Role of endothelin-1 in regulating proliferation of cultured rabbit airway smooth muscle cells

1992 ◽  
Vol 263 (3) ◽  
pp. L317-L324 ◽  
Author(s):  
J. P. Noveral ◽  
S. M. Rosenberg ◽  
R. A. Anbar ◽  
N. A. Pawlowski ◽  
M. M. Grunstein
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Phospholipase A2 ◽  
Airway Smooth Muscle ◽  
Pertussis Toxin ◽  
Potential Role ◽  
Cell Number ◽  
Airway Smooth Muscle Cells ◽  
Endothelin 1 ◽  
Mitogenic Action

Increased expression of the potent vasoconstrictor and bronchoactive peptide, endothelin-1 (ET-1), has recently been demonstrated in airway epithelial and endothelial cells of asthmatic patients. To identify its potential role in contributing to airway smooth muscle (ASM) hyperplasia, a characteristic feature of asthmatic airways, the mitogenic action of ET-1 was investigated in cultured rabbit ASM cells. ET-1 elicited significant dose-dependent (10(-12)-10(-6) M) increases in ASM cell number, with a mean potency (i.e., -log mean effective dose) of action of 9.82-log M. ET-1 also acutely stimulated intracellular inositol 1,4,5-trisphosphate accumulation. The latter response was blocked by phospholipase C inhibition with neomycin; however, neomycin had no effect on the promitogenic action of ET-1. By contrast, the ASM cell proliferative response to ET-1 was independently inhibited by pertussis toxin, inhibitors of phospholipase A2, cyclooxygenase, and thromboxane A2 (TxA2) synthesis, as well as blockade of the TxA2 receptor. Moreover, in complementary studies, we found that administration of the stable TxA2 mimetics, carbocyclic TxA2 (CTA2) and U-46619, induced ASM cell proliferation and that ET-1 evoked the release of endogenous TxA2 from the ASM cells. Collectively, these observations provide new evidence that 1) ET-1 is a potent mitogen of ASM cells, 2) the promitogenic effect of ET-1 is associated with activation of a pertussis toxin-sensitive G protein coupled to stimulation of phospholipase A2, and 3) the latter mediates ASM cell proliferation via the release and autocrine mitogenic action of TxA2. The findings support a potential role for ET-1 in mediating the characteristic hyperplasia of ASM in asthma.

Role and mechanism of thromboxane-induced proliferation of cultured airway smooth muscle cells

1992 ◽  
Vol 263 (5) ◽  
pp. L555-L561 ◽  
Author(s):  
J. P. Noveral ◽  
M. M. Grunstein
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Phospholipase A2 ◽  
Airway Smooth Muscle ◽  
Potential Role ◽  
Cell Mass ◽  
Cell Number ◽  
Airway Smooth Muscle Cells ◽  
Airway Diseases ◽  
D4 Receptor

Thromboxane (Tx)A2 has been reported to play an important role in modulating airway contractility under various conditions associated with airways inflammation. To identify its potential role in contributing to airway smooth muscle (ASM) hyperplasia, a characteristic feature of asthmatic airways, the mitogenic effect and mechanism of action of TxA2 were investigated in cultured rabbit ASM cells. The stable TxA2 mimetics, carbocyclic TxA2 (CTA2) and U-46619, elicited dose-dependent (10(-12) to 10(-6) M) increases in ASM cell number and induced acute augmentation of intracellular inositol 1,4,5-trisphosphate accumulation. The latter action was blocked by neomycin, a phospholipase C inhibitor; however, neomycin had no effect on the promitogenic action of the TxA2 mimetics. In contrast, TxA2-induced ASM cell proliferation was inhibited by inhibitors of phospholipase A2 and 5-lipoxygenase, as well as blockade of the leukotriene (LT)D4 receptor. Moreover, in complementary studies, we found that exogenous administration of LTD4 (10(-14) to 10(-6) M) potently induced ASM cell proliferation and that the TxA2 mimetics evoked the enhanced release of endogenous leukotrienes from the cultured ASM cells. Taken together, these observations provide new evidence that 1) TxA2 stimulates ASM cell proliferation; 2) the promitogenic effect of TxA2 is associated with activation of phospholipase A2; and 3) the latter mediates ASM cell proliferation via the release and autocrine mitogenic action of leukotrienes. The findings support a potential role for TxA2 in contributing to the characteristic increase in ASM cell mass obtained in asthma and other chronic airway diseases.

