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Simple Summary: The disialoganglioside GD2 is a molecule found in certain tumors, like neuroblastoma, but rarely in normal tissues. The main aim of this study was to understand if hu14.18K322A, an antibody targeting GD2, causes direct cell death in high-risk neuroblastoma and to delineate the pathways involved. Our results demonstrate that hu14.18K322A activates apoptosis and necroptosis but affects no other cell-death pathways. Hu14.18K322A synergistically increased cell death by induction chemotherapy drugs. We found an alteration in GD2 surface expression after chemotherapy treatment, emphasizing the complex interplay between them. These results highlight the multifaceted role of hu14.18K322A in high-risk neuroblastoma and suggest pathways that may be targeted to increase treatment efficacy. The disialoganglioside, GD2, is a promising therapeutic target due to its overexpression in certain tumors, particularly neuroblastoma (NB), with limited expression in normal tissues. Despite progress, the intricate mechanisms of action and the full spectrum of the direct cellular responses to anti-GD2 antibodies remain incompletely understood. In this study, we examined the direct cytotoxic effects of the humanized anti-GD2 antibody hu14.18K322A (hu14) on NB cell lines, by exploring the associated cell-death pathways. Additionally, we assessed the synergy between hu14 and conventional induction chemotherapy drugs. Our results revealed that hu14 treatment induced direct cytotoxic effects in CHLA15 and SK-N-BE1 cell lines, with a pronounced impact on proliferation and colony formation. Apoptosis emerged as the predominant cell-death pathway triggered by hu14. Furthermore, we saw a reduction in GD2 surface expression in response to hu14 treatment. Hu14 demonstrated synergy with induction chemotherapy drugs with alterations in GD2 expression. Our comprehensive investigation provides valuable insights into the multifaceted effects of hu14 on NB cells, shedding light on its direct cytotoxicity, cell-death pathways, and interactions with induction chemotherapy drugs. This study contributes to the evolving understanding of anti-GD2 antibody therapy and its potential synergies with conventional treatments in the context of NB. [ABSTRACT FROM AUTHOR]

The fragile X mental retardation protein FMRP regulates translation of its bound mRNAs through incompletely defined mechanisms. FMRP has been linked to the microRNA pathway, and we show here that it associates with the RNA helicase MOV10, also associated with the microRNA pathway. FMRP associates with MOV10 directly and in an RNA-dependent manner and facilitates MOV10's association with RNAs in brain and cells, suggesting a cooperative interaction. We identified the RNAs recognized by MOV10 using RNA immunoprecipitation and iCLIP. Examination of the fate of MOV10 on RNAs revealed a dual function for MOV10 in regulating translation: it facilitates microRNA-mediated translation of some RNAs, but it also increases expression of other RNAs by preventing AGO2 function. The latter subset was also bound by FMRP in close proximity to the MOV10 binding site, suggesting that FMRP prevents MOV10-mediated microRNA suppression. We have identified a mechanism for FMRP-mediated translational regulation through its association with MOV10.

Despite evidence of genetic signatures in normal tissue correlating with disease risk, prospectively identifying genetic drivers and cell types that underlie subsequent pathologies has historically been challenging. The human prostate is an ideal model to investigate this phenomenon because it is anatomically segregated into three glandular zones (central, peripheral, and transition) that develop differential pathologies: prostate cancer in the peripheral zone (PZ) and benign prostatic hyperplasia (BPH) in the transition zone (TZ), with the central zone (CZ) rarely developing disease. More specifically, prostatic basal cells have been implicated in differentiation and proliferation during prostate development and regeneration; however, the contribution of zonal variation and the critical role of basal cells in prostatic disease etiology are not well understood. Using single‐cell RNA sequencing of primary prostate epithelial cultures, we elucidated organ‐specific, zone‐specific, and cluster‐specific gene expression differences in basal cells isolated from human prostate and seminal vesicle (SV). Aggregated analysis identified ten distinct basal clusters by Uniform Manifold Approximation and Projection. Organ specificity compared gene expression in SV with the prostate. As expected, SV cells were distinct from prostate cells by clustering, gene expression, and pathway analysis. For prostate zone specificity, we identified two CZ‐specific clusters, while the TZ and PZ populations clustered together. Despite these similarities, differential gene expression was identified between PZ and TZ samples that correlated with gene expression profiles in prostate cancer and BPH, respectively. Zone‐specific profiles and cell type‐specific markers were validated using immunostaining and bioinformatic analyses of publicly available RNA‐seq datasets. Understanding the baseline differences at the organ, zonal, and cellular level provides important insight into the potential drivers of prostatic disease and guides the investigation of novel preventive or curative treatments. Importantly, this study identifies multiple prostate basal cell populations and cell type‐specific gene signatures within prostate basal epithelial cells that have potential critical roles in driving prostatic diseases. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

