Conversion of Arterial Smooth Muscle Phenotype in Human fetus and Adult

During recent years,it has become increasingly evident that there are obvious differences inthe ultrastructure of arterial smooth muscle cellsbetween fetuses and adults.To further characterize the ultrastructure of arterial smooth cells inhuman fetuses and adults,10 specimens of fetusesand 6 specimens of adults from aorta were collected.Moreover, 4 specimens of atherosclerosisplaques from adult aorta were taken. All thespecimens were processed for electron microscopy.We observed that the smooth muscle cells in fetues showed fibroblast-like appearance with intensive rough endoplasmic reticulum, a prominent     

Endothelial Cell–Smooth Muscle Cell Co-Culture in a Perfusion Bioreactor System

Vascular endothelial cells (EC) are exposed to a complex biomechanical environment in vivo and are responsible for relaying important messages to the underlying tissue. EC and smooth muscle cells (SMC) communicate to regulate vascular development and function. In this work, a vascular perfusion bioreactor is used to grow tubular constructs seeded with EC and SMC under pulsatile shear stress in long-term co-culture to study the effects of EC on SMC function. SMC seeded into porous poly(glycolic acid) tubular scaffolds are cultured in the bioreactor for 25 days. Constructs are seeded with EC on day 10 or day 23 creating 2-day (short-term) or 15-day (long-term) EC and SMC co-cultures. Long-term EC–SMC co-culture significantly increases cell proliferation and downregulates collagen and proteoglycan deposition compared to short-term co-culture. After 25 days of culture, 15-day co-culture constructs have a more uniform cell distribution across the construct thickness and SMC express a more contractile phenotype compared to 2-day co-culture constructs. These data demonstrate strong interactions between SMC and EC in the bioreactor under physiologically relevant conditions. Thus, the vascular construct perfusion bioreactor is an important tool to investigate cell–cell and cell–extracellular matrix interactions in vascular cell biology and tissue engineering.     

Gene Transfer into Vascular Smooth Muscle Cells (VSMCs) by Ultrasound with Microbubbles

1 Introduction Ultrasound is best known for its imaging capability in diagnostic medicine. However, there have been considerable efforts recently to develop therapeutic uses of ultrasound. Gene therapy will be increasingly important for the treatment of inherited or acquired diseases, such as atherosclerosis and cancer~([1]). However, its clinical application is hampered by concerns over the safety of viral vectors and the inefficiency of transfection techniques for local gene delivery to a sp…     

The Association Between β-Dystroglycan in Airway Smooth Muscle and Eosinophils in Allergic Asthma

Inflammation - Allergic asthma (AA) is a complex disorder with heterogeneous features of airway hyperresponsiveness, inflammation, and remodeling. The increase of airway smooth muscle (ASM) mass is...     

17Beta-estradiol Promotes Proliferation of Rat Synthetic Vascular Smooth Muscle Cells by Up-regulating Cyclin D_1

1 IntroductionCardiovascular disease (CVD) is the leading cause of morbidity and mortality in women after 50 years of age in most developed countries. Estrogen deficiency plays a key role in causing CVD in women. The cardiovascular protective actions of estrogen are partially mediated by a direct effect on the vessel wall, and the proliferation of vascular smooth muscle cells (VSMC) plays a major role as an initiating event of atherosclerosis. A previous study by us in cooperation with Ca…     

AIP1 Suppresses Transplant Arteriosclerosis Through Inhibition of Vascular Smooth Muscle Cell Inflammatory Response to IFNγ

IFNγ-induced vascular smooth muscle cells (VSMCs) inflammatory response plays a key role in transplant arteriosclerosis (TA). However, the mechanisms regulating this process remains poorly defined. Here, we show that ASK1-interacting protein 1 (AIP1) deletion markedly augments the expression of IFNγ-induced chemokines in mouse aortic allografts. Subsequently, donor arterial grafts from AIP1 deficient mice exhibited an accelerated development of TA. Furthermore, AIP1 knockdown significantly increased IFNγ signaling activation in cultured VSMCs and thus enhances chemokines production in response to IFNγ. Together, we conclude that AIP1 functions as an inhibitor of VSMCs inflammation by regulating IFNγ signaling and therefore suppresses TA progression. Our findings suggest that AIP1 might be a potential therapeutic target for chronic transplant rejection. Anat Rec, 302:1587–1593, 2019. © 2018 American Association for Anatomy     

