Issue published October 15, 2025 Previous issue
- Volume 135, Issue 20
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On the cover: SLFN14 in megakaryopoiesis and platelet function
Stapley et al. generated a conditional mouse model to assess the role of Schlafen 14 (SLFN14) in platelets and megakaryocytes (MKs) and to better understand the molecular mechanisms driving the bleeding phenotype in humans with SLFN14 mutations. The cover shows a transmission electron micrograph of enlarged platelets from a murine model with a platelet- and MK-specific Slfn14 deletion.
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Review Series
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Abstract
Pancreatic cancer (PC) is a devastating disease, due in part to its diagnosis frequently being made at an advanced stage. Ongoing efforts are aimed at identifying early-stage PC in high-risk individuals, as early detection leads to downstaging of PC and improvements in survival. However, there are a myriad of challenges that arise when trying to optimize PC early detection strategies, including selection of the appropriate high-risk individuals and selection of the test or combination of tests that should be performed. Here, we discuss the populations that are the strongest candidates for PC screening and review professional PC screening guidelines. We also summarize the current state of imaging techniques for early detection of PC and further review many studied biomarkers — ranging from nucleic acid targets, proteins, and the microbiome — to highlight the current state of the field and the challenges that remain in the years to come.
Authors
Michael J. Shen, Arsia Jamali, Bryson W. Katona
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Reviews
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Abstract
Peptidyl arginine deiminases (PADs) catalyze the conversion of arginine residues into peptidyl citrulline, a posttranslational modification known as protein citrullination (or arginine deimination). This process alters the charge of proteins from positive to neutral, thereby affecting their folding, stability, conformation, and function. PAD2 and PAD4 can translocate into the nucleus and citrullinate both cytoplasmic and nuclear proteins. In this Review, we focus on PAD2- and PAD4-mediated citrullination in immune cell subsets within the tumor microenvironment. We discuss how citrullination regulates immune cell function and tumor immunity and explore the potential of targeting citrullination as a strategy for cancer immunotherapy.
Authors
Michael R. Pitter, Weiping Zou
×Abstract
The increasing recognition of a new category of encephalitides that occur in association with antibodies against neuronal surface proteins has prompted the use of terms like “autoimmune psychosis” and “autoimmune psychiatric disorders.” However, although psychosis and other psychiatric symptoms can occur in autoimmune encephalitides and systemic autoimmune diseases, evidence for a distinct psychiatric entity beyond these conditions is lacking. A particularly defining condition is anti-NMDA receptor encephalitis, which has been central to promoting concepts such as autoimmune psychosis and autoimmune psychiatric disorders. While anti-NMDA receptor encephalitis can resemble primary psychiatric conditions, certain clinical features often suggest the specific diagnosis. This Review traces the development of the autoimmune psychosis concept and examines the implications of framing it as a separate entity. We discuss leading theories of psychosis and the convergence of the NMDA receptor hypofunction/glutamate hypothesis with anti-NMDA receptor encephalitis mechanisms. The interest generated by such disorders has driven uncontrolled antibody testing in psychiatric populations, often neglecting pretest probability and favoring prevalence over diagnostic specificity. Finally, we highlight the main limitations of current approaches and propose directions for future research.
Authors
José Maria Cabrera-Maqueda, Jesús Planagumà, Mar Guasp, Josep Dalmau
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Commentaries
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Abstract
Recent advances in sequencing technologies have enabled the identification of intermediate cell states during alveolar epithelial differentiation, which expand during repair following injury and in fibrotic lungs. Although ER stress has been implicated in pulmonary fibrosis, the underlying mechanisms remain elusive. The featured study by Auyeung and colleagues looked for links between the unfolded protein response sensor inositol-requiring enzyme 1α (IRE1α), intermediate epithelial cell states, and fibrotic remodeling in the lung. They identified Regulated IRE1-Dependent Decay (RIDD) as a key effector of IRE1α signaling that drives differentiation of alveolar epithelial type 2 cells to damage-associated intermediate cells and contributes to pulmonary fibrosis, likely by degrading Fgfr2 mRNA. These findings unveil therapeutic targets and open new avenues for investigating the interplay between cellular stress responses, epithelial differentiation, and fibrotic disease.
Authors
SeungHye Han
×Abstract
Chronic limb-threatening ischemia (CLTI), the advanced stage of peripheral artery disease (PAD), remains a leading cause of morbidity and limb loss. Effective vascular regeneration strategies will require increased understanding of molecular mechanisms underlying angiogenesis. Recent evidence revealed a new role for the vascular smooth muscle cell–enriched (VSMC-enriched) long noncoding RNA (lncRNA) CARMN in endothelial angiogenesis and postischemic vascular repair. CARMN was downregulated in both human CLTI muscle tissue and murine ischemia models. In VSMCs, CARMN deficiency suppressed a specific miRNA-mediated paracrine signaling axis that regulates Hedgehog signaling. In mice, deleting CARMN caused impariment in capillary growth and blood flow recovery after limb ischemia, an effect that was reversed by restoring miR-143-3p or silencing the Hedgehog inhibitor HHIP. The identification of lncRNA-mediated crosstalk between VSMCs and endothelial cells in PAD pathophysiology reveals possible therapeutic targets for CLTI and underscores the translational potential of RNA-based strategies in ischemic vascular disease.
