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Abstract
BACKGROUND. Asparaginase is essential for curing acute lymphoblastic leukemia (ALL), but its use is limited by asparaginase-associated pancreatitis (AAP), a severe and unpredictable toxicity lacking validated prospective biomarkers. We sought to define early systemic molecular features of susceptibility to AAP. METHODS. We performed longitudinal lipidomic and proteomic profiling in two independent pediatric ALL cohorts (n = 161; 79 AAP cases, 82 controls) using paired blood samples collected before asparaginase exposure and at the end of induction therapy (including a single dose of asparaginase), thereby capturing pre-injury biology rather than consequences of pancreatitis. We applied differential abundance and network-based analyses, and integrated lipid–cytokine associations using proteomics. RESULTS. Across cohorts, we identified a reproducible lysophosphatidylcholine (LPC)–centered signature characterized by attenuated induction therapy-associated LPC responses and disruption of LPC co-regulation at the network level. Proteomic profiling revealed enrichment of cytokine signaling pathways, and integrative analyses demonstrated altered lipid–cytokine coupling, including a flip in association direction for LPC species and interleukin-18 (IL-18) between cases and controls. Although IL-18/LPC ratios do not differ globally, elevated post-induction IL-18/LPC ratios identify AAP risk within a protocol-defined very high-risk ALL subgroup (AUC = 0.81). CONCLUSION. These findings support a systems-level model in which failure of coordinated lipid–immune responses under therapeutic stress confers vulnerability to AAP, providing a framework for validation and mitigation strategies. TRIAL REGISTRATION. NCT00400946; NCT01574274; NCT03020030 (parent trials). FUNDING. Servier Pharmaceuticals (IIT-95014-027-USA); SDRC (P30DK116074); Stanford SPARK; Fonds de Recherche du Québec – Santé; Fondation Charles-Bruneau; The Leukemia & Lymphoma Society of Canada.
Authors
Cheng-Yu Tsai, Na Bo, Thai Hoa Tran, Maisam Abu-El-Haija, Gayathri Swaminathan, Bomi Lee, Sudhir Ghandikota, Li Wen, Yves Théorêt, Steven D. Mittelman, Elena J. Ladas, Anil G. Jegga, Lewis B. Silverman, Ying Ding, Sohail Z. Husain
Abstract
Abdominal aortic aneurysm (AAA) lacks effective pharmacological therapies. Here, we investigate transcription factor 7-like 2 (TCF7L2), a genetic locus associated with both thoracic and abdominal aortic aneurysms, to elucidate its role in AAA pathogenesis. Integrating summary-data-based Mendelian randomization (SMR) with single-cell RNA sequencing (scRNA-seq) of human and mouse aortas, we identify TCF7L2 as a gene enriched in vascular smooth muscle cells (VSMCs) and causally linked to AAA development. Smooth muscle cell-specific TCF7L2 knockout significantly attenuates AAA formation across three distinct murine models (Ang II infusion-, BAPN/Ang II co-administration-, and elastase-induced AAA), independent of systemic blood pressure or lipid levels. Mechanistic studies reveal that TCF7L2 directly upregulates MMP14 and downregulates TIMP3 expression in vitro and in vivo, driving MMP2-mediated extracellular matrix (ECM) degradation. Concurrently, TCF7L2 represses integrin β1 (ITGB1) expression, reducing VSMC adhesion to the ECM. Collectively, these findings identify TCF7L2 as a key driver of pathological vascular remodeling in AAA, suggesting that targeting TCF7L2 may offer a novel therapeutic strategy for limiting AAA progression.
