Targeted inhibition of STATs and IRFs as a potential treatment strategy in cardiovascular disease

Identification of ALEKSIN as a novel multi-IRF inhibitor of IRF- and STAT-mediated transcription in vascular inflammation and atherosclerosis

Cardiovascular diseases (CVDs) include atherosclerosis, which is an inflammatory disease of large and medium vessels that leads to atherosclerotic plaque formation. The key factors contributing to the onset and progression of atherosclerosis include the pro-inflammatory cytokines interferon (IFN)α and IFNγ and the pattern recognition receptor (PRR) Toll-like receptor 4 (TLR4). Together, they trigger the activation of IFN regulatory factors (IRFs) and signal transducer and activator of transcription (STAT)s. Based on their promoting role in atherosclerosis, we hypothesized that the inhibition of pro-inflammatory target gene expression through multi-IRF inhibitors may be a promising strategy to treat CVDs. Using comparative in silico docking of multiple IRF-DNA-binding domain (DBD) models on a multi-million natural compound library, we identified the novel multi-IRF inhibitor, ALEKSIN. This compound targets the DBD of IRF1, IRF2, and IRF8 with the same affinity and simultaneously inhibits the expression of multiple IRF target genes in human microvascular endothelial cells (HMECs) in response to IIFNα and IFNγ. Under the same conditions, ALEKSIN also inhibited the phosphorylation of STATs, potentially through low-affinity STAT-SH2 binding but with lower potency than the known multi-STAT inhibitor STATTIC. This was in line with the common inhibition of ALEKSIN and STATTIC observed on the genome-wide expression of pro-inflammatory IRF/STAT/NF-κB target genes, as well as on the migration of HMECs. Finally, we identified a novel signature of 46 ALEKSIN and STATTIC commonly inhibited pro-atherogenic target genes, which was upregulated in atherosclerotic plaques in the aortas of high-fat diet-fed ApoEKO mice and associated with inflammation, proliferation, adhesion, chemotaxis, and response to lipids. Interestingly, the majority of these genes could be linked to macrophage subtypes present in aortic plaques in HFD-fed LDLR-KO mice. Together, this suggests that ALEKSIN represents a novel class of multi-IRF inhibitors, which inhibits IRF-, STAT-, and NF-κB-mediated transcription and could offer great promise for the treatment of CVDs. Furthermore, the ALEKSIN and STATTIC commonly inhibited pro-inflammatory gene signature could help monitor plaque progression during experimental atherosclerosis.

An Adipo-Pulmonary Axis Mediated by FABP4 Hormone Defines a Therapeutic Target Against Obesity-Induced Airway Disease

Obesity-related airway disease is a clinical condition without a clear description and effective treatment. Here, we define this pathology and its unique properties, which differ from classic asthma phenotypes, and identify a novel adipo-pulmonary axis mediated by FABP4 hormone as a critical mediator of obesity-induced airway disease. Through detailed analysis of murine models and human samples, we elucidate the dysregulated lipid metabolism and immunometabolic responses within obese lungs, particularly highlighting the stress response activation and downregulation of surfactant-related genes, notably SftpC. We demonstrate that FABP4 deficiency mitigates these alterations, demonstrating a key role in obesity-induced airway disease pathogenesis. Importantly, we identify adipose tissue as the source of FABP4 hormone in the bronchoalveolar space and describe strong regulation in the context of human obesity, particularly among women. Finally, our exploration of antibody-mediated targeting of circulating FABP4 unveils a novel therapeutic avenue, addressing a pressing unmet need in managing obesity-related airway disease. These findings not only define the presence of a critical adipo-pulmonary endocrine link but also present FABP4 as a therapeutic target for managing this unique airway disease that we refer to as fatty lung disease associated with obesity.

One Sentence Summary

Investigating FABP4's pivotal role in obesity-driven airway disease, this study unveils an adipo-pulmonary axis with potential therapeutic implications.

JAK/STAT3 signaling in cardiac fibrosis: a promising therapeutic target

Cardiac fibrosis is a serious health problem because it is a common pathological change in almost all forms of cardiovascular diseases. Cardiac fibrosis is characterized by the transdifferentiation of cardiac fibroblasts (CFs) into cardiac myofibroblasts and the excessive deposition of extracellular matrix (ECM) components produced by activated myofibroblasts, which leads to fibrotic scar formation and subsequent cardiac dysfunction. However, there are currently few effective therapeutic strategies protecting against fibrogenesis. This lack is largely because the molecular mechanisms of cardiac fibrosis remain unclear despite extensive research. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling cascade is an extensively present intracellular signal transduction pathway and can regulate a wide range of biological processes, including cell proliferation, migration, differentiation, apoptosis, and immune response. Various upstream mediators such as cytokines, growth factors and hormones can initiate signal transmission via this pathway and play corresponding regulatory roles. STAT3 is a crucial player of the JAK/STAT pathway and its activation is related to inflammation, malignant tumors and autoimmune illnesses. Recently, the JAK/STAT3 signaling has been in the spotlight for its role in the occurrence and development of cardiac fibrosis and its activation can promote the proliferation and activation of CFs and the production of ECM proteins, thus leading to cardiac fibrosis. In this manuscript, we discuss the structure, transactivation and regulation of the JAK/STAT3 signaling pathway and review recent progress on the role of this pathway in cardiac fibrosis. Moreover, we summarize the current challenges and opportunities of targeting the JAK/STAT3 signaling for the treatment of fibrosis. In summary, the information presented in this article is critical for comprehending the role of the JAK/STAT3 pathway in cardiac fibrosis, and will also contribute to future research aimed at the development of effective anti-fibrotic therapeutic strategies targeting the JAK/STAT3 signaling.

Identification of the shared mechanisms and common biomarkers between Sjögren's syndrome and atherosclerosis using integrated bioinformatics analysis

Background

Sjögren's syndrome (SS) is a chronic autoimmune disease characterized by exocrine and extra-glandular symptoms. The literature indicates that SS is an independent risk factor for atherosclerosis (AS); however, its pathophysiological mechanism remains undetermined. This investigation aimed to elucidate the crosstalk genes and pathways influencing the pathophysiology of SS and AS via bioinformatic analysis of microarray data.

Methods

Microarray datasets of SS (GSE40611) and AS (GSE28829) were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were acquired using R software's "limma" packages, and the functions of common DEGs were determined using Gene Ontology and Kyoto Encyclopedia analyses. The protein-protein interaction (PPI) was established using the STRING database. The hub genes were assessed via cytoHubba plug-in and validated by external validation datasets (GSE84844 for SS; GSE43292 for AS). Gene set enrichment analysis (GSEA) and immune infiltration of hub genes were also conducted.

Results

Eight 8 hub genes were identified using the intersection of four topological algorithms in the PPI network. Four genes (CTSS, IRF8, CYBB, and PTPRC) were then verified as important cross-talk genes between AS and SS with an area under the curve (AUC) ≥0.7. Furthermore, the immune infiltration analysis revealed that lymphocytes and macrophages are essentially linked with the pathogenesis of AS and SS. Moreover, the shared genes were enriched in multiple metabolisms and autoimmune disease-related pathways, as evidenced by GSEA analyses.

Conclusion

This is the first study to explore the common mechanism between SS and AS. Four key genes, including CTSS, CYBB, IRF8, and PTPRC, were associated with the pathogenesis of SS and AS. These hub genes and their correlation with immune cells could be a potential diagnostic and therapeutic target.

STAT3/NF‑κB decoy oligodeoxynucleotides inhibit atherosclerosis through regulation of the STAT/NF‑κB signaling pathway in a mouse model of atherosclerosis

Atherosclerosis is a progressive chronic inflammatory condition that is the cause of most cardiovascular and cerebrovascular diseases. The transcription factor nuclear factor‑κB (NF‑κB) regulates a number of genes involved in the inflammatory responses of cells that are critical to atherogenesis, and signal transducer and activator of transcription (STAT)3 is a key transcription factor in immunity and inflammation. Decoy oligodeoxynucleotides (ODNs) bind to sequence‑specific transcription factors and limit gene expression by interfering with transcription in vitro and in vivo. The present study aimed to investigate the beneficial functions of STAT3/NF‑κB decoy ODNs in liposaccharide (LPS)‑induced atherosclerosis in mice. Atherosclerotic injuries of mice were induced via intraperitoneal injection of LPS and the mice were fed an atherogenic diet. Ring‑type STAT3/NF‑κB decoy ODNs were designed and administered via an injection into the tail vein of the mice. To investigate the effect of STAT3/NF‑κB decoy ODNs, electrophoretic mobility shift assay, western blot analysis, histological analysis with hematoxylin and eosin staining, Verhoeff‑Van Gieson and Masson's trichrome staining were performed. The results revealed that STAT3/NF‑κB decoy ODNs were able to suppress the development of atherosclerosis by attenuating morphological changes and inflammation in atherosclerotic mice aortae, and by reducing pro‑inflammatory cytokine secretion through inhibition of the STAT3/NF‑κB pathway. In conclusion, the present study provided novel insights into the antiatherogenic molecular mechanism of STAT3/NF‑κB decoy ODNs, which may serve as an additional therapeutic intervention to combat atherosclerosis.

