PADI4 Haplotypes Contribute to mRNA Expression, the Enzymatic Activity of Peptidyl Arginine Deaminase and Rheumatoid Arthritis Risk in Patients from Western Mexico

Abstract

Citrullination is catalyzed by the peptidyl arginine deiminase 4 (PAD4) enzyme, encoded by the PADI4 gene. Increased PAD4 activity promotes the onset and progression of rheumatoid arthritis (RA). This study aimed to evaluate the association of PADI4 haplotypes with RA risk, mRNA expression, and the PAD4 activity in patients with RA from Mexico. Methodology: 100 RA patients and 100 control subjects (CS) were included. Genotyping was performed by PCR-RFLP method, PADI4 mRNA expression was quantified by real-time PCR, the contribution of PADI4 alleles ( PADI4_89 G>A, PADI4_90 T>C, and PADI4_92 G>C) to mRNA expression by the ASTQ method, and PAD4 activity by HPLC. Also, the anti-CCP and anti-PADI4 antibodies were quantified by ELISA. Results: The three PADI4 polymorphisms were associated with RA susceptibility (OR = 1.72, p = 0.005; OR = 1.62; p = 0.014; OR = 1.69; p = 0.009; respectively). The 89G, 90T, and 92G alleles have a higher relative contribution to PADI4 mRNA expression from RA patients than 89A, 90C, and 92C alleles in RA patients. Moreover, the GTG/GTG haplotype was associated with RA susceptibility (OR = 2.86; p = 0.024). The GTG haplotype was associated with higher PADI4 mRNA expression ( p = 0.04) and higher PAD4 enzymatic activity ( p = 0.007) in RA patients. Conclusions: The evaluated polymorphisms contribute to PADI4 mRNA expression and the enzymatic activity of PAD4 in leukocytes. Therefore, the GTG haplotype is a genetic risk factor for RA in western Mexico, and is associated with increased PADI4 mRNA expression and higher PAD4 activity in these patients.

Neutrophil extracellular traps in rheumatoid arthritis and periodontitis: Contribution of PADI4 gene polymorphisms

“…Likewise, GTG-positive individuals had worse periodontal clinical parameters. Previous in vitro studies using leukocytes from individuals with RA have reported greater activity of the PAD4 enzyme and greater affinity for calcium ions in carriers of the positive GTG haplotype (Hung et al, 2007;Matuz-Flores et al, 2022).…”

“…Other studies have also revealed an association between ACPAs and the presence of PADI4 polymorphisms (Gandjbakhch et al, 2009; Guzmán‐Guzmán et al, 2015). Recently, increased PADI4 expression was reported in Mexican RA individuals carrying the GTG haplotype (Matuz‐Flores et al, 2022). In line with our data, an increase in mRNA and higher levels of PAD4 transcripts have been detected in individuals carrying the GTG haplotype, which may lead to an increase in the release of citrullinated peptides that act as autoantigens (Guzmán‐Guzmán et al, 2015; Hill et al, 2003; Matuz‐Flores et al, 2022; Suzuki et al, 2003).…”

“…The genotype and GTG haplotype frequencies of the PADI4 SNPs in this Brazilian survey are original; however, no associations with the risk of developing RA were found. The association between the presence of polymorphisms and susceptibility to RA has been reported in Asian and Mexican populations (Bang et al, 2010;Kang et al, 2006;Matuz-Flores et al, 2022;Suzuki et al, 2003). Conversely, in a large study conducted on a Caucasian population of European descendants, PADI4 polymorphisms were not found to be a significant risk factor for RA (Burr et al, 2010).…”

“…Previous studies have shown that an increase in PAD4 activity is associated with the onset and progression of RA (Reyes-Castillo et al, 2018) and that single nucleotide polymorphisms (SNPs) in the gene encoding the PAD4 enzyme confer greater susceptibility to RA (Lee & Bae, 2016;Matuz-Flores et al, 2022;Suzuki et al, 2003).…”

“…Moreover, the enzyme peptidyl arginine deaminase type 4 (PAD4), which is expressed primarily by neutrophils, eosinophils and monocytes (Nakashima et al, 2002; Vossenaar et al, 2004), catalyses the conversion of arginine to citrulline residues (Mondal & Thompson, 2019). Previous studies have shown that an increase in PAD4 activity is associated with the onset and progression of RA (Reyes‐Castillo et al, 2018) and that single nucleotide polymorphisms (SNPs) in the gene encoding the PAD4 enzyme confer greater susceptibility to RA (Lee & Bae, 2016; Matuz‐Flores et al, 2022; Suzuki et al, 2003).…”