Neurosciences Commons^™

Cognitive Decline In Dutch-Type Hereditary And Sporadic Cerebral Amyloid Angiopathy: A 5-Year Follow-Up Study, Rosemarie Van Dort, Vera C.J. Van Stek-Smits, Sanne E. Schriemer, Reinier G.J. Van Der Zwet, Manon R. Schipper, Sabine Voigt, Ellen P. Hart, Vandhana Easwaran, Hamid R. Sohrabi, Kevin Taddei, Samantha L. Gardener, Ralph N. Martins, Steven M. Greenberg, Matthias J.P. Van Osch, Marianne A.A. Van Walderveen, Marieke J.H. Wermer, Ellis S. Van Etten

Research outputs 2022 to 2026

Introduction: Cerebral amyloid angiopathy (CAA) is associated with cognitive impairment, but its longitudinal course of cognitive decline remains unclear. We investigated domain-specific cognitive trajectories in Dutch-type hereditary (D-CAA) and sporadic CAA (sCAA) to compare patterns and rates of decline. Methods: We included 181 participants – 93 D-CAA mutation carriers (59 without, 34 with prior intracerebral hemorrhage [ICH]) and 88 with sCAA (57 without, 31 with ICH) – who underwent annual neuropsychological assessment. Longitudinal change in global cognition, memory, processing speed, and executive function was analyzed using linear mixed models. Results: Over 5 years, cognitive decline was subtle but measurable. Memory …

Circulating Sphingomyelins Correlate With Plasma T-Tau In Cognitively Unimpaired Older Adults At Risk Of Developing Alzheimer's Disease, Tahmida Sharmin, James D. Doecke, Pratishtha Chatterjee, Steve Pedrini, Hamid R. Sohrabi, Nicholas J. Ashton, Henrik Zetterberg, Manohar L. Garg, Kaj Blennow, Ralph N. Martins

Research outputs 2022 to 2026

Alterations in plasma sphingomyelin (SM) levels have been reported in Alzheimer's disease (AD), pointing to disturbances in lipid metabolism that may contribute to disease pathogenesis. Neuronal damage in early AD triggers tau release into central and peripheral systems. Despite influence from peripheral contributions, alterations in plasma total-tau (T-tau) remain valuable in indicating AD-related neurodegeneration. Investigating relationships between SM metabolism and tau release during preclinical AD may uncover important biochemical processes and support advancing early non-invasive detection and treatment approaches. This cross-sectional study investigated cognitively unimpaired (CU) older adults from the KARVIAH cohort, grouped by cortical amyloid-β (Aβ) status through positron …

Disrupted Nuclear Function And Nucleocytoplasmic Transport In Parkinson’S Disease, Ichiro M. Matoba

The Cardinal Edge

No abstract provided.

Cerebellar Dysfunction In A Mouse Model Of Childhood-Onset Manganese-Induced Dystonia Parkinsonism, Alexander N Rodichkin, Amanda M Brown, Pavani Devabathini, Jennifer L Mcglothan, Si Chen, Ajith Pattammattel, Yong S Chu, Tao Lin, Daniel D Pontow, Karam Abilmouna, Ritishka Kapoor, Sarah E Hardin, Yulia Pushkar, Roy V Sillitoe, Tomás R Guilarte

Duncan NRI Faculty and Staff Publications

Humans with pathogenic variants of the manganese (Mn) transporter gene SLC39A14 exhibit highly elevated brain Mn concentrations and childhood-onset dystonia-parkinsonism. Here we show that Slc39a14-knockout (KO) mice, a preclinical model of the disease with elevated Mn concentrations in the CB, express deficits in physiological tremor implicating cerebellar (CB) dysfunction. Imaging of intracellular Mn in Purkinje cells (PCs) using synchrotron-based X-ray fluorescence microscopy confirmed highly elevated Mn concentrations in the PCs of Slc39a14-KO mice. To determine biological pathways altered in the CB of Slc39a14-KO mice relative to wildtype (WT), we performed RNA sequencing and discovered significant upregulation of pathways and genes …

