Response Of Vascular Cells Research Articles

Effect of total flavones of Clematis filamentosa Dunn on the oxLDL-induced injury of vascular smooth muscle cells by regulating miR-455-5p

This experiment was conducted to investigate whether total flavones of Clematis filamentosa Dunn affect the inflammatory response and apoptosis of vascular smooth muscle cells induced by oxidized low-density lipoprotein (oxLDL) by regulating microRNA-455-5p (miR-455-5p). 50 mg/mL oxLDL was performed to stimulate the injury of vascular smooth muscle cells, and the total flavones of Clematis filamentosa Dunn were added at concentrations of 75, 150, and 300 μg/mL. The expressions of inflammatory factors IL-1β and TNF-α were analyzed by ELISA, the apoptosis was evaluated by flow cytometry, the expression of Bcl-2 and Bax was determined by western blot, and the real-time fluorescence quantitative PCR (qRT-PCR) was applied to detect miR-455-5p expression. MiR-455-5p mimic was transfected into vascular smooth muscle cells and then induced injury with oxLDL; miR-455-5p inhibitor was transfected into vascular smooth muscle cells and treated with oxLDL and 300 μg/mL total flavones of Clematis filamentosa Dunn. The above methods were employed to investigate the inflammatory response and apoptosis of cells. The total flavones of Clematis filamentosa Dunn significantly inhibited the expression of IL-1β, TNF-α, apoptosis rate, Bax protein expression of oxLDL induced vascular smooth muscle cells, and remarkably promoted the expression of Bcl-2 protein and miR-455-5p, which all showed concentration dependence (p<0.05). Overexpression of miR-455-5p reduced IL-1β, TNF-α expression, apoptosis rate, Bax protein expression, and greatly increased Bcl-2 protein expression in oxLDL injured vascular smooth muscle cells (p<0.05). After interfering with the expression of miR-455-5p, the inhibitory effect of total flavones of Clematis filamentosa Dunn on the expression of IL-1β, TNF-α, apoptosis, Bax protein expression of oxLDL-induced vascular smooth muscle cells was reversed, and its promotion effect on Bcl-2 protein expression was also reversed. Total flavones of Clematis filamentosa Dunn can reduce oxLDL-induced vascular smooth muscle cell inflammation and inhibit its apoptosis. The mechanism of action is related to the up-regulation of miR-455-5p expression.

The intracellular calcium dynamics in a single vascular endothelial cell being squeezed through a narrow microfluidic channel.

Revealing the mechanisms underlying the intracellular calcium responses in vascular endothelial cells (VECs) induced by mechanical stimuli contributes to a better understanding for vascular diseases, including hypertension, atherosclerosis, and aneurysm. Combining with experimental measurement and Computational Fluid Dynamics simulation, we developed a mechanobiological model to investigate the intracellular [Ca2+] response in a single VEC being squeezed through narrow microfluidic channel. The time-dependent cellular surface tension dynamics was quantified throughout the squeezing process. In our model, the various Ca2+ signaling pathways activated by mechanical stimulation is fully considered. The simulation results of our model exhibited well agreement with our experimental results. By using the model, we theoretically explored the mechanism of the two-peak intracellular [Ca2+] response in single VEC being squeezed through narrow channel and made some testable predictions for guiding experiment in the future.

PDMMLA derivatives as a promising cardiovascular metallic stent coating: Physicochemical and biological evaluation.

To reduce the risk of intra-stent restenosis and improve hemocompatibility of biomaterials, the therapeutic re-endothelialization is required. Indeed, the behavior of endothelial cells is affected by several factors such as wettability and surface energy of biomaterial in contact with cells and blood. The aim of this study was to evaluate the physicochemical and biological properties of new polymers derived from poly((R,S)-3,3-dimethylmalic acid) (PDMMLA) that will be used as cardiovascular stents coating. In fact, a comprehensive study of the roughness and topography and the thermal and rheological properties of these materials were investigated. Furthermore, this was correlated with the biological response of human vascular endothelial cells (HUVECs) and monocytes (MM6) to these biomaterials. Our results revealed very interesting surface properties of PDMMLAs, excellent thermal and thermo-mechanical properties and a suitable biological response. All these properties can be adjusted by simple chemical modification of the side chain of the studied polymers.

