Inflammatory events in a vascular remodeling model induced by surgical injury to the rat carotid artery

Arterial effects of anthracycline: structural and inflammatory assessments in non-human primates and lymphoma patients using 18F-FDG positron emission tomography

Background

Anthracyclines, such as doxorubicin, are important anti-cancer therapies but are associated with arterial injury. Histopathological insights have been limited to small animal models and the role of inflammation in the arterial toxic effects of anthracycline is unclear in humans. Our aims were: 1) To evaluate aortic media fibrosis and injury in non-human primates treated with anthracyclines; 2) To assess the effect of anthracycline on aortic inflammation in patients treated for lymphoma.

Methods

1) African Green monkeys (AGM) received doxorubicin (30-60 mg/m2/biweekly IV, cumulative dose: 240 mg/m2). Blinded histopathologic analyses of collagen deposition and cell vacuolization in the ascending aorta were performed 15 weeks after the last doxorubicin dose and compared to 5 age- and gender-matched healthy, untreated AGMs. 2) Analysis of the thoracic aorta of patients with diffuse large B-cell lymphoma (DLBCL), at baseline and after doxorubicin exposure, was performed using 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in this observational study. The primary outcome was change in maximal tissue-to-background ratio (TBRmax) of the thoracic aorta from baseline to their end-of-treatment clinical PET/CT.

Results

In AGMs, doxorubicin exposure was associated with greater aortic fibrosis (collagen deposition: doxorubicin cohort 6.23±0.88% vs. controls 4.67±0.54%; p=0.01) and increased intracellular vacuolization (doxorubicin 66.3 ± 10.1 vs controls 11.5 ± 4.2 vacuoles/field, p<0.0001) than untreated controls.In 101 patients with DLBCL, there was no change in aortic TBRmax after anthracycline exposure (pre-doxorubicin TBRmax 1.46±0.16 vs post-doxorubicin TBRmax 1.44±0.14, p=0.14). The absence of change in TBRmax was consistent across all univariate analyses.

Conclusions

In a large animal model, anthracycline exposure was associated with aortic fibrosis. In patients with lymphoma, anthracycline exposure was not associated with aortic inflammation.Further research is required to elucidate the mechanisms of anthracycline-related vascular harm.

Heat-Shock Protein 27 (HSPB1) Is Upregulated and Phosphorylated in Human Platelets during ST-Elevation Myocardial Infarction

Heat-shock proteins are a family of proteins which are upregulated in response to stress stimuli including inflammation, oxidative stress, or ischemia. Protective functions of heat-shock proteins have been studied in vascular disease models, and malfunction of heat-shock proteins is associated with vascular disease development. Heat-shock proteins however have not been investigated in human platelets during acute myocardial infarction ex vivo. Using two-dimensional electrophoresis and immunoblotting, we observed that heat-shock protein 27 (HSPB1) levels and phosphorylation are significantly increased in platelets of twelve patients with myocardial infarction compared to patients with nonischemic chest pain (6.4 ± 1.0-fold versus 1.0 ± 0.9-fold and 5.9 ± 1.8-fold versus 1.0 ± 0.8-fold; p < 0.05). HSP27 (HSPB1) showed a distinct and characteristic intracellular translocation from the cytoskeletal fraction into the membrane fraction of platelets during acute myocardial infarction that did not occur in the control group. In this study, we could demonstrate for the first time that HSP27 (HSPB1) is upregulated and phosphorylated in human platelets during myocardial infarction on a cellular level ex vivo with a characteristic intracellular translocation pattern. This HSP27 (HSPB1) phenotype in platelets could thus represent a measurable stress response in myocardial infarction and potentially other acute ischemic events.

Notch2 and Proteomic Signatures in Mouse Neointimal Lesion Formation

Supplemental Digital Content is available in the text.

Objective—

Vascular remodeling is associated with complex molecular changes, including increased Notch2, which promotes quiescence in human smooth muscle cells. We used unbiased protein profiling to understand molecular signatures related to neointimal lesion formation in the presence or absence of Notch2 and to test the hypothesis that loss of Notch2 would increase neointimal lesion formation because of a hyperproliferative injury response.