STAT3 signaling in prostate cancer progression and therapy resistance: An oncogenic pathway with diverse functions

The categorization of cancers demonstrates that prostate cancer is the most common malignancy in men and it causes high death annually. Prostate cancer patients are diagnosed mainly via biomarkers such as PSA test and patients show poor prognosis. Prostate cancer cells rapidly diffuse into different parts of body and their metastasis is also a reason for death. Current therapies for prostate cancer patients include chemotherapy, surgery and radiotherapy as well as targeted therapy. The progression of prostate cancer cells is regulated by different factors that STAT3 signaling is among them. Growth factors and cytokines such as IL-6 can induce STAT3 signaling and it shows carcinogenic impact. Activation of STAT3 signaling occurs in prostate cancer and it promotes malignant behavior of tumor cells. Induction of STAT3 signaling increases glycolysis and proliferation of prostate cancer cells and prevents apoptosis. Furthermore, STAT3 signaling induces EMT mechanism in increasing cancer metastasis. Activation of STAT3 signaling stimulates drug resistance and the limitation of current works is lack of experiment related to role of STAT3 signaling in radio-resistance in prostate tumor. Calcitriol, capsazepine and β-elemonic are among the compounds capable of targeting STAT3 signaling and its inhibition in prostate cancer therapy. In addition to natural products, small molecules targeting STAT3 signaling have been developed in prostate cancer therapy.

The Influence of Comorbidities on Chemokine and Cytokine Profile in Obstructive Sleep Apnea Patients: Preliminary Results

INTRODUCTION

Obstructive sleep apnea (OSA) is frequently associated with a chronic inflammatory state and cardiovascular/metabolic complications. The aim of this study was to evaluate the influence of certain comorbidities on a panel of 45 chemokines and cytokines in OSA patients with special regard to their possible association with cardiovascular diseases.

MATERIAL AND METHODS

This cross-sectional study was performed on 61 newly diagnosed OSA patients. For the measurement of the plasma concentration of chemokines and cytokines, the magnetic bead-based multiplex assay for the Luminex^® platform was used.

RESULTS

In the patients with concomitant COPD, there were increased levels of pro-inflammatory cytokines (CCL11, CD-40 ligand) and decreased anti-inflammatory cytokine (IL-10), while in diabetes, there were increased levels of pro-inflammatory cytokines (IL-6, TRIAL). Obesity was associated with increased levels of both pro-inflammatory (IL-13) and anti-inflammatory (IL-1RA) cytokines. Hypertension was associated with increased levels of both pro-inflammatory (CCL3) and anti-inflammatory (IL-10) cytokines. Increased daytime pCO₂, low mean nocturnal SaO₂, and the oxygen desaturation index were associated with increased levels of pro-inflammatory cytokines (CXCL1, PDGF-AB, TNF-α, and IL-15).

CONCLUSIONS

In OSA patients with concomitant diabetes and COPD, elevated levels of certain pro-inflammatory and decreased levels of certain anti-inflammatory cytokines may favor the persistence of a chronic inflammatory state with further consequences. Nocturnal hypoxemia, frequent episodes of desaturation, and increased daytime pCO₂ are factors contributing to the chronic inflammatory state in OSA patients.

Structural dynamics of the N‐terminal SH2 domain of PI3K in its free and CD28 ‐bound states

Protein conformational changes with fluctuations are fundamental aspects of protein-protein interactions (PPIs); understanding these motions is required for the rational design of PPI-regulating compounds. Src homology 2 (SH2) domains are commonly found in adapter proteins involved in signal transduction and specifically bind to consensus motifs of proteins containing phosphorylated tyrosine (pY). Here, we analysed the interaction between the N-terminal SH2 domain (nSH2) of the regulatory subunit in phosphoinositide 3-kinase (PI3K) and the cytoplasmic region of the T-cell co-receptor, CD28, using NMR and molecular dynamics (MD) simulations. First, we assigned the backbone signals of nSH2 on ¹ H-¹⁵ N heteronuclear single quantum coherence spectra in the absence or presence of the CD28 phosphopeptide, SDpYMNMTPRRPG. Chemical shift perturbation experiments revealed allosteric changes at the BC loop and the C-terminal region of nSH2 upon CD28 binding. NMR relaxation experiments showed a conformational exchange associated with CD28 binding in these regions. The conformational stabilisation of the C-terminal region correlated with the regulation of PI3K catalytic function. Further, using ¹⁹ F- and ³¹ P-labelled CD28 phosphopeptide, we analysed the structural dynamics of CD28 and demonstrated that the aromatic ring of the pY residue fluctuated between multiple conformations upon nSH2 binding. Our MD simulations largely explained the NMR results and the structural dynamics of nSH2 and CD28 in both bound and unbound states. Notably, in addition to its major conformation, we detected a minor conformation of nSH2 in the CD28 bound state that may explain the allosteric conformational change in the BC loop.

CD8+ T-Cells in Juvenile-Onset SLE: From Pathogenesis to Comorbidities

Diagnosis of systemic lupus erythematosus (SLE) in childhood [juvenile-onset (J) SLE], results in a more severe disease phenotype including major organ involvement, increased organ damage, cardiovascular disease risk and mortality compared to adult-onset SLE. Investigating early disease course in these younger JSLE patients could allow for timely intervention to improve long-term prognosis. However, precise mechanisms of pathogenesis are yet to be elucidated. Recently, CD8+ T-cells have emerged as a key pathogenic immune subset in JSLE, which are increased in patients compared to healthy individuals and associated with more active disease and organ involvement over time. CD8+ T-cell subsets have also been used to predict disease prognosis in adult-onset SLE, supporting the importance of studying this cell population in SLE across age. Recently, single-cell approaches have allowed for more detailed analysis of immune subsets in JSLE, where type-I IFN-signatures have been identified in CD8+ T-cells expressing high levels of granzyme K. In addition, JSLE patients with an increased cardiometabolic risk have increased CD8+ T-cells with elevated type-I IFN-signaling, activation and apoptotic pathways associated with atherosclerosis. Here we review the current evidence surrounding CD8+ T-cell dysregulation in JSLE and therapeutic strategies that could be used to reduce CD8+ T-cell inflammation to improve disease prognosis.

Dysregulated Interferon Response and Immune Hyperactivation in Severe COVID-19: Targeting STATs as a Novel Therapeutic Strategy

A disease outbreak in December 2019, caused by a novel coronavirus SARS-CoV-2, was named COVID-19. SARS-CoV-2 infects cells from the upper and lower respiratory tract system and is transmitted by inhalation or contact with infected droplets. Common clinical symptoms include fatigue, fever, and cough, but also shortness of breath and lung abnormalities. Still, some 5% of SARS-CoV-2 infections progress to severe pneumonia and acute respiratory distress syndrome (ARDS), with pulmonary edema, acute kidney injury, and/or multiple organ failure as important consequences, which can lead to death. The innate immune system recognizes viral RNAs and triggers the expression of interferons (IFN). IFNs activate anti-viral effectors and components of the adaptive immune system by activating members of the STAT and IRF families that induce the expression of IFN-stimulated genes (ISG)s. Among other coronaviruses, such as Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV, common strategies have been identified to antagonize IFN signaling. This typically coincides with hyperactive inflammatory host responses known as the “cytokine storm” that mediate severe lung damage. Likewise, SARS-CoV-2 infection combines a dysregulated IFN response with excessive production of inflammatory cytokines in the lungs. This excessive inflammatory response in the lungs is associated with the local recruitment of immune cells that create a pathogenic inflammatory loop. Together, it causes severe lung pathology, including ARDS, as well as damage to other vulnerable organs, like the heart, spleen, lymph nodes, and kidney, as well as the brain. This can rapidly progress to multiple organ exhaustion and correlates with a poor prognosis in COVID-19 patients. In this review, we focus on the crucial role of different types of IFN that underlies the progression of SARS-CoV-2 infection and leads to immune cell hyper-activation in the lungs, exuberant systemic inflammation, and multiple organ damage. Consequently, to protect from systemic inflammation, it will be critical to interfere with signaling cascades activated by IFNs and other inflammatory cytokines. Targeting members of the STAT family could therefore be proposed as a novel therapeutic strategy in patients with severe COVID-19.

Grapefruit Juice Flavanones Modulate the Expression of Genes Regulating Inflammation, Cell Interactions and Vascular Function in Peripheral Blood Mononuclear Cells of Postmenopausal Women

Grapefruit is a rich source of flavanones, phytochemicals suggested excreting vasculoprotective effects. We previously showed that flavanones in grapefruit juice (GFJ) reduced postmenopausal women’s pulse-wave velocity (PWV), a measure of arterial stiffness. However, mechanisms of flavanone action in humans are largely unknown. This study aimed to decipher molecular mechanisms of flavanones by multi-omics analysis in PBMCs of volunteers consuming GFJ and flavanone-free control drink for 6 months. Modulated genes and microRNAs (miRNAs) were identified using microarrays. Bioinformatics analyses assessed their functions, interactions and correlations with previously observed changes in PWV. GFJ modified gene and miRNA expressions. Integrated analysis of modulated genes and miRNA-target genes suggests regulation of inflammation, immune response, cell interaction and mobility. Bioinformatics identified putative mediators of the observed nutrigenomic effect (STAT3, NF-κB) and molecular docking demonstrated potential binding of flavanone metabolites to transcription factors and cell-signaling proteins. We also observed 34 significant correlations between changes in gene expression and PWV. Moreover, global gene expression was negatively correlated with gene expression profiles in arterial stiffness and hypertension. This study revealed molecular mechanisms underlying vasculoprotective effects of flavanones, including interactions with transcription factors and gene and miRNA expression changes that inversely correlate with gene expression profiles associated with cardiovascular risk factors.

