• Molecules and Cells
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• v.26 no.5
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• pp.468-473
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• 2008

Low-density lipoprotein (LDL) induces cell proliferation in human aortic smooth muscle cells (hAoSMCs), which may be involved in atherogenesis and intimal hyperplasia. Recent studies have demonstrated that $Cl^-$ channels are related to vessel cell proliferation induced by a variety of stimuli. In this study, we investigated a potential role of $Cl^-$ channels in the signaling pathway of LDL effects on hAoSMC proliferation with a focus on the activation of Erk1/2-PI3K/Akt and the subsequent upregulation of Egr-1. $Cl^-$ channel blockers, DIDS, but neither NPPB nor Furosemide, completely abolished the LDL-induced DNA synthesis and cell proliferation. Moreover, DIDS, but not NPPB, significantly decreased LDL-stimulated $Cl^-$ concentration, as judged by flow cytometry analysis using MQAE as a $Cl^-$-detection dye. DIDS pretreatment completely abolished the activation of Erk1/2 and PI3K/Akt in a dose-dependent manner that is the hallmark of LDL activation, as judged by Western blot and proliferation assays. Moreover, pretreatment with DIDS ($Cl^-$ channel blockers) but not LY294002 (PI3K inhibitors) completely abolished the LDL-induced upregulation of Egr-1 to the same extent as PD98059 (MEK inhibitors to inhibit Erk), as judged by Western blot and luciferase reporter assays. This is the first report, to our knowledge, that DIDS-sensitive $Cl^-$-channels play a key role in the LDL-induced cell proliferation of hAoSMCs via the activation of Erk1/2 and PI3K/Akt and the upregulation of Egr-1.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.293-302
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• 1994

The objective of this study was to establish a good methodology to isolate single smooth muscle cells that are alive and respond properly to pharmacological agents. Canine urinary bladders were employed as the source of single cells, and acetylcholine, atropine and imipramine were used as indicators of pharmacological responsiveness. Imipramine, an antidepressant drug exhibited the anticholinergic and calcium antagonizing properties on rat detrusor muscle. To establish a control value for a further experiment to elucidate the mechanism of action of imipramine on detrusor muscle, we measured the concentration-response of single cells to acetylcholine in the presesnce of imipramine by length of the cells and compared the result with the response in the presence of atropine. Tiny chops of smooth muscle taken from anesthetized canine urinary bladder were incubated in collagenase solution at $36^{\circ}C$ for 17-20 minutes. The collagenase solution included collagenase 1.2 mg/ml, soybean tryspin inhibitor 0.08 mg/ml, bovine serum albumin 2% in 10 ml Krebs-Henseleit buffer solution aerated with a consistent breeze of 95/5% $O_2/CO_2$, to maintain the pH at 7.4. After washing with plain K-H solution on 450 mesh, cells were dissociated from the digested tissue for 12-15 minutes. Cell suspension was transfered in 5 ml test tubes and acetylcholine was added for the final concentration to be $10^{-14}M{\sim}10^{-9}M$. To find the optimal time to fix the cells to determine the contractile responses, 1% acrolein was added 5, 10, 20, 30, 60 and 120 seconds after the administration of ACh. The length of cells fixed by acrolein were measured by microscaler via CCTV camera on phaes-contrast microscope. The average length of 50 cells from a slide glass was taken as the value of a sample at the very concentration point. Single cells were isolated from canine detrusor. The length of untreated cells varied from 82 ${\mu}m$ to 94 ${\mu}m$. The maximal response to actylcholine $10^{-9}M$ was accomplished within 5 seconds of exposure, and the shortening was $19{\pm}3$%. Atropine reduced the contraction of the cells concentration-dependently. Imipramine which exerts a cholinergic blocking action on some smooth muscles also reduced the contraction concentration-dependently and by a similar pattern as atropine. These findings document that imipramine may exerts a cholinergic blocking activity in the single smooth muscle cells isolated from canine urinary bladder.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.7.1-7.1
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• 2009

