TLR7/8 Activation in Immune Cells and Muscle by RNA-Containing Immune Complexes: Role in Inflammation and the Pathogenesis of Myositis.

OBJECTIVE: Activation of endosomal toll-like receptors (TLRs) is one possible driver of inflammation in idiopathic inflammatory myopathies (IIM). We investigated the potential contribution of TLR7 and TLR8 to IIM pathogenesis. METHODS: Activation of TLR7/8 in healthy donor peripheral blood mononuclear cells (PBMCs) by immune complexes from patients with IIM and lupus was tested. Autoantibody profiling of patient IgG samples was performed using a 1581-antigen array. TLR7 and/or TLR8 activation by RNA molecules associated with autoantibodies was assessed. Gene expression in human myoblasts and satellite cells following treatment with supernatants from TLR7/8-activated PBMCs was evaluated by NanoString. C57BL/6 mice were dosed intramuscularly with the TLR7/8 agonist R848 and single-cell RNA-sequencing was performed on the muscle to ascertain the cell types responding to TLR7/8 activation and the downstream effects. RESULTS: Overall, 69 patients with IIM were included with representation of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM) subsets. Immune complexes from patients with IIM, as well as autoantibody-associated RNAs His-tRNA, Y1, Y4 and U1, activated PBMCs to produce IFN-α and IL-6 via TLR7/8. Several canonical (Ro60, Ro52, HIST1H4A) and novel (IL-36RN) autoreactivities correlated highly with TLR7/8 activation. Supernatants from TLR7/8-activated PBMCs had a negative impact on human myoblasts and satellite cells. Endothelial cells were activated by R848 in mouse muscle in vivo, in addition to immune cells such as monocytes and macrophages. CONCLUSION: Our results suggest that patients with IIM have autoantibodies in their blood causing TLR7/8 activation, which leads to inflammation in muscles with potential deleterious effects.

Multiomics Profiling Distinguishes Sebaceous Carcinoma from Benign Sebaceous Neoplasms and Provides Insight into the Genetic Evolution of Sebaceous Carcinogenesis.

PURPOSE: Sebaceous carcinoma is the third most common nonkeratinocyte skin cancer in the United States with 1,000 cases per year. The clinicopathologic features of sebaceous carcinoma and benign sebaceous neoplasms (adenomas, sebaceomas) can overlap, highlighting the need for molecular biomarkers to improve classification. This study describes the genomic and transcriptomic landscape of sebaceous neoplasms in order to understand tumor etiology and biomarkers relevant for diagnosis and treatment. EXPERIMENTAL DESIGN: We performed whole-genome sequencing (WGS) and whole-transcriptome sequencing (WTS) of sebaceous neoplasms from six academic and two federal healthcare facilities in the United States diagnosed between January 1, 1999, and December 31, 2021. RESULTS: We evaluated 98 sebaceous neoplasms: 64 tumors (32 adenomas, 2 sebaceomas, 5 atypical sebaceous neoplasms, 25 carcinomas) had sufficient material for WGS, 96 tumors (42 adenomas, 11 sebaceomas, 8 atypical sebaceous neoplasms, 35 carcinomas) had sufficient material for WTS, and 62 tumors (31 adenomas, 2 sebaceomas, 5 atypical sebaceous neoplasms, 24 carcinomas) had sufficient material for combined WGS and WTS. Overall, we found decreased cholesterol biosynthesis and increased TP53 mutations, copy number gains (chromosome 6, 8q, and/or 18), and tumor mutation burden-high (>10 mutations/MB) in carcinomas compared to adenomas. Although diminished compared to adenomas, most carcinomas still had higher cholesterol biosynthesis than nonmalignant skin. Multiomics profiling also supported a precancerous model of tumor evolution with sebaceomas and atypical sebaceous neoplasms being likely intermediate lesions. CONCLUSIONS: The study findings highlight key diagnostic biomarkers for sebaceous carcinoma and suggest that immunotherapy and modulation of cholesterol biosynthesis could be effective treatment strategies.

Cutaneous Neurofibromas and Quality of Life in Adults With Neurofibromatosis Type 1.

Importance: There is a burgeoning interest in therapeutic development for cutaneous neurofibromas (cNFs), a major cause of morbidity in persons with neurofibromatosis type 1 (NF1). To determine meaningful clinical trial outcomes, deeper understanding is needed regarding how cNFs are associated with quality of life (QoL). However, this understanding has been hampered by challenges in recruiting participants with this rare genetic disease. Objective: To develop a large, crowdsourced validated registry of persons with NF1 and determine the association of specific cNF features with QoL, pain, and itch. Design, Setting, and Participants: From May 2021 to December 2023, a decentralized platform was developed and recruited persons 40 years or older with NF1 and at least 1 cNF from 49 states and 12 countries, who provided clinical survey data, detailed photographs, and genetic sequencing data. Photographs from 583 participants were scored on 12 features of cNFs, including general severity, number, size, facial severity, color, and subtypes. Exposure: cNF features derived from participant-supplied photographs. Main Outcomes and Measures: Total Skindex scores and subdomain scores (symptoms, emotion, function, pain, and itch). Results: Of 583 participants, 384 (65.9%) were female, and the mean (range) age was 51.7 (40.0-83.0) years. Female sex, general severity, number, size, and facial severity of cNFs were negatively associated with QoL, as demonstrated by increased total Skindex scores. QoL had the largest association with the number of cNFs and presence of facial cNFs. Increasing number of cNFs was associated with worse QoL, and even individuals with a low cNF burden (<10 total cNFs) experienced a decrease in QoL. Conclusions and Relevance: The results of this study suggest that reducing cNF number, particularly on the face, may be associated with improved QoL in individuals with NF1. In addition, early intervention before the development of numerous tumors may lead to the highest benefit in QoL. These data potentially provide insight into which individuals and cNF tumors may benefit most from therapy and highlights the utility of a completely decentralized, photograph-validated and age-controlled study for rare genetic disease. This cohort will allow analysis of disease and tumor heterogeneity after full phenotypic expression is achieved in NF1 and potentially serves as an example in its design for other rare diseases that struggle from poor recruitment.

