Treatment of Psoriasis Patients with Latent Tuberculosis Using IL-17 and IL-23 Inhibitors: A Retrospective, Multinational, Multicentre Study.

BACKGROUND: Tuberculosis has a major global impact. Immunocompetent hosts usually control this disease, resulting in an asymptomatic latent tuberculosis infection (LTBI). Because TNF inhibitors increase the risk of tuberculosis reactivation, current guidelines recommend tuberculosis screening before starting any biologic drug, and chemoprophylaxis if LTBI is diagnosed. Available evidence from clinical trials and real-world studies suggests that IL-17 and IL-23 inhibitors do not increase the risk of tuberculosis reactivation. OBJECTIVE: To evaluate psoriasis patients with treated or untreated newly diagnosed LTBI who received IL-17 and IL-23 inhibitors and the tolerability/safety of tuberculosis chemoprophylaxis. METHODS: This is a retrospective, observational, multinational study from a series of 14 dermatology centres based in Portugal, Spain, Italy, Greece and Brazil, which included adult patients with moderate-to-severe chronic plaque psoriasis and newly diagnosed LTBI who were treated with IL-23 or IL-17 inhibitors between January 2015 and March 2022. LTBI was diagnosed in the case of tuberculin skin test and/or interferon gamma release assay positivity, according to local guideline, prior to initiating IL-23 or IL-17 inhibitor. Patients with prior diagnosis of LTBI (treated or untreated) or treated active infection were excluded. RESULTS: A total of 405 patients were included; complete/incomplete/no chemoprophylaxis was administered in 62.2, 10.1 and 27.7% of patients, respectively. The main reason for not receiving or interrupting chemoprophylaxis was perceived heightened risk of liver toxicity and hepatotoxicity, respectively. The mean duration of biological treatment was 32.87 ± 20.95 months, and only one case of active tuberculosis infection (ATBI) was observed, after 14 months of treatment with ixekizumab. The proportion of ATBI associated with ixekizumab was 1.64% [95% confidence interval (CI): 0-5.43%] and 0% for all other agents and 0.46% (95% CI 0-1.06%) and 0% for IL-17 and IL-23 inhibitors, respectively (not statistically significant). CONCLUSIONS: The risk of tuberculosis reactivation in patients with psoriasis and LTBI does not seem to increase with IL-17 or IL-23 inhibitors. IL-17 or IL-23 inhibitors should be preferred over TNF antagonists when concerns regarding tuberculosis reactivation exists. In patients with LTBI considered at high risk for developing complications related to chemoprophylaxis, this preventive strategy may be waived before initiating treatment with IL-17 inhibitors and especially IL-23 inhibitors.

Multi-failure psoriasis patients: characterization of the patients and response to biological therapy in a multicenter Italian cohort.

INTRODUCTION: Patients with psoriasis who have failed multiple biologic drugs have been defined as "multi-failure," although there are no clear data on the characteristics, comorbidities, and best treatment strategies for this population. Nowadays, given the next generation and the number of biologics available, patients are considered multi-failure when ≥4 biologics fail to achieve a good response. METHODS: Demographic characteristics and efficacy of anti-interleukin drugs in multi-failure patients were compared to a cohort of general psoriatic patients treated with IL-23 or IL-17 inhibitors. RESULTS: In total 97 multi-failure patients (≥4 lines of biologics) were compared with 1,057 patients in the general cohort. The current drugs in the multi-failure group were risankizumab (34), ixekizumab (23), guselkumab (21), brodalumab (7), tildrakizumab (5), ustekinumab (4), secukinumab (2), and certolizumab pegol (1). A significant difference was found in the multi-failure cohort for age of psoriasis onset (mean 29.7 vs. 35.1, P < 0.001), concurrent psoriatic arthritis (45.4 vs. 26.9%, P < 0.001), diabetes mellitus (30.9 vs. 10.9%, P < 0.001), and cardiovascular comorbidity (54.6 vs. 39.8%, P = 0.005). In multi-failure patients, current biological therapy showed a good initial response (PASI 90 and 100 of 41.24 and 27.84%, respectively, at 16 weeks); the response tended to decline after 40 weeks. Anti-IL-17 agents showed clinical superiority over IL-23 agents in terms of achieving PASI90 at 28 weeks (P < 0.001) and 40 weeks (P = 0.007), after which they reached a plateau. In contrast, IL-23 agents showed a slower but progressive improvement that was maintained for up to 52 weeks. A similar trend was also seen for PASI100 (28 weeks P = 0.032; 40 weeks P = 0.121). CONCLUSIONS: The multi-failure patient is characterized by many comorbidities and longstanding inflammatory disease that frequently precedes the introduction of systemic biologic therapy. Further studies are needed to identify more specific criteria that could be applied as a guideline by clinicians.

