Replication of association between interleukin-23 receptor (IL-23R) and its ligand (IL-12B) polymorphisms and psoriasis in the Chinese Han population

Advances in psoriasis research: From pathogenesis to therapeutics

Psoriasis is a chronic inflammatory condition affecting approximately 2 % to 3 % of the global population. The pathogenesis of psoriasis is complex, involving immune dysregulation, hyperproliferation and angiogenesis. It is a multifactorial disease which is influenced by genetic and environmental factors. The development of various therapeutic agents, such as JAK inhibitors, small molecules, and biologics with potential anti-psoriatic properties was possible with the vast understanding of the pathogenesis of psoriasis. Various signalling pathways, including NF-κB, JAK-STAT, S1P, PDE-4, and A3AR that are involved in the pathogenesis of psoriasis as well as the preclinical models utilised in the research of psoriasis have been highlighted in this review. The review also focuses on technological advancements that have contributed to a better understanding of psoriasis. Then, the molecules targeting the respective signalling pathways that are still under clinical trials or recently approved as well as the latest breakthroughs in therapeutic and drug delivery approaches that can contribute to the improvement in the management of psoriasis are highlighted in this review. This review provides an extensive understanding of the current state of research in psoriasis, giving rise to opportunities for researchers to discover future therapeutic breakthroughs and personalised interventions. Efficient treatment options for individuals with psoriasis can be achieved by an extensive understanding of pathogenesis, therapeutic agents, and novel drug delivery strategies.

The Experimental Animal Models in Psoriasis Research: A Comprehensive Review

Psoriasis is an autoimmune, chronic, inflammatory skin condition mediated by T cells. It differs from other inflammatory conditions by causing significant alterations in epidermal cell proliferation and differentiation that are both complicated and prominent. The lack of an appropriate animal model has significantly hindered studies into the pathogenic mechanisms of psoriasis since animals other than humans typically do not exhibit the complex phenotypic features of human psoriasis. A variety of methods, including spontaneous mutations, drug-induced mutations, genetically engineered animals, xenotransplantation models, and immunological reconstitution approaches, have all been employed to study specific characteristics in the pathogenesis of psoriasis. Although some of these approaches have been used for more than 50 years and far more models have been introduced recently, they have surprisingly not yet undergone detailed validation. Despite their limitations, these models have shown a connection between keratinocyte hyperplasia, vascular hyperplasia, and a cell-mediated immune response in the skin. The xenotransplantation of diseased or unaffected human skin onto immune-compromised recipients has also significantly aided psoriasis research. This technique has been used in a variety of ways to investigate the function of T lymphocytes and other cells, including preclinical therapeutic studies. The design of pertinent in vivo and in vitro psoriasis models is currently of utmost concern and a crucial step toward its cure. This article outlines the general approach in the development of psoriasis-related animal models, aspects of some specific models, along with their strengths and limitations.

Psoriasis: An Immunogenetic Perspective

Psoriasis is an erythematous-squamous dermatosis with a polygenic inheritance history. Both environmental and genetic factors play a role in the etiology of the disease. Over the past two decades, numerous linkage analyzes and genome-wide association studies have been conducted to investigate the role of genetic variation in disease pathogenesis and progression. To date, >70 psoriasis susceptibility loci have been identified, including HLA-Cw6, IL12B, IL23R, and LCE3B/3C. Some genetic markers are used in clinical diagnosis, prognosis, treatment, and personalized new drug development that can further explain the pathogenesis of psoriasis. This review summarizes the immunological mechanisms involved in the etiopathogenesis of psoriasis and recent advances in susceptibility genes and highlights new potential targets for therapeutic intervention.

Association of interleukin-12B rs6887695 with susceptibility to allergic rhinitis

Interleukin-12 (IL-12) is a heterodimeric cytokine encoded by two separate genes, IL12A and IL12B, which may play a regulatory role in allergen-induced inflammation through CD4⁺ T-cell subsets polarization. The aim of this study was to investigate the association of single-nucleotide polymorphisms (SNPs) in the IL12B gene with susceptibility to allergic rhinitis (AR). We performed a case-control study including 130 AR patients and 130 healthy controls to evaluate the possible association between IL12B gene SNPs (rs3212227, rs6887695) and the risk of AR using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our results showed no significant association between IL12B rs3212227 A > C polymorphism with AR. In contrast, the GC genotype of rs6887695 G > C was associated with susceptibility to AR in comparison with the GG genotype (p = 0.049, OR = 1.684, 95% CI: 1.002-2.83). We also observed a statistically significant difference in the additive model (GC versus GG + CC, p = 0.03, OR = 1.705, 95% CI: 1.040-2.794) for SNPs rs6887695. Furthermore, haplotypes analysis demonstrated that C-C haplotype was associated with an increased risk of AR (p = 0.01, OR = 1.845, 95% CI: 1.114-3.057). Our findings suggest that IL12B rs6887695 polymorphism may be a potential biomarker for susceptibility to AR in an Iranian population.

MicroRNA-125a Correlates with Decreased Psoriasis Severity and Inflammation and Represses Keratinocyte Proliferation

BACKGROUND

Psoriasis has a complex etiology related to inflammation and dysregulated immune system. MicroRNA (miR)-125a is a miRNA intimately related to inflammation and immunity; therefore, we presumed that it might play a role in the pathogenesis of psoriasis. This study aimed to investigate the correlation of miR-125a with disease severity and inflammation in psoriasis patients, and the effect of miR-125a on proliferation, apoptosis as well as its target signaling pathway in keratinocytes.

METHODS

Sixty psoriasis patients were consecutively recruited, then lesional and non-lesional skin tissue samples were collected. miR-125a in lesional and non-lesional skin tissues, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-17 mRNA expressions in lesional skin tissues were detected. Then, miR-125a overexpression, control overexpression, miR-125a knockdown and control knockdown plasmids were transfected into HaCaT cells. Subsequently, cell proliferation, apoptosis, IL-23R, JAK2, and STAT3 expressions were assessed.

RESULTS

miR-125a was reduced in lesional skin tissue compared with non-lesional skin tissue (p < 0.001), and it distinguished lesional skin tissue from non-lesional skin tissue with a high area under curve of 0.917 (95% CI 0.866-0.968). Negative association of miR-125a in lesional skin tissue with lesional body surface area (p = 0.037) and psoriasis area and severity index score (p < 0.001) was found. Additionally, miR-125a was negatively correlated with TNF-α (p = 0.001), IL-1β (p = 0.014), and IL-17 (p = 0.003) in lesional skin tissue. In cellular experiments, miR-125a overexpression inhibited proliferation and promoted apoptosis, while miR-125a knockdown enhanced proliferation and repressed apoptosis in HaCaT cells. Additionally, miR-125a negatively regulated the IL-23R/JAK2/STAT3 pathway in HaCaT cells.

CONCLUSION

miR-125a could facilitate the disease monitoring and probably has the potential to be a therapeutic target in psoriasis.

Evaluation of interleukin-23 receptor (IL-23R) gene polymorphisms and serum IL-23 levels in patients with psoriasis

Background/aim

IL-23R gene polymorphisms and the association of these polymorphisms with serum IL-23 levels were investigated in patients with psoriasis in the current study.

Materials and methods

Sixty-seven patients with psoriasis who were admitted to our dermatology outpatient clinic and 67 healthy controls were included in the study. Polymorphisms of the IL-23R gene were determined by KASP-PCR method, and serum IL-23 levels were determined by ELISA method.

Results

The distribution of IL-23R gene polymorphisms rs2201841, rs11209026, rs7530511, rs1343152, and rs11465804 was not significantly different in the patient and control groups. The AA genotype of the rs2201841 locus in males and the GA genotype in females, as well as the AA genotype of the rs1343152 locus in males and the CA genotype in females, were statistically significant in patients with psoriasis. The mean serum IL-23 level was significantly lower in the patient group (42.62 ± 5.96) compared to the control groups (75.76 ± 13.24).

