Search Results (2,074)

Cardiovascular morbidity and mortality rise precipitously during the 6th–9th decades of life, identifying aging as a critical risk factor. Simultaneously, older individuals are susceptible to severe viral infection, raising the question whether shared mechanisms exist that predispose to both cardiovascular disease (CVD) and failing anti-viral immunity. The aging process causes steady decline in immune fitness (immune aging), which undermines the ability to generate protective anti-viral immune responses. Paradoxically, the aging immune system supports unopposed inflammatory pathways (inflammaging), which exacerbates tissue inflammation in CVD, specifically atherosclerosis. Here, we review the current evidence of how innate and adaptive immune aging promotes tissue-destructive inflammation in atherosclerosis while failing to fight viral infections. Further, we consider how these two disease processes mutually influence each other. We propose that mounting an effective anti-viral response induces off-target bystander activation and exhausts immune cells, ultimately exacerbating CVD. Additionally, we explore how atherosclerotic CVD impacts innate immunity through epigenetic modification of hematopoietic precursors and metabolically conditioning immune cells, leading to a dysfunctional immune system that accelerates plaque inflammation while simultaneously impairing host defense. Full article

Sickle cell disease comprises a group of prevalent inherited disorders defined by an underlying sickle cell allele that forms sickle hemoglobin. The incidence of this disease is rising, with more than 500,000 children born with it globally. The disease carries significant morbidity and mortality. Its only curative treatment was an allogeneic hematopoietic stem cell (HSC) transplant (HSCT) until late 2023, when two one-time gene therapies were approved for treating patients aged 12 years or older with severe sickle cell disease. This work aims to inform readers about these two gene therapies: one lentiviral-based and the other nonviral. The latter is based on the Nobel Prize-winning discovery of clustered, regularly interspaced, short, palindromic repeats (CRISPR)/CRISPR-associated (Cas)9 proteins and single-guide RNA (sgRNA)-based genome editing. Both approved gene therapies require an autologous HSCT with ex vivo genetically edited autologous hematopoietic stem and progenitor cells. Therefore, access to these gene therapies is limited to specialized centers with expertise in HSCTs. This review is meant for students, researchers, and clinical practitioners. It explains the basis for both approved gene therapies, their mechanisms of action, differences, risks, and other lentiviral-based and CRISPR-Cas9-based ex vivo gene therapies for sickle cell disease in clinical development. Additionally, it discusses the current state of preclinical studies for in vivo HSC gene therapy for sickle cell disease, which utilize advanced genome editing technologies developed after CRISPR-Cas9-sgRNA-based genome editing. In vivo HSC gene therapy, after it is clinically developed, would eliminate the need for an HSCT in receiving gene therapy and vastly increase access for numerous patients worldwide, even in low-income countries with the most significant disease burden. Full article

The process of aging is fundamentally driven by genomic instability and the accumulation of DNA damage, which progressively impair cellular and tissue function. In order to counteract these challenges, cells rely on the DNA damage response (DDR), a multilayered signaling and repair network that preserves genomic integrity and sustains homeostasis. Within this framework, nucleases and helicases have pivotal and complementary roles by remodeling aberrant DNA structures, generating accessible repair intermediates, and determining whether a cell achieves faithful repair, undergoes apoptosis, or enters senescence. Defects in these enzymes are exemplified in human progeroid syndromes, where inherited mutations lead to premature aging phenotypes. This phenomenon is also replicated in genetically engineered mouse models that exhibit tissue degeneration, stem cell exhaustion, and metabolic dysfunction. Beyond their canonical repair functions, helicases and nucleases also interface with the epigenome, as DNA damage-induced chromatin remodeling alters enzyme accessibility, disrupts transcriptional regulation, and drives progressive epigenetic drift and chronic inflammatory signaling. Moreover, their dysfunction accelerates the exhaustion of adult stem cell populations, such as hematopoietic, neural, and mesenchymal stem cells. As a result, tissue regeneration is undermined, establishing a self-perpetuating cycle of senescence, impaired repair, and organismal aging. Current research is focused on developing therapeutic strategies that target the DDR–aging axis on several fronts: by directly modulating repair pathways, by regulating the downstream consequences of senescence, or by preventing DNA damage from accumulating upstream. Taken together, evidence from human disease, animal models, molecular studies, and pharmacological interventions demonstrates that nucleases and helicases are not only essential for genome maintenance but also decisive in shaping aging trajectories. This provides valuable knowledge into how molecular repair pathways influence organismal longevity and age-related diseases. Full article

