Hematology
Abstract
Authors
Maiko Sezaki, Tian Li, Mingzhe Pan, Zhihong Wang, Jie Bai, Justin G. Horowitz, Julia Z. Xu, Gang Huang
Abstract
Myelodysplastic syndromes (MDSs) are malignant hematopoietic stem and progenitor cell (HSPC) disorders that lead to ineffective blood production with poor outcomes. We previously showed that F-box only protein 11 (FBXO11) is downregulated in MDS, and here we report how this event contributes to disease progression. Integration of multiomics data revealed that the SCF-FBXO11 complex regulates spliceosome and ribosome components in a nucleophosmin 1 (NPM1)-centric network. FBXO11 facilitates the ubiquitylation of NPM1, whereby deletion of FBXO11 results in the reorganization of NPM1 and a de-repression of alternative splicing. Label-free total quantitative proteomics demonstrated that the FBXO11-NPM1 interactome was markedly downregulated in cells from patients with CD34+ MDS. In addition, we discovered that MYC was evicted from the FBXO11 promoter by TLR2 activation, revealing that it was a MYC target gene and explaining why FBXO11 expression was decreased in MDS. In MDS mouse models, genetic ablation of Fbxo11 exacerbated neutropenia concomitant with a profound decrease in NPM1 protein levels. Finally, we discovered rare mutations in FBXO11, which mapped to a previously unstudied functional intrinsically disordered region (IDR) in the N-terminus responsible for binding NPM1. These data support a model in which FBXO11 rewires RNA binding and ribosomal subnetworks through ubiquitylation of NPM1, ultimately restricting MDS progression.
Authors
Madeline Niederkorn, Lavanya Bezavada, Anitria Cotton, Lance E. Palmer, Lahiri Konada, Trent Hall, Vishwajeeth R. Pagala, Jinbin Zhai, Zuo-Fei Yuan, Yingxue Fu, Jacob A. Steele, Shilpa Narina, Andrew Schild, Chengzhou Wu, Sarah Aminov, Michael Schieber, Erin McGovern, Aaron B. Taylor, Sandeep Gurbuxani, Peng Xu, Peng Ji, Laura J. Janke, Anthony A. High, Guolian Kang, Shondra M. Pruett-Miller, Mitchell Weiss, Amit Verma, Raajit K. Rampal, John D. Crispino
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
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
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
The metabolic microenvironment plays important roles in tumorigenesis, but how leukemia-initiating cells (LICs) response to the acidic BM niche remains largely unknown. Here, we show that acid-sensing ion channel 3 (ASIC3) dramatically delays leukemogenesis. Asic3 deletion results in a remarkably enhanced self-renewal, reduced differentiation, and 9-fold greater number of murine acute myeloid LICs. We developed an ultrasensitive, ratiometric, genetically encoded fluorescent pH sensor (pHluorin3) and demonstrated that LICs prefer localizing in the endosteal niche with a neutral pH range of 7.34–7.42, but not in the vascular niche with a lower pH range of 6.89–7.22. Unexpectedly, acid-ASIC3 signaling inhibits both murine and human LIC activities in a noncanonical manner by interacting with the N-terminal of STIM1 to reduce calcium-mediated CAMK1-CREB-MEIS1-LDHA levels, without inducing cation currents. This study reveals a pathway in suppression of leukemogenesis in the acidic BM niche and provides insight into targeting LICs or other cancer stem cells through pH-dependent ASICs.
Authors
Hao Gu, Lietao Weng, Chiqi Chen, Xiaoxin Hao, Rongkun Tao, Xin Qi, Xiaoyun Lai, Ligen Liu, Tinghua Zhang, Yiming Jiang, Jin Wang, Wei-Guang Li, Zhuo Yu, Li Xie, Yaping Zhang, Xiaoxiao He, Ye Yu, Yi Yang, Dehua Wu, Yuzheng Zhao, Tian-Le Xu, Guo-Qiang Chen, Junke Zheng
Abstract
Mitochondrial metabolism orchestrates T cell functions, yet the role of specific mitochondrial components in distinct T cell subsets remains poorly understood. Here, we explored the role of mitochondrial complex II (MC II), the only complex from the electron transport chain (ETC) that plays a role in both ETC and metabolism, in regulating T cell functions. Surprisingly, MC II exerts divergent effects on CD4+ and CD8+ T cell activation and function. Using T cell–specific MC II subunit, succinate dehydrogenase A–deficient (SDHA-deficient) mice, we integrated single-cell RNA-seq and metabolic profiling, with in vitro and in vivo T cell functional assays to illuminate these differences. SDHA deficiency induced metabolic changes and remodeled gene expression exclusively in activated T cells. In CD4+ T cells, SDHA loss dampened both oxidative phosphorylation (OXPHOS) and glycolysis, impaired cytokine production, proliferation, and reduced CD4+ T cell–mediated graft-versus-host disease after allogeneic stem cell transplantation (SCT). In contrast, SDHA deficiency in CD8+ T cells reduced OXPHOS but paradoxically upregulated glycolysis and demonstrated enhanced cytotoxic functions in vitro and in vivo. This metabolic reprogramming endowed SDHA-KO CD8+ T cells with superior in vivo antitumor efficacy after immune checkpoint inhibitor therapy and allogeneic SCT. These findings reveal MC II as a bifurcation point for metabolic and functional specialization in CD4+ and CD8+ T cells.
