CXCL5 limits macrophage foam cell formation in atherosclerosis

Elucidating the role of chemokines in inflammaging associated atherosclerotic cardiovascular diseases

Age-related inflammation or inflammaging is a critical deciding factor of physiological homeostasis during aging. Cardiovascular diseases (CVDs) are exquisitely associated with aging and inflammation and are one of the leading causes of high mortality in the elderly population. Inflammaging comprises dysregulation of crosstalk between the vascular and cardiac tissues that deteriorates the vasculature network leading to development of atherosclerosis and atherosclerotic-associated CVDs in elderly populations. Leukocyte differentiation, migration and recruitment holds a crucial position in both inflammaging and atherosclerotic CVDs through relaying the activity of an intricate network of inflammation-associated protein-protein interactions. Among these interactions, small immunoproteins such as chemokines play a major role in the progression of inflammaging and atherosclerosis. Chemokines are actively involved in lymphocyte migration and severe inflammatory response at the site of injury. They relay their functions via chemokine-G protein-coupled receptors-glycosaminoglycan signaling axis and is a principal part for the detection of age-related atherosclerosis and related CVDs. This review focuses on highlighting the detailed intricacies of the effects of chemokine-receptor interaction and chemokine oligomerization on lymphocyte recruitment and its evident role in clinical manifestations of atherosclerosis and related CVDs. Further, the role of chemokine mediated signaling for formulating next-generation therapeutics against atherosclerosis has also been discussed.

Investigating the Involvement of C-X-C Motif Chemokine 5 and P2X7 Purinoceptor in Ectopic Calcification in Mouse Models of Duchenne Muscular Dystrophy

Ectopic calcification of myofibers is an early pathogenic feature in patients and animal models of Duchenne muscular dystrophy (DMD). In previous studies using the Dmdmdx-βgeo mouse model, we found that the dystrophin-null phenotype exacerbates this abnormality and that mineralised myofibers are surrounded by macrophages. Furthermore, the P2X7 purinoceptor, functioning in immune cells offers protection against dystrophic calcification. In the present study, by exploring transcriptomic data from Dmdmdx mice, we hypothesised these effects to be mediated by C-X-C motif chemokine 5 (CXCL5) downstream of P2X7 activation. We found that CXCL5 is upregulated in the quadriceps muscles of Dmdmdx-βgeo mice compared to wild-type controls. In contrast, at the cell level, dystrophic (SC5) skeletal muscle cells secreted less CXCL5 chemokine than wild-type (IMO) controls. Although release from IMO cells was increased by P2X7 activation, this could not explain the elevated CXCL5 levels observed in dystrophic muscle tissue. Instead, we found that CXCL5 is released by dystrophin-null macrophages in response to P2X7 activation, suggesting that macrophages are the source of CXCL5 in dystrophic muscles. The effects of CXCL5 upon mineralisation were investigated using the Alizarin Red assay to quantify calcium deposition in vitro. In basal (low phosphate) media, CXCL5 increased calcification in IMO but not SC5 myoblasts. However, in cultures treated in high phosphate media, to mimic dysregulated phosphate metabolism occurring in DMD, CXCL5 decreased calcification in both IMO and SC5 cells. These data indicate that CXCL5 is part of a homoeostatic mechanism regulating intracellular calcium, that CXCL5 can be released by macrophages in response to the extracellular ATP damage-associated signal, and that CXCL5 can be part of a damage response to protect against ectopic calcification. This mechanism is affected by DMD gene mutations.

Suppression of autophagy induces senescence in the heart

Aging is a critical risk factor for heart disease, including ischemic heart disease and heart failure. Cellular senescence, characterized by DNA damage, resistance to apoptosis and the senescence-associated secretory phenotype (SASP), occurs in many cell types, including cardiomyocytes. Senescence precipitates the aging process in surrounding cells and the organ through paracrine mechanisms. Generalized autophagy, which degrades cytosolic materials in a non-selective manner, is decreased during aging in the heart. This decrease causes deterioration of cellular quality control mechanisms, facilitates aging and negatively affects lifespan in animals, including mice. Although suppression of generalized autophagy could promote senescence, it remains unclear whether the suppression of autophagy directly stimulates senescence in cardiomyocytes, which, in turn, promotes myocardial dysfunction in the heart. We addressed this question using mouse models with a loss of autophagy function. Suppression of general autophagy in cardiac-specific Atg7 knockout ( Atg7 cKO) mice caused accumulation of senescent cardiomyocytes. Induction of senescence via downregulation of Atg7 was also observed in chimeric Atg7 cardiac-specific KO mice and cultured cardiomyocytes in vitro , suggesting that the effect of autophagy suppression upon induction of senescence is cell autonomous. ABT-263, a senolytic agent, reduced the number of senescent myocytes and improved cardiac function in Atg7 cKO mice. Suppression of autophagy and induction of senescence were also observed in doxorubicin-treated hearts, where activation of autophagy alleviated senescence in cardiomyocytes and cardiac dysfunction. These results suggest that suppression of general autophagy directly induces senescence in cardiomyocytes, which in turn promotes cardiac dysfunction.

Huayu Qutan Recipe promotes lipophagy and cholesterol efflux through the mTORC1/TFEB/ABCA1-SCARB1 signal axis

This study aims to investigate the mechanism of the anti-atherosclerosis effect of Huayu Qutan Recipe (HYQT) on the inhibition of foam cell formation. In vivo, the mice were randomly divided into three groups: CTRL group, MOD group and HYQT group. The HYQT group received HYQT oral administration twice a day (20.54 g/kg/d), and the plaque formation in ApoE-/- mice was observed using haematoxylin-eosin (HE) staining and oil red O (ORO) staining. The co-localization of aortic macrophages and lipid droplets (LDs) was examined using fluorescent labelling of CD11b and BODIPY fluorescence probe. In vitro, RAW 264.7 cells were exposed to 50 μg/mL ox-LDL for 48 h and then treated with HYQT for 24 h. The accumulation of LDs was evaluated using ORO and BODIPY. Cell viability was assessed using the CCK-8 assay. The co-localization of LC3b and BODIPY was detected via immunofluorescence and fluorescence probe. LysoTracker Red and BODIPY 493/503 were used as markers for lysosomes and LDs, respectively. Autophagosome formation were observed via transmission electron microscopy. The levels of LC3A/B II/LC3A/B I, p-mTOR/mTOR, p-4EBP1/4EBP1, p-P70S6K/P70S6K and TFEB protein level were examined via western blotting, while SQSTM1/p62, Beclin1, ABCA1, ABCG1 and SCARB1 were examined via qRT-PCR and western blotting. The nuclear translocation of TFEB was detected using immunofluorescence. The components of HYQT medicated serum were determined using Q-Orbitrap high-resolution MS analysis. Molecular docking was employed to identify the components of HYQT medicated serum responsible for the mTOR signalling pathway. The mechanism of taurine was illustrated. HYQT has a remarkable effect on atherosclerotic plaque formation and blood lipid level in ApoE-/- mice. HYQT decreased the co-localization of CD11b and BODIPY. HYQT (10% medicated serum) reduced the LDs accumulation in RAW 264.7 cells. HYQT and RAPA (rapamycin, a mTOR inhibitor) could promote cholesterol efflux, while chloroquine (CQ, an autophagy inhibitor) weakened the effect of HYQT. Moreover, MHY1485 (a mTOR agonist) also mitigated the effects of HYQT by reduced cholesterol efflux. qRT-PCR and WB results suggested that HYQT improved the expression of the proteins ABCA1, ABCG1 and SCARB1.HYQT regulates ABCA1 and SCARB1 protein depending on the mTORC1/TFEB signalling pathway. However, the activation of ABCG1 does not depend on this pathway. Q-Orbitrap high-resolution MS analysis results demonstrated that seven core compounds have good binding ability to the mTOR protein. Taurine may play an important role in the mechanism regulation. HYQT may reduce cardiovascular risk by promoting cholesterol efflux and degrading macrophage-derived foam cell formation. It has been observed that HYQT and ox-LDL regulate lipophagy through the mTOR/TFEB signalling pathway, rather than the mTOR/4EBP1/P70S6K pathway. Additionally, HYQT is found to regulate cholesterol efflux through the mTORC1/TFEB/ABCA1-SCARB1 signal axis, while taurine plays a significant role in lipophagy.

Treatment of advanced atherosclerotic mice with ABT-263 reduced indices of plaque stability and increased mortality

The use of senolytic agents to remove senescent cells from atherosclerotic lesions is controversial. A common limitation of previous studies is the failure to rigorously define the effects of senolytic agent ABT-263 (Navitoclax) on smooth muscle cells (SMC) despite studies claiming that these cells are the major source of senescent cells. Moreover, there are no studies on the effect of ABT-263 on endothelial cells (EC), which - along with SMC - comprise 90% of α-smooth muscle actin+ (α-SMA+) myofibroblast-like cells in the protective fibrous cap. Here we tested the hypothesis that treatment of advanced atherosclerotic mice with ABT-263 will reduce lesion size and increase plaque stability. SMC (Myh11-CreERT2-eYFP) and EC (Cdh5-CreERT2-eYFP) lineage tracing Apoe-/- mice were fed a western diet (WD) for 18 weeks, followed by ABT-263 at 100 mg/kg/bw for 6 weeks or 50 mg/kg/bw for 9 weeks. ABT-263 treatment did not change lesion size or lumen area of the brachiocephalic artery (BCA). However, ABT-263 treatment reduced SMC by 90% and increased EC contributions to lesions via EC-to-mesenchymal transition (EndoMT) by 60%. ABT-263 treatment also reduced α-SMA+ fibrous cap thickness by 60% and was associated with a > 50% mortality rate. Taken together, ABT-263 treatment of WD-fed Apoe-/- mice with advanced lesions resulted in multiple detrimental changes, including reduced indices of stability and increased mortality.

