Glutamine synthetase (GS) catalyzes de novo synthesis of glutamine that facilitates cancer cell growth. In the liver, GS functions next to the urea cycle to remove ammonia waste. As dysregulated urea cycle is implicated in cancer development, the impact of GS’ ammonia clearance function has not been explored in cancer. Here we show that, oncogenic activation of beta-catenin led to decreased urea cycle and elevated ammonia waste burden. While beta-catenin induced the expression of GS, which is thought to be cancer-promoting, surprisingly, genetic ablation of hepatic GS accelerated the onset of liver tumors in several mouse models that involved β-catenin activation. Mechanistically, GS ablation exacerbated hyperammonemia and facilitated the production of glutamate-derived non-essential amino acids (NEAAs), which subsequently stimulated mTORC1. Pharmacological and genetic inhibition of mTORC1 and glutamic transaminases suppressed tumorigenesis facilitated by GS ablation. While HCC patients, especially those with CTNNB1 mutations, have an overall defective urea cycle and increased expression of GS, there exists a subset of patients with low GS expression that is associated with mTORC1 hyperactivation. Therefore, GS-mediated ammonia clearance serves as a tumor-suppressing mechanism in livers that harbor β-catenin activation mutations and a compromised urea cycle.
Weiwei Dai, Jianliang Shen, Junrong Yan, Alex J. Bott, Sara Maimouni, Heineken Q. Daguplo, Yujue Wang, Khoosheh Khayati, Jessie Yanxiang Guo, Lanjing Zhang, Yongbo Wang, Alexander Valvezan, Wen-Xing Ding, Xin Chen, Xiaoyang Su, Shenglan Gao, Wei-Xing Zong
Metabolic reprogramming is an important cancer hallmark. However, the mechanisms driving metabolic phenotypes of cancer cells are unclear. Here, we showed that the interferon (IFN)-inducible protein, viperin, drives metabolic alteration in cancer cells. Viperin was observed in various types of cancer and inversely correlated with the survival rate of patients with gastric, lung, breast, renal, pancreatic, or brain cancer. By generating viperin knockdown or stably expressing cancer cells, we showed that viperin, but not a mutant lacking its iron-sulfur cluster-binding motif, increased lipogenesis and glycolysis via inhibition of fatty acid β-oxidation in cancer cells. In the tumor microenvironment, deficiency of fatty acids and oxygen as well as production of IFNs upregulated viperin expression via the PI3K/AKT/mTOR/HIF-1α and JAK/STAT pathways. Moreover, viperin was primarily expressed in cancer stem-like cells (CSCs) and functioned to promote metabolic reprogramming and enhance CSC properties, thereby facilitating tumor growth in xenograft mouse models. Collectively, our data indicate that viperin-mediated metabolic alteration drives the metabolic phenotype and progression of cancer.
Kyung Mi Choi, Jeong Jin Kim, Jihye Yoo, Ku Sul Kim, Youngeun Gu, John Eom, Haengdueng Jeong, Kyungeun Kim, Ki Taek Nam, Young Soo Park, Joon-Yong Chung, Jun-Young Seo
Neuropathic pain is one of the most important clinical consequences of injury to the somatosensory system. Nevertheless, the critical pathophysiological mechanisms involved in neuropathic pain development are poorly understood. In this study, we found that neuropathic pain is abrogated when the kynurenine metabolic pathway initiated by the enzyme indoleamine 2,3-dioxygenase (IDO1) is ablated pharmacologically or genetically. Mechanistically, it was found that IDO1-expressing dendritic cells (DCs) accumulated in the dorsal root leptomeninges and led to an increase in kynurenine levels in the spinal cord. In the spinal cord, kynurenine was metabolized by kynurenine-3-monooxygenase-expressing astrocytes into a pro-nociceptive metabolite 3-hydroxykynurenine. Ultimately, 3-hydroxyanthranilate 3,4-dioxygenase-derived quinolinic acid formed in the final step of the canonical KYNPATH was also involved in neuropathic pain development through the activation of the glutamatergic N-methyl-D-aspartate (NMDA) receptor. In conclusion, these data revealed a novel role for DCs driving neuropathic pain development through elevation of the kynurenine metabolic pathway. This novel paradigm offers potential new targets for drug development against this type of chronic pain.