Desmosomal junctions provide structural stability supporting concerted cardiomyocyte contractility. Previously, we demonstrated that a deficiency in the desmosomal transmembrane cadherin desmoglein 2 (Dsg2) reduces desmosome formation and disrupts cardiac morphogenesis, leading to excessive endothelial-to-hematopoietic cell transformation and embryonic lethality. It remained unclear whether this phenotype was specifically driven by Dsg2-deficiency or was a broader consequence of impaired desmosome adhesion. To address this question, we generated Pkp2^mt/mt mouse embryos lacking the desmosomal plaque protein Pkp2, which resulted in loss of desmosome formation. Despite the absence of cardiac wall rupture, Pkp2^mt/mt and some Pkp2^wt/mt presented accumulations of Ter-119⁺ blood cells and RUNX1⁺/CD44⁺ hematopoietic stem cells in the pericardial space. Remarkably, in Pkp2^mt/mt hearts, the epicardium was detached from the myocardium, contained rounded cells expressing the hematopoietic stem cell marker RUNX1, and showed altered intermediate filament expression. These findings suggest a potential trans-differentiation of the epicardial cells into hematopoietic cells. In conclusion, deficiencies in both Dsg2 and Pkp2 promote hematopoiesis in the developing murine heart but target different cell types, i.e., endothelial cells, which lack desmosomes, or desmosome-containing epicardial cells. Our results provide evidence for the involvement of Pkp2 in epicardial morphogenesis and remodeling. Full article

Background: Posaconazole is an antifungal medication used to treat invasive fungal infections (IFI) in pediatric onco-hematological patients. Its approval for pediatric use was recent, and limitations still apply. Despite limited data, the safety and efficacy profile appear generally favorable in children. This study describes how posaconazole is used across centers affiliated with the Associazione Italiana Ematologia e Oncologia Pediatrica (AIEOP). Methods: A national survey was conducted among physicians within the AIEOP network to evaluate current use of posaconazole in pediatric cancer patients, including those undergoing hematopoietic stem cell transplantation (HSCT). A 25-item web questionnaire was developed and distributed in June 2024. Data analysis involved descriptive statistics. Results: Twenty-one of thirty-one centers (68%) responded, reporting availability of various posaconazole formulations: oral suspension (76%), delayed-release tablets (95%), and intravenous solution (14%). Posaconazole was primarily used for prophylaxis in patients with acute lymphoblastic leukemia (ALL, 38%), acute myeloid leukemia (AML, 38%), and aplastic anemia (19%). It was also used as secondary prophylaxis against previous possible or probable IFI or as salvage therapy for probable or confirmed aspergillosis or mucormycosis, often combined with other treatments. Drug plasma level monitoring was common but varied in scheduling across centers. Most centers (74%) discontinued posaconazole if adverse events suspected drug–drug interactions, such as with vincristine. Conclusions: Posaconazole is widely used in AIEOP centers, though application varies significantly. This variability emphasizes the need for prospective studies to better define indications, dosing, and monitoring protocols for pediatric use of this antifungal. Full article

