Medical Specialties Commons^™

Young Versus Aged Microbiota Transplants To Germ-Free Mice: Increased Short-Chain Fatty Acids And Improved Cognitive Performance, Juneyoung Lee, Venugopal R Venna, David J Durgan, Huanan Shi, Jacob Hudobenko, Nagireddy Putluri, Joseph Petrosino, Louise D Mccullough, Robert M Bryan

Faculty, Staff and Students Publications

Aging is associated with cognitive decline and decreased concentrations of short-chain fatty acids (SCFAs) in the gut. SCFAs are significant in that they are protective to the gut and other organs. We tested the hypothesis that the aged gut microbiome alone is sufficient to decrease SCFAs in the host and produce cognitive decline. Fecal transplant gavages (FTGs) from aged (18–20 months) or young (2–3 months) male C57BL/6 mice into germ-free male C57BL/6 mice (N = 11 per group) were initiated at ~3 months of age. Fecal samples were collected and behavioral testing was performed over the study period. Bacterial community …

Zmat3 Is A Key Splicing Regulator In The P53 Tumor Suppression Program, Kathryn T Bieging-Rolett, Alyssa M Kaiser, David W Morgens, Anthony M Boutelle, Jose A Seoane, Eric L Van Nostrand, Changyu Zhu, Shauna L Houlihan, Stephano S Mello, Brian A Yee, Jacob Mcclendon, Sarah E Pierce, Ian P Winters, Mengxiong Wang, Andrew J Connolly, Scott W Lowe, Christina Curtis, Gene W Yeo, Monte M Winslow, Michael C Bassik, Laura D Attardi

Faculty, Staff and Students Publications

Although TP53 is the most commonly mutated gene in human cancers, the p53-dependent transcriptional programs mediating tumor suppression remain incompletely understood. Here, to uncover critical components downstream of p53 in tumor suppression, we perform unbiased RNAi and CRISPR-Cas9-based genetic screens in vivo. These screens converge upon the p53-inducible gene Zmat3, encoding an RNA-binding protein, and we demonstrate that ZMAT3 is an important tumor suppressor downstream of p53 in mouse Kras

Adaptive Thermogenesis Enhances The Life-Threatening Response To Heat In Mice With An Ryr1 Mutation, Hui J Wang, Chang Seok Lee, Rachel Sue Zhen Yee, Linda Groom, Inbar Friedman, Lyle Babcock, Dimitra K Georgiou, Jin Hong, Amy D Hanna, Joseph Recio, Jong Min Choi, Ting Chang, Nadia H Agha, Jonathan Romero, Poonam Sarkar, Nicol Voermans, M Waleed Gaber, Sung Yun Jung, Matthew L Baker, Robia G Pautler, Robert T Dirksen, Sheila Riazi, Susan L Hamilton

Faculty, Staff and Students Publications

Mutations in the skeletal muscle Ca2+ release channel, the type 1 ryanodine receptor (RYR1), cause malignant hyperthermia susceptibility (MHS) and a life-threatening sensitivity to heat, which is most severe in children. Mice with an MHS-associated mutation in Ryr1 (Y524S, YS) display lethal muscle contractures in response to heat. Here we show that the heat response in the YS mice is exacerbated by brown fat adaptive thermogenesis. In addition, the YS mice have more brown adipose tissue thermogenic capacity than their littermate controls. Blood lactate levels are elevated in both heat-sensitive MHS patients with RYR1 mutations and YS mice due to …

Mir-30a Targets Gene Networks That Promote Browning Of Human And Mouse Adipocytes, Pradip K Saha, Mark P Hamilton, Kimal Rajapakshe, Vasanta Putluri, Jessica B Felix, Peter Masschelin, Aaron R Cox, Mandeep Bajaj, Nagireddy Putluri, Cristian Coarfa, Sean M Hartig

Faculty, Staff and Students Publications

MicroRNA-30a (miR-30a) impacts adipocyte function, and its expression in white adipose tissue (WAT) correlates with insulin sensitivity in obesity. Bioinformatic analysis demonstrates that miR-30a expression contributes to 2% of all miRNA expression in human tissues. However, molecular mechanisms of miR-30a function in fat cells remain unclear. Here, we expanded our understanding of how miR-30a expression contributes to antidiabetic peroxisome proliferator-activated receptor-γ (PPARγ) agonist activity and metabolic functions in adipocytes. We found that WAT isolated from diabetic patients shows reduced miR-30a levels and diminished expression of the canonical PPARγ target genes ADIPOQ and FABP4 relative to lean counterparts. In human adipocytes, …

An Autism-Linked Missense Mutation In Shank3 Reveals The Modularity Of Shank3 Function, Li Wang, Kaifang Pang, Kihoon Han, Carolyn J Adamski, Wei Wang, Lingjie He, Jason K Lai, Vitaliy V Bondar, Joseph G Duman, Ronald Richman, Kimberley F Tolias, Patrick Barth, Timothy Palzkill, Zhandong Liu, J Lloyd Holder, Huda Y Zoghbi

Faculty, Staff and Students Publications

Genome sequencing has revealed an increasing number of genetic variations that are associated with neuropsychiatric disorders. Frequently, studies limit their focus to likely gene-disrupting mutations because they are relatively easy to interpret. Missense variants, instead, have often been undervalued. However, some missense variants can be informative for developing a more profound understanding of disease pathogenesis and ultimately targeted therapies. Here we present an example of this by studying a missense variant in a well-known autism spectrum disorder (ASD) causing gene SHANK3. We analyzed Shank3's in vivo phosphorylation profile and identified S685 as one phosphorylation site where one ASD-linked variant has …