Efficacy and safety of risankizumab for Crohn's disease in patients from Asian countries: a post hoc subanalysis of the global phase 3 ADVANCE, MOTIVATE, and FORTIFY studies.

BACKGROUND AND AIM: The anti-interleukin-23 antibody risankizumab is being investigated as a treatment for moderate-to-severe Crohn's disease. This post hoc subanalysis evaluates the efficacy and safety of risankizumab therapy in Asian patients. METHODS: ADVANCE (NCT03105128) and MOTIVATE (NCT03104413) were randomized, double-blind, placebo-controlled, phase 3 induction studies. Patients with intolerance/inadequate response to biologic (MOTIVATE) and/or conventional therapy (ADVANCE) were randomized to receive intravenous risankizumab (600 or 1200 mg) or placebo at weeks 0, 4, and 8. Clinical responders to risankizumab could enter the phase 3, randomized, double-blind, placebo-controlled maintenance withdrawal study (FORTIFY; NCT03105102). Patients were rerandomized to receive subcutaneous risankizumab (180 or 360 mg) or placebo (withdrawal) every 8 weeks for 52 weeks. RESULTS: Among 198 Asian patients in the induction studies, clinical remission and endoscopic response at week 12 were achieved by 61.4% and 40.0%, 59.5% and 35.8%, and 27.3% and 9.1% of patients in the risankizumab 600 mg, risankizumab 1200 mg, and placebo groups, respectively. Among 67 patients who entered the maintenance study, clinical remission and endoscopic response at week 52 were achieved by 57.1% and 52.4%, 75.0% and 40.0%, and 53.8% and 34.6% of patients in the risankizumab 180 mg, risankizumab 360 mg, and placebo (withdrawal) groups, respectively. Fistula closure was observed with risankizumab treatment in 28.6% (induction) and 57.1% (maintenance) of patients. Efficacy trends and safety profile were similar to those in non-Asian patients. CONCLUSION: Consistent with non-Asian and global population results, risankizumab was effective and well tolerated in Asian patients with Crohn's disease.

Drug survival and clinical effectiveness of secukinumab, ixekizumab, brodalumab, guselkumab, risankizumab, tildrakizumab for psoriasis treatment.

BACKGROUND: Biologics targeting IL-23 and IL-17 show efficacy and safety in the treatment of moderate-to-severe psoriasis. OBJECTIVE: To investigate drug survival in patients with psoriasis treated with biologics. PATIENTS AND METHODS: We performed a comparative evaluation of the achievement of PASI 90 and PASI ≤ 3 at 16, 28, and 52 weeks along with a DS (drug survival) analysis with IL-17 and IL-23 inhibitors brodalumab, ixekizumab, secukinumab, risankizumab, tildrakizumab, and guselkumab on 1,057 patients. RESULTS: IL-17 inhibitors showed a faster achievement of PASI 90 and PASI ≤ 3 with significant superiority over IL-23 inhibitors at week 16 (p < 0.001; 56% vs. 42% and 70% vs. 59%, respectively). A difference was shown in favor of IL-23 inhibitors regarding DS (p < 0.001), which was 88% at 24 months vs. 75% for IL-17 inhibitors. In multivariate analysis, IL-23 inhibitors (HR 0.54 CI 0.37-0.78, p = 0.001), and male sex (HR 0.57 CI 0.42-0.76, p < 0.001) were all associated with a lower probability of drug interruption. Risankizumab (HR 0.42 CI 0.26-0.69, p = 0.001), guselkumab (HR 0.49 CI 0.24-0.99, p = 0.046), and male sex (HR 0.57 CI 0.43-0.77, p < 0.001) were associated with a lower probability of drug interruption than secukinumab. CONCLUSIONS: IL-23 inhibitors showed the best performance on DS. Overall, the most effective class was IL-17 inhibitors considering the short-term effectiveness, but long-term effectiveness is in favor of anti-IL-23.

