Digital Commons Network^™

Targeted Ablation Of Fn14 Receptor Improves Exercise Capacity And Inhibits Neurogenic Muscle Atrophy, Meiricris Tomaz Da Silva, Aniket S Joshi, Tatiana E Koike, Anirban Roy, Kavya Mathukumalli, Danesh H Sopariwala, Vihang A Narkar, Ashok Kumar

Faculty, Staff and Student Publications

Skeletal muscle atrophy is a prevalent complication in multiple chronic diseases and disuse conditions. Fibroblast growth factor-inducible 14 (Fn14) is a member of the TNF receptor superfamily and a bona fide receptor of the TWEAK cytokine. Accumulating evidence suggests that Fn14 levels are increased in catabolic conditions as well as during exercise. However, the role of Fn14 in the regulation of skeletal muscle mass and function remains poorly understood. In this study, through the generation of novel skeletal muscle-specific Fn14-knockout mice, we have investigated the muscle role of Fn14 in the regulation of exercise capacity and denervation-induced muscle atrophy. Our …

The Lack Of Natural Igm Increases Susceptibility And Impairs Anti-Vi Polysaccharide Igg Responses In A Mouse Model Of Typhoid, Akhil S. Alugupalli, Matthew P. Cravens, Justin A. Walker, Dania Gulandijany, Gregory S. Dickinson, Genevieve Lewis, Gudrun F. Debes, Dieter M. Schifferli, Andreas J. Bäumler, Kishore R. Alugupalli

Department of Microbiology and Immunology Faculty Papers

Circulating IgM present in the body prior to any apparent Ag exposure is referred to as natural IgM. Natural IgM provides protective immunity against a variety of pathogens. Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of typhoid fever in humans. Because mice are not permissive to S. Typhi infection, we employed a murine model of typhoid using S. enterica serovar Typhimurium expressing the Vi polysaccharide (ViPS) of S. Typhi (S. Typhimurium strain RC60) to evaluate the role of natural IgM in pathogenesis. We found that natural mouse IgM binds to S. Typhi and S. Typhimurium. The severity …

Uncloaking Cell-Impermeant Gold Nanorods Via Tumor Microenvironmental Cathepsin B Facilitates Cancer Cell Penetration And Potent Radiosensitization, Subhiksha Raghuram, Yuri Mackeyev, Jessica Symons, Yasmin Zahra, Valeria Gonzalez, Krishnan K Mahadevan, Katherinne I Requejo, Anton Liopo, Paul Derry, Eugene Zubarev, Onur Sahin, Joseph Byung-Kyu Kim, Pankaj K Singh, Sang Hyun Cho, Sunil Krishnan

Faculty, Staff and Student Publications

Major impediments to conveyance of intravenously administered drugs to tumors are biofouling, opsonization, and rapid clearance from the circulation by macrophages and reticuloendothelial phagocytes. Cloaking nanoparticles with stealth epilayers partly overcomes these hurdles but it also foils interactions with tumor cells. Here, we describe the synthesis, characterization, and validation of smart gold nanorods (GNRs) that spontaneously transform from inert passengers in the blood stream to active cell-penetrating nanoparticles within tumors to potently sensitize tumors to radiation therapy. Intrinsically cationic and cell-penetrating GNRs were shielded from phagocytosis with a cloaking polyethylene glycol epilayer containing an intervening cleavable peptide. In the absence …

Epidemiology And Antimicrobial Resistance Of Staphylococci Other Than Staphylococcus Aureus From Domestic Animals And Livestock In Africa: A Systematic Review, Remous Ocloo, Justin Nyasinga, Mohammed Munshi, Aisha Hamdy, Tessa Marciniak, Manonmani Soundararajan, Mae Newton-Foot, Wilma Ziebuhr, Manonmani Soundararajan, Gunturu Revathi

Pathology, East Africa

Introduction: Staphylococci other than Staphylococcus aureus (SOSA) in animals are becoming more pathogenic and antibiotic resistant and can potentially disseminate to humans. However, there is little synthesized information regarding SOSA from animals in Africa. This systematic review provides a comprehensive overview of the epidemiology and antimicrobial resistance of SOSA in companion animals (pets) and livestock in Africa.

