The IRG1-itaconate axis protects from cholesterol-induced inflammation and atherosclerosis.

Atherosclerosis is fueled by a failure to resolve lipid-driven inflammation within the vasculature that drives plaque formation. Therapeutic approaches to reverse atherosclerotic inflammation are needed to address the rising global burden of cardiovascular disease (CVD). Recently, metabolites have gained attention for their immunomodulatory properties, including itaconate, which is generated from the tricarboxylic acid-intermediate cis-aconitate by the enzyme Immune Responsive Gene 1 (IRG1/ACOD1). Here, we tested the therapeutic potential of the IRG1-itaconate axis for human atherosclerosis. Using single-cell RNA sequencing (scRNA-seq), we found that IRG1 is up-regulated in human coronary atherosclerotic lesions compared to patient-matched healthy vasculature, and in mouse models of atherosclerosis, where it is primarily expressed by plaque monocytes, macrophages, and neutrophils. Global or hematopoietic Irg1-deficiency in mice increases atherosclerosis burden, plaque macrophage and lipid content, and expression of the proatherosclerotic cytokine interleukin (IL)-1ß. Mechanistically, absence of Irg1 increased macrophage lipid accumulation, and accelerated inflammation via increased neutrophil extracellular trap (NET) formation and NET-priming of the NLRP3-inflammasome in macrophages, resulting in increased IL-1ß release. Conversely, supplementation of the Irg1-itaconate axis using 4-octyl itaconate (4-OI) beneficially remodeled advanced plaques and reduced lesional IL-1ß levels in mice. To investigate the effects of 4-OI in humans, we leveraged an ex vivo systems-immunology approach for CVD drug discovery. Using CyTOF and scRNA-seq of peripheral blood mononuclear cells treated with plasma from CVD patients, we showed that 4-OI attenuates proinflammatory phospho-signaling and mediates anti-inflammatory rewiring of macrophage populations. Our data highlight the relevance of pursuing IRG1-itaconate axis supplementation as a therapeutic approach for atherosclerosis in humans.

An OX-Tra'Ordinary Tale: The Role of OX40 and OX40L in Atopic Dermatitis.

The transmembrane glycoprotein OX40 receptor (OX40) and its ligand, OX40L, are instrumental modulators of the adaptive immune response in humans. OX40 functions as a costimulatory molecule that promotes T cell activation, differentiation, and survival through ligation with OX40L. T cells play an integral role in the pathogenesis of several inflammatory skin conditions, including atopic dermatitis (AD). In particular, T helper 2 (TH2) cells strongly contribute to AD pathogenesis via the production of cytokines associated with type 2 inflammation (e.g., IL-4, IL-5, IL-13, and IL-31) that lead to skin barrier dysfunction and pruritus. The OX40-OX40L interaction also promotes the activation and proliferation of other T helper cell populations (e.g., TH1, TH22, and TH17), and AD patients have demonstrated higher levels of OX40 expression on peripheral blood mononuclear cells than healthy controls. As such, the OX40-OX40L pathway is a potential target for AD treatment. Novel therapies targeting the OX40 pathway are currently in development, several of which have demonstrated promising safety and efficacy results in patients with moderate-to-severe AD. Herein, we review the function of OX40 and the OX40-OX40L signaling pathway, their role in AD pathogenesis, and emerging therapies targeting OX40-OX40L that may offer insights into the future of AD management.