Chromodomain helicase DNA-binding protein 8 (CHD8), a frequently mutated gene in autism spectrum disorder (ASD), is an ATP-dependent chromatin remodeler with emerging roles in hematopoiesis. While CHD8 is known to maintain hematopoietic stem and progenitor cells (HSPCs) in the bone marrow, its function during developmental hematopoiesis remains undefined. Here, using a zebrafish model, we demonstrate that chd8 loss severely depletes the HSPC pool in the caudal hematopoietic tissue through a p53-dependent apoptotic mechanism. Furthermore, chd8^−/− embryos exhibit a p53-independent expansion of myelopoiesis. chd8 deficiency upregulates brd4, which promotes systemic inflammatory cytokine expression. Inhibiting brd4 alleviates cytokine expression, suppresses excessive myelopoiesis, and restores HSPC development. Our findings reveal a dual regulatory mechanism in which chd8 governs HSPC development by repressing p53-mediated apoptosis and constraining brd4-driven immune cell differentiation. Full article

A systematic literature review was conducted to evaluate the emerging evidence on newborn screening (NBS) for metachromatic leukodystrophy (MLD; MIM #250100). The review focuses on (1) screening assay performance, (2) diagnostic confirmation methods and care pathways, (3) feasibility of population-based identification, and (4) the impact of early diagnosis and treatment on health outcomes. Electronic databases were searched in February 2025, and supplementary searches were performed up to 17 June 2025, for articles referencing NBS for MLD and treatments for MLD; 52 publications were eligible for inclusion. Nationwide NBS for MLD is currently carried out in Norway and large prospective pilots are running in Germany, Austria, Italy and the US. MLD meets established Wilson and Jungner criteria, with a reliable screening algorithm, established confirmatory diagnostics, and actionable care pathways. There is ongoing work to develop tools to predict disease severity and subtype. Early intervention—via gene therapy for early-onset MLD and hematopoietic stem cell transplantation (HSCT) for late-onset forms—significantly improves outcomes when initiated before symptom onset. This review provides the first comprehensive synthesis of the evidence supporting MLD for inclusion in NBS programs, underscoring the public health value of early identification and intervention. Full article

Background/Objectives: Dendritic cell (DC)-based immunotherapies offer a promising strategy for cancer treatment but are limited by inefficient activation of cytotoxic T cells and, in turn, the host immune system. This report demonstrated that CD34⁺ hematopoietic stem cell (HSC)-derived allogeneic DCs engineered by an optimized lentiviral vector (LVV) expressing CD93, CD40-ligand (CD40L), and Chemokine (C-X-C motif) ligand-13 (CXCL13) significantly enhanced the host immune system, activated tumor-specific cytotoxic T cells, and led to complete regression of both primary and metastatic pancreatic tumors in humanized mouse models. This LVV shows comparable pre-clinical efficacy compared to the first-generation vector, in addition to being compliant for clinical use, which allows further pre-clinical development towards the human trials. Methods: This 2nd generation (Gen) LVV incorporates codon-optimized transgenes (CD40L, CD93, and CXCL13) with rearranged sequence to enhance expression, driven by a strong EF1α promoter. CD34⁺ HSCs were transduced with this modified 2nd Gen LVV and differentiated to Engineered DCs. Therapeutic efficacy of the DC therapy with the modified vector was tested on humanized mouse models of pancreatic tumors. This was accomplished by establishing an early-stage disease model (using MIA PaCa-2 (MP2)-tumors) and late-stage metastatic disease model of the pancreatic tumors to mimic the clinical setting using luciferase-expressing MP2-(Luc)-pancreatic tumor-bearing humanized mice. Results: The modified lentiviral construct had 6-fold greater expression of CD40L, 2% less toxicity, 4.5-fold greater CD40L, and 2.2-fold greater CXCL13 secretion than its predecessor. In vitro, Engineered DCs induced robust T cell proliferation in up to 20% of T cells, up to 4-fold greater interferon-gamma (IFN-γ) secretion than controls, and showcased antigen-specific cytotoxicity by CD8⁺ T cells. In vivo, two intradermal doses of the 2nd Gen DCs led to complete regression of primary pancreatic tumors and metastases. Treated mice exhibited prolonged survival, indicating the induction of durable anti-tumor immunity. Conclusions: Vector optimization retained the efficacy of DC-based therapy, achieving curative responses in pancreatic tumor models. These findings support the clinical development of this 2nd Gen DC immunotherapy for pancreatic and potentially other tumors. Full article

