Quantitative proteomics by iTRAQ-PRM based reveals the new characterization for gout

Elucidating the mechanism of the Tibetan medicine sanguotang in treating gouty arthritis through network pharmacology and in vivo experiments

BACKGROUND

We explored the mechanisms of Sanguotang (SGT), a Tibetan medicine, in treating gout arthritis (GA).

METHODS

The main active components, action targets, and disease targets of SGT were identified through TCMSP databases. The gene functions were analyzed using protein interaction (PPI) networks, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and molecular docking. A GA model induced by monosodium urate was established in rats. The ankle joint swelling was observed. The levels of uric acid (UA) and albumin (ALB) in rat serum were measured. Hematoxylin and eosin (HE) staining was conducted to examine the pathological changes in rat ankle joints.

RESULTS

Twenty-nine active components of SGT with proven efficacy and 66 intersection targets were identified, primarily involved in inflammation and immune regulation pathways. The PPI results revealed that the key targets of SGT against GA included ALB, IL6, TNF, TP53, and PTGS. Molecular docking showed favorable binding energy between the ALB protein and the active components. The results from animal experiments demonstrated that SGT effectively alleviated the inflammatory reaction in ankle joints, and decreased UA and ALB levels. Furthermore, SGT effectively inhibited the proliferation of synovial cells in the ankle joint cavity, prevented infiltration of inflammatory cells, and protected synovial tissue, thereby improving GA.

CONCLUSIONS

SGT comprehensively contributes to the treatment of GA by regulating UA metabolism, reducing the release of inflammatory factors, and modulating immune and inflammatory pathways.

Sustained xanthine oxidase inhibitor treat to target urate lowering therapy rewires a tight inflammation serum protein interactome

Background

Effective xanthine oxidoreductase inhibition (XOI) urate-lowering treatment (ULT) to target significantly reduces gout flare burden and synovitis between 1-2 years therapy, without clearing all monosodium urate crystal deposits. Paradoxically, treat to target ULT is associated with increased flare activity for at least 1 year in duration on average, before gout flare burden decreases. Since XOI has anti-inflammatory effects, we tested for biomarkers of sustained, effective ULT that alters gouty inflammation.

Methods

We characterized the proteome of febuxostat-treated murine bone marrow macrophages. Blood samples (baseline and 48 weeks ULT) were analyzed by unbiased proteomics in febuxostat and allopurinol ULT responders from two, independent, racially and ethnically distinct comparative effectiveness trial cohorts (n=19, n=30). STRING-db and multivariate analyses supplemented determinations of significantly altered proteins via Wilcoxon matched pairs signed rank testing.

Results

The proteome of cultured IL-1b-stimulated macrophages revealed febuxostat-induced anti-inflammatory changes, including for classical and alternative pathway complement activation pathways. At 48 weeks ULT, with altered purine metabolism confirmed by serum metabolomics, serum urate dropped >30%, to normal (<6.8 mg/dL) in all the studied patients. Overall, flares declined from baseline. Treated gout patient sera and peripheral blood mononuclear cells (PBMCs) showed significantly altered proteins (p<0.05) in clustering and proteome networks. CRP was not a useful therapy response biomarker. By comparison, significant serum proteome changes included decreased complement C8 heterotrimer C8A and C8G chains essential for C5b-9 membrane attack complex assembly and function; increase in the NLRP3 inflammasome activation promoter vimentin; increased urate crystal phagocytosis inhibitor sCD44; increased gouty inflammation pro-resolving mediator TGFB1; decreased phagocyte-recruiting chemokine PPBP/CXCL7, and increased monocyte/macrophage-expressed keratin-related proteins (KRT9,14,16) further validated by PBMC proteomics. STRING-db analyses of significantly altered serum proteins from both cohorts revealed a tight interactome network including central mediators of gouty inflammation (eg, IL-1B, CXCL8, IL6, C5).

Conclusions

Rewiring of inflammation mediators in a tight serum protein interactome was a biomarker of sustained XOI-based ULT that effectively reduced serum urate and gout flares. Monitoring of the serum and PBMC proteome, including for changes in the complement pathway could help determine onset and targets of anti-inflammatory changes in response to effective, sustained XOI-based ULT.Trial Registration: ClinicalTrials.gov Identifier: NCT02579096.

ORMDL3‑mediated bronchial epithelial pyroptosis leads to lung inflammation in obese mice with asthma