Method: This systematic review (PROSPERO-CRD42021252303) was conducted according to the PRISMA guidelines, and 75 eligible studies from 13 countries were identified until August 2022. Three electronic databases (Pubmed, Scopus and Web of Science) were employed.

Results: The frequently isolated SOSA …

Randomization, Design And Analysis For Interdependency In Aging Research: No Person Or Mouse Is An Island, Daniella E Chusyd, Steven N Austad, Stephanie L Dickinson, Keisuke Ejima, Gary L Gadbury, Lilian Golzarri-Arroyo, Richard J Holden, Yasaman Jamshidi-Naeini, Doug Landsittel, Tapan Mehta, J Michael Oakes, Arthur H Owora, Greg Pavela, Javier Rojo, Michael W Sandel, Daniel L Smith, Colby J Vorland, Pengcheng Xun, Roger Zoh, David B Allison

Children’s Nutrition Research Center Staff Publications

Investigators traditionally use randomized designs and corresponding analysis procedures to make causal inferences about the effects of interventions, assuming independence between an individual's outcome and treatment assignment and the outcomes of other individuals in the study. Often, such independence may not hold. We provide examples of interdependency in model organism studies and human trials and group effects in aging research and then discuss methodologic issues and solutions. We group methodologic issues as they pertain to (1) single-stage individually randomized trials; (2) cluster-randomized controlled trials; (3) pseudo-cluster-randomized trials; (4) individually randomized group treatment; and (5) two-stage randomized designs. Although we present …

Direct Cd32 T-Cell Cytotoxicity: Implications For Breast Cancer Prognosis And Treatment, Giuseppe Sconocchia, Giulia Lanzilli, Valeriana Cesarini, Domenico A Silvestris, Katayoun Rezvani, Roberto Arriga, Sara Caratelli, Ken Chen, Jinzhuang Dou, Carlo Cenciarelli, Gabriele Toietta, Silvia Baldari, Tommaso Sconocchia, Francesca De Paolis, Anna Aureli, Giandomenica Iezzi, Maria Irno Consalvo, Francesco Buccisano, Maria I Del Principe, Luca Maurillo, Adriano Venditti, Alessio Ottaviani, Giulio C Spagnoli

Faculty, Staff and Student Publications

The FcγRII (CD32) ligands are IgFc fragments and pentraxins. The existence of additional ligands is unknown. We engineered T cells with human chimeric receptors resulting from the fusion between CD32 extracellular portion and transmembrane CD8α linked to CD28/ζ chain intracellular moiety (CD32-CR). Transduced T cells recognized three breast cancer (BC) and one colon cancer cell line among 15 tested in the absence of targeting antibodies. Sensitive BC cell conjugation with CD32-CR T cells induced CD32 polarization and down-regulation, CD107a release, mutual elimination, and proinflammatory cytokine production unaffected by human IgGs but enhanced by cetuximab. CD32-CR T cells protected immunodeficient mice …

Small Molecule Targeting Nav17 Via Inhibition Of The Crmp2-Ubc9 Interaction Reduces Pain In Chronic Constriction Injury (Cci) Rats, Jiahe Li, Harrison J Stratton, Sabina A Lorca, Peter M Grace, Rajesh Khanna

Faculty, Staff and Student Publications

The voltage-gated sodium channel isoform NaV1.7 is a critical player in the transmission of nociceptive information. This channel has been heavily implicated in human genetic pain disorders and is a validated pain target. However, targeting this channel directly has failed, and an indirect approach - disruption of interactions with accessory protein partners - has emerged as a viable alternative strategy. We recently reported that a small-molecule inhibitor of CRMP2 SUMOylation, compound

Evaluation Of Murine Host Sex As A Biological Variable In Transplanted Human Intestinal Organoid Development, Eoin P Mcneill, Vikas S Gupta, David J Sequeira, Noah F Shroyer, Allison L Speer

Faculty, Staff and Student Publications

Background: Human intestinal organoids (HIOs), when transplanted into immunocompromised mice (tHIOs), demonstrate significant growth and maturation. While both male and female mice are reported to be viable hosts for these experiments, a direct comparison of sex-related differences in tHIO structure and development has not been performed.