Background/objectives: Geographic and ethnic differences influence the genetic landscape of hemophagocytic lymphohistiocytosis (HLH) and the frequency of familial HLH (FHL); this in turn can affect outcomes. Methods: We collected data on 98 patients treated for HLH between 1 January 2001 and 31 July 2024 at four tertiary centers, characterizing the genotype/phenotype correlations. Results: Half of the patients, 51 (52%), were symptomatic by age 1 year and 43 (44%) were diagnosed by that age. Our varied population included 43% Sephardic/Ashkenazi/Ethiopian Jews, 50% Muslim Arabs, and 7% Druze. Molecular analysis was performed on 90.5% of patients and revealed an FHL-related variant in 72%. The genetic variation included biallelic variants in PRF1 (21), UNC13D (12), STXBP2 (15), and STX (1). Eight hemizygous variants were found in X-linked lymphoproliferative disorder-related genes. A RAB27A monoallelic variant in an infant with a severe phenotype was considered pathogenic. The recently described HLH-related gene, ZNFX1, was mutated with varying penetrance in three symptomatic siblings. Overall, of the 94/98 with follow-up, 77% are alive. Strikingly, 5/12 (41.6%) patients with UNC13D variants died while 14/15 (93.3%) patients with STXBP2 variants survived. Logistic regression found poor prognosis associated with young age at diagnosis (p < 0.001), any variant (p = 0.016), UNC13D variant (p < 0.001), poor initial treatment response (p = 0.009), and no BMT (p = 0.005). Conclusions: Our cohort included an extremely high rate of genetic testing and detection of FHL-related variants. UNC13D variations are associated with exceedingly poor outcomes. Response to initial treatment seems crucial for positive outcomes, as does access to hematopoietic stem cell transplantation. Overall, we report a high survival rate, possibly due to a high index of suspicion and prompt diagnosis. Full article

Background: T cell regeneration in the thymus is intrinsically linked to the T cell-biased lineage differentiation of hematopoietic stem and progenitor cells (HSPCs). Although nonhuman primates (NHPs) serve as indispensable models for studying thymic output under physiological and pathological conditions, a non-animal technology facilitating efficient TCR-selected T cell development and evaluating T cell output from NHP-derived HSPCs has been lacking. To address this gap, we established a rhesus macaque-specific artificial thymic organoid (RhATO) modeling primary thymus-tissue-free thymopoiesis. Methods: The RhATO was developed by expressing Rhesus macaque (RM) Delta-like Notch ligand 1 in mouse bone marrow stromal cell line (MS5-RhDLL1). The bone marrow-derived HSPCs were aggregated with MS5-RhDLL1 and cultured forming 3D artificial thymic organoids. These organoids were maintained under defined cytokine conditions to support complete T cell developmental ontogeny. T cell developmental progression was assessed by flow cytometry, and TCR-selected subsets were analyzed for phenotypic and functional properties. Results: RhATOs recapitulated the complete spectrum of thymopoietic events, including emergence of thymus-seeding progenitors, CD4⁺CD3⁻ immature single-positive and CD4⁺CD8⁺ double-positive early thymocytes, and mature CD4⁺ or CD8⁺ single-positive subsets. These subsets expressed CD38, consistent with the recent thymic emigrant phenotype, and closely mirrored canonical T cell ontogeny described in humans. RhATO-derived T cells were TCR-selected and demonstrated cytokine expression upon stimulation. Conclusions: This study provides the first demonstration of an NHP-specific artificial thymic technology that faithfully models thymopoiesis. RhATO represents a versatile ex vivo platform for studying T cell development, immunopathogenesis, and generating TCR selected T cells. Full article