Authors
Yongjie Deng, Yaozhong Liu, Yang Zhao, Hongyu Liu, Guizhen Zhao, Zhenguo Wang, Xu Zhang, Chao Xue, Wei Huang, Tianqing Zhu, Haocheng Lu, Yanhong Guo, Lin Chang, Ida Surakka, Y. Eugene Chen, Jifeng Zhang
Abstract
Immune checkpoint inhibitors have transformed cancer therapy, yet many patients fail to achieve durable responses due to insufficient T cell reinvigoration. Cytokines offer promise for enhancing immunotherapy, but their clinical use is limited by toxicity and a narrow therapeutic index. Immunocytokines, engineered fusion proteins combining antibody specificity with cytokine activity, aim to overcome these challenges by targeting cytokine delivery to immune cells or the tumor microenvironment. We describe SAR445877 (SAR’877), a novel PD-1-targeted immunocytokine that fuses a high-affinity anti-PD-1 antibody with a detuned IL-15/IL-15Rα sushi domain complex. SAR’877 blocks PD-1/PD-L1 and PD-1/PD-L2 interactions while selectively delivering IL-15 signals to PD-1+ T cells, enhancing proliferation and activation of antigen-experienced CD8+ and CD4+ T cells and NK cells, while minimizing systemic inflammation. Mechanistically, SAR’877 activates STAT5 signaling in PD-1+ lymphocytes and restores effector function in exhausted T cells. In preclinical models, a murine surrogate of SAR’877 accelerated viral clearance and induced robust anti-tumor immunity by expanding cytotoxic CD8+ T cells and promoting Th1 polarization. Notably, SAR’877 outperformed anti-PD-1 plus untargeted IL-15, highlighting the therapeutic potential of targeted IL-15 delivery. These findings position SAR’877 as a promising next-generation immunotherapy with enhanced efficacy and reduced cytokine-associated toxicities.
Authors
Isaraphorn Pratumchai, Marie Bernardo, Julien Tessier, Jaroslav Zak, Kristi L. Marquardt, Joon Sang Lee, Maheeka Bimal, AHyun Choi, Anthony M. Byers, Mikielia G. Devonish, Roberto Carrio, Dan Lu, Stella A. Martomo, Jeegar Patel, Yu-an Zhang, Ingeborg M. Langohr, Virna Cortez-Retamozo, Dinesh S. Bangari, Angela Hadjipanayis, Xiangming Li, Valeria R. Fantin, Donald R. Shaffer, John R. Teijaro
Abstract
Tumor-infiltrating CD8 cells recognize neoantigens created by tumor-specific mutations. Nonetheless, even after checkpoint inhibitor therapy, most patients progress. A deeper understanding of anti-tumor responses could facilitate development of better therapies. To enable such studies, we applied TCXpress, a high throughput platform that clones fully expressible TCRs from single cells into retro- or lenti- viral vectors without sequencing or gene synthesis, to study TCRs from CD8 cells infiltrating mouse MC38 tumors. We expressed cloned TCRs in reporter cells and interrogated TCR specificity by coculturing them with B6WT3 cells transduced with tandem minigenes encoding predicted neoantigens. We isolated TCRs reactive against epitopes from mutant Rpl18, Adpgk, Psmd2, and Zc3h7b along with self-reactive TCRs that recognized normal B6 and MC38 cells. Importantly, we successfully treated MC38-bearing mice with T cells transduced with anti-Rpl18 TCRs. These results establish a system that could be used to study many types of T cell responses and validates a therapeutic approach that could be tested in the clinic.
Authors
Alexander M. Rowe, Smriti Chaurasia, Wenzhong Wei, Laura García-Diéguez, Katherine Querry, Johnathon G. Schiebel, Christy Smolak, Alexander G. Muralles, Daniel Wikenheiser, Kevin Quann, Collin Pirner, Kentin Codispot, Mark J. Shlomchik, Warren D. Shlomchik
Abstract
Enhancing NAD+ levels with nicotinamide riboside (NR) confers anti-inflammatory effects in human disease, although immunoregulatory mechanisms remain poorly characterized. We previously showed that ex vivo NR supplementation of primary CD4+ T cells from psoriatic individuals dampened immune responsiveness. To validate this in vivo, we performed a randomized, placebo-controlled NR supplementation study in individuals with mild-to-moderate psoriasis. Participants received oral NR (500 mg twice daily) or matching placebo for 4 weeks, with blood samples collected at baseline and after supplementation. NR reduced Th17 immune responsiveness. Bulk CD4+ T cell RNA-seq identified induction of the SLIT-ROBO signaling pathway. NR supplementation increased circulating SLIT2 levels and enhanced SLIT2 production in dermal fibroblasts. Pharmacologic and genetic interrogation in CD4+ T cells and fibroblasts demonstrated that SLIT2, acting through the ROBO1 receptor, inhibited Rho GTPase signaling, thereby attenuating canonical Th17 polarization and fibroblast inflammatory activation. These findings indicate that NAD+ augmentation exerts anti-inflammatory effects in psoriasis through SLIT2-ROBO1-mediated crosstalk between dermal fibroblasts and circulating CD4+ T cells, leading to suppression of Th17-driven inflammation.