Actin reorganization in airway smooth muscle cells involves Gq and Gi-2 activation of Rho

1999 ◽  
Vol 277 (3) ◽  
pp. L653-L661 ◽  
Author(s):  
Carol A. Hirshman ◽  
Charles W. Emala
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Airway Smooth Muscle ◽  
Actin Polymerization ◽  
Muscle Cells ◽  
Fiber Formation ◽  
Airway Smooth Muscle Cells ◽  
Actin Reorganization ◽  
Endothelin 1 ◽  
In Cells

Extracellular stimuli induce cytoskeleton reorganization (stress-fiber formation) in cells and Ca2+ sensitization in intact smooth muscle preparations by activating signaling pathways that involve Rho proteins, a subfamily of the Ras superfamily of monomeric G proteins. In airway smooth muscle, the agonists responsible for cytoskeletal reorganization via actin polymerization are poorly understood. Carbachol-, lysophosphatidic acid (LPA)-, and endothelin-1-induced increases in filamentous actin staining are indicative of actin reorganization (filamentous-to-globular actin ratios of 2.4 ± 0.3 in control cells, 6.7 ± 0.8 with carbachol, 7.2 ± 0.8 with LPA, and 7.4 ± 0.9 with endothelin-1; P < 0.001; n = 14 experiments). Although the effect of all agonists was blocked by C3 exoenzyme (inactivator of Rho), only carbachol was blocked by pertussis toxin. Although carbachol-induced actin reorganization was blocked in cells pretreated with antisense oligonucleotides directed against Gαi-2 alone, LPA- and endothelin-1-induced actin reorganization were only blocked when both Gαi-2 and Gqα were depleted. These data indicate that in human airway smooth muscle cells, carbachol induces actin reorganization via a Gαi-2pathway, whereas LPA or endothelin-1 induce actin reorganization via either a Gαi-2 or a Gqα pathway.

scholarly journals Pro-inflammatory cytokines induce c-fos expression followed by IL-6 release in human airway smooth muscle cells

2001 ◽  
Vol 10 (3) ◽  
pp. 135-142 ◽  
Author(s):  
Sue McKay ◽  
Mechteld M. Grootte Bromhaar ◽  
Johan C. de Jongste ◽  
Henk C. Hoogsteden ◽  
Pramod R. Saxena ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Airway Inflammation ◽  
Conditioned Medium ◽  
Airway Smooth Muscle ◽  
Inflammatory Cytokines ◽  
Cell Counting ◽  
Airway Smooth Muscle Cells ◽  
Fos Expression ◽  
Pro Inflammatory Cytokines

Background: Airway smooth muscle (ASM) is considered to be a target for mediators released during airway inflammation.Aims: To investigate the expression of c-fos, a constituent of the transcription factor activator protein-1, in human ASM cells. In addition, to measure the release of interleukin (IL)-6 into the conditioned medium of stimulated ASM cells, as well as DNA biosynthesis and changes in cell number.Methods: Serum-deprived human ASM cells in the G0/G1phase were stimulated with the pro-inflammatory cytokines; tumour necrosis factor-α, IL-1β, IL-5 and IL-6. The expression of mRNA encoding the proto-oncogene c-fos was measured by Northern blot analysis. Cell proliferation was assessed by {3H}-thymidine incorporation assays and cell counting, and IL-6 levels in cell-conditioned medium were measured by enzyme-linked immunosorbent assay.Results: All of the cytokines investigated induced a rapid (within 1h) and transient increase in the expression of mRNA encoding c-fos, followed by the expression and enhanced release of IL-6. Cell proliferation remained unchanged in cytokine-stimulated cells.Conclusions: Cytokine-induced c-fos expression in human ASM cells could be described as a marker of cell ‘activation'. The possible association of these results with airway inflammation, through secondary intracellular mechanisms such as cytokine production, is discussed.

