Effects of the Janus kinase inhibitor CP-690550 (tofacitinib) in a rat model of oxazolone-induced chronic dermatitis

The evaluation of JAK inhibitors on effect and safety in alopecia areata: a systematic review and meta-analysis of 2018 patients

Background

JAK inhibitors treat various autoimmune diseases, but an updated systematic review in treating alopecia areata is currently lacking.

Objective

Evaluate the specific efficacy and safety of JAK inhibitors in alopecia areata by systematic review and meta-analysis.

Methods

Eligible studies in PubMed, Embase, Web of Science, and Clinical Trials up to May 30, 2022, were searched. We enrolled in randomized controlled trials and observational studies of applying JAK inhibitors in alopecia areata.

Results

6 randomized controlled trials with 1455 patients exhibited SALT₅₀ (odd ratio [OR], 5.08; 95% confidence interval [CI], 3.49-7.38), SALT₉₀ (OR, 7.40; 95% CI, 4.34-12.67) and change in SALT score (weighted mean difference [WSD], 5.55; 95% CI, 2.60-8.50) compared to the placebo. The proportion of 26 observational studies with 563 patients of SALT₅ was 0.71(95% CI, 0.65-0.78), SALT₅₀ was 0.54(95% CI 0.46-0.63), SALT₉₀ was 0.33(95% CI, 0.24-0.42), and SALT score (WSD, -2.18; 95% CI, -3.12 to -1.23) compared with baseline. Any adverse effects occurred in 921 of 1508 patients; a total of 30 patients discontinued the trial owing to adverse reactions.

Limitations

Few randomized controlled trials met the inclusion criteria and insufficiency of eligible data.

Conclusion

JAK inhibitors are effective in alopecia areata, although associated with an increased risk.

A Review on the Safety of Using JAK Inhibitors in Dermatology: Clinical and Laboratory Monitoring

Janus kinase (JAK) inhibitors are disease-modifying agents with efficacy in treating a spectrum of burdensome dermatologic conditions. The US Food and Drug Administration (FDA) recently placed a black box warning on this class of medications due to safety concerns based on data from studies investigating tofacitinib in patients with rheumatoid arthritis. Here we provide an overview of the timeline of FDA approval of JAK inhibitors in dermatology. We also discuss the available safety profiles of approved oral JAK1 inhibitors, namely abrocitinib and upadacitinib, oral baricitinib, a JAK1/2 inhibitor, deucravacitinib, a Tyk2 inhibitor, and the topical JAK1/2 inhibitor ruxolitinib in dermatology patients. Additionally, we offer suggestions for initial screening and laboratory monitoring for patients receiving JAK inhibitors. We found that the rates of venous thromboembolism reported in trials ranged from no events to 0.1-0.5% in dermatology-specific phase 3 clinical trials compared with no events in the placebo. The rates of cardiovascular events ranged from no events to 0.4-1.2% compared with no events to 0.5-1.2% in the placebo. The rates of serious infections were 0.4-4.8% compared with no events to 0.5-1.3% in the placebo. The rates of nonmelanoma skin cancer (NMSC) ranged from no event to 0.6-0.9% compared with no events in the placebo. The rates of non-NMSC ranged from no event to 0.2-0.7% compared with no event to 0.6% in the placebo. Most patients who developed these adverse events had risk factors for the specific event. The most common adverse events of oral JAK inhibitors included upper respiratory infections, nasopharyngitis, nausea, headache, and acne. Dermatologists should consider patients' baseline risk factors for developing serious complications when prescribing oral JAK inhibitors.

