VNN1 promotes atherosclerosis progression in apoE-/- mice fed a high-fat/high-cholesterol diet

Unveiling Atherosclerotic Plaque Heterogeneity and SPP1+/VCAN+ Macrophage Subtype Prognostic Significance Through Integrative Single-Cell and Bulk-Seq Analysis

Background

Dysregulated macrophages are important causes of Atherosclerosis (AS) formation and increased plaque instability, but the heterogeneity of these plaques and the role of macrophage subtypes in plaque instability have yet to be clarified.

Methods

This study integrates single-cell and bulk-seq data to analyze atherosclerotic plaques. Unsupervised clustering was used to reveal distinct plaque subtypes, while survival analysis and gene set variation analysis (GSVA) methods helped in understanding their clinical outcomes. Enrichment of differential expression of macrophage genes (DEMGs) score and pseudo-trajectory analysis were utilized to explore the biological functions and differentiation stages of macrophage subtypes in AS progression. Additionally, CellChat and the BayesPrism deconvolution method were used to elucidate macrophage subtype interaction and their prognostic significance at single-cell resolution. Finally, the expression of biomarkers was validated in mouse experiments.

Results

Three distinct AS plaque subtypes were identified, with cluster 3 plaque subtype being particularly associated with higher immune infiltration and poorer prognosis. The DEMGs score exhibited a significant elevation in three macrophage subtypes (SPP1+/VCAN+ macrophages, IL1B+ macrophages, and FLT3LG+ macrophages), associated with cluster 3 plaque subtype and highlighted the prognostic significance of these subtypes. Activation trajectory of the macrophage subtypes is divided into three states (Pre-branch, Cell fate 1, and Cell fate 2), and Cell fate 2 (SPP1+/VCAN+ macrophages, IL1B+ macrophages, and FLT3LG+ macrophages dominant) exhibiting the highest DEMGs score, distinct interactions with other cell components, and relating to poorer prognosis of ischemic events. This study also uncovered a unique SPP1+/VCAN+ macrophage subtype, rare in quantity but significant in influencing AS progression. Machine learning algorithms identified 10 biomarkers crucial for AS diagnosis. The validation of these biomarkers was performed using Mendelian Randomization analysis and in vitro methods, supporting their relevance in AS pathology.

Conclusion

Our study provides a comprehensive view of AS plaque heterogeneity and the prognostic significance of macrophage subtypes in plaque instability.

Urinary vanin-1 as a novel biomarker for survival in peripheral artery disease

BACKGROUND

Chronic kidney disease is associated with increased rates of incidence, morbidity, and mortality in lower-extremity peripheral artery disease (PAD). No specific marker for a functional risk assessment of kidney disease in PAD is known, especially at the early stages. Thus, we speculated that urinary vanin-1 (uVNN1), a marker of oxidative stress even in early kidney injury, could further stratify outcome assessment in patients with PAD.

METHODS

Patients with stable PAD (n = 304) of the Vienna medical cohort were followed up for up to 10 years and the outcome was assessed by central death database queries. uVNN1 was measured by enzyme-linked immunosorbent assay (ELISA) at study inclusion and normalized to urinary creatinine (uVNN1/Cr). During the observation time (9.3, 7.0-9.8 years), 104 patients died, 54.8% of which were due to cardiovascular causes.

RESULTS

uVNN1/Cr was associated with a urine albumin-creatinine ratio (UACR) (R = 0.166, p = 0.004) but not with an estimated glomerular filtration rate (R = 0.102, p = 0.077). Levels of uVNN1/Cr did not differ between asymptomatic and symptomatic PAD (p = 0.406). Kaplan-Meier curves showed a clear-cut association with higher all-cause (log-rank p = 0.034) and cardiovascular mortality (log-rank p = 0.032) with higher uVNN1/Cr levels. Similarly, significant associations for all-cause (hazard ratio [HR] 1.34, 95% CI [1.08-1.67], p = 0.009) and cardiovascular mortality (HR 1.45, 95% CI [1.06-1.99], p = 0.020) could be seen in multivariable Cox regression models.

CONCLUSIONS

uVNN1/Cr showed an independent association with both all-cause and cardiovascular mortality in patients with PAD and was associated with early kidney disease. Thus, uVNN1 could be a useful marker for risk stratification of kidney disease in PAD.

CRISPR/Cas9-mediated knockout of the Vanin-1 gene in the Leghorn Male Hepatoma cell line and its effects on lipid metabolism

OBJECTIVE

Vanin-1 (VNN1) is a pantetheinase that catalyses the hydrolysis of pantetheine to produce pantothenic acid and cysteamine. Our previous studies have shown that the VNN1 is specifically expressed in chicken liver which negatively regulated by microRNA-122. However, the functions of the VNN1 in lipid metabolism in chicken liver haven't been elucidated.

METHODS

First, we detected the VNN1 mRNA expression in 4-week chickens which were fasted 24 hours. Next, knocked out VNN1 via CRISPR/Cas9 system in the chicken Leghorn Male Hepatoma cell line. Detected the lipid deposition via oil red staining and analysis the content of triglycerides (TG), low-density lipoprotein-C (LDL-C), and highdensity lipoprotein-C (HDL-C) after VNN1 knockout in Leghorn Male Hepatoma cell line. Then we captured various differentially expressed genes (DEGs) between VNN1-modified LMH cells and original LMH cells by RNA-seq.

