Development of Degraders and 2-pyridinecarboxyaldehyde (2-PCA) as a recruitment Ligand for FBXO22.

Targeted protein degradation (TPD) is a promising therapeutic strategy that requires the discovery of small molecules that induce proximity between E3 ubiquitin ligases and proteins of interest. FBXO22 is an E3 ligase that is overexpressed in many cancers and implicated in tumorigenesis. While FBXO22 was previously identified as capable of recognizing ligands bearing a primary amine degron, further investigation and development of recruitment ligands is required to enable its broader utility for TPD.

Clonal Hematopoiesis and Risk of New-Onset Myocarditis and Pericarditis.

Importance: Clonal hematopoiesis of indeterminate potential (CHIP) is the age-related clonal expansion of hematopoietic stem cells with leukemia-associated mutations. Certain CHIP mutations promote atherosclerosis and heart failure through immune-related pathways.

Objective: To test whether CHIP is associated with the development of myocarditis and pericarditis.

Expanding the druggable zinc-finger proteome defines properties of drug-induced degradation.

Glutarimide analogs, such as thalidomide, redirect the E3 ubiquitin ligase CRL4 to induce degradation of certain zinc finger (ZF) proteins. Although the core structural motif recognized by CRBN has been characterized, it does not fully explain substrate specificity. To explore the role of residues adjacent to this core motif, we constructed a comprehensive ZF reporter library of 9,097 reporters derived from 1,655 human ZF proteins and conducted a library-on-library screen with 29 glutarimide analogs to identify compounds that collectively degrade 38 ZF reporters.

Somatic Mutations in STAG2 Are Associated with Separated Megakaryocyte Nuclear Lobes in Myelodysplastic Syndromes.

Myelodysplastic syndrome (MDS) is driven by genetic mutations, but diagnosis relies on morphologic evaluation of bone marrow hematopoiesis. Only a small number of genetic abnormalities define specific bone marrow morphologic features in MDS, such as those harboring SF3B1 mutations and deletions of chromosome 5q. We hypothesized that additional genetic alterations are associated with specific dysplastic morphologic features in MDS.

Germline genetic variation impacts clonal hematopoiesis landscape and progression to malignancy.

With age, clonal expansions occur pervasively across normal tissues yet only in rare instances lead to cancer, despite being driven by well-established cancer drivers. Characterization of the factors that influence clonal progression is needed to inform interventional approaches. Germline genetic variation influences cancer risk and shapes tumor mutational profile, but its influence on the mutational landscape of normal tissues is not well known.

A heterotrimeric protein complex assembles the metazoan V-ATPase upon dissipation of proton gradients.

Organelles such as lysosomes and synaptic vesicles are acidified by V-ATPases, which consist of a cytosolically oriented V complex that hydrolyzes ATP and a membrane-embedded V complex that pumps protons. In yeast, V-V association is facilitated by the RAVE (regulator of H-ATPase of the vacuolar and endosomal membrane) complex, but how higher eukaryotes assemble V-ATPases remains unclear. Here we identify a metazoan RAVE complex (mRAVE) whose structure and composition are notably divergent from the ancestral counterpart.

A Molecular Glue Approach to Control the Half-Life of CRISPR-Based Technologies.

Cas9 is a programmable nuclease that has furnished transformative technologies, including base editors and transcription modulators (e.g., CRISPRi/a), but several applications of these technologies, including therapeutics, mandatorily require precision control of their half-life.

An in vivo barcoded CRISPR-Cas9 screen identifies Ncoa4-mediated ferritinophagy as a dependence in Tet2-deficient hematopoiesis.

TET2 is among the most commonly mutated genes in both clonal hematopoiesis and myeloid malignancies; thus, the ability to identify selective dependencies in TET2-deficient cells has broad translational significance. Here, we identify regulators of Tet2 knockout (KO) hematopoietic stem and progenitor cell (HSPC) expansion using an in vivo CRISPR-Cas9 KO screen, in which nucleotide barcoding enabled large-scale clonal tracing of Tet2-deficient HSPCs in a physiologic setting. Our screen identified candidate genes, including Ncoa4, that are selectively required for Tet2 KO clonal outgrowth compared with wild type.

Niclosamide: CRL4 mediated degradation of cyclin D1 following mitochondrial membrane depolarization.

Targeted protein degradation has emerged as a promising approach in drug discovery, utilizing small molecules like molecular glue degraders to harness the ubiquitin-proteasome pathway for selective degradation of disease-driving proteins. Based on results from proteomics screens we investigated the potential of niclosamide, an FDA-approved anthelmintic drug with a 50 year history in treating tapeworm infections, as a molecular glue degrader targeting the proto-oncogene cyclin D1. Proteomics screens in HCT116 colon carcinoma and KELLY neuroblastoma cells, found that niclosamide induces rapid cyclin D1 degradation through a mechanism involving the ubiquitin-proteasome pathway.

Sex differences in DNMT3A-mutant clonal hematopoiesis and the effects of estrogen.

