PubMed HealthSearch

SEARCH · PubMed Health

Results for “vascular smooth muscle cell”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

A simple method for differentiating vascular smooth muscle cells and fibroblasts in tissue culture.

The morphologic differentiation of vascular smooth muscle cells and fibroblasts in tissue culture is difficult if not impossible. By direct immunofluorescence, it is possible to distinguish between vascular smooth muscle cells and fibroblasts after 6 to 10 days in tissue culture. Microfilaments appear from the 6th to the 10th day. After an incubation period of 30 minutes with antibody against smooth muscle actomyosin at room temperature, microfilaments are demonstrable in smooth muscle cells. In contrast, fibroblasts, if incubated for the same period, show strong nuclear fluorescence and a primary fluorescence of the cytoplasm, but filaments are not visible. If fibroblasts are incubated with antiactomyosin for one hour at 37 degrees C, however microfilaments are easily detectable. With this method it is possible to differentiate in a simple manner vascular smooth muscle cells from fibroblasts in a heterologous tissue culture.

Actomyosin

Coordinated inflammatory macrophage and vascular smooth muscle cell remodeling signatures in human atherosclerosis: An integrative single-cell and bulk transcriptomic analysis.

Atherosclerotic plaque progression is shaped by coordinated inflammatory and remodeling programs involving immune cells and vascular wall cells. Inflammatory macrophage activation and vascular smooth muscle cell (VSMC) phenotypic remodeling are central features of human atherosclerosis, but their transcriptomic relationships during plaque progression remain incompletely characterized. This study integrated single-cell and bulk transcriptomic datasets to examine highly inflammatory macrophage states, VSMC remodeling-related transcriptional programs, and candidate ligand-receptor expression patterns in human atherosclerotic plaques. Human atherosclerotic plaque single-cell RNA sequencing data from GSE260657 and bulk transcriptomic data from GSE28829 were analyzed. After quality control, 7628 cells were retained for single-cell analysis. Major cell types were annotated using canonical markers, followed by reclustering of macrophages and VSMC-related cells. Functional module scoring, differential expression analysis, Gene Ontology biological process enrichment, and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed to characterize macrophage transcriptional states. Slingshot was applied to infer VSMC pseudotime ordering. CellChat and NicheNet were used to prioritize candidate ligand-receptor expression patterns and ligand-associated VSMC target gene programs. External bulk transcriptomic analysis was performed to examine whether single-cell-derived inflammatory and remodeling signatures were represented at the tissue-transcriptome level during plaque progression. Macrophage reclustering identified a highly inflammatory macrophage state characterized by prominent inflammatory activation, cytokine-response, and stress-response features. Genes upregulated in this population were enriched in pathways related to tumor necrosis factor (TNF) response, nuclear factor kappa B signaling, leukocyte activation, cytokine signaling, lipid and atherosclerosis, toll-like receptor signaling, and inflammasome-associated inflammation. VSMC reclustering revealed contractile VSMCs, PTHLH+ synthetic VSMCs, KRT7+ VSMC-like cells, interferon-responsive VSMCs, pericyte-like mural cells, and osteogenic/modulated VSMCs. Pseudotime analysis showed a broad contractile-to-osteogenic/modulated transcriptional continuum accompanied by increased expression of remodeling-associated genes and selected inflammatory or remodeling-associated receptor genes. CellChat and NicheNet analyses prioritized candidate ligand-receptor and ligand-associated target gene expression patterns involving SPP1-CD44, TNF-TNFRSF1A, IL1B-IL1R1/IL1RAP, MIF-ACKR3, PDGFB-PDGFRB, and FN1-SDC1/ITGB1. In GSE28829, inflammatory macrophage-, osteogenic/modulated VSMC-, candidate ligand-receptor expression-, SPP1-CD44 candidate axis-, and NicheNet-prioritized target program-related signatures were more prominent in advanced plaques and were positively correlated with each other. This integrative transcriptomic analysis identified a highly inflammatory macrophage state and a VSMC remodeling continuum in human atherosclerotic plaques. Candidate ligand-receptor and ligand-associated target gene expression patterns linked inflammatory macrophage activation with osteogenic/modulated VSMC remodeling at the computational level. External bulk data further showed coordinated enrichment of inflammatory and remodeling signatures in advanced plaques. These findings provide a descriptive and hypothesis-generating transcriptomic framework for understanding inflammatory macrophage activation and VSMC remodeling in human atherosclerosis.

atherosclerosis

Ultrastructural study of contraction of pulmonary vascular smooth muscle cells.

