NAxtra magnetic nanoparticles for low-cost, efficient isolation of mammalian DNA and RNA.

A cost-effective, viral nucleic acid (NA) isolation kit based on NAxtra magnetic nanoparticles was developed at the Norwegian University of Science and Technology in response to the shortage of commercial kits for isolation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA during the coronavirus disease 2019 (COVID-19) pandemic. This method showed comparable sensitivity to available kits at significantly reduced cost, making its application for other biological sources an intriguing prospect. Thus, based on this low-cost nucleic acid extraction technology, we developed a simple, low- and high-throughput, efficient method for isolation of high-integrity total NA, DNA and RNA from mammalian cell lines (monolayer) and organoids (3D-cultures). The extracted NA are compatible with downstream applications including (RT-)qPCR and next-generation sequencing. When automated, NA isolation can be performed in 14 min for up to 96 samples, yielding similar quantities to available kits.

microRNA-451a prevents activation of matrix metalloproteinases 2 and 9 in human cardiomyocytes during pathological stress stimulation.

Matrix metalloproteinases (MMP) are important for cardiac remodeling. Recently, microRNA (miR)-451a has been found to inhibit the expression of both MMP-2 and MMP-9 in human malignancies, but its role in cardiomyocytes has not been explored. We hypothesized that miR-451a modulates MMP-2 and MMP-9 levels in human cardiomyocytes. The role of miR-451a on regulation of MMP-2 and MMP-9 was evaluated in two separate pathological models using Cor.4U human inducible pluripotent stem cell-derived cardiomyocytes (hiPS-CMs): 1) endothelin-1 (ET-1), and 2) 48-h hypoxia (1% O2). Both models were transfected with synthetic miR-451a mimics or scramble control. Expression of both mRNA and miR was determined by quantitative real-time polymerase chain reaction and protein activity by (MMP-2/9) activity assay. Bioinformatic analyses were performed using Targetscan 7.1 and STRING 10.5. hiPS-CMs stimulated by hypoxia increased both MMP-2 and MMP-9 expression levels compared with normoxia (P < 0.05), whereas ET-1 stimulation only increased the MMP-9 level compared with vehicle controls (P < 0.05). miR-451a mimics prevented the increase of MMP-2 and MMP-9 expression in both models. Protein activity of MMP-2 and MMP-9 was confirmed to be lower following treatment with miR-451a mimic compared with scramble-controls. Six of 28 predicted gene transcripts of miR-451a were linked to MMP-2 and MMP-9; Macrophage migration inhibitory factor (MIF) was the only predicted target of miR-451a that was increased by ET-1 and hypoxia and reduced following miR-451a mimic transfection. miR-451a prevent the increase of MMP-2 and MMP-9 in human cardiomyocytes during pathological stress. The modulation by miR-451a on MMP-2 and MMP-9 is caused by MIF.