The use of Duplex stainless steel as a thermo-implant categorizes into two clinical applications: hyperthermia and thermal ablation or destruction. The goal of hyperthermia is to destroy the heat-sensitive abnormal cells and minimize normal cell death maintaining heat between $42^{\circ}C$ and $46^{\circ}C$. Thermal ablation takes place when the local tissue temperature increases greater than $46^{\circ}C$. This elevated temperature denatures protein irreversibly resulting cellular death. The author introduced several thermo-implants such as thermo-rod, thermo-stent, thermo-coil and thermoacupuncture-needle. Those thermo-implants are made of duplex stainless steel which can produce regulated heat by itself within an induction magnetic field. Thermal ablation characteristics of the thermo-rod on tumor hyperthermia depend on configurations of the thermo-rods and the magnitude of the induction magnetic strength. The exothermic properties of the thermo-implants can be characterized using the calorimetric test and the heat affected zone(HAZ) analyses in vitro. Thermal radiation studies using thermo-coils and thermo-stents show the capability of the occlusion of animal blood vessels and inhibiting the proliferation of the abnormal smooth muscle cell growth and inflammatory cell reactions maintaining the heat between $42^{\circ}C$ and $46^{\circ}C$ minimizing a normal cell death in the study on external iliac artery of the New Zealand White (NZW) rabbit. Thermal stimulation study using thermo-acupuncture needles suggests the potential applications of the automated acupunctural therapies.

• BMB Reports
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• v.57 no.2
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• pp.116-121
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• 2024

We investigated the therapeutic potential of bone marrow-derived mesenchymal stem cell-conditioned medium (BMSC-CM) on immortalized renal proximal tubule epithelial cells (RPTEC/TERT1) in a fibrotic environment. To replicate the increased stiffness characteristic of kidneys in chronic kidney disease, we utilized polyacrylamide gel platforms. A stiff matrix was shown to increase α-smooth muscle actin (α-SMA) levels, indicating fibrogenic activation in RPTEC/TERT1 cells. Interestingly, treatment with BMSC-CM resulted in significant reductions in the levels of fibrotic markers (α-SMA and vimentin) and increases in the levels of the epithelial marker E-cadherin and aquaporin 7, particularly under stiff conditions. Furthermore, BMSC-CM modified microRNA (miRNA) expression and reduced oxidative stress levels in these cells. Our findings suggest that BMSC-CM can modulate cellular morphology, miRNA expression, and oxidative stress in RPTEC/TERT1 cells, highlighting its therapeutic potential in fibrotic kidney disease.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.247-250
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• 2008

The $CHCl_3$, EtOAc, and n-BuOH fractions showed a marked inhibition of 5% fatal bovine serum (FBS)-induced cell proliferation. The $IC_{50}$ values of the chloroform fractions from leaf, stem, and root as well as the n-BuOH and EtOAc fraction from root on cell proliferation were $1.2{\pm}0.4$, $17.2{\pm}6.4$, $81.8{\pm}33.2$, $40.8{\pm}8.0$, and $237.1{\pm}85.6\;{\mu}g/mL$, respectively. On the other hand, the EtOAc fractions, and the $CHCl_3$ fraction significantly inhibited collagen-, arachidonic acid-, U46619-, and thrombin-induced platelet aggregations. The $IC_{50}$ values of EtOAc fraction from leaf, and the $CHCl_3$ and EtOAc fraction from stem were $214.1{\pm}12.2$, $134.3{\pm}2.5$, and $42.6{\pm}7.0\;{\mu}g/mL$ with collagen, $312.4{\pm}7.5$, $158.9{\pm}1.7$, and $82.2{\pm}2.7\;{\mu}g/mL$ with arachidonic acid, $31.1{\pm}2.4$, $48.7{\pm}0.3$, and $29.7{\pm}1.1\;{\mu}g/mL$ with U46619, and $36.7{\pm}2.4$, $69.1{\pm}11.3$, and $34.2{\pm}0.1\;{\mu}g/mL$ with thrombin, respectively. Taken together, these data provide new evidence that fractions from Allium victorialis var. platyphyllum (AVP) are able to inhibit vascular smooth muscle cell (VSMC) proliferation and platelet aggregation, which may be a novel resource for the development of anti-atherothrombotic agents.

