Promoter Methylation Leads to Decreased ZFP36 Expression and Deregulated NLRP3 Inflammasome Activation in Psoriatic Fibroblasts

Chromosome 9p trisomy increases stem cells clonogenic potential and fosters T-cell exhaustion in JAK2-mutant myeloproliferative neoplasms

JAK2V617F is the most recurrent genetic mutation in Philadelphia-negative chronic Myeloproliferative Neoplasms (MPNs). Since the JAK2 locus is located on Chromosome 9, we hypothesized that Chromosome 9 copy number abnormalities may be a disease modifier in JAK2V617F-mutant MPN patients. In this study, we identified a subset of MPN patients with partial or complete Chromosome 9 trisomy (+9p patients), who differ from JAK2V617F-homozygous MPN patients as they carry three JAK2 alleles as well as three copies of all neighboring gene loci, including CD274, encoding immunosuppressive Programmed death-ligand 1 (PD-L1) protein. Investigation of the clonal hierarchy revealed that the JAK2V617F occurs first, followed by +9p. Functionally, CD34+ cells from +9p MPN patients demonstrated increased clonogenicity, generating a greater number of primitive colonies, due to high OCT4 and NANOG expression, with knock-down of these genes leading to a genotype-specific decrease in colony numbers. Moreover, our analysis revealed increased PD-L1 surface expression in malignant monocytes from +9p patients, while analysis of the T cell compartment unveiled elevated levels of exhausted cytotoxic T cells. Overall, here we identify a distinct novel subgroup of MPN patients, who feature a synergistic interplay between +9p and JAK2V617F that shapes immune escape characteristics and increased stemness in CD34+ cells.

Fibroblast: A Novel Target for Autoimmune and Inflammatory Skin Diseases Therapeutics

Fibroblasts are crucial components of the skin structure. They were traditionally believed to maintain the skin's structure by producing extracellular matrix and other elements. Recent research illuminated that fibroblasts can respond to external stimuli and exhibit diverse functions, such as the secretion of pro-inflammatory factors, adipogenesis, and antigen presentation, exhibiting remarkable heterogeneity and plasticity. This revelation positions fibroblasts as active contributors to the pathogenesis of skin diseases, challenging the traditional perspective that views fibroblasts solely as structural entities. Based on their diverse functions, fibroblasts can be categorized into six subtypes: pro-inflammatory fibroblasts, myofibroblasts, adipogenic fibroblasts, angiogenic fibroblasts, mesenchymal fibroblasts, and antigen-presenting fibroblasts. Cytokines, metabolism, and epigenetics regulate functional abnormalities in fibroblasts. The dynamic changes fibroblasts exhibit in different diseases and disease states warrant a comprehensive discussion. We focus on dermal fibroblasts' aberrant manifestations and pivotal roles in inflammatory and autoimmune skin diseases, including psoriasis, vitiligo, lupus erythematosus, scleroderma, and atopic dermatitis, and propose targeting aberrantly activated fibroblasts as a potential therapeutic strategy for inflammatory and autoimmune skin diseases.

Prevalence of Tobacco Smoking and Its Association With Disease Severity Among Patients With Psoriasis in China: A Cross-Sectional Study

Introduction

Tobacco smoking is associated with the onset and severity of psoriasis, and understanding the prevalence of tobacco smoking among patients with psoriasis is critical due to its high physical and mental influence and heavy disease burden. However, evidence on the association between tobacco smoking and psoriasis severity is still limited in China.

Objectives

The objective of this study was to examine the prevalence of tobacco smoking and explore the association between tobacco smoking and diseases severity among patients with psoriasis.

Methods

A total of 4,529 patients with psoriasis in 200 selected hospitals were recruited in China between January 2020 and September 2021. Detailed information covering demographic feature, tobacco smoking, and psoriasis history were collected through an electronic questionnaire, and clinical data were extracted from the health information system (HIS). SAS 9.4 was used for data analysis, and a p-value of <0.05 was considered statistically significant.

Results

The prevalence of tobacco smoking was 30.8%, with 24.6% for current smoking. The average Psoriasis Area and Severity Index (PASI) score for patients with psoriasis was 9.4, with male patients having a higher PASI score than female patients. The odds ratio (OR) of former tobacco smoking prevalence was 1.5 [95% confidence interval (CI): (1.0-2.3)] for PASI score (3.0-7.0), 2.2 for PASI score (7.1-13.0), and 4.2 for PASI score >13, when compared with patients with PASI score < 3.0. Similarly, the OR of current tobacco smoking prevalence was 1.8 [95% CI: (1.5-2.2)] for PASI score (3.0-7.0), 1.9 for PASI score (7.1-13.0), and 3.1 for PASI score >13, when compared with patients with PASI score <3.0. The Spearman correlation analysis indicated that both tobacco smoking intensity and smoking duration were positively correlated with psoriasis severity (p < 0.05).

Conclusion

The prevalence of tobacco smoking was high, especially among male patients with psoriasis and those with senior high education. Tobacco smoking was positively associated with psoriasis severity; moreover, both smoking intensity and smoking duration were positively correlated with the severity of psoriasis in a dose-dependent fashion.