Cellular Heterogeneity of Activated Primary Human Macrophages and Associated Drug-Gene Networks: From Biology to Precision Therapeutics

BACKGROUND

Interferon-γ (IFNγ) signaling plays a complex role in atherogenesis. IFNγ stimulation of macrophages permits in vitro exploration of proinflammatory mechanisms and the development of novel immune therapies. We hypothesized that the study of macrophage subpopulations could lead to anti-inflammatory interventions.

METHODS

Primary human macrophages activated by IFNγ (M(IFNγ)) underwent analyses by single-cell RNA sequencing, time-course cell-cluster proteomics, metabolite consumption, immunoassays, and functional tests (phagocytic, efferocytotic, and chemotactic). RNA-sequencing data were analyzed in LINCS (Library of Integrated Network-Based Cellular Signatures) to identify compounds targeting M(IFNγ) subpopulations. The effect of compound BI-2536 was tested in human macrophages in vitro and in a murine model of atherosclerosis.

RESULTS

Single-cell RNA sequencing identified 2 major clusters in M(IFNγ): inflammatory (M(IFNγ)i) and phagocytic (M(IFNγ)p). M(IFNγ)i had elevated expression of inflammatory chemokines and higher amino acid consumption compared with M(IFNγ)p. M(IFNγ)p were more phagocytotic and chemotactic with higher Krebs cycle activity and less glycolysis than M(IFNγ)i. Human carotid atherosclerotic plaques contained 2 such macrophage clusters. Bioinformatic LINCS analysis using our RNA-sequencing data identified BI-2536 as a potential compound to decrease the M(IFNγ)i subpopulation. BI-2536 in vitro decreased inflammatory chemokine expression and secretion in M(IFNγ) by shrinking the M(IFNγ)i subpopulation while expanding the M(IFNγ)p subpopulation. BI-2536 in vivo shifted the phenotype of macrophages, modulated inflammation, and decreased atherosclerosis and calcification.

CONCLUSIONS

We characterized 2 clusters of macrophages in atherosclerosis and combined our cellular data with a cell-signature drug library to identify a novel compound that targets a subset of macrophages in atherosclerosis. Our approach is a precision medicine strategy to identify new drugs that target atherosclerosis and other inflammatory diseases.

Pathophysiological impact of CXC and CX3CL1 chemokines in preeclampsia and gestational diabetes mellitus

Diabetes-related pathophysiological alterations and various female reproductive difficulties were common in pregnant women with gestational diabetes mellitus (GDM), who had 21.1 million live births. Preeclampsia (PE), which increases maternal and fetal morbidity and mortality, affects approximately 3%-5% of pregnancies worldwide. Nevertheless, it is unclear what triggers PE and GDM to develop. Therefore, the development of novel moderator therapy approaches is a crucial advancement. Chemokines regulate physiological defenses and maternal-fetal interaction during healthy and disturbed pregnancies. Chemokines regulate immunity, stem cell trafficking, anti-angiogenesis, and cell attraction. CXC chemokines are usually inflammatory and contribute to numerous reproductive disorders. Fractalkine (CX3CL1) may be membrane-bound or soluble. CX3CL1 aids cell survival during homeostasis and inflammation. Evidence reveals that CXC and CX3CL1 chemokines and their receptors have been the focus of therapeutic discoveries for clinical intervention due to their considerable participation in numerous biological processes. This review aims to give an overview of the functions of CXC and CX3CL1 chemokines and their receptors in the pathophysiology of PE and GDM. Finally, we examined stimulus specificity for CXC and CX3CL1 chemokine expression and synthesis in PE and GDM and preclinical and clinical trials of CXC-based PE and GDM therapies.

Mechanistic role of CXCL5 in cardiovascular disease, diabetes mellitus, and kidney disease

Chemokines, by modulating inflammation process, could contribute to the development of cardiovascular disease, diabetes mellitus (DM), and kidney disease. Chemokine CXC motif ligand 5 (CXCL5) is one of the inducible chemokines that may be involved in various inflammatory diseases. Given the bidirectional promiscuity characteristics of the chemokine system, the mechanistic roles of CXCL5 should be further explored in each specific disease. In this article, we sought to review the recent evidence on the differential effects of CXCL5 and their potential mechanisms in cardiovascular disease, DM, and renal disease individually. Future study is still required to verify if CXCL5 could be a novel therapeutic target in these diseases.

Treatment of advanced atherosclerotic mice with the senolytic agent ABT-263 is associated with reduced indices of plaque stability and increased mortality

The use of senolytic agents to remove senescent cells from atherosclerotic lesions is controversial. A common limitation of previous studies is the failure to rigorously define the effects of senolytic agent ABT-263 (Navitoclax) on smooth muscle cells (SMC) despite studies claiming that they are the major source of senescent cells. Moreover, there are no studies of the effect of ABT-263 on endothelial cells (EC), which along with SMC comprise 90% of α-SMA+ myofibroblast-like cells in the protective fibrous cap. Here we tested the hypothesis that treatment of advanced atherosclerotic mice with the ABT-263 will reduce lesion size and increase plaque stability. SMC (Myh11-CreERT2-eYFP) and EC (Cdh5-CreERT2-eYFP) lineage tracing Apoe-/- mice were fed a WD for 18 weeks, followed by ABT-263 100mg/kg/bw for six weeks or 50mg/kg/bw for nine weeks. ABT-263 treatment did not change lesion size or lumen area of the brachiocephalic artery (BCA). However, ABT-263 treatment reduced SMC by 90% and increased EC-contributions to lesions via EC-to-mesenchymal transition (EndoMT) by 60%. ABT-263 treatment also reduced α-SMA+ fibrous cap thickness by 60% and increased mortality by >50%. Contrary to expectations, treatment of WD-fed Apoe-/- mice with the senolytic agent ABT-263 resulted in multiple detrimental changes including reduced indices of stability, and increased mortality.

Melatonin and TGF-β-Mediated Release of Extracellular Vesicles

The immune system, unlike other systems, must be flexible and able to "adapt" to fully cope with lurking dangers. The transition from intracorporeal balance to homeostasis disruption is associated with activation of inflammatory signaling pathways, which causes modulation of the immunology response. Chemotactic cytokines, signaling molecules, and extracellular vesicles act as critical mediators of inflammation and participate in intercellular communication, conditioning the immune system's proper response. Among the well-known cytokines allowing for the development and proper functioning of the immune system by mediating cell survival and cell-death-inducing signaling, the tumor necrosis factor α (TNF-α) and transforming growth factor β (TGF-β) are noteworthy. The high bloodstream concentration of those pleiotropic cytokines can be characterized by anti- and pro-inflammatory activity, considering the powerful anti-inflammatory and anti-oxidative stress capabilities of TGF-β known from the literature. Together with the chemokines, the immune system response is also influenced by biologically active chemicals, such as melatonin. The enhanced cellular communication shows the relationship between the TGF-β signaling pathway and the extracellular vesicles (EVs) secreted under the influence of melatonin. This review outlines the findings on melatonin activity on TGF-β-dependent inflammatory response regulation in cell-to-cell communication leading to secretion of the different EV populations.

Standardized airway wall thickness Pi10 from routine CT scans of COPD patients as imaging biomarker for disease severity, lung function decline, and mortality

BACKGROUND

Chest computed tomography (CT) is increasingly used for phenotyping and monitoring of patients with COPD. The aim of this work was to evaluate the association of Pi10 as a measure of standardized airway wall thickness on CT with exacerbations, mortality, and response to triple therapy.

METHODS

Patients of GOLD grades 1-4 of the COSYCONET cohort with prospective CT scans were included. Pi10 was automatically computed and analyzed for its relationship to COPD severity, comorbidities, lung function, respiratory therapy, and mortality over a 6-year period, using univariate and multivariate comparisons.

RESULTS

We included n = 433 patients (61%male). Pi10 was dependent on both GOLD grades 1-4 (p = 0.009) and GOLD groups A-D (p = 0.008); it was particularly elevated in group D, and ROC analysis yielded a cut-off of 0.26 cm. Higher Pi10 was associated to lower FEV₁ % predicted and higher RV/TLC, moreover the annual changes of lung function parameters (p < 0.05), as well as to an airway-dominated phenotype and a history of myocardial infarction (p = 0.001). These associations were confirmed in multivariate analyses. Pi10 was lower in patients receiving triple therapy, in particular in patients of GOLD groups C and D. Pi10 was also a significant predictor for mortality (p = 0.006), even after including multiple other predictors.

