Reality of a Vaccine in the Prevention and Treatment of Atherosclerosis

Immunological perspectives on atherosclerotic plaque formation and progression

Atherosclerosis serves as the primary catalyst for numerous cardiovascular diseases. Growing evidence suggests that the immune response is involved in every stage of atherosclerotic plaque evolution. Rapid, but not specific, innate immune arms, including neutrophils, monocytes/macrophages, dendritic cells (DCs) and other innate immune cells, as well as pattern-recognition receptors and various inflammatory mediators, contribute to atherogenesis. The specific adaptive immune response, governed by T cells and B cells, antibodies, and immunomodulatory cytokines potently regulates disease activity and progression. In the inflammatory microenvironment, the heterogeneity of leukocyte subpopulations plays a very important regulatory role in plaque evolution. With advances in experimental techniques, the fine mechanisms of immune system involvement in atherosclerotic plaque evolution are becoming known. In this review, we examine the critical immune responses involved in atherosclerotic plaque evolution, in particular, looking at atherosclerosis from the perspective of evolutionary immunobiology. A comprehensive understanding of the interplay between plaque evolution and plaque immunity provides clues for strategically combating atherosclerosis.

Identification and verification of immune-related genes for diagnosing the progression of atherosclerosis and metabolic syndrome

BACKGROUND

Atherosclerosis and metabolic syndrome are the main causes of cardiovascular events, but their underlying mechanisms are not clear. In this study, we focused on identifying genes associated with diagnostic biomarkers and effective therapeutic targets associated with these two diseases.

METHODS

Transcriptional data sets of atherosclerosis and metabolic syndrome were obtained from GEO database. The differentially expressed genes were analyzed by RStudio software, and the function-rich and protein-protein interactions of the common differentially expressed genes were analyzed.Furthermore, the hub gene was screened by Cytoscape software, and the immune infiltration of hub gens was analyzed. Finally, relevant clinical blood samples were collected for qRT-PCR verification of the three most important hub genes.

RESULTS

A total of 1242 differential genes (778 up-regulated genes and 464 down-regulated genes) were screened from GSE28829 data set. A total of 1021 differential genes (492 up-regulated genes and 529 down-regulated genes) were screened from the data set GSE98895. Then 23 up-regulated genes and 11 down-regulated genes were screened by venn diagram. Functional enrichment analysis showed that cytokines and immune activation were involved in the occurrence and development of these two diseases. Through the construction of the Protein-Protein Interaction(PPI) network and Cytoscape software analysis, we finally screened 10 hub genes. The immune infiltration analysis was further improved. The results showed that the infiltration scores of 7 kinds of immune cells in GSE28829 were significantly different among groups (Wilcoxon Test < 0.05), while in GSE98895, the infiltration scores of 4 kinds of immune cells were significantly different between groups (Wilcoxon Test < 0.05). Spearman method was used to analyze the correlation between the expression of 10 key genes and 22 kinds of immune cell infiltration scores in two data sets. The results showed that there were 42 pairs of significant correlations between 10 genes and 22 kinds of immune cells in GSE28829 (|Cor| > 0.3 & P < 0.05). There were 41 pairs of significant correlations between 10 genes and 22 kinds of immune cells in GSE98895 (|Cor| > 0.3 & P < 0.05). Finally, our results identified 10 small molecules with the highest absolute enrichment value, and the three most significant key genes (CX3CR1, TLR5, IL32) were further verified in the data expression matrix and clinical blood samples.

CONCLUSION

We have established a co-expression network between atherosclerotic progression and metabolic syndrome, and identified key genes between the two diseases. Through the method of bioinformatics, we finally obtained 10 hub genes in As and MS, and selected 3 of the most significant genes (CX3CR1, IL32, TLR5) for blood PCR verification. This may be helpful to provide new research ideas for the diagnosis and treatment of AS complicated with MS.

