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New purple sulfur bacteria genomes from Nebraska salt marsh enrichments.

Two genomes from a Winogradsky column enrichment from the Nebraska salt marshes were sequenced. The analysis of whole-genome phylogeny and average nucleotide identity comparisons indicated that these belong to species of purple sulfur bacteria, Halochromatium and Ectothiorhodospira marina, that have not been described before.

Ectothiorhodospira↗

Anti-psychotic drugs act synergistically in combination with antifungal drugs to inhibit drug-resistant Cryptococcus neoformans and Candida albicans.

UNLABELLED: Systemic fungal infections cause an estimated 3.8 million deaths annually, approximately 10% of which are caused by drug-resistant infections. With only five classes of antifungal drugs, treatment options are limited. Here, we explore synergistic drug combinations-when the efficacy of two drugs combined is greater than expected based on the sum of each individual drug's efficacy-to improve treatment of drug-resistant Cryptococcus neoformans and Candida albicans. Chlorpromazine acts synergistically with both amphotericin B and fluconazole against multiple fungal species, including azole-resistant C. neoformans and C. albicans. We then performed a genome-wide knockout mutant screen and found that ESCRT pathway mutants are resistant to chlorpromazine, while knockout mutants of genes involved in fatty acid biosynthesis are sensitive. Based on these data, we investigated sterol and fatty acid composition in chlorpromazine-treated cells and found only minor increases in sterol precursors, but a substantial increase in lipid droplet size and decreased lipid droplet numbers. This lipid droplet formation potentially sequesters lipid bioavailability and response to membrane stress. Together, these data suggest that chlorpromazine and its analogs are potentially promising treatments for systemic fungal infections that act via lipid homeostasis and stress response. IMPORTANCE: Fungal infections are a large and expensive health burden with high mortality rates. People with compromised immune systems from cancer, solid organ transplant, HIV infection, and other conditions are particularly affected. Systemic fungal infections are difficult to treat because there are few available drugs and treatment periods last months or years. Long treatment times increase the risk of treatment failure and can contribute to the rise of resistance. We identified an additional class of drugs, chlorpromazine and other phenothiazine drugs, that amplify the activity of existing antifungal drugs amphotericin B (AmB) and fluconazole (FLZ). AmB and FLZ act by targeting ergosterol, the fungal equivalent of cholesterol, which is required for a functional plasma membrane. Chlorpromazine increases the formation of lipid drops, which sequester lipids such as ergosterol. When chlorpromazine is combined with AmB, the fungal cell cannot respond to the plasma membrane damage caused by AmB, inhibiting the fungal cells. This work identifies new target processes and drugs that could treat deadly fungal infections.

antifungal resistance↗

A bireporter recombinant SARS-CoV-2 Omicron BA.5 for in vitro and in vivo studies.

The continuous emergence of variants of concern (VoCs) represents a significant challenge to effectively control severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although FDA-approved vaccines and antivirals have been successfully developed and implemented for the prophylactic and therapeutic intervention of SARS-CoV-2 infection, recent VoCs could escape protection garnered by previous vaccine and antiviral approaches. Determining the efficacy of prophylactics and/or therapeutics against recent VoCs will assist in efficiently controlling currently circulating SARS-CoV-2 strains. We used our previously described bacterial artificial chromosome-based reverse genetics approach for Omicron BA.5 to generate a recombinant SARS-CoV-2 BA.5 encoding a fusion of ZsGreen to Nanoluciferase (rBA.5 ZsG-Nluc) from the locus of the viral nucleocapsid (N) protein separated by the porcine teschovirus-1 2A proteolytic cleavage site. The rBA.5 ZsG-Nluc replicates to levels comparable to recombinant BA.5 wild type (rBA.5 WT) and expresses high levels of ZsG and Nluc in cultured cells. This facilitates tracking viral infection and the identification of antivirals and neutralizing antibodies with EC50 and NT50 values, respectively, similar to those obtained with rBA.5 WT. Importantly, in Keratin-18 human angiotensin-converting enzyme-2 mice, rBA.5 ZsG-Nluc retains the same pathogenicity and ability to replicate in the lungs of infected mice as rBA.5 WT. Using rBA.5 ZsG-Nluc, we detected Nluc activity systemically and Nluc and ZsG expression in the lungs of infected mice using an in vivo imaging system. Our results demonstrate the feasibility of using rBA.5 ZsG-Nluc to track viral infections and identify prophylactics and therapeutics against recent SARS-CoV-2 VoCs in vitro, ex vivo, and in vivo.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of the coronavirus disease 2019 pandemic, is continually evolving to escape immunity acquired by previous natural infections or vaccinations. Moreover, recent SARS-CoV-2 variants of concern (VoCs) have acquired antiviral-resistant mutations to FDA-approved drugs. The emergence of these VoCs highlights the importance of identifying new prophylactics and therapeutics against currently circulating SARS-CoV-2 strains. We generated a recombinant bireporter Omicron BA.5 SARS-CoV-2 (rBA.5 ZsG-Nluc) that expresses reporter proteins, which are useful for cellular and whole animal studies, and has similar viral replication and pathogenicity to a wild-type recombinant Omicron BA.5 SARS-CoV-2. In Keratin-18 human angiotensin-converting enzyme-2 mice, rBA.5 ZsG-Nluc infection can be tracked systemically or in the lungs of infected mice using an in vivo imaging system. We establish a proof-of-concept platform of rBA.5 ZsG-Nluc in combination with an ancestral SARS-CoV-2 strain expressing mCherry to simultaneously identify antivirals and neutralizing antibodies against original and recent SARS-CoV-2 strains.