The transcription factor HMGB2 indirectly regulates APRIL expression and Gd-IgA1 production in patients with IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Proliferation-inducing ligand (APRIL) was identified as an important cause of glycosylation deficiency of IgA1 (Gd-IgA1), which can 'trigger' IgAN. Our previous study indicated that high migration group protein B2 (HMGB2) in peripheral blood mononuclear cells from patients with IgAN was associated with disease severity, but the underlying mechanism remains unclear. MATERIALS AND METHODS: The location of HMGB2 was identified by immunofluorescence. qRT-PCR and Western blotting were used to measure HMGB2, HMGA1, and APRIL expression. Gd-IgA1 levels were detected by enzyme-linked immunosorbent assay (ELISA). In addition, we used DNA pull-down, protein profiling, and transcription factor prediction software to identify proteins bound to the promoter region of the APRIL gene. RNA interference and coimmunoprecipitation (Co-IP) were used to verify the relationships among HMGB2, high mobility group AT-hook protein 1 (HMGA1), and APRIL. RESULTS: HMGB2 expression was greater in IgAN patients than in HCs and was positively associated with APRIL expression in B cells. DNA pull-down and protein profiling revealed that HMGB2 and HMGA1 bound to the promoter region of the APRIL gene. The expression levels of HMGA1, APRIL, and Gd-IgA1 were downregulated after HMGB2 knockdown. Co-IP indicated that HMGB2 binds to HMGA1. The Gd-IgA1 concentration in the supernatant was reduced after HMGA1 knockdown. HMGA1 binding sites were predicted in the promoter region of the APRIL gene. CONCLUSION: HMGB2 expression is greater in IgAN patients than in healthy controls; it promotes APRIL expression by interacting with HMGA1, thereby inducing Gd-IgA1 overexpression and leading to IgAN.

Differential gene expression and miRNA regulatory network in coronary slow flow.

Coronary slow flow (CSF) is characterized by slow progression of coronary angiography without epicardial stenosis. The aim of this study was to explore the potential biomarkers and regulatory mechanism for CSF. Peripheral blood mononuclear cells from 3 cases of CSF and 3 healthy controls were collected for high-throughput sequencing of mRNA and miRNA, respectively. The differentially expressed mRNAs (DE-mRNAs) and miRNAs (DE-miRNAs) was identified. A total of 117 DE-mRNAs and 32 DE-miRNAs were obtained and they were mainly enriched in immune and inflammatory responses. Twenty-six DE-mRNAs were the predicted target genes for miRNAs by RAID, and then the regulatory network of 15 miRNAs were constructed. In addition, through the PPI network, we identified the three genes (FPR1, FPR2 and CXCR4) with larger degrees as hub genes. Among them, FPR1 was regulated by hsa-miR-342-3p, hsa-let-7c-5p and hsa-miR-197-3p and participated in the immune response. Finally, we validated the differential expression of hub genes and key miRNAs between 20 CSF and 20 control. Moreover, we found that miR-342-3p has a targeted regulatory relationship with FPR1, and their expression is negatively correlated. Then we established a hypoxia/reoxygenation (H/R) HUVEC model and detected FPR1, cell proliferation and apoptosis. Transfection with miR-342-3p mimics can significantly promote the proliferation of HUVEC under H/R conditions. FPR1 were associated with CSF as a biomarker and may be regulated by miR-342-3p potential biomarkers.

Analysis of Human Peripheral Blood Mononuclear Cells in Patients with Neurodegenerative Diseases.

The role of immune system in the progression of neurodegenerative diseases has been studied for decades in animal models. However, invasive studies in human subjects remain controversial due to the heterogeneity of the presentation of different diagnostic categories at different stages of the disease. Peripheral blood mononuclear cells (PBMCs) contain immune cells including dendritic cells (DCs), monocytes, macrophages, and T lymphocytes. Isolating PBMCs from whole blood samples collected from patients provides a minimally invasive method for analyzing the immune system's function in patients with neurodegenerative diseases. By isolating single cell types from patients' peripheral blood, in vitro analyses can be conducted including RNA sequencing, immunofluorescence, and phagocytic analysis. In this chapter, we discuss PBMC separation and isolation of macrophages in pure culture in vitro. We also outline methods for performing RNA-seq on cultured macrophages and other techniques for investigating the role of macrophages in neurodegenerative disease pathophysiology.

Blood MALT1 expression could help predict treatment outcomes in psoriasis patients, especially in those receiving biologics.

