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Myeloid-mediated cerebral amyloid vasculitis and the potential role of the immune response in brain atrophy

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Authors

Rudy J. Castellani, Hinda Najem, Amy B. Heimberger, Pouya Jamshidi

Inhibiting inflammation in adipocytes accelerates mammary tumor development in mice

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Pro-inflammatory signaling in adipocytes is essential for healthy adipose expansion, remodeling, and tissue integrity. We investigated the effects of targeting inflammation in either adipocytes or mammary gland epithelial cells, in the context of mammary tumor development, by locally expressing the anti-inflammatory adenoviral RIDα/β protein complex in a cell type-specific manner. Suppression of adipocyte inflammation (“RIDad mice”) in a mammary tumor model driven by MMTV-PyMT (“PyMT-RIDad mice”) led to an elevated number of tumor-associated macrophages (TAMs) and upregulation of immunoregulatory molecules in the mammary fat pad (MFP). This was accompanied by metabolic dysfunction and abnormal mammary gland development. Importantly, this phenotype correlated with accelerated mammary tumor onset, enhanced growth, and lung metastasis. Tumors in PyMT-RIDad mice exhibited upregulated CD36 expression, suggesting enhanced fatty acid uptake. Conversely, suppression of inflammation in mammary gland epithelial cells by RIDα/β expression (“RIDMMTV mice”) decelerated mammary tumor growth without affecting tumor onset or macrophage accumulation. These findings highlight the differential impact on tumor development exerted through the suppression of inflammatory signals in different cell types in the microenvironment. Our results underscore the role of the suppression of adipocyte inflammation leading to a tumor-friendly microenvironment, promoting mammary cancer progression. This study sheds light on the complex interplay between inflammation, specifically driven by the adipocyte, in breast cancer pathogenesis.

Authors

Dae-Seok Kim, Toshiharu Onodera, Jan-Bernd Funcke, Kyounghee Min, Qingzhang Zhu, Qian Lin, Shiuhwei Chen, Chanmin Joung, Min Kim, R. Max Wynn, Joselin Velasco, Charlotte Lee, Megan Virostek, Chao Li, Philipp E. Scherer

E3 ubiquitin ligase Listerin regulates macrophage cholesterol efflux and atherosclerosis by targeting ABCA1

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Atherosclerosis arises from disrupted cholesterol metabolism, notably impaired macrophage cholesterol efflux leading to foam cell formation. Through single-cell and bulk RNA sequencing, we identified Listerin as a regulator of macrophage cholesterol metabolism. Listerin expression increased during atherosclerosis progression in humans and rodents. Its deficiency suppressed cholesterol efflux, promoted foam cell formation, and exacerbated plaque features (macrophage infiltration, lipid deposition, necrotic cores) in macrophage-specific knockout mice. Conversely, Listerin overexpression attenuated these atherosclerotic manifestations. Mechanistically, Listerin stabilizes ABCA1, a key cholesterol efflux mediator, by catalyzing K63-linked polyubiquitination at residues K1884/K1957, countering ESCRT-mediated lysosomal degradation of ABCA1 induced by oxLDL. ABCA1 agonist Erythrodiol restored cholesterol efflux in Listerin-deficient macrophages, while ABCA1 knockout abolished Listerin's effects in THP-1 cells. This study establishes Listerin as a protective factor in atherosclerosis via post-translational stabilization of ABCA1, offering a potential therapeutic strategy targeting ABCA1 ubiquitination to enhance cholesterol efflux.

