Abstract
Pancreatic cancer is a highly innervated gastrointestinal disease in which sympathetic nerves play a critical role in modulating tumor growth and the tumor microenvironment (TME). While recent studies suggest that sympathetic nerves influence various TME components, including lymphoid and myeloid immune cells, their interactions with cancer-associated fibroblasts (CAFs) remain poorly understood. CAFs are a hallmark of pancreatic tumors and are known to upregulate axon guidance and neuroactive cues, suggesting a potential feedback loop with tumor-innervating nerves. Here, we investigated the bidirectional crosstalk between sympathetic nerves and CAFs in human and mouse pancreatic tumors. Using a chemo-genetic ablation model, we selectively eliminated pancreatic sympathetic nerves and found that denervation significantly reduced tumor size in female mice. To further dissect this interaction, we established coculture systems with immortalized pancreatic fibroblasts and primary sympathetic neuron explants, identifying key transcriptional changes driven by CAF–sympathetic nerve signaling. Our findings demonstrated that sympathetic signaling enhanced CAF activation and extracellular matrix remodeling, while activated CAFs, in turn, induced transcriptional programs in sympathetic neurons associated with nerve injury response. These results establish CAFs as central mediators of the tumor-supportive role of sympathetic nerves, offering further insights into the neural regulation of pancreatic cancer progression.
Authors
Ariana L. Sattler, Parham Diba, Kevin Hawthorne, Carl Pelz, Joe Grieco, Tetiana Korzun, Bryan Chong, M.J. Kuykendall, Rosalie C. Sears, Daniel L. Marks, Mara H. Sherman, Teresa A. Zimmers, S. Ece Eksi
Abstract
Systemic sclerosis (SSc) is a complex and heterogeneous condition characterized by progressive fibrosis in multiple organs. Recent studies implicate plasminogen activator inhibitor-1 (PAI-1) in the pathogenesis of SSc, and PAI-1 is considered as a potential target for therapy. Here, using single-cell and spatial RNA-seq analysis of skin biopsies from 18 healthy individuals and 22 SSc patients, we found elevated PAI-1 colocalizing to myofibroblasts with enriched extracellular matrix–associated biological processes. Treatment of SSc dermal fibroblasts with the small-molecule PAI-1 inhibitor MDI-2517 reduced the expression of the profibrotic markers COL1A1 and ACTA2. To investigate the therapeutic potential of MDI-2517, we evaluated its efficacy in reducing fibrosis in a preclinical model of SSc. Treatment of mice with MDI-2517 significantly reduced both skin and lung fibrosis and was superior to treatment with either pirfenidone or mycophenolate mofetil. Additionally, MDI-2517 attenuated weight loss and significantly reduced the expression of key profibrotic markers. Compared with tiplaxtinin, another PAI-1 inhibitor previously shown to be effective in a model of SSc, MDI-2517 was found to have superior efficacy at a 10-fold lower dose. These findings highlight the role of PAI-1 in the pathogenesis of SSc, and the potential of MDI-2517 for the treatment of SSc.
Authors
Enming J. Su, Pei-Suen Tsou, Mark Warnock, Natalya Subbotina, Kris Mann, Sirapa Vichaikul, Alyssa Rosek, Lisa Leung, Xianying Xing, Enze Xing, Olesya Plazyo, Rachael Bogle, Lam C. Tsoi, Cory D. Emal, Dinesh Khanna, John Varga, Thomas H. Sisson, Johann E. Gudjonsson, Daniel A. Lawrence
Abstract
Alveolar macrophages (AMs) catabolize lipid-rich pulmonary surfactant to support gas exchange and have antiinflammatory programming to limit tissue damage in response to minor challenges. GATA transcription factors (TFs) shape immune cell fates, and GATA2 is expressed in a lung-specific manner in macrophages. GATA2 mutations and lung macrophage downregulation of GATA2 have been associated with chronic pulmonary pathologies in humans, but the role of GATA2 in coordinating AM function is not well defined. Using mice with myeloid-specific deletion of the GATA2 DNA binding C-terminal zinc finger domain, we show that GATA2 deficiency promotes enhanced inflammatory gene expression and metabolic dysfunction in AMs in response to type 2 stimuli. Although homeostatic functions of AMs remain largely intact, GATA2 deficiency increases expression of type 2 response genes during IL-33–induced inflammation. Coincident with GATA2-dependent expression of genes in metabolic pathways, Seahorse metabolic flux analysis indicates that AM metabolism is compromised in the absence of GATA2. AM GATA2-dependent gene networks are enriched for targets of TFs previously demonstrated to interact with GATA2 in other cellular contexts, including PU.1, PPARγ, and other regulators of AM function. Our data suggest that GATA2 modulates AM metabolic and transcriptomic programming to restrain responses and maintain AM identity during inflammation.
