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IFNγ-driven skewing towards Th1 over Th17 differentiation underlies CRS and neutropenia in CAR-T therapy

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Abstract

CAR-T therapy has led to significant improvements in patient survival. However, a subset of patients experience high-grade toxicities, including cytokine release syndrome (CRS) and immune cell-associated hematological toxicity (ICAHT). We utilized IL-2Rα knockout mice to model toxicities with elevated levels of IL6, IFNγ, and TNFα and increased M1-like macrophages. Onset of CRS was accompanied by a reduction in peripheral blood neutrophils due to disruption of bone marrow neutrophil homeostasis characterized by an increase in apoptotic neutrophils and a decrease in proliferative and mature neutrophils. Both non-tumor-bearing and Eμ-ALL tumor-bearing mice recapitulated the co-occurrence of CRS and neutropenia. IFNγ-blockade alleviated CRS and neutropenia without affecting CAR-T efficacy. Mechanistically, a Th1-Th17 imbalance was observed to drive co-occurrence of CRS and neutropenia in an IFNγ-dependent manner leading to decreased IL-17A and G-CSF, neutrophil production, and neutrophil survival. In patients, we observed an increase in the IFNγ-to-IL-17A ratio in the peripheral blood during high-grade CRS and neutropenia. We have uncovered a biological basis for ICAHT and provide support for the use of IFNγ-blockade to reduce both CRS and neutropenia.

Authors

Payal Goala, Yongliang Zhang, Nolan J. Beatty, Allan Pavy, Shannon L. McSain, Cooper J. Sailer, Muhammad Junaid Tariq, Showkat Hamid, Eduardo Cortes Gomez, Jianmin Wang, Duna Massillon, Maxwell Ilecki, Justin C. Boucher, Constanza Savid-Frontera, Sae Bom Lee, Hiroshi Kotani, Meredith L. Stone, Michael D. Jain, Marco L. Davila

Lnk Deficiency Enhances Translesion Synthesis to Alleviate Replication Stress and Promote Hematopoietic Stem Cell Fitness

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Abstract

The adaptor protein LNK/SH2B3 negatively regulates hematopoietic stem cell (HSC) homeostasis. Lnk-deficient mice show marked expansion of HSCs without premature exhaustion. Lnk deficiency largely restores HSC function in Fanconi Anemia (FA) mouse models and primary FA patient cells, albeit protective mechanisms remain enigmatic. Here, we uncover a novel role for LNK in regulating translesion synthesis (TLS) during HSC replication. Lnk deficiency reduced replication stress-associated DNA damage, particularly in the FA background. Lnk deficiency suppressed single-strand DNA breaks, while enhancing replication fork restart in FA-deficient HSCs. Diminished replication-associated damage in Lnk-deficient HSCs occurred commensurate with reduced ATR-p53 checkpoint activation that is linked to HSC attrition. Notably, Lnk deficiency ameliorated HSC attrition in FA mice without exacerbating carcinogenesis during ageing. Moreover, we demonstrated that enhanced HSC fitness from Lnk deficiency was associated with increased TLS activity via REV1 and, to a lesser extent, TLS polymerase eta. TLS polymerases are specialized to execute DNA replication in the presence of lesions or natural replication fork barriers that stall replicative polymerases. Our findings implicate elevated use of these specialized DNA polymerases as critical to the enhanced HSC function imparted by Lnk deficiency, which has important ramifications for stem cell therapy and regenerative medicine in general.

Authors

Brijendra Singh, Md Akram Hossain, Xiao Hua Liang, Jeremie Fages, Carlo Salas Salinas, Roger A. Greenberg, Wei Tong

Ciliopathy-related B9 protein complex regulates ciliary axonemal microtubule post-translational modifications and initiation of ciliogenesis

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Abstract

Ciliary dysfunction results in multi-organ involved developmental diseases, collectively known as ciliopathies. The B9D1-B9D2-MKS1 protein complex maintains the gatekeeper function at the ciliary transition zone (TZ). However, the function of B9 proteins and the mechanisms underlying why different variants in the same B9 gene cause different ciliopathies are not fully understood. Here, we investigated the function of B9 proteins and revealed two critical functions. First, the B9 complex interacted with and anchored TMEM67 to the TZ membrane. Disruption of the B9-TMEM67 complex reduced posttranslational-modifications of axonemal microtubules due to deregulation of tubulin-modifying enzymes within cilia. Second, B9 proteins localized to centrioles prior to ciliogenesis, where they facilitated the initiation of ciliogenesis. Finally, we identified B9D2 variants in a cohort of patients with Joubert syndrome (JBTS). Consistent with the dual functions, we found that the JBTS-associated B9D2 variants primarily affected axonemal microtubule modifications without disrupting ciliogenesis, whereas the Meckel syndrome (MKS)-associated B9D2 variant disrupted both ciliogenesis and axonemal microtubule modifications. Thus, besides its role as a gatekeeper for ciliary membrane proteins, the B9 complex also controls axonemal microtubule post-translational modifications and early stages of ciliogenesis, providing insights into the distinct pathologies arising from different variants of the same gene.