Gut Dysbiosis and Immune System in Atherosclerotic Cardiovascular Disease (ACVD)

Atherosclerosis is a leading cause of cardiovascular disease and mortality worldwide. Alterations in the gut microbiota composition, known as gut dysbiosis, have been shown to contribute to atherosclerotic cardiovascular disease (ACVD) development through several pathways. Disruptions in gut homeostasis are associated with activation of immune processes and systemic inflammation. The gut microbiota produces several metabolic products, such as trimethylamine (TMA), which is used to produce the proatherogenic metabolite trimethylamine-N-oxide (TMAO). Short-chain fatty acids (SCFAs), including acetate, butyrate, and propionate, and certain bile acids (BAs) produced by the gut microbiota lead to inflammation resolution and decrease atherogenesis. Chronic low-grade inflammation is associated with common risk factors for atherosclerosis, including metabolic syndrome, type 2 diabetes mellitus (T2DM), and obesity. Novel strategies for reducing ACVD include the use of nutraceuticals such as resveratrol, modification of glucagon-like peptide 1 (GLP-1) levels, supplementation with probiotics, and administration of prebiotic SCFAs and BAs. Investigation into the relationship between the gut microbiota, and its metabolites, and the host immune system could reveal promising insights into ACVD development, prognostic factors, and treatments.

Mettl3 promotes oxLDL-mediated inflammation through activating STAT1 signaling

Background

Atherosclerosis (AS) is the main cause of cerebrovascular diseases, and macrophages act important roles during the AS pathological process through regulating inflammation. Modification of the novel N(6)‐methyladenine (m6A) RNA is reported to be associated with AS, but its role in AS is largely unknown. The aim of this study was to investigate the role and mechanism of m6A modification in inflammation triggered by oxidized low‐density lipoprotein (oxLDL) in macrophages during AS.

Methods

RAW264.7 macrophage cells were stimulated with 40 μg/ml ox‐LDL, Dot blot, Immunoprecipitation, western blot, Rip and chip experiments were used in our study.

Results

We found oxLDL stimulation significantly promoted m6A modification level of mRNA in macrophages and knockdown of Methyltransferase‐Like Protein 3 (Mettl3) inhibited oxLDL‐induced m6A modification and inflammatory response. Mettl3 promoted oxLDL‐induced inflammatory response in macrophages through regulating m6A modification of Signal transducer and activator of transcription 1 (STAT1) mRNA, thereby affecting STAT1 expression and activation. Moreover, oxLDL stimulation enhanced the interaction between Mettl3 and STAT1 protein, promoting STAT1 transcriptional regulation of inflammatory factor expression in macrophages eventually.

Conclusions

These results indicate that Mettl3 promotes oxLDL‐triggered inflammation through interacting with STAT1 protein and mRNA in RAW264.7 macrophages, suggesting that Mettl3 may be as a potential target for the clinical treatment of AS.

Role of STAT3 Transcription Factor in Pathogenesis of Bronchial Asthma

Bronchial asthma is a heterogeneous chronic inflammatory disease of airways. The studies of molecular and cellular mechanisms of bronchial asthma have established that a wide range of immune (T and B cells, eosinophils, neutrophils, macrophages, etc.) and structural (epithelial and endothelial) cells are involved in its pathogenesis. These cells are activated in response to external stimuli (bacteria, viruses, allergens, and other pollutants) and produce pro-inflammatory factors (cytokines, chemokines, metalloproteinases, etc.), which ultimately leads to the initiation of pathological processes in the lungs. Genes encoding transcription factors of the STAT family (signal transducer and activator of transcription), that includes seven representatives, are involved in the cell activation. Recent studies have shown that the transcription factor STAT3 plays an important role in the activation of the abovementioned cells, thus contributing to the development of asthma. In animal studies, selective inhibition of STAT3 significantly reduces the severity of lung inflammation, which indicates its potential as a therapeutic target. In this review, we describe the mechanisms of STAT3 activation and its role in polarization of Th2/Th17 cells and M2 macrophages, as well as in the dysfunction of endothelial cells, which ultimately leads to development of bronchial asthma symptoms, such as infiltration of neutrophils and eosinophils into the lungs, bronchial hyperreactivity, and the respiratory tract remodeling.

SARS-CoV-2: Understanding the Transcriptional Regulation of ACE2 and TMPRSS2 and the Role of Single Nucleotide Polymorphism (SNP) at Codon 72 of p53 in the Innate Immune Response against Virus Infection

Human ACE2 and the serine protease TMPRSS2 of novel SARS-CoV-2 are primary entry receptors in host cells. Expression of these genes at the transcriptional level has not been much discussed in detail. The ISRE elements of the ACE2 promoter are a binding site for the ISGF3 complex of the JAK/STAT signaling pathway. TMPRSS2, including IFNβ, STAT1, and STAT2, has the PARP1 binding site near to TSS either up or downstream promoter region. It is well documented that PARP1 regulates gene expression at the transcription level. Therefore, to curb virus infection, both promoting type I IFN signaling to boost innate immunity and prevention of virus entry by inhibiting PARP1, ACE2 or TMPRSS2 are safe options. Most importantly, our aim is to attract the attention of the global scientific community towards the codon 72 Single Nucleotide Polymorphism (SNP) of p53 and its underneath role in the innate immune response against SARS-CoV-2. Here, we discuss codon 72 SNP of human p53's role in the different innate immune response to restrict virus-mediated mortality rate only in specific parts of the world. In addition, we discuss potential targets and emerging therapies using bioengineered bacteriophage, anti-sense, or CRISPR strategies.

STAT5a Confers Doxorubicin Resistance to Breast Cancer by Regulating ABCB1

Chemoresistance is a daunting challenge to the prognosis of patients with breast cancer. Signal transducer and activator of transcription (STAT) 5a plays vital roles in the development of various cancers, but its function in breast cancer is controversial, and its role in chemoresistance in breast cancer remains unexplored. Here we identified STAT5a as a chemoresistance inducer that regulates the expression of ABCB1 in breast cancer and can be targeted by pimozide, an FDA-approved psychotropic drug. First, we found that STAT5a and ABCB1 were expressed at higher levels in doxorubicin-resistant cell lines and chemoresistant patients, and their expression was positively correlated. Then, we confirmed the essential roles of STAT5a and ABCB1 in doxorubicin resistance in breast cancer cells and the regulation of ABCB1 transcription by STAT5a. Subsequently, the efficacy of pimozide in inhibiting STAT5a and sensitizing doxorubicin-resistant breast cancer cells was tested. Finally, we verified the role of STAT5a in doxorubicin resistance in breast cancer and the efficacy of pimozide in reversing this resistance in vivo. Our study demonstrated the vital role of STAT5a in doxorubicin resistance in breast cancer. Targeting STAT5a might be a promising strategy for treating doxorubicin-resistant breast cancer. Moreover, repurposing pimozide for doxorubicin resensitization is attractive due to the safety profile of pimozide.

An active marine halophenol derivative attenuates lipopolysaccharide-induced acute liver injury in mice by improving M2 macrophage-mediated therapy

2,4',5'-Trihydroxyl-5,2'-dibromo diphenylmethanone (LM49), an active halophenol derivative synthesized by our group, which exhibits a broad spectrum of therapeutic properties, such as antioxidant and anti-inflammatory activities. In this study, we found LM49 could obviously attenuate acute liver injury induced by lipopolysaccharide (LPS) in mice by polarizing macrophages. The protective effect was described by reducing the hepatic inflammation and improving hepatic function using aspartate transaminase (AST) and alanine transaminase (ALT) assay. Further study revealed that LM49 pretreatment induced the Kupffer cells (KCs) to M2 polarization and decreased the production of inflammatory cytokines. The action mechanism in RAW 264.7 macrophages showed that LM49 could induce the activation of JAK1/STAT6 signaling pathway and the inhibition of TLR-4/NF-kB axis. Morever, LM49 also upregulated the expression of SOCS1 and FLK-4, which can promote M2 polarization by cooperating with STAT6 and inhibit M1 formation by reducing JAK1/STAT1. Our results suggested that LM49 could protect against LPS-induced acute liver injury in mice via anti-inflammatory signaling pathways and subsequent induction of M2 Kupffer cells. The results provided the first experimental evidence of active halophenols for the anti-inflammatory therapy by targeting M2 macrophages.

Increased apolipoprotein-B:A1 ratio predicts cardiometabolic risk in patients with juvenile onset SLE

BACKGROUND

Cardiovascular disease is a leading cause of mortality in patients with juvenile-onset systemic lupus erythematosus (JSLE). Traditional factors for cardiovascular risk (CVR) prediction are less robust in younger patients. More reliable CVR biomarkers are needed for JSLE patient stratification and to identify therapeutic approaches to reduce cardiovascular morbidity and mortality in JSLE.

METHODS

Serum metabolomic analysis (including >200 lipoprotein measures) was performed on a discovery (n=31, median age 19) and validation (n=31, median age 19) cohort of JSLE patients. Data was analysed using cluster, receiver operating characteristic analysis and logistic regression. RNA-sequencing assessed gene expression in matched patient samples.

FINDINGS

Hierarchical clustering of lipoprotein measures identified and validated two unique JSLE groups. Group-1 had an atherogenic and Group-2 had an atheroprotective lipoprotien profile. Apolipoprotein(Apo)B:ApoA1 distinguished the two groups with high specificity (96.2%) and sensitivity (96.7%). JSLE patients with high ApoB:ApoA1 ratio had increased CD8+ T-cell frequencies and a CD8+ T-cell transcriptomic profile enriched in genes associated with atherogenic processes including interferon signaling. These metabolic and immune signatures overlapped statistically significantly with lipid biomarkers associated with sub-clinical atherosclerosis in adult SLE patients and with genes overexpressed in T-cells from human atherosclerotic plaque respectively. Finally, baseline ApoB:ApoA1 ratio correlated positively with SLE disease activity index (r=0.43, p=0.0009) and negatively with Lupus Low Disease Activity State (r=-0.43, p=0.0009) over 5-year follow-up.