Freeze–Thaw Induced Biomechanical Changes in Arteries: Role of Collagen Matrix and Smooth Muscle Cells

Applications involving freeze–thaw, such as cryoplasty or cryopreservation can significantly alter artery biomechanics including an increase in physiological elastic modulus. Since artery biomechanics plays a significant role in hemodynamics, it is important to understand the mechanisms underlying these changes to be able to help control the biomechanical outcome post-treatments. Understanding of these mechanisms requires investigation of the freeze–thaw effect on arterial components (collagen, smooth muscle cells or SMCs), as well as the components’ contribution to the overall artery biomechanics. To do this, isolated fresh swine arteries were subjected to thermal (freeze–thaw to ?20 °C for 2 min or hyperthermia to 43 °C for 2 h) and osmotic (0.1–0.2 M mannitol) treatments; these treatments preferentially altered either the collagen matrix (hydration/stability) or smooth muscle cells (SMCs), respectively. Tissue dehydration, thermal stability and SMC functional changes were assessed from bulk weight measurements, analyses of the thermal denaturation profiles using Fourier transform infrared (FTIR) spectroscopy and in vitro arterial contraction/relaxation responses to norepinephrine (NE) and acetylcholine (AC), respectively. Additionally, Second Harmonic Generation (SHG) microscopy was performed on fresh and frozen–thawed arteries to directly visualize the changes in collagen matrix following freeze–thaw. Finally, the overall artery biomechanics was studied by assessing responses to uniaxial tensile testing. Freeze–thaw of arteries caused: (a) tissue dehydration (15% weight reduction), (b) increase in thermal stability (~6.4 °C increase in denaturation onset temperature), (c) altered matrix arrangement observed using SHG and d) complete SMC destruction. While hyperthermia treatment also caused complete SMC destruction, no tissue dehydration was observed. On the other hand, while 0.2 M mannitol treatment significantly increased the thermal stability (~4.8 °C increase in denaturation onset), 0.1 M mannitol treatment did not result in any significant change. Both 0.1 and 0.2 M treatments caused no change in SMC function. Finally, freeze–thaw (506 ± 159 kPa), hyperthermia (268 ± 132 kPa) and 0.2 M mannitol (304 ± 125 kPa) treatments all caused significant increase in the physiological elastic modulus (E _artery) compared to control (185 ± 92 kPa) with the freeze–thaw resulting in the highest modulus. These studies suggest that changes in collagen matrix arrangement due to dehydration as well as SMC destruction occurring during freeze–thaw are important mechanisms of freeze–thaw induced biomechanical changes.     

Honokiol Inhibits Tumor Necrosis Factor-α-Stimulated Rat Aortic Smooth Muscle Cell Proliferation via Caspase- and Mitochondrial-Dependent Apoptosis

This study aims to investigate the effects of honokiol on proliferation, cell cycle, and apoptosis in tumor necrosis factor (TNF)-α-induced rat aortic smooth muscle cells (RASMCs). We found that honokiol treatment showed potent inhibitory effects on TNF-α-induced RASMC proliferation, which were associated with G0/G1 cell cycle arrest and downregulation of cell cycle-related proteins, including cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2 and CDK4. Furthermore, honokiol treatment led to the release of cytochrome c into cytosol and a loss of mitochondrial membrane potential (ΔΨm), as well as a decrease in the expression of Bcl-2 and an increase in the expression of Bax. Treatment with honokiol also reduced TNF-α-induced phosphorylation of p38, extracellular signal-regulated kinase 1/2, and c-Jun N-terminal kinase. Taken together, our results suggest that honokiol suppresses TNF-α-stimulated RASMC proliferation via caspase- and mitochondria-dependent apoptosis and highlight the therapeutic potential of honokiol in the prevention of cardiovascular diseases.     

