Foetal haemoglobin elevation, unfavourable prognosis, and protective role of genetic variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 in children with ALL.

In acute lymphoblastic leukaemia (ALL), elevated foetal haemoglobin (HbF) levels have been associated with the prognosis of patients. Genetic variants in HbF regulatory genes: BAF chromatin remodelling complex subunit (BCL11A), HBS1L-MYB transcriptional GTPase intergenic region (HBS1L-MYB), Krüppel-like factor 1 (KLF1), haemoglobin gamma subunit 2 (HBG2), haemoglobin gamma subunit 1 (HBG1), and haemoglobin subunit beta pseudogene 1 (HBBP1) are often associatedwith elevatedHbF concentration. This study investigated the association of genetic variants in HbF regulatory genes with HbF concentration, unfavourable prognosis, and outcome in children with ALL.We quantified HbF concentration and genotyped 17 genetic variants in 48 patients with ALL and 64 children without ALL as a reference group. HbF concentrationwas higher in patients than in the reference group (4.4%vs 1.4%), and 75%(n = 36) of thepatientshadHbF>2.5%.Unfavourable prognosis ALL was established in 68.8% (n = 33) of the patients. Variant HBG2 rs7482144 was associated with high HbF concentration (P = 0.015); while HBS1L-MYB rs9399137 (P = 0.001), HBG2 rs7482144 (P = 0.001) and the ß-globin genes HBG2, HBG1, and HBPP1 haplotypeTGC(P = 0.017) with unfavourable prognosisALL.Additionally, variantBCL11A rs4671393 showed a protective role (P = 0.0001). In conclusion, variants HBG2 rs7482144, HBS1L-MYB rs9399137 and BCL11A rs4671393 may play a significant role in ALL.

Ferroptosis inhibitor alleviates sorafenib-induced cardiotoxicity by attenuating KLF11-mediated FSP1-dependent ferroptosis.

Sorafenib is a standard first-line drug for advanced hepatocellular carcinoma, but the serious cardiotoxic effects restrict its therapeutic applicability. Here, we show that iron-dependent ferroptosis plays a vital role in sorafenib-induced cardiotoxicity. Remarkably, our in vivo and in vitro experiments demonstrated that ferroptosis inhibitor application neutralized sorafenib-induced heart injury. By analyzing transcriptome profiles of adult human sorafenib-treated cardiomyocytes, we found that Krüppel-like transcription factor 11 (KLF11) expression significantly increased after sorafenib stimulation. Mechanistically, KLF11 promoted ferroptosis by suppressing transcription of ferroptosis suppressor protein 1 (FSP1), a seminal breakthrough due to its ferroptosis-repressing properties. Moreover, FSP1 knockdown showed equivalent results to glutathione peroxidase 4 (GPX4) knockdown, and FSP1 overexpression counteracted GPX4 inhibition-induced ferroptosis to a substantial extent. Cardiac-specific overexpression of FSP1 and silencing KLF11 by an adeno-associated virus serotype 9 markedly improved cardiac dysfunction in sorafenib-treated mice. In summary, FSP1-mediated ferroptosis is a crucial mechanism for sorafenib-provoked cardiotoxicity, and targeting ferroptosis may be a promising therapeutic strategy for alleviating sorafenib-induced cardiac damage.

Oxidative stress promotes liver fibrosis by modulating the microRNA-144 and SIN3A-p38 pathways in hepatic stellate cells.

Background & Aims: Reactive oxygen species (ROS) act as modulators triggering cellular dysfunctions and organ damage including liver fibrosis in which hepatic stellate cell (HSC) activation plays a key role. Previous studies suggest that microRNA-144 (miR-144) acts as a pro-oxidant molecule; however, whether and how miR-144 affects HSC activation and liver fibrosis remain unknown. Methods: Carbon tetrachloride (CCl4) and bile duct ligation (BDL)-induced experimental liver fibrosis models were used. Hepatic miR-144 expression was analyzed by miRNA in situ hybridization with RNAscope probe. The in vivo effects of silencing or overexpressing miR-144 were examined with an adeno-associated virus 6 (AAV6) carrying miR-144 inhibitor or mimics in fibrotic mouse experimental models. Results: In this study, we demonstrated that ROS treatment significantly upregulated miR-144 in HSCs, which further promoted HSC activation in vitro. Interestingly, miR-144 was preferentially elevated in HSCs of experimental liver fibrosis in mice and in human liver fibrotic tissues. Furthermore, in vivo loss or gain-of-function experiments via AAV6 carrying miR-144 antagomir or agomir revealed that blockade of miR-144 in HSCs mitigated, while overexpression of miR-144 in HSCs accelerated the development of experimental liver fibrosis. Mechanistically, SIN3 transcription regulator family member A (SIN3A), a transcriptional repressor, was identified to be the target of miR-144 in HSCs. MiR-144 downregulated Sin3A, and in line with this result, specific knockdown of Sin3a in HSCs remarkedly activated p38 MAPK signaling pathway to promote HSC activation, eventually exacerbating liver fibrosis. Conclusions: Oxidative stress-driven miR-144 fuels HSC activation and liver fibrogenesis by limiting the SIN3A-p38 axis. Thus, a specific inhibition of miR-144 in HSCs could be a novel therapeutic strategy for the treatment of liver fibrosis.

