Resveratrol inhibits migration and Rac1 activation in EGF- but not PDGF-activated vascular smooth muscle cells

Isoxanthohumol reduces neointimal hyperplasia through the apelin/AKT pathway

The abnormal proliferation, migration, and inflammation of vascular smooth muscle cells (VSMCs) play crucial roles in the development of neointimal hyperplasia and restenosis. Exposure to inflammatory cytokines such as platelet-derived growth factor (PDGF)-BB and tumour necrosis factor-alpha (TNF-α) induces the transformation of contractile VSMCs into abnormal synthetic VSMCs. Isoxanthohumol (IXN) has significant anti-inflammatory, antiproliferative, and antimigratory effects. This study aimed to explore the therapeutic impact and regulatory mechanism of IXN in treating neointimal hyperplasia. The present findings indicate that IXN effectively hinders the abnormal proliferation, migration, and inflammation of VSMCs triggered by PDGF or TNF-α. This inhibition is primarily achieved through the modulation of the apelin/AKT or AKT pathway, respectively. In an in vivo model, IXN effectively reduced neointimal hyperplasia in denuded femoral arteries. These results suggest that IXN holds promise as a potential and innovative therapeutic candidate for the treatment of restenosis.

Role of resveratrol in protecting vasodilatation function in septic shock rats and its mechanism

BACKGROUND

Vascular dysfunction is a major cause of sepsis-induced multiple-organ dysfunction. Resveratrol is a polyphenol compound with extensive pharmacological effects including anti-inflammation. The aim of this study was to determine the role and mechanism of resveratrol in protecting vascular function following sepsis.

METHODS

The cecal ligation and puncture method was used to establish a septic shock rat model. Resveratrol (5 mg/kg and 10 mg/kg) was administered intravenously immediately and at 12 hours after cecal ligation and puncture, respectively. The effects of resveratrol on vasodilatation function, blood flow velocity, hemodynamics, and vital organ function and its relationship to Rac-1 and HIF-1α were observed.

RESULTS

Vascular relaxation reactivity and blood flow velocity were significantly decreased after septic shock, both were significantly improved by resveratrol 5 mg/kg and 10 mg/kg, and the effect of 10 mg/kg was greater. The relaxation reactivity of the superior mesenteric artery to acetylcholine (Ach) was increased by 43.2%. The blood flow velocity of mesenteric arterioles and venules was increased by 47.1% and 51%, respectively, after resveratrol (10 mg/kg) administration compared with the septic shock group. The hemodynamics and both liver and kidney blood flow were significantly decreased after septic shock, which were significantly improved them by resveratrol, which enhanced the vascular relaxation reactivity in septic shock rats. The 72-hour survival rate of septic shock rats in the resveratrol group (62.5%) was significantly higher than that in the septic shock group (6.3%). Resveratrol significantly upregulated the expression of endothelial nitric oxide synthase (eNOS) and downregulated the expression of inducible NOS, Rac-1, and HIF-1α. Inhibitors of Rac-1 and HIF-1α significantly improved the expression of eNOS, and inhibition of eNOS (L-NAME, 5 mg/kg) antagonized the resveratrol-induced improvement in vascular relaxation reactivity and survival.

CONCLUSION

Resveratrol was beneficial for vasodilatation function in rats with septic shock, which is the major contribution to resveratrol improving hemodynamics and organ perfusion. The mechanism involved resveratrol upregulating the expression of eNOS by inhibiting Rac-1 and HIF-1α.