A Cu(II) complex: treatment activity on intracerebral hemorrhage via inhibiting inflammatory response in vascular endothelial cells

A new Cu(II)-based coordination polymer (CP), {[Cu(bpa)(1,3-BDC)(H2O)](DMF)n}n (1), (DMF = dimethylformamide) was synthesized by reaction of the Cu(NO3)2·3H2O with the 3,6-bis(benzimidazol-1-yl)pyridazine (bpa) presence of the isophthalic acid (1,3-H2BDC). Its intracerebral hemorrhage (ICH) protective treatment was assessed and the related mechanism was explored as well. The real time RT-PCR was used to detect the relative expression levels of the ROS related genes, which reflected the intracellular ROS levels in the vascular endothelial cells. Next, the western blotting assay was performed and the inflammatory responses levels in the vascular endothelial cells were evaluated.

Salvia miltiorrhiza-Derived Sal-miR-58 Induces Autophagy and Attenuates Inflammation in Vascular Smooth Muscle Cells

Autophagy is associated with the cytoprotection of physiological processes against inflammation and oxidative stress. Salvia miltiorrhiza possesses cardiovascular protective actions and has powerful anti-oxidative and anti-inflammatory effects; however, whether and how Salvia miltiorrhiza-derived microRNAs (miRNAs) protect vascular smooth muscle cells (VSMCs) by inducing autophagy across species are unknown. We first screened and identified Sal-miR-58 from Salvia miltiorrhiza as a natural autophagy inducer. Synthetic Sal-miR-58 suppresses chronic angiotensin II (Ang II) infusion-induced abdominal aortic aneurysm (AAA) formation in mice, as well as induces autophagy in VSMCs and attenuates the inflammatory response elicited by Ang II in vivo and in vitro. Mechanistically, Sal-miR-58 downregulates Krüppel-like factor 3 (KLF3) expression through direct binding to the 3′ UTR of KLF3, which in turn relieves KLF3 repression of E3 ubiquitin ligase neural precursor cell-expressed developmentally downregulated 4-like (NEDD4L) expression, whereas NEDD4L upregulation increases the ubiquitination and degradation of the platelet isoform of phosphofructokinase (PFKP), subsequently leading to a decrease in the activation of Akt/mammalian target of rapamycin (mTOR) signaling and facilitating VSMC autophagy induced by Sal-miR-58 in the context of chronic Ang II stimulation and aneurysm formation. Our results provide the first evidence that plant-derived Sal-miR-58 induces autophagy and attenuates inflammation in VSMCs through cross-species modulation of the KLF3/NEDD4L/PFKP regulatory pathway.

3,4,5-Trihydroxycinnamic Acid Inhibits LPS-Induced Inflammatory Response by Increasing SIRT1 Expression in Human Umbilical Vein Endothelial Cells

3,4,5-Trihydroxycinnamic acid (THC) has been demonstrated to exert anti-inflammatory activities in LPS-induced RAW264.7 murine macrophage cells and in LPS-induced septic mice. However, the effect of THC on the inflammatory response in vascular endothelial cells has not been clearly examined. The goal of the present study was to elucidate the anti-inflammatory properties of THC and its underlying mechanism in LPS-challenged human umbilical vein endothelial cells (HUVECs). THC significantly suppressed LPS-induced interleukin-1β production and intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression and significantly decreased LPS-induced nuclear factor-κB activation by attenuating p65 phosphorylation and inhibitor of kappa B degradation. To understand the underlying mechanism of the anti-inflammatory effect of THC, the involvement of the sirtuin 1 (SIRT1) signaling pathway was examined. THC resulted in increased expression of SIRT1 in LPS-challenged HUVECs. Among the downstream molecular targets of SIRT1, the level of LPS-induced acetylated p53 was significantly decreased by THC treatment, whereas no noticeable change was observed in the levels of forkhead box O3 and peroxisome proliferator activated receptor gamma coactivator 1 alpha. In conclusion, the results clearly demonstrate that THC possesses anti-inflammatory properties by increasing SIRT1 expression and subsequent suppression of p53 activation in LPS-challenged HUVECs.

