Tristetraprolin (TTP, encoded by the Zfp36 gene) regulates the mRNA stability of several important cytokines. Due to the critical role of this RNA-binding protein in the control of inflammation, TTP deficiency leads to the spontaneous development of a complex inflammatory syndrome. So far, this phenotype has been largely attributed to dysregulated production of TNF and IL‑23 by myeloid cells, such as macrophages or DCs. Here, we generated mice with conditional deletion of TTP in keratinocytes (Zfp36fl/flK14-Cre mice, referred to herein as Zfp36ΔEP mice). Unlike DC-restricted (CD11c-Cre) or myeloid cell–restricted (LysM-Cre) TTP ablation, these mice developed exacerbated inflammation in the imiquimod-induced psoriasis model. Furthermore, Zfp36ΔEP mice progressively developed a spontaneous pathology with systemic inflammation, psoriatic-like skin lesions, and dactylitis. Finally, we provide evidence that keratinocyte-derived TNF production drives these different pathological features. In summary, these findings expand current views on the initiation of psoriasis and related arthritis by revealing the keratinocyte-intrinsic role of TTP.
Mathieu Andrianne, Assiya Assabban, Caroline La, Denis Mogilenko, Delphine Staumont Salle, Sébastien Fleury, Gilles Doumont, Gaëtan Van Simaeys, Sergei A. Nedospasov, Perry J. Blackshear, David Dombrowicz, Stanislas Goriely, Laurye Van Maele
Brateil Badal, Alexander Solovyov, Serena Di Cecilia, Joseph Minhow Chan, Li-Wei Chang, Ramiz Iqbal, Iraz T. Aydin, Geena S. Rajan, Chen Chen, Franco Abbate, Kshitij S. Arora, Antoine Tanne, Stephen B. Gruber, Timothy M. Johnson, Douglas R. Fullen, Leon Raskin, Robert Phelps, Nina Bhardwaj, Emily Bernstein, David T. Ting, Georg Brunner, Eric E. Schadt, Benjamin D. Greenbaum, Julide Tok Celebi
Pemphigus vulgaris (PV) is an epithelial blistering disease caused by autoantibodies to the desmosomal cadherin desmoglein 3 (DSG3). Glucocorticoids improve disease within days by increasing DSG3 gene transcription, although the mechanism for this observation remains unknown. Here, we show that DSG3 transcription in keratinocytes is regulated by Stat3. Treatment of primary human keratinocytes (PHKs) with hydrocortisone or rapamycin, but not the p38 MAPK inhibitor SB202190, significantly increases DSG3 mRNA and protein expression and correspondingly reduces phospho-S727 Stat3. Stat3 inhibition or shRNA-knockdown also significantly increases DSG3 mRNA and protein levels. Hydrocortisone- or rapamycin-treated PHKs demonstrate increased number and length of desmosomes by electron microscopy and are resistant to PV IgG–induced loss of cell adhesion, whereas constitutive activation of Stat3 in PHKs abrogates DSG3 upregulation and inhibits hydrocortisone and rapamycin’s therapeutic effects. Topical hydrocortisone, rapamycin, or Stat3 inhibitor XVIII prevents autoantibody-induced blistering in the PV passive transfer mouse model, correlating with increased epidermal DSG3 expression and decreased phospho-S727 Stat3. Our data indicate that glucocorticoids and rapamycin upregulate DSG3 transcription through inhibition of Stat3. These studies explain how glucocorticoids rapidly improve pemphigus and may also offer novel insights into the physiologic and pathophysiologic regulation of desmosomal cadherin expression in normal epidermis and epithelial carcinomas.
