Biology subjects

Huang, R.-T.

Publications and source records attributed to Huang, R.-T..

4 recordsLinked to original sources

bioRxiv2025

Mechanosensitive Endothelial METTL7A Regulates Internal m7G mRNA Methylation and Protects Against Atherosclerosis

BACKGROUNDInternal N7-methylguanosine (m7G) is a recently identified chemical modification of mammalian mRNA and a component of the epitranscriptome. While the epitranscriptome plays a key role in regulating RNA metabolism and cellular function, the specific contribution of internal m7G to cardiovascular health and disease remains unknown. Atherosclerosis preferentially develops at sites where disturbed blood flow activates endothelial cells, but whether internal m7G and its regulatory machinery influence endothelial mechanotransduction and atherogenesis is unclear. METHODSWe integrated epitranscriptomic profiling, human tissue analysis, genetically modified mouse models, and targeted nanomedicine approaches to investigate the role of Methyltransferase-like protein 7A (METTL7A), a putative internal m7G methyltransferase, in regulating the flow-sensitive endothelial transcriptome and atherosclerosis. Vascular endothelial cells were subjected to well-defined athero-protective and athero-prone flow waveforms in vitro and in vivo. METTL7A function was assessed using RNA sequencing (RNA-seq), liquid chromatography-tandem mass spectrometry (LC-MS/MS), crosslinking immunoprecipitation sequencing (CLIP-seq), RNA stability assays, and a CRISPR-Cas-inspired RNA targeting system (CIRTS). METTL7A expression in human coronary arteries with and without atherosclerosis was evaluated by RNA-seq and immunostaining. In vivo atherosclerosis studies were conducted in both global and endothelial-specific Mettl7a1 knockout mice. Endothelial METTL7A expression was restored using cationic polymer-based nanoparticles delivering CDH5 promoter-driven METTL7A plasmids or VCAM1-targeted lipid nanoparticles delivering N1-methylpseudouridine (m{superscript 1}{Psi})-modified METTL7A mRNA. RESULTSAthero-protective unidirectional flow significantly induced METTL7A expression, which promoted internal m7G methylation of endothelial transcripts, while other major epitranscriptomic marks and cap-associated m7G were not affected by METTL7A. METTL7A preferentially binds to AG-enriched motifs in protein-coding mRNAs and plays a key role in regulating KLF4 and NFKBIA transcripts, enhancing their internal m7G and stability and supporting vascular homeostasis. In contrast, endothelial METTL7A expression was significantly reduced by disturbed blood flow and in human atherosclerotic lesions. Global or endothelial-specific loss of METTL7A exacerbated disturbed flow-induced atherosclerosis in mice, independent of serum lipid levels. Restoration of endothelial METTL7A, via nanoparticle-mediated plasmid or m1{Psi} mRNA delivery, markedly reduced lesion formation in Mettl7a1-/- and ApoE-/- mice. CONCLUSIONSThese findings establish METTL7A as a previously unrecognized mechanosensitive methyltransferase that maintains endothelial homeostasis by stabilizing key anti-inflammatory transcripts, KLF4 and NFKBIA, through internal m7G methylation. Loss of METTL7A disrupts endothelial function and accelerates atherogenesis in response to disturbed flow. Therapeutic restoration of endothelial METTL7A, via targeted nanoparticle-mediated gene or m1{Psi} mRNA delivery, significantly lessens atherosclerosis. Collectively, these results uncover a novel epitranscriptomic mechanism governing vascular health and position METTL7A as a promising target for precision nanomedicine in atherosclerotic cardiovascular disease.

molecular biology↗

bioRxiv2025

Precision mRNA Nanomedicine for Targeted Vascular Therapies in ARDS and Atherosclerosis

Vascular diseases, including acute respiratory distress syndrome (ARDS) and atherosclerosis, are leading causes of global morbidity and mortality, underscoring the critical need for innovative therapies. While human genetics has uncovered specific molecular mechanisms in endothelial cells that drive acute and chronic vascular inflammation central to these conditions, effective in vivo strategies to spatiotemporally target these disease-causing pathways using therapeutic mRNAs remain limited. Here, we present a modular and tunable nanoparticle platform (PROGRAMMED nanoparticles) engineered to selectively deliver therapeutic mRNAs to target cells with distinct molecular signatures, such as inflamed endothelial cells expressing vascular cell adhesion molecule 1 (VCAM1). This approach restores key genetics-informed endothelial pathways implicated in disease, including the loss of Kruppel-like factor 2 (KLF2) in acute inflammation underlying ARDS and the suppression of phospholipid phosphatase 3 (PLPP3) in chronic inflammation driving atherosclerosis. In multiple preclinical models, these precision mRNA nanomedicine strategies demonstrated compelling therapeutic efficacy. VCAM1-targeting PROGRAMMED nanoparticles delivering KLF2 mRNA to inflamed lung microvascular endothelial cells significantly improved microvascular health and alleviated virus-induced ARDS. Similarly, PLPP3 mRNA delivery by VCAM1-targeting PROGRAMMED nanoparticles attenuated arterial inflammation, slowed atherosclerosis progression, and promoted regression of advanced plaques. This innovative platform offers a transformative approach for spatiotemporal mRNA therapies targeting inflamed endothelial cells, providing a minimally invasive and highly specific strategy to address acute and chronic vascular diseases. Moreover, the modularity of PROGRAMMED nanoparticles, particularly their ability to display diverse targeting motifs, holds substantial potential for addressing a broad spectrum of vascular complications and other diseases that require precise spatiotemporal correction of dysregulated genes.

