Gene regulatory network study of rheumatoid arthritis in single-cell chromatin landscapes of peripheral blood mononuclear cells.

OBJECTIVES: Assays for transposase-accessible chromatin with single-cell sequencing (scATAC-seq) contribute to the progress in epigenetic studies. The purpose of our project was to discover the transcription factors (TFs) that were involved in the pathogenesis of rheumatoid arthritis (RA) at a single-cell resolution using epigenetic technology. METHODS: Peripheral blood mononuclear cells of seven RA patients and seven natural controls were extracted nuclei suspensions for library construction. Subsequently, scATAC-seq was performed to generate a high-resolution map of active regulatory DNA for bioinformatics analysis. RESULTS: We obtained 22 accessible chromatin patterns. Then, 10 key TFs were involved in RA pathogenesis by regulating the activity of mitogen-activated protein kinase. Consequently, two genes (PTPRC and SPAG9) regulated by 10 key TFs were found, which may be associated with RA disease pathogenesis, and these TFs were obviously enriched in RA patients (P < .05, fold change value > 1.2). With further quantitative polymerase chain reaction validation on PTPRC and SPAG9 in monocytes, we found differential expression of these two genes, which were regulated by eight TFs [ZNF384, HNF1B, DMRTA2, MEF2A, NFE2L1, CREB3L4 (var. 2), FOSL2::JUNB (var. 2), and MEF2B], showing highly accessible binding sites in RA patients. CONCLUSIONS: These findings demonstrate the value of using scATAC-seq to reveal transcriptional regulatory variation in RA-derived peripheral blood mononuclear cells, providing insights into therapy from an epigenetic perspective.

Ameliorating role of microRNA-378 carried by umbilical cord mesenchymal stem cells-released extracellular vesicles in mesangial proliferative glomerulonephritis.

BACKGROUND: Mesenchymal stem cells (MSCs) and their released extracellular vesicles (Evs) have shown protective effects against kidney diseases. This study aims to study the functions of umbilical cord MSCs-released Evs (ucMSC-Evs) and their implicated molecules in mesangial proliferative glomerulonephritis (MsPGN). METHODS: A rat model of MsPGN was induced by anti-Thy-1.1, and rat mesangial cells (rMCs) HBZY-1 were treated with PDGF-BB/DD to mimic MsPGN condition in vitro. Rats and cells were treated with different doses of ucMSC-Evs, and then the pathological changes in renal tissues and proliferation of rMCs were determined. Differentially expressed microRNAs (miRNAs) after Evs treatment were screened by microarray analysis. The interactions among miR-378, PSMD14, and TGFBR1 were analyzed. Gain- and loss-of function studies of miR-378 and PSMD14 were performed to explore their effects on tissue hyperplasia and rMC proliferation and their interactions with the TGF-ß1/Smad2/3 signaling pathway. RESULTS: The ucMSC-Evs treatment ameliorated mesangial hyperplasia and fibrosis in rat renal tissues and suppressed the aberrant proliferation of rMCs in a dose-dependent manner. miR-378 was the most upregulated miRNA in tissues and cells after ucMSC-Evs treatment. miR-378 directly targeted PSMD14, and PSMD14 maintained the stability of TGFBR1 through deubiquitination modification, which led to TGF-ß1/Smad2/3 activation. Either miR-378 knockdown or PSMD14 overexpression diminished the protective functions of ucMSC-Evs by activating the TGF-ß1/Smad2/3 signaling pathway. CONCLUSION: UcMSC-Evs ameliorate pathological process in MsPGN through the delivery of miR-378, which suppresses PSMD14-mediated TGFBR1 stability and inactivates the TGF-ß1/Smad2/3 signaling pathway to reduce tissue hyperplasia and rMC proliferation. Video abstract.

Prospective Analysis of Proteins Carried in Extracellular Vesicles with Clinical Outcome in Hepatocellular Carcinoma.