Alexandre G.M. Maganin, Guilherme R. Souza, Miriam D. Fonseca, Alexandre H. Lopes, Rafaela M. Mano Guimarães, André Dagostin, Nerry T. Cecilio, Atlante S. Mendes, William A. Gonçalves, Conceição E.A. Silva, Francisco I. Fernandes Gomes, Lucas M. Mauriz Marques, Rangel L. Silva, Letícia M. Arruda, Denis A. Santana, Henrique Lemos, Lei Huang, Marcela Davoli-Ferreira, Danielle S. Santana-Coelho, Morena B. Sant'Anna, Ricardo Kusuda, Jhimmy Talbot, Gabriela Pacholczyk, Gabriela A. Buqui, Norberto Lopes, Jose C. Alves-Filho, Ricardo M. Leão, Jason C. O'Connor, Fernando Q. Cunha, Andrew Mellor, Thiago Cunha
The SARS-CoV-2 spike protein is the main antigen in all approved COVID-19 vaccines and is also the only target for monoclonal antibody therapies. Immune responses to other viral antigens are generated after SARS-CoV-2 infection, but their contribution to the antiviral response remains unclear. Here, we interrogate whether nucleocapsid-specific antibodies can improve protection against SARSCoV-2. We first immunized mice with a nucleocapsid-based vaccine, and then transferred sera from these mice into naïve mice, followed by challenge with SARS-CoV-2. We show that mice that received nucleocapsid-specific sera or a nucleocapsid-specific monoclonal antibody (mAb) exhibited enhanced control of SARS-CoV-2. Nucleocapsid-specific antibodies elicited NK-mediated antibodydependent cellular cytotoxicity (ADCC) against infected cells. These findings provide the first demonstration in the coronavirus literature that antibody responses specific to the nucleocapsid protein can improve viral clearance, providing a rationale for the clinical evaluation of nucleocapsid-based monoclonal antibody therapies to treat COVID-19.
Tanushree Dangi, Sarah Sanchez, Jacob Class, Michelle C. Richner, Lavanya Visvabharathy, Young Rock Chung, Kirsten Bentley, Richard J. Stanton, Igor J. Koralnik, Justin M. Richner, Pablo Penaloza-MacMaster
Prevalent copy number alteration (CNA) is the most prominent genetic characteristic associated with ovarian cancer (OV) development, but its role in immune evasion has not been fully elucidated. In this study, we identified RAD21, a key component of the cohesin complex, as a frequently amplified oncogene that could modulate immnue response in OV. Through interrogating RAD21-regulated transcriptional program we found that RAD21 directly interacts with YAP/TEAD4 transcriptional co-repressors and recruits NuRD complex to suppress interferon (IFN) signaling. In multiple clinical cohorts, RAD21 overexpression is inversely correlated with IFN signature gene expression in OV. We further demonstrated in murine syngeneic tumor models that RAD21 ablation potentiated anti-PD-1 efficacy with increased intratumoral CD8+ T-cell effector activity. Our study identified a previously unrecognized RAD21-YAP/TEAD4-NuRD co-repressor complex in immune modulation, and thus provided a potential target and biomarker for precision immunotherapy in OV.
Peng Deng, Zining Wang, Jinghong Chen, Shini Liu, Xiaosai Yao, Shaoyan Liu, Lizhen Liu, Zhaoliang Yu, Yulin Huang, Zhongtang Xiong, Rong Xiao, Jiuping Gao, Weiting Liang, Jieping Chen, Hui Liu, Jing Han Hong, Jason Yongsheng Chan, Peiyong Guan, Jianfeng Chen, Yali Wang, Jiaxin Yin, Jundong Li, Min Zheng, Chao Zhang, Penghui Zhou, Tiebang Kang, Bin Tean Teh, Qiang Yu, Zhixiang Zuo, Qingping Jiang, Jihong Liu, Ying Xiong, Xiaojun Xia, Jing Tan
The various functions of the skeleton are influenced by extracellular cues, hormones and neurotransmitters. One type of neuronal regulation favors bone mass accrual by inhibiting sympathetic nervous system activity. This observation raises questions about the transcriptional mechanisms regulating catecholamine synthesis. Using a combination of genetic and pharmacological studies we have found that the histone deacetylase SIRT1 is a transcriptional modulator of the neuronal control of bone mass. Neuronal SIRT1 reduced bone mass by increasing SNS signaling. SIRT1 did so by increasing expression of monoamine oxidase A (MAO-A), a SIRT1 target that reduces brain serotonin levels by inducing its catabolism, and by suppressing Tph2 expression and serotonin synthesis in the brainstem. SIRT1 upregulated brain catecholamine synthesis indirectly through serotonin but did not directly affect Dbh expression in the locus coeruleus. These results help understand skeletal changes associated with SSRIs and may have implications for treating skeletal and metabolic diseases.
