Issue published June 15, 2026 Previous issue
- Volume 136, Issue 12
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On the cover: Receptor tyrosine kinase–integrin crosstalk in endothelium
Sipilä et al. report X-ray crystallography, size-exclusion chromatography coupled with small-angle X-ray scattering (SEC-SAXS), and atomistic molecular dynamics of angiopoietin-2 (ANGPT2) in complex with the TIE2 receptor tyrosine kinase and α5β1-integrin, explaining receptor crosstalk in endothelium. The cover image shows a trimeric complex of ANGPT2 dimer bound to TIE2 and integrin α5 domains via asymmetric fibrinogen like domains. Image credit: Pipsa Saharinen, Kumar Ponna and Martina Trevisani.
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Reviews
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Abstract
Polycystic ovary syndrome (PCOS), also known as polyendocrine metabolic ovarian syndrome (PMOS), is the most common endocrinologic disorder to affect women. Despite this, the pathophysiology of the disease is not entirely known. This has hindered the diagnosis of the disease and appropriate treatment for millions of individuals. In this Review, we discuss the proposed pathophysiology of PCOS from a translational perspective. We review the existing diagnostic criteria of PCOS and current management strategies. Finally, we discuss the long-term health sequelae associated with PCOS, future directions, and areas of needed research in this often-overlooked disease.
Authors
Jessica L. Chan, Irene Masini, Margareta D. Pisarska
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Each year, sepsis claims more lives in the United States than many major cancers and HIV/AIDS combined, yet therapeutic progress has been modest. Adding to this crisis is the alarming rise of multidrug-resistant “superbugs,” which increasingly render conventional antibiotics ineffective. Pathogen-targeted antibiotics will always remain a cornerstone of sepsis treatment, and research into novel antibiotics must continue unabated. However, the consistent mortality in sepsis tells us this approach is insufficient. Most deaths in sepsis do not occur during the early cytokine storm–driven hyper-inflammatory phase but rather days or weeks after the initial insult, during a protracted phase of immune suppression. Here, we make the case that a crucial way to reduce sepsis mortality lies in restoration of the patient’s immune competence, enabling the patient to contain and kill the invading microbes. Adjuvant immune therapies will not only enable killing of the initial, invading pathogens but also prevent secondary, hospital-acquired infections. Immunotherapy revolutionized oncology by challenging the assumption that cancer was best treated through cytotoxic or targeted tumor-directed approaches, and sepsis now stands at a similar inflection point. We argue that embracing immune restoration as a core therapeutic objective offers the most promising means to improve survival in this lethal disorder.
Authors
Richard S. Hotchkiss, Guillaume Monneret
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The reality of an aging population demands a deeper understanding of aging as a biological process, rather than as a chronological descriptor. Chronological age poorly captures interindividual heterogeneity in physiological and functional decline, disease susceptibility, and mortality risk. In contrast, biological age encompasses deterioration at the molecular, cellular, tissue, organ, functional, and organismal levels and provides insight into why two individuals with the same chronological age exhibit differences in physiological function, disease susceptibility, and mortality risk. While early models of biological age relied on functional markers or composite scores derived largely from longitudinal cohort studies, more recent models integrate molecular profiling with machine learning to ascertain biological aging trajectories. In parallel, new artificial intelligence tools have been applied to various imaging modalities and other forms of complex data to elucidate latent patterns and estimate biological age. In this state-of-the-art Review, we explore historical and modern approaches to estimating biological age and highlight key conceptual, technical, and translational challenges that remain unresolved. As geroscience-guided interventions are incorporated into clinical evaluations, robust and accurate interpretable measures of biological aging are crucial to ascertain treatment effects in clinical trials.
Authors
Baljash S. Cheema, Bedirhan Boztepe, Moses O. Awofolaju, Mallory S. Hubbard, William B. Marcus, Frank J. Palella, Mohamed Abdel-Mohsen, David M. Liebovitz, Manjot K. Gill, R. James Cotton, John T. Wilkins, Douglas E. Vaughan
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As a widely distributed network of cells, tissues, and organs, the human immune system is profoundly vulnerable to the effects of aging. Intrinsic and extrinsic stressors progressively erode its structural integrity and functional resilience, weakening core protective responses and increasing susceptibility to infection, malignancy, and tissue degeneration. At the same time, aging heightens the risk of chronic inflammation and autoimmune disease. Hematopoietic stem cells become uniquely compromised as aging intensifies metabolic and replicative stress. Their continuous high-volume turnover results in diminished self-renewal capacity, skewed lineage output, and dominance of expanded clones. These changes undermine innate immune competence and amplify inflammatory activity. Adaptive immune function declines with age through coordinated cellular and molecular programs. T and B lymphocytes exhibit a decline in naive cells, progressive loss of stemness, shortened lifespan, and constrained clonal diversity. Aging lymphocytes reconfigure transcriptional networks, undergo widespread organelle dysfunction, develop maladaptive stress responses, and redistribute into noncanonical tissue niches. Collectively, these alterations reduce antigen specificity and precision, promote innate-like immune behavior, and confer resistance to tolerance. These mechanisms result in concurrent immunodeficiency and autoimmunity, exemplified by two autoimmune diseases disproportionately affecting older adults: rheumatoid arthritis and giant cell arteritis.
Authors
Cornelia M. Weyand, Jörg J. Goronzy
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Commentaries
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Abstract
Traumatic brain injury (TBI) disproportionately kills and disables older adults, yet the biology driving this vulnerability remains unresolved. In this issue of the JCI, Lu et al. combined single-cell transcriptomics, metabolomics, and chromatin profiling in mice, validated in human TBI tissue, to define an age-dependent microglial dichotomy. They report that an NLRP3+/IL-1β–linked state dominates the aged brain, while a Lysozyme+/Lyz2+ state predominates in the young. Microglia-targeted perturbation of NLRP3 and ELF1 each shifted the balance and improved survival in mouse models of TBI, and the repurposed drug Imeglimin improved outcomes in these models, confirming that this pathway is druggable. By connecting NLRP3 inflammasome dominance, ELF1-driven transcription, and glycolytic reprogramming to the loss of a protective Lyz2+ response, this work converts age from a clinical risk factor to a set of druggable microglial targets.
Authors
Josh M. Morganti, Adam D. Bachstetter
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Historically, research on chylomicron entry into intestinal lymphatic vessels (lacteals) has been polarized between paracellular and transcellular transport models. In this issue of the JCI, Sun et al. identified GPR182 as a lipoprotein receptor in lymphatic endothelial cells (LECs), profoundly advancing our understanding of intestinal lipid absorption. They observed poor fat absorption in GPR182-deficient mice and demonstrated the role of GPR182 in transporting chylomicrons across the LECs into the lacteal lumen. This discovery establishes a molecular basis for transcellular transport of chylomicrons, challenging the traditional view that lacteal lipid entry is predominantly paracellular. By linking receptor-mediated uptake to impaired fat absorption and protection against fat-induced obesity and steatosis, this study expands the biological and translational implications of lacteal transport. Consequently, rather than favoring a single model, future research should investigate the integration of both paracellular and transcellular transport models in vivo.
