Gene polymorphisms of LGALS2, LGALS3 and LGALS9 in patients with rheumatoid arthritis

A study of the association between Galectin-9 gene (LGALS9) polymorphisms and rheumatoid arthritis in Egyptian patients

Background

Rheumatoid arthritis (RA) is an incessant synovial inflammation of an autoimmune origin, destroying articular cartilages and bones. Galectins are an evolutionarily conserved family of immune-modulatory animal lectins detected in a number of immune cells like T cells, fibroblasts and macrophages. Galectin 9 (Gal-9) has been the subject of many studies for being linked to regulation of both innate and adaptive immune reactions. The objective of the study was to evaluate the link between the Galectin-9 gene (LGALS9) polymorphisms and the susceptibility of RA in Egyptian patients, as well as, detection of the serum level of Gal-9 in RA and its association with LGALS9 polymorphisms, the activity of RA and radiological damage.

Methods

A study of 85 participants; group (I): 60 RA cases and group (II): 25 apparently healthy subjects. RA Disease activity index (DAS-28) and Larsen index score were assessed. LGALS9 gene and serum Gal-9 were investigated.

Results

rs4239242 TT genotype and T allele occurred more frequently in RA cases than controls with a significant difference (P = 0.006; P < 0.001 respectively). Gal-9 level was significantly higher among RA cases than control group (P = 0.017). The Gal-9 level showed negative significant correlations with DAS-28 and Larsen score (P < 0.001).

Conclusion

RA is strongly linked to genetic alterations in the LGALS9 gene and the single nucleotide polymorphism (SNP) rs4239242 TT genotype in the Egyptian population. RA cases in remission or those with low disease activity had higher levels of serum Gal-9 in comparison to cases with moderate and high disease activity and this would be promising in the future of RA treatment.

Associations between urinary phthalate metabolite concentrations and rheumatoid arthritis in the U.S. adult population

Phthalates are ubiquitous environmental contaminants. Nevertheless, limited data is available about the impacts of phthalates on rheumatoid arthritis (RA). The purpose of this study was to use National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2018 to assess the individual and combined effects of exposure to phthalate mixtures on RA in adults. A total of 8240 participants with complete data participated in the study, of whom 645 had RA. The levels of ten phthalate metabolites were detected in urine samples. In the single-pollutant models, independent associations were identified between urinary mono-(carboxyoctyl) phthalate (MCOP), mono-(3-carboxylpropyl) phthalate (MCPP), mono-isobutyl phthalate (MiBP) and mono-benzyl phthalate (MBzP) with the incidence of RA. The results of multi-pollutant models, including weighted quantile sum (WQS) regression, quantile-based g computation (qgcomp), and Bayesian kernel machine regression (BKMR) approaches consistently revealed that co-exposure to phthalates was positively associated with RA incidence. Such association was more pronounced in adults over 60 years of age, where MCOP was identified as the dominant positive driver. Overall, our findings add novel evidence that co-exposures to phthalates might be positively associated with RA incidence. Given the limitations of the NHANES study, well-designed longitudinal studies are required to verify or disprove these results.

The Variations' in Genes Encoding TIM-3 and Its Ligand, Galectin-9, Influence on ccRCC Risk and Prognosis

Renal cell cancer is the most common type of kidney cancer in adults, and clear cell renal cell carcinoma (ccRCC) is the most diagnosed type. T cell immunoglobulin and mucin-domain-containing-3 (TIM-3) belongs to immunological checkpoints that are key regulators of the immune response. One of the known TIM-3 ligands is galectin-9 (LGALS9). A limited number of studies have shown an association between TIM-3 polymorphisms and cancer risk in the Asian population; however, there is no study on the role of LGALS9 polymorphisms in cancer. The present study aimed to analyze the influence of TIM-3 and LGALS9 polymorphisms on susceptibility to ccRCC and patient overall survival (OS), with over ten years of observations. Using TaqMan probes, ARMS-PCR, and RFPL-PCR, we genotyped two TIM-3 single-nucleotide polymorphisms (SNPs): rs1036199 and rs10057302, and four LGALS9 SNPs: rs361497, rs3751093, rs4239242, and rs4794976. We found that the presence of the rs10057302 A allele (AC + AA genotypes) as well as the rs4794976 T allele (GT + TT genotypes) decreased susceptibility to ccRCC by two-fold compared to corresponding homozygotes. A subgroup analysis showed the association of some SNPs with clinical features. Moreover, TIM-3 rs1036199 significantly influenced OS. Our results indicate that variations within TIM-3 and LGALS9 genes are associated with ccRCC risk and OS.

