Association of ERAP1 gene polymorphisms with the susceptibility to psoriasis vulgaris: A case-control study

ERAP1 Gene Variants and Haplotypes Associated With Psoriasis Vulgaris of Han Chinese in Inner Mongolia

BACKGROUND

This study aimed to investigate the association between genetic variants of ERAP1 (OMIM: 606832) and psoriasis vulgaris (PsV) susceptibility in Inner Mongolia Han nationality.

METHODS

For primary screening, the subjects included 142 PsV cases and 100 healthy controls without psoriasis. The 27 exons of ERAP1 gene were sequenced to screen significant genetic variants. For the validation study, the subjects included 1030 PsV cases and 965 healthy controls. A total of 18 mutations were detected for genetic variants of significance in primary screening and previously reported genetic variants.

RESULTS

In primary screening stage, 13 genetic variants of ERAP1 showed an association with psoriasis. A total of 18 genetic variants were typed for the validation, and 12 genetic variants were associated with PsV in Inner Mongolia Han population. Stratified analysis showed significant differences in the allele frequencies of 8 ERAP1 genetic variants in cases with positive family history, and significant differences in allele frequencies among 9 ERAP1 genetic variants in patients with negative family history. A risk haplotype (TCCCTCCAGACC) was significantly associated with PsV, and the most risk haplotype was E730/K528/R127/E56.

CONCLUSION

ERAP1 gene mutation may be associated with PsV and HLA-C*06:02 in Han nationality in Inner Mongolia. A risk haplotype of four-nonsynonymous mutation (E730/K528/R127/E56) is associated with PsV.

Association of a single nucleotide polymorphism (rs27434) in the ERAP1 gene with plural tissue weight

Our study was designed to examine the correlation between single nucleotide polymorphism (SNP) in the endoplasmic reticulum aminopeptidase 1 (ERAP1) gene, specifically focusing on rs27434, and plural tissue weight. We conducted this investigation using autopsy samples from the Japanese population. Blood samples were collected from 178 Japanese subjects who had undergone autopsies in Shimane Prefecture. Genomic DNA was subsequently extracted from these samples. SNP (rs27434, G＞A substitution) was analyzed by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. In the present study, rs27434 exhibited a statistically significant association with brain weight (g) in both female and male individuals. Among males, rs27434 displayed significant relationships with liver weight (g), and body surface area (m2). In females, rs27434 was significantly related to the length of the appendix. Across both genders, individuals with GA and AA genotypes tended to exhibit higher levels in these respective measurements compared to those with the GG genotype. These results suggest that genetic variant of ERAP1 gene may influence the weight of the organs. To the best of our knowledge, this is the first study investigating the interaction between the association of rs27434 in the ERAP1 gene and data routinely measured at autopsy, such as tissue weight. However, conducting further investigations with larger population samples could provide more comprehensive insights to clarify this issue.

The Role of Aminopeptidase ERAP1 in Human Pathology-A Review

Aminopeptidases are a group of enzymatic proteins crucial for protein digestion, catalyzing the cleavage of amino acids at the N-terminus of peptides. Among them are ERAP1 (coding for endoplasmic reticulum aminopeptidase 1), ERAP2 (coding for endoplasmic reticulum aminopeptidase 2), and LNPEP (coding for leucyl and cystinyl aminopeptidase). These genes encoding these enzymes are contiguous and located on the same chromosome (5q21); they share structural homology and functions and are associated with immune-mediated diseases. These aminopeptidases play a key role in immune pathology by cleaving peptides to optimal sizes for binding to the major histocompatibility complex (MHC) and contribute to cellular homeostasis. By their ability to remove the extracellular region of interleukin 2 and 6 receptors (IL2, IL6) and the tumor necrosis factor receptor (TNF), ERAP1 and ERAP2 are involved in regulating the innate immune response and, finally, in blood pressure control and angiogenesis. The combination of specific genetic variations in these genes has been linked to various conditions, including autoimmune and autoinflammatory diseases and cancer, as well as hematological and dermatological disorders. This literature review aims to primarily explore the impact of ERAP1 polymorphisms on its enzymatic activity and function. Through a systematic examination of the available literature, this review seeks to provide valuable insights into the role of ERAP1 in the pathogenesis of various diseases and its potential implications for targeted therapeutic interventions. Through an exploration of the complex interplay between ERAP1 and various disease states, this review contributes to the synthesis of current biomedical research findings and their implications for personalized medicine.