Effect of AFM Nanoindentation Loading Rate on the Characterization of Mechanical Properties of Vascular Endothelial Cell.

Vascular endothelial cells form a barrier that blocks the delivery of drugs entering into brain tissue for central nervous system disease treatment. The mechanical responses of vascular endothelial cells play a key role in the progress of drugs passing through the blood–brain barrier. Although nanoindentation experiment by using AFM (Atomic Force Microscopy) has been widely used to investigate the mechanical properties of cells, the particular mechanism that determines the mechanical response of vascular endothelial cells is still poorly understood. In order to overcome this limitation, nanoindentation experiments were performed at different loading rates during the ramp stage to investigate the loading rate effect on the characterization of the mechanical properties of bEnd.3 cells (mouse brain endothelial cell line). Inverse finite element analysis was implemented to determine the mechanical properties of bEnd.3 cells. The loading rate effect appears to be more significant in short-term peak force than that in long-term force. A higher loading rate results in a larger value of elastic modulus of bEnd.3 cells, while some mechanical parameters show ambiguous regulation to the variation of indentation rate. This study provides new insights into the mechanical responses of vascular endothelial cells, which is important for a deeper understanding of the cell mechanobiological mechanism in the blood–brain barrier.

TIM‑3 inhibits PDGF‑BB‑induced atherogenic responses in human artery vascular smooth muscle cells.

Increasing evidence suggests that T-cell immunoglobulin and mucin domain 3 (TIM-3) displays anti-atherosclerotic effects, but its role in vascular smooth muscle cells (VSMCs) has not been reported. The present study aimed to investigate the function of TIM-3 and its roles in human artery VSMCs (HASMCs). A protein array was used to investigate the TIM-3 protein expression profile, which indicated that TIM-3 expression was increased in the serum of patients with lower extremity arteriosclerosis obliterans disease (LEAOD) compared with healthy individuals. Immunohistochemistry and western blotting of arterial tissue further revealed that TIM-3 expression was increased in LEAOD artery tissue compared with normal artery tissue. Additionally, platelet-derived growth factor-BB (PDGF-BB) displayed a positive correlation with TIM-3 expression in HASMCs. TIM-3 decreased the migration and proliferation of PDGF-BB-induced HASMCs, and anti-TIM-3 blocked the effects of TIM-3. The effect of TIM-3 on the proliferation and migration of HASMCs was further investigated using LV-TIM-3-transduced cells. The results revealed that TIM-3 also inhibited PDGF-BB-induced expression of the inflammatory factors interleukin-6 and tumor necrosis factor-α by suppressing NF-κB activation. In summary, the present study revealed that TIM-3 displayed a regulatory role during the PDGF-BB-induced inflammatory reaction in HASMCs, which indicated that TIM-3 may display anti-atherosclerotic effects.

Lysine demethylase 1A exacerbates LPS-induced inflammation of vascular smooth muscle cells through modulation of NF-κB activation

Purpose: To study the effect of lysine demethylase 1A (LSD1) on inflammatory responses of vascular smooth muscle cells (VSMCs), and investigate the mechanism.
 Methods: VSMCs were treated with lipopolysaccharide (LPS). Overexpression and knockdown of LSD1 in VSMCs were performed by transfecting with LSD1 overexpression plasmid and small interfering RNAs (siRNAs), respectively. Western blot and quantitative real-time polymerase chain reaction (qRTPCR) were used to measure protein and mRNA levels. Enzyme-linked immunosorbent (ELISA) assay was used to determine the levels of inflammatory cytokines.
 Results: Phosphorylation of LSD1 (p-LSD1) was significantly increased in LPS-induced VSMCs. Monocyte chemoattractant protein-1 and IL-6 levels were also increased by LPS, but attenuated by LSD1 knockdown in VSMCs. Activation of NF-κB was increased by LPS, but was also decreased by LSD1 knockdown. Level of methylated p65 (p65-me) in VSMCs was increased by treatment with SET7/9 (p65 methyltransferase), but this effect was attenuated by overexpression of LSD1. Besides, the increased levels of MCP-1 and IL-6 induced by overexpression of LSD1 were reversed by NF-κB signaling inhibitor, PDTC.
 Conclusion: LSD1 exacerbates LPS-induced inflammation of VSMCs through NF-κB activation via p65 demethylation, which indicates that LSD1 might be a potential target for the treatment of cardiovascular diseases.
 Keywords: Vascular smooth muscle cells, Lysine demethylase 1A, Phosphorylation, NF-κB, p65, Demethylation