Authors

Lei Cao, Jie Zhang, Liwen Yu, Wei Yang, Wenqian Qi, Ruiqing Ren, Yapeng Liu, Yonghao Hou, Yu Cao, Qian Li, Xiaohong Wang, Zhengguo zhang, Bo Li, Wenhai Sui, Yun Zhang, Chengjiang Gao, Cheng Zhang, Meng Zhang

CNS-targeted base editing of the major late-onset Tay-Sachs mutation alleviates disease in mice

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Late-onset Tay-Sachs (LOTS) disease is a lysosomal storage disorder most commonly caused by a point mutation (c.805G>A) in the HEXA gene encoding the α-subunit of the lysosomal enzyme β-hexosaminidase A. LOTS manifests as a range of gradually worsening neurological symptoms beginning in young adulthood. Here, we explored the efficacy of an adenine base editor (ABE) programmed with a small guide RNA (sgRNA) to correct the HEXA c.805G>A mutation. Base editing in LOTS patient fibroblasts successfully converted the pathogenic HEXA c.805A to G and partially restored β-hexosaminidase activity, with minimal genome-wide off-target editing. We generated a LOTS mouse model in which the mice exhibited decreased β-hexosaminidase activity, accumulation of GM2 ganglioside in the brain, progressive neurological manifestations, and reduced lifespan. Treatment of LOTS mice with the neurotropic virus AAV-PHP.eB carrying the ABE and an sgRNA targeting the LOTS point mutation partially corrected the c.805G>A mutation in the CNS, significantly increased brain β-hexosaminidase activity, and substantially reduced GM2 ganglioside accumulation in the brain. Moreover, the therapy delayed symptom onset and significantly extended median lifespan. These findings highlight the potential of base editing as an effective treatment for LOTS and its broader applicability to other lysosomal storage disorders.

Authors

Maria L Allende, Mari Kono, Y. Terry Lee, Samantha M. Olmsted, Vienna Huso, Jenna Y. Bakir, Florencia Pratto, Cuiling Li, Colleen Byrnes, Galina Tuymetova, Hongling Zhu, Cynthia J. Tifft, Richard L. Proia

β-cell Gɑs signaling is critical for physiological and pharmacological enhancement of insulin secretion

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The incretin peptides glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors coordinate β-cell secretion that is proportional to nutrient intake. This effect permits consistent and restricted glucose excursions across a range of carbohydrate intake. The canonical signaling downstream of ligand-activated incretin receptors involves coupling to Gɑs protein and generation of intracellular cyclic adenosine monophosphate (cAMP). However, recent reports have highlighted the importance of additional signaling nodes engaged by incretin receptors, including other G-proteins and β-arrestin proteins. Here, the importance of Gɑs signaling was tested in mice with conditional, post-developmental β-cell deletion of Gnas (encoding Gɑs) under physiological and pharmacological conditions. Deletion of Gɑs/cAMP signaling induced immediate and profound hyperglycemia that responded minimally to incretin receptor agonists, a sulfonylurea, or bethanechol. While islet area and insulin content were not affected in Gnasβcell-/-, perifusion of isolated islets demonstrated impaired responses to glucose, incretins, acetylcholine and IBMX. In the absence of Gɑs, incretin-stimulated insulin secretion was impaired but not absent, with some contribution from Gɑq signaling. Collectively, these findings validate a central role for cAMP to mediate incretin signaling, but also demonstrate broad impairment of insulin secretion in the absence of Gɑs that causes both fasting hyperglycemia and glucose intolerance.

Authors

Megan E. Capozzi, David Bouslov, Ashot Sargsyan, Michelle Y. Chan, Sarah M. Gray, Katrina Viloria, Akshay Bareja, Jonathan D. Douros, Sophie L. Lewandowski, Jason C.L. Tong, Annie Hasib, Federica Cuozzo, Elizabeth C. Ross, Matthew W. Foster, Lee S. Weinstein, Mehboob A. Hussain, Matthew J. Merrins, Francis S. Willard, Mark O. Huising, Kyle W. Sloop, David J. Hodson, David A. D'Alessio, Jonathan E. Campbell

Allergens abrogate anti-inflammatory DNA effects and unmasks macrophage-driven neutrophilic asthma via ILC2/STING/TNFα signaling

