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Abstract
BACKGROUND. Chronic alcohol use leads to synaptic dysfunction in preclinical studies. However, whether in vivo synaptic density deficits are found in people with alcohol use disorder (AUD) remains unclear. METHODS. Thirty-two people with AUD (17 women) and 29 controls (17 women) completed one positron emission tomography (PET) brain imaging scan with the radiotracer [11C]UCB-J, which binds to SV2A, a marker of synaptic density. Levels of synaptic density were quantified by estimating binding potential (BPND) across four regions of interest: frontal cortex, striatum, hippocampus, and cerebellum. RESULTS. People with AUD were on average(±SD) 43±13 years old and most met criteria for mild or moderate AUD. Controls were 37±12 years old. People with AUD had on average 11% lower [11C]UCB-J BPND than controls in the frontal cortex (F(1,62)=13.074, p<0.001), striatum (F(1,60)=10.283, p=0.002), hippocampus (F(1,60)=5.964, p=0.018), and trending in the same direction in cerebellum (F(1,50)=3.438, p=0.070). Among people with AUD, lower [11C]UCB-J BPND was significantly related to more drinks per drinking day in the frontal cortex (p=0.022) and striatum (p=0.026). People with AUD performed worse on executive function than controls (p=0.020), but this was not related to [11C]UCB-J BPND. CONCLUSION. Synaptic density deficits are evident, even in people with mild-to-moderate AUD, with greater deficits in those with greater drinking severity. These findings underscore the potential of synaptic restoration as a therapeutic target for AUD. TRIAL REGISTRATION. N/A. FUNDING. This work was supported by the National Institute of Health.
Authors
Yasmin Zakiniaeiz, Nakul R. Raval, Will Riordan, Nabeel Nabulsi, Yiyun Huang, Brian Pittman, David Matuskey, Gustavo A. Angarita, Robin Bonomi, Sherry A. McKee, Ansel T. Hillmer, Kelly P. Cosgrove
Abstract
The lymphatic system maintains tissue fluid balance, and FOXC2 mutations cause lymphoedema-distichiasis syndrome, which is characterized by lymphatic valve defects. Although oscillatory shear stress regulates FOXC2 expression, other extracellular regulators remain unclear. In this study, we identified LPA4 and LPA6, two Gα12/Gα13-coupled receptors for the bioactive lipid lysophosphatidic acid (LPA), as key regulators of FOXC2 expression and lymphatic valve development. Lymphatic endothelial cell (LEC)-specific Lpa4;Lpa6-deficient mice exhibited impaired lymphatic valve formation and maintenance, which resembled phenotypes of LEC-specific Foxc2-deficient mice, including abnormal lymphatic vessel patterning. Mechanistically, lymphatic endothelial Lpa4/Lpa6 ablation reduced FOXC2 expression in vitro and in vivo. NF-κB was found essential for LPA-induced FOXC2 expression through the LPA4/LPA6-Gα12/Gα13-Rho kinase signaling axis. Accordingly, pharmacological inhibition of NF-κB and Rho kinase impaired lymphatic valve maintenance in mice. These results suggested that lymphatic endothelial LPA4 and LPA6 synergistically regulate FOXC2 expression through NF-κB activation and play an important role in lymphatic valve formation and maintenance. Our findings provide a molecular basis for lymphatic vessel development with a therapeutic potential for targeting lymphatic-associated diseases.
Authors
Daisuke Yasuda, Nana Sato, Keisuke Yanagida, Tomomi Hashidate-Yoshida, Tomohiro Shiiya, Hideo Shindou, Atsuki Taira, Takashi Ebihara, Takao Shimizu, Masanori Hirashima, Seiya Mizuno, Satoru Takahashi, Satoshi Ishii
Abstract
Authors
Robert Corty, Yash Pershad, J. Brett Heimlich, Caitlyn Vlasschaert, Leo Luo, Taralynn Mack, Kaushik Amancherla, Cassianne Robinson-Cohen, Michael Savona, Alexander G. Bick
Abstract
MRE11, a breast tumor suppressor and component of the MRE11-RAD50-NBS1 (MRN) complex, plays a critical role in DNA end resection and initiation of ATM-dependent DNA damage signaling. However, the precise mechanisms governing MRE11 function in the DNA damage response (DDR) remain incompletely understood. Here, we found that MRE11 is deacetylated by the SIRT2 sirtuin deacetylase and breast tumor suppressor, which promotes DNA binding to facilitate DNA end resection and ATM-dependent signaling. SIRT2 deacetylase activity promoted DNA end resection. SIRT2 further complexed with and deacetylated MRE11 at conserved lysine (K) 393 in response to DNA double-strand breaks (DSBs), which promoted MRE11 localization and DNA binding at DSBs but not interaction with RAD50, NBS1, or CtIP. Moreover, MRE11 K393 deacetylation by SIRT2 promoted ATM-dependent signaling. Our findings define a mechanism regulating MRE11 binding to DNA through SIRT2 deacetylation, elucidating a critical upstream signaling event directing MRE11 function in the DDR and providing insight into how SIRT2 dysregulation leads to genomic instability and tumorigenesis.