Down-regulation of ERAP1 mRNA expression in non-small cell lung cancer

BACKGROUND

ERAP1 is a major aminopeptidase that serves as an editor of the peptide repertoire by trimming N-terminal residues of antigenic peptides, creating a pool of peptides with the optimal length for MHC-I binding. As an important component of the antigen processing and presenting machinery - APM, ERAP1 is frequently down-regulated in many cancers. Since ERAP1 expression has not yet been thoroughly investigated in non-small cell lung cancer (NSCLC), we decided to analyze ERAP1 mRNA levels in tissues collected from NSCLC patients.

METHODS

Using real-time qPCR, we evaluated ERAP1 mRNA expression in samples of tumor and adjacent non-tumor tissue (serving as control tissue) from 61 NSCLC patients.

RESULTS

We observed a significantly lower level of ERAP1 mRNA expression in tumor tissue (Med_Tumor = 0.75) in comparison to non-tumor tissue (Med_Non-tumor = 1.1), p = 0.008. One of the five tested polymorphisms, namely rs26653, turned out to be significantly associated with ERAP1 expression in non-tumor tissue (difference [d] = 0.59 CI95% (0.14;1.05), p = 0.0086), but not in tumor tissue. The levels of ERAP1 mRNA expression did not affect the overall survival of NSCLC patients, either in the case of the tumor (p = 0.788) or in non-tumor (p = 0.298) tissue. We did not detect any association between mRNA ERAP1 expression level in normal tissue and: (i) age at diagnosis (p = 0.8386), (ii) patient's sex (p = 0.3616), (iii) histological type of cancer (p = 0.7580) and (iv) clinical stage of NSCLC (p = 0.7549). Furthermore, in the case of tumor tissue none of the abovementioned clinical parameters were associated with ERAP1 expression (p = 0.76).

CONCLUSION

Down-regulation of ERAP1 mRNA observed in NSCLC tissue may be related to tumor immune evasion strategy. The rs26653 polymorphism can be considered an expression quantitative trait locus (eQTL) associated with ERAP1 expression in normal lung tissue.

Associations between ERAP1 Gene Polymorphisms and Psoriasis Susceptibility: A Meta-Analysis of Case-Control Studies

This study is to investigate the relationship of endoplasmic reticulum aminopeptidase 1 (ERAP1) gene polymorphisms with psoriasis. Five databases of PubMed, China National Knowledge Infrastructure (CNKI), Embase, Web of Science, and Cochrane Library were searched for potential studies until 25 December 2019. Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included studies. Meta-analysis was performed with PRISMA. A total of 9 case-control studies including 4858 psoriasis cases and 10,542 healthy controls were included. Three loci of ERAP1 gene polymorphisms (rs26653, rs30187, and rs27524) were evaluated in this meta-analysis. There was no significant association between rs26653 polymorphism and risk of psoriasis (C vs. G, OR = 1.01, 95% CI: 0.80-1.28, P = 0.93). However, there was a significant association between rs30187 polymorphisms and psoriasis susceptibility (T vs. C, OR = 1.23, 95% CI: 1.15-1.32, P < 0.00001) and a significant association between rs27524 polymorphisms and psoriasis susceptibility (A vs. G, OR = 1.17, 95% CI: 1.09-1.25, P < 0.00001). For there were insufficient data of rs27044, rs151823, rs2248374, and rs2910686, we only conducted a systematic review for them. The rs30187 (C/T) and rs27524 (G/A) polymorphisms of ERAP1 are associated with increased risk of psoriasis. However, no significant association is observed between rs26653 (G/C) polymorphism and risk of psoriasis.

Polymorphisms of Antigen-Presenting Machinery Genes in Non-Small Cell Lung Cancer: Different Impact on Disease Risk and Clinical Parameters in Smokers and Never-Smokers