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The mechanism of neutrophilic and mixed neutrophilic-eosinophilic asthma is poorly understood. We found that extracellular DNA and nucleosomes (Nuc) were elevated in the airways from neutrophilic-eosinophilic asthma patients and correlated with bronchoalveolar lavage neutrophils. Bronchial tissue from neutrophilic-eosinophilic asthma expressed increased DNA sensor-positive cells. Intranasally administered DNA did not induce airway hyperreactivity (AHR) or any pathology but induced AHR and neutrophilic-eosinophilic inflammation when co- administered with the allergen Alternaria (Alt). Nuc alone induced anti-inflammatory/defensive genes whereas the Nuc-Alt combo increased TNF and innate cytokines. The Alt-Nuc phenotype was abolished in Cgas-/-, ALR-/-, Sting-/-, LysMCre:Stingf/f, IL7RCre:Rorαf/f and Tnfr2-/- mice. Alt, unexpectedly, played an essential role in the Nuc-induced phenotype. It abrogated Nuc-induction of anti-inflammatory genes, facilitated Nuc uptake, induced ILC2s, which, in presence of Nuc, produced high levels of TNFα and promoted neutrophilic infiltration. We established a paradigm where allergens inhibit the anti-inflammatory effects of DNA/Nuc and facilitate STING-TNFα-driven neutrophilic-eosinophilic inflammation in asthma.

Authors

Anand Sripada, Divya Verma, Rangati Varma, Kapil Sirohi, Carolyn Kwiat, Mohini Pathria, Mukesh Verma, Anita Sahu, Vamsi P. Guntur, Laurie A. Manka, Brian Vestal, Camille M. Moore, Richard J. Martin, Magdalena M. Gorska, John Cambier, Andrew Getahun, Rafeul Alam

MuSK cysteine-rich domain antibodies are pathogenic in a mouse model of autoimmune myasthenia gravis

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The neuromuscular junction (NMJ), synapse between the motor neuron terminal and a skeletal muscle fiber is crucial, throughout life, in maintaining the reliable neurotransmission required for functional motricity. Disruption of this system leads to neuromuscular disorders, such as auto-immune myasthenia gravis (MG), the most common form of NMJ diseases. MG is caused by autoantibodies directed mostly against the acetylcholine receptor (AChR) or the muscle-specific kinase MuSK. Several studies report immunoreactivity to the Frizzled-like cysteine-rich Wnt-binding domain of MuSK (CRD) in patients, although the pathogenicity of the antibodies involved remains unknown. We showed here that the immunoreactivity to MuSK CRD induced by the passive transfer of anti-MuSKCRD antibodies in mice led to typical MG symptoms, characterized by a loss of body weight and a locomotor deficit. The functional and morphological integrity of the NMJ was compromised with a progressive decay of neurotransmission and disruption of the structure of pre- and post-synaptic compartments. We found that anti-MuSKCRD antibodies completely abolished Agrin-mediated AChR clustering by decreasing the Lrp4-MuSK interaction. These results provide the first demonstration of the role of the MuSK CRD in MG pathogenesis and improve our understanding of the underlying pathophysiological mechanisms.

Authors

Marius Halliez, Steve Cottin, Axel You, Céline Buon, Antony Grondin, Léa S. Lippens, Megane Lemaitre, Jérome Ezan, Charlotte Isch, Yann Rufin, Mireille Montcouquiol, Nathalie Sans, Bertrand Fontaine, Julien Messéant, Rozen Le Panse, Laure Strochlic

Modulation of the Acod1/itaconate pathway differentially affects atherosclerosis severity across genetic models and sexes

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Authors

Lara Haase, Anouar Belkacemi, Laura Neises, Nicole Kiweler, Christine Wesely, Rosanna Huchzermeier, Maja Bozic, Arefeh Khakdan, Marta Sánchez, Arnaud Mary, Nadja Sachs, Hanna Winter, Enrico Glaab, Michael T. Heneka, Emiel P.C. van der Vorst, Michel Mittelbronn, Johannes Meiser, Jochen G. Schneider

