred in DICAR deficiency (DICAR+/−) mice, whereas the DCM was alleviated in DICAR-overexpressed DICARTg mice. At the cellular level, we found that overexpression of DICAR inhibited, but knockdown of DICAR enhanced the diabetic cardiomyocyte pyroptosis. At the molecular level, we identified that DICAR-VCP-Med12 degradation could be the underlying molecular mechanism in DICAR-mediated effects. The synthesized DICAR junction part (DICAR-JP) exhibited a similar effect to the entire DICAR. In addition, the expression of DICAR in circulating blood cells and plasma from diabetic patients was lower than that from health controls, which was consistent with the decreased DICAR expression in diabetic hearts. DICAR and the synthesized DICAR-JP may be drug candidates for DCM.
Human induced pluripotent stem cell (hiPSC)‐derived cardiac organoids (COs) have shown great potential in modelling human heart development and cardiovascular diseases, a leading cause of global death. However, several limitations such as low reproducibility, limited vascularization and difficulty in formation of cardiac chamber were yet to be overcome. We established a new method for robust generation of COs, via combination of methodologies of hiPSC‐derived vascular spheres and directly differentiated cardiomyocytes from hiPSCs, and investigated the potential application of human COs in cardiac injury modelling and drug evaluation. The human COs we built displayed a vascularized and chamber‐like structure, and hence were named vaschamcardioids (vcCOs). These vcCOs exhibited approximately 90% spontaneous beating ratio. Single‐cell transcriptomics identified a total of six cell types in the vcCOs, including cardiomyocytes, cardiac precursor cells, endothelial cells, fibroblasts, etc. We successfully recaptured the processes of cardiac injury and fibrosis in vivo on vcCOs, and showed that the FDA‐approved medication captopril significantly attenuated cardiac injury‐induced fibrosis and functional disorders. In addition, the human vcCOs exhibited an obvious drug toxicity reaction to doxorubicin in a dose‐dependent manner. We developed a three‐step method for robust generation of chamber‐like and vascularized complex vcCOs, and our data suggested that vcCOs might become a useful model for understanding pathophysiological mechanisms of cardiovascular diseases, developing intervention strategies and screening drugs.
Pancreatic cancer is one of the most lethal malignant tumors with a low survival rate, partly because the tumor microenvironment (TME), which consists of extracellular matrix (ECM), cancer-associated fibroblasts (CAFs), immune cells, and vascular systems, prevents effective drug delivery and chemoradiotherapy. Thus, modulating the microenvironment of pancreatic cancer is considered a promising therapeutic approach. Since nanoparticles are one of the most effective cancer treatment strategies, several nano-delivery platforms have been developed to regulate the TME and enhance treatment. Here, we summarize the latest advances in nano-delivery systems that alter the TME in pancreatic cancer by depleting ECM, inhibiting CAFs, reversing immunosuppression, promoting angiogenesis, or improving the hypoxic environment. We also discuss promising new targets for such systems. This review is expected to improve our understanding of how to modulate the pancreatic cancer microenvironment and guide the development of new therapies.Graphical Abstract
30 April 2020 in Frontiers in Cellular and Infection Microbiology
As the prevalence of systemic fungal infections caused by Candida albicans gradually increases, it is necessary to explore potential and effective antifungals. Carvacrol is reported to be lethally toxic to C. albicans, involving several potential mechanisms. However, the form and specific mechanism of cell death caused by this compound has not been delineated. In this study, we found that carvacrol could significantly decrease C. albicans survival rates, consistent with previous researches. Further examination proved that carvacrol treatment caused cell membrane permeability and depolarization. To elucidate the association between cell death and apoptosis, DNA fragmentation and metacaspase activation were determined; as expected, these two apoptosis-related markers were clearly observed. Moreover, total and mitochondrial reactive oxygen species (ROS) levels were elevated, and both mitochondrial transmembrane potential and morphology were disrupted. Additionally, cytosolic and mitochondrial calcium levels were also increased by carvacrol. Calcineurin inhibition experiments revealed cyclosporine A (CsA) addition notably rescued cell growth and inhibited metacaspase activation, indicating that carvacrol triggered C. albicans apoptosis through inducing calcineurin activation. Carvacrol was demonstrated to both have low toxicity and be effective in alleviating systemic infections with C. albicans, which might be via its antifungal and immunomodulation activities. This study suggests that carvacrol has excellent potential as a natural protective compound against C. albicans infections.
Heart failure (HF) is a deadly disease that is difficult to accurately diagnose. Circular RNAs (circRNAs) are a novel class of noncoding RNAs that might play important roles in many cardiovascular diseases. However, their role in HF remains unclear. CircRNA microarrays were performed on plasma samples obtained from three patients with HF and three healthy controls. The profiling results were validated by quantitative reverse transcription polymerase chain reaction. The diagnostic value of circRNAs for HF was evaluated by receiver operating characteristic (ROC) curves. The expression profiles indicated that 477 circRNAs were upregulated and 219 were downregulated in the plasma of patients with HF compared with healthy controls. Among the dysregulated circRNAs, hsa_circ_0112085 (p = 0.0032), hsa_circ_0062960 (p = 0.0006), hsa_circ_0053919 (p = 0.0074) and hsa_circ_0014010 (p = 0.025) showed significantly higher expression in patients with HF compared with healthy controls. The area under the ROC curve for hsa_circ_0062960 for HF diagnosis was 0.838 (p < 0.0001). Correlation analysis showed that the expression of hsa_circ_0062960 was highly correlated with B-type natriuretic peptide (BNP) serum levels. Some differential circRNAs were found to be related to platelet activity by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The landscape of circRNA expression profiles may play a role in HF pathogenesis and improve our understanding of platelet function in HF. Moreover, hsa_circ_0062960 has potential as a novel diagnostic biomarker for HF.