Y-box binding protein-1 controls CC chemokine ligand-5 (CCL5) expression in smooth muscle cells and contributes to neointima formation in atherosclerosis-prone mice

Y-box binding protein 1: A critical target for understanding and treating cardiovascular disease

Cardiovascular diseases (CVDs) remain a significant public health burden, characterized by escalating morbidity and mortality rates and demanding novel therapeutic approaches. Cold shock protein Y-box binding protein 1 (YB-1), a highly conserved RNA/DNA-binding protein, has emerged as a pivotal regulator in various pathophysiological processes, including CVDs. YB-1 exerts pleiotropic functions by modulating gene transcription, pre-mRNA splicing, mRNA translation, and stability. The expression and function of YB-1 are intricately regulated by its subcellular localization, post-translational modifications, upstream regulatory signals. YB-1 plays a multifaceted role in CVDs, influencing inflammation, oxidative stress, cell proliferation, apoptosis, phenotypic switching of smooth muscle cells, and mitochondrial dysfunction. However, the regulation of YB-1 expression and function in CVDs is complex and context-dependent, exhibiting divergent effects even in the same disease across different cell types or at disease stages. This review comprehensively explores the structure, regulation, and functional significance of YB-1 in CVDs. We delve into the transcriptional and translational control mechanisms of YB-1, as well as its post-translational modifications. Furthermore, we elucidate the upstream signaling pathways that influence YB-1 expression, with a particular emphasis on non-coding RNAs and specific upstream molecules. Finally, we systematically examine the role of YB-1 in CVDs, summarizing its expression patterns, regulatory mechanisms, and therapeutic potential as a promising target for novel therapeutic interventions. By providing a comprehensive overview of YB-1's involvement in CVDs, this review aims to stimulate further research and facilitate the development of targeted therapies to improve cardiovascular health.

ALKBH5 Regulates Macrophage Senescence and Accelerates Atherosclerosis by Promoting CCL5 m6A Modification

BACKGROUND

Senescent foamy macrophages are key drivers of atherosclerosis and plaque instability. N6-methyladenosine (m6A) modification of RNA plays an important role in the development of various diseases including aging. Here, we aim to investigate the role of m6A modification of RNA in the formation of senescent foamy macrophages in atherosclerosis.

METHODS

To assess m6A methylation, macrophages were isolated from the atherosclerotic plaques of patients with atherosclerosis, and Apoe-/- mice were fed a high-fat diet using CD68+ magnetic beads. An ALKBH5 (alkB homolog 5)f/f, Lyz2 (lysozyme 2)Cre, Apoe-/- mouse model was generated to determine the infiltration of senescent foamy macrophages into plaques and atherosclerosis progression. Methylated RNA immunoprecipitation, RNA immunoprecipitation sequencing, and dual-luciferase assays were performed to explore the mechanisms underlying the ALKBH5-mediated formation of senescent foamy macrophages.

RESULTS

Decreased m6A methylation and increased ALKBH5 expression were observed in arterial plaques and infiltrating macrophages from patients and mice with atherosclerosis. Compared with control mice, ALKBH5f/f, Lyz2Cre, Apoe-/- mice exhibited fewer atherosclerosis plaques with greater stability, which was attributed to the suppression of senescent foamy macrophage formation and senescence-associated secretory phenotype. In addition, ALKBH5 deletion reduced the mRNA expression level of CCL5 (CC chemokine ligand 5) by increasing m6A methylation in macrophages, which disrupts the stability of CCL5 mRNA. Mechanistically, ALKBH5 promoted senescent foamy macrophage formation through the CCL5/CCR5 (CC chemokine receptor 5)/autophagy signaling pathway. CCL5 also recruited CD8+ IFN (interferon)γ+ T cells via the CCL5-CCR5 axis. The ALKBH5 inhibitor IOX1 and the CCR5 antagonist maraviroc were identified as potential clinical interventions for inhibiting senescent foamy macrophage formation and atherosclerosis progression.

CONCLUSIONS

Myeloid ALKBH5 deletion attenuates atherosclerosis progression by suppressing the formation of senescent foamy macrophages and the recruitment of CD8+IFNγ+ T cells. These findings identify ALKBH5, CCL5, and CCR5 as novel therapeutic targets for atherosclerosis.

"Unveiling the impacts of climatic cold events on the cardiovascular health in animal models"

Climate change is increasingly driving extreme weather events, leading to drastic temperature fluctuations worldwide. While overall temperatures rise, many regions are simultaneously experiencing severe cold spells that threaten the health of human populations, especially to vulnerable populations including the elderly and those with pre-existing conditions. Exposure to cold stress triggers significant physiological and biochemical disruptions. As cardiovascular diseases (CVDs) rank among the leading causes of global morbidity and mortality, the exacerbation of these conditions by cold exposure underscores critical public health challenges. The complex pathophysiological processes in cold-induced CVDs require careful analysis at an organ-system level, making animal models an ideal tool for replicating human physiological and molecular responses in a controlled environment. However, a detailed mechanism linking cold exposure and cardiovascular dysfunction remains incompletely understood, particularly in the context of animal models. Therefore, this comprehensive review aims to address and analyze from traditional rodent models to less conventional ruminants, broilers, canines, and primate animal models to understand cold stress-induced CVDs, with an extensive account of the potential molecular mechanisms and pathways such as oxidative stress, inflammation, vasomotor dysfunction, and apoptosis, along with emerging roles of cold shock proteins (CSPs), etc. We also delve into various potential therapeutic approaches and preventive measures in cold stress conditions. In conclusion, this review is the first to comprehensively address the underexplored cardiovascular complications arising from cold stress and their underlying mechanisms, particularly using animal models. Furthermore, it provides a foundation for advancing the development of more effective and targeted therapies through translational research.

Peli1, regulated by m6A modification, suppresses NLRP3 inflammasome activation in atherosclerosis by inhibiting YB-1

The activation of pyrin domain-containing-3 (NLRP3) inflammasome in macrophages is a risk factor accelerating the progression of atherosclerosis (AS). Here, the function of pellino 1 (Peli1) in regulating the activation of NLRP3 inflammasome during the development of AS was investigated. Our results showed that Y-box binding protein 1 (YB-1) knockdown could inhibit the progression of AS in vivo, and YB-1 silencing repressed oxidized low-density lipoprotein (ox-LDL)-mediated lipid accumulation and inflammation in macrophages by inactivating NLRP3 inflammasome. E3 ubiquitination ligase Peli1 mediated ubiquitination-dependent degradation of YB-1 during AS progression. Moreover, it was found that YTH domain-containing 2 (YTHDC2) recognized methyltransferase-like 3 (METTL3)-mediated Peli1 N6-methyladenosine (m6A) modification and mediated Peli1 mRNA degradation. Rescue studies revealed that YB-1 upregulation abrogated the repressive effect of Peli1 upregulation on AS progression both in vitro and in vivo. Taken together, Peli1, regulated by m6A modification, inhibited YB-1-mediated activation of NLRP3 inflammasome in macrophages by promoting YB-1 ubiquitination to suppress the progression of AS.

DNA sensors in metabolic and cardiovascular diseases: Molecular mechanisms and therapeutic prospects

DNA sensors generally initiate innate immune responses through the production of type I interferons. While extensively studied for host defense against invading pathogens, emerging evidence highlights the involvement of DNA sensors in metabolic and cardiovascular diseases. Elevated levels of modified, damaged, or ectopically localized self-DNA and non-self-DNA have been observed in patients and animal models with obesity, diabetes, fatty liver disease, and cardiovascular disease. The accumulation of cytosolic DNA aberrantly activates DNA signaling pathways, driving the pathological progression of these disorders. This review highlights the roles of specific DNA sensors, such as cyclic AMP-GMP synthase and stimulator of interferon genes (cGAS-STING), absent in melanoma 2 (AIM2), toll-like receptor 9 (TLR9), interferon gamma-inducible protein 16 (IFI16), DNA-dependent protein kinase (DNA-PK), and DEAD-box helicase 41 (DDX41) in various metabolic disorders. We explore how DNA signaling pathways in both immune and non-immune cells contribute to the development of these diseases. Furthermore, we discuss the intricate interplay between metabolic stress and immune responses, offering insights into potential therapeutic targets for managing metabolic and cardiovascular disorders. Understanding the mechanisms of DNA sensor signaling in these contexts provides a foundation for developing novel interventions aimed at mitigating the impact of these pervasive health issues.