Authors
Kim Han, Rachael J. Klein, Thomas C. Recupero, Anna Chiara Russo, Rahul Sharma, Anand K. Gupta, Shahin Hassanzadeh, Rebecca D. Huffstutler, Pradeep K. Dagur, Bryan Fisk, Neelam R. Redekar, Michael N. Sack
Abstract
Physician-scientists represent one of the most impactful, yet underrecognized, innovations of 20th century academic medicine. Defined by a commitment to full-time careers in investigative work, physician-scientists have repeatedly demonstrated a unique ability to identify and solve problems of unmet medical need in a focused and intentional manner using their dual training in clinical medicine and the scientific method as both stethoscope and scalpel. Unfortunately, mounting financial pressures from both the clinical and research marketplaces have placed this storied workforce in jeopardy due to the absence of a dedicated and explicitly defined vocational structure and business model. This white paper reports the output of a consortium of academic medical centers, foundations and professional societies seeking to remedy this deficiency. This consortium specifically developed a framework to formalize the career path of physician-scientist faculty into a professionally unified and financially sustainable structure in a way that could be adopted to different U.S. academic medical centers and health systems. Key components of this framework included an administratively operational definition of physician-scientists, and three central and interconnected pillars (academic, financial, and organizational) that are rooted in this foundational definition. Herein, we detail core concepts and concrete recommendations.
Authors
Christopher S. Williams, Megan Allen, Paige Cooper Byas, John B. Hawley, Louis J. Muglia, E. Dale Abel, Julie A. Bastarache, Carolyn S. Calfee, John M. Carethers, David N. Cornfield, Oliver Eickelberg, Emily J. Gallagher, Anna Greka, Peter J. Gruber, Anthony N. Hollenberg, Heidi H. Kong, Barbara I. Kazmierczak, Gary A. Koretzky, Mark Lachs, Deborah J. Lenschow, Geoffrey S. Pitt, Don C. Rockey, Lisa M. Satlin, Barry P. Sleckman, David A. Stoltz, Jatin M. Vyas, Thomas J. Wang, Kyu Y. Rhee
Abstract
Germline BRCA1/2 pathogenic variant (PV) carriers have elevated young-onset breast cancer risk. To define the pretreatment genomic landscapes of young-onset gBRCA-associated breast cancer, we evaluated 136 treatment-naïve tumors diagnosed before age 50 (92.6% ≤40): gBRCA1 86(63.2%); gBRCA2 50(36.8%) in the prospective POSH study, and 66 noncarriers from The Cancer Genome Atlas. Using whole exome sequencing, we analyzed somatic variation, allele-specific loss of heterozygosity (asLOH), homologous recombination deficiency (HRD), and single-base substitution signatures (SBS). gBRCA1(93%) and gBRCA2(96%) breast cancers had high rates of asLOH, but differed significantly in average HRD scores (57.4 ± 1.3 vs 43.7 ± 1.5, P < 0.0001) and median SBS composition (%): SBS1 (aging-associated) 12.9 vs 7.3, P = 0.013; SBS18 (reactive oxygen species [ROS]-associated) 1.4 vs 0, P = 0.007; and SBS3 (HRD-associated) 27.3 vs 42.6, P = 0.002. Compared to gBRCA2 tumors, gBRCA1 tumors with asLOH were significantly enriched for alterations in Hallmark ROS, DNA repair, and epithelial-mesenchymal transition pathways. In ER-positive, HER2-negative tumors from gBRCA1/2 carriers compared to noncarriers, we found significant enrichment of RB1 (OR:6.3;95%CI:2.8–15.4;padj = 0.001), TP53 (OR:4.6;95%CI:1.9–12.1;padj = 0.017), FAT1 (OR:3.9;95%CI:1.84–8.7;padj = 0.013), and MYC (OR:4.0;95%CI:1.8–9.1;padj = 0.017) SNV/indels/CNVs, associated with CDK4/6i resistance. Together, these findings demonstrate significant differences between gBRCA1 and gBRCA2-associated breast cancers, and preexisting CDK4/6i resistance mechanisms supporting prospective trials with individualized therapy for gBRCA1 vs gBRCA2 carriers, and comparing PARPi to CDK4/6i for ER-positive gBRCA1/2-associated breast cancer.