Authors
Liqing Yu
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Cancer proteogenomics has revealed that RNA abundance often poorly predicts protein output, highlighting translation as a central determinant of malignant identity. In this issue of JCI, Mishra et al. showed that pharmacologic inhibition of eIF4E cap binding selectively rewired the prostate cancer translatome, suppressing basal keratin translation while promoting luminal features and renewed sensitivity to hormone therapy. More broadly, the study illustrates how tumors exploit selective translation to maintain lineage plasticity, survival, and therapeutic resistance. Targeting translational dependencies may therefore offer a powerful strategy to dismantle cancer-specific proteomic programs and convert resistant cell states into druggable vulnerabilities.
Authors
Davide Ruggero
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Vitiligo is a depigmenting disease marked by progressive T cell–driven destruction of melanocytes in the skin, hair, and mucosa. While vitiligo is known to be a T cell–mediated autoimmune disease, its triggers have remained poorly understood and treatment options limited. In this issue of the JCI, Kang et al. demonstrated how hyperglycemia exacerbates vitiligo progression through the succinate/SUCNR1 axis. These findings identify succinate as a potential biomarker for disease activity and highlight an independent pathway for targeting in therapeutic intervention. More broadly, the findings linking succinate and glucose metabolism to vitiligo suggest that lifestyle factors could be modified to slow development of vitiligo and other autoimmune diseases linked to succinate.
Authors
Kaitlyn G. O’Donnell, I. Caroline Le Poole
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Research Letter
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Abstract
Authors
Lawrence W. Rasmussen, Deepali Luthra, Diego Moncada-Giraldo, Crystal Lewis, Yixel M. Soto-Vazquez, Zhuo Li, Buqu Hu, Brian S. Dobosh, Delores A. Stacks, Jonathan L. Koff, Amit Gaggar, Rabindra Tirouvanziam, Camilla Margaroli
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Research Articles
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Abstract
Interrupting glucagon signaling decreases gluconeogenesis and the fractional extraction of amino acids by liver from blood, resulting in lower glycemia. The resulting hyperaminoacidemia stimulates α cell proliferation and glucagon secretion via a liver/α cell axis. We hypothesized that α cells detect and respond to circulating amino acids’ levels via a unique amino acid transporter repertoire. We found that Slc7a2/SLC7A2 is the most highly expressed cationic amino acid transporter in α cells, with its expression being 3-fold greater in α than β cells in both mouse and human. Employing cell culture, zebrafish, and knockout mouse models, we found that the cationic amino acid arginine and SLC7A2 are required for α cell proliferation in response to interrupted glucagon signaling. Ex vivo and in vivo assessment of islet function in Slc7a2–/– mice showed decreased arginine-stimulated glucagon and insulin secretion. We found that arginine activation of mTOR signaling and induction of the glutamine transporter SLC38A5 was dependent on SLC7A2, showing that the role of both in α cell proliferation is dependent on arginine transport and SLC7A2. Finally, we identified single nucleotide polymorphisms in SLC7A2 associated with HbA1c. Together, these data indicate a central role for SLC7A2 in amino acid–stimulated α cell proliferation and islet hormone secretion.
Authors
Erick Spears, Jade E. Stanley, Matthew Shou, Linlin Yin, Xuan Li, Chunhua Dai, Amber Bradley, Katelyn Sellick, Greg Poffenberger, Katie C. Coate, Shristi Shrestha, Anna Marie R. Schornack, Taverlyn Shepard, Madushika Wimalarathne, Regina Jenkins, Kyle W. Sloop, Keith T. Wilson, Alan D. Attie, Mark P. Keller, Wenbiao Chen, Alvin C. Powers, E. Danielle Dean
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Apolipoprotein B–containing (APOB-containing) lipoproteins contribute to atherosclerosis by entering the arterial wall through the endothelial cell (EC) surface receptors scavenger receptor-BI (SR-BI) and activin receptor-like kinase 1 (ALK1). We used N-terminal fragments of APOB, molecular modeling, and site-directed mutagenesis to identify and block the binding of chylomicrons and LDL to these receptors in cells and mice. We discovered that different APOB regions interact with SR-BI and ALK1 expressed on ECs. APOB48 lipoproteins were only internalized by SR-BI. A fragment of APOB comprising 18% of the N-terminal sequence, APOB18, reduced the uptake and transport of both chylomicrons and LDL by ECs, whereas a shorter fragment, APOB12, only blocked ALK1-mediated uptake of APOB100-containing lipoproteins. Importantly, overexpressing APOB18 decreased atherosclerosis in hypercholesterolemic mice. These findings identify the N-terminal region of APOB as the cause of atherosclerosis and illustrate an approach to treating or preventing vascular disease.
Authors
Ainara G. Cabodevilla, Camila Calistru, Waqas Younis, Dimitris Nasias, Tse W.W. Ho, Narasimha Anaganti, Swati Valmiki, Sujith Rajan, Jana Gjini, Rufina Kore, Carmen Hannemann, Nicholas O. Davidson, Tomas Vaisar, Jenny E. Kanter, Karin E. Bornfeldt, Edward A. Fisher, Warren L. Lee, Tobias Madl, M. Mahmood Hussain, Ira J. Goldberg
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The blood and lymphatic vascular systems are regulated by angiopoietin (ANGPT) growth factors, which signal via endothelial TIE receptor tyrosine kinases and integrins. However, mechanistic understanding of how these receptors crosstalk is limited. Here, we show how β1-integrin inactivation regulates endothelial ANGPT/TIE2 signaling. By integrating biophysical analyses, X-ray crystallography, size-exclusion chromatography–small-angle X-ray scattering and atomistic molecular dynamics simulations, we show that ANGPT2 binds through its asymmetrically positioned C-terminal fibrinogen-like domains to both TIE2 and α5β1-integrin, forming a trimeric complex compatible with the inactive α5β1-integrin conformation. Inactive β1-integrin colocalizes with ANGPT-induced TIE2 in cell-cell junctions and stabilizing β1-integrin in its inactive state enhances junctional TIE2 accumulation and promotes nuclear exclusion of the TIE2 transcriptional effector FOXO1 in cultured endothelial cells. Endothelial-specific β1-integrin deletion in adult mice reduces venous TIE2 phosphorylation, whereas endotoxemia diminishes junctional β1-integrin along with decreased phosphorylated TIE2. In contrast, without TIE2, ANGPT2 uniquely engages active β1-integrin, via its N-terminal superclustering domain. Altogether, our results provide structural and mechanistic evidence of ANGPT signaling via α5β1-integrin and support a model in which inactive α5β1-integrin acts as a junctional scaffold for ANGPT/TIE2/FOXO1 signaling, explaining how integrin conformational switching spatially organizes growth factor signaling in the endothelium.
