The ubiquitin ligase UBR4 and the deubiquitylase USP5 modulate the stability of DNA mismatch repair protein MLH1.

MLH1 plays a critical role in DNA mismatch repair and genome maintenance. MLH1 deficiency promotes cancer development and progression, but the mechanism underlying MLH1 regulation remains enigmatic. In this study, we demonstrated that MLH1 protein is degraded by the ubiquitin-proteasome system and have identified vital cis-elements and trans-factors involved in MLH1 turnover. We found that the region encompassing the amino acids 516 to 650 is crucial for MLH1 degradation. The mismatch repair protein PMS2 may shield MLH1 from degradation as it binds to the MLH1 segment key to its turnover. Furthermore, we have identified the E3 ubiquitin ligase UBR4 and the deubiquitylase USP5, which oppositely modulate MLH1 stability. In consistence, UBR4 or USP5 deficiency affects the cellular response to nucleotide analog 6-TG, supporting their roles in regulating mismatch repair. Our study has revealed important insights into the regulatory mechanisms underlying MLH1 proteolysis, critical to DNA mismatch repair related diseases.

Analysis of Gene Expression and TCR/B Cell Receptor Profiling of Immune Cells in Primary Sjögren's Syndrome by Single-Cell Sequencing.

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease that is estimated to affect 35 million people worldwide and is characterized by lymphocytic infiltration, elevated circulating autoantibodies, and proinflammatory cytokines. The key immune cell subset changes and the TCR/BCR repertoire alterations in pSS patients remain unclear. In this study, we sought to comprehensively characterize the transcriptional changes in PBMCs of pSS patients by single-cell RNA sequencing and single-cell V(D)J sequencing. Naive CD8+ T cells and mucosal-associated invariant T cells were markedly decreased but regulatory T cells were increased in pSS patients. There were a large number of differentially expressed genes shared by multiple subpopulations of T cells and B cells. Abnormal signaling pathways, including Ag processing and presentation, the BCR signaling pathway, the TCR signaling pathway, and Epstein-Barr virus infection, were highly enriched in pSS patients. Moreover, there were obvious differences in the CD30, FLT3, IFN-II, IL-1, IL-2, IL-6, IL-10, RESISTIN, TGF-ß, TNF, and VEGF signaling networks between pSS patients and healthy controls. Single-cell TCR and BCR repertoire analysis showed that there was a lower diversity of T cells in pSS patients than in healthy controls; however, there was no significant difference in the degree of clonal expansion, CDR3 length distribution, or degree of sequence sharing. Notably, our results further emphasize the functional importance of αß pairing in determining Ag specificity. In conclusion, our analysis provides a comprehensive single-cell map of gene expression and TCR/BCR profiles in pSS patients for a better understanding of the pathogenesis, diagnosis, and treatment of pSS.

Construction and application of fetal loss risk model in systemic lupus erythematosus patients with mild disease severity.

BACKGROUND: This dynamic nomogram model was developed to predict the probability of fetal loss in pregnant patients with systemic lupus erythematosus (SLE) with mild disease severity before conception. METHODS: An analysis was conducted on 314 pregnancy records of patients with SLE who were hospitalized between January 2015 and January 2022 at Shenzhen People's Hospital, and the Longhua Branch of Shenzhen People's Hospital. Data from the Longhua Branch of the Shenzhen People's Hospital were utilized as an independent external validation cohort. The nomogram, a widely used statistical visualization tool to predict disease onset, progression, prognosis, and survival, was created after feature selection using multivariate logistic regression analysis. To evaluate the model prediction performance, we employed the receiver operating characteristic curve, calibration curve, and decision curve analysis. RESULTS: Lupus nephritis, complement 3, immunoglobulin G, serum albumin, C-reactive protein, and hydroxychloroquine were all included in the nomogram model. The model demonstrated good calibration and discriminatory power, with an area under the curve of 0.867 (95% confidence interval: 0.787-0.947). According to decision curve analysis, the nomogram model exhibited clinical importance when the probability of fetal loss in patients with SLE ranged between 10 and 70%. The predictive ability of the model was demonstrated through external validation. CONCLUSION: The predictive nomogram approach may facilitate precise management of pregnant patients with SLE with mild disease severity before conception.

