Neuroscience and Neurobiology Commons^™

Stromal Interaction Molecule (Stim) Proteins In Microglia And The Impact On Store-Operated Calcium Entry (Soce) And Spinal Cord Injury Recovery, Norah G. Hill

College of Arts & Sciences Senior Theses

In spinal cord injury (SCI), worsening functional outcomes are largely because of secondary injury processes and prolonged chronic inflammation. A major contributor of secondary injury is overload of intracellular calcium, causing neuronal overexcitation and persistent inflammatory responses. One of the primary mediators of calcium entry into the cell is store-operated calcium entry (SOCE). In SOCE, sensors detecting calcium depletion from the endoplasmic reticulum stores are called STIM proteins (1-2). When calcium is low in the cell, STIM proteins will activate Orai channels to open, allowing for the influx of calcium into the cell. The purpose of this study was to …

Exposure To Manganese During Juvenile Development Increases Microglial Activation In The Hippocampus Following Systemic Infection With A/California/04/2009 Influenza A H1n1 Virus, Megan Hager, Adam Schuller, Omar Yanouri, Collin Bantle, Richard Smeyne, Ronald Tjalkens

Farber Institute for Neuroscience Faculty Papers

Up to 80% of patients with Parkinson’s Disease (PD) develop dementia within 20 years of diagnosis. Although the etiology of PD and related neurodegenerative disorders is poorly understood, risk factors including environmental toxicants and viral infections are linked to disease onset and progression. Exposure to high doses of the essential element, manganese (Mn), causes neurotoxicity associated with parkinsonian symptoms and cognitive impairment in humans. Additionally, epidemiologic studies indicate that viral infections increase risk of developing PD. Previously, our lab demonstrated that mice exposed to Mn during juvenile development showed greater neuroinflammatory changes in microglia within the substantia nigra following systemic …

Mitochondria Dynamics In Microglia During Health, Inflammation, And Aging, Alicia Nicole Pietramale

Dartmouth College Ph.D Dissertations

Microglia continually surveil the brain, allowing for rapid detection of tissue damage or infection. Microglial metabolism is linked to tissue homeostasis, yet how mitochondria are subcellularly partitioned in microglia and dynamically reorganize during surveillance, injury responses, and phagocytic engulfment in the intact brain has remained unclear. In this dissertation, I combine intravital imaging, ultrastructural analyses, and metabolic and cytoskeletal markers to investigate how mitochondrial organization relates to microglial function across health, inflammation, and aging.

I first show that microglial processes diverge in their mitochondrial content, with some containing multiple mitochondria while others are completely void. This heterogeneous partitioning is conserved …

Microglial Apoe Across Alzheimer’S Disease-Relevant Pathologies, Georgia Nolt

Theses and Dissertations--Physiology

APOE exists as three common alleles (APOE2, APOE3, APOE4) that encode their corresponding protein isoforms (apoE2, apoE3, apoE4). Despite differing by only one or two single-amino acid substitutions, each APOE allele confers a distinct AD risk profile with APOE4 increasing risk by 28% and APOE2 decreasing risk by 14% compared to the most commonly expressed APOE3 allele. While traditionally considered “neutral,” APOE3 still accounts for ~36% of AD cases while APOE4 contributes ~57%, indicating that the majority of AD cases would not occur in the absence of the APOE3 and APOE4 alleles. Microglia, the resident phagocytic immune cells …

Temporal Evolution Of Brain Inflammation In The Bilateral Common Carotid Artery Stenosis Model Of Chronic Cerebral Hypoperfusion, Makayla F. Cox, Jill M. Roberts, Ryan K. Shahidehpour, David L. Dornbos Iii, Adam D. Bachstetter

Neuroscience Faculty Publications

Chronic cerebral hypoperfusion is a major contributor to vascular cognitive impairment and dementia, primarily through its disruption of white matter integrity and promotion of neuroinflammatory cascades. The bilateral common carotid artery stenosis (BCAS) model has emerged as the predominant experimental approach for studying the effects of chronic cerebral hypoperfusion, particularly in aging-relevant contexts. This review synthesizes current knowledge of inflammatory responses in the BCAS model, with an emphasis on their temporal progression and functional consequences. We begin by outlining the clinical burden of hypoperfusion, the rationale for BCAS, and the hemodynamic phases it produces. We then examine early neurovascular unit …

