Gaineshood0977

Skeletal muscle experiences a decline in lean mass and regenerative potential with age, in part due to intrinsic changes in progenitor cells. However, it remains unclear how age-related changes in progenitors manifest across a differentiation trajectory. Here, we perform single-cell RNA sequencing (RNA-seq) on muscle mononuclear cells from young and aged mice and profile muscle stem cells (MuSCs) and fibro-adipose progenitors (FAPs) after differentiation. Differentiation increases the magnitude of age-related change in MuSCs and FAPs, but it also masks a subset of age-related changes present in progenitors. Using a dynamical systems approach and RNA velocity, we find that aged MuSCs follow the same differentiation trajectory as young cells but stall in differentiation near a commitment decision. Our results suggest that differentiation reveals latent features of aging and that fate commitment decisions are delayed in aged myogenic cells in vitro.The primary cilium (PC) regulates signalization linked to external stress sensing. Previous works established a functional interplay between the PC and the autophagic machinery. When ciliogenesis is promoted by serum deprivation, the autophagy protein ATG16L1 and the ciliary protein IFT20 are co-transported to the PC. Here, we demonstrate that IFT20 and ATG16L1 are part of the same complex requiring the WD40 domain of ATG16L1 and a Y-E-F-I motif in IFT20. We show that ATG16L1-deficient cells exhibit aberrant ciliary structures, which accumulate PI4,5P2, whereas PI4P, a lipid normally concentrated in the PC, is absent. Finally, we demonstrate that INPP5E, a phosphoinositide-associated phosphatase responsible for PI4P generation, interacts with ATG16L1 and that a perturbation of the ATG16L1/IFT20 complex alters its trafficking to the PC. Altogether, our results reveal a function of ATG16L1 in ciliary lipid and protein trafficking, thus directly contributing to proper PC dynamics and functions.Glioblastoma stem cells (GSCs) resist current glioblastoma (GBM) therapies. GSCs rely highly on oxidative phosphorylation (OXPHOS), whose function requires mitochondrial translation. Here we explore the therapeutic potential of targeting mitochondrial translation and report the results of high-content screening with putative blockers of mitochondrial ribosomes. We identify the bacterial antibiotic quinupristin/dalfopristin (Q/D) as an effective suppressor of GSC growth. Q/D also decreases the clonogenicity of GSCs in vitro, consequently dysregulating the cell cycle and inducing apoptosis. Cryoelectron microscopy (cryo-EM) reveals that Q/D binds to the large mitoribosomal subunit, inhibiting mitochondrial protein synthesis and functionally dysregulating OXPHOS complexes. These data suggest that targeting mitochondrial translation could be explored to therapeutically suppress GSC growth in GBM and that Q/D could potentially be repurposed for cancer treatment.Transforming growth factor β (TGF-β) family ligands are key regulators of dendritic cell (DC) differentiation and activation. Epidermal Langerhans cells (LCs) require TGF-β family signaling for their differentiation, and canonical TGF-β1 signaling secures a non-activated LC state. LCs reportedly control skin inflammation and are replenished from peripheral blood monocytes, which also give rise to pro-inflammatory monocyte-derived DCs (moDCs). By studying mechanisms in inflammation, we previously screened LCs versus moDCs for differentially expressed microRNAs (miRNAs). This revealed that miR-424/503 is the most strongly inversely regulated (moDCs > LCs). We here demonstrate that miR-424/503 is induced during moDC differentiation and promotes moDC differentiation in human and mouse. Inversely, forced repression of miR-424 during moDC differentiation facilitates TGF-β1-dependent LC differentiation. Mechanistically, miR-424/503 deficiency in monocyte/DC precursors leads to the induction of TGF-β1 response genes critical for LC differentiation. Therefore, the miR-424/503 gene cluster plays a decisive role in anti-inflammatory LC versus pro-inflammatory moDC differentiation from monocytes.Relatively little is known about features of T cells targeted by HIV in vivo. SN001 By applying bioinformatics analysis to mass cytometry (CyTOF)-phenotyped specimens from individuals with viremia and in-vitro-infected cells from uninfected donors, we provide an atlas of the phenotypes of in vivo and in vitro HIV-susceptible cells. T helper 17 (Th17) and α4β1+ cells are preferentially targeted in vivo, whereas T effector memory (Tem), T transitional memory (Ttm), Th1, and Th1/Th17 subsets are targeted in vitro. Multiple proteins-including chemokine and cytokine receptors-are remodeled by HIV in vivo, and these changes are mostly recapitulated in vitro. HIV remodels cells to a T follicular helper (Tfh) phenotype. Using clustering, we uncover a subset of CD29-expressing, Tem-like cells that are highly susceptible to infection in vivo and in vitro and experimentally confirm that susceptibility. These studies provide an in-depth look at features of HIV-susceptible cells in individuals with viremia and demonstrate that some-but not all-HIV-susceptible cells identified in vitro effectively model in vivo susceptibility.MYC-driven medulloblastoma is a major therapeutic challenge due to frequent metastasis and a poor 5-year survival rate. MYC gene amplification results in transcriptional dysregulation, proliferation, and survival of malignant cells. To identify therapeutic targets in MYC-amplified medulloblastoma, we employ a CRISPR-Cas9 essentiality screen targeting 1,140 genes. We identify CDK7 as a mediator of medulloblastoma tumorigenesis. Using chemical inhibitors and genetic depletion, we observe cessation of tumor growth in xenograft mouse models and increases in apoptosis. The results are attributed to repression of a core set of MYC-driven transcriptional programs mediating DNA repair. CDK7 inhibition alters RNA polymerase II (RNA Pol II) and MYC association at DNA repair genes. Blocking CDK7 activity sensitizes cells to ionizing radiation leading to accrual of DNA damage, extending survival and tumor latency in xenograft mouse models. Our studies establish the selective inhibition of MYC-driven medulloblastoma by CDK7 inhibition combined with radiation as a viable therapeutic strategy.