Genetic Phenomena Commons^™

Arcuate Dopaminergic/Gabaergic Neurons Project Within The Hypothalamus And To The Median Eminence, Somya Mittal, Benjamin R Arenkiel, Ariel M Lyons-Warren

Duncan NRI Faculty and Staff Publications

Cotransmission, meaning the release of multiple neurotransmitters from one synapse, allows for increased diversity of signaling in the brain. Dopamine (DA) and γ-aminobutyric acid (GABA) are known to coexpress in many regions such as the olfactory bulb and the ventral tegmental area. Tuberoinfundibular dopaminergic neurons (TIDA) in the arcuate nucleus of the hypothalamus (Arc) project to the median eminence (ME) and regulate prolactin release from the pituitary, and prior work suggests dopaminergic Arc neurons also cotransmit GABA. However, the extent of cotransmission, and the projection patterns of these neurons have not been fully revealed. Here, we used a genetic intersectional …

Dominant Missense Variants In Srebf2 Are Associated With Complex Dermatological, Neurological, And Skeletal Abnormalities, Matthew J Moulton, Kristhen Atala, Yiming Zheng, Debdeep Dutta, Dorothy K Grange, Wen-Wen Lin, Daniel J Wegner, Jennifer A Wambach, Angela L Duker, Michael B Bober, Lisa Kratz, Carol A Wise, Ila Oxendine, Anas Khanshour, Undiagnosed Diseases Network, Michael F Wangler, Shinya Yamamoto, F Sessions Cole, Jonathan Rios, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

Purpose: We identified 2 individuals with de novo variants in SREBF2 that disrupt a conserved site 1 protease (S1P) cleavage motif required for processing SREBP2 into its mature transcription factor. These individuals exhibit complex phenotypic manifestations that partially overlap with sterol regulatory element binding proteins (SREBP) pathway-related disease phenotypes, but SREBF2-related disease has not been previously reported. Thus, we set out to assess the effects of SREBF2 variants on SREBP pathway activation.

Methods: We undertook ultrastructure and gene expression analyses using fibroblasts from an affected individual and utilized a fly model of lipid droplet (LD) formation to investigate the consequences …

Mondoa And Aki And Aki-To-Ckd Transition, Shihomi Maeda, Shinsuke Sakai, Yoshitsugu Takabatake, Takeshi Yamamoto, Satoshi Minami, Jun Nakamura, Tomoko Namba-Hamano, Atsushi Takahashi, Jun Matsuda, Hiroaki Yonishi, Sho Matsui, Atsuhiro Imai, Ryuya Edahiro, Hitomi Yamamoto-Imoto, Isao Matsui, Seiji Takashima, Ryoichi Imamura, Norio Nonomura, Motoko Yanagita, Yukinori Okada, Andrea Ballabio, Shuhei Nakamura, Tamotsu Yoshimori, Yoshitaka Isaka

Duncan NRI Faculty and Staff Publications

Key Points:

1. The expression of MondoA was decreased in the renal tubules of patients with CKD.

2. Genetic ablation of MondoA in proximal tubules inhibited autophagy and increased vulnerability to AKI through increased expression of Rubicon.

3. MondoA ablation during the recovery phase after ischemia-reperfusion aggravated kidney injury through downregulation of the transcription factor EB-peroxisome proliferator-activated receptor-γ coactivator-1α axis.

Background: Elderly individuals and patients with CKD are at a higher risk of AKI. The transcription factor MondoA is downregulated in the kidneys of aged individuals or patients with AKI; however, its roles in AKI development and the AKI-to-CKD transition remain …

The Cerebellum Modulates Thirst, Ila Mishra, Bing Feng, Bijoya Basu, Amanda M Brown, Linda H Kim, Tao Lin, Mir Abbas Raza, Amelia Moore, Abigayle Hahn, Samantha Bailey, Alaina Sharp, Juan C Bournat, Claire Poulton, Brian Kim, Amos Langsner, Aaron Sathyanesan, Roy V Sillitoe, Yanlin He, Atul R Chopra