ISWI chromatin remodeling complexes recruit NSD2 and H3K36me2 in pericentromeric heterochromatin.

Histone H3 lysine36 dimethylation (H3K36me2) is generally distributed in the gene body and euchromatic intergenic regions. However, we found that H3K36me2 is enriched in pericentromeric heterochromatin in some mouse cell lines. We here revealed the mechanism of heterochromatin targeting of H3K36me2. Among several H3K36 methyltransferases, NSD2 was responsible for inducing heterochromatic H3K36me2. Depletion and overexpression analyses of NSD2-associating proteins revealed that NSD2 recruitment to heterochromatin was mediated through the imitation switch (ISWI) chromatin remodeling complexes, such as BAZ1B-SMARCA5 (WICH), which directly binds to AT-rich DNA via a BAZ1B domain-containing AT-hook-like motifs. The abundance and stoichiometry of NSD2, SMARCA5, and BAZ1B could determine the localization of H3K36me2 in different cell types. In mouse embryos, H3K36me2 heterochromatin localization was observed at the two- to four-cell stages, suggesting its physiological relevance.

Pyruvate kinase M2 sustains cardiac mitochondrial integrity in septic cardiomyopathy by regulating PHB2-dependent mitochondrial biogenesis.

Previous studies have highlighted the protective effects of pyruvate kinase M2 (PKM2) overexpression in septic cardiomyopathy. In our study, we utilized cardiomyocyte-specific PKM2 knockout mice to further investigate the role of PKM2 in attenuating LPS-induced myocardial dysfunction, focusing on mitochondrial biogenesis and prohibitin 2 (PHB2). Our findings confirmed that the deletion of PKM2 in cardiomyocytes significantly exacerbated LPS-induced myocardial dysfunction, as evidenced by impaired contractile function and relaxation. Additionally, the deletion of PKM2 intensified LPS-induced myocardial inflammation. At the molecular level, LPS triggered mitochondrial dysfunction, characterized by reduced ATP production, compromised mitochondrial respiratory complex I/III activities, and increased ROS production. Intriguingly, the absence of PKM2 further worsened LPS-induced mitochondrial damage. Our molecular investigations revealed that LPS disrupted mitochondrial biogenesis in cardiomyocytes, a disruption that was exacerbated by the absence of PKM2. Given that PHB2 is known as a downstream effector of PKM2, we employed PHB2 adenovirus to restore PHB2 levels. The overexpression of PHB2 normalized mitochondrial biogenesis, restored mitochondrial integrity, and promoted mitochondrial function. Overall, our results underscore the critical role of PKM2 in regulating the progression of septic cardiomyopathy. PKM2 deficiency impeded mitochondrial biogenesis, leading to compromised mitochondrial integrity, increased myocardial inflammation, and impaired cardiac function. The overexpression of PHB2 mitigated the deleterious effects of PKM2 deletion. This discovery offers a novel insight into the molecular mechanisms underlying septic cardiomyopathy and suggests potential therapeutic targets for intervention.

A conserved molecular logic for neurogenesis to gliogenesis switch in the cerebral cortex.