Aims: We sought to identify host sex-related differences in tHIO engraftment, morphology, and epithelial and mesenchymal development.

Methods: HIOs were generated in vitro and transplanted beneath the kidney capsule of NSG male and female mice. tHIOs were harvested at 8-9 weeks. Anthropometric measurements were captured. tHIOs were divided in half and histology or RT-qPCR …

Pet/Mr Imaging Of A Lung Metastasis Model Of Clear Cell Renal Cell Carcinoma With (2s,4r)-4-[18f]Fluoroglutamine, Alyssa C Pollard, Vincenzo Paolillo, Bhasker Radaram, Sarah Qureshy, Li Li, Tapati Maity, Lei Wang, Md Nasir Uddin, Christopher G Wood, Jose A Karam, Mark D Pagel, David Piwnica-Worms, Steven W Millward, Natalie Wall Fowlkes, William Norton, Brian J Engel, Federica Pisaneschi, Niki M Zacharias

Faculty, Staff and Student Publications

Purpose: Metabolic reprogramming plays an important role in the tumorigenesis of clear cell renal cell carcinoma (ccRCC). Currently, positron emission tomography (PET) reporters are not used clinically to visualize altered glutamine metabolism in ccRCC, which greatly hinders detection, staging, and real-time therapeutic assessment. We sought to determine if (2S,4R)-4-[18F]fluoroglutamine ([18F]FGln) could be used to interrogate altered glutamine metabolism in ccRCC lesions in the lung.

Procedures: We generated a novel ccRCC lung lesion model using the ccRCC cell line UMRC3 stably transfected with GFP and luciferase constructs. This cell line was used for characterization of [18F]FGln uptake and retention by transport …

The Circadian Nobiletin-Ror Axis Suppresses Adipogenic Differentiation And Iκbα/Nf-Κb Signaling In Adipocytes, Ji Ye Lim, Eunju Kim, Collin M Douglas, Marvin Wirianto, Chorong Han, Kaori Ono, Sun Young Kim, Justin H Ji, Celia K Tran, Zheng Chen, Karyn A Esser, Seung-Hee Yoo

Faculty, Staff and Student Publications

Numerous molecular and physiological processes in the skeletal muscle undergo circadian time-dependent oscillations in accordance with daily activity/rest cycles. The circadian regulatory mechanisms underlying these cyclic processes, especially at the post-transcriptional level, are not well defined. Previously, we reported that the circadian E3 ligase FBXL21 mediates rhythmic degradation of the sarcomere protein TCAP in conjunction with GSK-3β, and Psttm mice harboring an Fbxl21 hypomorph allele show reduced muscle fiber diameter and impaired muscle function. To further elucidate the regulatory function of FBXL21 in skeletal muscle, we investigated another sarcomere protein, Myozenin1 (MYOZ1), that we identified as an FBXL21-binding protein from …

Mdm2 Antagonist Improves Therapeutic Activity Of Azacitidine In Myelodysplastic Syndromes And Chronic Myelomonocytic Leukemia, Yue Wei, Hong Zheng, Pamela Pennington Lockyer, Faezeh Darbaniyan, Ziyi Li, Rashmi Kanagal-Shamanna, Kelly A Soltysiak, Hui Yang, Irene Ganan-Gomez, Guillermo Montalban-Bravo, Kelly S Chien, Kim-Anh Do, Naval Daver, Guillermo Garcia-Manero

Faculty, Staff and Student Publications

Failure of hypomethylation agent (HMA) treatments is an important issue in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML). Recent studies indicated that function of wildtype TP53 positively impacts outcome of HMA treatments. We investigated the combination of the HMA azacitidine (AZA) with DS-3032b and DS-5272, novel antagonists of the TP53 negative regulator MDM2, in cellular and animal models of MDS and CMML. In TP53 wildtype myeloid cell line, combinational effects of DS-3032b or DS-5272 with AZA were observed. In Tet2-knockout mouse model of MDS and CMML, DS-5272 and AZA combination ameliorated disease-like phenotype. RNA-Seq analysis in mouse bone …