Risankizumab to treat moderately to severely active Crohn's disease in adults: an evaluation of trials and data.

INTRODUCTION: Risankizumab is a humanized monoclonal antibody that selectively inhibits interleukin (IL)-23. It is approved for the treatment of moderate-to-severe plaque psoriasis, psoriatic arthritis, and more recently moderate-to-severe Crohn's disease (CD). AREAS COVERED: After examining the current landscape of CD management including therapies which are currently approved and those in late stages of development, we will review the interleukin pathway and discuss the specific mechanism of targeted IL-23 inhibition, summarize available clinical trial data on efficacy and safety of Risankizumab, consider future positioning of Risankizumab in the therapeutic armamentarium, and ultimately discuss future needs for the field. EXPERT OPINION: Risankizumab represents the first and only targeted IL-23 inhibitor approved for the treatment of CD, providing a promising addition to the therapeutic armamentarium for CD, with a favorable safety profile and demonstrated efficacy in both biologic-naïve and exposed populations. It is possible that the targeted nature of Risankizumab may enhance efficacy and safety over combined IL-12/23 inhibition, with trials underway attempting to shed light on that hypothesis.

Risankizumab in Adults with Psoriatic Arthritis.

Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disease associated with psoriasis. Its major clinical domains include peripheral and axial arthritis, enthesitis, dactylitis and skin and nail involvement. Approximately 30% of patients with psoriasis develop psoriatic arthritis. The pathophysiology of PsA is complex and involves a dysregulated immune response. In particular, interleukin (IL)-23 is a major regulatory cytokine that has been implicated in PsA, including bone remodeling, enthesitis, synovitis and psoriatic lesions. Risankizumab is a humanized immunoglobulin G1 monoclonal antibody that targets the p19 subunit of IL-23. It has been approved for the treatment of moderate-to-severe plaque psoriasis and, more recently, PsA. The efficacy and safety of risankizumab for the treatment of PsA has been demonstrated in phase 2 and phase 3 clinical trials. Risankizumab showed efficacy in decreasing the number of swollen and tender joints, clearing psoriatic plaque and improving quality of life. Treatment with risankizumab was well-tolerated, with the most common adverse event being upper respiratory tract infection. Overall, the current literature demonstrates that risankizumab is both a safe and effective therapeutic option for the treatment of PsA. Herein, week 24 and 52 results are reviewed.

Exogenous IL-25 ameliorates airway neutrophilia via suppressing macrophage M1 polarization and the expression of IL-12 and IL-23 in asthma.

BACKGROUND: Severe asthma is associated with substantial mortality and has unmet therapeutic need. A subset of severe asthma is characterized by neutrophilic airway inflammation. Classically activated (or M1) macrophages which express IL-12 and IL-23 are associated with airway neutrophilia in asthma. Exogenous IL-25 was reported to suppress intestinal inflammation in animal models of inflammatory bowel diseases via suppressing IL-12 and IL-23 production. We hypothesize that IL-25 ameliorates airway neutrophilia via inhibiting macrophage M1 polarization and the expression of IL-12 and IL-23 in asthma. METHODS: In a mouse model of neutrophil-dominant allergic airway inflammation, the effect of mouse recombinant IL-25 on airway inflammation were assessed by H&E staining and bronchoalveolar lavage (BAL) cell counting. The percentage of M1 macrophages in lung tissue and BAL cells were analyzed by flow cytometry. Quantitative PCR and immunostaining were performed to measure the expression of Il12, Il23, and inflammatory cytokines. Mechanistic experiments were performed in primary culture of macrophages from mouse lungs. The expression of IL-12, IL-23 and IL-25 in sputum was analyzed in a cohort of severe asthma and subjects with eosinophilic or non-eosinophilic asthma. RESULTS: Intranasal administration of IL-25 markedly decreased the number of neutrophils in BAL cells in a murine model of neutrophil-dominant allergic airway inflammation. Moreover, exogenous IL-25 decreased the number of M1 macrophages, and reduced the expression of IL-12, IL-23 in the lungs of the mouse model. Exogenous IL-25 also inhibited the expression of inflammatory cytokines IL-1ß, IFN-γ, TNF-α and IL-17 A. In vitro, IL-25 suppressed IL-12 and IL-23 expression in lipopolysaccharide (LPS)-stimulated primary culture of mouse pulmonary macrophages. Mechanistically, IL-25 inhibited LPS-induced c-Rel translocation to nucleus via STAT3-dependent signaling. In a cohort of severe asthma, IL-25 protein levels in sputum were significantly lower than control subjects. The transcript levels of IL-12 and IL-23 were increased whereas IL-25 transcripts were decreased in sputum cells from subjects with non-eosinophilic asthma compared to eosinophilic asthma. CONCLUSIONS: IL-25 expression is downregulated in subjects with severe or non-eosinophilic asthma. Exogenous IL-25 ameliorates airway neutrophilia, at least in part, via inhibiting macrophage M1 polarization and the expression of IL-12 and IL-23.