Authors
Shivangi Pande, George Ishak, Fahimeh Varzideh, Gaetano Santulli
×Abstract
Celiac disease, an enteropathy driven by a maladaptive immune response to dietary gluten, is marked by increased proliferation in intestinal crypts, or crypt hyperplasia. However, it is unknown whether this phenomenon is a compensatory response to loss of villus epithelial cells or if it is driven by independent mechanisms. In this issue of the JCI, Stamnaes et al. demonstrated that in untreated celiac disease, crypt cells had increased expression of proteins involved in the IFN response, with decreased expression of fatty acid metabolism pathways. These expression patterns were recapitulated in mice treated with IFN-γ, but not mice with intestinal epithelial cell–specific knockout of the IFN-γ receptor. The findings suggest that crypt cells were reprogrammed directly by IFN-γ signaling, independent of changes to epithelial villi.
Authors
Alexa R. Weingarden
×Abstract
Neutrophils are key drivers of inflammation in Sweet syndrome (SS), a rare inflammatory skin disorder, but how they remain persistently activated in SS skin lesions has been unclear. In this issue of the JCI, Huang, Sati, and colleagues applied single-cell RNA-Seq and immunofluorescence to identify a subset of neutrophils in SS skin that display antigen-presenting cell–like (APC-like) features. The authors showed that when neutrophils interacted with keratinocytes, their lifespan was markedly extended, and they expressed MHC class II via activation of the serum amyloid A1/formyl peptide receptor 2 (SAA1/FPR2) signaling pathway. This, in turn, enabled T cell activation and sustained self-perpetuating inflammatory loops. These findings reveal a previously unrecognized keratinocyte-neutrophil circuit in SS and point to the SAA1/FPR2 axis as a potential target for more precise, mechanism-based therapy.
Authors
Umi Tahara, Masayuki Amagai
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Research Letter
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Abstract
Authors
Nathalie Baumlin, Sumedha Gunewardena, Scott H. Randell, Frank T. Horrigan, Matthias Salathe
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Research Articles
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Abstract
Despite the potential of targeted epigenetic therapies, most cancers do not respond to current epigenetic drugs. The polycomb repressive complex EZH2 inhibitor tazemetostat was recently approved for the treatment of SMARCB1-deficient epithelioid sarcomas, based on the functional antagonism between PRC2 and SMARCB1. Through the analysis of tumors of patients treated with tazemetostat, we recently defined key principles of their response and resistance to EZH2 epigenetic therapy. Here, using transcriptomic inference from SMARCB1-deficient tumor cells, we nominate the DNA damage repair kinase ATR as a target for rational EZH2 combination epigenetic therapy. We showed that EZH2 inhibition promotes DNA damage in epithelioid and rhabdoid tumor cells, at least in part via its induction of piggyBac transposable element derived 5 (PGBD5). We leveraged this collateral synthetic lethal dependency to target PGBD5-dependent DNA damage by inhibition of ATR, but not CHK1, using the ATR inhibitor elimusertib. Consequently, combined EZH2 and ATR inhibition improved therapeutic responses in diverse patient-derived epithelioid and rhabdoid tumors in vivo. This advances a combination epigenetic therapy based on EZH2-PGBD5 synthetic lethal dependency suitable for immediate translation to clinical trials for patients.
Authors
Yaniv Kazansky, Helen S. Mueller, Daniel Cameron, Phillip Demarest, Nadia Zaffaroni, Noemi Arrighetti, Valentina Zuco, Prabhjot S. Mundi, Yasumichi Kuwahara, Romel Somwar, Rui Qu, Andrea Califano, Elisa de Stanchina, Filemon S. Dela Cruz, Andrew L. Kung, Mrinal M. Gounder, Alex Kentsis
×Jab1 promotes immune evasion and progression in acute myeloid leukemia models under oxidative stress
Abstract
Acute myeloid leukemia (AML) is the most common hematological malignancy. Leukemia stem cells exhibit high levels of oxidative stress, with ROS being the primary products of this stress, inducing the expression of c-JUN activation domain-binding protein 1 (Jab1). Previous studies have demonstrated that Jab1, as a transcriptional coactivator of c-JUN, promotes the malignant progression of AML under oxidative stress. However, its role in immune evasion is still under investigation. Here, we observed that knocking out Jab1 reduced the expression of immune checkpoints in vivo, effectively overcoming the immune evasion of AML. Interestingly, the deletion of Jab1 had no impact on the maturation of normal hematopoietic cells in mice. Mechanistically, Jab1 directly activated IGF2BP3 by driving the transcription factor c-JUN, consequently modulated the m6A modification of LILRB4 mRNA, and promoted immune evasion in AML. Finally, CSN5i-3 effectively disrupted the signaling pathway mediated by Jab1, thereby restoring cellular immune surveillance and halting the progression of AML. Thus, our results highlight the functional role of Jab1 in supporting AML survival and support the development of targeted therapeutic strategies.
