Biology subjects

Galko, M.

Publications and source records attributed to Galko, M..

2 recordsLinked to original sources

bioRxiv2025

ILP4 and InR regulate Paclitaxel-induced hypersensitivity differently in Drosophila larvae

Paclitaxel (PTX), a chemotherapeutic that stabilizes microtubules, induces nociceptive hypersensitivity and sensory neuron damage in humans, mice, and flies. To enhance our basic understanding of PTX-induced effects we undertook a molecular/genetic dissection of PTX-induced nociceptive hypersensitivity. Larvae fed viable doses of PTX exhibited dose-dependent hypersensitivity to sub-noxious thermal stimuli. Hypersensitivity developed rapidly and did not completely resolve at the larval stage. Live imaging of peripheral thermal nociceptors showed that lower doses of PTX (< 10 {micro}M) caused hyper-sprouting of tertiary dendritic branches. At 10 {micro}M and above, dendritic beading was observed. PTX-induced hypersensitivity does not depend on signaling pathways previously implicated in acute injury-induced nociceptive sensitization. However, the insulin-like peptide 4 (ILP4), was required for PTX-induced thermal hypersensitivity at 10 {micro}M PTX. Surprisingly, RNAi targeting the insulin receptor (InR) in nociceptors increased PTX-induced hypersensitivity, suggesting that ILP4 does not activate InR in this context. The salivary gland is likely the primary tissue source of functional ILP4. ILP4 mutant larvae did not exhibit PTX-induced beading (10 {micro}M) but did exhibit hypersprouting at lower PTX concentrations. In summary, our model of PTX-induced hypersensitivity reveals a disconnect between hypersensitivity and neuronal morphology and a genetic separation of ILP4 and InR in PTX-induced hypersensitivity.

genetics↗

bioRxiv2022

The Insulin receptor regulates the persistence of mechanical nociceptive sensitization in flies and mice

Early phase diabetes is often accompanied by pain sensitization. In the fruit fly Drosophila, the insulin receptor (InR) regulates the persistence of injury-induced thermal nociceptive sensitization. Whether Drosophila InR also regulates the persistence of mechanical nociceptive sensitization remains unclear. Mice with a sensory neuron deletion of the gene encoding the Insulin receptor (Insr) show normal nociceptive baselines, however, it is not known whether deletion of Insr in nociceptive sensory neurons leads to persistent nociceptive hypersensitivity in an inflammatory pain paradigm. In this study, we used fly and mouse nociceptive sensitization models to address these questions. In flies, InR mutants and larvae with sensory neuron-specific expression of RNAi transgenes targeting InR exhibited persistent mechanical hypersensitivity, as previously observed for the thermal sensory modality. Mice with a specific deletion of the Insr gene in NaV1.8+ nociceptive sensory neurons showed normal nociceptive thermal and mechanical baselines similar to controls. In an inflammatory paradigm, however, these mutant mice showed persistent mechanical (but not thermal) hypersensitivity, particularly in female mice. Mice with the NaV1.8+ sensory neuron specific deletion of Insr did not show metabolic abnormalities that would be typical of a systemic defect in insulin signaling. Our results show that some aspects of the regulation of nociceptive hypersensitivity by the Insulin receptor are shared between flies and mice and that this regulation is likely independent of metabolic effects.

neuroscience↗