INTRODUCTION: Mucosa-associated lymphoid tissue 1 (MALT1) modulates T helper cell differentiation, pro-inflammatory cytokine production, and epidermal hyperplasia to participate in the pathology of psoriasis. This study aimed to explore the correlation of blood MALT1 with treatment outcomes in psoriasis patients. METHODS: MALT1 was detected in peripheral blood mononuclear cells by reverse transcription-quantitative polymerase chain reaction in 210 psoriasis patients before starting or converting to a new therapy, 50 disease controls, and 50 healthy controls. The psoriasis area severity index (PASI) score was evaluated at month (M)1, M3, and M6 in psoriasis patients. RESULTS: MALT1 was increased in psoriasis patients versus disease controls and healthy controls (both p < .001); and positively related to body mass index (p = .019) and PASI score (p < .001) in psoriasis patients. PASI75 rate at M1, M3, and M6 was 22.9%, 46.2%, and 71.0%, respectively; while PASI90 rate at M1, M3, and M6 was 3.8%, 29.0%, and 50.5%, respectively, in psoriasis patients. PASI75/90 rates at M1, M3, and M6 were increased in psoriasis patients receiving biologics versus those without (all p < .05). Pretreatment MALT1 was higher in psoriasis patients who achieved PASI75 (p = .001) and PASI90 (p < .001) at M6 compared to those who did not achieve that. Subgroup analyses discovered that pretreatment MALT1 had a stronger ability to predict PASI75 and 90 realizations in psoriasis patients receiving biologics (area under the curve [AUC]: 0.723 and 0.808) versus those without (AUC: 0.594 and 0.675). CONCLUSION: Blood MALT1 measurement may assist in predicting outcomes in psoriasis patients, especially in those receiving biologics.

Ruxolitinib Improves Immune-Dysregulation Features but not Epigenetic Abnormality in a Patient with STAT1 GOF.

PURPOSE: Patients with STAT1 gain-of-function (GOF) mutations often exhibit autoimmune features. The JAK1/2 inhibitor ruxolitinib can be administered to alleviate autoimmune symptoms; however, it is unclear how immune cells are molecularly changed by ruxolitinib treatment. Then, we aimed to investigate the trnscriptional and epigenetic status of immune cells before and after ruxolitinib treatment in a patient with STAT1 GOF. METHODS: A patient with a heterozygous STAT1 GOF variant (p.Ala267Val), exhibiting autoimmune features, was treated with ruxolitinib, and peripheral blood mononuclear cells (PBMCs) were longitudinally collected. PBMCs were transcriptionally analyzed by single-cell cellular indexing of the transcriptomes and epitopes by sequencing (CITE-seq), and epigenetically analyzed by assay of transposase-accessible chromatin sequencing (ATAC-seq). RESULTS: CITE-seq analysis revealed that before treatment, the patient's PBMCs exhibited aberrantly activated inflammatory features, especially IFN-related features. In particular, monocytes showed high expression levels of a subset of IFN-stimulated genes (ISGs). Ruxolitinib treatment substantially downregulated aberrantly overexpressed ISGs, and improved autoimmune features. However, epigenetic analysis demonstrated that genetic regions of ISGs-e.g., STAT1, IRF1, MX1, and OAS1-were highly accessible even after ruxolitinib treatment. When ruxolitinib was temporarily discontinued, the patient's autoimmune features were aggravated, which is in line with sustained epigenetic abnormality. CONCLUSIONS: In a patient with STAT1 GOF, ruxolitinib treatment improved autoimmune features and downregulated aberrantly overexpressed ISGs, but did not correct epigenetic abnormality of ISGs.

Metacell-based differential expression analysis identifies cell type specific temporal gene response programs in COVID-19 patient PBMCs.

By profiling gene expression in individual cells, single-cell RNA-sequencing (scRNA-seq) can resolve cellular heterogeneity and cell-type gene expression dynamics. Its application to time-series samples can identify temporal gene programs active in different cell types, for example, immune cells' responses to viral infection. However, current scRNA-seq analysis has limitations. One is the low number of genes detected per cell. The second is insufficient replicates (often 1-2) due to high experimental cost. The third lies in the data analysis-treating individual cells as independent measurements leads to inflated statistics. To address these, we explore a new computational framework, specifically whether "metacells" constructed to maintain cellular heterogeneity within individual cell types (or clusters) can be used as "replicates" for increasing statistical rigor. Toward this, we applied SEACells to a time-series scRNA-seq dataset from peripheral blood mononuclear cells (PBMCs) after SARS-CoV-2 infection to construct metacells, and used them in maSigPro for quadratic regression to find significantly differentially expressed genes (DEGs) over time, followed by clustering expression velocity trends. We showed that such metacells retained greater expression variances and produced more biologically meaningful DEGs compared to either metacells generated randomly or from simple pseudobulk methods. More specifically, this approach correctly identified the known ISG15 interferon response program in almost all PBMC cell types and many DEGs enriched in the previously defined SARS-CoV-2 infection response pathway. It also uncovered additional and more cell type-specific temporal gene expression programs. Overall, our results demonstrate that the metacell-pseudoreplicate strategy could potentially overcome the limitation of 1-2 replicates.

Circular RNA Expression of Peripheral Blood Mononuclear Cells Associated with Risk of Acute Exacerbation in Smoking Chronic Obstructive Pulmonary Disease.

Purpose: Circular RNAs (circRNAs) are newly identified endogenous non-coding RNAs that function as crucial gene modulators in the development of several diseases. By assessing the expression levels of circRNAs in peripheral blood mononuclear cells (PBMCs) from patients with chronic obstructive pulmonary disease (COPD), this study attempted to find new biomarkers for COPD screening. Patients and Methods: We confirmed altered circRNA expression in PBMCs of COPD (n=41) vs controls (n=29). Further analysis focused on the highest and lowest circRNA expression levels. The T-test is used to assess the statistical variances in circRNAs among COPD patients in the smoking and non-smoking cohorts. Additionally, among smokers, the Spearman correlation test assesses the association between circRNAs and clinical indicators. Results: Two circRNAs, hsa_circ_0042590 and hsa_circ_0049875, that were highly upregulated and downregulated in PBMCs from COPD patients were identified and verified. Smokers with COPD had lower hsa_circ_0042590 and higher hsa_circ_0049875, in comparison to non-smokers. There was a significant correlation (r=0.52, P<0.01) between the number of acute exacerbations (AEs) that smokers with COPD experienced in the previous year and the following year (r=0.67, P<0.001). Moreover, hsa_circ_0049875 was connected to the quantity of AEs in the year prior (r=0.68, P<0.0001) as well as the year after (r=0.72, P<0.0001). AUC: 0.79, 95% CI: 0.1210-0.3209, P<0.0001) for hsa_circ_0049875 showed a strong diagnostic value for COPD, according to ROC curve analysis. Hsa_circ_0042590 showed a close second with an AUC of 0.83 and 95% CI: -0.1972--0.0739 (P <0.0001). Conclusion: This research identified a strong correlation between smoking and hsa_circ_0049875 and hsa_circ_0042590 in COPD PBMCs. The number of AEs in the preceding and succeeding years was substantially linked with the existence of hsa_circ_0042590 and hsa_circ_0049875 in COPD patients who smoke. Additionally, according to our research, hsa_circ_0049875 and hsa_circ_0042590 may be valuable biomarkers for COPD diagnosis.

MDSC-derived S100A8/9 contributes to lupus pathogenesis by promoting TLR7-mediated activation of macrophages and dendritic cells.

Toll-like receptors (TLRs), especially TLR7, play an important role in systemic lupus erythematosus (SLE) pathogenesis. However, the regulatory mechanism underlying the abnormal activation of TLR pathways in patients with SLE has not been elucidated. Notably, accumulating evidence indicates that myeloid-derived suppressor cells (MDSCs) are important regulators of inflammation and autoimmune diseases. Compared with healthy control subjects, patients with SLE have a greater proportion of MDSCs among peripheral blood mononuclear cells (PBMCs); however, the effect of MDSCs on TLR7 pathway activation has not been determined. In the present study, lupus MDSCs significantly promoted TLR7 pathway activation in macrophages and dendritic cells (DCs), exacerbating the imiquimod-induced lupus model. RNA-sequencing analysis revealed significant overexpression of S100 calcium-binding protein A8 (S100A8) and S100A9 in MDSCs from diseased MRL/lpr mice. In vitro and in vivo studies demonstrated that S100A8/9 effectively promoted TLR7 pathway activation and that S100A8/9 deficiency reversed the promoting effect of MDSCs on TLR7 pathway activation in lupus. Mechanistically, MDSC-derived S100A8/9 upregulated interferon gamma (IFN-γ) secretion by macrophages and IFN-γ subsequently promoted TLR7 pathway activation in an autocrine manner. Taken together, these findings suggest that lupus MDSCs promote TLR7 pathway activation and lupus pathogenesis through the S100A8/9-IFN-γ axis. Our study identified an important target for SLE therapy.

Biobran/MGN-3, an Arabinoxylan Rice Bran, Exerts Anti-COVID-19 Effects and Boosts Immunity in Human Subjects.

Corona Virus Disease 19 (COVID-19) has been a major pandemic impacting a huge population worldwide, and it continues to present serious health threats, necessitating the development of novel protective nutraceuticals. Biobran/MGN-3, an arabinoxylan rice bran, is a potent immunomodulator for both humans and animals that has recently been demonstrated to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. We here investigate Biobran/MGN-3's potential to enhance an antiviral immune response in humans. Peripheral blood mononuclear cells (PBMCs) derived from eight subjects taking Biobran/MGN-3 (age 55-65 years) and eight age-matched control subjects were stimulated with irradiated SARS-CoV-2 virus and then subjected to immuno-phenotyping and multiplex cytokine/chemokine assays. Results showed that PBMCs from subjects supplemented with Biobran/MGN-3 had significantly increased activation of plasmacytoid dendritic cells (pDCs) coupled with increased IFN-α secretion. We also observed higher baseline expression of HLA-DR (human leukocyte antigen-DR isotype) on dendritic cells (DCs) and increased secretion of chemokines and cytokines, as well as a substantial increase in cytotoxic T cell generation for subjects taking Biobran/MGN-3. Our results suggest that Biobran/MGN-3 primes immunity and therefore may be used for boosting immune responses against SARS-CoV-2 infections and other diseases, particularly in high-risk populations such as the elderly.

Expression of USP25 associates with fibrosis, inflammation and metabolism changes in IgG4-related disease.

IgG4-related disease (IgG4-RD) has complex clinical manifestations ranging from fibrosis and inflammation to deregulated metabolism. The molecular mechanisms underpinning these phenotypes are unclear. In this study, by using IgG4-RD patient peripheral blood mononuclear cells (PBMCs), IgG4-RD cell lines and Usp25 knockout mice, we show that ubiquitin-specific protease 25 (USP25) engages in multiple pathways to regulate fibrotic and inflammatory pathways that are characteristic to IgG4-RD. Reduced USP25 expression in IgG4-RD leads to increased SMAD3 activation, which contributes to fibrosis and induces inflammation through the IL-1ß inflammatory axis. Mechanistically, USP25 prevents ubiquitination of RAC1, thus, downregulation of USP25 leads to ubiquitination and degradation of RAC1. Decreased RAC1 levels result in reduced aldolase A release from the actin cytoskeleton, which then lowers glycolysis. The expression of LYN, a component of the B cell receptor signalosome is also reduced in USP25-deficient B cells, which might result in B cell activation deficiency. Altogether, our results indicate a potential anti-inflammatory and anti-fibrotic role for USP25 and make USP25 a promising diagnostic marker and potential therapeutic target in IgG4-RD.

Immune profiling analysis of double-negative T cells in patients with systemic sclerosis.