Authors
Morgan Jackson-Strong, Satarupa Ganguly, Aaron Francis, Flavia Rago, Jitendra Kanshana, Brandon A. Michalides, Lihong Teng, Omkar S. Betsur, Sonia Kruszelnicki, Karsen E. Shoger, Aaron Kim, Kay Bajpai, Amina Suleyman, Abigail Sekyere, Mika Hara, Varsha Sriram, Alok Kumar, Greg M. Delgoffe, Niranjana Natarajan, John F. Alcorn, Alison B. Kohan, Rachel A. Gottschalk
Abstract
Angiopoietin-2 (ANGPT2) is known to destabilize vascular barriers in most peripheral organs; however, its role in the brain vasculature remains poorly understood. To investigate its physiological function within the brain vasculature, we analyzed constitutive Angpt2-knockout mice in adulthood. We showed that loss of ANGPT2 leads to region-specific vascular malformations and blood-brain barrier (BBB) dysfunction, resulting in differential permeability to 1 kDa and 70 kDa fluorescent tracers. Notably, overt vascular malformations appeared only in select brain regions that allowed leakage of both tracers. These malformations were characterized by dilated, intertwined, and sprouting endothelial cells, surrounded by reactive perivascular cells, along with high levels of astrocyte- and neuron-derived vascular endothelial growth factor A (VEGFA) and elevated expression of the vascular receptors VEGF receptor 2 (KDR) and neuropilin-1 (NRP1). Other cortical areas without obvious malformations exhibited significant leakage of the 1 kDa tracer. We also demonstrated that different cell types took up the tracers after passing the BBB. Our findings identified ANGPT2 as an important factor involved in the regulation of cerebrovascular architecture, barrier integrity, and endothelial-parenchymal interactions, and uncovered surprising differences in the leakage patterns and cellular uptake of two widely used BBB tracers.
Authors
Weihan Li, Elisa Vázquez-Liébanas, Chanaëlle Fébrissy, Florent Sauvé, Jianhao Wang, Doğan E. Sayıner, Pia Buslaps, Amanda Norrén, Michael Vanlandewijck, Liqun He, Marie Jeansson, Lars Muhl, Maarja Andaloussi Mäe
Abstract
Heart failure (HF) persists as the primary cause of death among patients recovering from acute myocardial infarction (AMI). Protein ubiquitination has been implicated as a key modulator of HF pathogenesis, yet the role of ubiquitination in the Aldh2 rs671 mutant — the most common single-nucleotide variant in human populations — remains poorly understood. We discovered TRIM21 as a previously unrecognized E3 ubiquitin ligase for the ALDH2 rs671 mutant and elucidated its mechanistic involvement in HF progression. Using Aldh2 BM chimeric mice to model AMI, we observed that WT mice transplanted with Aldh2 rs671 donor BM developed severe myocardial fibrosis and markedly reduced cardiac systolic function 2 weeks after infarction compared with controls. This phenotype arose from defective macrophage efferocytosis caused by myeloid-specific Aldh2 rs671 mutation. Through high-resolution mass spectrometry proteomics, we identified TRIM21 as the E3 ligase targeting ALDH2. TRIM21 catalyzed K48-linked ubiquitination at ALDH2 lysine 73. Macrophage-specific Trim21 knockdown via AAV-shTrim21 reversed both the exacerbated cardiac fibrosis and systolic dysfunction by restoring macrophage efferocytosis. These findings delineate the upstream E3 ubiquitin ligase and the ubiquitination site of ALDH2, revealing a potential therapeutic target for HF.