SARS-CoV-2↗

Markers of microvascular instability predict severity and survival in idiopathic pulmonary fibrosis.

INTRODUCTION: Most research on idiopathic pulmonary fibrosis (IPF) has focused on the interplay among fibroblasts, the immune system and epithelial cells. There is growing evidence that microvascular dysfunction also plays a role in disease progression, but large human translational studies are lacking. In this research, we aim to identify a proteomic signature of microvascular instability and assess the impact of current therapeutics on the microvasculature. METHODS: Olink proteomic data from patients with IPF were obtained from the Pulmonary Fibrosis Foundation Patient Registry (PFF-PR) (n=914) and an independent validation cohort (n=366). Among the PFF-PR, 640 patients also have whole-blood RNA sequencing data available. A subset of 79 microvascular-associated proteins was curated, and their associations with disease severity and transplant-free survival were examined. An adaptive least absolute shrinkage and selection operator was used to generate a novel microvascular risk score. RESULTS: Higher plasma levels of five microvascular-associated proteins (SDC1, MMP10, THBS2, HGF and SERPINA5) were associated with lung function and survival in both cohorts. Whole-blood RNA sequencing of patients with microvascular risk revealed enrichment of immune-mediated processes. Patients with higher microvascular risk who were subsequently put on nintedanib in the following year had significantly better 3-year transplant-free survival compared with patients who did not receive antifibrotic intervention (HR 0.56, 95% CI 0.35 to 0.89, p=0.0142). DISCUSSION: Integrative multi-omics analyses suggest that perturbations to microvascular remodelling contribute to disease severity and progression in IPF. This analysis offers a framework for a precision medicine approach for IPF.

Idiopathic pulmonary fibrosis↗

Familial pulmonary fibrosis: a UK consensus framework for the investigation and management of patients and their relatives.

Background: There is a growing recognition that genetic predisposition contributes to the development of fibrotic interstitial lung disease. Adult onset monogenic disease is most commonly due to dysfunctional telomere maintenance, with a small proportion caused by surfactant biology disorders. These conditions can be associated with additional intrapulmonary and extrapulmonary features which themselves may require surveillance or treatment, making it important to make a genetic diagnosis. The recent introduction in England of a genetic testing panel accessible to respiratory physicians means that genetic information for these individuals is increasingly available but there is currently little standardisation of the subsequent management of patients and their relatives, which can be complex.Aims: This consensus considers the causes and clinical features of familial pulmonary fibrosis and provides a suggested framework for genetic investigation and clinical management of both patients and their relatives.Narrative: We suggest an initial workup that may help identify those with monogenic disease, with focus on key points in the history and examination that may identify features of a telomere or surfactant biology disorder. We highlight that clinical and radiological presentations are diverse and discuss the importance of making a genetic diagnosis to inform multidisciplinary management and facilitate screening of close family members. We also discuss the many outstanding uncertainties and challenges, including the investigation and management of non-monogenic familial pulmonary fibrosis and the management of asymptomatic family members who have inherited a potentially disease-causing genetic variant.Conclusions: We suggest a pathway for the workup and management of patients with familial pulmonary fibrosis, aiming to standardise clinical care for patients and their relatives and provide a framework for the development of a national database to facilitate disease phenotyping and clinical research to improve the evidence base for clinical practice.

