Abstract
Inflammatory bowel disease (IBD) is frequently accompanied by intestinal fibrosis, with nonresponse to long-term anti–TNF-α therapy occurring in approximately 23%–46% of patients. Integrated analysis of single-cell and bulk RNA-seq datasets revealed an expansion of IL11+ fibroblasts in inflamed intestine and their significant enrichment in nonresponders. We further identified IL11+ fibroblasts as a central communication hub that engaged in extensive crosstalk with monocytes and may contribute to inflammatory amplification and fibrotic remodeling. Additionally, we employed machine learning approaches, including least absolute shrinkage and selection operator, support vector machines, and random forest, to derive an IL11+ fibroblast–related gene signature effectively predicting nonresponse to anti–TNF-α in validation and test cohorts. IHC further confirmed the overexpression of IL-11 in nonresponders. The signature genes we found are not only associated with immune and inflammatory responses but also with fibrosis, indicating a robust association between fibrosis and anti–TNF-α treatment failure. In summary, this study highlights the important role of IL11+ fibroblasts in orchestrating both inflammation and fibrosis and provides an applicable model for predicting nonresponse to anti–TNF-α in IBD, thereby laying the foundation for precision medicine and targeted therapeutic strategies.
Authors
Wangyue Li, Wei Huang, Jiaxin Wang, Yiwen Tu, Qidi Yang, Yao Zhou, Zile Zhang, Haiming Zhuang, Yubei Gu, Duowu Zou, Yao Zhang
Abstract
Cardiovascular disease (CVD) contributes to morbidity and mortality in people with HIV (PWH) receiving antiretroviral therapy (ART). In the REPRIEVE trial, pitavastatin reduced atherosclerotic CVD risk to a magnitude inconsistent with pitavastatin’s impact solely on LDL cholesterol and inflammation. Here, atorvastatin and ART used in REPRIEVE, including tenofovir, emtricitabine, and dolutegravir, ritonavir and darunavir were examined in 2 mouse models: transgenic HIV-Tg26 mice and HIV-PDX mice engrafted with T cells from PWH. HIV-Tg26 and HIV-PDX mice had higher cardiac fibrosis than littermate controls without HIV. Administration of tenofovir, emtricitabine, and dolutegravir or ritonavir, but not darunavir, resulted in an approximately 2-fold increase in fibrosis. Mice depleted of platelet TGF-β1 or treated with atorvastatin were partially protected from HIV- and ART-induced cardiac fibrosis, steatosis, and diastolic dysfunction. Atorvastatin’s effects were independent of changes in inflammatory cytokines, which correlated with reduced platelet activation and TGF-β signaling in cardiac endothelial cells, fibroblasts, and macrophages undergoing mesenchymal transition. Our results indicate that certain ART regimens accelerate HIV-associated CVD characterized by heart failure with preserved ejection fraction via platelet TGF-β1–dependent processes, which were mitigated by atorvastatin. Our findings provide a potential mechanism for the pleiotropic effects of statins in HIV/ART-linked CVD, which could be targeted by antiplatelet agents or inhibition of TGF-β signaling.
Authors
Kumar Subramani, Denys Babii, Brienne Cole, Tayyab A. Afzal, Thamizhiniyan Venkatesan, Trevor Word, Sandra Gostynska, Sixia Chen, Kar-Ming Fung, Ali Danesh, Itzayana G. Miller, Paul Klotman, Brad R. Jones, Jeffrey Laurence, Jasimuddin Ahamed
Abstract
Heart failure with preserved ejection fraction (HFpEF) is a multifactorial disease that develops in several clinical settings. Despite its complex pathogenesis, evidence indicates a central role for fibrosis in the progression of left ventricular diastolic dysfunction (LVDD). Through exploratory research into adipokines derived from brown adipose tissue (BAT), we identified a secreted-type profibrotic protein, procollagen C-endopeptidase enhancer-1 (PCPE-1), whose expression increased in BAT with aging. PCPE-1 promotes the cleavage of procollagens and is a critical initiator of fibrillogenesis. This molecule was increased in the plasma of aged mice. In addition to aging, obesity led to an increase in PCPE-1 expression in the LV of mice. Both systemic and BAT-specific PCPE-1 depletion ameliorated LV fibrosis and LVDD in the obese HFpEF model. Our data also showed that age-associated LVDD was ameliorated in the systemic PCPE-1–KO mouse fed with a normal chow diet. Conversely, the overexpression of PCPE-1 expression in BAT was shown to lead to aggravation of LV fibrosis and LVDD. Mechanistically, we found ROS/DNA damage/c-Fos/c-Jun signaling resulted in an increased production of PCPE-1 in brown adipocytes. These results indicate PCPE-1 may represent a druggable target for aging- and obesity-related HFpEF.