Authors

Ruida He, Yan Li, Minjun Jin, Huike Jiao, Yue Shen, Qize Han, Xilang Pan, Suning Wang, Zaisheng Lin, Jingshi Li, Chao Lu, Dan Meng, Zongfu Cao, Qing Shang, Nan Lv, Kai Wan, Huafang Gao, Xu Ma, Haiyan Yin, Haishuang Chang, Liang Wang, Minna Luo, Junmin Pan, Chengtian Zhao, Muqing Cao

Molecular glue degrader function of SPOP enhances STING-dependent immunotherapy efficacy in melanoma models

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Abstract

The E3 ligase SPOP plays a context-dependent role in cancer by targeting specific cellular proteins for degradation, thereby influencing cell behavior. However, its role in tumor immunity remains largely unexplored. In this study, we revealed that SPOP targeted the innate immune sensor STING for degradation in a CK1γ phosphorylation-dependent manner to promote melanoma growth. Stabilization of STING by escaping SPOP-mediated degradation enhanced anti-tumor immunity by increasing IFNβ production and ISG expression. Notably, small-molecule SPOP inhibitors not only blocked STING recognition by SPOP, but also acted as molecular glues, redirecting SPOP to target neo-substrates such as CBX4 for degradation. This CBX4 degradation led to increased DNA damage, which in turn activated STING and amplified innate immune responses. In a xenografted melanoma B16 tumor model, single-cell RNA-seq analysis demonstrated that SPOP inhibition induced the infiltration of immune cells associated with anti-PD1 responses. Consequently, SPOP inhibitors synergized with immune checkpoint blockade to suppress B16 tumor growth in syngeneic murine models and enhanced the efficacy of CD19-CAR-T therapy. Our findings highlight a molecular glue degrader property of SPOP inhibitors, with potential implications for other E3 ligase-targeting small molecules designed to disrupt protein-protein interactions.

Authors

Zhichuan Zhu, Xin Zhou, Max Xu, Jianfeng Chen, Kevin C. Robertson, Gatphan N. Atassi, Mark G. Woodcock, Allie C. Mills, Laura E. Herring, Gianpietro Dotti, Pengda Liu

Secretory kinase FAM20C triggers adipocyte dysfunction inciting insulin resistance and inflammation in obesity

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Abstract

Obesity is a major driver of type 2 diabetes (T2D) and related metabolic disorders, characterized by chronic inflammation and adipocyte dysfunction. However, the molecular triggers initiating these processes remain poorly understood. We identify FAM20C, a serine/threonine kinase, as an early obesity-induced mediator of adipocyte dysfunction. Fam20c expression is substantially upregulated in adipocytes in response to obesity, correlating with a proinflammatory transcriptional signature. Forced expression of Fam20c in adipocytes promotes robust upregulation of proinflammatory cytokines and induces insulin resistance that is dependent on its kinase activity. Conversely, deletion of adipocyte Fam20c after established obesity and hyperglycemia improves glucose tolerance, augments insulin sensitivity, and reduces visceral adiposity, without altering body weight. Phosphoproteomic studies reveal that FAM20C regulates phosphorylation of intracellular and secreted proteins, modulating pathways critical to inflammation, metabolism, and extracellular matrix remodeling. We identify FAM20C-dependent substrates, such as CNPY4, whose phosphorylation contributes to proinflammatory adipocyte signaling. Of translational relevance, we show that in humans visceral adipose FAM20C expression positively correlates with insulin resistance. Our findings establish FAM20C as an early regulator of obesity-induced adipocyte dysfunction and systemic metabolic impairment. Our studies provide proof of concept that inhibition of FAM20C may serve as a potential therapy for T2D by restoring adipocyte health.

Authors

Ankit Gilani, Benjamin D. Stein, Anne Hoffmann, Renan Pereira de Lima, Elizabeth E. Ha, Edwin A. Homan, Lunkun Ma, Alfonso Rubio-Navarro, Tint Tha Ra Wun, Gabriel Jose Ayala Carrascal, Bhavneet Bhinder, Adhideb Ghosh, Falko J. Noé, Olivier Elemento, Christian Wolfrum, Matthias Blüher, James C. Lo

Tissue-specific anti-tumor NK cell subsets identified in colorectal cancer liver metastases express candidate therapeutic targets