RESULTS

Firstly, fasting-induced expression of VNN1. Meanwhile, we successfully used the CRISPR/Cas9 system to achieve targeted mutations of the VNN1 in the chicken LMH cell line. Moreover, the expression level of VNN1 mRNA in LMH-KO-VNN1 cells decreased compared with that in the wild-type LMH cells (p<0.0001). Compared with control, lipid deposition was decreased after knockout VNN1 via oil red staining, meanwhile, the contents of TG and LDL-C were significantly reduced, and the content of HDL-C was increased in LMH-KO-VNN1 cells. Transcriptome sequencing showed that there were 1,335 DEGs between LMH-KO-VNN1 cells and original LMH cells. Of these DEGs, 431 were upregulated, and 904 were downregulated. Gene ontology analyses of all DEGs showed that the lipid metabolism-related pathways, such as fatty acid biosynthesis and long-chain fatty acid biosynthesis, were enriched. KEGG pathway analyses showed that "lipid metabolism pathway", "energy metabolism", and "carbohydrate metabolism" were enriched. A total of 76 DEGs were involved in these pathways, of which 29 genes were upregulated (such as cytochrome P450 family 7 subfamily A member 1, ELOVL fatty acid elongase 2, and apolipoprotein A4) and 47 genes were downregulated (such as phosphoenolpyruvate carboxykinase 1) by VNN1 knockout in the LMH cells.

CONCLUSION

These results suggest that VNN1 plays an important role in coordinating lipid metabolism in the chicken liver.

Identification of potential biomarkers and therapeutic targets related to post-traumatic stress disorder due to traumatic brain injury

BACKGROUND

Post-traumatic stress disorder (PTSD), a disease state that has an unclear pathogenesis, imposes a substantial burden on individuals and society. Traumatic brain injury (TBI) is one of the most significant triggers of PTSD. Identifying biomarkers associated with TBI-related PTSD will help researchers to uncover the underlying mechanism that drives disease development. Furthermore, it remains to be confirmed whether different types of traumas share a common mechanism of action.

METHODS

For this study, we screened the eligible data sets from the Gene Expression Omnibus (GEO) database, obtained differentially expressed genes (DEGs) through analysis, conducted functional enrichment analysis on the DEGs in order to understand their molecular mechanisms, constructed a PPI network, used various algorithms to obtain hub genes, and finally evaluated, validated, and analyzed the diagnostic performance of the hub genes.

RESULTS

A total of 430 upregulated and 992 down-regulated differentially expressed genes were extracted from the TBI data set. A total of 1919 upregulated and 851 down-regulated differentially expressed genes were extracted from the PTSD data set. Functional enrichment analysis revealed that the differentially expressed genes had biological functions linked to molecular regulation, cell signaling transduction, cell metabolic regulation, and immune response. After constructing a PPI network and introducing algorithm analysis, the upregulated hub genes were identified as VNN1, SERPINB2, and ETFDH, and the down-regulated hub genes were identified as FLT3LG, DYRK1A, DCN, and FKBP8. In addition, by comparing the data with patients with other types of trauma, it was revealed that PTSD showed different molecular processes that are under the influence of different trauma characteristics and responses.

CONCLUSIONS

By exploring the role of different types of traumas during the pathogenesis of PTSD, its possible molecular mechanisms have been revealed, providing vital information for understanding the complex pathways associated with TBI-related PTSD. The data in this study has important implications for the design and development of new diagnostic and therapeutic methods needed to treat and manage PTSD.

Vanin1 (VNN1) in chronic diseases: Future directions for targeted therapy

Vanin1 (VNN1) is an exogenous enzyme with pantetheinase activity that mainly exerts physiological functions through enzyme catalysis products, including pantothenic acid and cysteamine. In recent years, the crosstalk between VNN1 and metabolism and oxidative stress has attracted much attention. As a result of the ability of VNN1 to affect multiple metabolic pathways and oxidative stress to exacerbate or alleviate pathological processes, it has become a key component of disease progression. This review discusses the functions of VNN1 in glucolipid metabolism, cysteamine metabolism, and glutathione metabolism to provide perspectives on VNN1-targeted therapy for chronic diseases.

High plasma concentrations of vanin-1 in patients with coronary artery disease

Vanin-1 is a pantetheinase that hydrolyzes pantetheine to pantothenic acid and cysteamine. Vanin-1 has become recognized to be associated with oxidative stress and inflammation. In animal models, vanin-1 was reported to accelerate atherosclerosis. However, no study has reported blood vanin-1 concentrations in patients with coronary artery disease (CAD). We investigated plasma vanin-1 concentrations in 388 patients undergoing elective coronary angiography for suspected CAD. Patients with acute coronary syndrome were excluded. Of the 388 study patients, CAD was found in 207 patients [1-vessel (1-VD), n = 88; 2-vessel (2-VD), n = 66; and 3-vessel disease (3-VD), n = 53]. Plasma vanin-1 concentrations were higher in patients with CAD than in those without CAD (median 0.59 vs. 0.46 ng/mL, P < 0.005). Vanin-1 concentrations in patients without CAD and those with 1-VD, 2-VD, and 3-VD were 0.46, 0.58, 0.57, and 0.61 ng/mL, respectively, and were highest in 3-VD (P < 0.05). A high vainin-1 concentration (> 0.48 ng/mL) was found in 46% of patients without CAD, 61% of 1-VD, 65% of 2-VD, and 66% of 3-VD (P < 0.01). Vanin-1 concentrations significantly correlated with the number of stenotic coronary segments (r = 0.14, P < 0.02). In the multivariate analysis, vanin-1 concentration was a significant factor associated with CAD independent of atherosclerotic risk factors. The odds ratio for CAD was 1.63 (95%CI = 1.04-2.55) for the high vanin-1 concentration of > 0.48 ng/mL. Thus, plasma vanin-1 concentrations in patients with CAD were found to be high and to be associated with the presence and severity of CAD.