CONCLUSION

In summary, Pi10 was found to be predictive for the course of the disease in COPD, in particular mortality. The fact that Pi10 was lower in patients with severe COPD receiving triple therapy might hint toward additional effects of this functional therapy on airway remodeling.

REGISTRATION

ClinicalTrials.gov, Identifier: NCT01245933.

Single-Cell RNA Sequencing Reveals the Pathogenic Relevance of Intracranial Atherosclerosis in Blood Blister-Like Aneurysms

Background

Intracranial non-branching site blood blister-like aneurysms (BBA) are extremely rare and vicious. Their etiology remains elusive, and no molecular study has been carried out to reveal its pathogenic relevance to intracranial atherosclerosis. To investigate its transcriptomic landscape and underlying potential pathogenesis, we performed single-cell RNA sequencing with extensive pathological validation.

Methods

In total, 12,245 cells were recovered for single-cell RNA sequencing analysis from 1 BBA and 2 saccular intracranial aneurysms (IAs). Unbiased clustering using Seurat-based pipeline was used for cellular landscape profiling. Cellchat was used to understand intracellular communications. Furthermore, 10 BBAs and 30 IAs were retrospectively collected for pathological validations like scanning electron microscopy, H&amp;E stain, Masson stain, Verhoeff Van Gielson stain, and immunofluorescence.

Results

Single-cell transcriptome profiled 14 total subclusters in 6 major groups, namely, 6 monocyte/macrophage clusters, 2 T&amp;NK clusters, 3 vascular smooth muscle cell (VSMC) clusters, 1 dendritic cell, 1 B cell, and 1 endothelial cell cluster. The only mural cell identified in BBAs was VSMC-2 cluster, while mural cells in IAs comprise most clusters of VSMCs and endothelial cells. Upregulated genes in BBA-derived VSMCs are related to arterial mineralization and atherosclerosis, such as PTX3, SPP1, LOX, etc., whereas vasodilation and physiological regulatory genes such as MGP, ACTA2, and MYL9 were conversely enriched in conventional IA-derived VSMCs. Immune cells in the BBA were predominantly macrophages, with a low fraction of T&amp;NK cells, while conventional IAs had a higher percentage of T&amp;NK. Gene enrichment analysis suggested that macrophages in BBA were highly enriched in lipid metabolism as well as atherosclerosis. Ligand–receptor interaction suggested that secretory phosphoprotein 1 (also known as osteopontin) played a major role in mediating the intracellular communication between VSMC and macrophages, especially in BBA. Pathological experiments corroborate with the bioinformatic findings and further characterized BBAs as a thin-walled thrombotic aneurysm with severe atherosclerotic lesions, where ApoE+ macrophages and OPN+ mural cells are intimately involved in the inflammation process.

Conclusions

The preexisting intracranial atherosclerosis might predispose the parent artery to the pathogenic occurrence of BBAs. These data shed light on the pathophysiology of intracranial aneurysms and might assist in the further resolution of the complexity in aneurysm pathogenesis.

A Holistic View of the Goto-Kakizaki Rat Immune System: Decreased Circulating Immune Markers in Non- Obese Type 2 Diabetes

Type-2 diabetes is a complex disorder that is now considered to have an immune component, with functional impairments in many immune cell types. Type-2 diabetes is often accompanied by comorbid obesity, which is associated with low grade inflammation. However,the immune status in Type-2 diabetes independent of obesity remains unclear. Goto-Kakizaki rats are a non-obese Type-2 diabetes model. The limited evidence available suggests that Goto-Kakizaki rats have a pro-inflammatory immune profile in pancreatic islets. Here we present a detailed overview of the adult Goto-Kakizaki rat immune system. Three converging lines of evidence: fewer pro-inflammatory cells, lower levels of circulating pro-inflammatory cytokines, and a clear downregulation of pro-inflammatory signalling in liver, muscle and adipose tissues indicate a limited pro-inflammatory baseline immune profile outside the pancreas. As Type-2 diabetes is frequently associated with obesity and adipocyte-released inflammatory mediators, the pro-inflammatory milieu seems not due to Type-2 diabetes per se; although this overall reduction of immune markers suggests marked immune dysfunction in Goto-Kakizaki rats.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.

The Role of CXC Chemokines in Cardiovascular Diseases

Cardiovascular disease (CVD) is a class of diseases with high disability and mortality rates. In the elderly population, the incidence of cardiovascular disease is increasing annually. Between 1990 and 2016, the age-standardised prevalence of CVD in China significantly increased by 14.7%, and the number of cardiovascular disease deaths increased from 2.51 million to 3.97 million. Much research has indicated that cardiovascular disease is closely related to inflammation, immunity, injury and repair. Chemokines, which induce directed chemotaxis of reactive cells, are divided into four subfamilies: CXC, CC, CX3C, and XC. As cytokines, CXC chemokines are similarly involved in inflammation, immunity, injury, and repair and play a role in many cardiovascular diseases, such as atherosclerosis, myocardial infarction, cardiac ischaemia-reperfusion injury, hypertension, aortic aneurysm, cardiac fibrosis, postcardiac rejection, and atrial fibrillation. Here, we explored the relationship between the chemokine CXC subset and cardiovascular disease and its mechanism of action with the goal of further understanding the onset of cardiovascular disease.

MK2206 attenuates atherosclerosis by inhibiting lipid accumulation, cell migration, proliferation, and inflammation

Cardiovascular disease is a common comorbidity in patients with cancer, and the main leading cause of noncancer-related deaths in cancer survivors. Considering that current antitumor drugs usually induce cardiovascular injury, the quest for developing new antitumor drugs, especially those with cardiovascular protection, is crucial for improving cancer prognosis. MK2206 is a phase II clinical anticancer drug and the role of this drug in cardiovascular disease is still unclear. Here, we revealed that MK2206 significantly reduced vascular inflammation, atherosclerotic lesions, and inhibited proliferation of vascular smooth muscle cell in ApoE^-/- mice in vivo. We demonstrated that MK2206 reduced lipid accumulation by promoting cholesterol efflux but did not affect lipid uptake and decreased inflammatory response by modulating inflammation-related mRNA stability in macrophages. In addition, we revealed that MK2206 suppressed migration, proliferation, and inflammation in vascular smooth muscle cells. Moreover, MK2206 inhibited proliferation and inflammation of endothelial cells. The present results suggest that MK2206, as a promising drug in clinical antitumor therapy, exhibits anti-inflammatory and antiatherosclerotic potential. This report provides a novel strategy for the prevention of cardiovascular comorbidities in cancer survivors.

Identification of Mep1a as a susceptibility gene for atherosclerosis in mice

Atherosclerosis is the underlying cause of heart attack, ischemic stroke and peripheral arterial disease, and genetic factors involved remain mostly unidentified. We previously identified a significant locus on mouse chromosome 17 for atherosclerosis, Ath49, in an intercross between BALB/c and SM strains. Ath49 partially overlaps in the confidence interval with Ath22 mapped in an AKR × DBA/2 intercross. Bioinformatics analysis prioritized Mep1a, encoding meprin 1α metalloendopeptidase, as a likely candidate gene for Ath49. To prove causality, Mep1a-/-Apoe-/- mice were generated and compared with Mep1a+/+Apoe-/- mice for atherosclerosis development. Mep1a was found abundantly expressed in atherosclerotic lesions but not in healthy aorta and liver of mice. Mep1a-/- Apoe-/- mice exhibited significant reductions in both early and advanced lesion sizes. Loss of Mep1a led to decreased necrosis but increased macrophage and neutrophil contents in advanced lesions, reduced plasma levels of CXCL5 and an oxidative stress biomarker. In addition, Mep1a-/- mice had significantly reduced triglyceride levels on a chow diet. Thus, Mep1a is a susceptibility gene for atherosclerosis and aggravates atherosclerosis partially through action on oxidative stress and inflammation.

CXCL5 secreted from macrophages during cold exposure mediates white adipose tissue browning

Adipose tissue affects metabolic-related diseases because it consists of various cell types involved in fat metabolism and adipokine release. CXC ligand 5 (CXCL5) is a member of the CXC chemokine family and is highly expressed by macrophages in white adipose tissue (WAT). In this study, we generated and investigated the function of CXCL5 in knockout (KO) mice using CRISPR/Cas9. The male KO mice did not show significant phenotype differences in normal conditions. However, proteomic analysis revealed that many proteins involved in fatty acid beta-oxidation and mitochondrial localization were enriched in the inguinal WAT (iWAT) of Cxcl5 KO mice. Cxcl5 KO mice also showed decreased protein and transcript expression of genes associated with thermogenesis, including uncoupling protein 1 (UCP1), a well-known thermogenic gene, and increased expression of genes associated with inflammation. The increase in UCP1 expression in cold conditions was significantly retarded in Cxcl5 KO mice. Finally, we found that CXCL5 treatment increased the expression of transcription factors that mediate Ucp1 expression and Ucp1 itself. Collectively, our data show that Ucp1 expression is induced in adipocytes by CXCL5, which is secreted upon β-adrenergic stimulation by cold stimulation in M1 macrophages. Our data indicate that CXCL5 plays a crucial role in regulating energy metabolism, particularly upon cold exposure. These results strongly suggest that targeting CXCL5 could be a potential therapeutic strategy for people suffering from disorders affecting energy metabolism.

