Hematology
Abstract
Patients with sickle cell disease (SCD) frequently receive red blood cell (RBC) units stored near the end of their permissible storage life. To evaluate whether storage duration influences recipient metabolism, clinical chemistry and hematological parameters, we conducted a prospective, randomized, blinded trial comparing transfusions of RBC units stored for ≤10 days versus ≥30 days. Chronically transfused adults with SCD (N=24) received three consecutive outpatient transfusions with randomized-age RBCs, and blood samples from units and recipients were analyzed by metabolomics and clinical chemistry. Transfusion of short-stored units resulted in significantly higher circulating levels of 2,3-bisphosphoglycerate, an essential regulator of oxygen unloading, up to two weeks post-transfusion. Conversely, transfusions of long-stored RBCs were associated with lower hemoglobin and RBC increments, higher iron and transferrin saturation, pro-inflammatory cytokines and metabolites, oxidative stress and markers of renal dysfunction. Plasma and RBC metabolomic profiles revealed time- and storage-age-dependent alterations, particularly affecting glycolysis, purine, and sphingolipid metabolism. Transfusion of long-stored RBCs consistently worsened laboratory surrogates of oxygen delivery and RBC efficacy, and increased the circulating levels of immunomodulatory metabolites and pro-inflammatory cytokines. These findings highlight metabolic and hematologic advantages associated with transfusing fresher RBCs in adults with SCD, independent of immediate clinical outcomes.
Authors
Matthew S. Karafin, Abby L. Grier, Ross M. Fasano, Anton Ilich, David Wichlan, Ada Chang, Sonjile M. James, Hailly E. Butler, Oleg Kolupaev, Melissa C. Caughey, Daniel J Stephenson, Julie A. Reisz, Nigel S. Key, Joshua J. Field, Jane A. Little, Steven L. Spitalnik, Angelo D’Alessandro
Abstract
Oncogene expression can cause replication stress (RS), leading to DNA double-strand breaks (DSB) that require repair through pathways such as homologous recombination, non-homologous end-joining, and microhomology-mediated end-joining (MMEJ). Cyclin D1 (encoded by CCND1) is a well-known oncoprotein overexpressed in cancer; however, its role in RS is unknown. Using mantle cell lymphoma (MCL) as a naturally occurring model of cyclin D1 overexpression, we examined its impact on RS and DSB-repair mechanisms. Cyclin D1 overexpression elevated RS, increased DNA damage, especially during mitosis, and caused specific upregulation of MMEJ. Furthermore, cyclin D1 activates the polymerase theta (POLQ) transcription by binding its promoter loci, driving POLΘ-mediated MMEJ that is essential to withstand cyclin D1-induced RS. Moreover, concurrent ATM deficiency further intensifies RS, enhances POLQ expression and heightens reliance on MMEJ mediated DNA damage repair. Consequently, inhibition of POLΘ in cyclin D1-overexpressed settings further exacerbates RS, causing single-strand DNA gap accumulations and chromosomal instability, ultimately leading to apoptosis, an effect amplified in ATM-deficient cells. Targeting MMEJ via POLΘ inhibition is, therefore, an effective strategy in the context of cyclin D1 overexpression and ATM deficiency and may provide a unique therapeutic approach for treating MCL and other malignancies characterized by similar alterations.
Authors
Jithma Abeykoon, Shuhei Asada, Guangli Zhu, Yuna Hirohashi, Lisa Moreau, Divya R. Iyer, Sirisha Mukkavalli, Kalindi Parmar, Gabriella Zambrano, Lige Jiang, Dongni Yi, Michelle Manske, Kimberly Gwin, Rebecca L. King, James R. Cerhan, Xiaosheng Wu, Zhenkun Lou, Geoffrey I. Shapiro, Thomas Witzig, Alan D'Andrea
Abstract
The balance of hematopoietic stem cell (HSC) self-renewal versus differentiation is essential to ensure long-term repopulation capacity while allowing response to events that require increased hematopoietic output. Proliferation and differentiation of HSCs and their progeny is controlled by the JAK/STAT pathway downstream of cytokine signaling. E3 ubiquitin ligases, like Cullin 5 (Cul5), can regulate JAK/STAT signaling by degrading signaling intermediates. Here we report that mice lacking Cul5 in hematopoietic cells (Cul5Vav-Cre) have increased numbers of HSPCs, splenomegaly, and extramedullary hematopoiesis. Differentiation in Cul5Vav-Cre mice is myeloid- and megakaryocyte-biased, resulting in leukocytosis, anemia and thrombocytosis. Cul5Vav-Cre mice increased HSC proliferation and circulation, associated with a decrease in CXCR4 surface expression. In bone marrow cells, we identified LRRC41 co-immunoprecipitated with CUL5, and vice versa, supporting that CRL5 forms a complex with LRRC41. We identified an accumulation of LRRC41 and STAT5 in Cul5Vav-Cre HSCs during IL-3 stimulation, supporting their regulation by Cul5. Whole cell proteome (WCP) analysis of HSPCs from Cul5Vav-Cre bone marrow identified upregulation of many STAT5 target genes and associated pathways. Finally, JAK1/2 inhibition with ruxolitinib normalized hematopoiesis in Cul5Vav-Cre mice. These studies demonstrate the function of Cul5 in HSC function, stem cell fate decisions, and regulation of IL-3 signaling.
