In-Press Preview
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
No posts were found with this tag.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)