Acute myeloid leukemia (AML) is an aggressive clonal hematopoietic malignancy, characterized by marked biological heterogeneity and variable clinical outcomes. Among its rarer genetic subsets is AML with rearrangements of the MDS1 and EVI1 complex locus (MECOM), occurring in fewer than 2% of newly diagnosed cases. This review examines the biology and clinical significance of MECOM-rearranged AML, with a focus on its diverse mechanisms of leukemogenesis, including chromosomal inversion and translocation involving 3q26. We discuss how aberrant EVI1/MECOM activity alters gene expression networks and drives malignant transformation. Current therapeutic approaches—including intensive chemotherapy, hypomethylating agents in combination with venetoclax, and allogeneic stem cell transplantation—are evaluated with particular emphasis on inv(3) and other t(3q26) subtypes. Despite these treatment strategies, outcomes remain poor, underscoring the urgent need for novel, more effective therapies for this high-risk form of AML. Full article

Background: Pediatric non-Down Syndrome Acute Megakaryoblastic Leukemia (non-DS-AMKL) is a rare subtype of Acute Myeloid Leukemia (AML) arising from primitive megakaryocytes and is associated with poor outcomes. Given its high incidence of relapse, this subpopulation of children is frequently referred for allogeneic hematopoietic stem cell transplant (allo-HSCT) in first complete remission (CR1). Objectives: The objective of this study was to describe the clinical outcomes of non-DS-AMKL pediatric patients in a large, single-institution cohort. Methods: A retrospective review of the medical records of thirty-six patients diagnosed with non-DS-AMKL treated at Texas Children’s Hospital from 2000 to 2022 was conducted. Results: Twenty-nine patients were included in the analysis, with cohorts defined by intention to treat. Twelve patients received chemotherapy only during upfront therapy, and seventeen received upfront HSCT. The 5-year overall survival (OS) and disease-free survival (DFS) for the entire cohort were 19.1% and 24.1%, respectively, with a median survival of 17.4 months. A higher percentage of patients in the chemotherapy-only group had relapsed/refractory disease at death (chemotherapy only, n = 9; HSCT, n = 8). However, 5-year OS and DFS were similar for both groups (OS = 18.8% vs. 31.3%, p = 0.58; DFS = 37.6% vs. 22.2%, p = 0.51). Relapse was the leading cause of death (5-year cumulative incidence of relapse (CIR) 0.78). Treatment with allo-HSCT did not improve outcomes due to the high CIR, even after HSCT in CR1. Conclusions: These dismal outcomes highlight the need for development and incorporation of novel targeted agents into upfront therapy or in the post-HSCT setting for patients with this challenging disease. Full article

Background: Myelosuppression is one of the most common chemotherapy side effects, seriously threatening the quality of life of cancer patients. Studies have shown that velvet antler polypeptides (VAPs) could enhance immunity and anti-aging and also have a hematopoietic-promoting effect. However, there are relatively few studies on the treatment of myelosuppression with VAPs, and the therapeutic mechanism remains unclear. Methods: This study employed both in vitro and in vivo models to explore the mechanism of VAPs against myelosuppression. In this study, the cyclophosphamide (CTX)-induced bone marrow mesenchymal stem cell (BMSC) injury model was used to evaluate the effects of VAPs on cell viability, apoptosis, reactive oxygen species activity, and protein expression. Furthermore, a CTX-induced myelosuppression mouse model was employed to evaluate peripheral blood counts, organ indices, femoral tissue histopathology, immunohistochemical expression of CD34, VEGF, and Notch1, and key proteins in the Notch1/PI3K/AKT pathway in vivo. Results: Our results showed that VAPs protected BMSCs from CTX-induced apoptosis, inhibited ROS production, and promoted the secretion of VEGF, TPO, and VCAM-1, thereby improving the bone marrow microenvironment. Furthermore, the results showed that VAPs improved the peripheral blood counts and bone marrow nucleated cell (BMNC) count in CTX-induced myelosuppression mice and ameliorated pathological injury of the spleen, thymus, and liver. VAPs inhibited the apoptosis of bone marrow cells, manifested by regulating the expression levels of proteins like PI3K/p-PI3K, AKT/p-AKT, Bcl-2, Bax, and Caspase-3. Simultaneously, it upregulated the expression of Notch1 and Hes1 proteins. The application of the PI3K inhibitor LY294002 and the Notch1 inhibitor DAPT demonstrated that the ameliorative effect of VAPs on myelosuppression was dependent on the activation of both the Notch1 and PI3K/AKT pathways. Conclusions: Our study indicates that VAPs may achieve treatment of myelosuppression by improving the hematopoietic microenvironment, inhibiting apoptosis of mouse bone marrow cells, and regulating the Notch1 and PI3K/AKT signaling pathways. Full article