Global Phosphoproteomics Unveils Kinase-Regulated Networks in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by immune complex deposition in multiple organs. Despite the severe symptoms caused by it, the underlying mechanisms of SLE, especially phosphorylation-dependent regulatory networks remain elusive. Herein, by combining high-throughput phosphoproteomics with bioinformatics approaches, we established the global phosphoproteome landscape of the peripheral blood mononuclear cells from a large number of SLE patients, including the remission stage (SLE_S), active stage (SLE_A), rheumatoid arthritis, and healthy controls, and thus a deep mechanistic insight into SLE signaling mechanism was yielded. Phosphorylation upregulation was preferentially in patients with SLE (SLE_S and SLE_A) compared with healthy controls and rheumatoid arthritis populations, resulting in an atypical enrichment in cell adhesion and migration signatures. Several specifically upregulated phosphosites were identified, and the leukocyte transendothelial migration pathway was enriched in the SLE_A group by expression pattern clustering analysis. Phosphosites identified by 4D-label-free quantification unveiled key kinases and kinase-regulated networks in SLE, then further validated by parallel reaction monitoring. Some of these validated phosphosites including vinculin S275, vinculin S579 and transforming growth factor beta-1-induced transcript 1 S68, primarily were phosphorylation of Actin Cytoskeleton -related proteins. Some predicted kinases including MAP3K7, TBK1, IKKß, and GSK3ß, were validated by Western blot using kinases phosphorylation sites-specific antibodies. Taken together, the study has yielded fundamental insights into the phosphosites, kinases, and kinase-regulated networks in SLE. The map of the global phosphoproteomics enables further understanding of this disease and will provide great help for seeking more potential therapeutic targets for SLE.

Proteomics Analysis of Plasma-Derived Exosomes Unveils the Aberrant Complement and Coagulation Cascades in Dermatomyositis/Polymyositis.

Dermatomyositis and polymyositis (DM/PM) are systemic autoimmune diseases characterized by proximal muscle weakness. The underlying pathogenetic mechanism of this disease remains under-researched. Here, using proteomics analysis, a great overlap of differentially expressed plasma exosomal proteins involved in the complement and coagulation cascade pathway, including FGA, FGB, FGG, C1QB, C1QC, and VWF, was identified in DM/PM patients versus healthy controls. Correlation analysis showed that the expression levels of complement-associated proteins (C1QB and C1QC) correlated positively with CRP, ESR, and platelet count. ROC curve analysis demonstrated that complement and coagulation cascade-associated proteins could be strong predictors for DM/PM. In addition, we also identified several other proteins that were differentially expressed in DM and PM. The selected candidate proteins were further validated by parallel reaction monitoring (PRM) and enzyme-linked immunosorbent assay (ELISA). Together, our findings indicate that these exosome-derived proteins might participate in microvascular damage in DM/PM through the activation of the complement and coagulation cascade pathway and function as biomarkers for the clinical diagnosis of DM/PM.

Serum proteome and metabolome uncover novel biomarkers for the assessment of disease activity and diagnosing of systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting thousands of people. There are still no effective biomarkers for SLE diagnosis and disease activity assessment. We performed proteomics and metabolomics analyses of serum from 121 SLE patients and 106 healthy individuals, and identified 90 proteins and 76 metabolites significantly changed. Several apolipoproteins and the metabolite arachidonic acid were significantly associated with disease activity. Apolipoprotein A-IV (APOA4), LysoPC(16:0), punicic acid and stearidonic acid were correlated with renal function. Random forest model using the significantly changed molecules identified 3 proteins including ATRN, THBS1 and SERPINC1, and 5 metabolites including cholesterol, palmitoleoylethanolamide, octadecanamide, palmitamide and linoleoylethanolamide, as potential biomarkers for SLE diagnosis. Those biomarkers were further validated in an independent cohort with high accuracy (AUC = 0.862 and 0.898 for protein and metabolite biomarkers respectively). This unbiased screening has led to the discovery of novel molecules for SLE disease activity assessment and SLE classification.

Spatial proteomics landscape and immune signature analysis of renal sample of lupus nephritis based on laser-captured microsection.