Authors
Mwangala P. Akamandisa, Mingyi Xia, Wilson Cheah, Bradley Wubbenhorst, Kurt P. D'Andrea, Mengyao Fan, Jake S. Shilan, Dana Pueschl, Anupma Nayak, Hayley McKenzie, William Tapper, Ellen R. Copson, Ramsey I. Cutress, Susan M. Domchek, Diana M. Eccles, Katherine L. Nathanson
Abstract
CHI3L1, a chitinase-like protein, is implicated in pulmonary fibrosis, yet its mechanisms incompletely understood. In this study, we demonstrated that CHI3L1 coordinates profibrotic macrophage activation and invasive myofibroblast differentiation, and their crosstalk. In vitro, CHI3L1 drove M2-like macrophage polarization as evidenced by increased CD163, CD206, and PD-L1, and amplified TGF-β1-induced fibroblast responses, including myofibroblast transformation, migration, and invasion. Mechanistically, CHI3L1 enhanced TGF-β1 signaling through SMAD, AKT, and ERK pathways, and PD-L1 was required for CHI3L1/TGF-β1-driven myofibroblast transformation. Co-culture studies further demonstrated the ability of CHI3L1 to induce profibrotic macrophage activation that enhanced myofibroblast transformation mediated via a CD44–PD-L1 axis. In vivo, following bleomycin challenge, CHI3L1 transgenic mice exhibited increased PD-L1+ M2 macrophages, PD-L1+/PDGFRα+ fibroblasts, and PD-1+ immune cells compared with wild-type controls. Therapeutically, combined anti-CHI3L1 and anti-PD-1 antibodies, as well as a bispecific anti-CHI3L1-anti-PD-1 antibody, produced greater anti-fibrotic efficacy than monotherapy. These findings demonstrate crosstalk between CHI3L1 and the PD-1/PD-L1 pathway that promotes profibrotic macrophage activation and invasive fibroblast differentiation and support dual targeting of CHI3L1 and PD-1/PD-L1 as a promising therapeutic strategy for pulmonary fibrosis.
Authors
Han-Seok Jeong, Takayuki Sadanaga, Joyce H. Lee, Suchitra Kamle, Bing Ma, Yang Zhou, Sung Jae Shin, Jack A. Elias, Chun Geun Lee
Abstract
Aortic dissection or rupture is a leading cause of mortality in vascular Ehlers-Danlos syndrome (VEDS), a disorder caused by mutations in the COL3A1 gene. Col3a1G938D/+ mice recapitulate features of VEDS, including high risk of aortic rupture. As in people with VEDS, aortic risk in this model accelerates at the onset of puberty, especially in males. We identify developmentally regulated gene programs associated with this vulnerability and that are targeted by treatments that mitigate aortic risk. Both genetic and pharmacological inhibition of the androgen receptor (AR) eliminated survival differences between sexes, while treatment with a dual AR and mineralocorticoid receptor (MR) antagonist provided near-complete and durable protection in both sexes. Pathways targeted by dual AR/MR inhibition, including those related to extracellular matrix (ECM) organization and cell-ECM interactions, largely overlapped with those also modulated by isolated MR antagonism. Selective targeting of MR signaling emerged as an effective therapeutic strategy in both sexes that avoids sexual side effects in males.