ErbB3 Governs Endothelial Dysfunction in Hypoxia-Induced Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension, characterized by vascular remodeling, currently lacks curative therapeutic options. The dysfunction of pulmonary artery endothelial cells plays a pivotal role in the initiation and progression of pulmonary hypertension (PH). ErbB3 (human epidermal growth factor receptor 3), also recognized as HER3, is a member of the ErbB family of receptor tyrosine kinases.

METHODS

Microarray, immunofluorescence, and Western blotting analyses were conducted to investigate the pathological role of ErbB3. Blood samples were collected for biomarker examination from healthy donors or patients with hypoxic PH. The pathological functions of ErbB3 were further validated in rodents subjected to chronic hypoxia- and Sugen-induced PH, with or without adeno-associated virus-mediated ErbB3 overexpression, systemic deletion, or endothelial cell-specific ErbB3 knockdown. Primary human pulmonary artery endothelial cells and pulmonary artery smooth muscle cells were used to elucidate the underlying mechanisms.

RESULTS

ErbB3 exhibited significant upregulation in the serum, lungs, distal pulmonary arteries, and pulmonary artery endothelial cells isolated from patients with PH compared with those from healthy donors. ErbB3 overexpression stimulated hypoxia-induced endothelial cell proliferation, exacerbated pulmonary artery remodeling, elevated systolic pressure in the right ventricle, and promoted right ventricular hypertrophy in murine models of PH. Conversely, systemic deletion or endothelial cell-specific knockout of ErbB3 yielded opposite effects. Coimmunoprecipitation and proteomic analysis identified YB-1 (Y-box binding protein 1) as a downstream target of ErbB3. ErbB3 induced nuclear translocation of YB-1 and subsequently promoted hypoxia-inducible factor 1/2α transcription. A positive loop involving ErbB3-periostin-hypoxia-inducible factor 1/2α was identified to mediate the progressive development of this disease. MM-121, a human anti-ErbB3 monoclonal antibody, exhibited both preventive and therapeutic effects against hypoxia-induced PH.

CONCLUSIONS

Our study reveals, for the first time, that ErbB3 serves as a novel biomarker and a promising target for the treatment of PH.

Transcriptome wide changes in long noncoding RNAs in diabetic ischemic heart disease

More than 10% of adults in the United States have type 2 diabetes mellitus (DM) with a 2-4 times higher prevalence of ischemic heart disease than the non-diabetics. Despite extensive research approaches to limit this life-threatening condition have proven unsuccessful, highlighting the need for understanding underlying molecular mechanisms. Long noncoding RNAs (lncRNAs), which regulate gene expression by acting as signals, decoys, guides, or scaffolds have been implicated in diverse cardiovascular conditions. However, their role in ischemic heart disease in DM remains poorly understood. We provide new insights into the lncRNA expression profile after ischemic heart disease in DM mice. We performed unbiased RNA sequencing of well-characterized type 2 DM model db/db mice or its control db/+ subjected to sham or MI surgery. Computational analysis of the RNA sequencing of these LV tissues identified several differentially expressed lncRNAs between (db/db sham vs. db/db MI) including Gm19522 and Gm8075. lncRNA Gm-19522 may regulate DNA replication via DNA protein kinases, while lncRNA Gm-8075 is associated with cancer gene dysregulation and PI3K/Akt pathways. Thus, the downregulation of lncRNAs Gm19522 and Gm8075 post-MI may serve as potential biomarkers or novel therapeutic targets to improve cardiac repair/recovery in diabetic ischemic heart disease.

Potential biomarkers and immune characteristics for polycythemia vera-related atherosclerosis using bulk RNA and single-cell RNA datasets: a combined comprehensive bioinformatics and machine learning analysis

Background

Polycythemia vera (PV) is a myeloproliferative disease characterized by significantly higher hemoglobin levels and positivity for JAK2 mutation. Thrombosis is the main risk event of this disease. Atherosclerosis (AS) can markedly increase the risk of arterial thrombosis in patients with PV. The objectives of our study were to identify potential biomarkers for PV-related AS and to explore the molecular biological association between PV and AS.

Methods

We extracted microarray datasets from the Gene Expression Omnibus (GEO) dataset for PV and AS. Common differentially expressed genes (CGs) were identified by differential expression analysis. Functional enrichment and protein-protein interaction (PPI) networks were constructed from the CG by random forest models using LASSO regression to identify pathogenic genes and their underlying processes in PV-related AS. The expression of potential biomarkers was validated using an external dataset. A diagnostic nomogram was constructed based on potential biomarkers to predict PV-related AS, and its diagnostic performance was assessed using ROC, calibration, and decision curve analyses. Subsequently, we used single-cell gene set enrichment analysis (GSEA) to analyze the immune signaling pathways associated with potential biomarkers. We also performed immune infiltration analysis of AS with "CIBERSORT" and calculated Pearson's correlation coefficients for potential biomarkers and infiltrating immune cells. Finally, we observed the expression of potential biomarkers in immune cells based on the single-cell RNA dataset.

Results

Fifty-two CGs were identified based on the intersection between up-regulated and down-regulated genes in PV and AS. Most biological processes associated with CGs were cytokines and factors associated with chemotaxis of immune cells. The PPI analysis identified ten hub genes, and of these, CCR1 and MMP9 were selected as potential biomarkers with which to construct a diagnostic model using machine learning methods and external dataset validation. These biomarkers could regulate Toll-like signaling, NOD-like signaling, and chemokine signaling pathways associated with AS. Finally, we determined that these potential biomarkers had a strong correlation with macrophage M0 infiltration. Further, the potential biomarkers were highly expressed in macrophages from patients with AS.

Conclusion

We identified two CGs (CCR1 and MMP9) as potential biomarkers for PV-related AS and established a diagnostic model based on them. These results may provide insight for future experimental studies for the diagnosis and treatment of PV-related AS.

YBX-1 alleviates sepsis-stimulated lung epithelial cell injury

OBJECTIVE

To explore the role of Y-box binding protein 1 (YBX-1) in the lipopolysaccharide (LPS)-stimulated inflammation and oxidative stress of BEAS-2B cell line and clarify the underlying mechanism.

METHODS

LPS-stimulated BEAS-2B cells were used as a cell model of sepsis-stimulated acute lung injury (ALI). Immunoblot and quantitative polymerase chain reaction assays were used to detect the expression of YBX-1 in LPS-stimulated BEAS-2B cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, TdT-mediated dUTP nick end labeling, and immunoblot assays were conducted to determine the effects of YBX-1 on cell survival. JC-1 staining and adenosine triphosphate production were used to detect the effects of YBX-1 on mitochondrial function. Immunostaining and enzyme-linked immunosorbent serologic assay were performed to examine the effects of YBX-1 on the inflammation and oxidative stress of cells. Immunoblot assay was conducted to confirm the mechanism.

RESULTS

YBX-1 was lowly expressed in LPS-stimulated BEAS-2B cells and enhanced the survival of LPS-stimulated lung epithelial cells. In addition, YBX-1 improved mitochondrial function of LPS-stimulated BEAS-2B cells. YBX-1 inhibited the inflammation and oxidative stress of LPS-stimulated BEAS-2B cells. Mechanically, YBX-1 inhibited mitogen-activated protein kinase (MAPK) axis, thereby alleviating sepsis-stimulated ALI.

CONCLUSION

YBX-1 alleviated inflammation and oxidative stress of LPS-stimulated BEAS-2B cells via MAPK axis.

