ObjectiveGenetic 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.MethodsWe 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.ResultsWe 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.ConclusionsOur 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.

No abstract

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.

BackgroundAnkylosing 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 MethodsAnkylosing 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.ResultsLiquid 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.ConclusionThe 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.