Authors
Nan Zhang, Qian Wang, Guopeng Chen, Li Liu, Zhiying Wang, Linlu Ma, Yuxing Liang, Jinxian Wu, Xinqi Li, Xiaoyan Liu, Fuling Zhou
×Abstract
Diabetic peripheral neuropathy (DPN) is a prevalent complication of diabetes mellitus caused by metabolic toxicity to peripheral axons. We aimed to gain deep mechanistic insight into the disease using transcriptomics on tibial and sural nerves recovered from lower leg amputations in a mostly diabetic population and control sural nerves from cross-facial nerve graft surgery. First, comparing DPN versus control sural nerves revealed inflammatory activation and sensory changes in DPN. Second, when comparing mixed sensory and motor tibial and purely sensory sural nerves, we identified key pathway differences in affected DPN nerves, with distinct immunological features observed in sural nerves. Third, spatial transcriptomics of sural nerves revealed shifts in immune cell types associated with axonal loss progression. We also found clear evidence of neuronal transcript changes, like PRPH, in nerves with axonal loss, suggesting perturbed RNA transport into distal sensory axons. This motivated further investigation into neuronal mRNA localization in peripheral nerve axons, generating evidence of robust localization of mRNAs such as SCN9A and TRPV1 in human sensory axons. Our work provides insight into altered cellular and transcriptomic profiles in human nerves in DPN and highlights sensory axon mRNA transport as a potential contributor to nerve degeneration.
Authors
Diana Tavares-Ferreira, Breanna Q. Shen, Juliet M. Mwirigi, Stephanie Shiers, Ishwarya Sankaranarayanan, Akshitha Sreerangapuri, Miriam B. Kotamarti, Nikhil N. Inturi, Khadijah Mazhar, Eroboghene E. Ubogu, Geneva L. Thomas, Trapper Lalli, Shai M. Rozen, Dane K. Wukich, Theodore J. Price
×Abstract
Inflammatory diseases contribute to secondary osteoporosis. Hypertension is a highly prevalent inflammatory condition that is clinically associated with reduced bone mineral density and increased risk of fragility fracture. In this study, we showed that a significant loss in bone mass and strength occurs in two preclinical models of hypertension. This accompanied increases in immune cell populations, including monocytes, macrophages, and IL-17A–producing T cell subtypes in the bone marrow of hypertensive mice. Neutralizing IL-17A in angiotensin II–infused mice blunted hypertension-induced loss of bone mass and strength as a result of decreased osteoclastogenesis. Likewise, the inhibition of the CSF1 receptor blunted loss of bone mass and prevented loss of bone strength in hypertensive mice. In an analysis of UK Biobank data, circulating bone remodeling markers exhibited striking associations with blood pressure and bone mineral density in more than 27,000 humans. These findings illustrate a potential mechanism by which hypertension activates immune cells in the bone marrow, encouraging osteoclastogenesis and eventual loss in bone mass and strength.
Authors
Elizabeth M. Hennen, Sasidhar Uppuganti, Néstor de la Visitación, Wei Chen, Jaya Krishnan, Lawrence A. Vecchi III, David M. Patrick, Mateusz Siedlinski, Matteo Lemoli, Rachel Delgado, Mark P. de Caestecker, Wenhan Chang, Tomasz J. Guzik, Rachelle W. Johnson, David G. Harrison, Jeffry S. Nyman
×Abstract
Stress-induced epithelial plasticity is central to lung regeneration, fibrosis, and malignancy, but how cellular stress leads to differentiation is incompletely understood. Here, we found a central role for IRE1α, a conserved mediator of the unfolded protein response (UPR), in stimulating the plasticity of alveolar type 2 (AT2) cells. In single-cell RNA-seq, IRE1α activity was associated with loss of AT2 identity and progression toward a damage-associated transitional state unique to fibrosis. AT2 plasticity required destructive regulated IRE1α-dependent decay (RIDD), which we demonstrated by deploying PAIR2, a kinase modulator that inhibits RIDD while preserving IRE1α’s adaptive XBP1 mRNA splicing activity. In vivo, selective inhibition of RIDD with PAIR2 reduced AT2 differentiation into profibrotic transitional cells and protected mice from bleomycin-induced pulmonary fibrosis. Mechanistically, we identified the Fgfr2 mRNA as a direct and regulated substrate for IRE1α’s RNase in primary AT2 cells and in a biochemically reconstituted cell-free system. Loss of Fgf signaling caused AT2 differentiation, while gain of signaling protected cells from IRE1α-induced differentiation. We propose that IRE1α downregulates Fgf signaling through RIDD, provoking loss of AT2 identity and differentiation towards a profibrotic phenotype. Thus, IRE1α’s RIDD activity emerges as a novel target for treatment of pulmonary fibrosis and potentially other diseases driven by aberrant epithelial cell plasticity.