Single-cell transcriptome analysis reveals cellular heterogeneity in the ascending aortas of normal and high-fat diet-fed mice

The aorta contains numerous cell types that contribute to vascular inflammation and thus the progression of aortic diseases. However, the heterogeneity and cellular composition of the ascending aorta in the setting of a high-fat diet (HFD) have not been fully assessed. We performed single-cell RNA sequencing on ascending aortas from mice fed a normal diet and mice fed a HFD. Unsupervised cluster analysis of the transcriptional profiles from 24,001 aortic cells identified 27 clusters representing 10 cell types: endothelial cells (ECs), fibroblasts, vascular smooth muscle cells (SMCs), immune cells (B cells, T cells, macrophages, and dendritic cells), mesothelial cells, pericytes, and neural cells. After HFD intake, subpopulations of endothelial cells with lipid transport and angiogenesis capacity and extensive expression of contractile genes were defined. In the HFD group, three major SMC subpopulations showed increased expression of extracellular matrix-degradation genes, and a synthetic SMC subcluster was proportionally increased. This increase was accompanied by upregulation of proinflammatory genes. Under HFD conditions, aortic-resident macrophage numbers were increased, and blood-derived macrophages showed the strongest expression of proinflammatory cytokines. Our study elucidates the nature and range of the cellular composition of the ascending aorta and increases understanding of the development and progression of aortic inflammatory disease.

Does kisspeptin act as a neuropeptide or as an adipokine in obese people?

Objectives

Obesity is a serious global issue with a massive impact on the health and life of people worldwide. Besides being a neuropeptide, kisspeptin is an important adipokine involved in regulating energy homeostasis and body weight. This study aims to clarify the underlying role of kisspeptin in obesity.

Methods

This case-control study included 110 obese individuals with BMI of 33.45 ± 0.36 kg/m² and 84 normal-weight individuals with BMI 21.35 ± 0.24 kg/m². The individuals' ages ranged from 21 to 45 years (31.56 ± 0.67 year). Kisspeptin, neutrophil epithelial activating peptide (ENA-78), and ghrelin were determined using the enzyme-linked immunosorbent assay (ELISA) technique. Lipid profile parameters were determined using the commercial colorimetric techniques.

Results

Plasma concentrations of kisspeptin and ENA-78 were significantly higher in obese subjects (kisspeptine of obese: 437.66 ± 34.96 pg/ml; kisspeptine of normal-weight: 250.10 ± 16.16 pg/ml, p< 0.0001; ENA-78 of obese: 144.80 ± 23.94 pg/ml; ENA-78 of normal-weight: 50.97 ± 3.91 pg/ml, p< 0.001). Ghrelin concentrations showed no significant difference between obese and normal-weight subjects. The lipid profile parameters significantly differed between obese and normal-weight subjects.

Conclusion

Kisspeptin is associated with obesity. An increased mass of adipose tissue could be responsible not only for increased kisspeptin secretion but also for the increased ENA-78 secretion. Kisspeptin may act as an adipokine more than a neuropeptide in obese population. Further studies on humans are required to establish the underlying role of kisspeptin in adipocyte differentiation and lipogenesis.

The 3-Year Effect of the Mediterranean Diet Intervention on Inflammatory Biomarkers Related to Cardiovascular Disease

The intervention with the Mediterranean diet (MD) pattern has evidenced short-term anti-inflammatory effects, but little is known about its long-term anti-inflammatory properties at molecular level. This study aims to investigate the 3-year effect of MD interventions compared to low-fat diet (LFD) on changes on inflammatory biomarkers related to atherosclerosis in a free-living population with a high-risk of cardiovascular disease (CD). Participants (n = 285) in the PREDIMED trial were randomly assigned into three intervention groups: MD with extra-virgin olive oil (EVOO) or MD-Nuts, and a LFD. Fourteen plasma inflammatory biomarkers were determined by Luminex assays. An additional pilot study of gene expression (GE) was determined by RT-PCR in 35 participants. After 3 years, both MDs showed a significant reduction in the plasma levels of IL-1β, IL-6, IL-8, TNF-α, IFN-γ, hs-CRP, MCP-1, MIP-1β, RANTES, and ENA78 (p < 0.05; all). The decreased levels of IL-1β, IL-6, IL-8, and TNF-α after MD significantly differed from those in the LFD (p < 0.05). No significant changes were observed at the gene level after MD interventions, however, the GE of CXCR2 and CXCR3 tended to increase in the control LFD group (p = 0.09). This study supports the implementation of MD as a healthy long-term dietary pattern in the prevention of CD in populations at high cardiovascular risk.

Targeting the chemokine network in atherosclerosis

Chemokines and their receptors represent a potential target for immunotherapy in chronic inflammation. They comprise a large family of cytokines with chemotactic activity, and their cognate receptors are expressed on all cells of the body. This network dictates leukocyte recruitment and activation, angiogenesis, cell proliferation and maturation. Dysregulation of chemokine and chemokine receptor expression as well as function participates in many pathologies including cancer, autoimmune diseases and chronic inflammation. In atherosclerosis, a lipid-driven chronic inflammation of middle-sized and large arteries, chemokines and their receptors participates in almost all stages of the disease from initiation of fatty streaks to mature atherosclerotic plaque formation. Atherosclerosis and its complications are the main driver of mortality and morbidity in cardiovascular diseases (CVD). Hence, exploring new fields of therapeutic targeting of atherosclerosis is of key importance. This review gives an overview of the recent advances on the role of key chemokines and chemokine receptors in atherosclerosis, addresses chemokine-based biomarkers at biochemical, imaging and genetic level in human studies, and highlights the clinial trials targeting atherosclerosis.

MiR-520b inhibits endothelial activation by targeting NF-κB p65-VCAM1 axis

MiR-520b belongs to the miR-373/520 family, is expressed only in human and nonhuman primates. Previous reports indicated that the expression of miR-520b was repressed in human atherosclerotic plaque tissue compared with healthy vessels. However, the role of miR-520b in coronary artery disease still remains to be uncovered. In this study, we demonstrated that endothelial cells (ECs) in human atherosclerotic plaques expressed miR-520b and aimed to elucidate the impact of miR-520b on EC activation and inflammatory response. To determine the potential targets of miR-520b, we performed RNA-seq analysis by transfecting miR-520b mimics in ECs. The quantitative real-time PCR (qPCR) validation suggested that miR-520b over-expression reduced pro-inflammatory gene expression (e.g. ICAM1, VCAM1, SELE) while the inhibition of miR-520b induced their expression. By combining bioinformatics prediction and functional assays, we identified that RELA (Nuclear Factor-κB (NF-κB) Transcription Factor P65) was a direct target of miR-520b. Moreover, miR-520b mimics attenuated monocyte adhesion and monocyte trans-endothelial migration (the initial steps of atherosclerotic formation) in response to lipopolysaccharides (LPS) stimulation. Re-expression of a non-miR-targetable version of p65 could rescue the reduced monocyte cell attachment, suggesting that this process is NF-κB p65 dependent. MiR-520b reduced the abundance of NF-κB p65 in cytoplasmic fractions without corresponding increase in nuclear fractions, indicating that this regulation is independent of p65 translocation process. MiR-520b mimics attenuated the activity of VCAM-1 promoter, whereas miR-520b inhibitor activated its activity. However, miR-520b inhibitor had no effect on promoter activity containing the mutated NF-κB p65 binding sites, strongly demonstrating that the impact of miR-520b on VCAM1 gene is mediated by NF-κB p65. Thus, we concluded that miR-520b suppressed EC inflammation and the cross-talk between monocytes and ECs by down-regulating NF-κB p65-ICAM1/VCAM1 axis and might serve as a potential therapeutic target for EC dysfunction and atherosclerosis.

CXCL5/CXCR2 axis in tumor microenvironment as potential diagnostic biomarker and therapeutic target

The components of the tumor microenvironment (TME) in solid tumors, especially chemokines, are currently attracting much attention from scientists. C-X-C motif chemokine ligand 5 (CXCL5) is one of the important chemokines in TME. Overexpression of CXCL5 is closely related to the survival time, recurrence and metastasis of cancer patients. In TME, CXCL5 binds to its receptors, such as C-X-C motif chemokine receptor 2 (CXCR2), to participate in the recruitment of immune cells and promote angiogenesis, tumor growth, and metastasis. The CXCL5/CXCR2 axis can act as a bridge between tumor cells and host cells in TME. Blocking the transmission of CXCL5/CXCR2 signals can increase the sensitivity and effectiveness of immunotherapy and slow down tumor progression. CXCL5 and CXCR2 are also regarded as biomarkers for predicting prognosis and molecular targets for customizing the treatment. In this review, we summarized the current literature regarding the biological functions and clinical significance of CXCL5/CXCR2 axis in TME. The possibility to use CXCL5 and CXCR2 as potential prognostic biomarkers and therapeutic targets in cancer is also discussed.