Authors
Emily E. Juzwiak, Caitlin J. Bowen, Rhiannon Edwards, Leda Restrepo, Serena Lee, Cassie A. Parks, Anthony Zeng, Maya M. Black, Oscar E. Reyes Gaido, Emily E. Bramel, Dustin T. Shigaki, Michael A. Beer, Chiara Bellini, Harry C. Dietz, Elena Gallo MacFarlane
Abstract
Eosinophilic esophagitis (EoE) is a type 2 allergic disease characterized by esophageal inflammation and epithelial cell dysfunction. The acquired loss of the anti-serine protease of kazal type 7 (SPINK7) in the squamous epithelium of the esophagus has a causal role in EoE pathogenesis. Yet there is a limited understanding of the factors that regulate its expression and responsiveness to inflammatory stimuli. Herein, we have identified the transcription factor, ovo like transcriptional repressor 1 (OVOL1) as an esophageal selective gene product that regulates SPINK7 promoter activity. Overexpression of OVOL1 increased SPINK7 expression, whereas its depletion decreased SPINK7 expression, impaired epithelial barrier and increased production of the pro-atopy cytokine thymic stromal lymphopoietin (TSLP). Stimulation with IL-13 abrogated the nuclear translocation of OVOL1 and promoted enhanced degradation of OVOL1 protein. This effect of IL-13 was dependent on the esophageal specific cysteine protease calpain-14 at least in part. Analysis of human esophageal biopsies demonstrated that the expression of esophageal OVOL1 correlated with SPINK7 transcript expression and was lost as a function of EoE disease activity. In summary, our study identifies key regulatory mechanisms in EoE pathogenesis, demonstrating that OVOL1 promotes SPINK7 transcription, whereas IL-13 suppresses this pathway in EoE.
Authors
Nurit P. Azouz, Andrea M. Klingler, Sierra S. Beach, Kalen A. Rossey, Mark Rochman, Misu Paul, Julie M. Caldwell, Michael Brusilovsky, Alexander T. Dwyer, Xiaoting Chen, Daniel Miller, Carmy Forney, Leah C. Kottyan, Matthew T. Weirauch, Marc E. Rothenberg
Abstract
Heterozygous TBX4 variants are the second most common genetic cause of pediatric pulmonary hypertension (PH), yet mechanisms underlying TBX4-related lung disease remain poorly understood. This study developed a lung mesenchyme-specific Tbx4 loss-of-function (Tbx4cKO) mouse model that bypasses embryonic lethality to investigate this condition. Adult Tbx4cKO mice demonstrated significantly impaired pulmonary flow acceleration consistent with PH. Three-dimensional analysis of embryonic lungs revealed reduced lobe volumes and decreased distance between pleural edges and muscularized vessels. In adult Tbx4cKO lungs, we identified extensive vascular remodeling characterized by medial thickening and the extension of muscularized arteries into normally non-muscularized subpleural parenchymal zones. Contrary to previous reports suggesting vascular simplification, three-dimensional analysis demonstrated an elaborated pulmonary artery (PA) tree in addition to pathologic wall muscularization. Depletion of a single Tbx5 allele in addition to both Tbx4 alleles exacerbated histologic phenotypes with worsened right ventricular dilation. This model also demonstrated dysregulated airway smooth muscle patterning and prominent subpleural smooth muscle bands, similar to those in human TBX4 syndrome. We identify TBX4 as a critical regulator of smooth muscle differentiation and patterning across multiple lung compartments. Our model recapitulates key features of human TBX4 syndrome and identifies dysregulated smooth muscle differentiation as a potential future therapeutic target.
Authors
Lea C. Steffes, Kaylie A. Chiles, Sehar R. Masud, Aleen Rahman, Madeline Dawson, Csaba Galambos, Maya E. Kumar, Ripla Arora
Abstract
Human γδ T cells are a rare but functionally diverse lymphocyte subset critical for tumor surveillance and antimicrobial immunity. Although they express natural killer (NK) cell-associated receptors such as Killer-cell Immunoglobulin-like Receptors (KIRs), the relevance of KIR expression on γδ T cells remains largely unexplored. Using flow cytometry, ATAC-seq and RNA-seq, we identified KIR expression as a marker that distinguished two functionally and molecularly distinct γδ T cell subsets. KIR⁺ γδ T cells exhibited an advanced, memory-like differentiation state characterized by heightened cytotoxicity, stable epigenetic remodeling and a predominant IFNγ-producing profile. In contrast, KIR⁻ γδ T cells maintained a naïve-like phenotype and preferentially produced IL-17 upon polarization. Notably, KIR+ γδ T cells were consistently observed across individuals but were significantly enriched in cytomegalovirus (CMV)-seropositive donors, suggesting that chronic antigenic stimulation could promote the emergence of KIR⁺ effector γδ T cells. These findings reveal a functional dichotomy in human γδ T cells defined by KIR expression, linking IFNγ-driven cytotoxicity with KIR⁺ cells and IL-17 production with KIR⁻ cells. This insight advances our understanding of γδ T cell heterogeneity and has implications for viral immunity, immune memory and the development of γδ T cell-based immunotherapies.
