Biology subjects

Jennbacken, K.

Publications and source records attributed to Jennbacken, K..

4 recordsLinked to original sources

bioRxiv2025

Targeted delivery of mRNA to the heart via extracellular vesicles or lipid nanoparticles

Targeted mRNA transport plays a crucial role in enhancing the therapeutic efficacy of the molecule, reducing its side effects, and minimizing off-target effects. Systemic administration of mRNA through lipid nanoparticles (LNPs) or extracellular vesicles (EVs) predominantly results in mRNA accumulation in the liver. We hypothesized that cardiac-specific EVs could more effectively target the transport of mRNA to the heart, in comparison to non-cardiac-specific EVs or LNPs. In mice, after intravenous administration, EVs from cardiac progenitor cells (CPC-EVs) were the most efficient to transport the modified mRNA, encoding vascular endothelial growth factor A (VEGF-A), to mouse heart, with minimal liver accumulation compared to non-cardiac-specific EVs or LNPs. Additionally, intracardiac injections of CPC-EVs not only demonstrate that they are the most adapted vehicle for interacting with heart tissue, delivering the mRNA to cells, and inducing maximal VEGF-A protein production, but RNA-seq analyses also revealed their minimal impact on overall gene expression, compared to LNPs or non-cardiac-specific EVs. Furthermore, immunofluorescence staining of CD31 and -SMA, markers of microvascular density, showed increased vessel density in mouse aortic rings following the delivery of VEGF-A mRNA via CPC-EVs. These findings suggest that CPC-EVs are superior in mRNA targeting to heart, communication with cardiac cells, and causing minimal transcriptomic changes during VEGF-A mRNA delivery. Therefore, CPC-EVs could be promising vectors for heart-targeted mRNA delivery, potentially reducing liver accumulation.

molecular biology↗

bioRxiv2024

Reversal of contractile defects by mediating calcium homeostasis in human mini-heart models of heart failure with preserved ejection fraction (HFpEF) leads to first-in-human gene therapy clinical trial

AimsHeart failure with preserved ejection fraction (HFpEF), is a global health problem lacking disease-modifying therapeutic options, reflecting a lack of predictive models for preclinical drug testing. Aligned with FDA Modernization Act 2.0, we aimed to create the first in vitro human-specific mini-heart models of HFpEF, and to test the efficacy of a candidate gene therapy to improve cardiac kinetics and correct the disease phenotype. Methods and ResultsHealthy human pluripotent stem cell-derived ventricular cardiomyocytes were used to bioengineer beating cardiac tissue strips and pumping cardiac chambers. When conditioned with transforming growth factor-{beta}1 and endothelin-1, these mini-heart models exhibited signature disease phenotypes of significantly elevated diastolic force and tissue stiffness, and slowed contraction and relaxation kinetics, with no significant deficit in systolic force or ejection fraction versus unconditioned controls. Bioinformatic analysis of bulk RNA sequencing data from HFpEF mini-heart models and patient ventricular samples identified downregulation of SERCA2a of the calcium signalling pathway as a key differentially expressed gene. After dosage optimization, AAV-mediated expression of SERCA2a abrogated the disease phenotype and improved the cardiac kinetics in HFpEF mini-Hearts. ConclusionsThese findings contributed to FDA approval of an ongoing first-in-human gene therapy clinical trial for HFpEF, with Fast Track designation. We conclude that such human-based disease-specific mini-heart platforms are relevant for target discovery and validation that can facilitate clinical translation of novel cardiac therapies. Translational PerspectiveHeart failure with preserved ejection fraction (HFpEF) is a significant and growing global health concern lacking disease-modifying therapeutic options, reflecting inadequate preclinical models of the disease. Aligned with FDA Modernization Act 2.0, we created the first in vitro human-specific mini-heart models of HFpEF, demonstrated phenotypic disease characteristics of elevated stiffness and slowed kinetics, showed transcriptomic consistency with HFpEF patient data, identified SERCA2a as a key downregulated gene, performed dosing titration of SERCA2a gene therapy, and showed improvement of cardiac kinetics post-treatment. The findings contributed to FDA approval of an ongoing first-in-human gene therapy clinical trial for HFpEF.

bioengineering↗

bioRxiv2023

A transient modified mRNA encoding Myc and Cyclin T1 induces cardiac regeneration and improves cardiac function after myocardial injury

Cardiac injury, such as myocardial infarction (MI), results in permanent loss of cardiomyocytes and in many cases heart failure. Transgenic expression of the pro-proliferative transcription factor Myc and Cyclin T1 can drive substantial adult cardiomyocyte proliferation to replace lost cardiomyocytes. Herein, we show that Myc and Cyclin T1 induced cardiomyocyte proliferation leads to myocardial repair and functional (long-term) recovery post-MI in mice. To provide a more translational approach, we developed modified mRNA (modRNA) encoding Myc-Ccnt1 as a transient and non-integrating strategy for regeneration. One dose of Myc-Ccnt1 modRNA is sufficient to transiently drives cardiomyocyte proliferation in human pluripotent stem cell-derived cardiomyocytes and a mouse MI model, where it leads to better heart function. Using single nuclei sequencing and proteomics, we show this was functionally mediated by transcriptional activation of cell-cycle regulating genes, which ultimately results in mitosis and cytokinesis of cardiomyocytes. Collectively, these findings indicate that Myc-Ccnt1 modRNA has the potential to be an effective regenerative therapeutic.

molecular biology↗

bioRxiv2020

Barbadin selectively modulates FPR2-mediated neutrophil functions independent of receptor endocytosis

Formyl peptide receptor 2 (FPR2), a member of the family of G protein-coupled receptors (GPCRs), mediates neutrophil migration, a response that has been linked to {beta}-arrestin recruitment. {beta}-Arrestin regulates GPCR endocytosis and can also elicit non-canonical receptor signaling. To determine the poorly understood role of {beta}-arrestin in FPR2 endocytosis and in NADPH-oxidase activation in neutrophils, Barbadin was used as a research tool in this study. Barbadin has been shown to bind the clathrin adaptor protein (AP2) and thereby prevent {beta}- arrestin/AP2 interaction and {beta}-arrestin-mediated GPCR endocytosis. In agreement with this, AP2/{beta}-arrestin interaction induced by an FPR2-specific agonist was inhibited by Barbadin. Unexpectedly, however, Barbadin did not inhibit FPR2 endocytosis, indicating that a mechanism independent of {beta}-arrestin/AP2 interaction may sustain FPR2 endocytosis. This was confirmed by the fact, that FPR2 also underwent agonist-promoted endocytosis in {beta}-arrestin deficient cells, albeit at a diminished level as compared to wild type cells. Dissection of the Barbadin effects on FPR2-mediated neutrophil functions including NADPH-oxidase activation mediated release of reactive oxygen species (ROS) and chemotaxis reveled that Barbadin had no effect on chemotactic migration whereas the release of ROS was potentiated/primed. The effect of Barbadin on ROS production was reversible, independent of {beta}-arrestin recruitment, and similar to that induced by latrunculin A. Taken together, our data demonstrate that endocytic uptake of FPR2 occurs independently of {beta}-arrestin, while Barbadin selectively augments FPR2-mediated neutrophil ROS production independently of receptor endocytosis. Given that Barbadin binds to AP2 and prevents the AP2/{beta}-arrestin interaction, our results indicate a role for AP2 in FPR2-mediated ROS release from human neutrophils.

pharmacology and toxicology↗