• The Korean Journal of Physiology and Pharmacology
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• v.19 no.5
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• pp.421-426
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• 2015

The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through $G_0/G_1$ to S phase of the cell cycle, as measured by [$^3H$]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at $G_0/G_1$ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.782-788
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• 1997

This study was designed to characterize glucose-enhancing effects on endotoxin-induced prostaglandin production in primary cultured rat vascular smooth muscle cells (VSMC). High glucose treatment significantly augmented prostaglandin (PG) synthesis in lipopolysaccharide (LPS)-stimulated VSMC and this effect was maximal at the concentration of 4mg/ml. It has been reported that increases in glucose metabolism through sorbitol pathway could alter the cytosolic $NADH/NAD^+$ ratio and this change favors de novo synthesis of diacylglycerol (DAG) and, in turn. Results in the activation of protein kinase C (PKC) in vascular tissues. Protein kinase C (PKC) inhibitors, staurosporin and H7, blocked the glucose enhancing effect, and DAG, a PKC activator, significantly increased the PG production stimuated by LPS. Sodium pyruvate, which can reverse the alteration in cytosolic NADH/NAD+ ratio, reduced the high glucose effect on PG production. And also, zopolrestat, a strong aldose reductase inhibitor, almost completely blocked the augmentation effect of glucose on PG synthesis. Arachidonic acid release was significantly increased in high glucose treated group, which implied the increase in $PLA_2$ activity was associated with glucose enhancing effect. Metabloic, labeling study clearly showed that de novo synthesis of prostaglandin H synthase-2 (PGHS-2) is greatly increased in high glucose treated group and this was mitigated by the treatment of zopolrestat. Taken together, the activation of PKC through sorbitol pathway increased the activities of $PLA_2$ and PGHS which resulted in the augmentation in LPS-induced PG production in high glucose treated VSMC.

• Journal of Life Science
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• v.22 no.12
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• pp.1595-1599
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• 2012

Cell cycle activation and progression in vascular proliferative disease represent potent therapeutic targets. Luteolin, which occurs as glycosylated forms in celery, green pepper, perilla leaf, and camomile tea, has demonstrated antimutagenic, antitumorigenic, antioxidant, and antiinflammatory properties. In this study, we investigated the effect of luteolin on the proliferation of primary cultured rat aortic vascular smooth muscle cells induced by 5% fetal bovine serum. Luteolin at concentrations of 5, 20, and $50{\mu}M$ significantly inhibited this proliferation by 29.6, 50.8, and 83.1%, respectively. The incorporation of $[^3H]$-thymidine into DNA was also inhibited by 25.8, 57.6, and 81.0%, respectively. Flow cytometry analysis of DNA content revealed that FBS-inducible cell cycle progression was blocked by luteolin. Luteolin showed no cytotoxicity in VSMCs in this experimental condition according to WST-1 assays. Luteolin may represent a potential anti-proliferative agent for treatment of angioplasty restenosis and atherosclerosis.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.519-530
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• 2022

Recent research indicates that lactate promotes the switching of vascular smooth muscle cells (VSMCs) to a synthetic phenotype, which has been implicated in various vascular diseases. This study aimed to investigate the effects of lactate on the VSMC phenotype switch and the underlying mechanism. The CCK-8 method was used to assess cell viability. The microRNAs and mRNAs levels were evaluated using quantitative PCR. Targets of microRNA were predicted using online tools and confirmed using a luciferase reporter assay. We found that lactate promoted the switch of VSMCs to a synthetic phenotype, as evidenced by an increase in VSMC proliferation, mitochondrial activity, migration, and synthesis but a decrease in VSMC apoptosis. Lactate inhibited miR-23b expression in VSMCs, and miR-23b inhibited VSMC's switch to the synthetic phenotype. Lactate modulated the VSMC phenotype through downregulation of miR-23b expression, suggesting that overexpression of miR-23b using a miR-23b mimic attenuated the effects of lactate on VSMC phenotype modulation. Moreover, we discovered that SMAD family member 3 (SMAD3) was the target of miR-23b in regulating VSMC phenotype. Further findings suggested that lactate promotes VSMC switch to synthetic phenotype by targeting SMAD3 and downregulating miR-23b. These findings suggest that correcting the dysregulation of miR-23b/SMAD3 or lactate metabolism is a potential treatment for vascular diseases.

