Dermatology
Abstract
Mammalian injury responses are predominantly characterized by fibrosis and scarring rather than functional regeneration. This limited regenerative capacity in mammals could reflect a loss of pro-regeneration programs or active suppression by genes functioning akin to tumor suppressors. To uncover programs governing regeneration in mammals, we screened transcripts in human subjects following laser rejuvenation treatment and compared them to mice with enhanced Wound Induced Hair Neogenesis (WIHN), a rare example of mammalian organogenesis. We found that Rnasel-/- mice exhibit an increased regenerative capacity, with elevated WIHN through enhanced IL-36α. Consistent with RNase L’s known role to stimulate caspase-1, we found that pharmacologic inhibition of caspases promoted regeneration in an IL-36 dependent manner in multiple epithelial tissues. We identified a negative feedback loop, where RNase L activated caspase-1 restrains the pro-regenerative dsRNA-TLR3 signaling cascade through the cleavage of toll-like adaptor protein TRIF. Through integrated single-cell RNA sequencing and spatial transcriptomic profiling, we confirmed Oas & Il36 genes to be highly expressed at the site of wounding and are elevated in Rnasel-/- mice wounds. This work suggests that RNase L functions as a regeneration repressor gene, in a functional tradeoff that tempers immune hyper-activation during viral infection at the cost of inhibiting regeneration.
Authors
Charles S. Kirby, Nasif Islam, Eric Wier, Martin P. Alphonse, Evan Sweren, Gaofeng Wang, Haiyun Liu, Dongwon Kim, Ang Li, Sam S. Lee, Andrew M. Overmiller, Yingchao Xue, Sashank Reddy, Nathan K. Archer, Lloyd S. Miller, Jianshi Yu, Weiliang Huang, Jace W. Jones, Sooah Kim, Maureen A. Kane, Robert H. Silverman, Luis A. Garza
Abstract
The continuous rise in skin cancer incidence highlights an imperative for improved skin cancer prevention. Topical calcipotriol-plus–5-fluorouracil (calcipotriol-plus–5-FU) immunotherapy effectively eliminates precancerous skin lesions and prevents squamous cell carcinoma (SCC) in patients. However, its mechanism of action remains unclear. Herein, we demonstrate that calcipotriol-plus–5-FU immunotherapy induces T helper type 2 (Th2) immunity, eliminating premalignant keratinocytes in humans. CD4+ Th2 cells were required and were sufficient downstream of thymic stromal lymphopoietin cytokine induction by calcipotriol to suppress skin cancer development. Th2-associated cytokines induced IL-24 expression in cancer cells, resulting in toxic autophagy and anoikis followed by apoptosis. Calcipotriol-plus–5-FU immunotherapy was dependent on IL-24 to suppress skin carcinogenesis in vivo. Collectively, our findings establish a critical role for Th2 immunity in cancer immunoprevention and highlight the Th2/IL-24 axis as an innovative target for skin cancer prevention and therapy.
Authors
Tomonori Oka, Sabrina S. Smith, Heehwa G. Son, Truelian Lee, Valeria S. Oliver-Garcia, Mahsa Mortaja, Kathryn E. Trerice, Lily S. Isakoff, Danielle N. Conrad, Marjan Azin, Neel S. Raval, Mary Tabacchi, Luni Emdad, Swadesh K. Das, Paul B. Fisher, Lynn A. Cornelius, Shadmehr Demehri
Abstract
Dysregulations of epithelial-immune interactions frequently culminate in chronic inflammatory diseases of the skin, lungs, kidneys, and gastrointestinal tract. Yet, the intraepithelial processes which initiate and perpetuate inflammation in these organs are poorly understood. Here, by utilizing redox lipidomics we identified ferroptosis-associated peroxidation of polyunsaturated phosphatidylethanolamines in the epithelia of patients with asthma, cystic fibrosis, psoriasis and renal failure. Focusing on psoriasis as a disease model, we used high-resolution mass spectrometry imaging and identified keratin 14 (K14)-expressing keratinocytes executing a ferroptotic death program in human psoriatic skin. Psoriatic phenotype with characteristic Th1/Th17 skin and extracutaneous immune responses was initiated and maintained in a murine model designed to actuate ferroptosis in a fraction of K14+ glutathione peroxidase 4 (Gpx4)-deficient epidermal keratinocytes. Importantly, an anti-ferroptotic agent, Liproxstatin-1, was as effective as clinically relevant biologic IL-12/IL-23/TNFα-targeting therapies or the depletion of T cells in completely abrogating molecular, biochemical and morphologic features of psoriasis. As ferroptosis in select epidermal keratinocytes triggers and sustains a pathologic psoriatic multi-organ inflammatory circuit, we suggest that strategies targeting ferroptosis, or its causes, may be effective in preventing or ameliorating a variety of chronic inflammatory diseases.