OBJECTIVE: We aimed to reveal a spatial proteomic and immune signature of kidney function regions in lupus nephritis (LN). MATERIAL AND METHODS: The laser capture microdissection (LCM) was used to isolate the glomerulus, tubules, and interstitial of the kidney from paraffin samples. The data-independent acquisition (DIA) method was used to collect proteomics data. The bioinformatic analysis was performed. RESULTS: A total of 49,658 peptides and 4056 proteins were quantitated. Our results first showed that a high proportion of activated NK cells, naive B cells, and neutrophils in the glomerulus, activated NK cells in interstitial, and resting NK cells were accumulated in tubules in LN. The immune-related function analysis of differential expression proteins in different regions indicated that the glomerulus and interstitial were major sites of immune disturbance and regulation connected with immune response activation. Furthermore, we identified 7, 8, and 9 hub genes in LN's glomerulus, renal interstitial, and tubules. These hub genes were significantly correlated with the infiltration of immune cell subsets. We screened out ALB, CTSB, LCN2, A2M, CDC42, VIM, LTF, and CD14, which show higher performance as candidate biomarkers after correlation analysis with clinical indexes. The function within three regions of the kidney was analyzed. The differential expression proteins (DEGs) between interstitial and glomerulus were significantly enriched in the immune-related biological processes, and myeloid leukocyte-mediated immunity and cellular response to hormone stimulus. The DEGs between tubules and glomerulus were significantly enriched in cell activation and leukocyte-mediated immunity. While the DEGs between tubules and interstitial were enriched in response to lipid, antigen processing, and presentation of peptide antigen response to oxygen-containing compound, the results indicated a different function within kidney regions. CONCLUSIONS: Collectively, we revealed spatial proteomics and immune signature of LN kidney regions by combined using LCM and DIA.

Intrawound vancomycin powder in orthopaedic surgery as surgical site wound infection prophylaxis: A meta-analysis.

A meta-analysis research was executed to appraise the consequence of intrawound vancomycin powder (IWVP) in orthopaedic surgery (OPS) as surgical site wound infection (SSWI) prophylaxis. Inclusive literature research till March 2023 was carried out and 2756 interconnected researches were revised. Of the 18 picked researches enclosed 13 214 persons with OPS were in the used researches' starting point, 5798 of them were utilising IWVP, and 7416 were control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to appraise the consequence of the IWVP in OPS as SSWI prophylaxis by the dichotomous approaches and a fixed or random model. IWVP had significantly lower SSWIs (OR, 0.61; 95% CI, 0.50-0.74, P < .001), deep SSWIs (OR, 0.57; 95% CI, 0.36-0.91, P = .02), and superficial SSWIs (OR, 0.67; 95% CI, 0.46-0.98, P = .04) compared with control in persons with OPS. IWVP had significantly lower SSWIs, deep SSWIs, and superficial SSWIs compared with control in persons with OPS. However, when interacting with its values, caution must be taken and more research is needed to confirm this finding.

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.

Comprehensive analysis of differentially expressed mRNA and circRNA in Ankylosing spondylitis patients' platelets.

Ankylosing spondylitis (AS) is a chronic inflammatory disease significantly decreasing the quality of life. Platelets play an important and active role in the development of AS. Accumulating evidence demonstrated platelets contain diverse RNA repository inherited from megakaryocytes or microvesicles. Platelet RNAs are dynamically affected by pathological conditions and could be used as diagnostic or prognostic biomarkers. However, the role of the platelet RNAs in AS is elusive. In this study, we compared mRNA and circRNA profiles in platelets between AS patients and healthy controls using RNA sequencing and bioinformatic analysis, and found 4996 mRNAs and 2942 circRNAs were differently expressed. The significantly over-expressed mRNAs in AS patients are involved in platelet activity, gap junction, focal adhesion, rap1 and toll and Imd signaling pathway. The previous identified platelet-derived immune mediators such as P2Y1, P2Y12, PF4, GPIbα, CD40L, ICAM2, CCL5 (RANTES), TGF-ß (TGF-ß1 and TGF-ß2) and PDGF (PDGFB and PDGFA) are also included in these over expressed mRNAs, implying these factors may trigger inflammatory cascades and promote the development of AS. Additionally, we found two down-regulated circRNA (circPTPN22 and circFCHSD2) from the intersection analyses of platelets and spinal ligament tissues of AS patients. The circRNA-miRNA-mRNA regulatory network of these two circRNAs was constructed, and the target mRNAs were enriched in Th17 cell differentiation, inflammatory bowel disease, cell adhesion molecules, cytokine-cytokine receptor interaction, Jak-STAT and Wnt signaling pathway, all these pathways participate in the bone remodeling and pro/anti-inflammatory immune regulation in AS. Then, qRT-PCR was performed to validate the expression of selected key mRNAs and circRNAs and the results demonstrated that the expression levels of P2Y12, GPIbα, circPTPN22 and circFCHSD2 were consistent with the sequencing analysis. In addition, the high expression of five predicted miRNAs interacting with circPTPN22 and circFCHSD2 were also detected in AS by qRT-PCR. Taken together, our study presents a comprehensive overview of mRNAs and circRNAs in platelets in AS patients and offers new insight into the mechanisms of platelet involving in the pathogenesis of AS. The mRNAs and circRNAs identified in this study may serve as candidates for diagnosis and targeted treatment of AS.