Blood cancers are generally more common in males, and the prevalence of most mutations that drive clonal hematopoiesis and myeloid malignancies is higher in males. In contrast, hematopoietic DNMT3A mutations are more common in females. Among ∼450,000 participants in the UK Biobank, the prevalence of DNMT3A mutations and copy-number abnormalities is higher in females than males.

The Prolonged Half-Life of the p53 Missense Variant R248Q Promotes Accumulation and Heterotetramer Formation with Wild-Type p53 to Exert the Dominant-Negative Effect.

Missense mutants of p53, such as the frequent hotspot variant R248Q, exert a dominant-negative effect (DNE) on wild-type (WT) p53 in cancer cells with monoallelic TP53 mutations. However, the precise functional and molecular mechanisms of the DNE have remained elusive due to a lack of appropriate model systems. In this study, we developed a variety of model systems, including CRISPR-edited human isogenic cell lines and transcriptional reporter cell lines, and targeted protein degradation assays that were combined with functional and molecular analyses to functionally characterize the DNE.

Particle uptake by macrophages triggers bifurcated transcriptional pathways that differentially regulate inflammation and lysosomal gene expression.

Exposure to particles is a driver of several inflammatory diseases. Here, we investigated macrophage responses to monosodium urate crystals, calcium pyrophosphate crystals, aluminum salts, and silica nanoparticles. While each particle induced a distinct gene expression pattern, we identified a common inflammatory signature and acute activation of lysosomal acidification genes.

Discovery of electrophilic degraders that exploit SAr chemistry.

Targeted covalent inhibition (TCI) and targeted protein degradation (TPD) have proven effective in pharmacologically addressing formerly 'undruggable' targets. Integration of both methodologies has resulted in the development of electrophilic degraders where recruitment of a suitable E3 ubiquitin ligase is achieved through formation of a covalent bond with a cysteine nucleophile. Expanding the scope of electrophilic degraders requires the development of electrophiles with tempered reactivity that enable selective ligase recruitment and reduce cross-reactivity with other cellular nucleophiles.

Exploration of the tunability of BRD4 degradation by DCAF16 trans-labelling covalent glues.

Chemically induced proximity modalities such as targeted protein degradation (TPD) hold promise for expanding the number of proteins that can be manipulated pharmacologically. However, current TPD strategies are often limited to proteins with preexisting ligands. Molecular glues (e.

Long-term longitudinal analysis of 4,187 participants reveals insights into determinants of clonal hematopoiesis.

Clonal hematopoiesis of indeterminate potential (CHIP) is linked to diverse aging-related diseases, including hematologic malignancy and atherosclerotic cardiovascular disease (ASCVD). While CHIP is common among older adults, the underlying factors driving its development are largely unknown. To address this, we performed whole-exome sequencing on 8,374 blood DNA samples collected from 4,187 Atherosclerosis Risk in Communities Study (ARIC) participants over a median follow-up of 21 years.

Colchicine prevents accelerated atherosclerosis in TET2-mutant clonal haematopoiesis.

Background And Aims: Somatic mutations in the TET2 gene that lead to clonal haematopoiesis (CH) are associated with accelerated atherosclerosis development in mice and a higher risk of atherosclerotic disease in humans. Mechanistically, these observations have been linked to exacerbated vascular inflammation. This study aimed to evaluate whether colchicine, a widely available and inexpensive anti-inflammatory drug, prevents the accelerated atherosclerosis associated with TET2-mutant CH.

Loss-of-function mutations in Dnmt3a and Tet2 lead to accelerated atherosclerosis and concordant macrophage phenotypes.

Clonal hematopoiesis of indeterminate potential (CHIP) is defined by the presence of a cancer-associated somatic mutation in white blood cells in the absence of overt hematological malignancy. It arises most commonly from loss-of-function mutations in the epigenetic regulators DNMT3A and TET2. CHIP predisposes to both hematological malignancies and atherosclerotic cardiovascular disease in humans.

JAK2-mutant clonal hematopoiesis is associated with venous thromboembolism.

Venous thromboembolism (VTE) is common among older individuals, but provoking factors are not identified in many cases. Patients with myeloid malignancies, especially myeloproliferative neoplasms (MPNs), are at increased risk for venous thrombosis. Clonal hematopoiesis of indeterminate potential (CHIP), a precursor state to myeloid malignancies, is common among older individuals and may similarly predispose to venous thrombosis.

Sex-Based Differences in Risk of Therapy-Related Myeloid Neoplasms.

Purpose: Therapy-related myeloid neoplasm (t-MN) is a life-threatening complication of autologous peripheral blood stem cell (PBSC) transplantation for non-Hodgkin lymphoma (NHL). Previous studies report an association between clonal hematopoiesis (CH) in PBSC and risk of t-MN, but small samples precluded examination of risk within specific subpopulations.

Methods: Targeted DNA sequencing was performed to identify CH mutations in PBSC from a retrospective cohort of 984 patients with NHL (median age at transplant, 57 years; range, 18-78).