Background: Extracellular vehicles (EVs) contain different proteins that relay information between tumor cells, thus promoting tumorigenesis. Therefore, EVs can serve as an ideal marker for tumor pathogenesis and clinical application. Objective: Here, we characterised EV-specific proteins in hepatocellular carcinoma (HCC) samples and established their potential protein-protein interaction (PPI) networks. Materials and Methods: We used multi-dimensional bioinformatics methods to mine a network module to use as a prognostic signature and validated the model's prediction using additional datasets. The relationship between the prognostic model and tumor immune cells or the tumor microenvironment status was also examined. Results: 1134 proteins from 316 HCC samples were mapped to the exoRBase database. HCC-specific EVs specifically expressed a total of 437 proteins. The PPI network revealed 321 proteins and 938 interaction pathways, which were mined to identify a three network module (3NM) with significant prognostic prediction ability. Validation of the 3NM in two more datasets demonstrated that the model outperformed the other signatures in prognostic prediction ability. Functional analysis revealed that the network proteins were involved in various tumor-related pathways. Additionally, these findings demonstrated a favorable association between the 3NM signature and macrophages, dendritic, and mast cells. Besides, the 3NM revealed the tumor microenvironment status, including hypoxia and inflammation. Conclusion: These findings demonstrate that the 3NM signature reliably predicts HCC pathogenesis. Therefore, the model may be used as an effective prognostic biomarker in managing patients with HCC.

Quantitative proteomics analysis of lysine 2-hydroxyisobutyrylation in IgA nephropathy.

BACKGROUND: Protein posttranslational modification is an indispensable regulatory element that can fine-tune protein functions and regulate diverse cellular processes. Lysine 2-hydroxyisobutyrylation (Khib) is a protein posttranslational modification that was recently identified and is thought to play a role in a wide variety of active cellular functions. METHODS: In this report, for the first time, we comparatively studied the 2-hydroxyisobutyrylation proteome in peripheral blood mononuclear cells from a biopsy-proven immunoglobulin A nephropathy (IgAN) group and a normal control group based on liquid chromatography-tandem mass spectrometry. RESULTS: Altogether, 7405 proteins were identified and added to a Khib library. Of these proteins, we identified 111 with upregulated expression and 83 with downregulated expression. Furthermore, we identified 428 Khib modification sites on 290 Khib-modified proteins, including 171 sites with increased modification on 122 Khib-modified proteins and 257 specific sites with reduced modification on 168 Khib-modified proteins. CONCLUSIONS: Importantly, the abundance of lipocalin 2 was increased in the differentially expressed proteins, and a KEGG-based functional enrichment analysis showed that Khib proteins clustered in the IL-17 signaling pathway and phagosome category, which may have important associations with IgAN. Our data enlighten our understanding of Khib in IgAN and indicate that Khib may have important regulatory roles in IgAN.

A single-cell map for the transcriptomic signatures of peripheral blood mononuclear cells in end-stage renal disease.

BACKGROUND: Immune aberrations in end-stage renal disease (ESRD) are characterized by systemic inflammation and immune deficiency. The mechanistic understanding of this phenomenon remains limited. METHODS: We generated 12 981 and 9578 single-cell transcriptomes of peripheral blood mononuclear cells (PBMCs) that were pooled from 10 healthy volunteers and 10 patients with ESRD by single-cell RNA sequencing. Unsupervised clustering and annotation analyses were performed to cluster and identify cell types. The analysis of hallmark pathway and regulon activity was performed in the main cell types. RESULTS: We identified 14 leukocytic clusters that corresponded to six known PBMC types. The comparison of cells from ESRD patients and healthy individuals revealed multiple changes in biological processes. We noticed an ESRD-related increase in inflammation response, complement cascade and cellular metabolism, as well as a strong decrease in activity related to cell cycle progression in relevant cell types in ESRD. Furthermore, a list of cell type-specific candidate transcription factors (TFs) driving the ESRD-associated transcriptome changes was identified. CONCLUSIONS: We generated a distinctive, high-resolution map of ESRD-derived PBMCs. These results revealed cell type-specific ESRD-associated pathways and TFs. Notably, the pooled sample analysis limits the generalization of our results. The generation of larger single-cell datasets will complement the current map and drive advances in therapies that manipulate immune cell function in ESRD.

Comprehensive analysis of lysine crotonylation modification in patients with chronic renal failure.

