GPR84-mediated signal transduction affects metabolic function by promoting brown adipocyte activity
The G protein–coupled receptor 84 (GPR84), a medium-chain fatty acid receptor, has garnered attention because of its potential involvement in a range of metabolic conditions. However, the precise mechanisms underlying this effect remain elusive. Our study has shed light on the pivotal role of GPR84, revealing its robust expression and functional significance within brown adipose tissue (BAT). Mice lacking GPR84 exhibited increased lipid accumulation in BAT, rendering them more susceptible to cold exposure and displaying reduced BAT activity compared with their WT counterparts. Our in vitro experiments with primary brown ...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Xue-Nan Sun, Yu A. An, Vivian A. Paschoal, Camila O. de Souza, May-yun Wang, Lavanya Vishvanath, Lorena M.A. Bueno, Ayanna S. Cobb, Joseph A. Nieto Carrion, Madison E. Ibe, Chao Li, Harrison A. Kidd, Shiuhwei Chen, Wenhong Li, Rana K. Gupta, Da Young Oh Source Type: research
A friend in a forest of radiation-immune interactions: BAMBI improves antitumor effects by limiting radioresistance
Radiation therapy (RT) remains one of the most effective and utilized oncologic treatments available. While it can directly yield tumor cell death, its impact on the immune microenvironment is more complex, promoting either an antitumor response or, conversely, a tumor-promoting state. TGF-β, induced by RT, yields a more immunosuppressive environment, including potentially blunting response to immune-checkpoint blockade. In this issue of the JCI, Wang and colleagues demonstrate that RT reduced expression of bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), a TGF-β pseudoreceptor. Limiting this effe...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Sean Sachdev Source Type: research
Epitranscriptional regulation of TGF-β pseudoreceptor BAMBI by m6A/YTHDF2 drives extrinsic radioresistance
Activation of TGF-β signaling serves as an extrinsic resistance mechanism that limits the potential for radiotherapy. Bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) antagonizes TGF-β signaling and is implicated in cancer progression. However, the molecular mechanisms of BAMBI regulation in immune cells and its impact on antitumor immunity after radiation have not been established. Here, we show that ionizing radiation (IR) specifically reduces BAMBI expression in immunosuppressive myeloid-derived suppressor cells (MDSCs) in both murine models and humans. Mechanistically, YTH N6-methyladenosine RN...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Liangliang Wang, Wei Si, Xianbin Yu, Andras Piffko, Xiaoyang Dou, Xingchen Ding, Jason Bugno, Kaiting Yang, Chuangyu Wen, Linda Zhang, Dapeng Chen, Xiaona Huang, Jiaai Wang, Ainhoa Arina, Sean Pitroda, Steven J. Chmura, Chuan He, Hua Laura Liang, Ralph We Source Type: research
Endothelial lipid droplets suppress eNOS to link high fat consumption to blood pressure elevation
Metabolic syndrome, today affecting more than 20% of the US population, is a group of 5 conditions that often coexist and that strongly predispose to cardiovascular disease. How these conditions are linked mechanistically remains unclear, especially two of these: obesity and elevated blood pressure. Here, we show that high fat consumption in mice leads to the accumulation of lipid droplets in endothelial cells throughout the organism and that lipid droplet accumulation in endothelium suppresses endothelial nitric oxide synthase (eNOS), reduces NO production, elevates blood pressure, and accelerates atherosclerosis. Mechani...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Boa Kim, Wencao Zhao, Soon Y. Tang, Michael G. Levin, Ayon Ibrahim, Yifan Yang, Emilia Roberts, Ling Lai, Jian Li, Richard K. Assoian, Garret A. FitzGerald, Zoltan Arany Source Type: research
ADORA2A-driven proline synthesis triggers epigenetic reprogramming in neuroendocrine prostate and lung cancers
Cell lineage plasticity is one of the major causes for the failure of targeted therapies in various cancers. However, the driver and actionable drug targets in promoting cancer cell lineage plasticity are scarcely identified. Here, we found that a G protein-coupled receptor, ADORA2A, is specifically upregulated during neuroendocrine differentiation, a common form of lineage plasticity in prostate cancer and lung cancer following targeted therapies. Activation of the ADORA2A signaling rewires the proline metabolism via an ERK/MYC/PYCR cascade. Increased proline synthesis promotes deacetylases SIRT6/7-mediated deacetylation ...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Na Jing, Kai Zhang, Xinyu Chen, Kaiyuan Liu, Jinming Wang, Lingling Xiao, Wentian Zhang, Pengfei Ma, Penghui Xu, Chaping Cheng, Deng Wang, Huifang Zhao, Yuman He, Zhongzhong Ji, Zhixiang Xin, Yujiao Sun, Yingchao Zhang, Wei Bao, Yiming Gong, Liancheng Fan Source Type: research