Wilms’ tumor 1 impairs apoptotic clearance of fibroblasts in distal fibrotic lung lesions

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Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease characterized by impaired fibroblast clearance and excessive extracellular matrix (ECM) protein production. Wilms' Tumor 1 (WT1), a transcription factor, is selectively upregulated in IPF fibroblasts. However, the mechanisms by which WT1 contributes to fibroblast accumulation and ECM production remain unknown. Here, we investigated the heterogeneity of WT1-expressing mesenchymal cells using single-nucleus RNA sequencing of distal lung tissues from IPF patients and control donors. WT1 was selectively upregulated in a subset of IPF fibroblasts that co-expressed several pro-survival and ECM genes. The results of both loss-of-function and gain-of-function studies are consistent with a role for WT1 as a positive regulator of pro-survival genes to impair apoptotic clearance and promote ECM production. Fibroblast-specific overexpression of WT1 augmented fibroproliferation, myofibroblast accumulation, and ECM production during bleomycin-induced pulmonary fibrosis in young and aged mice. Together, these findings suggest that targeting WT1 is a promising strategy for attenuating fibroblast expansion and ECM production during fibrogenesis.

Authors

Harshavardhana H. Ediga, Chanukya P. Vemulapalli, Vishwaraj Sontake, Pradeep K. Patel, Hikaru Miyazaki, Dimitry Popov, Martin B. Jensen, Anil G. Jegga, Steven K. Huang, Christoph Englert, Andreas Schedl, Nishant Gupta, Francis X. McCormack, Satish K. Madala

Kidney-specific WNK1 amplifies kidney tubule responsiveness to potassium via WNK body condensates

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To maintain potassium homeostasis, the kidney’s distal convoluted tubule (DCT) evolved to convert small changes in blood [K+] into robust effects on salt reabsorption. This process requires NaCl cotransporter (NCC) activation by the With-No-Lysine (WNK) kinases. During hypokalemia, the Kidney-Specific WNK1 isoform (KS-WNK1) scaffolds the DCT-expressed WNK signaling pathway within biomolecular condensates of unknown function termed WNK bodies. Here, we show that KS-WNK1 amplifies kidney tubule reactivity to blood [K+], in part via WNK bodies. Genetically modified mice with targeted condensate disruption trap the WNK pathway, causing renal salt wasting that is more pronounced in females. In humans, WNK bodies accumulate as plasma potassium falls below 4.0 mmol/L, suggesting that the human DCT experiences the stress of potassium deficiency even when [K+] is in the low-normal range. These data identify WNK bodies as kinase signal amplifiers that mediate tubular [K+] responsiveness, nephron sexual dimorphism, and blood pressure salt-sensitivity. Our results illustrate how biomolecular condensate specialization can optimize a mammalian physiologic stress response that impacts human health.

Authors

Cary R. Boyd-Shiwarski, Rebecca T. Beacham, Jared A. Lashway, Katherine E. Querry, Shawn E. Griffiths, Daniel J. Shiwarski, Sophia A. Knoell, Nga H. Nguyen, Lubika J. Nkashama, Melissa N. Valladares, Anagha Bandaru, Allison L. Marciszyn, Jonathan Franks, Mara Sullivan, Simon C. Watkins, Aylin R. Rodan, Chou-Long Huang, Sean D. Stocker, Ossama B. Kashlan, Arohan R. Subramanya

TNFα impairs platelet function by inhibiting autophagy and disrupting metabolism via Syntaxin-17 downregulation

