Expression density of receptors to IL-1β in atopic dermatitis

Negative regulator IL-1 receptor 2 (IL-1R2) and its roles in immune regulation of autoimmune diseases

The decoy receptor interleukin 1 receptor 2 (IL-1R2), also known as CD121b, has different forms: membrane-bound (mIL-1R2), soluble secreted (ssIL-1R2), shedded (shIL-1R2), intracellular domain (IL-1R2ICD). The different forms of IL-1R2 exert not exactly similar functions. IL-1R2 can not only participate in the regulation of inflammatory response by competing with IL-1R1 to bind IL-1 and IL-1RAP, but also regulate IL-1 maturation and cell activation, promote cell survival, participate in IL-1-dependent internalization, and even have biological activity as a transcriptional cofactor. In this review, we provide a detailed description of the biological characteristics of IL-1R2 and discuss the expression and unique role of IL-1R2 in different immune cells. Importantly, we summarize the role of IL-1R2 in immune regulation from different autoimmune diseases, hoping to provide a new direction for in-depth studies of pathogenesis and therapeutic targets in autoimmune diseases.

Therapeutic effects and mechanisms of Ku-Gan formula on atopic dermatitis: A pilot clinical study and modular pharmacology analysis with animal validation

ETHNOPHARMACOLOGICAL RELEVANCE

Atopic dermatitis (AD) is a persistent, recurrent inflammatory skin disorder with a rapid upward trend worldwide. The first-line treatment for AD consists of topical medicines such as topical corticosteroids (TCSs). However, long-term use of conventional topical medicine results in side effects and recurrence, presenting therapeutic challenges for the management of AD. Ku-Gan formula (KG) has been extensively used to treat skin diseases since the Song dynasty. In particular, topical administration of the KG alleviates the cutaneous symptoms of AD and reduces recurrence rates with a good safety profile; however, the mechanisms of the KG's action remain unknown.

AIM OF THE STUDY

The current study aimed to evaluate the efficacy and safety of KG in AD patients and to investigate the molecular mechanisms that underlie the efficacy of KG in the treatment of AD.

MATERIALS AND METHODS

A single-arm prospective pilot study with historical controls was conducted. This study evaluated 11 patients with mild to moderate AD, who underwent topical KG treatment. The primary outcome was the change in local eczema area and severity index (EASI) scores. The secondary outcomes included the recurrence rate and safety. The recurrence rate were compared to those of a matched historical control group. Secondly, modular pharmacology analysis was used to elucidate the therapeutic mechanism of KG in AD treatment by identifying the hub genes and kernel pathways. Moreover, we evaluated treatment effects and verified modular pharmacology-based findings using the calcipotriol (MC903)-induced mouse model and bioinformatics analysis.

RESULTS

Our clinical pilot study demonstrated that the KG wet wrapping could effectively ameliorate skin lesions in AD patients with a significant drop from 4.18 to 1.63 in local EASI. Compared to the historical controls, KG had a reduced recurrence rate (36%) and a longer median time to relapse (>12 weeks). Modular pharmacology analysis identified the hub genes including IL6, IL1B, VEGFA, STAT3, JUN, TIMP1 and ARG1, and kernel pathway including IL-17 signaling pathway of KG. Pharmacodynamic results suggested that KG ameliorated skin symptoms and demonstrated no less efficacy than halcinonide (HC) in MC903-induced AD-like mice. In addition, KG regulated the mRNA expression of hub genes as well as the related genes involved in IL-17 signaling pathway including Il25, Il17a,Traf3ip2, and Traf6, in skin lesions of AD-like mice.

CONCLUSION

These results showed that KG is a safe and effective topical treatment for AD with low recurrence. In addition, our study identified potential molecular pathways and therapeutic candidate targets of the KG formula, providing evidence for its clinical applicability in AD.