Dim Light At Night Impacts Circadian Rhythms And Alzheimer’S Disease-Like Neuroinf Lammation And Neuropathology In Humanized App Saa Knock-In Mice, Marilyn J. Duncan, Margaret R. Hawkins, Leke Bytyqi, Haleigh R. Whitlock, Savannah M. Shepard, Makayla F. Cox, Esther G. Drinkard, Teresa Macheda, Kelly N. Roberts, Katharina Kohler, Mary-Claire Schmidt, Carrie E. Johnson, Sridhar Sunderam, Bruce F. O'Hara, Michael Paul Murphy, Adam D. Bachstetter

Neuroscience Faculty Publications

Artificial light at night (light pollution) is widespread but understudied in the context of Alzheimer’s disease (AD). Sleep and circadian disruption have been linked to amyloid-β (Aβ) accumulation and neuroinflammation, but whether dim light at night (dLAN) modifies these processes remains unclear. We tested whether chronic dLAN exposure (8 lux during the dark phase, 8 weeks) alters circadian rhythms, amyloid pathology, and neuroinflammation in 12–13 month-old humanized APP knock-in (KI) mice. hAPP^SAA KI mice, which develop plaques, were compared with hAPP^WT KI controls carrying only a humanized APP sequence. dLAN reduced circadian rhythm amplitude and stability while increasing …

Microglial Expression Of Serotonin Receptors Reveals Parallel Regulation Of 5-Ht2b And Bdnf In The Rat Hippocampus, Andrei Turkin, Maria Sidorova, Ekaterina Kurilova, Natalia Alenina, Oksana Tuchina, Friederike Klempin

School of Graduate Studies Faculty Publications

Growing evidence suggests that psychiatric disorders are characterized by a prolonged inflammatory state, which may influence the efficacy of compounds targeting serotonin. Serotonin is a key signaling molecule in neuroplasticity of the adult hippocampus and involved in antidepressant action. Recent in vitro studies indicate the neurotransmitter may also facilitate the response to inflammation and potentially modulate microglial function towards neuroprotection. Using Tph2−/− rats depleted of brain serotonin, we examined microglial expression of various serotonin receptors (5-HTRs) in vivo in both the hippocampus and prefrontal cortex and assessed mRNA levels of cytokines and brain-derived neurotrophic factor (BDNF). We observed age-dependent and …

Investigating Potential Alzheimer's Disease Therapies Through An Agent-Based Model Of Impaired Microglia Metabolismmodeling Impaired Microglia Metabolism, Cheyenne Ty, Abigail Penland, John Gerving, Martin Mendoza-Ceja, Megan Pratt, Kamila Larripa

Spora: A Journal of Biomathematics

Alzheimer’s disease is the leading cause of dementia globally and is marked by amyloid-β plaque accumulation, decreased brain pH, disrupted metabolism, and increased permeability of the blood-brain barrier. Microglia, the resident immune cells of the central nervous system, are essential for maintaining brain homeostasis and are critically involved in the progression of AD. While microglia can initiate protective immune responses to injury and disease, dysregulated microglial metabolism may contribute to the exacerbation of Alzheimer's pathology. To investigate potential therapeutic strategies, we developed an agent-based model simulating the effects of exercise and metabolic enhancement on dysfunctional microglia. Our findings suggest that …

Microbial Metabolite Regulation Of Microglial Ahr Signaling In Alzheimer’S Disease, Ghalya E. Alrousan

Dissertations and Theses (Open Access)

Introduction: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by amyloid-β plaque accumulation, neuroinflammation, and cognitive decline. Recent evidence suggests that systemic factors, particularly the gut microbiota and its metabolites, play a significant role in shaping brain immune responses, including microglial activation. However, the mechanisms linking gut dysbiosis to microglial dysfunction in AD are poorly understood. The aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor responsive to tryptophan metabolites, has recently gained attention as a key regulator of neuroinflammation and microglial function. I hypothesize that the loss of beneficial microbial AHR ligands, specifically indole derivatives, during aging and AD …