CETP-derived Peptide Seq-1, the Key Component of HB-ATV-8 Vaccine Prevents Stress Responses, and Promotes Downregulation of Pro-Fibrotic Genes in Hepatocytes and Stellate Cells

BACKGROUND

The nasal vaccine HB-ATV-8 has emerged as a promising approach for NAFLD (non-alcoholic fatty liver disease) and atherosclerosis prevention. HB-ATV-8 contains peptide seq-1 derived from the carboxy-end of the Cholesteryl Ester Transfer Protein (CETP), shown to reduce liver fibrosis, inflammation, and atherosclerotic plaque formation in animal models. Beyond the fact that this vaccine induces B-cell lymphocytes to code for antibodies against the seq-1 sequence, inhibiting CETP's cholesterol transfer activity, we have hypothesized that beyond the modulation of CETP activity carried out by neutralizing antibodies, the observed molecular effects may also correspond to the direct action of peptide seq-1 on diverse cellular systems and molecular features involved in the development of liver fibrosis.

METHODS

The HepG2 hepatoma-derived cell line was employed to establish an in vitro steatosis model. To obtain a conditioned cell medium to be used with hepatic stellate cell (HSC) cultures, HepG2 cells were exposed to fatty acids or fatty acids plus peptide seq-1, and the culture medium was collected. Gene regulation of COL1A1, ACTA2, TGF-β, and the expression of proteins COL1A1, MMP-2, and TIMP-2 were studied.

AIM

To establish an in vitro steatosis model employing HepG2 cells that mimics molecular processes observed in vivo during the onset of liver fibrosis. To evaluate the effect of peptide Seq-1 on lipid accumulation and pro-fibrotic responses. To study the effect of Seq-1-treated steatotic HepG2 cell supernatants on lipid accumulation, oxidative stress, and pro-fibrotic responses in HSC.

RESULTS AND CONCLUSION

Peptide seq-1-treated HepG2 cells show a downregulation of COLIA1, ACTA2, and TGF-β genes, and a decreased expression of proteins such as COL1A1, MMP-2, and TIMP-2, associated with the remodeling of extracellular matrix components. The same results are observed when HSCs are incubated with peptide Seq-1-treated steatotic HepG2 cell supernatants. The present study consolidates the nasal vaccine HB-ATV-8 as a new prospect in the treatment of NASH directly associated with the development of cardiovascular disease.

Research progress on the active ingredients of traditional Chinese medicine in the intervention of atherosclerosis: A promising natural immunotherapeutic adjuvant

Atherosclerosis (AS) is a chronic inflammatory disease caused by disorders of lipid metabolism. Abnormal deposition of low-density lipoproteins in the arterial wall stimulates the activation of immune cells, including the adhesion and infiltration of monocytes, the proliferation and differentiation of macrophages and lymphocytes, and the activation of their functions. The complex interplay between immune cells coordinates the balance between pro- and anti-inflammation and plays a key role in the progression of AS. Therefore, targeting immune cell activity may lead to the development of more selective drugs with fewer side effects to treat AS without compromising host defense mechanisms. At present, an increasing number of studies have found that the active ingredients of traditional Chinese medicine (TCM) can regulate the function of immune cells in multiple ways to against AS, showing great potential for the treatment of AS and promising clinical applications. In this paper, we review the mechanisms of immune cell action in AS lesions and the potential targets and/or pathways for immune cell regulation by the active ingredients of TCM to promote the understanding of the immune system interactions of AS and provide a relevant basis for the use of active ingredients of TCM as natural adjuvants for AS immunotherapy.

Peptide Helix-Y12 as Potential Effector for Peroxisome Proliferator-Activated Receptors

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors involved in the regulation of lipids and glucose metabolism, and immune response. Therefore, they have been considered pharmacological targets for treating metabolic diseases, such as dyslipidemia, atherosclerosis, and non-alcoholic fatty liver disease. However, the available synthetic ligands of PPARs have mild to significant side effects, generating the necessity to identify new molecules that are selective PPAR ligands with specific biological responses. This study aimed to evaluate some components of the atheroprotective and hepatoprotective HB-ATV-8 nanoparticles [the amphipathic peptide Helix-Y¹², thermozeaxanthin, thermozeaxanthin-13, thermozeaxanthin-15, and a set of glycolipids], as possible ligands of PPARs through blind molecular docking. According to the change in free energy upon protein-ligand binding, ∆G _b, thermozeaxanthins show a more favorable interaction with PPARs, followed by Helix-Y¹². Moreover, Helix-Y¹² interacts with most parts of the Y-shaped ligand-binding domain (LBD), surrounding helix 3 of PPARs, and reaching helix 12 of PPARα and PPARγ. As previously reported for other ligands, Tyr314 and Tyr464 of PPARα interact with Helix-Y¹² through hydrogen bonds. Several PPARα's amino acids are involved in the ligand binding by hydrophobic interactions. Furthermore, we identified additional PPARs' amino acids interacting with Helix-Y¹² through hydrogen bonds still not reported for known ligands. Our results show that, from the studied ligand set, the Helix-Y¹² peptide and Tzeaxs have the most significant probability of binding to the PPARs' LBD, suggesting novel ligands for PPARs.