Authors
Vincent C. Auyeung, Tavienne L. Steinberg, Alina Olivier, Luka Suzuki, Mary E. Moreno, Imran S. Khan, Michael S. Downey, Maike Thamsen, Lu Guo, Dustin J. Maly, Bradley J. Backes, Dean Sheppard, Feroz R. Papa
×Abstract
Protein arginine methyltransferase 5 (PRMT5) complexes with methylosome protein 50 (MEP50) play crucial roles in tumor progress. However, the regulatory mechanism of governing the PRMT5-MEP50 hetero-octameric complex remains unclear. Here, we demonstrate that C6orf223, to our knowledge an uncharacterized protein, facilitates PRMT5-MEP50 multiprotein complex assembling, thereby promoting colorectal cancer (CRC) growth and metastasis. C6orf223 forms dimers through disulfide bonds, with its N-terminal arginine-enriched region binding to the C-terminal negatively charged groove of PRMT5, thus stabilizing PRMT5-MEP50 multiprotein and enhancing PRMT5 methyltransferase activity. Consequently, PRMT5-mediated H4R3me2s substantially decreases the expression of the tumor suppressor GATA5, leading to the upregulation of multiple oncogenic target genes including WWTR1, FGFR1, and CLU. Targeting C6orf223 using siRNAs encapsulated in ferritin protein shells effectively suppresses CRC tumor growth and metastasis. Collectively, our findings characterize the role of C6orf223 in facilitating PRMT5-MEP50 hetero-octameric complex assembling and suggest that C6orf223 could serve as a potential therapeutic target for CRC.
Authors
Yufeng Qiao, Zhenzhen Wu, Peng Wang, Yiliang Jin, Furong Bai, Fei Zhang, Yunhe An, Meiying Xue, Han Feng, Yong Zhang, Yaxin Hou, Junfeng Du, Huiyun Cai, Guizhi Shi, Bing Zhou, Pu Gao, Jizhong Lou, Peng Zhang, Kelong Fan, Jinbo Liu, Pengcheng Bu
×Abstract
Genome editing has the potential to treat genetic hearing loss. However, current editing therapies for genetic hearing loss have shown efficacy only in hearing rescue. In this study, we evaluated a rescue strategy using adeno-associated virus (AAV) type 2–mediated delivery of Staphylococcus aureus Cas9-sgRNA in the mature inner ear of the P2rx2V61L/+ mouse model of autosomal dominant deafness-41 (DFNA41), a dominant, delayed-onset, and progressive hearing loss in humans. We demonstrate that local injection in adult mice results in efficient and specific editing that abolishes the mutation without notable off-target effects or AAV genome integration. Editing effectively restores long-term auditory and vestibular function. Editing further protects P2rx2V61L/+ mice from hypersensitivity to noise-induced hearing loss, a phenotype also observed in patients with DFNA41. Intervention in mice at a juvenile stage broadens the frequency range rescued, highlighting the importance of early intervention. An effective and specific gRNA for the human P2RX2 V60L mutation has been identified. Our study establishes the feasibility of editing to treat DFNA41 caused by P2RX2 V60L mutation in humans and opens an avenue for using editing to rescue hearing and vestibular function while mitigating noise-induced hearing loss.
Authors
Wei Wei, Wenliang Zhu, Stewart Silver, Ariel M. Armstrong, Fletcher S. Robbins, Arun Prabhu Rameshbabu, Katherina Walz, Yizhou Quan, Wan Du, Yehree Kim, Artur A. Indzhykulian, Yilai Shu, Xue-Zhong Liu, Zheng-Yi Chen
×Abstract
Dysfunction of striatal medium spiny neurons (MSNs) is implicated in several neurological disorders, including Huntington’s disease (HD). Despite progress in characterizing MSN pathology in HD, mechanisms underlying MSN susceptibility remain unknown, driving the need for MSNs derived from human pluripotent stem cells (hPSCs), especially subtypes in research and therapy. Here, we established a scalable 3D-default culture system to produce striatal MSNs efficiently from hPSCs by activation of the endogenous sonic hedgehog (SHH) pathway. These cells expressed canonical markers of striatal progenitors and dopamine D1 (D1) and dopamine D2 (D2) MSNs and presented dynamic specification and transcriptional signatures that closely resemble endogenous MSNs at single-cell resolution, both in vitro and post-transplantation in HD mice with quinolinic acid (QA) lesions. Grafted human cells survived and matured into D1-/D2-like MSNs and projected axons to endogenous targets including globus pallidus externus, globus pallidus internus, and substantia nigra pars reticulata to reconstruct the basal ganglia pathways. Functionally, they displayed spontaneous synaptic currents, received regulation from host cortex and thalamus, and were modulated by dopamine to either enhance or reduce neuronal excitability, similar to the endogenous D1-/D2-MSNs, subsequently improving behavior in QA-lesioned HD mice. Our study presents a method for generating authentic MSNs, providing a reliable cell source for HD cell therapy, mechanistic studies, and drug screening.
Authors
Yuting Mei, Yuan Xu, Xinyue Zhang, Ban Feng, Yingying Zhou, Qian Cheng, Yuan Li, Xingsheng Peng, Mengnan Wu, Lianshun Xie, Lei Xiao, Wenhao Zhou, Yuejun Chen, Man Xiong
×Abstract
Peripheral artery disease (PAD) often advances to chronic limb-threatening ischemia (CLTI), resulting in severe complications such as limb amputation. Despite the potential of therapeutic angiogenesis, the mechanisms of cell-cell communication and transcriptional changes driving PAD are not fully understood. Profiling long noncoding RNAs (lncRNAs) from gastrocnemius muscles of participants with or without CLTI revealed that a vascular smooth muscle cell–enriched (SMC-enriched) lncRNA, CARMN, was reduced with CLTI. This study explored how a SMC lncRNA-miRNA signaling axis regulates angiogenesis in limb ischemia. CARMN-KO mice exhibited reduced capillary density and impaired blood flow recovery and tissue necrosis following limb ischemia. We found that CARMN-KO SMC supernatants inhibited endothelial cell (EC) proliferation, spheroid sprouting, and network formation. RNA-seq identified downregulation of the Hedgehog signaling pathway in CARMN-KO models and revealed that CARMN regulates this pathway through its downstream miRNA, miR-143-3p, which targets Hedgehog-interacting protein (HHIP), an antagonist of Hedgehog signaling. Delivery of HHIP-specific siRNA or miR-143-3p mimics rescued EC angiogenic defects and improved blood flow recovery in both CARMN-KO and WT mice. These findings underscore the critical role of CARMN in modulating angiogenesis through the miR-143-3p-HHIP-Hedgehog signaling axis, providing insights into SMC-EC interactions and potential therapeutic strategies for CLTI.