Corticobasal Syndrome With Mixed Pathology In The Absence Of Grn Mutation: A Clinico-Pathological Case Of Ftld-Tdp With Coexisting Alzheimer’S And Lewy Body Pathology, Hugo Zamarron, David Irwin, Jeffery Phillips, Edward Lee, Matthew Tisdall, Corey Mcmillan

Research Colloquium

Background: Corticobasal syndrome (CBS) is a neurodegenerative disorder characterized by often asymmetric fronto-pariteal and extra-pyramidal features that is traditionally associated with tauopathy, but pathological findings are heterogenous, including other forms of frontotemporal lobar degeneration (FTLD) and mixed pathologies of aging. We present clinical, radiographic, and histopathologic features of asymmetry in a unique patient with CBS and underlying FTLD with TDP-43 pathology (FTLD-TDP), co-occurring with other age-related pathologies.

Case Presentation: A 76-year-old man presented with progressive cognitive and motor dysfunction including asymmetric parkinsonism, left-sided dystonia and rigidity, apraxia, visuospatial impairment, and a subtle social disorder including apathy and social withdrawal. The …

A Single Center Study Of The Symbol Digit Modalities Test As A Screening Tool For Cognitive Impairment In Parkinson’S Disease, Daniyell Thomason, Morganne Manuel, Shannin Moody, Jesus Lovera, Brain Copeland, Deidre Devier

School of Medicine Faculty Publications

Background: Parkinson’s Disease (PD) can include physical signs and possibly cognitive impairment, resulting from the convergence of pathologicalprocesses involving dopaminergic dysfunction, accumulation ofalpha-synuclein, cholinergic deficits, and disruption of otherneurotransmitter systems. We used screening tests to evaluate thecharacteristics of cognitive performance in patients with PD and to assess their validity compared tothe Montreal Cognitive Assessment (MoCA). Methods: This is a natural history study of participants with PD and controls screened for possible cognitive impairment using the MoCA, Symbol Digit Modalities Test (SDMT), and King-Devick (KD). The groups were compared on performance and then factors associated with cognitive performance (age, diagnosis, and …

Glucose Uptake In Pigment Glia Suppresses Tau-Induced Inflammation And Photoreceptor Degeneration, Mikiko Oka, Sho Nakajima, Emiko Suzuki, Shinya Yamamoto, Kanae Ando

Duncan NRI Faculty and Staff Publications

Brain inflammation contributes to the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease (AD). Glucose hypometabolism and glial activation are pathological features seen in AD brains; however, the connection between the two is not fully understood. Using a Drosophila model of AD, we identified that glucose metabolism in glia plays a critical role in neuroinflammation under disease conditions. Expression of human MATP (hereafter referred to as Tau) in the retinal cells, including photoreceptor neurons and pigment glia, causes photoreceptor degeneration accompanied by the formation of dark-stained round inclusion-like structures and swelling of the lamina cortex. We found that inclusion-like structures …

Motor Pool Selectivity Of Neuromuscular Degeneration In Type I Spinal Muscular Atrophy Is Conserved Between Human And Mouse, Justin C Lee, Wendy K Chung, David J Pisapia, Christopher E Henderson

Faculty, Staff and Students Publications

Spinal muscular atrophy (SMA) is caused by low levels of the survival motor neuron (SMN) protein. Even though SMN is ubiquitously expressed, the disease selectively affects motor neurons, leading to progressive muscle weakness. Even among motor neurons, certain motor units appear more clinically resistant to SMA. To quantitatively survey selective resistance, we studied extensive neuromuscular autopsies of Type I SMA patients and age-matched controls. We found highly divergent degrees of degeneration of neighboring motor units, even within individual cranial nerves or a single anatomical area such as the neck. Examination of a Type I SMA patient maintained on life support …