During development, neural stem cells in the cerebral cortex, also known as radial glial cells (RGCs), generate excitatory neurons, followed by production of cortical macroglia and inhibitory neurons that migrate to the olfactory bulb (OB). Understanding the mechanisms for this lineage switch is fundamental for unraveling how proper numbers of diverse neuronal and glial cell types are controlled. We and others recently showed that Sonic Hedgehog (Shh) signaling promotes the cortical RGC lineage switch to generate cortical oligodendrocytes and OB interneurons. During this process, cortical RGCs generate intermediate progenitor cells that express critical gliogenesis genes Ascl1, Egfr, and Olig2. The increased Ascl1 expression and appearance of Egfr+ and Olig2+ cortical progenitors are concurrent with the switch from excitatory neurogenesis to gliogenesis and OB interneuron neurogenesis in the cortex. While Shh signaling promotes Olig2 expression in the developing spinal cord, the exact mechanism for this transcriptional regulation is not known. Furthermore, the transcriptional regulation of Olig2 and Egfr has not been explored. Here, we show that in cortical progenitor cells, multiple regulatory programs, including Pax6 and Gli3, prevent precocious expression of Olig2, a gene essential for production of cortical oligodendrocytes and astrocytes. We identify multiple enhancers that control Olig2 expression in cortical progenitors and show that the mechanisms for regulating Olig2 expression are conserved between the mouse and human. Our study reveals evolutionarily conserved regulatory logic controlling the lineage switch of cortical neural stem cells.

TRPS1 maintains luminal progenitors in the mammary gland by repressing SRF/MRTF activity.

The transcription factor TRPS1 is a context-dependent oncogene in breast cancer. In the mammary gland, TRPS1 activity is restricted to the luminal population and is critical during puberty and pregnancy. Its function in the resting state remains however unclear. To evaluate whether it could be a target for cancer therapy, we investigated TRPS1 function in the healthy adult mammary gland using a conditional ubiquitous depletion mouse model where long-term depletion does not affect fitness. Using transcriptomic approaches, flow cytometry and functional assays, we show that TRPS1 activity is essential to maintain a functional luminal progenitor compartment. This requires the repression of both YAP/TAZ and SRF/MRTF activities. TRPS1 represses SRF/MRTF activity indirectly by modulating RhoA activity. Our work uncovers a hitherto undisclosed function of TRPS1 in luminal progenitors intrinsically linked to mechanotransduction in the mammary gland. It may also provide new insights into the oncogenic functions of TRPS1 as luminal progenitors are likely the cells of origin of many breast cancers.

Combined Effects of Clonal Hematopoiesis and Carotid Stenosis on Cardiovascular Mortality.

BACKGROUND: The expansion of hematopoietic stem cells caused by acquired somatic mutations (clonal hematopoiesis [CH]) is a novel cardiovascular risk factor. The prognostic value of CH in patients with carotid atherosclerosis remains to be evaluated. OBJECTIVES: This study assessed the prognostic significance of CH in patients with atherosclerosis as detected by ultrasound of the carotid artery. METHODS: We applied deep sequencing of selected genomic regions within the genes DNMT3A, TET2, ASXL1, and JAK2 to screen for CH in 968 prospectively collected patients with asymptomatic carotid atherosclerosis evaluated by duplex sonography. RESULTS: We detected clonal markers at variant allele frequency ≥2% in 133 (13.7%) of 968 patients (median age 69.2 years), with increasing prevalence at advanced age. Multivariate analyses including age and established cardiovascular risk factors revealed overall presence of CH to be significantly associated with increased risk of cardiovascular death (HR: 1.50; 95% CI: 1.12-2.00; P = 0.007), reflected also at the single gene level. The effect of CH was more pronounced in older patients and independent of the patients' inflammatory status as measured by high-sensitivity C-reactive protein. Simultaneous assessment of CH and degree of carotid stenosis revealed combined effects on cardiovascular mortality, depicted by a superior risk for patients with >50% stenosis and concomitant CH (adjusted HR: 1.60; 95% CI: 1.08-2.38; P = 0.020). CONCLUSIONS: CH status in combination with the extent of carotid atherosclerosis jointly predict long-term mortality. Determination of CH can provide additional prognostic information in patients with asymptomatic carotid atherosclerosis.

Comprehensive analysis of the REST transcription factor regulatory networks in IDH mutant and IDH wild-type glioma cell lines and tumors.

