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Hunt, E.

Publications and source records attributed to Hunt, E..

3 recordsLinked to original sources

Early visual experience redistributes cFos-tagged neurons toward the cortex while preserving presynaptic spatial stereotypy

The macroscale functional organization of the brain is spatially stereotyped across individuals, but whether this extends to finer spatial scales is not known. Furthermore, how experience shapes this organization across the brain remains unclear. To address this, we developed cFos promoter-driven reporter mouse lines that permanently label either the cell bodies or presynaptic terminals of neurons during defined temporal windows. Using serial two-photon tomography and voxel-wise statistics, we mapped brain-wide distributions of cFos-tagged somata or their presynaptic terminals during the first week of visual experience or its deprivation. We found that midbrain and subcortical regions show greater stereotypy for cFos-tagged neurons and their presynaptic terminals compared to cortical regions. This fine-scale spatial stereotypy remained largely preserved despite visual deprivation, which shifted the relative recruitment of cFos-tagged neurons from cortical toward the highly stereotyped midbrain and subcortical regions. Our findings identify heterogeneous, spatially constrained functional organization across the brain that is conserved across subjects yet accommodates experience-dependent reorganization of neuronal recruitment.

neuroscience↗

Multifaceted mRNA analysis using programmed RNA cleavage byMucilaginibacter paludis Argonaute

Argonaute (Ago) endonucleases are ubiquitous across all domains of life and, like Cas nucleases, can be programmed by guide oligonucleotides to target and cleave specific nucleic acid sequences. However, unlike Cas enzymes, Agos are not restricted by sequence requirements such as protospacer adjacent motifs (PAMs) enhancing their utility as molecular tools. This study demonstrates diverse applications of the DNA-guided RNA-endonuclease Mucilaginibacter paludis Argonaute (Mpa Ago) for in vitro mRNA processing, e.g., 3 end polishing, and for mRNA analysis in combination with liquid chromatography tandem mass spectrometry (LC-MS/MS). Applications of the latter include the comprehensive assessment of 5 capping efficiency, 3 poly(A) tail length and composition, one-pot multiplexed cleavage for RNA sequencing, modification detection, and fingerprinting.

molecular biology↗

Basigin Links Altered Skeletal Stem Cell Lineage Dynamics with Glucocorticoid-induced Bone Loss and Impaired Angiogenesis

Glucocorticoid (GC) induced osteoporosis (GIOP) and osteonecrosis remain a significant health issue with few approved therapies that can treat the bone loss and dysfunction of skeletal vasculature. Therefore, we aimed to investigate the cellular and molecular processes by which GCs affect osteogenesis and angiogenesis, as well as how treatment with parathyroid hormone (hPTH 1-34) modifies these effects in a mouse model of GIOP. GC treatment reduced bone mass through decreased bone formation by skeletal stem cells (SSCs) while also increasing osteoclast mediated resorption. Concomitantly, endothelial cells were increased in numbers but displayed distorted phenotypical features. However, hPTH treatment reversed GC induced changes in osteogenesis and angiogenesis to control levels. Transplantation studies of SSCs combined with molecular analysis by single cell RNA-sequencing and functional testing of primary human cells tied GC-induced skeletal changes to altered stem and progenitor cell differentiation dynamics. This in turn perpetuated reduced osteogenesis and vascular malformation through direct SSC-endothelial crosstalk mediated at least in part by Basigin. Intriguingly, antibody-mediated blockade of Basigin during GC treatment prevented detrimental bone loss. In addition, when administered to aged mice, anti-Basigin therapy reinstated bone remodeling to significantly improve bone mass independent of sex. These findings, while helping to explain the cellular and molecular basis of how hPTH treatment can mitigate GC induced bone loss, provide new therapeutic vantage points for GIOP and other conditions associated with bone loss.

cell biology↗