Authors
Ming Zhai, Anurag Jamaiyar, Jun Qian, Winona W. Wu, Emre Bektik, Vinay Randhawa, Camila Vaz, Arvind K. Pandey, Akm Khyrul Wara, Madhur Sachan, Yi Hu, Jéssica L. Garcia, Claire E. Alford, Terence E. Ryan, Wenhui Peng, Mark W. Feinberg
×Abstract
Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have transformed the treatment landscape for hormone receptor+ (HR+) breast cancer. However, their long-term efficacy is limited by acquired resistance, and CDK4/6i monotherapy remains ineffective in triple-negative breast cancer (TNBC). Here, we demonstrate that dual inhibition of CDK4/6 and CDK7 is a promising strategy to overcome therapeutic resistance in both HR+ and TNBC models. Kinetic analyses revealed that CDK7 inhibitors (CDK7i) primarily impair RNA polymerase II–mediated transcription rather than directly targeting cell cycle CDKs. This transcriptional suppression attenuated E2F-driven transcriptional amplification, a key mechanism for developing CDK4/6i resistance following the degradation of the retinoblastoma protein. Consequently, combining CDK7i at minimal effective concentrations with CDK4/6i potently inhibited the growth of drug-resistant tumors. Furthermore, dual CDK4/6 and CDK7 inhibition stimulated immune-related signaling and cytokine production in cancer cells, promoting antitumor immune responses within the tumor microenvironment. These findings provide mechanistic insights into CDK inhibition and support the therapeutic potential of combining CDK7i with CDK4/6i for breast cancer treatment.
Authors
Sungsoo Kim, Eugene Son, Ha-Ram Park, Minah Kim, Hee Won Yang
×Abstract
Schlafen 14–related (SLFN14-related) thrombocytopenia is a rare bleeding disorder caused by SLFN14 mutations altering hemostasis in patients with platelet dysfunction. SLFN proteins are highly conserved in mammals where SLFN14 is specifically expressed in megakaryocyte (MK) and erythroblast lineages. The role of SLFN14 in megakaryopoiesis and platelet function has not been elucidated. Therefore, we generated a murine model with a platelet- and MK-specific SLFN14 deletion using platelet factor 4 (PF4) Cre-mediated deletion of exons 2 and 3 in Slfn14 (Slfn14 PF4-Cre) to decipher the molecular mechanisms driving the bleeding phenotype. Slfn14 PF4-Cre+ platelets displayed reduced platelet signaling to thrombin, reduced thrombin formation, increased bleeding tendency, and delayed thrombus formation as assessed by intravital imaging. Moreover, fewer in situ bone marrow MKs were present compared with controls. RNA-Seq and Gene Ontology analysis of MKs and platelets from Slfn14 PF4-Cre homozygous mice revealed altered pathways of ubiquitination, adenosine triphosphate activity, and cytoskeleton and molecular function. In summary, we investigated how SLFN14 deletion in MKs and platelets leads to platelet dysfunction and alters their transcriptome, explaining the platelet dysfunction and bleeding in humans and mice with SLFN14 mutations.
Authors
Rachel J. Stapley, Xenia Sawkulycz, Gabriel H.M. Araujo, Maximilian Englert, Lourdes Garcia-Quintanilla, Sophie R.M. Smith, Amna Ahmed, Elizabeth J. Haining, Nayandeep Kaur, Andrea Bacon, Andrey V. Pisarev, Natalie S. Poulter, Dean Kavanagh, Steven G. Thomas, Samantha J. Montague, Julie Rayes, Zoltan Nagy, Neil V. Morgan
×Abstract
Aspergillus fumigatus is the most common cause of invasive aspergillosis (IA), a devastating infection in immunocompromised patients. Plasmacytoid DCs (pDCs) regulate host defense against IA by enhancing neutrophil antifungal properties in the lung. Here, we define the pDC activation trajectory during A. fumigatus infection and the molecular events that underlie the protective pDC–neutrophil crosstalk. Fungus-induced pDC activation began after bone marrow egress and resulted in pDC-dependent regulation of lung type I and type III IFN levels. These pDC-derived products acted on type I and type III IFN receptor–expressing neutrophils and controlled neutrophil fungicidal activity and ROS production via STAT1 signaling in a cell-intrinsic manner. Mechanistically, neutrophil STAT1 signaling regulated transcription and expression of Cybb, which encodes one of 5 NADPH oxidase subunits. Thus, the results indicate that pDCs regulate neutrophil-dependent immunity against inhaled molds by controlling local expression of a subunit required for NADPH oxidase assembly and activity in the lung.
