Evaluation of apoptosis-related gene Fas (CD95) and FasL (CD178) polymorphisms in Iranian rheumatoid arthritis patients

Association between FAS gene -670 A/G and -1377 G/A polymorphisms and the risk of autoimmune diseases: a meta-analysis

Objectives: FAS plays a critical role in the extrinsic apoptosis pathway in autoimmune diseases. Previous studies investigating the association between FAS gene −670 A/G and −1377 G/A polymorphisms and the risk of autoimmune diseases reported controversial results. We performed the meta-analysis to evaluate the possible association. Methods: Relevant studies were identified by searching the PubMed, Embase, CNKI, and Wanfang databases up to December 2018. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to determine the association. Results: A total of 43 articles including 67 studies (52 studies for FAS −670 A/G and 15 studies for −1377 G/A) were included in the meta-analysis. Our meta-analysis showed that the FAS −670 A/G polymorphism was associated with the risk of autoimmune diseases (GG vs. GA: OR = 1.079, 95% CI = 1.004–1.160, P=0.038), especially in Caucasians (GG vs. GA: OR = 1.12, 95% CI = 1.03–1.23, P=0.012), Asians (G vs. A: OR = 0.89, 95% CI = 0.83–0.96, P=0.002), systemic lupus erythematosus (SLE) (G vs. A: OR = 0.85, 95% CI = 0.77–0.94, P=0.001), multiple sclerosis (MS) (GG+GA vs. AA: OR = 0.83, 95% CI = 0.70–0.99, P=0.043), systemic sclerosis (SSc) (GG vs. GA: OR = 1.20, 95% CI = 1.07–1.36, P=0.003) and Hashimoto’s thyroiditis (HT) (G vs. A: OR = 1.45, 95% CI = 1.10–1.90, P=0.008); the FAS −1377 G/A polymorphism was associated with the risk of autoimmune diseases (A vs. G: OR = 1.11, 95% CI = 1.03–1.20, P=0.008), especially in Asians (A vs. G: OR = 1.15, 95% CI = 1.05–1.25, P=0.002) and high quality studies (A vs. G: OR = 1.14, 95% CI = 1.05–1.24, P=0.002). Conclusion: This meta-analysis demonstrated that the FAS –670A/G and –1377 G/A polymorphisms were associated with the risk of autoimmune diseases.

Identification of a FAS/FASL haplotype associated with endometriosis in Iranian patients

Risk factors for ovarian cancer include a number of genetic variants as well as endometriosis. The FAS-FASL system is one of the apoptotic pathways that play an essential role in the apoptotic process within the endometrium. Here, we evaluate the correlation between FAS-FASL polymorphisms with the risk of endometriosis in Iranian patients and healthy controls. We extracted DNA from whole blood samples using a DNA Purification Kit. Using the PCR-RFLP method, three SNPs, including FAS (-670 A/G) and FASL (-844 C/T and _124G/A) genes, were genotyped in 112 patients with endometriosis as well as 110 healthy controls. The frequency of genotypes and the alleles of these SNPs were analyzed by the chi-squared test for the significant association. Haplotype analysis was done by the PLINK software. The frequency distribution of haplotypes was significant between SNPs so that the ACG haplotype was more frequent in the cases than in the controls (p = .017). These results indicate that haplotype analysis can be useful for SNP analysis. The ACG haplotypes in FAS-670A/G, FASL-844C/T, and _124G/A genes may be correlated with the progression of endometriosis.

Association between Fas/FasL gene polymorphism and musculoskeletal degenerative diseases: a meta-analysis

Background

It was reported that Fas (rs1800682, rs2234767) and FasL (rs5030772, rs763110) gene polymorphism might be related to the risk of musculoskeletal degenerative diseases (MSDD), such as osteoarthritis (OA), intervertebral disc degeneration (IVDD) and rheumatoid arthritis (RA). However, data from different studies was inconsistent. Here we aim to elaborately summarize and explore the association between the Fas (rs1800682, rs2234767) and FasL (rs5030772, rs763110) and MSDD.