Blood Biomarker Profiles In Young-Onset Neurocognitive Disorders: A Cohort Study, Oneil G. Bhalala, Jessica Beamish, Dhamidhu Eratne, Patrick Summerell, Tenielle Porter, Simon M. Laws, Matthew J.Y. Kang, Aamira J. Huq, Wei Hsuan Chiu, Claire Cadwallader, Mark Walterfang, Sarah Farrand, Andrew H. Evans, Wendy Kelso, Leonid Churilov, Rosie Watson, Nawaf Yassi, Dennis Velakoulis, Samantha M. Loi

Research outputs 2022 to 2026

Introduction: Young-onset neurocognitive symptoms result from a heterogeneous group of neurological and psychiatric disorders which present a diagnostic challenge. To identify such factors, we analysed the Biomarkers in Younger-Onset Neurocognitive Disorders cohort, a study of individuals < 65 years old presenting with neurocognitive symptoms for a diagnosis and who have undergone cognitive and biomarker analyses. Methods: Sixty-five participants (median age at assessment of 56 years, 45% female) were recruited during their index presentation to the Royal Melbourne Hospital Neuropsychiatry Centre, a tertiary specialist service in Melbourne, Australia, and categorized as either early-onset Alzheimer’s disease (n = 18), non-Alzheimer’s disease neurodegeneration (n = 23) or primary psychiatric disorders (n = 24). Levels of neurofilament light chain, glial fibrillary acidic protein …

Imaging Markers Of Future Neurodegeneration Following Moderate-Severe Traumatic Brain Injury, Daniel Brennan

Dissertations, Theses, and Capstone Projects

The overall goal of this dissertation was to identify patterns of cerebral atrophy following traumatic brain injury and relate relevant imaging measures to that atrophy. In Chapter 2, we outline a spatiotemporal profile of atrophy in the first year following moderate-severe TBI: prior to 3-months post injury, the frontal and temporal cortices were observed to be thinner than controls, and thalamic volumes were reduced. From 3-12 months post-injury, significant atrophy was observed in white matter, subcortical gray matter structures (including thalamus), and cortical thinning was observed in the parietal and occipital cortices.

In Chapter 3, we identified widespread white matter …

Roles Of Mitochondrial Chchd2 And Gpcr-Associated Β-Arrestin2 In The Pathogenesis Of Lewy Body Disorders, Teresa R. Kee

USF Tampa Graduate Theses and Dissertations

Coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2) is a mitochondrial protein that plays important roles in cristae structure, oxidative phosphorylation, and apoptosis. Multiple mutations in CHCHD2 have been associated with Lewy body disorders (LBDs), such as Parkinson’s disease (PD) and dementia with Lewy bodies (DLB), with the CHCHD2T61I mutation being the most widely studied. We generated the first transgenic mouse models expressing human CHCHD2WT and the PD-linked CHCHD2T61I mutation driven by the mPrP promoter. CHCHD2T61I Tg, but not CHCHD2WT Tg mice exhibit perinuclear mitochondrial aggregates, neuroinflammation, and have impaired long-term synaptic plasticity associated with synaptic dysfunction. Dopaminergic neurodegeneration, a hallmark of PD, …

Tmem106b Coding Variant Is Protective And Deletion Detrimental In A Mouse Model Of Tauopathy, George A Edwards, Caleb A Wood, Yang He, Quynh Nguyen, Peter J Kim, Ruben Gomez-Gutierrez, Kyung-Won Park, Yong Xu, Cody Zurhellen, Ismael Al-Ramahi, Joanna L Jankowsky

Duncan NRI Faculty and Staff Publications

TMEM106B is a risk modifier of multiple neurological conditions, where a single coding variant and multiple non-coding SNPs influence the balance between susceptibility and resilience. Two key questions that emerge from past work are whether the lone T185S coding variant contributes to protection, and if the presence of TMEM106B is helpful or harmful in the context of disease. Here, we address both questions while expanding the scope of TMEM106B study from TDP-43 to models of tauopathy. We generated knockout mice with constitutive deletion of TMEM106B, alongside knock-in mice encoding the T186S knock-in mutation (equivalent to the human T185S variant), and …