Authors
Yahui Guo, Mariano A. Aufiero, Kathleen A.M. Mills, Simon A. Grassmann, Hyunu Kim, Mergim Gjonbalaj, Paul Zumbo, Audrey Billips, Katrina B. Mar, Yao Yu, Laura C. Echeverri Tirado, Lena Heung, Amariliz Rivera, Doron Betel, Joseph C. Sun, Tobias M. Hohl
×Abstract
Mechanisms responsible for delayed wound repair are poorly understood despite the common impact of this disorder on health. To study how Staphylococcus aureus disrupts healing, mouse and human wound repair models were evaluated after exposure to S. aureus or commensal Staphylococcus. Quorum sensing by S. aureus, but not S. hominis, delayed repair and inhibited the expression of genes responsible for lipid metabolism in keratinocytes. S. aureus with inactive accessory gene regulator (agr) did not delay healing, and the inhibition of lipid metabolism was recapitulated in vitro by synthetic phenol soluble modulin α1 (psmα1) and psmα4, genes that are under agr control. However, S. aureus strains with single deletion of psmA, psmB, alpha-hemolysin (hla), or hld gene continued to delay repair, suggesting that S. aureus used multiple agr-dependent virulence factors to disrupt healing. These observations provide insight into mechanisms for delayed wound healing, identify quorum sensing as a critical event, and highlight the role of lipid biosynthesis in wound reepithelialization.
Authors
Michelle D. Bagood, Jelena Marjanovic, Nina Jiang, Hung Chan, Tatsuya Dokoshi, Kellen J. Cavagnero, Fengwu Li, Andrea Roso-Mares, Samia Almoughrabie, Edward Liu, Irena Pastar, Marjana Tomic-Canic, Alexander R. Horswill, Richard L. Gallo
×Abstract
Osteosarcoma is the most common primary malignant bone cancer, characterized by a high incidence of lung metastasis and a lack of therapeutic targets. Here, by combining an in vivo CRISPR activation screen with the interactome of STUB1, a tumor suppressor in osteosarcoma, we identified that myeloid leukemia factor 2 (MLF2) promotes osteosarcoma metastasis. Mechanistically, MLF2 disrupted the interaction between BiP and IRE1α, thereby activating the IRE1α/XBP1-S-MMP9 axis. The E3 ligase STUB1 ubiquitinated MLF2 at Lys119 and targeted it for proteasomal degradation, whereas PIM3-mediated phosphorylation of MLF2 at Ser65 enhanced its stabilizing interaction with USP21. Our findings demonstrate that the PIM3/MLF2 axis is a critical regulator of osteosarcoma lung metastasis. We propose PIM3 as a potential therapeutic target for patients with osteosarcoma lung metastasis.
Authors
Cuiling Zeng, Xin Wang, Jinkun Zhong, Yu Zhang, Ju Deng, Wenqiang Liu, Weixuan Chen, Xinhao Yu, Dian Lin, Ruhua Zhang, Shang Wang, Jianpei Lao, Qi Zhao, Li Zhong, Tiebang Kang, Dan Liao
×Abstract
Fibroblast growth factor homologous factors (FHFs) bind to the cytoplasmic C-terminus of voltage-gated sodium channels (VGSCs) and modulate channel function. Variants in FHFs or VGSCs perturbing that bimolecular interaction are associated with arrhythmias. Like some channel auxiliary subunits, FHFs exert additional cellular regulatory roles, but whether these alternative roles affect VGSC regulation is unknown. Using a separation-of-function strategy, we show that a structurally guided, binding-incompetent, mutant fibroblast growth factor 13 (FGF13; the major FHF in mouse heart), confers complete regulation of VGSC steady-state inactivation (SSI), the canonical effect of FHFs. In cardiomyocytes isolated from Fgf13-KO mice, expression of the mutant FGF13 completely restores WT regulation of SSI. FGF13 regulation of SSI derives from effects on local accessible membrane cholesterol, which is unexpectedly polarized and concentrated in cardiomyocytes at the intercalated disc (ID), where most VGSCs localize. Fgf13-KO eliminates the polarized cholesterol distribution and causes loss of VGSCs from the ID. Moreover, we show that the previously described FGF13-dependent stabilization of VGSC currents at elevated temperatures depends on the cholesterol mechanism. These results provide new insights into how FHFs affect VGSCs and alter the canonical model by which channel auxiliary subunits exert influence.
Authors
Aravind R. Gade, Mattia Malvezzi, Lala Tanmoy Das, Maiko Matsui, Cheng-I J. Ma, Keon Mazdisnian, Steven O. Marx, Frederick R. Maxfield, Geoffrey S. Pitt
×Abstract
Cancer cells present neoantigens dominantly through MHC class I (MHCI) to drive tumor rejection through cytotoxic CD8+ T cells. There is growing recognition that a subset of tumors express MHC class II (MHCII), causing recognition of antigens by TCRs of CD4+ T cells that contribute to the antitumor response. We found that mouse BrafV600E-driven anaplastic thyroid cancers (ATCs) responded markedly to the RAF plus MEK inhibitors dabrafenib and trametinib (dab/tram) and that this was associated with upregulation of MhcII in cancer cells and increased CD4+ T cell infiltration. A subset of recurrent tumors lost MhcII expression due to silencing of Ciita, the master transcriptional regulator of MhcII, despite preserved IFN-γ signal transduction, which could be rescued by EZH2 inhibition. Orthotopically implanted Ciita–/– and H2-Ab1–/– ATC cells into immune-competent mice became unresponsive to the MAPK inhibitors. Moreover, depletion of CD4+, but not CD8+, T cells also abrogated the response to dab/tram. These findings implicate MHCII-driven CD4+ T cell activation as a key determinant of the response of Braf-mutant ATCs to MAPK inhibition.