BACKGROUND: Post-translational modifications (PTMs) are at the heart of many cellular signaling events, which changes the function of protein. Crotonylation, one of the most important and common PTMs, plays a crucial role in the regulation of various biological processes. However, no study has evaluated the role of lysine crotonylation modification in chronic renal failure (CRF) patients. METHODS: Here, we comparatively evaluated the crotonylation proteome of normal controls and chronic renal failure patients using liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with highly sensitive immune-affinity purification. RESULTS: A total of 1109 lysine modification sites were identified, of which 772 sites were up-regulated and 69 sites were down-regulated. This suggested that crotonylation modification maintains high levels in the patients with chronic renal failure. Gene ontology(GO) enrichment analysis showed that the crotonylated proteins were significantly enriched in the platelet alpha granule lumen, platelet degradulation, and cell adhesion molecule binding. In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG)-based functional enrichment analysis in the Kyoto encyclopedia showed that crotonylated protein was enriched in CD36, which is closely linked to renal failure. CONCLUSIONS: This is the first report of the global crotonylation proteome in chronic renal failure patients. Crotonylation of histone and non-histone may play important roles in delaying the continuous deterioration of renal function in patients with chronic renal failure.

The potential role of tRNAs and small RNAs derived from tRNAs in the occurrence and development of systemic lupus erythematosus.

BACKGROUND: Emerging evidence has shown the involvement of dysregulated transfer RNAs (tRNAs) and small RNAs derived from transfer RNAs (tsRNAs) in the pathophysiology of human diseases. The role of tRNAs and tsRNAs in systemic lupus erythematosus (SLE) remains unclear. Therefore, this study aims to investigate the possible regulatory roles of tRNAs and tsRNAs in the pathological mechanism of SLE. METHODS: Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 20 SLE patients and 20 normal controls (NCs) to obtain tRNAs and tsRNAs, followed by tRNA and tsRNA expression profiling by the NextSeq system. Target genes were predicted by informatics analysis. Subsequently, to explore the function of messenger RNA (mRNA) in these target genes, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the Cytoscape plug-in BinGo, the DAVID database, and Cytoscape software. RESULTS: A total of 101 tRNAs and 355 tsRNAs were found to be differentially expressed in SLE patients versus NCs by RNA microarray. GO analysis revealed that the altered target genes of the selected tRNAs and tsRNAs were most enriched similarly in immune response and the immune system process. Moreover, KEGG pathway analysis demonstrated that altered target genes of tRNAs were most enriched in systemic lupus erythematosus, while the altered target genes of tsRNAs were most enriched in the T cell receptor signalling pathway, Th1 and Th2 cell differentiation and primary immunodeficiency. These pathways may be related to the initiation of SLE. CONCLUSION: Our results provide a novel perspective for studying the tRNA-related and tsRNA-related pathogenesis of SLE.

NAC1 transcriptional activation of LDHA induces hepatitis B virus immune evasion leading to cirrhosis and hepatocellular carcinoma development.

Our study aimed to elucidate the molecular mechanisms underlying NAC1 (nucleus accumbens associated 1) transcriptional regulation of LDHA and its role in HBV immune evasion, thus contributing to the development of cirrhosis and hepatocellular carcinoma (HCC). Utilizing public datasets, we performed differential gene expression and weighted gene co-expression network analysis (WGCNA) on HBV-induced cirrhosis/HCC data. We identified candidate genes by intersecting differentially expressed genes with co-expression modules. We validated these genes using the TCGA database, conducting survival analysis to pinpoint key genes affecting HBV-HCC prognosis. We also employed the TIMER database for immune cell infiltration data and analyzed correlations with identified key genes to uncover potential immune escape pathways. In vitro, we investigated the impact of NAC1 and LDHA on immune cell apoptosis and HBV immune evasion. In vivo, we confirmed these findings using an HBV-induced cirrhosis model. Bioinformatics analysis revealed 676 genes influenced by HBV infection, with 475 genes showing differential expression in HBV-HCC. NAC1 emerged as a key gene, potentially mediating HBV immune escape through LDHA transcriptional regulation. Experimental data demonstrated that NAC1 transcriptionally activates LDHA, promoting immune cell apoptosis and HBV immune evasion. Animal studies confirmed these findings, linking NAC1-mediated LDHA activation to cirrhosis and HCC development. NAC1, highly expressed in HBV-infected liver cells, likely drives HBV immune escape by activating LDHA expression, inhibiting CD8 + T cells, and promoting cirrhosis and HCC development.