Authors
Tuomas Sipilä, Srinivas Kumar Ponna, Abhinandan Venkatesha Murthy, Anne Pink, Giray Enkavi, Shraman Kumar Bohra, Klaudia Lewna, Keerthana Ganesh, Qina Liu, Mirka Korhonen, Tommi Kajander, Michael Potente, Johanna Ivaska, Ilpo Vattulainen, Veli-Matti Leppänen, Pipsa Saharinen
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Neuropathic pain affects over 20 million people in the United States, and painful diabetic neuropathy (PDN), a common complication of diabetes, is among its most prevalent and treatment-resistant forms. Although PDN is characterized by nociceptor dysfunction, the upstream peripheral mechanisms remain incompletely understood. While dorsal root ganglion (DRG) nociceptor hyperexcitability is a hallmark of PDN, emerging evidence suggests that nonneuronal skin cells may modulate nociceptor function. Here, we investigated whether epidermal Langerhans cells (LCs) contribute to neuropathic pain in PDN through neuroimmune signaling. Using a clinically relevant high-fat diet (HFD) mouse model, transgenic LC ablation, behavioral assays, human skin biopsies, and single-cell RNA seq of epidermis and DRG, we found that LC density increased in male diabetic mice in parallel with mechanical allodynia. In skin samples of people with PDN, LCs exhibited increased volume and dendritic complexity correlating with diabetes duration. Genetic depletion of LCs prevented mechanical allodynia and spontaneous pain-like behavior in male, but not female, HFD mice, revealing a sex-dependent contribution. Single-cell and interactome analyses identified male-specific inflammatory LC programs, including upregulation of chemokine signaling pathways. Consistently, LC secretome profiling showed increased CCL2 release, and local CCR2 blockade reversed allodynia. These findings identify epidermal LCs as peripheral regulators of PDN pain and highlight sex-dependent chemokine-mediated neuron-immune communication at the skin-nerve interface.
Authors
Paola Pacifico, Dale George, Nirupa D. Jayaraj, Dongjun Ren, James S. Coy-Dibley, Abdelhak A. Belmadani, Sofia Veronesi, Mirna Andelic, Daniele Cartelli, Grazia Devigili, Raffaella Lombardi, Giuseppe Lauria Pinter, Amy S. Paller, Richard J. Miller, Daniela M. Menichella
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BACKGROUND Approaches to achieving antiretroviral therapy–free (ART-free) remission from HIV-1 must consider that people over 50 years now comprise the majority of people with HIV (PWH) on ART in various regions, including the United States.METHODS We report a double-blind, randomized trial in which PWH on ART, aged 21–60 years, received modified vaccinia Ankara–vectored (MVA-vectored) vaccines, MVA.tHIVconsv3 (M3) and MVA.tHIVconsv4 (M4), either alone or in combination (n = 7/group), or saline placebo (n = 3). M3 and M4 contain complementary HIVconsvX immunogens that each span the same regions in HIV-1 Gag and Pol but differ by approximately 8% at the amino acid level.RESULTS M3, M4, and M3M4 regimens were well tolerated and all significantly increased both the frequency (peak median increase ~3-fold) and breadth of the HIVconsvX-specific T cell response while redirecting T cells to target conserved regions in HIV-1 for up to 10 weeks after vaccination. We also demonstrated that vaccination increased frequencies of T cells targeting participant autologous HIV-1 sequences. Vaccination mostly expanded preexisting HIV-1–specific T cells and did not impact CD4+ T cell activation, low-level viremia, or integrated HIV-1 provirus. Linear regression indicated that age was independently and negatively associated with the change in T cell frequency at 1, 2, and 10 weeks after vaccination (~1.41-fold decrease per 10 years older). After adjusting for age, years on ART was positively associated with HIVconsvX-specific T cell frequencies at 1 and 2 weeks following vaccination.CONCLUSION In PWH receiving ART, MVA.HIVconsvX vaccines significantly increased T cells targeting conserved regions of HIV-1. Novel strategies may be required to enhance anti–HIV-1 immunity in older adults.TRIAL REGISTRATION ClinicalTrials.gov NCT03844386FUNDING NIH National Institute of Allergy and Infectious Diseases (NIAID) grants U01AI131310, HHSN272201100021I/HHSN27200037 (subcontract OX-14007.004.0037-212), UM1TR004406, P30AI050410, and P30CA016086; International AIDS Vaccine Initiative; European and Developing Countries Clinical Trials Partnership SRIA2015-1066; European Commission’s Horizon 2020 Research and Innovation Programme 681137.
Authors
Cynthia L. Gay, Yinyan Xu, Ann Marie K. Weideman, Fiona R. Shaw, JoAnn D. Kuruc, Shayla Z. Conrad, Sofia A. Mariano, Shahryar Samir, Sallay Kallon, Alexis T. Sponaugle, Joanna A. Warren, Genevieve T. Clutton, Maria Abad-Fernandez, Carolina Kapper, Alex B. Bradley, Caroline E. Baker, Susan M. Pedersen, Matthew J. Moeser, Lauren Burke, Edmund G.-T. Wee, Alison Crook, Gregory M. Laird, Joshua C. Cyktor, John W. Mellors, Shuntai Zhou, Lawrence Fox, Joseph J. Eron, David M. Margolis, Michael G. Hudgens, Tomáš Hanke, Nilu Goonetilleke
×Abstract
Sphingosine-1-phosphate lyase (SPL) insufficiency syndrome (SPLIS), also known as nephrotic syndrome type 14, is an autosomal recessive multisystem disorder caused by loss-of-function mutations in SGPL1, encoding the enzyme responsible for the terminal degradation of sphingosine-1-phosphate (S1P). We investigated a patient carrying a previously undescribed c.1084T>A (p.Ser362Thr) SGPL1 variant and analyzed the metabolic and cellular consequences of SPL deficiency, using patient fibroblasts, SGPL1-KO HEK293T cells, and Sgpl1–/– and Sgpl1rosa+fl/fl mice. Metabolic stable isotope labeling revealed that SPL deficiency does not invariably result in S1P accumulation. Instead, SPL-deficient cells maintain near-normal S1P levels through (a) feedback regulation of de novo sphingolipid synthesis via the ORMDL–ceramide axis and (b) increased diversion of excess ceramides into glycosphingolipids. However, perturbation of sphingolipid homeostasis, either by exogenous sphingolipid load or disruption of compensatory regulation, induces pathological intracellular S1P accumulation. In vivo, Sgpl1–/– mice had pronounced urinary S1P excretion and renal S1P enrichment, accompanied by cytoskeletal disorganization and impaired epithelial morphogenesis. Mechanistically, we identify aberrant Rho/ROCK signaling as a key mediator of S1P-driven cytoskeletal dysregulation. Pharmacological ROCK inhibition with fasudil mitigated renal cytoskeletal defects in Sgpl1–/– and Sgpl1rosa+fl/fl mice and partially restored epithelial architecture. These findings redefine the metabolic consequences of SPL deficiency and identify S1P-driven Rho/ROCK hyperactivation as a tractable therapeutic target in SPLIS.
Authors
Adam Majcher, Ranjha Khan, Kathrin Buder, Florence Bourquin, Julie D. Saba, Thorsten Hornemann
×Abstract
Spinocerebellar ataxia type 1 (SCA1) is a neurodegenerative disease marked by progressive motor deficits and Purkinje cell (PC) degeneration, driven by polyglutamine expansion in ataxin-1. While oligodendroglial dysfunction precedes PC loss, its direct contribution toward SCA1 pathogenesis remains unclear. Here, using an oligodendroglia-specific SCA1 conditional knockin mouse model, we demonstrate that mutant ataxin-1 in oligodendrocytes is sufficient to drive aspects of SCA1-related pathology, including dysregulated myelination, PC axonal shrinkage, and torpedo formation, ultimately impairing motor coordination. Transcriptomic analysis uncovers cerebellar oligodendrocyte subtypes with distinct gene expression signatures and aberrant abundance that contribute to demyelination. This, compounded by a progressive decline in the neuroprotective functions of a cerebellum-specific oligodendrocyte subtype, establishes a critical link between demyelination, axo-myelinic dysfunction, and axonal pathology in SCA1. Upstream transcriptional regulator analysis in oligodendroglia identifies transcription factor 7-like 2 (TCF7L2) and huntingtin (HTT) as key mediators of oligodendroglial dysfunction in SCA1, suggesting shared pathogenic mechanisms with other polyglutamine diseases. Collectively, these findings establish oligodendroglia as key mediators of SCA1 pathogenesis and underscore their critical role in preserving PC axonal integrity.