Na Luo, Ioanna Mosialou, Mattia Capulli, Brygida Bisikirska, Chyuan-Sheng Lin, Yung-yu Huang, Peter Timothy Shyu, X. Edward Guo, Aris Economides, J. John Mann, Stavroula Kousteni
Platelets and megakaryocytes are critical players in immune responses. Recent reports suggest infection and inflammation alter the megakaryocyte and platelet transcriptome to induce altered platelet reactivity. We examined if non-viral sepsis induces differential platelet gene expression and reactivity. Non-viral sepsis upregulated IFITM3, an interferon responsive gene that restricts viral replication. As IFITM3 has been linked to clathrin-mediated endocytosis, we examined if IFITM3 promoted endocytosis of alpha granule proteins. Interferon stimulation enhanced fibrinogen endocytosis in megakaryocytes and platelets from Ifitm+/+ mice, but not Ifitm-/- mice. IFITM3 overexpression or deletion in megakaryocytes demonstrated IFITM3 was necessary and sufficient to regulate fibrinogen endocytosis. Mechanistically, IFITM3 interacts with clathrin and αIIb and altered their plasma membrane localization into lipid rafts. In vivo interferon administration increased fibrinogen endocytosis, platelet reactivity, and thrombosis in an IFITM-dependent manner. In contrast, Ifitm-/- mice were completely rescued from interferon-induced platelet hyperreactivity and thrombosis. During murine sepsis, platelets from Ifitm+/+ mice demonstrated increased fibrinogen content and platelet reactivity, which was dependent on interferon-alpha and IFITMs. Platelets from patients with non-viral sepsis had increases in platelet IFITM3 expression, fibrinogen content, and hyperreactivity. These data identify IFITM3 as a regulator of platelet endocytosis, hyperreactivity, and thrombosis during inflammatory stress.
Robert A. Campbell, Bhanu Kanth Manne, Meenakshi Banerjee, Elizabeth A. Middleton, Abigail Ajanel, Hansjorg Schwertz, Frederik Denorme, Chris Stubben, Emilie Montenont, Samantha Saperstein, Lauren Page, Neal D. Tolley, Diana L. Lim, Samuel M. Brown, Colin K. Grissom, Douglas W. Sborov, Anandi Krishnan, Matthew T. Rondina
People with kidney disease are disproportionately affected by atherosclerosis for unclear reasons. Soluble urokinase plasminogen activator receptor (suPAR) is an immune-derived mediator of kidney disease, levels of which are strongly associated with cardiovascular outcomes. We assessed suPAR’s pathogenic involvement in atherosclerosis using epidemiologic, genetic, and experimental approaches. We found serum suPAR levels to be predictive of coronary artery calcification and cardiovascular events in 5,406 participants without known coronary disease. In a genome-wide association meta-analysis including over 25,000 individuals, we identified a missense variant in the PLAUR gene (rs4760) confirmed experimentally to lead to higher suPAR levels. Mendelian randomization analysis in the UK Biobank using rs4760 indicated a causal association between genetically predicted suPAR levels and atherosclerotic phenotypes. In an experimental model of atherosclerosis, Pcsk9 transfection in mice over-expressing suPAR (suPARTg) led to substantially increased atherosclerotic plaques with necrotic cores and macrophage infiltration compared to wild-type mice, despite similar cholesterol levels. Pre-atherosclerosis, aortas of suPARTg mice excreted higher levels of CCL2 and had higher monocyte counts compared to wild-type aortas. Aortic and circulating suPARTg monocytes exhibited a pro-inflammatory profile and enhanced chemotaxis. These findings characterize suPAR as a pathogenic factor for atherosclerosis acting at least partially through modulation of monocyte function.