The RE1-silencing transcription factor (REST) acts either as a repressor or activator of transcription depending on the genomic and cellular context. REST is a key player in brain cell differentiation by inducing chromatin modifications, including DNA methylation, in a proximity of its binding sites. Its dysfunction may contribute to oncogenesis. Mutations in IDH1/2 significantly change the epigenome contributing to blockade of cell differentiation and glioma development. We aimed at defining how REST modulates gene activation and repression in the context of the IDH mutation-related phenotype in gliomas. We studied the effects of REST knockdown, genome wide occurrence of REST binding sites, and DNA methylation of REST motifs in IDH wild type and IDH mutant gliomas. We found that REST target genes, REST binding patterns, and TF motif occurrence proximal to REST binding sites differed in IDH wild-type and mutant gliomas. Among differentially expressed REST targets were genes involved in glial cell differentiation and extracellular matrix organization, some of which were differentially methylated at promoters or gene bodies. REST knockdown differently impacted invasion of the parental or IDH1 mutant glioma cells. The canonical REST-repressed gene targets showed significant correlation with the GBM NPC-like cellular state. Interestingly, results of REST or KAISO silencing suggested the interplay between these TFs in regulation of REST-activated and repressed targets. The identified gene regulatory networks and putative REST cooperativity with other TFs, such as KAISO, show distinct REST target regulatory networks in IDH-WT and IDH-MUT gliomas, without concomitant DNA methylation changes. We conclude that REST could be an important therapeutic target in gliomas.

Valproic Acid Treatment after Traumatic Brain Injury in Mice Alleviates Neuronal Death and Inflammation in Association with Increased Plasma Lysophosphatidylcholines.

The histone deacetylase inhibitor (HDACi) valproic acid (VPA) has neuroprotective and anti-inflammatory effects in experimental traumatic brain injury (TBI), which have been partially attributed to the epigenetic disinhibition of the transcription repressor RE1-Silencing Transcription Factor/Neuron-Restrictive Silencer Factor (REST/NRSF). Additionally, VPA changes post-traumatic brain injury (TBI) brain metabolism to create a neuroprotective environment. To address the interconnection of neuroprotection, metabolism, inflammation and REST/NRSF after TBI, we subjected C57BL/6N mice to experimental TBI and intraperitoneal VPA administration or vehicle solution at 15 min, 1, 2, and 3 days post-injury (dpi). At 7 dpi, TBI-induced an up-regulation of REST/NRSF gene expression and HDACi function of VPA on histone H3 acetylation were confirmed. Neurological deficits, brain lesion size, blood-brain barrier permeability, or astrogliosis were not affected, and REST/NRSF target genes were only marginally influenced by VPA. However, VPA attenuated structural damage in the hippocampus, microgliosis and expression of the pro-inflammatory marker genes. Analyses of plasma lipidomic and polar metabolomic patterns revealed that VPA treatment increased lysophosphatidylcholines (LPCs), which were inversely associated with interleukin 1 beta (Il1b) and tumor necrosis factor (Tnf) gene expression in the brain. The results show that VPA has mild neuroprotective and anti-inflammatory effects likely originating from favorable systemic metabolic changes resulting in increased plasma LPCs that are known to be actively taken up by the brain and function as carriers for neuroprotective polyunsaturated fatty acids.

The factor inhibiting HIF regulates T cell differentiation and anti-tumour efficacy.

T cells must adapt to variations in tissue microenvironments; these adaptations include the degree of oxygen availability. The hypoxia-inducible factor (HIF) transcription factors control much of this adaptation, and thus regulate many aspects of T cell activation and function. The HIFs are in turn regulated by oxygen-dependent hydroxylases: both the prolyl hydroxylases (PHDs) which interact with the VHL tumour suppressor and control HIF turnover, and the asparaginyl hydroxylase known as the Factor inhibiting HIF (FIH), which modulates HIF transcriptional activity. To determine the role of this latter factor in T cell function, we generated T cell-specific FIH knockout mice. We found that FIH regulates T cell fate and function in a HIF-dependent manner and show that the effects of FIH activity occur predominantly at physiological oxygen concentrations. T cell-specific loss of FIH boosts T cell cytotoxicity, augments T cell expansion in vivo, and improves anti-tumour immunotherapy in mice. Specifically inhibiting FIH in T cells may therefore represent a promising strategy for cancer immunotherapy.

[Advance of research on the role of BCL11A in the occurrence and treatment of ß-Thalassemia].

ß-Thalassemia is a single-gene disease caused by mutations in ß-globin and has a distinct geographical characteristics. Current treatment for patients with moderate to severe thalassemia has mainly relied on long-term blood transfusion and/or hematopoietic stem cell transplantation. B cell lymphoma/leukemia 11A (BCL11A) as a transcriptional repressor plays a vital role in monitoring γ/ß hemoglobin switching, maintaining the normal function of hematopoietic stem cells, and regulating erythrocyte differentiation and lymphocyte development. With the rapid progress in gene editing technology, the BCL11A as a therapeutic target for ß-thalassemia has shown promising results. This article has systematically summarized the regulatory mechanism and therapeutic potential of the BCL11A, with an aim to provide new ideas for the treatment of ß-thalassemia.

