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.

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.

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.

Integrative Single-Cell RNA-Seq and ATAC-Seq Analysis of Peripheral Mononuclear Cells in Patients With Ankylosing Spondylitis.

Objective: Genetic studies on ankylosing spondylitis (AS) have identified more than 100 pathogenic genes. Building a bridge between these genes and biologically targeted therapies is the current research hotspot. Methods: We integrated single-cell assaying transposase-accessible chromatin sequencing (scATAC-seq) and single-cell RNA sequencing (scRNA-seq) to explore the key genes and related mechanisms associated with AS pathogenesis. Results: We identified 18 cell types in peripheral mononuclear cells from patients with AS and normal controls and summarized the cell-type-specific abnormal genes by scRNA-seq. Interestingly, we found that the pathogenic gene NFKB involved in AS progression originated from CD8+ T cells. Moreover, we observed an abnormal tumor TNF pathway mediated by abnormal expression of TNF, NFKB, FOS, JUN, and JUNB, and scATAC-seq results confirmed the abnormal accessible binding sites of transcriptional factors FOS, JUN, and JUNB. The final magnetic bead sorting and quantitative real-time PCR(RT-qPCR) confirmed that NFKB, FOS, JUN, and JUNB in CD8+ T cells differed in the AS group. Conclusions: Our results revealed a possible mechanism by which NFKB abnormally regulates FOS, JUN, and JUNB and drives AS progression, providing a novel perspective from a single cell point of view in AS.

Immune cell and TCR/BCR repertoire profiling in systemic lupus erythematosus patients by single-cell sequencing.

The immune cells and the repertoire of T cells and B cells play an important role in the pathogenesis of systemic lupus erythematosus (SLE). Exploring their expression and distribution in SLE can help us better understand this lethal autoimmune disease. In this study, we used a single-cell 5' RNA sequence and single-cell T cell receptor (TCR)/B cell receptor (BCR) to study the immune cells and the repertoire from ten SLE patients and the paired normal controls (NC). The results showed that 9732 cells correspondence to 12 cluster immune cell types were identified in NC, whereas 11042 cells correspondence to 16 cluster immune cell types were identified in SLE. The results demonstrated that neutrophil, macrophage, and dendritic cells were accumulated in SLE by annotating the immune cell types. Besides, the bioinformatics analysis of differentially expressed genes (DEGs) in these cell types indicates their role in inflammation response. In addition, patients with SLE showed increased TCR and BCR clonotypes compared with the healthy controls. Furthermore, patients with SLE showed biased usage of TCR and BCR V(D)J genes. Taken together, we characterized the transcriptome and TCR/BCR immune repertoire profiles of SLE patients, which may provide a new avenue for the diagnosis and treatment of SLE.

The Landscape and Potential Regulatory Mechanism of Lysine 2-Hydroxyisobutyrylation of Protein in End-Stage Renal Disease.

BACKGROUND: Acetylation has a vital role in the pathogenesis of end-stage renal disease (ESRD). Lysine 2-hydroxyisobutyrylation (Khib) is a novel type of acetylation. In this study, we aimed to reveal the key features of Khib in peripheral blood monocytes (PBMCs) of patients with ESRD. METHOD: We combined TMT labeling with LC-MS/MS analysis to compare Khib modification of PBMCs between 20 ESRD patients and 20 healthy controls. The pan 2-hydroxyisobutyrylation antibody-based affinity enrichment method was used to reveal the features of Khib, and the bioinformatics analysis was conducted to analyze the pathology of these Khib-modified proteins. RESULT: Compared to healthy controls, we identified 440 upregulated proteins and 552 downregulated proteins in PBMCs of ESRD, among which 579 Khib sites on 324 upregulated proteins and 287 Khib sites on 188 downregulated proteins were identified. The site abundance, distribution, and function of the Khib protein were further analyzed. The bioinformatics analysis revealed that the Rho/ROCK signaling pathway was highly enriched in ESRD, suggesting that it might contribute to renal fibrosis in ESRD patients. CONCLUSION: In this study, we found that Khib-modified proteins correlated with the occurrence and progression of ESRD.

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.

Antibody responses to SARS-CoV-2 in healthy individuals returning to Shenzhen.

To verify reliability of antibody detection and investigate population immunity to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) in the local Chinese population. A cross-sectional study was conducted in Shenzhen to detect anti-coronavirus antibodies including, immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA). In the COVID-19 group, nine patients were enrolled after diagnosis. In the control group, 1589 individuals without clinical symptoms (cough, fever, and fatigue) and returning from outside Shenzhen were enrolled. The first study enrollment occurred at the end of February 2020; the final study visit was 18 March 2020. In the COVID-19 group, the seven of nine patients were positive for IgM, IgG, and IgA. Meanwhile, six of the 1589 healthy individuals were found to be weakly positive for IgG. According to SARS-CoV-2 nucleic acid tests, the six individuals were all negative. Strong supplemental support for clinical information can be provided by antibody detection, especially for IgA. According to comparison with overseas reports, the infection rate of the Chinese population outside Shenzhen, China, is significantly low, so most of the population in China is still susceptible. Hence, social distancing measures are still inevitable until a vaccine is developed successfully.

Integrated proteome and phosphoproteome analyses of peripheral blood mononuclear cells in primary Sjögren syndrome patients.

Primary Sjögren syndrome (pSS) is a common autoimmune disease. Here, we performed the first proteome and phosphoproteome analyses of peripheral blood mononuclear cells in pSS patients to obtain a comprehensive profile and identify the potential crucial proteins and pathways for the screening and evaluation of pSS patients. Peripheral blood mononuclear cells from 8 pSS-confirmed patients (American-European Consensus Group Criteria, 2002) and 10 normal controls were selected. Label-free quantitative proteomics was utilized to obtain quantitative information. In total, 787 proteins were identified as differentially expressed proteins, and 175 phosphosites on 123 proteins were identified as differentially phosphorylated proteins. We performed functional enrichment analyses with these proteins and phosphoproteins based on public database. Furthermore, protein-protein interaction network analyses were performed by using multiple algorithms. Using module and hub protein analyses, we identified 16 modules for the proteins, 2 clusters for the phosphoproteins and selected the top 10 hub proteins. Finally, we identified 22 motifs using motif analysis of the phosphosites and found 17 newly identified motifs, while 6 motifs were experimentally verified for known protein kinases. The findings distinguished pSS patients from normal controls at the peripheral blood mononuclear cells level and revealed potential candidates for use in pSS diagnosis.

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.

Controversial treatments: An updated understanding of the coronavirus disease 2019.

An outbreak of severe acute respiratory syndrome-related coronavirus 2 infection has posed significant threats to international health and the economy. In the absence of specific treatment for this virus, there is an urgent need to learn from the experience and lessons in China. To reduce the case-fatality rate among coronavirus disease 2019 patients, we should not ignore the complications, such as RNAaemia, acute respiratory distress syndrome, and multiple organ dysfunction. To help understand the advantages and limitations of differential treatments, we provide a timely review and discuss the complications and corresponding major treatments, especially controversial ones such as antiviral therapy (remdesivir, ribavirin, and chloroquine), glucocorticoid therapy, extracorporeal support including an artificial liver system, and extracorporeal membrane oxygenation based on available evidence. As a result, we suggest that antiviral therapy and organ function support are vital to reduce mortality for mild patients and critical patients, respectively.