Approach and Results—

Murine carotid arteries isolated at 6 or 14 days after ligation injury were analyzed by mass spectrometry using a data-independent acquisition strategy in comparison to uninjured or sham injured arteries. We used a tamoxifen-inducible, cell-specific Cre recombinase strain to delete the Notch2 gene in smooth muscle cells. Vessel morphometric analysis and immunohistochemical staining were used to characterize lesion formation, assess vascular smooth muscle cell proliferation, and validate proteomic findings. Loss of Notch2 in smooth muscle cells leads to protein profile changes in the vessel wall during remodeling but does not alter overall lesion morphology or cell proliferation. Loss of smooth muscle Notch2 also decreases the expression of enhancer of rudimentary homolog, plectin, and annexin A2 in vascular remodeling.

Conclusions—

We identified unique protein signatures that represent temporal changes in the vessel wall during neointimal lesion formation in the presence and absence of Notch2. Overall lesion formation was not affected with loss of smooth muscle Notch2, suggesting compensatory pathways. We also validated the regulation of known injury- or Notch-related targets identified in other vascular contexts, providing additional insight into conserved pathways involved in vascular remodeling.

Inhibition of p110δ PI3K prevents inflammatory response and restenosis after artery injury

Inflammatory cells play key roles in restenosis upon vascular surgical procedures such as bypass grafts, angioplasty and stent deployment but the molecular mechanisms by which these cells affect restenosis remain unclear. The p110δ isoform of phosphoinositide 3-kinase (PI3K) is mainly expressed in white blood cells. Here, we have investigated whether p110δ PI3K is involved in the pathogenesis of restenosis in a mouse model of carotid injury, which mimics the damage following arterial grafts. We used mice in which p110δ kinase activity has been disabled by a knockin (KI) point mutation in its ATP-binding site (p110δD910A/D910A PI3K mice). Wild-type (WT) and p110δD910A/D910A mice were subjected to longitudinal carotid injury. At 14 and 30 days after carotid injury, mice with inactive p110δ showed strongly decreased infiltration of inflammatory cells (including T lymphocytes and macrophages) and vascular smooth muscle cells (VSMCs), compared with WT mice. Likewise, PI-3065, a p110δ-selective PI3K inhibitor, almost completely prevented restenosis after artery injury. Our data showed that p110δ PI3K plays a main role in promoting neointimal thickening and inflammatory processes during vascular stenosis, with its inhibition providing significant reduction in restenosis following carotid injury. p110δ-selective inhibitors, recently approved for the treatment of human B-cell malignancies, therefore, present a new therapeutic opportunity to prevent the restenosis upon artery injury.

Osthole inhibits intimal hyperplasia by regulating the NF-κB and TGF-β1/Smad2 signalling pathways in the rat carotid artery after balloon injury

Osthole (7-methoxy-8-isopentenoxy-coumarin), a compound extracted from Cnidiummonnieri (L.) Cusson seeds, has been found to exhibit potent therapeutic effects in cancer due to its ability to inhibit inflammation and cell proliferation. However, its effects on arterial wall hypertrophy-related diseases remain unclear. Therefore, in this study, we aimed to investigate the effects of Osthole on intimal hyperplasia in a rat model of carotid artery balloon injury. We established the balloon-induced carotid artery injury rat model in male Sprague-Dawley rats, after which we administered Osthole (20mg/kg/day or 40mg/kg/day) or volume-matched normal saline orally by gavage for 14 consecutive days. Intimal hyperplasia and the degree of vascular smooth muscle cell proliferation were then evaluated by histopathological examination of the changes in the carotid artery, as well as by examination of proliferating cell nuclear antigen (PCNA) expression. Tumour necrosis factor-ɑ (TNF-α), interleukin-1β (IL-1β), transforming growth factor-beta (TGF-β1) and PCNA mRNA expression levels were examined by real-time RT-PCR, while nuclear factor-κB (NF-κB (p65)), IκB-α, TGF-β1 and phospho-Smad2 (p-Smad2) protein expression levels were analysed by immunohistochemistry or western blot analysis. We found that Osthole significantly attenuated neointimal thickness and decreased the elevations in PCNA protein expression induced by balloon injury. Moreover, Osthole down-regulated the pro-inflammatory factors TNF-α and IL-1β and NF-κB (p65), whose expression had been upregulated after balloon injury. Moreover, IκB-α protein expression levels increased following Osthole treatment. In addition, the elevations in TGF-β1 and p-Smad2 protein expression induced by balloon injury were both significantly attenuated by Osthole administration. We concluded that Osthole significantly inhibited neointimal hyperplasia in balloon-induced rat carotid artery injury and that the mechanism by which this occurs may involve NF-κB, IL-1β and TNF-ɑ down-regulation, which alleviates the inflammatory response, and TGF-β1/Smad2 signalling pathway inhibition.

