IL36G genetic variant is independently associated with susceptibility, severity and joint involvement in psoriasis

Biomarker discovery in psoriatic disease

PURPOSE OF REVIEW

Psoriasis, a chronic skin condition, characterized by scaly erythematous plaques, is prevalent in around 2% of the population. Around 25% of psoriasis patients have psoriatic arthritis (PsA), an inflammatory musculoskeletal disease that often leads to progressive joint damage and disability. Psoriatic diseases (PsD) encompassing psoriasis and PsA, are often associated with pathophysiologically related conditions like uveitis and inflammatory bowel disease as well as comorbidities such as cardiovascular disease. Due to the heterogeneous nature of PsD, diagnosis and treatment is a challenge. Biomarkers can objectively measure variables, such as disease state, disease progress, and treatment outcomes, thus offering the possibility for better management of disease. This review focuses on some of the biomarker research that was carried out in PsD in the past year.

RECENT FINDINGS

Diverse biomarker types ranging from SNPs, mRNA, proteins, metabolites and immune cell profiles have been categorized as per the Biomarkers, EndpointS and other Tools (BEST) resource developed by the FDA/NIH. Some of the latest research has focused on multiomic assays and these along with advanced bioinformatic tools can help in better disease management.

SUMMARY

Recent developments in PsA biomarker research show promise in identifying markers that can help in diagnosis, assess disease activity and predict treatment response. However, most studies are in the early discovery and verification state. Large-scale studies to replicate findings and develop and validate predictive algorithms are required.

IL17RA genetic variants are associated with susceptibility and severity of psoriasis

BACKGROUND

Genetic variants that can play an important role in psoriasis (PsO) ethiology and pathophysiology.

OBJECTIVE

To evaluate the association between the IL17RA genetic variants with the susceptibility and severity of PsO.

METHODS

This study included 154 patients with PsO and 154 healthy controls. The severity of PsO was determined using Psoriatic Activity and Severity Index (PASI). The IL17RA single nucleotide variants T > C rs2241043, A > G rs2241049, and G > A rs6518661 were genotyped.

RESULTS

The IL17RA A > G (rs2241049) GG genotype was associated with protection against PsO [odds ratio (OR): 0.391, 95 % confidence interval (CI):0.199-0.768, p = 0.006)] while the IL17RA T > C (rs2241043) CC genotype and the IL17RA G > A (rs6518661) AA genotype were associated with the PsO severity (OR = 0.30, 95 % CI 0.10-0.093, p = 0.020 and OR = 0.22, 95 % CI 0.05-0.99, p = 0.020, respectively).

CONCLUSION

The results demonstrated that the IL17RA A > G (rs2241049) GG genotype may be a protective factor against the development of PsO and the CC genotype of the IL17RA T > C (rs2241043) and the AA genotype of the IL17RA G > A (rs6518661) variants were associated with protection against the severity of PsO. Considering that these variants are located in intronic regions of the IL17RA, other genetic and epigenetic mechanisms involved in these associations should be investigated.

Dysbiosis of the Gut Microbiota in Patients with Psoriatic Arthritis is Closely Related to Lymphocyte Subsets and Cytokines

The purpose of this research was to characterize the microbiota of patients with psoriatic arthritis (PsA) and to compare the relationship between the microbiota and peripheral lymphocyte subsets and cytokines. We collected stool samples from 13 PsA patients and 26 sex- and age-matched healthy controls (HCs) and researched the gut microbiota by sequencing the V3-V4 variable region of the bacterial 16S rRNA gene with the Illumina Miseq PE300 system. Flow cytometry was used to assess the peripheral lymphocyte subsets in these participants. Record measures of disease activity such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Alpha and beta diversity were assessed using results from QIIME2. Panel demonstrated the average relative abundance of the different genera in PsA and HCs. Correlation between clinical parameters and the relative abundance of the genus in samples was assessed by the Pearson correlation analysis using R (version 4.0.1). Compared with HC, the abundance of gut microbiota (Chao 1 and ACE) decreased in patients with PsA, and the diversity of bacteria (Shannon and Simpson indices) also decreased in PsA (Fig. 1a). β Diversity analysis indicated differences in microbial communities between PsA and HC (Fig. 1b, r = 0.039, p = 0.264, ANOSIM). Furthermore, 18 bacterial groups were significantly different at the genus level in PsA compared to HCs (p < 0.05) (Fig. 2).In the phylum and genus, lymphocyte subsets and cytokines are associated with the microbiota. The gut microbiota of patients with PsA differs from HC, which was closely related to lymphocyte subsets.

IL-36 antagonism blunts the proliferation and migration of oral squamous cell carcinoma cells

IL-36 is known to mediate inflammation and fibrosis. Nevertheless, IL-36 signalling axis has also been implicated in cancer, although understanding of exact contribution of IL-36 to cancer progression is very limited, partly due to existence of multiple IL-36 ligands with agonistic and antagonistic function. Here we explored the role of IL-36 in oral squamous cell carcinoma (OSCC). Firstly, we analyzed expression of IL-36 ligands and receptor and found that the expression of IL-36γ was significantly higher in head and neck cancer (HNSCC) than that of normal tissues, and that the high expression of IL-36γ predicted poor clinical outcomes. Secondly, we investigated the direct effect of IL-36γ on OSCC cells and found that IL-36γ stimulated proliferation of OSCC cells with high expression of IL-36R expression. Interestingly, IL-36γ also promoted migration of OSCC cells with low to high IL-36R expression. Critically, both proliferation and migration of OSCC cells induced by IL-36γ were abrogated by anti-IL-36R mAb. Fittingly, RNA sequence analysis revealed that IL-36γ regulated genes involved in cell cycle and cell division. In summary, our results showed that IL-36γ can be a tumor-promoting factor, and targeting of IL-36R signalling may be a beneficial targeted therapy for patients with abnormal IL-36 signalling.