Authors
Yung-Ting Hsiao, Yohko Yoshida, Hirotsugu Tsuchimochi, Jingyuan Tang, Tin May Aung, Chun-Han Chang, Agian Jeffilano Barinda, Zhihong Li, Nur Syakirah Binti Othman, Tom Yoshizaki, Yiwei Ling, Shujiro Okuda, Manabu Abe, Seiya Mizuno, Satoru Takahashi, Takayuki Inomata, Hidetaka Kioka, Yasushi Sakata, Daichi Maeda, Yuya Matsue, Takaaki Furihata, Hiroshi Iwata, James T. Pearson, Kinya Otsu, Kenneth Walsh, Akihito Ishigami, Tohru Minamino, Ippei Shimizu
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease driven by aberrant fibroblast-to-myofibroblast differentiation, which requires metabolic reprogramming. Here, we identify alanine as an essential metabolite for myofibroblast differentiation. TGF-β increases intracellular alanine levels through enhanced synthesis and import in both normal and IPF lung fibroblasts. Alanine synthesis is primarily mediated by glutamate-pyruvate transaminase 2 (GPT2), whose expression is regulated by the glutamine/glutamate/α-ketoglutarate axis. Inhibition of GPT2 depletes alanine and suppresses TGF-β–induced α-SMA and COL1A1 expression, which are rescued by exogenous alanine. We also identify solute carrier family 38 member 2 (SLC38A2) as a transporter for both alanine and glutamine, upregulated by TGF-β or alanine deprivation. SLC38A2 and GPT2 form a coordinated regulatory axis sustaining intracellular alanine levels to support myofibroblast differentiation. Mechanistically, alanine deficiency impairs glycolytic flux and depletes tricarboxylic acid cycle intermediates, while alanine supplementation provides carbon and nitrogen for intracellular glutamate and proline biosynthesis, particularly under glutamine deprivation. Combined inhibition of alanine synthesis and uptake suppresses fibrogenic responses in fibroblasts and human precision-cut lung slices, highlighting dual metabolic targeting as a potential therapeutic strategy for fibrotic lung disease.
Authors
Fei Li, Niv Vigder, David R. Ziehr, Mari Kamiya, Hung N. Nguyen, Diana E. Ferreyra Faustino, Aseel H. Khalil, Hilaire C. Lam, Matthew L. Steinhauser, Edy Y. Kim, William M. Oldham
Abstract
Impaired adhesion and differentiation of keratinocytes is a hallmark of several skin diseases, but only some of the factors that regulate these processes have been identified. Here, we studied the role of isoform-rich dermokine — a wound- and tumor-regulated protein — in keratinocytes using a combination of multiomics and functional approaches. CRISPR/Cas9-induced knockout of dermokine isoforms in human keratinocytes inhibited differentiation of these cells in 3-dimensional organotypic skin cultures, which was confirmed by quantitative proteomics. In 2-dimensional monocultures, dermokine deficiency affected the proteome and phosphoproteome as revealed by mass spectrometry. We found reduced abundance of differentiation-specific proteins and increased phosphorylation of the cell adhesion protein p120 (catenin δ-1). The adhesive strength of dermokine-knockout keratinocytes was impaired, which was rescued by p120 knockdown or ROCK inhibition. Finally, we verified the correlation between decreased dermokine expression and increased p120 phosphorylation in human non-healing wounds. These results identify dermokine as a regulator of keratinocyte adhesion and differentiation, involving at least in part its effect on p120 phosphorylation and ROCK. Our data point to a function of dermokine in the pathogenesis of chronic wounds.
