Biology subjects

Rawls, A.

Publications and source records attributed to Rawls, A..

3 recordsLinked to original sources

bioRxiv2024

Microglial MyD88-dependent pathways are regulated in a sex specific manner in the context of HMGB1-induced anxiety

Chronic stress is a significant risk factor for the development and recurrence of anxiety disorders. Chronic stress impacts the immune system, causing microglial functional alterations in the medial prefrontal cortex (mPFC), a brain region involved in the pathogenesis of anxiety. High mobility group box 1 protein (HMGB1) is an established modulator of neuronal firing and a potent pro-inflammatory stimulus released from neuronal and non-neuronal cells following stress. HMGB1, in the context of stress, acts as a danger-associated molecular pattern (DAMP), instigating robust proinflammatory responses throughout the brain, so much so that localized drug delivery of HMGB1 alters behavior in the absence of any other forms of stress, i.e., social isolation, or behavioral stress models. Few studies have investigated the molecular mechanisms that underlie HMGB1-associated behavioral effects in a cell-specific manner. The aim of this study is to investigate cellular and molecular mechanisms underlying HMGB1-induced behavioral dysfunction with regard to cell-type specificity and potential sex differences. Here, we report that both male and female mice exhibited anxiety-like behavior following increased HMGB1 in the mPFC as well as changes in microglial morphology. Interestingly, our results demonstrate that HMGB1-induced anxiety may be mediated by distinct microglial MyD88-dependent mechanisms in females compared to males. This study supports the hypothesis that MyD88 signaling in microglia may be a crucial mediator of the stress response in adult female mice.

neuroscience↗

bioRxiv2021

Age-dependent Effect Imposed by Rotenone Exposure

BackgroundThe increasing awareness that environmental exposure may lead to sporadic neurological disorders has implicated rotenone to the etiology of some neurodegenerative diseases. However, the risk associated with rotenone toxicity remains controversial as a limited amount of research has studied its effects on brain health. ObjectivesThis work assessed the risk of rotenone exposure to mice of different ages, gender, and duration by examining in vivo effects on brains. MethodsUsing a mouse model, the impact of rotenone exposure was determined by analyzing the cellular phenotype in the murine brain. ResultsOur results highlight the neurological susceptibility to long-term rotenone exposure in younger ages. For such, younger mice exhibit seizures and convulsions, resulting in shorter lifespan. At the cellular level, rotenone exposure specifically alters the migrating neuroblast populations in the dentate gyrus and causes disorganized pyramidal neurons in the CA3 within the hippocampus. Our findings, albeit the absence of transgenerational inheritance, demonstrated age-related outcomes from rotenone exposure. DiscussionWe demonstrated that rotenone exposure specifically influences the population of neuroblasts and pyramidal neurons residing in the hippocampus, a brain region important for learning/memory and associated with convulsive seizure. Our understanding of how exactly rotenone affected region-specific neuronal cells and the molecular mechanism behind exposure risk is still limited. From the perspective of public health, our in vivo study highlights age-related susceptibility to rotenone toxicity. Future investigations in environmental epidemiology should determine whether age and duration of exposure to rotenone in human subjects pertains to the development of seizures or other neurological abnormalities over time.

neuroscience↗

bioRxiv2019

Consecutive signaling pathways are activated in progression of Duchenne muscular dystrophy in C. elegans

BackgroundDuchenne muscular dystrophy (DMD) is a lethal, X-linked disease characterized by progressive muscle degeneration. The condition is driven by nonsense and missense mutations in the dystrophin gene, but the resulting changes in muscle-specific gene expression that take place in dystrophins absence remain uncharacterized, as they are potentially obscured by the chronic inflammation elicited by muscle damage in humans. C. elegans possess a mild inflammatory response that allows for the characterization of the transcriptome rearrangements affecting disease progression independently of inflammation. ResultsIn effort to better understand these dynamics we have isolated and sequenced body muscle-specific transcriptomes from C. elegans lacking functional dystrophin at distinct stages of disease progression. We have identified two consecutively altered gene networks, which are also disrupted in the dystrophin deficient mdx mouse model. We found an upregulation of genes involved in mitochondrial function early in disease progression, and an upregulation of genes related to muscle fibre repair in later stages. This suggests that dystrophin may have a signaling role early in development, and its absence may activate compensatory mechanisms that counteract muscle degradation caused by loss of dystrophin. We have also developed a temperature-based screening method for synthetic paralysis that can be used to rapidly identify genetic partners of dystrophin. ConclusionsOur results allow for the comprehensive identification of transcriptome rearrangements that potentially serve as independent drivers of disease progression and may in turn allow for the identification of new therapeutic targets for the treatment of DMD. One Sentence SummaryA tissue specific transcriptome analysis of dystrophin deficient muscle in C. elegans reveals that dystrophin has distinct, dynamic signaling roles in early and late stage progression of Duchenne muscular dystrophy.

genetics↗