Ionizing Radiation Regulates Vascular Endothelial Growth Factor-A Transcription in Cultured Human Vascular Endothelial Cells Via the PERK/eIF2α/ATF4 Pathway

The delivery of high-dose hypofractionated radiation to a tumor induces vascular damage, but little is known about the responses of vascular endothelial cells to high-dose radiation. We examined whether high-dose irradiation alters vascular endothelial growth factor (VEGF) signaling, which is a critical regulator of the functional integrity and viability of vascular endothelial cells. Human umbilical vein endothelial cells and human coronary artery endothelial cells were treated with 5, 10, 20, or 30 Gy ionizing radiation (IR). Expression values of VEGFA mRNA were analyzed by real-time polymerase chain reaction at 4 hours after irradiation and normalized to the average value of mock-irradiated human umbilical vein endothelial cell or human coronary artery endothelial cell controls. Irradiation with doses higher than 10 Gy causes an acute increase in VEGFA transcript levels, which was accompanied by activation of the PERK/eIF2α/activating transcription factor 4 (ATF4) pathway in human vascular endothelial cells. ATF4 knockdown with siRNA completely prevented the IR-induced upregulation of VEGFA transcripts, and chromatin immunoprecipitation assays demonstrated that ATF4 binding to the VEGFA locus was enriched in response to IR. Postirradiation treatment with an intracellular inhibitor of VEGF signaling significantly enhances high-dose IR-induced apoptosis in human vascular endothelial cells. Human vascular endothelial cells activate PERK/eIF2α/ATF4/VEGF signaling in response to high-dose IR to mitigate the apoptotic response. Thus, for cancer treatment, intracellular inhibitors of VEGF signaling could be employed to enhance stereotactic body radiation therapy-induced vascular damage, which would augment tumor cell death.

Custom tissue engineered aneurysm models with varying neck size and height for early stage in vitro testing of flow diverters

Endovascular techniques for treating cerebral aneurysms are rapidly advancing and require testing to optimize device configurations. The purpose of this work was to customize tissue-engineered aneurysm “blood vessel mimics” (aBVMs) for early stage in vitro assessment of vascular cell responses to flow diverters and other devices. Aneurysm scaffolds with varying neck size and height were created through solid modeling, mold fabrication, mandrel creation, and electrospinning. Scaffold dimensions and fiber morphology were characterized. aBVMs were created by depositing human smooth muscle and endothelial cells within scaffolds, and cultivating within perfusion bioreactors. These vessels were left untreated or used for flow diverter implantation. Cellular responses to flow diverters were evaluated at 3 days. Custom scaffolds were created with aneurysm neck diameters of 2.3, 3.5, and 5.5 mm and with aneurysm heights of 2, 5, and 8 mm. A set of scaffolds with varying neck size was used for aBVM creation, and dual-sodding of endothelial and smooth muscle cells resulted in consistent and confluent cellular linings. Flow diverters were successfully implanted in a subset of aBVMs, and initial cell coverage over devices was seen in the parent vessel at 3 days. Direct visualization of the device over the neck region was feasible, supporting the future use of these models for evaluating and comparing flow diverter healing. Tissue-engineered aneurysm models can be created with custom neck sizes and heights, and used to evaluate cellular responses to flow diverters and other endovascular devices.

Effects of 1,25-dihydroxyvitamin D3 on the Inflammatory Responses of Stromal Vascular Cells and Adipocytes from Lean and Obese Mice.

