Ficolin Gene Polymorphisms in Systemic Lupus Erythematosus and Rheumatoid Arthritis

Multi-omics evaluation of the prognostic value and immune signature of FCN1 in pan-cancer and its relationship with proliferation and apoptosis in acute myeloid leukemia

Background

The FCN1 gene encodes the ficolin-1 protein, implicated in the pathogenesis of various diseases, though its precise role in tumorigenesis remains elusive. This study aims to elucidate the prognostic significance, immune signature, and treatment response associated with FCN1 across diverse cancer types.

Methods

Employing multi-omics data, we conducted a comprehensive assessment, encompassing tissue-specific and single-cell-specific expression disparities, pan-cancer expression patterns, epigenetic modifications affecting FCN1 expression, and the immune microenvironment. Our investigation primarily focused on the clinical prognostic attributes, immune profiles, potential molecular mechanisms, and candidate therapeutic agents concerning FCN1 and acute myeloid leukemia (AML). Additionally, in vitro experiments were performed to scrutinize the impact of FCN1 knockdown on cell proliferation, apoptosis, and cell cycle dynamics within the AML cell line U937 and NB4.

Results

FCN1 expression exhibits widespread dysregulation across various cancers. Through both univariate and multivariate Cox regression analyses, FCN1 has been identified as an independent prognostic indicator for AML. Immunological investigations elucidate FCN1's involvement in modulating inflammatory responses within the tumor microenvironment and its correlation with treatment efficacy. Remarkably, the deletion of FCN1 influences the proliferation, apoptosis, and cell cycle dynamics of U937 cells and NB4 cells.

Conclusion

These findings underscore FCN1 as a promising pan-cancer biomarker indicative of macrophage infiltration, intimately linked with the tumor microenvironment and treatment responsiveness, and pivotal for cellular mechanisms within AML cell lines.

Selected SNPs of FCN2 Associated with Chronic Tonsillitis in the Polish Adult Population

Chronic tonsillitis is a problem related to bacterial and viral infections. Ficolins play a key role in the defence against various pathogens. In the present study, we investigated the associations between the selected single nucleotide polymorphisms (SNPs) of the FCN2 gene and chronic tonsillitis in the Polish population. The study included 101 patients with chronic tonsillitis and 101 healthy individuals. The selected SNPs of FCN2 (rs3124953, rs17514136 and rs3124954) were genotyped using TaqMan SNP Genotyping Assays (Applied Biosystem, Foster City, CA, USA). The analysis of rs17514136 and rs3124953 showed no significant differences in genotype frequencies between the chronic tonsillitis patients and controls (p > 0.01). The CT genotype of rs3124954 was significantly more frequent, while the CC genotype was less frequent in chronic tonsillitis patients (p = 0.003 and p = 0.001, respectively). The frequency of the A/G/T haplotype (rs17514136/rs3124953/rs3124954) was significantly more common in chronic tonsillitis patients (p = 0.0011). Moreover, the FCN2 CT genotype of rs3124954 was associated with a higher risk of chronic tonsillitis, while the CC genotype of rs3124954 decreased this risk. Our findings demonstrate that FCN2 rs3124954 may be associated with chronic tonsillitis in the Polish adult population.

Effect of Polymorphisms in the FCN1, FCN2, and FCN3 Genes on the Susceptibility to Develop Rheumatoid Arthritis: A Systematic Review

Genetic association studies in rheumatoid arthritis conducted in various populations have yielded heterogeneous results. The present systematic review was conducted to synthesize the results of the studies in order to establish the impact of polymorphisms in the ficolin-coding genes FCN1, FCN2, and FCN3 on the susceptibility to develop rheumatoid arthritis. A systematic literature review was performed using the following keywords "gene (FCN1/FCN2/FCN3)", "Polymorphism/Genetic Variant", and "rheumatoid arthritis" in different databases until January 2022. Authors assessed articles by title/abstract and then assessed by full text for data extraction. The risk of bias was assessed using the Newcastle-Ottawa scale. Data synthesis was performed qualitatively and quantitatively. A total of 1519 articles were eligible for inclusion in this review, 3 were identified as relevant for the quantitative synthesis with 670 patients and 1019 controls. For the FCN1 gene, an association was found in the dominant and recessive genetic models of the variants rs2989727 (genotype TT = OR: 0.577, 95% CI: 0.430-0.769) and rs1071583 (genotype GG = OR: 1.537, 95% CI: 1.153-2.049, p = 0.0032) with the development of rheumatoid arthritis as a protective or susceptibility factor. FCN2 and FCN3 genes did not show association with disease development. The FCN1 gene variants rs2989727 and rs1071583 are associated with the risk of developing rheumatoid arthritis in populations from Brazil and Belgium, but not in FCN2 and FCN3 gene variants.