There is urgent need to treat atherosclerotic cardiovascular disease risk earlier, more intensively, and with greater precision: A review of current practice and recommendations for improved effectiveness

Atherosclerotic cardiovascular disease (ASCVD) is epidemic throughout the world and is etiologic for such acute cardiovascular events as myocardial infarction, ischemic stroke, unstable angina, and death. ASCVD also impacts risk for dementia, chronic kidney disease peripheral arterial disease and mobility, impaired sexual response, and a host of other visceral impairments that adversely impact the quality and rate of progression of aging. The relationship between low-density lipoprotein cholesterol (LDL-C) and risk for ASCVD is one of the most highly established and investigated issues in the entirety of modern medicine. Elevated LDL-C is a necessary condition for atherogenesis induction. Basic scientific investigation, prospective longitudinal cohorts, and randomized clinical trials have all validated this association. Yet despite the enormous number of clinical trials which support the need for reducing the burden of atherogenic lipoprotein in blood, the percentage of high and very high-risk patients who achieve risk stratified LDL-C target reductions is low and has remained low for the last thirty years. Atherosclerosis is a preventable disease. As clinicians, the time has come for us to take primordial and primary prevention more serously. Despite a plethora of therapeutic approaches, the large majority of patients at risk for ASCVD are poorly or inadequately treated, leaving them vulnerable to disease progression, acute cardiovascular events, and poor aging due to loss of function in multiple visceral organs. Herein we discuss the need to greatly intensify efforts to reduce risk, decrease disease burden, and provide more comprehensive and earlier risk assessment to optimally prevent ASCVD and its complications. Evidence is presented to support that treatment should aim for far lower goals in cholesterol management, should take into account many more factors than commonly employed today and should begin significantly earlier in life.

Cardiovascular Involvement in Sjögren’s Syndrome

Sjögren Syndrome (SS) seems to be associated with a greater “overall risk” of cardiovascular (CV) and cerebrovascular events. Although not conventionally considered a feature of the disease, CV events represent a major burden in SS patients. CV risk is the consequence of a complex combination of multiple factors, including traditional risk factors and disease-related mechanisms. A complex relationships between disease-related features, endothelial dysfunction and traditional risk factor has been suggested. Several drugs are available for treating the systemic manifestations of SS, however they have shown positive effects on different outcomes of the disease, but until today the data on the role of these drugs on CV events are scarse. Given these data, the aim of this review was to evaluate the risk of CV risk in primary SS and the effect of the drugs on this manifestation.

Recent Patents on Nasal Vaccines Containing Nanoadjuvants

Vaccines are one of the greatest medical achievements of modern medicine. The nasal mucosa represents an effective route of vaccination for both mucosal immunity and peripheral, being at the same time an inductive and effector site of immunity. In this paper, the innovative and patented compositions and manufacturing procedures of nanomaterials have been studied using the peerreviewed research literature. Nanomaterials have several properties that make them unique as adjuvant for vaccines. Nanoadjuvants through the influence of antigen availability over time affect the immune response. Namely, the amount of antigen reaching the immune system or its release over prolonged periods of time can be effectively increased by nanoadjuvants. Mucosal vaccines are an interesting alternative for immunization of diseases in which pathogens access the body through these epithelia. Nanometric adjuvants are not only a viable approach to improve the efficacy of nasal vaccines but in most of the cases they represent the core of the intellectual property related to the innovative vaccine.

Association between serum uric acid and carotid atherosclerosis in elderly postmenopausal women: A hospital-based study

BACKGROUND

Carotid atherosclerosis (CAS) is associated with increased cardiovascular risk and implicated in 20-30% of strokes.