Evaluation of topical oclacitinib and nail trimming as a treatment for murine ulcerative dermatitis in laboratory mice

Murine ulcerative dermatitis (UD) is a common, multifactorial skin disease of C57BL/6 and C57BL/6-background strains of mice. Many treatment options have been previously reported but have been variably successful and may interfere with specific research studies. Janus kinase (JAK) inhibitors, such as oclacitinib, have been used to treat allergic dermatitis in humans, dogs, and other species. Additionally, topical oclacitinib was shown to improve an induced model of dermatitis in mice. We hypothesized that topical application of oclacitinib in conjunction with hind limb nail trimming would improve UD lesion scores more than our institutional standard treatment regime using meloxicam, topical antibiotic ointment, and nail trimming or nail trimming alone. To test this, mice with naturally occurring UD were recruited to the study and assigned to one of three treatment groups (n = 14/group): nail trim only; nail trim plus meloxicam and topical triple antibiotic ointment; or nail trim plus topical oclacitinib. UD was assessed on days 1, 7, and 14 for all treatment groups, and scored based on a previously published scoring system that quantitatively scored UD lesions based on pruritus, character of the lesion, size of lesion, and location of lesion. Here we found that mean UD scores decreased from day 1 to day 7 and from day 1 to day 14 for all treatment groups. However, there was no significant difference in mean UD score between the treatment groups at any timepoint. These data show that topical oclacitinib and nail trimming together improved UD lesion scores comparably to our institutional standard treatment and nail trimming alone. However, further studies may be warranted to investigate other potential applications of oclacitinib to treat UD.

Target-Based Small Molecule Drug Discovery Towards Novel Therapeutics for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a class of severe and chronic diseases of the gastrointestinal (GI) tract with recurrent symptoms and significant morbidity. Long-term persistence of chronic inflammation in IBD is a major contributing factor to neoplastic transformation and the development of colitis-associated colorectal cancer. Conversely, persistence of transmural inflammation in CD is associated with formation of fibrosing strictures, resulting in substantial morbidity. The recent introduction of biological response modifiers as IBD therapies, such as antibodies neutralizing tumor necrosis factor (TNF)-α, have replaced nonselective anti-inflammatory corticosteroids in disease management. However, a large proportion (~40%) of patients with the treatment of anti-TNF-α antibodies are discontinued or withdrawn from therapy because of (1) primary nonresponse, (2) secondary loss of response, (3) opportunistic infection, or (4) onset of cancer. Therefore, the development of novel and effective therapeutics targeting specific signaling pathways in the pathogenesis of IBD is urgently needed. In this comprehensive review, we summarize the recent advances in drug discovery of new small molecules in preclinical or clinical development for treating IBD that target biologically relevant pathways in mucosal inflammation. These include intracellular enzymes (Janus kinases, receptor interacting protein, phosphodiesterase 4, IκB kinase), integrins, G protein-coupled receptors (S1P, CCR9, CXCR4, CB2) and inflammasome mediators (NLRP3), etc. We will also discuss emerging evidence of a distinct mechanism of action, bromodomain-containing protein 4, an epigenetic regulator of pathways involved in the activation, communication, and trafficking of immune cells. We highlight their chemotypes, mode of actions, structure-activity relationships, characterizations, and their in vitro/in vivo activities and therapeutic potential. The perspectives on the relevant challenges, new opportunities, and future directions in this field are also discussed.

Progranulin promotes osteogenic differentiation of periodontal membrane stem cells in both inflammatory and non-inflammatory conditions

Objective

The growth factor progranulin (PGRN) is widely expressed and plays important roles in anti-inflammatory signaling and bone regeneration. However, the anti-inflammatory and pro-osteogenic roles of PGRN in periodontitis are seldom studied. We used an in vitro model to investigate whether PGRN can promote osteogenic differentiation of periodontal ligament stem cells (PDLSCs).

Methods

PDLSCs were treated with PGRN (0 to 100 ng/mL) and the optimal concentrations required to induce proliferation and osteogenesis were identified. PDLSCs were cultured with 10 ng/mL tumor necrosis factor (TNF)-α, 25 ng/mL PGRN, or 10 ng/mL TNF-α + 25 ng/ml PGRN; untreated PDLSCs were used as controls. The effects of PGRN on PDLSC proliferation and osteogenic differentiation were assessed.