• Archives of Plastic Surgery
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• v.49 no.1
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• pp.115-120
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• 2022

Background In addition to vascular endothelial cells, vascular smooth muscle cells (VSMCs) are subject to continuous shear stress because of blood circulation. The angiogenic properties of VSMCs in extracranial arteriovenous malformations (AVMs) may exceed those of normal blood vessels if the body responds more sensitively to mechanical stimuli. This study was performed to investigate the hypothesis that rapid angiogenesis may be achieved by mechanical shear stress. Methods VSMCs were obtained from six patients who had AVMs and six normal controls. The target genes were set to angiopoietin-2 (AGP2), aquaporin-1 (AQP1), and transforming growth factor-beta receptor 1 (TGFBR1). Reverse-transcriptase polymerase chain reaction (RT-PCR) and real-time PCR were implemented to identify the expression levels for target genes. Immunofluorescence was also conducted. Results Under the shear stress condition, mean relative quantity values of AGP2, AQP1, and TGFBR1 in AVM tissues were 1.927±0.528, 1.291±0.031, and 2.284±1.461 when compared with neutral conditions. The expression levels of all three genes in AVMs were higher than those in normal tissue except for AQP1 under shear stress conditions. Immunofluorescence also revealed increased staining of shear stress-induced genes in the normal tissue and in AVM tissue. Conclusions Shear stress made the VSMCs of AVMs more sensitive. Although the pathogenesis of AVMs remains unclear, our study showed that biomechanical stimulation imposed by shear stress may aggravate angiogenesis in AVMs.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.4
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• pp.399-406
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• 2023

Voltage-dependent K⁺ (Kv) channels are widely expressed on vascular smooth muscle cells and regulate vascular tone. Here, we explored the inhibitory effect of encainide, a class Ic anti-arrhythmic agent, on Kv channels of vascular smooth muscle from rabbit coronary arteries. Encainide inhibited Kv channels in a concentration-dependent manner with an IC₅₀ value of 8.91 ± 1.75 μM and Hill coefficient of 0.72 ± 0.06. The application of encainide shifted the activation curve toward a more positive potential without modifying the inactivation curve, suggesting that encainide inhibited Kv channels by altering the gating property of channel activation. The inhibition by encainide was not significantly affected by train pulses (1 and 2 Hz), indicating that the inhibition is not use (state)-dependent. The inhibitory effect of encainide was reduced by pretreatment with the Kv1.5 subtype inhibitor. However, pretreatment with the Kv2.1 subtype inhibitor did not alter the inhibitory effects of encainide on Kv currents. Based on these results, encainide inhibits vascular Kv channels in a concentration-dependent and use (state)-independent manner by altering the voltage sensor of the channels. Furthermore, Kv1.5 is the main Kv subtype involved in the effect of encainide.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.5
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• pp.974-979
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• 2009

Proliferation of vascular smooth muscle cell(VSMC) is one of the key features in onset of atherosclerosis and restenosis after vascular surgery such as stent implant. Atherosclerotic plaques are usually composed of collagen, elatsin and smooth muscle cells. Release of matrix metalloproteinases(MMPs) is considered to have correlation with development of atherosclerotic plaques. Based on the hypothesis that MMP inhibition would be helpful in the treatment of atherosclerosis, we investigated inhibition of MMP activity and migration of TNF-$\alpha$-induced human aortic smooth muscle cell(HASMC) by Cinnamomi Ramulus(CC). The result from gelatin zymography showed that CC inhibited MMP-9 activity in a dose-dependent manner. In addition, CC considerably inhibited the migration of HASMC induced by TNF-$\alpha$, while it showed little cytotoxic effect on HASMC. These results suggest that CC can be a potential anti-atherosclerotic agent through inhibition of MMP-9 activity and SMC migration.