Psoriasis: Striving for Potential Biomarkers.

Psoriasis is a chronic disease that is caused by multiple factors and is identified by itchiness, unpleasant, red, or white scaly patches on the skin, particularly on regularly chafed body regions such as the lateral areas of the limbs. Reports suggest that globally around 2%-3% of the population suffers from psoriasis. In this review, we have discussed the clinical classification of psoriasis and also the ideal characteristics of the biomarkers. An overview regarding the discovery of the biomarker and method for validating the study has been discussed. A growing body of research suggests a link to certain other systemic symptoms such as cardiovascular disorder, metabolic syndrome, and few other comorbidities such as hypertension and nonalcoholic fatty liver disease. Natural killer (NK) cells are lymphocyte cells that concentrate on the destruction of virally infected and malignant cells; these tend to produce a wide range of inflammatory cytokines, some of which are associated with the etiology of psoriasis. Detailed information on the molecular pathogenesis of psoriasis in which interleukin (IL)-17, IL-23, tumor necrosis factor-α (TNF-α), and CCL20 play a very significant role in the development of psoriasis. In this review, we have discussed an overview of the recent state of the biomarkers available for the diagnosis and treatment of psoriasis by emphasizing on the available biomarkers such as epigenomic, transcriptomic, glycomic, and metabolomic. The most recent advancements in molecular-targeted therapy utilizing biologics and oral systemic therapy (methotrexate, apremilast) enable to adequately treat the most serious psoriatic symptoms and also the studies have validated the efficacy of biologic therapy such as TNF-α antagonist (infliximab, adalimumab), IL-23 antagonist (guselkumab, risankizumab), and IL-17 antagonist (secukinumab, ixekizumab). Finally, an overview about the technological opportunities as well as various challenges has been discussed.

The preclinical discovery and development of deucravacitinib for the treatment of psoriasis.

INTRODUCTION: Psoriasis is a chronic inflammatory skin disease that most commonly presents as plaque psoriasis. The understanding of the pivotal pathogenetic role of the IL-23/IL-17 axis has dramatically changed the therapeutic approach to the disease. The identification of intracellular signaling pathways mediating IL-23 activity provided the rationale for targeting TYK2. AREAS COVERED: This review assesses the underlying rationale that led to development of deucravacitinib, a novel oral TYK2 inhibitor, as a therapeutic option for the treatment of moderate-to-severe psoriasis, primarily focusing on pre-clinical and early phase clinical studies. EXPERT OPINION: Innovative therapies used in patients with moderate-to-severe psoriasis include biologic agents and small molecules, which are associated with less adverse events than traditional systemic agents. Deucravacitinib, which selectively targets TYK2, has demonstrated to be effective in treating psoriasis, preserving a more favorable safety profile compared to other JAK inhibitors approved for the treatment of other immune diseases that block the ATP-binding site. Because of its oral administration, deucravacitinib represents an intriguing option in the therapeutic armamentarium of psoriasis, though the evaluation of long-term efficacy and safety is necessary to establish its place-in-therapy.

Treatment Strategies in Inflammatory Bowel Diseases.