The circRNA-miRNA-mRNA regulatory network in plasma and peripheral blood mononuclear cells and the potential associations with the pathogenesis of systemic lupus erythematosus.

OBJECTIVES: This study aimed to explore the possible role of plasma and peripheral blood mononuclear cells (PBMCs) circular RNA (circRNA) in systemic lupus erythematosus (SLE). METHOD: Total RNA was extracted from blood plasma samples obtained from 10 patients with SLE and 10 healthy controls and subjected to microarray analysis to define the profile of circRNA expression. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) amplification was conducted. The overlapped circRNA between PBMCs and plasma was performed, the interactions with microRNAs were predicted, the miRNA target mRNA was predicted, and the GEO database was used. The Gene ontology and pathway analysis was performed. RESULTS: One hundred thirty-one upregulated and 314 significantly downregulated circRNAs were identified in the plasma of patients with SLE by the Fold change criteria (≥ 2.0) and P < 0.05. The qRT-PCR results showed that the expression of has-circRNA-102531, has-circRNA-103984, and has-circRNA-104262 was increased in plasma of SLE, and the expression of has-circRNA-102972, has-circRNA-102006, has-circRNA-104313 was decreased in plasma of SLE. Twenty-eight upregulated circRNAs and 119 downregulated circRNAs were overlapped from PBMCs and plasma, and ubiquitination was enriched. Furthermore, the circRNA-miRNA-mRNA network was constructed in SLE after analyzing dataset GSE61635 from GEO. The circRNA-miRNA-mRNA network comprises 54 circRNAs, 41 miRNAs, and 580 mRNAs. In addition, the TNF signaling pathway and the MAPK pathway were enriched from the mRNA of the miRNA target. CONCLUSION: We first revealed the differentially expressed circRNAs in plasma and PBMCs, and then the circRNA-miRNA-mRNA network was constructed. The network's circRNAs could be a potential diagnostic biomarker and potentially play an important role in the pathogenesis and development of SLE. Key Points • This study analyzed the circRNAs expression profiles combined with the plasma and PBMCs, which provided a comprehensive overview of circRNAs expression patterns in SLE. • The network of the circRNA-miRNA-mRNA in SLE was constructed, which contributes to a better understanding of the pathogenesis and development of SLE.

Integrated Analysis and Identification of mRNAs, Circular RNAs, and Long Noncoding RNAs in Immunoglobulin A Nephropathy.

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) have a role in monitoring the appearance and progression of a great many diseases. They are useful markers for the prognosis and diagnosis of some diseases. In previous studies, the expression patterns of mRNAs, circRNAs, and lncRNAs related to immunoglobulin A (IgA) nephropathy have not been sufficiently discussed. Active prevention methods and treatment for IgA nephropathy (IgAN) are still not used. Integrated analyses and identification of the circRNAs and lncRNAs in IgAN have not been executed. We carried out a deep RNA sequencing analysis between controls and subjects with IgAN. In total, 125 antisense lncRNAs were identified to be greatly differentially expressed between the control and experimental groups. In addition, 606 mRNAs and 1275 circRNAs with differential expression levels were found between the groups. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways were used as bioinformatic methods in this study. Our study showed the expression patterns of mRNAs, circRNAs, and lncRNAs in IgAN. We revealed the key roles of circRNAs and lncRNAs in the molecular mechanism of IgAN.

Global-feature of autoimmune glomerulonephritis using proteomic analysis of laser capture microdissected glomeruli.