INTERPRETATION

Multi-omic analysis identified high ApoB:ApoA1 as a potential biomarker of increased cardiometabolic risk and worse clinical outcomes in JSLE. ApoB:ApoA1 could help identify patients that require increased disease monitoring, lipid modification or lifestyle changes.

FUNDING

Lupus UK, The Rosetrees Trust, British Heart Foundation, UCL & Birkbeck MRC Doctoral Training Programme and Versus Arthritis.

Synergistic inflammatory signaling by cGAS may be involved in the development of atherosclerosis

Inappropriate activation or overactivation of cyclic GMP-AMP synthase (cGAS) by double-stranded deoxyribonucleic acid (dsDNA) initiates a regulatory signaling cascade triggering a variety of inflammatory responses, which are a great threat to human health. This study focused on identifying the role of cGAS in atherosclerosis and its potential mechanisms. The relationship between cGAS and atherosclerosis was identified in an ApoE ^-/- mouse model. Meanwhile, RNA sequencing (RNA-seq) analysis of the underlying mechanisms of atherosclerosis in RAW264.7 macrophages treated with cGAS inhibition was conducted. Results showed that cGAS was positively correlated with atherosclerotic plaque area, and was mainly distributed in macrophages. RNA-seq analysis revealed that inflammatory response, immune response and cytokine–cytokine receptor interaction may play important roles in the development of atherosclerosis. Real-time quantitative polymerase chain reaction (RT-qPCR) results showed that the expression of the pro-inflammatory factors, signal transducer and activator of transcription (Stat), interferon regulatory factor (Irf), toll-like receptors (Tlrs), and type I interferons (Ifns) were synergistically reduced when cGAS was inhibited. Furthermore, cGAS inhibition significantly inhibited RAW264.7 macrophage M1 polarization. These results demonstrate that cGAS may contribute to the development of atherosclerosis through synergistic inflammatory signaling of TLRs, STAT/IRF as well as IFNs, leading to macrophage M1 polarization.

Scrodentoids H and I, a Pair of Natural Epimerides from Scrophularia dentata, Inhibit Inflammation through JNK-STAT3 Axis in THP-1 Cells

Background

Scrophularia dentata is an important medicinal plant and used for the treatment of exanthema and fever in Traditional Tibetan Medicine. Scrodentoids H and I (SHI), a pair of epimerides of C₁₉-norditerpenoids isolated from Scrophularia dentata, could transfer to each other in room temperature and were firstly reported in our previous work. Here, we first reported the anti-inflammatory effects of SHI on LPS-induced inflammation.

Purpose

To evaluate the anti-inflammatory property of SHI, we investigated the effects of SHI on LPS-activated THP-1 cells.

Methods

THP-1 human macrophages were pretreated with SHI and stimulated with LPS. Proinflammatory cytokines IL-1β and IL-6 were measured by RT-PCR and enzyme-linked immunosorbent assays (ELISA). The mechanism of action involving phosphorylation of ERK, JNK, P38, and STAT3 was measured by western Blot. The NF-κB promoter activity was evaluated by Dual-Luciferase Reporter Assay System in TNF-α stimulated 293T cells.

Results

SHI dose-dependently reduced the production of proinflammatory cytokines IL-1β and IL-6. The ability of SHI to reduce production of cytokines is associated with phosphorylation depress of JNK and STAT3 rather than p38, ERK, and NF-κB promoter.

Conclusions

Our experimental results indicated that anti-inflammatory effects of SHI exhibit attenuation of LPS-induced inflammation and inhibit activation through JNK/STAT3 pathway in macrophages. These results suggest that SHI might have a potential in treating inflammatory disease.

Type-I interferons in atherosclerosis

Chen et al. review the effects of type-I IFNs and the potential of anti–type-I IFN therapies in atherosclerosis.

The contribution of dyslipidemia and inflammation in atherosclerosis is well established. Along with effective lipid-lowering treatments, the recent success of clinical trials with anti-inflammatory therapies and the accelerated atherosclerosis in many autoimmune diseases suggest that targeting inflammation may open new avenues for the prevention and the treatment for cardiovascular diseases (CVDs). In the past decades, studies have widened the role of type-I interferons (IFNs) in disease, from antivirus defense to autoimmune responses and immuno-metabolic syndromes. While elevated type-I IFN level in serum is associated with CVD incidence in patients with interferonopathies, experimental data have attested that type-I IFNs affect plaque-residing macrophages, potentiate foam cell and extracellular trap formation, induce endothelial dysfunction, alter the phenotypes of dendritic cells and T and B lymphocytes, and lead to exacerbated atherosclerosis outcomes. In this review, we discuss the production and the effects of type-I IFNs in different atherosclerosis-associated cell types from molecular biology studies, animal models, and clinical observations, and the potential of new therapies against type-I IFN signaling for atherosclerosis.

CTHRC1 in Ovarian Cancer Promotes M2-Like Polarization of Tumor-Associated Macrophages via Regulation of the STAT6 Signaling Pathway

Purpose

The infiltration of tumor-associated macrophages (TAMs) facilitates the progression of epithelial ovarian cancer (EOC). TAMs are mainly M2-like due to exposure to various factors in the tumor microenvironment. In our previous study, we reported that collagen triple helix repeat containing 1(CTHRC1), a secreted protein, is associated with ovarian cancer progression and metastasis. However, the correlation between CTHRC1 and the immunological microenvironment in EOC remains unknown.

Methods

The association with the expression of CTHRC1 and CD68⁺CD163⁺ TAMs infiltration density and phosphorylation of STAT6 was analyzed in tumor tissues of ovarian cancer patients by immunohistochemistry. Western blot and flow cytometry analysis were used to analyze M2-like macrophage polarization induced by CTHRC1. Cell Counting Kit-8 and adhesion assays were used to detect cell proliferation and adhesion, respectively. Cell migration and invasion were detected using transwell assays.

Results

In the present study, we observed that the overexpression of CTHRC1 and increased TAMs infiltration density are closely correlated to an advanced stage of EOC. Meanwhile, CTHRC1 expression was positively associated with the infiltration density of M2-like CD68⁺CD163⁺TAMs and phosphorylation of STAT6 in EOC. In human PBMC-derived monocytes, recombinant CTHRC1 protein (rCTHRC1) induces an M2-like macrophage phenotype, in a dose-dependent manner, characterized by activating the STAT6 signaling pathway. The conditioned culture medium of Lenti-CTHRC1 EOC cells promoted M2 polarization of macrophages, and by contrast, CTHRC1 knockdown abolished STAT6-mediated M2 polarization of macrophages. Moreover, the culture supernatants of rCTHRC1-treated macrophages efficiently increased the migration and invasion abilities of ovarian cancer cells.

Conclusion

Our data indicate that CTHRC1 might play an important role in regulating M2 polarization of macrophages in the ovarian tumor microenvironment and suggest that it is a potential therapeutic target for antitumor immunity.

Artemisinin inhibits the replication of flaviviruses by promoting the type I interferon production

Flaviviruses are considered to be major emerging human pathogens globally. Currently available anti-flavivirus approaches are ineffective, thus there is a desperate need for broad-spectrum drugs that can be active against existing and emerging flaviviruses. Artemisinin has been found to cause an antiviral effect against several viruses; however, its antiviral effect against flaviviruses remains unexplored. Here the antiviral activity of artemisinin against flaviviruses such as JEV, DENV, and ZIKV was evaluated by measuring the hallmark features of virus replication both in vitro and in vivo. Mechanistically, the artemisinin-induced antiviral effect was associated with enhanced host type I interferon response. The blocking of interferon signaling inhibited the artemisinin-induced interferon-stimulated genes expression and rescued the artemisinin-suppressed virus replication. This study demonstrated for the first time the antiviral activity of artemisinin against flaviviruses with a novel antiviral mechanism. The therapeutic application of artemisinin may constitute a broad-spectrum approach to cure infections caused by flaviviruses.

Induction of Samhd1 by interferon gamma and lipopolysaccharide in murine macrophages requires IRF1

SAMHD1 is an enzyme with phosphohydrolase activity. Mutations in SAMHD1 have been linked to the development of Aicardi-Goutières syndrome in humans. This enzyme also has the capacity to restrict HIV virus replication in macrophages. Here, we report that Samhd1 is highly expressed in murine macrophages and is regulated by proinflammatory (IFN-γ and LPS) but not by anti-inflammatory (IL-4 or IL-10) activators. The induction of Samhd1 follows the pattern of an intermediate gene that requires protein synthesis. In transient transfection experiments using the Samhd1 promoter, we found that a fragment of 27 bps of this gene, falling between -937 and -910 bps relative to the transcription start site, is required for IFN-γ-dependent activation. Using EMSAs, we determined that IFN-γ treatment led to the elimination of a protein complex. Chromatin immunoprecipitation assays and siRNA experiments revealed that IRF1 is required for IFN-γ- or LPS-induced Samhd1 expression. Therefore, our results indicate that Samhd1 is stimulated by proinflammatory agents IFN-γ and LPS. Moreover, they reveal that these two agents, via IRF1, eliminate a protein complex that may be related to a repressor, thereby, triggering Samhd1 expression.