Glomerular-tubular crosstalk via cold shock Y-box binding protein-1 in the kidney

Glomerular-tubular crosstalk within the kidney has been proposed, but the paracrine signals enabling this remain largely unknown. The cold-shock protein Y-box binding protein 1 (YBX1) is known to regulate inflammation and kidney diseases but its role in podocytes remains undetermined. Therefore, we analyzed mice with podocyte specific Ybx1 deletion (Ybx1ΔPod). Albuminuria was increased in unchallenged Ybx1ΔPod mice, which surprisingly was associated with reduced glomerular, but enhanced tubular damage. Tubular toll-like receptor 4 (TLR4) expression, node-like receptor protein 3 (NLRP3) inflammasome activation and kidney inflammatory cell infiltrates were all increased in Ybx1ΔPod mice. In vitro, extracellular YBX1 inhibited NLRP3 inflammasome activation in tubular cells. Co-immunoprecipitation, immunohistochemical analyses, microscale cell-free thermophoresis assays, and blunting of the YBX1-mediated TLR4-inhibition by a unique YBX1-derived decapeptide suggests a direct interaction of YBX1 and TLR4. Since YBX1 can be secreted upon post-translational acetylation, we hypothesized that YBX1 secreted from podocytes can inhibit TLR4 signaling in tubular cells. Indeed, mice expressing a non-secreted YBX1 variant specifically in podocytes (Ybx1PodK2A mice) phenocopied Ybx1ΔPod mice, demonstrating a tubular-protective effect of YBX1 secreted from podocytes. Lipopolysaccharide-induced tubular injury was aggravated in Ybx1ΔPod and Ybx1PodK2A mice, indicating a pathophysiological relevance of this glomerular-tubular crosstalk. Thus, our data show that YBX1 is physiologically secreted from podocytes, thereby negatively modulating sterile inflammation in the tubular compartment, apparently by binding to and inhibiting tubular TLR4 signaling. Hence, we have uncovered an YBX1-dependent molecular mechanism of glomerular-tubular crosstalk.

The Duality of Adiponectin: The Role of Sex in Atherosclerosis

The hormone adiponectin has many beneficial effects in atherosclerosis, as gene deficiency in adiponectin or its receptor has shown detrimental effects on plaque burden in mice. Our objective was to understand the potential roles adiponectin deficiency has on aortic plaque content, inflammation, and markers of cardiovascular disease according to sex and age. To study the influence of adiponectin status on sex and atherosclerosis, we used young male and female adipoq-/-apoe-/-, adipoq+/-apoe-/-, and apoe-/- mice, which were given a high-fat diet (HFD). Even a 50% reduction in the expression of adiponectin led to a plaque reduction in males and an increase in females compared with apoe-/- controls. Changes in plaque were not attributed to changes in cholesterol or cardiovascular disease markers but correlated with inflammatory markers. Plaque reduction in males was associated with reduced monocyte chemoattractant protein 1 (MCP1) and increased colony stimulating factor 3 (CSF3), while the increase in plaque in females correlated with the opposite effect in these markers. In old mice, both adiponectin-deficient genotypes and sexes accumulated more plaque than their respective apoe-/- controls. The increase in plaque with adiponectin deficiency according to age was not explained by a worsening lipid profile but correlated with increased levels of C-C motif chemokine ligand 5 (CCL5). Overall, our study uncovered genotype-specific effects that differed by sex and age of adiponectin deficiency in atherosclerosis.

The immune response to arterial damage in a mouse model of intermittent hypoxia: a transcriptomics analysis

PURPOSE

Mice can develop arterial damage and even atherosclerosis under intermittent hypoxia (IH); however, the specific mechanism of arterial damage induced by IH remains unclear. Hence, this research aimed to illustrate the underlying mechanism linking IH to arterial injury.

MATERIALS AND METHODS

The differential gene expression of the thoracic aorta under normoxia or IH mice was analyzed utilizing RNA sequencing. Furthermore, GO, KEGG pathway, and CIBERSORT analyses were carried out. For verification of the expression of candidate genes affected by IH, quantitative RT-qPCR (qRT-PCR) was conducted. Immunohistochemical (IHC) staining revealed immune cell infiltration in the thoracic aorta.

RESULTS

The thickness of the intima-media of the mouse aorta was increased, and the fiber structure was disordered under IH. Transcriptomics analysis showed that in the aorta, 1137 upregulated genes and 707 downregulated genes were affected by IH, significantly related to the activation of the immune system and cell adhesion. Furthermore, B cell infiltration around the aorta was observed under IH.

CONCLUSIONS

IH might lead to structural changes in the aorta by activating the immune response and enhancing cell adhesion.

FUS regulates the alternative splicing of cell proliferation genes related to atherosclerosis

FUS plays a significant role as an RNA-binding protein in several cellular processes, including RNA splicing, DNA repair, and transcriptional regulation. However, the RNA-binding capacity of FUS in atherosclerosis is unclear. We aimed to study the functions of FUS in inflammatory regulation through the role of the splicing factor. We knocked down FUS with siRNA to further study the overall transcriptional level and select alternative splicing (AS) of FUS regulation in human umbilical vein endothelial cells (HUVECs) by RNA sequencing. The results suggested that the knockdown of FUS significantly affected gene expression in HUVECs. In addition, the knockdown of FUS resulted in 200 differentially expressed genes (DEGs) that were highly related to apoptotic process, signal transduction, multicellular organism development, cell adhesion and regulation of transcription, and DNA-templated pathways. Importantly, FUS extensively regulated 2870 AS events with a significant difference. Functional analysis of its modulated AS genes revealed they were highly enriched in cell cycle and cell population proliferation pathways. The qRT-PCR and RNA-seq data showed consistent results. Our findings suggested new knowledge of the mechanisms of FUS associated with atherosclerosis.

DNA-Dependent Protein Kinase Mediates YB-1 (Y-Box Binding Protein)-Induced Double Strand Break Repair

BACKGROUND

DNA-PK (DNA-dependent protein kinase) is a stress-activated serine/threonine kinase that plays a central role in vascular smooth muscle cell proliferation and vascular proliferative disease processes such as neointimal formation. In this study, we link the activation of DNA-PK to the function of the transcription factor YB-1 (Y-box binding protein).

METHODS

To identify YB-1 phosphorylation by DNA-PK, we generated different YB-1-expressing vectors. YB-1 nuclear translocation was investigated using immunoblotting and immunofluorescence staining. For YB-1 activity, luciferase assays were performed.

RESULTS

We show by mutational analysis and kinase assay that the transcriptional regulator YB-1 is a substrate of DNA-PK. Blockade of DNA-PK by specific inhibitors revealed its critical involvement in YB-1phosphorylation as demonstrated by inhibition of an overexpressed YB-1 reporter construct. Using DNA-PK-deficient cells, we demonstrate that the shuttling of YB-1 from the cytoplasm to the nucleus is dependent on DNA-PK and that the N-terminal domain of YB-1 is phosphorylated at threonine 89. Point mutation of YB-1 at this residue abrogated the translocation of YB-1 into the nucleus. The phosphorylation of YB-1 by DNA-PK increased cellular DNA repair after exposure to ionizing radiation. Atherosclerotic tissue specimens were analyzed by immunohistochemistry. The DNA-PK subunits and YB-1 phosphorylated at T89 were found colocalized suggesting their in vivo interaction. In mice, the local application of the specific DNA-PK inhibitor NU7026 via thermosensitive Pluronic F-127 gel around dilated arteries significantly reduced the phosphorylation of YB-1.

CONCLUSIONS

DNA-PK directly phosphorylates YB-1 and, this way, modulates YB-1 function. This interaction could be demonstrated in vivo, and colocalization in human atherosclerotic plaques suggests clinical relevance of our finding. Phosphorylation of YB-1 by DNA-PK may represent a novel mechanism governing atherosclerotic plaque progression.