FCN1 polymorphisms are not the markers of dental caries susceptibility in Polish children: A case-control study

OBJECTIVE

To examine the association of four FCN1 SNPs: -542G>A (rs10120023), -144C>A (rs10117466), +6658C>T (rs148649884), and +7895A>G (rs150625869) with dental caries in Polish children.

SUBJECTS AND METHODS

The study group consisted of 261 15-year-old Polish teenagers: 82 children with "higher" caries experience (having Decayed Missing Filled Teeth, DMFT >5) and 179 children with "lower" caries experience (having DMFT ≤5). Moreover, in additional comparison, a group of 229 children with caries experience (DMFT ≥1) was compared to a caries-free (DMFT =0) group of 32 children. Extraction of genomic DNA was performed from buccal swabs, and genotyping was performed by Real-Time PCR.

RESULTS

FCN1 SNPs +6658C>T and +7895A>G appeared to be monomorphic in our sample. The genotype, allele, or haplotype distributions in FCN1 SNPs -542G>A and -144C>A in children with "higher" caries experience did not differ significantly from those in "lower" caries experience group. Similar results with no significant differences were demonstrated for subjects with DMFT ≥1 compared to subjects with DMFT =0.

CONCLUSION

FCN1 SNPs are not the markers of dental caries susceptibility in Polish children.

Pattern Recognition Molecules of Lectin Complement Pathway in Ischemic Stroke

Purpose

The current study aimed to investigate in an Armenian population the levels of pattern recognition molecules (PRMs) of lectin complement pathway (LCP), MBL (mannan-binding lectin) and M-ficolin in plasma in ischemic stroke (IS), and the possible association of 11 single nucleotide polymorphisms (SNPs) in MBL2, FCN1 and FCN2 genes.

Patients and Methods

A total of 122 patients with IS and 150 control subjects were included in this study. Immunofluorometric assays (TRIFMAs) and real-time polymerase chain reactions with TaqMan probes were conducted.

Results

According to the results, the levels of M-ficolin in IS patients are significantly higher than in control subjects, and the MBL2 rs11003125 and rs12780112 SNPs, as well as MBL2 rs12780112*T and FCN1 rs10120023*T minor alleles (MAs) are negatively associated with the risk of IS. Further, MBL2 rs11003125 and rs1800450 SNPs and the carriage of their MAs, as well as FCN1 rs2989727 SNP and the carriage of FCN1 rs10120023*T MA significantly alter plasma MBL and M-ficolin levels in IS patients, respectively. Five common haplotypes in MBL2 gene and three common haplotypes in FCN1 and FCN2 genes were revealed, among which CGTC was negatively associated with IS and decreasing MBL plasma levels in IS.

Conclusion

In conclusion, we suggest that LCP PRMs are associated with the risk of developing IS, and may also participate in pathological events leading to post-ischemic brain damage. This study emphasizes the important contribution of alterations of LCP PRMs on genomic and proteomic levels to the pathomechanisms of ischemic stroke, at least in an Armenian population.

Association of ficolin-1 and ficolin-3 gene variation and pulmonary tuberculosis susceptibility in a Chinese population

BACKGROUND

The aim of our study was to estimate the association of ficolin-1 (FCN1) gene (rs10120023, rs1071583) and ficolin-3 (FCN3) gene (rs3813800, rs10794501) polymorphisms and pulmonary tuberculosis (PTB) susceptibility, as well as their several clinical features, in a Chinese population.

METHODS

This study included a cohort of 489 PTB patients and 489 healthy controls, and the four SNPs were genotyped by improved multiple ligase detection reaction (iMLDR).