JAK-STAT-dependent regulation of scavenger receptors in LPS-activated murine macrophages

In atherosclerosis progression, atherosclerotic plaques develop upon accumulated foam cells derived from macrophages that take up modified low-density lipoprotein (LDL). CD36 and CD204 are the principal scavenger receptors responsible for the uptake of modified LDL. Lipopolysaccharide (LPS) exacerbates atherosclerosis by enhancing the expression of scavenger receptors and thus increasing the uptake of modified LDL into macrophages. However, the signaling pathways that mediate LPS and scavenger receptor expression have not been fully elucidated. We used mouse bone marrow-derived macrophages and investigated the effects of LPS in vitro. LPS enhanced the phosphorylation of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription-1 (STAT-1). Inhibitors of the mitogen-activated protein kinase (MAPK)/ERK kinase (MEK) pathway (U0126 and PD0325901) suppressed the uptake of acetylated-LDL (Ac-LDL) and the expression of CD204 but not CD36 in LPS-activated macrophages. Inhibitors of the Janus tyrosine kinase (JAK)-STAT pathway (ruxolitinib and tofacitinib) suppressed the uptake of Ac-LDL and the expression of both CD36 and CD204 in LPS-activated macrophages. We next injected LPS into the peritoneal cavity of mice and analyzed the effects of LPS. MEK inhibitor U0126 suppressed the uptake of Ac-LDL and the expression of CD204 but not CD36 in LPS-activated macrophages. JAK inhibitor ruxolitinib suppressed the uptake of Ac-LDL and the expression of both CD36 and CD204 in LPS-activated macrophages. These results suggest that scavenger receptors in LPS-activated mouse macrophages are regulated through a JAK-STAT-dependent pathway. Although further evaluation is necessary, JAK-STAT inhibition could be useful in atherosclerosis therapy, at least for atherosclerosis exacerbated by LPS.

Causes and consequences of genomic instability in laminopathies: Replication stress and interferon response

Mammalian nuclei are equipped with a framework of intermediate filaments that function as a karyoskeleton. This nuclear scaffold, formed primarily by lamins (A-type and B-type), maintains the spatial and functional organization of the genome and of sub-nuclear compartments. Over the past decade, a body of evidence has highlighted the significance of these structural nuclear proteins in the maintenance of nuclear architecture and mechanical stability, as well as genome function and integrity. The importance of these structures is now unquestioned given the wide range of degenerative diseases that stem from LMNA gene mutations, including muscular dystrophy disorders, peripheral neuropathies, lipodystrophies, and premature aging syndromes. Here, we review our knowledge about how alterations in nuclear lamins, either by mutation or reduced expression, impact cellular mechanisms that maintain genome integrity. Despite the fact that DNA replication is the major source of DNA damage and genomic instability in dividing cells, how alterations in lamins function impact replication remains minimally explored. We summarize recent studies showing that lamins play a role in DNA replication, and that the DNA damage that accumulates upon lamins dysfunction is elicited in part by deprotection of replication forks. We also discuss the emerging model that DNA damage and replication stress are “sensed” at the cytoplasm by proteins that normally survey this space in search of foreign nucleic acids. In turn, these cytosolic sensors activate innate immune responses, which are materializing as important players in aging and cancer, as well as in the response to cancer immunotherapy.

Targeted inhibition of STAT3 as a potential treatment strategy for atherosclerosis

Atherosclerosis is the main pathological basis of ischemic cardiovascular and cerebrovascular diseases and has attracted more attention in recent years. Multiple studies have demonstrated that the signal transducer and activator of transcription 3 (STAT3) plays essential roles in the process of atherosclerosis. Moreover, aberrant STAT3 activation has been shown to contribute to the occurrence and development of atherosclerosis. Therefore, the study of STAT3 inhibitors has gradually become a focal research topic. In this review, we describe the crucial roles of STAT3 in endothelial cell dysfunction, macrophage polarization, inflammation, and immunity during atherosclerosis. STAT3 in mitochondria is mentioned as well. Then, we present a summary and classification of STAT3 inhibitors, which could offer potential treatment strategies for atherosclerosis. Furthermore, we enumerate some of the problems that have interfered with the development of mature therapies utilizing STAT3 inhibitors to treat atherosclerosis. Finally, we propose ideas that may help to solve these problems to some extent. Collectively, this review may be useful for developing future STAT3 inhibitor therapies for atherosclerosis.

Anti-inflammatory and antioxidative effects of Dan-Lou tablets in the treatment of coronary heart disease revealed by metabolomics integrated with molecular mechanism studies

ETHNOPHARMACOLOGICAL EVIDENCE

The Dan-Lou tablet (DLT), a well-known Chinese prescription, has definitive clinical efficacy in the treatment of precordial discomfort and pain caused by coronary heart disease (CHD). However, the pharmacological mechanism of DLT in the treatment of CHD has not been clearly elucidated and needs to be further explored.

AIM OF THE STUDY

We aimed to identify relevant biological pathways by assessing changes in biomarkers in response to DLT intervention in CHD to reveal the potential biological mechanism of DLT treatment for CHD.

MATERIALS AND METHODS

The major chemical components in DLT were qualitatively analyzed using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), and a model of CHD in rats was subsequently established with a high-fat diet and left anterior coronary artery ligation (LADCA) followed by DLT intervention. Next, the metabolic profile of rat serum samples was analyzed using nontargeted metabolomics, wherein changes in the metabolites in serum samples before and after DLT administration were measured by PLS-DA, and two pathways of DLT treatment for CHD were predicted. Finally, predicted metabolomic pathways were verified by detecting and analyzing tissues from the rat model, revealing the mechanism of DLT in the treatment of CHD.

RESULTS

Forty-five major chemical components were identified by the chemical characterization of DLT. In terms of metabolism, 17 biomarkers of CHD in rats were identified. Among these biomarkers, linoleic acid, γ-linolenic acid and lysophosphatidylcholines (LPCs) were found to play an important role in energy metabolism and glycerophospholipid metabolism. Protein analysis revealed that EGFR phosphorylation was inhibited in CHD rats after DLT treatment, which lowered the expression of TNF-α, IL-6 and MMP9, decreased the expression levels of ox-LDL and MDA, and increased the expression of SOD.

CONCLUSION

The mechanism of DLT in the treatment of CHD involves inhibiting the expression of EGFR and the activation of the MAPK signaling pathway by regulating glycerophospholipid metabolism (LPCs) and energy metabolism (linoleic acid and γ-linolenic acid). Therefore, inflammation-related (TNF-α, IL-6, MMP9) and oxidative stress-related (ox-LDL, MDA, SOD) indicators are affected, leading to the regulation of the oxidative stress state and anti-inflammatory effects.

Genomic instability and innate immune responses to self-DNA in progeria

In the last decade, we have seen increasing evidence of the importance of structural nuclear proteins such as lamins in nuclear architecture and compartmentalization of genome function and in the maintenance of mechanical stability and genome integrity. With over 400 mutations identified in the LMNA gene (encoding for A-type lamins) associated with more than ten distinct degenerative disorders, the role of lamins as genome caretakers and the contribution of lamins dysfunction to disease are unarguable. However, the molecular mechanisms whereby lamins mutations cause pathologies remain less understood. Here, we review pathways and mechanisms recently identified as playing a role in the pathophysiology of laminopathies, with special emphasis in Hutchinson Gilford Progeria Syndrome (HGPS). This devastating incurable accelerated aging disease is caused by a silent mutation in the LMNA gene that generates a truncated lamin A protein "progerin" that exerts profound cellular toxicity and organismal decline. Patients usually die in their teens due to cardiovascular complications such as myocardial infarction or stroke. To date, there are no efficient therapies that ameliorate disease progression, stressing the need to understand molecularly disease mechanisms that can be targeted therapeutically. We will summarize data supporting that replication stress is a major cause of genomic instability in laminopathies, which contributes to the activation of innate immune responses to self-DNA that in turn accelerate the aging process.

Immune Reconstitution Disorders: Spotlight on Interferons

Three decades of research in hematopoietic stem cell transplantation and HIV/AIDS fields have shaped a picture of immune restoration disorders. This manuscript overviews the molecular biology of interferon networks, the molecular pathogenesis of immune reconstitution inflammatory syndrome, and post-hematopoietic stem cell transplantation immune restoration disorders (IRD). It also summarizes the effects of thymic involution on T cell diversity, and the results of the assessment of diagnostic biomarkers of IRD, and tested targeted immunomodulatory treatments.

Hutchinson-Gilford Progeria Syndrome: Challenges at Bench and Bedside

The structural nuclear proteins known as "lamins" (A-type and B-type) provide a scaffold for the compartmentalization of genome function that is important to maintain genome stability. Mutations in the LMNA gene -encoding for A-type lamins- are associated with over a dozen of degenerative disorders termed laminopathies, which include muscular dystrophies, lipodystrophies, neuropathies, and premature ageing diseases such as Hutchinson Gilford Progeria Syndrome (HGPS). This devastating disease is caused by the expression of a truncated lamin A protein named "progerin". To date, there is no effective treatment for HGPS patients, who die in their teens from cardiovascular disease. At a cellular level, progerin expression impacts nuclear architecture, chromatin organization, response to mechanical stress, and DNA transactions such as transcription, replication and repair. However, the current view is that key mechanisms behind progerin toxicity still remain to be discovered. Here, we discuss new findings about pathological mechanisms in HGPS, especially the contribution of replication stress to cellular decline, and therapeutic strategies to ameliorate progerin toxicity. In particular, we present evidence for retinoids and calcitriol (hormonal vitamin D metabolite) being among the most potent compounds to ameliorate HGPS cellular phenotypes in vitro, providing the rationale for testing these compounds in preclinical models of the disease in the near term, and in patients in the future.