Methods

Literatures were selected from PubMed, Web of Science, Embase, Scopus and Medline in English and VIP, SinoMed, Wanfang and the China National Knowledge Infrastructure (CNKI) in Chinese up to August 21, 2017. All the researches included are case-control studies about human. We calculated the pooled odds ratios (ORs) with 95% confidence intervals (95% CI) to evaluate the strengths of the associations of Fas (rs1800682, rs2234767) and FasL (rs5030772, rs763110) polymorphisms with MSDD risk.

Results

Eleven eligible studies for rs1800682 with 1930 cases and 1720 controls, 6 eligible studies for rs2234767 with 1794 cases and 1909 controls, 3 eligible studies for rs5030772 with 367 cases and 313 controls and 8 eligible studies for rs763110 with 2010 cases and 2105 controls were included in this analysis. The results showed that the G allele of Fas (rs1800682) is associated with an increased risk of IVDD in homozygote and recessive models. The G allele of Fas (rs2234767) is linked to a decreased risk of RA but an enhanced risk of OA in allele and recessive models. In addition, the T allele of FasL (rs763110) is correlated with a reduced risk of IVDD in all of models. However, no relationship was found between FasL (rs5030772) and these three types of MSDD in any models.

Conclusions

Fas (rs1800682) and FasL (rs763110) polymorphism were associated with the risk of IVDD and Fas (rs2234767) was correlated to the susceptibility of OA and RA. Fas (rs1800682) and Fas (rs2234767) are more likely to be associated with MSDD for Chinese people. FasL (rs763110) is related to the progression of MSDD for both Caucasoid and Chinese race groups. But FasL (rs5030772) might not be associated with any types of MSDD or any race groups statistically.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2057-z) contains supplementary material, which is available to authorized users.

Dual Role of Fas/FasL-Mediated Signal in Peripheral Immune Tolerance

Fas-mediated apoptosis contributes to physiological and pathological cellular processes, such as differentiation and survival. In particular, the roles of Fas in immune cells are complex and critical for the maintenance of immune tolerance. The precise pathways and unique functions associated with Fas/FasL-mediated signaling in the immune system are known. The dual character of Fas/FasL-mediated immune regulation that induces beneficial or harmful effects is associated with the onset or development of immune disorders. Studies on mutations in genes encoding Fas and FasL gene of humans and mice contributed to our understanding of the pathogenesis of autoimmune diseases. Here, we review the opposing functions of Fas/FasL-mediated signaling, bilateral effects of Fas/FasL on in immune cells, and complex pathogenesis of autoimmunity mediated by Fas/FasL.

Diminished soluble levels of growth arrest specific protein 6 and tyrosine kinase receptor Axl in patients with rheumatoid arthritis

AIM

Growth arrest specific protein 6 (Gas-6) and its tyrosine kinase receptor Axl plays an important role in apoptosis, and regulation of innate immune response, therefore, we investigated their plasma concentrations in Rheumatoid arthritis (RA) patients and correlated them to clinical, laboratory and radiological parameters of the disease.

METHODS

Plasma from 77 RA patients and 50 normal healthy subjects were assayed for plasma Gas6 and Axl levels. Demographic, clinical and serological data were prospectively assessed. Rheumatoid arthritis disease activity was assessed using 28-joint Disease Activity Score (DAS-28) and functional capacity by modified health assessment questionnaire (mHAQ). Standardized x-rays for hands and feet were done to all participants.

RESULTS

The level of Gas6 and Axl were significantly decreased in the RA patients compared to those of the healthy control subjects. Levels of Gas6 correlated positively with Axl levels in both patients and healthy control. Gas6 levels were remarkably reduced in those patients with erosive RA than those without. Levels of Gas6 were found to be negatively correlated with the presence of erosive disease and positively correlated with DAS-28, ESR, Leucocytosis and IL6.