A bibliometric analysis of T cell and atherosclerosis

Atherosclerosis (AS) is widespread and develops into circulatory system problems. T cells play an essential regulatory role in AS occurrence and development. So far, there is no bibliometric research on T cells and AS. To learn more about T cell and AS development, 4,381 records were retrieved from Web of Science™ Core Collection. Then, these records were scientometrically analyzed using CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, references, and keywords. Our analysis provides basic information on research in the field, demonstrates that the field has stabilized over the past decade, and identifies potential partners for interested researchers. Current research hotspots in this field mainly include the inflammatory mechanism, immune mechanism, related diseases, and related cytokines of AS. B cell, mortality, inhibition, and monocyte represent the frontiers of research in this field, undergoing an explosive phase. We hope that this work will provide new ideas for advancing the scientific research and clinical application of T cell and AS.

Transcriptional and Epigenetic Factors Associated with Early Thrombosis of Femoral Artery Involved in Arteriovenous Fistula

Arteriovenous fistulas (AVFs), created for hemodialysis in end-stage renal disease patients, mature through the outward remodeling of the outflow vein. However, early thrombosis and chronic inflammation are detrimental to the process of AVF maturation and precipitate AVF maturation failure. For the successful remodeling of the outflow vein, blood flow through the fistula is essential, but early arterial thrombosis attenuates this blood flow, and the vessels become thrombosed and stenosed, leading to AVF failure. The altered expression of various proteins involved in maintaining vessel patency or thrombosis is regulated by genes of which the expression is regulated by transcription factors and microRNAs. In this study, using thrombosed and stenosed arteries following AVF creation, we delineated transcription factors and microRNAs associated with differentially expressed genes in bulk RNA sequencing data using upstream and causal network analysis. We observed changes in many transcription factors and microRNAs that are involved in angiogenesis; vascular smooth muscle cell proliferation, migration, and phenotypic changes; endothelial cell function; hypoxia; oxidative stress; vessel remodeling; immune responses; and inflammation. These factors and microRNAs play a critical role in the underlying molecular mechanisms in AVF maturation. We also observed epigenetic factors involved in gene regulation associated with these molecular mechanisms. The results of this study indicate the importance of investigating the transcriptional and epigenetic regulation of AVF maturation and maturation failure and targeting factors precipitating early thrombosis and stenosis.

Role of YB-1 Protein in Inflammation

This review discusses the role of the multifunctional DNA/RNA-binding protein YB-1 in inflammation. YB-1 performs multiple functions in the cell depending on its location: it acts as transcriptional factor for many genes in the nucleus, regulates translation and stability of mRNA in the cytoplasm, and becomes a paracrine factor when secreted from the cells. The review presents the data on the YB-1-mediated regulation of inflammation-associated genes, as well as results of studies on the YB-1 role in animal model of various inflammatory diseases, such as glomerulonephritis, tubulointerstitial fibrosis, and bacterial sepsis, and on the YB-1 expression in different human diseases associated with inflammatory processes in kidney, liver, and endometrium. The last section of the review presents several approaches to the regulation of YB-1 with small molecules in the treatment of inflammatory diseases.

ZFP36 promotes VDR mRNA degradation to facilitate cell death in oral and colonic epithelial cells

BACKGROUND

Vitamin D receptor (VDR) plays a vital protective role in oral and colonic epithelial cells. Albeit we know that VDR expression is reduced in the mucosal epithelial layers of autoimmune diseases, the mechanism by which VDR is decreased remains elusive.

METHODS

VDR and zinc finger protein 36 (ZFP36) levels in human samples and cell lines were detected by real-time PCR, western blot and immunostaining. Luciferase report assay was used to test cis-elements in VDR gene promoter, real-time PCR was applied to measure mRNA decay and western blot was performed to evaluate protein degradation. RNA affinity chromatography assay was used to test protein-mRNA interaction. Co-immunoprecipitation was used to detect protein-protein interaction. The role of ZFP36 in AU-rich elements (AREs) in the 3' untranslated region (UTR) of VDR mRNA was also measured by luciferase report assay.

RESULTS

We identify ZFP36 can bind with the AREs in the 3'UTR of VDR mRNA, leading to mRNA degradation in oral and colonic epithelial cells under inflammatory circumstance. Either ZFP36 protein or AREs of VDR mRNA mutation abolishes this protein-mRNA binding process. After the key amino acid's mutation, ZFP36 fails to decrease VDR mRNA expression. We also find that VDR physically binds with Y box-binding protein 1 (YBX-1) to block YBX-1's nuclear translocation and ameliorate cell death in the presence of inflammation.

CONCLUSION

These findings provide insights into the cause of VDR decrease in oral and colonic epithelial cells under inflammatory condition and explain how VDR maintains cell viability in these cells. Video abstract.

Cardiometabolic risks and atherosclerotic disease in ApoE knockout mice: Effect of spinal cord injury and Salsalate anti-inflammatory pharmacotherapy

OBJECTIVE

To test in mice with a double mutation of the ApoE gene (ApoE-/-) whether spinal cord injury (SCI) hastens the native trajectory of, and established component risks for, atherosclerotic disease (AD), and whether Salsalate anti-inflammatory pharmacotherapy attenuates the impact of SCI.

METHODS

ApoE-/- mice were anesthetized and underwent a T9 laminectomy. Exposed spinal cords were given a contusion injury (70 k-dynes). Sham animals underwent all surgical procedures, excluding injury. Injured animals were randomized to 2 groups: SCI or SCI+Salsalate [120 mg/Kg/day i.p.]. Mice were serially sacrificed at 20-, 24-, and 28-weeks post-SCI, and body mass was recorded. At sacrifice, heart and aorta were harvested intact, fixed in 10% buffered formalin, cleaned and cut longitudinally for en face preparation. The aortic tree was stained with oil-red-O (ORO). AD lesion histomorphometry was calculated from the proportional area of ORO. Plasma total cholesterol, triglycerides and proatherogenic inflammatory cytokines (PAIC's) were analyzed.

RESULTS

AD lesion in the aortic arch progressively increased in ApoE-/-, significant at 24- and 28-weeks. AD in SCI is significantly greater at 24- and 28-weeks compared to time-controlled ApoE-/-. Salsalate treatment attenuates the SCI-induced increase at these time points. Body mass in all SCI groups are significantly reduced compared to time-controlled ApoE-/-. Cholesterol and triglycerides are significantly higher with SCI by 24- and 28-weeks, compared to ApoE-/-, and Salsalate reduces the SCI-induced effect on cholesterol. PAIC's interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor α (TNFα), monocyte chemoattractant protein-1 (MCP-1), and chemokine (C-C motif) ligand 5 (CCL-5) are significantly greater with SCI compared to ApoE-/- at varying timepoints. Salsalate confers a marginal reducing effect on PAIC's by 28-weeks compared to SCI. Regression models determine that each PAIC is a significant and positive predictor of lesion. (p's <0.05).

CONCLUSIONS

SCI accelerates aortic AD and associated risk factors, and anti-inflammatory treatment may attenuate the impact of SCI on AD outcomes. PAIC's IL-1β, IL-6, TNFα, MCP-1, and CCL-5 may be effective predictors of AD.

DNA methyltransferase 3B deficiency unveils a new pathological mechanism of pulmonary hypertension

DNA methylation plays critical roles in vascular pathology of pulmonary hypertension (PH). The underlying mechanism, however, remains undetermined. Here, we demonstrate that global DNA methylation was elevated in the lungs of PH rat models after monocrotaline administration or hypobaric hypoxia exposure. We showed that DNA methyltransferase 3B (DNMT3B) was up-regulated in both PH patients and rodent models. Furthermore, Dnmt3b -/- rats exhibited more severe pulmonary vascular remodeling. Consistently, inhibition of DNMT3B promoted proliferation/migration of pulmonary artery smooth muscle cells (PASMCs) in response to platelet-derived growth factor-BB (PDGF-BB). In contrast, overexpressing DNMT3B in PASMCs attenuated PDGF-BB-induced proliferation/migration and ameliorated hypoxia-mediated PH and right ventricular hypertrophy in mice. We also showed that DNMT3B transcriptionally regulated inflammatory pathways. Our results reveal that DNMT3B is a previously undefined mediator in the pathogenesis of PH, which couples epigenetic regulations with vascular remodeling and represents a therapeutic target to tackle PH.

Two genetic variants in the promoter region of the CCL5 gene are associated with the risk of acute coronary syndrome and with a lower plasma CCL5 concentration

Acute coronary syndrome (ACS) is a multi-factorial condition with a strong inflammatory component, which is immune-mediated by chemokines. The CCL5 is a chemokine that has been suggested to be an important participant in the development of the atherosclerotic plaque. Therefore, in this work, we evaluated whether three polymorphisms located in the promoter region of the CCL5 gene [CCL5 -28 G/C (rs2280788), CCL5-109 G/A (rs1800825), and CCL5-403 G/A (rs2107538)] are significantly associated with the acute coronary syndrome (ACS), and plasma CCL5 levels. The determination of the gene polymorphisms was performed by 5'exonuclease TaqMan assays in 625 patients with ACS and 700 control individuals. Plasma CCL5 levels were evaluated by ELISA. Under co-dominant, dominant, and additive models, the G allele of the -109 G/A polymorphism was associated with a higher risk of ACS (OR = 1.27, pC_Co-dom = 0.041, OR = 1.33, pC_Dom = 0.03, and OR = 1.33, pC_Add = 0.015, respectively). In the same way, under co-dominant and recessive models, the A allele of the -403 G/A polymorphism was associated with an increased risk of ACS (OR = 1.62, pC_Co-dom = 0.042, and OR = 1.63, pC_Res = 0.012, respectively). The CCL5-109 G allele carriers had a lower concentration of the CCL5 than subjects with the A allele. Also, carriers of CCL5-403 A allele showed a lower concentration of the CCL5 than individuals with the G allele. Our data suggest the association of the CCL5-109 G/A and CCL5-403 G/A polymorphisms with the risk of developing ACS and with a lower concentration of CCL5 in our population.

YB-1 Interferes with TNFα-TNFR Binding and Modulates Progranulin-Mediated Inhibition of TNFα Signaling

Inflammation and an influx of macrophages are common elements in many diseases. Among pro-inflammatory cytokines, tumor necrosis factor α (TNFα) plays a central role by amplifying the cytokine network. Progranulin (PGRN) is a growth factor that binds to TNF receptors and interferes with TNFα-mediated signaling. Extracellular PGRN is processed into granulins by proteases released from immune cells. PGRN exerts anti-inflammatory effects, whereas granulins are pro-inflammatory. The factors coordinating these ambivalent functions remain unclear. In our study, we identify Y-box binding protein-1 (YB-1) as a candidate for this immune-modulating activity. Using a yeast-2-hybrid assay with YB-1 protein as bait, clones encoding for progranulin were selected using stringent criteria for strong interaction. We demonstrate that at physiological concentrations, YB-1 interferes with the binding of TNFα to its receptors in a dose-dependent manner using a flow cytometry-based binding assay. We show that YB-1 in combination with progranulin interferes with TNFα-mediated signaling, supporting the functionality with an NF-κB luciferase reporter assay. Together, we show that YB-1 displays immunomodulating functions by affecting the binding of TNFα to its receptors and influencing TNFα-mediated signaling via its interaction with progranulin.

A Novel Model of Balloon Angioplasty Injury in Rat Arteriovenous Fistula

BACKGROUND

There are very few animal models of balloon angioplasty injury in arteriovenous fistula (AVF), hindering insight into the pathophysiologic processes following angioplasty in AVF. The objective of the study was to develop and characterize a rat model of AVF angioplasty injury.

METHODS

Balloon angioplasty in 12- to 16-week-old Sprague-Dawley rats was performed at the arteriovenous anastomosis 14 days post-AVF creation with a 2F Fogarty balloon catheter. Morphometry and protein expression of endothelial nitric oxide synthase (eNOS), monocyte-chemoattractant protein-1 (MCP-1), alpha-smooth muscle actin (α-SMA), CD68 (macrophage marker), and collagen expression in AVFs with and without angioplasty were assessed.

RESULTS

In AVFs with angioplasty versus without angioplasty: (1) angioplasty increased AVF-vein and artery intimal hyperplasia, (2) angioplasty decreased eNOS protein expression in AVF-vein and artery at 21 days post-AVF creation and remained decreased in the AVF-vein angioplasty group at 35 days, (3) angioplasty increased AVF-vein and artery α-SMA expression within the intimal region at 35 days, (4) angioplasty increased the expression of AVF-vein MCP-1 at 21 days and CD68 at 21 and 35 days, and (5) angioplasty increased AVF-vein and artery collagen expression at 35 days.

CONCLUSION

Our findings describe a reproducible rat model to better understand the pathophysiologic mechanisms that ensue following AVF angioplasty.

Soyasaponin II protects against acute liver failure through diminishing YB-1 phosphorylation and Nlrp3-inflammasome priming in mice

Acute liver failure is characterized by the rapid development of liver dysfunction and remarkably high mortality. Accumulating evidence suggests that soyasaponin possesses potential anti-inflammatory activities. Here, we aimed to investigate the potential role of soyasaponin II in acute liver failure and establish the underlying mechanism. Methods: Lipopolysaccharide/D-galactosamine (LPS/GalN) was employed to induce acute liver failure. We applied liquid chromatography and mass spectrometry (LC/MS) to characterize the changes of soyasaponin II levels in the cecal content and liver. Transcriptomics and proteomics analysis were used to evaluate the functional molecule mediated by soyasaponin II in macrophages. Results: LPS/GalN administration markedly decreased fecal and hepatic soyasaponin II levels. Soyasaponin II treatment protected mice against LPS/GalN induced acute liver injury. Additionally, soyasaponin II markedly diminished Y-Box Binding Protein 1 (YB-1) phosphorylation and nuclear translocation, Nlrp3 inflammasome priming, and interleukin 1β (Il-1β) production in macrophages. Phosphorylated YB-1 could activate Nlrp3 mRNA transcription by binding the promoter region. Finally, immunofluorescence analysis showed elevated p-YB-1 nuclear translocation in macrophages of acute liver failure patients compared to controls. Conclusion: Our data shows that soyasaponin II which serves as a novel inhibitor for YB-1 phosphorylation and Nlrp3 inflammasome priming could protect mice against LPS/GalN induced acute liver failure.

Anti-Atherosclerosis Effect of Angong Niuhuang Pill via Regulating Th17/Treg Immune Balance and Inhibiting Chronic Inflammatory on ApoE-/- Mice Model of Early and Mid-Term Atherosclerosis

Angong Niuhuang Pill (ANP) is a well-known patented Chinese medicine which is used for hundreds of years for treating the central nervous system diseases. Atherosclerosis is a poly-aetiological chronic inflammatory vascular disease. Preventing inflammation is fundamental for treating atherosclerosis in early stages. In this study, we investigated the protective effects and possible mechanisms of ANP action on a high-fat diet induced early and mid-term atherosclerosis ApoE^-/- mice. The effects of ANP were compared with accepted drug simvastatin. Twelve male C57BL/6J mice were used as the control group, and 60 male ApoE^-/- mice were randomly divided into five groups: Model group, Simvastatin group, Low-, Medium-, and High-dose ANP group these groups received, respectively, saline, simvastatin (3.0mg/kg), low-dose ANP (0.25 g/kg), medium-dose ANP (0.50 g/kg), and high-dose ANP (1.0 g/kg), once every other day for 10 weeks. After administration, serum biochemical indices were detected by the automatic biochemical analyzer, the concentrations of IL-6 and IL-10 in the serum were assayed by ELISA, expression levels of IL-1β, TNF-α, MMP-2, MMP-9, CCL2, and its receptor CCR2 in the full-length aorta, and expression levels of transcription factors Foxp3, RORγt in the spleen were assayed via western blotting and RT-qPCR. Flow cytometry was used to analyze Th17 cells and Treg cells. Pathological and histological analysis was completed on aortic root. ANP decreased LDL/HDL ratio, concentrations of IL-6 while increased IL-10 in serum. Moreover, ANP down-regulated the expression levels of IL-1β, TNF-α, MMP-2, MMP-9, CCL2, and CCR2 receptor in the full-length aorta. In addition, ANP decreased Th17 cells and expression levels of transcription factor RORγt, increased Treg cells and expression levels of transcription factor Foxp3. ANP decreased content of collagen fibers and infiltration of inflammatory cells in the aortic root. In conclusion, we demonstrated that ANP has anti-atherosclerosis effects on a high-fat diet induced ApoE^-/- mice early and mid-term AS model via regulating Th17/Treg balance, inhibiting chronic inflammation, reducing plaque collagen fibers, and reducing inflammatory cells infiltration, to exert its multi-channel multi-target anti-early and mid-term AS effects.