Authors
Vera Tiedje, Jillian Greenberg, Tianyue Qin, Soo-Yeon Im, Gnana P. Krishnamoorthy, Laura Boucai, Bin Xu, Jena D. French, Eric J. Sherman, Alan L. Ho, Elisa de Stanchina, Nicholas D. Socci, Jian Jin, Ronald A. Ghossein, Jeffrey A. Knauf, Richard P. Koche, James A. Fagin
×Abstract
CD24 promotes prostate cancer progression and metastasis by disrupting the ARF-NPM interaction and impairing p53 signaling. However, the mechanisms underlying CD24-driven metastasis remain unclear. This study identifies a novel interaction between CD24 and Regulator of Chromosome Condensation 2 (RCC2), a protein involved in cell proliferation and migration. IHC analysis of prostate adenocarcinoma samples showed frequent coexpression of CD24 (49%) and RCC2 (82%) with a positive correlation between coexpression of CD24 (49%) and RCC2 (82%). Functional assays revealed complex roles: RCC2 KO suppressed proliferation but increased migration and invasion, while CD24 KO reduced both proliferation and migration. Dual KO of CD24 and RCC2 further inhibited proliferation but had varied effects on migration. In mouse xenografts, RCC2 KO increased lung metastasis without significantly affecting primary tumor growth, while CD24 KO reduced both tumor growth and metastasis. Mechanistically, RCC2 controls migration by promoting ubiquitination and degradation of vimentin, affecting cytoskeletal dynamics. In contrast, CD24 targets RCC2 for degradation, thereby regulating β-catenin signaling. Notably, RCC2 KO enhances β-catenin activity by suppressing inhibitors AXIN2 and APC, whereas CD24 KO inhibits this pathway. These findings reveal a regulatory loop where CD24 and RCC2 reciprocally control proliferation and metastasis, positioning the CD24-RCC2 axis as a promising therapeutic target in prostate cancer.
Authors
Xuelian Cui, Yicun Wang, Chao Zhang, Zhichao Liu, Haiyan Yu, Lizhong Wang, Jiangbing Zhou, Runhua Liu
×Abstract
Sympathetic tone is a central signaling axis inhibiting osteogenesis; however, the combination of durable local and systemic sympathetic effects on bone argues that multiple mechanisms, including yet-undiscovered pathways, are involved. Here, we found that sympathetic nerves constituted a component of the skeletal stem cell (SSC) niche: mice with conditional deletion of the classical axonal repellent Slit2 in sympathetic nerves (Slit2th mice), but not in bone stem/progenitor cells or sensory nerves, showed osteopenia due to an increase in sympathetic innervation and an associated decrease in SSCs. Mice with increased skeletal sympathetic innervation displayed impaired SSC niche function in an SSC orthotopic transplantation and engraftment system. Follistatin-like 1 (FSTL1) is a SLIT2-regulated soluble factor suppressing SSC self-renewal and osteogenic capacity. Accordingly, ablation of Fstl1 in sympathetic neurons enhanced SSC-driven osteogenesis and attenuated the bone loss seen in Slit2th mice. Together, the findings indicate that SLIT2 is a regulator of a sympathetic nerve–mediated SSC niche.
Authors
Zuoxing Wu, Na Li, Zhengqiong Luo, Zihan Chen, Xuemei He, Jie Han, Xixi Lin, Fan Shi, Haitao Huang, Baohong Shi, Yu Li, Xin Wang, Lin Meng, Dachuan Zhang, Lanfen Chen, Dawang Zhou, Weinan Cheng, Matthew B. Greenblatt, Ren Xu
×Abstract
Sweet syndrome (also known as acute febrile neutrophilic dermatosis) is a rare inflammatory skin disorder characterized by erythematous plaques with a dense dermal neutrophilic infiltrate. The first-line therapy remains oral corticosteroids, which suppresses inflammation nonspecifically. Although neutrophils are typically short-lived, how they persist in Sweet syndrome skin and contribute to disease pathogenesis remains unclear. Here, we identify a previously unrecognized population of antigen-presenting cell–like (APC-like) neutrophils expressing MHC class II genes that are uniquely present in Sweet syndrome skin but absent in healthy tissue and the circulation. Keratinocytes extended neutrophil lifespan 10-fold in coculture experiments and drove the emergence of an APC-like phenotype in approximately 30% of neutrophils, mirroring observations in patients’ lesions. Mechanistically, keratinocyte-derived serum amyloid A1 (SAA1) signals through the formyl peptide receptor 2 (FPR2) on neutrophils to promote their survival. These long-lived neutrophils actively orchestrate local immune responses by recruiting T cells and inducing cytokine production. Strikingly, dual blockade of SAA1/FPR2 signaling restores neutrophil turnover to baseline levels, with efficacy comparable to high-dose corticosteroids. These findings uncover a keratinocyte/neutrophil/T cell axis that sustains chronic inflammation in Sweet syndrome and highlight the SAA1/FPR2 pathway as a promising target for precision therapy.