BACKGROUND: The prevalence of inflammatory bowel disease (IBD) is rising globally. In Germany, these conditions affect 0.7% of the population, or approximately 600 000 patients. Treatment strategies have become more diversified as a result of an improved understanding of disease pathogenesis. It remains unclear how the currently available drugs should best be used in each individual patient. METHODS: This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to phase III and IV trials and to the German and European guidelines on the treatment of IBD. RESULTS: An improved understanding of the immunological mechanisms of disease underlies the current treatment strategies in patients with IBD. For those with a complex clinical course, monoclonal antibodies against pro-inflammatory cytokines (TNF, IL-12/IL-23, IL-23) and cell adhesion molecules (α4ß7) are of established therapeutic value, along with "small molecules" such as JAK inhibitors and sphingosine-1-phosphate receptor modulators. The numerous studies that have been performed, only a few of which have been head-to-head comparison trials, and the (network) meta-analyses that have been published to date do not imply that any single one of these drugs can be considered the universal, primary treatment for all patients with IBD. In this review, we discuss the available substances and certain important differential-therapeutic aspects of the treatment of IBD. CONCLUSION: The treatment of a patient with IBD must take his or her prior treatment(s) and comorbidities into account, along with individual patient characteristics and treatment goals. Rational decision-making is required on the basis of the mechanism of action and the side-effect profile of the various drugs that are now available for use.

Safety of IL-23 p19 Inhibitors for the Treatment of Patients With Moderate-to-Severe Plaque Psoriasis: A Narrative Review.

The approved biologics targeting interleukin (IL)-23 p19 for the treatment of moderate-to-severe plaque psoriasis, including guselkumab, tildrakizumab, and risankizumab, have generally favorable safety profiles. The aim of the current review is to describe in detail the safety of these selective inhibitors. A literature search was performed using PubMed from inception to 1 November 2022, to identify clinical trials and real-world evidence publications using the keywords "guselkumab," "tildrakizumab," and "risankizumab." Overall, the most common adverse events (AEs) associated with IL-23 p19 inhibitors in clinical trials were nasopharyngitis, headache, and upper respiratory tract infections. Rates of serious AEs and AEs of interest, including serious infections, nonmelanoma skin cancer (NMSC), malignancies excluding NMSC, major adverse cardiovascular events, and serious hypersensitivity reactions, were not increased with long-term use in clinical trials. Selectively targeting IL-23 p19 was also not associated with elevated risk of opportunistic infections, tuberculosis reactivation, oral candidiasis, or inflammatory bowel disease. Results from real-world studies were similar, supporting the safe long-term use of these biologics in a wider population of patients with psoriasis, including older patients, patients for whom multiple biologics failed, and those with comorbidities such as obesity, metabolic syndrome, cardiovascular disease, dyslipidemia, diabetes, hypertension, and psoriatic arthritis. This review is limited by the lack of direct comparisons among therapeutic agents due to differences among study designs and safety data reporting methods. In conclusion, the favorable safety profiles of IL-23 p19 inhibitors support their long-term use in the management of patients with moderate-to-severe psoriasis.

Pulmonary fibrosis and type-17 immunity.

Fibrosis of the lung can occur in idiopathic pulmonary fibrosis, collagen vascular diseases, and hypersensitivity pneumonitis, among other diseases. Transforming growth factor (TGF)-ß, vascular epithelial growth factor, fibroblast growth factor, and platelet-derived growth factor contribute to the pathophysiology of fibrosis. TGF-ß and other cytokines, including interleukin (IL)-1ß, IL-6, and IL-23, activate type-17 immunity, which is involved in pulmonary fibrosis. The components of type-17 immunity include type-17 helper T cells, γδT cells, IL-17A-producing CD8-positive T cells, invariant NKT cells, and group 3 innate lymphoid cells. IL-17A, the main cytokine of type-17 immunity, is able to induce the epithelial-mesenchymal transition in epithelial cells via a production of TGF-ß, directly stimulate fibroblasts and fibrocytes, and inhibit autophagy, which otherwise protects against pulmonary fibrosis. IL-23 induces type-17 immunity and plays an important role in the acute exacerbation of pulmonary fibrosis. Clinical studies have also linked type-17 immunity to the pathogenesis of pulmonary fibrosis. Consequently, targeting type-17 immunity may serve as a new therapeutic strategy to prevent the development or exacerbation of pulmonary fibrosis.

