Comprehensive bioinformatics analysis reveals the crosstalk genes and immune relationship between the systemic lupus erythematosus and venous thromboembolism

Background

It is well known that patients with systemic lupus erythematosus (SLE) had a high risk of venous thromboembolism (VTE). This study aimed to identify the crosstalk genes between SLE and VTE and explored their clinical value and molecular mechanism initially.

Methods

We downloaded microarray datasets of SLE and VTE from the Gene Expression Omnibus (GEO) dataset. Differential expression analysis was applied to identify the crosstalk genes (CGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the shared genes. The shared diagnostic biomarkers of the two diseases were further screened from CGs using least absolute shrinkage and selection operator (Lasso) regression. Two risk scores for SLE and VTE were constructed separately to predict the likelihood of illness according to the diagnostic biomarkers using a logical regression algorithm. The immune infiltration levels of SEL and VTE were estimated via the CIBERSORT algorithm and the relationship of CGs with immune cell infiltration was investigated. Finally, we explored potential phenotype subgroups in SLE and VTE based on the expression level of CGs through the consensus clustering method and studied immune cell infiltration in different subtypes.

Result

A total of 171 CGs were obtained by the intersection of differentially expressed genes (DEGs) between SLE and VTE cohorts. The functional enrichment shown these CGs were mainly related to immune pathways. After screening by lasso regression, we found that three hub CGs (RSAD2, HSP90AB1, and FPR2) were the optimal shared diagnostic biomarkers for SLE and VTE. Based on the expression level of RSAD2 and HSP90AB1, two risk prediction models for SLE and VTE were built by multifactor logistic regression and systemically validated in internal and external validation datasets. The immune infiltration results revealed that CGs were highly correlated with multiple infiltrated immunocytes. Consensus clustering was used to respectively regroup SLE and VTE patients into C1 and C2 clusters based on the CGs expression profile. The levels of immune cell infiltration and immune activation were higher in C1 than in C2 subtypes.

Conclusion

In our study, we further screen out diagnostic biomarkers from crosstalk genes SLE and VTE and built two risk scores. Our findings reveal a close relationship between CGs and the immune microenvironment of diseases. This provides clues for further exploring the common mechanism and interaction between the two diseases.

Polymorphisms in Genes Involved in Inflammation and Periodontitis: A Narrative Review

Current evidence pinpoints that the variability in periodontitis traits in humans may be attributable to genetic factors. Different allelic variants can result in alterations in tissue structure, antibody responses and inflammatory mediators. Consequently, genetic variations may act as protective or risk factors for periodontal diseases. A number of features of the inflammatory and immune response that seem to play a role in the development of periodontitis have a clearly established genetic basis. Identifying genes that contribute to the pathogenesis of periodontitis may be utilized for risk assessment in both aggressive and chronic periodontitis. The aim of this narrative review is to summarize the role of polymorphisms in genes involved in inflammation and periodontitis, including cellular receptors, tissue compatibility antigens, antibodies and cytokines.

Annexin A1 and its receptor gene polymorphisms in systemic lupus erythematosus in the Tunisian population

BACKGROUND

An association between ANXA1, FPR1 and FPR2 gene polymorphisms and the patho-physiology of many human diseases was suggested by numerous studies.

OBJECTIVE

Our study aimed to evaluate association between common polymorphisms in the 9q21.13 and 19q13.41 and susceptibility to systemic lupus erythematosus (SLE) in the Tunisian population.

MATERIALS

We performed a case-control study on 107 Tunisian SLE patients and 122 healthy controls to explore 9 polymorphisms of the three studied genes: rs2811226 and rs3739959 (ANXA1), rs5030880, rs1042229, rs1461765570, rs17849971, rs867228 (FPR1), rs17694990 and rs11666254 (FPR2).

RESULTS

Four polymorphisms were found to be linked with SLE susceptibility: rs3739959-ANXA1 > G and GG (p = 0.021, OR = 1.73 and p = 0.014, OR = 2.06 respectively), rs867228-FPR1 > TT (p = 0.014, OR = 4.59), rs11666254-FPR2 > GG (p = 0.019, OR = 8.34) and rs17694990-FPR2 > T (p = 0.05, OR = 1.506). In homogenous groups of SLE patients depending on clinical manifestations and serological results, previous associations were confirmed with a panoply of manifestations of lupus including lupus nephritis, malar rash, mouth ulceration and hypocomplementia.

CONCLUSION

Our study showed an association between ANXA1 > rs3739959, FPR1 > rs867228, FPR2 > rs11666254, FPR2 > rs17694990 and SLE susceptibility. Our results also showed a strong association between the two ANXA1 studied SNPs and LN which allowed us to suggest these two SNPs as biomarkers of LN development in SLE. Further research is needed to understand by which mechanism the gene variants affect susceptibility to SLE. Key Points • Lupus erythematosus is an autoimmune disease in which a panoply of factors are implicated • Annexin A1 interaction with its receptors are suggested as a target in therapy of a panoply of human disease in particular cancers • The present results highlighted the implication of Annexin A1 and its receptors gene polymorphisms in the physiopathology of lupus, in particular in the involvement of renal and cutaneous lesions.