• The Journal of Internal Korean Medicine
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• v.29 no.2
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• pp.318-333
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• 2008

Objectives : In this study, the author tried to examine whether Cheogjogupye-tang (淸燥救肺湯, CGPT) and Yieum-jeon (理陰煎, YEJ) significantly affect in vitro and in vivo mucin secretion, MUC5AC gene expression in airway epithelial cells and contractility of isolated tracheal smooth muscle of rabbit. Materials and Methods : For in vitro experiment, confluent hamster tracheal surface epithelial (HTSE) cells were chased for 30 minutes in the presence of CGPT and YEJ to assess the effects of the agents on mucin secretion by enzyme-linked immunosorbent assay (ELISA), with removal of oriental herbal medicine extract from each agent-treated sample by centrifuge microfilter. Also, the effects of the agents on TNF-alpha or EGF-induced MUC5AC gene expression in human airway epithelial cells (NCI-H292) were investigated. Possible cytotoxicities of the agent were assessed by examining both LDH release from HTSE cells and the rate of survival and proliferation of NCI-H292 cells. For in vivo experiment, hypersecretion of airway mucin and goblet cell hyperplasia was induced by exposure of rats to $SO_2$ over 3 weeks. Effects of CGPT and YEJ orally administered for 1 week on in vivo mucin secretion from tracheal goblet cells of rats and hyperplasia of goblet cells were assessed using ELISA and histological analysis after staining the epithelial tissue with alcian blue, respectively. Also, the effects of CGPT and YEJ on contractility of isolated tracheal smooth muscle were investigated. Results : (1) CGPT significantly inhibited in vitro mucin secretion from cultured HTSE cells. However, YEJ did not affect in vitro mucin secretion; (2) CGPT and YEJ did not affect hypersecretion of in vivo mucin and hyperplasia of tracheal goblet cells; (3) CGPT and YEJ slightly increased the expression levels of TNF-alpha or EGF-induced MUC5AC gene in NCI-H292 cells; (4) CGPT and YEJ inhibited acetylcholine-induced contraction of isolated tracheal smooth muscle of rabbit; (5) CGPT and YEJ did not affect LDH release from HTSE cells and the survival and proliferation of NCI-H292 cells. Conclusion : The results from the present study suggest that CGPT and YEJ mainly affect the expression of mucin gene rather than secretion of mucin and do not show remarkable cytotoxicity to respiratory epithelial cells.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.191-203
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• 1994

$K^+$ channel openers (KCOs) are known to have a wide range of effects by opening the $K^+$ channel in plasma membranes of various smooth muscles, cardiac muscle and pancreatic ${\beta}-cell$. In the present study, we investigated the effects of 5 types of KCOs, cromakalim, RP49356, pinacidil, nicorandil and diazoxide on the contractility of isolated rat uterus. All KCOs tested inhibited the uterine contraction induced by 0.2 nM oxytocin in a dose-dependent manner. Individual KCO and its $pD_2$ values were cromakalim 6.5, RP49356 6.3, pinacidil 5.92, nicorandil 4.43 and diazoxide 4.18. The relaxant effects of KCO were inhibited by glibenclamide (0.3, 1 and $10\;{\mu}M$) with $pA_2$ values of cromakalim 6.91, RP49356 6.59, pinacidil 6.55, nicorandil 5.97 and diazoxide 6.37. In addition, the relaxant effect of cromakalim or pinacidil was antagonised by TEA, a non-selective $K^+$ channel blocker, but not by apamin. Contractions induced by low concentration of KCI (< 40 mM) were inhibited by cromakalim $(100{\mu}M)$ and nicorandil $(300{\mu}M)$, but those evoked by higher concentration (> 40 mM) of KCI were little affected. In ovariectomized rat uterus, cromakalim dose-dependently inhibited oxytocin-induced contraction and glibenclamide $(10{\mu}M)$ inhibited the relaxant effect of cromakalim with $pD_2$ and $K_B$ values of 7.48 and $1.26{\times}10^{-7}M$, respectively. In estrogen-primed rat uterus, these values were 6.51 and $1.57{\times}10^{-7}M$, respectively, indicating that the cromakalim is less effective on the estrogen-treated uterine smooth muscle. Our results suggest that the KCO-sensitive $K^+$ channels participate in the motility of uterine smooth muscle and such channels are, at least in part, under the control of estrogen. In addition, our data Indicate that the type of $K^+$ channels activated by KCO is ATP-sensitive $K^+$ channels which is blocked by glibenclamide.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.181-190
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• 1994