A brain-tumor neural circuit controls breast cancer progression in mice
Tumor burden, considered a common chronic stressor, can cause widespread anxiety. Evidence suggests that cancer-induced anxiety can promote tumor progression, but the underlying neural mechanism remains unclear. Here, we used neuroscience and cancer tools to investigate how the brain contributes to tumor progression via nerve-tumor crosstalk in a mouse model of breast cancer. We show that tumor-bearing mice exhibited significant anxiety-like behaviors and that corticotropin-releasing hormone (CRH) neurons in the central medial amygdala (CeM) were activated. Moreover, we detected newly formed sympathetic nerves in tumors, w...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Si-Yi Xiong, Hui-Zhong Wen, Li-Meng Dai, Yun-Xiao Lou, Zhao-Qun Wang, Yi-Lun Yi, Xiao-Jing Yan, Ya-Ran Wu, Wei Sun, Peng-Hui Chen, Si-Zhe Yang, Xiao-Wei Qi, Yi Zhang, Guang-Yan Wu Source Type: research
Rational design of a SOCS1-edited tumor-infiltrating lymphocyte therapy using CRISPR/Cas9 screens
Cell therapies such as tumor-infiltrating lymphocyte (TIL) therapy have shown promise in the treatment of patients with refractory solid tumors, with improvement in response rates and durability of responses nevertheless sought. To identify targets capable of enhancing the antitumor activity of T cell therapies, large-scale in vitro and in vivo clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 screens were performed, with the SOCS1 gene identified as a top T cell–enhancing target. In murine CD8+ T cell–therapy models, SOCS1 served as a critical checkpoint in restraining the accumulation of central...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Michael R. Schlabach, Sharon Lin, Zachary R. Collester, Christopher Wrocklage, Sol Shenker, Conor Calnan, Tianlei Xu, Hugh S. Gannon, Leila J. Williams, Frank Thompson, Paul R. Dunbar, Robert A. LaMothe, Tracy E. Garrett, Nicholas Colletti, Anja F. Hohman Source Type: research
Host immunity contributes to the anti-melanoma activity of BRAF inhibitors
(Source: Journal of Clinical Investigation)
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Deborah A. Knight, Shin Foong Ngiow, Ming Li, Tiffany Parmenter, Stephen Mok, Ashley Cass, Nicole M. Haynes, Kathryn Kinross, Hideo Yagita, Richard C. Koya, Thomas G. Graeber, Antoni Ribas, Grant A. McArthur, Mark J. Smyth Source Type: research
Impaired T cell IRE1α/XBP1 signaling directs inflammation in experimental heart failure with preserved ejection fraction
Heart failure with preserved ejection fraction (HFpEF) is a widespread syndrome with limited therapeutic options and poorly understood immune pathophysiology. Using a 2-hit preclinical model of cardiometabolic HFpEF that induces obesity and hypertension, we found that cardiac T cell infiltration and lymphoid expansion occurred concomitantly with cardiac pathology and that diastolic dysfunction, cardiomyocyte hypertrophy, and cardiac phospholamban phosphorylation were T cell dependent. Heart-infiltrating T cells were not restricted to cardiac antigens and were uniquely characterized by impaired activation of the inositol-re...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Sasha Smolgovsky, Abraham L. Bayer, Kuljeet Kaur, Erin Sanders, Mark Aronovitz, Mallory E. Filipp, Edward B. Thorp, Gabriele G. Schiattarella, Joseph A. Hill, Robert M. Blanton, Juan R. Cubillos-Ruiz, Pilar Alcaide Source Type: research
Foxp3-mediated blockage of ryanodine receptor 2 underlies contact-based suppression by regulatory T cells
The suppression mechanism of Tregs remains an intensely investigated topic. As our focus has shifted toward a model centered on indirect inhibition of DCs, a universally applicable effector mechanism controlled by the transcription factor forkhead box P3 (Foxp3) expression has not been found. Here, we report that Foxp3 blocked the transcription of ER Ca2+-release channel ryanodine receptor 2 (RyR2). Reduced RyR2 shut down basal Ca2+ oscillation in Tregs, which reduced m-calpain activities that are needed for T cells to disengage from DCs, suggesting a persistent blockage of DC antigen presentation. RyR2 deficiency rendered...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Xiaobo Wang, Shuang Geng, Junchen Meng, Ning Kang, Xinyi Liu, Yanni Xu, Huiyun Lyu, Ying Xu, Xun Xu, Xinrong Song, Bin Zhang, Xin Wang, Nuerdida Nuerbulati, Ze Zhang, Di Zhai, Xin Mao, Ruya Sun, Xiaoting Wang, Ruiwu Wang, Jie Guo, S.R. Wayne Chen, Xuyu Zh Source Type: research
Activation of mTOR signaling in adult lung microvascular progenitor cells accelerates lung aging
