The Experts below are selected from a list of 25053 Experts worldwide ranked by ideXlab platform
Reinoud Gosens - One of the best experts on this subject based on the ideXlab platform.
-
bronchoconstriction induces tgf β release and airway remodelling in guinea pig lung slices
PLOS ONE, 2013Co-Authors: Tjitske A Oenema, Marieke Smit, Harm Maarsingh, Herman Meurs, Geny M. M. Groothuis, Reinoud GosensAbstract:Airway remodelling, including smooth muscle remodelling, is a primary cause of airflow limitation in asthma. Recent evidence links bronchoconstriction to airway remodelling in asthma. The mechanisms involved are poorly understood. A possible player is the multifunctional cytokine TGF-β, which plays an important role in airway remodelling. Guinea pig lung slices were used as an in vitro model to investigate mechanisms involved in bronchoconstriction-induced airway remodelling. To address this aim, mechanical effects of bronchoconstricting stimuli on Contractile Protein expression and TGF-β release were investigated. Lung slices were viable for at least 48 h. Both methacholine and TGF-β1 augmented the expression of Contractile Proteins (sm-α-actin, sm-myosin, calponin) after 48 h. Confocal fluorescence microscopy showed that increased sm-myosin expression was enhanced in the peripheral airways and the central airways. Mechanistic studies demonstrated that methacholine-induced bronchoconstriction mediated the release of biologically active TGF-β, which caused the increased Contractile Protein expression, as inhibition of actin polymerization (latrunculin A) or TGF-β receptor kinase (SB431542) prevented the methacholine effects, whereas other bronchoconstricting agents (histamine and KCl) mimicked the effects of methacholine. Collectively, bronchoconstriction promotes the release of TGF-β, which induces airway smooth muscle remodelling. This study shows that lung slices are a useful in vitro model to study mechanisms involved in airway remodelling.
-
muscarinic receptor stimulation augments tgf β1 induced Contractile Protein expression by airway smooth muscle cells
American Journal of Physiology-lung Cellular and Molecular Physiology, 2012Co-Authors: Tjitske A Oenema, Marieke Smit, Herman Meurs, Andrew J Halayko, Lyanne Smedinga, Kurt Racke, Reinoud GosensAbstract:Acetylcholine (ACh) is the primary parasympathetic neurotransmitter in the airways. Recently, it was established that ACh, via muscarinic receptors, regulates airway remodeling in animal models of asthma and chronic obstructive pulmonary disease (COPD). The mechanisms involved are not well understood. Here, we investigated the functional interaction between muscarinic receptor stimulation and transforming growth factor (TGF)-β(1) on the expression of Contractile Proteins in human airway smooth muscle (ASM) cells. ASM cells expressing functional muscarinic M(2) and M(3) receptors were stimulated with methacholine (MCh), TGF-β(1), or their combination for up to 7 days. Western blot analysis revealed a strong induction of sm-α-actin and calponin by TGF-β(1), which was increased by MCh in ASM cells. Immunocytochemistry confirmed these results and revealed that the presence of MCh augmented the formation of sm-α-actin stress fibers by TGF-β(1). MCh did not augment TGF-β(1)-induced gene transcription of Contractile phenotype markers. Rather, translational processes were involved in the augmentation of TGF-β(1)-induced Contractile Protein expression by muscarinic receptor stimulation, including phosphorylation of glycogen synthase kinase-3β and 4E-binding Protein 1, which was enhanced by MCh. In conclusion, muscarinic receptor stimulation augments functional effects of TGF-β(1) in human ASM cells on cellular processes that underpin ASM remodeling in asthma and COPD.