Lung cancer is strongly associated with cigarette smoking; nevertheless some never-smokers develop cancer. Immune eradication of cancer cells is dependent on polymorphisms of HLA class I molecules and antigen-processing machinery (APM) components. We have already published highly significant associations of single nucleotide polymorphisms (SNPs) of the ERAP1 gene with non-small cell lung cancer (NSCLC) in Chinese, but not in Polish populations. However, the smoking status of participants was not known in the previous study. Here, we compared the distribution of APM polymorphic variants in larger cohorts of Polish patients with NSCLC and controls, stratified according to their smoking status. We found significant but opposite associations in never-smokers and in smokers of all tested SNPs (rs26653, rs2287987, rs30187, and rs27044) but one (rs26618) in ERAP1. No significant associations were seen in other genes. Haplotype analysis indicated that the distribution of many ERAP1/2 haplotypes is opposite, depending on smoking status. Additionally, haplotypic combination of low activity ERAP1 and the lack of an active form of ERAP2 seems to favor the disease in never-smokers. We also revealed interesting associations of some APM polymorphisms with: age at diagnosis (ERAP1 rs26653), disease stage (ERAP1 rs27044, PSMB9 rs17587), overall survival (ERAP1 rs30187), and response to chemotherapy (ERAP1 rs27044). The results presented here may suggest the important role for ERAP1 in the anti-cancer response, which is different in smokers versus never-smokers, depending to some extent on the presence of ERAP2, and affecting NSCLC clinical course.

Two Variants in the NOTCH4 and HLA-C Genes Contribute to Familial Clustering of Psoriasis

Psoriasis is a multifactorial immune-mediated skin disease with a strong genetic background. Previous studies reported that psoriasis with a family history (PFH) and sporadic psoriasis (SP) have a distinct manifestation and genetic predisposition. However, the genetic heterogeneity of PFH and SP in the major histocompatibility complex (MHC) region has not been fully elucidated. To explore genetic variants in the MHC region that drive family aggregation of psoriasis, we included a total of 8,127 psoriasis cases and 9,906 healthy controls from Han Chinese and divided psoriasis into two subtypes, PFH (n = 1,538) and SP (n = 5,262). Then, we calculated the heritability of PFH and SP and performed a large-scale stratified association analysis. We confirmed that variants in the MHC region collectively explained a higher heritability of PFH (16.8%) than SP (13.3%). Further stratified association analysis illustrated that HLA-C∗06:02 and NOTCH4:G511S contribute to the family aggregation of psoriasis, and BTNL2:R281K specifically confers risk for SP. HLA-C∗06:02 and NOTCH4:G511S could partially explain why patients with PFH have a stronger genetic predisposition, more complex phenotypes, and more frequent other autoimmune diseases. The identification of the SP-specific variant BTNL2:R281K revealed that the genetic architecture of SP is not just a subset of PFH.

Endoplasmic reticulum aminopeptidase 1 (ERAP1) polymorphisms and psoriasis susceptibility: A systematic review and meta-analysis

BACKGROUND

Psoriasis has a complex genetic background with a strong heritable component. Herein, the present meta-analysis aims to evaluate the association of ERAP1 polymorphisms with psoriasis susceptibility.

METHODS

PubMed, Web of Sciences, Scopus, and Cochrane Library databases were examined with no time limits up to March 2019, without language, age, and sex restrictions. The odds ratio (OR) and 95% confidence interval (CI) were calculated by CMA 2.0 software in a dichotomous analysis using computed effect sizes and having OR and confidence limits for each study. The subgroup analysis based on ethnicity, type of study, and genotyping method was performed.

RESULTS

Thirteen articles were involved in the meta-analysis, in details eight were cohort studies and five were case-control studies. The results showed an association between rs27524 [OR = 1.179; 95%CI: 1.081, 1.286; p < 0.001] and rs30187 [OR = 1.237; 95%CI: 1.133, 1.351; p < 0.001] polymorphisms and psoriasis susceptibility; whereas no association was detected with rs26653 [OR = 1.013; 95%CI: 0.798, 1.286; p = 0.914] and rs27044 [OR = 1.164; 95%CI: 0.982, 1.381; p = 0.080] polymorphisms. Psoriasis susceptibility in both Caucasian and Asian ethnicities was related to rs27524 polymorphism, while rs30187 and rs27044 polymorphisms were over-represented in patients belonging to Caucasian ethnicity. In addition, in cohort studies, psoriasis susceptibility was related to rs27524 polymorphism, while the associated polymorphisms were rs26653 and rs27044 in case-control studies, and rs30187 in both cohort and case-control studies.

CONCLUSIONS

These findings showed an association between rs27524 and rs30187 polymorphisms and susceptibility to psoriasis, while lack of association was obtained for rs26653 and rs27044 polymorphisms. In order to confirm our results, further studies are needed, also considering different factors, such as type of psoriasis and ethnicity.