Authors
Siera A. Tomishima, Dale D. Kim, Nadia Porter, Ipsita Guha, Asif A. Dar, Yohaniz Ortega-Burgos, Jennifer Roof, Hossein Fazelinia, Lynn A. Spruce, Christopher S. Thom, Robert L. Bowman, Paula M. Oliver
Abstract
BACKGROUND. Axicabtagene ciloleucel (axi-cel), anti-CD19 chimeric antigen receptor (CAR) T-cell therapy demonstrated remarkable efficacy with manageable toxicity in relapsed/refractory indolent B-cell lymphomas in the ZUMA-5 trial. METHODS. Here, we report associations of product attributes, serum biomarkers, clinical features, and tumor characteristics with outcome in 124 follicular lymphoma (FL) patients. RESULTS. In univariate and multivariate analyses, pre-treatment inflammatory markers, including TNFα and IL12p40, as well as total metabolic tumor volume (TMTV) associated with disease progression. Conversely, T-naïve-like product phenotype associated with improved outcome, particularly in high TMTV patients. These covariates improved risk stratification when combined with the FL International Prognostic Index. Post-infusion, CAR T-cell expansion associated with improved outcome, while serum inflammatory and immuno-modulatory markers, including TNFα associated with disease progression and occurrence of high-grade cytokine release syndrome or neurologic events, presenting targets to improve the therapeutic index of axi-cel in FL. Tumor gene expression profiling revealed that both type I and II IFN signaling associated with disease progression and higher expression of T cell exhaustion markers, including TIM3 and LAG3. Pre- or post-treatment CD19 expression on tumor was not associated with outcome. CONCLUSION. These findings offer insights into mechanisms of resistance and toxicity, risk stratification, and strategies for development of next generation CAR-T approaches. TRIAL REGISTRATION. ClinicalTrials.gov NCT03105336. FUNDING. Kite, a Gilead Company.
Authors
Soumya Poddar, Jiali Yan, Gayatri Tiwari, Darawan Rinchai, Justin Budka, Wangshu Zhang, Weixin Peng, Shruti Salunkhe, Madison Davis, Qinghua Song, Sara Beygi, Harry Miao, Mike Mattie, Rhine S. Shen, Caron A. Jacobson, Davide Bedognetti, Simone Filosto, Sattva S. Neelapu
Abstract
Authors
Caitlin M. Stewart, Sonya Parpart-Li, James R. White, Mitesh Patel, Oliver Artz, Michael B. Foote, Erika Gedvilaite, Michelle F. Lamendola-Essel, Drew Gerber, Rohini Bhattacharya, Justin M. Haseltine, Kety Huberman, Kelly L. Bolton, Ross L. Levine, Luis A. Diaz, Jr.
Abstract
Platelets play a dual role in hemostasis and inflammation-associated thrombosis and hemorrhage. While the mechanisms linking inflammation to platelet dysfunction remain poorly understood, our previous work demonstrated that TNFα alters mitochondrial mass, platelet activation, and autophagy-related pathways in megakaryocytes. Here, we hypothesized that TNFα impairs platelet function by disrupting autophagy, a process critical for mitochondrial health and cellular metabolism. Using human and murine models of TNFα-driven diseases, including myeloproliferative neoplasms and rheumatoid arthritis, we found that TNFα downregulates STX17, a key mediator of autophagosome–lysosome fusion. This disruption inhibited autophagy, leading to the accumulation of dysfunctional mitochondria and reduced mitochondrial respiration. These metabolic alterations compromised platelet-driven clot contraction, a process linked to thrombotic and hemorrhagic complications. Our findings reveal a mechanism by which TNFα disrupts hemostasis through autophagy inhibition, highlighting TNFα as a critical regulator of platelet metabolism and function. This study provides new insights into inflammation-associated pathologies and suggests autophagy-targeting strategies as potential therapeutic avenues to restore hemostatic balance.