Results

PGRN (5, 25, and 50 ng/mL) promoted PDLSC proliferation and osteogenic differentiation, with the 25-ng/mL dose showing the largest effect. Furthermore, 25 ng/mL PGRN reversed inhibition of osteogenic differentiation by TNF-α.

Conclusion

PGRN promotes PDLSC proliferation, osteogenic differentiation, and mineralization in both inflammatory and non-inflammatory conditions. The 25-ng/mL PRGN dose was the most suitable for inducing proliferation and osteogenesis. Further studies using animal models will be required to obtain pre-clinical evidence to support using PGRN as a treatment for periodontitis.

Single-Cell Profiling Reveals Divergent, Globally Patterned Immune Responses in Murine Skin Inflammation

Inflammatory response heterogeneity has impeded high-resolution dissection of diverse immune cell populations during activation. We characterize mouse cutaneous immune cells by single-cell RNA sequencing, after inducing inflammation using imiquimod and oxazolone dermatitis models. We identify 13 CD45⁺ subpopulations, which broadly represent most functionally characterized immune cell types. Oxazolone pervasively upregulates Jak2/Stat3 expression across T cells and antigen-presenting cells (APCs). Oxazolone also induces Il4/Il13 expression in newly infiltrating basophils, and Il4ra and Ccl24, most prominently in APCs. In contrast, imiquimod broadly upregulates Il17/Il22 and Ccl4/Ccl5. A comparative analysis of single-cell inflammatory transcriptional responses reveals that APC response to oxazolone is tightly restricted by cell identity, whereas imiquimod enforces shared programs on multiple APC populations in parallel. These global molecular patterns not only contrast immune responses on a systems level but also suggest that the mechanisms of new sources of inflammation can eventually be deduced by comparison to known signatures.

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Oxazolone pervasively upregulates Jak2/Stat3 expression across T cells and APCs

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Il4/Il13 induction in skin by oxazolone is dominated by infiltrating basophils

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Imiquimod broadly increases Il17/Il22 and Ccl4/Ccl5, extending to non-T cells

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Oxazolone induces more highly compartmentalized immune cell responses than imiquimod

Recent updates on the basic mechanisms and pathogenesis of inflammatory bowel diseases in experimental animal models

The specific pathogenesis underlining inflammatory bowel disease (IBD) is very complicated, and it is further more difficult to clearly explain the pathophysiology of 2 major forms of IBD, Crohn’s disease (CD) and ulcerative colitis (UC), and both disorders affect individuals throughout life. Despite every extensive effort, the interplay among genetic factors, immunological factors, environmental factors and intestinal microbes is still completely unrevealed. Animal models are indispensable to find out mechanistic details that will facilitate better preclinical setting to target specific components involved in the pathogenesis of IBD. Based on many recent reports, dysbiosis of the commensal microbiota is implicated in the pathogenesis of several diseases, not only IBD but also colon cancer, obesity, psoriasis as well as allergic disorders, in both human and animal models. Advanced technologies including cell-specific and inducible knockout systems, which are recently employed to mouse IBD models, have further enhanced the ability of developing new therapeutic strategies for IBD. Furthermore, data from these mouse models highlight the critical involvement of dysregulated immune responses and impaired colonic epithelial defense system in the pathogenesis of IBD. In this review, we will explain from the history of animal models of IBD to the recent reports of the latest compounds, therapeutic strategies, and approaches tested on IBD animal models.