Endothelial Cell Response in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children

Although Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share some clinical manifestations, their cardiovascular outcomes are different, and this may be reflected at the level of the endothelial cell (EC). We performed RNA-seq on cultured ECs incubated with pre-treatment sera from KD (n = 5), MIS-C (n = 7), and healthy controls (n = 3). We conducted a weighted gene co-expression network analysis (WGCNA) using 935 transcripts differentially expressed between MIS-C and KD using relaxed filtering (unadjusted p < 0.05, >1.1-fold difference). We found seven gene modules in MIS-C, annotated as an increased TNFα/NFκB pathway, decreased EC homeostasis, anti-inflammation and immune response, translation, and glucocorticoid responsive genes and endothelial-mesenchymal transition (EndoMT). To further understand the difference in the EC response between MIS-C and KD, stringent filtering was applied to identify 41 differentially expressed genes (DEGs) between MIS-C and KD (adjusted p < 0.05, >2-fold-difference). Again, in MIS-C, NFκB pathway genes, including nine pro-survival genes, were upregulated. The expression levels were higher in the genes influencing autophagy (UBD, EBI3, and SQSTM1). Other DEGs also supported the finding by WGCNA. Compared to KD, ECs in MIS-C had increased pro-survival transcripts but reduced transcripts related to EndoMT and EC homeostasis. These differences in the EC response may influence the different cardiovascular outcomes in these two diseases.

A plasma proteomic approach in patients with heart failure after acute myocardial infarction: insights into the pathogenesis and progression of the disease

Aims

The pathogenesis of disease progression targets for patients with heart failure after acute myocardial infarction was investigated by using plasma proteomics.

Methods

The plasma proteomes of acute myocardial infarction patients with (MI-HF) and without (MI-WHF) heart failure were compared. Each group consisted of 10 patients who were matched for age and sex. The peptides were analyzed by 2-dimensional liquid chromatography coupled to tandem mass spectrometry in a high definition mode. Parallel reaction monitoring (PRM) verified the selected target proteins.

Results

We identified and quantified 2,589 and 2,222 proteins, respectively, and found 117 differentially expressed proteins (DEPs) (≥1.5-fold), when the MI-HF and MI-WHF groups were compared. Of these 51 and 66 were significantly up-regulated and down-regulated, respectively. The significant DEPs was subjected to protein-protein interaction network analysis which revealed a central role of the NF-κB signaling pathway in the MI-HF patients. PRM verified that MB, DIAPH1, VNN1, GOT2, SLC4A1, CRP, CKM, SOD3, F7, DLD, PGAM2, GOT1, UBA7 and HYOU1 were 14 proteins which were highly expressed in MI-HF patients.

Conclusions

These findings showed a group of proteins related to the NF-κB signaling pathway in the pathogenesis of patients with poor outcomes after experiencing MI-HF. These proteins may be useful candidate markers for the diagnosis of MI-HF as well as help to elucidate the pathophysiology of this major cause of mortality in older patients.

Glycosides from Buyang Huanwu Decoction inhibit atherosclerotic inflammation via JAK/STAT signaling pathway

BACKGROUND

Buyang Huanwu Decoction (BYHWD) has been used to treat or prevent cardiovascular disease. The prescription and its glycosides have the effects of protecting blood vessels, and resisting atherosclerosis. However, their protective mechanism of anti-atherosclerosis remains unclear.

PURPOSE

This study aims to explore whether glycosides are the main effective components of BYHWD in anti-atherosclerotic inflammation and whether their mechanism is related to the classical JAK/STAT inflammatory signaling pathway.

METHODS

UPLC-MSMS method was used to determine the main components of BYHWD and its glycosides. Network pharmacological analysis and molecular docking were used to predict the potential therapeutic targets of glycosides. Atherosclerosis model was prepared by feeding HFD in ApoE^-/- mice. The effects of glycosides on atherosclerosis were detected by blood lipids measurement, Masson staining, immunohistochemistry, immunofluorescence, western-blot and droplet digital PCR. RAW264.7 cells were used to establish foam cells model. The mechanism of glycosides anti-atherosclerotic inflammation was detected by measuring intracellular lipids, Oil Red O staining, ELISA, western-blot and droplet digital PCR.