Authors
Tianrui Han, Xin Wen, Yunyun Guo, Xiangkai Zhao, Jian Zhang, Yuguo Chen, Feng Xu
Abstract
Proper development of the umbilical cord and placental vasculature is essential for embryonic development. While the allantois is known give rise to endothelial cells (ECs) within the placenta, whether the allantois gives rise to ECs in the umbilical cord is debated. Furthermore, a lack of genetic tools to study placental vascular development independent of the embryo proper has hindered robust investigation into the primary cause of vascular defects from early studies utilizing global KOs. In this study, we delineate the contribution of the allantois to the umbilical vessels and utilize a mouse genetic tool previously developed by our lab to revisit the role of Notch signaling during placental development. We show that the allantois has mosaic contribution to the umbilical endothelium with higher contributions closer to the placenta. Allantoic deletion of Dll4 disrupts umbilical cord and placental vascular formation with secondary defects in the heart. Lastly, we identify Unc5b downstream of Notch signaling that restricts EC migration while promoting chemokine signaling for vascular smooth muscle cell (vSMC) recruitment to arteries. These findings identify a genetic tool for investigating placental vascular development and give insights into the ontogeny and mechanisms of placental vascular and umbilical cord development.
Authors
Derek C. Sung, Hana A. Ahanger, Sweta Narayan, Jesse A. Pace, Mei Chen, Jisheng Yang, Siqi Gao, T.C.S. Keller IV, Jenna Bockman, Xiaowen Chen, Erica Nguyen, Alan T. Tang, Patricia Mericko-Ishizuka, Ivan Maillard, Mark L. Kahn
Abstract
The biological mechanisms underlying long COVID in the pediatric population are poorly understood. Our study aimed to characterize the immune pathophysiology of long COVID in this population. We analyzed major immune cell compartments in PBMCs and the specific SARS-CoV-2 antibody response in 99 patients with long COVID and in 18 patients without long COVID at 3 months after acute infection. Our findings indicate that pediatric long COVID is associated with a dysregulated immune response characterized by altered innate immunity and overactivated T, B, and NK cell responses. Furthermore, young people with long COVID had an impaired humoral response to SARS-CoV-2 marked by a dysregulated B cell compartment and lower levels of anti-RBD IgG and IgA. This correlated with reduced neutralizing capacity against SARS-CoV-2. Random forest analysis identified CCR6 expression on myeloid cells as the most relevant biomarker that distinguishes individuals with long COVID from control individuals with 79% accuracy.
Authors
Jon Izquierdo-Pujol, Núria Pedreño-López, Tetyana Pidkova, Maria Nevot, Victor Urrea, Fernando Laguía, Francisco Muñoz-López, Judith Dalmau, Alba Gonzalez-Aumatell, Clara Carreras-Abad, Maria Mendez, Carlos Rodrigo, Marta Massanella, Julià Blanco, Jorge Carrillo, Benjamin Trinité, Javier Martinez-Picado, Sara Morón-López
Abstract
The contribution of 9p deletion to B cell acute lymphoblastic leukemia (B-ALL) has remained elusive since its discovery more than 40 years ago. Here we show that loss of CD72 is recurrent in B-ALL cases containing PAX5 deletions, and that Cd72 haploinsufficiency drives B-ALL development in Pax5+/– mice. Mechanistically, Cd72+/–;Pax5+/– precursor B cells exhibited an inflammatory transcriptional profile characterized by a decrease in Myd88 expression, a finding that aligns with our previous studies of B-ALL development in Pax5+/– mice following exposure to immune stressors. These combined genomic analyses and functional models provide compelling evidence that co-deletion of 2 contiguous genes, Pax5 and Cd72, drives B cell leukemogenesis.