Exploring the molecular mechanisms and shared gene signatures between rheumatoid arthritis and diffuse large B cell lymphoma

The relationship between rheumatoid arthritis (RA) and diffuse large B-cell lymphoma (DLBCL) is well characterized, but the molecular mechanisms underlying this association have not been clearly investigated. Our study aimed to identify shared gene signatures and molecular mechanisms between RA and DLBCL. We selected multiple Gene Expression Omnibus (GEO) datasets (GSE93272, GSE83632, GSE12453, GSE1919) to obtain gene expression levels and clinical information about patients with RA and DLBCL. Weighted gene co-expression network analysis (WGCNA) was used to research co-expression networks associated with RA and DLBCL. Subsequently, we performed enrichment analysis of shared genes and screened the most significant core genes. We observed expression of the screened target gene, galectin 2 (LGALS2), in DLBCL patients and its impact on patient prognosis. Finally, we analyzed the molecular functional mechanism of LGALS2 and observed its relationship with the immune response in DLBCL using single-sample Gene Set Enrichment Analysis (ssGSEA). WGCNA recognized two major modules for RA and DLBCL, respectively. Shared genes (551) were identified for RA and DLBCL by observing the intersection. In addition, a critical shared gene, LGALS2, was acquired in the validation tests. Next, we found that the expression level of LGALS2 gradually decreased with tumor progression in DLBCL and that increased expression of LGALS2 predicted a better prognosis for DLBCL patients. ssGSEA revealed that LGALS2 is involved in immune-related pathways and has a significant regulatory effect on human immune responses. Additionally, we observed that LGALS2 is closely related to the sensitivity of multiple chemotherapeutic drugs. There is extremely little research on the molecular mechanism of correlation between RA and DLBCL. Our study identified that LGALS2 is a potential therapeutic target and an immune-related biomarker for patients with RA and DLBCL.

Galectin-3 protects auditory function in female mice

Sex differences in the development of sensorineural hearing loss have been recognized in various inner ear disorders, but the molecular basis for such differences is poorly understood. Autosomal genes have been shown to cause sex differences in disease susceptibility, but many genes exerting sex-dependent effects on auditory function remain to be identified. Galectin-3 (Gal-3), a protein encoded by the autosomal gene Lgals3, is a member of the β-galactoside-binding protein family, and has been linked to multiple biological processes, including immune responses, apoptosis, and cell adhesion. Here, we investigated auditory function and hair cell integrity in Gal-3 knockout (KO, Lgals3^-/-) and wild-type (WT, Lgals3^+/+) mice from age 1 to 6 months. KO mice show a more rapid age-related increase in ABR thresholds compared to WT mice. Noticeably, the threshold deterioration in female KO mice is significantly greater than in the male KO and WT mice. The ABR threshold elevation manifests over a broad frequency range in female KO mice, whereas the threshold elevations are confined to high frequencies in the male KO and WT mice. Moreover, DPOAE input/output functions reveal a similar pattern of auditory dysfunction, with the female KO mice displaying a significantly greater reduction in DPOAE amplitudes than male KO mice and WT mice of both sexes. Finally, age-related outer hair cell loss is greater for female KO mice compared to male KO mice and WT mice of both sexes. Together, these results indicate that Gal-3 deficiency exacerbates age-related cochlear degeneration and auditory dysfunction in female mice. Our study identifies Gal-3 as a sex-dependent molecule for maintaining female cochlear integrity.

Revealing the Immune Heterogeneity between Systemic Lupus Erythematosus and Rheumatoid Arthritis Based on Multi-Omics Data Analysis