RESULTS

We found that there were no significant differences regarding the allele and genotype frequencies of FCN1 rs10120023, rs1071583 and FCN3 rs3813800, rs10794501 between PTB patients and healthy controls (all p > 0.05). The association of three main haplotypes (CC, CT, and TC) in FCN1 and three main haplotypes (CT, GA, and GT) in FCN3 with PTB susceptibility was also analyzed, and no significant association was detected (all p > 0.05). In FCN1, the rs1071583 TT genotype was significantly associated with the occurrence of drug resistance in PTB patients (p = 0.040). In addition, the GG genotype and G allele frequencies of rs3813800 in FCN3 gene were significantly higher in PTB patients with pulmonary infection (p = 0.027, p = 0.020, respectively).

CONCLUSIONS

FCN1 and FCN3 genetic variation were not contributed to the pathogenesis of PTB in Chinese. While rs1071583 and rs3813800 variant might associate with several clinical characteristics of PTB.

The clinical value of ficolin-3 gene polymorphism in rheumatic heart disease. An Egyptian adolescents study

OBJECTIVE

Ficolin-3 is one of the innate immunity molecules that was thought to play a pivotal role in Streptococcus pyogenes autoimmunity and its complications; rheumatic fever (RF) and rheumatic heart disease (RHD). We aimed to disclose if there is an association between ficolin-3 (FCN3) gene polymorphisms (rs4494157 and rs10794501) and RF with or without RHD for the first time in Egyptian adolescents.

RESULTS

Serum ficolin-3 level was significantly elevated in patients suffering from RF with and without RHD in comparison with control. Regarding FCN3 gene (rs4494157) polymorphism, a significant correlation was found between the A allele and the susceptibility to RF with or without RHD (OR = 2.93, P = 0.0002 and OR = 2.23, P = 0.008 respectively). Besides, AA homozygous genotype showed a significant association with RHD risk (OR = 3.47, P = 0.026). Patients carrying the A allele (CA + AA) had significantly higher serum ficolin-3 than those carrying the CC genotype (P ˂ 0.0001). While the frequency of (rs10794501) polymorphism revealed no significant differences between the controls and RF patients with or without RHD (OR = 1.43, P = 0.261 and OR = 1.48, P = 0.208 respectively).

Emerging role of ficolins in autoimmune diseases

Ficolins are pattern-recognition molecules (PRMs) that could form complexes with mannose-binding lectin-associated serine proteases (MASPs) to trigger complement activation via the lectin pathway, thereby mediating a series of immune responses including opsonization, phagocytosis and cytokine production. In the past few decades, accumulating evidence have suggested that ficolins play a major role in the onset and development of several autoimmune diseases (ADs), including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), Type 1 diabetes (T1D), inflammatory bowel disease (IBD), etc. In this review, we synthesized previous literatures and recent advances to elucidate the immunological regulations of ficolins and discuss the potential diagnostic ability of ficolins in ADs, as well as giving an insight into the future therapeutic options for ficolins in ADs.

Current, New and Future Therapeutic Targets in Inflammatory Bowel Disease: A Systematic Review

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic relapsing conditions resulting from immune system activity in a genetically predisposed individual. IBD is based on progressive damage to the inflamed gut tissue. As its pathogenesis remains unknown, recent accumulating data have demonstrated that IBD is a complex and multi-factorial disorder correlated with host luminal factors, which lead to an imbalance between pro- and anti-inflammatory signaling. The growing understanding of the molecular mechanisms responsible for IBD has suggested a wide range of potential therapeutic targets to treat this condition. Some patients do not have a satisfactory response to current therapeutic medications such as antitumor necrosis factor (TNF) agents, or their response decreases over time. As a result, IBD therapeutics have been changed recently, with several new agents being evaluated. The identification of various inflammatory cascades has led to forming the idea to have novel medications developed. Medications targeting Janus kinases (JAK), leukocyte trafficking Interleukin (IL) 12/23, and Sphingosine 1 phosphate (S1P) are among these newly developed medications and highlight the role of microbial-host interaction in inflammation as a safe promising strategy. This systematic review aims to summarize different molecular targeting therapeutics, the most potent candidates for IBD treatment in recent studies.