Mapping Sca1 Regional Vulnerabilities Reveals Neural And Skeletal Muscle Contributions To Disease, Lisa Duvick, W Michael Southern, Kellie A Benzow, Zoe N Burch, Hillary P Handler, Jason S Mitchell, Hannah Kuivinen, Udaya Gadiparthi, Praseuth Yang, Alyssa Soles, Carrie A Sheeler, Orion Rainwater, Shannah Serres, Erin B Lind, Tessa Nichols-Meade, Yun You, Brennon O'Callaghan, Huda Y Zoghbi, Marija Cvetanovic, Vanessa C Wheeler, James M Ervasti, Michael D Koob, Harry T Orr

Duncan NRI Faculty and Staff Publications

Spinocerebellar ataxia type 1 (SCA1) is a fatal neurodegenerative disease caused by an expanded polyglutamine tract in the widely expressed ataxin-1 (ATXN1) protein. To elucidate anatomical regions and cell types that underlie mutant ATXN1-induced disease phenotypes, we developed a floxed conditional knockin mouse (f-ATXN1146Q/2Q) with mouse Atxn1 coding exons replaced by human ATXN1 exons encoding 146 glutamines. f-ATXN1146Q/2Q mice manifested SCA1-like phenotypes including motor and cognitive deficits, wasting, and decreased survival. Central nervous system (CNS) contributions to disease were revealed using f-ATXN1146Q/2Q;Nestin-Cre mice, which showed improved rotarod, open field, and Barnes maze performance by 6-12 weeks of age. In contrast, …

Longitudinal Single-Cell Transcriptional Dynamics Throughout Neurodegeneration In Sca1, Leon Tejwani, Neal G Ravindra, Changwoo Lee, Yubao Cheng, Billy Nguyen, Kimberly Luttik, Luhan Ni, Shupei Zhang, Logan M Morrison, John Gionco, Yangfei Xiang, Jennifer Yoon, Hannah Ro, Fatema Haidery, Rosalie M Grijalva, Eunwoo Bae, Kristen Kim, Regina T Martuscello, Harry T Orr, Huda Y Zoghbi, Hayley S Mcloughlin, Laura P W Ranum, Vikram G Shakkottai, Phyllis L Faust, Siyuan Wang, David Van Dijk, Janghoo Lim

Duncan NRI Faculty and Staff Publications

Neurodegeneration is a protracted process involving progressive changes in myriad cell types that ultimately results in the death of vulnerable neuronal populations. To dissect how individual cell types within a heterogeneous tissue contribute to the pathogenesis and progression of a neurodegenerative disorder, we performed longitudinal single-nucleus RNA sequencing of mouse and human spinocerebellar ataxia type 1 (SCA1) cerebellar tissue, establishing continuous dynamic trajectories of each cell population. Importantly, we defined the precise transcriptional changes that precede loss of Purkinje cells and, for the first time, identified robust early transcriptional dysregulation in unipolar brush cells and oligodendroglia. Finally, we applied a …

Anthocyanins: Molecular Aspects On Their Neuroprotective Activity, César A Zaa, Álvaro J Marcelo, Zhiqiang An, José L Medina-Franco, Marco A Velasco-Velázquez

Faculty, Staff and Student Publications

Anthocyanins are a type of flavonoids that give plants and fruits their vibrant colors. They are known for their potent antioxidant properties and have been linked to various health benefits. Upon consumption, anthocyanins are quickly absorbed and can penetrate the blood-brain barrier (BBB). Research based on population studies suggests that including anthocyanin-rich sources in the diet lower the risk of neurodegenerative diseases. Anthocyanins exhibit neuroprotective effects that could potentially alleviate symptoms associated with such diseases. In this review, we compiled and discussed a large body of evidence supporting the neuroprotective role of anthocyanins. Our examination encompasses human studies, animal models, …