Design, synthesis, and pharmacological evaluation of 4- or 6-phenyl-pyrimidine derivatives as novel and selective Janus kinase 3 inhibitors

As non-receptor tyrosine kinases, Janus kinases (JAKs) have become an attractive target for the treatment of autoimmune diseases and cancers. JAKs play a pivotal role in innate immunity, inflammation, and hematopoiesis by mediating the signaling of numerous cytokines, growth factors, and interferons (IFNs). Selective inhibitors of a variety of JAK members are expected to inhibit pro-inflammatory cytokine-mediated inflammation and immune responses, while preventing targeting other subtypes of JAKs. In this work, poorly selective compounds based on 4- or 6-phenyl-pyrimidine derivatives have been improved to highly potent and selective compounds by designing a covalent binding tether, which attaches to the unique cysteine (Cys909) residue in JAK3. Compound 12 exhibited potent JAK3 inhibitory activity (IC₅₀ = 1.7 nM) with an excellent selectivity profile when compared to the other JAK isoforms (>588-fold). In a cellular assay, compound 12 strongly inhibited JAK3-dependent signaling and T cell proliferation. Moreover, in vivo data revealed that compound 12 significantly suppressed oxazolone (OXZ)-induced delayed hypersensitivity responses in Balb/c mice. Compound 12 also displayed decent pharmacokinetic properties and was suitable for in vivo use. Taken together, these results indicated that compound 12 may be a promising tool compound as a selective JAK3 inhibitor for treating autoimmune diseases.

Emerging Topical and Systemic JAK Inhibitors in Dermatology

Accumulating data on cellular and molecular pathways help to develop novel therapeutic strategies in skin inflammation and autoimmunity. Examples are psoriasis and atopic dermatitis, two clinically and immunologically well-defined disorders. Here, the elucidation of key pathogenic factors such as IL-17A/IL-23 on the one hand and IL-4/IL-13 on the other hand profoundly changed our therapeutic practice. The knowledge on intracellular pathways and governing factors is shifting our attention to new druggable molecules. Multiple cytokine receptors signal through Janus kinases (JAKs) and associated signal transducer and activators of transcription (STATs). Inhibition of JAKs can simultaneously block the function of multiple cytokines. Therefore, JAK inhibitors (JAKi) are emerging as a new class of drugs, which in dermatology can either be used systemically as oral drugs or locally in topical formulations. Inhibition of JAKs has been shown to be effective in various skin disorders. The first oral JAKi have been recently approved for the treatment of rheumatoid arthritis and psoriatic arthritis. Currently, multiple inhibitors of the JAK/STAT pathway are being investigated for skin diseases like alopecia areata, atopic dermatitis, dermatomyositis, graft-versus-host-disease, hidradenitis suppurativa, lichen planus, lupus erythematosus, psoriasis, and vitiligo. Here, we aim to discuss the immunological basis and current stage of development of JAKi in dermatology.

Targeting the Janus Kinase Family in Autoimmune Skin Diseases

Autoimmune skin diseases are characterized by significant local and systemic inflammation that is largely mediated by the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway. Advanced understanding of this pathway has led to the development of targeted inhibitors of Janus kinases (JAKinibs). As a class, JAK inhibitors effectively treat a multitude of hematologic and inflammatory diseases. Growing evidence suggests that JAK inhibitors are efficacious in atopic dermatitis, alopecia areata, psoriasis, and vitiligo. Additional evidence suggests that JAK inhibition might be broadly useful in dermatology, with early reports of efficacy in several other conditions. JAK inhibitors can be administered orally or used topically and represent a promising new class of medications. Here we review the evolving data on the role of the JAK-STAT pathway in inflammatory dermatoses and the potential therapeutic benefit of JAK-STAT antagonism.

Inhibition of pSTAT1 by tofacitinib accounts for the early improvement of experimental chronic synovitis

Background

In order to gain insight into the early effects drawn by JAK inhibitors on intra-joint JAK/STAT-dependent signaling, we sought synovial activation of STATs and their end-products, along with their modification with tofacitinib (TOFA), at flare-up in antigen induced arthritis (AIA). New Zealand rabbits were randomly assigned to four groups –healthy controls, AIA, TOFA-treated AIA, or TOFA-treated controls–. AIA was induced with 4 weekly intra-articular ovalbumin injections in sensitized animals. TOFA (10 mg·kg^− 1·day^− 1) was administered for the last 2 weeks. Animals were euthanized 24 h after the last injection.