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Abstract

Liver metastases are relatively resistant to checkpoint blockade immunotherapy. The hepatic tissue has distinctive features including high numbers of NK cells. It was therefore important to conduct in depth single-cell analysis of NK cells in colorectal cancer liver metastases (CRLMs) with the effort to dissect their diversity and to identify candidate therapeutic targets. By combining unbiased single-cell transcriptomic with multiparametric flow cytometry analysis, we identified an abundant family of intrahepatic CD56Bright NK cells in CRLMs endowed with anti-tumor functions resulting from specific transcriptional liver programs. Intrahepatic CD56Bright and CD56Dim NK lymphocytes expressed unique transcription factors (IRF8, TOX2), high level of chemokines, and targetable immune checkpoints (ICs), including CXCR4 and the IL-1 receptor family member IL-1R8. CXCR4 pharmacological blocking and an anti-IL-1R8 mAb enhanced the effector function of CRLM NK cells. Targeting the diversity of liver NK cells and their distinct immune-checkpoint repertoires is key to optimize the current immune-therapy protocols in CRLM.

Authors

Joanna Mikulak, Domenico Supino, Paolo Marzano, Sara Terzoli, Roberta Carriero, Valentina Cazzetta, Rocco Piazza, Elena Bruni, Paolo Kunderfranco, Alessia Donato, Sarah Natalia Mapelli, Roberto Garuti, Silvia Carnevale, Francesco Scavello, Elena Magrini, Jelena Zeleznjak, Clelia Peano, Matteo Donadon, Guido Costa, Guido Torzilli, Alberto Mantovani, Cecilia Garlanda, Domenico Mavilio

T-cell acute lymphoblastic leukemia exploits a neural proinflammatory pathway to colonize the meninges

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Abstract

Infiltration of T-cell acute lymphoblastic leukemia (T-ALL) into the meninges worsens prognosis, underscoring the need to understand mechanisms driving meningeal involvement. Here, we show that T-ALL cells expressing CXCR3 exploit normal T-cell function to infiltrate the inflamed meninges. CXCR3 deletion hampered disease progression and extramedullary dissemination by reducing leukemic cell proliferation and migration. Conversely, forced expression of CXCR3 facilitated T-ALL trafficking to the meninges. We identified the ubiquitin-specific protease 7 as a key regulator of CXCR3 protein stability in T-ALL. Furthermore, we discovered elevated levels of CXCL10, a CXCR3 ligand, in the cerebrospinal fluid from T-ALL patients and leukemia-bearing mice. Our studies demonstrate that meningeal stromal cells, specifically pericytes and fibroblasts, induce CXCL10 expression in response to leukemia, and that loss of CXCL10 attenuated T-ALL influx into the meninges. Moreover, we report that leukemia-derived proinflammatory cytokines, TNFα, IL27 and IFNγ, induced CXCL10 in the meningeal stroma. Pharmacological inhibition or deletion of CXCR3 or CXCL10 reduced T-ALL cell migration and adhesion to meningeal stromal cells. Finally, we reveal that CXCR3 and CXCL10 upregulated VLA-4/VCAM-1 signaling, promoting cell-cell adhesion and thus T-ALL retention in the meninges. Our findings highlight the pivotal role of CXCR3-CXCL10 signaling in T-ALL progression and meningeal colonization.

Authors

Nitesh D. Sharma, Esra'a Keewan, Wojciech Ornatowski, Silpita Paul, Monique Nysus, Christopher C. Barnett, Julie Wolfson, Quiteria Jacquez, Bianca L. Myers, Huining Kang, Katherine E. Zychowski, Stuart S. Winter, Mignon L. Loh, Stephen P. Hunger, Eliseo F. Castillo, Tom Taghon, Christina Halsey, Tou Yia Vue, Nicholas Jones, Panagiotis Ntziachristos, Ksenia Matlawska-Wasowska

The hematopoietic stem cell MYB enhancer is essential and recurrently amplified during T-cell leukemogenesis

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Abstract

There is an urgent need to find targeted agents for T-cell acute lymphoblastic leukemia (T-ALL). NOTCH1 is the most frequently mutated oncogene in T-ALL, but clinical trials showed that pan-Notch inhibitors caused dose-limiting toxicities. Thus, we shifted our focus to ETS1, which is one of the transcription factors that most frequently co-bind Notch-occupied regulatory elements in the T-ALL context. To identify the most essential enhancers, we performed a genome-wide CRISPR interference screen of the strongest ETS1-dependent regulatory elements. The #1-ranked element is located in an intron of AHI1 that interacts with the MYB promoter and is amplified with MYB in ~8.5% of T-ALL patients. Using mouse models, we showed that this enhancer promotes self-renewal of hematopoietic stem cells and T-cell leukemogenesis, maintains early T-cell precursors, and restrains myeloid expansion with aging. We named this enhancer the hematopoietic stem cell MYB enhancer (H-Me). The H-Me shows limited activity and function in committed T-cell progenitors but is accessed during leukemogenesis. In one T-ALL context, ETS1 binds the ETS motif in the H-Me to recruit cBAF to promote chromatin accessibility and activation. ETS1 or cBAF degraders impaired H-Me function. Thus, we identified a targetable stem cell element that is co-opted for T-cell transformation.