Authors
Fatmata Sesay, Hui Zhang, Priya Kapoor-Vazirani, Andrew T. Jung, Mark E. Essien, Amanda J. Bastien, Nho C. Luong, Xu Liu, PamelaSara E. Head, Duc M. Duong, Xiaofeng Yang, Zachary S. Buchwald, Xingming Deng, Nicholas T. Seyfried, David S. Yu
Abstract
Large-cohort genome-wide association studies (GWAS) for alcohol use disorder (AUD) drug treatment outcomes and AUD risk have repeatedly identified genetic loci which are splicing quantitative trait loci for the fibronectin III domain containing 4 (FNDC4) gene in the brain. However, FNDC4 function in the brain and how it might contribute to AUD pathophysiology remain unclear. In the present study, we characterized GWAS loci-associated FNDC4 splice isoforms and demonstrated that FNDC4 alternative splicing results in loss-of-function for FNDC4. We also investigated FNDC4 function using CRISPR/cas9 editing, and the creation of human induced pluripotent stem cell (iPSC)-derived neural organoids joined with single-nucleus RNA sequencing, a series of studies which showed that FNDC4 knock-out (KO) resulted in a striking shift in the relative proportions of glutamatergic and GABAergic neurons in iPSC-derived forebrain organoids as well as changes in their electrical activity. We further explored potential mechanism(s) of FNDC4-dependent neurogenesis with results that suggested a role for FNDC4 in mediating neural cell surface interactions. In summary, this series of experiments indicates that FNDC4 plays a role in regulating cerebral cortical neurogenesis in the brain. This regulation may contribute to the response to AUD pharmacotherapy as well as the effects of alcohol on the brain.
Authors
Xiujuan Zhu, August J. John, Sooan Kim, Li Wang, Enci Ding, Jing Zheng, Ateka Saleh, Irene Marín-Goñi, Abedalrahman Jomaa, Huanyao Gao, Meijie Wang, Ching Man Wai, Irene Moon, Cindy Chen, Alireza Agahi, Brandon J. Coombes, Tony M. Kerr, Nobuyoshi Suto, Liewei Wang, Mark A. Frye, Joanna M. Biernacka, Victor M. Karpyak, Hu Li, Richard M. Weinshilboum, Duan Liu
Abstract
WHIM syndrome is an immunodeficiency caused by autosomal dominant hyperfunctional mutations in chemokine receptor CXCR4 that promote panleukopenia due to BM retention. We previously reported a preclinical gene therapy protocol involving allele-nonspecific Cxcr4 CRISPR/Cas9 inactivation, leveraging the known in vivo dominance of Cxcr4+/o (+, WT; o, inactivated) hematopoietic stem cells (HSCs) for autologous BM engraftment and leukocyte reconstitution over HSCs with other Cxcr4 genotypes. Here, we show that without BM conditioning, this approach is not able to correct leukopenia in WHIM mice. We therefore modified the protocol by adding conditioning with a non-genotoxic CD117-targeted immunotoxin, CD117-antibody-saporin-conjugate (CD117-ASC). With this change, donor-derived blood cells rapidly reached ~95% chimerism after transplantation, which was stable without adverse events for more than 400 days. Mice receiving edited HSCs showed rapid normalization of absolute myeloid cell counts, the key blood subset responsible for WHIM syndrome. In competitive transplants using equal numbers of edited and unedited donor HSCs, over 80% of blood cells originated from the edited population, predominantly with the Cxcr4+/o genotype. These results provide proof of principle that CRISPR/Cas9-mediated inactivation of the Cxcr4 disease allele, combined with non-genotoxic HSC-targeted conditioning, may offer a safe and effective gene therapy strategy generalizable to all WHIM mutations.