Antagonizing Effects of Clematis apiifolia DC. Extract against Benzo[a]pyrene-Induced Damage to Human Keratinocytes

Background. Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon present in the atmosphere, has cytotoxic and carcinogenic effects. There have been no reports to demonstrate involvement of Clematis apiifolia DC. extract (CAE) in B[a]P-induced effects. This study was conducted to investigate the effect of CAE on B[a]P-induced effects and to elucidate its mechanism of action in HaCaT human keratinocytes. CAE inhibited aryl hydrocarbon receptor (AhR) signaling by decreasing both XRE reporter activity and expression of cytochrome P450 1A1 (CYP1A1) induced by B[a]P treatment in HaCaT cells. We also found that B[a]P-induced nuclear translocation of AhR and production of reactive oxygen species (ROS) and proinflammatory cytokines were attenuated by CAE treatment. CAE treatment suppressed B[a]P-induced phosphorylation of Src (Tyr416). In addition, dasatinib, a Src inhibitor, also inhibited B[a]P-induced nuclear translocation of AhR, similar to CAE treatment. In addition, CAE activated antioxidant response element (ARE) signaling by increasing ARE luciferase reporter activity and expression of ARE-dependent genes such as nuclear factor (erythroid-derived 2)-like 2 (Nrf2), NAD(P)H dehydrogenase [quinone] 1 (NQO1), and heme oxygenase-1 (HO-1). Nuclear translocation of Nrf2 by CAE was demonstrated by Western blot analysis and immunocytochemistry. The effects of CAE on ARE signaling were attenuated by knockdown of the Nrf2 gene. Inhibition of AhR signaling and activation of antioxidant activity by CAE operated in a reciprocally independent manner as evidenced by AhR and Nrf2 siRNA experiments. These findings indicate that CAE exerts protective effects against B[a]P by inhibiting AhR signaling and activating Nrf2-mediated signaling, suggesting its potential in protection from harmful B[a]P-containing pollutants.

Ubiquitin Carboxyl Terminal Hydrolase L1 Attenuates TNF-α-Mediated Vascular Smooth Muscle Cell Migration Through Suppression of NF-κB Activation

Ubiquitin carboxyl terminal hydrolase L1 (UCH-L1) is one of the deubiquitinating enzymes in the ubiquitin-proteasome system. It has been shown that UCH-L1 could markedly decrease neointima formation through suppressing vascular smooth muscle cell (VSMC) proliferation in the balloon-injured rat carotid. However, whether UCH-L1 plays roles in VSMC migration remains to be determined. In this study, the primary VSMCs were isolated from aortic media of rats and TNF-α to was used to induce VSMC migration. Using a modified Boyden chamber and wound healing assay, it was found that TNF-α can dose and time-dependently induce VSMC migration with a maximal effect at 10 ng/mL. Moreover, UCH-L1 expression increased gradually with the prolonged induction time at 10 ng/mL of TNF-α. UCH-L1 content in VSMC was then modulated by recombinant adenoviruses expressing UCH-L1 or RNA interference to evaluate its roles in cell migration. The results showed that over-expression of UCH-L1 attenuated VSMC migration, while knockdown of it enhanced cell migration significantly no matter whether TNF-α treatment or not. Finally, the effect of UCH-L1 on NF-κB activation was demonstrated by NF-κB nuclear translocation and DNA binding activity, and the levels of IL-6 and IL-8 in cell culture media were examined by ELISA. It was showed that UCH-L1 over-expression inhibited NF-κB activation and decrease IL-6 and IL-8 levels, while knockdown of it enhanced NF-κB activation and increase IL-6 and IL-8 levels during TNF-α treatment. These data suggest that UCH-L1 can inhibit TNF-α-induced VSMCs migration, and this kind of effect may partially due to its suppression role in NF-κB activation.

Resveratrol alleviates sepsis-induced acute lung injury by suppressing inflammation and apoptosis of alveolar macrophage cells

Sepsis is a major cause of death in intensive care units. The purpose of this study was to investigate the effect of resveratrol (RSV) on sepsis-induced acute lung injury (ALI). The underlying molecular mechanisms were deciphered by both in vitro and in vivo experiments. Polymicrobial sepsis was induced in C57BL/6 mice by cecal ligation and puncture (CLP). RSV pretreatment significantly attenuated CLP-induced acute lung injury, which was associated with enhanced expression of VEGF-B. The protective properties of RSV were assayed in lipopolysaccharide (LPS)-stimulated MH-S cells. We determine that RSV administration inhibited the increased production of TNF-α, IL-6, and IL-1β in LPS-stimulated MH-S cells, which was associated with inhibition of the nuclear factor-κB, P38, and ERK signaling pathways. We also provide evidence that RSV administration reduced LPS-induced apoptosis of MH-S cells by altering the unbalance of Bax/Bcl-2 and inhibiting LPS-induced autophagy. The inhibitory effects of RSV on cytokine levels and apoptosis of alveolar macrophages were both blocked by VEGF-B siRNA. Furthermore, RSV administration regulated LPS-induced C5aR and C5L2 expression, revealing an additional mechanism underlying RSV's anti-inflammatory and anti-apoptosis effects. Collectively, these results demonstrated that RSV was able to protect against sepsis-induced acute lung injury by activating the VEGF-B signaling pathway.