A Cell-Intrinsic Interferon-like Response Links Replication Stress to Cellular Aging Caused by Progerin

Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disease caused by a truncated lamin A protein (progerin) that drives cellular and organismal decline. HGPS patient-derived fibroblasts accumulate genomic instability, but its underlying mechanisms and contribution to disease remain poorly understood. Here, we show that progerin-induced replication stress (RS) drives genomic instability by eliciting replication fork (RF) stalling and nuclease-mediated degradation. Rampant RS is accompanied by upregulation of the cGAS/STING cytosolic DNA sensing pathway and activation of a robust STAT1-regulated interferon (IFN)-like response. Reducing RS and the IFN-like response, especially with calcitriol, improves the fitness of progeria cells and increases the efficiency of cellular reprogramming. Importantly, other compounds that improve HGPS phenotypes reduce RS and the IFN-like response. Our study reveals mechanisms underlying progerin toxicity, including RS-induced genomic instability and activation of IFN-like responses, and their relevance for cellular decline in HGPS.

Direct Inhibition of IRF-Dependent Transcriptional Regulatory Mechanisms Associated With Disease

Interferon regulatory factors (IRFs) are a family of homologous proteins that regulate the transcription of interferons (IFNs) and IFN-induced gene expression. As such they are important modulating proteins in the Toll-like receptor (TLR) and IFN signaling pathways, which are vital elements of the innate immune system. IRFs have a multi-domain structure, with the N-terminal part acting as a DNA binding domain (DBD) that recognizes a DNA-binding motif similar to the IFN-stimulated response element (ISRE). The C-terminal part contains the IRF-association domain (IAD), with which they can self-associate, bind to IRF family members or interact with other transcription factors. This complex formation is crucial for DNA binding and the commencing of target-gene expression. IRFs bind DNA and exert their activating potential as homo or heterodimers with other IRFs. Moreover, they can form complexes (e.g., with Signal transducers and activators of transcription, STATs) and collaborate with other co-acting transcription factors such as Nuclear factor-κB (NF-κB) and PU.1. In time, more of these IRF co-activating mechanisms have been discovered, which may play a key role in the pathogenesis of many diseases, such as acute and chronic inflammation, autoimmune diseases, and cancer. Detailed knowledge of IRFs structure and activating mechanisms predisposes IRFs as potential targets for inhibition in therapeutic strategies connected to numerous immune system-originated diseases. Until now only indirect IRF modulation has been studied in terms of antiviral response regulation and cancer treatment, using mainly antisense oligonucleotides and siRNA knockdown strategies. However, none of these approaches so far entered clinical trials. Moreover, no direct IRF-inhibitory strategies have been reported. In this review, we summarize current knowledge of the different IRF-mediated transcriptional regulatory mechanisms and how they reflect the diverse functions of IRFs in homeostasis and in TLR and IFN signaling. Moreover, we present IRFs as promising inhibitory targets and propose a novel direct IRF-modulating strategy employing a pipeline approach that combines comparative in silico docking to the IRF-DBD with in vitro validation of IRF inhibition. We hypothesize that our methodology will enable the efficient identification of IRF-specific and pan-IRF inhibitors that can be used for the treatment of IRF-dependent disorders and malignancies.

Integrative Analysis Identified IRF6 and NDST1 as Potential Causal Genes for Ischemic Stroke

Objective: To highlight potential functional variants and causal genes for ischemic stroke (IS) in genomic loci identified by genome-wide association studies (GWAS).

Methods: We examined the association between m⁶A-SNPs and IS in large scale GWAS. Furthermore, eQTL analysis was performed to evaluate the effect of m⁶A-SNPs on gene expression. The top associations between m⁶A-SNPs and gene expressions were validated in 40 individuals from the Chinese Han population. Besides, we applied differential expression analysis and Mendelian randomization (MR) analysis to detect potential causal genes for IS.

Results: We found 310 (7.39%) m⁶A-SNPs which were nominally associated with IS. The proportion of m⁶A-SNPs with P < 0.05 for IS was significantly higher than the non-m⁶A-SNPs (95%CI: [5.84%, 7.36%], P = 0.02). We found that the IS-associated m⁶A-SNP rs2013162 was associated with IRF6 expression (P = 6.30 × 10⁻²³), meanwhile IRF6 was differentially expressed between IS cases and controls (P = 6.15 × 10⁻³) and showed a causal association with IS (P = 3.64 × 10⁻⁴). Similar results were found for m⁶A-SNP rs2273235 in the NDST1 gene which was associated with cardioembolic stroke (P = 8.47 × 10⁻³). The associations of rs2013162 and rs2273235 with the expression of IRF6 and NDST1 were validated in blood cells (P = 0.0247 and 0.0007), respectively.

Conclusions: This study showed that m⁶A-SNPs may affect IS risk through altering gene expressions. The results suggested that m⁶A might play a role in IS etiology and gene expressions that affected by m⁶A may be causal factors for IS.

In silico epigenetics of metal exposure and subclinical atherosclerosis in middle aged men: pilot results from the Aragon Workers Health Study

We explored the association of metal levels with subclinical atherosclerosis and epigenetic changes in relevant biological pathways. Whole blood DNA Infinium Methylation 450 K data were obtained from 23 of 73 middle age men without clinically evident cardiovascular disease (CVD) who participated in the Aragon Workers Health Study in 2009 (baseline visit) and had available baseline urinary metals and subclinical atherosclerosis measures obtained in 2010-2013 (follow-up visit). The median metal levels were 7.36 µg g^-1, 0.33 µg g^-1, 0.11 µg g^-1 and 0.07 µg g^-1, for arsenic (sum of inorganic and methylated species), cadmium, antimony and tungsten, respectively. Urine cadmium and tungsten were associated with femoral and carotid intima-media thickness, respectively (Pearson's r = 0.27; p = 0.03 in both cases). Among nearest genes to identified differentially methylated regions (DMRs), 46% of metal-DMR genes overlapped with atherosclerosis-DMR genes (p < 0.001). Pathway enrichment analysis of atherosclerosis-DMR genes showed a role in inflammatory, metabolic and transport pathways. In in silico protein-to-protein interaction networks among proteins encoded by 162 and 108 genes attributed to atherosclerosis- and metal-DMRs, respectively, with proteins known to have a role in atherosclerosis pathways, we observed hub proteins in the network associated with both atherosclerosis and metal-DMRs (e.g. SMAD3 and NOP56), and also hub proteins associated with metal-DMRs only but with relevant connections with atherosclerosis effectors (e.g. SSTR5, HDAC4, AP2A2, CXCL12 and SSTR4). Our integrative in silico analysis demonstrates the feasibility of identifying epigenomic regions linked to environmental exposures and potentially involved in relevant pathways for human diseases. While our results support the hypothesis that metal exposures can influence health due to epigenetic changes, larger studies are needed to confirm our pilot results.This article is part of a discussion meeting issue 'Frontiers in epigenetic chemical biology'.

Physalactone and 4β-Hydroxywithanolide E Isolated from Physalis peruviana Inhibit LPS-Induced Expression of COX-2 and iNOS Accompanied by Abatement of Akt and STAT1

In previous studies, withanolides isolated from Physalis peruviana were found to exhibit anti-inflammatory potential by suppressing nitrite production induced by lipopolysaccharide (LPS) treatment. Currently, we selected two of the most potent compounds, 4β-hydroxywithanolide E (1) and physalactone (2), to examine the underlying mechanism of action. With LPS-stimulated RAW 264.7 cells in culture, the compounds inhibited the mRNA and protein expression of iNOS and COX-2. To determine which upstream signaling proteins were involved in these effects, phosphorylation levels of three mitogen-activated protein kinases (MAPKs) including ERK1/2, JNK1/2, and p38, were examined, but found unaffected. Similarly, the degradation of IκBα was not attenuated by the compounds. However, phosphorylation of Akt at the Ser-473 residue was inhibited, as was the phosphorylation of STAT1. Interestingly, the compounds also reduced the protein level of total STAT1, possibly by ubiquitin-dependent protein degradation. In sum, these results indicate the potential of 1 and 2 to mediate anti-inflammatory effects through the unexpected mechanism of inhibiting the transcription of iNOS and COX-2 via Akt- and STAT1-related signaling pathways.

IRF1 inhibits the proliferation and metastasis of colorectal cancer by suppressing the RAS-RAC1 pathway

Background

Interferon regulatory factor 1 (IRF1) plays a role in the immune response, cellular necrosis, DNA damage, and DNA repair, offering an attractive target for anticancer treatment. However, little is known about the role of IRF1 in the regulation of CRC progression.

Methods

Quantitative reverse transcription-PCR, Western blot, and immunohistochemistry were used to examine the expression level of IRF1; Cell Counting Kit-8, migration assay, and xenograft mouse models were used to examine the function of IRF1 in CRC cell lines; a ChIP assay was used to examine the binding between IRF1 and Ras association domain-containing protein 5 (RASSF5).

Results

IRF1 expression was lower in colorectal cancer (CRC) than in normal mucosa and the IRF1 expression level was inversely associated with CRC metastasis. In addition, IRF1 could inhibit CRC cell proliferation, migration, and metastasis in vivo and in vitro; IRF1 also induced cell cycle arrest but had no effect on cell apoptosis. IRF1 enhanced the expression of RASSF5 by increasing its promoter activity. Moreover, this study revealed a novel mechanism for inhibiting the RAS-RAC1 pathway by overexpression of RASSF5.

Conclusion

Altogether, the results indicate that IRF1, which promotes RASSF5 expression, suppresses CRC metastasis and proliferation possibly through downregulation of the RAS-RAC1 pathway.