The pulmonary vessels of rats treated with fulvine were studied electron microscopically for morphologic signs of contraction of smooth muscle cells. Except for a number of indirect indications of vasoconstriction such as medial smooth muscle cell hypertrophy and excessive crenation of elastic laminae, conspicuous smooth muscle cell excrescences were observed and were interpreted to be a direct result of contraction. The close relationship between contraction and smooth muscle cell excrescences was confirmed by their simultaneous occurrence within 1 minute after administration of histamine to isolated perfused guinea pig lungs. The images of pulmonary vessels of rats with prolonged survival times after fulvine administration suggested a gradual increase in the size of the excrescences with a simultaneous degeneration of their cytoplasmic content, and in some cases their eventual detachment from the main cell body. The latter changes were possibly associated with the widespread vasculitis that often occurred at longer intervals after fulvine application. The smooth muscle cell excrescences in pulmonary veins were generally much more prominent than those in pulmonary arteries. This difference was probably caused by the more rigid structure of the arterial wall whcih prevented the formation of large excrescences. The mechanism of the formation of smooth muscle cell excrescences, their possible general validity as markers of vascular smooth muscle cell contraction, and the implications for the mechanism of action of fulvine are briefly discussed.

Animals

Athero-oncology: Vascular smooth muscle cell tumor-like transformation in atherosclerosis and therapeutic opportunities.

Atherosclerosis (AS) is the main pathological basis of cardiovascular diseases, and its pathogenesis and treatment strategies remain major challenges. Recent advances in single-cell RNA sequencing and lineage tracing have revealed that vascular smooth muscle cells (VSMCs) are not merely passive structural components of atherosclerotic plaques, but highly plastic participants that undergo clonal expansion, phenotypic modulation, and transdifferentiation into functionally diverse cell states. These findings have prompted the emergence of an "athero-oncology" framework, which explores selected tumor-like cellular programs in VSMCs during AS without equating atherosclerosis with cancer. In this review, we summarize the evidence supporting VSMC-derived clonal expansion and phenotypic diversification in atherosclerotic lesions and discuss key mechanisms involved in this process, including proliferative expansion and survival programs, metabolic reprogramming, epigenetic regulation, DNA damage and genomic stress, VSMC senescence, pathological angiogenesis, and remodeling of the inflammatory and immune microenvironment. We further highlight shared signaling pathways between VSMC-driven plaque remodeling and tumor biology, while emphasizing fundamental differences between AS and malignant disease in growth limitation, mutational burden, metastatic potential, and clinical behavior. Finally, we discuss oncology-inspired therapeutic opportunities and boundaries, including pathway-level targeting of proliferative, metabolic, epigenetic, and inflammatory programs, as well as the risks of directly repurposing anticancer therapies for chronic vascular disease. This framework may provide new insights into vascular biology and therapeutic development.

atherosclerosis

Vascular smooth muscle cell kinetics: a new assay for studying patterns of cellular proliferation in vivo.

A new quantitative assay for studying the kinetics of vascular smooth muscle cells in vivo is reported. The assay was used to determine the specific activity of DNA from rabbit aortic smooth muscle cells stimulated to grow by removal of the endothelial layer. The specific activity of the DNA was correlated with the rate of tritiated thymidine incorporation as measured by autoradiography and with the rate of DNA synthesis as estimated by direct measurement of cellular proliferation. Smooth muscle cells exhibit a 24-hour latent period in vivo prior to DNA synthesis; the synthesis peaks at 48 hours and then rapidly declines. The decline in DNA synthesis is not related to endothelial regrowth, and may be of homeostatic significance in limiting luminal stenosis. The assay offers a rapid and reliable alternative to autoradiographic and morphometric techniques for evaluating growth kinetics and growth regulation in vivo.

Animals

Evagination of vascular smooth muscle cells during the early stages of Crotalaria pulmonary hypertension.