Xuming Mao, Michael Jeffrey T. Cho, Christoph T. Ellebrecht, Eric M. Mukherjee, Aimee S. Payne
Despite the rising incidence of autoimmunity, therapeutic options for patients with autoimmune disease still rely on decades-old immunosuppressive strategies that risk severe and potentially fatal complications. Thus, novel therapeutic approaches for autoimmune diseases are greatly needed in order to minimize treatment-related toxicity. Such strategies would ideally target only the autoreactive immune components to preserve beneficial immunity. Here, we review how several decades of basic, translational, and clinical research on the immunology of pemphigus vulgaris (PV), an autoantibody-mediated skin disease, have enabled the development of targeted immunotherapeutic strategies. We discuss research to elucidate the pathophysiology of PV and how the knowledge afforded by these studies has led to the preclinical and clinical testing of targeted approaches to neutralize autoantibodies, to induce antigen-specific tolerance, and to specifically eliminate autoreactive B cells in PV.
Christoph T. Ellebrecht, Aimee S. Payne
Systemic sclerosis (SSc) is a rare autoimmune disease with the highest case-fatality rate of all connective tissue diseases. Current efforts to determine patient response to a given treatment using the modified Rodnan skin score (mRSS) are complicated by interclinician variability, confounding, and the time required between sequential mRSS measurements to observe meaningful change. There is an unmet critical need for an objective metric of SSc disease severity. Here, we performed an integrated, multicohort analysis of SSc transcriptome data across 7 datasets from 6 centers composed of 515 samples. Using 158 skin samples from SSc patients and healthy controls recruited at 2 centers as a discovery cohort, we identified a 415-gene expression signature specific for SSc, and validated its ability to distinguish SSc patients from healthy controls in an additional 357 skin samples from 5 independent cohorts. Next, we defined the SSc skin severity score (4S). In every SSc cohort of skin biopsy samples analyzed in our study, 4S correlated significantly with mRSS, allowing objective quantification of SSc disease severity. Using transcriptome data from the largest longitudinal trial of SSc patients to date, we showed that 4S allowed us to objectively monitor individual SSc patients over time, as (a) the change in 4S of a patient is significantly correlated with change in the mRSS, and (b) the change in 4S at 12 months of treatment could predict the change in mRSS at 24 months. Our results suggest that 4S could be used to distinguish treatment responders from nonresponders prior to mRSS change. Our results demonstrate the potential clinical utility of a novel robust molecular signature and a computational approach to SSc disease severity quantification.
Shane Lofgren, Monique Hinchcliff, Mary Carns, Tammara Wood, Kathleen Aren, Esperanza Arroyo, Peggie Cheung, Alex Kuo, Antonia Valenzuela, Anna Haemel, Paul J. Wolters, Jessica Gordon, Robert Spiera, Shervin Assassi, Francesco Boin, Lorinda Chung, David Fiorentino, Paul J. Utz, Michael L. Whitfield, Purvesh Khatri
Psoriasis patients are at increased risk of heart attack and stroke and have elevated MRP8/14 levels that predict heart attack. The KC-Tie2 psoriasiform mouse model exhibits elevated MRP8/14 and is prothrombotic.