• BMB Reports
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• v.46 no.7
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• pp.352-357
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• 2013

Atherosclerosis, which manifests as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic inflammatory disease of the arterial wall. Prunella vulgaris, a perennial herb with a worldwide distribution, has been used as a traditional medicine in inflammatory disease. Here, we investigated the effects of P. vulgaris ethanol extract on TNF-${\alpha}$-induced inflammatory responses in human aortic smooth muscle cells (HASMCs). We found that P. vulgaris ethanol extract inhibited adhesion of monocyte/macrophage-like THP-1 cells to activated HASMCs. It also decreased expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and ROS, No production in TNF-${\alpha}$-induced HASMCs and reduced NF-${\kappa}B$ activation. Furthermore, P. vulgaris extract suppressed TNF-${\alpha}$-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK). These results demonstrate that P. vulgaris possesses anti-inflammatory properties and can regulate TNF-${\alpha}$-induced expression of adhesion molecules by inhibiting the p38 MAPK/ERK signaling pathway.

• The Journal of Korean Medicine
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• v.27 no.4
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• pp.74-83
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• 2006

Ssanghwatang (SHT) has been known to prove effective in the treatment for erectile dysfunction (ED), and its modified formula is widely used in clinical practice. However, its fundamental mechanism of action is not clearly known. It is well known that endothelial cells can achieve the relaxation of vascular smooth muscles by the release of nitric oxide (NO). NO is synthesized by the enzyme NO synthase (NOS) from L-arginine and oxygen. It is widely accepted that NO plays an important role in the relaxation of corpus cavernous smooth muscle and vasculature. In addition, in terms of the penile erection, the NO/cGMP pathway is more potent than the PCE1/cAMP pathway. The main purpose of the present study was to investigate the mechanism of the erectile effects of SHT by focusing on its direct effects on corpus cavernous smooth muscle cells. We investigated the NOS activity, nitrite concentration and cGMP levels in rat corpus cavernous smooth muscle cell lines activated by SHT extracts. Furthermore, we evaluated the effect of SHT extracts on penile smooth muscle relaxation following oral administration of SHT extract powder to rats by the dosage of 1 g/kg over fifteen days. As a result, we found that SHT stimulated NO release. NOS activity and cGMP levels were increased by SHT respectively. Furthermore, SHT relaxed the corpus cavernous smooth muscle. These results are consistent with the concept that penile erection by SHT is carried out through the NO/cGMP pathway. In conclusion, the present study shows that SHT increases the NOS activity, synthesizes NO and augments the cGMP, which mediates penile erection. Further determination of the SHT mechanism related with the NO/cGMP pathway strongly indicates that SHT can be used as a remedy for erectile impotence.

• The Journal of Korean Physical Therapy
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• v.20 no.4
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• pp.35-42
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• 2008

Purpose: Alterations in the structure and function of vascular smooth muscle cells (VSMCs) are important in cardiovascular disease and maintaining chronic hypertension. Chronic hypertension is associated with changes in vascular smooth muscle tone. The spontaneous or myogenic tone of a blood vessel reflects the ability to adapt smooth muscle tone to changes in transmural pressure. However, the intracellular signaling mechanisms involved in myogenic tone are not fully understood. Methods: Here, we investigated the relationship between mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3 kinase (PI3K) in isometric contraction and enzymatic activity using muscle strips from rats made hypertensive with aldosterone-analogue deoxycorticosterone acetate (DOCA) salts. Results: Changes in myogenic tone and intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) were different after physiological salt solution (PSS) in normotensive and hypertensive rats. The myogenic tone and quiescent phosphorylation induced by the PSS treatment were inhibited by 10 ${\mu}$M PD098059, an extracellular-regulated protein kinase 1/2 (ERK1/2) inhibitor, and 10 ${\mu}$M wortmannin, an inhibitor of PI3K, in hypertensive rats. Conclusion: The development of DOCA-induced hypertension is associated with altered isometric contractions and $[Ca^{2+}]_i$ via changes in activation of ERK1/2 and PI3K after DOCA-salt treatment. Therefore, ERK1/2 and PI3K activity affect hypertension and may be suitable targets for physical therapy in cardiovascular disease.