RESULTS

1. Glycosides were absorbed into the blood through oral administrations and existed in the blood in the form of glycosides structures. 2. Glycosides attenuated hyperlipidemia, alleviated atherosclerotic lesions and inhibited inflammatory reaction. They could regulate blood lipids by decreasing TC, TG, LDL-c, increasing HDL-c level in ApoE^-/- mice, alleviating intimal area and thickness, and inhibiting atherosclerotic plaque formation, which were similar to BYHWD. 3. Glycosides anti-atherosclerotic inflammation was related to JAK/STAT signaling pathway by network pharmacology analysis. Interactions between glycosides (astragaloside IV, paeoniflorin and amygdalin) and JAK/STAT pathway-related proteins by molecular docking. 4. Glycosides alleviated atherosclerotic inflammation by decreasing the release of pro-inflammatory factors and adhesions molecules, inhibiting the activation of JAK/STAT pathway in vivo. 5. Glycosides reduced the number of foam cells and intracellular lipid content. It also prevented the inflammation of macrophages by decreasing the levels of pro-inflammatory factors, reducing the phosphorylation of JAK2, STAT1 and STAT3 in vitro.

CONCLUSION

This study demonstrated that glycosides were the main active components of BYHWD, and they could inhibit atherosclerosis by alleviating atherosclerotic inflammation. the mechanism is inhibiting the activation of JAK/STAT signaling pathway.

VNN1 contributes to the acute kidney injury-chronic kidney disease transition by promoting cellular senescence via affecting RB1 expression

The mechanisms underlying acute kidney injury (AKI) and chronic kidney disease (CKD) progression include interstitial inflammation, cellular senescence, and oxidative stress (OS). Although vanin-1 (VNN1) plays an important role in OS, its contribution to the AKI-CKD transition remains unknown. Here, we explored the roles and mechanisms of VNN1 in the progression of the AKI-CKD transition. We observed that VNN1 expression was upregulated after ischemia/reperfusion (I/R) injury and high VNN1 expression levels were associated with poor renal repair after I/R injury. In VNN1 knockout (KO) mice, recovery of serum creatinine and blood urea nitrogen levels after I/R injury was accelerated and renal fibrosis was inhibited after severe I/R injury. Furthermore, in VNN1 KO mice, senescence of renal tubular cells was inhibited after severe I/R injury, as assessed by P16 expression and SA-β-Gal assays. However, our results also revealed that VNN1 KO renal tubular cells did not resist senescence when OS was blocked. To elucidate the mechanism underlying VNN1-mediated regulation of senescence during the AKI-CKD transition, retinoblastoma 1 (RB1) was identified as a potential target. Our results suggest that the reduced senescence in VNN1 KO renal tubular cells was caused by suppressed RB1 expression and phosphorylation. Collectively, our results unveil a novel molecular mechanism by which VNN1 promotes AKI-CKD transition via inducing senescence of renal tubular cells by activating RB1 expression and phosphorylation after severe renal injury. The present study proposes a new strategy for designing therapies wherein VNN1 can be targeted to obstruct the AKI-CKD transition.

Identification of Potential Biomarkers and Immune Infiltration Characteristics in Ulcerative Colitis by Combining Results from Two Machine Learning Algorithms

Objective

This study was designed to identify potential biomarkers for ulcerative colitis (UC) and analyze the immune infiltration characteristics in UC.

Methods

Datasets containing human UC and normal control tissues (GSE87466, GSE107597, and GSE13367) were downloaded from the GEO database. Then, the GSE87466 and GSE107597 datasets were merged, and the differentially expressed genes (DEGs) between UC and normal control tissues were screened out by the “limma R” package. The LASSO regression model and support vector machine recursive feature elimination (SVM-RFE) were performed to screen out the best biomarkers. The GSE13367 dataset was used as a validation cohort, and the receiver operating characteristic curve (ROC) was used to evaluate the diagnostic performance. Finally, the immune infiltration characteristics in UC were explored by CIBERSORT, and we further analyzed the correlation between potential biomarkers and different immune cells.

Results

A total of 76 DEGs were screened out, among which 56 genes were upregulated and 20 genes were downregulated. Functional enrichment analysis revealed that these DEGs were mainly involved in immune response, chemokine signaling, IL−17 signaling, cytokine receptor interactions, inflammatory bowel disease, etc. ABCG2, HSPB3, SLC6A14, and VNN1 were identified as potential biomarkers for UC and validated in the GSE13367 dataset (AUC = 0.889, 95% CI: 0.797~0.961). Immune infiltration analysis by CIBERSORT revealed that there were significant differences in immune infiltration characteristics between UC and normal control tissues. A high level of memory B cells, γδ T cells, activated mast cells, M1 macrophages, neutrophils, etc. were found in the UC group, while a high level of M2 type macrophages, resting mast cells, eosinophils, CD8+ T cells, etc. were found in the normal control group.

Conclusion

ABCG2, HSPB3, SLC6A14, and VNN 1 were identified as potential biomarkers for UC. There was an obvious difference in immune infiltration between UC and normal control tissues, which may provide help to guide individualized treatment and develop new research directions.