Authors
Kavita Vats, Hua Tian, Kunal Singh, Yulia Y. Tyurina, Louis J. Sparvero, Vladimir A. Tyurin, Oleg Kruglov, Alexander Chang, Jiefei Wang, Felicia Green, Svetlana N. Samovich, Jiying Zhang, Ansuman Chattopadhyay, Natalie Murray, Vrusha K. Shah, Alicia R. Mathers, Uma R. Chandran, Joseph M. Pilewski, John A. Kellum, Sally E. Wenzel, Hülya Bayir, Valerian E. Kagan, Yuri L. Bunimovich
Abstract
BACKGROUND. Cutaneous lichen planus (LP) is a recalcitrant, difficult-to-treat, inflammatory skin disease characterized by pruritic, flat-topped, violaceous papules on the skin. Baricitinib is an oral Janus kinase (JAK) 1/2 inhibitor that interrupts the signaling pathway of interferon gamma (IFN)-γ, a cytokine implicated in the pathogenesis of LP. METHODS. In this phase II trial, twelve patients with cutaneous LP received baricitinib 2 mg daily for 16 weeks, accompanied by in-depth spatial, single-cell, and bulk transcriptomic profiling of pre- and post-treatment samples. RESULTS. An early and sustained clinical response was seen, with 83.3% of patients responsive at week 16. Our molecular data identified a unique, oligoclonal IFN-γ, CD8+, CXCL13+ cytotoxic T-cell population in LP skin and demonstrated a rapid decrease in IFN signature within 2 weeks of treatment, most prominently in the basal layer of the epidermis. CONCLUSION. This study demonstrates the efficacy and molecular mechanisms of JAK inhibition in LP. TRIAL REGISTRATION. NCT05188521. ROLE OF FUNDING SOURCE. Eli Lilly, Appignani Benefactor Funds, 5P30AR075043, Mayo Clinic Clinical Trials Stimulus Funds.
Authors
Angelina S. Hwang, Jacob A. Kechter, Tran H. Do, Alysia N. Hughes, Nan Zhang, Xing Li, Rachael Bogle, Caitlin M. Brumfiel, Meera H. Patel, Blake Boudreaux, Puneet Bhullar, Shams Nassir, Miranda L. Yousif, Alyssa L. Stockard, Zachary Leibovit-Reiben, Ewoma Ogbaudu, David J. DiCaudo, Jennifer Fox, Mehrnaz Gharaee-Kermani, Xianying Xing, Samantha Zunich, Emily Branch, J. Michelle Kahlenberg, Allison C. Billi, Olesya Plazyo, Lam C. Tsoi, Mark R. Pittelkow, Johann E. Gudjonsson, Aaron R. Mangold
Abstract
Sarcoidosis is a multiorgan granulomatous disease that lacks diagnostic biomarkers and targeted treatments. Using blood and skin from patients with sarcoid and non-sarcoid skin granulomas, we discovered that skin granulomas from different diseases exhibit unique immune cell recruitment and molecular signatures. Sarcoid skin granulomas were specifically enriched for type 1 innate lymphoid cells (ILC1s) and B cells and exhibited molecular programs associated with formation of mature tertiary lymphoid structures (TLSs), including increased CXCL12/CXCR4 signaling. Lung sarcoidosis granulomas also displayed similar immune cell recruitment. Thus, granuloma formation was not a generic molecular response. In addition to tissue-specific effects, patients with sarcoidosis exhibited an 8-fold increase in circulating ILC1s, which correlated with treatment status. Multiple immune cell types induced CXCL12/CXCR4 signaling in sarcoidosis, including Th1 T cells, macrophages, and ILCs. Mechanistically, CXCR4 inhibition reduced sarcoidosis-activated immune cell migration, and targeting CXCR4 or total ILCs attenuated granuloma formation in a noninfectious mouse model. Taken together, our results show that ILC1s are a tissue and circulating biomarker that distinguishes sarcoidosis from other skin granulomatous diseases. Repurposing existing CXCR4 inhibitors may offer a new targeted treatment for this devastating disease.