Background: IgA nephropathy (IgAN), (LN), membranous nephropathy (MN), and minimal change nephropathy (MCN) are all belonged to autoimmune glomerulonephritis. This study aimed to identify the specific proteomic characteristics of the four GNs diseases in order to provide frameworks for developing the appropriate drug for patients diagnosed with GNs disease. Methods: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized to investigate proteomic features of glomerular tissues obtained by laser capture microdissection (LCM). 8 normal control cases, 11 IgAN cases, 19 LN cases, 5 MN cases, and 3 MCN cases in this study were selected for bioinformatics analyses. Results: The shared overlapping proteins among the top 100 DEPs of each GNs type were mostly downregulated, in which only FLII was significantly downregulated in the four GNs diseases. A2M was significantly upregulated in MN, IgAN, and LN subgroups. The pathway of complement and coagulation cascades was notably activated with NES value ranging 2.77 to 3.39 among MCN, MN, IgAN, and LN diseases, but the pattern of protein expression level were significantly different. In LN patients, the increased activity of complement and coagulation cascades was contributed by the high expression of multiple complements (C1QB, C3, C4A, C4B, C6, C8B, C8G, C9). Meanwhile, both C1QC and C4B were remarkably upregulated in MN patients. On the contrary, complement-regulating proteins (CD59) was substantially decreased in MCN and IgAN subgroup. Conclusions: The integrative proteomics analysis of the four GNs diseases provide insights into unique characteristics of GNs diseases and further serve as frameworks for precision medicine diagnosis and provide novel targets for drug development.

Proteomic analysis of lysine 2-hydroxyisobutyryl in SLE reveals protein modification alteration in complement and coagulation cascades and platelet activation Pathways.

BACKGROUND: Post-translational modifications (PTMs) are considered to be an important factor in the pathogenesis of Systemic lupus erythematosus (SLE). Lysine 2-hydroxyisobutyryl (Khib), as an emerging post-translational modification of proteins, is involved in some important biological metabolic activities. However, there are poor studies on its correlation with diseases, especially SLE. OBJECTIVE: We performed quantitative, comparative, and bioinformatic analysis of Khib proteins in Peripheral blood mononuclear cells (PBMCs) of SLE patients and PBMCs of healthy controls. Searching for pathways related to SLE disease progression and exploring the role of Khib in SLE. METHODS: Khib levels in SLE patients and healthy controls were compared based on liquid chromatography tandem mass spectrometry, then proteomic analysis was conducted. RESULTS: Compared with healthy controls, Khib in SLE patients was up-regulated at 865 sites of 416 proteins and down-regulated at 630 sites of 349 proteins. The site abundance, distribution and function of Khib protein were investigated further. Bioinformatics analysis showed that Complement and coagulation cascades and Platelet activation in immune-related pathways were significantly enriched, suggesting that differentially modified proteins among them may affect SLE. CONCLUSION: Khib in PBMCs of SLE patients was significantly up- or down-regulated compared with healthy controls. Khib modification of key proteins in the Complement and coagulation cascades and Platelet activation pathways affects platelet activation and aggregation, coagulation functions in SLE patients. This result provides a new direction for the possible significance of Khib in the pathogenesis of SLE patients.

Machine learning-based intradialytic hypotension prediction of patients undergoing hemodialysis: A multicenter retrospective study.

BACKGROUND AND OBJECTIVE: Intradialytic hypotension (IDH) is closely associated with adverse clinical outcomes in HD-patients. An IDH predictor model is important for IDH risk screening and clinical decision-making. In this study, we used Machine learning (ML) to develop IDH model for risk prediction in HD patients. METHODS: 62,227 dialysis sessions were randomly partitioned into training data (70%), test data (20%), and validation data (10%). IDH-A model based on twenty-seven variables was constructed for risk prediction for the next HD treatment. IDH-B model based on ten variables from 64,870 dialysis sessions was developed for risk assessment before each HD treatment. Light Gradient Boosting Machine (LightGBM), Linear Discriminant Analysis, support vector machines, XGBoost, TabNet, and multilayer perceptron were used to develop the predictor model. RESULTS: In IDH-A model, we identified the LightGBM method as the best-performing and interpretable model with C- statistics of 0.82 in Fall30Nadir90 definitions, which was higher than those obtained using the other models (P<0.01). In other IDH standards of Nadir90, Nadir100, Fall20, Fall30, and Fall20Nadir90, the LightGBM method had a performance with C- statistics ranged 0.77 to 0.89. As a complementary application, the LightGBM model in IDH-B model achieved C- statistics of 0.68 in Fall30Nadir90 definitions and 0.69 to 0.78 in the other five IDH standards, which were also higher than the other methods, respectively. CONCLUSION: Use ML, we identified the LightGBM method as the good-performing and interpretable model. We identified the top variables as the high-risk factors for IDH incident in HD-patient. IDH-A and IDH-B model can usefully complement each other for risk prediction and further facilitate timely intervention through applied into different clinical setting.