Lung Diseases, Interstitial↗

Multi-omics analysis of glucocorticoid receptor crosstalk with Type I and Type II inflammatory signaling in human airway smooth muscle cells.

Airway smooth muscle (ASM) dysfunction in obstructive airway disease is treated with glucocorticoids. Through RNA-seq analysis of cultured human ASM, we identified repressive effects of dexamethasone, a glucocorticoid, on the baseline expression of a subset of genes that are induced by either IL1B or IL13, which model Type I and Type II inflammation, respectively. ChIP-seq analysis of glucocorticoid receptor (GR) and the p65 subunit of NFkB occupancy indicated canonical motifs for both factors occur at sites of p65 occupancy but did not provide biochemical support for significant repressive tethering between GR and p65. Instead, ATAC-seq revealed significant chromatin remodeling and increased accessibility at binding motifs for the NFkB complex in association with dex + IL1B co-treatment in comparison to IL1B treatment alone. Our data support a competition-based primary repressive effect of glucocorticoids on both IL1B and IL13 signaling and provide evidence for transcriptional cooperation between GR and NFkB on a genome-wide basis in ASM, including at regulatory elements that control expression of anti-inflammatorygenes.

chromatin↗

Genetic Basis of Pancreatic Steatosis: A Systematic Review of Comparison between African and Non-African Populations.

This systematic review compared genetic evidence of pancreatic steatosis across African and non-African populations to illuminate ancestry-specific mechanisms and precision-prevention opportunities. Following PRISMA guidelines for reporting, a search was conducted across PubMed, Scopus, Web of Science, and NHGRI-EBI GWAS Catalog for studies spanning 2011 to 31st March 2026. Eligible studies included genome-wide association studies (GWAS), polygenic risk score (PRS), and Mendelian randomization (MR) analyses that reported genetic associations with pancreatic fat phenotypes and had explicit ancestry stratification or comparison. Narrative thematic synthesis was performed due to methodological heterogeneity. Six core genetic studies (N > 120,000 participants) were included. The only multi-ethnic GWAS found a strong protective variant of African ancestry, rs73449607 (near PDX1/PLUTO), which reduced pancreatic fat (&#x3b2; = -0.67, P = 4.50 &#xd7; 10&#x207b;&#x2078;) and explained 14.3% of the variance in African Americans (versus 5.3% overall). UK Biobank race-stratified PRS analyses confirmed the lowest pancreatic fat fraction in Black participants, with the strongest HbA1c PRS-fat association in this group (&#x3c1; = 0.23, P < 0.0001). European-dominant GWAS highlighted risk loci, including FUT2 rs601338 (higher fat and chronic pancreatitis risk, OR 1.26). MR studies demonstrated causal links between genetically predicted intra-pancreatic fat deposition (IPFD) and pancreatic ductal adenocarcinoma (PDAC) (OR 2.46 per SD) but not diabetes. African-ancestry genomes confer substantial protection against pancreatic steatosis, whereas non-African genomes are enriched for risk alleles that amplify the non-alcoholic fatty pancreas disease (NAFPD)-to-PDAC cascade. These ancestry-differentiated mechanisms position NAFPD as a precision medicine target.

Africa↗

Target Antigen Identification for Antibody Drug Conjugate Therapy in Biliary Tract Cancer.

