Human Aortic Muscle Research Articles

Inhibitory effects of herbal decoction Ojeoksan on proliferation and migration in vascular smooth muscle cells.

The proliferation of vascular smooth muscle cells plays a crucial role in pathogenesis of cardiovascular disease. The principal objective of this study was to determine the effects of Ojeoksan (OJS) on human aortic smooth muscle cell (HASMC) proliferation induced by tumor necrosis factor α (TNF-aα). Thymidine incorporation after TNF-α treatment was increased and this effect was inhibited significantly by OJS treatment. HASMC proliferation and migration by kinetic live cell imaging were also reduced by treatment with OJS. TNF-α induced the expression of cyclins/cyclin-dependent kinases (CDKs) and reduced the expression of p21waf1/cip1/p27kip1. However, OJS also attenuated the expression of TNF-α-induced cell-cycle regulatory proteins. The results of Western blot analysis demonstrated that the TNF-α treated HASMC secreted gelatinases, probably including MMP-2/-9, which may be involved in the invasion and migration of HASMC. Additionally, OJS suppressed the mRNA expression levels of matrix metalloproteinase-2/-9 (MMP-2/-9) in a dose-dependent manner. OJS inhibited the production of TNF-α-induced hydrogen peroxide (H2O2) and the formation of DCF-sensitive intracellular reactive oxygen species (ROS). Further, OJS suppressed the nuclear translocation and phosphorylation of inhibitor of kappa B-α (IκB-α) of nuclear factor κB (NF-κB) under TNF-α conditions. Our results demonstrate that OJS exerts inhibitory effects on TNF-α-induced HASMC proliferation and migration, suggesting the involvement of the inhibition of both MMP-2 and MMP-9 expressions, and the downregulation of ROS/NF-κB signaling. Thus, herbal decoction OJS may be a possible therapeutic approach to the inhibition of cardiovascular disease including atherosclerosis.

The role of Toll like receptor 4 pathway in palmitate-induced interleukin-6 expression in human aortic vascular smooth muscle cells

The recombinant adenovirus Toll like receptor 4 (TLR4) shRNA vector (pGSadeno-TLR4) was constructed and transfected into human aortic vascular smooth muscle cells (HA-VSMC).After HA-VSMC were treated with palmitate or different signaling pathway inhibitors,the mRNA and protein levels of interleukin-6 (IL-6)and NF-κB activity were tested with real-time PCR and ELISA,respectively.The results showed that palmitate increased mRNA and protein levels of IL-6 in HA-VSMC in a dose-dependent manner.The expression of IL-6 mRNA reached peak after treatment with 400 μmol/L of palmitate for 6 h,being 10.43 fold of control (P＜0.01).Treatment with 400 pmol/L of palmitate for 24 h maximally upregulated the protein level of IL-6,which was 2.18 fold of control (P＜0.01).NF-κB inhibitor parthenolide markedly inhibited palmitate-stimulated increased in IL-6 mRNA level by 65％ and protein level by 59％ (both P＜0.01).Protein kinase C (PKC) inhibitor chlerythrine suppressed palmitateinduced IL-6 mRNA expression by 24％ and IL-6 protein level by 28％.By contrast,extracellular signal-regulated protein kinase inhibitor PD98059 and phosphatidylinositol 3-kinase inhibitor wortmannin had no effect on the induction of IL-6 by palmitate.Blockade of TLR4 with pGSadeno-TLR4 significantly suppressed palmitate-induced IL-6 mRNA expression by 72％ and IL-6 protein expression by 75％ (both P＜0.01),along with decrease of NF-κB p65 activity decreased by 62％.These results suggest that TLR4/NF-κB and PKC pathways mediate palmitate-induced IL-6 expression in HA-VSMC. Key words: Human aortic vascular smooth muscle cells; Palmitate; Toll like receptor 4 ; Intedeukin-6

The effect of the neurolytic agent ethanol on cytoplasmic calcium in arterial smooth muscle and endothelium.

Celiac plexus neurolysis, although effective in relieving pain associated with upper abdominal malignancy, occasionally results in paraplegia. Diffusion of the neurolytic agent to arteries supplying the spinal cord has been postulated as a cause, and previous studies with isolated lumbar segmental arteries have demonstrated contraction in response to ethanol and phenol. The mechanism of this contractile effect is unknown, but a role for insular free calcium (Ca2+i) is suggested by the known involvement of Ca2+i in both smooth muscle vasoconstriction and toxic cell injury. The authors sought to determine whether nontoxic concentrations of ethanol cause a direct elevation of Ca2+i in arterial smooth muscle and endothelium. Primary cultures of human aortic smooth muscle and endothelial cells were studied to determine the direct effect of ethanol independent of interactions with agonists or contractile proteins. Ca2+i levels were determined in single cells with digitized video fluorescence microscopy, using ratio imaging of the Ca2+i-sensitive fluorophore fura-2. In aortic smooth muscle cells, initial Ca2+i was 98 +/- 41 nM (n = 59 cells). Histamine (10 microM) as a positive control caused an increase in Ca2+i, as expected. Ethanol alone, at doses of 2-5% (v/v) also caused a sustained elevation in Ca2+i of physiologically significant magnitude. Ethanol at doses of 5% or lower did not cause any visibly apparent injury within 30 minutes. In contrast, 10% or higher ethanol doses quickly caused membrane blebbing, a sign of toxic injury, followed by cell death within 20 minutes. Aortic endothelial cells were more resistant to ethanol than smooth muscle cells, in terms of both Ca2+i elevation and cell death. Ethanol, even at nontoxic concentrations, has a direct effect on aortic smooth muscle Ca2+i, large enough to be associated with significant vasoconstriction. The findings suggest a possible role for pharmacologic agents that preserve Ca2+i homeostasis in protecting against neurolysis-induced paraplegia, although additional study is required before clinical application is appropriate.

Immortalization of human aortic smooth muscle cells with origin-minus simian virus 40 DNA.

We established two cell lines of human smooth muscle cells (SMC) by transfection of cells from the aortic intima and aortic media with origin-minus simian virus 40 (ori-minus SV40) DNA. Ori-minus SV40 DNA very efficiently immortalized human smooth muscle cells in culture. Proteins that these cell lines produced included type I, III, IV, and V collagens, fibronectin, and human matrix metalloproteinases (MMP)-1 (tissue collagenase), -2 ("type IV collagenase"), and -3 (stromelysin). The protein production in these cell lines generally mimicked that of normal SMC, but the immortalization stimulated the cell line of medial SMC to produce excessive MMP-2 and to secrete MMP-9 (92-kDa gelatinase). However, since these cell lines did not show a fully malignant phenotype, we concluded that, in addition to the degradation of extracellular matrix macromolecules, including basement membrane components by MMP-2, -3, and/or -9, some additional factors must be involved for the malignancy of fully transformed cells and that these immortalized human aortic SMC, which share many characteristics with normal SMC, will prove useful to study the role(s) of metalloproteinases in atherosclerosis.