Nicotine Induces Pro-inflammatory Response in Aortic Vascular Smooth Muscle Cells Through a NFκB/Osteopontin Amplification Loop-Dependent Pathway

Nicotine has anti- and pro-inflammatory properties in various cells. Its role in aortic vascular smooth muscle cells (VSMC) was explored. Human aortic VSMC were cultured. After nicotine (1.0 μM) and/or pyrrolidinedithiocarbamic acid (PDTC, 50 μM) treatment, the activation of nuclear factor κB (NFκB) was investigated. The levels of pro-inflammatory cytokines, osteopontin (OPN), interleukin-6 (IL-6), and monocyte chemoattractant protein 1 (MCP-1) were also assessed. After OPN was downregulated by small interfering RNA (siRNA) transfection, the pro-inflammatory effect was reassessed. We found that NFκB was activated after nicotine administration. Nicotine upregulated OPN, IL-6, and MCP-1 expressions, and this effect attenuated after PDTC pretreatment. RNAi knocked down the OPN expression in nicotine-treated cells and abolished its pro-inflammatory effects. We concluded that nicotine induces a pro-inflammatory response in VSMC through a NFκB/osteopontin amplification loop-dependent pathway.     

C-Reactive Protein Induces TNF-α Secretion by p38 MAPK–TLR4 Signal Pathway in Rat Vascular Smooth Muscle Cells

Atherosclerosis is a chronic inflammatory disease. C-reactive protein (CRP) not only is an inflammatory marker but also regulates the expressions of other inflammatory cytokines associated with the pathogenesis of atherosclerosis. Toll-like receptor 4 (TLR4) also contributes to atherogenesis via transducting inflammatory signals. Herein, our studies focused on characterizing the effect of CRP on tumor necrosis factor α (TNF-α) production and TLR4-related molecular mechanisms in rat vascular smooth muscle cells (VSMCs). The results showed that CRP stimulated VSMCs to secrete TNF-α and enhanced TLR4 expression in a time-concentration-dependent manner. TLR4 knockdown significantly inhibited CRP-induced TNF-α generation, and p38 mitogen-activated protein kinase (MAPK) blocker SB203580 depressed TLR4 expression and TNF-α production initiated by CRP in VSMCs. The data demonstrate that CRP triggers an inflammatory response in rat VSMCs by inducing TNF-α secretion, which is mediated by p38 MAPK–TLR4 signaling pathway.     

Effects of Transforming Growth Factor-β1 on Proliferation of Smooth Muscle Cells in Human Aortic Intima and Human Promonocytic Leukemia THP-1 Cells

We studied the effects of transforming growth factor on proliferation of cultured smooth muscle cells from human aortic intima and proliferation and differentiation of human leukemia THP-1 promonocytes. Transforming growth factor inhibited proliferation of these cells, but stimulated differentiation of THP-1 cells. Therefore, transforming growth factor probably modulates proliferation and differentiation of smooth muscle cells and monocytes/macrophages involved in the pathogenesis of atherosclerotic damages.     

Zinc Sulfate Inhibited Inflammation of Der p2-Induced Airway Smooth Muscle Cells by Suppressing ERK1/2 and NF-κB Phosphorylation

Inflammation of airway smooth muscle cells (ASMCs) is believed to be important in causing airway hyperresponsiveness. However, zinc has been reported to be implicated in many kinds of cell inflammation. Little is known about the effect of zinc treatment on Der p2 (group II Dermatophagoides pteronyssinus)-induced inflammation from ASMCs. This study investigated effects and mechanisms of zinc in Der p2-treated ASMCs. Der p2-treated primary ASMCs were cultured with various concentrations of zinc sulfate (ZnSO₄) 6 μM, 12 μM, 24 μM, and 96 μM. The proteins and mRNAs of cytokines in ASMCs were examined by ELISA and real-time PCR. Intracellular zinc was stained with Zinquin fluorescence. The cell signaling protein expression was detected by Western blot. Der p2 was used to induce interleukin (IL)-6, IL-8, IL-1, and monocyte chemotactic protein-1 production of ASMCs. However, we found that 24 μM ZnSO₄ reduced these inflammatory mediators production of Der p2-treated primary ASMCs. Der p2-induced extracellular signal-regulated kinases (ERK) and nuclear factor-kappa B (NF-κB) phosphorylation were suppressed by supplementation of 24 μM ZnSO₄. Zinc is an anti-inflammatory agent that reduces inflammation of Der p2-treated ASMCs through the suppression of the ERK and NF-κB pathway. The results may be helpful for the development of effective treatments.     