Authors
Changwoo Lee, Rosalie M. Grijalva, Leon Tejwani, Eunwoo Bae, Alison Chase, Hannah Ro, Hannah Kim, Victor Olmos, James P. Orengo, Janghoo Lim
×Abstract
Traumatic brain injury (TBI) disproportionately affects the elderly, yet the underlying mechanisms remain unclear. Here, we demonstrate that aged TBI brains predominantly harbor proinflammatory NLRP3+ microglia, in stark contrast to the neuroprotective Lysozyme+ microglia prevalent in young TBI brains. This age-dependent microglial dichotomy correlates with elevated mortality and impaired recovery in aged TBI mice. By leveraging an integrative multiomics approach combined with metabolomics and epigenome analysis, we identified a previously unrecognized link between enhanced glycolysis and the proinflammatory chromatin landscape in NLRP3+ microglia. Further investigation identified ELF1 as a key transcription factor driving NLRP3+ microglia formation. Importantly, ablation of ELF1 reversed age-associated microglial dysfunction and improved TBI outcomes. Finally, we report that Imeglimin, a clinically approved antihyperglycemic agent capable of crossing the blood-brain barrier, inhibits ELF1 and reverses microglial phenotype, reducing acute mortality rate and leading to improved functional recovery of aged mice with TBI. Our work elucidates the mechanistic basis of age-dependent TBI outcomes, reveals the crosstalk between metabolic rewiring and epigenetic regulation in microglial aging, and identifies ELF1 as a promising therapeutic target for improving TBI outcomes.
Authors
Zhichao Lu, Yi Shuai, Chenxing Wang, Zongheng Liu, Ziheng Wang, Qianqian Liu, Rui Jiang, Jue Zhu, Yongqi Zhu, Weiquan Liao, Xingjia Zhu, Jingwei Zhao, Kaibin Shi, Wei Shi, Peipei Gong
×Abstract
Iron overload has emerged as a significant risk factor for metabolic dysfunction–associated steatotic liver disease (MASLD), a growing global health concern. Despite this association, the precise mechanisms by which hepatic iron and its regulatory genes connect liver pathology to systemic metabolic dysfunction remain elusive. Here, we demonstrate that humoral signals originating from iron-overloaded hepatocytes acted as critical mediators driving systemic metabolic dysfunction in MASLD. Ferroportin (FPN, SLC40A1), the sole cellular iron exporter, exhibited markedly reduced expression in hepatocytes of both patients with MASLD and mouse models of the disease, concomitant with hepatic iron accumulation. Functionally, hepatocyte-specific FPN deletion significantly exacerbated diet-induced obesity and insulin resistance, with these metabolic perturbations accompanied by decreased energy expenditure and impaired thermogenic capacity. Mechanistically, we establish that hepatic iron accumulation resulting from FPN deficiency enhanced the production of 2 specific hepatokines, fetuin-A and LECT2, through activation of the transcription factor FoxO1. Notably, therapeutic interventions — including genetic silencing of these hepatokines, hepatocyte-specific FPN overexpression, or oral iron chelation — effectively reversed the metabolic dysfunction phenotypes. These findings provide critical insights into the pathophysiological mechanisms linking MASLD to systemic metabolic disorders and highlight promising therapeutic strategies to combat these diseases.
Authors
Hye Jin Jo, Ayoung Kim, Hyunsoo Rho, Ae Kyung Park, Gil-Hwan Kim, Seo Jeong Jo, Hao Yuxin, You-Jung Hong, Ji Min Yeon, Hwang Chan Yu, Mi-Young Song, Jeongwoo Park, Yeon Hee Jeong, Sung Eun Hong, Hyo Jin Yeon, Da Young Oh, Philipp E. Scherer, Cheol Soo Choi, Dong Hyeon Lee, Sung Hwan Ki, Keon Wook Kang, Murim Choi, Byung-Hyun Park, Eun Ju Bae, Sang Geon Kim, Won Kim, Chang Yeob Han
×Abstract
BACKGROUND Liquid biopsy has emerged as a minimally invasive method for tumor diagnosis, monitoring, and therapeutic guidance. For CNS tumors, cerebrospinal fluid (CSF) provides a reliable and accessible source of tumor-derived cell-free DNA (ctDNA).METHODS This study evaluates the clinical utility of CSF liquid biopsy in a real-world prospective setting. A total of 148 CSF samples from 120 patients underwent molecular analysis using droplet digital PCR (ddPCR) and/or next-generation sequencing to detect mutations, fusions, copy number alterations, and mismatch-repair deficient signatures (MMRDness). Samples were collected via lumbar puncture (n = 82; 45% ctDNA positive) or from ventricle sources at the time of surgery or through shunts (n = 66; 65% ct DNA positive).RESULTS Overall, ctDNA was detected in 54% of samples with higher detection in high-grade gliomas at diagnosis (100%, 1 sample equivocal) compared with low-grade gliomas (50%). Among low-grade gliomas, ctDNA detection was higher in disseminated cases (80% versus 43%) and from ventricular versus lumbar samples (56% versus 38%).CONCLUSION Liquid biopsy distinguished relapse from second malignancy and serial sampling demonstrated the potential for ctDNA levels to track treatment response and disease progression. In patients with MMRD tumors, high MMRDness score from ctDNA supported active disease. These findings demonstrate that combined liquid biopsy assays facilitate diagnosis, monitoring, and personalized treatment decisions, offering a viable alternative to invasive surgical biopsies in pediatric CNS tumors.TRIAL REGISTRATION None.FUNDING Proof of Principle Grant from The Hospital for Sick Children; The Canadian Institutes of Health Research; The Canadian Cancer Society; The We Love You Connie Foundation; Garron Family Cancer Center at SickKids; SickKids Clinician Training Program; Ben Stelter Foundation through the Women and Children’s Health Research Institute; Jeffrey Brock Cancer Genetics Research Fellowship; Garron Family Cancer Center Research Fellowship/Scotiabank Clinician Scientist Fellowship; Atrium/CMCC and Hold’em for Life Oncology Fellowship; Tokyo Children’s Cancer Study Group Scholarship of the Gold Ribbons Network.