Neuroinflammation In The Ventral Tegmental Area Of Chronically Stressed Rats, Marie M. Hafez

Honors Projects

Chronic stress has been associated with maladaptive behaviors in both human and animal research models, but the underlying mechanisms are unclear. In this research study, we sought to define whether stress induces neural inflammation in the ventral tegmental area, the brain region primarily responsible for regulating reward consumption, learning, memory, and addictive behaviors through moderating dopamine release in other brain areas. To do this, male Sprague-Dawley rats were subjected to a chronic intermittent stress paradigm that included stressors such as wet bedding, delayed feedings, social isolation, strobe lights, and forced swims. Following the chronic stress intervention, brain sections were collected …

Comprehensive Sumo Proteomic Analyses Identify Hiv Latency-Associated Proteins In Microglia., Fergan Imbert, Dianne Langford

Rowan-Virtua School of Osteopathic Medicine Departmental Research

SUMOylation, the post-translational modification of proteins by small ubiquitin-like modifiers, plays a critical role in regulating various cellular processes, including innate immunity. This modification is essential for modulating immune responses and influencing signaling pathways that govern the activation and function of immune cells. Recent studies suggest that SUMOylation also contributes to the pathophysiology of central nervous system (CNS) viral infections, where it contributes to the host response and viral replication dynamics. Here, we explore the multifaceted role of SUMOylation in innate immune signaling and its implications for viral infections within the CNS. Notably, we present novel proteomic analyses aimed at …

An Agent-Based Model Of Microglia And Neuron Interaction: Implications In Neurodegenerative Disease, Cheyenne Ty, Amanda Case, Emmanuel Mezzulo, Abigail Penland, Kamila Larripa

Spora: A Journal of Biomathematics

Whether immune cells protect or harm the brain is an open question depending on context, and their role is implicated in multiple diseases such as Alzheimer's disease, dementia, and other neurological disorders. Microglia, a specific type of immune cell in the central nervous system, play a key role in homeostasis, and genes associated with an elevated risk of Alzheimer's disease correspond with deficiencies in their behavior. We created an agent-based model that incorporates inflammatory signaling, chemotaxis, and phagocytosis of damaged neurons and allows the exploration of crucial pathways in the maintenance of brain health. We specifically investigated pathways related to …

Leveraging Transcriptomics And Behavior To Investigate Potential Neuronal And Glial Drivers Of Substance Use Disorder Endophenotypes, Jack V. Keady

Theses and Dissertations--Pharmacy

Over 54 million Americans needed substance use treatment in 2023. While there are many facets of substance use disorder, two major issues of interest are the negative reinforcing aspects of substances of abuse, manifesting in part as withdrawal symptomologies, and why a subset of people who use substances of abuse escalate to a use disorder. Nicotine exposure models were used to investigate the mechanisms of withdrawal endophenotypes, as smoking is the leading cause of preventable death in the United States, and a fentanyl self-administration model was used to probe individual differences in escalation phenotypes, as 80% of overdose deaths in …

Cell-Type Specific Apoe4 To Apoe2 ‘Switching’ In Astrocytes And Microglia Alters Alzheimer’S Disease Neuropathology, Lesley R. Golden

Theses and Dissertations--Physiology

Apolipoprotein E (APOE) is the strongest genetic risk factor for late-onset Alzheimer’s disease (LOAD). APOE exists in three common protein isoforms throughout the population: ApoE2 (E2), ApoE3 (E3), and ApoE4 (E4). While APOE allele frequencies and the degree of AD-associated risk vary across different ethnic groups, when compared to the ‘neutral’ and most common E3 allele, the E4 allele confers up to a 33-fold increase in Alzheimer’s Disease (AD) risk. Conversely, the neuroprotective E2 allele decreases AD risk by up to 67%. Here, we aimed to determine the therapeutic potential of cell-type specific APOE allele ‘switching’ and explore …

A Pathologic Study Of Perivascular Ptdp-43 Lin Bodies In Late-Nc, Ryan K. Shahidehpour, Peter T. Nelson, Adam D. Bachstetter

