Stearoyl CoA Desaturase 1 and Inositol-Requiring Protein 1α Determine the Efficiency of Oleic Acid in Alleviating Silica Nanoparticle-Induced Insulin Resistance

Cannabidiol attenuates lipid metabolism and induces CB1 receptor-mediated ER stress associated apoptosis in ovarian cancer cells

Ovarian cancer (OC) is the most deadly gynecological tumor. OC cells utilize cellular metabolic reprogramming to gain a survival advantage, particularly through aberrant lipid metabolic process. As the primary ingredient in exogenous cannabinoids, cannabidiol (CBD) has been confirmed to exhibit antitumor activity in preclinical studies. However, it is still unclear whether CBD can disrupt fatty acid metabolism and induce apoptosis in OC cells. In this study, we have demonstrated that CBD significantly inhibits the proliferation of OCs through a cannabinoid receptor type 1 (CB1R)-mediated manner. Fatty acid metabolic profiling and flow cytometry analysis revealed that CBD has the ability to decrease fatty acid levels and significantly suppress the transcription of genes involved in fatty acid uptake and synthesis in ES-2 cells. In addition, the analysis from RNA-seq and real-time RT-PCR revealed that CBD activated the endoplasmic reticulum (ER) stress pathway. Conversely, by supplementation with unsaturated fatty acid or blocking CB1R, ER stress or reactive oxygen species (ROS) signals with specific inhibitors could significantly relieve CBD induced, dose-dependent, ER stress associated apoptosis, G0-G1 phase arrest, and mitochondrial dysfunction. Taken collectively, these data indicate that CBD may disrupt lipid metabolism, and lead to ER stress-related apoptosis in OCs. Our findings may provide a theoretical mechanism for anti-ovarian cancer using CBD.

Long noncoding RNA lncPostn links TGF-β and p53 signaling pathways to transcriptional regulation of cardiac fibrosis

Cardiac fibroblasts are essential for the homeostasis of the extracellular matrix, whose remodeling in many cardiovascular diseases leads to fibrosis. Long noncoding RNAs (lncRNAs) are associated with cardiac pathologies, but their functions in cardiac fibroblasts and contributions to cardiac fibrosis remain unclear. Here, we aimed to identify fibroblast-enriched lncRNAs essential in myocardial infarction (MI)-induced fibrosis and explore the molecular mechanisms responsible for their functions. Global lncRNA profiling was performed in post-MI mouse heart ventricles and transforming growth factor-β (TGF-β)-treated primary cardiac fibroblasts and confirmed in published data sets. We identified the cardiac fibroblast-enriched lncPostn, whose expression is stimulated in cardiac fibrosis induced by MI and the extracellular growth factor TGF-β. The promoter of lncPostn contains a functional TGF-β response element, and lncPostn knockdown suppresses TGF-β-stimulated cardiac fibroblast activation and improves cardiac functions post-MI. LncPostn stabilizes and recruits EP300 to the profibrotic periostin's promoter, representing a major mechanism for its transcriptional activation. Moreover, both MI and TGF-β enhance lncPostn expression while suppressing the cellular growth gatekeeper p53. TGF-β and p53 knockdown-induced profibrotic gene expression and fibrosis occur mainly through lncPostn and show additive effects. Finally, levels of serum lncPostn are significantly increased in patients' postacute MI and show a strong correlation with fibrosis markers, revealing a potential biomarker of cardiac fibrosis. Our findings identify the fibroblast-enriched lncPostn as a potent profibrotic factor, providing a transcriptional link between TGF-β and p53 signaling pathways to regulate fibrosis in cardiac fibroblasts.NEW & NOTEWORTHY Cardiac fibroblasts are essential for the homeostasis of the extracellular matrix, whose remodeling in many cardiovascular diseases leads to fibrosis. Long noncoding RNAs are functional and contribute to the biological processes of cardiovascular development and disorders. Our findings identify the fibroblast-enriched lncPostn as a potent profibrotic factor and demonstrate that serum lncPostn level may serve as a potential biomarker of human cardiac fibrosis postacute myocardial infarction.