bioengineering↗

bioRxiv2021

Endothelial restoration of CAD GWAS gene PLPP3 by nanomedicine suppresses YAP/TAZ activity and reduces atherosclerosis in vivo

Genome-wide association studies (GWAS) have suggested new molecular mechanisms in vascular cells driving atherosclerotic diseases such as coronary artery disease (CAD) and ischemic stroke (IS). Nevertheless, a major challenge to develop new therapeutic approaches is to spatiotemporally manipulate these GWAS-identified genes in specific vascular tissues in vivo. YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif) have merged as critical transcriptional regulators in cells responding to biomechanical stimuli, such as in athero-susceptible endothelial cells activated by disturbed flow (DF). The molecular mechanisms by which DF activates while unidirectional flow (UF) inactivates YAP/TAZ remain incompletely understood. Recent studies demonstrated that DF and genetic predisposition (risk allele) of CAD/IS locus 1p32.2 converge to reduce phospholipid phosphatase 3 (PLPP3) expression in vascular endothelium. Restoration of endothelial PLPP3 in vivo, although remains challenging and unexplored, is hypothesized to reduce atherosclerosis. We devised a nanomedicine system integrating nanoparticles and Cdh5 promoter-driven plasmids to successfully restore PLPP3 expression in activated endothelium, resulting in suppressed YAP/TAZ activity and reduced DF-induced atherosclerosis in mice. Mechanistically, our studies discovered a molecular paradigm by which CAD/IS GWAS gene PLPP3 inactivates YAP/TAZ by reducing lysophosphatidic acid (LPA)-induced myosin II and ROCK in endothelium under UF. These results highlight a new mechanistic link between GWAS and YAP/TAZ mechano-regulation and moreover, establish a proof of concept of vascular wall-based therapies employing targeted nanomedicine to manipulate CAD/IS GWAS genes in vivo.

bioengineering↗

bioRxiv2018

A genetic variant at coronary artery disease and ischemic stroke locus 1p32.2 regulates endothelial responses to hemodynamics

Biomechanical cues dynamically control major cellular processes but whether genetic variants actively participate in mechano-sensing mechanisms remains unexplored. Vascular homeostasis is tightly regulated by hemodynamics. Exposure to disturbed blood flow at arterial sites of branching and bifurcation causes constitutive activation of vascular endothelium contributing to atherosclerosis, the major cause of coronary artery disease (CAD) and ischemic stroke (IS). Conversely, unidirectional flow promotes quiescent endothelium. Genome-wide association studies have identified chromosome 1p32.2 as one of the most strongly associated loci with CAD/IS; however, the causal mechanism related to this locus remains unknown. Employing statistical analyses, ATAC-seq, and H3K27ac/H3K4me2 ChIP-Seq in human aortic endothelium (HAEC), our results demonstrate that rs17114036, a common noncoding polymorphism at the 1p32.2, is located in an endothelial enhancer dynamically regulated by hemodynamics. CRISPR/Cas9-based genome editing shows that rs17114036-containing region promotes endothelial quiescence under unidirectional flow by regulating phospholipid phosphatase 3 (PLPP3). Chromatin accessibility quantitative trait locus mapping using HAECs from 56 donors, allelic imbalance assay from 7 donors, and luciferase assays further demonstrate that CAD/IS protective allele at rs17114036 in PLPP3 intron 5 confers an increased endothelial enhancer activity. ChIPPCR and luciferase assays show that CAD/IS protective allele at rs17114036 creates a binding site for transcription factor Kruppel-like factor 2, which increases the enhancer activity under unidirectional flow. These results demonstrate for the first time that a human single-nucleotide polymorphism contributes to critical endothelial mechanotransduction mechanisms and suggest that human haplotypes and related cisregulatory elements provide a previously unappreciated layer of regulatory control in cellular mechano-sensing mechanisms.\n\nSignificance StatementBiomechanical stimuli control major cellular functions and play critical roles in the pathogenesis of diverse human diseases. Although recent studies have implicated genetic variation in regulating key biological processes, whether human genetic variants contribute to the cellular mechano-sensing mechanisms remains unclear. This study provides the first line of evidence supporting an underappreciated role of genetic predisposition in cellular mechanotransduction mechanisms. Employing epigenomic profiling, genome-editing, and latest human genetics approaches, our data demonstrate that rs17114036, a common noncoding polymorphism implicated in coronary artery disease and ischemic stroke by genome-wide association studies, dynamically regulates endothelial responses to blood flow (hemodynamics) related to atherosclerosis via regulation of an intronic enhancer. The results provide new molecular insights linking disease-associated genetic variants to cellular mechanobiology.

genomics↗