-
inhibition of allergen induced airway remodelling by tiotropium and budesonide a comparison
European Respiratory Journal, 2007Co-Authors: Reinoud Gosens, Herman Meurs, Andrew J Halayko, Anetta Zuidhof, Dedmer Schaafsma, Johan ZaagsmaAbstract:Chronic inflammation in asthma and chronic obstructive pulmonary disease drives pathological structural remodelling of the airways. Using tiotropium bromide, acetylcholine was recently identified as playing a major regulatory role in airway smooth muscle remodelling in a guinea pig model of ongoing allergic asthma. The aim of the present study was to investigate other aspects of airway remodelling and to compare the effectiveness of tiotropium to the glucocorticosteroid budesonide. Ovalbumin-sensitised guinea pigs were challenged for 12 weeks with aerosolised ovalbumin. The ovalbumin induced airway smooth muscle thickening, hypercontractility of tracheal smooth muscle, increased pulmonary Contractile Protein (smooth-muscle myosin) abundance, mucous gland hypertrophy, an increase in mucin 5 subtypes A and C (MUC5AC)-positive goblet cell numbers and eosinophilia. It was reported previously that treatment with tiotropium inhibits airway smooth muscle thickening and Contractile Protein expression, and prevents tracheal hypercontractility. This study demonstrates that tiotropium also fully prevented allergen-induced mucous gland hypertrophy, and partially reduced the increase in MUC5AC-positive goblet cell numbers and eosinophil infiltration. Treatment with budesonide also prevented airway smooth muscle thickening, Contractile Protein expression, tracheal hypercontractility and mucous gland hypertrophy, and partially reduced MUC5AC-positive goblet cell numbers and eosinophilia. This study demonstrates that tiotropium and budesonide are similarly effective in inhibiting several aspects of airway remodelling, providing further evidence that the beneficial effects of tiotropium bromide might exceed those of bronchodilation.
Ger J M Stienen - One of the best experts on this subject based on the ideXlab platform.
-
troponin activator augments muscle force in nemaline myopathy patients with nebulin mutations
Journal of Medical Genetics, 2013Co-Authors: Josine M De Winter, Danielle Buck, Jeffrey R Jasper, Fady I Malik, Nigel F Clarke, Ger J M Stienen, Carlos Hidalgo, Michael W LawlorAbstract:Background Nemaline myopathy—the most common non-dystrophic congenital myopathy—is caused by mutations in thin filament genes, of which the nebulin gene is the most frequently affected one. The nebulin gene codes for the giant sarcomeric Protein nebulin, which plays a crucial role in skeletal muscle Contractile performance. Muscle weakness is a hallmark feature of nemaline myopathy patients with nebulin mutations, and is caused by changes in Contractile Protein function, including a lower calcium-sensitivity of force generation. To date no therapy exists to treat muscle weakness in nemaline myopathy. Here, we studied the ability of the novel fast skeletal muscle troponin activator, CK-2066260, to augment force generation at submaximal calcium levels in muscle cells from nemaline myopathy patients with nebulin mutations. Methods Contractile Protein function was determined in permeabilised muscle cells isolated from frozen patient biopsies. The effect of 5 μM CK-2066260 on force production was assessed. Results Nebulin Protein concentrations were severely reduced in muscle cells from these patients compared to controls, while myofibrillar ultrastructure was largely preserved. Both maximal active tension and the calcium-sensitivity of force generation were lower in patients compared to controls. Importantly, CK-2066260 greatly increased the calcium-sensitivity of force generation—without affecting the cooperativity of activation—in patients to levels that exceed those observed in untreated control muscle. Conclusions Fast skeletal troponin activation is a therapeutic mechanism to augment Contractile Protein function in nemaline myopathy patients with nebulin mutations and with other neuromuscular diseases.