Authors
Ji-Liang Gao, Zhanzhuo Li, Rafael Calderon-Perez, Antonia Pavek, Lina Kim, David H. McDermott, Philip M. Murphy
Abstract
Vessels encapsulating tumor clusters (VETC), a distinct vascular pattern in hepatocellular carcinoma (HCC), facilitates non-invasive metastasis in whole cluster. The interaction between VETC and tumor microenvironment requires exploration. Here, we found that compared to human Non-VETC-HCCs, VETC-tumors exhibited more PD1+CD8+ T cells and Tregs, especially TNFRSF4+Tregs and Ki67+Tregs which showed increased immunosuppressive and proliferative activity. Such immunosuppressive status was also detected in tumor emboli of VETC-HCCs, and Treg density in emboli was positively associated with metastatic cell proliferation. VETC-HCCs revealed abundance correlation, closer spatial proximity, and stronger immunosuppressive ligand-receptor interactions between TNFRSF4+Tregs/Ki67+Tregs and PD1+CD8+ T cells. Depleting Tregs in mice reduced PD1+CD8+ T cells in primary lesions, tumor emboli and metastatic foci of VETC-allografts, and attenuated allograft metastasis. TGF-β1 levels were upregulated in endothelial cells of VETC-HCCs and associated with TNFRSF4+Tregs/Ki67+Tregs enrichment. Disrupting VETC formation decreased endothelial TGF-β1 expression, and reduced TNFRSF4+Tregs/Ki67+Tregs, PD1+CD8+ T cells, Treg/CD8+ T cells ratio. Collectively, VETC may enhance Tregs’ activity via TGF-β1, while Tregs promote and sustain CD8+ T cell exhaustion through immune inhibitory ligand-receptor interaction, thereby shaping immunosuppressive microenvironment and enabling tumor cluster to carry such niche to disseminate. These findings disclose mechanisms of tumor immune microenvironment formation and provide rationales for precision medicine.
Authors
Bi-Yu Huang, Zheng-Qi Mi, Xiao-Yu Zhang, Yu-Chen Ji, Meng-Zhi Wu, Zi-Feng Cheng, Chen Xie, Shuai He, Jing Zhu, Jian-Hong Fang, Chong Wu, Bin-Kui Li, Yun-Fei YUAN, Limin Zheng, Shi-Mei Zhuang
Abstract
Aged individuals with somatic TP53 mutations manifest clonal hematopoiesis (CH) and are at high risk of developing myeloid neoplasms. However, the underlying mechanisms are not fully understood. Here we show that inflammatory stress confers a competitive advantage to p53 mutant hematopoietic stem and progenitor cells (HSPCs) by activating the NLRP1 inflammasome and increasing the secretion of pro-inflammatory cytokines such as IL-1β, inhibiting wild type (WT) HSPC fitness in a paracrine fashion. During aging, mutant p53 dysregulates pre-mRNA splicing in HSPCs, leading to enhanced NF-κB activation and increased secretion of IL-1β and IL-6, thereby generating a chronic inflammatory bone marrow microenvironment. Furthermore, blocking IL-1β with IL-1β neutralizing antibody or inhibiting IL-1β secretion using gasdermin D (GSDMD) inhibitor decreases the fitness of p53 mutant HSPCs. Thus, our findings uncover an important role for mutant p53 in regulating inflammatory signaling in CH and suggest that curbing inflammation may prevent the progression of TP53-mutant clonal hematopoiesis to myeloid neoplasms.
