Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2020.04.16.044925

The evaluation of miR-874 antagomiR and miR-146a toxicity in cardiomyocytes

Zhang, Y.·Xu, H.·Wu, J.
View original source ↗Export metadata ↓

Abstract

More and more studies have shown that microRNAs (miRNAs) play key roles in the treatment of heart failure. Studies have shown that miR-874 (miR-874) inhibitors can reduce H2O2-induced cardiomyocyte necrosis and may have a therapeutic effect on heart failure in terms of cardiomyocyte necrosis. Therefore, the purpose of this experiment is to study the other effects of miR-874 and miR-146a on the key pathways in cardiomyocytes and cardiac fibroblasts. In this study, the roles of miR-874 antagomiR and miR-146a in cardiomyocytes and cardiac fibroblasts were analyzed. we investigated the level of miR-874 expression in H9C2 cardiomyocytes after miR-874 antagomiR transfection and found that the miR-874 expression in the H9C2 cells transfected with miR-874 antagomiR group was significantly lower than that in the control group. The results showed that miR-874 was successfully knocked down by the transfection of miR-874 antagomiR. Our results demonstrated that miR-874 inhibition has no effect on the activity of Caspase-3/7 in cardiomyocytes. miR-874 antagomiR has no effect on the proliferation of cardiac fibroblasts, whereas it can inhibit the activity of caspase-8 in cardiac fibroblasts. In addition, the potential effect of miR-874 antagomiR on cardiac remodeling associated genes were examined. miR-874 antagomiR had no effect on SERCA2a mRNA level in H9C2 cells. In addition, miR-874 antagomiR were able to down-regulate the mRNA level of MMP9 and had no effect on MMP2 mRNA levels in H9C2 cells. Finally, The concentration of Ca2+ was measured using Fluo-4 NW Calcium Assay Kits following transfection of miRNAs or negative control in primary cardiomyocytes. miR-874 antagomiR was found to have no effect on Ca2+ concentration in cardiomyocytes. the concentration of Ca2+ in the cardiomyocytes transfected with miR-146a mimics was significantly lower than the mimic negative control group. In summary, miR-874 antagomiR and miR-146a may have a therapeutic effect on heart failure, but may also have side effects on heart failure treatment. Therefore, miR-874 antagomiR should be further studied to provide a basis for the development of drugs for heart failure.

Explore related subjects

cell biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Zhang, Y., Xu, H., Wu, J.. 2020-04-18. The evaluation of miR-874 antagomiR and miR-146a toxicity in cardiomyocytes. https://doi.org/10.1101/2020.04.16.044925

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Functional characterization of Rho GTPase activating proteins SYDE1 and SYDE2

The human genome encodes more than 60 proteins containing Rho GTPase activating protein (RhoGAP) domains, many of which remain understudied with respect to their target specificity and biological roles. SYDE1 and SYDE2 are two such orphan RhoGAPs, for which there are few studies characterizing their biochemical and cellular functions and conflicting reports identifying their cognate GTPases. We previously identified SYDE1 and SYDE2 in a screen for substrates of the c-Jun N-terminal kinases. Here, we show that SYDE1 and SYDE2 are preferentially phosphorylated by JNK1 relative to other mitogen-activated protein kinases (MAPKs) at sites proximal to a kinase docking region. Purified SYDE1 and SYDE2 are shown to have significant catalytic GAP activity toward RhoA, Rac1, and Cdc42. However, neither up- nor down-regulation of SYDE1/2 expression leads to detectable changes in bulk GTP loading of any of these GTPases. Nevertheless, we demonstrate that SYDE1 and SYDE2, in a partially GAP-dependent manner, increase cell spreading and number of focal adhesions, and promote more directionally persistent migration in HEK293 cells. Together, these findings establish SYDE1 and SYDE2 as robust JNK substrates with catalytic activity toward a set of Rho GTPases and reveal basic functions of SYDE1 and SYDE2 in regulating cell morphology, adhesion, and migration.

cell biology↗
bioRxiv2026

The filopodial scaffold polyphosphate dictates cell adhesion-versus-invasion decisions

Inorganic polyphosphate (polyP) is an ancient polymer conserved across all life, serving cell type and location specific functions in every major compartment. Yet its role at the plasma membrane, where it accumulates to peak levels in many primary cells, is largely unknown. Here we identify polyP as a stabilizing component of filopodia, actin based membrane protrusions that govern cell adhesion, contact inhibition, and chemotaxis. Elevating cellular polyP increases filopodial stability and enhances cell adhesion, whereas reducing polyP accelerates filopodial disassembly and promotes cell migration. Mechanistically, we find that polyP acts as a structural filopodial scaffold, recruiting and organizing IRSp53, a membrane curvature inducing protein. We show that metastatic fibroblasts and breast cancer organoids carry markedly reduced and intracellularly reorganized polyP levels relative to their non transformed counterparts. Restoring endogenous polyP via lipid nanoparticle delivery suppresses their invasive phenotypes and reverses prometastatic gene expression signatures, implicating polyP as a primordial tumor suppressor.

cell biology↗
bioRxiv2026

Mitochondrial transfer mediates metabolic communication between beta cells and islet macrophages

Pancreatic islet macrophages support islet homeostasis and adapt their metabolic program in response to environmental cues, including beta cell released factors. Intercellular mitochondrial transfer is a biological process that modulates cellular responses. To test whether beta cells, which are strongly secretory, transfer mitochondria to islet macrophages, we generated mice with beta cell-specific expression of mitochondrial GFP (PhAMfloxIns1Cre). We demonstrate that beta cells transfer mitochondria to islet macrophages in vivo and in vitro. Diabetogenic stressors did not alter the frequency of mitochondrial transfer and macrophages containing beta cell-derived GFP exhibit increased protein synthesis rates. RNA-seq identified upregulation of activity-regulated cytoskeleton associated protein (Arc) in macrophages receiving beta cell-derived mitochondria, while disruption of actin cytoskeleton dynamics prevented mitochondrial transfer. Together, these findings identify mitochondrial transfer as a previously unrecognized mechanism of beta cell-macrophage communication that may contribute to islet homeostasis and immune regulation.

cell biology↗