-
Effects of Contractile Protein phosphorylation on force development in permeabilized rat cardiac myocytes
Basic Research in Cardiology, 2007Co-Authors: S. C. Verduyn, R Zaremba, J. Velden, Ger J M StienenAbstract:The phosphorylation status of myofibrillar Proteins influences the Ca^2+ responsiveness of the myofilaments,but the contribution of and the interaction between the individual components is poorly characterized. Therefore, in Langendorff perfused rat hearts (n=30), the phosphorylation levels of cardiac myosin binding Protein-C (cMyBP-C), troponin I and T (cTnI, cTnT) and myosin light chain 1 and 2 (MLC-1, MLC-2) were determined by 1- and 2-dimensional gel electrophoresis. Isometric force development, its Ca^2+-sensitivity, the rate of tension redevelopment (k_tr) and passive force (F_pas) were studied at optimal sarcomere length (2.2 μm) in mechanically isolated,permeabilized cardiomyocytes at 15 °C. Protein phosphorylation was varied by: 1) blocking spontaneous cardiac activity by lidocaine (0.35 mM; Quiescence); 2) electrical stimulation of the hearts at 5 Hz (Contraction) and 3. treatment of contracting hearts with Isoprenaline (1 μM). MLC-2 phosphorylation was increased in the Contraction group almost 2-fold, relative to the Quiescence group, whereas cMyBP-C and cTnI phosphorylation remained the same. Isoprenaline resulted in 3.7-fold increases in both cMyBP-C and cTnI phosphorylation, but did not result in a further increase in MLC-2 phosphorylation.No significant differences were found in maximum force and k_tr between groups, both before and after Protein kinase A (PKA) treatment. Ca^2+-sensitivity in the Contraction and Isoprenaline groups was significantly reduced in comparison to the Quiescence group. These differences were largely abolished by PKA and F_pas was reduced. These results highlight the impact of PKA-dependent phosphorylation on Ca^2+-sensitivity and provide evidence for an interaction between the effects of TnI and MLC-2 phosphorylation.
-
alterations in Contractile Protein composition and function in human atrial dilatation and atrial fibrillation
Journal of Molecular and Cellular Cardiology, 2006Co-Authors: S Eiras, N A Narolska, R B Van Loon, Nicky M Boontje, R Zaremba, Connie R Jimenez, Frans C Visser, Wim Stooker, J Van Der Velden, Ger J M StienenAbstract:The cellular mechanisms responsible for Contractile dysfunction associated with atrial fibrillation (AF) are still poorly understood. Atrial fibrillation is often preceded by atrial dilatation. This study aimed to explain Contractile alterations associated with AF and their relation to atrial dilatation, by studying the relationships between atrial dimensions, Contractile Protein composition, force production and Ca2+-sensitivity. Force development was determined in mechanically isolated single skinned cardiomyocytes from right atrial appendages from patients with sinus rhythm without (SR;n = 9), or with atrial dilation (SR + AD;n = 11) or atrial fibrillation (AF;n = 16). Echocardiography showed that, compared to the SR group, mean right atrial dimensions were increased by 18% and 35% in the SR + AD and AF group, respectively (P < 0.05). Protein composition was determined by 1- and 2-dimensional gel electrophoresis. Compared to the SR group, the AF group exhibited: a reduction in the kinetics of force redevelopment (Ktr) in isolated atrial cardiomyocytes, enhanced Protein expression of the slow myosin heavy chain isoform (β-MHC), an increase in troponin T (TnT) phosphorylation and a marked increase (70%) of the cytoskeletal Protein desmin. Significant correlations were observed between the right atrial major axis (RAmajor) and β-MHC expression as well as the desmin/actin ratio. Our findings indicate that dilatation may influence cardiomyocyte stability through altered desmin expression, but that it does not predispose to the alterations in Contractile function observed in AF.
Frank V Brozovich - One of the best experts on this subject based on the ideXlab platform.