Authors
Liana Nobre, Yoshiko Nakano, Ian Burns, Robert Siddaway, Michal Zápotocky, Monique Johnson, Mansuba Rana, Cyril Li, Rodney K. Lyn, Richard Yuditskiy, Michelle Ku, Javal Sheth, Adrian B. Levine, Cody L. Nesvick, Anirban Das, Chantel Cacciotti, Shayna Zelcer, Seth A. Climans, Maria MacDonald, Logine Negm, Jiil Chung, Julie Bennett, Andrew Bondoc, Jim Loukides, Lucie Stengs, Melissa Edwards, Eric Bouffet, Vijay Ramaswamy, Anthony P.Y. Liu, Annie Huang, Ute Bartels, Peter B. Dirks, Uri Tabori, Cynthia Hawkins
×Abstract
Idiopathic pulmonary fibrosis (IPF) is a devastating chronic lung disorder with limited treatment options. Macropinocytosis is one of the key cellular processes involved in nutrient consumption from the extracellular environment under stress conditions. Here, we studied the role of macropinocytosis in experimental pulmonary fibrosis models. We found that macropinocytosis is increased in human lung fibroblasts (HLFs) derived from patients with IPF. The inhibition of macropinocytosis with 5-(n-ethyl-n-isopropyl)-amiloride (EIPA) inhibited profibrotic responses in IPF-derived and TGF-β1–stimulated HLFs and reduced pulmonary fibrosis in bleomycin-injured (Bleo-injured) mice. EIPA exerted its antifibrotic effects by regulating amino acid uptake, mammalian target of rapamycin complex 1 (mTORC1) activation and mesenchyme homeobox1 (MEOX1) expression in activated HLFs. Fittingly, genetic inhibition of macropinocytosis also ameliorated lung fibroblast activation and pulmonary fibrosis in mice. Using IPF-derived precision cut lung slices (PCLSs), we observed robust repression of profibrotic gene expression programs in EIPA-treated PCLSs across different fibroblast subpopulations. Finally, we found that imipramine (Imi), a tricyclic antidepressant approved by the FDA, effectively inhibited macropinocytosis and ameliorated profibrotic responses in lung fibroblasts, Bleo-injured mice, and IPF-derived PCLSs. Taken together, our results suggest that macropinocytosis inhibition can be considered as a potential therapeutic strategy to treat pulmonary fibrosis.
Authors
Ivan O. Rosas, Aaron K. McDowell-Sanchez, Santiago Sanchez, Juan D. Cala-Garcia, Alan R. Waich Cohen, Elisa Ruiz-Echartea, Scott A. Ochsner, Daniel C. Kraushaar, Lindsay J. Celada, Dandan Sun, Francesca Polverino, Cristian Coarfa, Neil J. McKenna, Konstantin Tsoyi
×Abstract
Alveolar type 2 (AT2) progenitor cell exhaustion and impaired regenerative capacity are key pathogenic hallmarks in idiopathic pulmonary fibrosis (IPF). Nicotinamide adenine dinucleotide (NAD+) functions as a central regulator of cellular energy metabolism. We have previously reported that downregulation of NAD+-dependent sirtuin signaling contributes to the impaired progenitor cell function of IPF AT2 cells. In this study, we found that a key NAD+ biosynthesis enzyme, nicotinamide phosphoribosyltransferase (NAMPT), was significantly downregulated in IPF AT2 cells. NAMPT deficiency impaired AT2 renewal and enhanced lung fibrosis through downregulation of SIRT7 and SOD2, which resulted in increased oxidative stress, mitochondrial dysfunction, accumulated aberrant transitional cells, and impaired differentiation from AT2 to alveolar type 1 (AT1) cells. A mouse model with AT2-specific deletion of Nampt showed severely impaired AT2 renewal capacity and increased susceptibility to bleomycin lung injury. Activation of NAMPT by small-molecule activators promoted IPF AT2 renewal and reversed lung fibrosis in WT mice. NAMPT activation is a potentially promising therapeutic strategy for restoring AT2 progenitor cell function and halting or reversing progressive pulmonary fibrosis.
Authors
Xuexi Zhang, Xue Liu, Yujie Qiao, Anas Rabata, Ningshan Liu, Changfu Yao, Tanyalak Parimon, Danica Chen, Cory Hogaboam, Peter Chen, Barry Stripp, Stephen J. Gardell, Dianhua Jiang, Paul W. Noble, Jiurong Liang
×Abstract
The human epidermal growth factor receptor 2 (HER2) is a major therapeutic target in cancer. While the oncogenic effects of HER2 hyperactivation are well characterized, the biological consequences of its deficiency remain poorly defined. Here, through exome sequencing analyses of a cohort of 720 families affected by isolated or syndromic orofacial clefts, we unexpectedly identified 5 distinct rare germline HER2 variants in 5 unrelated families with growth deficits, orofacial clefts, and other craniofacial, skeletal, and auditory anomalies. In Xenopus embryos, these variants failed to recapitulate the developmental effects of WT HER2. In cultured cells, they disrupted HER2 protein stability, membrane localization, or site-specific phosphorylation, resulting in diminished ERK signaling. Strikingly, knock-in mice expressing a patient-derived HER2 variant and mice maternally exposed to Tucatinib, a recently approved anti-HER2 drug, both replicated patient phenotypes: delayed growth and diverse craniofacial abnormalities, including ocular dysgenesis, short jaws, and cleft palate. Collectively, our findings define a developmental disorder that we designate GRACE syndrome (Growth Retardation and Craniofacial Malformations Caused by HER2 Deficiency), establish HER2’s essential role in human growth and craniofacial morphogenesis, and reveal that HER2-targeted therapies during pregnancy can induce craniofacial defects and lifelong growth impairment in fetuses.
Authors
Huaxiang Zhao, Pan Wang, Yuhua Jiao, Huimei Huang, Min Yu, Qing He, Chengkai Pan, Shuang Guo, Wenbin Huang, Yunfei Jia, Qianying Kong, Huifang Peng, Yandong Han, Yuxia Hou, Zhanping Ren, Yongwei Tao, Fei Huang, Hongwei Jiang, Shan Sun, Yanying Dong, Jiuxiang Lin, Chunyan Yin, Xuechen Zhu, Feng Chen, Yi Ding
×Abstract
Type 1 conventional dendritic cells (cDC1s) play an integral role in mediating immune responses and maintaining homeostasis, yet the molecular mechanisms underlying their functions remain poorly understood. In this study, we identified dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) as a key kinase that responded to TLR and growth factor stimulation and acted as an essential regulator of cDC1 function. Genetic ablation of Dyrk1a specifically in cDC1s impaired antitumor immunity and accelerated tumor progression in murine models. Mechanistically, DYRK1A mediated the phosphorylation of the mTOR complex 1 (mTORC1) inhibitor TSC2 at serine 540, triggering the degradation of TSC2 and promoting mTORC1 signaling in cDC1s. Notably, Tsc2 deletion in Dyrk1a-deficient cDC1s remarkably restored their antitumor immune functions. Furthermore, DYRK1A-mediated mTORC1 signaling in cDC1s positively correlated with effector T cell responses across multiple human cancers. Our findings highlight a critical role for the DYRK1A/TSC2/mTORC1 signaling pathway in regulating cDC1 functions in antitumor immunity, offering potential strategies to improve cancer immunotherapy.
Authors
Hongjiao Wang, He Jiang, Songlin He, Songwen Ren, Haiwen Li, Wangnan Liu, Chunyun Zhou, Pan Zhu, Keren Chen, Weijia Cao, Yan Qin, Dan Du, Nengming Xiao, Hongling Huang, Chun-Jung Ko, Yiming Zheng, Bo Wang, Qiang Zou, Jian-Hong Shi, Xun Li, Zuliang Jie
×Abstract
Lineage plasticity underscores the resilience of cancer cells in the context of drug treatment. However, lineage fates can also be therapeutically directed. We demonstrate that the eukaryotic initiation factor 4E (eIF4E) cap-binding domain is a critical regulator of lineage plasticity in prostate cancer. Using a first-in-class cap-binding domain inhibitor, we found that plasticity is driven by translational repression of basal keratins through a shared cis-regulatory element enciphered in their 5’ untranslated regions (UTRs). Simultaneously, this stabilized the androgen receptor (AR) through translational upregulation of the deubiquitinases BAP1 and OTUD3. This lineage program is essential for cell survival and drives a druggable vulnerability. Notably, tumors resistant to AR blockade regained sensitivity upon eIF4E cap-binding domain inhibition, which reprogrammed them toward a luminal state. In patients with castration-resistant prostate cancer (CRPC), elevated eIF4E expression was associated with a basal phenotype, reduced luminal differentiation, and accelerated resistance to AR pathway inhibitors (ARPIs). These discoveries uncover a role for the eIF4E cap-binding domain in lineage plasticity and highlight that targeting this domain offers a promising strategy to overcome treatment resistance in prostate cancer.