Asthma associated with obesity is a chronic disease that poses a threat to health in children and results in severe wheezing, earlier airway remodeling and increased insensitivity to hormone therapy compared with those who only have asthma. Despite its clinical importance, knowledge on the underlying mechanisms of this disease is limited. The present study aimed to elucidate the pathogenesis of asthma associated with obesity using a murine model. A total of 30 female BALB/c mice were divided into three groups: Normal, mice with asthma and obese mice with asthma. Obese mice with asthma were fed a high‑fat diet to induce obesity. Mice with asthma were sensitized and challenged with ovalbumin (OVA). Obese mice were subjected to OVA sensitization and challenge to develop asthma associated with obesity. Airway remodeling was observed in obese mice with asthma through HE and Masson staining. Proteomic and bioinformatics analyses were conducted on lung tissue from obese mice with asthma and normal mice. A total of 200 proteins were differentially expressed in obese mice with asthma compared with normal mice; of these, 53 and 47% were up‑ and downregulated, respectively. Pathway analysis revealed that asthma associated with obesity primarily affected the 'lysosome', 'phagosome', and 'sphingolipid metabolism' pathways. Gene Set Enrichment Analysis demonstrated the presence of pyroptosis in obese asthmatic mice, along with significant increases in pyroptosis‑-associated factors such as GSDMD and Caspase. High protein expression of orosomucoid‑like 3 (ORMDL3), NOD‑like receptor thermal protein domain associated protein 3 (NLRP3) and Gasdermin‑D (GSDMD) was observed in obese mice with asthma. In vitro experiments using HBE cells infected with ORMDL3‑overexpressing lentivirus demonstrated that the overexpression of ORMDL3 led to increased expression of NLRP3, GSDMD and cathepsin D (CTSD). These findings suggested that ORMDL3 may regulate pyroptosis and subsequent airway remodeling in asthma associated with obesity via the CTSD/NLRP3/GSDMD pathway.

Gout Remission as a Goal of Urate-Lowering Therapy: A Critical Review

Urate-lowering therapies for the management of gout lead to a reduction in serum urate levels, monosodium urate crystal deposition, and the clinical features of gout, including painful and disabling gout flares, chronic gouty arthritis, and tophi. Thus, disease remission is a potential goal of urate-lowering therapy. In 2016, preliminary gout remission criteria were developed by a large group of rheumatologists and researchers with expertise in gout. The preliminary gout remission criteria were defined as: serum urate < 0.36 mmol/L (6 mg/dL); an absence of gout flares; an absence of tophi; pain due to gout < 2 on a 0-10 scale; and a patient global assessment < 2 on a 0-10 scale over a 12-month period. In this critical review, we describe the development of the preliminary gout remission criteria, the properties of the preliminary gout remission criteria, and clinical studies of gout remission in people taking urate-lowering therapy. We also describe a future research agenda for gout remission.

The biomarkers discovery of hyperuricemia and gout: proteomics and metabolomics

Background

Hyperuricemia and gout are a group of disorders of purine metabolism. In recent years, the incidence of hyperuricemia and gout has been increasing, which is a severe threat to people's health. Several studies on hyperuricemia and gout in proteomics and metabolomics have been conducted recently. Some literature has identified biomarkers that distinguish asymptomatic hyperuricemia from acute gout or remission of gout. We summarize the physiological processes in which these biomarkers may be involved and their role in disease progression.

Methodology

We used professional databases including PubMed, Web of Science to conduct the literature review. This review addresses the current landscape of hyperuricemia and gout biomarkers with a focus on proteomics and metabolomics.

Results

Proteomic methods are used to identify differentially expressed proteins to find specific biomarkers. These findings may be suggestive for the diagnosis and treatment of hyperuricemia and gout to explore the disease pathogenesis. The identified biomarkers may be mediators of the link between hyperuricemia, gout and kidney disease, metabolic syndrome, diabetes and hypertriglyceridemia. Metabolomics reveals the main influential pathways through small molecule metabolites, such as amino acid metabolism, lipid metabolism, or other characteristic metabolic pathways. These studies have contributed to the discovery of Chinese medicine. Some traditional Chinese medicine compounds can improve the metabolic disorders of the disease.

Conclusions

We suggest some possible relationships of potential biomarkers with inflammatory episodes, complement activation, and metabolic pathways. These biomarkers are able to distinguish between different stages of disease development. However, there are relatively few proteomic as well as metabolomic studies on hyperuricemia and gout, and some experiments are only primary screening tests, which need further in-depth study.

Urine inter‐alpha‐trypsin inhibitor family‐related proteins may serve as biomarkers for disease activity of lupus

Background

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease involving multiple tissues. Inter‐Alpha‐Trypsin Inhibitor (ITI) family proteins have a role in maintaining tissue homeostasis, but their possible clinical significance in the SLE patients has not been reported. The aim of this study was to analyze and verify the expression of ITI‐related proteins in the urine of SLE patients, further explore the features of these proteins in disease activity.

Methods

Based on label‐free proteomics technology and bioinformatics technology, we analyzed the expression of ITI family‐related proteins in the urine of lupus. Subsequently, Western‐blot and targeted proteomics were used to qualitatively and quantitatively verify the expression of these proteins, respectively.

Results

A total of seven ITI family‐related proteins were screened and identified; and six of these proteins were differentially expressed in the urine of SLE patients. Further quantitative analysis showed that the expressions of ITIH2, ECM1, and ITIH5 in urine between active SLE group and stable SLE group were consistent with the preliminary screening results. The expression of ITIH2 and ECM1 in the renal damage group were also consistent with the screening results. Moreover, ITIH2 and ECM1 have a good correlation with disease activity and have a certain correlation with renal damage.

Conclusions

In this exploratory study, we evaluated the expression of ITI family‐related proteins in the urine of SLE and found that urine ITIH2 and ECM1 were closely related to SLE activity, especially kidney damage, providing an experimental basis for further exploration of the potential roles in monitoring lupus and lupus nephritis activity.