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Platelets play a dual role in hemostasis and inflammation-associated thrombosis and hemorrhage. While the mechanisms linking inflammation to platelet dysfunction remain poorly understood, our previous work demonstrated that TNFα alters mitochondrial mass, platelet activation, and autophagy-related pathways in megakaryocytes. Here, we hypothesized that TNFα impairs platelet function by disrupting autophagy, a process critical for mitochondrial health and cellular metabolism. Using human and murine models of TNFα-driven diseases, including myeloproliferative neoplasms and rheumatoid arthritis, we found that TNFα downregulates STX17, a key mediator of autophagosome–lysosome fusion. This disruption inhibited autophagy, leading to the accumulation of dysfunctional mitochondria and reduced mitochondrial respiration. These metabolic alterations compromised platelet-driven clot contraction, a process linked to thrombotic and hemorrhagic complications. Our findings reveal a mechanism by which TNFα disrupts hemostasis through autophagy inhibition, highlighting TNFα as a critical regulator of platelet metabolism and function. This study provides new insights into inflammation-associated pathologies and suggests autophagy-targeting strategies as potential therapeutic avenues to restore hemostatic balance.

Authors

Guadalupe Rojas-Sanchez, Jorge Calzada-Martinez, Brandon McMahon, Aaron C. Petrey, Gabriela Dveksler, Gerardo P. Espino-Solis, Orlando Esparza, Giovanny Hernandez, Dennis Le, Eric P. Wartchow, Ken Jones, Lucas H. Ting, Catherine Jankowski, Marguerite R. Kelher, Marilyn Manco-Johnson, Marie L. Feser, Kevin D. Deane, Travis Nemkov, Angelo D'Alessandro, Andrew Thorburn, Paola Maycotte, José A. López, Pavel Davizon-Castillo

Expression of full-length dystrophin reverses muscular dystrophy defects in young and old mdx^4cv mice

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Gene replacement therapies mediated by adeno-associated viral (AAV) vectors represent a promising approach for treating genetic diseases. However, their modest packaging capacity (~4.7 kb) remains an important constraint and significantly limits their application for genetic disorders involving large genes. A prominent example is Duchenne muscular dystrophy (DMD), whose protein product dystrophin is generated from an 11.2 kb segment of the DMD mRNA. Here, we explored methods that enable efficient expression of full-length dystrophin via triple AAV co-delivery. This method exploits the protein trans-splicing mechanism mediated by split inteins. We identified a combination of efficient and specific split intein pairs that enables the reconstitution of full-length dystrophin from three dystrophin fragments. We show that systemic delivery of low doses of the myotropic AAVMYO1 in mdx4cv mice leads to efficient expression of full-length dystrophin in the hindlimb, diaphragm, and heart muscles. Notably, muscle morphology and physiology were significantly improved in triple AAV-treated mdx4cv mice versus saline-treated controls. This method shows the feasibility of expressing large proteins from several fragments that are delivered using low doses of myotropic AAV vectors. It can be adapted to other large genes involved in disorders for which gene replacement remains challenged by the modest AAV cargo capacity.

Authors

Hichem Tasfaout, Timothy S. McMillen, Theodore R. Reyes, Christine L. Halbert, Rong Tian, Michael Regnier, Jeffrey S. Chamberlain

Impact of SGLT2 inhibitors on cerebrospinal fluid dynamics and implications for hydrocephalus management

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Authors

Nishanth S. Sadagopan, Rushmin Khazanchi, Rishi Jain, Amy B. Heimberger, Stephen T. Magill

B cell deficiency induces cytotoxic memory CD8⁺ T cells during influenza-associated bacterial pneumonia

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Influenza-associated bacterial super-infections in the lung lead to increased morbidity and mortality. Nearly all people have pre-existing memory to influenza virus, which can protect against subsequent infection in the lung. This study explored the role B cells play in protection against bacterial (Staphylococcus aureus or Klebsiella pneumoniae) super-infection with previous heterotypic influenza memory. B cell deficiency resulted in an increased inflammatory lung environment and lung tissue injury during super-infection. Loss of B cells increased populations of memory CD8+ T cells in the lung and these CD8+ T cells were transcriptionally and functionally distinct from WT mice. Use of antibody-deficient mouse models showed that this phenotype was specifically due to loss of antibody production from B cells. Passive immunization with influenza-antibody serum in B cell deficient mice rescued the CD8+ T cell phenotype. CD8+ T cell depletion and lethal super-infection challenge experiments showed that the cytotoxic memory CD8+ T cells from B cell deficient mice protect against super-infection bacterial burden and mortality. These findings provide insight into the importance of B cells for regulating immune responses against infection.