-
the vasculature in hfpef vs hfref differences in Contractile Protein expression produce distinct phenotypes
Heliyon, 2020Co-Authors: Melissa Lyle, Young Soo Han, Mohamad S Alabdaljabar, Frank V BrozovichAbstract:Abstract Both heart failure with reduced (HFrEF) and preserved (HFpEF) ejection fraction are associated with abnormalities of the vasculature, including a resting vasoconstriction and a decrease in sensitivity to nitric oxide (NO) mediated vasodilation. Vascular tone is controlled by the expression and activation of both smooth muscle (SM) and nonmuscle (NM) myosin, and NO mediated vasodilation is regulated by the expression of the leucine zipper positive (LZ+) isoform of the myosin targeting subunit (MYPT1) of myosin light chain phosphatase (MLCP). This study was designed to determine the expression of these Contractile Proteins in humans with HFrEF and HFpEF vs normal controls. We isolated tertiary mesenteric vessels from remnant biospecimens of patients undergoing partial or total colectomy at Mayo Clinic Rochester from August 2017 to December 2018, and examined the expression of MYPT1 and the LZ + MYPT1 isoform with immunoblots, while 2D SDS-PAGE was used to resolve the phosphorylated and nonphosphorylated regulatory light chains of NM and SM myosin. Our data show that NM myosin expression, as a percentage of total myosin, was 12 ± 3% (controls, n = 6), 7 ± 5% (HFpEF, n = 4) and 37 ± 18% (HFrEF, n = 5, p
-
the role of pulmonary vascular Contractile Protein expression in pulmonary arterial hypertension
Journal of Molecular and Cellular Cardiology, 2013Co-Authors: Ewa Konik, Young Soo Han, Frank V BrozovichAbstract:Pulmonary arterial hypertension (PAH) is associated with refractory vasoconstriction and impaired NO-mediated vasodilatation of the pulmonary vasculature. Vascular tone is regulated by light chain (LC) phosphorylation of both nonmuscle (NM) and smooth muscle (SM) myosins, which are determined by the activities of MLC kinase and MLC phosphatase. Further, NO mediated vasodilatation requires the expression of a leucine zipper positive (LZ+) isoform of the myosin targeting subunit (MYPT1) of MLC phosphatase. The objective of this study was to define Contractile Protein expression in the pulmonary arterial vasculature and vascular reactivity in PAH. In severe PAH, compared to controls, relative LZ+MYPT1 expression was decreased (100 ± 14% vs. 60 ± 6%, p<0.05, n=7-8), and NM myosin expression was increased (1 5 ± 4% vs. 53 ± 5% of total myosin, p<0.05, n=4-6). These changes in Contractile Protein expression should alter vascular reactivity; following activation with Ang II, force activation and relaxation were slowed, and sustained force was increased. Further, the sensitivity to ACh-mediated relaxation was reduced. These results demonstrate that changes in the pulmonary arterial SM Contractile Protein expression may participate in the molecular mechanism producing both the resting vasoconstriction and the decreased sensitivity to NO-mediated vasodilatation associated with PAH.
-
The role of pulmonary vascular Contractile Protein expression in pulmonary arterial hypertension
Journal of Molecular and Cellular Cardiology, 2013Co-Authors: Ewa Konik, Young Soo Han, Frank V BrozovichAbstract:Pulmonary arterial hypertension (PAH) is associated with refractory vasoconstriction and impaired NO-mediated vasodilatation of the pulmonary vasculature. Vascular tone is regulated by light chain (LC) phosphorylation of both nonmuscle (NM) and smooth muscle (SM) myosins, which are determined by the activities of MLC kinase and MLC phosphatase. Further, NO mediated vasodilatation requires the expression of a leucine zipper positive (LZ+) isoform of the myosin targeting subunit (MYPT1) of MLC phosphatase. The objective of this study was to define Contractile Protein expression in the pulmonary arterial vasculature and vascular reactivity in PAH. In severe PAH, compared to controls, relative LZ+MYPT1 expression was decreased (100 ± 14% vs. 60 ± 6%, p
Wei Tan - One of the best experts on this subject based on the ideXlab platform.