BACKGROUND: Data on antibody-drug conjugates (ADCs) target expression prevalence, intertumoral heterogeneity, genomic concordance, and its effect on clinical outcomes is limited in biliary tract cancers (BTC). METHODS: Resected primary BTC specimens, and when available, matched metastatic samples were assembled into tissue microarrays and tested for CLDN18.2, c-MET, Nectin-4, TROP2, and HER2 expression by immunohistochemistry (IHC). A subset underwent targeted next-generation sequencing using MSK-IMPACT (NCT01775072). Exploratory associations of target expression with clinicopathologic parameters, genomic alterations, recurrence-free (RFS), and overall (OS) survival were evaluated. RESULTS: 65 patients with resected BTC and 18 paired metastatic sites were identified-43% extrahepatic cholangiocarcinoma, 40% intrahepatic cholangiocarcinoma, and 17% gallbladder cancer. All evaluated target antigens were expressed; percent positivity and H-score &#x2265;200 were: TROP2 (83%, 26%), c-MET (75%, 26%), Nectin-4 (66%, 35%), and CLDN18.2 (46%, 7.7%). HER2 overexpression occurred in 3.1% of tumors. Overall agreement among paired primary and metastatic samples on calling either positive or negative ranged from 43% to 75% with the highest observed for HER2 [75%; &#x3ba;=0.29 (95%CI: -0.32 to 0.91)] and TROP2 (71%; &#x3ba; not available) and lowest for c-MET, CLDN18.2, and Nectin-4. Frequently altered genes included TP53 (36%), SMAD4 (27%), ELF3 (21%). We observed no significant association between target antigen expression with genomics, RFS, or OS. CONCLUSIONS: BTC displays frequent but heterogeneous expression of multiple ADC targets. These hypothesis generating findings suggest inherent complexity of target protein quantification, target threshold determination, and target sampling discordance. Future studies will be required to refine our understanding the utlitiy of ADCs in BTC.

Journal Article↗

KRAS Q61 NSCLC: When Alleles Matter.

A recent article provides the largest characterization to date of KRAS Q61-mutant NSCLC. The findings reveal clinically relevant differences between Q61 alleles and highlight the importance of interpreting KRAS mutations within their genomic context. As RAS-directed therapies evolve, understanding this heterogeneity becomes increasingly relevant for patient stratification and therapeutic development.

Journal Article↗

Endothelial cell cycle inhibition enables blood vessel maturation to normalize the tumor vasculature.

Dysfunctional tumor vessels promote disease progression, whereas improved function enhances therapeutic delivery. However, current approaches to normalize tumor vasculature have limited efficacy. In vascular malformations, vessels are similarly dysfunctional, with endothelial cell (EC) hyperproliferation impairing arterial-venous specification. These defects are corrected with palbociclib, a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) that has beneficial effects on tumor and immune cells, but the effects on tumor vasculature are not well characterized. In our studies, murine mammary tumor ECs (TECs) exhibited disrupted cell cycle and specification, and CDK4/6i promoted TEC cycle control, enabling improved tumor vascular function. To investigate transcriptomic changes, we performed single-cell RNA sequencing (scRNAseq) of treated and untreated tumors, and healthy tissues. CDK4/6i-mediated TEC cycle arrest promoted arterial-venous specification, cellular junctions, and pericyte association, and suppressed glycolytic and immunosuppressive gene expression. These effects were associated with increased vessel perfusion, decreased tumor hypoxia, and a more favorable immune landscape with immunotherapy. In scRNAseq datasets from patients treated long-term with CDK4/6i, TECs exhibited similar transcriptomic changes associated with arterial-venous specification, pericyte recruitment, and immune signaling. Thus, in contrast to current strategies, CDK4/6i-mediated vascular changes may be maintained with continued treatment, highlighting the relevance of modulating TEC cycle to improve vessel maturation/function.

Angiogenesis↗

Microglial GRB2 is essential for brain ventriculogenesis and CSF homeostasis.

Microglia play essential yet poorly understood roles in brain development, including axon guidance, regulation of neurogenesis, and pruning of neuronal projections. Congenital hydrocephalus (CH), characterized by enlarged cerebrospinal fluid (CSF)-filled ventricles, is a leading cause of pediatric brain surgery, but its molecular mechanisms remain unclear. We have identified what we believe to be novel, recurrent, damaging missense variants in the SH3-binding domain of the adaptor protein Growth Factor Receptor-Bound Protein 2 (GRB2) in unrelated patients with CH. GRB2 is significantly co-expressed with one of its known upstream receptor tyrosine kinase partners, CSF1R, in the developing human brain, particularly in a microglial subtype associated with regulation of neural stem cells. Immunoprecipitation validated GRB2-CSF1R binding in mouse microglial cells and human monocyte cell line. Cx3cr1-Grb2fl/fl mice engineered with conditional deletion of Grb2 in microglia exhibit congenital absence of microglia and early postnatal severe communicating (non-obstructive) hydrocephalus, mimicking GRB2-mutant patients. The severe ventriculomegaly of Cx3cr1-Grb2fl/fl mice is associated with both depletion of cerebral cortical neurons and impairment of glia-lymphatic-mediated CSF flow. Together, these findings implicate a role of GRB2 in microglia that could be essential for brain development and CSF homeostasis.

