Impaired expression of innate immunity-related genes in IgG4-related disease: A possible mechanism in the pathogenesis of IgG4-RD

TCN1 Expression Is Increased in Asthma

INTRODUCTION

Asthma is a chronic disease that affects populations worldwide. The purpose of this study was to investigate the expression of TCN1 in sputum and its correlation with inflammation and lung function in asthma.

METHODS

We recruited 141 subjects, detected TCN1 mRNA level by quantitative reverse transcription polymerase chain reaction, detected TCN1 protein expression by Western blot, detected TCN1 protein level by enzyme-linked immunosorbent assay, and analyzed the correlation between TCN1 and fraction of exhaled nitric oxide (FeNO), IgE, EOS%, lung functions, and some Th2 cytokines. The diagnostic value of TCN1 was evaluated by receiver operating characteristics curve. The expression of TCN1 was further confirmed by human bronchial epithelial cell in vitro.

RESULTS

Compared with the health group, the expression of TCN1 in induced sputum cells increased in asthma group and was correlated with FeNO, IgE, and EOS%. TCN1 level was also elevated in the induced sputum supernatant of asthma patients. The protein level of TCN1 in induced sputum supernatant was correlated with FeNO, IgE and PC-20, forced expiratory volume in the first second (FEV1)%pred, FEV1/FVC, and some cytokines (IL-4, IL-5, IL-10, IL-13, MUC5AC). TCN1 was also differentially expressed in patients with different severity of asthma. Four weeks after ICS treatment, the expression of TCN1 in induced sputum supernatant increased. In vitro, the protein level of TCN1 in human bronchial epithelial cells' supernatant increased after stimulated with IL-4 and IL-13.

CONCLUSION

The expression of TCN1 was increased in asthma patients' sputum, and was positively correlated with some inflammatory markers, negatively correlated with lung function. TCN1 may be used as a potential biomarker for the diagnosis and treatment of asthma.

Comprehensive Analysis of Immune-Related Metabolic Genes in Lung Adenocarcinoma

PURPOSE

The immunotherapy of lung adenocarcinoma (LUAD) has received much attention in recent years and metabolic reprogramming is linked to immune infiltration in the tumor microenvironment. Therefore, it is indispensable to dissect the role of immune-related metabolic genes in lung adenocarcinoma.

METHODS

In this study, we screened immune-related genes by Pearson correlation. The function of these genes was explored by gene ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis. The differently expressed immune-related genes were analyzed by Limma. Furthermore, the LUAD patients were clustered based on immune-related genes through consensus clustering. The Unicox was used to identify survival-immune-related metabolic genes. The Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis was used to optimize the gene sets. A prediction model was constructed and tested. The potential therapeutic target was selected based on two criteria, these immune-related metabolic genes that were highly expressed in tumor tissues and negatively correlated with the survival of patients in LUAD. Quantitative real-time PCR (qRT-PCR) was used for in vitro experimental validations.

RESULTS

We identified 346 immune-related genes, mainly involved in arachidonic acid metabolism and peroxisome proliferator-activated receptor (PPAR) signaling. Moreover, a total of 141 immune-related genes were dysregulated between tumor and normal tissues. We clustered three subtypes of LUAD based on immune-related metabolic genes and these subtypes exhibited different survival and immune status. We found Ribonucleotide Reductase Regulatory Subunit M2 (RRM2) as a potential therapeutic target, which is positively correlated with the cyclin-dependent kinase family of genes.

CONCLUSION

We comprehensively analyzed the immune-related metabolic genes in LUAD. RRM2 was determined as a promising metabolic checkpoint for lung adenocarcinoma.

CD163+ M2 macrophages promote fibrosis in IgG4-related disease via TLR7/IRAK4/NF-κB signaling

Objective

IgG4‐related disease (IgG4‐RD) is a fibro‐inflammatory condition that can affect multiple organs. We previously demonstrated that TLR7‐transgenic C57BL/6 mice showed elevated serum IgG1 levels and inflammation with fibrosis in the salivary glands (SGs), lungs, and pancreas. Moreover, we observed extensive Toll‐like receptor 7 (TLR‐7)–positive CD163+ M2 macrophage infiltration in SGs from IgG4‐RD patients. We undertook this study to examine the fibrotic mechanism via the TLR‐7 pathway.

Methods

Gene expression in SGs from human TLR7‐transgenic mice and IgG4‐RD patients was analyzed using DNA microarrays. We extracted the common up‐regulated TLR‐7–related genes in SGs from TLR7‐transgenic mice and IgG4‐RD patients. Finally, we investigated the interaction between CD163+ M2 macrophages and fibroblasts before and after stimulation with the TLR‐7 agonist loxoribine.

Results

In TLR7‐transgenic mice and IgG4‐RD patients, IRAK3 and IRAK4 were significantly overexpressed. Real‐time polymerase chain reaction validated the up‐regulation of only IRAK4 in IgG4‐RD patients compared with the other groups (P < 0.05). Interleukin‐1 receptor–associated kinase 4 (IRAK4) was strongly detected in and around germinal centers in SGs from patients with IgG4‐related dacryoadenitis and sialadenitis alone. Double immunofluorescence staining showed that IRAK4‐positive cells were mainly colocalized with CD163+ M2 macrophages in SGs (P < 0.05). After stimulation with loxoribine, CD163+ M2 macrophages exhibited significantly enhanced expression of IRAK4 and NF‐κB and increased supernatant concentrations of fibrotic cytokines. Finally, we confirmed that the number of fibroblasts was increased by culture with the supernatant of CD163+ M2 macrophages following stimulation with loxoribine (P < 0.05).

Conclusion

CD163+ M2 macrophages promote fibrosis in IgG4‐RD by increasing the production of fibrotic cytokines via TLR‐7/IRAK4/NF‐κB signaling.

Management of IgG4-related disease

IgG4-related disease was unrecognised as a unified disease entity until this century, yet in a short period of time the disease has been appreciated to have a worldwide distribution, and its clinical, pathological, and radiological features have been described in considerable detail. The disease has strong organ predilections, and many of the clinical presentations of disease are increasingly familiar to both generalists and specialists. Early recognition of IgG4-related disease is crucial because although the disease is highly treatable, it can lead to serious organ damage and even death if undiagnosed until advanced stages. Its indolent nature often makes diagnosis challenging, and IgG4-related disease is one of the great mimickers of other diseases in the current era. Glucocorticoids are an effective treatment for IgG4-related disease, but their long-term use is problematic in a disease that frequently affects middle-aged to elderly individuals and often leads to pancreatic dysfunction. Our understanding of the pathophysiology of the disease is surprisingly advanced given the relatively recent recognition of this condition. Insights into disease pathophysiology offer the possibility of a variety of targeted treatment approaches. Looking ahead, biological therapies could profoundly alter the way in which IgG4-related disease is managed, permitting the use of specific therapies that are tailored to patients' clinical phenotypes.