Identification and validation of candidate genes dysregulated in alveolar macrophages of acute respiratory distress syndrome

The activation of FPR3/PKA/Rap1/ERK1/2 and FPR3/p-IκB/NF-κB axis in fibroblasts promote capsular contracture after rhinoplasty

BACKGROUND

Capsular contracture may occur after rhinoplasty due to rejection of silicone implants by the immune system. Our previous high-throughput sequencing of RNA in nasal capsular contracture tissue revealed that FPR3 was significantly increased in grade IV capsular contracture tissue, compared with grade II.

OBJECTIVE

This study aimed to elucidate the effect and specific mechanism of FPR3 on capsular formation and contracture following rhinoplasty.

METHODS

Using the GeneMANIA Database, the genes involved with FPR3 expression were searched, and the Gene Ontology analysis was performed to annotate the biological functions of the aforementioned genes. The mRNA and protein expressions of related genes in fibroblasts and capsular contracture tissues were analyzed using quantitative real-time PCR, western blot, and immunohistochemical staining. CCK-8 was used to determine the viability of cells. The migration capacity of fibroblasts was assessed using a wound healing assay. ELISA was used to detect levels of IL-1β, TNF-α, and IL-6.

RESULTS

After rhinoplasty, the expression of FPR3 in the capsular tissue increased in proportion to the degree of contracture. By activating the PKA/Rap1/ERK1/2 axis, overexpression of FPR3 can significantly increase the cell viability of fibroblasts and promote their transformation into myofibroblasts. Moreover, FPR3 phosphorylates IκB to decrease NF-κB inhibition, thereby promoting the synthesis and release of the inflammatory cytokines IL-1β, TNF-α, and IL-6.

CONCLUSION

FPR3 is a crucial molecule that causes capsular development and contracture following rhinoplasty. In the future, local suppression of FPR3 may be an effective treatment for relieving capsular contracture.

Identification and Validation of Prognostic Biomarkers Specifically Expressed in Macrophage in IgA Nephropathy Patients Based on Integrated Bioinformatics Analyses

Background: Immunoglobulin A nephropathy (IgAN) is the most common type of primary glomerulonephritis worldwide and a frequent cause of end-stage renal disease. The inflammation cascade due to the infiltration and activation of immune cells in glomeruli plays an essential role in the progression of IgAN. In this study, we aimed to identify hub genes involved in immune infiltration and explore potential prognostic biomarkers and therapeutic targets in IgAN.

Methods: We combined the single-cell and bulk transcriptome profiles of IgAN patients and controls with clinical data. Through single-cell analysis and weighted gene co-expression network analysis (WGCNA), Gene Ontology (GO) enrichment analysis, and differentially expressed gene (DEG) analysis in the bulk profile, we identified cell-type-specific potential hub genes in IgAN. Real hub genes were extracted via validation analysis and clinical significance analysis of the correlation between the expression levels of genes and the estimated glomerular filtration rate (eGFR) in the external dataset. Gene set enrichment analysis was performed to predict the probable roles of the real hub genes in IgAN.

Results: A total of eleven cell clusters were classified via single-cell analysis, among which macrophages showed a variable proportion between the IgAN and normal control samples. We recognized six functional co-expression gene modules through WGCNA, among which the black module was deemed an IgAN-related and immune-involving module via GO enrichment analysis. DEG analysis identified 45 potential hub genes from genes enriched in GO terms. A total of twenty-three potential hub genes were specifically expressed in macrophages. Furthermore, we validated the differential expression of the 23 potential hub genes in the external dataset and identified nine genes with prognostic significance as real hub genes, viz., CSF1R, CYBB, FPR3, GPR65, HCLS1, IL10RA, PLA2G7, TYROBP, and VSIG4. The real hub gens are thought to contribute to immune cell regulation, immunoreaction, and regulation of oxidative stress, cell proliferation, and material metabolism.

Conclusion: In this study, we demonstrated that macrophages infiltrated the glomeruli and contributed to the inflammatory response in IgAN. Based on integrated bioinformatics analyses of single-cell and bulk transcriptome data, we highlighted nine genes as novel prognostic biomarkers, which may enable the development of innovative prognostic and therapeutic strategies for IgAN.