Vitamin D status has been implicated in obesity and adipose tissue inflammation. In the present study, we explored the effects of dietary vitamin D supplementation on adipose tissue inflammation and immune cell population, and the effects of in vitro 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) treatment on pro-inflammatory cytokine production by stromal vascular cells (SVCs) and adipocytes in lean and high-fat diet-induced obese mice. The results show that epididymal fat Mcp-1 and Rantes mRNA levels, which were higher in obese mice compared with lean mice, were significantly down-regulated by vitamin D supplementation. While obese mice had higher numbers of macrophages and natural killer (NK) cells within adipose tissue, these remained unaltered by vitamin D supplementation. In accordance with these in vivo findings, the in vitro 1,25(OH)2D3 treatment decreased IL-6, MCP-1, and IL-1β production by SVCs from obese mice, but not by adipocytes. In addition, 1,25(OH)2D3 treatment significantly decreased Tlr2 expression and increased mRNA levels of Iκba and Dusp1 in SVCs. These findings suggest that vitamin D supplementation attenuates inflammatory response in adipose tissue, especially in SVCs, possibly through inhibiting NF-κB and MAPK signaling pathways in SVCs but not by the inhibition of macrophage infiltration.

Effects of LPS and TNFα on the histamine responsiveness of vascular endothelial cells

Effects of LPS and TNFα on the histamine responsiveness of vascular endothelial cells

Prostanoids regulate vascular permeability

In normal condition, vasculature transports only small molecules such as nutrients across vascular wall. When inflammation occurs, inflammatory stimuli increase the permeability of vessel, which induces the extravasation of molecules larger than 40 kDa including plasma proteins. These extravasated molecules cause further inflammation by promoting the infiltration of inflammatory cells and the production of inflammatory mediators. Although it is known that vascular hyper-permeability plays an important role in inflammation, the detailed mechanism of vascular permeability regulation is still unclear. It is known that vascular permeability is controlled by two types of cells: endothelial cells and vascular mural cells. Endothelial cells cover the luminal side of vascular wall in a single layer and form endothelial barrier. Vascular mural cells regulate the blood flow volume of the downstream tissue by contracting or relaxing vascular wall. Endothelial barrier enhancement and vasocontraction suppress the vascular permeability, while endothelial barrier disruption and vasorelaxation promote it. Vascular permeability is regulated by the balance between the response of endothelial cells and vascular mural cells. Prostanoids are cell membrane-derived lipid mediators which bind to each specific G protein-coupled receptor (GPCR), prostanoid receptors. Recently, several studies showed that prostanoids regulate vascular permeability by acting on endothelial cells and/or vascular mural cells. In this review, we would like to describe the role of each prostanoid in vascular permeability by focusing on the characteristics of each specific receptor.

Vascular cell responses to silicone surfaces grafted with heparin-like polymers: surface chemical composition vs. topographic patterning.

Heparin-like polymers are promising synthetic materials with biological functionalities, such as anticoagulant ability, growth factor binding to regulate cellular functions, and inflammation mediation, similar to heparin. The biocompatibility of heparin-like polymers with well-defined chemical structures has inspired many researchers to design heparin-like surfaces to explore their biological applications. The concept of the recombination of functional heparin structural units (sulfonate- and glyco-containing units) was proven to be successful in designing heparin-mimicking surfaces. However, besides surface structural units, topographic patterning is also an important contributor to the biological activity of the surfaces modified with heparin-like polymers. In this work, both surface structural units and topographic patterning were taken into account to investigate the vascular cell behaviors on the silicone surfaces. A facile method for the production of patterned bromine-containing polydimethylsiloxane surface (PDMS-Br) was developed from a one-step multicomponent thermocuring procedure and replica molding using a nanohole-arrayed silicon template. Different structural units of heparin-like polymers, i.e. homopolymer of sulfonate-containing sodium 4-vinylbenzenesulfonate (pSS), homopolymer of glyco-containing 2-(methacrylamido)glucopyranose (pMAG), and copolymers of MAG and SS (pSG), were then introduced on the flat and patterned PDMS-Br surface using visible light-induced graft polymerization. For the flat surfaces, compared with the PDMS-Br surface, pSS-grafted and pSG-grafted surfaces significantly increased cell densities of both human umbilical vein endothelial cells (HUVECs) and human umbilical vein smooth muscle cells (HUVSMCs), indicating that they are "vascular cell-friendly". In contrast, the pMAG-grafted surface showed decreased cell attachment of both HUVECs and HUVSMCs, indicating that the pMAG-grafted surface is "vascular cell-resistant". Moreover, surface topographic patterning enhanced the cell responses to the corresponding flat surfaces. That is to say, surface patterning can make the "vascular cell-friendly" surface still friendly, and the "vascular cell-resistant" surface much more resistant. The combination of surface structural units and topographic patterning shows promise in the preparation of new heparin-like surfaces with improved cell compatibility that is suitable for blood-compatible biomaterials.