Attenuation of experimentally induced atopic dermatitis in mice by sulforaphane: effect on inflammation and apoptosis

Atopic dermatitis (AD) is characterized by progressive skin inflammation. In addition, sulforaphane is an isothiocyanate organosulfur compound from cruciferous vegetables. Sulforaphane was reported to ameliorate inflammatory responses. Therefore, this study was conducted to evaluate the protective effects of sulforaphane in AD through affecting the balance between pro-inflammatory and anti-inflammatory cytokines and to evaluate its effect on AD-induced activation of the apoptotic pathway. The method of repeated rubbing of 2,4-dinitrochlorobenzene (DNCB) on shaved dorsal skin and ears of mice was used for induction of AD. After the development of AD, part of the mice was injected with 1 mg/kg sulforaphane, subcutaneously three times weekly. Samples of skin were isolated for assessment of gene and protein expression of 8-hydroxy2'-deoxyguanosine, IgE, NFκB, TNF-α, IL-1β, IL-4, IL-10, Nrf2, and caspase-3. In addition, skin sections from different groups were stained with anti-caspase-3 antibodies. Mice in the AD group were characterized by increased gene and protein expression of 8-hydroxy2'-deoxyguanosine, IgE, NFκB, TNF-α, IL-1β, and caspase-3 associated with reduced expression of Nrf2, IL-4, and IL-10. Treatment of AD mice with sulforaphane significantly reduced the number of scratches, dermatitis score, and ear thickness. In addition, sulforaphane significantly attenuated the gene and protein expressions produced by AD. Therefore, sulforaphane alleviated AD induced in mice through inhibition of oxidative stress, oxidative DNA damage, inflammation, and apoptosis. HIGHLIGHTSAtopic dermatitis is a chronic relapsing inflammatory disease.Sulforaphane is an isothiocyanate organosulfur compound obtained from cruciferous vegetables.Sulforaphane alleviated AD induced in mice.Sulforaphane inhibits oxidative stress, oxidative DNA damage, inflammation, and apoptosis.

Th2 Modulation of Transient Receptor Potential Channels: An Unmet Therapeutic Intervention for Atopic Dermatitis

Atopic dermatitis (AD) is a multifaceted, chronic relapsing inflammatory skin disease that affects people of all ages. It is characterized by chronic eczema, constant pruritus, and severe discomfort. AD often progresses from mild annoyance to intractable pruritic inflammatory lesions associated with exacerbated skin sensitivity. The T helper-2 (Th2) response is mainly linked to the acute and subacute phase, whereas Th1 response has been associated in addition with the chronic phase. IL-17, IL-22, TSLP, and IL-31 also play a role in AD. Transient receptor potential (TRP) cation channels play a significant role in neuroinflammation, itch and pain, indicating neuroimmune circuits in AD. However, the Th2-driven cutaneous sensitization of TRP channels is underappreciated. Emerging findings suggest that critical Th2-related cytokines cause potentiation of TRP channels, thereby exaggerating inflammation and itch sensation. Evidence involves the following: (i) IL-13 enhances TRPV1 and TRPA1 transcription levels; (ii) IL-31 sensitizes TRPV1 via transcriptional and channel modulation, and indirectly modulates TRPV3 in keratinocytes; (iii) The Th2-cytokine TSLP increases TRPA1 synthesis in sensory neurons. These changes could be further enhanced by other Th2 cytokines, including IL-4, IL-25, and IL-33, which are inducers for IL-13, IL-31, or TSLP in skin. Taken together, this review highlights that Th2 cytokines potentiate TRP channels through diverse mechanisms under different inflammatory and pruritic conditions, and link this effect to distinct signaling cascades in AD. This review strengthens the notion that interrupting Th2-driven modulation of TRP channels will inhibit transition from acute to chronic AD, thereby aiding the development of effective therapeutics and treatment optimization.

Epigenetic Regulation of Macrophage Marker Expression Profiles in Kawasaki Disease

Kawasaki disease (KD) is a common systemic vasculitides in children younger than 5 years of age. Activated macrophages are key drivers of vascular inflammation in KD. The aim of this study was to examine differences in M1 and M2 macrophage marker expression in patients with KD. Blood samples were obtained from 18 healthy controls and 18 patients with KD at 24 h prior and 21 days after to intravenous immunoglobulin therapy. GeneChip Human Transcriptome Array 2.0 and Illumina HumanMethylation450 BeadChip were used to examined the mRNA expression and corresponding CpG site methylation ratios of 10 M1 surface markers and 15 M2 surface markers. Of the markers examined 2 M1 markers (TLR2, IL2RA) and 8 M2 markers (ARG1, CCR2, TLR1, TLR8, TLR5, MS4A6A, CD36, and MS4A4A) showed increased mRNA expression in the acute phase of KD which decreased after IVIG therapy (P < 0.05). Corresponding CpG sites in the promoter regions these markers were hypomethylated in the acute phase of KD and significantly increased after IVIG therapy. In conclusion, both M1 and M2 markers showed increased mRNA expression in the acute phase of KD. CpG site methylation may be one of the mechanisms governing macrophage polarization in KD.