Calycosin ameliorates atherosclerosis by enhancing autophagy via regulating the interaction between KLF2 and MLKL in apoE-/- mice

BACKGROUND AND PURPOSE

Atherosclerosis is one of the underlying causes of cardiovascular disease. Formation of foam cells and necrotic core in the plaque is a hallmark of atherosclerosis, which results from lipid deposition, apoptosis, and inflammation in macrophage. Macrophage autophagy is a critical anti-atherogenic process and defective autophagy aggravates atherosclerosis by enhancing foam cell formation, apoptosis, and inflammation. Hence, enhancing autophagy can be a strategy for atherosclerosis treatment. Calycosin, a flavonoid from Astragali Radix, displays antioxidant and anti-inflammatory activities, and therefore is potential to reduce the risk of cardiovascular disease. However, the antiatherogenic effect of calycosin and the involved mechanism remains unclear. In this study, we assessed the potential benefits of calycosin on autophagy and atherosclerosis, and revealed the underlying mechanism.

EXPERIMENTAL APPROACH

In this study, apoE^-/- mice were fed high-fat diet for 16 weeks in presence of calycosin and/or autophagy inhibitor chloroquine, which was followed by determination of atherosclerosis development, autophagy activity, and the involved mechanisms.

KEY RESULTS

Calycosin protected against atherosclerosis and enhanced plaque stability via promoting autophagy. Calycosin inhibited foam cells formation, inflammation, and apoptosis by enhancing autophagy. MLKL was demonstrated as a new autophagy regulator, which can be negatively regulated by KLF2. Mechanistically, inhibitory effects of calycosin on atherogenesis were via improving autophagy through modulating KLF2-MLKL signaling pathway.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated the atheroprotective effect of calycosin was through upregulating KLF2-MLKL-mediated autophagy, which not only proposed novel mechanistic insights into the atherogenesis but also identified calycosin as a potential drug candidate for atherosclerosis treatment.

Atractylenolide III alleviates sepsis-mediated lung injury via inhibition of FoxO1 and VNN1 protein

PURPOSE

To evaluate the influence of atractylenolide (Atr) III on sepsis-induced lung damage.

METHODS

We constructed a mouse sepsis model through cecal ligation and puncture. These mice were allocated to the normal, sepsis, sepsis + Atr III-L (2 mg/kg), as well as Atr III-H (8 mg/kg) group. Lung injury and pulmonary fibrosis were accessed via hematoxylin-eosin (HE) and Masson's staining. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and flow cytometry for detecting sepsis-induced lung cell apoptosis. The contents of the inflammatory cytokines in lung tissue were measured via enzyme-linked immunosorbent assay (ELISA).

RESULTS

Atr III-H did not only reduce sepsis-induced lung injury and apoptosis level, but also curbed the secretion of inflammatory factors. Atr III-H substantially ameliorated lung function and raised Bcl-2 expression. Atr III-H eased the pulmonary fibrosis damage and Bax, caspase-3, Vanin-1 (VNN1), as well as Forkhead Box Protein O1 (FoxO1) expression.

CONCLUSIONS

Atr III alleviates sepsis-mediated lung injury via inhibition of FoxO1 and VNN1 protein.

Differentially Expressed Circular Non-coding RNAs in Atherosclerotic Aortic Vessels and Their Potential Functions in Endothelial Injury

Background: Circular non-coding RNA (circRNA) has a variety of biological functions. However, the expression profile and potential effects of circRNA on atherosclerosis (AS) and vascular endothelial injury have not been fully elucidated. This study aims to identify the differentially expressed circRNAs in atherosclerotic aortic vessels and predict their potential functions in endothelial injury.

Method: ApoE-/- mice were fed with high-fat diet for 12 weeks to induce AS. Atherosclerotic plaques were evaluated by H&E and Masson staining and immunohistochemistry; differentially expressed circRNAs were detected by Arraystar Circular RNA Microarray and verified by RT-PCR; the potential target mircoRNAs of circRNAs were predicted by miRanda, Tarbase, Targetscan and their expression changes were verified by RT-PCR; the potential target genes of mircoRNAs were predicted by Targetscan and verified by Western blot; the signaling pathways that they might annotate or regulate and their potential functions in vascular endothelial injury were predicted by gene enrichment analysis.

Results: Fifty two circRNAs were up-regulated more than twice and 47 circRNAs were down-regulated more than 1.5 times in AS aortic vessels. Mmmu_circRNA_36781 and 37699 were up-regulated both in AS aortic vessels and H₂O₂-treated mouse aortic endothelial cells (MAECs). The expression of miR-30d-3p and miR-140-3p, the target microRNA of circRNA_37699 and circRNA_36781, were downregulated both in AS vessels and H₂O₂-treated MAECs. On the contrary, MKK6 and TP53RK, the potential target gene of miR-140-3p and miR-30d-3p, were upregulated both in AS aortic roots and H₂O₂-treated MAECs. Besides, gene enrichment analysis showed that MAPK and PI3K-AKT signaling pathway were the most potential signaling pathways regulated by the differentially expressed circRNAs in atherosclerosis.

Conclusions: Mmu_circRNA_36781 (circRNA ABCA1) and 37699 (circRNA KHDRBS1) were significantly up-regulated in AS aortic vessels and H₂O₂-treated MAECs. They have potential regulatory effects on atherosclerosis and vascular endothelial injury by targeting miR-30d-3p-TP53RK and miR-140-3p-MKK6 axis and their downstream signaling pathways.