George Hindy, Daniel J. Tyrrell, Alexi Vasbinder, Changli Wei, Feriel Presswalla, Hui Wang, Pennelope K. Blakely, Ayse Bilge Ozel, Sarah E. Graham, Grace H. Holton, Joseph Dowsett, Akl C. Fahed, Kingsley-Michael Amadi, Grace K. Erne, Annika Tekumulla, Anis Ismail, Christopher Launius, Nona Sotoodehnia, James S. Pankow, Lise Wegner Thørner, Christian Erikstrup, Ole Birger Pedersen, Karina Banasik, Søren Brunak, Henrik Ullum, Jesper Eugen-Olsen, Sisse Rye Ostrowski, Mary E. Haas, Jonas B. Nielsen, Luca A. Lotta, Gunnar Engström, Olle Melander, Marju Orho-Melander, Lili Zhao, Venkatesh L. Murthy, David J. Pinsky, Cristen J. Willer, Susan R. Heckbert, Jochen Reiser, Daniel R. Goldstein, Karl C. Desch, Salim S. Hayek
Testosterone is the canonical growth factor of prostate cancer but can paradoxically suppress its growth when present at supraphysiological levels. We have previously demonstrated that the cyclical administration of supraphysiological androgen (SPA), termed Bipolar Androgen Therapy (BAT), can result in tumor regression and clinical benefit for patients with castration-resistant prostate cancer. However, predictors and mechanisms of response and resistance have been ill-defined. Here we show that growth inhibition of prostate cancer models by SPA required high androgen receptor (AR) activity and was driven in part by downregulation of MYC. Using matched sequential patient biopsies, we show that high pre-treatment AR activity predicted downregulation of MYC, clinical response, and prolonged progression-free and overall survival for patients on BAT. BAT induced strong downregulation of AR in all patients, which is shown to be a primary mechanism of acquired resistance to SPA. Acquired resistance could be overcome by alternating SPA with the AR inhibitor enzalutamide, which induced adaptive upregulation of AR and re-sensitized prostate cancer to SPA. This work identifies high AR activity as a predictive biomarker of response to BAT and supports a treatment paradigm for prostate cancer involving alternating between AR inhibition and activation.
Laura A. Sena, Rajendra Kumar, David E. Sanin, Elizabeth A. Thompson, D. Marc Rosen, Susan L. Dalrymple, Lizamma Antony, Yuhan Yang, Carolina Gomes-Alexandre, Jessica L. Hicks, Tracy Jones, Kiara A. Bowers, Jillian N. Eskra, Jennifer Meyers, Anuj Gupta, Alyza Skaist, Srinivasan Yegnasubramanian, Jun Luo, W. Nathaniel Brennen, Sushant K. Kachhap, Emmanuel S. Antonarakis, Angelo M. De Marzo, John T. Isaacs, Mark C. Markowski, Samuel R. Denmeade
During cutaneous tick attachment, the feeding cavity becomes a site of transmission for tick salivary compounds and tick-borne pathogens. However, the immunological consequences of tick feeding on human skin remain unclear. Here, we assessed human skin and blood samples upon tick bite and developed a human skin explant model mimicking Ixodes ricinus bite and tick-borne pathogen infection. Following tick attachment, we observed rapidly occurring patterns of immunomodulation including increase in neutrophils and cutaneous B and T cells. T cells up-regulated tissue-residency markers, while lymphocytic cytokine production was impaired. In early stages of Borrelia burgdorferi model infections, we detected strain-specific immune responses and close spatial relationships of macrophages and spirochetes. Pre-incubation of spirochetes with tick salivary gland extracts hampered accumulation of immune cells and increased spirochete loads. Collectively, we showed that tick feeding exerts profound changes on the skin immune network, which interfere with the primary response against tick-borne pathogens.
Johanna Strobl, Verena Muendler, Sophie Müller, Anna Gindl, Sara Berent, Anna-Margarita Schötta, Lisa Kleissl, Clement Staud, Anna Redl, Luisa Unterluggauer, Ana Elena Aguilar González, Sophie Therese Weninger, Denise Atzmüller, Romana Klasinc, Gerold Stanek, Mateusz Markowicz, Hannes Stockinger, Georg Stary
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