Association of STAT4 rs7574865 polymorphism with susceptibility to inflammatory bowel disease: A systematic review and meta-analysis

Understanding the efficacy of individual Janus kinase inhibitors in the treatment of ulcerative colitis for future positioning in inflammatory bowel disease treatment

Recent studies have gradually elucidated the pathogenesis of inflammatory bowel disease; thus, the Janus kinase (JAK)-signal transducers and activators of transcription pathway are strongly involved in the pathophysiology of inflammatory bowel disease. Generally, Janus kinase inhibitors are being used for the treatment of rheumatoid arthritis and other immunological diseases, with the therapeutic promising effects. Currently, in Japan, three Janus kinase inhibitors, namely tofacitinib, filgotinib, and upadacitinib, are available for the treatment of patients with active ulcerative colitis. Therefore, evaluating the efficacy and safety of each JAK inhibitor is essential for determining the role of JAK inhibitors in future therapeutic strategies for inflammatory bowel disease (IBD).

SJÖGREN SENDROMU İLE BAZI GEN POLİMORFİZMLERİ ARASINDAKİ OLASI BAĞLANTILAR

Objective: Sjögren’s syndrome is a complex and widespread autoimmune disease whose pathogenesis is not fully elucidated and environmental and genetic factors affect the development of the disease. In order to reveal the effect of genetic contribution, studies have been conducted on the genes previously shown to play a role in other autoimmune diseases such as systemic lupus erythromatosus. In addition, two GWAS studies were conducted to investigate the role of more genes in the disease by screening the entire genome and the relationship of previously unknown genes with SS was shown. Result and Discussion: Studies are being conducted with spontaneous and genetically modified animal models in order to better reveal the relationship between SS and genes and to reinforce the data obtained from humans. In this study, the relationship between the genes previously studied in other autoimmune diseases and the genes associated with SS in GWAS studies and the possible pathways that may contribute to the pathogenesis of the disease through related genes were investigated.

Genetic determinants of immune-related adverse events in patients with melanoma receiving immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) can cause profound immune-related adverse events (irAEs). The host genetic background is likely to play a role in irAE susceptibility because the presentation of toxicity varies among patients and many do not develop irAEs despite continued ICI use. We sought to identify potential genetic markers conferring risk for irAEs.

METHODS

We conducted a pilot exploratory study in 89 melanoma patients who received ICIs (44 with irAEs, and 45 without irAEs after at least 1 year from starting treatment). Genotyping was performed using the Infinium Multi-Ethnic Global-8 v1.0 Bead Chip. The genotype data were extracted using PLINK (v1.90b3.34) and processed for quality control. Population structure-based clustering was carried out using IBS matrix, pairwise population concordance test (p < 1 × 10-3), and phenotype distribution for all study participants, resulting in seven population structure-based clusters. In the analytical stage, 599,931 variants in autosomal chromosomes were included for the association study. The association test was performed using an additive genetic model with exact logistic regression, adjusted for age, sex, and population cluster.

RESULTS

A total of 30 variants or single-nucleotide polymorphisms with p < 1 × 10-4 were identified; 12 were associated with an increased risk of irAEs, and the remaining 18 were associated with a decreased risk. Overall, nine of the identified single-nucleotide polymorphisms mapped to eight unique genes that have been associated with autoimmunity or inflammatory diseases.

CONCLUSION

Several genetic variants associated with irAEs were identified. Additional larger studies are needed to validate these findings and establish their potential functional relevance.

Differential regulation of JAK/STAT-signaling in patients with ulcerative colitis and Crohn’s disease

In 2018, the pan-Janus kinase (JAK) inhibitor tofacitinib was launched for the treatment of ulcerative colitis (UC). Although tofacitinib has proven efficacious in patients with active UC, it failed in patients with Crohn’s disease (CD). This finding strongly hints at a different contribution of JAK signaling in both entities. Here, we review the current knowledge on the interplay between the JAK/signal transducer and activator of transcription (STAT) pathway and inflammatory bowel diseases (IBD). In particular, we provide a detailed overview of the differences and similarities of JAK/STAT-signaling in UC and CD, highlight the impact of the JAK/STAT pathway in experimental colitis models and summarize the published evidence on JAK/STAT-signaling in immune cells of IBD as well as the genetic association between the JAK/STAT pathway and IBD. Finally, we describe novel treatment strategies targeting JAK/STAT inhibition in UC and CD and comment on the limitations and challenges of the new drug class.

Human diseases caused by impaired signal transducer and activator of transcription and Janus kinase signaling

PURPOSE OF REVIEW

The Janus kinase (JAK) and signal transducer of activation (STAT) pathway plays a key role in the immune system. It is employed by diverse cytokines, interferons, growth factors and related molecules. Mutations in JAK/STAT pathway have been implicated in human disease. Here we review JAK/STAT biology and diseases associated with mutations in this pathway.

RECENT FINDINGS

Over the past 10 years, many mutations in JAK/STAT pathway has been discovered. These disorders have provided insights to human immunology.

SUMMARY

In this review, we summarize the biology of each STAT and JAK as well as discuss the human disease that results from somatic or germline mutations to include typical presentation, immunological parameters and treatment.