Inhibition of Collagen Synthesis and Regulation of Cell Motility in Vascular Smooth Muscle Cells by Suppression of Connective Tissue growth Factor Expression Using RNAInterference

1 IntroductionVascular smooth muscle cell (VSMC) hyperplasia plays an important role in both chronic and acute pathologies including atherosclerosis and restenosis. Recent studies have shown that connective tissue growth factor (CTGF) is a novel growth factor involved in the development and progression of atherosclerosis. However, previous data about the role of CTGF on the VSMC is conflicting. Hishikawa et al demonstrated that CTGF could act as a growth inhibitor in human VSMC; but …     

Agonistic AT1 Receptor Autoantibody Increases in Serum of Patients with Refractory Hypertension and Improves Ca^2＋ Mobilization in Cultured Rat Vascular Smooth Muscle Cells

Agonistic AT1 receptor autoantibodies （AT1-AAs） have been described in the patients with malignant hypertension or preeclampia. Furthermore, AT1-AAs were highly associated with refractory hypertension. Function of vascular smooth muscle cells （VSMCs） is important in the regulation of blood pressure. We investigated and compared the ability of angiotensin II （Ang II） and AT1-AAs to stimulate the intracellular calcium mobilization and cellular proliferation of rat VSMCs. Twenty-two patients with refractory hypertension, 24 patients with non-refractory hypertension and 37 normotensives were recruited. The serum of each patient was detected for the presence of AT1-AAs by ELISA. Ang II and the AT1-AAs from the sera of patients were used to stimulate rat VSMCs in vitro. AT1-AAs were detected in 10/22, 3/24 and 3/37 of patients with refractory hypertension, non-refractory hypertension and normotensives, respectively. AT1-AAs led the increase intracellular calcium mobilization in a dose-dependent manner and cellular proliferation of VSMCs just as Ang II. Both of these effects caused by AT1-AAs were blocked with losartan or a peptide corresponding to a part of the second extracellular loop of AT1 receptor. Since AT1-AAs exhibited pharmacological activity in rat VSMCs just as Ang II, they might play a role in the elevation of peripheral vascular resistance and in vascular remodeling. And AT1-AAs were suggested to involve in resistance to antihypertensive therapy.     

Co-cultures of Human Coronary Smooth Muscle Cells and Dimethyl Sulfoxide-differentiated HL60 Cells Upregulate ProMMP9 Activity and Promote Mobility—Modulation By Reactive Oxygen Species

Vascular cells and leukocytes, involved in the development of atherosclerosis, produce cytokines and/or reactive oxygen species (ROS) and matrix metalloproteinases (MMPs) implicated in cell mobility. We investigated by co-culture experiments the effects of human coronary smooth muscle cells (HCSMC) on MMPs characteristics and mobility of neutrophil-like dimethyl sulfoxide-differentiated HL60 cells (≠HL60). The effects of superoxide dismutase (SOD) and catalase were also analyzed. All the studied MMP2 characteristics remained unchanged. HCSMC stimulated MMP9 protein level, activity and mobility of ≠HL60 cells and expressed and secreted a variety of cytokines implicated in atherosclerosis. SOD and catalase increased MMP9 expression, protein level and activity of ≠HL60, but migration of ≠HL60 cells was only decreased by catalase, demonstrating that ROS are more efficient in modulating MMP9 activity of ≠HL60 than their mobility. Finally, HCSMC being able to stimulate ≠HL60, their co-cultures may represent an in vitro approach to study cellular interactions occurring in vivo during atherosclerosis.     