Fifteen adult female Wistar albino rats were fed on a diet containing powdered Crotalaria spectabilis seeds for periods of up to 5 wk. Electron microscopic studies were carried out on the lungs of these animals and also of three control rats. Both groups of animals showed protuberances of smooth muscle cells. In the control rats such protuberances were small and filled out spaces created by undulation of the internal elastic lamina produced by collapse of the vessel. These protuberances could be prevented by fixing the lung in distension. Evaginations of smooth muscle cells in the test rats were larger, devoid of myofilaments and organelles and arose from the parent cell between dense attachment points on the sarcolemma. Frequently they arose through a narrow cytoplasmic isthmus and had such electron-lucent contents as to resemble a cyst within the endothelium. In fact they pressed onto the undersurface of endothelial cells which fitted over them like a cap. Such evaginations are thought to arise as a result of sustained vasoconstriction.

Animals

Comparison of vascular smooth muscle cells from adult human, monkey and rabbit in primary culture and in subculture.

A method is presented for growing large numbers of pure isolated smooth muscle cells from adult human, monkey, and rabbit blood vessels in primary culture. In the first few days in culture these cells closely resembled those in vivo and could be induced to contract with angiotensin II, noradrenaline and mechanical stimulation. They stained intensely with antibodies against smooth muscle actin and myosin. Fibroblasts and endothelial cells did not stain with these antibodies thereby allowing the purity of each batch of cultures to be monitored. This was consistently found to be better than 99%. The smooth muscle cells modified or "dedifferentiated" after about 9 days in culture to morphologically resemble fibroblasts. At this stage cells could no longer be induced to contract and did not stain with the myosin antibodies. Intense proliferation of these cells soon resulted in a confluent monolayer being formed at which stage some differentiated characteristics returned. The modification of "dedifferentiation" process could be inhibited by the presence of a feeder layer of fibroblasts or endothelial cells, or the addition of cAMP to the culture medium. Smooth muscle cells which had migrated from explants in primary culture, and cells in subculture, had morphological and functional properties of "dedifferentiated" cells at all times. The advantages of differentiated rather than "dedifferentiated" smooth muscle cells in culture for the study of mitogenic agents in atherosclerosis is discussed.

Actins

Lysosomal composition in cultured vascular smooth muscle cells: electron probe analysis.

Spherical electron-dense organelles in the perinuclear region of cultured guinea pig aortic smooth muscle cells were identified as lysosomes by their ability to accumulate acridine orange and by cytochemical demonstration of their acid phosphatase content. The number and size of lysosomes increased in subcultured cells. The elemental composition of the lysosomes was quantitated by electron probe analysis of whole freeze-dried cells and of cryosections. In lysosomes at this stage in their development, the sulfur concentration was higher than that in the cytoplasm and the K/Na concentration ratio was similar to that in the cytoplasm.

Acid Phosphatase

Sodium and calcium interactions in vascular smooth muscle cells of the rabbit ear artery.

The effects of Na-free and of K-free solutions on the membrane potential, on tension development, and on 45Ca exchange have been investigated in rabbit ear artery. The contraction induced by Na-free solutions and the tension which develops in K-free solutions after a delay of about 1 h are both submaximal. Exposure for 4 h to K-free solutions does not affect the membrane potential, whereas Na-free solutions depolarize the cells by 10-20 mV, depending on the Na-substitute. Neither the amplitude nor the rate constant of the slowly exchanging 45Ca-fraction is affected by these experimental procedures. Substituting external Na by choline or TMA induces a transient increase of the 45Ca-efflux rate which does not occur in a Ca-free efflux medium, and which can be blocked with La. K readmission to Na-enriched tissues hyperpolarizes the cells up to -100 mV and induces a relaxation, without exerting any effect on the 45Ca efflux rate. The release of Ca from intracellular stores, induced by histamine and FCCP, and its subsequent extrusion through the plasma membrane produce a transient stimulation of the 45Ca efflux, which is not affected by the reduction of the Na gradient. The transient contraction induced by histamine in Ca-free solutions is affected in a different way by different Na substitutes. The results do not fit the Na-Ca exchange hypothesis but are consistent with an effect of the Na gradient on the passive Ca influx.

Animals

[Bioelectrical properties and ultrastructure of vascular smooth muscle cells in tissue culture].

Intracellular recording was performed in tissue culture of the rabbit vena portae from the smooth muscle cells (SMC) with spontaneous discharges. In inactive SMC the dischartges could be elicited by hyperpolarizing current. The membrane potentials and the input impedance of the SMC decreased with the growth of osmolarity of extracellular medium. The cells were identified as those of smooth muscle on the ground of electronmicroscopic studies. Cellular contacts of nexus type existed between adjacent SMC.

Animals