Dataset Information

RNA-seq analysis of non-vascular smooth muscle cells (NVSMCs) isolated from the lung, intestine and bladder

ABSTRACT: None of the currently available Cre recombinase-expressing mouse lines allows for exclusive and specific manipulation of non-vascular smooth muscle cells (NVSMCs). To address this, we focused on the Chrm2 gene, which encodes the M2 muscarinic acetylcholine receptor (M2R), a G protein-coupled receptor (GPCR) previously reported to be expressed selectively in NVSMCs and also in CD45-positive immune cells. In contrast, Acta2 is broadly and strongly expressed in all smooth muscle cells (SMCs), including both vascular and non-vascular populations. To achieve specific labeling of NVSMCs, we generated NVSMC-effector mice by combining Chrm2-Dre with Acta2-Rox-CreER and R26-LoxP-GFP alleles. Following tamoxifen administration, we observed robust GFP fluorescence specifically in NVSMCs of the lung, stomach, and intestine. Notably, GFP labeling was virtually absent in vascular SMCs across multiple organs, confirming the specificity of this genetic strategy.

ORGANISM(S): Mus musculus

PROVIDER: GSE301480 | GEO | 2026/04/11

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:BACKGROUND: Vascular smooth muscle cells (vSMCs), the predominant cell type in the aortic wall, play a crucial role in maintaining aortic integrity, blood pressure, and cardiovascular function. vSMC contractility and function depend on smooth muscle alpha-actin 2 (ACTA2). The pathogenic variant ACTA2 c.536G>A (p. R179H) causes multisystemic smooth muscle dysfunction syndrome (MSMDS), a severe disorder marked by widespread smooth muscle abnormalities, resulting in life-threatening aortic disease and high risk early mortality from aneurysms or stroke. No effective treatments exist for MSMDS. METHODS: To develop a comprehensive therapy for MSMDS, we utilized CRISPR-Cas9 adenine base editing to correct the ACTA2 R179H mutation. We generated isogenic human induced pluripotent stem cell (iPSC) lines and humanized mice carrying this pathogenic missense mutation. iPSC-SMCs were evaluated for key functional characteristics, including proliferation, migration, and contractility. The adenine base editor (ABE) ABE8e-SpCas9-VRQR under control of either a SMC-specific promoter or a CMV promoter, and an optimized single guide RNA (sgRNA) under control of U6 promoter were delivered intravenously to humanized R179H mice using adeno-associated virus serotype 9 (AAV9) and phenotypic outcomes were evaluated. RESULTS: The R179H mutation causes a dramatic phenotypic switch in human iPSC-SMCs from a contractile to a synthetic state, a transition associated with aneurysm formation. Base editing prevented this pathogenic phenotypic switch and restored normal SMC function. In humanized mice, the ACTA2R179H/+ mutation caused widespread smooth muscle dysfunction, manifesting as decreased blood pressure, aortic dilation and dissection, bladder enlargement, gut dilation, and hydronephrosis. In vivo base editing rescued these pathological abnormalities, normalizing smooth muscle function. CONCLUSIONS: This study demonstrates the effectiveness of adenine base editing to treat MSMDS and restore aortic smooth muscle function. By correcting the ACTA2 R179H mutation, the pathogenic phenotypic shift in SMCs was prevented, key aortic smooth muscle functions were restored, and life-threatening aortic dilation and dissection were mitigated in humanized mice. These findings underscore the promise of gene-editing therapies in addressing the underlying genetic causes of smooth muscle disorders and offer a potential transformative treatment for patients facing severe vascular complications.

Project description:Smooth muscle cells (SMCs) are important in a number of physiological systems and organs, including the cardiovascular system. The hallmark property of differentiated SMCs is the ability to contract, but contractile SMCs themselves show a range of phenotypes allowing prolonged tonic contraction in vascular smooth muscle or rapid phasic contraction in tissues such as bladder. Another distinctive characteristic, in contrast with terminally differentiated striated muscle cells, is that SMCs exhibit phenotypic plasticity. Vascular SMCs are able to modulate their phenotype along a continuum between a contractile phenotype, characteristic of healthy blood vessels, and a more proliferative âsyntheticâ phenotype, so-named for the enhanced synthesis and secretion of extracellular matrix components. Synthetic phenotype cells are found in a number of pathological situations such as atherosclerosis and arterial injury. We used mouse exon-junction (MJAY) arrays to gain insights into both the global contribution of alternative splicing events in re-shaping the transcriptome of dedifferentiating mouse aorta and bladder SMCs, and into the underlying regulatory mechanisms of the alternative splicing program. Affymetrix splice junction arrays (MJAY) were used to profile changes in both alternative splicing and transcript levels during the phenotypic modulation of smooth muscle cells when placed in culture. RNA extracted from intact aorta and bladder smooth muscle tissue was used for differentiated samples. For dedifferentiated, proliferative samples smooth muscle cells were enzymatically dispersed and grown in tissue culture for a week. Triplicate RNA samples were prepared from smooth muscle tissue of mouse aorta and bladder (differentiated) and from smooth muscle cells from each tissue cultured for 7 days (proliferative). The samples allowed comparison of alternative splicing (and other transcriptome) changes between differentiated and proliferative smooth muscle cell samples from two distinct types of smooth muscle cell, as well as allowing direct comparison of aorta (tonic smooth muscle) and bladder (phasic smooth muscle).

Dataset Information

RNA-seq analysis of non-vascular smooth muscle cells (NVSMCs) isolated from the lung, intestine and bladder

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets