Neurology Commons^™

Antagonistic Effect Of Cyclin-Dependent Kinases And A Calcium-Dependent Phosphatase On Polyglutamine-Expanded Androgen Receptor Toxic Gain Of Function, Diana Piol, Laura Tosatto, Emanuela Zuccaro, Eric N Anderson, Antonella Falconieri, Maria J Polanco, Caterina Marchioretti, Federica Lia, Joseph White, Elisa Bregolin, Giovanni Minervini, Sara Parodi, Xavier Salvatella, Giorgio Arrigoni, Andrea Ballabio, Albert R La Spada, Silvio C E Tosatto, Fabio Sambataro, Diego L Medina, Udai B Pandey, Manuela Basso, Maria Pennuto

Duncan NRI Faculty and Staff Publications

Spinal and bulbar muscular atrophy is caused by polyglutamine (polyQ) expansions in androgen receptor (AR), generating gain-of-function toxicity that may involve phosphorylation. Using cellular and animal models, we investigated what kinases and phosphatases target polyQ-expanded AR, whether polyQ expansions modify AR phosphorylation, and how this contributes to neurodegeneration. Mass spectrometry showed that polyQ expansions preserve native phosphorylation and increase phosphorylation at conserved sites controlling AR stability and transactivation. In small-molecule screening, we identified that CDC25/CDK2 signaling could enhance AR phosphorylation, and the calcium-sensitive phosphatase calcineurin had opposite effects. Pharmacologic and genetic manipulation of these kinases and phosphatases modified polyQ-expanded AR …

Cissus Quadrangularis (Hadjod) Inhibits Rankl-Induced Osteoclastogenesis And Augments Bone Health In An Estrogen-Deficient Preclinical Model Of Osteoporosis Via Modulating The Host Osteoimmune System, Zaffar Azam, Leena Sapra, Kalpana Baghel, Niharika Sinha, Rajesh K Gupta, Vandana Soni, Chaman Saini, Pradyumna K Mishra, Rupesh K Srivastava

Faculty, Staff and Student Publications

Osteoporosis is a systemic skeletal disease characterised by low bone mineral density (BMD), degeneration of bone micro-architecture, and impaired bone strength. Cissus quadrangularis (CQ), popularly known as Hadjod (bone setter) in Hindi, is a traditional medicinal herb exhibiting osteoprotective potential in various bone diseases, especially osteoporosis and fractures. However, the cellular mechanisms underpinning its direct effect on bone health through altering the host immune system have never been elucidated. In the present study, we interrogated the osteoprotective and immunoporotic (the osteoprotective potential of CQ via modulating the host immune system) potential of CQ in preventing inflammatory bone loss under oestrogen-deficient …

The Lysosomal Ragulator Complex Activates Nlrp3 Inflammasome In Vivo Via Hdac6, Kohei Tsujimoto, Tatsunori Jo, Daiki Nagira, Hachiro Konaka, Jeong Hoon Park, Shin-Ichiro Yoshimura, Akinori Ninomiya, Fuminori Sugihara, Takehiro Hirayama, Eri Itotagawa, Yusei Matsuzaki, Yuki Takaichi, Wataru Aoki, Shotaro Saita, Shuhei Nakamura, Andrea Ballabio, Shigeyuki Nada, Masato Okada, Hyota Takamatsu, Atsushi Kumanogoh

Duncan NRI Faculty and Staff Publications

The cellular activation of the NLRP3 inflammasome is spatiotemporally orchestrated by various organelles, but whether lysosomes contribute to this process remains unclear. Here, we show the vital role of the lysosomal membrane-tethered Ragulator complex in NLRP3 inflammasome activation. Deficiency of Lamtor1, an essential component of the Ragulator complex, abrogated NLRP3 inflammasome activation in murine macrophages and human monocytic cells. Myeloid-specific Lamtor1-deficient mice showed marked attenuation of NLRP3-associated inflammatory disease severity, including LPS-induced sepsis, alum-induced peritonitis, and monosodium urate (MSU)-induced arthritis. Mechanistically, Lamtor1 interacted with both NLRP3 and histone deacetylase 6 (HDAC6). HDAC6 enhances the interaction between Lamtor1 and NLRP3, resulting …

A Low-Fat/Sucrose Diet Rich In Complex Carbohydrates Reverses High-Fat/Sucrose Diet-Induced Corneal Dysregulation, Prince K Akowuah, Carolina Lema, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

High-fat/sucrose diet feeding in mice causes loss of corneal nerve function and impairs corneal wound healing. While changing to a diet with a low fat/sugar composition and enrichments in complex carbohydrates mitigates the reduction in nerve function, it remains to be determined if it has an effect on corneal wound healing. In this study, 6-week-old C57BL/6 male mice were fed either a normal diet or a high-fat/sucrose diet for 20 weeks. A third group (diet reversal) was placed on a high-fat/sucrose diet for 10 weeks followed by a normal diet for an additional 10 weeks. A central corneal epithelial abrasion …

Fn14-Directed Dart Nanoparticles Selectively Target Neoplastic Cells In Preclinical Models Of Triple-Negative Breast Cancer Brain Metastasis, Christine P Carney, Anshika Kapur, Pavlos Anastasiadis, Rodney M Ritzel, Chixiang Chen, Graeme F Woodworth, Jeffrey A Winkles, Anthony J Kim

Faculty, Staff and Student Publications

Triple-negative breast cancer (TNBC) patients with brain metastasis (BM) face dismal prognosis due to the limited therapeutic efficacy of the currently available treatment options. We previously demonstrated that paclitaxel-loaded PLGA−PEG nanoparticles (NPs) directed to the Fn14 receptor, termed “DARTs”, are more efficacious than Abraxane—an FDA-approved paclitaxel nanoformulation—following intravenous delivery in a mouse model of TNBC BM. However, the precise basis for this difference was not investigated. Here, we further examine the utility of the DART drug delivery platform in complementary xenograft and syngeneic TNBC BM models. First, we demonstrated that, in comparison to nontargeted NPs, DART NPs exhibit preferential association …

Exaptation And Evolutionary Adaptation In Nociceptor Mechanisms Driving Persistent Pain, Edgar T Walters

Faculty, Staff and Student Publications

Background: Several evolutionary explanations have been proposed for why chronic pain is a major clinical problem. One is that some mechanisms important for driving chronic pain, while maladaptive for modern humans, were adaptive because they enhanced survival. Evidence is reviewed for persistent nociceptor hyperactivity (PNH), known to promote chronic pain in rodents and humans, being an evolutionarily adaptive response to significant bodily injury, and primitive molecular mechanisms related to cellular injury and stress being exapted (co-opted or repurposed) to drive PNH and consequent pain.

Summary: PNH in a snail (Aplysia californica), squid (Doryteuthis pealeii), fruit fly (Drosophila melanogaster), mice, rats, …

Aβ Plaques Do Not Protect Against Hsv-1 Infection In A Mouse Model Of Familial Alzheimer’S Disease, And Hsv-1 Does Not Induce Aβ Pathology In A Model Of Late Onset Alzheimer’S Disease, Olga V Bocharova, Aidan Fisher, Narayan P Pandit, Kara Molesworth, Olga Mychko, Alison J Scott, Natallia Makarava, Rodney Ritzel, Ilia V Baskakov

Faculty, Staff and Student Publications

The possibility that the etiology of late onset Alzheimer's disease is linked to viral infections of the CNS has been actively debated in recent years. According to the antiviral protection hypothesis, viral pathogens trigger aggregation of Aβ peptides that are produced as a defense mechanism in response to infection to entrap and neutralize pathogens. To test the causative relationship between viral infection and Aβ aggregation, the current study examined whether Aβ plaques protect the mouse brain against Herpes Simplex Virus 1 (HSV-1) infection introduced via a physiological route and whether HSV-1 infection triggers formation of Aβ plaques in a mouse …

Editorial: Molecular Mechanisms In Ocular Development And Disease, Rajalekshmy Shyam, Daisy Y Shu, Elizabeth Zuniga-Sanchez, Deepika Vasudevan

Faculty, Staff and Students Publications

No abstract provided.

Spatial Analysis Of Nanoparticle Distribution In Human Breast Xenografts Reveals Nanoparticles Targeted To Cancer Cells Localized With Tumor-Associated Stromal Cells, Sean Healy, Elizabeth T Henderson, Suqi Ke, Jacqueline Kelly, Brian W Simons, Chen Hu, Robert Ivkov, Preethi Korangath

Faculty, Staff and Students Publications

The biological influence of physicochemical parameters of “targeted” nanoparticles on their delivery to cancer tumors remains poorly understood. A comparative analysis of nanoparticle distributions in tumors following systemic delivery across several models can provide valuable insights.

Methods: Bionized nanoferrite nanoparticles (iron oxide core coated with starch), either conjugated with a targeted anti-HER2 antibody (BH), or unconjugated (BP), were intravenously injected into athymic nude or NOD-scid gamma (NSG) female mice bearing one of five human breast cancer tumor xenografts growing in a mammary fat pad. Tumors were harvested 24 hours after nanoparticle injection, fixed, mounted, and stained. We performed detailed histopathology …

Forniceal Deep Brain Stimulation In A Mouse Model Of Rett Syndrome Increases Neurogenesis And Hippocampal Memory Beyond The Treatment Period, Qi Wang, Bin Tang, Shuang Hao, Zhenyu Wu, Tingting Yang, Jianrong Tang

Faculty, Staff and Students Publications

BACKGROUND: Rett syndrome (RTT), caused by mutations in the X-linked gene encoding methyl-CpG binding protein 2 (MeCP2), severely impairs learning and memory. We previously showed that forniceal deep brain stimulation (DBS) stimulates hippocampal neurogenesis with concomitant improvements in hippocampal-dependent learning and memory in a mouse model of RTT.

OBJECTIVES: To determine the duration of DBS benefits; characterize DBS effects on hippocampal neurogenesis; and determine whether DBS influences MECP2 genotype and survival of newborn dentate granular cells (DGCs) in RTT mice.

METHODS: Chronic DBS was delivered through an electrode implanted in the fimbria-fornix. We tested separate cohorts of mice in contextual …

Gata1 Controls Numbers Of Hematopoietic Progenitors And Their Response To Autoimmune Neuroinflammation, Daniel Hwang, Larissa Ishikawa, Maryam S. Seyedsadr, Elisabeth R. Mari, Ezgi Kasimoglu, Ziver Sahin, Alexandra Boehm, Soohwa Jang, Javad Rasouli, Courtney Vaccaro, Michael Gonzalez, Hakon Hakonarson, Mohamad Rostami, Guang-Xian Zhang, Bogoljub Ciric

Department of Neurology Faculty Papers

GATA-binding factor 1 (GATA1) is a transcription factor that governs the development and function of multiple hematopoietic cell lineages. GATA1 is expressed in hematopoietic stem and progenitor cells (HSPCs) and is essential for erythroid lineage commitment; however, whether it plays a role in hematopoietic stem cell (HSC) biology and the development of myeloid cells, and what that role might be, remains unclear. We initially set out to test the role of eosinophils in experimental autoimmune encephalomyelitis (EAE), a model of central nervous system autoimmunity, using mice lacking a double GATA-site (ΔdblGATA), which lacks eosinophils due to the deletion of the …

Treatment Of Epilepsy Using A Targeted P38Γ Kinase Gene Therapy, Nicolle Morey, Magdalena Przybyla, Julia Van Der Hoven, Yazi D Ke, Fabien Delerue, Janet Van Eersel, Lars M Ittner

Faculty, Staff and Student Publications

Hyperphosphorylated microtubule-associated protein tau has been implicated in dementia, epilepsy, and other neurological disorders. In contrast, site-specific phosphorylation of tau at threonine 205 (T205) by the kinase p38γ was shown to disengage tau from toxic pathways, serving a neuroprotective function in Alzheimer's disease. Using a viral-mediated gene delivery approach in different mouse models of epilepsy, we show that p38γ activity-enhancing treatment reduces seizure susceptibility, restores neuronal firing patterns, reduces behavioral deficits, and ameliorates epilepsy-induced deaths. Furthermore, we show that p38γ-mediated phosphorylation of tau at T205 is essential for this protection in epilepsy, as a lack of this critical interaction reinstates …

Propranolol Modulates Cerebellar Circuit Activity And Reduces Tremor., Joy Zhou, Meike E Van Der Heijden, Luis E Salazar Leon, Tao Lin, Lauren N Miterko, Dominic J Kizek, Ross M Perez, Matea Pavešković, Amanda M Brown, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Tremor is the most common movement disorder. Several drugs reduce tremor severity, but no cures are available. Propranolol, a β-adrenergic receptor blocker, is the leading treatment for tremor. However, the in vivo circuit mechanisms by which propranolol decreases tremor remain unclear. Here, we test whether propranolol modulates activity in the cerebellum, a key node in the tremor network. We investigated the effects of propranolol in healthy control mice and Car8^wdl/wdl mice, which exhibit pathophysiological tremor and ataxia due to cerebellar dysfunction. Propranolol reduced physiological tremor in control mice and reduced pathophysiological tremor in Car8^wdl/wdl mice to control levels. …

Oxytocin Signaling Is Necessary For Synaptic Maturation Of Adult-Born Neurons, Brandon T Pekarek, Mikhail Kochukov, Brittney Lozzi, Timothy Wu, Patrick J Hunt, Burak Tepe, Elizabeth Hanson Moss, Evelyne K Tantry, Jessica L Swanson, Sean W Dooling, Mayuri Patel, Benjamin D W Belfort, Juan M Romero, Suyang Bao, Matthew C Hill, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

Neural circuit plasticity and sensory response dynamics depend on forming new synaptic connections. Despite recent advances toward understanding the consequences of circuit plasticity, the mechanisms driving circuit plasticity are unknown. Adult-born neurons within the olfactory bulb have proven to be a powerful model for studying circuit plasticity, providing a broad and accessible avenue into neuron development, migration, and circuit integration. We and others have shown that efficient adult-born neuron circuit integration hinges on presynaptic activity in the form of diverse signaling peptides. Here, we demonstrate a novel oxytocin-dependent mechanism of adult-born neuron synaptic maturation and circuit integration. We reveal spatial …

Distinct Organization Of Two Cortico-Cortical Feedback Pathways, Shan Shen, Xiaolong Jiang, Federico Scala, Jiakun Fu, Paul Fahey, Dmitry Kobak, Zhenghuan Tan, Na Zhou, Jacob Reimer, Fabian Sinz, Andreas S Tolias

Duncan NRI Faculty and Staff Publications

Neocortical feedback is critical for attention, prediction, and learning. To mechanically understand its function requires deciphering its cell-type wiring. Recent studies revealed that feedback between primary motor to primary somatosensory areas in mice is disinhibitory, targeting vasoactive intestinal peptide-expressing interneurons, in addition to pyramidal cells. It is unknown whether this circuit motif represents a general cortico-cortical feedback organizing principle. Here we show that in contrast to this wiring rule, feedback between higher-order lateromedial visual area to primary visual cortex preferentially activates somatostatin-expressing interneurons. Functionally, both feedback circuits temporally sharpen feed-forward excitation eliciting a transient increase–followed by a prolonged decrease–in pyramidal …

Mapping The Universe Of Eph Receptor And Ephrin Ligand Transcripts In Epithelial And Fiber Cells Of The Eye Lens, Michael P Vu, Catherine Cheng

Faculty, Staff and Student Publications

The eye lens is a transparent, ellipsoid organ in the anterior chamber of the eye that is required for fine focusing of light onto the retina to transmit a clear image. Cataracts, defined as any opacity in the lens, remains the leading cause of blindness in the world. Recent studies in humans and mice indicate that Eph-ephrin bidirectional signaling is important for maintaining lens transparency. Specifically, mutations and polymorphisms in the EphA2 receptor and the ephrin-A5 ligand have been linked to congenital and age-related cataracts. It is unclear what other variants of Ephs and ephrins are expressed in the lens …

Preventive And Therapeutic Reduction Of Amyloid Deposition And Behavioral Impairments In A Model Of Alzheimer’S Disease By Whole Blood Exchange, Akihiko Urayama, Ines Moreno-Gonzalez, Diego Morales-Scheihing, Vineetkumar Kharat, Sandra Pritzkow, Claudio Soto

Faculty, Staff and Student Publications

Alzheimer's disease (AD) is the major form of dementia in the elderly population. The main neuropathological changes in AD patients are neuronal death, synaptic alterations, brain inflammation, and the presence of cerebral protein aggregates in the form of amyloid plaques and neurofibrillary tangles. Compelling evidence suggests that the misfolding, aggregation, and cerebral deposition of amyloid-beta (Aβ) plays a central role in the disease. Thus, prevention and removal of misfolded protein aggregates is considered a promising strategy to treat AD. In the present study, we describe that the development of cerebral amyloid plaques in a transgenic mice model of AD (Tg2576) …

Loss Of Lamp5 Interneurons Drives Neuronal Network Dysfunction In Alzheimer’S Disease, Yuanyuan Deng, Mian Bi, Fabien Delerue, Shelley L Forrest, Gabriella Chan, Julia Van Der Hoven, Annika Van Hummel, Astrid F Feiten, Seojin Lee, Ivan Martinez-Valbuena, Tim Karl, Gabor G Kovacs, Grant Morahan, Yazi D Ke, Lars M Ittner

Faculty, Staff and Student Publications

In Alzheimer's disease (AD), where amyloid-β (Aβ) and tau deposits in the brain, hyperexcitation of neuronal networks is an underlying disease mechanism, but its cause remains unclear. Here, we used the Collaborative Cross (CC) forward genetics mouse platform to identify modifier genes of neuronal hyperexcitation. We found LAMP5 as a novel regulator of hyperexcitation in mice, critical for the survival of distinct interneuron populations. Interestingly, synaptic LAMP5 was lost in AD brains and LAMP5 interneurons degenerated in different AD mouse models. Genetic reduction of LAMP5 augmented functional deficits and neuronal network hypersynchronicity in both Aβ- and tau-driven AD mouse models. …

Causal Evidence For A Role Of Cerebellar Lobulus Simplex In Prefrontal-Hippocampal Interaction In Spatial Working Memory Decision-Making, Yu Liu, Samuel S Mcafee, Meike E Van Der Heijden, Mukesh Dhamala, Roy V Sillitoe, Detlef H Heck

Duncan NRI Faculty and Staff Publications

Spatial working memory (SWM) is a cerebrocerebellar cognitive skill supporting survival-relevant behaviors, such as optimizing foraging behavior by remembering recent routes and visited sites. It is known that SWM decision-making in rodents requires the medial prefrontal cortex (mPFC) and dorsal hippocampus. The decision process in SWM tasks carries a specific electrophysiological signature of a brief, decision-related increase in neuronal communication in the form of an increase in the coherence of neuronal theta oscillations (4-12 Hz) between the mPFC and dorsal hippocampus, a finding we replicated here during spontaneous exploration of a plus maze in freely moving mice. We further evaluated …

Identifying Phenotypic Expansions For Congenital Diaphragmatic Hernia Plus (Cdh+) Using Decipher Data, Amy Hardcastle, Aliska M Berry, Ian M Campbell, Xiaonan Zhao, Pengfei Liu, Amanda E Gerard, Jill A Rosenfeld, Saumya D Sisoudiya, Andres Hernandez-Garcia, Sara Loddo, Silvia Di Tommaso, Antonio Novelli, Maria L Dentici, Rossella Capolino, Maria C Digilio, Ludovico Graziani, Cecilie F Rustad, Katherine Neas, Giovanni B Ferrero, Alfredo Brusco, Eleonora Di Gregorio, Diana Wellesley, Claire Beneteau, Madeleine Joubert, Kris Van Den Bogaert, Anneleen Boogaerts, Dominic J Mcmullan, John Dean, Maria G Giuffrida, Laura Bernardini, Vinod Varghese, Nora L Shannon, Rachel E Harrison, Wayne W K Lam, Shane Mckee, Peter D Turnpenny, Trevor Cole, Jenny Morton, Jacqueline Eason, Marilyn C Jones, Rebecca Hall, Michael Wright, Karen Horridge, Chad A Shaw, Wendy K Chung, Daryl A Scott

Duncan NRI Faculty and Staff Publications

Congenital diaphragmatic hernia (CDH) can occur in isolation or in conjunction with other birth defects (CDH+). A molecular etiology can only be identified in a subset of CDH cases. This is due, in part, to an incomplete understanding of the genes that contribute to diaphragm development. Here, we used clinical and molecular data from 36 individuals with CDH+ who are cataloged in the DECIPHER database to identify genes that may play a role in diaphragm development and to discover new phenotypic expansions. Among this group, we identified individuals who carried putatively deleterious sequence or copy number variants affecting CREBBP, SMARCA4, …

Sex-Specific Epigenetic Development In The Mouse Hypothalamic Arcuate Nucleus Pinpoints Human Genomic Regions Associated With Body Mass Index, Harry Mackay, Chathura J Gunasekara, Kit-Yi Yam, Dollada Srisai, Hari Krishna Yalamanchili, Yumei Li, Rui Chen, Cristian Coarfa, Robert A Waterland

Duncan NRI Faculty and Staff Publications

Recent genome-wide association studies corroborate classical research on developmental programming indicating that obesity is primarily a neurodevelopmental disease strongly influenced by nutrition during critical ontogenic windows. Epigenetic mechanisms regulate neurodevelopment; however, little is known about their role in establishing and maintaining the brain's energy balance circuitry. We generated neuron and glia methylomes and transcriptomes from male and female mouse hypothalamic arcuate nucleus, a key site for energy balance regulation, at time points spanning the closure of an established critical window for developmental programming of obesity risk. We find that postnatal epigenetic maturation is markedly cell type and sex specific and …

A Potential Role For Substance P In West Nile Virus Neuropathogenesis, Shannon E Ronca, Sarah M Gunter, Rebecca Berry Kairis, Allison Lino, Jonathan Romero, Robia G Pautler, Alan Nimmo, Kristy O Murray

Faculty, Staff and Students Publications

Of individuals who develop West Nile neuroinvasive disease (WNND), ~10% will die and >40% will develop long-term complications. Current treatment recommendations solely focus on supportive care; therefore, we urgently need to identify novel and effective therapeutic options. We observed a correlation between substance P (SP), a key player in neuroinflammation, and its receptor Neurokinin-1 (NK1R). Our study in a wild-type BL6 mouse model found that SP is upregulated in the brain during infection, which correlated with neuroinvasion and damage to the blood−brain barrier. Blocking the SP/NK1R interaction beginning at disease onset modestly improved survival and prolonged time to death in …

The Tfeb-Tgif1 Axis Regulates Emt In Mouse Epicardial Cells, Elena Astanina, Gabriella Doronzo, Davide Corà, Francesco Neri, Salvatore Oliviero, Tullio Genova, Federico Mussano, Emanuele Middonti, Edoardo Vallariello, Chiara Cencioni, Donatella Valdembri, Guido Serini, Federica Limana, Eleonora Foglio, Andrea Ballabio, Federico Bussolino

Duncan NRI Faculty and Staff Publications

Epithelial-mesenchymal transition (EMT) is a complex and pivotal process involved in organogenesis and is related to several pathological processes, including cancer and fibrosis. During heart development, EMT mediates the conversion of epicardial cells into vascular smooth muscle cells and cardiac interstitial fibroblasts. Here, we show that the oncogenic transcription factor EB (TFEB) is a key regulator of EMT in epicardial cells and that its genetic overexpression in mouse epicardium is lethal due to heart defects linked to impaired EMT. TFEB specifically orchestrates the EMT-promoting function of transforming growth factor (TGF) β, and this effect results from activated transcription of thymine-guanine-interacting …

Mir-486 Is Essential For Muscle Function And Suppresses A Dystrophic Transcriptome, Adrienne Samani, Rylie M Hightower, Andrea L Reid, Katherine G English, Michael A Lopez, J Scott Doyle, Michael J Conklin, David A Schneider, Marcas M Bamman, Jeffrey J Widrick, David K Crossman, Min Xie, David Jee, Eric C Lai, Matthew S Alexander

Faculty, Staff and Student Publications

miR-486 is a muscle-enriched microRNA, or “myomiR,” that has reduced expression correlated with Duchenne muscular dystrophy (DMD). To determine the function of miR-486 in normal and dystrophin-deficient muscles and elucidate miR-486 target transcripts in skeletal muscle, we characterized mir-486 knockout mice (mir-486 KO). mir-486 KO mice developed disrupted myofiber architecture, decreased myofiber size, decreased locomotor activity, increased cardiac fibrosis, and metabolic defects were exacerbated in mir-486 KO:mdx5cv (DKO) mice. To identify direct in vivo miR-486 muscle target transcripts, we integrated RNA sequencing and chimeric miRNA eCLIP sequencing to identify key transcripts and pathways that contribute towards mir-486 …

Removal Of Kcnq2 From Parvalbumin-Expressing Interneurons Improves Anti-Seizure Efficacy Of Retigabine, Junzhan Jing, Corrinne Dunbar, Alina Sonesra, Ana Chavez, Suhyeorn Park, Ryan Yang, Heun Soh, Maxwell Lee, Anastasios V Tzingounis, Edward C Cooper, Xiaolong Jiang, Atul Maheshwari

Duncan NRI Faculty and Staff Publications

Anti-seizure drug (ASD) targets are widely expressed in both excitatory and inhibitory neurons. It remains unknown if the action of an ASD upon inhibitory neurons could counteract its beneficial effects on excitatory neurons (or vice versa), thereby reducing the efficacy of the ASD. Here, we examine whether the efficacy of the ASD retigabine (RTG) is altered after removal of the Kv7 potassium channel subunit KCNQ2, one of its drug targets, from parvalbumin-expressing interneurons (PV-INs). Parvalbumin-Cre (PV-Cre) mice were crossed with Kcnq2-floxed (Kcnq2fl/fl) mice to conditionally delete Kcnq2 from PV-INs. In these conditional knockout mice (cKO, PV-Kcnq2 …

Kctd7 Deficiency Induces Myoclonic Seizures Associated With Purkinje Cell Death And Microvascular Defects, Justine H Liang, Jonathan Alevy, Viktor Akhanov, Ryan Seo, Cory A Massey, Danye Jiang, Joy Zhou, Roy V Sillitoe, Jeffrey L Noebels, Melanie A Samuel

Duncan NRI Faculty and Staff Publications

Mutations in the potassium channel tetramerization domain-containing 7 (KCTD7) gene are associated with a severe neurodegenerative phenotype characterized by childhood onset of progressive and intractable myoclonic seizures accompanied by developmental regression. KCTD7-driven disease is part of a large family of progressive myoclonic epilepsy syndromes displaying a broad spectrum of clinical severity. Animal models of KCTD7-related disease are lacking, and little is known regarding how KCTD7 protein defects lead to epilepsy and cognitive dysfunction. We characterized Kctd7 expression patterns in the mouse brain during development and show that it is selectively enriched in specific regions as the brain matures. We further …

Genetic Impairment Of Succinate Metabolism Disrupts Bioenergetic Sensing In Adrenal Neuroendocrine Cancer, Priyanka Gupta, Keehn Strange, Rahul Telange, Ailan Guo, Heather Hatch, Amin Sobh, Jonathan Elie, Angela M Carter, John Totenhagen, Chunfeng Tan, Yogesh A Sonawane, Jiri Neuzil, Amarnath Natarajan, Ashley J Ovens, Jonathan S Oakhill, Thorsten Wiederhold, Karel Pacak, Hans K Ghayee, Laurent Meijer, Sushanth Reddy, James A Bibb

Faculty, Staff and Student Publications

Metabolic dysfunction mutations can impair energy sensing and cause cancer. Loss of function of the mitochondrial tricarboxylic acid (TCA) cycle enzyme subunit succinate dehydrogenase B (SDHB) results in various forms of cancer typified by pheochromocytoma (PC). Here we delineate a signaling cascade where the loss of SDHB induces the Warburg effect, triggers dysregulation of [Ca2+]i, and aberrantly activates calpain and protein kinase Cdk5, through conversion of its cofactor from p35 to p25. Consequently, aberrant Cdk5 initiates a phospho-signaling cascade where GSK3 inhibition inactivates energy sensing by AMP kinase through dephosphorylation of the AMP kinase γ subunit, PRKAG2. Overexpression of p25-GFP …

Genetic Impairment Of Succinate Metabolism Disrupts Bioenergetic Sensing In Adrenal Neuroendocrine Cancer, Priyanka Gupta, Keehn Strange, Rahul Telange, Ailan Guo, Heather Hatch, Amin Sobh, Jonathan Elie, Angela M Carter, John Totenhagen, Chunfeng Tan, Yogesh A Sonawane, Jiri Neuzil, Amarnath Natarajan, Ashley J Ovens, Jonathan S Oakhill, Thorsten Wiederhold, Karel Pacak, Hans K Ghayee, Laurent Meijer, Sushanth Reddy, James A Bibb

Faculty, Staff and Student Publications

Metabolic dysfunction mutations can impair energy sensing and cause cancer. Loss of function of the mitochondrial tricarboxylic acid (TCA) cycle enzyme subunit succinate dehydrogenase B (SDHB) results in various forms of cancer typified by pheochromocytoma (PC). Here we delineate a signaling cascade where the loss of SDHB induces the Warburg effect, triggers dysregulation of [Ca

Regulation Of Microglial Activation In Stroke In Aged Mice: A Translational Study, Conelius Ngwa, Abdullah Al Mamun, Shaohua Qi, Romana Sharmeen, Yan Xu, Fudong Liu

Faculty, Staff and Student Publications

Numerous neurochemical changes occur with aging and stroke mainly affects the elderly. Our previous study has found interferon regulatory factor 5 (IRF5) and 4 (IRF4) regulate neuroinflammation in young stroke mice. However, whether the IRF5-IRF4 regulatory axis has the same effect in aged brains is not known. In this study, aged (18-20-month-old), microglial IRF5 or IRF4 conditional knockout (CKO) mice were subjected to a 60-min middle cerebral artery occlusion (MCAO). Stroke outcomes were quantified at 3d after MCAO. Flow cytometry and ELISA were performed to evaluate microglial activation and immune responses. We found aged microglia express higher levels of IRF5 …

Sox9 Directs Divergent Epigenomic States In Brain Tumor Subtypes, Debosmita Sardar, Hsiao-Chi Chen, Amanda Reyes, Srinidhi Varadharajan, Antrix Jain, Carrie Mohila, Rachel Curry, Brittney Lozzi, Kavitha Rajendran, Alexis Cervantes, Kwanha Yu, Ali Jalali, Ganesh Rao, Stephen C Mack, Benjamin Deneen

Duncan NRI Faculty and Staff Publications

Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations; however, the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here, we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). Using our autochthonous mouse models, we found that Sox9 suppresses HGG growth and expands associated H3K27ac states, while promoting ZFTA-RELA (ZR