Neurology Faculty Publications

Background TAR DNA-Binding Protein 43 (TDP-43) pathological inclusions are a distinctive feature in dozens of neurodegenerative pathologies, including limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Prior investigations identified vascular-associated TDP-43-positive micro-lesions, known as “Lin bodies,” located on or near the brain capillaries of some individuals with LATE-NC. This study aimed to investigate the relationship between the accumulation of Lin bodies and glial cells in LATE-NC and the potential co-localization with ferritin, a protein associated with iron storage. Using multiplexed immunohistochemistry and digital pathology tools, we conducted pathological analyses to investigate the relationship between Lin bodies and glial markers (GFAP for …

Complement Propagates Visual System Pathology After Traumatic Brain Injury, Davis Marchant Borucki

MUSC Theses and Dissertations

Background: Traumatic brain injury is associated with the development of visual system disorders, including deficits in visual acuity. Visual deficits can present with delay and worsen over time, suggesting that ongoing neuroinflammatory changes contribute to their development and progression. Complement activation is strongly associated with the neuroinflammatory response after TBI and has been shown to contribute to neuronal and synaptic loss. However, the contributions of complement activation after TBI to vision loss remains unclear.

Methods: We employed an open skull controlled cortical impact model of traumatic brain injury in adult male mice to study how TBI affects vision. Animals were …

Deciphering The Contribution Of Microglia To Neurodegeneration In Friedreich's Ataxia, Sydney N. Gillette

Master's Theses

Friedreich's ataxia (FRDA) is the most prevalent inherited ataxia, affecting one in every 50,000 individuals in the United States. This hereditary condition is caused by an abnormal GAA trinucleotide repeat expansion within the first intron of the frataxin gene resulting in decreased levels of the frataxin protein (FXN). Insufficient cellular frataxin levels results in iron accumulation, increased reactive oxygen species production and mitochondrial dysfunction. Tissues most heavily impacted are those most dependent on oxidative phosphorylation as an energy source and include the nervous system and muscle tissue. This is evident in the clinical phenotype which includes muscle weakness, ataxia, neurodegeneration …

Isolation Of Aged Mouse Primary Microglia As A Model System For Alzheimer’S Disease Research, Michael Landis

Biology Honors Papers

Microglia and their role as the immune cells of the central nervous system are an emerging area of interest within Alzheimer’s research, particularly as they have shown in a benevolent and malevolent cellular context. Models of Alzheimer’s disease are very light in studying microglia, so in this study a model of microglia isolated from aged mice is established in order to study the phagocytic activity and protein expression of microglia in response to Amyloid Beta. The cells were isolated from aged mice and cultured before being used to confirm cellular identity, as well as to measure phagocytic activity. This study …

The Mitochondrial Membrane Potential As A Screening Tool For Immunostimulation, Kendra Mcglothen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The rise of neuroinflammatory disorders highlights the importance of early detection and intervention for more effective treatment options. Neuroinflammation is associated with the pathogenesis of many neurological disorders, including Major Depressive Disorder, Alzheimer's disease, and Multiple Sclerosis. There has been a focus on neurons to advance our understanding of the underlying mechanisms of neuroinflammation and its role in neurodegeneration. However, recent studies have highlighted the pivotal role of glial cells, particularly microglia, in neuroinflammation due to their active participation in the immune response. This study investigates glial-specific indicators of morphology, metabolic changes, and drug efficacy in neuroinflammatory conditions. By analyzing …

Effects Of Methamphetamine On Microglia Through Reactive Oxygen Species, Chase Seiter, Jordan Yorgason, Nathan Sheets, James Blood, Lydia Hawley, Erin Taylor, Eliza White, Hillary Wadsworth, Jason Hansen

Library/Life Sciences Undergraduate Poster Competition 2024

▪ Dopamine release in the Nucleus Accumbens (NAc) underlies motivational behavior for methamphetamine (METH) reward.

▪ ATP is a chemoattractant to microglia and is METH on ATP release and clearance are unknown.

▪ Furthermore, METH is known to produce reactive dopamine terminal function, microglia morphology and METH interactions are unknown.