Xanthohumol Blocks Proliferation and Migration of Vascular Smooth Muscle Cells in Vitro and Reduces Neointima Formation in Vivo

Xanthohumol (1) is a principal prenylated chalcone found in hops. The aim of this study was to examine its influence on platelet-derived growth factor (PDGF)-BB-triggered vascular smooth muscle cell (VSMC) proliferation and migration in vitro and on experimentally induced neointima formation in vivo. Quantification of resazurin conversion indicated that 1 can inhibit PDGF-BB-induced VSMC proliferation concentration-dependently (IC₅₀ = 3.49 μM). Furthermore, in a wound-healing assay 1 potently suppresses PDGF-BB-induced VSMC migration at 15 μM. Tested in a mouse femoral artery cuff model, 1 significantly reduces neointima formation. Taken together, we show that 1 represses PDGF-BB-induced VSMC proliferation and migration in vitro as well as neointima formation in vivo. This novel activity suggests 1 as an interesting candidate for further studies addressing a possible therapeutic application to counteract vascular proliferative disease.

Resveratrol attenuates myocardial ischemia/reperfusion injury through up-regulation of vascular endothelial growth factor B

The objective was to examine the protective effect of resveratrol (RSV) on myocardial ischemia/reperfusion (IR) injury and whether the mechanism was related to vascular endothelial growth factor B (VEGF-B) signaling pathway. Rat hearts were isolated for Langendorff perfusion test and H9c2 cells were used for in vitro assessments. RSV treatment significantly improved left ventricular function, inhibited CK-MB release, and reduced infarct size in comparison with IR group ex vivo. RSV treatment markedly decreased cell death and apoptosis of H9c2 cells during IR. We found that RSV was responsible for the up-regulation of VEGF-B mRNA and protein level, which caused the activation of Akt and the inhibition of GSK3β. Additionally, RSV prevented the generation of reactive oxygen species (ROS) by up-regulating the expression of MnSOD either in vitro or ex vivo. We also found that the inhibition of VEGF-B abolished the cardioprotective effect of RSV, increased apoptosis, and led to the down-regulation of phosphorylated Akt, GSK3β, and MnSOD in H9c2 cells. These results demonstrated that RSV was able to attenuate myocardial IR injury via promotion of VEGF-B/antioxidant signaling pathway. Therefore, the up-regulation of VEGF-B can be a promising modality for clinical myocardial IR injury therapy.

Anti-atherosclerotic plants which modulate the phenotype of vascular smooth muscle cells

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of global death, with atherosclerosis being a major contributor to this mortality. Several mechanisms are implicated in the pathogenesis of this disease. A key element in the development and progression of atherosclerotic lesions is the phenotype of vascular smooth muscle cells. Under pathophysiologic conditions such as injury, these cells switch from a contractile to a synthetic phenotype that often possesses high proliferative and migratory capacities.

PURPOSE

Despite major advances made in the management and treatment of atherosclerosis, mortality associated with this disease remains high. This mandates that other approaches be sought. Herbal medicine, especially for the treatment of CVD, has been gaining more attention in recent years. This is in no small part due to the evidence-based values associated with the consumption of many plants as well as the relatively cheaper prices, easier access and conventional folk medicine "inherited" over generations. Sections: In this review, we provide a brief introduction about the pathogenesis of atherosclerosis then we highlight the role of vascular smooth muscle cells in this disease, especially when a phenotypic switch of these cells arises. We then thoroughly discuss the various plants that show potentially beneficial effects as anti-atherosclerotic, with prime attention given to herbs and plants that inhibit the phenotypic switch of vascular smooth muscle cells.