The nucleic acid binding protein YB-1-controlled expression of CXCL-1 modulates kidney damage in liver fibrosis

Acute kidney injury is a common complication of advanced liver disease and increased mortality of these patients. Here, we analyzed the role of Y-box protein-1 (YB-1), a nucleic acid binding protein, in the bile duct ligation model of liver fibrosis and monitored liver and subsequent kidney damage. Following bile duct ligation, both serum levels of liver enzymes and expression of hepatic extracellular matrix components such as type I collagen were significantly reduced in mice with half-maximal YB-1 expression (Yb1^+/-) as compared to their wild-type littermates. By contrast, expression of the chemokine CXCL1 was significantly augmented in these Yb1^+/- mice. YB-1 was identified as a potent transcriptional repressor of the Cxcl1 gene. Precision-cut kidney slices from Yb1^+/- mice revealed higher expression of the CXCL1 receptor CXCR2 as well as enhanced responsivity to CXCL1 compared to those from wild-type mice. Increased CXCL1 content in Yb1^+/- mice led to pronounced bile duct ligation-induced damage of the kidneys monitored as parameters of tubular epithelial injury and immune cell infiltration. Pharmacological blockade of CXCR2 as well as application of an inhibitory anti-CXCL1 antibody significantly mitigated early systemic effects on the kidneys following bile duct ligation whereas it had only a modest impact on hepatic inflammation and function. Thus, our analyses provide direct evidence that YB-1 crucially contributes to hepatic fibrosis and modulates liver-kidney crosstalk by maintaining tight control over chemokine CXCL1 expression.

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.

Y-box binding protein 1 regulates ox-LDL mediated inflammatory responses and lipid uptake in macrophages

AIMS

Y-box protein 1 (YB1) is a key regulator of inflammatory mediators. However, the roles of YB1 in oxidized low-density lipoprotein (ox-LDL)-induced macrophage inflammation and lipid uptake remain less understood. Thus, we explored the roles of YB1 in ox-LDL-induced macrophage inflammation and lipid uptake and its underlying molecular mechanisms.

METHODS

An ox-LDL-induced atherosclerosis (AS) model was used in this study. Western blotting, RT-PCR, immunofluorescence, ELISA, dil-ox-LDL staining, a dual-luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) and in vivo experiments were used to detect each target.

RESULTS

ox-LDL downregulates YB1 expression in THP-1-derived macrophages and human monocyte-derived macrophages (hMDMs) via the NF-κB pathway. Downregulation of YB1 is facilitated by lipid uptake in macrophages, and CD36 is involved in this process. Furthermore, YB1 suppresses CD36 protein levels by directly binding to the coding sequence of the CD36 gene to promote CD36 mRNA decay but does not affect its mRNA transcription. Additionally, YB1 knockdown enhances the inflammatory response and lipid deposition via the NF-κB pathway in vivo.

CONCLUSION

ox-LDL decreases YB1 expression in macrophages, resulting in enhanced inflammatory responses by affecting NF-κB and facilitating lipid uptake by promoting scavenger receptor CD36 mRNA decay.

A remedy for kidney disease successfully alters the cold shock protein response during inflammation

Kidneys undergoing acute inflammatory responses are characterized by cell infiltration and a cytokinergic milieu. The hazard resides in the perpetuation of inflammation and ensuing fibrosis. In this issue of Kidney International, Wang et al.⁴ identify the cold shock Y-box binding protein-1 as the key orchestrator of cell infiltration in experimental tubulointerstitial nephritis following ureteral obstruction. Intriguingly, a small molecule previously designed to interfere with Y-box binding protein-1 interactions mediates an anti-inflammatory response and halts fibrogenesis.

Cold shock proteins: from cellular mechanisms to pathophysiology and disease

Cold shock proteins are multifunctional RNA/DNA binding proteins, characterized by the presence of one or more cold shock domains. In humans, the best characterized members of this family are denoted Y-box binding proteins, such as Y-box binding protein-1 (YB-1). Biological activities range from the regulation of transcription, splicing and translation, to the orchestration of exosomal RNA content. Indeed, the secretion of YB-1 from cells via exosomes has opened the door to further potent activities. Evidence links a skewed cold shock protein expression pattern with cancer and inflammatory diseases. In this review the evidence for a causative involvement of cold shock proteins in disease development and progression is summarized. Furthermore, the potential application of cold shock proteins for diagnostics and as targets for therapy is elucidated.

Cold shock Y-box binding protein-1 acetylation status in monocytes is associated with systemic inflammation and vascular damage

BACKGROUND AND AIMS

In dialysis patients, vascular morbidities are highly prevalent and linked to leukocyte extravasation, especially of polarized monocytes. Experimental data demonstrate that phenotypic changes in monocytes require Y-box binding protein-1 (YB-1) upregulation.

METHODS

We determined YB-1 expression in circulating and vessel-invading monocytes from healthy controls and dialysis patients to correlate results with intima plaque formation and systemic inflammation.

RESULTS

Compared to healthy subjects, dialysis patients have fewer classical and more intermediate and non-classical monocytes. Post-translationally modified YB-1 (lysine 301/304 acetylation) is detected at high levels in the nucleus of adherent and invading CD14⁺CD68⁺ monocytes from umbilical cord and atherosclerosis-prone vessels. The content of non-acetylated YB-1 is significantly decreased (p < 0.001), whereas acetylated YB-1 is correspondingly increased (p < 0.001) throughout all monocyte subpopulations, such that the overall content remains unchanged.

CONCLUSIONS

In dialysis patients the YB-1 acetylation status is higher with prevailing diabetes and intima plaque formation. Pro-inflammatory mediators TNFα, IL-6, uPAR, CCL2, M-CSF, progranulin, ANP, and midkine, as well as anti-inflammatory IL-10 are significantly increased in dialysis patients, emphasizing a systemic inflammatory milieu. Strong positive correlations of monocytic YB-1 content are seen with ANP, IP-10, IL-6, and IL-10 serum levels. This is the first study demonstrating an association of cold shock protein YB-1 expression with inflammation in hemodialysis patients.

Expression and network analysis of YBX1 interactors for identification of new drug targets in lung adenocarcinoma

Y-Box Binding protein 1 (YBX-1) is known to be involved in various types of cancers. It's interactors also play major role in various cellular functions. Present work aimed to study the expression profile of the YBX-1 interactors during lung adenocarcinoma (LUAD). The differential expression analysis involved 57 genes from 95 lung adenocarcinoma samples, construction of gene network and topology analysis. A Total of 43 genes were found to be differentially expressed from which 17 genes were found to be down regulated and 26 genes were up-regulated. We observed that Polyadenylate-binding protein 1 (PABPC1), a protein involved in YBX1 translation, is highly correlated with YBX1. The interaction network analysis for a differentially expressed non-coding RNA Growth Arrest Specific 5 (GAS5) suggests that two proteins namely, Growth Arrest Specific 2 (GAS2) and Peripheral myelin protein 22 (PMP22) are potentially involved in LUAD progression. The network analysis and differential expression suggests that Collagen type 1 alpha 2 (COL1A2) can be potential biomarker and target for LUAD.