Pirh2-Dependent Dna Damage In Neurons Induced By The G-Quadruplex Ligand Pyridostatin, Rocio Diaz Escarcega, Abhijeet A Patil, Jose F Moruno-Manchon, Akihiko Urayama, Sean P Marrelli, Nayun Kim, David Monchaud, Louise D Mccullough, Andrey S Tsvetkov

Faculty, Staff and Student Publications

Noncanonical base pairing between four guanines (G) within single-stranded G-rich sequences leads to formation of а G-quartet. Self-stacking of G-quartets results in a columnar four-stranded DNA structure known as the G-quadruplex (G4 or G4-DNA). In cancer cells, G4-DNA regulates multiple DNA-dependent processes, including transcription, replication, and telomere function. How G4s function in neurons is poorly understood. Here, we performed a genome-wide gene expression analysis (RNA-Seq) to identify genes modulated by a G4-DNA ligand, pyridostatin (PDS), in primary cultured neurons. PDS promotes stabilization of G4 structures, thus allowing us to define genes directly or indirectly responsive to G4 regulation. We found …

Plasma Glial Fibrillary Acidic Protein In Autosomal Dominant Alzheimer's Disease: Associations With Aβ-Pet, Neurodegeneration, And Cognition, Pratishtha Chatterjee, Lisa Vermunt, Brian A. Gordon, Steve Pedrini, Lynn Boonkamp, Nicola J. Armstrong, Chengjie Xiong, Abhay K. Singh, Yan Li, Hamid R. Sohrabi, Kevin Taddei, Mark Molloy, Tammie L. S. Benzinger, John C. Morris, Celeste Karch, Sarah Berman, Jasmeer Chhatwal, Carlos Cruchaga, Neill R. Graff-Radford, Gregory S. Day, Martin Farlow, Nick Fox, Alison Goate, Jason Hassenstab, Jae-Hong Lee, Johannes Levin, Eric Mcdade, Hiroshi Mori, Richard Perrin, Raquel Sanchez-Valle, Peter R. Schofield, Allan Levey, Mathias Jucker, Colin L. Masters, Anne M. Fagan, Randall J. Bateman, Ralph N. Martins, Charlotte Teunissen, Dominantly Inherited Alzheimer Network

Research outputs 2022 to 2026

Background: Glial fibrillary acidic protein (GFAP) is a promising candidate blood-based biomarker for Alzheimer's disease (AD) diagnosis and prognostication. The timing of its disease-associated changes, its clinical correlates, and biofluid-type dependency will influence its clinical utility. Methods: We evaluated plasma, serum, and cerebrospinal fluid (CSF) GFAP in families with autosomal dominant AD (ADAD), leveraging the predictable age at symptom onset to determine changes by stage of disease. Results: Plasma GFAP elevations appear a decade before expected symptom onset, after amyloid beta (A ) accumulation and prior to neurodegeneration and cognitive decline. Plasma GFAP distinguished A -positive from A -negative ADAD …

Evolutionarily Conserved Regulators Of Tau Identify Targets For New Therapies, Jiyoen Kim, Maria De Haro, Ismael Al-Ramahi, Lorena Laura Garaicoechea, Hyun-Hwan Jeong, Jun Young Sonn, Bakhos Tadros, Zhandong Liu, Juan Botas, Huda Yahya Zoghbi

Duncan NRI Faculty and Staff Publications

Tauopathies are neurodegenerative diseases that involve the pathological accumulation of tau proteins; in this family are Alzheimer disease, corticobasal degeneration, and chronic traumatic encephalopathy, among others. Hypothesizing that reducing this accumulation could mitigate pathogenesis, we performed a cross-species genetic screen targeting 6,600 potentially druggable genes in human cells and Drosophila. We found and validated 83 hits in cells and further validated 11 hits in the mouse brain. Three of these hits (USP7, RNF130, and RNF149) converge on the C terminus of Hsc70-interacting protein (CHIP) to regulate tau levels, highlighting the role of CHIP in maintaining tau proteostasis in the brain. …