Response of airway smooth muscle cells to TGF-beta 1: effects on growth and synthesis of glycosaminoglycans

1996 ◽  
Vol 271 (6) ◽  
pp. L910-L917 ◽  
Author(s):  
P. N. Black ◽  
P. G. Young ◽  
S. J. Skinner
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Cell Size ◽  
Airway Smooth Muscle ◽  
Thymidine Incorporation ◽  
Muscle Cells ◽  
Cell Number ◽  
Airway Smooth Muscle Cells ◽  
Tgf Beta

Transforming growth factor-beta (TGF-beta) is formed in the airways and may have a role in airway remodeling in asthma. We have studied the effects of TGF-beta on bovine airway smooth muscle cells (BASMC) in vitro. Thymidine incorporation by BASMC was inhibited after a 24-h incubation with TGF-beta 1. In contrast, thymidine incorporation by BASMC was stimulated (35.1 +/- 11.2%) after a 48-h incubation with 1 ng/ml TGF-beta 1. Cell number was also increased (25.9 +/- 7.6%) after a 72-h incubation with 3 ng/ml TGF-beta 1. TGF-beta 1 also increased cell size at 72 h, with a 24.3 +/- 6.2% increase in cell, diameter. Increases in BASMC size were accompanied by increased [3H]proline incorporation into cell protein. In cells from any individual animal, there was a strong inverse correlation (r = -0.97) between changes in cell number and cell size. In cells from some animals, the main effect of TGF-beta 1 was to promote an increase in cell number, whereas in others the predominant effect was cell hypertrophy. In contrast epidermal growth factor (EGF) led to an increase in thymidine incorporation and cell number in all preparations but did not increase cell size. TGF-beta 1 also promoted secretion of glycosaminoglycans into culture medium by BASMC with a preferential increase in hyaluronan secretion (4.5-fold) after 24 h. Latent TGF-beta (0.89 +/- 0.06 ng/ml) was also detected in conditioned medium from cultured BASMC, and TGF-beta 1 expression was demonstrated with RNA extracts from BASMC. Varying degrees of both smooth muscle cell hypertrophy and hyperplasia occur in asthma. These results obtained with airway smooth muscle cells indicate that TGF-beta could play a role in the structural changes seen in asthma.

scholarly journals Midkine Promotes the Proliferation of Airway Smooth Muscle Cells Induced by LPS Through Notch2 Pathway

2021 ◽  
Author(s):  
Qi Feng Huang ◽  
Tang Deng ◽  
Lihua Li ◽  
Jin Qian ◽  
Qi Li ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Signaling Pathway ◽  
Airway Smooth Muscle ◽  
Airway Remodeling ◽  
Muscle Cells ◽  
Control Group ◽  
Airway Smooth Muscle Cells ◽  
Proliferation And Apoptosis

Abstract Background: Airway smooth muscle cells (ASMC) can produce a variety of cytokine during inflammation, causing changes in the components of the extracellular matrix, which are related to airway remodeling. Midkine (MK) can promote the chemotaxis of various inflammatory cells and release inflammatory factors. Whether Notch and Midkine together affect the proliferation and apoptosis of airway smooth muscle cells is unclear.Objective: To study the mechanism of Midkine on LPS-induced acute lung injury caused by airway smooth muscle cells.Methods: Airway smooth muscle cells were cultured in vitro and divided into 5 groups: control group, lipopolysaccharide group (LPS), Non-targeted siRNA group, MKsiRNA group, Notch inhibitor group (LY411575). The cell proliferation level was detected by CCK-8. The apoptosis level was detected by flow cytometry. The changes of cytokine in the Midkine/Notch2 signaling pathway were detected by Westernblot, qPCR and cellular immunofluorescence.Results: Midkine and Notch2 were highly expressed in the LPS group. MKsiRNA can effectively block the expression of Midkine induced by LPS while down-regulating the expression of Notch2. This result is the same as that of Notch inhibitor (LY411575). Exogenous Midkine promoted the proliferation of airway smooth muscle cells and reduced the rate of apoptosis in the LPS group. When the expression of Midkine was blocked, the proliferation of airway smooth muscle cells in the LPS group was significantly reduced, while apoptosis increased. Inhibiting the expression of Notch, the proliferation of airway smooth muscle cells in the LPS group decreased, and apoptosis increased.Conclusions: Midkine/Notch2 signaling pathway plays an important role in regulating airway smooth muscle cell proliferation and apoptosis in airway inflammation.