CCL5 deficiency rescues pulmonary vascular dysfunction, and reverses pulmonary hypertension via caveolin-1-dependent BMPR2 activation

Pulmonary arterial hypertension (PAH) is a devastating cardiopulmonary disorder characterized by pulmonary arterial remodeling mainly due to excess cellular proliferation and apoptosis resistance of pulmonary arterial smooth muscle cells (PASMCs). Reduced bone morphogenetic protein receptor 2 (BMPR2) expression in patients with PAH impairs pulmonary arterial endothelial cells (PAECs) function. This can adversely affect PAEC survival and promote PASMCs proliferation. We hypothesized that interventions to normalize the expression of genes that are targets of the BMPR2 signaling could restore PAECs function and prevent or reverse PAH. Here we characterized for the first time, in human PAECs, chemokine (C-C motif) ligand 5 (CCL5/RANTES) deficiency restore BMP-mediated PAECs function. In the cell culture experiments, we found that CCL5 deficiency increased apoptosis and tube formation of PAECs, but suppressed proliferation and migration of PASMCs. Silencing CCL5 expression in PAH PAECs restored bone morphogenetic protein (BMP) signaling responses and promoted phosphorylation of SMADs and transcription of ID genes. Moreover, CCL5 deficiency inhibited angiogenesis by increasing pSMAD-dependent and-independent BMPR2 signaling. This was linked mechanistically to enhanced interaction of BMPR2 with caveolin-1 via CCL5 deficiency-mediated stabilization of endothelial surface caveolin-1. Consistent with these functions, deletion of CCL5 significantly attenuated development of Sugen5416/hypoxia-induced PAH by restoring BMPR2 signaling in mice. Taken together, our findings suggest that CCL5 deficiency could reverse obliterative changes in pulmonary arteries via caveolin-1-dependent amplification of BMPR2 signaling. Our results shed light on better understanding of the disease pathobiology and provide a possible novel target for the treatment of PAH.

YB-1 orchestrates onset and resolution of renal inflammation via IL10 gene regulation

The Y‐box‐binding protein (YB)‐1 plays a non‐redundant role in both systemic and local inflammatory response. We analysed YB‐1‐mediated expression of the immune regulatory cytokine IL‐10 in both LPS and sterile inflammation induced by unilateral renal ischaemia–reperfusion (I/R) and found an important role of YB‐1 not only in the onset but also in the resolution of inflammation in kidneys. Within a decisive cis‐regulatory region of the IL10 gene locus, the fourth intron, we identified and characterized an operative YB‐1 binding site via gel shift experiments and reporter assays in immune and different renal cells. In vivo, YB‐1 phosphorylated at serine 102 localized to the fourth intron, which was paralleled by enhanced IL‐10 mRNA expression in mice following LPS challenge and in I/R. Mice with half‐maximal expression of YB‐1 (Yb1^+/−) had diminished IL‐10 expression upon LPS challenge. In I/R, Yb1^+/− mice exhibited ameliorated kidney injury/inflammation in the early‐phase (days 1 and 5), however showed aggravated long‐term damage (day 21) with increased expression of IL‐10 and other known mediators of renal injury and inflammation.

In conclusion, these data support the notion that there are context‐specific decisions concerning YB‐1 function and that a fine‐tuning of YB‐1, for example, via a post‐translational modification regulates its activity and/or localization that is crucial for systemic processes such as inflammation.

Inflammatory cell infiltration and resolution of kidney inflammation is orchestrated by the cold-shock protein Y-box binding protein-1

Tubular cells recruit monocytic cells in inflammatory tubulointerstitial kidney diseases. The cell-cell communication that establishes pro- or anti-inflammatory activities is mainly influenced by cytokines, reactive oxygen species, nitric oxide, and phagocytosis. Key proteins orchestrating these processes such as cold-shock proteins linked with chemoattraction and cell maturation have been identified. The prototypic member of the cold-shock protein family, Y-box binding protein (YB)-1, governs specific phenotypic alterations in monocytic cells and was explored in the present study. Following tubulointerstitial injury by unilateral ureteral obstruction, increased inflammatory cell infiltration and tubular cell CCL5 expression was found in conditional Ybx1 knockout animals with specific depletion in monocytes/macrophages (YB-1^ΔLysM). Furthermore, YB-1^ΔLysM mice exhibit enhanced tissue damage, myofibroblast activation, and fibrosis. To investigate relevant molecular mechanism(s), we utilized bone marrow-derived macrophage cultures and found that YB-1-deficient macrophages display defects in cell polarization and function, including reduced proliferation and nitric oxide production, loss of phagocytic activity, and failure to upregulate IL-10 and CCL5 expression in response to inflammatory stimuli. Co-culture with primary tubular cells confirmed these findings. Thus, monocytic YB-1 has prominent and distinct roles for cellular feed-forward crosstalk and resolution of inflammatory processes by its ability to regulate cell differentiation and cytokine/chemokine synthesis.

Induced Pluripotent Stem Cell-Derived Endothelial Cells Overexpressing Interleukin-8 Receptors A/B and/or C-C Chemokine Receptors 2/5 Inhibit Vascular Injury Response

Recruitment of neutrophils and monocytes/macrophages to the site of vascular injury is mediated by binding of chemoattractants to interleukin (IL) 8 receptors RA and RB (IL8RA/B) C‐C chemokine receptors (CCR) 2 and 5 expressed on neutrophil and monocyte/macrophage membranes. Endothelial cells (ECs) derived from rat‐induced pluripotent stem cells (RiPS) were transduced with adenovirus containing cDNA of IL8RA/B and/or CCR2/5. We hypothesized that RiPS‐ECs overexpressing IL8RA/B (RiPS‐IL8RA/B‐ECs), CCR2/5 (RiPS‐CCR2/5‐ECs), or both receptors (RiPS‐IL8RA/B+CCR2/5‐ECs) will inhibit inflammatory responses and neointima formation in balloon‐injured rat carotid artery. Twelve‐week‐old male Sprague‐Dawley rats underwent balloon injury of the right carotid artery and intravenous infusion of (a) saline vehicle, (b) control RiPS‐Null‐ECs (ECs transduced with empty virus), (c) RiPS‐IL8RA/B‐ECs, (d) RiPS‐CCR2/5‐ECs, or (e) RiPS‐IL8RA/B+CCR2/5‐ECs. Inflammatory mediator expression and leukocyte infiltration were measured in injured and uninjured arteries at 24 hours postinjury by enzyme‐linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. Neointima formation was assessed at 14 days postinjury. RiPS‐ECs expressing the IL8RA/B or CCR2/5 homing device targeted the injured arteries and decreased injury‐induced inflammatory cytokine expression, neutrophil/macrophage infiltration, and neointima formation. Transfused RiPS‐ECs overexpressing IL8RA/B and/or CCR2/5 prevented inflammatory responses and neointima formation after vascular injury. Targeted delivery of iPS‐ECs with a homing device to inflammatory mediators in injured arteries provides a novel strategy for the treatment of cardiovascular diseases. Stem Cells Translational Medicine2017;6:1168–1177

Therapeutic nuclear shuttling of YB-1 reduces renal damage and fibrosis

Virtually all chronic kidney diseases progress towards tubulointerstitial fibrosis. In vitro, Y-box protein-1 (YB-1) acts as a central regulator of gene transcription and translation of several fibrosis-related genes. However, it remains to be determined whether its pro- or antifibrotic propensities prevail in disease. Therefore, we investigated the outcome of mice with half-maximal YB-1 expression in a model of renal fibrosis induced by unilateral ureteral obstruction. Yb1^+/- animals displayed markedly reduced tubular injury, immune cell infiltration and renal fibrosis following ureteral obstruction. The increase in renal YB-1 was limited to a YB-1 variant nonphosphorylated at serine 102 but phosphorylated at tyrosine 99. During ureteral obstruction, YB-1 localized to the cytoplasm, directly stabilizing Col1a1 mRNA, thus promoting fibrosis. Conversely, the therapeutic forced nuclear compartmentalization of phosphorylated YB-1 by the small molecule HSc025 mediated repression of the Col1a1 promoter and attenuated fibrosis following ureteral obstruction. Blunting of these effects in Yb1^+/- mice confirmed involvement of YB-1. HSc025 even reduced tubulointerstitial damage when applied at later time points during maximum renal damage. Thus, phosphorylation and subcellular localization of YB-1 determines its effect on renal fibrosis in vivo. Hence, induced nuclear YB-1 shuttling may be a novel antifibrotic treatment strategy in renal diseases with the potential of damage reversal.