Atherosclerosis Alters Loading-Induced Arterial Damage: Implications for Robotic Surgery

Background

Lack of intra-operative haptic information during robotic surgery increases the risk for unintended tissue overload and damage. Knowledge about the acute and chronic fundamental relationship between force load and induced damage in healthy and diseased arteries is crucial to enable intra-operative haptic feedback or shared autonomy and improve patient safety.

Methods

Arteries of wildtype and atherosclerotic mice were clamped in vivo for 2 minutes (0.0N, 0.6N or 1.27N). Histological analysis (Verhoeff’s-Van Gieson, Osteopontin, CD45, CD105) was performed immediately, or after 6 hours, 2 weeks or 1 month. Endothelium-dependent and–independent vasodilatation was assessed immediately or 1 month after clamping.

Results

Endothelium dependent vasodilatation is worse after clamping of wildtype arteries, but is restored after one month. Clamping also results in flattening of the innermost elastic membrane of both genotypes, which is reversed over time for wildtype arteries but not for vessels from atherosclerotic mice. Higher osteopontin content in wildtype and LDLR-/- mice after 2 weeks suggests a phenotypic switch of the medial smooth muscle cells (SMCs), an effect that is reversed after 1 month. While inflammation in the intima diminishes, medial CD45 content rises through time in both genotypes. CD105 staining shows that even manipulation without clamping results in endothelial cell loss in both LDLR+/+ and LDLR-/- mice.

Conclusions

Arterial clamping induces different acute and long-term injury to the vessel wall of atherosclerotic and healthy arteries.

Stimulatory interactions between human coronary smooth muscle cells and dendritic cells

Despite inflammatory and immune mechanisms participating to atherogenesis and dendritic cells (DCs) driving immune and non-immune tissue injury response, the interactions between DCs and vascular smooth muscle cells (VSMCs) possibly relevant to vascular pathology including atherogenesis are still unclear. To address this issue, immature DCs (iDCs) generated from CD14+ cells isolated from healthy donors were matured either with cytokines (mDCs), or co-cultured (ccDCs) with human coronary artery VSMCs (CASMCs) using transwell chambers. Co-culture induced DC immunophenotypical and functional maturation similar to cytokines, as demonstrated by flow cytometry and mixed lymphocyte reaction. In turn, factors from mDCs and ccDCs induced CASMC migration. MCP-1 and TNFα, secreted from DCs, and IL-6 and MCP-1, secreted from CASMCs, were primarily involved. mDCs adhesion to CASMCs was enhanced by CASMC pre-treatment with IFNγ and TNFα ICAM-1 and VCAM-1 were involved, since the expression of specific mRNAs for these molecules increased and adhesion was inhibited by neutralizing antibodies to the counter-receptors CD11c and CD18. Adhesion was also inhibited by CASMC pre-treatment with the HMG-CoA-reductase inhibitor atorvastatin and the PPARγ agonist rosiglitazone, which suggests a further mechanism for the anti-inflammatory action of these drugs. Adhesion of DCs to VSMCs was shown also in vivo in rat carotid 7 to 21 days after crush and incision injury. The findings indicate that DCs and VSMCs can interact with reciprocal stimulation, possibly leading to perpetuate inflammation and vascular wall remodelling, and that the interaction is enhanced by a cytokine-rich inflammatory environment and down-regulated by HMGCoA-reductase inhibitors and PPARγ agonists.