IFN-β Plays Both Pro- and Anti-inflammatory Roles in the Rat Cardiac Fibroblast Through Differential STAT Protein Activation

Cardiac fibroblasts (CFs) contribute to theinflammatory response to tissue damage, secreting both pro- and anti-inflammatory cytokines and chemokines. Interferon beta (IFN-β) induces the phosphorylation of signal transducer and activator of transcription (STAT) proteins through the activation of its own receptor, modulating the secretion of cytokines and chemokines which regulate inflammation. However, the role of IFN-β and STAT proteins in modulating the inflammatory response of CF remains unknown. CF were isolated from adult male rats and subsequently stimulated with IFN-β to evaluate the participation of STAT proteins in secreting chemokines, cytokines, cell adhesion proteins expression and in their capacity to recruit neutrophils. In addition, in CF in which the TRL4 receptor was pre-activated, the effect of INF-β on the aforementioned responses was also evaluated. Cardiac fibroblasts stimulation with IFN-β showed an increase in STAT1, STAT2, and STAT3 phosphorylation. IFN-β stimulation through STAT1 activation increased proinflammatory chemokines MCP-1 and IP-10 secretion, whereas IFN-β induced activation of STAT3 increased cytokine secretion of anti-inflammatory IL-10. Moreover, in TLR4-activated CF, IFN-β through STAT2 and/or STAT3, produced an anti-inflammatory effect, reducing pro-IL-1β, TNF-α, IL-6, MCP-1, and IP-10 secretion; and decreasing neutrophil recruitment by decreasing ICAM-1 and VCAM-1 expression. Altogether, our results indicate that IFN-β exerts both pro-inflammatory and anti-inflammatory effects in non-stimulated CF, through differential activation of STAT proteins. When CF were previously treated with an inflammatory agent such as TLR-4 activation, IFN-β effects were predominantly anti-inflammatory.

Genome-Wide Inhibition of Pro-atherogenic Gene Expression by Multi-STAT Targeting Compounds as a Novel Treatment Strategy of CVDs

Cardiovascular diseases (CVDs), including atherosclerosis, are globally the leading cause of death. Key factors contributing to onset and progression of atherosclerosis include the pro-inflammatory cytokines Interferon (IFN)α and IFNγ and the Pattern Recognition Receptor (PRR) Toll-like receptor 4 (TLR4). Together, they trigger activation of Signal Transducer and Activator of Transcription (STAT)s. Searches for compounds targeting the pTyr-SH2 interaction area of STAT3, yielded many small molecules, including STATTIC and STX-0119. However, many of these inhibitors do not seem STAT3-specific. We hypothesized that multi-STAT-inhibitors that simultaneously block STAT1, STAT2, and STAT3 activity and pro-inflammatory target gene expression may be a promising strategy to treat CVDs. Using comparative in silico docking of multiple STAT-SH2 models on multi-million compound libraries, we identified the novel multi-STAT inhibitor, C01L_F03. This compound targets the SH2 domain of STAT1, STAT2, and STAT3 with the same affinity and simultaneously blocks their activity and expression of multiple STAT-target genes in HMECs in response to IFNα. The same in silico and in vitro multi-STAT inhibiting capacity was shown for STATTIC and STX-0119. Moreover, C01L_F03, STATTIC and STX-0119 were also able to affect genome-wide interactions between IFNγ and TLR4 by commonly inhibiting pro-inflammatory and pro-atherogenic gene expression directed by cooperative involvement of STATs with IRFs and/or NF-κB. Moreover, we observed that multi-STAT inhibitors could be used to inhibit IFNγ+LPS-induced HMECs migration, leukocyte adhesion to ECs as well as impairment of mesenteric artery contractility. Together, this implicates that application of a multi-STAT inhibitory strategy could provide great promise for the treatment of CVDs.

Atlas of the Immune Cell Repertoire in Mouse Atherosclerosis Defined by Single-Cell RNA-Sequencing and Mass Cytometry

RATIONALE

Atherosclerosis is a chronic inflammatory disease that is driven by the interplay of pro- and anti-inflammatory leukocytes in the aorta. Yet, the phenotypic and transcriptional diversity of aortic leukocytes is poorly understood.

OBJECTIVE

We characterized leukocytes from healthy and atherosclerotic mouse aortas in-depth by single-cell RNA-sequencing and mass cytometry (cytometry by time of flight) to define an atlas of the immune cell landscape in atherosclerosis.

METHODS AND RESULTS

Using single-cell RNA-sequencing of aortic leukocytes from chow diet- and Western diet-fed Apoe^-/- and Ldlr^-/- mice, we detected 11 principal leukocyte clusters with distinct phenotypic and spatial characteristics while the cellular repertoire in healthy aortas was less diverse. Gene set enrichment analysis on the single-cell level established that multiple pathways, such as for lipid metabolism, proliferation, and cytokine secretion, were confined to particular leukocyte clusters. Leukocyte populations were differentially regulated in atherosclerotic Apoe^-/- and Ldlr^-/- mice. We confirmed the phenotypic diversity of these clusters with a novel mass cytometry 35-marker panel with metal-labeled antibodies and conventional flow cytometry. Cell populations retrieved by these protein-based approaches were highly correlated to transcriptionally defined clusters. In an integrated screening strategy of single-cell RNA-sequencing, mass cytometry, and fluorescence-activated cell sorting, we detected 3 principal B-cell subsets with alterations in surface markers, functional pathways, and in vitro cytokine secretion. Leukocyte cluster gene signatures revealed leukocyte frequencies in 126 human plaques by a genetic deconvolution strategy. This approach revealed that human carotid plaques and microdissected mouse plaques were mostly populated by macrophages, T-cells, and monocytes. In addition, the frequency of genetically defined leukocyte populations in carotid plaques predicted cardiovascular events in patients.

CONCLUSIONS

The definition of leukocyte diversity by high-dimensional analyses enables a fine-grained analysis of aortic leukocyte subsets, reveals new immunologic mechanisms and cell-type-specific pathways, and establishes a functional relevance for lesional leukocytes in human atherosclerosis.

JAK inhibition as a therapeutic strategy for immune and inflammatory diseases

This corrects the article DOI: 10.1038/nrd.2017.201.

Lysophosphatidylcholine induces cytotoxicity/apoptosis and IL-8 production of human endothelial cells: Related mechanisms

Increased levels of oxidized low-density lipoprotein oxLDL) are shown to elevate the risk of cardiovascular diseases such as atherosclerosis, thrombosis, stroke, and myocardial infarction. This is possibly due to the toxic effects of oxLDLs on vascular cells. Various oxLDLs including lysophosphatidylcholine (LPC) and 7-ketocholesterol injure vascular endothelial cells and stimulate inflammatory reaction. However the toxicity of LPC on endothelial cells is not clear. In this study, human endothelial cells were exposed to LPC. Cytotoxicity was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. Propidium iodide (PI) staining or PI/Annexin V dual staining flow cytometry were used to determine cell cycle progression and apoptosis. Reactive oxygen species (ROS) level was analyzed by DCFH-DA labeling flow cytometry. RNA and protein expression of endothelial cells was studied by reverse transcriptase-polymerase chain reaction and western blotting. IL-8 secretion was measured by enzyme-linked immunosorbant assay. LPC showed cytotoxicity to endothelial cells (>50 µg/ml). LPC induced cell cycle arrest and apoptosis with concomitant inhibition of cdc2 and cyclin B1 expression. LPC stimulated intracellular ROS production and ATM/Chk2, ATR/Chk1 and Akt activation. IL-8 expression and secretion in endothelial cells were induced by LPC. LPC-induced apoptosis, and IL-8 expression/secretion was attenuated by LY294002, a PI3K/Akt inhibitor. These results reveal that LPC is involved in the pathogenesis of atherosclerosis and vascular diseases by stimulation of inflammation and injury to endothelial cells. These events are related to ROS, ATM/Chk2, ATR/Chk2 and PI3K/Akt signaling. Understanding the toxic mechanisms of LPC is useful for future prevention and treatment atherosclerosis.

JAK inhibition as a therapeutic strategy for immune and inflammatory diseases

The discovery of cytokines as key drivers of immune-mediated diseases has spurred efforts to target their associated signalling pathways. Janus kinases (JAKs) are essential signalling mediators downstream of many pro-inflammatory cytokines, and small-molecule inhibitors of JAKs (jakinibs) have gained traction as safe and efficacious options for the treatment of inflammation-driven pathologies such as rheumatoid arthritis, psoriasis and inflammatory bowel disease. Building on the clinical success of first-generation jakinibs, second-generation compounds that claim to be more selective are currently undergoing development and proceeding to clinical trials. However, important questions remain about the advantages and limitations of improved JAK selectivity, optimal routes and dosing regimens and how best to identify patients who will benefit from jakinibs. This Review discusses the biology of jakinibs from a translational perspective, focusing on recent insights from clinical trials, the development of novel agents and the use of jakinibs in a spectrum of immune and inflammatory diseases.