BackgroundSongbirds hold great promise for biomedical, environmental and evolutionary research. A complete draft sequence of the zebra finch genome is imminent, yet a need remains for application of genomic resources within a research community traditionally focused on ethology and neurobiological methods. In response, we developed a core set of genomic tools and a novel collaborative strategy to probe gene expression in diverse songbird species and natural contexts.ResultsWe end-sequenced cDNAs from zebra finch brain and incorporated additional sequences from community sources into a database of 86,784 high quality reads. These assembled into 31,658 non-redundant contigs and singletons, which we annotated via BLAST search of chicken and human databases. The results are publicly available in the ESTIMA:Songbird database. We produced a spotted cDNA microarray with 20,160 addresses representing 17,214 non-redundant products of an estimated 11,500-15,000 genes, validating it by analysis of immediate-early gene (zenk) gene activation following song exposure and by demonstrating effective cross hybridization to genomic DNAs of other songbird species in the Passerida Parvorder. Our assembly was also used in the design of the "Lund-zfa" Affymetrix array representing approximately 22,000 non-redundant sequences. When the two arrays were hybridized to cDNAs from the same set of male and female zebra finch brain samples, both arrays detected a common set of regulated transcripts with a Pearson correlation coefficient of 0.895. To stimulate use of these resources by the songbird research community and to maintain consistent technical standards, we devised a "Community Collaboration" mechanism whereby individual birdsong researchers develop experiments and provide tissues, but a single individual in the community is responsible for all RNA extractions, labelling and microarray hybridizations.ConclusionImmediately, these results set the foundation for a coordinated set of 25 planned experiments by 16 research groups probing fundamental links between genome, brain, evolution and behavior in songbirds. Energetic application of genomic resources to research using songbirds should help illuminate how complex neural and behavioral traits emerge and evolve.

Extended periods of bed rest and limb immobilization are required for healing post‐injury or disease, yet disuse can result in significant muscle atrophy and decreased quality of life in older adults. Physical rehabilitation is commonly prescribed to recover these deficits, yet accumulation of reactive oxygen species and sustained rates of protein degradation persist during the rehabilitation period that can significantly delay or prevent recovery. Pericytes, considered the primary mesenchymal and vascular stromal cell in skeletal muscle, secrete beneficial factors that maintain baseline muscle mass, yet minimal information exists regarding the pericyte response to disuse and recovery. In the current study, single‐cell RNA sequencing and functional assays were performed to demonstrate that pericytes in mouse skeletal muscle lose the capacity to synthesize antioxidants during disuse and recovery. This information was used to guide the design of a strategy in which healthy donor pericytes were stimulated with hydrogen peroxide (H2O2) to produce small extracellular vesicles (sEVs) that effectively restored myofibre size in adult and aged muscle after disuse. Proteomic assessment detected 11 differentially regulated proteins in primed sEVs that may account for recovery of muscle, including proteins associated with extracellular matrix composition and anti‐inflammatory and antioxidant processes. This study demonstrates that healthy H2O2‐primed pericyte‐derived sEVs effectively improve skeletal muscle recovery after immobilization, presenting a novel acellular approach to rebuild muscle mass in older adults after a period of disuse. Key points: Previous studies suggest that prolonged oxidative stress is a barrier to skeletal muscle recovery after a period of immobilization.In this study we demonstrate that muscle‐resident perivascular stromal cells (pericytes) become dysfunctional and lack the capacity to mount an antioxidant defence after disuse in mice.Hydrogen peroxide treatment of healthy pericytes in vitro simulates the release of small extracellular vesicles (sEVs) that effectively recover skeletal muscle fibre size and extracellular matrix remodelling in young adult and aged mice after disuse.Pericyte‐derived sEVs present a novel acellular strategy to recover skeletal muscle after disuse. [ABSTRACT FROM AUTHOR]