CONCLUSION

Accumulating evidence provides the justification for the use of botanicals in the treatment or prevention of atherosclerosis. However, further studies, especially clinical ones, are warranted to better define several pharmacological parameters of these herbs, such as toxicity, tolerability, and efficacy.

Increased aerobic glycolysis is important for the motility of activated VSMC and inhibited by indirubin-3'-monoxime

Increased aerobic glycolysis is a recognized feature of multiple cellular phenotypes and offers a potential point for drug interference, as pursued by anti-tumor agents targeting the Warburg effect. This study aimed at examining the role of aerobic glycolysis for migration of vascular smooth muscle cells (VSMC) and its susceptibility to the small molecule indirubin-3′-monoxime (I3MO). Activation of VSMC with platelet-derived growth factor (PDGF) resulted in migration and increased glycolytic activity which was accompanied by an increased glucose uptake and hexokinase (HK) 2 expression. Inhibition of glycolysis or hexokinase by pharmacological agents or siRNA-mediated knockdown significantly reduced the migratory behavior in VSMC without affecting cell viability or early actin cytoskeleton rearrangement. I3MO, previously recognized as inhibitor of VSMC migration, was able to counteract the PDGF-activated increase in glycolysis and HK2 abundance. Activation of signal transducer and activator of transcription (STAT) 3 could be identified as crucial event in upregulation of HK2 and glycolytic activity in PDGF-stimulated VSMC and as point of interference for I3MO. I3MO did not inhibit hypoxia-inducible factor (HIF)1α-dependent transcription nor influence miRNA 143 levels, other potential regulators of HK2 levels. Overall, we demonstrate that increased aerobic glycolysis is an important factor for the motility of activated VSMC and that the anti-migratory property of I3MO may partly depend on impairment of glycolysis via a compromised STAT3/HK2 signaling axis.

Long-term oral resveratrol intake provides nutritional preconditioning against myocardial ischemia/reperfusion injury: involvement of VDAC1 downregulation

SCOPE

This study elucidates the effects of long-term nutritional preconditioning by resveratrol on ischemia/reperfusion (I/R) injury and its underlying mechanisms.

METHODS AND RESULTS

Mice were treated with resveratrol at 2.0 mg/kg/day by gastric gavages for 6 wk. Then hearts were isolated and subjected to I/R injury in a Langendorff apparatus. Resveratrol significantly improved left ventricular pressure, ±dp/dtmax, and coronary flow; decreased the lactate dehydrogenase and creatine phosphokinase activities; and reduced the infarction size. Additionally, long-term oral resveratrol intake prevented mitochondrial permeability transition pore opening and subsequently inhibited mitochondria-mediated apoptosis, as demonstrated by decrease of cytochrome c release, inactivation of caspase-3, and reduction of terminal deoxynucleotidyl transferase mediated nick end labeling positive cells. Furthermore, resveratrol inhibited the upregulation of voltage-dependent anion channel 1 (VDAC1) expression induced by I/R injury. Local left-ventricle overexpression of VDAC1 by adenovirus diminished the protective effect of resveratrol against I/R injury, indicating that VDAC1 plays an important role in resveratrol-mediated cardioprotection.

CONCLUSION

Our data revealed that long-term oral intake of resveratrol sets nutritional preconditioning to cope with myocardial I/R injury. Strikingly, we found that resveratrol downregulates VDAC1, leading to prevention of mitochondrial permeability transition pore opening and cardiomyocyte apoptosis.

Resveratrol and cardiovascular health--promising therapeutic or hopeless illusion?