Authors
Guadalupe Rojas-Sanchez, Jorge Calzada-Martinez, Brandon McMahon, Aaron C. Petrey, Gabriela Dveksler, Gerardo P. Espino-Solis, Orlando Esparza, Giovanny Hernandez, Dennis Le, Eric P. Wartchow, Ken Jones, Lucas H. Ting, Catherine Jankowski, Marguerite R. Kelher, Marilyn Manco-Johnson, Marie L. Feser, Kevin D. Deane, Travis Nemkov, Angelo D'Alessandro, Andrew Thorburn, Paola Maycotte, José A. López, Pavel Davizon-Castillo
Abstract
BACKGROUND. Telomere biology disorders (TBDs) exhibit incomplete penetrance and variable expressivity, even among individuals harboring the same pathogenic variant. We assessed whether common genetic variants associated with telomere length combine with large-effect variants to impact penetrance and expressivity in TBDs. METHODS. We constructed polygenic scores (PGS) for telomere length in the UK Biobank to quantify common variant burden, and assessed the PGS distribution across patient cohorts and biobanks to determine whether individuals with severe TBD presentations have increased polygenic burden causing short telomeres. We also characterized rare TBD variant carriers in the UK Biobank. RESULTS. Individuals with TBDs in cohorts enriched for severe pediatric presentations have polygenic scores predictive of short telomeres. In the UK Biobank, we identify carriers of pathogenic TBD variants who are enriched for adult-onset manifestations of TBDs. Unlike individuals in disease cohorts, the PGS of adult carriers do not show a common variant burden for shorter telomeres, consistent with the absence of childhood-onset disease. Notably, TBD variant carriers are enriched for idiopathic pulmonary fibrosis diagnoses, and telomere length PGS stratifies pulmonary fibrosis risk. Finally, common variants affecting telomere length were enriched in enhancers regulating known TBD genes. CONCLUSION. Common genetic variants combine with large-effect causal variants to impact clinical manifestations in rare TBDs. These findings offer a framework for understanding phenotypic variability in other presumed monogenic disorders. FUNDING. This work was supported by National Institutes of Health grants R01DK103794, R01HL146500, R01CA265726, R01CA292941, and the Howard Hughes Medical Institute.
Authors
Michael Poeschla, Uma P. Arora, Amanda Walne, Lisa J. McReynolds, Marena R. Niewisch, Neelam Giri, Logan P. Zeigler, Alexander Gusev, Mitchell J. Machiela, Hemanth Tummala, Sharon A. Savage, Vijay G. Sankaran
Abstract
Anemia is the primary clinical manifestation of myelodysplastic syndromes (MDS), but the molecular pathogenesis of ineffective erythropoiesis remains incompletely understood. Luspatercept, an activin receptor 2B (ACVRIIB-Fc) ligand trap, has been approved to treat anemia, however its molecular mechanism of action is unclear. We found that the ACVR2B, its ligand GDF11, and effector, SMAD2, are upregulated in MDS patient samples. GDF11 inhibited human erythropoiesis in vitro and caused anemia in zebrafish, effects that were abrogated by luspatercept. Upon GDF11 stimulation of human erythroid progenitors, SMAD2 binding occurred in the erythroid regulatory regions, including at GATA1 intron. Intronic SMAD2 binding led to skipping of exon 2 of GATA1, resulting in a shorter, hypomorphic isoform (GATA1s). CRISPR deletion of the SMAD2 binding intronic region decreased GATA1s production upon GDF11 stimulation. Expression of gata1s in a mouse model led to anemia, rescued by a murine ActRIIB-Fc (RAP-536). Finally, RNA-seq analysis of samples from the Phase 3 MEDALIST trial revealed that responders to Luspatercept had a higher proportion of GATA1s compared to non-responders. Moreover, the increase RBCs post-treatment was linked to a relative decrease in GATA1s isoform. Our study indicates that GDF11-mediated SMAD2 activation results in an increase in functionally impaired GATA1 isoforms, consequently contributing to anemia and influencing responses to Luspatercept in MDS.