Authors

Leigh M. Miller, Alexis M. Duray, Ellyse M. Cipolla, Flavia Rago, Brooke P. Dresden, Kristen L. Parenteau, Abhigya Gupta, John F. Alcorn

Patterns of intra- and inter-tumor phenotypic heterogeneity in lethal prostate cancer

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Metastatic prostate cancer (mPC) is a clinically and molecularly heterogeneous disease. While there is increasing recognition of diverse tumor phenotypes across patients, less is known about the molecular and phenotypic heterogeneity present within an individual. In this study, we aimed to define the patterns, extent, and consequences of inter- and intra-tumoral heterogeneity in lethal prostate cancer. By combining and integrating in situ tissue-based and sequencing approaches, we analyzed over 630 tumor samples from 52 mPC patients. Our efforts revealed phenotypic heterogeneity at the patient, metastasis, and cellular levels. We observed that intra-patient, inter-tumoral molecular subtype heterogeneity was common in mPC and showed associations with genomic and clinical features. Additionally, cellular proliferation rates varied within a given patient across molecular subtypes and anatomic sites. Single-cell sequencing studies revealed features of morphologically and molecularly divergent tumor cell populations within a single metastatic site. These data provide a deeper insight into the complex patterns of tumoral heterogeneity in mPC with implications for clinical management and the future development of diagnostic and therapeutic approaches.

Authors

Martine P. Roudier, Roman Gulati, Erolcan Sayar, Radhika A. Patel, Micah Tratt, Helen M. Richards, Paloma Cejas, Miguel Munoz Gomez, Xintao Qiu, Yingtian Xie, Brian Hanratty, Samir Zaidi, Jimmy L. Zhao, Mohamed Adil, Chitvan Mittal, Yibai Zhao, Ruth Dumpit, Ilsa Coleman, Jin-Yih Low, Thomas Persse, Patricia C. Galipeau, John K. Lee, Maria Tretiakova, Meagan Chambers, Funda Vakar-Lopez, Lawrence D. True, Marie Perrone, Hung-Ming Lam, Lori A. Kollath, Chien-Kuang C. Ding, Stephanie Harmon, Heather H. Cheng, Evan Y. Yu, Robert B. Montgomery, Jessica E. Hawley, Daniel W. Lin, Eva Corey, Michael T. Schweizer, Manu Setty, Gavin Ha, Charles L. Sawyers, Colm Morrissey, Henry W. Long, Peter S. Nelson, Michael C. Haffner

The macrophage-intrinsic MDA5-IRF5 axis drives HIV-1 intron-containing RNA-induced inflammatory responses

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Despite effective antiretroviral therapy (ART), transcriptionally competent HIV-1 reservoirs persist and contribute to persistent immune activation in people living with HIV (PWH). HIV-1-infected macrophages are important mediators of chronic innate immune activation, though mechanisms remain unclear. We previously reported that nuclear export and cytoplasmic expression of HIV-1 intron-containing RNA (icRNA) activates mitochondrial antiviral signaling protein (MAVS)-mediated type I interferon (IFN) responses in macrophages. In this study, we demonstrate an essential role of melanoma differentiation-associated protein 5 (MDA5) in sensing HIV-1 icRNA and promoting MAVS-dependent IRF5 activation in macrophages. Suppression of MDA5, but not RIG-I expression nor disruption of endosomal TLR pathway, abrogated HIV-1 icRNA-induced type I IFN responses and IP-10 expression in macrophages. Furthermore, induction of IP-10 in macrophages upon HIV-1 icRNA sensing by MDA5 was dependent on IRF5. Additionally, monocytes and MDMs from older (>50 years) individuals exhibit constitutively higher levels of IRF5 expression compared to younger (<35 years) individuals, and HIV-1 icRNA induced IP-10 expression was significantly enhanced in older macrophages, which was attenuated upon ablation of IRF5 expression suggesting that IRF5 functions as a major mediator of pro-inflammatory response downstream of MDA5-dependent HIV-1 icRNA sensing, dysregulation of which might contribute to chronic inflammation in older PWH.