Decreasing Mutant Atxn1 Nuclear Localization Improves A Spectrum Of Sca1-Like Phenotypes And Brain Region Transcriptomic Profiles, Hillary P Handler, Lisa Duvick, Jason S Mitchell, Marija Cvetanovic, Molly Reighard, Alyssa Soles, Kathleen B Mather, Orion Rainwater, Shannah Serres, Tessa Nichols-Meade, Stephanie L Coffin, Yun You, Brian L Ruis, Brennon O'Callaghan, Christine Henzler, Huda Y Zoghbi, Harry T Orr

Duncan NRI Faculty and Staff Publications

Spinocerebellar ataxia type 1 (SCA1) is a dominant trinucleotide repeat neurodegenerative disease characterized by motor dysfunction, cognitive impairment, and premature death. Degeneration of cerebellar Purkinje cells is a frequent and prominent pathological feature of SCA1. We previously showed that transport of ATXN1 to Purkinje cell nuclei is required for pathology, where mutant ATXN1 alters transcription. To examine the role of ATXN1 nuclear localization broadly in SCA1-like disease pathogenesis, CRISPR-Cas9 was used to develop a mouse with an amino acid alteration (K772T) in the nuclear localization sequence of the expanded ATXN1 protein. Characterization of these mice indicates that proper nuclear localization …

Nrf2 Sequestration By Ssh1 Tips The Balance From Neuroprotection To Neurodegeneration In Alzheimer’S Disease, Sara G. Cazzaro Buosi

USF Tampa Graduate Theses and Dissertations

Oxidative damage is one of the earliest events in Alzheimer’s disease (AD) pathogenesis and precedes the clinical stage of disease. The nuclear factor erythroid 2-related factor (Nrf2) is activated in response to oxidative stress, which protects the brain from oxidative damage and AD pathogenesis. Although Nrf2-mediated oxidative stress response declines with age and becomes dysfunctional in AD brains, the mechanistic basis for this dysfunction is unknown. Here, we demonstrate through in vitro and in vivo models, as well as in human AD brain tissue, that Slingshot homolog-1 (SSH1) acts as a counterweight to neuroprotective Nrf2 in response to oxidative stress …

Sex-Biased Autophagy As A Potential Mechanism Mediating Sex Differences In Ischemic Stroke Outcome, Brian Noh, Louise D Mccullough, Jose F Moruno-Manchon

Faculty, Staff and Student Publications

Stroke is the second leading cause of death and a major cause of disability worldwide, and biological sex is an important determining factor in stroke incidence and pathology. From childhood through adulthood, men have a higher incidence of stroke compared with women. Abundant research has confirmed the beneficial effects of estrogen in experimental ischemic stroke but genetic factors such as the X-chromosome complement can also play an important role in determining sex differences in stroke. Autophagy is a self-degrading cellular process orchestrated by multiple core proteins, which leads to the engulfment of cytoplasmic material and degradation of cargo after autophagy …

Upregulation Of The Escrt Pathway And Multivesicular Bodies Accelerates Degradation Of Proteins Associated With Neurodegeneration, Ron Benyair, Sai Srinivas Panapakkam Giridharan, Pilar Rivero-Ríos, Junya Hasegawa, Emily Bristow, Eeva-Liisa Eskelinen, Merav D Shmueli, Vered Fishbain-Yoskovitz, Yifat Merbl, Lisa M Sharkey, Henry L Paulson, Phyllis I Hanson, Samarjit Patnaik, Ismael Al-Ramahi, Juan Botas, Juan Marugan, Lois S Weisman