Authors
Sisi Chen, Sergio Barajas, Sasidhar Vemula, Yuxia Yang, Ed Simpson, Hongyu Gao, Rudong Li, Farzaneh Behzadnia, Sarah C. Nabinger, David A. Schmitz, Hongxia Chen, Wenjie Cai, Shiyu Xiao, Ruyue Luo, Mohammed Abdullahel Amin, Maegan L. Capitano, James P. Ropa, Aidan Fahey, Shuyi Zhou, Tiffany M. Mays, Magdalena Sotelo, Hao Pan, Sophie K. Hu, Sophia Veranga, Moiez Ali, Maria Shumilina, Reuben Kapur, Kehan Ren, Yuzhi Jia, Huiping Liu, Irum Khan, Yasmin Abaza, Jessica K. Altman, Elizabeth A. Eklund, Lucy A. Godley, Christine R. Zhang, Peng Ji, Seth L. Masters, Ben A. Croker, H. Scott Boswell, George E. Sandusky, Zhonghua Gao, Lindsey D. Mayo, Sharon A. Savage, Stephanie Halene, Yali Dou, Leonidas C. Platanias, Madina Sukhanova, Yunlong Liu, Omar Abdel-Wahab, Yan Liu
Abstract
Lymphatics maintains fluid homeostasis, immune surveillance, and tissue integrity. Here, we identified the E26 transformation-specific (ETS) transcription factors Erg and Fli1 as essential, cooperative regulators of lymphatic integrity and function. Using inducible, lymphatic endothelial cell-specific deletion in mice, we demonstrated that combined loss of Erg and Fli1 in adults results in fatal lymphatic failure, including chylothorax, chylous ascites, and impaired lymphatic drainage. Single-cell transcriptomic analysis revealed that loss of Erg and Fli1 caused disrupted lymphatic heterogeneity and dysregulation of key lymphatic genes, including valve-specific gene profiles. Erg and Fli1 coordinated lymphatic-immune crosstalk by transcriptionally regulating C-C motif chemokine ligand 21 (Ccl21), which mediates dendritic cell trafficking. Their loss also induced pro-inflammatory and pro-thrombotic gene expression, further contributing to lymphatic dysfunction. During embryonic development, the co-deletion led to lymphatic mis-patterning and loss of valve-initiating lymphatic endothelial cell clusters. The impact of loss of Erg and Fli1 function on lymphatic development in mice is consistent with FOXC2 mutations in lymphedema-distichiasis syndrome or ERG gene variants underlying primary lymphoedema in humans. Moreover, Erg and Fli1 were required for regenerative lymphangiogenesis and lymphatic repair following injury in adults. Our findings establish Erg and Fli1 as core transcriptional regulators of lymphatic identity, integrity, and function.
Authors
Myung Jin Yang, Seok Kang, Seon Pyo Hong, Hokyung Jin, Jin-Hui Yoon, Cheolhwa Jin, Chae Min Yuk, Lidiya G Gebeyehu, Junho Jung, Sung-hwan Yoon, Hyuek jong Lee, Gou Young Koh
Abstract
BACKGROUND. Infection is an important complication of implanted devices and prosthetics. Identifying infections sufficiently early to salvage implants and avoid reconstructive failure is a persistent medical challenge. METHODS. Two female cohorts >21 years undergoing breast implant reconstruction were recruited. Seroma fluid (82 breasts, 70 patients) was collected upon implant removal for infectious or non-infectious causes. Post-implantation drain fluid (100 samples, 44 breasts, 32 patients) was collected at routine visits prior to implant removal. A liquid-chromatography/mass spectrometry-based metabolomic approach was used to identify infection correlates. RESULTS. In seroma fluid specimens, infection was associated with a diverse set of small molecules including acetylated polyamines, defensins, glucosyl-sphingosine, and several peptide-like features (all P<0.001, diagnostic areas under the receiver operating curve 0.82-0.93). Notably, a subset of these markers were significantly elevated (p<0.05) in post-implantation drain fluid before recorded infection symptoms and diagnosis. Pseudomonas aeruginosa and its specialized exometabolites in drain specimens were also associated with subsequent P. aeruginosa infections. CONCLUSION. Tissue fluid from infected patients has a distinctive metabolome reflecting human and bacterial physiologic processes that often precede clinical diagnoses. A diagnostic based on these findings has potential to improve patient outcomes through early recognition of infection. TRIAL REGISTRATION. Not applicable. FUNDING. Work was supported by U54CK000609 from the CDC and an unencumbered research gift to TMM from Sientra. Metabolomic approaches were supported by RO1DK125860 and RO1DK111930 to JPH. The contents are solely the responsibility of the authors and do not necessarily represent the official views of CDC.