Authors
Srinivas Aluri, Te Ling, Ellen Fraint, Samarpana Chakraborty, Kevin Zhang, Aarif Ahsan, Leah Kravets, Gowri Poigaialwar, Rongbao Zhao, Kith Pradhan, Anitria Cotton, Kimo Bachiashvili, Jung-In Yang, Anjali Budhathoki, Beamon Agarwal, Shanisha Gordon-Mitchell, Milagros Carbajal, Srabani Sahu, Jacqueline Boultwood, Andrea Pellagatti, Ulrich Steidl, Amittha Wickrema, Satish Nandakumar, Aditi Shastri, Rajasekhar N.V.S. Suragani, Teresa V. Bowman, John D. Crispino, Sadanand Vodala, Amit Verma
Abstract
Altered protein homeostasis through proteasomal degradation of ubiquitinated proteins is a hallmark of many cancers. Ubiquitination, coordinated by E1, E2, and E3 enzymes, involves up to 40 E2-conjugating enzymes in humans to specify substrates and ubiquitin linkages. In a screen for E2 dependencies in acute myeloid leukemia (AML), ubiquitin conjugating enzyme E2 N (UBE2N) emerged as the top candidate. To investigate UBE2N’s role in AML, we characterized an enzymatically defective mouse model of UBE2N, revealing UBE2N’s requirement in AML without an impact on normal hematopoiesis. Unlike other E2s, which mediate lysine-48 (K48) polyubiquitination and degradation of proteins, UBE2N primarily synthesizes K63-linked chains, stabilizing or altering protein function. Proteomic analyses and a whole-genome CRISPR-activation screen in pharmacologically and genetically UBE2N-inhibited AML cells unveiled a network of UBE2N-regulated proteins, many of which are implicated in cancer. UBE2N inhibition reduced their protein levels, leading to increased K48-linked ubiquitination and degradation through the immunoproteasome and revealing UBE2N activity is enriched in immunoproteasome-positive AML. Furthermore, an interactome screen identified tripartite motif–containing protein 21 (TRIM21) as the E3 ligase partnering with activated UBE2N in AML to modulate UBE2N-dependent proteostasis. In conclusion, UBE2N maintains proteostasis in AML by stabilizing target proteins through K63-linked ubiquitination and prevention of K48 ubiquitin–mediated degradation by the immunoproteasome. Thus, inhibition of UBE2N catalytic function suppresses leukemic cells through selective degradation of critical proteins in immunoproteasome-positive AML.
Authors
Chiharu Ishikawa, Laura Barreyro, Avery M. Sampson, Kathleen M. Hueneman, Kwangmin Choi, Sophia Y. Philbrook, Issac Choi, Lyndsey C. Bolanos, Mark Wunderlich, Andrew G. Volk, Stephanie S. Watowich, Kenneth D. Greis, Daniel T. Starczynowski
Abstract
The nucleolus is a membraneless organelle and an excellent stress sensor. Any changes in its architecture or composition lead to nucleolar stress, resulting in cell cycle arrest and interruption of ribosomal activity, critical factors in aging and cancer. In this study, we identified and described the pivotal role of the RNA-binding protein (RBP) HNRNPK in ribosome and nucleolar dynamics. We developed an in vitro model of endogenous HNRNPK overexpression and an in vivo mouse model of ubiquitous HNRNPK overexpression. These models showed disruptions in translation and caused alterations in the nucleolar structure, resulting in p53-dependent nucleolar stress, cell cycle arrest, senescence, and bone marrow failure phenotype, similar to what is observed in patients with ribosomopathies. Together, our findings identify HNRNPK as a master regulator of ribosome biogenesis (RiBi) and nucleolar homeostasis through p53, providing a new perspective on the orchestration of nucleolar integrity, ribosome function and cellular senescence.
Authors
Pedro Aguilar-Garrido, María Velasco-Estévez, Miguel Ángel Navarro-Aguadero, Alvaro Otero-Sobrino, Marta Ibañez-Navarro, Miguel Ángel Marugal, María Hernández-Sánchez, Prerna Malaney, Ashley Rodriguez, Oscar Benitez, Xiaorui Zhang, Marisa J.L. Aitken, Alejandra Ortiz-Ruiz, Diego Megias, Manuel Pérez-Martínez, Gadea Mata, Jesús Gomez, Miguel Lafarga, Orlando Dominguez, Osvaldo Graña-Castro, Eduardo Caleiras, Pilar Ximenez-Embun, Marta Isasa, Paloma J. de Andrés, Sandra Rodriguez-Perales, Raul Torres-Ruiz, Enrique Revilla, Rosa María García-Martín, Daniel Azorín, Josune Zubicaray, Julian Sevilla, Oleksandra Sirozh, Vanesa Lafarga, Joaquín Martinez-Lopez, Sean M. Post, Miguel Gallardo
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)