Integrated analysis of competing endogenous RNA networks in peripheral blood mononuclear cells of systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease with a complicated pathogenesis, and its aetiology has not been clearly unveiled. The lack of effective diagnosis and treatment methods makes it necessary to explore the molecular mechanism of SLE. We aimed to identify some critical signalling pathways and key competing endogenous RNAs (ceRNAs) underlying the molecular mechanism of SLE and to map out the systematic signalling networks by integrating the data on different kinds of RNAs. METHODS: Peripheral blood mononuclear cells (PBMCs) were collected from both SLE patients and healthy subjects, RNA was extracted from the PBMCs, and RNA libraries including ribosomal RNA-depleted strand-specific libraries and small RNA libraries were built for deep RNA sequencing (RNA-seq). RNA-seq yielded differential expression profiles of lncRNAs/circRNAs/miRNAs/mRNAs related to SLE. The DAVID database (v. 6.8) was employed for Gene Ontology (GO) and KEGG pathway analysis. ceRNA networks (circRNA/lncRNA-miRNA-mRNA) were constructed and visualized using Cytoscape software (v. 3.5.0). The TargetScan and miRanda databases were used to predict target relationships in ceRNA networks. qRT-PCR was used to verify our data. RESULTS: Differential expression of ceRNAs related to SLE was detected in SLE patients' PBMCs: 644 mRNAs (384 upregulated, 260 downregulated), 326 miRNAs (223 upregulated, 103 downregulated), 221 lncRNAs (79 upregulated, 142 downregulated), and 31 circRNAs (21 upregulated, 10 downregulated). We drew ceRNA signalling networks made up of the differentially expressed mRNAs/miRNAs/lncRNAs/circRNAs mentioned above, and the hub genes included IRF5, IFNAR2, TLR7, IRAK4, STAT1, STAT2, C2, and Tyk2. These hub genes were involved in ceRNA signalling pathways, such as the IL-17 signalling pathway and type I interferon signalling pathway. CONCLUSIONS: We explored the differential expression profiles of various kinds of ceRNAs and integrated signalling networks constructed by ceRNAs. Our findings offer new insights into the pathogenesis of SLE and hint at therapeutic strategies.

Elevated interleukin-37 associated with tophus and pro-inflammatory mediators in Chinese gout patients.

INTRODUCTION: Interleukin-37(IL-37), a natural inhibitor of innate immunity, has been identified to protect against various inflammatory diseases, including monosodium urate (MSU)-induced inflammation. However, the association of IL-37 with clinical indexes and pro-inflammatory mediators in gout patients remains unclear. The aim of this study was to determine IL-37 level in hyperuricemia and gout patients with or without tophus, and to investigate the correlations of IL-37 with clinical indexs such as Uric Acid (UA), CRP(C-reactive protein), Creatinine Clearance Rate (Ccr), Erythrocyte Sedimentation Rate (ESR) and so on, as well as with the pro-inflammatory mediators in serum including Interleukin-1ß(IL-1ß), Interleukin-6(IL-6) and Interleukin-18(IL-18) from gout patients. METHODOLOGY: The serum levels of IL-37, IL-1ß, IL-6 and IL-18 levels in serum of gout patients were determined by ELISA; the correlations between IL-37 and clinical values or pro-inflammatory mediators in serum of gout were analyzed by Spearman correlation test. RESULTS: The serum levels of IL-37 were higher in active gout patients than inactive gout patients and HCs, especially in active gout patients with tophus. No significant difference was observed in serum IL-37 levels between hyperuricemia and normal controls. IL-1ß, IL-6 and IL-18 levels were significant elevated in gout patients with tophus than those without tophus; Serum IL-37 were positively correlated with CRP and ESR, as well as with IL-1ß, IL-6 and IL-18, negatively correlated with Ccr, and not correlated with UA, creatinine (Cr) and triglyceride (TG) in gout patients. CONCLUSIONS: IL-37 increased in gout patients positively associated CRP and ESR, as well as with proinflammatory mediators IL-1ß, IL-6, IL-18, the presence of tophus and chronic kidney disease in gout. It may be a novel marker for predicting this pathology.

Integrative genomic expression analysis reveals stable differences between lung cancer and systemic sclerosis.

BACKGROUND: The incidence and mortality of lung cancer are the highest among all cancers. Patients with systemic sclerosis show a four-fold greater risk of lung cancer than the general population. However, the underlying mechanism remains poorly understood. METHODS: The expression profiles of 355 peripheral blood samples were integratedly analyzed, including 70 cases of lung cancer, 61 cases of systemic sclerosis, and 224 healthy controls. After data normalization and cleaning, differentially expressed genes (DEGs) between disease and control were obtained and deeply analyzed by bioinformatics methods. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed online by DAVID and KOBAS. The protein-protein interaction (PPI) networks were constructed from the STRING database. RESULTS: From a total of 14,191 human genes, 299 and 1644 genes were identified as DEGs in systemic sclerosis and lung cancer, respectively. Among them, 64 DEGs were overlapping, including 36 co-upregulated, 10 co-downregulated, and 18 counter-regulated DEGs. Functional and enrichment analysis showed that the two diseases had common changes in immune-related genes. The expression of innate immune response and response to virus-related genes increased significantly, while the expression of negative regulation of cell cycle-related genes decreased notably. In contrast, the expression of mitophagy regulation, chromatin binding and fatty acid metabolism-related genes showed distinct trends. CONCLUSIONS: Stable differences and similarities between systemic sclerosis and lung cancer were revealed. In peripheral blood, enhanced innate immunity and weakened negative regulation of cell cycle may be the common mechanisms of the two diseases, which may be associated with the high risk of lung cancer in systemic sclerosis patients. On the other hand, the counter-regulated DEGs can be used as novelbiomarkers of pulmonary diseases. In addition, fat metabolism-related DEGs were consideredto be associated with clinical blood lipid data.

Increased GITRL Impairs the Function of Myeloid-Derived Suppressor Cells and Exacerbates Primary Sjögren Syndrome.

Although the expansion of myeloid-derived suppressor cells (MDSCs) has been reported in autoimmune disorders, it is largely unclear how MDSCs contribute to the development of primary Sjögren syndrome (pSS). In this study, we found significantly increased MDSCs with gradually diminished suppressive capacity during disease development in mice with experimental Sjögren syndrome (ESS). The ligand for glucocorticoid-induced TNFR family-related protein (GITRL) was increased along ESS progression, whereas the increased GITRL was found to attenuate the immunosuppressive function of MDSCs. Moreover, blocking GITR signal in MDSCs significantly restored their immunosuppressive function and alleviated ESS progression in mice. In pSS patients, expanded MDSCs were found to express low levels of arginase. Significantly increased serum GITRL levels were closely correlated with patients with higher Sjögren syndrome disease activity index. Furthermore, treatment with recombinant GITRL markedly reduced the immunosuppressive function of human MDSCs. Together, our studies have demonstrated a critical role of GITRL in modulating the suppressive function of MDSCs, which may facilitate the validation of GITRL as a therapeutic target for the treatment of pSS.

Current state of technologies and recognition of anti-SSA/Ro antibodies in China: A multi-center study.