Authors

Sita Ramaswamy, Hisashi Akiyama, Jacob Berrigan, Andrés A. Quiñones-Molina, Alex J. Olson, Yunhan Chen, YanMei Liang, Andrew J. Henderson, Archana Asundi, Manish Sagar, Suryaram Gummuluru

Disruption of KLHL37-N-Myc complex restores N-Myc degradation and arrests neuroblastoma growth in mouse models

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MYCN amplification accounts for the most common genetic aberration in neuroblastoma and strongly predicts the aggressive progression and poor clinical prognosis. However, clinically effective therapies that directly target N-Myc activity are limited. N-Myc is a transcription factor, and its stability are tightly controlled by ubiquitination-dependent proteasomal degradation. Here, we discovered that Kelch-like protein 37 (KLHL37) played a crucial role in enhancing the protein stability of N-Myc in neuroblastoma. KLHL37 directly interacted with N-Myc to disrupt the N-Myc/FBXW7 interaction, thereby stabilizing N-Myc and enabling tumor progression. Suppressing KLHL37 effectively induced the degradation of N-Myc and exhibited a profound inhibitory effect on the growth of MYCN-amplified neuroblastoma. Notably, we identified RTA-408 as an inhibitor of KLHL37 to disrupt KLHL37-N-Myc complex, promoting the degradation of N-Myc and suppressing neuroblastoma in vivo and in vitro. Moreover, we elucidated the therapeutic potential of RTA-408 for neuroblastoma by utilizing the PDC and PDX tumor models. RTA408's anti-tumor effects may not be exclusively via KLHL37, and specific KLHL37 inhibitors are expected to be developed in the future. These findings not only uncover the biological function of KLHL37 in regulating N-Myc stability, but also indicate that KLHL37 inhibition is a promising therapeutic regimen for neuroblastoma, especially in MYCN-amplified patients.

Authors

Senfeng Xiang, Pengfei Chen, Xiaoxian Shi, Hanqi Cai, Zihan Shen, Luyang Liu, Aixiao Xu, Jianhua Zhang, Xingya Zhang, Shaowei Bing, Jinhu Wang, Xuejing Shao, Ji Cao, Bo Yang, Qiaojun He, Meidan Ying

Diet-induced obesity promotes endothelial cell desensitization to VEGF-A and permanent islet vessel dysfunction in mice

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Pancreatic islet microvasculature is essential for optimal islet function and glucose homeostasis. However, islet vessel pathogenesis in obesity and its role in the manifestation of metabolic disorders remain understudied. Here, we depict the time-resolved decline of intra-islet endothelial cell responsiveness to vascular endothelial cell growth factor A (VEGF-A) and islet vessel function in a mouse model of diet-induced obesity. Longitudinal imaging of sentinel islets transplanted into mouse eyes revealed substantial vascular remodeling and diminished VEGF-A response in islet endothelial cells after 12 weeks of western diet (WD) feeding. This led to islet vessel barrier dysfunction and hemodynamic dysregulation, delaying transportation of secreted insulin into the blood. Notably, islet vessels exhibited a metabolic memory of previous WD feeding. Neither VEGF-A sensitivity nor the other vascular alterations was fully restored by control diet (CD) refeeding, resulting in modest yet significant impairment in glucose clearance despite normalized insulin sensitivity. Mechanistic analysis implicated hyperactivation of atypical protein kinase C (aPKC) under both WD and recovery conditions, which inhibited VEGF receptor 2 (VEGFR2) internalization and blunted VEGF-A triggered signal transduction in endothelial cells. In summary, prolonged WD feeding causes irreversible islet endothelial cell desensitization to VEGF-A and islet vessel dysfunction, directly undermining glucose homeostasis.