A radioiodinated FR-β-targeted tracer with improved pharmacokinetics through modification with an albumin binder for imaging of macrophages in AS and NAFL

PURPOSE

The formation of advanced plaques, which is characterized by the uninterrupted aggregation of macrophages with high expression of folate receptor-β (FR-β), is observed in several concomitant metabolic syndromes. The objective of this study was to develop a novel FR-β-targeted single-photon emission computed tomography (SPECT) radiotracer and validate its application to the noninvasive detection of atherosclerosis (AS) plaque and non-alcoholic fatty liver (NAFL).

METHODS

Two radioiodinated probes, [¹³¹I]IPBF and [¹³¹I]IBF, were developed, and cell uptake studies were used to identify their specific targets for activated macrophages. Biodistribution in normal mice was performed to obtain the pharmacokinetic information of the probes. Apolipoprotein E knockout (ApoE^-/-) mice with atherosclerotic aortas were induced by a high-fat and high-cholesterol (HFHC) diet. To investigate the affinity of radiotracers to FR-β, K_d values were determined using in vitro assays. In addition, the assessments of the aorta in the ApoE^-/- mice at different stages were performed using in vivo SPECT/CT imaging, and the findings were compared by histology.

RESULTS

Both [¹³¹I]IPBF and [¹³¹I]IBF were synthesized with > 95% radiochemical purity and up to 3 MBq/nmol molar activity. In vitro assay of [¹³¹I]IPBF showed a moderate binding affinity to plasma proteins and specific uptake in activated macrophages. The prolonged blood elimination half-life (t_1/2z) of [¹³¹I]IPBF (8.14 h) was observed in a pharmacokinetic study of normal mice, which was significantly longer than that of [¹³¹I]IBF (t_1/2z = 2.95 h). As expected, the K_d values of [¹³¹I]IPBF and [¹³¹I]IBF in the Raw 264.7 cells were 43.94 ± 9.83 nM and 61.69 ± 15.19 nM, respectively. SPECT imaging with [¹³¹I]IPBF showed a high uptake in advanced plaques and NAFL. Radioactivity in excised aortas examined by ex vivo autoradiography further confirmed the specific uptake of [¹³¹I]IPBF in high-risk AS plaques.

CONCLUSIONS

In summary, we reported a proof-of-concept study of an albumin-binding folate derivative for macrophage imaging. The FR-β-targeted probe, [¹³¹I]IPBF, significantly prolongs the plasma elimination half-life and has the potential for the monitoring of AS plaques and concomitant fatty liver.

Perfluorooctanoic acid activates multiple nuclear receptor pathways and skews expression of genes regulating cholesterol homeostasis in liver of humanized PPARα mice fed an American diet

Humans are exposed to per- and polyfluoroalkyl substances (PFAS) in their drinking water, food, air, dust, and by direct use of consumer products. Increased concentrations of serum total cholesterol and low density lipoprotein cholesterol are among the endpoints best supported by epidemiology. The objectives of this study were to generate a new model for examining PFAS-induced dyslipidemia and to conduct molecular studies to better define mechanism(s) of action. We tested the hypothesis that perfluorooctanoic acid (PFOA) exposure at a human-relevant level dysregulates expression of genes controlling cholesterol homeostasis in livers of mice expressing human PPARα (hPPARα). Female and male hPPARα and PPARα null mice were fed a diet based on the "What we eat in America" analysis and exposed to PFOA in drinking water (8 μM) for 6 weeks. This resulted in a serum PFOA concentration of 48 μg/ml. PFOA increased liver mass, which was associated with histologically-evident lipid accumulation. Pooled analyses of serum lipoprotein cholesterol suggest that PFOA increased serum cholesterol, particularly in male mice. PFOA induced PPARα and constitutive androstane receptor target gene expression in liver. Expression of genes in four pathways regulating cholesterol homeostasis were also measured. PFOA decreased expression of Hmgcr in a PPARα-dependent manner. PFOA decreased expression of Ldlr and Cyp7a1 in a PPARα-independent manner. Apob expression was not changed. Sex differences were evident. This novel study design (hPPARα mice, American diet, long term exposure) generated new insight on the effects of PFOA on cholesterol regulation in the liver and the role of hPPARα.

Assessment of candidate biomarkers to detect resistance to Mycobacterium bovis in Holstein-Friesian cattle

Bovine tuberculosis (bTB) caused by Mycobacterium bovis has a significant economic impact worldwide each year. Control of bTB is based on skin testing and removal of reactors. However, additional strategies are required to control this disorder. Natural disease resistance has been defined as the inherent capacity of an individual to resist disease when exposed to pathogens without previous exposure or immunization. However, little is known about natural disease resistance against Mycobacterium bovis in cattle. In this study, we aimed to identify candidate biomarkers to detect host resistance to M. bovis. We used a microbicidal assay to identify the resistance phenotype. A genomic microarray analysis was carried out on RNA from 2 resistant (R) and 2 susceptible (S) cows. Our results evidenced 69 differentially expressed genes. A subset of six genes that showed differential up (IL1RN), and down-regulation (VNN, GATM, ARHGEF11, NAAA and HSPA2) were selected for further analysis. To further validate the candidate biomarkers, we identified the R phenotype in 31 cattle (9 R and 22 S). Macrophage mRNA was isolated from this group of cattle. Expression of candidate biomarkers was evaluated by qPCR 2^-ΔCt and ROC curves to determine their diagnostic potential. Candidates IL1RN and ARHGEF11 discriminates between R and S cattle. Furthermore, combination of candidates ARHGEF11: VNN: HSPA2 discriminate between R from S with AUC 0.7993 and agreement index of 0.853 (p ≤ 0.01). Our data suggest that candidate biomarkers may support the preliminary screening to identify natural resistance in herds against Mycobacterium bovis in Holstein-Friesian cattle.