Authors

Carea Mullin, Karena Lin, Elizabeth Choe, Cher Sha, Zeel Shukla, Koral Campbell, Anna C. McCarter, Annie Wang, Jannaldo Nieves-Salva, Sarah Khan, Theresa M. Keeley, Shannon Liang, Qing Wang, Ashley F. Melnick, Pearl Evans, Alexander C. Monovich, Ashwin Iyer, Rohan Kodgule, Yamei Deng, Felipe da Veiga Leprevost, Kelly R. Barnett, Petri Pölönen, Rami Khoriaty, Daniel Savic, David T. Teachey, Charles G. Mullighan, Marcin Cieslik, Alexey I. Nesvizhskii, Linda C. Samuelson, Morgan Jones, Qing Li, Russell J.H. Ryan, Mark Y. Chiang

Distinct human small intestinal microbiome communities underlie visceral hypersensitivity in a humanized mouse model

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Abstract

Authors

Isin Y. Comba, Tijs Louwies, Ruben A. Mars, Yang Xiao, Prabhjot Kaur Sekhon, Brian S. Edwards, Adam Willits, Robin R. Shields-Cutler, Shreya Bellampalli, Arnaldo Mercado-Perez, Dennis R. Tienter, Lisa M. Till, David R. Linden, Gianrico Farrugia, Arthur Beyder, Kristen M. Smith-Edwards, Purna C. Kashyap

Spinal α2δ-1 induces GluA3 degradation to regulate assembly of calcium-permeable AMPA receptors and pain hypersensitivity

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Abstract

The increased prevalence of GluA2-lacking, Ca2+-permeable AMPA receptors (CP-AMPARs) at spinal cord sensory synapses amplifies nociceptive transmission and maintains chronic neuropathic pain. Nerve injury–induced upregulation of α2δ-1 disrupts the assembly of GluA1/GluA2 heteromers, favoring the synaptic incorporation of GluA1 homotetramers in the spinal dorsal horn. Although GluA1-GluA3 subunits are broadly expressed, whether α2δ-1 regulates GluA3-containing AMPARs remains unknown. Here, we unexpectedly found that coexpression with α2δ-1—but not α2δ-2 or α2δ-3—diminished GluA3 AMPAR currents and protein levels, an effect blocked by pregabalin, an α2δ-1 C-terminus peptide, or proteasome inhibition. Both nerve injury and α2δ-1 overexpression reduced protein levels of GluA3 and GluA2/GluA3 heteromers in the spinal cord. Furthermore, α2δ-1 coexpression or nerve injury increased GluA3 ubiquitination, with Lys-861 at the C terminus of GluA3 identified as a key ubiquitination site mediating α2δ-1–induced GluA3 degradation. Additionally, intrathecal delivery of the Gria3 gene reversed nerve injury–induced nociceptive hypersensitivity and synaptic CP-AMPARs by restoring protein levels of GluA3 and GluA2/GluA3 heteromers in the spinal cord. These findings reveal that α2δ-1 promotes GluA1 homotetramer assembly and synaptic CP-AMPAR expression by driving ubiquitin-proteasomal degradation of GluA3, providing insights into the molecular mechanisms of neuropathic pain and the therapeutic actions of gabapentinoids.

Authors

Meng-Hua Zhou, Shao-Rui Chen, Daozhong Jin, Yuying Huang, Hong Chen, Guanxing Chen, Jiusheng Yan, Hui-Lin Pan

Targeting STING–induced immune evasion with nanoparticulate binary pharmacology improves tumor control in mice

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Abstract

Harnessing the stimulator of interferon genes (STING) signaling pathway to trigger innate immune responses has shown remarkable promise in cancer immunotherapy; however, overwhelming resistance to intratumoral STING monotherapy has been witnessed in clinical trials, and the underlying mechanisms remain to be fully explored. Herein, we show that pharmacological STING activation following the intratumoral injection of a non-nucleotide STING agonist (i.e., MSA-2) results in apoptosis of the cytolytic T cells, interferon-mediated overexpression of indoleamine 2,3-dioxygenase 1 (IDO1), and evasion from immune surveillance. We leverage a noncovalent chemical strategy for developing immunomodulatory binary nanoparticles (iBINP) that include both the STING agonist and an IDO1 inhibitor for treating immune-evasive tumors. This iBINP platform developed by dual prodrug engineering and subsequent nanoparticle assembly enables tumor-restricted STING activation and IDO1 inhibition, achieving immune activation while mitigating immune tolerance. A systemic treatment of preclinical models of colorectal cancer with iBINP resulted in robust antitumor immune responses, reduced infiltration of regulatory T cells, and enhanced activity of CD8+ T cells. Importantly, this platform exhibits great therapeutic efficacy by overcoming STING–induced immune evasion and controlling the progression of multiple tumor models. This study unveils the mechanisms by which STING monotherapy induces immunosuppression in the tumor microenvironment and provides a combinatorial strategy for advancing cancer immunotherapies.