Impact of exercise and metabolic disorders on heat shock proteins and vascular inflammation

Heat shock proteins (Hsp) play critical roles in the body's self-defense under a variety of stresses, including heat shock, oxidative stress, radiation, and wounds, through the regulation of folding and functions of relevant cellular proteins. Exercise increases the levels of Hsp through elevated temperature, hormones, calcium fluxes, reactive oxygen species (ROS), or mechanical deformation of tissues. Isotonic contractions and endurance- type activities tend to increase Hsp60 and Hsp70. Eccentric muscle contractions lead to phosphorylation and translocation of Hsp25/27. Exercise-induced transient increases of Hsp inhibit the generation of inflammatory mediators and vascular inflammation. Metabolic disorders (hyperglycemia and dyslipidemia) are associated with type 1 diabetes (an autoimmune disease), type 2 diabetes (the common type of diabetes usually associated with obesity), and atherosclerotic cardiovascular disease. Metabolic disorders activate HSF/Hsp pathway, which was associated with oxidative stress, increased generation of inflammatory mediators, vascular inflammation, and cell injury. Knock down of heat shock factor-1 (HSF1) reduced the activation of key inflammatory mediators in vascular cells. Accumulating lines of evidence suggest that the activation of HSF/Hsp induced by exercise or metabolic disorders may play a dual role in inflammation. The benefits of exercise on inflammation and metabolism depend on the type, intensity, and duration of physical activity.

Heat-shock proteins in cardiovascular disease

Heat-shock proteins (HSPs) belong to a group of highly conserved families of proteins expressed by all cells and organisms and their expression may be constitutive or inducible. They are generally considered as protective molecules against different types of stress and have numerous intracellular functions. Secretion or release of HSPs has also been described, and potential roles for extracellular HSPs reported. HSP expression is modulated by different stimuli involved in all steps of atherogenesis including oxidative stress, proteolytic aggression, or inflammation. Also, antibodies to HSPs may be used to monitor the response to different types of stress able to induce changes in HSP levels. In the present review, we will focus on the potential implication of HSPs in atherogenesis and discuss the limitations to the use of HSPs and anti-HSPs as biomarkers of atherothrombosis. HSPs could also be considered as potential therapeutic targets to reinforce vascular defenses and delay or avoid clinical complications associated with atherothrombosis.

Rosiglitazone reduces the inflammatory response in a model of vascular injury in rats

Thiazolidinediones are ligands that bind to and activate the nuclear peroxisome proliferator-activated receptor gamma. They are widely used as insulin sensitizers for the treatment of type 2 diabetes. Several studies have implicated the peroxisome proliferator-activated receptor gamma agonists rosiglitazone and pioglitazone in inflammatory events. To assess the anti-inflammatory properties of rosiglitazone, we investigated its effects on the molecular and cellular inflammatory response induced by a carotid injury in the rat. Male Wistar rats were randomized into a rosiglitazone-treated group (10 mg kg(-1) day(-1)) and a control group (0.9% w/v NaCl). The drug or vehicle was administered by gavage for 7 days before carotid injury and for up to 21 days after injury. The inflammatory markers p38 mitogen-activated protein kinase, cyclooxygenase 2, nuclear factor-kappaB, and heat shock protein 47 and the influx and activity of cells in response to injury were measured. Rosiglitazone treatment significantly reduced the expression of the inflammatory markers compared with control group. p38 mitogen-activated protein kinase and nuclear factor-kappaB started to decrease a few hours after injury, whereas cyclooxygenase 2 and heat shock protein 47 expression decreased 7 and 14 days, respectively, after injury. Rosiglitazone also reduced neointima formation and inflammatory cell infiltration. In conclusion, rosiglitazone negatively regulated the inflammatory events involved in tissue repair at molecular and cellular levels. These results suggest that rosiglitazone plays a protective role in inflammatory vascular diseases.