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural polyphenolic compound that exists in Polygonum cuspidatum, grapes, peanuts and berries, as well as their manufactured products, especially red wine. Resveratrol is a pharmacologically active compound that interacts with multiple targets in a variety of cardiovascular disease models to exert protective effects or induce a reduction in cardiovascular risks parameters. This review attempts to primarily serve to summarize the current research findings regarding the putative cardioprotective effects of resveratrol and the molecular pathways underlying these effects. One intent is to hopefully provide a relatively comprehensive resource for clues that may prompt ideas for additional mechanistic studies which might further elucidate and strengthen the role of the stilbene family of compounds in cardiovascular disease and cardioprotection. Model systems that incorporate a significant functional association with tissues outside of the cardiovascular system proper, such as adipose (cell culture, obesity models) and pancreatic (diabetes) tissues, were reviewed, and the molecular pathways and/or targets related to these models and influenced by resveratrol are discussed. Because the body of work encompassing the stilbenes and other phytochemicals in the context of longevity and the ability to presumably mitigate a plethora of afflictions is replete with conflicting information and controversy, especially so with respect to the human response, we tried to remain as neutral as possible in compiling and presenting the more current data with minimal commentary, permitting the reader free reign to extract the knowledge most helpful to their own investigations.

Positive feedback regulation of proliferation in vascular smooth muscle cells stimulated by lipopolysaccharide is mediated through the TLR 4/Rac1/Akt pathway

Toll-like receptor 4 (TLR4) are important in inflammation and regulating vascular smooth muscle cells (VSMCs) proliferation, which are related to atherosclerosis and restenosis. We have investigated the mechanisms involved in Lipopolysaccharide (LPS)-induced proliferation of VSMCs. Stimulation of rat aortic VSMCs with LPS significantly increases the proliferation of VSMCs. This effect is regulated by Rac1 (Ras-related C3 botulinum toxin substrate l), which mediates the activation of phosphatidylinositol 3-kinase/Akt (PI3K/Akt) signaling pathways. Inhibition of Rac1 activity by NSC23766 is associated with inhibition of Akt activity. Treatment with NSC23766 or LY294002 significantly decreases LPS-induced TLR4 protein and mRNA expression. The data show that positive feedback regulation of proliferation in VSMCs is mediated through the TLR4/Rac1/Akt pathway.

Resveratrol inhibits glucose-induced migration of vascular smooth muscle cells mediated by focal adhesion kinase

SCOPE

Diabetes is a critical factor for atherosclerosis, as hyperglycemia induces vascular smooth muscle cell (VSMC) proliferation and migration and subsequently contributes to the formation of atherosclerotic lesions. This study investigates whether resveratrol plays a regulatory role in the proliferation and migration of VSMCs under high glucose induction to imitate a hyperglycemic condition.

METHODS AND RESULTS

Resveratrol inhibited the migration of VSMCs in the wound-healing assay and the formation of lamellipodia and filopodia as assessed by atomic force microscopy scanning. Resveratrol suppressed the mRNA expression of c-Src, Rac1, cdc42, IRS-1, MEKK1, MEKK4, and mitogen-activated protein kinase along with the protein levels of c-Src, p-Src, and cdc42 in VSMCs. Resveratrol decreased the level of p-FAK protein under normal glucose conditions. Resveratrol could inhibit the activities of matrix metalloproteinase (MMP) 2 and MMP 9 as shown by zymography. Moreover, resveratrol also regulated the mitogen-activated protein kinase pathway and MMP activities of VSMC migration under the high glucose condition.

CONCLUSION

The antimigratory effects of resveratrol by reduced MMP expression through the inhibition of Rac1, p-FAK, and lamellipodia formation and the activation of p-AKT and p-ERK1/2 suggest that resveratrol is a potential compound for the treatment of vascular diseases via the regulation of VSMC migration.

Layer-by-layer assembly of epidermal growth factors on polyurethane films for wound closure

To facilitate the healing of chronic wounds, growth factors such as epidermal growth factor need to be safely encapsulated for their sustained and effective delivery to the wound bed. Using a layer-by-layer assembly technique, epidermal growth factor is successfully encapsulated on the surface of poly(acrylic acid)-modified polyurethane film. The amount of encapsulated epidermal growth factor is controlled by adjusting the number of chitosan/epidermal growth factor bilayers. A controlled release of epidermal growth factor from the surface of polyurethane film for a period of five days is achieved with well-retained bioactivity (over 90%) as evidenced by a cell proliferation assay. In an in vitro cellular wounding assay, the cell gap covered with the epidermal growth factor-loaded polyurethane film closes at a rate more than twice as fast as that covered with a control polyurethane film. Fluorescent staining of F-actin reveals that the released epidermal growth factor induces differences in cytoskeletal organization, suggesting that stimulated cell migration also contributes to the close of the cell gap.