Endothelial STAT3 Modulates Protective Mechanisms in a Mouse Ischemia-Reperfusion Model of Acute Kidney Injury

STAT3 is a transcriptional regulator that plays an important role in coordinating inflammation and immunity. In addition, there is a growing appreciation of the role STAT3 signaling plays in response to organ injury following diverse insults. Acute kidney injury (AKI) from ischemia-reperfusion injury is a common clinical entity with devastating consequences, and the recognition that endothelial alterations contribute to kidney dysfunction in this setting is of growing interest. Consequently, we used a mouse with a genetic deletion of Stat3 restricted to the endothelium to examine the role of STAT3 signaling in the pathophysiology of ischemic AKI. In a mouse model of ischemic AKI, the loss of endothelial STAT3 signaling significantly exacerbated kidney dysfunction, morphologic injury, and proximal tubular oxidative stress. The increased severity of ischemic AKI was associated with more robust endothelial-leukocyte adhesion and increased tissue accumulation of F4/80+ macrophages. Moreover, important proximal tubular adaptive mechanisms to injury were diminished in association with decreased tissue mRNA levels of the epithelial cell survival cytokine IL-22. In aggregate, these findings suggest that the endothelial STAT3 signaling plays an important role in limiting kidney dysfunction in ischemic AKI and that selective pharmacologic activation of endothelial STAT3 signaling could serve as a potential therapeutic target.

MicroRNA-125a-5p plays a role as a tumor suppressor in lung carcinoma cells by directly targeting STAT3

Increasing evidence supports that the dysregulation of microRNA expression plays an important role in the process of tumor occurrence and development. Studies have found that mir-125a-5p expression was downregulated in a variety of tumors, but the effects and mechanism of mir-125a-5p in lung cancer are still unclear. The aim of this study is to detect the expression of mir-125a-5p in lung cancer tissues and lung cancer cell lines and to explore the effects of mir-125a-5p on the biological characteristics of lung cancer cells; thus, this study aims to provide new methods and new strategies for the treatment of lung cancer. The result from quantitative reverse transcription polymerase chain reaction showed that the expression of miR-125a-5p was significantly lower in lung cancer tissues and lung cancer cell lines (95-D, A549, HCC827, and NCI-H1299) than that in normal tissue adjacent to lung cancer or normal human bronchial epithelial cells. In order to explore the function and mechanism of mir-125a-5p in lung cancer cells, miR-125a-5p mimic or mir-125a-5p inhibitor was transfected into A549 cells. Mir-125a-5p displayed an obvious upregulation in A549 cells transfected with miR-125a-5p and an obvious downregulation in A549 cells transfected with mir-125a-5p inhibitor compared to that in A549 cells transfected with control miRNA. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, BrdU staining, flow cytometry, and Transwell assay showed that the upregulation of miR-125a-5p could significantly decrease the cell viability, proliferation, and invasion of lung cancer cells and increase apoptosis of lung cancer cells. The downregulation of miR-125a-5p provided very contrasting results. Computational algorithms predicted that the STAT3 is a target of miR-125a-5p. Here, we validated that miR-125a-5p could directly bind to the 3'-untranslated region of STAT3, and miR-125a-5p overexpression could significantly inhibit the protein expression of STAT3. These results suggested that mir-125a-5p can regulate the expression of STAT3 in lung cancer cells. To further verify whether mir-125a-5p can play a biological role through regulating STAT3, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, flow cytometry, and Transwell analysis demonstrated that overexpression of STAT3 can reverse the cells' biological effects induced by mir-125a-5p overexpression. Mir-125a-5p downregulated in lung cancer tissue and cell lines can negatively regulate STAT3 protein expression. Taken together, mir-125a-5p inhibited the proliferation and invasion of lung cancer cells and facilitated lung cancer cell apoptosis through suppressing STAT3. Enhancing the expression of miR-125a-5p is expected to benefit the therapy for the patients with lung cancer.

A novel engineered interferon-α hybrid molecule increases anticancer efficacy of doxorubicin in breast cancer chemotherapy

Breast cancer is the most common carcinoma among Chinese women. Interferon α (IFNα) has been used to treat various types of cancer, including breast cancer, but its antitumor activity is relative low, which significantly hinders its clinical application. In this study, we utilized a Ph.D.-12 peptide library screening system to identify a short peptide that specifically binds to MCF-7 breast cancer cells. By fusing the MCF-7 binding peptide (MBP) to the C-terminus of IFNα, we constructed an engineered IFNα-MBP fusion molecule (IMBP), and applied this novel fusion protein to the treatment of breast cancer. We found that IMBP exhibited significantly higher activity than wild-type IFNα in inhibiting cell growth and inducing cell apoptosis. Additionally, IMBP potentiated the therapeutic efficacy of doxorubicin-based breast cancer chemotherapy via the activation of cell cycle arrest and cell apoptosis pathway genes including p53, p21, CDK2, cyclin A, caspase 9, Bcl-2 and Bax. The enhanced activity of the synthetic IMBP was also associated with the activation of signal transducer and activation of transcription 1 (STAT1) pathway target genes (STAT1, IFIT1, IFITM1 and MX1). This study evaluated the potential value of the synthetic IMBP as a novel anti-breast cancer agent.

STAT6 Upregulation Promotes M2 Macrophage Polarization to Suppress Atherosclerosis

Background

Macrophages are highly heterogeneous and plastic cells that are involved in all stages of atherogenesis. They can undergo polarization by shifting between M1 and M2 functional phenotypes. However, the role of macrophage polarization and the molecular mechanism in modulating atherosclerotic plaque stability remain incompletely understood. Our study investigated the role of STAT6 in regulating macrophage phenotypes to affect atherosclerotic plaque stability.

Material/Methods

A murine atherosclerosis model with vulnerable plaques was induced with high-cholesterol diet and PCCP surgeries in ApoE^−/− mice. Murine macrophages RAW264.7 treated with ox-LDL or IL-4 were used to simulate the in vitro process. pcDNA3.1(−)/STAT6-expressing vectors were transfected into RAW264.7 to evaluate its effect on cell polarization and the involved molecules.

Results

Unstable plaques presented significantly increased M1 markers (CD86 and iNOS) and less M2 markers (Arg-1 and TGF-β) than the stable plaques. Moreover, we found that STAT6 and p-STAT6 were greatly decreased in the vulnerable plaques and ox-LDL-induced macrophages, while their expression was elevated after IL-4 stimulation. The overexpression of STAT6 substantially reversed the ox-LDL-stimulated macrophage apoptosis and lipid accumulation. STAT6 upregulation promoted the differentiation of macrophage to M2 subtype as reflected by the increased expression of Arg-1 and TGF-β. Furthermore, we found that STAT6 overexpression activated the Wnt-β-catenin signaling by enhancing the translocation of β-catenin, while β-catenin suppression inhibited STAT6 overexpression-induced M2 polarization.

Conclusions

STAT6 facilitated atherosclerotic plaque stabilization by promoting the polarization of macrophages to M2 subtype and antagonizing ox-LDL-induced cell apoptosis and lipid deposition in a Wnt-β-catenin-dependent manner.

Reprogramming Interferon Regulatory Factor Signaling in Cardiometabolic Diseases

Interferon regulatory factors (IRFs) are evolutionarily conserved proteins expressed not only in immune cells but also in other tissues and organs outside the immune system. In this review, we discuss mechanisms responsible for IRF-mediated innate immune responses and the function and mechanism of IRFs in cardiometabolic diseases. We focus on the role of IRFs in innate immunity and cardiometabolic homeostasis, and highlight reprogrammed IRF signaling.

STAT5-Interacting Proteins: A Synopsis of Proteins that Regulate STAT5 Activity

Signal Transducers and Activators of Transcription (STATs) are key components of the JAK/STAT pathway. Of the seven STATs, STAT5A and STAT5B are of particular interest for their critical roles in cellular differentiation, adipogenesis, oncogenesis, and immune function. The interactions of STAT5A and STAT5B with cytokine/hormone receptors, nuclear receptors, transcriptional regulators, proto-oncogenes, kinases, and phosphatases all contribute to modulating STAT5 activity. Among these STAT5 interacting proteins, some serve as coactivators or corepressors to regulate STAT5 transcriptional activity and some proteins can interact with STAT5 to enhance or repress STAT5 signaling. In addition, a few STAT5 interacting proteins have been identified as positive regulators of STAT5 that alter serine and tyrosine phosphorylation of STAT5 while other proteins have been identified as negative regulators of STAT5 via dephosphorylation. This review article will discuss how STAT5 activity is modulated by proteins that physically interact with STAT5.

Quercetin Inhibits LPS-Induced Inflammation and ox-LDL-Induced Lipid Deposition

Aberrant activation of inflammation and excess accumulation of lipids play crucial role in the occurrence and progression of atherosclerosis (AS). Quercetin (QCT) has been tested effectively to cure AS. It is widely distributed in plant foods and has been proved to have potential antioxidative and anticancer activities. However, the underlying molecular mechanisms of OCT in AS are not completely understood. In the present study, we stimulated murine RAW264.7 cells with lipopolysaccharide (LPS) or oxidized low-density lipoproteins (ox-LDL) to mimic the development of AS. The data show that QCT treatment leads to an obvious decrease of multiple inflammatory cytokines in transcript level, including interleukin (IL)-1α, IL-1β, IL-2, IL-10, macrophage chemoattractant protein-1 (MCP-1), and cyclooxygenase-2 (COX-2) induced by LPS. Moreover, expressions of other factors that contribute to the AS development, such as matrix metalloproteinase-1 (MMP-1) and suppressor of cytokine signaling 3 (SOCS3) induced by LPS are also downregulated by QCT. Furthermore, we found that QCT suppressed LPS-induced the phosphorylation of STAT3. Meanwhile, QCT could ameliorate lipid deposition and overproduction of reactive oxygen species induced by ox-LDL, and block the expression of lectin-like oxidized LDL receptor-1 (LOX-1) in cultured macrophages. Taken together, our data reveal that QCT has obvious anti-inflammatory and antioxidant virtues and could be a therapeutic agent for the prevention and treatment of AS.