Ficolin-1 and ficolin-3 polymorphisms and susceptibility to rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease, which compromises the synovial membrane resulting in chronic inflammation. Ficolins are key proteins of the lectin pathway of complement able to recognize pathogen-associated molecular patterns, apoptotic cells, and cellular debris mediating the clearance by phagocytes. High ficolin-1 and ficolin-3 levels have been observed in RA patients, however, the influence of polymorphisms in the FCN1 gene in RA is not completely established, while no study evaluated FCN3 gene polymorphisms in RA to date. We investigated the influence of FCN1 and FCN3 gene polymorphisms in the susceptibility and clinical presentation of RA. A total of 148 patients with RA and up to 160 controls from Southern Brazil were genotyped by sequence-specific PCR (PCR-SSP) for five FCN1 promoter polymorphisms (rs2989727, rs10120023, rs17039495, rs10117466, and rs10858293) and three FCN3 gene variants (rs532781899, rs28362807, and rs4494157). The FCN1 g.-542GG (rs10120023) genotype and g.-542G allele, were associated with increased susceptibility to RA (p = .025, OR = 1.69 [1.07-2.69]; p = .041, OR = 1.47 [1.02-2.12], respectively) and related to decreased FCN1 gene expression in whole blood (p < .00001), according to gene expression databases. In addition, the FCN1 AAGAG haplotype was more prevalent in rheumatoid factor seronegative in comparison to seropositive patients (p = .006, OR = 0.042 [0.002-0.80]). There was no association of FCN3 polymorphisms with the susceptibility or clinical characteristics of RA. Our results indicate that the FCN1 rs10120023 [g.-542G>A] polymorphism in the promoter region might contribute to RA susceptibility, probably by impacting FCN1 gene expression.

An update on genetic susceptibility in lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multiple system involvement and positive serum autoantibodies. Lupus nephritis (LN) is the most common and serious complication of SLE, and it is the main cause of death in patients with SLE. Abnormalities in the immune system lead to LN and involve a variety of cells (T cells, B cells, macrophages, NK cells, etc.), cytokines (interleukin, tumor necrosis factor α, etc.) and their related pathways. Previous studies have shown that the interactions of genetic, epigenetic and environmental factors contribute to the pathogenesis and development of LN. In recent years, one genome-wide association study (GWAS) and a number of gene association studies have explored the susceptibility genes of LN, including immunization-, inflammation-, adhesion- and other pathway-related genes. These genes participate in or suggest the pathogenesis and progression of LN. In this review, we summarize the genetic susceptibility of LN and discuss the possible mechanism underlying the susceptibility genes of LN.

An update on genetic susceptibility in lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multiple system involvement and positive serum autoantibodies. Lupus nephritis (LN) is the most common and serious complication of SLE, and it is the main cause of death in patients with SLE. Abnormalities in the immune system lead to LN and involve a variety of cells (T cells, B cells, macrophages, NK cells, etc.), cytokines (interleukin, tumor necrosis factor α, etc.) and their related pathways. Previous studies have shown that the interactions of genetic, epigenetic and environmental factors contribute to the pathogenesis and development of LN. In recent years, one genome-wide association study (GWAS) and a number of gene association studies have explored the susceptibility genes of LN, including immunization-, inflammation-, adhesion- and other pathway-related genes. These genes participate in or suggest the pathogenesis and progression of LN. In this review, we summarize the genetic susceptibility of LN and discuss the possible mechanism underlying the susceptibility genes of LN.

Association of ficolin-2 gene polymorphisms and susceptibility to systemic lupus erythematosus in Egyptian children and adolescents: a multicenter study

BACKGROUND

Pediatric-onset SLE (pSLE) is a multisystem autoimmune disease. Recently, the ficolin-2 (FCN2) gene has emerged as a potential candidate gene for susceptibility to SLE.

OBJECTIVES

The objective of this study was to evaluate the association of the FCN2 gene polymorphisms at positions -986 (G/A), -602 (G/A), -4 (A/G) and SNP C/T (rs3124954) located in intron 1, with susceptibility to pSLE in Egyptian children and adolescents.