Yunmei Wang, Jackelyn B. Golden, Yi Fritz, Xiufen Zhang, Doina Diaconu, Maya I. Camhi, Huiyun Gao, Sean M. Dawes, Xianying Xing, Santhi K. Ganesh, Johann E. Gudjonsson, Daniel I. Simon, Thomas S. McCormick, Nicole L. Ward
Secondary lymphedema is a common postcancer treatment complication, but the underlying pathological processes are poorly understood and no curative treatment exists. To investigate lymphedema pathomechanisms, a top-down approach was applied, using genomic data and validating the role of a single target. RNA sequencing of lymphedematous mouse skin indicated upregulation of many T cell–related networks, and indeed depletion of CD4+ cells attenuated lymphedema. The significant upregulation of Foxp3, a transcription factor specifically expressed by regulatory T cells (Tregs), along with other Treg-related genes, implied a potential role of Tregs in lymphedema. Indeed, increased infiltration of Tregs was identified in mouse lymphedematous skin and in human lymphedema specimens. To investigate the role of Tregs during disease progression, loss-of-function and gain-of-function studies were performed. Depletion of Tregs in transgenic mice with Tregs expressing the primate diphtheria toxin receptor and green fluorescent protein (
Epameinondas Gousopoulos, Steven T. Proulx, Samia B. Bachmann, Jeannette Scholl, Dimitris Dionyssiou, Efterpi Demiri, Cornelia Halin, Lothar C. Dieterich, Michael Detmar
The challenge of translating findings from animal models to the clinic is well known. An example of this challenge is the striking effectiveness of neurokinin-1 receptor (NK-1R) antagonists in mouse models of inflammation coupled with their equally striking failure in clinical investigations in humans. Here, we provide an explanation for this dichotomy: Mas-related GPCRs (Mrgprs) mediate some aspects of inflammation that had been considered mediated by NK-1R. In support of this explanation, we show that conventional NK-1R antagonists have off-target activity on the mouse receptor MrgprB2 but not on the homologous human receptor MRGPRX2. An unrelated tripeptide NK-1R antagonist has dual activity on MRGPRX2. This tripeptide both suppresses itch in mice and inhibits degranulation from the LAD-2 human mast cell line elicited by basic secretagogue activation of MRGPRX2. Antagonists of Mrgprs may fill the void left by the failure of NK-1R antagonists.
Ehsan Azimi, Vemuri B. Reddy, Kai-Ting C. Shade, Robert M. Anthony, Sebastien Talbot, Paula Juliana Seadi Pereira, Ethan A. Lerner
BACKGROUND. Alopecia areata (AA) is an autoimmune disease characterized by hair loss mediated by CD8+ T cells. There are no reliably effective therapies for AA. Based on recent developments in the understanding of the pathomechanism of AA, JAK inhibitors appear to be a therapeutic option; however, their efficacy for the treatment of AA has not been systematically examined.
METHODS. This was a 2-center, open-label, single-arm trial using the pan-JAK inhibitor, tofacitinib citrate, for AA with >50% scalp hair loss, alopecia totalis (AT), and alopecia universalis (AU). Tofacitinib (5 mg) was given twice daily for 3 months. Endpoints included regrowth of scalp hair, as assessed by the severity of alopecia tool (SALT), duration of hair growth after completion of therapy, and disease transcriptome.
RESULTS. Of 66 subjects treated, 32% experienced 50% or greater improvement in SALT score. AA and ophiasis subtypes were more responsive than AT and AU subtypes. Shorter duration of disease and histological peribulbar inflammation on pretreatment scalp biopsies were associated with improvement in SALT score. Drug cessation resulted in disease relapse in 8.5 weeks. Adverse events were limited to grade I and II infections. An AA responsiveness to JAK/STAT inhibitors score was developed to segregate responders and nonresponders, and the previously developed AA disease activity index score tracked response to treatment.
CONCLUSIONS. At the dose and duration studied, tofacitinib is a safe and effective treatment for severe AA, though it does not result in a durable response. Transcriptome changes reveal unexpected molecular complexity within the disease.
TRIAL REGISTRATION. ClinicalTrials.gov NCT02197455 and NCT02312882.
FUNDING. This work was supported by the US Department of Veterans Affairs Office of Research and Development, National Institute of Arthritis and Musculoskeletal and Skin Diseases National Institutes of Health grant R01 AR47223 and U01 AR67173, the National Psoriasis Foundation, the Swedish Society of Medicine, the Fernström Foundation, the Locks of Love Foundation, the National Alopecia Areata Foundation, and the Ranjini and Ajay Poddar Resource Fund for Dermatologic Diseases Research.