[Primary cardiac synovial sarcoma: a clinicopathological analysis of five cases].

Objective: To assess the clinicopathological features, immunophenotype, molecular characteristics and differential diagnosis of primary cardiac synovial sarcoma (PCSS). Methods: Five cases of PCSS were collected at Guangdong Provincial People's Hospital from 2008 to 2023, and their clinicopathological features were summarized. Immunohistochemical staining, fluorescence in-situ hybridization (FISH) and next-generation sequencing (NGS) were performed, and relevant literatures were reviewed. Results: The cases were found in four males and one female, ranging in ages from 16 to 51 years (median 30 years). Two cases were located in the pericardium, two in the right ventricle, and one in the left ventricle. Follow-up data were available in four cases. All the four patients died of disease at 3, 7, 13 and 26 months, respectively, after diagnosis. The tumor maximum diameter ranged from 6.0 to 14.0 cm in (mean 10.0 cm). Microscopically, three cases were monophasic and two cases were biphasic. Immunohistochemically, all cases were immunoreactive for EMA, vimentin, bcl-2 and CD56. The tumor cells were variably positive for pan-cytokeratin, SS18-SSX, SOX2, TLE1, CD99, synaptophysin, calretinin and calponin. FISH showed the presence of SS18 rearrangement in all the cases. NGS detected SS18-SSX gene fusion in three cases (SS18-SSX1 in one and SS18-SSX2 in two). Conclusions: PCSS is an exceedingly rare neoplasm, and should be distinguished from other various malignant epithelial and mesenchymal tumors. The clinical history, histopathological and immunohistochemical features, and molecular findings are all essential to the definitive diagnosis of PCSS.

Associations in cell type-specific hydroxymethylation and transcriptional alterations of pediatric central nervous system tumors.

Although intratumoral heterogeneity has been established in pediatric central nervous system tumors, epigenomic alterations at the cell type level have largely remained unresolved. To identify cell type-specific alterations to cytosine modifications in pediatric central nervous system tumors, we utilize a multi-omic approach that integrated bulk DNA cytosine modification data (methylation and hydroxymethylation) with both bulk and single-cell RNA-sequencing data. We demonstrate a large reduction in the scope of significantly differentially modified cytosines in tumors when accounting for tumor cell type composition. In the progenitor-like cell types of tumors, we identify a preponderance differential Cytosine-phosphate-Guanine site hydroxymethylation rather than methylation. Genes with differential hydroxymethylation, like histone deacetylase 4 and insulin-like growth factor 1 receptor, are associated with cell type-specific changes in gene expression in tumors. Our results highlight the importance of epigenomic alterations in the progenitor-like cell types and its role in cell type-specific transcriptional regulation in pediatric central nervous system tumors.

Dual T cell receptor/chimeric antigen receptor engineered NK-92 cells targeting the HPV16 E6 oncoprotein and the tumor-associated antigen L1CAM exhibit enhanced cytotoxicity and specificity against tumor cells.

The human papillomavirus type 16 (HPV16) causes a large fraction of genital and oropharyngeal carcinomas. To maintain the transformed state, the tumor cells must continuously synthesize the E6 and E7 viral oncoproteins, which makes them tumor-specific antigens. Indeed, specific T cell responses against them have been well documented and CD8+ T cells engineered to express T cell receptors (TCRs) that recognize epitopes of E6 or E7 have been tested in clinical studies with promising results, yet with limited clinical success. Using CD8+ T cells from peripheral blood of healthy donors, we have identified two novel TCRs reactive to an unexplored E618-26 epitope. These TCRs showed limited standalone cytotoxicity against E618-26-HLA-A*02:01-presenting tumor cells. However, a single-signaling domain chimeric antigen receptor (ssdCAR) targeting L1CAM, a cell adhesion protein frequently overexpressed in HPV16-induced cancer, prompted a synergistic effect that significantly enhanced the cytotoxic capacity of NK-92/CD3/CD8 cells armored with both TCR and ssdCAR when both receptors simultaneously engaged their respective targets, as shown by live microscopy of 2-D and 3-D co-cultures. Thus, virus-specific TCRs from the CD8+ T cell repertoire of healthy donors can be combined with a suitable ssdCAR to enhance the cytotoxic capacity of the effector cells and, indirectly, their specificity.