Duncan NRI Faculty and Staff Publications

Many neurodegenerative diseases, including Huntington’s disease (HD) and Alzheimer’s disease (AD), occur due to an accumulation of aggregation-prone proteins, which results in neuronal death. Studies in animal and cell models show that reducing the levels of these proteins mitigates disease phenotypes. We previously reported a small molecule, NCT-504, which reduces cellular levels of mutant huntingtin (mHTT) in patient fibroblasts as well as mouse striatal and cortical neurons from an HdhQ111 mutant mouse. Here, we show that NCT-504 has a broader potential, and in addition reduces levels of Tau, a protein associated with Alzheimer’s disease, as well as other tauopathies. We …

Sphingolipids In Neurodegenerative Diseases, Xueyang Pan, Debdeep Dutta, Shenzhao Lu, Hugo J Bellen

Faculty, Staff and Students Publications

Neurodegenerative Diseases (NDDs) are a group of disorders that cause progressive deficits of neuronal function. Recent evidence argues that sphingolipid metabolism is affected in a surprisingly broad set of NDDs. These include some lysosomal storage diseases (LSDs), hereditary sensory and autonomous neuropathy (HSAN), hereditary spastic paraplegia (HSP), infantile neuroaxonal dystrophy (INAD), Friedreich’s ataxia (FRDA), as well as some forms of amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD). Many of these diseases have been modeled in Drosophila melanogaster and are associated with elevated levels of ceramides. Similar changes have also been reported in vertebrate cells and mouse models. Here, we …

Loss Of Activity-Induced Mitochondrial Atp Production Underlies The Synaptic Defects In A Drosophila Model Of Als, Nicholas E Karagas, Richa Gupta, Elham Rastegari, Kai Li Tan, Ho Hang Leung, Hugo J Bellen, Kartik Venkatachalam, Ching-On Wong

Faculty, Staff and Students Publications

Mutations in the gene encoding vesicle-associated membrane protein B (VAPB) cause a familial form of amyotrophic lateral sclerosis (ALS). Expression of an ALS-related variant of vapb (vapb^P58S) in Drosophila motor neurons results in morphologic changes at the larval neuromuscular junction (NMJ) characterized by the appearance of fewer, but larger, presynaptic boutons. Although diminished microtubule stability is known to underlie these morphologic changes, a mechanism for the loss of presynaptic microtubules has been lacking. By studying flies of both sexes, we demonstrate the suppression of vapb^P58S-induced changes in NMJ morphology by either a loss of endoplasmic …

‘Fly-Ing’ From Rare To Common Neurodegenerative Disease Mechanisms, Mengqi Ma, Matthew J Moulton, Shenzhao Lu, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

Genome sequencing advances have enabled researchers and clinicians to probe vast numbers of human variants to distinguish pathogenic from benign variation. Model organisms have been critical in variant assessment and delineating molecular mechanisms of some of the diseases caused by these variants. The fruit fly, Drosophila melanogaster, has played a valuable role in this endeavor, taking advantage of its genetic technologies and established biological knowledge. In this review, we highlight the utility of the fly in studying the function of genes associated with rare neurological diseases that have led to a better understanding of common disease mechanisms. We emphasize …

Cross-Species Genetic Screens Identify Transglutaminase 5 As A Regulator Of Polyglutamine-Expanded Ataxin-1, Won-Seok Lee, Ismael Al-Ramahi, Hyun-Hwan Jeong, Youjin Jang, Tao Lin, Carolyn J Adamski, Laura A Lavery, Smruti Rath, Ronald Richman, Vitaliy V Bondar, Elizabeth Alcala, Jean-Pierre Revelli, Harry T Orr, Zhandong Liu, Juan Botas, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Many neurodegenerative disorders are caused by abnormal accumulation of misfolded proteins. In spinocerebellar ataxia type 1 (SCA1), accumulation of polyglutamine-expanded (polyQ-expanded) ataxin-1 (ATXN1) causes neuronal toxicity. Lowering total ATXN1, especially the polyQ-expanded form, alleviates disease phenotypes in mice, but the molecular mechanism by which the mutant ATXN1 is specifically modulated is not understood. Here, we identified 22 mutant ATXN1 regulators by performing a cross-species screen of 7787 and 2144 genes in human cells and Drosophila eyes, respectively. Among them, transglutaminase 5 (TG5) preferentially regulated mutant ATXN1 over the WT protein. TG enzymes catalyzed cross-linking of ATXN1 in a polyQ-length–dependent manner, …