Authors
Jianhe Huang, Satish Sati, Olivia Ahart, Emmanuel Rapp-Reyes, Linda Zhou, Robert G. Micheletti, William D. James, Misha Rosenbach, Thomas H. Leung
×Abstract
Hypoxia in the tumor microenvironment promotes lymphatic metastasis, yet the role of cancer-associated fibroblasts (CAFs) in this process remains insufficiently elucidated in colorectal cancer (CRC). In this study, we developed a large language model–based cellular hypoxia–predicting classifier to identify hypoxic CAFs (HCAFs) at single-cell resolution. Our findings revealed that HCAFs enhance CRC lymphatic metastasis by secreting CLEC11A, a protein that binds to the LGR5 receptor on tumor cells, subsequently activating the WNT/β-catenin signaling pathway. This promotes epithelial-mesenchymal transition and lymphangiogenesis, facilitating the spread of tumor cells via the lymphatic system. Furthermore, we demonstrate that the hypoxia-induced transcription factor HIF1A regulates the conversion of normoxic CAFs to HCAFs, driving CLEC11A expression and promoting metastasis. In vivo and vitro experiments confirmed the pro-metastatic role of CLEC11A in CRC, with its inhibition reducing lymphatic metastasis. This effect was markedly reversed by targeting the LGR5 receptor on tumor cells or inhibiting the WNT/β-catenin pathway, further elucidating the underlying mechanisms of CLEC11A-driven metastasis. These findings underscore the potential of targeting the CLEC11A-LGR5 axis to prevent lymphatic dissemination in CRC. Our study highlights the role of HCAFs in CRC progression and reveals mechanisms of lymphatic metastasis for intervention.
Authors
Chuhan Zhang, Teng Pan, Yuyuan Zhang, Yushuai Wu, Anning Zuo, Shutong Liu, Yuhao Ba, Benyu Liu, Shuaixi Yang, Yukang Chen, Hui Xu, Peng Luo, Quan Cheng, Siyuan Weng, Long Liu, Xing Zhou, Jingyuan Ning, Xinwei Han, Jinhai Deng, Zaoqu Liu
×Abstract
Crypt hyperplasia is a key feature of celiac disease (CeD) and several other small intestinal inflammatory conditions. Analysis of the gut epithelial crypt zone by mass spectrometry–based tissue proteomics revealed a strong IFN-γ signal in active CeD. This signal, hallmarked by increased expression of MHC molecules, was paralleled by diminished expression of proteins associated with fatty acid metabolism. Crypt hyperplasia and the same proteomic changes were observed in WT mice administered IFN-γ. In mice with conditional KO of the IFN-γ receptor in gut epithelial cells, these signature morphological and proteomic changes were not induced with IFN-γ administration. IFN-γ was thus a driver of crypt hyperplasia in CeD by acting directly on crypt epithelial cells. The results are relevant to other enteropathies with involvement of IFN-γ.
Authors
Jorunn Stamnaes, Daniel Stray, M. Fleur du Pré, Louise F. Risnes, Alisa E. Dewan, Jakeer Shaik, Maria Stensland, Knut E.A. Lundin, Ludvig M. Sollid
×Abstract
Multiple sclerosis (MS) is a progressive, chronic, and highly disabling neuroinflammatory disorder characterized by demyelination and T cell–driven inflammation. Pathogenic T cells play a central role in MS, but effective therapeutic targeting remains challenging. Here, we identified ankyrin repeat domain–containing protein 55 (ANKRD55) as a key regulator of T cell function by single-cell transcriptomic analysis of cerebrospinal fluid and blood from MS patients. ANKRD55 was predominantly expressed in CD4+ T cells in both compartments. Genetic ablation of Ankrd55 led to a robustly reduced disease severity and neuroinflammation in experimental autoimmune encephalomyelitis (EAE), a widely used animal model for MS. Furthermore, T cell–specific deficiency of Ankrd55 significantly impaired Th1 polarization and Th17 differentiation, reducing EAE pathogenicity. Mechanistically, we found that Ankrd55 deficiency disrupted T cell receptor (TCR) signaling integrity. We demonstrated that ANKRD55 regulates the formation of the immune synapse, an essential prerequisite for TCR activation, by interacting with subunits of the chaperonin-containing TCP1 (CCT) complex and modulating its activity, enhancing its assembly by competing with CCT5 for binding to TCP1, CCT3, and CCT6. This facilitates proper microtubule organization and TCR activation. These findings establish ANKRD55 as a critical regulator of TCR signaling and highlight its therapeutic potential in pathogenic T cell–driven autoimmune diseases.
Authors
Chuyu Wu, Meiling Jiang, Xue Yang, Yixuan Liu, Bin Huang, Yi Guo, Runjing Cao, Zhihui Cui, Guozhen Deng, Weiyan Wang, Mengdi Guo, Zhiyong Lin, Jiahui Fan, Lin-ming Zhang, Lorenzo Di Cesare Mannelli, Tao Pang, Chenhui Wang, Cun-Jin Zhang
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)