Conclusion

IL-23R gene polymorphisms including rs2201841, rs11209026, rs7530511, rs11465804, and rs1343152 were not found to be significantly related to psoriasis. Different genetic polymorphisms may play a role in the development of psoriasis in female and male populations. Ethnic differences between different populations may have led to differences in the distribution of polymorphisms in the current study with compared to other published studies. Additionally, many different genes, polymorphisms, and environmental factors that have an effect on the development of psoriasis may affect the disease process.

Models in the Research Process of Psoriasis

Psoriasis is an ancient, universal chronic skin disease with a significant geographical variability, with the lowest incidence rate at the equator, increasing towards the poles. Insights into the mechanisms responsible for psoriasis have generated an increasing number of druggable targets and molecular drugs. The development of relevant in vitro and in vivo models of psoriasis is now a priority and an important step towards its cure. In this review, we summarize the current cellular and animal systems suited to the study of psoriasis. We discuss the strengths and limitations of the various models and the lessons learned. We conclude that, so far, there is no one model that can meet all of the research needs. Therefore, the choice model system will depend on the questions being addressed.

Association between rs6887695 and 3'-untranslated region polymorphisms within the interleukin-12B gene and susceptibility to autoimmune diseases in Asian and European population: A meta-analysis

BACKGROUND

The associations between rs6887695 and 3'-untranslated region (3'-UTR) single-nucleotide polymorphisms (SNPs) within interleukin-12B (IL-12B) and autoimmune diseases (ADs) remain controversial and inconclusive. The aim of this study was to evaluate the association between IL-12B (3'-UTR A/C and rs6887695 C/G SNPs) and ADs by meta-analysis.

METHODS

PubMed and EMBASE were exhaustively searched for studies on the association between IL-12B SNPs and ADs. Publication bias was examined by a funnel plot and Egger's test. The robustness of the pooled results was assessed by sensitivity analysis. A fixed- or a random-effects model was applied to calculate the pooled odds ratios (ORs).

RESULTS

A total of 34 studies were included in this meta-analysis. The pooled results demonstrated that IL-12B rs6887695 SNPs were significantly associated with the risk of ADs. However, there was no significant association between IL-12B 3'-UTR SNPs and ADs. When the studies were stratified by ethnicity, significant association between IL-12B 3'-UTR SNPs and ADs was observed in both Asian and European population. In addition, allele A within 3'-UTR of IL-12B gene was found to be a protective factor for T1DM, but a risk factor for psoriasis.

CONCLUSION

The IL-12B 3'-UTR and rs6887695 SNPs are associated with susceptibility to ADs.

Association of Interleukin-23 receptor gene polymorphisms with susceptibility to Crohn's disease: A meta-analysis

Studies investigating the association between Interleukin-23 receptor (IL-23R) gene polymorphisms and Crohn’s disease (CD) report conflicting results. Thus, a meta-analysis was carried out to assess the association between the IL-23R polymorphisms and CD. A systematic literature search was conducted to identify all relevant studies. Pooled odds ratio (ORs) with 95% confidence interval (CIs) was used to estimate the strength of association. Finally, a total of 60 case-control studies in 56 articles, involving 22,820 CD patients and 27,401 healthy controls, were included in the meta-analysis. Overall, a significant association was found between all CD and the rs7517847 polymorphism (OR = 0.699, 95% CI = 0.659 ~ 0.741, P < 0.001). Meta-analysis of the rs11209026, rs1343151, rs10489629 and rs11465804 polymorphisms indicated the same pattern as for rs7517847. Meta-analysis showed an association between the rs10889677A allele and CD (OR = 1.393, 95% CI = 1.328 ~ 1.461, P < 0.001). Similarly, meta-analysis of the rs2201840, rs1004819, rs1495965 and rs11209032 polymorphisms revealed the same pattern as that shown by meta-analysis of rs10889677. Stratification by ethnicity revealed that IL-23R gene polymorphisms were associated with CD in the Caucasian group, but not in Asians. In summary, the meta-analysis suggests a significant association between IL-23R polymorphisms and CD, especially in Caucasians.