Activation of the MKK3-p38-MK2-ZFP36 Axis by Coronavirus Infection Restricts the Upregulation of AU-Rich Element-Containing Transcripts in Proinflammatory Responses

Coronavirus infections induce the expression of multiple proinflammatory cytokines and chemokines. We have previously shown that in cells infected with gammacoronavirus infectious bronchitis virus (IBV), interleukin 6 (IL-6), and IL-8 were drastically upregulated, and the MAP kinase p38 and the integrated stress response pathways were implicated in this process. In this study, we report that coronavirus infection activates a negative regulatory loop that restricts the upregulation of a number of proinflammatory genes. As revealed by the initial transcriptomic and subsequent validation analyses, the anti-inflammatory adenine-uridine (AU)-rich element (ARE)-binding protein, zinc finger protein 36 (ZFP36), and its related family members were upregulated in cells infected with IBV and three other coronaviruses, alphacoronaviruses porcine epidemic diarrhea virus (PEDV), human coronavirus 229E (HCoV-229E), and betacoronavirus HCoV-OC43, respectively. Characterization of the functional roles of ZFP36 during IBV infection demonstrated that ZFP36 promoted the degradation of transcripts coding for IL-6, IL-8, dual-specificity phosphatase 1 (DUSP1), prostaglandin-endoperoxide synthase 2 (PTGS2) and TNF-α-induced protein 3 (TNFAIP3), through binding to AREs in these transcripts. Consistently, knockdown and inhibition of JNK and p38 kinase activities reduced the expression of ZFP36, as well as the expression of IL-6 and IL-8. On the contrary, overexpression of mitogen-activated protein kinase kinase 3 (MKK3) and MAPKAP kinase-2 (MK2), the upstream and downstream kinases of p38, respectively, increased the expression of ZFP36 and decreased the expression of IL-8. Taken together, this study reveals an important regulatory role of the MKK3-p38-MK2-ZFP36 axis in coronavirus infection-induced proinflammatory response. IMPORTANCE Excessive and uncontrolled induction and release of proinflammatory cytokines and chemokines, the so-called cytokine release syndrome (CRS), would cause life-threatening complications and multiple organ failure in severe coronavirus infections, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and COVID-19. This study reveals that coronavirus infection also induces the expression of ZFP36, an anti-inflammatory ARE-binding protein, promoting the degradation of ARE-containing transcripts coding for IL-6 and IL-8 as well as a number of other proteins related to inflammatory response. Furthermore, the p38 MAP kinase, its upstream kinase MKK3 and downstream kinase MK2 were shown to play a regulatory role in upregulation of ZFP36 during coronavirus infection cycles. This MKK3-p38-MK2-ZFP36 axis would constitute a potential therapeutic target for severe coronavirus infections.

ZC3H12C expression in dendritic cells is necessary to prevent lymphadenopathy of skin‐draining lymph nodes

The role of RNA‐binding proteins of the CCCH‐containing family in regulating proinflammatory cytokine production and inflammation is increasingly recognized. We have identified ZC3H12C (Regnase‐3) as a potential post‐transcriptional regulator of tumor necrosis factor expression and have investigated its role in vivo by generating Zc3h12c‐deficient mice that express green fluorescent protein instead of ZC3H12C. Zc3h12c‐deficient mice develop hypertrophic lymph nodes. In the immune system, ZC3H12C expression is mostly restricted to the dendritic cell (DC) populations, and we show that DC‐restricted ZC3H12C depletion is sufficient to cause lymphadenopathy. ZC3H12C can regulate Tnf messenger RNA stability via its RNase activity in vitro, and we confirmed the role of Tnf in the development of lymphadenopathy. Finally, we found that loss of ZC3H12C did not impact the outcome of skin inflammation in the imiquimod‐induced murine model of psoriasis, despite Zc3h12c being identified as a risk factor for psoriasis susceptibility in several genome‐wide association studies. Our data suggest a role for ZC3H12C in DC‐driven skin homeostasis.

NLRP3 Inflammasome: Checkpoint Connecting Innate and Adaptive Immunity in Autoimmune Diseases

Autoimmune diseases are a broad spectrum of human diseases that are characterized by the breakdown of immune tolerance and the production of autoantibodies. Recently, dysfunction of innate and adaptive immunity is considered to be a key step in the initiation and maintenance of autoimmune diseases. NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a multimeric protein complex, which can detect exogenous pathogen irritants and endogenous danger signals. The main function of NLRP3 inflammasome is to promote secretion of interleukin (IL)-1β and IL-18, and pyroptosis mediated by caspase-1. Served as a checkpoint in innate and adaptive immunity, aberrant activation and regulation of NLRP3 inflammasome plays an important role in the pathogenesis of autoimmune diseases. This paper reviewed the roles of NLRP3 inflammasome in autoimmune diseases, which shows NLRP3 inflammasome may be a potential target for autoimmune diseases deserved further study.