OBJECTIVE: To construct a molecular immune map of patients with systemic sclerosis (SSc) by mass flow cytometry, and compare the number and molecular expression of double-negative T (DNT) cell subsets between patients and healthy controls (HC). METHODS: Peripheral blood mononuclear cells (PBMCs) were extracted from the peripheral blood of 17 SSc patients and 9 HC. A 42-channel panel was set up to perform mass cytometry by time of flight (CyTOF) analysis for DNT subgroups. Flow cytometry was used to validate subpopulation functions. The clinical data of patients were collected for correlation analysis. RESULTS: Compared with HC, the number of total DNT cells decreased in SSc patients. Six DNT subsets were obtained from CyTOF analysis, in which the proportion of cluster1 increased, while the proportion of cluster3 decreased. Further analysis revealed that cluster1 was characterized by high expression of CD28 and CCR7, and cluster3 was characterized by high expression of CD28 and CCR5. After in vitro stimulation, cluster1 secreted more IL-4 and cluster3 secreted more IL-10 in SSc patients compared to HC. Clinical correlation analysis suggested that cluster1 may play a pathogenic role while cluster3 may play a protective role in SSc. ROC curve analysis further revealed that cluster3 may be a potential indicator for determining disease activity in SSc patients. CONCLUSION: We found a new CCR5+CD28+ DNT cell subset, which played a protective role in the pathogenesis of SSc. Key Points • The number of DNT cells decreased in SSc patients' peripheral blood. • DNT cells do not infiltrate in the skin but secrete cytokines to participate in the pathogenesis of SSc. • A CCR5+CD28+ DNT cell population may play a protective role in SSc.

Revealing the changes in signaling pathways caused by tofacitinib in patients with rheumatoid arthritis through RNA sequencing and the correlation with clinical parameters.

OBJECTIVES: The current study is to accelerate the understanding of how tofacitinib works in patients with rheumatoid arthritis (RA) due to the lack of relevant information. METHOD: We selected ten patients with active RA and obtained the expression profile for their peripheral blood mononuclear cells before and after the tofacitinib treatment by RNA sequencing. The gene set enrichment analysis was conducted, and the significantly enriched gene sets were identified. The hub gene highly correlated with clinical parameters in the gene set was selected. We constructed the weighted gene co-expression network, linked modules with clinical indicators, and screened hub genes. The expression of representative hub genes was validated by real-time quantitative PCR (qPCR). RESULTS: Gene set interferon (IFN) α and IFN ß signaling was the most significantly down-regulated after tofacitinib treatment. In this gene set, genes Oas2 and Oasl showed a significant positive correlation with morning stiffness. In co-expression network, gene Vgll3 from the violet module with the highest correlation coefficient, was positively correlated with morning stiffness. Among them, Oasl and Vgll3 have shown significant down-regulation in qPCR validation. CONCLUSIONS: Our results highlighted the role of type I IFN, mainly including IFN α and IFN ß, in the pathogenesis of RA and action for tofacitinib, and provided a new entry point for further elucidating the mechanism of morning stiffness. Key Points • Gene set IFN α and IFN ß signaling was the most significantly down-regulated after tofacitinib treatment in RA patients. • Gene Oasl and Vgll3 were correlated with morning stiffness and significantly down-regulated due to the action of tofacitinib. • Type I IFN system was highlighted in the action of tofacitinib.

Identification of EPSTI1 as a new potential biomarker for SLE based on GEO database.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with highly heterogeneous. The aim of this study is to find the key genes in peripheral blood mononuclear cells (PBMCs) of SLE patients and to provide a new direction for the diagnosis and treatment of lupus. METHODS: GSE121239, GSE50772, GSE81622, and GSE144390 mRNA expression profiles were obtained from the website of Gene Expression Omnibus (GEO), and differential expressed genes (DEGs) analysis was performed by R. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to elucidate signaling pathways for the DEGs. Real-time qPCR (RT-qPCR) was used to verify the key gene EPSTI1 in PBMCs of SLE patients. Finally, the correlation analysis and ROC curve analysis of EPSTI1 for SLE were performed. RESULTS: A total of 12 upregulated DEGs were identified, including MMP8, MX1, IFI44, EPSTI1, OAS1, OAS3, HERC5, IFIT1, RSAD2, USP18, IFI44L, and IFI27. GO and KEGG pathway enrichment analysis showed that those DEGs were mainly concentrated in the response to virus and IFN signaling pathways. Real-time qPCR (RT-qPCR) revealed that EPSTI1 was increased in PBMCs of SLE. EPSTI1 was positively correlated with SLEDAI score in SLE patients. Besides, EPSTI1 was positively correlated with T cell activation- or differentiation-associated genes (BCL6 and RORC). Furthermore, ROC analyses proved EPSTI1 may have diagnostic value for SLE. CONCLUSION: Together, EPSTI1 was found to be a potential biomarker for SLE, closely related to T cell immune imbalance. Key Points • EPSTI1 expression was significantly increased in PBMCs of SLE patients. • EPSTI1 was positively correlated with disease activity and T cell activation- or differentiation-associated genes in SLE patients. • EPSTI1 might have a good diagnostic value for SLE.