Authors
Belén Ruiz-Corzo, Ana Casado-García, Ninad Oak, Paula Somoza-Cotillas, Andrea López-Álvarez de Neyra, Jorge Martínez-Cano, Alba Pérez-Pons, Elena G. Sánchez, Oscar Blanco, Diego Alonso-López, Javier De Las Rivas, Susana Riesco, Pablo Prieto-Matos, Francisco Javier García Criado, María Begoña García Cenador, Alberto Orfao, Manuel Ramírez-Orellana, César Cobaleda, Carolina Vicente-Dueñas, Kim E. Nichols, Isidro Sánchez-García
Abstract
Fanconi anemia (FA) is the most common BM failure (BMF) syndrome. FA genes have a role in suppressing DNA-RNA hybrids, termed R-loops, which can be generated via transcription mediated by RNA polymerase (RNAP). How these processes, including a role in fate determination of hematopoietic stem cells (HSCs), are related to BMF is largely unknown. Single FA gene KO in mice does not recapitulate most phenotypes observed in patients with FA. Thus, we generated a mouse model for FA by introducing heterozygous Setd2, which restricts RNAP-dependent transcription. We showed that FA patient–derived cells and Setd2+/– Fanca–/– HSCs share increased R-loop and dsRNA levels and a ribosomal biogenesis defect. Further, Setd2+/– Fanca–/– HSCs displayed cell cycle arrest, mitotic errors, and BMF phenotypes. Importantly, utilizing our Setd2+/– Fanca–/– mice, we discovered that Juglone, a pan-RNAP inhibitor, reduces R-loop and dsRNA and reverses ribosomal biogenesis defects and mitotic errors, thereby rescuing BMF. This study establishes a mouse model that underscores a key role for R-loop formation, ribosomal biogenesis defects, and mitotic errors in HSCs in driving BMF in FA. We also introduce a potential therapeutic avenue based upon pan-inhibition of RNAPs utilizing Juglone.
Authors
Michihiro Hashimoto, Xiaomin Feng, Jie Bai, Huimin Zeng, Tian Li, Jue Li, Terumasa Umemoto, Paul R. Andreassen, Gang Huang
Abstract
Aberrant polymorphonuclear neutrophil (PMN) accumulation in tissues induces chronic vascular diseases. Endothelial cells (ECs) regulate the access of PMNs into the tissue from the blood. However, the mechanisms that prevent PMNs from being activated and accumulating in the tissue, a hallmark of acute lung injury (ALI), remain elusive. We demonstrate that conditional deletion of Erg in ECs spontaneously alters the PMN transcriptome, which is enriched with genes that induce PMN recruitment, adhesion, activation, and “do not eat me” signals due to impaired synthesis of the deubiquitinase A20. Decreased A20 levels, in turn, activated the transcription factor NF-κB and the secretion of MIP2α (human homolog of IL-8) in ECs. EC-secreted MIP2α/IL-8 engaged the CXCR2 cascade on PMNs, leading to their activation and inflammatory injury. These findings were recapitulated in the lungs and blood of PMNs from patients dying of ALI. Overexpression of the A20 gene in ECs or pharmacological inhibition of CXCR2 on PMNs in iEC-Erg–/– mice rescued EC control of PMNs and tissue homeostasis, and enhanced mouse survival after pneumonia. Thus, the EC/Erg/A20 axis regulates PMN accumulation and hyperactivation in the lungs by inhibiting EC-mediated IL-8 activation of PMN CXCR2, thereby providing a potential target for neutrophilic inflammatory vascular diseases.
Authors
Vigneshwaran Vellingiri, Vijay Avin Balaji Ragunathrao, Jagdish Chandra Joshi, Md Zahid Akhter, Mumtaz Anwar, Somenath Banerjee, Sayanti Datta, Viktor Pinneker, Steven Dudek, Yoshikazu Tsukasaki, Sandra Pinho, Dolly Mehta
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