Classification and Prognostic Characteristics of Hepatocellular Carcinoma Based on Glycolysis Cholesterol Synthesis Axis.

Background: Liver hepatocellular carcinoma (LIHC) is among the most frequent causes of cancer-related death across the world with a considerably poor prognosis. The current study targeted providing a new type of LIHC from the perspective of the glycolysis/cholesterol synthesis axis, predicting its prognostic characteristics, and exploring the potential role and mechanism of the glycolysis/cholesterol synthesis axis in the occurrence and development of LIHC. Methods: Based on the two expression profile data and clinical information of LIHC in The Cancer Genome Atlas (TCGA) database and hepatocellular carcinoma database (HCCDB), as well as glycolysis/cholesterol-related genes from the Molecular Signatures Database (MSigDB), unsupervised consistent clustering method was used to identify molecular subtypes. In addition, the differential genes were identified by limma package, and then the gene set was enriched, analyzed, and annotated by WebGestaltR package. At the same time, the immune infiltration analysis of tumor samples was carried out using the ESTIMATE to evaluate the tumor immune score of the samples. Finally, the differences in clinical characteristics among molecular subtypes were measured using univariate and multivariate Cox analyses. Results: According to the median standardized expression levels of glycolysis/cholesterol production genes, samples were divided into four groups (molecular subtypes): Quiescent group, Glycolysis group, Cholesterol group, and Mixed group. Significant prognostic differences were observed among the four groups. In both TCGA and HCCDB18 datasets, the prognosis of subtype Mixed was the worst, while Quiescent had a good prognosis. Cell cycle and oncogenic pathways were significantly enriched in the Mixed group. In addition, glycolysis and cholesterol production gene expressions were related to the prognostic LIHC subtype classification genes' expression levels. Conclusion: Metabolic classification regarding glycolysis and cholesterol production pathways provided new insights into the biological aspects of LIHC molecular subtypes and might help to develop personalized therapies for unique tumor metabolic profiles.

The Association between Immune Subgroups and Gene Modules for the Clinical, Cellular, and Molecular Characteristic of Hepatocellular Carcinoma.

The heterogeneity of hepatocellular carcinoma (HCC) is related to immune cell infiltration and genetic aberrations in the tumor microenvironment. This study aimed to identify the novel molecular typing of HCC according to the genetic and immune characteristics, to obtain accurate clinical management of this disease. We performed consensus clustering to divide 424 patients into different immune subgroups and assessed the reproducibility and efficiency in two independent cohorts with 921 patients. The associations between molecular typing and molecular, cellular, and clinical characteristics were investigated by a multidimensional bioinformatics approach. Furthermore, we conducted graph structure learning-based dimensionality reduction to depict the immune landscape to reveal the interrelation between the immune and gene systems in molecular typing. We revealed and validated that HCC patients could be segregated into 5 immune subgroups (IS1-5) and 7 gene modules with significantly different molecular, cellular, and clinical characteristics. IS5 had the worst prognosis and lowest enrichment of immune characteristics and was considered the immune cold type. IS4 had the longest overall survival, high immune activity, and antitumorigenesis, which were defined as the immune hot and antitumorigenesis types. In addition, immune landscape analysis further revealed significant intraclass heterogeneity within each IS, and each IS represented distinct clinical, cellular, and molecular characteristics. Our study provided 5 immune subgroups with distinct clinical, cellular, and molecular characteristics of HCC and may have clinical implications for precise therapeutic strategies and facilitate the investigation of immune mechanisms in HCC.

Analyzing the gene regulatory network in hepatitis B patients by single-cell ATAC sequencing.