Authors
Rashmi Mishra, Sihyeon Song, Dhruv Choradia, Dmytro Rudoy, Cynthia L. Wladyka, Patrick Hoang, Jin Yeong Kim, Ilsa M. Coleman, Sonali Arora, Stephanie Dobersch, Alexander E. Orellana, Chenwei Lin, Philip R. Gafken, Eva Corey, Peter S. Nelson, Sita Kugel, Haolong Li, Arnab Sengupta, Andrew C. Hsieh
×Abstract
Vitiligo is an autoimmune skin disease characterized by depigmentation, mainly due to CD8+ T cell–mediated destruction of melanocytes. Hyperglycemia exacerbates autoimmune responses and is associated with vitiligo; however, the underlying immunometabolic mechanisms are poorly understood. Here, we demonstrated the correlation between hyperglycemia and vitiligo in a case-control study and demonstrated that hyperglycemia aggravated vitiligo based on a mouse model. Targeted metabolomics identified succinate as the potential metabolite mediating hyperglycemia-aggravated vitiligo. Mechanistically, succinate promotes the activation of CD8+ T cells through succinate receptor 1 (SUCNR1) and promotes keratinocytes to secrete CXCL9 and CXCL10 by enhancing the stability and nuclear translocation of hypoxia-inducible factor-1α, facilitating the skin-homing of CD8+ T cells. Thus, hyperglycemia aggravates vitiligo through succinate/SUCNR1 axis–regulated CD8+ T cell hyperactivation. Our study provides insights into the long-observed yet previously unclear mechanism by which hyperglycemia accelerates vitiligo progression and highlights SUCNR1 as a potential therapeutic target.
Authors
Pan Kang, Yuqian Chang, Tingting Wang, Xiuli Yi, Yinghan Wang, Pengran Du, Jiaxi Chen, Baizhang Li, Shuli Li, Zhongjun Shao, Jianru Chen, Chunying Li
×Abstract
BACKGROUND Primary therapy for high-risk bladder cancer (BCa) is repeated instillations of the tuberculosis vaccine Bacillus Calmette-Guérin (BCG). Although BCG reduces the risk of recurrence by more than half, the mechanisms underlying its immune-activating effects remain unknown. Our objective was to investigate how the immune response differs between BCG responders and nonresponders and to compare systemic and local immune responses.METHODS We performed scRNA-seq of isolated immune cells adjacent to high-risk bladders in BCG responders and nonresponders before and after BCG. We also compared concurrent scRNA-seq profiles of circulating immune cell populations with those of bladder immune cells.RESULTS We observed an increase in Th17-like Th1 cells in BCG responders, characterized by greater expression of proinflammatory cytokines. By contrast, nonresponders showed increased CD8+ T cell exhaustion and Treg cells. We found that the primary mechanism driving divergent T cell activity is altered polarization and immunosuppressive signaling with myeloid cells. Using a machine learning–based approach, we identified that Th17-like Th1 cytokines, such as IL-17, IL-21, and IL-26, are predictive of response, which was subsequently validated in a separate BCG-treated BCa cohort.CONCLUSION Together, these findings suggest that dynamic regulation of myeloid–T cell interactions can be critical for outcomes of BCG-treated BCa.FUNDING BX005599 and BX003692 (Veterans Health Administration), HT94252410507 (Department of Defense), R01CA298333 (National Cancer Institute), and Robert H. Lurie Comprehensive Cancer Center H Foundation Core Facility Pilot Project Award.
Authors
Ryan J. Brown, Mairah T. Khan, Andrew J. Houston, Hongshen Niu, Joseph R. Podojil, Bonnie Choy, Weiguo Cui, Joshua J. Meeks
×Abstract
The lymphatic system plays a central role in lipid absorption by transporting triglyceride-rich particles called chylomicrons (CMs) from the small intestine to the systemic circulation. However, the molecular mechanism by which CMs get into the intestinal lymphatics is unknown. Here, we demonstrated that GPR182, an atypical chemokine receptor in lymphatic endothelial cells, mediates dietary fat absorption. GPR182-KO mice exhibited a selective increase in circulating high-density lipoproteins and are resistant to diet-induced obesity. GPR182 ablation in mice led to poor lipid absorption and thereby a delay in growth during development. GPR182 broadly interacted with and transported lipoproteins. Transmission electron microscopy analysis revealed that, mechanistically, loss of GPR182 prevented CMs from entering the lacteal lumen of the small intestine. Consistent with this, GPR182 blockade with mAbs protected mice from diet-induced obesity and treated existing obesity. Together, our study identifies GPR182 as a lipoprotein receptor that mediates dietary fat absorption and supports GPR182 blockade as a feasible approach to treating obesity and related disorders.
Authors
Zhiwei Sun, Robert J. Torphy, Emily N. Miller, Anza Darehshouri, Isaac Vigil, Taichi Terai, Eleanor Eck, Yi Sun, Yujie Guo, Dustin P. Fykstra, Elliott J. Yee, Junyi Hu, Ross M. Kedl, Erika L. Lasda, Jay R. Hesselberth, Julie A. Siegenthaler, Paul S. MacLean, Kimberley D. Bruce, Gwendalyn J. Randolph, Richard D. Schulick, Yuwen Zhu
×Abstract
Stroke remains a leading cause of morbidity and mortality worldwide, with few effective interventions to promote recovery. Targeting circadian timing and glymphatic function may represent viable therapeutic strategies. Here, we show that the small-molecule clock modulator, KL001; high-dose melatonin; acute light pulses; and active-phase time-restricted feeding were each sufficient to enhance glymphatic function in mice. Moreover, initiating treatment with either KL001 or active-phase time-restricted feeding 3 days after preclinical models of stroke improved motor outcomes, reduced lesion volume, increased glymphatic flow, and lowered poststroke brain cytokine burden. These findings suggest that reinforcing normal daily rhythmicity after stroke can markedly enhance neurological recovery, even when interventions are initiated several days after stroke onset.