Duncan NRI Faculty and Staff Publications

The cerebellum, a phylogenetically ancient brain region, has long been considered strictly a motor control structure. Recent studies have implicated the cerebellum in cognition, sensation, emotion and autonomic function, making it an important target for further investigation. Here, we show that cerebellar Purkinje neurons in mice are activated by the hormone asprosin, leading to enhanced thirst, and that optogenetic or chemogenetic activation of Purkinje neurons induces rapid manifestation of water drinking. Purkinje neuron-specific asprosin receptor (Ptprd) deletion results in reduced water intake without affecting food intake and abolishes asprosin's dipsogenic effect. Purkinje neuron-mediated motor learning and coordination were unaffected by …

A Single-Cell Transcriptomic Map Of The Developing Atoh1 Lineage Identifies Neural Fate Decisions And Neuronal Diversity In The Hindbrain, Jessica C Butts, Sih-Rong Wu, Mark A Durham, Ryan S Dhindsa, Jean-Pierre Revelli, M Cecilia Ljungberg, Olivier Saulnier, Madison E Mclaren, Michael D Taylor, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Proneural transcription factors establish molecular cascades to orchestrate neuronal diversity. One such transcription factor, Atonal homolog 1 (Atoh1), gives rise to cerebellar excitatory neurons and over 30 distinct nuclei in the brainstem critical for hearing, breathing, and balance. Although Atoh1 lineage neurons have been qualitatively described, the transcriptional programs that drive their fate decisions and the full extent of their diversity remain unknown. Here, we analyzed single-cell RNA sequencing and ATOH1 DNA binding in Atoh1 lineage neurons of the developing mouse hindbrain. This high-resolution dataset identified markers for specific brainstem nuclei and demonstrated that transcriptionally heterogeneous progenitors require ATOH1 for …

Tfeb Activation Hallmarks Antigenic Experience Of B Lymphocytes And Directs Germinal Center Fate Decisions, Matthias Münchhalfen, Richard Görg, Michael Haberl, Jens Löber, Jakob Willenbrink, Laura Schwarzt, Charlotte Höltermann, Christian Ickes, Leonard Hammermann, Jan Kus, Björn Chapuy, Andrea Ballabio, Sybille D Reichardt, Alexander Flügel, Niklas Engels, Jürgen Wienands

Duncan NRI Faculty and Staff Publications

Ligation of the B cell antigen receptor (BCR) initiates humoral immunity. However, BCR signaling without appropriate co-stimulation commits B cells to death rather than to differentiation into immune effector cells. How BCR activation depletes potentially autoreactive B cells while simultaneously primes for receiving rescue and differentiation signals from cognate T lymphocytes remains unknown. Here, we use a mass spectrometry-based proteomic approach to identify cytosolic/nuclear shuttling elements and uncover transcription factor EB (TFEB) as a central BCR-controlled rheostat that drives activation-induced apoptosis, and concurrently promotes the reception of co-stimulatory rescue signals by supporting B cell migration and antigen presentation. CD40 co-stimulation …

Loss Of Transient Receptor Potential Channel 5 Causes Obesity And Postpartum Depression, Yongxiang Li, Tessa M Cacciottolo, Na Yin, Yang He, Hesong Liu, Hailan Liu, Yuxue Yang, Elana Henning, Julia M Keogh, Katherine Lawler, Edson Mendes De Oliveira, Eugene J Gardner, Katherine A Kentistou, Panayiotis Laouris, Rebecca Bounds, Ken K Ong, John R B Perry, Inês Barroso, Longlong Tu, Jonathan C Bean, Meng Yu, Kristine M Conde, Mengjie Wang, Olivia Ginnard, Xing Fang, Lydia Tong, Junying Han, Tia Darwich, Kevin W Williams, Yongjie Yang, Chunmei Wang, Shelagh Joss, Helen V Firth, Yong Xu, I Sadaf Farooqi

Duncan NRI Faculty and Staff Publications

Hypothalamic neural circuits regulate instinctive behaviors such as food seeking, the fight/flight response, socialization, and maternal care. Here, we identified microdeletions on chromosome Xq23 disrupting the brain-expressed transient receptor potential (TRP) channel 5 (TRPC5). This family of channels detects sensory stimuli and converts them into electrical signals interpretable by the brain. Male TRPC5 deletion carriers exhibited food seeking, obesity, anxiety, and autism, which were recapitulated in knockin male mice harboring a human loss-of-function TRPC5 mutation. Women carrying TRPC5 deletions had severe postpartum depression. As mothers, female knockin mice exhibited anhedonia and depression-like behavior with impaired care of offspring. Deletion of …