Reconstruction and functional analysis of altered molecular pathways in human atherosclerotic arteries

Background

Atherosclerosis affects aorta, coronary, carotid, and iliac arteries most frequently than any other body vessel. There may be common molecular pathways sustaining this process. Plaque presence and diffusion is revealed by circulating factors that can mediate systemic reaction leading to plaque rupture and thrombosis.

Results

We used DNA microarrays and meta-analysis to study how the presence of calcified plaque modifies human coronary and carotid gene expression. We identified a series of potential human atherogenic genes that are integrated in functional networks involved in atherosclerosis. Caveolae and JAK/STAT pathways, and S100A9/S100A8 interacting proteins are certainly involved in the development of vascular disease. We found that the system of caveolae is directly connected with genes that respond to hormone receptors, and indirectly with the apoptosis pathway.

Cytokines, chemokines and growth factors released in the blood flux were investigated in parallel. High levels of RANTES, IL-1ra, MIP-1alpha, MIP-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-17, PDGF-BB, VEGF and IFN-gamma were found in plasma of atherosclerotic patients and might also be integrated in the molecular networks underlying atherosclerotic modifications of these vessels.

Conclusion

The pattern of cytokine and S100A9/S100A8 up-regulation characterizes atherosclerosis as a proinflammatory disorder. Activation of the JAK/STAT pathway is confirmed by the up-regulation of IL-6, STAT1, ISGF3G and IL10RA genes in coronary and carotid plaques. The functional network constructed in our research is an evidence of the central role of STAT protein and the caveolae system to contribute to preserve the plaque. Moreover, Cav-1 is involved in SMC differentiation and dyslipidemia confirming the importance of lipid homeostasis in the atherosclerotic phenotype.

Smooth muscle cells, dendritic cells and mast cells are sources of TNFalpha and nitric oxide in human carotid artery atherosclerosis

INTRODUCTION

In atherogenesis, dendritic cells, beside presenting antigens, may be sources of tumour necrosis factor (TNF)alpha and nitric oxide (NO), together with mast cells and smooth muscle cells.

MATERIAL AND METHODS

We have looked at the expression of TNFalpha and inducible NO synthase (iNOs) by these cells by affinity cytochemistry in autoptical specimens from normal carotid arteries and not ruptured, hemorrhagic or calcified atheromata.

RESULTS

Round to dendritic, major histocompatibility complex class II molecules (MHC-II+) cells and avidin-labeled mast cells were rare in normal arteries and significantly more numerous in atheromata. Many MHC-II+ cells expressed S-100 antigen; while a few were positive for phalloidin; appreciable fractions of these cells were immunoreactive for TNFalpha and iNOs, both in control specimens and atheromata. The fraction of mast cells labeled for iNOs was significantly lower in atheromata than in controls. Phalloidin positive cells were the most abundant cell type in the normal intima and atheromata; the fractions of these cells labeled for TNFalpha and iNOs were significantly higher in atheromata than in controls. Very few of these cells were also labeled for MHC-II. Computerized image analysis confirmed that the amounts of iNOs and TNFalpha were higher in atheromata than in controls. The increase in TNFalpha in atheromata was also confirmed by western blot.

CONCLUSIONS

Dendritic cells and mast cells can participate to the generation of TNFalpha and NO in the normal arterial wall and in atheromata, but myointimal cells are candidates as major sources of these molecules.

Heavy Metal Ions in Normal Physiology, Toxic Stress, and Cytoprotection

As a group, heavy metals include both those essential for normal biological functioning (e.g., Cu and Zn), and nonessential metals (e.g., Cd, Hg, and Pb). Both essential and nonessential metals can be present at concentrations that disturb normal biological functions, and which evoke cellular stress responses. The cellular targets for metal toxicity include tissues of the kidney, liver, heart, and the immune response and nervous systems. Intriguingly, manipulations of specific metals, their reservoirs, and the cellular stress response can have therapeutic effects on certain diseases. In this minireview, we will consider both the biological responses to stressful levels of heavy metal cations, and experimental and clinical manipulations of these cations as a means to improve human health parameters.