Formyl peptide receptor 2, as an important target for ligands triggering the inflammatory response regulation: a link to brain pathology

Formyl peptide receptors (FPRs) belong to the family of seven-transmembrane G protein-coupled receptors. Among them, FPR2 is a low affinity receptor for N-formyl peptides and is considered the most promiscuous member of FPRs. FPR2 is able to recognize a broad variety of endogenous or exogenous ligands, ranging from lipid to proteins and peptides, including non-formylated peptides. Due to this property FPR2 has the ability to modulate both pro- and anti-inflammatory response, depending on the nature of the bound agonist and on the different recognition sites of the receptor. Thus, FPR2 takes part not only in the proinflammatory response but also in the resolution of inflammation (RoI) processes. Recent data have indicated that the malfunction of RoI may be the background for some central nervous system (CNS) disorders. Therefore, much interest is focused on endogenous molecules called specialized pro-resolving mediators (SPMs), as well as on new synthetic FPR2 agonists, which kick-start the resolution of inflammation (RoI) and modulate its course. Here, we shed some light on the general characteristics of the FPR family in humans and in the experimental animals. Moreover, we present a guide to understanding the "double faced" action of FPR2 activation in the context of immune-related diseases of the CNS.

Peptides from allergenic lipocalins bind to formyl peptide receptor 3 in human dendritic cells to mediate TH2 immunity

BACKGROUND

How TH2-mediated allergic immune responses are induced is still under investigation.

OBJECTIVE

In an in vitro system we compared the effect of lipocalin allergens and nonallergenic homologues on human monocyte-derived dendritic cells (DCs) to investigate how they polarize naive CD4+ TH cells. Microarray data gained with these DCs showed a significant difference in expression of formyl peptide receptors (FPRs). Activation of FPR3 in human monocyte-derived DCs leads to inhibition of IL-12 production. Low concentrations of IL-12 during T-cell priming biases immune responses toward TH2. We hypothesize that binding of allergenic lipocalins to FPR3 might be a mechanism for induction of allergic immune responses.

METHODS

We examined whether lipocalins and FPR3 colocalize within the cells by using confocal microscopy. With calcium mobilization assays of FPR3-transfected HEK 293 cells, we measured FPR3 signaling in response to allergenic and nonallergenic lipocalins. Silencing of FPR3 in DCs and pretreatment with an antagonistic peptide were used to assess the function of FPR3 in TH2 induction.

RESULTS

FPR3 and lipocalins colocalize in the same vesicles in DCs. Cathepsin S-digested allergenic lipocalins, but not digestion products of nonallergenic homologues, activate FPR3 signaling. FPR3 silencing in DCs or pretreatment with an antagonistic peptide restores IL-12 and induces IL-10 expression by DCs treated with lipocalin allergens, attenuating the TH2 bias and inducing IL-10 production in cocultured TH cells.

CONCLUSION

We describe a novel molecular mechanism for induction of TH2-mediated allergic immune responses.

Periodontal tissue destruction in aggressive periodontitis: Determination of gene or environmental factors

Aim

This study observed the role of defective neutrophil function in aggressive periodontitis through FPR1 gene polymorphism and the level of Il-8 compared with the role of dental plaque presence towards periodontal tissue damage (Clinical Attachment Loss/CAL) in patients in Indonesia.

Methods

Case-control study was used to detect differences in polymorphism expression of FPR1 gene, the level of Il-8, dental plaque, and Clinical Attachment Loss/CAL from 32 Aggressive Periodontitis (AP) and 29 Non-Aggressive Periodontitis (NAP) samples, selected with consecutive sampling method. Polymorphism was identified using polymerase chain reaction (PCR) technique, and the level of IL-8 in the gingival crevicular fluid was identified using the enzyme-linked immunosorbent assay (ELISA) test. The Clinical Attachment Loss was analysed by using William periodontal probe, and the oral environment analysis was performed by using the OHI-S plaque index. Statistical analysis was used to determine the significance of the polymorphism difference of FPR gene, Il-8, Plaque and CAL amongst all subjects and also the control and correlations among these factors.

Results

The results showed that in the Aggressive Periodontitis (AP), the presence of the polymorphism of c576 T > C > G of FPR1 gene caused as much as 5.04 times higher occurrence of aggressive periodontitis (p = 0.006; OR = 5.040 (1.51–16.74)). The low level of Il-8 (below 0.064 pg/μl), showed as much as 34.5 times higher occurrence of aggressive periodontitis (OR = 34.5 (6.76–176.08)). The oral hygiene of the AP samples were better significantly (p = 0.002), and on the Clinical Attachment Loss (CAL) sample was even more (p = 0.02). The polymorphism of c301 G > C of FPR1 gene correlated with the CAL (r = 0.37; p = 0.039). The polymorphism of c576 T > C > G correlated significantly with the Il-8 (r = 0.5; p = 0.0287). The polymorphism of c348 T > C correlated significantly with the dental plaque (r = 0.355; p = 0.049), whereas the dental plaque correlation with CAL was not significant.

Conclusion

The research conclusion showed that in aggressive periodontitis, genetic and environmental factors were correlated with the cause of periodontal tissue injury, and the role of genetic factors was more prominent on the injury.

Formyl-Peptide Receptors in Infection, Inflammation, and Cancer

Formyl-peptide receptors (FPRs) recognize bacterial and mitochondrial formylated peptides as well as endogenous non-formylated peptides and even lipids. FPRs are expressed on various host cell types but most strongly on neutrophils and macrophages. After the discovery of FPRs on leukocytes, it was assumed that these receptors predominantly govern a proinflammatory response resulting in chemotaxis, degranulation, and oxidative burst during infection. However, it is clear that the activation of FPRs has more complex consequences and can also promote the resolution of inflammation. Recent studies have highlighted associations between FPR function and inflammatory conditions, including inflammatory disorders, cancer, and infection. In this review we discuss these recent findings.