Plasminogen activator inhibitor-1 C/G polymorphism in relation to plasma levels in rheumatoid arthritis

Decoding the genetic influence of CT60 non-coding polymorphism in CTLA-4 gene and sCTLA-4 biomarker with rheumatoid arthritis in the Indian population

BACKGROUND

Cytoplasmic T Lymphocyte Antigen - 4 (CTLA-4) gene encodes an immunoregulatory receptor expressed on surface of activated T-cells to mediate peripheral tolerance against self-antigen. It suppresses auto-reactive T-cell proliferation either by inactivation or apoptosis of T-cells. The CTLA-4 mRNA undergoes alternative splicing to synthesize a native soluble form of CTLA-4 (sCTLA-4) protein, which lacks exon 3 that encodes for transmembrane region. As a result, sCTLA-4 circulates as a soluble serum protein and acts as an immunoregulator molecule to maintain homeostasis in the blood.

MATERIALS AND RESULTS

Techniques coupled with quantitative Polymerase Chain Reaction (qPCR) and High-Resolution Melting Analysis (HRMA) were used to screen CTLA-4 3'Untranslated Region (UTR) CT60 (A/G) rs3087243 Single Nucleotide Polymorphism (SNP) and their association with Rheumatoid Arthritis (RA) in the Indian population. In addition, we also evaluated the concentration of sCTLA-4 serum protein in RA patients carrying rs3087243 SNP with different genotypes (A/A, G/A, and G/G). Statistical analysis of Odds Ratio (OR), Confidence Interval (C.I), and Relative Risk (RR) have shown that frequency of CTLA-4 rs3087243 SNP G/G genotype was significantly associated with RA in the Indian population (OR 1.7140; CI = 1.0765 to 2.7290; RR = 1.5434; p = 0.0232). The sCTLA-4 concentration was also significantly lower in RA patients carrying rs3087243 SNP G/G genotype than control group (p < 0.001).

CONCLUSION

Co-inheritance of CTLA-4 signal peptide and 3'UTR SNPs may activate RAPP pathway. Downregulation of CTLA-4 and sCTLA-4 serum protein by rs3087243 SNP can increase the hyperactivation of T-cells, which causes RA.

Relationship of metabolic syndrome and its components with -844 G/A and HindIII C/G PAI-1 gene polymorphisms in Mexican children

Background

Several association studies have shown that -844 G/A and HindIII C/G PAI-1 polymorphisms are related with increase of PAI-1 levels, obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, which are components of metabolic syndrome. The aim of this study was to analyze the allele and genotype frequencies of these polymorphisms in PAI-1 gene and its association with metabolic syndrome and its components in a sample of Mexican mestizo children.

Methods

This study included 100 children with an age range between 6-11 years divided in two groups: a) 48 children diagnosed with metabolic syndrome and b) 52 children metabolically healthy without any clinical and biochemical alteration. Metabolic syndrome was defined as the presence of three or more of the following criteria: fasting glucose levels ≥ 100 mg/dL, triglycerides ≥ 150 mg/dL, HDL-cholesterol < 40 mg/dL, obesity BMI ≥ 95^th percentile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) ≥ 95^th percentile and insulin resistance HOMA-IR ≥ 2.4. The -844 G/A and HindIII C/G PAI-1 polymorphisms were analyzed by PCR-RFLP.

Results

For the -844 G/A polymorphism, the G/A genotype (OR = 2.79; 95% CI, 1.11-7.08; p = 0.015) and the A allele (OR = 2.2; 95% CI, 1.10-4.43; p = 0.015) were associated with metabolic syndrome. The -844 G/A and A/A genotypes were associated with increase in plasma triglycerides levels (OR = 2.6; 95% CI, 1.16 to 6.04; p = 0.02), decrease in plasma HDL-cholesterol levels (OR = 2.4; 95% CI, 1.06 to 5.42; p = 0.03) and obesity (OR = 2.6; 95% CI, 1.17-5.92; p = 0.01). The C/G and G/G genotypes of the HindIII C/G polymorphism contributed to a significant increase in plasma total cholesterol levels (179 vs. 165 mg/dL; p = 0.02) in comparison with C/C genotype.

Conclusions

The -844 G/A PAI-1 polymorphism is related with the risk of developing metabolic syndrome, obesity and atherogenic dyslipidemia, and the HindIII C/G PAI-1 polymorphism was associated with the increase of total cholesterol levels in Mexican children.

Plasminogen activator inhibitor-1 polymorphisms (-844 G>A and HindIII C>G) in systemic lupus erythematosus: association with clinical variables

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the presence of autoantibodies against nuclear autoantigens as well as cytoplasmic and circulating proteins. Recent studies have demonstrated mechanisms responsible for modulation of the immune response by the plasminogen activator inhibitor-1 (PAI-1). Furthermore, the endogenous PAI-1 has shown to promote a Th2 immune response. We assessed the -844 G>A and HindIII C>G PAI-1 polymorphisms in SLE. In a case-control study of 71 SLE patients classified according to ACR criteria and 71 healthy subjects (HS). The A allele of -844 PAI-1 polymorphism showed a significant difference in SLE patients (41%) when compared with HS (27%) [P = 0.01; OR = 1.8, 95%, CI = 1.1-3.0]. In addition, the -844 G>A PAI-1 polymorphism was associated with increased risk for SLE in a dominant genetic model (G/G vs. G/A + A/A; OR = 2.3, 95% CI = 1.14-4.44). Also, anti-RNP positive antibodies in SLE were associated with G/G -844 PAI-1 genotype. The HindIII polymorphism did not show any differences. The haplotype analysis showed that the AC haplotype confers susceptibility to SLE (OR = 3.1, 95% CI, 1.45-6.52; P = 0.003). The AC haplotype of the -844 and HindIII PAI-1 polymorphism might be an additional susceptibility factor to SLE in Mexicans.