-
high pulsatility flow stimulates smooth muscle cell hypertrophy and Contractile Protein expression
American Journal of Physiology-lung Cellular and Molecular Physiology, 2013Co-Authors: Devon Scott, Yan Tan, Robin Shandas, Kurt R Stenmark, Wei TanAbstract:Proximal arterial stiffening is an important predictor of events in systemic and pulmonary hypertension, partly through its contribution to downstream vascular abnormalities. However, much remains ...
Tjitske A Oenema - One of the best experts on this subject based on the ideXlab platform.
-
bronchoconstriction induces tgf β release and airway remodelling in guinea pig lung slices
PLOS ONE, 2013Co-Authors: Tjitske A Oenema, Marieke Smit, Harm Maarsingh, Herman Meurs, Geny M. M. Groothuis, Reinoud GosensAbstract:Airway remodelling, including smooth muscle remodelling, is a primary cause of airflow limitation in asthma. Recent evidence links bronchoconstriction to airway remodelling in asthma. The mechanisms involved are poorly understood. A possible player is the multifunctional cytokine TGF-β, which plays an important role in airway remodelling. Guinea pig lung slices were used as an in vitro model to investigate mechanisms involved in bronchoconstriction-induced airway remodelling. To address this aim, mechanical effects of bronchoconstricting stimuli on Contractile Protein expression and TGF-β release were investigated. Lung slices were viable for at least 48 h. Both methacholine and TGF-β1 augmented the expression of Contractile Proteins (sm-α-actin, sm-myosin, calponin) after 48 h. Confocal fluorescence microscopy showed that increased sm-myosin expression was enhanced in the peripheral airways and the central airways. Mechanistic studies demonstrated that methacholine-induced bronchoconstriction mediated the release of biologically active TGF-β, which caused the increased Contractile Protein expression, as inhibition of actin polymerization (latrunculin A) or TGF-β receptor kinase (SB431542) prevented the methacholine effects, whereas other bronchoconstricting agents (histamine and KCl) mimicked the effects of methacholine. Collectively, bronchoconstriction promotes the release of TGF-β, which induces airway smooth muscle remodelling. This study shows that lung slices are a useful in vitro model to study mechanisms involved in airway remodelling.
-
muscarinic receptor stimulation augments tgf β1 induced Contractile Protein expression by airway smooth muscle cells
American Journal of Physiology-lung Cellular and Molecular Physiology, 2012Co-Authors: Tjitske A Oenema, Marieke Smit, Herman Meurs, Andrew J Halayko, Lyanne Smedinga, Kurt Racke, Reinoud GosensAbstract:Acetylcholine (ACh) is the primary parasympathetic neurotransmitter in the airways. Recently, it was established that ACh, via muscarinic receptors, regulates airway remodeling in animal models of asthma and chronic obstructive pulmonary disease (COPD). The mechanisms involved are not well understood. Here, we investigated the functional interaction between muscarinic receptor stimulation and transforming growth factor (TGF)-β(1) on the expression of Contractile Proteins in human airway smooth muscle (ASM) cells. ASM cells expressing functional muscarinic M(2) and M(3) receptors were stimulated with methacholine (MCh), TGF-β(1), or their combination for up to 7 days. Western blot analysis revealed a strong induction of sm-α-actin and calponin by TGF-β(1), which was increased by MCh in ASM cells. Immunocytochemistry confirmed these results and revealed that the presence of MCh augmented the formation of sm-α-actin stress fibers by TGF-β(1). MCh did not augment TGF-β(1)-induced gene transcription of Contractile phenotype markers. Rather, translational processes were involved in the augmentation of TGF-β(1)-induced Contractile Protein expression by muscarinic receptor stimulation, including phosphorylation of glycogen synthase kinase-3β and 4E-binding Protein 1, which was enhanced by MCh. In conclusion, muscarinic receptor stimulation augments functional effects of TGF-β(1) in human ASM cells on cellular processes that underpin ASM remodeling in asthma and COPD.