Cerebellar Functions Beyond Movement And Learning, Linda H Kim, Detlef H Heck, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

The cerebellum has a well-established role in controlling motor functions, including coordination, posture, and the learning of skilled movements. The mechanisms for how it carries out motor behavior remain under intense investigation. Interestingly though, in recent years the mechanisms of cerebellar function have faced additional scrutiny since nonmotor behaviors may also be controlled by the cerebellum. With such complexity arising, there is now a pressing need to better understand how cerebellar structure, function, and behavior intersect to influence behaviors that are dynamically called upon as an animal experiences its environment. Here, we discuss recent experimental work that frames possible neural …

Circuit-Specific Deep Brain Stimulation Provides Insights Into Movement Control., Aryn H Gittis, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Deep brain stimulation (DBS), a method in which electrical stimulation is delivered to specific areas of the brain, is an effective treatment for managing symptoms of a number of neurological and neuropsychiatric disorders. Clinical access to neural circuits during DBS provides an opportunity to study the functional link between neural circuits and behavior. This review discusses how the use of DBS in Parkinson's disease and dystonia has provided insights into the brain networks and physiological mechanisms that underlie motor control. In parallel, insights from basic science about how patterns of electrical stimulation impact plasticity and communication within neural circuits are …

Cerebellar Nuclei Cells Produce Distinct Pathogenic Spike Signatures In Mouse Models Of Ataxia, Dystonia, And Tremor, Meike E Van Der Heijden, Amanda M Brown, Dominic J Kizek, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

The cerebellum contributes to a diverse array of motor conditions, including ataxia, dystonia, and tremor. The neural substrates that encode this diversity are unclear. Here, we tested whether the neural spike activity of cerebellar output neurons is distinct between movement disorders with different impairments, generalizable across movement disorders with similar impairments, and capable of causing distinct movement impairments. Using in vivo awake recordings as input data, we trained a supervised classifier model to differentiate the spike parameters between mouse models for ataxia, dystonia, and tremor. The classifier model correctly assigned mouse phenotypes based on single-neuron signatures. Spike signatures were shared …

Ragopathies And The Rising Influence Of Raggtpases On Human Diseases, Irene Sambri, Marco Ferniani, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

RagGTPases (Rags) play an essential role in the regulation of cell metabolism by controlling the activities of both mechanistic target of rapamycin complex 1 (mTORC1) and Transcription factor EB (TFEB). Several diseases, herein named ragopathies, are associated to Rags dysfunction. These diseases may be caused by mutations either in genes encoding the Rags, or in their upstream regulators. The resulting phenotypes may encompass a variety of clinical features such as cataract, kidney tubulopathy, dilated cardiomyopathy and several types of cancer. In this review, we focus on the key clinical, molecular and physio-pathological features of ragopathies, aiming to shed light on …

What’S The N? On Sample Size Vs. Subject Number For Brain-Behavior Neurophysiology And Neuromodulation, Wael F Asaad, Sameer A Sheth

Duncan NRI Faculty and Staff Publications

Neurophysiology and neuromodulation strive to understand the neural basis of behavior through a one-to-one correspondence between a particular brain and its behavioral output. Within this framework, studies with few subjects but sufficient sample sizes can be both rigorous and impactful.

Purkinje Cell Dysfunction Causes Disrupted Sleep In Ataxic Mice, Luis E Salazar Leon, Amanda M Brown, Heet Kaku, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Purkinje cell dysfunction disrupts movement and causes disorders such as ataxia. Recent evidence suggests that Purkinje cell dysfunction may also alter sleep regulation. Here, we used an ataxic mouse model generated by silencing Purkinje cell neurotransmission (L7Cre;Vgatfx/fx) to better understand how cerebellar dysfunction impacts sleep physiology. We focused our analysis on sleep architecture and electrocorticography (ECoG) patterns based on their relevance to extracting physiological measurements during sleep. We found that circadian activity was unaltered in the mutant mice, although their sleep parameters and ECoG patterns were modified. The L7Cre;Vgatfx/fx mutant mice had decreased wakefulness and rapid eye movement (REM) sleep, …

Clinical, Genetic, And Cognitive Correlates Of Seizure Occurrences In Phelan-Mcdermid Syndrome, Tess Levy, Jacob Gluckman, Paige M Siper, Danielle Halpern, Jessica Zweifach, Rajna Filip-Dhima, J Lloyd Holder, M Pilar Trelles, Kristina Johnson, Jonathan A Bernstein, Elizabeth Berry-Kravis, Craig M Powell, Latha Valluripalli Soorya, Audrey Thurm, Joseph D Buxbaum, Mustafa Sahin, Alexander Kolevzon, Siddharth Srivastava

Duncan NRI Faculty and Staff Publications

Background: Phelan-McDermid syndrome (PMS) is a genetic neurodevelopmental disorder caused by SHANK3 haploinsufficiency and is associated with an increased risk for seizures. Previous literature indicates that around one third of individuals with PMS also have epilepsy or seizures, with a wide range of types and ages of onset. Investigating the impact of seizures on intellectual and adaptive functioning for PMS is a primary concern for caregivers and is important to understanding the natural history of this syndrome.

Methods: We report on results from 98 individuals enrolled in a prospective, longitudinal study. We detailed seizure frequency, type, and age of onset, …

Targeted Accurate Rna Consensus Sequencing (Tarc-Seq) Reveals Mechanisms Of Replication Error Affecting Sars-Cov-2 Divergence, Catherine C Bradley, Chen Wang, Alasdair J E Gordon, Alice X Wen, Pamela N Luna, Matthew B Cooke, Brendan F Kohrn, Scott R Kennedy, Vasanthi Avadhanula, Pedro A Piedra, Olivier Lichtarge, Chad A Shaw, Shannon E Ronca, Christophe Herman

Duncan NRI Faculty and Staff Publications

RNA viruses, like SARS-CoV-2, depend on their RNA-dependent RNA polymerases (RdRp) for replication, which is error-prone. Monitoring replication errors is crucial for understanding the virus’s evolution. Current methods lack the precision to detect rare de novo RNA mutations, particularly in low-input samples such as those from patients. Here, we introduce a new targeted Accurate RNA Consensus sequencing method (tARC-seq) to accurately determine the mutation frequency and types in SARS-CoV-2, both in cell culture and clinical samples. Our findings show an average of 2.68×10−5 new errors per cycle with a C>T bias that cannot be solely attributed to APOBEC …

Signaling Mechanisms Underlying Activity-Dependent Integration Of Adult-Born Neurons In The Mouse Olfactory Bulb, Suyang Bao, Juan M Romero, Benjamin D W Belfort, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

Adult neurogenesis has fascinated the field of neuroscience for decades given the prospects of harnessing mechanisms that facilitate the rewiring and/or replacement of adult brain tissue. The subgranular zone of the hippocampus and the subventricular zone of the lateral ventricle are the two main areas in the brain that exhibit ongoing neurogenesis. Of these, 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 continued circuit integration within adult brain tissue. This review focuses on some of the recognized molecular and signaling …

Glial Lipid Droplets Resolve Ros During Sleep, Lindsey D Goodman, Matthew J Moulton, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

The Sehgal lab presents data showing that the non-cell autonomous pathway of glial lipid droplet formation occurs during sleep and helps to resolve neuronal reactive oxygen species (ROS). This promotes neuronal function after an active day. Hence, this pathway has an important physiological function beyond its previously described role in ROS-associated diseases, including Alzheimer’s disease.

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 …

Variants In Zfx Are Associated With An X-Linked Neurodevelopmental Disorder With Recurrent Facial Gestalt\, James L Shepherdson, Katie Hutchison, Dilan Wellalage Don, George Mcgillivray, Tae-Ik Choi, Carolyn A Allan, David J Amor, Siddharth Banka, Donald G Basel, Laura D Buch, Deanna Alexis Carere, Renée Carroll, Jill Clayton-Smith, Ali Crawford, Morten Dunø, Laurence Faivre, Christopher P Gilfillan, Nina B Gold, Karen W Gripp, Emma Hobson, Alexander M Holtz, A Micheil Innes, Bertrand Isidor, Adam Jackson, Panagiotis Katsonis, Leila Amel Riazat Kesh, Genomics England Research Consortium;, Sébastien Küry, François Lecoquierre, Paul Lockhart, Julien Maraval, Naomichi Matsumoto, Julie Mccarrier, Josephine Mccarthy, Noriko Miyake, Lip Hen Moey, Andrea H Németh, Elsebet Østergaard, Rushina Patel, Kate Pope, Jennifer E Posey, Rhonda E Schnur, Marie Shaw, Elliot Stolerman, Julie P Taylor, Erin Wadman, Emma Wakeling, Susan M White, Lawrence C Wong, James R Lupski, Olivier Lichtarge, Mark A Corbett, Jozef Gecz, Charles M Nicolet, Peggy J Farnham, Cheol-Hee Kim, Marwan Shinawi

Duncan NRI Faculty and Staff Publications

Pathogenic variants in multiple genes on the X chromosome have been implicated in syndromic and non-syndromic intellectual disability disorders. ZFX on Xp22.11 encodes a transcription factor that has been linked to diverse processes including oncogenesis and development, but germline variants have not been characterized in association with disease. Here, we present clinical and molecular characterization of 18 individuals with germline ZFX variants. Exome or genome sequencing revealed 11 variants in 18 subjects (14 males and 4 females) from 16 unrelated families. Four missense variants were identified in 11 subjects, with seven truncation variants in the remaining individuals. Clinical findings included …

Novel Hemizygous Single-Nucleotide Duplication In Rpgr In A Patient With Retinal Dystrophy And Sensorineural Hearing Loss, Ryan J German, Blake Vuocolo, Liesbeth Vossaert, Nichole Owen, Richard A Lewis, Lisa Saba, Texome Project, Michael F Wangler, Sandesh Nagamani

Duncan NRI Faculty and Staff Publications

Background: The RPGR gene has been associated with X-linked cone-rod dystrophy. This report describes a variant in RPGR detected with exome sequencing (ES). Genes like RPGR have not always been included in panel-based testing and thus genome-wide tests such as ES may be required for accurate diagnosis.

Methods: The Texome Project is studying the impact of ES in medically underserved patients who are in need of genomic testing to guide diagnosis and medical management. The hypothesis is that ES could uncover diagnoses not made by standard medical care.

Results: A 58-year-old male presented with retinitis pigmentosa, sensorineural hearing loss, and …

Matr3 Pathogenic Variants Differentially Impair Its Cryptic Splicing Repression Function, Mashiat Khan, Xiao Xiao Lily Chen, Michelle Dias, Jhune Rizsan Santos, Sukhleen Kour, Justin You, Rebekah Van Bruggen, Mohieldin M M Youssef, Ying-Wooi Wan, Zhandong Liu, Jill A Rosenfeld, Qiumin Tan, Udai Bhan Pandey, Hari Krishna Yalamanchili, Jeehye Park

Duncan NRI Faculty and Staff Publications

Matrin-3 (MATR3) is an RNA-binding protein implicated in neurodegenerative and neurodevelopmental diseases. However, little is known regarding the role of MATR3 in cryptic splicing within the context of functional genes and how disease-associated variants impact this function. We show that loss of MATR3 leads to cryptic exon inclusion in many transcripts. We reveal that ALS-linked S85C pathogenic variant reduces MATR3 solubility but does not impair RNA binding. In parallel, we report a novel neurodevelopmental disease-associated M548T variant, located in the RRM2 domain, which reduces protein solubility and impairs RNA binding and cryptic splicing repression functions of MATR3. Altogether, our research …

Tfeb Drives Mtorc1 Hyperactivation And Kidney Disease In Tuberous Sclerosis Complex, Nicola Alesi, Damir Khabibullin, Dean M Rosenthal, Elie W Akl, Pieter M Cory, Michel Alchoueiry, Samer Salem, Melissa Daou, William F Gibbons, Jennifer A Chen, Long Zhang, Harilaos Filippakis, Laura Graciotti, Caterina Miceli, Jlenia Monfregola, Claudia Vilardo, Manrico Morroni, Chiara Di Malta, Gennaro Napolitano, Andrea Ballabio, Elizabeth P Henske

Duncan NRI Faculty and Staff Publications

Tuberous Sclerosis Complex (TSC) is caused by TSC1 or TSC2 mutations, leading to hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and lesions in multiple organs including lung (lymphangioleiomyomatosis) and kidney (angiomyolipoma and renal cell carcinoma). Previously, we found that TFEB is constitutively active in TSC. Here, we generated two mouse models of TSC in which kidney pathology is the primary phenotype. Knockout of TFEB rescues kidney pathology and overall survival, indicating that TFEB is the primary driver of renal disease in TSC. Importantly, increased mTORC1 activity in the TSC2 knockout kidneys is normalized by TFEB knockout. In TSC2-deficient …

Rragd-Associated Autosomal Dominant Kidney Hypomagnesemia With Cardiomyopathy: A Review On The Clinical Manifestations And Therapeutic Options, Francesco Trepiccione, Irene Sambri, Barbara Ruggiero, Francesco Emma, Andrea Ballabio, Giulia Florio, Ines Vanderheyden, Anna Iervolino, François Jouret

Duncan NRI Faculty and Staff Publications

Background: A hereditary condition primarily affecting the kidneys and heart has newly been identified: the RRAGD-associated autosomal dominant kidney hypomagnesemia with cardiomyopathy (ADKH-RRAGD). This disorder is characterized by renal loss of magnesium and potassium, coupled with varying degrees of cardiac dysfunction. These range from arrhythmias to severe dilated cardiomyopathy, which may require heart transplantation. Mutations associated with RRAGD significantly disrupt the non-canonical branch of the mechanistic target of rapamycin complex 1 pathway. This disruption hinders the nuclear translocation and transcriptional activity of the transcription factor EB a crucial regulator of lysosomal and autophagic function.

Summary: All identified RRAGD variants compromise …

Metabolink Is A Novel Algorithm For Unveiling Cell-Specific Metabolic Pathways In Longitudinal Datasets, Jared Lichtarge, Gerarda Cappuccio, Soumya Pati, Alfred Kwabena Dei-Ampeh, Senghong Sing, Lihua Ma, Zhandong Liu, Mirjana Maletic-Savatic

Duncan NRI Faculty and Staff Publications

Introduction: In the rapidly advancing field of 'omics research, there is an increasing demand for sophisticated bioinformatic tools to enable efficient and consistent data analysis. As biological datasets, particularly metabolomics, become larger and more complex, innovative strategies are essential for deciphering the intricate molecular and cellular networks.

Methods: We introduce a pioneering analytical approach that combines Principal Component Analysis (PCA) with Graphical Lasso (GLASSO). This method is designed to reduce the dimensionality of large datasets while preserving significant variance. For the first time, we applied the PCA-GLASSO algorithm (i.e., MetaboLINK) to metabolomics data derived from Nuclear Magnetic Resonance (NMR) spectroscopy …

Precision Therapy For A Medically Actionable Atp1a3 Variant From A Genomic Medicine Program In An Underserved Population, Cara P Ford, Rebecca O Littlejohn, Ryan German, Blake Vuocolo, Jose Aceves, Liesbeth Vossaert, Nichole Owen, Michael Wangler, Carrie A Schmid

Duncan NRI Faculty and Staff Publications

Background: Genomic medicine is revolutionizing the diagnosis of rare diseases, but the implementation has not benefited underrepresented populations to the same degree. Here, we report the case of a 7-year-old boy with hypotonia, global developmental delay, strabismus, seizures, and previously suspected mitochondrial myopathy. This proband comes from an underrepresented minority and was denied exome sequencing by his public insurance.

Methods: After informed consent was obtained, buccal cells from the proband were collected and whole exome sequencing was performed. Illumina Dragen and Emedgene software was used to analyze the data at Baylor Genetics. The variants were further intepreted according to ACMG …

Tfeb And Tfe3 Control Glucose Homeostasis By Regulating Insulin Gene Expression, Adrien Pasquier, Nunzia Pastore, Luca D'Orsi, Rita Colonna, Alessandra Esposito, Veronica Maffia, Rossella De Cegli, Margherita Mutarelli, Susanna Ambrosio, Gennaro Tufano, Antonio Grimaldi, Marcella Cesana, Davide Cacchiarelli, Nathalie Delalleau, Gennaro Napolitano, Andrea Ballabio

Duncan NRI Faculty and Staff Publications

To fulfill their function, pancreatic beta cells require precise nutrient-sensing mechanisms that control insulin production. Transcription factor EB (TFEB) and its homolog TFE3 have emerged as crucial regulators of the adaptive response of cell metabolism to environmental cues. Here, we show that TFEB and TFE3 regulate beta-cell function and insulin gene expression in response to variations in nutrient availability. We found that nutrient deprivation in beta cells promoted TFEB/TFE3 activation, which resulted in suppression of insulin gene expression. TFEB overexpression was sufficient to inhibit insulin transcription, whereas beta cells depleted of both TFEB and TFE3 failed to suppress insulin gene …