OBJECTIVE: This study aims to provide a new perspective of determining the pathophysiology of chronic hepatitis B (CHB) development by analyzing the gene regulatory network in CHB patients using single-cell ATAC sequencing. BACKGROUND: Hepatitis B virus (HBV)-related liver disease induces liver damage by hepatic immune and inflammatory responses. The exact mechanism is unknown. As such, there is an urgent need to address this problem and study the relationship between aberrant peripheral blood mononuclear cell (PBMC) immune response and progression of liver disease. METHOD: The sequencing of the chromatin accessibility of 8016 cells from the whole venous blood of normal control (NC) individuals and CHB patients was performed through assay for transposase-accessible chromatin in single-cell sequencing (ScATAC-seq). Unsupervised clustering and annotation analyses were performed by Signac (version 1.7.0) and Seurat clustering to identify different cell types. Then, TF motif enrichment analysis and differentially expressed peak analysis were performed to identify cell-type-specific candidate open chromatins related to CHB. RESULT: We identified 12 leukocytic clusters corresponding to five cell types. The specific cell types associated with CHB were found to be located in B-0 and T-3. We have drawn the regulatory network of the hepatitis B signal pathway composed of genes linked to the differentially expressed peaks of these two CHB disease-specific cell types. Further, we profoundly explored the potential mechanisms of B-0-associated TF motif IRF2 and T-3-associated TF motif FOXC2 in the occurrence of CHB. CONCLUSION: We have drawn a systematic and distinguishing gene regulatory network of CHB-related PBMCs. Key Points • Peripheral blood mononuclear cells were robustly clustered based on their types without using antibodies. • We draw a systematic and distinctive gene regulatory network of CHB-related PBMC through ScATAC-seq.

Identification and Characterization of Genes Related to the Prognosis of Hepatocellular Carcinoma Based on Single-Cell Sequencing.

The heterogeneity of hepatocellular carcinoma (HCC) highlights the importance of precision therapy. In recent years, single-cell RNA sequencing has been used to reveal the expression of genes at the single-cell level and comprehensively study cell heterogeneity. This study combined big data analytics and single-cell data mining to study the influence of genes on HCC prognosis. The cells and genes closely related to the HCC were screened through single-cell RNA sequencing (71,915 cells, including 34,414 tumor cells) and big data analysis. Comprehensive bioinformatics analysis of the key genes of HCC was conducted for molecular classification and multi-dimensional correlation analyses, and a prognostic model for HCC was established. Finally, the correlation between the prognostic model and clinicopathological features was analyzed. 16,880 specific cells, screened from the single-cell expression profile matrix, were divided into 20 sub-clusters. Cell typing revealed that 97% of these cells corresponded to HCC cell lines, demonstrating the high specificity of cells derived from single-cell sequencing. 2,038 genes with high variability were obtained. The 371 HCC samples were divided into two molecular clusters. Cluster 1 (C1) was associated with tumorigenesis, high immune score, immunotherapy targets (PD-L1 and CYLA-4), high pathological stage, and poor prognosis. Cluster 2 (C2) was related to metabolic and immune function, low immune score, low pathological stage, and good prognosis. Seven differentially expressed genes (CYP3A4, NR1I2, CYP2C9, TTR, APOC3, CYP1A2, and AFP) identified between the two molecular clusters were used to construct a prognostic model. We further validated the correlation between the seven key genes and clinical features, and the established prognostic model could effectively predict HCC prognosis. Our study identified seven key genes related to HCC that were used to construct a prognostic model through single-cell sequencing and big data analytics. This study provides new insights for further research on clinical targets of HCC and new biomarkers for clinical application.

Global Proteomic Analyses Reveals Abnormal Immune Regulation in Patients With New Onset Ankylosing Spondylitis.

Background: Ankylosing spondylitis (AS) is a chronic inflammatory disease with serious consequences and a high rate of morbidity and mortality, In our previous work, we reveal the key features of proteins in new-onset ankylosing spondylitis patients. Material and Methods: Ankylosing spondylitis (AS) is a chronic inflammatory condition that affects the spine, and inflammation plays an essential role in AS pathogenesis. The inflammatory process in AS, however, is still poorly understood due to its intricacy. Systematic proteomic and phosphorylation analyses of peripheral blood mononuclear cells (PBMCs) were used to investigate potential pathways involved in AS pathogenesis. Results: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was performed and discovered 782 differentially expressed proteins (DEPs) and 122 differentially phosphorylated proteins (DPPs) between 9 new-onset AS patients and 9 healthy controls. The DEPs were further verified using parallel reaction monitoring (PRM) analysis. PRM analysis verified that 3 proteins (HSP90AB1, HSP90AA1 and HSPA8) in the antigen processing and presentation pathway, 6 proteins (including ITPR1, MYLK and STIM1) in the platelet activation pathway and 10 proteins (including MYL12A, MYL9 and ROCK2) in the leukocyte transendothelial migration pathway were highly expressed in the PBMCs of AS patients. Conclusion: The key proteins involved in antigen processing and presentation, platelet activation and leukocyte transendothelial migration revealed abnormal immune regulation in patients with new-onset AS. These proteins might be used as candidate markers for AS diagnosis and new therapeutic targets, as well as elucidating the pathophysiology of AS.