Positive association between MIC gene polymorphism and tuberculosis in Chinese population

The disease progression and morbidity of tuberculosis (TB) infections are determined by virulence of the micro-organism, host genetic factors and environmental factors. The highly polymorphic MHC class I chain-related gene (MIC) could serve as a potential host genetic candidate. To investigate the association of MIC polymorphism with TB infection, 124 patients and 191 ethnically matched controls from Hunan province, Southern China, were genotyped for the MIC polymorphism using polymerase chain reaction-sequence specific priming and sequencing-based typing. The results showed that allele frequencies of MIC-sequence and MICA-STR were different in TB patients in comparison to normal controls (both P < 0.05). MICA-A4 and MICA*012:01 alleles were positive associated (OR = 2.42, 95% CI: 1.69-3.87; OR = 3.41, 95% CI: 2.19-5.33, respectively, both P_c < 0.05) while MICA -A5 were inversely associated (OR = 0.59, 95%CI: 0.41-0.94, P_c < 0.05) with TB. Homozygote MICA*012:01/012:01 was observed to have significant risk effects on TB (OR = 4.76, 95% CI: 1.94-11.69, P_c0000-0001-5151-1853 < 0.05). Additionally, MICB*008 allele conduct a significant risk effect for TB (OR = 3.17, 95%CI: 1.80-5.61, P_c < 0.05). All the data showed that MIC polymorphism was associated with the variable susceptibility to TB in Chinese population.

Polymorphisms in the STAT4 gene and tuberculosis susceptibility in a Chinese Han population

The signal transducer and activator of transcription 4 (STAT4) gene encodes a transcription factor that transmits signals induced by several cytokines which play critical roles in the development of autoimmune and chronic inflammatory diseases. We performed an association study between STAT4 single nucleotide polymorphisms (SNPs) and tuberculosis (TB). 624 TB cases and 598 healthy controls were studied to compare allele/genotype frequencies of 4 SNPs in STAT4. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. Genotyping was performed with the Sequenom MassARRAY SNP genotyping platform. Out of 4 SNPs tested in the study, rs4853542 allele A showed a 25% decreased risk of TB compared with allele G (P = 0.013, OR = 0.75, 95%CI: 0.60-0.94). However, it did not show significant differences under any genetic model after Bonferroni correction. No association was found for the other 3 SNPs with TB. In subgroup analyses, the protective effects of rs485342 allele A were stronger among younger subjects <25 years (P = 0.002, OR = 0.49, 95%CI: 0.31-0.76). Allele A of the rs4853542 polymorphism in STAT4 is not associated with TB susceptibility, but we demonstrated that rs4853542A allele decreased risk of TB in younger adults after Bonferroni correction.

Polymorphisms of the STAT4 gene in the pathogenesis of tuberculosis

The signal transducer and activator of transcription 4 (STAT4) gene encodes a transcription factor that transmits signals induced by several cytokines which play critical roles in the development of autoimmune and chronic inflammatory diseases. In the present study, we have investigated the association between STAT4 polymorphisms and a predisposition to Mycobacterium tuberculosis (MTB) infection and pulmonary tuberculosis (PTB). In the present study, a total of 209 cases of PTB, 201 subjects with latent TB infection (LTBI), and 204 healthy controls (HC) were included. Logistic regression analyses were used to calculate P-values, odds ratios (ORs), and 95% confidence intervals (CIs) for assessing the association between single nucleotide polymorphisms (SNPs) and disease risk. We used Bonferroni correction to adjust the P-values. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR) method. For the rs7574865 polymorphism, the GT genotype is less frequent in the LTBI group compared with HC (P=0.028, OR = 0.62; 95%CI: 0.40-0.95). In addition, the prevalence of the rs897200 CC genotype was lower in the PTB cases compared with LTBI individuals (P=0.039, OR = 0.54; 95%CI: 0.30-0.97). However, no SNPs within STAT4 were associated with PTB or LTBI after Bonferroni correction. Our study demonstrated that STAT4 variants were not related to LTBI and PTB.

STAT4 gene polymorphism in patients after renal allograft transplantation

Introduction

STAT4 (signal transducer and activator of transcription 4) is involved in the regulation of innate and adaptive immune responses. Some studies have suggested that STAT4 may be involved in the immune response after graft transplantation. Several polymorphisms in the STAT4 gene have been identified. The most commonly studied polymorphism in the STAT4 gene is rs7574865. In our study, we examined whether this polymorphism is associated with the early and late functions of renal allografts.

Material and methods

A total of 270 recipients of first renal transplants were included in the study. Single nucleotide polymorphisms (SNPs) within the STAT4 gene were genotyped using TaqMan genotyping assays.

Results

There were no statistically significant associations between the STAT4 gene rs7574865 polymorphism and delayed graft function, acute rejection, chronic allograft dysfunction, post-transplant diabetes mellitus, or creatinine serum concentrations after transplantation.

Conclusions

Our results suggest a lack of association between the STAT4 rs7574865 SNP and kidney allograft function in the Polish population.

Integrating Immunologic Signaling Networks: The JAK/STAT Pathway in Colitis and Colitis-Associated Cancer

Cytokines are believed to be crucial mediators of chronic intestinal inflammation in inflammatory bowel diseases (IBD) such as Crohn's disease (CD) and ulcerative colitis (UC). Many of these cytokines trigger cellular effects and functions through signaling via janus kinase (JAK) and signal transducer and activator of transcription (STAT) molecules. In this way, JAK/STAT signaling controls important events like cell differentiation, secretion of cytokines or proliferation and apoptosis in IBD in both adaptive and innate immune cells. Moreover, JAK/STAT signaling, especially via the IL-6/STAT3 axis, is believed to be involved in the transition of inflammatory lesions to tumors leading to colitis-associated cancer (CAC). In this review, we will introduce the main cellular players and cytokines that contribute to pathogenesis of IBD by JAK/STAT signaling, and will highlight the integrative function that JAK/STATs exert in this context as well as their divergent role in different cells and processes. Moreover, we will explain current concepts of the implication of JAK/STAT signaling in CAC and finally discuss present and future therapies for IBD that interfere with JAK/STAT signaling.

Genetically engineered mouse models for studying inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation.