Genetic Phenomena Commons^™

Labeling Piezo2 Activity In The Peripheral Nervous System, Nicholas W Villarino, Yasmeen M F Hamed, Britya Ghosh, Adrienne E Dubin, Amanda H Lewis, Max A Odem, Meaghan C Loud, Yu Wang, M Rocio Servin-Vences, Ardem Patapoutian, Kara L Marshall

Duncan NRI Faculty and Staff Publications

Sensory neurons detect mechanical forces from both the environment and internal organs to regulate physiology. PIEZO2 is a mechanosensory ion channel critical for touch, proprioception, and bladder stretch sensation, yet its broad expression in sensory neurons suggests it has undiscovered physiological roles. To fully understand mechanosensory physiology, we must know where and when PIEZO2-expressing neurons detect force. The fluorescent styryl dye FM 1-43 was previously shown to label sensory neurons. Surprisingly, we find that the vast majority of FM 1-43 somatosensory neuron labeling in mice in vivo is dependent on PIEZO2 activity within the peripheral nerve endings. We illustrate the …

Piezo2 In Somatosensory Neurons Controls Gastrointestinal Transit, M Rocio Servin-Vences, Ruby M Lam, Alize Koolen, Yu Wang, Dimah N Saade, Meaghan Loud, Halil Kacmaz, Suzanne Frausto, Yunxiao Zhang, Arthur Beyder, Kara L Marshall, Carsten G Bönnemann, Alexander T Chesler, Ardem Patapoutian

Duncan NRI Faculty and Staff Publications

The gastrointestinal tract is in a state of constant motion. These movements are tightly regulated by the presence of food and help digestion by mechanically breaking down and propelling gut content. Mechanical sensing in the gut is thought to be essential for regulating motility; however, the identity of the neuronal populations, the molecules involved, and the functional consequences of this sensation are unknown. Here, we show that humans lacking PIEZO2 exhibit impaired bowel sensation and motility. Piezo2 in mouse dorsal root, but not nodose ganglia is required to sense gut content, and this activity slows down food transit rates in …

Cerebellar Dysfunction As A Source Of Dystonic Phenotypes In Mice, Amanda M Brown, Meike E Van Der Heijden, H A Jinnah, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

There is now a substantial amount of compelling evidence demonstrating that the cerebellum may be a central locus in dystonia pathogenesis. Studies using spontaneous genetic mutations in rats and mice, engineered genetic alleles in mice, shRNA knockdown in mice, and conditional genetic silencing of fast neurotransmission in mice have all uncovered a common set of behavioral and electrophysiological defects that point to cerebellar cortical and cerebellar nuclei dysfunction as a source of dystonic phenotypes. Here, we revisit the Ptf1aCre/+;Vglut2flox/flox mutant mouse to define fundamental phenotypes and measures that are valuable for testing the cellular, circuit, and …

The Cerebellum Contributes To Generalized Seizures By Altering Activity In The Ventral Posteromedial Nucleus, Jaclyn Beckinghausen, Joshua Ortiz-Guzman, Tao Lin, Benjamin Bachman, Luis E Salazar Leon, Yu Liu, Detlef H Heck, Benjamin R Arenkiel, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Thalamo-cortical networks are central to seizures, yet it is unclear how these circuits initiate seizures. We test whether a facial region of the thalamus, the ventral posteromedial nucleus (VPM), is a source of generalized, convulsive motor seizures and if convergent VPM input drives the behavior. To address this question, we devise an in vivo optogenetic mouse model to elicit convulsive motor seizures by driving these inputs and perform single-unit recordings during awake, convulsive seizures to define the local activity of thalamic neurons before, during, and after seizure onset. We find dynamic activity with biphasic properties, raising the possibility that heterogenous …

Loss Of The Batten Disease Protein Cln3 Leads To Mis-Trafficking Of M6pr And Defective Autophagic-Lysosomal Reformation, Alessia Calcagni', Leopoldo Staiano, Nicolina Zampelli, Nadia Minopoli, Niculin J Herz, Giuseppe Di Tullio, Tuong Huynh, Jlenia Monfregola, Alessandra Esposito, Carmine Cirillo, Aleksandar Bajic, Mahla Zahabiyon, Rachel Curnock, Elena Polishchuk, Luke Parkitny, Diego Luis Medina, Nunzia Pastore, Peter J Cullen, Giancarlo Parenti, Maria Antonietta De Matteis, Paolo Grumati, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

Batten disease, one of the most devastating types of neurodegenerative lysosomal storage disorders, is caused by mutations in CLN3. Here, we show that CLN3 is a vesicular trafficking hub connecting the Golgi and lysosome compartments. Proteomic analysis reveals that CLN3 interacts with several endo-lysosomal trafficking proteins, including the cation-independent mannose 6 phosphate receptor (CI-M6PR), which coordinates the targeting of lysosomal enzymes to lysosomes. CLN3 depletion results in mis-trafficking of CI-M6PR, mis-sorting of lysosomal enzymes, and defective autophagic lysosomal reformation. Conversely, CLN3 overexpression promotes the formation of multiple lysosomal tubules, which are autophagy and CI-M6PR-dependent, generating newly formed proto-lysosomes. Together, our …

Reprogramming Tumour-Associated Macrophages To Outcompete Cancer Cells, Xian Zhang, Shun Li, Isha Malik, Mytrang H Do, Liangliang Ji, Chun Chou, Wei Shi, Kristelle J Capistrano, Jing Zhang, Ting-Wei Hsu, Briana G Nixon, Ke Xu, Xinxin Wang, Andrea Ballabio, Laura S Schmidt, W Marston Linehan, Ming O Li

Duncan NRI Faculty and Staff Publications

In metazoan organisms, cell competition acts as a quality control mechanism to eliminate unfit cells in favour of their more robust neighbours1,2. This mechanism has the potential to be maladapted, promoting the selection of aggressive cancer cells3-6. Tumours are metabolically active and are populated by stroma cells7,8, but how environmental factors affect cancer cell competition remains largely unknown. Here we show that tumour-associated macrophages (TAMs) can be dietarily or genetically reprogrammed to outcompete MYC-overexpressing cancer cells. In a mouse model of breast cancer, MYC overexpression resulted in an mTORC1-dependent 'winner' cancer cell state. A low-protein diet inhibited mTORC1 signalling in …

Aging Fly Cell Atlas Identifies Exhaustive Aging Features At Cellular Resolution, Tzu-Chiao Lu, Maria Brbić, Ye-Jin Park, Tyler Jackson, Jiaye Chen, Sai Saroja Kolluru, Yanyan Qi, Nadja Sandra Katheder, Xiaoyu Tracy Cai, Seungjae Lee, Yen-Chung Chen, Niccole Auld, Chung-Yi Liang, Sophia H Ding, Doug Welsch, Samuel D'Souza, Angela Oliveira Pisco, Robert C Jones, Jure Leskovec, Eric C Lai, Hugo J Bellen, Liqun Luo, Heinrich Jasper, Stephen R Quake, Hongjie Li

Duncan NRI Faculty and Staff Publications

Aging is characterized by a decline in tissue function, but the underlying changes at cellular resolution across the organism remain unclear. Here, we present the Aging Fly Cell Atlas, a single-nucleus transcriptomic map of the whole aging Drosophila. We characterize 163 distinct cell types and perform an in-depth analysis of changes in tissue cell composition, gene expression, and cell identities. We further develop aging clock models to predict the fly age and show that ribosomal gene expression is a conserved predictive factor for age. Combining all aging features, we find unique cell type-specific aging patterns. This atlas provides a …

Poly(A)-Binding Protein Is An Ataxin-2 Chaperone That Regulates Biomolecular Condensates, Steven Boeynaems, Yanniv Dorone, Yanrong Zhuang, Victoria Shabardina, Guozhong Huang, Anca Marian, Garam Kim, Anushka Sanyal, Nesli-Ece Şen, Daniel Griffith, Roberto Docampo, Keren Lasker, Iñaki Ruiz-Trillo, Georg Auburger, Alex S Holehouse, Edor Kabashi, Yi Lin, Aaron D Gitler

Duncan NRI Faculty and Staff Publications

Biomolecular condensation underlies the biogenesis of an expanding array of membraneless assemblies, including stress granules (SGs) which form under a variety of cellular stresses. Advances have been made in understanding the molecular grammar of a few scaffold proteins that make up these phases, but how the partitioning of hundreds of SG proteins is regulated remains largely unresolved. While investigating the rules that govern the condensation of ataxin-2, a SG protein implicated in neurodegenerative disease, we unexpectedly identified a short 14aa sequence that acts as a condensation switch and is conserved across the eukaryote lineage. We identify poly(A)-binding proteins as unconventional …

Implication Of Chromosomal Microarray Analysis Prior To In-Utero Repair Of Fetal Open Neural Tube Defect, R Zemet, E Krispin, R M Johnson, N R Kumar, L E Westerfield, S Stover, D G Mann, J Castillo, H A Castillo, A A Nassr, M Sanz Cortes, R Donepudi, J Espinoza, W E Whitehead, M A Belfort, A A Shamshirsaz, I B Van Den Veyver

Duncan NRI Faculty and Staff Publications

Objective: In-utero repair of open neural tube defects (ONTD) is an accepted treatment option with demonstrated superior outcome for eligible patients. While current guidelines recommend genetic testing by chromosomal microarray analysis (CMA) when a major congenital anomaly is detected prenatally, the requirement for an in-utero repair, based on the Management of Myelomeningocele Study (MOMS) criteria, is a normal karyotype. In this study, we aimed to evaluate if CMA should be recommended as a prerequisite for in-utero ONTD repair.

Methods: This was a retrospective cohort study of pregnancies complicated by ONTD that underwent laparotomy-assisted fetoscopic repair or open-hysterotomy fetal surgery at …

De Novo Variants In Mrtfb Have Gain-Of-Function Activity In Drosophila And Are Associated With A Novel Neurodevelopmental Phenotype With Dysmorphic Features, Jonathan C Andrews, Jung-Wan Mok, Oguz Kanca, Sharayu Jangam, Cynthia Tifft, Ellen F Macnamara, Bianca E Russell, Lee-Kai Wang, Undiagnosed Diseases Network, Stanley F Nelson, Hugo J Bellen, Shinya Yamamoto, May Christine V Malicdan, Michael F Wangler

Duncan NRI Faculty and Staff Publications

Purpose: Myocardin-related transcription factor B (MRTFB) is an important transcriptional regulator, which promotes the activity of an estimated 300 genes but is not known to underlie a Mendelian disorder.

Methods: Probands were identified through the efforts of the Undiagnosed Disease Network. Because the MRTFB protein is highly conserved between vertebrate and invertebrate model organisms, we generated a humanized Drosophila model expressing the human MRTFB protein in the same spatial and temporal pattern as the fly gene. Actin binding assays were used to validate the effect of the variants on MRTFB.

Results: Here, we report 2 pediatric probands with de novo …

Glutamatergic Cerebellar Neurons Differentially Contribute To The Acquisition Of Motor And Social Behaviors, Meike E Van Der Heijden, Alejandro G Rey Hipolito, Linda H Kim, Dominic J Kizek, Ross M Perez, Tao Lin, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Insults to the developing cerebellum can cause motor, language, and social deficits. Here, we investigate whether developmental insults to different cerebellar neurons constrain the ability to acquire cerebellar-dependent behaviors. We perturb cerebellar cortical or nuclei neuron function by eliminating glutamatergic neurotransmission during development, and then we measure motor and social behaviors in early postnatal and adult mice. Altering cortical and nuclei neurons impacts postnatal motor control and social vocalizations. Normalizing neurotransmission in cortical neurons but not nuclei neurons restores social behaviors while the motor deficits remain impaired in adults. In contrast, manipulating only a subset of nuclei neurons leaves social …

Ragd Auto-Activating Mutations Impair Mit/Tfe Activity In Kidney Tubulopathy And Cardiomyopathy Syndrome, Irene Sambri, Marco Ferniani, Giulia Campostrini, Marialuisa Testa, Viviana Meraviglia, Mariana E G De Araujo, Ladislav Dokládal, Claudia Vilardo, Jlenia Monfregola, Nicolina Zampelli, Francesca Del Vecchio Blanco, Annalaura Torella, Carolina Ruosi, Simona Fecarotta, Giancarlo Parenti, Leopoldo Staiano, Milena Bellin, Lukas A Huber, Claudio De Virgilio, Francesco Trepiccione, Vincenzo Nigro, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

Heterozygous mutations in the gene encoding RagD GTPase were shown to cause a novel autosomal dominant condition characterized by kidney tubulopathy and cardiomyopathy. We previously demonstrated that RagD, and its paralogue RagC, mediate a non-canonical mTORC1 signaling pathway that inhibits the activity of TFEB and TFE3, transcription factors of the MiT/TFE family and master regulators of lysosomal biogenesis and autophagy. Here we show that RagD mutations causing kidney tubulopathy and cardiomyopathy are "auto- activating", even in the absence of Folliculin, the GAP responsible for RagC/D activation, and cause constitutive phosphorylation of TFEB and TFE3 by mTORC1, without affecting the phosphorylation …

Tfeb And Tfe3 Drive Kidney Cystogenesis And Tumorigenesis, Chiara Di Malta, Angela Zampelli, Letizia Granieri, Claudia Vilardo, Rossella De Cegli, Laura Cinque, Edoardo Nusco, Salvatore Pece, Daniela Tosoni, Francesca Sanguedolce, Nicolina Cristina Sorrentino, Maria J Merino, Deborah Nielsen, Ramaprasad Srinivasan, Mark W Ball, Christopher J Ricketts, Cathy D Vocke, Martin Lang, Baktiar Karim, Luisa Lanfrancone, Laura S Schmidt, W Marston Linehan, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

Birt-Hogg-Dubé (BHD) syndrome is an inherited familial cancer syndrome characterized by the development of cutaneous lesions, pulmonary cysts, renal tumors and cysts and caused by loss-of-function pathogenic variants in the gene encoding the tumor-suppressor protein folliculin (FLCN). FLCN acts as a negative regulator of TFEB and TFE3 transcription factors, master controllers of lysosomal biogenesis and autophagy, by enabling their phosphorylation by the mechanistic Target Of Rapamycin Complex 1 (mTORC1). We have previously shown that deletion of Tfeb rescued the renal cystic phenotype of kidney-specific Flcn KO mice. Using Flcn/Tfeb/Tfe3 double and triple KO mice, we now show that both Tfeb …

Glia-Neuron Coupling Via A Bipartite Sialylation Pathway Promotes Neural Transmission And Stress Tolerance Iglia-Neuron Coupling Via A Bipartite Sialylation Pathway Promotes Neural Transmission And Stress Tolerance In Drosophila, Hilary Scott, Boris Novikov, Berrak Ugur, Brooke Allen, Ilya Mertsalov, Pedro Monagas-Valentin, Melissa Koff, Sarah Baas Robinson, Kazuhiro Aoki, Raisa Veizaj, Dirk J Lefeber, Michael Tiemeyer, Hugo Bellen, Vladislav Panin

Duncan NRI Faculty and Staff Publications

Modification by sialylated glycans can affect protein functions, underlying mechanisms that control animal development and physiology. Sialylation relies on a dedicated pathway involving evolutionarily conserved enzymes, including CMP-sialic acid synthetase (CSAS) and sialyltransferase (SiaT) that mediate the activation of sialic acid and its transfer onto glycan termini, respectively. In Drosophila, CSAS and DSiaT genes function in the nervous system, affecting neural transmission and excitability. We found that these genes function in different cells: the function of CSAS is restricted to glia, while DSiaT functions in neurons. This partition of the sialylation pathway allows for regulation of neural functions via …

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. …

New Mouse Models With Hypomorphic Sumf1 Variants Mimic Attenuated Forms Of Multiple Sulfatase Deficiency, Nicolina Cristina Sorrentino, Maximiliano Presa, Sergio Attanasio, Vincenzo Cacace, Martina Sofia, Aamir Zuberi, Jennifer Ryan, Somdatta Ray, Igor Petkovic, Karthikeyan Radhakrishnan, Lars Schlotawa, Andrea Ballabio, Cathleen Lutz, Nicola Brunetti-Pierri

Duncan NRI Faculty and Staff Publications

Multiple sulfatase deficiency (MSD) is an ultrarare lysosomal storage disorder due to deficiency of all known sulfatases. MSD is caused by mutations in the Sulfatase Modifying Factor 1 (SUMF1) gene encoding the enzyme responsible for the post-translational modification and activation of all sulfatases. Most MSD patients carry hypomorph SUMF1 variants resulting in variable degrees of residual sulfatase activities. In contrast, Sumf1 null mice with complete deficiency in all sulfatase enzyme activities, have very short lifespan with significant pre-wean lethality, owing to a challenging preclinical model. To overcome this limitation, we genetically engineered and characterized in mice two commonly …

Egr1 Drives Cell Proliferation By Directly Stimulating Tfeb Transcription In Response To Starvation, Marcella Cesana, Gennaro Tufano, Francesco Panariello, Nicolina Zampelli, Susanna Ambrosio, Rossella De Cegli, Margherita Mutarelli, Lorenzo Vaccaro, Micheal J Ziller, Davide Cacchiarelli, Diego L Medina, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

The stress-responsive transcription factor EB (TFEB) is a master controller of lysosomal biogenesis and autophagy and plays a major role in several cancer-associated diseases. TFEB is regulated at the posttranslational level by the nutrient-sensitive kinase complex mTORC1. However, little is known about the regulation of TFEB transcription. Here, through integrative genomic approaches, we identify the immediate-early gene EGR1 as a positive transcriptional regulator of TFEB expression in human cells and demonstrate that, in the absence of EGR1, TFEB-mediated transcriptional response to starvation is impaired. Remarkably, both genetic and pharmacological inhibition of EGR1, using the MEK1/2 inhibitor Trametinib, significantly reduced the …

Tfeb-Mediated Lysosomal Exocytosis Alleviates High-Fat Diet-Induced Lipotoxicity In The Kidney, Jun Nakamura, Takeshi Yamamoto, Yoshitsugu Takabatake, Tomoko Namba-Hamano, Satoshi Minami, Atsushi Takahashi, Jun Matsuda, Shinsuke Sakai, Hiroaki Yonishi, Shihomi Maeda, Sho Matsui, Isao Matsui, Takayuki Hamano, Masatomo Takahashi, Maiko Goto, Yoshihiro Izumi, Takeshi Bamba, Miwa Sasai, Masahiro Yamamoto, Taiji Matsusaka, Fumio Niimura, Motoko Yanagita, Shuhei Nakamura, Tamotsu Yoshimori, Andrea Ballabio, Yoshitaka Isaka

Duncan NRI Faculty and Staff Publications

Obesity is a major risk factor for end-stage kidney disease. We previously found that lysosomal dysfunction and impaired autophagic flux contribute to lipotoxicity in obesity-related kidney disease, in both humans and experimental animal models. However, the regulatory factors involved in countering renal lipotoxicity are largely unknown. Here, we found that palmitic acid strongly promoted dephosphorylation and nuclear translocation of transcription factor EB (TFEB) by inhibiting the mechanistic target of rapamycin kinase complex 1 pathway in a Rag GTPase-dependent manner, though these effects gradually diminished after extended treatment. We then investigated the role of TFEB in the pathogenesis of obesity-related kidney …

Structure Of The Lysosomal Mtorc1-Tfeb-Rag-Ragulator Megacomplex, Zhicheng Cui, Gennaro Napolitano, Mariana E G De Araujo, Alessandra Esposito, Jlenia Monfregola, Lukas A Huber, Andrea Ballabio, James H Hurley

Duncan NRI Faculty and Staff Publications

The transcription factor TFEB is a master regulator of lysosomal biogenesis and autophagy1. The phosphorylation of TFEB by the mechanistic target of rapamycin complex 1 (mTORC1)2–5 is unique in its mTORC1 substrate recruitment mechanism, which is strictly dependent on the amino acid-mediated activation of the RagC GTPase activating protein FLCN6,7. TFEB lacks the TOR signalling motif responsible for the recruitment of other mTORC1 substrates. We used cryogenic-electron microscopy to determine the structure of TFEB as presented to mTORC1 for phosphorylation, which we refer to as the ‘megacomplex’. Two full Rag–Ragulator complexes …

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 …

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 …

Cerebellar Dysfunction In Rodent Models With Dystonia, Tremor, And Ataxia, Meike E Van Der Heijden, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Dystonia is a movement disorder characterized by involuntary co- or over-contractions of the muscles, which results in abnormal postures and movements. These symptoms arise from the pathophysiology of a brain-wide dystonia network. There is mounting evidence suggesting that the cerebellum is a central node in this network. For example, manipulations that target the cerebellum cause dystonic symptoms in mice, and cerebellar neuromodulation reduces these symptoms. Although numerous findings provide insight into dystonia pathophysiology, they also raise further questions. Namely, how does cerebellar pathophysiology cause the diverse motor abnormalities in dystonia, tremor, and ataxia? Here, we describe recent work in rodents …

An Initial Experience Of Completion Hemispherotomy Via Magnetic Resonance-Guided Laser Interstitial Therapy, Vijay M Ravindra, Lucia Ruggieri, Nisha Gadgil, Angela P Addison, Ilana Patino, David D Gonda, Jason Chu, Laura Whitehead, Anne Anderson, Gloria Diaz-Medina, Kimberly Houck, Akshat Katyayan, Laura Masters, Audrey Nath, Michael Quach, James John Riviello, Elaine Seto, Krystal Elizabeth Sully, Latanya Agurs, Sonali Sen, Maureen Handoko, Rohini Coorg, Irfan Ali, Daniel Ikeda, Howard Weiner, Daniel J Curry

Duncan NRI Faculty and Staff Publications

Introduction: In carefully selected patients with medically refractory epilepsy, disconnective hemispherotomy can result in significant seizure freedom; however, incomplete disconnection can result in ongoing seizures and poses a significant challenge. Completion hemispherotomy provides an opportunity to finish the disconnection. We describe the use of magnetic resonance-guided laser interstitial thermal ablation (MRgLITT) for completion hemispherotomy.

Methods: Patients treated with completion hemispherotomy using MRgLITT at our institution were identified. Procedural and seizure outcomes were evaluated retrospectively.

Results: Five patients (3 males) underwent six MRgLITT procedures (one child treated twice) for completion hemispherotomy at a median age of 6 years (range 1.8-12.9). Two …

Social Behavioral Impairments In Syngap1-Related Intellectual Disability, Hajer Naveed, Maria Mccormack, J Lloyd Holder

Duncan NRI Faculty and Staff Publications

Introduction: Developmental synaptopathies are neurodevelopmental disorders caused by genetic mutations disrupting the development and function of neuronal synapses.