Results

AIA animals showed high-grade synovitis, which was partially improved by TOFA. No effects of the treatment were found on serum C-reactive protein or on the synovial macrophage infiltration at this stage. Synovial MMP-1,-3 and -13 expression levels in treated AIA rabbits were found to drop to those of controls, while a downregulation of IL6, IFNγ and TNF was evident in treated versus untreated AIA rabbits. Concurrently, a reduction in pSTAT1 and SOCS1, but not in pSTAT3, SOCS3 or active NFκB-p65, was noted with TOFA.

Conclusions

Studying the mechanism of action of immunomodulatory drugs represents a major challenge in vivo, since drug-dependent decreases in inflammation very likely mask direct effects on disease mechanisms. This study design allowed us to prevent any confounding effect resulting from reductions in the overall inflammatory status, hence assessing the true pharmacological actions of TOFA in a very severe synovitis. Our findings point to pSTAT1 and MMPs as early molecular readouts of response to this JAK inhibitor.

Electronic supplementary material

The online version of this article (10.1186/s12950-019-0206-2) contains supplementary material, which is available to authorized users.

Neural Network Modeling of AChE Inhibition by New Carbazole-Bearing Oxazolones

Acetylcholine esterase (AChE) is one of the targeted enzymes in the therapy of important neurodegenerative diseases such as Alzheimer's disease. Many studies on carbazole- and oxazolone-based compounds have been conducted in the last decade due to the importance of these compounds. New carbazole-bearing oxazolones were synthesized from several carbazole aldehydes and p-nitrobenzoyl glycine as AChE inhibitors by the Erlenmeyer reaction in the present study. The inhibitory effects of three carbazole-bearing oxazolone derivatives on AChE were studied in vitro and the experimental results were modeled using artificial neural network (ANN). The developed ANN provided sufficient correlation between several dependent systems, including enzyme inhibition. The inhibition data for AChE were modeled by a two-layered ANN architecture. High correlation coefficients were observed between the experimental and predicted ANN results. Synthesized carbazole-bearing oxazolone derivatives inhibited AChE under in vitro conditions, and further research involving in vivo studies is recommended. An ANN may be a useful alternative modeling approach for enzyme inhibition.

Tofacitinib restores the inhibition of reverse cholesterol transport induced by inflammation: understanding the lipid paradox associated with rheumatoid arthritis

BACKGROUND AND PURPOSE

Patients with active rheumatoid arthritis (RA) have increased cardiovascular mortality, paradoxically associated with reduced circulating lipid levels. The JAK inhibitor tofacitinib ameliorates systemic and joint inflammation in RA with a concomitant increase in serum lipids. We analysed the effect of tofacitinib on the lipid profile of hyperlipidaemic rabbits with chronic arthritis (CA) and on the changes in reverse cholesterol transport (RCT) during chronic inflammation.

EXPERIMENTAL APPROACH

CA was induced in previously immunized rabbits, fed a high-fat diet, by administering four intra-articular injections of ovalbumin. A group of rabbits received tofacitinib (10 mg·kg-1 ·day-1 ) for 2 weeks. Systemic and synovial inflammation and lipid content were evaluated. For in vitro studies, THP-1-derived macrophages were exposed to high lipid concentrations and then stimulated with IFNγ in the presence or absence of tofacitinib in order to study mediators of RCT.

KEY RESULTS

Tofacitinib decreased systemic and synovial inflammation and increased circulating lipid levels. Although it did not modify synovial macrophage density, it reduced the lipid content within synovial macrophages. In foam macrophages in culture, IFNγ further stimulated intracellular lipid accumulation, while the JAK/STAT inhibition provoked by tofacitinib induced lipid release by increasing the levels of cellular liver X receptor α and ATP-binding cassette transporter (ABCA1) synthesis.