Dicarboxylic Acylcarnitine Biomarkers In Peroxisome Biogenesis Disorders, Michael F Wangler, Barbara Lesko, Rejwi Dahal, Sharayu Jangam, Pradnya Bhadane, Theodore E Wilson, Molly Mcpheron, Marcus J Miller

Duncan NRI Faculty and Staff Publications

The peroxisome is an essential eukaryotic organelle with diverse metabolic functions. Inherited peroxisomal disorders are associated with a wide spectrum of clinical outcomes and are broadly divided into two classes, those impacting peroxisome biogenesis (PBD) and those impacting specific peroxisomal factors. Prior studies have indicated a role for acylcarnitine testing in the diagnosis of some peroxisomal diseases through the detection of long chain dicarboxylic acylcarnitine abnormalities (C16-DC and C18-DC). However, there remains limited independent corroboration of these initial findings and acylcarnitine testing for peroxisomal diseases has not been widely adopted in clinical laboratories. To explore the utility of acylcarnitine testing …

Rna-Based Translation Activators For Targeted Gene Upregulation, Yang Cao, Huachun Liu, Shannon S Lu, Krysten A Jones, Anitha P Govind, Okunola Jeyifous, Christine Q Simmons, Negar Tabatabaei, William N Green, Jimmy L Holder, Soroush Tahmasebi, Alfred L George, Bryan C Dickinson

Duncan NRI Faculty and Staff Publications

Technologies capable of programmable translation activation offer strategies to develop therapeutics for diseases caused by insufficient gene expression. Here, we present "translation-activating RNAs" (taRNAs), a bifunctional RNA-based molecular technology that binds to a specific mRNA of interest and directly upregulates its translation. taRNAs are constructed from a variety of viral or mammalian RNA internal ribosome entry sites (IRESs) and upregulate translation for a suite of target mRNAs. We minimize the taRNA scaffold to 94 nucleotides, identify two translation initiation factor proteins responsible for taRNA activity, and validate the technology by amplifying SYNGAP1 expression, a haploinsufficiency disease target, in patient-derived cells. …

Clinical Genome Sequencing: Three Years’ Experience At A Tertiary Children’S Hospital, Runjun D Kumar, Lisa F Saba, Haley Streff, Chad A Shaw, Elizabeth Mizerik, Matthew T Snyder, Dolores Lopez-Terrada, Jennifer Scull

Duncan NRI Faculty and Staff Publications

Purpose: Genome sequencing (GS) may shorten the diagnostic odyssey for patients, but clinical experience with this assay in nonresearch settings remains limited. Texas Children's Hospital began offering GS as a clinical test to admitted patients in 2020, providing an opportunity to study GS utilization, possibilities for test optimization, and testing outcomes.

Methods: We retrospectively reviewed GS orders for admitted patients for a nearly 3-year period from March 2020 through December 2022. We gathered anonymized clinical data from the electronic health record to answer the study questions.

Results: The diagnostic yield over 97 admitted patients was 35%. The majority of GS …

Hematopoietic Stem And Progenitor Cells Confer Cross-Protective Trained Immunity In Mouse Models, Bailee N Kain, Brandon T Tran, Pamela N Luna, Ruoqiong Cao, Duy T Le, Marcus A Florez, Laure Maneix, Jack D Toups, Daniel E Morales-Mantilla, Scott Koh, Hyojeong Han, Roman Jaksik, Yun Huang, Andre Catic, Chad A Shaw, Katherine Y King

Duncan NRI Faculty and Staff Publications

Recent studies suggest that infection reprograms hematopoietic stem and progenitor cells (HSPCs) to enhance innate immune responses upon secondary infectious challenge, a process called “trained immunity.” However, the specificity and cell types responsible for this response remain poorly defined. We established a model of trained immunity in mice in response to Mycobacterium avium infection. scRNA-seq analysis revealed that HSPCs activate interferon gamma-response genes heterogeneously upon primary challenge, while rare cell populations expand. Macrophages derived from trained HSPCs demonstrated enhanced bacterial killing and metabolism, and a single dose of recombinant interferon gamma exposure was sufficient to induce similar training. Mice transplanted …