Reactivation and dysregulation of the mTOR signaling pathway are a hallmark of aging and chronic lung disease; however, the impact on microvascular progenitor cells (MVPCs), capillary angiostasis, and tissue homeostasis is unknown. While the existence of an adult lung vascular progenitor has long been hypothesized, these studies show that Abcg2 enriches for a population of angiogenic tissue-resident MVPCs present in both adult mouse and human lungs using functional, lineage, and transcriptomic analyses. These studies link human and mouse MVPC-specific mTORC1 activation to decreased stemness, angiogenic potential, and disru...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Emma C. Mason, Swapna Menon, Benjamin R. Schneider, Christa F. Gaskill, Maggie M. Dawson, Camille M. Moore, Laura Craig Armstrong, Okyong Cho, Bradley W. Richmond, Jonathan A. Kropski, James D. West, Patrick Geraghty, Brigitte N. Gomperts, Kevin C. Ess, F Source Type: research
Germline and conditional ghrelin knockout increases islet size
Conflicting studies in recent years report that genetic or pharmacological increases or decreases in ghrelin either increase or have no effect on islet size. In this issue of the JCI, Gupta, Burstein, and colleagues applied a rigorous approach to determine the effects of reducing ghrelin on islet size in germline and conditional ghrelin-knockout mice as well as across varying ages and weight. Both germline and conditional ghrelin-knockout mice associated with increased islet size, which was further exacerbated by older age and diet-induced obesity. These findings suggest that modulation of ghrelin may open a therapeutic wi...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Sean M. Tatum, William L. Holland Source Type: research
Ghrelin deletion and conditional ghrelin cell ablation increase pancreatic islet size in mice
Ghrelin exerts key effects on islet hormone secretion to regulate blood glucose levels. Here, we sought to determine whether ghrelin’s effects on islets extend to the alteration of islet size and β cell mass. We demonstrate that reducing ghrelin — by ghrelin gene knockout (GKO), conditional ghrelin cell ablation, or high-fat diet (HFD) feeding — was associated with increased mean islet size (up to 62%), percentage of large islets (up to 854%), and β cell cross-sectional area (up to 51%). In GKO mice, these effects were more apparent in 10- to 12-week-old mice than in 4-week-old mice. Higher β cell numbers from dec...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Deepali Gupta, Avi W. Burstein, Dana C. Schwalbe, Kripa Shankar, Salil Varshney, Omprakash Singh, Subhojit Paul, Sean B. Ogden, Sherri Osborne-Lawrence, Nathan P. Metzger, Corine P. Richard, John N. Campbell, Jeffrey M. Zigman Source Type: research
SARS-CoV-2 mRNA vaccination–induced immunological memory in human nonlymphoid and lymphoid tissues
Tissue-resident lymphocytes provide organ-adapted protection against invading pathogens. Whereas their biology has been examined in great detail in various infection models, their generation and functionality in response to vaccination have not been comprehensively analyzed in humans. We therefore studied SARS-CoV-2 mRNA vaccine–specific T cells in surgery specimens of kidney, liver, lung, bone marrow, and spleen compared with paired blood samples from largely virus-naive individuals. As opposed to lymphoid tissues, nonlymphoid organs harbored significantly elevated frequencies of spike-specific CD4+ T cells compared wit...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Vanessa Proß, Arne Sattler, Sören Lukassen, Laura Tóth, Linda Marie Laura Thole, Janine Siegle, Carolin Stahl, An He, Georg Damm, Daniel Seehofer, Christina Götz, Christian Bayerl, Pia Jäger, Alexander Macke, Stephan Eggeling, Bernadette Kirzinger, T Source Type: research
Metixene is an incomplete autophagy inducer in preclinical models of metastatic cancer and brain metastases
A paucity of chemotherapeutic options for metastatic brain cancer limits patient survival and portends poor clinical outcomes. Using a CNS small-molecule inhibitor library of 320 agents known to be blood-brain barrier permeable and approved by the FDA, we interrogated breast cancer brain metastasis vulnerabilities to identify an effective agent. Metixene, an antiparkinsonian drug, was identified as a top therapeutic agent that was capable of decreasing cellular viability and inducing cell death across different metastatic breast cancer subtypes. This agent significantly reduced mammary tumor size in orthotopic xenograft as...
Source: Journal of Clinical Investigation - December 15, 2023 Category: Biomedical Science Authors: Jawad Fares, Edgar Petrosyan, Deepak Kanojia, Crismita Dmello, Alex Cordero, Joseph T. Duffy, Ragini Yeeravalli, Mayurbhai H. Sahani, Peng Zhang, Aida Rashidi, Victor A. Arrieta, Ilya Ulasov, Atique U. Ahmed, Jason Miska, Irina V. Balyasnikova, C. David J Source Type: research