METHODS

504 patients were included in this study. The detailed medical history and the results of physical examination, carotid ultrasound examination, and routine laboratory tests were collected. Logistic regression analyses were conducted to analyze the relationship between the SUA and the presence of carotid plaques. And the relationship between SUA and the progression of CAS was analyzed by multiple linear regression. The effect of hormone replacement therapy (HRT) on CAS has also be evaluated.

RESULTS

412 patients (81.7%) had carotid plaques of different sizes by carotid ultrasound examination. We found a positive association between the level of SUA and the probability of having carotid plaque by univariate logistic regression (OR: 2.01, 95% CI: 1.83-2.19, p = 0.003). At 2 years post-discharge, we found that 1 mg/dL increase in SUA levels was expected to 0.946% increase in plaque score and 0.026 cm increase in carotid intima-media thickness, separately. Moreover, patients treated by long-term HRT (≥5 years) had a lower level of SUA and blood lipid and the less change of plaque score and carotid intima-media thickness than patients without HRT.

CONCLUSION

The presence and progression of CAS had significantly positive associations with the level of SUA. And the HRT may have the ability to prevent the presence and progression of CAS. However, the safety and long-term outcome of HRT on CAS should be evaluated in further studies.

Impact of cholesterol-pathways on breast cancer development, a metabolic landscape

ApoB-lipoproteins and their components modulate intracellular metabolism and have been associated with the development of neoplastic phenomena, such as proliferation, anchorage-independent growth, epithelial-mesenchymal transition, and cancer invasion. In cancer cells, the modulation of targets that regulate cholesterol metabolism, such as synthesis de novo, endocytosis, and oxidation, are contributing factors to cancer development. While mechanisms associated with sterol regulatory element-binding protein 2 (SREBP-2)/mevalonate, the low-density lipoprotein receptor (LDL-R) and liver X receptor (LXR) have been linked with tumor growth; metabolites derived from cholesterol-oxidation, such as oxysterols and epoxy-cholesterols, also have been described as tumor processes-inducers. From this notion, we perform an analysis of the role of lipoproteins, their association with intracellular cholesterol metabolism, and the impact of these conditions on breast cancer development, mechanisms that can be shared during atherogenesis promoted mainly by LDL. Pathways connecting plasma dyslipidemias in conjunction with the effect of cholesterol-derived metabolites on intracellular mechanisms and cellular plasticity phenomena could provide new approaches to elucidate the triggering factors of carcinogenesis, conditions that could be considered in the development of new therapeutic approaches.

Hepatic Accumulation of Hypoxanthine: A Link Between Hyperuricemia and Nonalcoholic Fatty Liver Disease

BACKGROUND

An elevated level of plasma uric acid has been widely recognized as a risk factor for non-alcoholic fatty liver disease (NAFLD), where oxidative stress and inflammation play an important role in the pathophysiology of the disease. Although the complete molecular mechanisms involved remain unknown, while under physiological conditions uric acid presents antioxidant properties, hyperuricemia has been linked to oxidative stress, chronic low-grade inflammation, and insulin resistance, basic signs of NAFLD.

AIM OF STUDY

Employing in vivo experimentation, we aim to investigate whether a high-fat diet rich in cholesterol (HFD), modifies the metabolism of purines in close relationship to molecular events associated with the development of NAFLD. In vitro experiments employing HepG2 cells are also carried out to study the phenomenon of oxidative stress.

METHODS

Adult male rabbits were fed for 8 weeks an HFD to induce NAFLD. At the beginning of the experiment and every 15 d until the completion of the study, plasma levels of lipids, lipoproteins, and uric acid were measured. Liver tissue was isolated, and histology performed followed by the biochemical determination of hypoxanthine, protein expression of xanthine oxidoreductase (XOR) by western blot analysis, and xanthine oxidase (XO) activity using an enzymatic kinetic assay. Furthermore, we employed in vitro experimentation studying HepG2 cells to measure the effect of hypoxanthine and H₂O₂ upon the production of radical oxygen species (ROS), XO activity, and cell viability.