Mathematical model of atherosclerotic aneurysm

Atherosclerosis is a major cause of abdominal aortic aneurysm (AAA) and up to 80% of AAA patients have atherosclerosis. Therefore it is critical to understand the relationship and interactions between atherosclerosis and AAA to treat atherosclerotic aneurysm patients more effectively. In this paper, we develop a mathematical model to mimic the progression of atherosclerotic aneurysms by including both the multi-layer structured arterial wall and the pathophysiology of atherosclerotic aneurysms. The model is given by a system of partial differential equations with free boundaries. Our results reveal a 2D biomarker, the cholesterol ratio and DDR1 level, assessing the risk of atherosclerotic aneurysms. The efficacy of different treatment plans is also explored via our model and suggests that the dosage of anti-cholesterol drugs is significant to slow down the progression of atherosclerotic aneurysms while the additional anti-DDR1 injection can further reduce the risk.

Role of inflammatory chemokines in hypertension

Hypertension is associated with immune cells activation and their migration into the kidney, vasculature, heart and brain. These inflammatory mechanisms are critical for blood pressure regulation and mediate target organ damage, creating unique novel targets for pharmacological modulation. In response to angiotensin II and other pro-hypertensive stimuli, the expression of several inflammatory chemokines and their receptors is increased in the target organs, mediating homing of immune cells. In this review, we summarize the contribution of key inflammatory chemokines and their receptors to increased accumulation of immune cells in target organs and effects on vascular dysfunction, remodeling, oxidative stress and fibrosis, all of which contribute to blood pressure elevation. In particular, the role of CCL2, CCL5, CXCL8, CXCL9, CXCL10, CXCL11, CXCL16, CXCL1, CX3CL1, XCL1 and their receptors in the context of hypertension is discussed. Recent studies have tested the efficacy of pharmacological or genetic targeting of chemokines and their receptors on the development of hypertension. Promising results indicate that some of these pathways may serve as future therapeutic targets to improve blood pressure control and prevent target organ consequences including kidney failure, heart failure, atherosclerosis or cognitive impairment.

The emerging role of exosomes in the pathogenesis, prognosis and treatment of necrotizing enterocolitis

Exosomes are a subtype of extracellular vesicles. They contain bioactive molecules, including nucleic acids, proteins and lipids. Among the currently described exosomes, a majority are potential candidates for the diagnosis and treatment of necrotizing enterocolitis (NEC). In this work, we reviewed existing literature reports on exosomes and explored their roles in NEC. Exosomes derived from intestinal epithelial cells (IECs) participates in the development of intestinal diseases, thus can potentially be utilized as biomarkers for NEC. Besides, exosomes of human milk have been demonstrated to protect IECs from oxidative stress, stimulate intestinal stem cells activity, improve the proliferation and migration of IECs, and lower the incidence and severity of experimental NEC. Further, exosomes produced by stem cells can reduce the severity of experimental NEC and protect the intestinal barrier function during NEC. Conclusively, exosomes have been shown to influence the pathogenesis of NEC and exert a protective effect on NEC. However, additional investigations would be urgently necessary to comprehensively elucidate the underlying mechanisms of exosomes in NEC.

Resolving the Ionotropic P2X4 Receptor Mystery Points Towards a New Therapeutic Target for Cardiovascular Diseases

Adenosine triphosphate (ATP) is a primordial versatile autacoid that changes its role from an intracellular energy saver to a signaling molecule once released to the extracellular milieu. Extracellular ATP and its adenosine metabolite are the main activators of the P2 and P1 purinoceptor families, respectively. Mounting evidence suggests that the ionotropic P2X4 receptor (P2X4R) plays pivotal roles in the regulation of the cardiovascular system, yet further therapeutic advances have been hampered by the lack of selective P2X4R agonists. In this review, we provide the state of the art of the P2X4R activity in the cardiovascular system. We also discuss the role of P2X4R activation in kidney and lungs vis a vis their interplay to control cardiovascular functions and dysfunctions, including putative adverse effects emerging from P2X4R activation. Gathering this information may prompt further development of selective P2X4R agonists and its translation to the clinical practice.

Analysis of Low Molecular Weight Substances and Related Processes Influencing Cellular Cholesterol Efflux

Cholesterol efflux is the key process protecting the vascular system from the development of atherosclerotic lesions. Various extracellular and intracellular events affect the ability of the cell to efflux excess cholesterol. To explore the possible pathways and processes that promote or inhibit cholesterol efflux, we applied a combined cheminformatic and bioinformatic approach. We performed a comprehensive analysis of published data on the various substances influencing cholesterol efflux and found 153 low molecular weight substances that are included in the Chemical Entities of Biological Interest (ChEBI) database. Pathway enrichment was performed for substances identified within the Reactome database, and 45 substances were selected in 93 significant pathways. The most common pathways included the energy-dependent processes related to active cholesterol transport from the cell, lipoprotein metabolism and lipid transport, and signaling pathways. The activators and inhibitors of cholesterol efflux were non-uniformly distributed among the different pathways: the substances influencing ‘biological oxidations’ activate cholesterol efflux and the substances influencing ‘Signaling by GPCR and PTK6’ inhibit efflux. This analysis may be used in the search and design of efflux effectors for therapies targeting structural and functional high-density lipoprotein deficiency.

Immune-Inflammation in Atherosclerosis: A New Twist in an Old Tale

Background and Objective:

Atherosclerosis, a chronic and progressive inflammatory disease, is triggered by the activation of endothelial cells followed by infiltration of innate and adaptive immune cells including monocytes and T cells in arterial walls. Major populations of T cells found in human atherosclerotic lesions are antigen-specific activated CD4+ effectors and/or memory T cells from Th1, Th17, Th2 and Treg subsets. In this review, we will discuss the significance of T cell orchestrated immune inflammation in the development and progression of atherosclerosis.

Discussion:

Pathogen/oxidative stress/lipid induced primary endothelial wound cannot develop to a full-blown atherosclerotic lesion in the absence of chronically induced inflammation. While the primary inflammatory response might be viewed as a lone innate response, the persistence of such a profound response over time must be (and is) associated with diverse local and systemic T cell responses. The interplay between T cells and innate cells contributes to a phenomenon called immuneinflammation and has an impact on the progression and outcome of the lesion. In recent years immuneinflammation, an old term, has had a comeback in connecting the puzzle pieces of chronic inflammatory diseases.

Conclusion:

Taking one-step back and looking from afar at the players of immune-inflammation may help us provide a broader perspective of these complicated interactions. This may lead to the identification of new drug targets and the development of new therapies as well as preventative measures.

Cardiotrophin-1 Deficiency Abrogates Atherosclerosis Progression

Cardiotrophin-1 (CT-1) is associated with cardiovascular (CV) diseases. We investigated the effect of CT-1 deficiency in the development and progression of atherosclerosis in double knockout Apoe^-/-ct-1^-/- mice. Apoe^-/- C57Bl/6 or Apoe^-/-ct-1^-/- C57Bl/6 mice were fed a normal chow diet (NCD) or a high-cholesterol diet (HCD). After sacrifice, serum triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), free fatty acids and systemic paracrine factors were measured. Intraplaque lipid and collagen content were quantified in the aortic sections. Immune cell populations in spleen, lymph nodes and aorta were analysis by flow cytometry. Apoe^-/-ct-1^-/- mice in accelerated atherosclerosis exhibited a reduction of total cholesterol, LDL-C, atherosclerotic plaques size in the aortic root and in the abdominal aorta and improved plaque stability in comparison to Apoe^-/- mice. CT-1 deficiency in Apoe^-/- mice on (HCD) promoted atheroprotective immune cell responses, as demonstrated by a rise in plasma anti-inflammatory immune cell populations (regulatory T cells, Tregs; regulatory B cells, Bregs and B1a cells) and atheroprotective IgM antibodies. CT-1 deficiency in advanced atherosclerosis mediated regulation of paracrine factors, such as interleukin (IL)-3, IL-6, IL-9, IL-15, IL-27, CXCL5, MCP-3, MIP-1α and MIP-1β. In a model of advanced atherosclerosis, CT-1 deficiency induced anti-inflammatory and atheroprotective effects which resulted in abrogation of atheroprogression.