CONCLUSION

The plasma concentrations of Gas6 and Axl are altered in RA patients and thus may have a role in RA pathogenesis. Further mechanistic studies on the involvement of all TAM receptors tyrosine kinases pathway in RA are needed to help in understanding the pathogenesis and possibly aid in diagnosis and future treatments of RA especially for patients with erosive disease.

Fas/FasL, Bcl2 and Caspase-8 gene polymorphisms in Chinese patients with rheumatoid arthritis

Apoptosis signals are necessary for maintaining homeostasis and an adequate immune response. Dysregulation of apoptosis-related genes in the immune system has an important impact on autoimmune diseases such as rheumatoid arthritis (RA). Thus, we investigated the association between Fas rs2234767 G/A, FasL rs763110 C/T, Bcl2 rs12454712 T/C, Bcl2 rs17757541 C/G, and Caspase-8 rs1035142 G/T polymorphisms and RA susceptibility in a Chinese population. These five single-nucleotide polymorphisms (SNPs) were studied in a Chinese population consisting of 615 patients with RA and 839 controls. Genotyping was performed using a custom-by-design 48-Plex SNP scan TM kit. Furthermore, we undertook a meta-analysis between FasL rs763110 C/T and RA. This study indicated that Fas rs2234767 and Bcl2 rs17757541 polymorphisms were risk factors for RA. No association was observed between FasL rs763110 C/T, Bcl2 rs12454712 T/C, and Caspase-8 rs1035142 G/T polymorphisms and RA in this study. The results of this meta-analysis suggested no significant association between FasL rs763110 C/T and RA. However, stratification analysis of this meta-analysis indicated that FasL rs763110 C/T increased the risk of Caucasian RA patients. In conclusion, this study demonstrated that Fas rs2234767 G/A and Bcl2 rs17757541 T/C polymorphisms might be associated with an increased risk of RA. This meta-analysis revealed that FasL rs763110 C/T was associated with an increased risk of Caucasian RA patients.

Association between the CTLA-4, CD226, FAS polymorphisms and rheumatoid arthritis susceptibility: a meta-analysis

OBJECTIVE

We explored whether cytotoxic T lymphocyte antigen-4 (CTLA-4) rs5742909, CD226 rs763361, FAS rs1800682, and FASL rs763110 polymorphisms are associated with rheumatoid arthritis (RA).

METHODS

We performed a meta-analysis on the association between the four gene polymorphisms and RA.

RESULTS

Nineteen studies were included in the meta-analysis. Meta-analysis of all study subjects showed no association between RA and the CTLA-4 rs5742909 T allele (OR=1.057, 95% CI=0.782-1.429, p=0.719). However, the meta-analysis revealed an association between RA and the CD226 rs763361 T allele in all study subjects (OR=1.294, 95% CI=1.063-1.576, p=0.010), and an association was found between the CD226 rs763361 TT genotype and RA in Asians (OR=1.363, 95% CI=1.126-1.651, p=0.001). Meta-analysis showed no association between RA and the FAS rs1800682 G/A polymorphism. However, meta-analysis revealed an association between RA and the FASL rs763110 T allele in all study subjects (OR=1.366, 95% CI=1.093-1.707, p=0.006) and in Asians (OR=1.402, 95% CI=1.059-1.855, p=0.014).

CONCLUSIONS

Our meta-analysis demonstrates that the CD226 rs763361 and FASL rs763110 polymorphisms are associated with RA, especially in Asians.

Fas signal promotes the immunosuppressive function of regulatory dendritic cells via the ERK/β-catenin pathway

Dendritic cells (DCs) play important roles in the initiation of immune response and also in the maintenance of immune tolerance. Now, many kinds of regulatory DCs with different phenotypes have been identified to suppress immune response and contribute to the control of autoimmune diseases. However, the mechanisms by which regulatory DCs can be regulated to exert the immunosuppressive function in the immune microenvironment remain to be fully investigated. In addition, how T cells, once activated, can feedback affect the function of regulatory DCs during immune response needs to be further identified. We previously identified a unique subset of CD11b(hi)Ia(low) regulatory DCs, differentiated from mature DCs or hematopoietic stem cells under a stromal microenvironment in spleen and liver, which can negatively regulate immune response in a feedback way. Here, we show that CD11b(hi)Ia(low) regulatory DCs expressed high level of Fas, and endothelial stromal cell-derived TGF-β could induce high expression of Fas on regulatory DCs via ERK activation. Fas ligation could promote regulatory DCs to inhibit CD4(+) T cell proliferation more significantly. Furthermore, Fas ligation preferentially induced regulatory DCs to produce IL-10 and IP-10 via ERK-mediated inactivation of GSK-3 and subsequent up-regulation of β-catenin. Interestingly, activated T cells could promote regulatory DCs to secrete more IL-10 and IP-10 partially through FasL. Therefore, our results demonstrate that Fas signal, at least from the activated T cells, can promote the immunosuppressive function of Fas-expressing regulatory DCs, providing a new manner for the regulatory DCs to regulate adaptive immunity.

Functional polymorphisms in cell death pathway genes FAS and FAS ligand and risk of alopecia areata

FAS and FAS ligand (FASLG) are important proapoptotic proteins that have a significant function in regulating cell growth and apoptosis and play essential roles in many human autoimmune diseases. Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease mediated by T cells to the hair follicles. The concept of an autoimmune mechanism as the basis for AA led us to investigate a possible association between the FAS and FASLG polymorphism with AA susceptibility and disease progression on AA patients in Turkish population. The study group consisted of 118 unrelated patients with AA and 118 unrelated healthy controls. We genotyped FAS-670 A/G and FASLG-124 A/G polymorphisms and assessed their association with AA risk. A statistically significant difference was observed between patients and controls according to genotype frequencies of FAS gene (p = 0.0002). GG genotype of 670 A/G polymorphism was found to be protective against AA (p = 0.000, OR 0.07, 95 % CI 0.00-0.41). It can be concluded there is a reduced risk of AA risk appeared to be associated with FAS-670 A/G. No association was observed between AA patients and controls according to genotype and allele distribution of FASLG gene 124 A/G polymorphism (p = 0.1297, p = 453, respectively). In conclusion, we provide evidence that FAS/FASLG polymorphisms may have an effect on the risk of AA in the Turkish population. These findings provide an additional support to a genetic basis for AA development.

Apoptosis-related Fas and FasL gene polymorphisms' associations with knee osteoarthritis

To investigate the associations between Fas and FasL gene polymorphisms and susceptibility to knee osteoarthritis. Genomic DNA was obtained from 146 patients with knee osteoarthritis and 102 healthy controls. Genotype distributions and allelic frequencies of four polymorphisms of Fas (-670 G>A rs1800682, -1377 G>A rs2234767) and FasL (IVS2nt-124 A>G rs5030772, -844 T>C rs763110) genes were compared between the groups. Thereafter, this association was investigated between patients and controls of the same sex. There were significant differences between patients with knee osteoarthritis and controls regarding the genotype distributions and allelic frequencies of Fas-1377 G>A polymorphism (P = 0.0001 and P = 0.005, respectively). The Fas-1377 GG genotype and G allele were significantly more frequent in patients with knee osteoarthritis than in controls. Genotype distributions and allelic frequencies of Fas-670 G>A, FasL-844 T>C, and FasL IVS2nt-124 A>G polymorphisms did not differ between the groups (P > 0.05). However, there were no significant differences between patients and controls of the same sex (P > 0.05). These findings suggest that the Fas-1377 G>A polymorphism in the Fas gene related with apoptosis may contribute to susceptibility to knee osteoarthritis in the Turkish population. There is a need for further studies to evaluate the role of apoptosis in large cohorts.