Authors
Keisuke Seike, Shih-Chun A. Chu, Yuichi Sumii, Takashi Ikeda, Meng-Chih Wu, Laure Maneix, Dongchang Zhao, Yaping Sun, Marcin Cieslik, Pavan Reddy
Abstract
During the progression of acute myeloid leukemia (AML), extramedullary hematopoiesis (EMH) compensates for impaired bone marrow hematopoiesis. However, the specific cellular dynamics of EMH and its influence on AML progression remain poorly understood. In this study, we identified a substantial expansion of the CD81+ erythroblast subpopulation (CD81+ Erys) in the spleens of AML mice, which promoted AML cell proliferation and reduced survival. Mechanistically, CD81+ Erys secrete elevated levels of macrophage migration-inhibitory factor (MIF), which interacted with the CD74 receptor on AML cells, activating the mTORC1 signaling pathway and upregulating Egln3. Consequently, AML cells cocultured with CD81+ Erys exhibited reprogrammed phospholipid metabolism, characterized by an increased phospholipid-to-lysophospholipid ratio. Modulating this metabolic shift, either by supplementing exogenous lysophospholipids or depleting Egln3 in AML cells, restored the phospholipid balance and mitigated the protumorigenic effects induced by CD81+ Erys. Overall, our findings elucidate the molecular crosstalk between erythroblasts and AML cells, extend our insights into the mechanisms driving AML progression, and suggest potential therapeutic strategies.
Authors
Yue Li, Jiaxuan Cao, Jingyuan Tong, Peixia Tang, Haoran Chen, Guohuan Sun, Zining Yang, Xiaoru Zhang, Fang Dong, Shangda Yang, Jie Gao, Xiangnan Zhao, Jinfa Ma, Di Wang, Lei Zhang, Lin Wang, Tao Cheng, Hui Cheng, Lihong Shi
Abstract
Acute myeloid leukemia (AML) is an aggressive cancer with very poor outcomes. To identify additional drivers of leukemogenesis, we analyzed sequencing data from 1,727 unique individual AML patients, which revealed mutations in ubiquitin ligase family genes in 11.2% of adult AML samples with mutual exclusivity. The SKP1/CUL1/F-box (SCF) E3 ubiquitin ligase complex gene, FBXO11, was the most significantly downregulated gene of the SCF complex in AML. We found that FBXO11 interacts with and catalyzes K63-linked ubiquitination of LONP1 in the cytosol, to promote LONP1 entry into mitochondria. We show that depletion of FBXO11 or LONP1 reduces mitochondrial respiration through impaired LONP1 chaperone activity to assemble electron transport chain Complex IV. Reduced mitochondrial respiration secondary to FBXO11 or LONP1 depletion imparted myeloid-biased stem cell properties in primary CD34+ hematopoietic stem and progenitor cells (HSPC) in vitro. In a human xenograft model, depletion of FBXO11 cooperated with AML1-ETO and mutant KRASG12D to generate serially transplantable AML. Our findings suggest that reduced FBXO11 cooperates to initiate AML by priming HSPC for myeloid-biased self-renewal through attenuation of LONP1-mediated regulation of mitochondrial respiration.
Authors
Hayle Kincross, Ya-Chi Angela Mo, Xuan Wang, Linda Chang, Gerben Duns, Franziska Mey, Jihong Jiang, Zurui Zhu, Naomi Isak, Harwood Kwan, Tammy T.Y. Lau, T. Roderick Docking, Pranav Garg, Jessica Tran, Shane Colborne, Se-Wing Grace Cheng, Shujun Huang, Nadia Gharaee, Elijah Willie, Jeremy D.K. Parker, Joshua Bridgers, Davis Wood, Ramon I. Klein Geltink, Gregg B. Morin, Aly Karsan
Abstract
Venous thromboembolism (VTE) is a leading cause of morbidity and mortality, with risk heightened in premenopausal women with obesity or use estrogen-based oral contraceptives. When both risk factors are present, the thrombosis risk increases substantially. Protein S (PS), an essential anticoagulant cofactor, is downregulated by both estrogen and obesity, but the molecular basis for this suppression remains poorly defined. We investigated the effect of estrogen and obesity on PS expression using plasma samples from 157 women stratified by BMI and contraceptive use, alongside 40 mice categorized as lean or obese with or without estrogen pellet treatment. The levels of PS were reduced by either estrogen or obesity alone, and the combined effect increased thrombin generation. In HepG2 hepatocytes, hypoxic conditions (1%–10% O2) mimicking obesity, with or without 17 β-estradiol, suppressed PROS1 transcription and promoter activity. ChIP confirmed direct binding of hypoxia-inducible factor 1α (HIF1α) to the PROS1 promoter, repressing gene expression. These findings define a mechanistic pathway through which estrogen and obesity converge to suppress PS synthesis, providing insight into the elevated thrombosis risk observed in women with obesity using estrogen-based contraceptives.
Authors
Mohammad A. Mohammad, Narender Kumar, Sonali Ghosh, Ashley Paysse, Claudia Leonardi, Vijaya Pilli, Ma Lorena Duhaylungsod, Eric Lazartigues, Diana C. Polania-Villanueva, Sadaf Nouman, Logan A. Barrios, Rima Chattopadhyay, Rafika Yasmin, Alaina Guilbeau, Manoj Kumar, Tina Nguyen, Jovanny Zabaleta, Li Li, Luis Del Valle, Mallory T. Barbier, Samarpan Majumder, Laurent O. Mosnier, Rinku Majumder
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)