BACKGROUND: Previous studies have demonstrated that Ro60 and Ro52 have different clinical implications, and anti-Ro52 antibodies are an independent serum marker of systemic autoimmune diseases, including Sjögren's syndrome. Many different assays have been adopted to detect anti-Sjögren's syndrome antigen A (SSA)/Ro antibodies, while to date no specific approach has been recommended as optimal for anti-SSA/Ro antibody testing. Herein, we performed a multi-center study to explore the current clinical utility of different strategies for anti-SSA/Ro antibody testing in China. METHODS: Twenty-one tertiary care centers were included in this questionnaire-based study. The self-administered questionnaire mainly includes testing methods for anti-SSA/Ro antibodies, reporting system of results, and interpretation of results by clinicians. RESULTS: Six different methods were applied to detect anti-SSA/Ro antibodies in the 21 centers. Line immunoassay (eight different commercial kits) was the most frequently adopted method (21/21, 100%), with different cutoff values and strategies for intensity stratification. There were two reporting systems: One was reported as "anti-SSA antibodies" and "anti-Ro52 antibodies" (12/21, 57%), while the other was "anti-SSA/Ro60 antibodies" and "anti-SSA/Ro52 antibodies" (9/21, 43%). Notably, six centers (29%) considered either positive anti-Ro60 or anti-Ro52 antibodies as positive anti-SSA antibodies, all of which adopted the latter reporting system. CONCLUSION: Significant variabilities existed among anti-SSA/Ro assays. Nearly 30% of centers misinterpreted the definition of positive anti-SSA antibodies, which may be attributed to the confusing reporting systems of line immunoassay. Therefore, we advocate standardization of the nomenclature of anti-SSA/Ro antibodies, changing the "anti-SSA/Ro52" label in favor of the "anti-Ro52" antibodies for a clear designation.

The ubiquitinase ZFP91 promotes tumor cell survival and confers chemoresistance through FOXA1 destabilization.

The forkhead box A1 (FOXA1), one of the forkhead class of DNA-binding proteins, functions as a transcription factor and plays a vital role in cellular control of embryonic development and cancer progression. Downregulation of FOXA1 has reported in several types of cancer, which contributes to cancer cell survival and chemoresistance. However, the mechanism for FOXA1 downregulation in cancer remains unclear. Here, we report that the ubiquitination enzyme zinc finger protein 91 (ZFP91) ubiquitinates and destabilizes FOXA1, which promotes cancer cell growth. High level of ZFP91 expression correlates with low level of FOXA1 protein in human gastric cancer (GC) cell lines and patient samples. Furthermore, ZFP91 knockdown reduces FOXA1 polyubiquitination, which decreases FOXA1 turnover and enhances cellular sensitivity to chemotherapy. Taken together, our findings reveal ZFP91-FOXA1 axis plays an important role in promoting GC progression and provides us a potential therapeutic intervention in the treatment of GC.

STUB1 suppresseses tumorigenesis and chemoresistance through antagonizing YAP1 signaling.

Yes-associated protein (YAP) is a component of the canonical Hippo signaling pathway that is known to play essential roles in modulating organ size, development, and tumorigenesis. Activation or upregulation of YAP1, which contributes to cancer cell survival and chemoresistance, has been verified in different types of human cancers. However, the molecular mechanism of YAP1 upregulation in cancer is still unclear. Here we report that the E3 ubiquitin ligase STUB1 ubiquitinates and destabilizes YAP1, thereby inhibiting cancer cell survival. Low levels of STUB1 expression were correlated with increased protein levels of YAP1 in human gastric cancer cell lines and patient samples. Moreover, we revealed that STUB1 ubiquitinates YAP1 at the K280 site by K48-linked polyubiquitination, which in turn increases YAP1 turnover and promotes cellular chemosensitivity. Overall, our study establishes YAP1 ubiquitination and degradation mediated by the E3 ligase STUB1 as an important regulatory mechanism in gastric cancer, and provides a rationale for potential therapeutic interventions.