Methods: We administered the validated Social Responsiveness Scale, Second Edition (SRS-2) to investigate the phenotypic presentation of social-behavioral impairments for the developmental synaptopathy-SYNGAP1-related Intellectual Disability (SYNGAP1-ID) (n = 32) compared with a phenotypically similar disorder Phelan-McDermid syndrome (PMD) (n = 27) and healthy controls (n = 43). A short form SRS-2 analysis (n = 85) was also conducted.

Results: Both SYNGAP1-ID and PMD had significantly elevated total and subcategory T-scores, with no significant score differences between SYNGAP1 …

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 …

Function And Dysfunction Of The Dystonia Network: An Exploration Of Neural Circuits That Underlie The Acquired And Isolated Dystonias, Jason S Gill, Megan X Nguyen, Mariam Hull, Meike E Van Der Heijden, Ken Nguyen, Sruthi P Thomas, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Dystonia is a highly prevalent movement disorder that can manifest at any time across the lifespan. An increasing number of investigations have tied this disorder to dysfunction of a broad "dystonia network" encompassing the cerebellum, thalamus, basal ganglia, and cortex. However, pinpointing how dysfunction of the various anatomic components of the network produces the wide variety of dystonia presentations across etiologies remains a difficult problem. In this review, a discussion of functional network findings in non-mendelian etiologies of dystonia is undertaken. Initially acquired etiologies of dystonia and how lesion location leads to alterations in network function are explored, first through …

Xcvatr: Detection And Characterization Of Variant Impact On The Embeddings Of Single -Cell And Bulk Rna-Sequencing Samples, Arif Harmanci, Akdes Serin Harmanci, Tiemo J Klisch, Akash J Patel

Duncan NRI Faculty and Staff Publications

Background: RNA-sequencing has become a standard tool for analyzing gene activity in bulk samples and at the single-cell level. By increasing sample sizes and cell counts, this technique can uncover substantial information about cellular transcriptional states. Beyond quantification of gene expression, RNA-seq can be used for detecting variants, including single nucleotide polymorphisms, small insertions/deletions, and larger variants, such as copy number variants. Notably, joint analysis of variants with cellular transcriptional states may provide insights into the impact of mutations, especially for complex and heterogeneous samples. However, this analysis is often challenging due to a prohibitively high number of variants and …

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. …

Neurobehavioral Deficits And A Progressive Ictogenesis In The Tetrodotoxin Model Of Epileptic Spasms, John T Le, Carlos J Ballester-Rosado, James D Frost, John W Swann

Duncan NRI Faculty and Staff Publications

Objective: Our goal was to determine whether animals with a history of epileptic spasms have learning and memory deficits. We also used continuous (24/7) long-term electroencephalographic (EEG) recordings to evaluate the evolution of epileptiform activity in the same animals over time.

Methods: Object recognition memory and object location memory tests were undertaken, as well as a matching to place water maze test that evaluated working memory. A retrospective analysis was undertaken of long-term video/EEG recordings from rats with epileptic spasms. The frequency and duration of the ictal events of spasms were quantified.

Results: Rats with a history of epileptic spasms …

A Minimal Role For Synonymous Variation In Human Disease, Ryan S Dhindsa, Quanli Wang, Dimitrios Vitsios, Oliver S Burren, Fengyuan Hu, James E Dicarlo, Leonid Kruglyak, Daniel G Macarthur, Matthew E Hurles, Slavé Petrovski

Duncan NRI Faculty and Staff Publications

Synonymous mutations change the DNA sequence of a gene without affecting the amino acid sequence of the encoded protein. Although some synonymous mutations can affect RNA splicing, translational efficiency, and mRNA stability, studies in human genetics, mutagenesis screens, and other experiments and evolutionary analyses have repeatedly shown that most synonymous variants are neutral or only weakly deleterious, with some notable exceptions. Based on a recent study in yeast, there have been claims that synonymous mutations could be as important as nonsynonymous mutations in causing disease, assuming the yeast findings hold up and translate to humans. Here, we argue that there …