Authors

Fanchao Meng, Hengyan Zhu, Shuo Wu, Bohan Li, Xiaona Chen, Hangxiang Wang

Selective targeting of HIV infected clones by cognate peptide stimulation and antiproliferative drugs

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Clonal expansion of HIV infected CD4+ T cells is a barrier to HIV eradication. We previously described a marked reduction in the frequency of the most clonally expanded infected CD4+ T cells in an individual with elite control (ES24) after initiating chemoradiation for metastatic lung cancer with a regimen that included paclitaxel and carboplatin. We tested the hypothesis that this phenomenon was due to a higher susceptibility to the chemotherapeutic drugs of CD4+ T cell clones that were sustained by proliferation. We studied a CD4+ T cell clone with replication-competent provirus integrated into the ZNF721 gene, termed ZNF721i. We stimulated the clone with its cognate peptide and then exposed the cells to paclitaxel and/or carboplatin or the antiproliferative drug, mycophenolate mofetil. While treatment of cells with the cognate peptide alone led to a marked expansion of the ZNF721i clone, treatment with the cognate peptide followed by culture with either paclitaxel or mycophenolate mofetil abrogated this process. The drugs did not affect the proliferation of other CD4+ T cell clones that were not specific for the cognate peptide. This strategy of antigen-specific stimulation followed by treatment with an antiproliferative agent may lead to the selective elimination of clonally expanded HIV-infected cells.

Authors

Filippo Dragoni, Joel Sop, Isha Gurumurthy, Tyler P. Beckey, Kellie N. Smith, Francesco R. Simonetti, Joel N. Blankson

High 4E-BP-1 expression associates with chromosome 8 gain and CDK4/6 sensitivity in Ewing Sarcoma

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Chromosome 8 (chr8) gains are common in cancer, but their contribution to tumor heterogeneity is largely unexplored. Ewing sarcoma (EwS) is defined by FET::ETS fusions with few other recurrent mutations to explain clinical diversity. In EwS, chr8 gains are the second most frequent alteration, making it an ideal model to study their relevance in an otherwise silent genomic context. We report that chr8 gain-driven expression patterns correlate with poor overall survival of EwS patients. This effect is mainly mediated by increased expression of the translation initiation factor binding protein 4E-BP1, encoded by EIF4EBP1 on chr8. Among all chr8-encoded genes, EIF4EBP1 expression showed the strongest association with poor survival and correlated with chr8 gains in EwS tumors. Similar findings emerged across multiple TCGA cancer entities. Multi-omics profiling revealed that 4E-BP1 orchestrates a pro-proliferative proteomic network. Silencing 4E-BP1 reduced proliferation, clonogenicity, spheroidal growth in vitro, and tumor growth in vivo. Drug screens demonstrated that high 4E-BP1 expression sensitizes EwS to pharmacological CDK4/6-inhibition. Chr8 gains and elevated 4E-BP1 emerge as prognostic biomarkers in EwS, with poor outcomes driven by 4E-BP1-mediated pro-proliferative networks that sensitize tumors to CDK4/6 inhibitors. Testing for chr8 gains may enhance risk stratification and therapy in EwS and other cancers.

Authors

Cornelius M. Funk, Anna C. Ehlers, Martin F. Orth, Karim Aljakouch, Jing Li, Tilman L.B. Hoelting, Rainer Will, Florian H. Geyer, A. Katharina Ceranski, Franziska Willis, Endrit Vinca, Shunya Ohmura, Roland Imle, Jana Siebenlist, Angelina Yershova, Maximilian M.L. Knott, Felina Zahnow, Ana Sastre, Javier Alonso, Felix Sahm, Heike Peterziel, Anna Loboda, Martin Schneider, Ana Banito, Gabriel Leprivier, Wolfgang Hartmann, Uta Dirksen, Olaf Witt, Ina Oehme, Stefan M. Pfister, Laura Romero-Pérez, Jeroen Krijgsveld, Florencia Cidre-Aranaz, Thomas G.P. Grünewald, Julian Musa

A positive allosteric modulator of the β₁AR with antagonist activity for catecholaminergic polymorphic ventricular tachycardia