The P2RY12 receptor promotes VSMC-derived foam cell formation by inhibiting autophagy in advanced atherosclerosis

Vascular smooth muscle cells (VSMCs) are an important source of foam cells in atherosclerosis. The mechanism for VSMC-derived foam cell formation is, however, poorly understood. Here, we demonstrate that the P2RY12/P2Y12 receptor is important in regulating macroautophagy/autophagy and VSMC-derived foam cell formation in advanced atherosclerosis. Inhibition of the P2RY12 receptor ameliorated lipid accumulation and VSMC-derived foam cell formation in high-fat diet-fed apoe^-/- mice (atherosclerosis model) independent of LDL-c levels. Activation of the P2RY12 receptor blocked cholesterol efflux via PI3K-AKT, while genetic knockdown or pharmacological inhibition of the P2RY12 receptor inhibited this effect in VSMCs. Phosphoproteomic analysis showed that the P2RY12 receptor regulated the autophagy pathway in VSMCs. Additionally, activation of the P2RY12 receptor inhibited MAP1LC3/LC3 maturation, SQSTM1 degradation, and autophagosome formation in VSMCs. Genetic knockdown of the essential autophagy gene Atg5 significantly attenuated P2RY12 receptor inhibitor-induced cholesterol efflux in VSMCs. Furthermore, activation of the P2RY12 receptor led to the activation of MTOR through PI3K-AKT in VSMCs, whereas blocking MTOR activity (rapamycin) or reducing MTOR expression reversed the inhibition of cholesterol efflux mediated by the P2RY12 receptor in VSMCs. In vivo, inhibition of the P2RY12 receptor promoted autophagy of VSMCs through PI3K-AKT-MTOR in advanced atherosclerosis in apoe^-/- mice, which could be impeded by an autophagy inhibitor (chloroquine). Therefore, we conclude that activation of the P2RY12 receptor decreases cholesterol efflux and promotes VSMC-derived foam cell formation by blocking autophagy in advanced atherosclerosis. Our study thus suggests that the P2RY12 receptor is a therapeutic target for treating atherosclerosis.Abbreviations: 2-MeSAMP: 2-methylthioadenosine 5'-monophosphate; 8-CPT-cAMP: 8-(4-chlorophenylthio)-adenosine-3',5'-cyclic-monophosphate; ABCA1: ATP binding cassette subfamily A member 1; ABCG1: ATP binding cassette subfamily G member 1; ACTB: actin beta; ADPβs: adenosine 5'-(alpha, beta-methylene) diphosphate; ALs: autolysosomes; AMPK: AMP-activated protein kinase; APOA1: apolipoprotein A1; APs: autophagosomes; ATG5: autophagy related 5; ATV: atorvastatin; AVs: autophagic vacuoles; CD: chow diet; CDL: clopidogrel; CQ: chloroquine; DAPI: 4',6-diamidino-2-phenylindole; dbcAMP: dibutyryl-cAMP; DIL-oxLDL: dioctadecyl-3,3,3,3-tetramethylin docarbocyanine-oxLDL; EIF4EBP1/4E-BP1: eukaryotic translation initiation factor 4E binding protein 1; EVG: elastic van gieson; HE: hematoxylin-eosin; HDL: high-density lipoprotein; HFD: high-fat diet; KEGG: Kyoto Encyclopedia of Genes and Genomes; LDL-c: low-density lipoprotein cholesterol; LDs: lipid droplets; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; Masson: masson trichrome; MCPT: maximal carotid plaque thickness; MK2206: MK-2206 2HCL; NBD-cholesterol: 22-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl] amino)-23,24-bisnor-5-cholen-3β-ol; OLR1/LOX-1: oxidized low density lipoprotein receptor 1; ORO: oil Red O; ox-LDL: oxidized low-density lipoprotein; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; TIC: ticagrelor; ULK1: unc-51 like autophagy activating kinase 1; VSMCs: vascular smooth muscle cells.

CXCL5 overexpression predicts a poor prognosis in pancreatic ductal adenocarcinoma and is correlated with immune cell infiltration

Background: C-X-C motif chemokine 5 (CXCL5) is an important attractant for immune cell accumulation in tumor tissues. Recent evidence has shown that CXCL5 could promote carcinogenesis and cancer progression in a variety of cancer types. However, the relationships between CXCL5, immune cell infiltration and pancreatic ductal adenocarcinoma (PDAC) remain largely unknown. This study aimed to explore the role and regulative mechanism of CXCL5 in PDAC carcinogenesis.

Materials and Methods: The expression of CXCL5 in PDAC was analyzed based on online databases and tissue microarray staining, and Western blotting of CXCL5 in PDAC cell lines and patient samples. The correlation between CXCL5 expression and clinicopathological features, prognosis and immune cell infiltration in tumor tissues was analyzed.

Results: High expression of CXCL5 was observed both in PDAC tumor tissue and PDAC cell lines, compared to normal pancreas tissues and normal ductal epithelium cells. High CXCL5 expression in tumor tissues was positively correlated with an advanced T stage (p=0.036), a positive tumor lymph node metastasis (p=0.014), a poor differentiation status (p=0.003) and a poor prognosis (p=0.001). Combination of CA242 and CXCL5 expression (p<0.0001) served as a better prognostic factor than CA242 alone (p=0.006). In addition, PDAC patients with high CXCL5 expression had more intratumoral M2 polarized macrophages (p=0.0248), neutrophils (p=0.0068) and IgG⁺ plasma cells (p=0.0133) than patients with low CXCL5 expression.

Conclusions: The expression of CXCL5 is elevated in pancreatic cancer cells. High CXCL5 expression is positively correlated with poor survival and the increased infiltration of several types of immune suppressive cells. Thus, CXCL5 could be a promising therapeutic target for PDAC immunotherapy.

Sphingosine kinase-2 prevents macrophage cholesterol accumulation and atherosclerosis by stimulating autophagic lipid degradation

Atherosclerosis is the major cause of ischemic coronary heart diseases and characterized by the infiltration of cholesterol-accumulating macrophages in the vascular wall. Although sphingolipids are implicated in atherosclerosis as both membrane components and lipid mediators, the precise role of sphingolipids in atherosclerosis remains elusive. Here, we found that genetic deficiency of sphingosine kinase-2 (SphK2) but not SphK1 aggravates the formation of atherosclerotic lesions in mice with ApoE deficiency. Bone marrow chimaera experiments show the involvement of SphK2 expressed in bone marrow-derived cells. In macrophages, deficiency of SphK2, a major SphK isoform in this cell type, results in increases in cellular sphingosine and ceramides. SphK2-deficient macrophages have increases in lipid droplet-containing autophagosomes and autolysosomes and defective lysosomal degradation of lipid droplets via autophagy with an impaired luminal acidic environment and proteolytic activity in the lysosomes. Transgenic overexpression of SphK1 in SphK2-deficient mice rescued aggravation of atherosclerosis and abnormalities of autophagosomes and lysosomes in macrophages with reductions of sphingosine, suggesting at least partial overlapping actions of two SphKs. Taken together, these results indicate that SphK2 is required for autophagosome- and lysosome-mediated catabolism of intracellular lipid droplets to impede the development of atherosclerosis; therefore, SphK2 may be a novel target for treating atherosclerosis.

Both gut microbiota and cytokines act to atherosclerosis in ApoE-/- mice

BACKGROUND

Several studies have suggested a role for the gut microbiome and cytokines in atherosclerosis development, but combined analyses of the changes of the gut microbiota and cytokines have not been explored previously.

METHODS

We treated ApoE-/- and wild-type mice with a high-fat diet for 12 weeks. The gut microbiome and cytokine composition were analyzed using 16S ribosomal DNA sequencing and RayBio Quantibody Arrays, respectively. GO and KEGG analysis were performed to rationalize the potential mechanisms involved in the process of atherosclerosis.

RESULTS

Gut bacterial characteristics in ApoE-/- mice were clearly separated and 21 gut bacterial clades were detected by the LEfSe analysis showing significant differences during the development of atherosclerosis. The relative abundance of Verrucomicrobia, Bacteroidaceae, Bacteroides, and Akkermansia showed significant positive correlations with serum total cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Additionally, the relative abundance of Ruminococcaceae was positive with the level of HDL and the abundance of Rikenellaceae showed a negative relationship with the level of TG and LDL. Thirteen differentially expressed proteins were identified with P-value < 0.05. CXCL5, FGF2, and E-Selectin were significantly negatively associated with Akkermansia and Verrucomicrobia. Additionally, CXCL5 was significantly negatively correlated with Bacteroides and Bacteroidaceae. Three "cellular component" subcategories, 24 ″molecular function" subcategories, 752 ″biological process" subcategories and 29 statistically remarkable KEGG pathway categories were identified.

CONCLUSIONS

Gut microbiota changes of the mice having atherosclerosis and their relationship with the inflammatory status could be one of the major etiological mechanisms underlying atherosclerosis.

Immunobiology of Atherosclerosis: A Complex Net of Interactions

Cardiovascular disease is the leading cause of mortality worldwide, and atherosclerosis the principal factor underlying cardiovascular events. Atherosclerosis is a chronic inflammatory disease characterized by endothelial dysfunction, intimal lipid deposition, smooth muscle cell proliferation, cell apoptosis and necrosis, and local and systemic inflammation, involving key contributions to from innate and adaptive immunity. The balance between proatherogenic inflammatory and atheroprotective anti-inflammatory responses is modulated by a complex network of interactions among vascular components and immune cells, including monocytes, macrophages, dendritic cells, and T, B, and foam cells; these interactions modulate the further progression and stability of the atherosclerotic lesion. In this review, we take a global perspective on existing knowledge about the pathogenesis of immune responses in the atherosclerotic microenvironment and the interplay between the major innate and adaptive immune factors in atherosclerosis. Studies such as this are the basis for the development of new therapies against atherosclerosis.