Genetics↗

Genetically Predicted Muscle Mass and Function in Relation to Deep Vein Thrombosis: A Two-step Mendelian Randomization Study Highlighting the Mediating Role of BMI.

BackgroundSarcopenia is observationally linked to venous thromboembolism, but the causal architecture and underlying biological pathways remain largely unclear. This study investigated the causal effects of sarcopenia-related traits on lower extremity deep vein thrombosis (DVT) and quantified potential mediating mechanisms.MethodsWe performed two-sample bidirectional Mendelian randomization (MR) and two-step mediation MR using large-scale GWAS data from UK Biobank, EMBL-EBI, and FinnGen. Exposures included appendicular lean mass (ALM), leg fat-free mass (LFM), hand grip strength, and walking pace. Eighteen candidate mediators were screened for indirect pathways.ResultsGenetically predicted higher ALM was significantly associated with increased DVT risk (FinnGen: OR = 1.288, 95% CI: 1.215-1.365, P < 0.001). Similar positive associations were observed for LFM (OR = 1.920-1.954, P < 0.001). By contrast, muscle functional traits - grip strength and walking pace - demonstrated no consistent causal effects. Reverse MR confirmed a unidirectional relationship. Body mass index (BMI) emerged as a pivotal mediator, accounting for 7.58% - 10.50% of the ALM-DVT effect and 52.74% - 62.73% of the LFM-DVT effect. Notably, the independent effect of ALM was largely attenuated after adjusting for metabolic confounders in multivariable MR.ConclusionGenetic predisposition to high muscle mass, rather than functional strength, increases DVT risk. This relationship appears to be significantly driven by metabolic adiposity, suggesting that the "muscle-vascular-coagulation" interaction is partly explained by body-size-related metabolic burden. Risk stratification should integrate muscle mass evaluation with comprehensive metabolic health assessments.

Humans↗

Inhibition of the atypical kinase WNK1 as a therapeutic strategy in TAL-related T-cell acute lymphoblastic leukemia.

Driver mutations in T-cell acute lymphoblastic leukemia (T-ALL) rarely affect druggable kinases. However, these kinases can be aberrantly activated or repressed as secondary oncogenic events. Thus, integrating unbiased phosphoproteomics with genomic approaches may offer novel opportunities for target discovery and therapeutic interventions. In our study, we identified WNK1 (with no lysine [K]) as a potential target in T-ALL by pairing a list of vulnerable kinases with data from a phosphoproteomic screen of T-ALL cell lines. We subsequently validated WNK1 by loss-of-function-based studies and tested WNK inhibitors in several in vitro and in vivo T-ALL models and clinical T-ALL samples. We showed that therapeutic WNK1 repression promotes polyploidy, resulting in cell proliferation arrest, and morphometric changes, such as incomplete cell division or chromosome segregation through altered mitotic spindle assembly and abscission defects. Furthermore, we found that WNK1 is overexpressed in the TAL1/2-related subgroup, but not in normal thymus or lymph nodes, suggesting a potential translational area for clinical exploitation in poor-prognosis T-ALL carrying PTEN mutations and del(6q). Our work also reports a functional contribution of WNK1 in the leukemia establishment and progression. Structurally WNK1 is an atypical serine/threonine kinase that diverges from canonical kinases by lacking the conserved lysine in subdomain II, instead featuring a cysteine in subdomain I, which is critical for adenosine triphosphate (ATP) binding. This unusual structural configuration creates a distinct ATP-binding pocket with limited sequence similarity to conventional kinases, offering a unique opportunity to develop highly selective small molecules. Targeting this atypical ATP domain could thus provide a therapeutic advantage and broaden the treatment landscape for T-ALL.

WNK Lysine-Deficient Protein Kinase 1↗

Targeting ACKR3/CXCR7 enhances platelet anticoagulant acylcarnitines and modulates procoagulant function.