METHODS

This was a multicenter study of 280 patients diagnosed with pSLE, and 280 well-matched healthy controls. The FCN2 promoter polymorphisms at -986 G/A (rs3124952), -602 G/A (rs3124953), -4 A/G (rs17514136) and SNP C/T (rs3124954) located in intron 1 were genotyped by polymerase chain reaction, while serum ficolin-2 levels were assessed using enzyme-linked immunosorbent assay.

RESULTS

The frequencies of the FCN2 GG genotype and G allele at -986 and -602 positions were significantly more represented in patients with pSLE than in controls (p < 0.001). Conversely, the FCN2 AA genotype and A allele at position -4 were more common in patients than in controls (p < 0.001). Moreover, patients carrying the FCN2 GG genotype in -986 position were more likely to develop lupus nephritis (odds ratio: 2.6 (95% confidence interval: 1.4-4.78); p = 0.006). The FCN2 AA genotype at position -4 was also identified as a possible risk factor for lupus nephritis (odds ratio: 3.12 (95% confidence interval: 1.25-7.84); p = 0.024).

CONCLUSION

The FCN2 promoter polymorphisms may contribute to susceptibility to pSLE in Egyptian children and adolescents. Moreover, the FCN2 GG genotype at position -986 and AA genotype at position -4 were associated with low serum ficolin-2 levels and may constitute risk factors for lupus nephritis in pSLE.

Sickening or Healing the Heart? The Association of Ficolin-1 and Rheumatic Fever

Rheumatic fever (RF) and its subsequent progression to rheumatic heart disease (RHD) are chronic inflammatory disorders prevalent in children and adolescents in underdeveloped countries, and a contributing factor for high morbidity and mortality rates worldwide. Their primary cause is oropharynx infection by Streptococcus pyogenes, whose acetylated residues are recognized by ficolin-1. This is the only membrane-bound, as well as soluble activator molecule of the complement lectin pathway (LP). Although LP genetic polymorphisms are associated with RF, FCN1 gene's role remains unknown. To understand this role, we haplotyped five FCN1 promoter polymorphisms by sequence-specific amplification in 193 patients (138 with RHD and 55, RF only) and 193 controls, measuring ficolin-1 serum concentrations in 78 patients and 86 controls, using enzyme-linked immunosorbent assay (ELISA). Patients presented lower ficolin-1 serum levels (p < 0.0001), but did not differ according to cardiac commitment. Control's genotype distribution was in the Hardy-Weinberg equilibrium. Four alleles (rs2989727: c.-1981A, rs10120023: c.-542A, rs10117466: c.-144A, and rs10858293: c.33T), all associated with increased FCN1 gene expression in whole blood or adipose subcutaneous tissue (p = 0.000001), were also associated with increased protection against the disease. They occur within the *3C2 haplotype, associated with an increased protection against RF (OR = 0.41, p < 0.0001) and with higher ficolin-1 levels in patient serum (p = 0.03). In addition, major alleles of these same polymorphisms comprehend the most primitive *1 haplotype, associated with increased susceptibility to RF (OR = 1.76, p < 0.0001). Nevertheless, instead of having a clear-cut protective role, the minor c.-1981A and c.-144A alleles were also associated with additive susceptibility to valvar stenosis and mitral insufficiency (OR = 3.75, p = 0.009 and OR = 3.37, p = 0.027, respectively). All associations were independent of age, sex or ethnicity. Thus, minor FCN1 promoter variants may play a protective role against RF, by encouraging bacteria elimination as well as increasing gene expression and protein levels. On the other hand, they may also predispose the patients to RHD symptoms, by probably contributing to chronic inflammation and tissue injury, thus emphasizing the dual importance of ficolin-1 in both conditions.

Autoantibodies Targeting Ficolin-2 in Systemic Lupus Erythematosus Patients With Active Nephritis

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multisystem inflammatory disease characterized by the production of various autoantibodies. The aim of this study was to investigate the presence of anti-ficolin-2 antibodies in SLE patients and to evaluate the association between the levels of these autoantibodies, clinical manifestations, and disease activity.

METHODS

This is a comparative study using a cohort of 165 SLE patients and 48 healthy subjects. SLE patients were further divided into 2 groups (low disease activity [SLE Disease Activity Index (SLEDAI) score ≤4, n = 88] and high disease activity [SLEDAI score >4, n = 77]). Clinical manifestations were defined according to the physician in charge. Active lupus nephritis (LN) was documented by kidney biopsy. Detection of anti-ficolin-2 antibodies was performed by enzyme-linked immunosorbent assay.