Authors
Mahya Razmi, Yeganeh Almasi, Marilee Larrivée, Jonathan B. Angel, Alexandre Blais, Zakia Djaoud
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 multi-omic profiling to characterize gene expression and chromatin accessibility in MCs isolated from lavage fluid of lung transplant recipients with and without CLAD, collected early post-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 > 98% accuracy using signature genes. Chromatin accessibility analyses identified enrichment of CCAAT-enhancer-binding protein family transcription factors, specifically CEBPD, in CLAD MCs. Early post-transplant MCs showed minimal accessibility differences, suggesting that CEBPD-associated regulatory changes emerge over time. Integration analyses identified eight MC states and a CLAD-specific shift towards 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 post-transplant MCs, nominating 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
Pulmonary fibrosis is frequently accompanied by pulmonary hypertension, which can occur disproportionate to the extent of fibrosis, suggesting a fibrosis-independent vascular remodeling process. Here, we demonstrated that plasma growth differentiation factor 15 (GDF15) is elevated across diverse fibrotic lung disease subtypes and correlates with markers of elevated right heart pressures, but not pulmonary function indices, indicating a possible link to endothelial cell dysfunction. To investigate the import of endothelial GDF15 as a modifier of lung fibrosis pathogenesis, we generated endothelial cell-specific Gdf15 knockout mice, which showed protection from bleomycin-induced lung injury and fibrosis, with preserved lung function. RNA sequencing of human pulmonary microvascular endothelial cells revealed altered expression of barrier-regulatory genes in GDF15-deficient endothelial cells compared to controls. Functional studies confirmed that GDF15 knockdown attenuates thrombin-induced barrier disruption by reducing cytosolic Ca2+ responses. Together, these findings implicate endothelial GDF15 as a modifier of vascular permeability and Ca2+ signaling, and a contributor to lung injury and fibrosis.
Authors
Kristen Raffensperger, Marta Bueno, Brian J. Philips, Megan Miller, Máté Katona, Shuai Yuan, Adriana Estrada-Bernal, Byron Chuan, Pavan Suresh, Stephanie Taiclet, Scott Hahn, Yingze Zhang, Jonathan K. Alder, Seyed Mehdi Nouraie, Daniel J. Kass, Oliver Eickelberg, Adam C. Straub
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. Transforming growth factor–β1 (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
In Vivo Characterization of Candida Extracellular Vesicles Reveals Unique Infection Pathway Proteins
Abstract
Authors
Justin Massey, Robert Zarnowski, William Hartman Jr., Jeniel E. Nett, David R. Andes
Abstract
Fibroblast-like synoviocytes (FLSs) are crucial in driving synovial inflammation and joint damage in rheumatoid arthritis (RA). This study explored the functions and underlying mechanisms of GALNT1-mediated O-glycosylation, which is markedly upregulated in RA FLSs, in synovial aggression and subsequent experimental joint damage. Targeted suppression of GALNT1 effectively curtailed migration and invasion in RA FLSs and mitigated arthritis severity in a rat collagen-induced arthritis (CIA) model. Mechanistically, NEK9 was identified as a pivotal substrate and downstream effector of GALNT1, affecting the aggressive phenotype of RA FLSs. In vitro experiments further demonstrated that O-glycosylation of NEK9, mediated by GALNT1, promotes the pathogenic phenotype of RA FLSs by promoting cytoskeleton reorganization and restraining excessive endoplasmic reticulum (ER) stress activation. Our study provides mechanistic insights into the activation of RA FLSs and identifies GALNT1 as a potential therapeutic target for RA.