Authors
John A. Wildenthal, Margaret A. Olsen, Hung D. Tran, John I. Robinson, Terence M. Myckatyn, David K. Warren, Keith E. Brandt, Marissa M. Tenenbaum, Joani M Christensen, Thomas H. Tung, Justin M. Sacks, Rachel A. Anolik, Katelin B. Nickel, Hideji Fujiwara, Peter J. Mucha, Jeffrey P. Henderson
Abstract
Human gastrointestinal (GI) tissues are a major site of HIV-1 viral persistence, but the nature of the GI reservoir remains poorly described. To characterize the GI HIV reservoir, we profiled cells from GI tissue and matched peripheral blood mononuclear cells from ten people with HIV on antiretroviral therapy using single cell RNA sequencing. We identified distinct compartment-specific patterns of gene expression, highlighting key differences between blood and colon CD4 T cell populations. vRNA+ cells from both blood and GI tissue were heterogeneous and found in multiple subtypes of CD4 T cells, although vRNA+ cells were particularly enriched in cells with Th17 or Treg17 phenotypes. Transcriptomic comparison of HIV vRNA+ and vRNA- T cells revealed 116 differentially expressed genes that were associated with HIV infection including ZBED2, MAF and IL17F. These data provide novel information regarding the GI-resident HIV reservoir and suggest that compartment-specific patterns of gene expression are associated with HIV infection.
Authors
Jackson J. Peterson, Shipra Chandel, Katherine James, Elizabeth S. Bennett, Vincent Wu, Cory H. White, Brigitte Allard, Matthew Clohosey, Taylor Whitaker, Caroline Baker, Susan Pedersen, Anne F. Peery, Cynthia L. Gay, Michael R. Betts, David M. Margolis, Nancie M. Archin, Edward P. Browne
Abstract
Mutations in DNA mismatch repair (MMR) pathway genes (MSH2, MSH6, MLH1, and PMS2) are linked to acquired resistance to temozolomide (TMZ) and high tumor mutation burden (TMB) in high-grade gliomas (HGG), including glioblastoma (GBM). However, the specific roles of individual MMR genes in the initiation, progression, TMB, microsatellite instability (MSI), and resistance to TMZ in glioma remain unclear. Here, we developed de novo mouse models of germline and somatic MMR-deficient (MMRd) HGG. Surprisingly, loss of Msh2 or Msh6 does not lead to high TMB, MSI, nor confer response to anti-PD-1 in GBM. Similarly, human GBM shows discordance between MMR gene mutations and TMB/MSI.Germline MMRd leads to promoted progression from low-grade to HGG and reduced survival compared to MMR-proficient (MMRp) tumor-bearing mice. This effect is not tumor cell intrinsic but is associated with MMRd in the tumor immune microenvironment, driving immunosuppressive myeloid programs, reduced lymphoid infiltration, and CD8+ T cell exhaustion. Both MMR-reduced (MMRr) and MMRd GBM are resistant to temozolomide (TMZ), unlike MMRp tumors. Our study shows that KL-50, a imidazotetrazine-based DNA targeting agent inducing MMR-independent cross-link–mediated cytotoxicity, was effective against germline and somatic MMRr/MMRd GBM, offering a potential therapy for TMZ-resistant HGG with MMR alterations.
Authors
Montserrat Puigdelloses Vallcorba, Nishant Soni, Seung-Won Choi, Kavita Rawat, Tanvi Joshi, Sam Friedman, Alice Buonfiglioli, Angelo Angione, Zhihong Chen, Gonzalo Piñero, Gabrielle Price, Mehek Dedhia, Raina Roche, Emir Radkevich, Anne M. Bowcock, Deepti Bhatt, Winfried Edelmann, Robert M. Samstein, Timothy E. Richardson, Nadejda M. Tsankova, Alexander M. Tsankov, Ranjit S. Bindra, Raul Rabadan, Juan C. Vasquez, Dolores Hambardzumyan
Abstract
BACKGROUND. Amino acid (AA) concentrations are increased in prediabetes and diabetes. Since AA stimulate glucagon secretion which should then increase hepatic AA catabolism, it has been hypothesized that hepatic resistance (associated with hepatic fat content) to glucagon’s actions on AA metabolism leads to hyperglucagonemia and hyperglycemia. METHODS. To test this hypothesis, we therefore studied lean and obese individuals, the latter group with and without hepatic steatosis as defined by Proton Density Fat Fraction (PDFF) > 5%. After an overnight fast, femoral vein, femoral artery, and hepatic vein catheters were placed. [3-3H] glucose and L-[1-13C,15N]-leucine were used to measure glucose turnover and leucine oxidation respectively. During a hyperglycemic clamp, an amino acid mixture was infused together with insulin and glucagon (1.5 ng/kg/min 0 – 120 min; 3.0 ng/kg/min 120 – 240 min). Tracer-based measurement of hepatic leucine oxidation in response to rising glucagon concentrations and splanchnic balance (measured using arterio-venous differences across the liver), of the other AA were the main outcomes measured. RESULTS. The presence of hepatic steatosis did not alter hepatic glucose metabolism and leucine oxidation in response to insulin and rising concentrations of glucagon. Splanchnic balance of a few amino acids, and related metabolites differed amongst the groups. However, across-group differences of AA splanchnic balance in response to glucagon were unaffected by the presence of hepatic steatosis. CONCLUSION. The action of glucagon on hepatic amino acid metabolism is unaffected by hepatic steatosis in humans. TRIAL REGISTRATION. This study was registered at Clinical Trials.Gov: NCT05500586. FUNDING. This work was funding by the NIH.