Milène Kennedy Crispin, Justin M. Ko, Brittany G. Craiglow, Shufeng Li, Gautam Shankar, Jennifer R. Urban, James C. Chen, Jane E. Cerise, Ali Jabbari, Mårten C.G. Winge, M. Peter Marinkovich, Angela M. Christiano, Anthony E. Oro, Brett A. King
Julian Mackay-Wiggan, Ali Jabbari, Nhan Nguyen, Jane E. Cerise, Charlotte Clark, Grace Ulerio, Megan Furniss, Roger Vaughan, Angela M. Christiano, Raphael Clynes
Infantile hemangioma (IH) is the most common vascular tumor of infancy, and it uniquely regresses in response to oral propranolol. MicroRNAs (miRNAs) have emerged as key regulators of vascular development and are dysregulated in many disease processes, but the role of miRNAs in IH growth has not been investigated. We report expression of C19MC, a primate-specific megacluster of miRNAs expressed in placenta with rare expression in postnatal tissues, in glucose transporter 1–expressing (GLUT-1–expressing) IH endothelial cells and in the plasma of children with IH. Tissue or circulating C19MC miRNAs were not detectable in patients having 9 other types of vascular anomalies or unaffected children, identifying C19MC miRNAs as the first circulating biomarkers of IH. Levels of circulating C19MC miRNAs correlated with IH tumor size and propranolol treatment response, and IH tissue from children treated with propranolol or from children with partially involuted tumors contained lower levels of C19MC miRNAs than untreated, proliferative tumors, implicating C19MC miRNAs as potential drivers of IH pathogenesis. Detection of C19MC miRNAs in the circulation of infants with IH may provide a specific and noninvasive means of IH diagnosis and identification of candidates for propranolol therapy as well as a means to monitor treatment response.
Graham M. Strub, Andrew L. Kirsh, Mark E. Whipple, Winston P. Kuo, Rachel B. Keller, Raj P. Kapur, Mark W. Majesky, Jonathan A. Perkins
The deubiquitinase-encoding gene
Yingai Jane Jin, Sally Wang, Joshua Cho, M. Angelica Selim, Tim Wright, George Mosialos, Jennifer Y. Zhang
Atopic dermatitis (AD) is characterized by reduced barrier function, reduced innate immune activation, and susceptibility to
Ian A. Myles, Kelli W. Williams, Jensen D. Reckhow, Momodou L. Jammeh, Nathan B. Pincus, Inka Sastalla, Danial Saleem, Kelly D. Stone, Sandip K. Datta
Immune-suppressed organ transplant recipients (OTRs) can develop catastrophic squamous cell carcinoma (SCC), characterized by multiple primary tumors, extensive body surface area involvement, or metastases. There are currently no curative systemic therapies available. We previously showed that IL-22 enhances SCC proliferation. Herein, we examined links between cyclosporine (CSA), IL-22, and SCC in patients, cell lines, and mice with UV light–induced SCC. Eighteen of 114 OTRs developed catastrophic SCC, which was strongly associated with CSA treatment. We found that CSA drives T cell polarization toward IL-22–producing T22 cells, and CSA treatment increased IL-22 receptor in SCC cells. SCC tissue from OTRs showed increased expression of IL-22RA1. CSA potentiated rescue by IL-22 of serum-starved SCC cells; treatment of SCC cells with IL-22 and CSA increased both their migratory and invasive capacity. In a UV-induced model of SCC in SKH-1 immunocompetent mice, treatment with anti–IL-22 antibody reduced tumor number and tumor burden. We found that catastrophic SCC in OTRs is associated with CSA use, which may be acting by favoring T22 polarization. Since anti–IL-22 antibody administration decreased tumor number and tumor burden in vivo, blockade of the IL-22 axis may be developed as a viable therapeutic option for catastrophic SCC.
Melody Abikhair, Hiroshi Mitsui, Valerie Yanofsky, Nazanin Roudiani, Channa Ovits, Teddy Bryan, Tatiana M. Oberyszyn, Kathleen L. Tober, Juana Gonzalez, James G. Krueger, Diane Felsen, John A. Carucci
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