The Therapeutic Potential of Nanoparticles to Reduce Inflammation in Atherosclerosis

Chronic inflammation is one of the main determinants of atherogenesis. The traditional medications for treatment of atherosclerosis are not very efficient in targeting atherosclerotic inflammation. Most of these drugs are non-selective, anti-inflammatory and immunosuppressive agents that have adverse effects and very limited anti-atherosclerotic effects, which limits their systemic administration. New approaches using nanoparticles have been investigated to specifically deliver therapeutic agents directly on atherosclerotic lesions. The use of drug delivery systems, such as polymeric nanoparticles, liposomes, and carbon nanotubes are attractive strategies, but some limitations exist. For instance, nanoparticles may alter the drug kinetics, based on the pathophysiological mechanisms of the diseases. In this review, we will update pathophysiological evidence for the use of nanoparticles to reduce inflammation and potentially prevent atherogenesis in different experimental models.

Early Local Inhibition of Club Cell Protein 16 Following Chest Trauma Reduces Late Sepsis-Induced Acute Lung Injury

Blunt thoracic trauma (TxT) deteriorates clinical post-injury outcomes. Ongoing inflammatory changes promote the development of post-traumatic complications, frequently causing Acute Lung Injury (ALI). Club Cell Protein (CC)16, a pulmonary anti-inflammatory protein, correlates with lung damage following TxT. Whether CC16-neutralization influences the inflammatory course during ALI is elusive. Ninety-six male CL57BL/6N mice underwent a double hit model of TxT and cecal ligation puncture (CLP, 24 h post-TxT). Shams underwent surgical procedures. CC16 was neutralized by the intratracheal application of an anti-CC16-antibody, either after TxT (early) or following CLP (late). Euthanasia was performed at 6 or 24 h post-CLP. Systemic and pulmonary levels of IL-6, IL-1β, and CXCL5 were determined, the neutrophils were quantified in the bronchoalveolar lavage fluid, and histomorphological lung damage was assessed. ALI induced a significant systemic IL-6 increase among all groups, while the local inflammatory response was most prominent after 24 h in the double-hit groups as compared to the shams. Significantly increased neutrophilic infiltration upon double hit was paralleled with the enhanced lung damage in all groups as compared to the sham, after 6 and 24 h. Neutralization of CC16 did not change the systemic inflammation. However, early CC16-neutralization increased the neutrophilic infiltration and lung injury at 6 h post-CLP, while 24 h later, the lung injury was reduced. Late CC16-neutralization increased neutrophilic infiltration, 24 h post-CLP, and was concurrent with an enhanced lung injury. The data confirmed the anti-inflammatory potential of endogenous CC16 in the murine double-hit model of ALI.

Detection of systemic inflammation in severely impaired chronic pain patients and effects of a multimodal pain rehabilitation program

Background and aims

Recent research indicates a previously unknown low-grade systemic or neurogenic inflammation in groups of chronic pain (CP) patients. Low-grade inflammation may have an important role in symptoms that have previously not been well depicted: widespread pain, tiredness and cognitive dysfunctions frequently seen in severely impaired CP patients. This study aimed to investigate the plasma inflammatory profile in a group of very complex CP patients at baseline and at a 1-year follow-up after participation in a cognitive behavior therapy (CBT)-based multimodal pain rehabilitation program (PRP).

Methods

Blood samples were collected from 52 well-characterized CP patients. Age- and sex-matched healthy blood donors served as controls. The samples were analyzed with a multiple Proximal Extension Analysis allowing a simultaneous analysis of 92 inflammation-related proteins consisting mainly of cytokines, chemokines and growth-factors. At follow-up, 1-year after participation in the RPR samples from 28 patients were analyzed. The results were confirmed by a multi-array technology that allows quantitative estimation.

Results

Clear signs of increased inflammatory activity were detected in the CP patients. Accepting a false discovery rate (FDR) of 5%, there were significant differences in 43/92 inflammatory biomarkers compared with the controls. In three biomarkers (CXCL5, SIRT2, AXIN1) the expression levels were elevated more than eight times. One year after the PRP, with the patients serving as their own controls, a significant decrease in overall inflammatory activity was found.

Conclusions

Our results indicate that the most impaired CP patients suffer from low-grade chronic systemic inflammation not described earlier with this level of detail. The results may have implications for a better understanding of the cluster of co-morbid symptoms described as the “sickness-syndrome” and the wide-spread pain seen in this group of patients. The decrease in inflammatory biomarkers noted at the follow-up after participation in the PRP may reflect the positive effects obtained on somatic and psycho-social mechanisms involved in the inflammatory process by a rehabilitation program. Besides the PRP, no major changes in medication or lifestyle factors were implemented during the same period. To our knowledge, this is the first study reporting that a PRP may induce inflammatory-reducing effects. Further studies are needed to verify the objective findings in CP patients and address the question of causality that remains to be solved.

Implications

The findings offer a new insight into the complicated biological processes underlying CP. It may have implications for the understanding of symptoms collectively described as the “sickness-syndrome” – frequently seen in this group of patients. The lowering of cytokines after the participation in a PRP indicate a new way to evaluate this treatment; by measuring inflammatory biomarkers.

Treg-Cell Control of a CXCL5-IL-17 Inflammatory Axis Promotes Hair-Follicle-Stem-Cell Differentiation During Skin-Barrier Repair

Restoration of barrier-tissue integrity after injury is dependent on the function of immune cells and stem cells (SCs) residing in the tissue. In response to skin injury, hair-follicle stem cells (HFSCs), normally poised for hair generation, are recruited to the site of injury and differentiate into cells that repair damaged epithelium. We used a SC fate-mapping approach to examine the contribution of regulatory T (Treg) cells to epidermal-barrier repair after injury. Depletion of Treg cells impaired skin-barrier regeneration and was associated with a Th17 inflammatory response and failed HFSC differentiation. In this setting, damaged epithelial cells preferentially expressed the neutrophil chemoattractant CXCL5, and blockade of CXCL5 or neutrophil depletion restored barrier function and SC differentiation after epidermal injury. Thus, Treg-cell regulation of localized inflammation enables HFSC differentiation and, thereby, skin-barrier regeneration, with implications for the maintenance and repair of other barrier tissues.

Identification of atherosclerosis-related prioritizing metabolites based on a multi-omics composite network

Metabolites are the final products of cellular regulation processes, their level is the ultimate response of biological systems to environmental and genetic changes. Therefore, the identification of key metabolites is required for the diagnosis and therapy of diseases. In this study, atherosclerosis-related gene expression profile information was extracted from ArrayExpress database (GEOD-57691), and analyzed with limma package. Furthermore, we constructed an intricate multi-omics network involved in genes, phenotypes, metabolites and their associations. To identify the prioritization of atherosclerosis-related metabolites, the relation score of each metabolite in the composite network was computed with the random walk with restart (RWR) method. The top 50 metabolites and top 100 genes were chosen based on the score in the weighted composite network. Consequently, several key metabolites that were ranked in the top 5 of relation score or degree greater than 70 were confirmed. Particularly, metabolites Tretinoin and Estraderm not only have high relation scores, but also contain more degrees. Moreover, we obtained 24 co-expression genes that may be regarded as the targets of atherosclerosis therapy. Therefore, identification of metabolite prioritizations by the composite network integrated the information of genes, phenotypes and metabolites may be available to diagnose atherosclerosis, and can provide the potential therapeutic strategies for atherosclerosis.

Transcriptome-wide analysis of filarial extract-primed human monocytes reveal changes in LPS-induced PTX3 expression levels

Filarial nematodes modulate immune responses in their host to enable their survival and mediate protective effects against autoimmunity and allergies. In this study, we examined the immunomodulatory capacity of extracts from the human pathogenic filaria Brugia malayi (BmA) on human monocyte responses in a transcriptome-wide manner to identify associated pathways and diseases. As previous transcriptome studies often observed quiescent responses of innate cells to filariae, the potential of BmA to alter LPS driven responses was investigated by analyzing >47.000 transcripts of monocytes from healthy male volunteers stimulated with BmA, Escherichia coli LPS or a sequential stimulation of both. In comparison to ~2200 differentially expressed genes in LPS-only stimulated monocytes, only a limited number of differentially expressed genes were identified upon BmA priming before LPS re-stimulation with only PTX3↓ reaching statistical significance after correcting for multiple testing. Nominal significant differences were reached for metallothioneins↑, MMP9↑, CXCL5/ENA-78↑, CXCL6/GCP-2↑, TNFRSF21↓, and CCL20/MIP3α↓ and were confirmed by qPCR or ELISA. Flow cytometric analysis of activation markers revealed a reduced LPS-induced expression of HLA-DR and CD86 on BmA-primed monocytes as well as a reduced apoptosis of BmA-stimulated monocytes. While our experimental design does not allow a stringent extrapolation of our results to the development of filarial pathology, several genes that were identified in BmA-primed monocytes had previously been associated with filarial pathology, supporting the need for further research.