Investigation of association of the IL-12B and IL-23R genetic variations with psoriatic risk in a South Indian Tamil cohort

BACKGROUND

Psoriasis is a T-cell mediated chronic systemic inflammatory skin disease. Emerging evidences suggest the interleukin (IL)-12B and IL-23R genes encoding the common p40 subunit of IL-12 and IL-23 are the key cytokines in T-helper (Th)1 and Th17 differentiation and function. Certain allelic variants of these genes significantly influence the risk of psoriasis. Hence we undertook to study the association of IL-12B and IL-23R gene polymorphisms with disease susceptibility in South Indian Tamil patients with psoriasis.

METHODS

360 psoriatics and 360 healthy controls were included in this case control study. IL-12B gene (rs3212227) and IL-23R gene (rs2201841, rs10889677 and rs11805303) polymorphisms were typed by using TaqMan 5'allele discrimination assay and cytokine levels were assayed by ELISA.

RESULTS

We observed that the patients carrying the risk genotypes of IL-12B (rs3212227) and IL-23R (rs2201841) conferred an increased susceptibility to psoriasis. We did not find any significant association between IL-23R (rs10889677 and rs11805303) gene polymorphisms and psoriasis risk in South Indian Tamil population. We did not observe any significant difference in haplotypes between the psoriasis cases and controls. We observed a significant increase in the mean IL-23 levels in psoriatics and the higher levels of IL-23 were found in the minor variant genotype CC when compared with that of heterozygous CT and major variant TT genotypes of rs2201841. Individual genotypes of rs10889677 and rs11805303 and IL-12 (rs3212227) were not significantly associated with their plasma levels.

CONCLUSION

Our results suggest that IL-12B (rs3212227) and IL-23R (rs2201841) polymorphisms confer increased risk of psoriasis in our ethnic South Indian Tamils.

Genetics of psoriasis

Psoriasis is a common and debilitating immune-mediated skin disease with a complex genetic basis. Genetic studies have provided critical insights into the pathogenesis of disease. This article focuses on the results of genetic association studies, which provide evidence that psoriasis susceptibility genes are involved in innate and adaptive immunity and skin barrier functions. The potential for disease stratification and the development of more effective treatments with fewer side effects using genetic data are highlighted.

Genetics of psoriasis and pharmacogenetics of biological drugs

Psoriasis is a chronic inflammatory disease of the skin. The causes of psoriasis are unknown, although family and twin studies have shown genetic factors to play a key role in its development. The many genes associated with psoriasis and the immune response include TNFα, IL23, and IL12. Advances in knowledge of the pathogenesis of psoriasis have enabled the development of new drugs that target cytokines (e.g., etanercept, adalimumab, and infliximab, which target TNFα, and ustekinumab, which targets the p40 subunit of IL23 and IL12). These drugs have improved the safety and efficacy of treatment in comparison with previous therapies. However, not all patients respond equally to treatment, possibly owing to interindividual genetic variability. In this review, we describe the genes associated with psoriasis and the immune response, the biological drugs used to treat chronic severe plaque psoriasis, new drugs in phase II and III trials, and current knowledge on the implications of pharmacogenomics in predicting response to these treatments.

Association of IL-12B gene rs6887695 polymorphism with hereditary susceptibility and clinical characterization of psoriasis vulgaris in the Chinese Han population

We aimed to investigate the role of IL-12B gene polymorphism (rs6887695) in the disease susceptibility and clinical phenotypes of psoriasis vulgaris patients in the Chinese Han population. The genotype data of the IL-12B gene polymorphism (rs6887695) in 575 psoriasis patients and 1,403 normal controls were investigated using TaqMan technology. The Chi-square test was used to compare the genotype and allele frequency distribution among the groups. The genotypic and allelic frequencies of rs6887695 in the IL-12B gene between the cases and controls, as well as between the guttate and plaque psoriasis cases, were statistically significant (P genotype <0.01, P allele <0.01). However, the differences between the pediatric and adult onset psoriasis patients, between familial and sporadic cases, and between female and male cases were not statistically significant (P > 0.05). The genetic polymorphism of the IL-12B gene (rs6887695) may be associated with the psoriasis susceptibility in the Chinese Han population, especially for the plaque cases, but not associated with the age at onset, family history, or sex.