Endothelium-derived relaxing factor (EDRF) activates guanylate cyclase which mediates the formation of cGMP from GTP in vascular smooth muscle. It is well known that endothelium-dependent relaxation is impaired in spontaneously hypertensive rats (SHR). However, it is still unknown whether the impaired endothelium-dependent relaxation in SHR results from the reduced release of EDRF or from the decrease of vascular response to EDRF. We investigated the effects of cGMP on the contractility and Ca movement in the aorta of SHR and Wistar-Kyoto rats (WKY). The amplitude of the endothelium-dependent relaxation to actylcholine (ACh) was significantly less in SHR than in WKY. L-arginine $(10^{-3}M)$ did not increase endothelium-dependent relaxation in both strains. Sodium nitroprusside (SNP), an activator of guanylate cyclase, relaxed the 40 mM $K^+-induced$ contraction in a dose-dependent manner $(10^{-10}{\sim}10^{-6}\;M)$ in the endothelium-rubbed aortic strips of both strains. However, there was no significant difference in these relaxations between WKY and SHR. 8-bromo-cyclic guanosine monophosphate (8-Br-cGMP), a cell membrane-permeable derivative of cGMP relaxed the 40 mM $K^+-induced$ contraction in a dose-dependent manner $(10^{-6}{\sim}10^{-4}\;M)$ in the endothelium-rubbed aortic strips of both strains. Also norepinephrine $(10^{-6}\;M)-induced$ contractions in normal and Ca-free Tyrode's solution were suppressed by the pretreatment with 8-Br-cGMP $(10^{-4}\;M)$ in either strain. However, the amplitudes of suppression induced by 8-Br-cGMP were greater in SHR than that in WKY. Basal $^{45}Ca$ uptake and 40mM $K^+-stimulated\;^{45}Ca$ uptake were not suppressed by pretreatment with 8-Br-cGMP $(10^{-4}\;M)$ in single aortic smooth muscle cells of both SHR and WKY. From the above results, it is suggested that cGMP decreases Ca sensitivity in vascular smooth muscle cells and that the impaired endothelium-dependent relaxation in the aortic strips of SHR is not the result of a reduced vascular response to EDRF.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1652-1660
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• 2004

Apoptosis of vascular smooth muscle cells(VSMCs) is essential in atherogenesis, being a factor that modulates its early progression rather than a terminal event in the course of the disease. Various stimuli, including oxide lipoproteins, altered hemodynamic stress and free radical, can induced VSMCs apoptosis in vitro. The protective effects of Sophorae Radix (SR) on apoptotic cell death induced by H₂O₂ were investigated in VSMCs. The viability of VSMCs was markedly decreased by H₂O₂. Sophorae Radix protected the H202-induced apoptotic death of VSMCs, which was characterized as nuclear fragmentation and increase of sub-G0/G1 fraction .. Sophorae Radix decreased the activation of caspase-3 like protease induced by H₂O₂ and recovered control level from H202-induced PARP, Bak, Bcl-XL and mitochondrial membrane potential. These results suggest that Sophorae Radix protected VSMCs apoptotic death induced by H₂O₂ via inactivation of caspase-3 and modulation of mitochondrial function. Also, the expression profile of proteins by using two-dimensional (2-D) gel electrophoresis was screened. Future investigations will need to explore the use of an anti atherosclerotic therapy of Sophorae Radix, which relies on inhibition of the proapoptotic activation of the vascular smooth muscle cells.

• Journal of Life Science
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• v.25 no.2
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• pp.231-236
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• 2015

Angiotensin II (AngII) is an essential hormone that affects vascular physiology. For example, stimulation of vascular smooth muscle cells (VSMCs) rapidly induces vasoconstriction and results in the up-regulation of blood pressure. Chronic stimulation of VSMCs with AngII also results in hypertrophy. In this study, we confirmed an involvement of phosphatidylinositol 3-kinase (PI3K)-dependent calcium mobilization in AngII-induced generation of reactive oxygen species (ROS). Stimulation of rat aortic smooth muscle cells (RASMCs) with AngII significantly induced the generation of ROS in a dose- and time-dependent manner. AngII-induced generation of ROS was completely abolished by pharmacological inhibition of PI3K (with LY294002), but inhibition of the ERK signaling pathway had no effect. AngII-induced calcium mobilization was completely blocked by inhibition of PI3K, whereas inhibition of the ERK signaling pathway by PD98059 was ineffective. Depletion of extracellular calcium or inhibition of the L-type calcium channel by nifedipine completely blocked AngII-induced calcium mobilization. Depletion of extracellular calcium by EGTA and incubation of RASMCs with calcium-free medium both significantly blocked AngII-induced ROS generation. Inhibition of the L-type calcium channel also significantly blocked AngII-induced ROS generation. These results suggest that AngII-induced ROS generation is regulated by calcium mobilization, which, in turn, is modulated by a PI3K/L-type calcium channel signaling pathway.