Inherited platelet function disorders (IPFD) are characterized by normal platelet count and morphology but impaired function due to pathogenic variants in genes encoding membrane receptors, granule constituents, or intracellular signaling proteins. Glanzmann’s thrombasthenia, the most representative IPFD, results from ITGA2B or ITGB3 mutations that disrupt the αIIbβ3 integrin complex, producing severe mucocutaneous bleeding. Advances in molecular genetics have expanded the IPFDs landscape to include defects in other platelet receptors (Glycoprotein (GP)-VI, P2Y₁₂, and thromboxane A₂[TxA₂]-R), signaling mediators (RASGRP2, FERMT3, G-protein regulators, PLC, and TxA₂ pathway enzymes), and granule biogenesis disorders such as Hermansky–Pudlak and Chediak–Higashi syndromes. High-throughput sequencing technologies, including long-read approaches, have greatly improved diagnostic yield and clarified genotype–phenotype correlations. Clinically, bleeding severity varies from mild to life-threatening, and management relies on antifibrinolytics, desmopressin, or platelet transfusion; recombinant activated factor VII and hematopoietic stem cell transplantation are reserved for selected cases. Emerging strategies such as gene therapy and bispecific antibodies that link platelets and coagulation factors represent promising advances toward targeted and preventive treatment. A better knowledge of the clinical features and understanding molecular pathogenesis of IPFDs not only enhances diagnostic precision and therapeutic options but also provides key insights into platelet biology, intracellular signaling, and the broader mechanisms of human hemostasis. Full article

Myelodysplastic neoplasms represent a diverse group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, peripheral cytopenias, and an inherent risk of progression to acute myeloid leukemia. Accurate risk assessment and patient stratification are critical to optimizing therapeutic approaches and clinical outcomes. In 2022, significant advancements reshaped both the classification and prognostic stratification of MDSs. The revised WHO Classification introduced crucial genetically defined subtypes, particularly those involving biallelic TP53 inactivation and SF3B1 mutations, shifting the emphasis from traditional morphology-based criteria to molecular ones. Simultaneously, morphological subtypes such as hypoplastic and hyperfibrotic MDSs were established as distinct entities with unique prognostic implications. At the same time, the introduction of the International Molecular Prognostic Scoring System (IPSS-M) provided a more precise prognostic stratification by integrating comprehensive molecular data alongside traditional clinical and cytogenetic parameters. Several validation studies have confirmed IPSS-M’s superior discriminative power compared to previous models, notably IPSS-R, improving predictions regarding overall survival and leukemia transformation. Nevertheless, practical considerations regarding the widespread application of IPSS-M have emerged, including concerns over economic feasibility and accessibility of advanced molecular testing methods, such as extensive Next-Generation Sequencing panels. This review synthesizes the recent literature and critical studies validating these classification and prognostic updates, discussing their clinical impact, practical considerations, and implications for targeted therapeutic strategies. By focusing on molecular pathogenesis, the latest classification systems and prognostic models promise significant advances in patient-specific management, setting the stage for future innovations in treatment and improved patient outcomes. Full article