Targeting The Mtor Pathway For The Prevention Of Er-Negative Breast Cancer, Abhijit Mazumdar, William M Tahaney, Jamal L Hill, Yun Zhang, Sumankalai Ramachandran, Jitesh Kawedia, Jing Qian, Alejandro Contreras, Michelle I Savage, Lana A Vornik, Shizuko Sei, Altaf Mohammed, Powel H Brown

Faculty, Staff and Student Publications

Our results show that everolimus delays mammary tumor formation in multiple mouse models, suggesting that mTOR inhibitors will be useful for the prevention of ER-negative and triple-negative breast cancer in humans. See related Spotlight, p. 787.

Metabolome And Microbiome Multi-Omics Integration From A Murine Lung Inflammation Model Of Bronchopulmonary Dysplasia, Ahmed El Saie, Chenlian Fu, Sandra L Grimm, Matthew J Robertson, Kristi Hoffman, Vasanta Putluri, Chandra Shekar R Ambati, Nagireddy Putluri, Binoy Shivanna, Cristian Coarfa, Mohan Pammi

Faculty, Staff and Students Publications

BACKGROUND: Respiratory tract microbial dysbiosis can exacerbate inflammation and conversely inflammation may cause dysbiosis. Dysbiotic microbiome metabolites may lead to bronchopulmonary dysplasia (BPD). Hyperoxia and lipopolysaccharide (LPS) interaction alters lung microbiome and metabolome, mediating BPD lung injury sequence.

METHODS: C57BL6/J mice were exposed to 21% (normoxia) or 70% (hyperoxia) oxygen during postnatal days (PND) 1-14. Pups were injected with LPS (6 mg/kg) or equal PBS volume, intraperitoneally on PND 3, 5, and 7. At PND14, the lungs were collected for microbiome and metabolomic analyses (n = 5/group).

RESULTS: Microbiome alpha and beta diversity were similar between groups. Metabolic changes included …

Human Islet Amyloid Polypeptide (Hiapp) Protofibril-Specific Antibodies For Detection And Treatment Of Type 2 Diabetes, Angelina S Bortoletto, W Vallen Graham, Gabriella Trout, Alessandra Bonito-Oliva, Manija A Kazmi, Jing Gong, Emily Weyburne, Brandy L Houser, Thomas P Sakmar, Ronald J Parchem

Faculty, Staff and Students Publications

Type 2 diabetes mellitus (T2D) is a major public health concern and is characterized by sustained hyperglycemia due to insulin resistance and destruction of insulin-producing β cells. One pathological hallmark of T2D is the toxic accumulation of human islet amyloid polypeptide (hIAPP) aggregates. Monomeric hIAPP is a hormone normally co-secreted with insulin. However, increased levels of hIAPP in prediabetic and diabetic patients can lead to the formation of hIAPP protofibrils, which are toxic to β cells. Current therapies fail to address hIAPP aggregation and current screening modalities do not detect it. Using a stabilizing capping protein, monoclonal antibodies (mAbs) can …

Loss Of Wnt4 In The Gubernaculum Causes Unilateral Cryptorchidism And Fertility Defects, Abhishek Seth, Juan C Bournat, Olga Medina-Martinez, Armando Rivera, Joshua Moore, Hunter Flores, Jill A Rosenfeld, Liya Hu, Carolina J Jorgez

Faculty, Staff and Students Publications

Undescended testis (UDT) affects 6% of male births. Despite surgical correction, some men with unilateral UDT may experience infertility with the contralateral descended testis (CDT) showing no A-dark spermatogonia. To improve our understanding of the etiology of infertility in UDT, we generated a novel murine model of left unilateral UDT. Gubernaculum-specific Wnt4 knockout (KO) mice (Wnt4-cKO) were generated using retinoic acid receptor β2-cre mice and were found to have a smaller left-unilateral UDT. Wnt4-cKO mice with abdominal UDT had an increase in serum follicle-stimulating hormone and luteinizing hormone and an absence of germ cells in the undescended testicle. Wnt4-cKO mice …

Effects Of Α And Β-Adrenergic Signaling On Innate Immunity And Porphyromonas Gingivalis Virulence In An Invertebrate Model, Renata Mendonça Moraes, Maíra Terra Garcia, Fabio Stossi, Patrícia Pimentel De Barros, Juliana Campos Junqueira, Ana Lia Anbinder

Faculty, Staff and Students Publications

To investigate the role of adrenergic signalling (AS) in the host immune response and Porphyromonas gingivalis virulence, we compared norepinephrine (NE) and isoproterenol (ISO) responses in Galleria mellonella. P. gingivalis infection was evaluated by survival; humoral immune responses (i.e. melanization and cecropin and gloverin mRNA expression); cellular immune responses (i.e. haemocyte count, nodulation by histology); and P. gingivalis recovery (CFU/mL). P. gingivalis was cultivated in the presence of ISO (PgISO) or NE and injected into the larvae for survival evaluation. Finally, we co-injected ISO and PgISO to evaluate the concomitant effects on the immune response and bacterial virulence. None …

Analysis Of Genome-Wide Knockout Mouse Database Identifies Candidate Ciliopathy Genes, Kendall Higgins, Bret A Moore, Zorana Berberovic, Hibret A Adissu, Mohammad Eskandarian, Ann M Flenniken, Andy Shao, Denise M Imai, Dave Clary, Louise Lanoue, Susan Newbigging, Lauryl M J Nutter, David J Adams, Fatima Bosch, Robert E Braun, Steve D M Brown, Mary E Dickinson, Michael Dobbie, Paul Flicek, Xiang Gao, Sanjeev Galande, Anne Grobler, Jason D Heaney, Yann Herault, Martin Hrabe De Angelis, Hsian-Jean Genie Chin, Fabio Mammano, Chuan Qin, Toshihiko Shiroishi, Radislav Sedlacek, J-K Seong, Ying Xu, Impc Consortium, K C Kent Lloyd, Colin Mckerlie, Ala Moshiri

Faculty, Staff and Students Publications

We searched a database of single-gene knockout (KO) mice produced by the International Mouse Phenotyping Consortium (IMPC) to identify candidate ciliopathy genes. We first screened for phenotypes in mouse lines with both ocular and renal or reproductive trait abnormalities. The STRING protein interaction tool was used to identify interactions between known cilia gene products and those encoded by the genes in individual knockout mouse strains in order to generate a list of "candidate ciliopathy genes." From this list, 32 genes encoded proteins predicted to interact with known ciliopathy proteins. Of these, 25 had no previously described roles in ciliary pathobiology. …

Histopathologic And Transcriptomic Phenotypes Of A Conditional Rankl Transgenic Mouse Thymus, Maria M Szwarc, Lan Hai, Vineet K Maurya, Kimal Rajapakshe, Dimuthu Perera, Michael M Ittmann, Qianxing Mo, Yong Lin, Matthew L Bettini, Cristian Coarfa, John P Lydon

Faculty, Staff and Students Publications

Although conventional knockout and transgenic mouse models have significantly advanced our understanding of Receptor Activator of NF-κB Ligand (RANKL) signaling in intra-thymic crosstalk that establishes self-tolerance and later stages of lymphopoiesis, the unique advantages of conditional mouse transgenesis have yet to be explored. A main advantage of conditional transgenesis is the ability to express a transgene in a spatiotemporal restricted manner, enabling the induction (or de-induction) of transgene expression during predetermined stages of embryogenesis or during defined postnatal developmental or physiological states, such as puberty, adulthood, and pregnancy. Here, we describe the K5: RANKL bigenic mouse, in which transgene derived …

Cic Missense Variants Contribute To Susceptibility For Spina Bifida, Xiao Han, Xuanye Cao, Vanessa Aguiar-Pulido, Wei Yang, Menuka Karki, Paula Andrea Pimienta Ramirez, Robert M Cabrera, Ying Linda Lin, Bogdan J Wlodarczyk, Gary M Shaw, M Elizabeth Ross, Cuilian Zhang, Richard H Finnell, Yunping Lei

Faculty, Staff and Students Publications

Neural tube defects (NTDs) are congenital malformations resulting from abnormal embryonic development of the brain, spine, or spinal column. The genetic etiology of human NTDs remains poorly understood despite intensive investigation. CIC, homolog of the Capicua transcription repressor, has been reported to interact with ataxin-1 (ATXN1) and participate in the pathogenesis of spinocerebellar ataxia type 1. Our previous study demonstrated that CIC loss of function (LoF) variants contributed to the cerebral folate deficiency syndrome by downregulating folate receptor 1 (FOLR1) expression. Given the importance of folate transport in neural tube formation, we hypothesized that CIC variants could contribute to increased …

Human Loss-Of-Function Variants In The Serotonin 2c Receptor Associated With Obesity And Maladaptive Behavior, Yang He, Bas Brouwers, Hesong Liu, Hailan Liu, Katherine Lawler, Edson Mendes De Oliveira, Dong-Kee Lee, Yongjie Yang, Aaron R Cox, Julia M Keogh, Elana Henning, Rebecca Bounds, Aliki Perdikari, Vikram Ayinampudi, Chunmei Wang, Meng Yu, Longlong Tu, Nan Zhang, Na Yin, Junying Han, Nikolas A Scarcelli, Zili Yan, Kristine M Conde, Camille Potts, Jonathan C Bean, Mengjie Wang, Sean M Hartig, Lan Liao, Jianming Xu, Inês Barroso, Jacek Mokrosinski, Yong Xu, I Sadaf Farooqi

Children’s Nutrition Research Center Staff Publications

Serotonin reuptake inhibitors and receptor agonists are used to treat obesity, anxiety and depression. Here we studied the role of the serotonin 2C receptor (5-HT2CR) in weight regulation and behavior. Using exome sequencing of 2,548 people with severe obesity and 1,117 control individuals without obesity, we identified 13 rare variants in the gene encoding 5-HT2CR (HTR2C) in 19 unrelated people (3 males and 16 females). Eleven variants caused a loss of function in HEK293 cells. All people who carried variants had hyperphagia and some degree of maladaptive behavior. Knock-in male mice harboring a human loss-of-function HTR2C variant developed …

Lifespan Benefits For The Combination Of Rapamycin Plus Acarbose And For Captopril In Genetically Heterogeneous Mice, Randy Strong, Kerry Kornfeld, Et Al.

2020-Current year OA Pubs

Mice bred in 2017 and entered into the C2017 cohort were tested for possible lifespan benefits of (R/S)-1,3-butanediol (BD), captopril (Capt), leucine (Leu), the Nrf2-activating botanical mixture PB125, sulindac, syringaresinol, or the combination of rapamycin and acarbose started at 9 or 16 months of age (RaAc9, RaAc16). In male mice, the combination of Rapa and Aca started at 9 months and led to a longer lifespan than in either of the two prior cohorts of mice treated with Rapa only, suggesting that this drug combination was more potent than either of its components used alone. In females, lifespan in mice …

Mouse Tissue Harvest-Induced Hypoxia Rapidly Alters The In Vivo Metabolome, Between-Genotype Metabolite Level Differences, And 13c-Tracing Enrichments, Adam J Rauckhorst, Nicholas Borcherding, Daniel J Pape, Alora S Kraus, Diego A Scerbo, Eric B Taylor

2020-Current year OA Pubs

OBJECTIVE: Metabolomics as an approach to solve biological problems is exponentially increasing in use. Thus, this a pivotal time for the adoption of best practices. It is well known that disrupted tissue oxygen supply rapidly alters cellular energy charge. However, the speed and extent to which delayed mouse tissue freezing after dissection alters the broad metabolome is not well described. Furthermore, how tissue genotype may modulate such metabolomic drift and the degree to which traced

METHODS: By combined liquid chromatography (LC)- and gas chromatography (GC)-mass spectrometry (MS), we measured how levels of 255 mouse liver metabolites changed following 30-second, 1-minute, …

Guidelines For Assessment Of Cardiac Electrophysiology And Arrhythmias In Small Animals, Crystal M Ripplinger, Stacey L Rentschler, Et Al.