Oxidized Low Density Lipoprotein-Induced Atherogenic Response of Human Umbilical Vascular Endothelial Cells (HUVECs) was Protected by Atorvastatin by Regulating miR-26a-5p/Phosphatase and Tensin Homolog (PTEN).

BackgroundAtherosclerosis is a chronic and multifactorial disease, and it is the main reason of coronary heart disease, cerebral infarction, and peripheral vascular disease, which leads to the formation of lesions in arterial blood vessels. Our study aimed to explore the protective effect and its underlying mechanism of atorvastatin (ATV) on oxidized low-density lipoprotein (ox-LDL)-induced atherosclerosis.Material/MethodsHuman umbilical vascular endothelial cells (HUVECs) were cultured and pretreated with ox-LDL to establish an in vitro atherosclerotic cell model. Cell Counting Kit-8 (CCK-8) assay, TUNEL staining, and Transwell assay were used to detect the cell activity, apoptosis, and migration in HUVECs. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to measure the mRNA and protein expressions of adhesion-related genes in HUVECs.ResultsPretreated with 100 mg/L ox-LDL resulted in a 57.23% decrease of cell viability and 81.09% increase of apoptotic injury in HUVECs compare to the control. Meanwhile, ox-LDL pretreatment increased the cell migration and the expression of miR-26a-5p in HUVECs. ATV treatment could effectively reverse the cellular damage induced by ox-LDL, decrease the release of adhesion-related molecules, and downregulate the expression of miR-26a-5p by 44.79% in HUVECs. Moreover, phosphatase and tensin homolog (PTEN) was demonstrated to be the target gene of miR-26a-5p.ConclusionsOur results highlight that ATV protects against ox-LDL-induced downregulation of cell viability, upregulation of cell apoptosis, migration, as well as the release of adhesion-related molecules in HUVECs through the miR-26a-5p/PTEN axis. This study provides new insights into the underlying mechanism of ATV therapeutic potential in atherosclerosis, and also provides a new strategy for the treatment of atherosclerosis.

Endothelin B Receptor is Involved in Endothelin-1 Induced Cell Response in Vascular Smooth Muscle Cells.

Cardiovascular disease is an important problem in developed countries and the effective target of treatment should be further developed. ETB receptor is one of receptor of ET system, which may affect the function of vascular smooth muscle cell via NO released. In order to clarify the theory, we had cell culture with or without ET-1 treatment. Flow cytometry had been used to prove cell apoptosis and transwell assay had been used to detect the ability of cell migration. The expression of ET-1, ICAM-1, VCAM-1, MMP-9 and CRP were detected by using qRT-PCR and Western blot assay. After we had found that RES-701-1 one of ETB receptor antagonists can induced VSMC apoptosis and migration. Also RES-701-1 can down regulated ICAM-1, VCAM-1, MMP-9 and CRP while ET-1 was the opposite. In a conclusion ETB receptor is one of the role target to mediate vascular smooth muscle cell through the ET system and it may be a significant treating target in cardiovascular disease in the future.

Tetramethylpyrazine Inhibits Platelet Adhesion and Inflammatory Response in Vascular Endothelial Cells by Inhibiting P38 MAPK and NF-κB Signaling Pathways.