Hiv-1 Mrna Knockdown With Crispr/Cas9 Enhances Neurocognitive Function, Kristen A. Mclaurin, Hailong Li, Kamel Khalili, Charles F. Mactutus, Rosemarie M. Booze

Neurology Faculty Publications

Mixed glia are infiltrated with HIV-1 virus early in the course of infection leading to the development of a persistent viral reservoir in the central nervous system. Modification of the HIV-1 genome using gene editing techniques, including CRISPR/Cas9, has shown great promise towards eliminating HIV-1 viral reservoirs; whether these techniques are capable of removing HIV-1 viral proteins from mixed glia, however, has not been systematically evaluated. Herein, the efficacy of adeno-associated virus 9 (AAV9)-CRISPR/Cas9 gene editing for eliminating HIV-1 messenger RNA (mRNA) from cortical mixed glia was evaluated in vitro and in vivo. In vitro, a within-subjects experimental design was …

Biogenesis And Function Of Microglial Extracellular Vesicles In Neuroinflammation And Parkinson’S Disease, Karl E. Biggs

Dartmouth College Ph.D Dissertations

Microglia are subject to chronic proteinaceous and environmental stress during the progression of prevalent neurodegenerative diseases such as Parkinson’s Disease (PD). Chronic stress can activate the NLR family pyrin domain containing 3 (NLRP3) pattern recognition receptor resulting in the formation of the NLRP3 inflammasome, proinflammatory signaling, and pyroptotic cell death. A distinct subset of extracellular vesicles (EVs) are released from cells upon NLRP3 activation. We studied WT and Nlrp3^-/- primary microglia exposed to bacterial stimulating agents and alpha synuclein preformed fibrils (αsyn PFFs), which model Parkinson’s disease and associated synucleinopathies. We identified the NLRP3-dependent release of the endosome fate …

Evaluating Reactive Gliosis In The Brain Of Adult Zebrafish Following The Ingestion Of Nanopolystyrene., Hannah A. Kelehear

College of Graduate Studies: Theses & Dissertations

Polystyrene nanoplastics are one of the most pervasive environmental contaminants and have been shown to infiltrate multiple organ systems following ingestion. Studies in several animal models and humans have demonstrated that nanoplastics can cross the blood-brain barrier. Additionally, there is evidence that plastics will induce an inflammatory response in the brain involving reactive gliosis of microglia and astrocytes. This process has yet to be thoroughly investigated in the zebrafish model system in the context of micro-/nanoplastic ingestion. In the current study, we examined microglial and astrocytic phenotypes in the adult zebrafish telencephalon after consuming food contaminated with 44 nm polystyrene …

Cyclophosphamide And Epirubicin Induce Apoptotic Cell Death In Microglia Cells, Rafael De La Hoz-Camacho

Research Symposium

Background. Chemotherapy Related Cognitive Impairment’s (CRCI), diminish patient’s quality life, being breast cancer (BC) patients the most affected. Microglia is described to play a major role in CRCI; hence, the aim of this research was to describe the cytotoxicity of cyclophosphamide (CTX) and Epirubicin (EPI), on microglia (SIM-A9), compared to BC cells (4T1).

Methods. We assessed cell viability (Resazurin) and cell death (AnnV), as well as nuclear damage with γ-H2AX, p53, p16 and cell cycle analysis (PI staining) by flow cytometry (FC). Furthermore, we evaluated ΔΨm (DIOC6), ROS (DCFDA) and NO (DAF-FM) production. Finally, caspase activation (TF2-VAD-FMK) and autophagy (CYTO-ID). …

Inhibition Of Acid Sphingomyelinase Reduces Reactive Astrocyte Secretion Of Mitotoxic Extracellular Vesicles And Improves Alzheimer’S Disease Pathology In The 5xfad Mouse, Simone M. Crivelli, Zainuddin Quadri, Hemendra J. Vekaria, Zhihui Zhu, Priyanka Tripathi, Ahmed Elsherbini, Liping Zhang, Patrick G. Sullivan, Erhard Bieberich