scholarly journals Matrix stiffness-modulated proliferation and secretory function of the airway smooth muscle cells

2015 ◽  
Vol 308 (11) ◽  
pp. L1125-L1135 ◽  
Author(s):  
Artem Shkumatov ◽  
Michael Thompson ◽  
Kyoung M. Choi ◽  
Delphine Sicard ◽  
Kwanghyun Baek ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Elastic Modulus ◽  
Smooth Muscle Cells ◽  
Airway Smooth Muscle ◽  
Tissue Remodeling ◽  
Muscle Cells ◽  
Bioactive Molecules ◽  
Airway Smooth Muscle Cells ◽  
Mechanical Stiffness

Multiple pulmonary conditions are characterized by an abnormal misbalance between various tissue components, for example, an increase in the fibrous connective tissue and loss/increase in extracellular matrix proteins (ECM). Such tissue remodeling may adversely impact physiological function of airway smooth muscle cells (ASMCs) responsible for contraction of airways and release of a variety of bioactive molecules. However, few efforts have been made to understand the potentially significant impact of tissue remodeling on ASMCs. Therefore, this study reports how ASMCs respond to a change in mechanical stiffness of a matrix, to which ASMCs adhere because mechanical stiffness of the remodeled airways is often different from the physiological stiffness. Accordingly, using atomic force microscopy (AFM) measurements, we found that the elastic modulus of the mouse bronchus has an arithmetic mean of 23.1 ± 14 kPa (SD) (median 18.6 kPa). By culturing ASMCs on collagen-conjugated polyacrylamide hydrogels with controlled elastic moduli, we found that gels designed to be softer than average airway tissue significantly increased cellular secretion of vascular endothelial growth factor (VEGF). Conversely, gels stiffer than average airways stimulated cell proliferation, while reducing VEGF secretion and agonist-induced calcium responses of ASMCs. These dependencies of cellular activities on elastic modulus of the gel were correlated with changes in the expression of integrin-β1 and integrin-linked kinase (ILK). Overall, the results of this study demonstrate that changes in matrix mechanics alter cell proliferation, calcium signaling, and proangiogenic functions in ASMCs.

scholarly journals Mitochondria depletion abolishes agonist-induced Ca2+ plateau in airway smooth muscle cells: potential role of H2O2

2010 ◽  
Vol 298 (2) ◽  
pp. L178-L188 ◽  
Author(s):  
Taoxiang Chen ◽  
Liping Zhu ◽  
Tao Wang ◽  
Hong Ye ◽  
Kewu Huang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Airway Smooth Muscle ◽  
Potential Role ◽  
Reactive Oxygen Species Generation ◽  
Muscle Cells ◽  
Airway Smooth Muscle Cells ◽  
Cellular Energy ◽  
Dependent Mechanism

The mechanisms by which mitochondria regulate the sustained phase of agonist-induced responses in cytosolic Ca2+ concentration as an independent organelle in whole is not clear. By exposing to ethidium bromide and supplying pyruvate and uridine, we established mitochondrial DNA (mtDNA)-depleted rat airway smooth muscle cells (RASMCs) with maintained cellular energy. Upon an exposure to 2 μM histamine, [Ca2+]i in control RASMCs increased to a peak followed by a plateau above baseline, whereas [Ca2+]i in mtDNA-depleted RASMCs jumped to a peak and then declined to baseline without any plateau. mtDNA depletion apparently attenuated intracellular reactive oxygen species generation induced by histamine. By coexposure to 2 μM histamine and 0.1 μM exogenous H2O2, which did not affect [Ca2+]i by itself, the above difference in [Ca2+]i kinetics in mtDNA-depleted RASMCs was reversed. Intracellular H2O2 decomposition abolishes histamine-induced sustained elevation in [Ca2+]i in RASMCs. Thus, mitochondria regulate agonist-induced sustained [Ca2+]i elevation by a H2O2-dependent mechanism.

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