Damaged vascular endothelial cells after ischemic stroke release inflammatory cytokines and adhesion molecules, which could trigger platelet adhesion to vascular endothelial cells and platelet activation, and accelerate thrombus formation. Tetramethylpyrazine is the main bioactive component of Chuanxiong, which has demonstrated considerable protective effects in cerebrovascular diseases. However, the effect and mechanisms of tetramethylpyrazine on platelet adhesion to ischemia/reperfusion-injured endothelial cells have not been elucidated. In this study, we established an oxygen-glucose deprivation/reoxygenation (OGD/R)-induced brain microvascular endothelial cells (BMECs) injury model to investigate the protective effects of tetramethylpyrazine on platelet adhesion to endothelial cells and potential mechanisms. Experimental results showed that tetramethylpyrazine inhibited platelets adhesion to BMECs, alleviated expression of inflammatory cytokines and adhesion molecules on BMECs, and protected BMECs injured by OGD/R. Furthermore, tetramethylpyrazine could inhibit P38 MAPK and NF-κB activation in injured BMECs by OGD/R and inhibition of P38 MAPK with SB303580 and NF-κB with Bay-11-7082 attenuated the reduction of platelets adhesion to BMECs by tetramethylpyrazine. In conclusion, tetramethylpyrazine protected BMECs and inhibited platelets adhesion to BMECs after OGD/R injury, which was partially mediated by inhibiting P38 MAPK and NF-κB signaling pathways.

Resident multipotent vascular stem cells exhibit amplitude dependent strain avoidance similar to that of vascular smooth muscle cells

Atherosclerosis is one of the leading causes of mortality worldwide, and presents as a narrowing or occlusion of the arterial lumen. Interventions to re-open the arterial lumen can result in re-occlusion through intimal hyperplasia. Historically only de-differentiated vascular smooth muscle cells were thought to contribute to intimal hyperplasia. However recent significant evidence suggests that resident medial multipotent vascular stem cells (MVSC) may also play a role. We therefore investigated the strain response of MVSC since these resident cells are also subjected to strain within their native environment. Accordingly, we applied uniaxial 1 Hz cyclic uniaxial tensile strain at three amplitudes around a mean strain of 5%, (4–6%, 2–8% and 0–10%) to either rat MVSC or rat VSMC before their strain response was evaluated. While both cell types strain avoid, the strain avoidant response was greater for MVSC after 24 h, while VSMC strain avoid to a greater degree after 72 h. Additionally, both cell types increase strain avoidance as strain amplitude is increased. Moreover, MVSC and VSMC both demonstrate a strain-induced decrease in cell number, an effect more pronounced for MVSC. These experiments demonstrate for the first time the mechano-sensitivity of MVSC that may influence intimal thickening, and emphasizes the importance of strain amplitude in controlling the response of vascular cells in tissue engineering applications.

Matrine pre-treatment suppresses AGEs- induced HCSMCs fibrotic responses by regulating Poldip2/mTOR pathway

The fibrotic response of vascular smooth muscle cells (VSMCs) takes responsibilities in atherosclerosis. Advanced glycation end products (AGEs) induce and promote the fibrotic responses of VSMCs. Matrine shows potent anti-fibrotic and cardio-protective effects. This study was aimed to investigate the underlying mechanisms of matrine's inhibitory effects on AGEs-induced VSMCs fibrotic responses. Cultured human coronary smooth muscle cells (HCSMCs) were pre-treated with matrine and exposed to AGEs. Specific siRNA was used to silence polymerase delta interacting protein 2 (Poldip2) expression. Sircol collagen assay was used to assess collagen content. Protein expression and phosphorylation levels were determined by Western blotting. Matrine pre-treatment significantly reduced collagen content, increased smooth muscle myosin heavy chain 11 (MYH11) and Poldip2 expression, decreased expressions of collagen I, β1-integrin, phsphoinositide-3-kinase (PI3K) and nuclear phosphorylated p70S6k, and reduced phosphorylation levels of protein kinase B (Akt) and mechanistic target of rapamycin (mTOR) in HCSMCs exposed to AGEs in a concentration dependent manner. Specific siRNA effectively silenced Poldip2 expression and impaired matrine's effect on collagen content, expressions of MYH11, collagen I, β1-integrin, PI3K, nuclear p-p70S6k and phosphorylation levels of Akt and mTOR in HCSMCs exposed to AGEs. Matrine suppresses AGEs- induced fibrotic responses in HCSMCs via regulating Poldip2/mTOR signaling pathway.