Expression Density of Receptors as a Potent Regulator of Cell Function and Property in Health and Pathology

The expression of cytokine receptors has a crucial role in many cellular processes. Recent studies reported that changes of receptor expression could control the action of mediators on target cells. The initiation of different signaling pathways and, therefore, specific effects on cells, depends on certain components forming the cytokine-receptor complex. These mechanisms control the immune response and affect both the course of diseases (oncological, autoimmune, inflammatory) and the effectiveness of therapy. This review describes the potential of immune mediator receptors to regulate the efficiency of cytokine activity during pathologic processes and ensure the variability of their biological effects. Our aim was to investigate the spectrum of potential roles of changes in mediator receptor expression for main classes of pathologies. For all major types of immune mediators (cytokines, interleukins, chemokines, growth factors, and tumor necrosis factors), it has been shown that changes in their receptor expression are associated with impaired functioning of the organism in chronic diseases.

Regulation of IL-1 signaling by the decoy receptor IL-1R2

The pleiotropic cytokine IL-1 mediates its biological functions via association with the signaling receptor IL-1R1. Despite an apparent simplicity in IL-1 signaling activation, multiple negative regulators have been identified. The decoy receptor IL-1R2 (also known as CD121b) can suppress IL-1 maturation, sequester its active forms or hinder the signaling complex assembly. IL-1R2 is differentially expressed among numerous cell types and displays cis- and trans- modes of action. In this review, we link different forms of IL-1R2 (membrane-bound (mIL-1R2), secreted (sIL-1R2), shedded (shIL-1R2), cytoplasmic, and intracellular domain (IL-1R2^ICD) restricted) with their ability to interfere with IL-1, thereby regulating immune responses. We also discuss the intriguing possible function of IL-1R2 as a transcriptional regulator. Finally, we summarize the known impact of IL-1R2 in disease pathogenesis and discuss its potential role in treatment of inflammatory conditions.

Blocking TGF-β type 1 receptor partially reversed skin tissue damage in experimentally induced atopic dermatitis in mice

Animals with impaired transforming growth factor (TGF)-β1 signaling developed spontaneous lethal autoimmune inflammationand autoimmune diseases. Moreover, evidence for modified TGF-β signaling in atopic dermatitis (AD) exists. Therefore, the goal of this study was to determine whether SB-431542, a potent and selective inhibitor of the TGF-β type 1 receptor (TGF-βR1), could attenuate such a severe reaction in mice. In addition, the molecular underpinnings the possible protective effects were also investigated. Repeated epicutaneous application of DNCB was performed on the ear and shaved dorsal skin of miceto induce AD-like symptoms and skin lesions. SB-431542 (1 mg/kg) was given by intra-peritoneal injection three times weekly for 3 weeks to assess the anti-pruritic effects. Serum levels of TGF-β1, TGF-βR1, latency-associated peptide (LAP), tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 were assessed by ELISA. Moreover, the gene expression of TNF-α, IL-1β and IL-6 were determined. Apoptotic pathway was evaluated by measuring the activity of caspase-3 and by staining skin sections with anti-caspase-3 antibodies. We found that SB-431542 alleviated DNCB-induced AD-like symptoms as quantified by skin lesion,dermatitisscore, ear thickness and scratching behavior. In parallel, SB-431542 blocked DNCB-induced elevation in serum levels of TNF-α, TGF-β1, TGF-βR1, LAP, IL-1β, IL-6 and IgE. The collective results indicate that SB-431542 partially suppresses DNCB-induced AD in micevia reduction of TGF-β1 signaling pathway associated with inhibition of inflammation and apoptosis.