Authors

Yan Xiong, Andrea Dicker, Montse Visa, Erwin Ilegems, Per-Olof Berggren

CAR-T cells targeting CD155 reduce tumor burden in preclinical models of leukemia and solid tumors

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CAR-T cells are a powerful yet expensive tool in cancer immunotherapy. While their use in targeting hematological malignancies is well-established, using a single CAR-T cell therapy to treat both hematological and solid tumors, which can reduce cost, remains largely unexplored. In this study, we identified CD155, an adhesion molecule that is upregulated during tumor progression, as a target for CAR-T cell therapy in both leukemia and solid tumors. We engineered CAR-T cells using human and mouse anti-CD155 antibodies generated from a Berkeley Lights' Beacon platform. These CAR-T cells demonstrated potent anti-tumor activity, significantly reducing tumor burden in preclinical models of acute myeloid leukemia (AML), non-small cell lung cancer (NSCLC), and pancreatic cancer. To reduce potential allogeneic rejection, we generated CAR-T cells using humanized anti-CD155 antibody sequences that retained efficacy. Additionally, murine CAR-T cells targeting mouse CD155 exhibited limited toxic side effects in immunocompetent mice, highlighting the favorable safety profile of this therapy. These findings suggest that CD155 can be targeted by CD155 CAR-T cells safely and effectively, representing an innovative cellular therapeutic strategy that has the potential to expand its scope across both AML and multiple solid tumors, thereby lowering the cost of cellular immunotherapy, especially as allogenic, universal and off-the-shelf CAR-T cell therapies advance to the clinic.

Authors

Tianchen Xiong, Ge Wang, Peng Yu, Zhenlong Li, Debao Li, Jianying Zhang, Song Lu, Ruiqi Yang, Xiaolong Lian, Jianhong Mi, Rui Ma, Zhiyao Li, Guido Marcucci, Tingting Zhao, Michael A. Caligiuri, Jianhua Yu

Panose prevents acute-on-chronic liver failure by reducing bacterial infection in mice

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Acute-on-chronic liver failure (ACLF) is a leading cause of global liver-related mortality. Bacterial infection, especially in patients with decompensated cirrhosis (DC), commonly triggers ACLF and is difficult to treat with antibiotics. Therefore, finding alternative strategies for preventing and managing bacterial infection is an urgent priority. Here, we observed that infected DC patients and ACLF mice exhibited lower fecal panose levels than uninfected controls. Megamonas funiformis (M. funiformis), with 4α-glucanosyltransferase (4αGT) as a key enzyme for panose production, was identified as a potential panose producer. Animal experiments demonstrated that panose efficiently reduced liver injury and extended survival in ACLF mice by mitigating bacterial infection. Further results revealed that panose enhanced resistance to bacterial infection by inhibiting oxidative stress-induced gut barrier disruption, thereby limiting bacterial dissemination. Mechanistically, panose interacted with the solute carrier family 7 member 11 (SLC7A11, also known as xCT) protein to boost antioxidant glutathione (GSH) levels in intestinal epithelial cells. These findings highlight panose's potential in preventing bacterial infection, offering a valuable insight into mitigating ACLF progression.

Authors

Jiaxin Li, Shihao Xie, Meiling Chen, Changze Hong, Yuqi Chen, Fengyuan Lyu, Niexin Tang, Tianqi Chen, Lingyan Zhao, Weihao Zou, Hongjuan Peng, Jingna Bao, Peng Gu, Bernd Schnabl, Jinjun Chen, Peng Chen