Multi-Platform-Based Analysis Characterizes Molecular Alterations of the Nucleus in Human Colorectal Cancer.

Background: The disturbed molecular alterations of nucleus may promote the development of colorectal cancer (CRC). A multi-platform-based analysis of nucleus of CRC patients helps us to better understand the underlying mechanism of CRC and screen out the potential drug targets for clinical treatment. However, such studies on nucleus in human CRC are still lacking. Methods: We collected the cancerous and para-cancerous tissues from eight CRC patients and performed a multiplex analysis of the molecular changes of the nucleus, including structural variations (SVs), DNA methylation, chromatin accessibility, proteome and phosphorproteome. Results: In our study, we revealed a significant molecular change of nucleus of CRC patients using our original proteomic and phosphorylomic datasets. Subsequently, we characterized the molecular alterations of nucleus of CRC patients at multiple dimensionalities, including DNA, mRNA, protein and epigenetic modification. Next, we found that the great molecular changes of nucleus might affect the biological processes named endocytosis and ubiquitin-mediated proteolysis. Besides, we identified DYNC1LI2 and TPR as the potentially hub proteins within the network of nuclear genes in CRC cells. Furthermore, we identified 1905 CRC-specific SVs, and proclaimed 17 CRC-specific SVs were probably associated with the disturbance of immune microenvironment of CRC patients. We also revealed that the SVs of CXCL5, CXCL10 and CXCL11 might be the core SVs among all the immune-relevant SVs. Finally, we identified seven genes as the upstream transcriptional factors potentially regulating the expression of nuclear genes, such as YY1 and JUN, using a multi-omics approach. Conclusion: Here, we characterized the molecular changes of nucleus of CRC patients, disclosed the potentially core nuclear genes within the network, and identified the probable upstream regulator of nucleus. The findings of this study are helpful to understand the pathogenic molecular changes of nucleus in CRC patients and provide a functional context for drug development in future.

Proteomics analysis of lysine crotonylation and 2-hydroxyisobutyrylation reveals significant features of systemic lupus erythematosus.

INTRODUCTION/OBJECTIVES: To seek significant features of systemic lupus erythematosus (SLE) by utilizing bioinformatics analysis. METHOD: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify lysine crotonylation (Kcr) and lysine 2-hydroxyisobutyrylation (Khib) in peripheral blood mononuclear cells (PBMCs) of systemic lupus erythematosus (SLE) patients and normal controls. RESULTS: Seventy-six differentially modified proteins (DMPs) dually modified by Kcr and Khib were identified between SLE patients and healthy people. GO enrichment analysis prompted significant enrichment of seventy-six DMPs in MHC class II protein complex binding and leukocyte migration. KEGG pathways were enriched in antigen processing and presentation pathway and leukocyte transendothelial migration pathway. Six DMPs (CLTC, HSPA1B, HSPA8, HSP90AB1, HSPD1, and PDIA3) were identified in antigen processing and presentation pathway, of which HSPA8 was the core protein. Significant changes of Kcr and Khib in HSPA8 may increase ATP hydrolysis and promote antigen binding to MHC II molecule. In leukocyte transendothelial migration pathway, 7 DMPs (ACTN1, ACTN4, EZR, MSN, RAC1, RHOA, and VCL) were identified. MSN was the protein with the most modification sites in this pathway. In amino terminal ferm region of MSN, Kcr and Khib expression change may lead to the adhesion between leukocytes and endothelial cells, which was an important step of leukocyte migration. CONCLUSION: Kcr and Khib may promote the antigen presentation and jointly regulate the tissue damage mediated by leukocyte migration in SLE patients, which may play key roles in the pathogenesis of SLE probably. Key Points • Antigen processing and presentation and leukocyte transendothelial migration may play key roles in the pathogenesis of SLE.