Effect of body mass index on treatment response of biologic/targeted-synthetic DMARDs in patients with rheumatoid arthritis, psoriatic arthritis or axial spondyloarthritis. A systematic review.

BACKGROUND: Overweight and/or obese patients with inflammatory arthritis (IA) have higher disease activity and lower chances of achieving and/or maintaining the treatment targets. Weight/obesity also appears to negatively affect the response to tumor necrosis factor (TNF) inhibitors in IA patients, including rheumatoid arthritis -RA, psoriatic arthritis -PsA, axial spondyloarthritis -AxSpA. We conducted a systematic literature review (SLR) for the effect of weight/body-mass-index (BMI) in the efficacy of all approved biologic (b) and targeted-synthetic (ts) DMARDs for the treatment of IA. METHODS: For this PROSPERO-registered SLR, we searched PubMed, Scopus and Cohrane-Library from inception up to June 21st 2022. Clinical-trials (randomized and non-randomized) and observational studies of RA, PsA or AxSpA patients that reported the effect of weight/BMI on response (all possible outcomes) to b/ts-DMARDs were included. Risk-of-bias was assessed via RoB2-Cochrane-tool and Newcastle-Ottawa-scale for randomized and non-randomized studies, respectively. FINDINGS: Out of 996 references, 75 eventually fulfilled the inclusion criteria (of which 10 studies were retrieved through manual-search). Among the included studies (TNF-inhibitors: 34, IL-12/23 inhibitors: 4, IL-23 inhibitor: 1, IL-17 inhibitors: 7, tocilizumab: 18, abatacept: 8, rituximab: 3, JAK-inhibitors: 5), most had medium RoB. Efficacy of TNF-inhibitors was affected by BMI in all forms of IA. Data are not robust to compare the effect among various TNF-inhibitors. In contrast, favorable results of IL-23 and IL-17 inhibitors did not appear to be influenced by increased BMI in PsA or AxSpA patients. Similar evidence exists for tocilizumab (in RA) and for abatacept (in RA and PsA), while no conclusion can be drawn for rituximab. More data are needed for JAK-inhibitors, although the effect of weight/BMI does not seem to be significant so far. INTERPRETATION: Weight/BMI should be considered in the treatment-plan of IA patients, with its effect being more pronounced for TNF-inhibitors compared to other b/ts-DMARDs.

Guselkumab More Effectively Neutralizes Psoriasis-Associated Histologic, Transcriptomic, and Clinical Measures than Ustekinumab.

Given the key role of the IL-23/Th17 axis in the pathogenesis of moderate-to-severe plaque psoriasis, several specific inhibitors of the p19 subunit of IL-23 have been approved to treat this chronic inflammatory disease. Clinical data indicate that guselkumab, one such selective IL-23 inhibitor, achieves greater clinical efficacy compared with ustekinumab, which inhibits both IL-12 and IL-23 via binding their shared p40 subunit. To understand mechanisms underlying the enhanced efficacy observed with the p19 subunit of IL-23-specific inhibition, we explored cellular and molecular changes in skin of psoriasis patients treated with ustekinumab or guselkumab and in ustekinumab inadequate responders (Investigator's Global Assessment of psoriasis score ≥ 2) subsequently treated with guselkumab (ustekinumab→guselkumab). Skin biopsies were collected pretreatment and posttreatment to assess histologic changes and molecular responses in ustekinumab- and guselkumab-treated patients. Serum cytokines and skin transcriptomics from the subset of ustekinumab→guselkumab-treated patients were also analyzed to characterize differential treatment effects. Ustekinumab and guselkumab demonstrated differential effects on secretion of pathogenic Th17-related cytokines induced by IL-23 in in vitro assays, which suggest guselkumab is a more potent therapeutic agent. Consistent with these findings, guselkumab elicited a significantly greater reduction in cellular and molecular psoriasis-related disease indicators than ustekinumab. In ustekinumab→guselkumab patients, suppression of serum IL-17A and IL-17F levels and neutralization of molecular scar and psoriasis-related gene markers in skin were significantly greater compared with patients continuing ustekinumab. This comparative study demonstrates that guselkumab inhibits psoriasis-associated pathology, suppresses Th17-related serum cytokines, and normalizes the psoriasis skin gene expression profile more effectively than ustekinumab.

