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Mase, A.

Publications and source records attributed to Mase, A..

4 recordsLinked to original sources

Evaluation of Locomotor Activity in Group-Housed Hamsters: Effects of Cage Size and Running Wheel Availability

While hamsters are commonly housed in groups within pet shops in Japan, small cages are often thought to restrict their physical activity, leading to arguments that larger cages should be provided. Although previous research has investigated how cage size and running wheel availability influence activity levels in individually housed hamsters, no studies to date have examined these specific effects in a social housing context. Therefore, this study investigated how cage size and the presence of a running wheel affect the activity levels of individual hamsters using the group-housing conditions with five hamsters. Video recordings were captured for 24 hours across four distinct cage environments using a camera installed directly above each cage. From these recordings, the distances traveled on both the cage floor and the running wheel were calculated for each hamster and statistically analyzed. The results revealed that overall activity levels were significantly higher in cages equipped with a running wheel than in those without. Although cage size did not yield a statistically significant difference, a marginal trend toward higher activity in larger cages was observed.

animal behavior and cognition↗

A critical role for PLCG1 in RAS activation by BCR-ABL1 and FLT3-ITD

Myeloid leukemias are frequently associated with pathologically activating mutations in tyrosine kinases [BCR-ABL1 in chronic myeloid leukemia (CML); FLT3 juxtamembrane internal tandem duplication (ITD) mutations, FLT3 and KIT activation loop mutations in acute myeloid leukemia (AML)]. Mutations in these kinases activate RAS, which initiates multiple downstream signaling pathways that regulate cell proliferation, differentiation, and apoptosis. The mechanisms whereby RAS is activated by these kinases is incompletely understood, and a better understanding of the molecular mediators involved in RAS activation may uncover new therapeutic strategies. Here we identify a biologically and therapeutically important novel mechanism whereby BCR-ABL1 and FLT3-ITD activate the critical downstream effector RAS in part through phospholipase C gamma-1 (PLCG1). PLCG1 knockout decreases proliferation of CML and FLT3-ITD-expressing AML cells, reduces RAS nucleotide exchange factor activity, and increases sensitivity of CML cells to BCR-ABL1 tyrosine kinase inhibitors (TKIs). Collectively, these studies suggest that PLCG1 inhibition may augment clinical responses to BCR-ABL1 and FLT3 TKIs in CML and AML.

cancer biology↗

Dscam1 promotes blood cell survival in Drosophila melanogaster through a dual role in blood cells and neurons

Down Syndrome Cell Adhesion Molecule 1 (Dscam1) is a receptor-like cell adhesion molecule that is conserved across the animal kingdom, but its roles in hematopoiesis remain unknown. Dscam1 related genes in vertebrates and invertebrates are key regulators of neuron morphogenesis and neuronal tiling. In Drosophila, Dscam1 in addition has roles in blood cells (hemocytes) in innate immunity and phagocytosis of pathogens. Given the anatomical and functional role of peripheral sensory neurons as microenvironments for resident hematopoietic sites in the Drosophila larva, we sought to investigate the role of Dscam1 in this context. Interestingly, we find that Dscam1 fills the role of a previously anticipated factor in neuron-hemocyte communication that supports trophic survival: tissue specific silencing of Dscam1 by in vivo RNAi in sensory neurons leads to neuron reduction, which in turn results in reduced hemocyte numbers due to apoptosis. Dscam1 silencing in hemocytes also results in a reduction of hemocytes and increased apoptosis. This cell-autonomous effect of Dscam1 silencing can be mimicked by RNAi silencing of dreadlocks (dock), suggesting that intracellular Dscam1 signaling relies on the adapter protein Dock in this system. Our findings reveal a dual role for Dscam1 in Drosophila hematopoiesis, by promoting survival of the sensory neuron microenvironments that in turn support hemocyte survival, and by promoting survival of hemocytes cell-autonomously. It will be interesting to explore possible functions of vertebrate Dscam1 related genes such as DSCAML1 in blood cells and their trophic survival.

developmental biology↗

Regulation of blood cell transdifferentiation by oxygen sensing neurons in Drosophila

Transdifferentiation generates specialized cell types independent of stem or progenitor cells. Despite the unique process, it remains poorly understood how transdifferentiation is regulated in vivo. Here we reveal a mechanism of environmental control of blood cell transdifferentiation in a Drosophila model of hematopoiesis. Functional lineage tracing provides evidence for transdifferentiation from macrophage-like plasmatocytes to crystal cells that execute melanization. Interestingly, this transdifferentiation is promoted by neuronal activity of a specific subset of sensory neurons, in the caudal sensory cones of the larva. Crystal cells develop from plasmatocyte clusters surrounding the sensory cones, triggered by environmental conditions: oxygen sensing, and the atypical guanylyl cyclase Gyc88E specifically expressed in the sensory cone neurons, drive plasmatocyte-to-crystal cell transdifferentiation. Our findings reveal an unexpected functional and molecular link of environment-monitoring sensory neurons that govern blood cell transdifferentiation in vivo, suggesting similar principles in vertebrate systems where environmental sensors and blood cell populations coincide. HighlightsO_LIFunctional lineage tracing reveals in vivo transdifferentiation in a Drosophila model of hematopoiesis C_LIO_LIActive sensory neurons of the caudal sensory cones promote blood cell transdifferentiation in the Drosophila larva C_LIO_LIEnvironmental oxygen sensing and atypical guanylyl cyclase activity in sensory cone neurons drive blood cell transdifferentiation C_LI

developmental biology↗