Thermal Injury Prediction During Cryoplasty Through <Emphasis Type="Italic">In Vitro</Emphasis> Characterization of Smooth Muscle Cell Biophysics and Viability

Restenosis in peripheral arteries is a major health care problem in the United States. Typically, 30–40% of angioplasties result in restenosis and hence alternative treatment techniques are being actively investigated. Cryoplasty, a novel technique involving simultaneous stretching and freezing of the peripheral arteries (e.g., femoral, iliac, popliteal) using a cryogen-filled balloon catheter, has shown the potential to combat restenosis. However, evaluation of the thermal and biophysical mechanisms that affect cellular survival during cryoplasty is lacking. To achieve this, the thermal history in arteries was predicted for different balloon temperatures using a thermal model. Cellular biophysical responses (water transport (WT) and intracellular ice formation (IIF)) were then characterized, using in vitro model systems, based on the thermal model predictions. The thermal and biophysical effects on cell survival were eventually determined. For this study, smooth muscle cells (SMC) isolated from porcine femoral arteries were used in suspensions and attached in vitro systems (monolayer and fibrin gel). Results showed that for different balloon temperatures, the thermal model predicted cooling rates from 2200 to 5 °C/min in the artery. Biophysical parameters (WT & IIF) were higher for SMCs in attached systems as compared to suspensions. The “combined” fit WT parameters for SMCs in suspension (at 5, 10, and 25 °C/min) are L _pg = 0.12 μm/(min atm) and E _Lp = 24.1 kcal/mol. Individual WT parameters for SMCs in attached cell systems at higher cooling rates are approximately an order of magnitude higher compared to suspensions (e.g., at 130 °C/min, WT parameters in monolayer and fibrin TE systems are L _pg = 18.6, 19.4 μm/(min atm) and E _Lp = 112, 127 kcal/mol, respectively). Similarly, IIF parameters assessed at 130 °C/min are higher for SMCs in attached systems than suspensions ( = 1.1, 354, 378 (× 10⁸ (1/m² s)) and κ_o = 1.6, 1.8, 2.1 (× 10⁹ K⁵) for suspensions, monolayer, and fibrin TE, respectively). One possible reason for the differences in IIF kinetics was verified to be the presence of gap junctions, which facilitate cell–cell connections through which ice can propagate. This is reflected by the change in the predicted IIF parameters when a gap junction inhibitor was added and tested in monolayer ( (1/m² s)); κ_o = 2.1 × 10⁹ K⁵). SMC viability was affected by the model system (lower viability in attached systems), the thermal conditions and the biophysics. For e.g., IIF is lethal to cells and SMC viability was verified to be the least in fibrin TE (most % IIF) and the most in suspensions (least % IIF) at all cooling rates. Using the results from the fibrin TE (suggested as the best in vitro system to mimic a restenosis environment), conservative estimates of injury regimes in the artery during cryoplasty is predicted. The results can be used to suggest future optimizations and modifications during cryoplasty and also to design future in vivo studies.

Muscle autoantibodies in myasthenia gravis: beyond diagnosis?

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction. A number of molecules, including ion channels and other proteins at the neuromuscular junction, may be targeted by autoantibodies leading to abnormal neuromuscular transmission. In approximately 85% of patients, autoantibodies, directed against the postsynaptic nicotinic acetylcholine receptor can be detected in the serum and confirm the diagnosis, but in general, do not precisely predict the degree of weakness or response to therapy. Antibodies to the muscle-specific tyrosine kinase are detected in approximately 50% of generalized myasthenia gravis patients who are seronegative for anti-acetylcholine receptor antibodies, and levels of anti-muscle-specific tyrosine kinase antibodies do appear to correlate with disease severity and treatment response. Antibodies to other muscle antigens may be found in the subsets of myasthenia gravis patients, potentially providing clinically useful diagnostic information, but their utility as relevant biomarkers (measures of disease state or response to treatment) is currently unclear.