Authors
Hannah E. Christie, Sneha Mohan, Aoife M. Egan, Federica Boscolo, Chiara Dalla Man, Scott M. Thompson, Michael Jundt, Chad J. Fleming, James C. Andrews, Kent R. Bailey, Michael D. Jensen, K. Sree Nair, Adrian Vella
Abstract
Recent studies suggest that prediabetes is an independent risk factor for cardiovascular thrombotic events. However, the mechanisms that may promote platelet activation and thrombosis in prediabetes remain elusive. To determine mechanisms linking prediabetes and thrombosis as a function of age, we recruited prediabetic and normoglycemic Veterans in young and middle-age groups. Compared to normoglycemic subjects, platelets from those with prediabetes exhibited increased activation, mitochondrial-oxidant load, mitochondrial-membrane hyperpolarization, and greater thrombus formation ex vivo regardless of age. Preincubation of platelets with mitochondria targeted antioxidants such as superoxide dismutase (SOD) mimetic or Mito quinol (MitoQ), rescued this prothrombotic phenotype. These phenotypes were recapitulated in C57BL6/J mice exhibiting early onset of glucose intolerance when fed high fat (HF) diet for two weeks. Treatment of HF-fed mice with a SOD-mimetic or MitoQ, or genetic overexpression of catalase within mitochondria, not only lowered mitochondrial-oxidants, hyperpolarization, Ca2+ levels and platelet activation, but also protected against increased potential for carotid and pulmonary thrombosis. We also observed a bidirectional regulation of platelet activation by Ca2+ and mitochondrial oxidants. These findings support the idea that mitochondrial-oxidant dependent platelet activation induces a prothrombotic state in clinical prediabetes and preclinical models of short-term glucose intolerance and can be reversed by mitochondria-targeted antioxidants.
Authors
Azaj Ahmed, Pooja Yadav, Melissa Jensen, Katharine Geasland, Jagadish S. Swamy, Douglas R. Spitz, E. Dale Abel, Diana Jalal, Sanjana Dayal
Abstract
PP2A B55α, a regulatory subunit of protein phosphatase 2 (PP2A), is underexpressed in over 40% of non-small cell lung cancer (NSCLC) cases due to loss of heterozygosity of PPP2R2A, the gene encoding this protein. Given that low PPP2R2A expression correlates with poor prognosis, treating PPP2R2A-deficient NSCLC represents an unmet medical need. Here, we show that PPP2R2A knockdown or its heterozygosity (PPP2R2A+/–) increases cytosolic DNA, leading to cGAS-STING-type I interferon (IFN) pathway activation. PPP2R2A deficiency results in elevated expression of immune checkpoint protein PD-L1 via GSK-3β- and STING-dependent mechanisms. PPP2R2A+/– cancer cells have enhanced sensitivity to PD-L1 blockade in a mouse model of lung cancer due to modulation of the tumor immune microenvironment, resulting in increased NK cells and reduced infiltration and function of regulatory T cells (Tregs). Consequently, PD-L1 antibody treatment increases CD8+ T infiltration and activity, especially in tumors with PPP2R2A heterozygosity. Further, systemic or Treg-specific IFNAR1 blockade reduces the efficacy of PD-L1 blockade in PPP2R2A+/– tumors. Patients with NSCLC with a low PPP2R2A/PD-L1 ratio respond better to immune checkpoint blockade (ICB). These findings underscore the therapeutic potential of ICB in treating PPP2R2A-deficient NSCLC while suggesting that PPP2R2A deficiency could serve as a biomarker for guiding ICB-based therapies.