Authors
Vahap Canbay, Till Wüstemann, Weihua Tian, Tobias A. Beyer, Camilla Reiter Elbæk, Michael Stumpe, Gaetana Restivo, Chatpakorn Christiansen, Anabel Migenda Herranz, Susanne Mailand, Jürg Hafner, Rune Busk Damgaard, Steffen Goletz, Jörn Dengjel, Ulrich auf dem Keller, Chiara Francavilla
Abstract
Adaptive remodeling of retrodiscal tissue following anterior disc displacement (ADD) of the temporomandibular joint (TMJ) has been recognized for decades, yet the underlying cellular dynamics and molecular mechanisms remain unclear. Using a porcine ADD model, this study investigated the cellular and molecular basis driving retrodiscal tissue adaptation. Histological staining revealed adaptive remodeling of retrodiscal tissue after ADD induction, with dense connective tissue and cartilaginous masses replacing loose connective tissue. Single-cell RNA-Seq captured pronounced fibroblast expansion during tissue remodeling, notably the FB2 subcluster with high developmental potential, and the emergence of a mural cell subcluster, MC4, associated with extracellular matrix (ECM) remodeling. CellChat analysis highlighted MC4-FB2 crosstalk via FGF2 and BMP5 signaling. The combination of pathway-aware multilayered hierarchical network (P-NET) and Seurat with drug database screening identified 5 promising compounds. Among them, zaprinast demonstrated the most robust effects by enhancing the remodeling capability of fibroblasts in vitro and alleviated TMJ deformation in vivo. Collectively, fibroblast activation is pivotal for early retrodiscal tissue adaptation after ADD, which is driven by MC4-derived FGF2/BMP5 signaling. Zaprinast treatment potentiates this remodeling process. These findings provide potentially new insights into the cellular basis of TMJ adaptation and identify potential therapeutic targets for ADD management.
Authors
Wenlin Yuan, Yilin Chen, Ruojin Yan, Wei Liu, Chenyu Wang, Ying Wang, Qiaoli Dai, Wen Li, Mengqi Zhu, Xiao Chen, Jiejun Shi
Abstract
Survival after lung transplantation is limited by chronic, progressive graft failure, termed chronic lung allograft dysfunction (CLAD). Graft-resident mesenchymal cells (MCs) drive CLAD pathogenesis and exhibit stable dysregulated signaling, yet the transcriptomic and epigenomic drivers underlying this fibrogenic transformation remain elusive. We used single-cell multiomic profiling to characterize gene expression and chromatin accessibility in MCs isolated from bronchoalveolar lavage fluid of lung transplant recipients with and without CLAD, collected early after transplantation or after disease onset. MCs obtained after CLAD onset demonstrated a distinct transcriptomic signature compared with non-CLAD controls, enabling classification of disease status at the single-cell level with greater than 98% accuracy using signature genes. Chromatin accessibility analyses identified enrichment of CCAAT-enhancer-binding protein family transcription factors, specifically CEBPD, in CLAD MCs. MCs early after transplantation showed minimal accessibility differences, suggesting that CEBPD-associated regulatory changes emerge over time. Integration analyses identified 8 MC states and a CLAD-specific shift toward a fibrotic state. CEBPD, SOX4, and FOXP2 were identified as putative regulators of this state with substantial overlap in predicted targets. Targeting CEBPD reversed fibrotic phenotypes of CLAD MCs (decreased ECM expression, contractility, proliferation, and migration). Together, these data provide insights into transcriptomic and epigenomic changes in posttransplant MCs, facilitating the nomination of biomarkers and therapeutic targets.