Multiple Functions of B Cells in the Pathogenesis of Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by excessive autoantibody production and multi-organ involvement. Although the etiology of SLE still remains unclear, recent studies have characterized several pathogenic B cell subsets and regulatory B cell subsets involved in the pathogenesis of SLE. Among pathogenic B cell subsets, age-associated B cells (ABCs) are a newly identified subset of autoreactive B cells with T-bet-dependent transcriptional programs and unique functional features in SLE. Accumulation of T-bet+ CD11c+ ABCs has been observed in SLE patients and lupus mouse models. In addition, innate-like B cells with the autoreactive B cell receptor (BCR) expression and long-lived plasma cells with persistent autoantibody production contribute to the development of SLE. Moreover, several regulatory B cell subsets with immune suppressive functions have been identified, while the impaired inhibitory effects of regulatory B cells have been indicated in SLE. Thus, further elucidation on the functional features of B cell subsets will provide new insights in understanding lupus pathogenesis and lead to novel therapeutic interventions in the treatment of SLE.

TLR4+CXCR4+ plasma cells drive nephritis development in systemic lupus erythematosus.

OBJECTIVES: In patients with systemic lupus erythematosus (SLE), immune tolerance breakdown leads to autoantibody production and immune-complex glomerulonephritis. This study aimed to identify pathogenic plasma cells (PC) in the development of lupus nephritis. METHODS: PC subsets in peripheral blood and renal tissue of patients with SLE and lupus mice were examined by flow cytometry and confocal microscopy, respectively. Sorting-purified PCs from lupus mice were adoptively transferred into Rag2-deficient recipients, in which immune-complex deposition and renal pathology were investigated. In culture, PCs from lupus mice and patients with SLE were treated with a TLR4 inhibitor and examined for autoantibody secretion by enzyme-linked immunospot assay (ELISPOT). Moreover, lupus mice were treated with a TLR4 inhibitor, followed by the assessment of serum autoantibody levels and glomerulonephritis activity. RESULTS: The frequencies of TLR4+CXCR4+ PCs in peripheral blood and renal tissue were found significantly increased with the potent production of anti-dsDNA IgG, which were associated with severe renal damages in patients with SLE and mice with experimental lupus. Adoptive transfer of TLR4+CXCR4+ PCs from lupus mice led to autoantibody production and glomerulonephritis development in Rag2-deficient recipients. In culture, TLR4+CXCR4+ PCs from both lupus mice and patients with SLE showed markedly reduced anti-dsDNA IgG secretion on TLR4 blockade. Moreover, in vivo treatment with TLR4 inhibitor significantly attenuated autoantibody production and renal damages in lupus mice. CONCLUSIONS: These findings demonstrate a pathogenic role of TLR4+CXCR4+ PCs in the development of lupus nephritis and may provide new therapeutic strategies for the treatment of SLE.

Bioavailability and pharmacokinetic profile of a newly-developed twice-a-day sustained-release paracetamol formulation.

OBJECTIVE: A new twice daily sustained-release (SR) paracetamol formulation was developed to improve convenience and enhance patient compliance for treatment of pain from chronic diseases. This research aimed to evaluate bioavailability and compare pharmacokinetic (PK) properties of the new SR paracetamol formulation (2x1,000 mg) with those of immediate-release (IR) paracetamol (2x500 mg) and existing extended-release (ER) paracetamol (2x665 mg). METHODS: Two randomized, single-dose, 4-way crossover studies were conducted. A total of 28 healthy male and female volunteers participated in each study. The relative bioavailability, partial extent of absorption, overall elimination, food effect, and safety were evaluated. RESULTS: The estimates of relative bioavailability of new SR with IR formulation based on dose-adjusted AUC0-inf were 91% (0.86-0.96) for the fasted state and 99% (0.95-1.02) for the fed state, while these estimates comparing new SR with ER formulation were 99% (0.96-1.03) in the fasted state and 98% (0.95-1.02) in the fed state. The accumulated mean time period at or above the minimal therapeutic plasma paracetamol concentration for the new SR was from 90% to 112% longer than that of the IR formulation, in fasted and fed state, respectively. Food significantly increased Cmax of SR formulation, with ratios fast vs. fed 0.79 (p<0.0001) and 0.77 (p<0.0001) in study I and II, respectively. CONCLUSIONS: The new SR formulation was well absorbed, with more than 90% relative bioavailability as compared to the currently marketed IR and ER products and better sustained-release PK characteristics, which make it suitable for twice-daily paracetamol treatment.