Authors
Yaoyao Zou, Haobo Lin, Jianling Su, Jieying Wang, Qin Zeng, Tianxiao Feng, Yunxia Lei, Jianda Ma, Hudan Pan, Hanshi Xu, Lie Dai, Yang Li
Abstract
Aortic dissection (AD) is a catastrophic vascular emergency with high mortality, and current pharmacologic interventions to prevent its progression are limited. Vascular smooth muscle cells (VSMCs) undergo a pathological phenotypic switch from a contractile to a synthetic state during AD, compromising aortic wall integrity; however, the underlying metabolic mechanisms remain poorly understood. In this study, we performed integrative transcriptomic analyses and identified glutaminase 1 (GLS1) as a key regulator of VSMC phenotypic switching in AD. GLS1 expression was significantly downregulated in VSMCs from both human AD aortic tissues and mouse models. Functionally, GLS1 deficiency promoted PDGF-BB–induced VSMC dedifferentiation in vitro. Smooth muscle cells specific Gls1 knockout (Gls1SMKO) mice exhibited aggravated AD upon BAPN treatment, whereas VSMCs specific GLS1 overexpression improved the contractile phenotype and reduced AD incidence. Mechanistically, GLS1 downregulation impaired glutamate metabolism, leading to reduced levels of glutathione and α-ketoglutarate. This metabolic disruption promoted reactive oxygen species accumulation and mitochondrial dysfunction, ultimately triggering VSMC phenotypic switching. Furthermore, we found that GLS1 transcription was repressed by retinoic acid receptor-α (RARα). Pharmacologic inhibition of RARα with AR7 restored GLS1 expression, ameliorated VSMC phenotypic switching, and conferred protection against AD. These findings reveal a critical role of GLS1-mediated glutamate metabolism in VSMC phenotypic switching and suggest a promising therapeutic strategy for AD.
Authors
Wei Xie, Chen Ning, Chen Lu, Dongjin Wang, Shuang Zhao, Tianyu Song, Hailong Cao
Abstract
Inflammatory bowel disease (IBD) is frequently accompanied by intestinal fibrosis, with non-response (NR) to long-term anti-tumor necrosis factor α (anti-TNFα) therapy occurring in approximately 23-46% of patients. Integrated analysis of single-cell and bulk RNA sequencing datasets revealed an expansion of IL11⁺ fibroblasts in inflamed intestine and their significant enrichment in non-responders. 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 (LASSO), support vector machines (SVM), and random forest (RF) to derive an IL11⁺ fibroblast-related gene signature effectively predicting NR to anti-TNFα in validation and test cohorts. IHC further confirmed the overexpression of IL-11 in non-responders. 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-TNFα 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 NR to anti-TNFα 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
Inhibiting the mammalian target of rapamycin (mTOR) during acute viral infection generates highly functional memory CD8 T cells. We investigated the effects of inhibiting mTOR by using rapamycin during the effector and contraction phases of the immune response to a DNA prime and Modified Vaccinia Ankara (MVA) boost SIV vaccination in rhesus macaques. Rapamycin administered either during MVA boosts alone (DMR) or during both primes and boosts (DRMR) reduced the contraction of effector CD8 T cells, resulting in higher frequencies of SIV-specific memory CD8 T cells with enhanced quality as indicated by expression of Bcl-2 and CD127. Additionally, rapamycin reduced the frequency of proliferating CCR5+ CD4 T cells in the blood following the MVA boost. Post SIV251 infection, rapamycin-treated macaques demonstrated marked expansion of SIV-specific CD8 T cells (reaching up to 50% in blood and 25% in gut). The heightened expansion of SIV-specific CD8 T cells in the DMR group was associated with markedly lower (2-logs compared to unvaccinated and 1-log compared to DM) peak viral load in the gut and set-point viremia, along with improved survival post infection. Thus, inhibiting the mTOR pathway during MVA boosts of a DNA/MVA vaccine enhances vaccine efficacy by improving memory CD4 and CD8 T cell function.
Authors
Shanmugalakshmi Sadagopal, Kasey Stokdyk, Suefen Kwa, Rahul Basu, Sailaja Gangadhara, Rafi Ahmed, Smita S. Iyer, Koichi Araki, Rama Rao Amara