Chlamydia pneumoniae infection induces vascular smooth muscle cell migration via Rac1 activation

Chlamydia pneumoniae infection has been shown to be associated with the development of atherosclerosis by promoting the migration of vascular smooth muscle cells (VSMCs). However, how C. pneumoniae infection induces VSMC migration is not fully understood. A primary role of Ras-related C3 botulinum toxin substrate 1 (Rac1) is to generate a protrusive force at the leading edge that contributes to cell migration. Whether Rac1 activation plays a role in C. pneumoniae infection-induced VSMC migration is not well defined. In the present study, we therefore examined Rac1 activation in C. pneumoniae-infected rat primary VSMCs and the role of Rac1 activation in C. pneumoniae infection-induced VSMC migration. Glutathione S-transferase pull-down assay results showed that Rac1 was activated in C. pneumoniae-infected rat primary VSMCs. A Rac1 inhibitor, NSC23766 (50 µM,) suppressed Rac1 activation stimulated by C. pneumoniae infection, and thereby inhibited C. pneumoniae infection-induced VSMC migration. In addition, C. pneumoniae infection-induced Rac1 activation in the VSMCs was blocked by LY294002 (25 µM), an inhibitor of phosphatidylinositol 3-kinase (PI3K). Taken together, these data suggest that C. pneumoniae infection promotes VSMC migration, possibly through activating Rac1 via PI3K.

Polyphenols: benefits to the cardiovascular system in health and in aging

Numerous studies have demonstrated the importance of naturally occurring dietary polyphenols in promoting cardiovascular health and emphasized the significant role these compounds play in limiting the effects of cellular aging. Polyphenols such as resveratrol, epigallocatechin gallate (EGCG), and curcumin have been acknowledged for having beneficial effects on cardiovascular health, while some have also been shown to be protective in aging. This review highlights the literature surrounding this topic on the prominently studied and documented polyphenols as pertaining to cardiovascular health and aging.

Pharmacokinetics and tissue distribution of resveratrol, emodin and their metabolites after intake of Polygonum cuspidatum in rats

ETHNOPHARMACOLOGICAL RELEVANCE

The rhizome of Polygonum cuspidatum SIEB. et ZUCC. (Polygonaceae, PC), a widely used Chinese medicine, is commonly prescribed for the treatments of amenorrhea, arthralgia, jaundice, abscess, scald and bruises.

AIM OF THE STUDY

PC contains various polyphenols including stilbenes, anthraquinones and flavonoids. This study investigated the pharmacokinetics and tissue distribution of emodin and resveratrol in PC.

MATERIAL AND METHODS

Male Sprague-Dawley rats were orally administered PC (2 and 4 g/kg) and blood samples were withdrawn at the designed time points via cardiopuncture. Moreover, after 7-dose administrations of PC (4 g/kg), brain, liver, lung, kidney and heart were collected. The concentrations of resveratrol and emodin in the plasma and tissues were assayed by HPLC before and after hydrolysis with β-glucuronidase and sulfatase.

RESULTS

The glucuronides/sulfates of emodin and resveratrol were exclusively present in the plasma. In liver, kidney, lung and heart, the glucuronides/sulfates of resveratrol were the major forms. For emodin, its glucuronides/sulfates were the major forms in kidney and lung, whereas considerable concentration of emodin free form was found in liver. Neither free forms nor conjugated metabolites of resveratrol and emodin were detected in brain.

CONCLUSION

The sulfates/glucuronides of resveratrol and emodin were the major forms in circulation and most assayed organs after oral intake of PC. However, the free form of emodin was predominant in liver.