CONCLUSIONS AND IMPLICATIONS

Active inflammation could be associated with lipid accumulation within macrophages of CA rabbits. JAK inhibition induced lipid release through RCT activation, providing a plausible explanation for the effect of tofacitinib on the lipid profile of RA patients.

JAK inhibitors in dermatology: The promise of a new drug class

New molecularly targeted therapeutics are changing dermatologic therapy. Janus kinase-signal transducer and activator of transcription (JAK-STAT) is an intracellular signaling pathway upon which many different proinflammatory signaling pathways converge. Numerous inflammatory dermatoses are driven by soluble inflammatory mediators, which rely on JAK-STAT signaling, and inhibition of this pathway using JAK inhibitors might be a useful therapeutic strategy for these diseases. Growing evidence suggests that JAK inhibitors are efficacious in atopic dermatitis, alopecia areata, psoriasis, and vitiligo. Additional evidence suggests that JAK inhibition might be broadly useful in dermatology, with early reports of efficacy in several other conditions. JAK inhibitors can be administered orally or used topically and represent a promising new class of medications. The use of JAK inhibitors in dermatology is reviewed here.

JAK3 as an Emerging Target for Topical Treatment of Inflammatory Skin Diseases

The recent interest and elucidation of the JAK/STAT signaling pathway created new targets for the treatment of inflammatory skin diseases (ISDs). JAK inhibitors in oral and topical formulations have shown beneficial results in psoriasis and alopecia areata. Patients suffering from other ISDs might also benefit from JAK inhibition. Given the development of specific JAK inhibitors, the expression patterns of JAKs in different ISDs needs to be clarified. We aimed to analyze the expression of JAK/STAT family members in a set of prevalent ISDs: psoriasis, lichen planus (LP), cutaneous lupus erythematosus (CLE), atopic dermatitis (AD), pyoderma gangrenosum (PG) and alopecia areata (AA) versus healthy controls for (p)JAK1, (p)JAK2, (p)JAK3, (p)TYK2, pSTAT1, pSTAT2 and pSTAT3. The epidermis carried in all ISDs, except for CLE, a strong JAK3 signature. The dermal infiltrate showed a more diverse expression pattern. JAK1, JAK2 and JAK3 were significantly overexpressed in PG and AD suggesting the need for pan-JAK inhibitors. In contrast, psoriasis and LP showed only JAK1 and JAK3 upregulation, while AA and CLE were characterized by a single dermal JAK signal (pJAK3 and pJAK1, respectively). This indicates that the latter diseases may benefit from more targeted JAK inhibitors. Our in vitro keratinocyte psoriasis model displayed reversal of the psoriatic JAK profile following tofacitinib treatment. This direct interaction with keratinocytes may decrease the need for deep skin penetration of topical JAK inhibitors in order to exert its effects on dermal immune cells. In conclusion, these results point to the important contribution of the JAK/STAT pathway in several ISDs. Considering the epidermal JAK3 expression levels, great interest should go to the investigation of topical JAK3 inhibitors as therapeutic option of ISDs.

JAK inhibitor JTE-052 regulates contact hypersensitivity by downmodulating T cell activation and differentiation

BACKGROUND

Using JAK inhibitors to inhibit cytokine signaling is presumed to be a possible means of treating skin inflammatory disorders such as contact dermatitis.

OBJECTIVE

To clarify the action site of JAK inhibitors in skin inflammatory disorders.

METHODS

We analyzed the mechanism of action of the JAK inhibitor JTE-052 using murine skin inflammation models, including contact hypersensitivity (CHS) and irritant contact dermatitis. Cells isolated from ear tissue or lymph node (LN) were analyzed by flow cytometry. The amounts of cytokines in the culture medium were measured by ELISA or bead array system. Proliferation of LN cells was evaluated by measurement of tritiated thymidine incorporation.