Predictive three-biomarker panel in peripheral blood mononuclear cells for detecting hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) ranks among the most prevalent cancers and accounts for a significant proportion of cancer-associated deaths worldwide. This disease, marked by multifaceted etiology, often poses diagnostic challenges. Finding a reliable and non-invasive diagnostic method seems to be necessary. In this study, we analyzed the gene expression profiles of 20 HCC patients, 12 individuals with chronic hepatitis, and 15 healthy controls. Enrichment analysis revealed that platelet aggregation, secretory granule lumen, and G-protein-coupled purinergic nucleotide receptor activity were common biological processes, cellular components, and molecular function in HCC and chronic hepatitis B (CHB) compared to healthy controls, respectively. Furthermore, pathway analysis demonstrated that "estrogen response" was involved in the pathogenesis of HCC and CHB conditions, while, "apoptosis" and "coagulation" pathways were specific for HCC. Employing computational feature selection and logistic regression classification, we identified candidate genes pivotal for diagnostic panel development and evaluated the performance of these panels. Subsequent machine learning evaluations assessed these panels' performance in an independent cohort. Remarkably, a 3-marker panel, comprising RANSE2, TNF-α, and MAP3K7, demonstrated the best performance in qRT-PCR-validated experimental data, achieving 98.4% accuracy and an area under the curve of 1. Our findings highlight this panel's promising potential as a non-invasive approach not only for detecting HCC but also for distinguishing HCC from CHB patients.

PCSK9 stimulates Syk, PKCδ, and NF-κB, leading to atherosclerosis progression independently of LDL receptor.

Proprotein convertase subtilisin/kexin type-9 (PCSK9) binds to and degrades low-density lipoprotein (LDL) receptor, leading to increase of LDL cholesterol in blood. Its blockers have emerged as promising therapeutics for cardiovascular diseases. Here we show that PCSK9 itself directly induces inflammation and aggravates atherosclerosis independently of the LDL receptor. PCSK9 exacerbates atherosclerosis in LDL receptor knockout mice. Adenylyl cyclase-associated protein 1 (CAP1) is the main binding partner of PCSK9 and indispensable for the inflammatory action of PCSK9, including induction of cytokines, Toll like receptor 4, and scavenger receptors, enhancing the uptake of oxidized LDL. We find spleen tyrosine kinase (Syk) and protein kinase C delta (PKCδ) to be the key mediators of inflammation after PCSK9-CAP1 binding. In human peripheral blood mononuclear cells, serum PCSK9 levels are positively correlated with Syk, PKCδ, and p65 phosphorylation. The CAP1-fragment crystallizable region (CAP1-Fc) mitigates PCSK9-mediated inflammatory signal transduction more than the PCSK9 blocking antibody evolocumab does.

Systematic immune cell dysregulation and molecular subtypes revealed by single-cell RNA-seq of subjects with type 1 diabetes.