Relationship of Genetic Polymorphisms of the Chemokine, CCL5, and Its Receptor, CCR5, with Coronary Artery Disease in Taiwan

The chemokine receptor CCR5 polymorphism, which confers resistance to HIV infection, has been associated with reduced risk of cardiovascular disease. However, the association of the chemokine, CCL5, and its receptor, CCR5, polymorphism and coronary artery disease (CAD) in the Taiwanese has not been studied. In this study, 483 subjects who received elective coronary angiography were recruited from Chung Shan Medical University Hospital. CCL5-403 and CCR5-59029 were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that CCL5-403 with TT genotype frequencies was significantly associated with the risk of CAD group (odds ratio = 3.063 and p = 0.012). Moreover, the frequencies of CCR5-59029 with GG or GA genotype were higher than AA genotype in acute coronary syndrome individuals (odds ratio = 1.853, CI = 1.176–2.921, p = 0.008). In conclusion, we found that CCL5-403 polymorphism may increase genetic susceptibility of CAD. CCL5-403 or CCR5-59029 single nucleotide polymorphism may include genotype score and it may predict cardiovascular event.

PDGFRβ signalling regulates local inflammation and synergizes with hypercholesterolaemia to promote atherosclerosis

Platelet-derived growth factor (PDGF) is a mitogen and chemoattractant for vascular smooth muscle cells (VSMCs). However, the direct effects of PDGF receptor β (PDGFRβ) activation on VSMCs have not been studied in the context of atherosclerosis. Here, we present a new mouse model of atherosclerosis with an activating mutation in PDGFRβ. Increased PDGFRβ signaling induces chemokine secretion and leads to leukocyte accumulation in the adventitia and media of the aorta. Furthermore, PDGFRβ^D849V amplifies and accelerates atherosclerosis in hypercholesterolemic ApoE^−/− or Ldlr^−/− mice. Intriguingly, increased PDGFRβ signaling promotes advanced plaque formation at novel sites in the thoracic aorta and coronary arteries. However, deletion of the PDGFRβ-activated transcription factor STAT1 in VSMCs alleviates inflammation of the arterial wall and reduces plaque burden. These results demonstrate that PDGFRβ pathway activation has a profound effect on vascular disease and support the conclusion that inflammation in the outer arterial layers is a driving process for atherosclerosis.

Cytokines in atherosclerosis: Key players in all stages of disease and promising therapeutic targets

Atherosclerosis, a chronic inflammatory disorder of the arteries, is responsible for most deaths in westernized societies with numbers increasing at a marked rate in developing countries. The disease is initiated by the activation of the endothelium by various risk factors leading to chemokine-mediated recruitment of immune cells. The uptake of modified lipoproteins by macrophages along with defective cholesterol efflux gives rise to foam cells associated with the fatty streak in the early phase of the disease. As the disease progresses, complex fibrotic plaques are produced as a result of lysis of foam cells, migration and proliferation of vascular smooth muscle cells and continued inflammatory response. Such plaques are stabilized by the extracellular matrix produced by smooth muscle cells and destabilized by matrix metalloproteinase from macrophages. Rupture of unstable plaques and subsequent thrombosis leads to clinical complications such as myocardial infarction. Cytokines are involved in all stages of atherosclerosis and have a profound influence on the pathogenesis of this disease. This review will describe our current understanding of the roles of different cytokines in atherosclerosis together with therapeutic approaches aimed at manipulating their actions.

Myocardin regulates vascular smooth muscle cell inflammatory activation and disease

OBJECTIVE

Atherosclerosis, the cause of 50% of deaths in westernized societies, is widely regarded as a chronic vascular inflammatory disease. Vascular smooth muscle cell (VSMC) inflammatory activation in response to local proinflammatory stimuli contributes to disease progression and is a pervasive feature in developing atherosclerotic plaques. Therefore, it is of considerable therapeutic importance to identify mechanisms that regulate the VSMC inflammatory response.

APPROACH AND RESULTS

We report that myocardin, a powerful myogenic transcriptional coactivator, negatively regulates VSMC inflammatory activation and vascular disease. Myocardin levels are reduced during atherosclerosis, in association with phenotypic switching of smooth muscle cells. Myocardin deficiency accelerates atherogenesis in hypercholesterolemic apolipoprotein E(-/-) mice. Conversely, increased myocardin expression potently abrogates the induction of an array of inflammatory cytokines, chemokines, and adhesion molecules in VSMCs. Expression of myocardin in VSMCs reduces lipid uptake, macrophage interaction, chemotaxis, and macrophage-endothelial tethering in vitro, and attenuates monocyte accumulation within developing lesions in vivo. These results demonstrate that endogenous levels of myocardin are a critical regulator of vessel inflammation.

CONCLUSIONS

We propose myocardin as a guardian of the contractile, noninflammatory VSMC phenotype, with loss of myocardin representing a critical permissive step in the process of phenotypic transition and inflammatory activation, at the onset of vascular disease.

Cytokines and Immune Responses in Murine Atherosclerosis

Atherosclerosis is an inflammatory disease of the vessel wall characterized by activation of the innate immune system, with macrophages as the main players, as well as the adaptive immune system, characterized by a Th1-dominant immune response. Cytokines play a major role in the initiation and regulation of inflammation. In recent years, many studies have investigated the role of these molecules in experimental models of atherosclerosis. While some cytokines such as TNF or IFNγ clearly had atherogenic effects, others such as IL-10 were found to be atheroprotective. However, studies investigating the different cytokines in experimental atherosclerosis revealed that the cytokine system is complex with both disease stage-dependent and site-specific effects. In this review, we strive to provide an overview of the main cytokines involved in atherosclerosis and to shed light on their individual role during atherogenesis.

Calcineurin-mediated YB-1 dephosphorylation regulates CCL5 expression during monocyte differentiation

Y-box (YB) protein-1 serves as a master regulator in gene transcription and mRNA translation. YB-1 itself is regulated at various levels, e.g. through post-translational modifications. In our previous work, we identified RANTES/CCL5 as a transcriptional target of YB-1. We previously demonstrated that YB-1 protein is transiently up-regulated during monocyte/macrophage differentiation evidenced in monocytic cells (THP-1 cells) that were differentiated using phorbol myristate acetate (PMA). Here we provide evidence that YB-1 phosphorylation, specifically at its serine residue 102 (Ser-102), increases early on in THP-1 cells following PMA treatment as well as in differentiated primary human monocytes. This process is mediated through the Akt signaling pathway. Ser-102-phosphorylated YB-1 displays stronger binding affinity and trans-activating capacity at the CCL5 gene promoter. Notably, Ser-102-phosphorylated YB-1 disappears at later stages of the monocyte/macrophage differentiation process. We demonstrate that serine-threonine phosphatase calcineurin (CN) dephosphorylates YB-1 preventing it from binding to and trans-activating the CCL5 promoter. Co-immunoprecipitation assays prove a direct YB-1/CN interaction. Furthermore, analyses in kidney tissues from mice that were treated with the CN inhibitor cyclosporine A revealed an in vivo effect of CN on the YB-1 phosphorylation status. We conclude that YB-1 phosphorylation at Ser-102 is an important prerequisite for CCL5 promoter activation during macrophage differentiation. Our findings point to a critical role of YB-1 in the resolution of inflammatory processes which may largely be due to CN-mediated dephosphorylation.