Biology subjects

Rice, M. E.

Publications and source records attributed to Rice, M. E..

3 recordsLinked to original sources

bioRxiv2026

BDNF Regulates Pituitary Stem Cell Engagement towards precursor state

Following their engagement towards differentiation, tissue stem cells often transit through a precursor state that is difficult to define because of its transient nature; similarly, the precise role of lineage precursors in implementation of tissue architecture and function is unknown. In the present work, we used two mouse models of deficient feedback regulation to characterize precursors of the pituitary corticotrope lineage that regulates the stress response. Both the POMC knockout and adrenalectomized mouse models develop glucocorticoid deficiency and compensatory accumulation of corticotrope precursors that have so far eluded characterization. We found that pre-corticotrope differentiation depends on the lineage-specific factor Tpit and is repressed by glucocorticoids. We identified brain-derived neurotrophic factor (BDNF) as the signal that engages pituitary stem cells towards differentiation in these models as well as in normal pituitary development. A glucocorticoid-sensitive BDNF autocrine loop active in pre-corticotropes turns these cells into signaling hubs for maintenance of pituitary-adrenal homeostasis. HighlightsO_LIPituitary lineage precursors expand in conditions of deficient feedback regulation C_LIO_LIBDNF mobilizes pituitary stem cells during establishment of tissue size and architecture C_LIO_LICorticotrope precursors are a signaling hub for tissue homeostasis C_LI

developmental biology↗

bioRxiv2023

Dopamine neuron dysfunction and loss in the PrknR275W mouse model of Juvenile Parkinsonism

Mutations in the PRKN gene encoding the protein PARKIN cause Autosomal Recessive Juvenile Parkinsonism (ARJP). Harnessing this mutation to create an early-onset Parkinsons disease (PD) mouse model would provide a unique opportunity to clarify the mechanisms involved in the neurodegenerative process and lay the groundwork for the development of neuroprotective strategies. We created a knock-in mouse carrying the homozygous PrknR275W mutation, which is the missense mutation with the highest allelic frequency in PRKN patients. In PrknR275W mice, we analysed the anatomical and functional integrity of the nigrostriatal pathway, including striatal DA content and evoked striatal dopamine (DA) release, as well as the motor phenotype. We report here that PrknR275W mice show early DA neuron dysfunction, age-dependent loss of DA neurons in the substantia nigra, decreased DA content and stimulus-evoked DA release in the striatum, and progressive motor impairment. Together, these data show that the PrknR275W mouse recapitulates key features of ARJP. Thus, these studies fill a critical need in the field by introducing a promising new PD model in which to study causative mechanisms of the disease, as well as test therapeutic strategies.

neuroscience↗

bioRxiv2020

Genetic reduction of PERK-eIF2α signaling in dopaminergic neurons drives cognitive and age-dependent motor dysfunction

An array of phenotypes in animal models of neurodegenerative disease have been shown to be reversed by neuronal inhibition of PERK, an eIF2 kinase that modulates the unfolded protein response (UPR). This suggests that targeting PERK therapeutically could be beneficial for treatment of human disease. Herein, using multiple genetic approaches we show that selective deletion of the PERK in mouse midbrain dopaminergic (DA) neurons results in multiple cognitive and age-dependent motor phenotypes. Conditional expression of phospho-mutant eIF2 in DA neurons recapitulated the phenotypes caused by deletion of PERK, consistent with a causal role of decreased eIF2 phosphorylation. In addition, deletion of PERK in DA neurons resulted in altered de novo translation, as well as age-dependent changes in axonal DA release and uptake in the striatum that mirror the pattern of motor changes observed. Taken together, our findings show that proper regulation of PERK-eIF2 signaling in DA neurons is required for normal cognitive and motor function across lifespan, and also highlight the need for caution in the proposed use of sustained PERK inhibition in neurons as a therapeutic strategy in the treatment of neurodegenerative disorders.

neuroscience↗