Targeting ACKR3/CXCR7 regulates enzymatic generation of prothrombotic lipids while favoring antithrombotic lipids that inhibit platelets through the AC-cAMP-PKA pathway in coordination with prostacyclin IP receptor. This investigation validated the effect of CXCR7 in modulating nonenzymatic lipid (per)oxidation, platelet response to lipoproteins, mitochondrial metabolism, and procoagulant functions. CXCR7 agonist VUF11207 preserved mitochondrial membrane integrity, counteracted activation-induced mitochondrial superoxide generation, and reduced nonenzymatic lipid (per)oxidation. Moreover, it regulated lipoprotein-induced platelet adhesion to thrombogenic matrices, degranulation, &#x3b1;IIb&#x3b2;III-integrin activation, aggregation, and thrombotic responses by reducing lipoprotein uptake through CD36 and ApoER2. CXCR7 ligation triggered the activation of AMP-dependent kinaseSer-172 and prompted AMPK-mediated inhibitory phosphorylation of acetyl-coenzyme A carboxylaseSer-79 to foster lipolysis over lipogenesis. Consequently, the AMPKSer-172-ACCSer-79 pathway increased generation of anticoagulant FXa-inhibitory long-chain acylcarnitines (LC-CAR) in platelets of healthy subjects and patients with coronary artery disease. Enrichment of intraplatelet LC-CARs was not attributable to dysregulated mitochondrial respiration because VUF11207 improved maximal respiration, spare respiratory capacity, and ATP-linked respiration in thrombin-activated platelets, suggesting sustained mitochondrial metabolism. Exerting a 2-pronged effect on procoagulant function, VUF11207 downregulated phosphatidylserine exposure on activated platelets and reduced FX/FXa binding, while platelet-derived anticoagulant LC-CARs regulated thrombin generation. VUF11207 administration reduced thrombus formation, platelet degranulation, &#x3b1;IIb&#x3b2;III-integrin activation, procoagulant activity, and circulating platelet-leukocyte aggregates in murine venous thrombosis model, also decreased plasma procoagulant lipids derived from platelet cyclooxygenase-1 and 12-lipooxygenase (LOX), and leukocyte 5/15-LOX, decreased thromboinflammatory mediators (IL-1&#x3b2;, IL-6, IFN-&#x3b3;, TNF-&#x3b1;, and MCP-1), and increased plasma LC-CAR levels. Therefore, pharmacological targeting of CXCR7 could regulate (non)enzymatic lipid processing and promote anticoagulant LC-CAR generation to limit platelet-driven thrombotic propensity and hypercoagulability, also replenish reduced levels of circulatory LC-CARs in patients with STEMI and VTE.

Humans↗

Reduced platelet formation associated with serine metabolic dysregulation in integrin &#x3b1;IIb&#x3b2;3-deficient megakaryocytes.

Glanzmann thrombasthenia (GT) is characterized by absent platelet aggregation in response to all agonists except ristocetin and is caused by recessive inactivating variants in ITGA2B or ITGB3. Although patients with GT typically are described as having normal platelet counts, autosomal dominant activating variants in ITGA2B or ITGB3 cause macrothrombocytopenia. Interestingly, in our cohort of 16 patients with GT, 8 consistently exhibited platelet counts at the lower end of the normal range. We studied the role of integrin &#x3b1;IIb&#x3b2;3 in platelet formation using megakaryocytes (MKs) derived from genetically modified immortalized MK cell lines (imMKCLs), focusing on 2 modifications of ITGB3: ITGB3-/- (inactivating) and ITGB3WT/D673_E713del (activating). In static differentiation cultures, ITGB3-/- and ITGB3WT/D673_E713del imMKCLs exhibited normal MK differentiation but reduced proplatelet formation. Platelet production was also impaired in a 3-dimensional silk-based bone marrow system and in shaking cultures, confirming a quantitative role for ITGB3 in platelet production independent of the type of variant. Although thrombin receptor activating protein-activated, in vitro-generated platelets lacking &#x3b1;IIb&#x3b2;3 failed to bind the activation-dependent PAC-1 antibody, ITGB3WT/D673_E713del platelets bound PAC-1 before activation, mimicking the patient's phenotype. Transcriptome profiling and metabolomic analyses of integrin &#x3b1;IIb&#x3b2;3-deficient MKs revealed impaired serine metabolism and downregulation of SLC3A2 (CD98hc), an amino acid transporter chaperon known to interact with the &#x3b2;3 subunit. Flow cytometry confirmed decreased CD98hc in mutant MKs, whereas reexpression of wild-type ITGB3 in ITGB3-/- MKs restored &#x3b1;IIb&#x3b2;3 and CD98hc expression, normalized proplatelet formation, and enhanced serine uptake. These results uncover a previously unrecognized role of integrin &#x3b1;IIb&#x3b2;3 in coupling serine metabolism to platelet biogenesis.

Humans↗