RESULTS AND CONCLUSION

Hepatic tissue from rabbits fed the HFD diet showed signs of NAFLD associated with an increased ROS concentration and an altered purine metabolism characterized by the increase in hypoxanthine, together with an apparent equilibrium displacement of XOR towards the xanthine dehydrogenase (XDH) isoform of the enzyme. This protein shift visualized by a western blot analysis, associated with an increase in plasma uric acid and hepatocyte hypoxanthine could be understood as a compensatory series of events secondary to the establishment of oxidative stress associated with the chronic establishment of fatty liver disease.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

Peptidic vaccines: The new cure for heart diseases?

Cardiovascular disease continues to be the most common cause of death worldwide. The global burden is so high that numerous organizations are providing counseling recommendations and annual revisions of current pharmacological and non-pharmacological treatments as well as risk prediction for disease prevention and further progression. Although primary preventive interventions targeting risk factors such as obesity, hypertension, smoking, and sedentarism have led to a global decline in hospitalization rates, the aging population has overwhelmed these efforts on a global scale. This review focuses on peptidic vaccines, with the known and not well-known autoantigens in atheroma formation or acquired cardiac diseases, as novel potential immunotherapy approaches to counteract harmful heart disease continuance. We summarize how cancer immunomodulatory strategies started novel approaches to modulate the innate and adaptive immune responses, and how they can be targeted for therapeutic purposes in the cardiovascular system. Brief descriptions focused on the processes that start as either immunologic or non-immunologic, and the ultimate loss of cardiac muscle cell contractility as the outcome, are discussed. We conclude debating how novel strategies with nanoparticles and nanovaccines open a promising therapeutic option to reduce or prevent cardiovascular diseases.

Thioredoxin-1 promotes macrophage reverse cholesterol transport and protects liver from steatosis

Atherosclerosis is characterized by the accumulation of excess cholesterol in plaques. Reverse cholesterol transport (RCT) plays a key role in the removal of cholesterol. In the present study, we examined the effect of thioredoxin-1 (Trx-1) on RCT and explored the underlying mechanism. We found that Trx-1 promoted RCT in vivo, as did T0901317, a known liver X receptor (LXR) ligand. T0901317 also inhibited the development of atherosclerotic plaques but promoted liver steatosis. Furthermore, Trx-1 promoted macrophage cholesterol efflux to apoAI in vitro. Mechanistically, Trx-1 promoted nuclear translocation of LXRα and induced the expression of ATP-binding cassette transporter A1 (ABCA1). Apolipoprotein E knockout (apoE-/-) mice fed an atherogenic diet were daily injected intraperitoneally with saline or Trx-1 (0.33 mg/kg). Trx-1 treatment significantly inhibited the development of atherosclerosis and induced the expression of ABCA1 in macrophages retrieved from apoE-/- mice. Moreover, the liver steatosis was attenuated by Trx-1. Overall, we demonstrated that Trx-1 promotes RCT by upregulating ABCA1 expression through induction of nuclear translocation of LXRα, and protects liver from steatosis.

Macrophage Foam Cell-Targeting Immunization Attenuates Atherosclerosis

Background: Macrophage foam cells (FCs) play a crucial role in the initiation and progression of atherosclerosis. Reducing the formation or inducing the removal of FCs could ameliorate atherosclerosis. The present study examined whether the whole-cell vaccination using FCs could be used as novel prevention and treatment strategies to battle atherosclerosis.

Methods: ApoE^−/− mice with initial or established atherosclerosis were subcutaneously immunized three times with FCs in Freund's adjuvant.

Results: Immunization with FCs resulted in an overt reduction of atherosclerotic lesion in the whole aorta and the aortic root with enhanced lesion stability. Subsequent study in mechanism showed that FCs vaccination dramatically increased CD4⁺ T cell and CD8⁺ T cell populations. Immunization with FCs significantly raised the plasma FCs-specific IgG antibodies. Of note, the FCs immune plasma could selectively recognize and bind to FC. FCs immune plasma significantly blocked the process of FCs formation, finally reduced the accumulation of FCs in plaque. Additionally, it was observed that FCs immunization down-regulated the expression level of atherosclerosis related pro-inflammatory cytokines, including IFN-γ, MCP-1, and IL-6 and enhanced the lesion stability with a significant increase in TGF-β1 level and collagen content.

Conclusions: These findings demonstrate that the whole-cell vaccination using FCs significantly decreased lesion development and positively modulated lesion progression and stability by targeting FCs. The whole-cell FCs vaccine might represent a potential novel strategy for development of new antibodies and vaccines to the prevention or treatment of atherosclerosis.