The Impact of Proinflammatory Cytokines and Imiquimod on GLUT1 in HaCaT Keratinocytes - a Potential Anti-Psoriatic Therapeutic Target?

BACKGROUND/AIMS: Glucose metabolism has been proven as an essential process for proliferating keratinocytes, which highlights the importance of glucose transporter-1 (GLUT1) not only in the onset of psoriasis but also in the progression and severity of this inflammation-driven disease. In this study, we attempted to find a connection between proinflammatory cytokines (IL-6, IL-17, IL-23, IL-36, TNF-α), a skin inflammation inducing agent - imiquimod (IMQ) and GLUT1 expression. METHODS: Human keratinocyte HaCaT cell line was incubated with exogenous cytokines: IL-6, IL-17A, IL-23, IL-36, TNF-α at a final concentration of 100 ng/ml, or with 1 µM of IMQ, for 48 h. Following the stimulation, glucose uptake and GLUT1 expression were evaluated. The activity of GLUT1 was measured in the presence of a selective GLUT1 inhibitor, BAY-876. The expression of GLUT1 was examined by immunofluorescence and quantified by qPCR, Western blotting and densitometry. RESULTS: The results from qPCR analysis showed that the administration of exogenous IL-6, IL-17, IL-23 and IL-36 to HaCaT cells resulted in upregulation of GLUT1-encoding SLC2A1 gene, while TNF-α had no significant effect. The same results were confirmed by immunofluorescence analysis, as the fluorescent intensity of GLUT1 was elevated following cytokine and IMQ stimulation. Western blot and densitometry showed that all examined cytokines, as well as IMQ, increased GLUT1 expression. HaCaT cells displayed an improved intracellular 2-deoxy-D-glucose (2-DG) uptake and GLUT1 activity after stimulation by exogenous cytokines and IMQ. The highest uptake of 2-DG was observed after IL-23 stimulation (1.93x) and the lowest after TNF-α stimulation (1.07x). BAY-876 inhibited the 2-DG uptake compared to control. CONCLUSION: Our findings suggest that cytokines and IMQ may play a key role in regulating GLUT1 expression in HaCaT cells. We believe that GLUT1 overexpression could potentially be utilized in the targeted treatment of psoriasis.

Celastrol attenuates Guillain-Barré syndrome by inhibiting TLR4/NF-κB/STAT3 pathway-mediated Th1/Th17 cell differentiation.

Guillain-Barré syndrome (GBS) is an acute immune-mediated paralytic neuropathy with variable disease course and outcome. In this study, we aimed to investigate the therapeutic effects of celastrol on GBS and uncover its underlying mechanisms. Experimental autoimmune neuritis (EAN) is a typical animal model for GBS, and thus an EAN rat model was established with the injection of celastrol or/and LPS. We assessed the body weights and EAN clinical scores of rats. HE staining, flow cytometry, RT-qPCR, and Western blotting were respectively employed to measure pathological damage, proportions of cells (Th1, Th17, and Treg), Th1/Th17 cell differentiation-related mRNAs (IFN-γ, TBX21, IL-18, RORγT, IL-17, and IL-23) and TLR4/NF-κB/STAT3 pathway-related proteins (TLR4, NF-κB, p-NF-κB, STAT3, and p-STAT3). We found that celastrol attenuated clinical symptoms and pathological damage of GBS in EAN rats. Moreover, celastrol down-regulated Th1 and Th17 cell proportions, and the levels of IFN-γ, TBX21, IL-18, RORγT, IL-17, and IL-23 in EAN rats. Meanwhile, the levels of TLR4, p-NF-κB, and p-STAT3 were decreased by celastrol. Taken together, celastrol could restrain Th1/Th17 cell differentiation through inhibition of the TLR4/NF-κB/STAT3 pathway in EAN rats. Our findings suggest that celastrol may exert therapeutic effects on GBS by suppressing TLR4/NF-κB/STAT3 pathway-mediated Th1/Th17 cell differentiation.