Authors
Zhaojun Qiu, No-Joon Song, Anqi Li, Deepika Singh, Chandra B. Prasad, Chunhong Yan, David P. Carbone, Qi-en Wang, Xiaoli Zhang, Zihai Li, Junran Zhang
Abstract
Non-small cell lung cancer (NSCLC) exhibits the highest rates of brain metastases (BM) among all solid tumors and presents a significant clinical challenge. The development of novel therapeutic strategies targeting BM is clearly needed. We identified a significant enrichment of MET amplification in lung adenocarcinoma (LUAD) BM compared to primary LUAD and extracranial metastases in oncogene driver-negative patients. Of note, MET amplified BM were responsive to MET inhibitors in vivo including models with acquired MET amplification at the time of metastasis. MET alterations (amplifications and/or mutations) were also more frequently detected in circulating tumor DNA from LUAD BM patients than in those without BM. MET altered BM also demonstrated unique genomic features compared to non-MET altered BM. Transcriptomic analyses revealed that in contrast to MET wildtype BM, MET amplified BM exhibited a more inflamed tumor microenvironment and displayed evidence of metabolic adaptation, particularly a reliance on glycolysis in contrast to oxidative phosphorylation in MET wildtype BM. Further, MET amplified BM demonstrated evidence of epithelial-mesenchymal transition signaling including increased expression of TWIST1. Patients with MET amplified BM had significantly shorter overall survival. These findings highlight MET amplification as a critical driver of LUAD BM, emphasizing its potential as a therapeutic target.
Authors
Timothy F. Burns, Sanja Dacic, Anish Chakka, Ethan Miller, Maria A. Velez, Ashwin Somasundaram, Saveri Bhattacharya, Autumn Gaither-Davis, Princey Devadassan, Jingxiao Jin, Vinod Kumar, Arjun Pennathur, Joanne Xiu, Matthew Oberley, Michael J. Glantz, Sonikpreet Aulakh, Uma R. Chandran, Riyue Bao, Curtis Tatsuoka, Laura P. Stabile
Abstract
Fanconi anemia (FA) confers a high risk (~700-fold increase) of solid tumor formation, most often head and neck squamous cell carcinoma (HNSCC). FA germline DNA repair defects preclude administration of most chemotherapies and prior hematopoietic stem cell transplantation limits use of immunotherapy. Thus, surgery and judicious delivery of radiation offer the only treatment options, with most patients succumbing to their cancers. A paucity of preclinical models has limited the development of new treatments. Here, we report, to our knowledge, the first patient-derived xenografts (PDXs) of FA-HNSCC and highlight the efficacy of FDA-approved EGFR targeted therapies in tumors with high EGFR/p-EGFR levels and the activity of the FDA-approved Bcl-2 inhibitor venetoclax in a FA-HNSCC PDX overexpressing Bcl-2. These findings support the development of precision medicine approaches for FA-HNSCC.
Authors
Jennifer Grandis, Hua Li, Benjamin A. Harrison, Andrew L.H. Webster, Joanna Pucilowska, Austin Nguyen, Jinho Lee, Gordon B. Mills, Jovanka Gencel-Augusto, Yan Zeng, Steven R. Long, Mi-Ok Kim, Rex H. Lee, David I. Kutler, Theresa Scognamiglio, Margaret Brandwein-Weber, Mark Urken, Inna Khodos, Elisa de Stanchina, Yu-Chien Lin, Frank X. Donovan, Settara C. Chandrasekharappa, Moonjung Jung, Mathijs A. Sanders, Agata Smogorzewska, Daniel E. Johnson
Abstract
Mitochondrial fission is mediated by dynamin-related protein 1 (gene name DNM1L) and fusion by mitofusins (MFN1 and MFN2) and optic atrophy 1 (OPA1). The role of mitochondrial dynamics in liver disease and cancer remains poorly understood. We used single, double, and triple liver-specific knockout (KO) mice lacking mitochondrial fission and fusion proteins, along with systematic analyses of mitochondrial morphology, untargeted metabolomics, RNA sequencing, hydrodynamic tail vein injection of oncogenes, and human hepatocellular carcinoma samples. Liver-specific Dnm1l KO (L-Dnm1l) mice showed increased ALT levels and hepatic fibrosis, with spontaneous liver tumors developing by 12 to 18 months of age. L-Mfn1 KO and L-Mfn2 KO mice showed no significant liver damage or tumor development, although a small percentage of double knockout (DKO) mice developed tumors. Triple knockout of Dnm1l, Mfn1, and Mfn2 (TKO) mice experienced significantly reduced liver injury and fibrosis, along with decreased spontaneous and oncogene-induced tumorigenesis. L-Dnm1l KO mice showed increased activation of the cGAS-STING-interferon pathway and pyrimidine metabolism, which were significantly normalized in TKO mice. Deletion of hepatic cGas reduced both basal and oncogene-induced liver injury and tumor development in L-Dnm1l KO mice. These findings indicate that mitochondrial dynamics are crucial for maintaining hepatic pyrimidine metabolism and regulating the cGAS-STING-mediated immune response to prevent liver tumorigenesis.