Recent Advances in the Development of Vaccines for Diabetes, Hypertension, and Atherosclerosis

Vaccines are commonly used in the prevention of infectious diseases. The basic principle of vaccination is to use specific antigens, endogenous or exogenous to stimulate immunity against the specific antigens or cells producing them. Autoantigen or oligo vaccination has been used for disease animal models. More recently humanized monoclonal antibodies have been successfully used for the treatment of neoplastic disorders or familial hypercholesterolemia. Humanized monoclonal antibody therapy needs repeated injection, and the therapy is expensive. Therapeutic vaccination can lead to persistent immunized or immune tolerant against the therapeutic molecule(s) or site. However, immunization against those endogenous substances may also elicit persistent autoimmune reaction or destruction that do harm to health. Therefore, rigorous studies are needed before any clinical application. In this review, we briefly reviewed vaccines used in protection against common metabolic diseases including atherosclerosis, hypertension, and diabetes mellitus.

Atherosclerosis and autoimmunity: a growing relationship

Atherosclerosis is regarded as one of the leading causes of mortality and morbidity in the world. Nowadays, it seems that atherosclerosis cannot be defined merely through the Framingham traditional risk factors and that autoimmunity settings exert a remarkable role in its mechanobiology. Individuals with autoimmune disorders show enhanced occurrence of cardiovascular complications and subclinical atherosclerosis. The mechanisms underlying the atherosclerosis in disorders like rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, systemic sclerosis and Sjögren's syndrome, seem to be the classical risk factors. However, chronic inflammatory processes and abnormal immune function may also be involved in atherosclerosis development. Autoantigens, autoantibodies, infectious agents and pro-inflammatory mediators exert a role in that process. Being armed with the mechanisms underlying autoimmunity in the etiopathogenesis of atherosclerosis in rheumatic autoimmune disorders and the shared etiologic pathway may result in substantial developing therapeutics for these patients.

Synthesis, Biological Evaluation, and Molecular Modeling Study of Substituted Benzyl Benzamides as CETP Inhibitors

Cardiovascular disease is the most common cause for mortality and morbidity in the developed world; its risk is inversely related to the high-density lipoprotein (HDL) cholesterol levels. Therefore, there is a great interest in developing new cholesteryl ester transfer protein (CETP) inhibitors capable of raising HDL as a novel approach for the prevention of cardiovascular disease. Herein, the synthesis and characterization of ten benzyl benzamides 8a-j that aim at CETP inhibition was performed. The in vitro CETP inhibition bioassay revealed that benzamide 8j had the best activity, with a percent inhibition of 82.2% at 10 μM concentration and an IC₅₀ value of 1.3 μM. The docking study shows that the verified compounds accommodate the binding cleft of CETP and are enclosed by a hydrophobic lining. Furthermore, the scaffold of 8a-j matches the pharmacophoric points of CETP inhibitors, particularly in its hydrophobic and aromatic functionalities.

Atherosclerosis and Cancer; A Resemblance with Far-reaching Implications

Atherosclerosis and cancer are chronic diseases considered two of the main causes of death all over the world. Taking into account that both diseases are multifactorial, they share not only several important molecular pathways but also many ethiological and mechanistical processes from the very early stages of development up to the advanced forms in both pathologies. Factors involved in their progression comprise genetic alterations, inflammatory processes, uncontrolled cell proliferation and oxidative stress, as the most important ones. The fact that external effectors such as an infective process or a chemical insult have been proposed to initiate the transformation of cells in the artery wall and the process of atherogenesis, emphasizes many similarities with the progression of the neoplastic process in cancer. Deregulation of cell proliferation and therefore cell cycle progression, changes in the synthesis of important transcription factors as well as adhesion molecules, an alteration in the control of angiogenesis and the molecular similarities that follow chronic inflammation, are just a few of the processes that become part of the phenomena that closely correlates atherosclerosis and cancer. The aim of the present study is therefore, to provide new evidence as well as to discuss new approaches that might promote the identification of closer molecular ties between these two pathologies that would permit the recognition of atherosclerosis as a pathological process with a very close resemblance to the way a neoplastic process develops, that might eventually lead to novel ways of treatment.