2020-Current year OA Pubs

Cardiac arrhythmias are a major cause of morbidity and mortality worldwide. Although recent advances in cell-based models, including human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM), are contributing to our understanding of electrophysiology and arrhythmia mechanisms, preclinical animal studies of cardiovascular disease remain a mainstay. Over the past several decades, animal models of cardiovascular disease have advanced our understanding of pathological remodeling, arrhythmia mechanisms, and drug effects and have led to major improvements in pacing and defibrillation therapies. There exist a variety of methodological approaches for the assessment of cardiac electrophysiology and a plethora of parameters may be assessed with each approach. …

A Sarm1-Mitochondrial Feedback Loop Drives Neuropathogenesis In A Charcot-Marie-Tooth Disease Type 2a Rat Model, Yurie Sato-Yamada, Amy Strickland, Yo Sasaki, Joseph Bloom, Aaron Diantonio, Jeffrey Milbrandt

2020-Current year OA Pubs

Charcot-Marie-Tooth disease type 2A (CMT2A) is an axonal neuropathy caused by mutations in the mitofusin 2 (MFN2) gene. MFN2 mutations result in profound mitochondrial abnormalities, but the mechanism underlying the axonal pathology is unknown. Sterile α and Toll/IL-1 receptor motif-containing 1 (SARM1), the central executioner of axon degeneration, can induce neuropathy and is activated by dysfunctional mitochondria. We tested the role of SARM1 in a rat model carrying a dominant CMT2A mutation (Mfn2H361Y) that exhibits progressive dying-back axonal degeneration, neuromuscular junction (NMJ) abnormalities, muscle atrophy, and mitochondrial abnormalities - all hallmarks of the human disease. We generated Sarm1-KO (Sarm1-/-) and …

Macrophage Depletion Blocks Congenital Sarm1-Dependent Neuropathy, Caitlin B Dingwall, Amy Strickland, Sabrina W Yum, Aldrin Ky Yim, Jian Zhu, Peter L. Wang, Yurie Yamada, Robert E. Schmidt, Yo Sasaki, A. Joseph Bloom, Aaron Diantonio, Jeffrey Milbrandt

2020-Current year OA Pubs

Axon loss contributes to many common neurodegenerative disorders. In healthy axons, the axon survival factor NMNAT2 inhibits SARM1, the central executioner of programmed axon degeneration. We identified 2 rare NMNAT2 missense variants in 2 brothers afflicted with a progressive neuropathy syndrome. The polymorphisms resulted in amino acid substitutions V98M and R232Q, which reduced NMNAT2 NAD+-synthetase activity. We generated a mouse model to mirror the human syndrome and found that Nmnat2V98M/R232Q compound-heterozygous CRISPR mice survived to adulthood but developed progressive motor dysfunction, peripheral axon loss, and macrophage infiltration. These disease phenotypes were all SARM1-dependent. Remarkably, macrophage depletion therapy blocked and reversed …

Genome Protection By Dna Polymerase Θ, Richard D Wood, Sylvie Doublié

Faculty, Staff and Student Publications

DNA polymerase θ (Pol θ) is a DNA repair enzyme widely conserved in animals and plants. Pol θ uses short DNA sequence homologies to initiate repair of double-strand breaks by theta-mediated end joining. The DNA polymerase domain of Pol θ is at the C terminus and is connected to an N-terminal DNA helicase-like domain by a central linker. Pol θ is crucial for maintenance of damaged genomes during development, protects DNA against extensive deletions, and limits loss of heterozygosity. The cost of using Pol θ for genome protection is that a few nucleotides are usually deleted or added at the …