Authors
Emma Waight, Yuxi Zhu, Ashley Caudell, Velia S. Vizcarra, Evan Newbold, Michael J. Giannetto, Evalien Duyvestyn, Estephanie Balbuena, Wei Song, Tanzil M. Arefin, Yuki Mori, Maiken Nedergaard, Lauren M. Hablitz
×Abstract
Androgen deprivation therapy (ADT), a cornerstone of advanced prostate cancer treatment, effectively suppresses androgen signaling but frequently induces systemic metabolic dysregulation. Here, we delineate an unrecognized intestinal steroid/bile acid regulatory axis that mechanistically links androgen suppression to extratumoral metabolic aberrations. HSD3B1 is the most common inherited link to prostate cancer mortality and mediates its effects by regulating steroid metabolism. Integrated metabolomic profiling of patients undergoing ADT revealed a rapid genotype-associated reduction in circulating bile acids, most pronounced in carriers of the adrenal-permissive HSD3B1 (1245C) allele. Surprisingly, analyses in human intestinal tissue and mechanistic investigations in in vitro models identified the terminal ileum as a unique site of HSD3B1 and SLC10A2 (ASBT) coexpression, where catalytically active 3βHSD1 is transcriptionally governed by liver receptor homolog-1 (LRH-1). Pharmacologic or genetic LRH-1 inhibition coordinately suppressed HSD3B1 and SLC10A2 expression and function, while inducing adaptive HSD11B2 upregulation and enhanced glucocorticoid inactivation. This LRH-1–dependent regulatory program persisted independently of androgen and glucocorticoid receptor signaling under in vitro conditions modeling androgen deprivation. These findings establish LRH-1 as a central integrator of intestinal steroidogenesis and bile acid transport and implicate the LRH-1/HSD3B1/SLC10A2 network as a mechanistic driver of ADT-associated metabolic disturbances and a potential target for therapeutic intervention.
Authors
Nikou Fotouhi, Robert Diaz, Mohammad Alyamani, Yoon-Mi Chung, Gail West, Pranab K. Mukherjee, Alireza Abdshah, Robert A. Burgess, Samreen Jatana, Rana R. McKay, Florian Rieder, Mary-Ellen Taplin, Nima Sharifi
×Abstract
BACKGROUND Elevated lipoprotein(a) [Lp(a)] is associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD). Although Lp(a) is a genetically determined risk factor, the plasma proteomic features associated with Lp(a) and whether they provide information about ASCVD risk beyond Lp(a) concentration are not well characterized.OBJECTIVE We sought to identify plasma proteomic features associated with Lp(a) concentration and to evaluate whether an Lp(a)-associated proteomic signature is associated with ASCVD phenotypes in young, healthy adults.METHODS In the Coronary Artery Risk Development in Young Adults (CARDIA) study, we measured year 7 Lp(a) and 184 cardiovascular proteins using the Olink proximity extension assay in 3,920 participants without prior coronary heart disease. Lp(a)-associated proteomic signatures were derived using least absolute shrinkage and selection operator (LASSO) regression in a split-sample design and tested for association with coronary artery calcification (CAC), incident coronary heart disease (CHD), and high-sensitivity C-reactive protein (hs-CRP) over 27 years of follow-up. External replication was performed in the UK Biobank (n = 37,996).RESULTS Lp(a) was associated with CAC (OR 1.23 [1.13–1.34]; P < 0.0001) and incident CHD (HR 1.23 [1.07–1.41]; P = 0.004). Lp(a) was correlated with proteomic features reflecting immune activation, coagulation, and vascular dysfunction. A quantitative Lp(a)-associated proteomics score was independently associated with incident CAC (standardized β = 0.40, P < 0.0001) and hs-CRP (standardized β = 0.11, P = 0.00015) after adjustment for Lp(a) concentration. In the UK Biobank, a recalibrated Lp(a)-associated proteomics score was associated with CRP, incident CHD, and all-cause mortality.CONCLUSIONS In young adults, Lp(a) was associated with distinct proteomic features that independently predicted ASCVD phenotypes beyond Lp(a) concentration, generating hypotheses regarding biological pathways linked to Lp(a)-related cardiovascular risk.FUNDING VA MERIT grant (1I01CX002560); Taubman Medical Research Institute (Wolfe Scholarship); National Institute of Diabetes, Digestive, and Kidney Diseases (NIDDK), NIH (U01DK123013-03); National Institute on Aging (NIA), NIH (R01AG059729); National Heart, Lung and Blood Institute (NHLBI), NIH (R01HL136685); American Heart Association Strategically Focused Research Network grant in Cardiometabolic Disease (funded proteomics in CARDIA); NIH (K23MD017253 and R01HL167733); Blue Cross Blue Shield of Michigan Foundation; A. Alfred Taubman Medical Research Institute; National Institute of Nursing Research (R01NR019628); National Institute of General Medical Sciences (NIGMS), NIH (R35-GM124836). The CARDIA study was conducted and supported by the NHLBI in collaboration with the University of Alabama at Birmingham (75N92023D00002 and 75N92023D00005), Northwestern University (75N92023D00004), University of Minnesota (75N92023D00006), and the Kaiser Foundation Research Institute (75N92023D00003).ROLE OF FUNDING SOURCE The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
Authors
Sascha N. Goonewardena, Shanshan Yao, Tomasz Jurga, Lanyue Zhang, Donald Lloyd-Jones, Dilna Damodaran, Bharat Thyagarajan, David R. Jacobs Jr., Supriya Shore, Eric J. Brandt, Clary Clish, Kahraman Tanriverdi, Jane E. Freedman, Chirag J. Patel, Mark A. Sarzynski, Brian T. Emmer, John T. Wilkins, Ron Do, Vera Bittner, Ravi V. Shah, Marios K. Georgakis, Robert S. Rosenson, Venkatesh L. Murthy
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Abstract
Dominant mutations in Progranulin (GRN) gene cause frontotemporal lobar degeneration (FTLD-GRN), whereas homozygous GRN mutations lead to neuronal ceroid lipofuscinosis, a childhood neurodegenerative disorder. While recent transcriptomic studies reveal profound glial and neuronal pathology in FTLD-GRN at the disease end stage, the mechanism that disrupts glia-neuron homeostasis remains unclear. Using induced pluripotent stem cell (iPSC)-derived cortical organoids, we showed that GRN-/- and GRNR493X mutations lead to precocious astrogliosis that promotes neuronal stress and synaptic loss. Single-cell transcriptomics and histopathology analyses revealed a robust activation in TGFb signaling pathway in GRN-/- and GRNR493X/R493X astrocytes, which was accompanied by features of immune activation, loss of synaptic support, and abundant pTDP-43+ fibrils in astroglial cytoplasm, a feature characteristic of FTLD-GRN. Intriguingly, blocking TGFb signaling mitigated astroglial activation and pTDP-43 proteinopathy in GRN-/- organoids. Together, these results provide new insights into the cell-autonomous role of astroglial activation in neurodegeneration caused by Progranulin deficiency.
Authors
Arren C. Ramsey, Xiao-Yan Tang, Magdalena J. Macias, Patricia R. Nano, Rufei Lu, Brian Benito, Cameron M. Lau, Jisu Park, Jiasheng Zhang, Wandy Beatty, Tanzila Mukhtar, Arnold R. Kriegstein, Aparna Bhaduri, Elise Marsan, Eric J. Huang
Abstract
CIC::DUX4 sarcoma (CDS) is a lethal cancer driven by a fusion between tumor suppressor Capicua (CIC) and pioneer transcription factor double homeobox 4 (DUX4). We previously generated three genetically engineered mouse models (GEMMs) of CDS with CIC::DUX4 regulated by loxP-STOP-loxP cassettes, however, all three models developed spontaneous tumors without Cre recombinase. Here, we established a next-generation GEMM of CDS (dFLEx CDS) that employs a dual recombinase (Cre + FLPE) FLEx-switch design to activate CIC::DUX4 expression and initiate sarcomagenesis in a spatially and temporally-controlled manner. Because CIC::DUX4 drives sarcoma development by activating a oncogenic transcriptional program, we performed a drug screen on human-derived CDS cell lines using a library of compounds that modulate transcription. This screen identified Minnelide, an inhibitor of RNA polymerase II-mediated transcription, as a selective inhibitor of CDS. Mechanistically, Minnelide acted through xeroderma pigmentosum type B to alter phosphorylation of RPB1, the largest subunit of RNA polymerase II. Subsequently, RPB1 underwent degradation leading to apoptosis of CDS cells. Minnelide demonstrated in vivo efficacy in dFLEx CDS GEMMs and in human CDS xenografts. As Minnelide has already been demonstrated to be safe in clinical trials, these findings nominate Minnelide as a potential therapeutic option to test in CDS patients.