Markey Cancer Center Faculty Publications

In Alzheimer’s disease (AD), reactive astrocytes produce extracellular vesicles (EVs) that affect mitochondria in neurons. Here, we show that Aβ-induced generation of the sphingolipid ceramide by acid sphingomyelinase (A-SMase) triggered proinflammatory cytokine (C1q, TNF-α, IL-1α) release by microglia, which induced the reactive astrocytes phenotype and secretion of EVs enriched with ceramide. These EVs impeded the capacity of neurons to respond to energy demand. Inhibition of A-SMase with Arc39 and Imipramine reduced the secretion of cytokines from microglia, prompting us to test the effect of Imipramine on EV secretion and AD pathology in the 5xFAD mouse model. Brain derived-EVs from 5xFAD …

Complement System In Multiple Sclerosis: Its Role In Disease Course And Potential As A Therapeutic Target, Michael R. Linzey

Dartmouth College Ph.D Dissertations

Multiple sclerosis (MS) is a clinically heterogeneous neurological condition characterized by neuroinflammation and neurodegeneration. Relapsing-remitting MS, defined by inflammatory attacks, is the most common initial form of MS and there are currently 23 FDA-approved treatments for these patients. These therapies work primarily by reducing inflammation in the CNS; they do not work well in progressive disease. Therefore, an unmet medical need exists for effective therapeutic options to treat progressive MS (PMS).

In MS, intrathecal immunoglobulins synthesis (IIgS) correlates with disease progression. My goals for this dissertation were to establish the pathological role of IIgS and identify new potential therapeutic …

Editorial: Microglia In Neuroinflammation, Pinar Ayata, Ido Amit, Carla M. Cuda

Advanced Science Research Center

Microglia are a resident innate immune cell population of the central nervous system (CNS) derived from yolk sac erythro-myeloid progenitors that migrate to the developing brain prior to the formation of the blood-brain barrier. This critical cell population has gained considerable traction in the literature as it is considered a protective barrier from CNS damage and, yet, can also serve as a primary mediator of neuroinflammation. Under normal physiological conditions, microglia perform homeostatic functions, such as parenchymal surveillance, neurotrophic support, pathogen or debris removal, and maintenance of synaptic homeostasis and neuronal plasticity.

The Role Of Dha In The Impact Of Trem2 On Microglia Activation And Alzheimer’S Disease, Michael A. Palmieri Iii

Seton Hall University Dissertations and Theses (ETDs)

Alzheimer’s disease (AD) is a neurological disease that is associated with microglia activation. An important receptor involved in microglia activation is Triggering receptor expressed on myeloid cells 2 (TREM2). Recent studies suggest that docosahexaenoic acid (DHA) could reduce the neuroinflammation that is associated with microglia activation. We hypothesized that when DHA concentration was increased, TREM2 expression would decrease, microglia activity would be inhibited, and a resulting decrease in neuroinflammation would be observed. We examined peer-reviewed journal articles from 2017-2022 that investigated the relationship between TREM2 activation and severity of AD symptoms, the protective properties of DHA against AD, and the …

The Characterization Of Microglia In The Murine Dorsal Telencephalon In Development And Disease, Victoria Neckles

All Dissertations

Microglia are the primary immune cells of the central nervous system and contribute substantially to both development and maintenance of the brain. Negative alterations to microglia often result in detrimental outcomes and significant effort is being made to understand these powerful cells. The goal of this research is to characterize microglia in the developing and diseased murine dorsal telencephalon. In vivo cell labeling and confocal microscopy identified a transient cell type, amoeboid microglia cells (AMCs), that appear to contribute to the development of microglia. Moreover, the spatial distribution and morphological change of microglia was thoroughly characterized during postnatal development. The …

Sex-Specific Effects Of Chaperone And Glial Defenses On Experimental Lewy Body Disease, Tarun Bhatia

Electronic Theses and Dissertations

Lewy body disorders are a group of neurodegenerative conditions characterized by the pathological misfolding and aggregation of the abundant protein, α-synuclein. The most common Lewy body disorders are Parkinson’s disease and dementia with Lewy bodies. Apart from ageing, male sex is a major risk factor for Lewy body disorders, as men are at ~1.5-fold higher risk for these diseases than women. Yet, preclinical studies on Lewy body disorders rarely examine sex as a biological variable, and the mechanisms underlying sex-skewedness in disease risk remain undetermined.

Here, we developed a sex-stratified model of Lewy body disorders by exposing primary neurons harvested …