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Abstract

Orthosteric β-blockers represent the leading pharmacological intervention for managing heart diseases owing to their ability to competitively antagonize β-adrenergic receptors (βARs). However, their use is often limited by the development of adverse effects such as fatigue, hypotension, and reduced exercise capacity, due in part to the nonselective inhibition of multiple βAR subtypes. These challenges are particularly problematic in treating catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease characterized by lethal tachyarrhythmias directly triggered by cardiac β1AR activation. To identify small molecule allosteric modulators of the β1AR that could offer enhanced subtype specificity and robust functional antagonism of β1AR-mediated signaling, we conducted a DNA-encoded small molecule library screen and discovered Compound 11 (C11). C11 selectively potentiates the binding affinity of orthosteric agonists to the β1AR while potently inhibiting downstream signaling following β1AR activation. Moreover, C11 prevents agonist-induced spontaneous contractile activity, Ca2+ release events, and exercise-induced ventricular tachycardia in the CSQ2–/– murine model of CPVT. Collectively, our studies demonstrate that C11 belongs to an emerging class of allosteric modulators termed PAM-antagonists that positively modulate agonist binding but block downstream function. With unique pharmacological properties and selective functional antagonism of β1AR-mediated signaling, C11 represents a promising therapeutic candidate for the treatment of CPVT and other forms of cardiac disease associated with excessive β1AR activation.

Authors

Alyssa Grogan, Robin M. Perelli, Seungkirl Ahn, Haoran Jiang, Arun Jyothidasan, Damini Sood, Chongzhao You, David I. Israel, Alex Shaginian, Qiuxia Chen, Jian Liu, Jialu Wang, Jan Steyaert, Alem W. Kahsai, Andrew P. Landstrom, Robert J. Lefkowitz, Howard A. Rockman

Excessive collagen type VII mediates pleural fibrosis via increasing extracellular matrix stiffness

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Abstract

The interaction between cells and extracellular matrix (ECM) has been recognized in mechanism of fibrotic diseases. Collagen type VII (collagen VII) is an ECM component which plays an important role in cell-ECM interaction, particularly in cell anchoring and maintaining ECM integrity. Pleural mesothelial cells (PMCs) drive inflammatory reactions and ECM production in pleura. However, the role of collagen VII and PMCs in pleural fibrosis was poorly understood. In this study, collagen VII protein was found increase in pleura of patients with tuberculous pleural fibrosis. Investigation of cellular and animal models revealed that collagen VII began to increase at early stage in pleural fibrotic process. Increase of collagen VII occurred ahead of collagen I and α-SMA in PMCs and pleura of animal models. Inhibition of collagen VII by mesothelial cell-specific deletion of collagen VII gene (WT1-Cre+-COL7A1flox/flox) attenuated mouse experimental pleural fibrosis. At last, it was found that excessive collagen VII changed collagen conformation which resulted in elevation of ECM stiffness. Elevation of ECM stiffness activated integrin/PI3K-AKT/JUN signaling and promoted more ECM deposition, as well as mediated pleural fibrosis. In conclusion, excessive collagen VII mediated pleural fibrosis via increasing extracellular matrix stiffness.

Authors

Qian Li, Xin-Liang He, Shuai-Jun Chen, Qian Niu, Tan-Ze Cao, Xiao-Ling Cui, Zi-Heng Jia, He-De Zhang, Xiao Feng, Ye-Han Jiang, Li-Mei Liang, Pei-Pei Cheng, Shi-He Hu, Liang Xiong, Meng Wang, Hong Ye, Wan-Li Ma

Biallelic variants in ARHGAP19 cause a progressive inherited motor-predominant neuropathy

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Abstract

Charcot-Marie-Tooth Disease is a clinically and genetically heterogeneous group of hereditary neuropathies. Despite progress in genetic sequencing, around a quarter of patients remain unsolved. Here, we identify 16 recessive variants in the RhoGTPase activating protein 19 gene (ARHGAP19) causing motor-predominant neuropathy in 25 individuals from 20 unrelated families. The ARHGAP19 protein acts as a negative regulator of the RhoA GTPase. In vitro biochemical and cellular assays revealed that patient variants impair the GTPase-activating protein (GAP) activity of ARHGAP19 and reduce ARHGAP19 protein levels. Combined in vitro and in vivo studies reveal that human ARHGAP19, and conserved ARHGAP19 orthologs in Drosophila and Zebrafish, influence motoneuron morphology and promote locomotor capacity. Transcriptomic studies further demonstrate that ARHGAP19 regulates cellular pathways associated with motor proteins and the cell cycle. Taken together, our findings establish ARHGAP19 variants as a cause of inherited neuropathy acting through a loss-of-function mechanism.