RESULTS

Levels of anti-ficolin-2 autoantibodies were significantly higher in SLE patients as compared to healthy subjects and associated with SLEDAI score. They were found to be positive in 61 of 165 SLE patients (37%). The presence of anti-ficolin-2 antibodies was significantly related only to renal involvement, with a very high prevalence (86%) of anti-ficolin-2 antibodies in SLE patients with active LN. Patients with active proliferative LN had significantly more positive anti-ficolin-2 antibodies than those with nonproliferative LN. The combination of anti-ficolin-2, anti-ficolin-3, and anti-C1q demonstrated a very high specificity (98%) for the diagnosis of active LN.

CONCLUSION

Our results support the usefulness of anti-ficolin-2 as a complementary serologic biomarker for the diagnosis of active lupus with renal manifestations.

Lectin pathway factors in patients suffering from juvenile idiopathic arthritis

Both complement activation and certain infections (including those with Yersinia sp.) may contribute to the pathogenesis of juvenile idiopathic arthritis (JIA). We investigated factors specific for the lectin pathway of complement: mannose-binding lectin (MBL), ficolins and MBL-associated serine protease-2 (MASP-2), in 144 patients and 98 controls. One hundred and six patients had oligoarticular disease and 38 had polyarticular disease. In 51 patients (out of 133 tested), Yersinia-reactive antibodies were found (JIA Ye+ group). MBL deficiency was significantly more frequent in the JIA Ye+ group than in patients without Yersinia-reactive antibodies or in controls. Median serum ficolin-2 level was significantly lower (and proportion of values deemed ficolin-2 insufficient greater) in JIA patients irrespective of their Yersinia antibody status. The minority (C) allele at -64 of the FCN2 gene was less frequent among JIA patients than among control subjects. No differences were found in the frequency of FCN3 gene +1637delC or MASP2 +359 A>G mutations nor for median values of serum ficolin-1, ficolin-3 or MASP-2. However, high levels of serum ficolin-3 were under-represented in patients, in contrast to MBL. MBL, ficolin-1, ficolin-2, ficolin-3 and MASP-2 were also readily detectable in synovial fluid samples but at a considerably lower level than in serum. Our findings suggest a possible role for the lectin pathway in the pathogenesis of JIA, perhaps secondary to a role in host defence, and indicate that investigations on the specificity of lectin pathway recognition molecules towards specific infectious agents in JIA might be fruitful.

Plasma ficolin levels and risk of nephritis in Danish patients with systemic lupus erythematosus

Given the scavenging properties of ficolins, we hypothesized that variation in the plasma concentrations of the three ficolins may be associated with development of lupus nephritis (LN), type of LN, end-stage renal disease (ESRD), and/or mortality among patients with systemic lupus erythematosus (SLE). SLE patients attending a Danish tertiary rheumatology referral center were included. Plasma concentrations of ficolin-1, ficolin-2, and ficolin-3 were determined and dichotomized by the median into high and low. LN was defined by clinical criteria; type of LN by renal biopsy; ESRD follow-up time was defined as time from onset of LN to the development of ESRD or censoring at the end of follow-up. The study included 112 SLE patients with median disease duration of 8 years of which 53 (47%) had LN at the time of inclusion. During a median follow-up of 10 years, five patients developed ESRD. Sixteen patients died. Odds ratios (ORs) of LN were 1.2 (95% CI: 0.6-2.7), 4.1 (95% CI: 1.7-9.7), and 0.9 (95% CI: 0.4-2.0) for patients with low ficolin-1, ficolin-2, and ficolin-3 plasma levels, respectively. The distribution of histological classes differed between patients with high and low plasma levels of ficolin-1 (p = 0.009). Patients with high ficolin-1 plasma levels had an increased risk of ESRD. There was no association between the levels of the analyzed plasma ficolins and mortality. Low plasma ficolin-2 levels were associated with an increased risk of having LN. High plasma levels of ficolin-1 were associated with the histological subtype of LN and development of ESRD.