The pathogenesis of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are greatly influenced by different immune cells. Nowadays both T-cell receptor (TCR) and B-cell receptor (BCR) sequencing technology have emerged with the maturity of NGS technology. However, both SLE and RA peripheral blood TCR or BCR repertoire sequencing remains lacking because repertoire sequencing is an expensive assay and consumes valuable tissue samples. This study used computational methods TRUST4 to construct TCR repertoire and BCR repertoire from bulk RNA-seq data of both SLE and RA patients’ peripheral blood and analyzed the clonality and diversity of the immune repertoire between the two diseases. Although the functions of immune cells have been studied, the mechanism is still complicated. Differentially expressed genes in each immune cell type and cell–cell interactions between immune cell clusters have not been covered. In this work, we clustered eight immune cell subsets from original scRNA-seq data and disentangled the characteristic alterations of cell subset proportion under both SLE and RA conditions. The cell–cell communication analysis tool CellChat was also utilized to analyze the influence of MIF family and GALECTIN family cytokines, which were reported to regulate SLE and RA, respectively. Our findings correspond to previous findings that MIF increases in the serum of SLE patients. This work proved that the presence of LGALS9, PTPRC and CD44 in platelets could serve as a clinical indicator of rheumatoid arthritis. Our findings comprehensively illustrate dynamic alterations in immune cells during pathogenesis of SLE and RA. This work identified specific V genes and J genes in TCR and BCR that could be used to expand our understanding of SLE and RA. These findings provide a new insight inti the diagnosis and treatment of the two autoimmune diseases.

Association of Growth and Differentiation Factor 15 in Rheumatoid Arthritis

Purpose

Rheumatoid arthritis (RA) is an inflammatory rheumatic disease, which has been demonstrated to correlate with mutated genetics. Growth and differentiation factor 15 (GDF-15) is a member of the transforming growth factor-β superfamily and is expressed in different organs, tissues and immune cells. To date, limited studies have evaluated plasma levels of GDF-15 in RA patients, and whether GDF-15 gene polymorphisms correlate with RA risk in the Chinese Han population has not been clarified.

Patients and Methods

This case-control study recruited 910 age- and sex-matched RA patients and healthy controls. Plasma levels of GDF-15 were examined by enzyme linked immunosorbent assay, and polymorphisms (rs1055150, rs1058587, rs3787023, and rs4808793) were genotyped by KASP method.

Results

RA patients had higher levels of GDF-15 as compared to that in healthy controls. Patients with positive CRP also showed higher levels of GDF-15 when compared to that in patients with negative CRP. Levels of GDF-15 correlated with disease activity score. Frequencies of GG, GC, GG+GC genotypes and G allele in GDF-15 gene rs1058587 were significantly elevated in RA patients compared to controls. Frequencies of CC genotype and C allele in GDF-15 gene rs3787023 were higher in RA patients compared to controls. Other polymorphisms did not correlate with RA susceptibility. Moreover, the four polymorphisms were not correlated with levels of GDF-15.

Conclusion

Plasma levels of GDF-15 were elevated in RA patients and GDF-15 gene polymorphisms were related to RA risk in the Chinese Han population.

Galectin-9 Regulates Monosodium Urate Crystal-Induced Gouty Inflammation Through the Modulation of Treg/Th17 Ratio

Gout is caused by depositing monosodium urate (MSU) crystals within the articular area. The infiltration of neutrophils and monocytes drives the initial inflammatory response followed by lymphocytes. Interestingly, emerging evidence supports the view that in situ imbalance of T helper 17 cells (Th17)/regulatory T cells (Treg) impacts the subsequent damage to target tissues. Galectin-9 (Gal-9) is a modulator of innate and adaptive immunity with both pro- and anti-inflammatory functions, dependent upon its expression and cellular location. However, the specific cellular and molecular mechanisms by which Gal-9 modulates the inflammatory response in the onset and progression of gouty arthritis has yet to be elucidated. In this study, we sought to comprehensively characterise the functional role of exogenous Gal-9 in an in vivo model of MSU crystal-induced gouty inflammation by monitoring in situ neutrophils, monocytes and Th17/Treg recruited phenotypes and related cyto-chemokines profile. Treatment with Gal-9 revealed a dose-dependent reduction in joint inflammation scores, knee joint oedema and expression of different pro-inflammatory cyto-chemokines. Furthermore, flow cytometry analysis highlighted a significant modulation of infiltrating inflammatory monocytes (CD11b⁺/CD115⁺/LY6-C^hi) and Th17 (CD4⁺/IL-17⁺)/Treg (CD4⁺/CD25⁺/FOXP-3⁺) cells following Gal-9 treatment. Collectively the results presented in this study indicate that the administration of Gal-9 could provide a new therapeutic strategy for preventing tissue damage in gouty arthritic inflammation and, possibly, in other inflammatory-based diseases.