Authors

Natalia Dominik, Stephanie Efthymiou, Christopher J. Record, Xinyu Miao, Renee Q. Lin, Jevin M. Parmar, Annarita Scardamaglia, Reza Maroofian, Simon A. Lowe, Gabriel N. Aughey, Abigail D. Wilson, Riccardo Curro, Ricardo P. Schnekenberg, Shahryar Alavi, Leif Leclaire, Yi He, Kristina Zhelcheska, Yohanns Bellaiche, Isabelle Gaugué, Mariola Skorupinska, Liedewei Van de Vondel, Sahar I. Da'as, Valentina Turchetti, Serdal Güngör, Gavin V. Monahan, Ehsan Ghayoor Karimiani, Yalda Jamshidi, Phillipa J. Lamont, Camila Armirola-Ricaurte, Haluk Topaloglu, Albena Jordanova, Mashaya Zaman, Selina H. Banu, Wilson Marques, Pedro J. Tomaselli, Busra Aynekin, Ali Cansu, Huseyin Per, Ayten Güleç, Javeria Raza Alvi, Tipu Sultan, Arif Khan, Giovanni Zifarelli, Shahnaz Ibrahim, Grazia M. S. Mancini, M.M. Motazacker, Esther Brusse, Vincenzo Lupo, Teresa Sevilla, A. Nazli Başak, Seyma Tekgul, Robin J. Palvadeau, Jonathan Baets, Yesim Parman, Arman Çakar, Rita Horvath, Tobias B. Haack, Jan-Hendrik Stahl, Kathrin Grundmann-Hauser, Joohyun Park, Stephan Zuchner, Nigel G. Laing, Lindsay A. Wilson, Alexander M. Rossor, James Polke, Fernanda Barbosa Figueiredo, André Pessoa, Fernando Kok, Antônio Rodrigues Coimbra-Neto, Marcondes C. Franca Jr, Gianina Ravenscroft, Sherifa A. Hamed, Wendy K. Chung, Alan M. Pittman, Daniel P. Osborn, Michael Hanna, Andrea Cortese, Mary M. Reilly, James E.C. Jepson, Nathalie Lamarche-Vane, Henry Houlden

Stimulated thyroid hormone synthesis machinery drives thyrocyte cell death independent of ER stress

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It is now recognized that patients and animal models expressing genetically-encoded misfolded mutant thyroglobulin (TG, the protein precursor for thyroid hormone synthesis) exhibit dramatic swelling of the endoplasmic reticulum (ER) with ER stress and cell death in thyrocytes — seen both in homozygotes (with severe hypothyroidism) and heterozygotes (with subclinical hypothyroidism). The thyrocyte death phenotype is exacerbated upon thyroidal stimulation (by thyrotropin, TSH), as cell death is inhibited upon treatment with exogenous thyroxine. TSH stimulation might contribute to cytotoxicity by promoting ER stress, or by an independent mechanism. Here we’ve engineered knockout mice completely lacking Tg expression. Like other animals/patients with mutant TG, these animals rapidly develop severe goitrous hypothyroidism; however, thyroidal ER stress is exceedingly low — lower even than that seen in wildtype mice. Nevertheless, mice lacking TG exhibit abundant thyroid cell death, which depends upon renegade thyroidal iodination — it is completely suppressed in a genetic model lacking effective iodination, or in Tg-KO mice treated with propylthiouracil (iodination inhibitor), or iodide deficiency. Thyrocytes in culture are killed not in the presence of H2O2 alone, but rather upon peroxidase-mediated iodination, with cell death blocked by propylthiouracil. Thus, in the thyroid gland bearing Tg mutation(s), TSH-stimulated iodination activity triggers thyroid cell death.

Authors

Crystal Young, Xiaohan Zhang, Xiaofan Wang, Aaron P. Kellogg, Kevin Pena, August Z. Cumming, Xiao-Hui Liao, Dennis Larkin, Hao Zhang, Emma Mastroianni, Helmut Grasberger, Samuel Refetoff, Peter Arvan

A PP2A molecular glue overcomes ras/mapk inhibitor resistance in kras-mutant non-small cell lung cancer

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Abstract

The effectiveness of RAS/MAPK inhibitors in treating metastatic KRAS-mutant NSCLC is often hindered by the development of resistance driven by disrupted negative feedback mechanisms led by phosphatases like PP2A. PP2A is frequently suppressed in lung cancer to maintain elevated RAS/MAPK activity. Despite its established role in regulating oncogenic signaling, targeting PP2A with RAS/MAPK to prevent resistance has not been previously demonstrated. In this study, we aimed to establish a treatment paradigm by combining a PP2A molecular glue with a RAS/MAPK inhibitor to restore PP2A activity and counteract resistance. We demonstrated that KRASG12C and MEK1/2 inhibitors disrupted PP2A carboxymethylation and destabilized critical heterotrimeric complexes. Furthermore, genetic disruption of PP2A carboxymethylation enhanced intrinsic resistance to MEK1/2 inhibition both in vitro and in vivo. We developed RPT04402, a PP2A molecular glue that selectively stabilizes PP2A-B56α heterotrimers. In both commercial cell lines and a patient-derived model, combining RPT04402 with a RAS/MAPK inhibitor slowed proliferation and enhanced apoptosis. In mouse xenografts, this combination induced tumor regressions, extended median survival, and delayed the onset of treatment resistance. These findings highlight that promoting PP2A stabilization and RAS/MAPK inhibition presents a promising therapeutic strategy to improve treatment outcomes and overcome resistance in metastatic KRAS-mutant NSCLC.