The role of the LncRNA-FA2H-2-MLKL pathway in atherosclerosis by regulation of autophagy flux and inflammation through mTOR-dependent signaling

Atherosclerosis is a progressive, chronic inflammation in arterial walls. Long noncoding RNAs (lncRNAs) participate in inflammation, but the exact mechanism in atherosclerosis is unclear. Our microarray analyses revealed that the levels of lncRNA-FA2H-2 were significantly decreased by oxidized low-density lipoprotein (OX-LDL). Bioinformatics analyses indicated that mixed lineage kinase domain-like protein (MLKL) might be regulated by lncRNA-FA2H-2. In vitro experiments showed that lncRNA-FA2H-2 interacted with the promoter of the MLKL gene, downregulated MLKL expression, and the binding sites between -750 and 471 were necessary for lncRNA-FA2H-2 responsiveness to MLKL. Silencing lncRNA-FA2H-2 and overexpression of MLKL could activate inflammation and inhibited autophagy flux. Both lncRNA-FA2H-2 knockdown and overexpression of MLKL could significantly aggravate inflammatory responses induced by OX-LDL. We found that the 3-methyladenine (3-MA) and Atg7-shRNA enhanced inflammatory responses induced by knockdown of lncRNA-FA2H-2 and overexpression of MLKL. We demonstrated that the effects of MLKL on autophagy might be associated with a mechanistic target of rapamycin (mTOR)-dependent signaling pathways. In vivo experiments with apoE knockout mice fed a western diet demonstrated that LncRNA-FA2H-2 knockdown decreased microtubule-associated expression of microtubule-associated protein 1 light chain 3 II and lysosome-associated membrane protein 1, but increased expression of sequestosome 1 (p62), MLKL, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, and interleukin-6 in atherosclerotic lesions. Our findings indicated that the lncRNA-FA2H-2-MLKL pathway is essential for regulation of autophagy and inflammation, and suggested that lncRNA-FA2H-2 and MLKL could act as potential therapeutic targets to ameliorate atherosclerosis-related diseases.

MicroRNA-203 Acts as a Potent Suppressor in Septic Shock by Alleviating Lung Injury via Inhibition of VNN1

BACKGROUND

Septic shock, the most serious complication of sepsis, is a life-threatening disease that is mainly characterized by hypoperfusion and multiple organ failure. Various aberrantly expressed microRNAs (miRNAs) have been reported to be related to septic shock. We explored the regulatory effect of microRNA-203 (miR-203) on lung injury in septic shock mice.

METHODS

Microarray-based gene expression profiling related to septic shock identified the differentially expressed gene vanin-1 (VNN1) and potential regulatory miR-203. miR-203 was predicted to mediate VNN1 expression, thus affecting septic shock, which was investigated by treatment with miR-203 mimic, miR-203 inhibitor, and siRNA-VNN1 in septic shock mouse models. Polymorphonuclear neutrophils (PMNs) and pulmonary alveolar macrophages in bronchoalveolar lavage fluid (BALF) as well as the wet/dry ratio of the lung were also measured to assess lung injury. Additionally, the effects of miR-203 on inflammatory cytokines, oxidative stress indexes, blood biochemical indexes, serine-threonine protein kinase (AKT) signaling pathway-related factors, and apoptosis-related factors were determined.

RESULTS

VNN1 was verified to be targeted and negatively regulated by miR-203. In mouse models of septic shock, weak expression of miR-203, high expression of VNN1, and inhibition of AKT signaling pathway were identified. In response to miR-203 mimic and VNN1 gene silencing, mouse models of septic shock displayed reduced apoptosis, MDA, ALT, and AST in lung tissues, decreased levels of TNF-α, IL-1β, IFN-γ, IL-10, and IL-6, in serum, and reduced PMN and PAM levels in BALF, in addition to elevated SOD activity. Notably, the presence of miR-203 mimic led to AKT signaling pathway activation.

CONCLUSION

This study shows that upregulating miR-203 can alleviate lung injury through activation of the AKT signaling pathway by downregulating VNN1 in septic shock.

Gene expression analysis of vascular pathophysiology related to anti-TNF treatment in rheumatoid arthritis

OBJECTIVES

Impaired vascular pathophysiology and increased cardiovascular (CV) mortality are associated with rheumatoid arthritis (RA). To date, no genomic analysis of RA- and RA treatment-related vascular pathophysiology has been published. In this pilot study, we performed gene expression profiling in association with vascular pathophysiology in RA patients.

METHODS

Sixteen and 19 biologic-naïve RA patients were included in study 1 and study 2, respectively. In study 1, genetic signatures determined by microarray were related to flow-mediated vasodilation (FMD), pulse-wave velocity (PWV), and common carotid intima-media thickness (IMT) of patients. In study 2, clinical response (cR) vs non-response (cNR) to 1-year etanercept (ETN) or certolizumab pegol (CZP) treatment, as well as "vascular" response (vR) vs non-response (vNR) to biologics, were also associated with genomic profiles. Multiple testing could not be performed due to the relatively small number of patients; therefore, our pilot study may lack power.