Authors
Xiaowen Ma, Xiaoli Wei, Mengwei Niu, Chen Zhang, Zheyun Peng, Wanqing Liu, Junrong Yan, Xiaoyang Su, Lichun Ma, Shaolei Lu, Wei Cui, Hiromi Sesaki, Wei-Xing Zong, Hong-Min Ni, Wen-Xing Ding
Abstract
Type 1 Diabetes Mellitus (T1D) is a chronic disease caused by an unremitting autoimmune attack on pancreatic beta cells. This autoimmune chronicity is mediated by stem-like progenitor CD8+ T cells that continually repopulate the pool of beta cell-specific cytolytic effectors. Factors governing the conversion of progenitors to effectors, however, remain unclear. T1D has been linked to a chromosomal region (Xp13-p11) that contains the epigenetic regulator UTX, which suggests a key role for UTX in T1D pathogenesis. Here, we show that T cell-specific UTX deletion in NOD mice protects against T1D development. In T cells of NOD mice and T1D patients, UTX ablation resulted in the accumulation of CD8+ progenitor cells with concomitant deficiency of effectors, suggesting a key role for UTX in poising progenitors for transition to effectors. Mechanistically, UTX’s role in T1D was independent of its inherent histone demethylase activity but instead relied on binding with transcription factors (TCF1 and STAT3) to co-regulate genes important in the maintenance and differentiation of progenitor CD8+ T cells. Together, these findings identify a critical role for UTX in T1D and the UTX:TCF1:STAT3 complex as a therapeutic target for terminating the long-lived autoimmune response.
Authors
Ho-Chung Chen, Madison F. Bang, Hsing-Hui Wang, Karl B. Shpargel, Lisa A. Kohn, David Sailer, Shile Zhang, Ethan C. McCarthy, Maryamsadat Seyedsadr, Satchel Stevens, Caitlyn L. H. Pham, Zikang Zhou, Xihui Yin, Nicole M. Wilkinson, Esther M. Peluso, Christian Bustillos, Jessica G. Ortega, Lixin Yang, Ashlyn A. Buzzelli, Reina C. Capati, Dennis J. Chia, Steven D. Mittelman, Christina M. Reh, Jason K. Whitmire, Melissa G. Lechner, Willy Hugo, Maureen A. Su
Abstract
While current antivirals primarily target viral proteins, host-directed strategies remain underexplored. Here, we performed a genome-wide CRISPRi screening to identify the host protein, Hepatocyte Growth Factor-Regulated Tyrosine Kinase Substrate (HGS), as essential for the pan-coronaviruses infection both in vitro and in vivo. Mechanistically, HGS directly interacts with the viral membrane (M) protein, facilitating its trafficking to the ER-Golgi intermediate compartment (ERGIC) for virion assembly. Conversely, HGS deficiency caused M retention in the ER, blocking assembly. Leveraging this interaction, we designed M-derived peptides and screened over 5,000 FDA-approved drugs, identifying riboflavin tetrabutyrate (RTB). Both the peptides and RTB bind HGS and disrupt its interaction with the M protein, leading to M retention in the ER and subsequent blockade of virion assembly. These agents demonstrated broad anti-pan-coronavirus activity in vitro and in vivo. Collectively, our findings establish HGS as a druggable host target and identify RTB as a promising broad-spectrum antiviral candidate.
Authors
Xubing Long, Rongrong Chen, Rong Bai, Buyun Tian, Yu Cao, Kangying Chen, Fuyu Li, Yiliang Wang, Yongjie Tang, Qi Yang, Liping Ma, Fan Wang, Maoge Zhou, Xianjie Qiu, Yongzhi Lu, Jie Zheng, Peng Zhou, Xinwen Chen, Qian Liu, Xuepeng Wei, Yongxia Shi, Yanhong Xue, Jincun Zhao, Wei Ji, Liqiao Hu, Jinsai Shang, Tao Xu, Zonghong Li
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)