The homeostatic effects of the RE-1 silencing transcription factor on cortical networks are altered under ictogenic conditions in the mouse.

AIM: The Repressor Element-1 Silencing Transcription Factor (REST) is an epigenetic master regulator playing a crucial role in the nervous system. In early developmental stages, REST downregulation promotes neuronal differentiation and the acquisition of the neuronal phenotype. In addition, postnatal fluctuations in REST expression contribute to shaping neuronal networks and maintaining network homeostasis. Here we investigate the role of the early postnatal deletion of neuronal REST in the assembly and strength of excitatory and inhibitory synaptic connections. METHODS: We investigated excitatory and inhibitory synaptic transmission by patch-clamp recordings in acute neocortical slices in a conditional knockout mouse model (RestGTi) in which Rest was deleted by delivering PHP.eB adeno-associated viruses encoding CRE recombinase under the control of the human synapsin I promoter in the lateral ventricles of P0-P1 pups. RESULTS: We show that, under physiological conditions, Rest deletion increased the intrinsic excitability of principal cortical neurons in the primary visual cortex and the density and strength of excitatory synaptic connections impinging on them, without affecting inhibitory transmission. Conversely, in the presence of a pathological excitation/inhibition imbalance induced by pentylenetetrazol, Rest deletion prevented the increase in synaptic excitation and decreased seizure severity. CONCLUSION: The data indicate that REST exerts distinct effects on the excitability of cortical circuits depending on whether it acts under physiological conditions or in the presence of pathologic network hyperexcitability. In the former case, REST preserves a correct excitatory/inhibitory balance in cortical circuits, while in the latter REST loses its homeostatic activity and may become pro-epileptogenic.

Predictors of radioiodine (RAI)-avidity restoration for NTRK fusion-positive RAI-resistant metastatic thyroid cancers.

Context: Two-thirds of metastatic differentiated thyroid cancer (DTC) patients have radioiodine (RAI)-resistant disease, resulting in poor prognosis and high mortality. For rare NTRK and RET fusion-positive metastatic, RAI-resistant thyroid cancers, variable success of re-induction of RAI avidity during treatment with NTRK or RET inhibitors has been reported. Case presentation and results: We report two cases with RAI-resistant lung metastases treated with larotrectinib: an 83-year-old male presenting with an ETV6::NTRK3 fusion-positive tumor with the TERT promoter mutation c.-124C>T, and a 31-year-old female presenting with a TPR::NTRK1 fusion-positive tumor (and negative for TERT promoter mutation). Post larotrectinib treatment, diagnostic I-123 whole body scan revealed unsuccessful RAI-uptake re-induction in the TERT-positive tumor, with a thyroid differentiation score (TDS) of -0.287. In contrast, the TERT-negative tumor exhibited successful I-131 reuptake with a TDS of -0.060. Conclusion: As observed for RAI-resistance associated with concurrent TERT and BRAF mutations, the co-occurrence of TERT mutations and NTRK fusions may also contribute to re-sensitization failure.

Foxp1 suppresses cortical angiogenesis and attenuates HIF-1alpha signaling to promote neural progenitor cell maintenance.

Neural progenitor cells within the cerebral cortex undergo a characteristic switch between symmetric self-renewing cell divisions early in development and asymmetric neurogenic divisions later. Yet, the mechanisms controlling this transition remain unclear. Previous work has shown that early but not late neural progenitor cells (NPCs) endogenously express the autism-linked transcription factor Foxp1, and both loss and gain of Foxp1 function can alter NPC activity and fate choices. Here, we show that premature loss of Foxp1 upregulates transcriptional programs regulating angiogenesis, glycolysis, and cellular responses to hypoxia. These changes coincide with a premature destabilization of HIF-1α, an elevation in HIF-1α target genes, including Vegfa in NPCs, and precocious vascular network development. In vitro experiments demonstrate that stabilization of HIF-1α in Foxp1-deficient NPCs rescues the premature differentiation phenotype and restores NPC maintenance. Our data indicate that the endogenous decline in Foxp1 expression activates the HIF-1α transcriptional program leading to changes in the tissue environment adjacent to NPCs, which, in turn, might alter their self-renewal and neurogenic capacities.

Exagamglogene Autotemcel for Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs). METHODS: We conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent ß-thalassemia and a ß0/ß0, ß0/ß0-like, or non-ß0/ß0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed. RESULTS: A total of 52 patients with transfusion-dependent ß-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred. CONCLUSIONS: Treatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent ß-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.).