BACKGROUND: Type 1 diabetes mellitus (T1DM) is a prototypic endocrine autoimmune disease resulting from an immune-mediated destruction of pancreatic insulin-secreting ß  cells. A comprehensive immune cell phenotype evaluation in T1DM has not been performed thus far at the single-cell level. METHODS: In this cross-sectional analysis, we generated a single-cell transcriptomic dataset of peripheral blood mononuclear cells (PBMCs) from 46 manifest T1DM (stage 3) cases and 31 matched controls. RESULTS: We surprisingly detected profound alterations in circulatory immune cells (1784 dysregulated genes in 13 immune cell types), far exceeding the count in the comparator systemic autoimmune disease SLE. Genes upregulated in T1DM were involved in WNT signaling, interferon signaling and migration of T/NK cells, antigen presentation by B cells, and monocyte activation. A significant fraction of these differentially expressed genes were also altered in T1DM pancreatic islets. We used the single-cell data to construct a T1DM metagene z-score (TMZ score) that distinguished cases and controls and classified patients into molecular subtypes. This score correlated with known prognostic immune markers of T1DM, as well as with drug response in clinical trials. CONCLUSIONS: Our study reveals a surprisingly strong systemic dimension at the level of immune cell network in T1DM, defines disease-relevant molecular subtypes, and has the potential to guide non-invasive test development and patient stratification.

Trimetazidine Improves Mitochondrial Dysfunction in SOD1G93A Cellular Models of Amyotrophic Lateral Sclerosis through Autophagy Activation.

Amyotrophic Lateral Sclerosis (ALS) is considered the prototype of motor neuron disease, characterized by motor neuron loss and muscle waste. A well-established pathogenic hallmark of ALS is mitochondrial failure, leading to bioenergetic deficits. So far, pharmacological interventions for the disease have proven ineffective. Trimetazidine (TMZ) is described as a metabolic modulator acting on different cellular pathways. Its efficacy in enhancing muscular and cardiovascular performance has been widely described, although its molecular target remains elusive. We addressed the molecular mechanisms underlying TMZ action on neuronal experimental paradigms. To this aim, we treated murine SOD1G93A-model-derived primary cultures of cortical and spinal enriched motor neurons, as well as a murine motor-neuron-like cell line overexpressing SOD1G93A, with TMZ. We first characterized the bioenergetic profile of the cell cultures, demonstrating significant mitochondrial dysfunction that is reversed by acute TMZ treatments. We then investigated the effect of TMZ in promoting autophagy processes and its impact on mitochondrial morphology. Finally, we demonstrated the effectiveness of TMZ in terms of the mitochondrial functionality of ALS-rpatient-derived peripheral blood mononuclear cells (PBMCs). In summary, our results emphasize the concept that targeting mitochondrial dysfunction may represent an effective therapeutic strategy for ALS. The findings demonstrate that TMZ enhances mitochondrial performance in motor neuron cells by activating autophagy processes, particularly mitophagy. Although further investigations are needed to elucidate the precise molecular pathways involved, these results hold critical implications for the development of more effective and specific derivatives of TMZ for ALS treatment.

Detection of myeloid-derived suppressor cells by flow cytometry.

Recently discovered heterogeneous myeloid-derived suppressor cells (MDSCs) are some of the most discussed immunosuppressive cells in contemporary immunology, especially in the tumor microenvironment, and are defined primarily by their T cell immunosuppressive function. The importance of these cells extend to other chronic pathological conditions as well, including chronic infection, inflammation, and tissue remodeling. In many of these conditions, their accumulation/expansion correlates with disease progression, poor prognosis, and reduced survival, which highlights the potential of how these cells may be used in a clinical setting as both prognostic factor and therapeutic target. In healthy individuals, these cells are usually not present in the circulation. Therefore, monitoring this cell population is of potential clinical significance, and utility in basic research. However, these cells have a complex phenotype without one single marker of sufficient specificity for their identification. Flow cytometry is a powerful tool allowing multi-parameter analysis of heterogeneous cell populations, which makes it ideally suitable for the complex phenotypic analysis essential for identification and enumeration of circulating MDSCs. This approach has the potential to provide a novel clinically useful tool for assessment of prognosis and treatment outcomes. The protocol in this chapter describes a flow cytometric analysis to identify and quantify MDSCs from human or mouse whole blood leukocytes and peripheral blood mononuclear cells, as well as a single cell suspension from solid tissue, by using multicolor fluorescence-conjugated antibodies against their surface markers.