Association of IL23R polymorphisms with psoriasis and psoriatic arthritis: a meta-analysis

BACKGROUND

The association of variants in the IL23R gene with psoriasis and psoriatic arthritis (PsA) is a robust genetic finding

OBJECTIVES

To assess whether combined evidence shows the association between IL23R polymorphisms and susceptibility to psoriasis/PsA.

METHODS

We conducted a meta-analysis to examine the association between the IL23R rs11209026 (Q381R), rs7530511 (L310P), and rs2201841 polymorphisms and psoriasis/PsA.

RESULTS

Thirteen articles met the inclusion criteria and contributed data to the meta-analysis. For rs11209026, the odds ratios (ORs) of minor alleles for psoriasis and PsA were 0.616 [95 % confidence interval (CI) 0.563-0.674] and 0.630 (95 % CI 0.524-0.757), respectively. For rs7530511, the pooled ORs were 0.820 (95 % CI 0.764-0.879) for psoriasis and 0.875 (95 % CI 0.766-1.000) for PsA; for rs2201841 the OR was 1.121 (95 % CI 1.031-1.219) for psoriasis. In genotypic analysis, the association of rs11209026 (A) and rs7530511 (T) were compatible with the dominant model (P < 0.0001, P = 0.001 respectively). The overall ORs for GG vs. AA (OR 1.339; 95 % CI 1.151-1.558), GG vs. GA (OR 1.143; 95 % CI 1.004-1.300), dominant (OR 1.226; 95 % CI 1.143-1.316), and recessive (OR 1.254; 95 % CI 1.115-1.411) models of rs2201841 were all significantly increased in psoriasis. No publication bias was present.

CONCLUSIONS

Our results demonstrate a significant association between IL23R gene polymorphisms and psoriasis/PsA.

Replication study of 10 genes showing evidence for association with multiple sclerosis: validation of TMEM39A, IL12B and CBLB [correction of CLBL] genes

BACKGROUND AND OBJECTIVES

Ten genes previously showing different evidence of association with multiple sclerosis have been selected to validate.

METHODS

Eleven polymorphisms were genotyped with the iPLEX™ Sequenom in a well-powered collection of Spanish origin including 2863 multiple sclerosis cases and 2930 controls.

RESULTS

Replication extended to the following polymorphisms: PKN2 (rs305217), GTF2B (rs7538427), EPHA4 (rs1517440), YTHDF3 (rs12115114), ANKFN1 (rs17758761) and PTPRM (rs4798571), which did not reach the threshold of significance in a follow-up of the first genome-wide association study (GWAS) conducted in multiple sclerosis; TMEM39A (rs1132200), which appeared as a newly identified susceptibility gene in the same study; a gene previously reaching GWAS significance in Italy, CBLB (rs9657904); IL12B (rs6887695, rs10045431), a susceptibility gene shared by diverse autoimmune diseases and, finally, another gene showing inconclusive association with multiple sclerosis, CNR1 (rs1049353).

CONCLUSIONS

Pooled analysis corroborated the effect on MS predisposition of three genes: TMEM39A [rs1132200: p(M-H)=0.001; OR(M-H) (95% CI)= 0.84 (0.75-0.93)], IL12B [rs6887695: p(M-H)=0.03; OR(M-H) (95% CI)= 1.09 (1.01-1.17)] and CBLB [rs9657904: p(M-H)=0.01; OR(M-H) (95% CI)= 0.89 (0.81-0.97)].