Authors

Brynne Raines, Stephanie Tseng-Rogenski, Amanda C. Dowdican, Irene Peris, Matthew Hinderman, Kaitlin P. Zawacki, Kelsey Barrie, Gabrielle Hodges Onishi, Alexander M. Dymond, Tahra K. Luther, Sydney Musser, Behirda Karaj Majchrowski, J. Chad Brenner, Aqila Ahmed, Derek J. Taylor, Caitlin M. O'Connor, Goutham Narla

Kidney-specific claudin-2 deficiency leads to medullary nephrocalcinosis in mice

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Abstract

Deposits of hydroxyapatite called Randall's plaques are found in the renal papilla of calcium oxalate kidney stone formers and likely serve as the nidus for stone formation, but their pathogenesis is unknown. Claudin-2 is a paracellular ion channel that mediates calcium reabsorption in the renal proximal tubule. To investigate the role of renal claudin-2, we generated kidney tubule-specific claudin-2 conditional knockout mice (KS-Cldn2 KO). KS-Cldn2 KO mice exhibited transient hypercalciuria in early life. Normalization of urine calcium was accompanied by a compensatory increase in expression and function of renal tubule calcium transporters, including in the thick ascending limb. Despite normocalciuria, KS-Cldn2 KO mice developed papillary hydroxyapatite deposits, beginning at 6 months of age, that resembled Randall's plaques and tubule plugs. Bulk chemical tissue analysis and laser ablation-inductively coupled plasma mass spectrometry revealed a gradient of intrarenal calcium concentration along the corticomedullary axis in normal mice, that was accentuated in KS-Cldn2 KO mice. Our findings provide evidence for the “vas washdown” hypothesis for Randall's plaque formation, and identify the corticomedullary calcium gradient as a target for therapies to prevent kidney stone disease.

Authors

Christine V. Behm, Duuamene Nyimanu, Ony Araujo Galdino, Sadhana Kanoo, Young Chul Kim, Natalia Lopez, Helen Goodluck, Peter S. Rowe, Andrew P. Evan, André J. Sommer, Matthew N. Barr, Tracy Punshon, Volker Vallon, Brian P. Jackson, James C. Williams Jr., Alan S.L. Yu

S100a9 lactylation triggers neutrophil trafficking and cardiac inflammation in myocardial ischemia/reperfusion injury

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Abstract

Lactylation, a post-translational modification derived from glycolysis, plays a pivotal role in ischemic heart diseases. Neutrophils are predominantly glycolytic cells that trigger intensive inflammation of myocardial ischemia reperfusion (MI/R). However, whether lactylation regulates neutrophil function during MI/R remains unknown. Employing lactyl proteomics analysis, S100a9 was lactylated at lysine 26 (S100a9K26la) in neutrophils, with elevated levels observed in both acute myocardial infarction (AMI) patients and MI/R model mice. S100a9K26la was demonstrated driving the development of MI/R using mutant knock-in mice. Mechanistically, lactylated S100a9 translocated to the nucleus of neutrophils, where it binded to the promoters of migration-related genes, thereby enhancing their transcription as a co-activator and promoting neutrophil migration and cardiac recruitment. Additionally, lactylated S100a9 was released during NETosis, leading to cardiomyocyte death by disrupting mitochondrial function. The enzyme dihydrolipoyllysine-residue acetyltransferase (DLAT) was identified as the lactyltransferase facilitating neutrophil S100a9K26la post-MI/R, a process that could be restrained by α-lipoic acid. Consistently, targeting DLAT/S100a9K26la axis suppressed neutrophil burden and improved cardiac function post-MI/R. In patients with AMI, elevated S100a9K26la levels in plasma were positively correlated with cardiac death. These findings highlight S100a9 lactylation as a potential therapeutic target for MI/R and as a promising biomarker for evaluating poor prognosis of MI/R.

Authors

Xiaoqi Wang, Xiangyu Yan, Ge Mang, Yujia Chen, Shuang Liu, Jiayu Sui, Zhonghua Tong, Penghe Wang, Jingxuan Cui, Qiannan Yang, Yafei Zhang, Dongni Wang, Ping Sun, Weijun Song, Zexi Jin, Ming Shi, Peng Zhao, Jia Yang, Mingyang Liu, Naixin Wang, Tao Chen, Yong Ji, Bo Yu, Maomao Zhang