Authors
Lu Lu, A. Patrick McLinden, Natalie M. Walker, Ragini Vittal, Yichen Wang, Fatemeh Fattahi, Stephen T. Russell, Michael P. Combs, Joshua D. Welch, Vibha N. Lama
Abstract
Cutaneous radiation injury is an unintended consequence of radiotherapy for many common cancers and can progress to debilitating radiation-induced skin fibrosis (RISF). Existing radiation injury models do not fully capture the skin toxicities observed in patients, contributing to the lack of efficacious therapies to mitigate RISF. To address this, we developed an ex vivo human skin model that recapitulates the temporal radiation injury and RISF response. Human skin explants (n = 12) subjected to ionizing radiation demonstrated DNA double-stranded breaks and robust p53-driven transcriptional programming of cell cycle arrest, apoptosis, and senescence compared with nonirradiated controls. Irradiated skin also exhibited induction of pro-inflammatory cytokines, epithelial-mesenchymal transition, profibrotic TGF-β1–mediated signaling, and thickened collagen over time. P53 regulators murine double minute 2 (MDM2) and miR-34a were induced after irradiation and may be leveraged to modulate injury response. Notably, RNA-sequencing of postradiotherapy breast skin from patients who had undergone mastectomy showed similar p53, inflammatory, and TGF-β1 signatures as the ex vivo model, supporting its translational relevance. Together, this model provides a platform for identifying biomarkers and testing therapies to prevent or mitigate cutaneous radiation toxicities. Targeting the dynamic p53-driven profibrotic radiation response represents a potentially new therapeutic avenue to improve quality of life for patients after radiotherapy.
Authors
Caroline Dodson, Sophie M. Bilik, Gabrielle DiBartolomeo, Hannah Pachalis, Lindsey G. Siegfried, Jordan A.K. Johnson, Seth R. Thaller, Irena Pastar, Marjana Tomic-Canic, Anthony J. Griswold, Rivka C. Stone
Abstract
Resident cardiac fibroblast–derived (RCF-derived) cardiac myofibroblasts (CMFs) contribute to myocardial repair but also drive adverse ventricular remodeling and contractile dysfunction after myocardial infarction (MI). The sodium-activated potassium channel Slick (Slo2.1) has been described in cardiomyocyte (CM) mitochondria; however, transcriptomic analyses indicate higher Slick expression in RCFs/CMFs. Here, we investigated the role of Slick in cardiac fibroblast function and post-MI remodeling. Using live-cell imaging and whole-cell patch-clamp recordings, we found that plasma membrane Slick channels in RCFs and CMFs regulated potassium (K+) efflux and modulated store-operated calcium entry (SOCE), particularly in CMFs. Global Slick KO and conditional CMF-specific KO hearts exhibited reduced fibrosis and preserved left ventricular function after ischemia/reperfusion injury. This cardioprotection was associated with diminished CMF activation and proliferation, reduced inflammation, and improved CM survival after MI. Collectively, these findings identify fibroblast Slick channels as regulators of SOCE-dependent fibrogenesis and demonstrate that their deletion mitigates maladaptive remodeling and functional decline after MI.
Authors
Jiaqi Yang, Lin Zhu, David Spähn, Melanie Cruz Santos, Sophia Schanz, Selina Maier, Lena Birkenfeld, Helmut Bischof, Anna Roslan, Nina Wettschureck, Oliver Borst, Lucas Matt, Robert Lukowski
Abstract
The lungs have a remarkable capacity to undergo homoeostatic repair and regeneration after injury, which often occurs in patients with acute respiratory distress syndrome (ARDS) and in the single-dose bleomycin mouse model. Fibroblasts are critical mediators of fibrotic disease and RNA sequencing has identified significant heterogeneity within pulmonary fibroblast populations. However, the contribution of distinct fibroblast subsets to the repair process has been understudied compared with their role in fibrosis initiation and progression. Therefore, we sought to define the transcriptional landscape of 3 phenotypically defined fibroblast subsets that occupy discrete spatial locations in naive lungs. Using TdTomato-lineage tracing approaches, we identified and interrogated collagen1a1+ (Col1a1) fibroblasts, perilipin 2+ (Plin2) alveolar fibroblasts, and α-smooth muscle actin+ (Acta2) myofibroblasts during fibrosis development and resolution after single-dose bleomycin. Quantification of fibroblast numbers showed that all 3 subsets expanded during fibrosis and contracted toward naive levels with resolution. Principal component and gene set enrichment analyses indicate that each subset underwent major transcriptomic shifts during fibrosis development, converging on a similar profibrotic transcriptional profile. However, during resolution, Plin2+ and Acta2+ fibroblasts reverted toward a prefibrotic transcriptional state, whereas Col1a1+ fibroblasts acquired a distinct program that suggests an active role in mediating the repair processes.
Authors
Daniel G. Foster, Nomin Javkhlan, Bart P. Black, Brian E. Vestal, David W.H. Riches, Elizabeth F. Redente
No posts were found with this tag.
