Biology subjects

Van Vactor, D.

Publications and source records attributed to Van Vactor, D..

4 recordsLinked to original sources

bioRxiv2025

Regulation of miR-219 and its target RalGPS dictates acute synaptic plasticity at the Drosophila neuromuscular junction

RNA regulatory mechanisms mediate adaptive responses requiring rapid gene expression changes. Examining microRNA (miRNA)-mediated control of structural synaptic plasticity, we identified miR-219 and six other conserved miRNAs regulating activity-induced morphogenesis at Drosophila glutamatergic synapses. Among miRNA targets downregulated by acute stimulation, the Ral-activating factor RalGPS is necessary for presynaptic morphogenesis and sufficient to block plasticity. Stimulation elevates miR-219 loading into Argonaute complexes without altering mature miR-219 levels, revealing a post-transcriptional regulatory mechanism. We conclude that activity-induced miRNA loading modulates Ral signaling via RalGPS to enable presynaptic remodeling and growth, establishing a novel link between neuronal activity and synaptic structural plasticity.

neuroscience↗

bioRxiv2025

A brain-specific microRNA, miR-1000, regulates lipid homeostasis via Neuropeptide-like precursor 1 in Drosophila melanogaster

Metabolism requires precise gene regulation to balance energy intake and expenditure for an organisms well-being, with misregulation often leading to metabolic syndromes. This study reveals that the brain-specific microRNA miR-1000 regulates fat storage by controlling the expression of a neuropeptide gene, Nplp1. Loss of miR-1000 increases Nplp1 expression, leading to higher body weight, increased fat storage, improved survival under food deprivation conditions, and a reduced overall lifespan in Drosophila. We further show that miR-1000 promotes fat storage upon feeding by regulating TAG synthesis and storage in lipid droplets, thereby playing a crucial role in metabolic regulation.

neuroscience↗

bioRxiv2022

Integrated transcriptome analysis of Huntingtons disease iPSC-derived and mouse astrocytes implicates dysregulated synaptogenesis, actin, and astrocyte maturation

Huntingtons disease (HD) is a neurodegenerative disease caused by an expanded CAG repeat within the Huntingtin (HTT) gene having dysregulated cellular homeostasis in the central nervous system, particularly in the striatum and cortex. Astrocytes establish and maintain neuronal functions through the secretion of soluble factors and physical interactions with other neurovascular unit cell types. Under pathological conditions, astrocytes can become reactive, causing cell state transitions that affect brain function. To investigate transitions between cellular states in unaffected and HD astrocytes at high resolution, single-nuclei RNA-sequencing (snRNA-seq) was performed on human HD patient induced pluripotent stem cell (iPSC)-derived astrocytes and on striatal and cortical tissue from a rapidly progressing HD mouse model (R6/2). Analysis of HD human and mouse astrocytes revealed both models have alterations in morphology, glutamate uptake, and dysregulation of astrocyte identity and maturation, whereas dysregulated actin-mediated signaling was unique to human iPSC-derived astrocytes. Representative proteins showed altered levels by Western. In both species, HD transcriptional changes reveal potential astrocyte maturation deficits that were potentially driven by astrogliogenesis transcription factors, including ATF3 and NFIA. When perturbed in a drosophila model of HD, knockdown of NFIA in glia rescued the climbing deficit. These data further support the hypothesis that mutant HTT induces dysregulated astrocyte cell states resulting in dysfunctional astrocytic properties, suggests that some of these states are cell autonomous and maybe unique to human HD, and implicate ATF3 and maturation deficits in HD pathogenesis.

neuroscience↗

bioRxiv2020

Control of feeding by Piezo-mediated gut mechanosensation in Drosophila

Across animal species, meals are terminated after ingestion of large food volumes, yet underlying mechanosensory receptors have so far remained elusive. Here, we identify an essential role for Drosophila Piezo in volume-based control of meal size. We discover a rare population of fly neurons that express Piezo, innervate the anterior gut and crop (a food reservoir organ), and respond to tissue distension in a Piezo-dependent manner. Activating Piezo neurons decreases appetite, while Piezo knockout and Piezo neuron silencing cause gut bloating and increase both food consumption and body weight. These studies reveal that disrupting gut distension receptors changes feeding patterns, and identify a key role for Drosophila Piezo in internal organ mechanosensation.

neuroscience↗