Unveiling the genetic landscape of hereditary melanoma: From susceptibility to surveillance.

The multifactorial etiology underlying melanoma development involves an array of genetic, phenotypic, and environmental factors. Genetic predisposition for melanoma is further influenced by the complex interplay between high-, medium-, and low-penetrance genes, each contributing to varying degrees of susceptibility. Within this network, high-penetrance genes, including CDKN2A, CDK4, BAP1, and POT1, are linked to a pronounced risk for disease, whereas medium- and low-penetrance genes, such as MC1R, MITF, and others, contribute only moderately to melanoma risk. Notably, these genetic factors not only heighten the risk of melanoma but may also increase susceptibility towards internal malignancies, such as pancreatic cancer, renal cell cancer, or neural tumors. Genetic testing and counseling hold paramount importance in the clinical context of suspected hereditary melanoma, facilitating risk assessment, personalized surveillance strategies, and informed decision-making. As our understanding of the genomic landscape deepens, this review paper aims to comprehensively summarize the genetic underpinnings of hereditary melanoma, as well as current screening and management strategies for the disease.

Germline BARD1 variants predispose to mesothelioma by impairing DNA repair and calcium signaling.

We report that ~1.8% of all mesothelioma patients and 4.9% of those younger than 55, carry rare germline variants of the BRCA1 associated RING domain 1 (BARD1) gene that were predicted to be damaging by computational analyses. We conducted functional assays, essential for accurate interpretation of missense variants, in primary fibroblasts that we established in tissue culture from a patient carrying the heterozygous BARD1V523A mutation. We found that these cells had genomic instability, reduced DNA repair, and impaired apoptosis. Investigating the underlying signaling pathways, we found that BARD1 forms a trimeric protein complex with p53 and SERCA2 that regulates calcium signaling and apoptosis. We validated these findings in BARD1-silenced primary human mesothelial cells exposed to asbestos. Our study elucidated mechanisms of BARD1 activity and revealed that heterozygous germline BARD1 mutations favor the development of mesothelioma and increase the susceptibility to asbestos carcinogenesis. These mesotheliomas are significantly less aggressive compared to mesotheliomas in asbestos workers.

Effect of NFX-179 MEK inhibitor on cutaneous neurofibromas in persons with neurofibromatosis type 1.

This phase 2a trial investigated the efficacy of NFX-179 Topical Gel, a metabolically labile MEK inhibitor, in the treatment of cutaneous neurofibromas (cNFs) in neurofibromatosis type 1. Forty-eight participants were randomized to four treatment arms: NFX-179 Topical Gel 0.05%, 0.15%, and 0.5% or vehicle applied once daily to five target cNFs for 28 days. Treatment with NFX-179 Topical Gel resulted in a dose-dependent reduction in p-ERK levels in cNFs at day 28, with a 47% decrease in the 0.5% NFX-179 group compared to the vehicle (P = 0.0001). No local or systemic toxicities were observed during the treatment period, and systemic concentrations of NFX-179 remained below 1 ng/ml. In addition, 20% of cNFs treated with 0.5% NFX-179 Topical Gel showed a ≥50% reduction in volume compared to 6% in the vehicle group by ruler measurement with calculated volume (P = 0.021). Thus, NFX-179 Topical Gel demonstrated significant inhibition of MEK in cNF with excellent safety and potential therapeutic benefit.

Parental E-Cigarette Use and Pediatric Atopic Dermatitis.

This cross-sectional study uses data from the 2014-2018 National Health Interview Survey to assess whether there is an association between parental e-cigarette use and atopic dermatitis in children.

Noninvasive virtual biopsy using micro-registered optical coherence tomography (OCT) in human subjects.

Histological hematoxylin and eosin-stained (H&E) tissue sections are used as the gold standard for pathologic detection of cancer, tumor margin detection, and disease diagnosis. Producing H&E sections, however, is invasive and time-consuming. While deep learning has shown promise in virtual staining of unstained tissue slides, true virtual biopsy requires staining of images taken from intact tissue. In this work, we developed a micron-accuracy coregistration method [micro-registered optical coherence tomography (OCT)] that can take a two-dimensional (2D) H&E slide and find the exact corresponding section in a 3D OCT image taken from the original fresh tissue. We trained a conditional generative adversarial network using the paired dataset and showed high-fidelity conversion of noninvasive OCT images to virtually stained H&E slices in both 2D and 3D. Applying these trained neural networks to in vivo OCT images should enable physicians to readily incorporate OCT imaging into their clinical practice, reducing the number of unnecessary biopsy procedures.