C-X-C motif chemokine ligand 8 promotes endothelial cell homing via the Akt-signal transducer and activator of transcription pathway to accelerate healing of ischemic and hypoxic skin ulcers

C-X-C motif chemokine ligand 8 (CXCL-8) promotes cell homing and angiogenesis. However, under hypoxic conditions, the role of CXCL-8 in the homing of human umbilical vein endothelial cells (HUVECs), and its effect on the healing of skin ulcers caused by ischemia and hypoxia remain unknown. In the current study, assays measuring cell proliferation, in vitro angiogenesis and cell migration were performed to evaluate alterations in the proliferation, angiogenic capacity and chemotaxis of HUVECs treated with CXCL-8 protein and/or an Akt inhibitor (AZD5363 group) under hypoxic conditions. Changes in the levels of Akt, signal transducer and activator of transcription 3 (STAT3), vascular endothelial growth factor (VEGF), malondialdehyde (MDA) and total-superoxide dismutase (total-SOD) were also detected by western blotting and ELISA. In addition, in vivo experiments were performed using a skin ulcer model in mice. Ischemic and hypoxic skin ulcers were created on the thighs of C57BL/6J mice, and the effects of CXCL-8 and HUVEC transplantation on the healing capacity of skin ulcers was determined by injecting mice with HUVECs and/or CXCL-8 recombinant protein (CXCL-8, HUVEC and HUVEC + CXCL-8 groups). Vascular endothelial cell homing, changes in vascular density and the expression of VEGF, SOD, EGF and MDA within the ulcer tissue were subsequently measured. In vitro experiments demonstrated that HUVEC proliferation, migration and tube forming capacity were significantly increased by CXCL-8 under hypoxic conditions. Additionally, levels of VEGF, MDA and SOD were significantly higher in the CXCL-8 group, though were significantly decreased by the Akt and STAT3 inhibitors. In vivo experiments demonstrated that the expression of VEGF, total-SOD and EGF proteins were higher in the skin ulcer tissue of mice treated with CXCL-8 + HUVEC, relative to mice treated with HUVECs alone. Furthermore, vascular endothelial cell homing and vascular density were significantly increased in the CXCL-8 + HUVEC group, indicating that combined use of HUVECs and CXCL-8 may promote the healing of ischemic skin ulcers. The present results demonstrate that CXCL-8 may stimulate vascular endothelial cells to secrete VEGF, SOD and other cytokines via the Akt-STAT3 pathway, which in turn serves a key regulatory role in the recruitment of vascular endothelial cells, reduction of hypoxia-related injury and promotion of tissue repair following hypoxic/ischemic injury.

Engineering nanomaterials to address cell-mediated inflammation in atherosclerosis

Atherosclerosis is an inflammatory disorder with a pathophysiology driven by both innate and adaptive immunity and a primary cause of cardiovascular disease (CVD) worldwide. Vascular inflammation and accumulation of foam cells and their products induce maturation of atheromas, or plaques, which can rupture by metalloprotease action, leading to ischemic stroke or myocardial infarction. Diverse immune cell populations participate in all stages of plaque maturation, many of which directly influence plaque stability and rupture via inflammatory mechanisms. Current clinical treatments for atherosclerosis focus on lowering serum levels of low-density lipoprotein (LDL) using therapeutics such as statins, administration of antithrombotic drugs, and surgical intervention. Strategies that address cell-mediated inflammation are lacking, and consequently have recently become an area of considerable research focus. Nanomaterials have emerged as highly advantageous tools for these studies, as they can be engineered to target specific inflammatory cell populations, deliver therapeutics of wide-ranging solubilities and enhance analytical methods that include imaging and proteomics. Furthermore, the highly phagocytic nature of antigen presenting cells (APCs), a diverse cell population central to the initiation of immune responses and inflammation, make them particularly amenable to targeting and modulation by nanoscale particulates. Nanomaterials have therefore become essential components of vaccine formulations and treatments for inflammation-driven pathologies like autoimmunity, and present novel opportunities for immunotherapeutic treatments of CVD. Here, we review recent progress in the design and use of nanomaterials for therapeutic assessment and treatment of atherosclerosis. We will focus on promising new approaches that utilize nanomaterials for cell-specific imaging, gene therapy and immunomodulation.