Authors
Satish Sati, Jianhe Huang, Anna E. Kersh, Parker Jones, Olivia Ahart, Christina Murphy, Stephen M. Prouty, Matthew L. Hedberg, Vaibhav Jain, Simon G. Gregory, Denis H. Leung, John T. Seykora, Misha Rosenbach, Thomas H. Leung
Abstract
Delayed-type drug hypersensitivity reactions are major causes of morbidity and mortality. The origin, phenotype and function of pathogenic T cells across the spectrum of severity requires investigation. We leveraged recent technical advancements to study skin-resident memory T cells (TRM) versus recruited T cell subsets in the pathogenesis of severe systemic forms of disease, SJS/TEN and DRESS, and skin-limited disease, morbilliform drug eruption (MDE). Microscopy, bulk transcriptional profiling and scRNAseq + CITEseq + TCRseq supported in SJS/TEN clonal expansion and recruitment of cytotoxic CD8+ T cells from circulation into skin, along with expanded and non-expanded cytotoxic CD8+ skin TRM. Comparatively, MDE displayed a cytotoxic T cell profile in skin without appreciable expansion and recruitment of cytotoxic CD8+ T cells from circulation, implicating TRM as potential protagonists in skin-limited disease. Mechanistic interrogation in patients unable to recruit T cells from circulation into skin and in a parallel mouse model supported that skin TRM were sufficient to mediate MDE. Concomitantly, SJS/TEN displayed a reduced regulatory T cell (Treg) signature compared to MDE. DRESS demonstrated recruitment of cytotoxic CD8+ T cells into skin like SJS/TEN, yet a pro-Treg signature like MDE. These findings have important implications for fundamental skin immunology and clinical care.
Authors
Pranali N. Shah, George A. Romar, Artür Manukyan, Wei-Che Ko, Pei-Chen Hsieh, Gustavo A. Velasquez, Elisa M. Schunkert, Xiaopeng Fu, Indira Guleria, Roderick T. Bronson, Kevin Wei, Abigail H. Waldman, Frank R. Vleugels, Marilyn G. Liang, Anita Giobbie-Hurder, Arash Mostaghimi, Birgitta A.R. Schmidt, Victor Barrera, Ruth K. Foreman, Manuel Garber, Sherrie J. Divito
Abstract
Transforming growth factor β (TGF-β) signaling is a core pathway of fibrosis, but the molecular regulation of the activation of latent TGF-β remains incompletely understood. Here, we demonstrate a crucial role of WNT5A/JNK/ROCK signaling that rapidly coordinates the activation of latent TGF-β in fibrotic diseases. WNT5A was identified as a predominant noncanonical WNT ligand in fibrotic diseases such as systemic sclerosis, sclerodermatous chronic graft-versus-host disease, and idiopathic pulmonary fibrosis, stimulating fibroblast-to-myofibroblast transition and tissue fibrosis by activation of latent TGF-β. The activation of latent TGF-β requires rapid JNK- and ROCK-dependent cytoskeletal rearrangements and integrin αV (ITGAV). Conditional ablation of WNT5A or its downstream targets prevented activation of latent TGF-β, rebalanced TGF-β signaling, and ameliorated experimental fibrosis. We thus uncovered what we believe to be a novel mechanism for the aberrant activation of latent TGF-β in fibrotic diseases and provided evidence for targeting WNT5A/JNK/ROCK signaling in fibrotic diseases as a new therapeutic approach.
Authors
Thuong Trinh-Minh, Chih-Wei Chen, Cuong Tran Manh, Yi-Nan Li, Honglin Zhu, Xiang Zhou, Debomita Chakraborty, Yun Zhang, Simon Rauber, Clara Dees, Neng-Yu Lin, Delf Kah, Richard Gerum, Christina Bergmann, Alexander Kreuter, Christiane Reuter, Florian Groeber-Becker, Beate Eckes, Oliver Distler, Ben Fabry, Andreas Ramming, Alexandra Schambony, Georg Schett, Jörg H.W. Distler
Abstract
Virtually all patients with BRAF-mutant melanoma develop resistance to MAPK inhibitors largely through non-mutational events. Although the epigenetic landscape is shown to be altered in therapy-resistant melanomas and other cancers, a specific targetable epigenetic mechanism has not been validated to date. Here, we evaluate the CoREST repressor complex and the recently developed bivalent inhibitor, corin, within the context of melanoma phenotype plasticity and therapeutic resistance. We find that CoREST is a critical mediator of the major distinct melanoma phenotypes and that corin treatment of melanoma cells leads to phenotype reprogramming. Global assessment of transcript and chromatin changes conferred by corin reveals specific effects on histone marks connected to EMT-associated transcription factors and the dual-specificity phosphatases (DUSPs). Remarkably, treatment of BRAF inhibitor (BRAFi)-resistant melanomas with corin promotes resensitization to BRAFi therapy. DUSP1 is consistently downregulated in BRAFi-resistant melanomas which is reversed by corin treatment and associated with inhibition of p38 MAPK activity and resensitization to BRAFi therapies. Moreover, this activity can be recapitulated by the p38 MAPK inhibitor, BIRB 796. These findings identify the CoREST repressor complex as a central mediator of melanoma phenotype plasticity and resistance to targeted therapy and suggest that CoREST inhibitors may prove beneficial to patients with BRAFi-resistant melanoma.