Hdac2 In Primary Sensory Neurons Constitutively Restrains Chronic Pain By Repressing Α2Δ-1 Expression And Associated Nmda Receptor Activity, Jixiang Zhang, Shao-Rui Chen, Meng-Hua Zhou, Daozhong Jin, Hong Chen, Li Wang, Ronald A Depinho, Hui-Lin Pan

Faculty, Staff and Student Publications

α2δ-1 (encoded by the Cacna2d1 gene) is a newly discovered NMDA receptor-interacting protein and is the therapeutic target of gabapentinoids (e.g., gabapentin and pregabalin) frequently used for treating patients with neuropathic pain. Nerve injury causes sustained α2δ-1 upregulation in the dorsal root ganglion (DRG), which promotes NMDA receptor synaptic trafficking and activation in the spinal dorsal horn, a hallmark of chronic neuropathic pain. However, little is known about how nerve injury initiates and maintains the high expression level of α2δ-1 to sustain chronic pain. Here, we show that nerve injury caused histone hyperacetylation and diminished enrichment of histone deacetylase-2 (HDAC2), …

Synaptic Development In Diverse Olfactory Neuron Classes Uses Distinct Temporal And Activity-Related Programs, Michael A. Aimino, Alison T. Depew, Lucas Restrepo, Timothy J. Mosca

Farber Institute for Neuroscience Faculty Papers

Developing neurons must meet core molecular, cellular, and temporal requirements to ensure the correct formation of synapses, resulting in functional circuits. However, because of the vast diversity in neuronal class and function, it is unclear whether or not all neurons use the same organizational mechanisms to form synaptic connections and achieve functional and morphologic maturation. Moreover, it remains unknown whether neurons united in a common goal and comprising the same sensory circuit develop on similar timescales and use identical molecular approaches to ensure the formation of the correct number of synapses. To begin to answer these questions, we took advantage …

Hippo-Yap Signaling Maintains Sinoatrial Node Homeostasis, Mingjie Zheng, Rich G Li, Jia Song, Xiaolei Zhao, Li Tang, Shannon Erhardt, Wen Chen, Bao H Nguyen, Xiao Li, Min Li, Jianxin Wang, Sylvia M Evans, Vincent M Christoffels, Na Li, Jun Wang

Faculty, Staff and Student Publications

BACKGROUND: The sinoatrial node (SAN) functions as the pacemaker of the heart, initiating rhythmic heartbeats. Despite its importance, the SAN is one of the most poorly understood cardiac entities because of its small size and complex composition and function. The Hippo signaling pathway is a molecular signaling pathway fundamental to heart development and regeneration. Although abnormalities of the Hippo pathway are associated with cardiac arrhythmias in human patients, the role of this pathway in the SAN is unknown.

METHODS: We investigated key regulators of the Hippo pathway in SAN pacemaker cells by conditionally inactivating the Hippo signaling kinases

RESULTS: We …

Inactivation Of Lats1/2 Drives Luminal-Basal Plasticity To Initiate Basal-Like Mammary Carcinomas, Joseph G Kern, Andrew M Tilston-Lunel, Anthony Federico, Boting Ning, Amy Mueller, Grace B Peppler, Eleni Stampouloglou, Nan Cheng, Randy L Johnson, Marc E Lenburg, Jennifer E Beane, Stefano Monti, Xaralabos Varelas

Faculty, Staff and Student Publications

Basal-like breast cancers, an aggressive breast cancer subtype that has poor treatment options, are thought to arise from luminal mammary epithelial cells that undergo basal plasticity through poorly understood mechanisms. Using genetic mouse models and ex vivo primary organoid cultures, we show that conditional co-deletion of the LATS1 and LATS2 kinases, key effectors of Hippo pathway signaling, in mature mammary luminal epithelial cells promotes the development of Krt14 and Sox9-expressing basal-like carcinomas that metastasize over time. Genetic co-deletion experiments revealed that phenotypes resulting from the loss of LATS1/2 activity are dependent on the transcriptional regulators YAP/TAZ. Gene expression analyses of …