RESULTS

In study 1, multiple genes were up- or downregulated in patients with abnormal vs normal FMD, IMT, and PWV. In study 2, there were 13 cR and 6 cNR anti-tumor necrosis factor (TNF)-treated patients. In addition, 10, 9, and 8 patients were FMD-20%, IMT-20%, and PWV-20% responders. Again, vascular responder status was associated with changes of the expression of various genes. The highest number of genes showing significant enrichment were involved in positive regulation of immune effector process, regulation of glucose transport, and Golgi vesicle budding.

CONCLUSION

Differential expression of multiple genetic profiles may be associated with vascular pathophysiology associated with RA. Moreover, distinct genetic signatures may also be associated with clinical and vascular responses to 1-year anti-TNF treatment.

MicroRNA-24 aggravates atherosclerosis by inhibiting selective lipid uptake from HDL cholesterol via the post-transcriptional repression of scavenger receptor class B type I

BACKGROUND AND AIMS

Liver scavenger receptor class B type I (SR-BI) exerts atheroprotective effects through selective lipid uptake (SLU) from high-density lipoprotein cholesterol (HDL-C). Low hepatic SR-BI expression leads to high HDL-C levels in the circulation and an increased risk of atherosclerosis. Furthermore, macrophage SR-BI mediates bidirectional cholesterol flux and may protect against atherogenesis. Previous studies have revealed that miR-24 is closely related to cardiovascular disease (CVD) progression. We aimed to investigate the molecular mechanisms by which miR-24 participates in SR-BI-mediated selective HDL cholesteryl ester (HDL-CE) uptake and further atherogenesis in apoE^-/- mice.

METHODS

Bioinformatic predictions and luciferase reporter assays were utilized to detect the association between miR-24 and the SR-BI 3' untranslated region (3' UTR), and RT-PCR and western blotting were used to evaluate SR-BI mRNA and protein expression, respectively. The effects of miR-24 on Dil-HDL uptake were determined by flow cytometry assay. Double-radiolabeled HDL (¹²⁵I-TC-/[³H] CEt-HDL) was utilized to measure the effects of miR-24 on HDL and CE binding and SLU in HepG2 and PMA-treated THP-1 cells. In addition, total cholesterol (TC) levels in HepG2 cells were analyzed using enzymatic methods, and macrophage lipid content was evaluated by high-performance liquid chromatography (HPLC) assay. Small interfering RNA (siRNA) and pcDNA3.1(-)-hSR-BI plasmid transfection procedures were utilized to confirm the role of SR-BI in the effects of miR-24 on Dil-HDL uptake, SLU and cholesterol levels in both cell types. Hepatic SR-BI level in apoE^-/- mice was measured by western blotting. Liver TC, FC and CE levels and plasma triglycerides (TG), TC and HDL-C levels were evaluated enzymatically using commercial test kits. Atherosclerotic lesion sizes were measured using Oil Red O and hematoxylin-eosin staining.

RESULTS

miR-24 directly repressed SR-BI expression by targeting its 3'UTR. In addition, miR-24 decreased Dil-HDL uptake and SLU in HepG2 and THP-1 macrophages. In the presence of HDL, miR-24 decreased TC levels in HepG2 cells and TC, free cholesterol (FC) and CE levels in macrophages. Overexpression and down-regulation assays showed that SR-BI mediated the effects of miR-24 on Dil-HDL uptake, SLU and cholesterol levels. Lastly, miR-24 administration decreased hepatic SR-BI expression and promoted atheromatous plaque formation in apoE^-/- mice, findings in line with those of our in vitro studies.

CONCLUSIONS

These findings indicate that miR-24 accelerates atherogenesis by repressing SR-BI-mediated SLU from HDL-C.

miR-497 accelerates oxidized low-density lipoprotein-induced lipid accumulation in macrophages by repressing the expression of apelin

microRNAs (miRNAs) play important roles in the pathogenesis of atherosclerosis. A previous study has reported that miR-497 is elevated in advanced atherosclerotic lesions in an apoE-deficient (apoE-/-) mouse model. The purpose of this study is to test whether miR-497 can modulate macrophage foam cell formation, an initiating event in atherosclerosis. We found that miR-497 was upregulated in THP-1 macrophages after treatment with oxidized low-density lipoprotein (oxLDL). Enforced expression of miR-497 promoted lipid accumulation and decreased cholesterol efflux in oxLDL-exposed THP-1 macrophages. In contrast, downregulation of miR-497 suppressed oxLDL-induced lipid accumulation in THP-1 macrophages. Apelin was identified to be a downstream target of miR-497. Overexpression of miR-497 significantly reduced the expression of apelin in THP-1 macrophages. Interestingly, delivery of a miR-497-resistant variant of apelin significantly inhibited lipid accumulation and enhanced cholesterol efflux in miR-497-overexpressing THP-1 macrophages in response to oxLDL. In addition, miR-497 expression was increased and negatively correlated with apelin protein expression in human atherosclerotic lesions. In conclusion, miR-497 contributes to oxLDL-induced lipid deposition in macrophages largely via targeting of apelin and thus represents a potential therapeutic target for atherosclerosis.