Authors
Muzhou Wu, Ailish Hanly, Frederick Gibson, Robert Fisher, Samantha Rogers, Kihyun Park, Angelina Zuger, Kevin Kuang, Jay H. Kalin, Sarah Nocco, Matthew Cole, Amy Xiao, Filisia Agus, Adam Labadorf, Samuel Beck, Marianne Collard, Philip A. Cole, Rhoda M. Alani
Abstract
Patients with chronic inflammatory disorders such as psoriasis have an increased risk of cardiovascular disease and elevated levels of LL37, a cathelicidin host defense peptide that has both antimicrobial and proinflammatory properties. To explore if LL37 could contribute to the risk of heart disease, we examined its effects on lipoprotein metabolism and show that LL37 enhances LDL uptake in macrophages through LDLR, SR-B1 and CD36. This interaction led to increased cytosolic cholesterol in macrophages and changes in expression of lipid metabolism genes consistent with increased cholesterol uptake. Structure-function analysis and synchrotron small angle X-ray scattering show structural determinants of the LL37-LDL complex that underlie its ability to bind its receptors and promote uptake. This function of LDL uptake is unique to cathelicidins from humans and some primates and was not observed with cathelicidins from mice or rabbits. Notably, Apoe-/- mice expressing LL37 develop larger atheroma plaques than control mice and a positive correlation between plasma LL37 and OxPL-apoB levels was observed in human subjects with cardiovascular disease. These findings provide evidence that LDL uptake can be increased via interaction with LL37 and may explain the increased risk of cardiovascular disease associated with the chronic inflammatory disorders.
Authors
Yoshiyuki Nakamura, Nikhil N. Kulkarni, Toshiya Takahashi, Haleh Alimohamadi, Tatsuya Dokoshi, Edward L. Liu, Michael Shia, Tomofumi Numata, Elizabeth W.C. Luo, Adrian F. Gombart, Xiaohong Yang, Patrick Secrest, Philip L.S.M. Gordts, Sotirios Tsimikas, Gerard C.L. Wong, Richard L. Gallo
Abstract
Aplasia cutis congenita (ACC) is a congenital epidermal defect of the midline scalp and has been proposed to be due to a primary keratinocyte abnormality. Why it forms mainly at this anatomic site has remained a longstanding enigma. KCTD1 mutations cause ACC, ectodermal abnormalities, and kidney fibrosis, whereas KCTD15 mutations cause ACC and cardiac outflow tract abnormalities. Here, we find that KCTD1 and KCTD15 can form multimeric complexes and can compensate for each other's loss, and that disease mutations are dominant-negative, resulting in lack of KCTD1/KCTD15 function. We demonstrate that KCTD15 is critical for cardiac outflow tract development, whereas KCTD1 regulates distal nephron function. Combined inactivation of KCTD1/KCTD15 in keratinocytes results in abnormal skin appendages, but not in ACC. Instead, KCTD1/KCTD15 inactivation in neural crest cells results in ACC linked to midline skull defects, demonstrating that ACC is not caused by a primary defect in keratinocytes but is a secondary consequence of impaired cranial neural crest cells giving rise to midline cranial suture cells that express keratinocyte-promoting growth factors. Our findings explain the clinical observations in patients with KCTD1 versus KCTD15 mutations, establish KCTD1/KCTD15 as critical regulators of ectodermal and neural crest cell functions, and define ACC as a neurocristopathy.
Authors
Jackelyn R. Raymundo, Hui Zhang, Giovanni Smaldone, Wenjuan Zhu, Kathleen E. Daly, Benjamin J. Glennon, Giovanni Pecoraro, Marco Salvatore, William A. Devine, Cecilia W. Lo, Luigi Vitagliano, Alexander G. Marneros
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)