RESULTS

Oral administration of JTE-052 during both sensitization and elicitation phase attenuated CHS, but did not affect croton oil-induced irritant contact dermatitis. JTE-052 potently inhibited T cell proliferation and activation by antigen presentation in vitro, and attenuated skin inflammation in a sensitized-lymphocyte transfer model without suppressing T cell migration. JTE-052 did not affect hapten-induced cutaneous dendritic cell migration into draining lymph nodes or their costimulatory molecule expressions.

CONCLUSION

The JAK inhibitor JTE-052 exerts an inhibitory effect on antigen-specific T cell activation and subsequent inflammation in acquired skin immunity, such as CHS.

Treatment of recalcitrant atopic dermatitis with the oral Janus kinase inhibitor tofacitinib citrate

BACKGROUND

Treatment of moderate to severe atopic dermatitis (AD) is often inadequate.

OBJECTIVE

We sought to evaluate the efficacy of the oral Janus kinase inhibitor tofacitinib citrate in the treatment of moderate to severe AD.

METHODS

Six consecutive patients with moderate to severe AD who had failed standard treatment were treated with tofacitinib citrate. Response to treatment was assessed using the Scoring of AD index.

RESULTS

Decreased body surface area involvement of dermatitis and decreased erythema, edema/papulation, lichenification, and excoriation were observed in all patients. The Scoring of AD index decreased by 66.6% from 36.5 to 12.2 (P < .05) during 8 to 29 weeks of treatment. There were no adverse events.

LIMITATIONS

Small sample size, lack of placebo control group, and the possibility of bias are limitations.

CONCLUSION

The oral Janus kinase inhibitor tofacitinib citrate may be beneficial in the treatment of moderate to severe AD.

Protective effect of small molecule analogues of the Acanthocheilonema viteae secreted product ES-62 on oxazolone-induced ear inflammation

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Small molecule analogues (SMAs) of the immunomodulator, ES-62, have been produced.

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Two SMAs protect against oxazolone-induced skin inflammation in mouse ears.

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Protection is associated with reduced cellular infiltration and collagen deposition.

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Protection is associated with decreased IFNγ mRNA in the ears.

ES-62 is the major secreted protein of the rodent filarial nematode Acanthocheilonema viteae. The molecule contains covalently attached phosphorylcholine (PC) residues, which confer anti-inflammatory properties on ES-62, underpinning the idea that drugs based on this active moiety may have therapeutic potential in human diseases associated with aberrant inflammation. Here we demonstrate that two synthetic small molecule analogues (SMAs) of ES-62 termed SMA 11a and SMA 12b are protective in the oxazolone-induced acute allergic contact dermatitis mouse model of skin inflammation, as measured by a significant reduction in ear inflammation following their administration before oxazolone sensitisation and before oxazolone challenge. Furthermore, it was found that when tested, 12b was effective at reducing ear swelling even when first administered before challenge. Histological analysis of the ears showed elevated cellular infiltration and collagen deposition in oxazolone-treated mice both of which were reduced by treatment with the two SMAs. Likewise, the oxazolone-induced increase in IFNγ mRNA in the ears was reduced but no effect on other cytokines investigated was observed. Finally, no influence on the mast cell populations in the ear was observed.

Hand dermatitis: an allergist's nightmare

Hand dermatitis is a common skin complaint. We use our hands to explore our environment; subsequently, our hands are in frequent contact with potential allergens and irritants. Patients with hand dermatitis may present to their allergist with this complaint. Approaching the diagnosis and treatment of hand dermatitis can be challenging, as both internal and external factors may contribute to the overall condition. Furthermore, the differential diagnosis of hand dermatitis is broad and the cause often multifactorial. Obtaining a thorough history and performing a focused examination may help the clinician differentiate between multiple causes of hand dermatitis. Numerous treatment options exist for hand dermatitis, and new potential treatments are in development as well. We aim to provide the allergist with a streamlined toolkit for help in the diagnosis and management of hand dermatitis.