Bacterial and viral pathogen-associated molecular patterns induce divergent early transcriptomic landscapes in a bovine macrophage cell line

Background

Pathogens stimulate immune functions of macrophages. Macrophages are a key sentinel cell regulating the response to pathogenic ligands and orchestrating the direction of the immune response. Our study aimed at investigating the early transcriptomic changes of bovine macrophages (Bomacs) in response to stimulation with CpG DNA or polyI:C, representing bacterial and viral ligands respectively, and performed transcriptomics by RNA sequencing (RNASeq). KEGG, GO and IPA analytical tools were used to reconstruct pathways, networks and to map out molecular and cellular functions of differentially expressed genes (DE) in stimulated cells.

Results

A one-way ANOVA analysis of RNASeq data revealed significant differences between the CpG DNA and polyI:C-stimulated Bomac. Of the 13,740 genes mapped to the bovine genome, 2245 had p-value ≤0.05, deemed as DE. At 6 h post stimulation of Bomac, poly(I:C) induced a very different transcriptomic profile from that induced by CpG DNA. Whereas, 347 genes were upregulated and 210 downregulated in response to CpG DNA, poly(I:C) upregulated 761 genes and downregulated 414 genes. The topmost DE genes in poly(I:C)-stimulated cells had thousand-fold changes with highly significant p-values, whereas in CpG DNA stimulated cells had 2–5-fold changes with less stringent p-values. The highest DE genes in both stimulations belonged to the TNF superfamily, TNFSF18 (CpG) and TNFSF10 (poly(I:C)) and in both cases the lowest downregulated gene was CYP1A1. CpG DNA highly induced canonical pathways that are unrelated to immune response in Bomac. CpG DNA influenced expression of genes involved in molecular and cellular functions in free radical scavenging. By contrast, poly(I:C) highly induced exclusively canonical pathways directly related to antiviral immune functions mediated by interferon signalling genes. The transcriptomic profile after poly(I:C)-stimulation was consistent with induction of TLR3 signalling.

Conclusion

CpG DNA and poly(I:C) induce different early transcriptional landscapes in Bomac, but each is suited to a specific function of macrophages during interaction with pathogens. Poly(I:C) influenced antiviral response genes, whereas CpG DNA influenced genes important for phagocytic processes. Poly(I:C) was more potent in setting the inflammatory landscape desirable for an efficient immune response against virus infection.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-5411-5) contains supplementary material, which is available to authorized users.

Wound exudate CXCL6: a potential biomarker for wound healing of diabetic foot ulcers

AIM

The aim of this study was to investigate the relationship between CXCL-6 levels in wound exudates and healing of diabetic foot ulcers (DFU).

MATERIALS & METHODS

One hundred patients with neuropathic DFU were recruited. Wound exudate CXCL-6 levels were measured by enzyme-linked immunosorbent assay. Patients were followed for 24 weeks and divided into rapidly healing and nonhealing groups.

RESULTS

Compared with the NH group, the mean CXCL-6 levels in the wound exudates of the rapidly healing group were significantly higher. After adjusting for traditional risk factors, wound exudate CXCL-6 levels were still significantly associated with wound healing.

CONCLUSION

CXCL6 is an independent predictor of wound healing in DFU patients and may be a potentially novel therapeutic target for the treatment of DFU.

Centrilobular emphysema and coronary artery calcification: mediation analysis in the SPIROMICS cohort

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with a two-to-five fold increase in the risk of coronary artery disease independent of shared risk factors. This association is hypothesized to be mediated by systemic inflammation but this link has not been established.

METHODS

We included 300 participants enrolled in the SPIROMICS cohort, 75 each of lifetime non-smokers, smokers without airflow obstruction, mild-moderate COPD, and severe-very severe COPD. We quantified emphysema and airway disease on computed tomography, characterized visual emphysema subtypes (centrilobular and paraseptal) and airway disease, and used the Weston visual score to quantify coronary artery calcification (CAC). We used the Sobel test to determine whether markers of systemic inflammation mediated a link between spirometric and radiographic features of COPD and CAC.

RESULTS

FEV1/FVC but not quantitative emphysema or airway wall thickening was associated with CAC (p = 0.036), after adjustment for demographics, diabetes mellitus, hypertension, statin use, and CT scanner type. To explain this discordance, we examined visual subtypes of emphysema and airway disease, and found that centrilobular emphysema but not paraseptal emphysema or bronchial thickening was independently associated with CAC (p = 0.019). MMP3, VCAM1, CXCL5 and CXCL9 mediated 8, 8, 7 and 16% of the association between FEV1/FVC and CAC, respectively. Similar biomarkers partially mediated the association between centrilobular emphysema and CAC.

CONCLUSIONS

The association between airflow obstruction and coronary calcification is driven primarily by the centrilobular subtype of emphysema, and is linked through bioactive molecules implicated in the pathogenesis of atherosclerosis.

TRIAL REGISTRATION

ClinicalTrials.gov: Identifier: NCT01969344 .

Targeting Inflammation With Nanosized Drug Delivery Platforms in Cardiovascular Diseases: Immune Cell Modulation in Atherosclerosis

Atherosclerosis (AS) is a disorder of large and medium-sized arteries; it consists in the formation of lipid-rich plaques in the intima and inner media, whose pathophysiology is mostly driven by inflammation. Currently available interventions and therapies for treating atherosclerosis are not always completely effective; side effects associated with treatments, mainly caused by immunodepression for anti-inflammatory molecules, limit the systemic administration of these and other drugs. Given the high degree of freedom in the design of nanoconstructs, in the last decades researchers have put high effort in the development of nanoparticles (NPs) formulations specifically designed for either drug delivery, visualization of atherosclerotic plaques, or possibly the combination of both these and other functionalities. Here we will present the state of the art of these subjects, the knowledge of which is necessary to rationally address the use of NPs for prevention, diagnosis, and/or treatment of AS. We will analyse the work that has been done on: (a) understanding the role of the immune system and inflammation in cardiovascular diseases, (b) the pathological and biochemical principles in atherosclerotic plaque formation, (c) the latest advances in the use of NPs for the recognition and treatment of cardiovascular diseases, (d) the cellular and animal models useful to study the interactions of NPs with the immune system cells.

The Potential of Fluocinolone Acetonide to Mitigate Inflammation and Lipid Accumulation in 2D and 3D Foam Cell Cultures

Inflammation plays an important role in all stages of atherosclerosis development. Therefore, the use of anti-inflammatory drugs could reduce the risk of major adverse cardiovascular events due to atherosclerosis. Herein, we explored the capacity of fluocinolone acetonide (FA), a glucocorticoid (GC), in modulating foam cell formation and response. Human THP-1 derived foam cells were produced using 100 μg/mL oxidized low-density lipoproteins (OxLDL) and fetal bovine serum (1 and 10%). 2D cultures of these cells were treated with FA (0.1, 1, 10, and 50 μg/mL) in comparison with dexamethasone (Dex). Results showed that treatment with 0.1 and 1 μg/mL FA and Dex improved foam cell survival. FA and Dex also inhibited inflammatory cytokine (CD14, M-CSF, MIP-3α, and TNF-α) secretion. Notably, at the concentration of 1 μg/mL, both FA and Dex reduced cholesteryl ester accumulation. Compared to Dex, FA was significantly better in reducing lipid accumulation at the therapeutic concentrations of 1 and 10 μg/mL. In a novel 3D foam cell spheroid model, FA was shown to be more effective than Dex in diminishing lipid accumulation, at the concentration of 0.1 μg/mL. Taken together, FA was demonstrated to be effective in preventing both lipid accumulation and inflammation in foam cells.

miR-505-3p controls chemokine receptor up-regulation in macrophages: role in familial hypercholesterolemia

Familial hypercholesterolemia (FH) conveys a high risk of premature atherosclerosis as a result of lifelong exposure to high LDL cholesterol levels that are not fully reduced by standard-of-care lipid-lowering treatment. Inflammatory mediators have played a role in the progression of atherosclerotic lesions. Here, we investigated whether innate immunity cells in patients with FH have a specific proinflammatory phenotype that is distinct from that of cells in normal participants. To this end, miR-505-3p-a microRNA related to chronic inflammation-and its target genes were investigated in monocyte-derived macrophages (MACs) of patients with FH (FH-MACs) and non-FH controls (co-MACs). On the basis of the profiler PCR array analysis of agomiR-505-3p-transfected MACs, we identified the chemokine receptors, CCR3, CCR4, and CXCR1, as genes that are regulated by miR-505-3p via the transcription factor, RUNX1. miR-505-3p was significantly down-regulated, whereas CCR3, CCR4, CXCR, and RUNX1 were increased in FH-MAC compared with co-MAC, with the increase being more evident in the proinflammatory M1-like FH-MAC. Chemokine receptor levels were unrelated to LDL plasma levels at entry, but correlated with age in patients with FH, not in controls. In summary, we demonstrate for first time to our knowledge that MACs from FH-MACs have an inflammatory phenotype that is characterized by the up-regulation of CCR3, CCR4, and CXCR1 under the control of miR-505-3p. These results suggest a chronic inflammatory condition in FH innate immunity cells that is not reverted by standard lipid-lowering treatment.-Escate, R., Mata, P., Cepeda, J. M., Padró, T., Badimon, L. miR-505-3p controls chemokine receptor up-regulation in macrophages: role in familial hypercholesterolemia.