Reduction Of Mutant Atxn1 Rescues Premature Death In A Conditional Sca1 Mouse Model, James P Orengo, Larissa Nitschke, Meike E Van Der Heijden, Nicholas A Ciaburri, Harry T Orr, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Spinocerebellar ataxia type 1 (SCA1) is an adult-onset neurodegenerative disorder. As disease progresses, motor neurons are affected, and their dysfunction contributes toward the inability to maintain proper respiratory function, a major driving force for premature death in SCA1. To investigate the isolated role of motor neurons in SCA1, we created a conditional SCA1 (cSCA1) mouse model. This model suppresses expression of the pathogenic SCA1 allele with a floxed stop cassette. cSCA1 mice crossed to a ubiquitous Cre line recapitulate all the major features of the original SCA1 mouse model; however, they took twice as long to develop. We found that …

Spata7 Is Required For Maintenance Of The Retinal Connecting Cilium, Jiaxiong Lu, Kaitlyn Xiong, Xinye Qian, Jongsu Choi, Yoon-Kyung Shim, Jacob Burnett, Graeme Mardon, Rui Chen

Faculty, Staff and Students Publications

SPATA7, an early onset LCA3 retinal disease gene, encodes a putative scaffold protein that is essential for the proper assembly of the connecting cilium (CC) complex in photoreceptors. Previous studies have shown that SPATA7 interacts with other photoreceptor-specific ciliary proteins, such as RPGR and RPGRIP1, and maintains the integrity of CC integrity. However, although it is known that Spata7 is required for early formation of the CC, it is unclear if Spata7 is also required for the maintenance of the CC. To investigate Spata7 function in the retina at the adult stage, loss of function was induced in the …

Epigenetic Pathogenesis Of Neurological Disorders In Utero And Considerations For Genetic Counseling, Lauren Juga

Senior Honors Theses

Epigenetic modifications are a major focus of study in the pathogenesis of many disorders regarding metabolism, aging, neurodevelopment, and neurodegeneration. Epigenetic mechanisms are present throughout life but are especially vital to guiding fetal development. The precise timing of gene activation and deactivation guides stem cell differentiation through each embryonic stage. After exposure to environmental stimuli, gene expression can be altered by transcription factors, resulting in observable phenotypes and even pathology. Here, the epigenetic mechanisms responsible for the pathogenesis of neurodevelopmental and neuropsychiatric disorders are explored in response to environmental perturbations in utero. The present goal is to identify correlations between …

Impact Of Arginine Metabolism And Sensing In Mouse Models Of Alzheimer’S Disease, Chao Ma

USF Tampa Graduate Theses and Dissertations

Alzheimer’s disease (AD) remains the most common neurodegenerative disease in the central nervous system (CNS), with amyloidosis and tauopathy as their two main hallmarks. Typical AD pathologies include cerebral plaques deposited by amyloid-β, neurofibrillary tangles aggregated by tau, and neuroinflammation caused by activated brain myeloid cells. A critical theme is centered on impaired brain metabolism. Emerging evidence showed that impaired arginine metabolism was a novel biomarker pathway for AD. The manipulation of arginine metabolism by a critical enzyme arginase 1 (ARG1) in neurons indicated therapeutic benefits in alleviating tau pathology. Balanced cellular proteostasis was governed by the mechanistic target of …