Authors
MaKenna R. Browne, Axel V. Silver, Risha Banerjee, Brendan C. Dickson, Benigno Aquino, Kristianne M. Oristian, Jonathon E. Himes, Peter G. Hendrickson, David G. Kirsch
Abstract
Most mitochondrial proteins are nuclear encoded, translated in the cytosol, and imported into the mitochondria. Through gene expression analysis and functional assays, we demonstrated that mitochondrial protein import is increased in acute myeloid leukemia (AML) cells compared to normal hematopoietic cells. Increased mitochondrial protein import was positively correlated with increased mitochondrial unfolded protein response (UPRmt), a stress activated pathway of mitochondrial proteases and chaperones that maintains protein solubility and prevents the formation of toxic aggregates. The UPRmt protease LONP1 (Lon Peptidase 1) was upregulated in AML and positively correlated with increased mitochondrial protein import and UPRmt. Genetically or chemically inhibiting the LONP1 ATPase domain induced mitochondrial protein aggregation and selectively killed AML cells with high LONP1 expression while sparing AML cells with low LONP1 expression and normal hematopoietic cells in vitro and in vivo. Thus, we uncovered a critical role of the UPRmt protease LONP1 in buffering stress from mitochondrial protein import in AML.
Authors
Matthew Tcheng, Veronique Voisin, Geethu Emily Thomas, Anastasija A. Piric, Marcela Gronda, Rose Hurren, Dakai Ling, Yongran Yan, Lan Xin Zhang, Yue Feng, Ali Chegini, Nathan Duong, Ross S. Mancini, Stefan Quinn W. Currie, Zaynab Mamai, Brady Stock, Shahbaz Khan, Yulia Jitkova, Chaitra Sarathy, Edward Ayoub, Po Yee Mak, Andrea Arruda, Thomas Kislinger, Mark Reed, Bing Z. Carter, Michael Andreeff, Steven M. Kornblau, Mark D. Minden, Siavash Vahidi, Aaron D. Schimmer
Abstract
Renal water reabsorption is classically regulated by vasopressin V2 receptor (V2R) signaling through cyclic AMP and protein kinase A, driving apical accumulation of aquaporin-2 (AQP2). However, collecting duct water handling is also modulated by vasopressin-independent mechanisms. Here, we examined intracellular soluble urate as a vasopressin-independent regulator of AQP2 trafficking. Intracellular urate accumulation in collecting duct cells was mediated by enhanced apical urate uptake via GLUT9b and reduced apical urate efflux through ABCG2, triggering phosphodiesterase-4 activation, reduced cAMP, and downstream AMP-activated protein kinase (AMPK) activation. The resulting AQP2 accumulation at the apical membrane was independent of V2R signaling, required ongoing endocytosis and was associated with features of post-endocytic apical trafficking of internalized AQP2. In vivo ABCG2 inhibition with probenecid increased apical AQP2 abundance and markedly attenuated tolvaptan-induced polyuria in both wild-type and Pkd1RC/RC autosomal dominant polycystic kidney disease (ADPKD) mice in a uricase-independent manner, while preserving tolvaptan’s ADPKD-modifying efficacy. In a Phase 2 trial with tolvaptan-treated ADPKD patients, probenecid reduced urine volume and nocturia frequency. Together, these findings support a vasopressin-independent urate–AMPK–AQP2 pathway that regulates renal water handling and, in a preclinical ADPKD model, can uncouple cyst growth attenuation from the dose-limiting aquaretic effects of V2R antagonism.
Authors
Mohamad Hadla, Jean Marc Mardirossian, Daniel G. Bichet, Abdul Hamid Borghol, Georges Abboud, Ahmad Ghanem, Eduardo N. Chini, Peter C. Harris, Vicente E. Torres, Seth L. Alper, Volker Vallon, Fouad T. Chebib
Abstract
Gene therapy-based biological pacemakers have been proposed as an alternative to their hardware-based counterparts. In this context, short-term ectopic expression of the T-box transcription factor 18 (TBX18) in the ventricle has been reported to generate potent short-term pacemaker function in various animal models. Here, we investigated the impact of adeno-associated virus (AAV)-mediated long-term expression of TBX18, and compared the outcomes to those of the pacemaker ion channel Hcn2. Our findings revealed that CMV-driven ectopic TBX18 expression in mouse hearts led to severe cardiac fibrosis. At lower, non-fibrogenic levels, TBX18 maintained its transcriptional function but failed to induce pacemaker phenotypes. TBX18-expressing cells showed suppressed expression of key working myocardial genes, but the pacemaker gene program was not induced. Electrophysiological studies showed abnormal automaticity in TBX18-expressing cells, combined with prolonged repolarization and various current changes. However, no hyperpolarization-activated funny current was detected. In a complete AV-block rat model, AAV-mediated Hcn2 expression induced robust ectopic pacemaker activity in the presence of isoproterenol, whereas TBX18 expression neither generated such activity nor augmented Hcn2-mediated pacing. In conclusion, at functionally non-fibrogenic levels, TBX18 is neither sufficient nor necessary to induce pacemaker activity. In contrast, Hcn2 generates reliable pacing, making it a more viable candidate for biological pacemaker development.
Authors
Jianan Wang, Mathilde R. Rivaud, Mischa Klerk, Arie R. Boender, Ruud N. Visser, Rinske Sparrius, Hee Young Lee, Karel van Duijvenboden, Huiling Zhou, Yuting Yang, Emiel J.M. Kramer, Kyung Ho Park, Larry C. Park, Silke Schrödel, Christian Thirion, Eric Ehrke-Schulz, Anja Ehrhardt, Osne F. Kirzner, Klaus Neef, Hanno L. Tan, Arie O. Verkerk, Vincent M. Christoffels, Gerard J.J. Boink
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Series edited by Alexander Stegh
The cGAS-STING pathway: DNA sensing in health and disease
Series edited by Alexander Stegh
The cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a key component of innate immunity, linking DNA detection to inflammatory and antiviral responses. Originally identified as a sensor for microbial DNA, cGAS is now understood to also respond to endogenous cytosolic DNA, and the pathway has been implicated in a wide range of physiological and pathological processes, including cancer, autoimmunity, neuroinflammation, and aging. This review series, organized by Dr. Alex Stegh, consolidates current knowledge and highlights emerging developments that may lead to therapeutic targeting of the cGAS-STING pathway across a range of disorders.
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Poststroke outcomes and glymphatic function in mice are improved by chronotherapy
In this episode, Lauren Hablitz describes how the manuscript's findings suggest that reinforcing normal daily rhythmicity after stroke can markedly enhance neurological recovery, even when interventions are initiated several days after stroke onset...
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ISSN: 0021-9738 (print), 1558-8238 (online)