Ampk Regulation Of Raptor And Tsc2 Mediate Metformin Effects On Transcriptional Control Of Anabolism And Inflammation, Jeanine L Van Nostrand, Kristina Hellberg, En-Ching Luo, Eric L Van Nostrand, Alina Dayn, Jingting Yu, Maxim N Shokhirev, Yelena Dayn, Gene W Yeo, Reuben J Shaw

Faculty, Staff and Students Publications

Despite being the frontline therapy for type 2 diabetes, the mechanisms of action of the biguanide drug metformin are still being discovered. In particular, the detailed molecular interplays between the AMPK and the mTORC1 pathway in the hepatic benefits of metformin are still ill defined. Metformin-dependent activation of AMPK classically inhibits mTORC1 via TSC/RHEB, but several lines of evidence suggest additional mechanisms at play in metformin inhibition of mTORC1. Here we investigated the role of direct AMPK-mediated serine phosphorylation of RAPTOR in a new

Yebc Regulates Variable Surface Antigen Vlse Expression And Is Required For Host Immune Evasion In Borrelia Burgdorferi, Yan Zhang, Tong Chen, Sajith Raghunandanan, Xuwu Xiang, Jing Yang, Qiang Liu, Diane G Edmondson, Steven J Norris, X Frank Yang, Yongliang Lou

Faculty, Staff and Student Publications

Borrelia burgdorferi, the Lyme disease pathogen causes persistent infection by evading the host immune response. Differential expression of the surface-exposed lipoprotein VlsE that undergoes antigenic variation is a key immune evasion strategy employed by B. burgdorferi. Most studies focused on the mechanism of VlsE antigen variation, but little is known about VlsE regulation and factor(s) that regulates differential vlsE expression. In this study, we investigated BB0025, a putative YebC family transcriptional regulator (and hence designated BB0025 as YebC of B. burgdorferi herein). We constructed yebC mutant and complemented strain in an infectious strain of B. burgdorferi. The yebC mutant could …

Atrial Myocyte Nlrp3/Camkii Nexus Forms A Substrate For Postoperative Atrial Fibrillation, Jordi Heijman, Azinwi Phina Muna, Tina Veleva, Cristina E Molina, Henry Sutanto, Marcel Tekook, Qiongling Wang, Issam H Abu-Taha, Marcel Gorka, Stephan Künzel, Ali El-Armouche, Hermann Reichenspurner, Markus Kamler, Viacheslav Nikolaev, Ursula Ravens, Na Li, Stanley Nattel, Xander H T Wehrens, Dobromir Dobrev

Faculty, Staff and Students Publications

RATIONALE: Postoperative atrial fibrillation (POAF) is a common and troublesome complication of cardiac surgery. POAF is generally believed to occur when postoperative triggers act on a preexisting vulnerable substrate, but the underlying cellular and molecular mechanisms are largely unknown.

OBJECTIVE: To identify cellular POAF mechanisms in right atrial samples from patients without a history of atrial fibrillation undergoing open-heart surgery.

METHODS AND RESULTS: Multicellular action potentials, membrane ion-currents (perforated patch-clamp), or simultaneous membrane-current (ruptured patch-clamp) and [Ca

CONCLUSIONS: Preexisting Ca

Loss Of Speg Inhibitory Phosphorylation Of Ryanodine Receptor Type-2 Promotes Atrial Fibrillation, Hannah M Campbell, Ann P Quick, Issam Abu-Taha, David Y Chiang, Carlos F Kramm, Tarah A Word, Sören Brandenburg, Mohit Hulsurkar, Katherina M Alsina, Hui-Bin Liu, Brian Martin, Dennis Uhlenkamp, Oliver M Moore, Satadru K Lahiri, Eleonora Corradini, Markus Kamler, Albert J R Heck, Stephan E Lehnart, Dobromir Dobrev, Xander H T Wehrens

Faculty, Staff and Students Publications

BACKGROUND: Enhanced diastolic calcium (Ca

METHODS: Western blotting was performed with right atrial biopsies from patients with paroxysmal AF. SPEG atrial knockout mice were generated using adeno-associated virus 9. In mice, AF inducibility was determined using intracardiac programmed electric stimulation, and diastolic Ca

RESULTS: Western blotting revealed decreased SPEG protein levels in atrial biopsies from patients with paroxysmal AF in comparison with patients in sinus rhythm. SPEG atrial-specific knockout mice exhibited increased susceptibility to pacing-induced AF by programmed electric stimulation and enhanced Ca

CONCLUSIONS: Unlike other kinases (PKA, CaMKII) that increase RyR2 activity, SPEG phosphorylation reduces RyR2-mediated sarcoplasmic reticulum Ca

Long Noncoding Rna H19x Is A Key Mediator Of Tgf-Β-Driven Fibrosi, Elena Pachera, Shervin Assassi, Gloria A Salazar, Mara Stellato, Florian Renoux, Adam Wunderlin, Przemyslaw Blyszczuk, Robert Lafyatis, Fina Kurreeman, Jeska De Vries-Bouwstra, Tobias Messemaker, Carol A Feghali-Bostwick, Gerhard Rogler, Wouter T Van Haaften, Gerard Dijkstra, Fiona Oakley, Maurizio Calcagni, Janine Schniering, Britta Maurer, Jörg Hw Distler, Gabriela Kania, Mojca Frank-Bertoncelj, Oliver Distler

Faculty, Staff and Student Publications

TGF-β is a master regulator of fibrosis, driving the differentiation of fibroblasts into apoptosis-resistant myofibroblasts and sustaining the production of extracellular matrix (ECM) components. Here, we identified the nuclear long noncoding RNA (lncRNA) H19X as a master regulator of TGF-β-driven tissue fibrosis. H19X was consistently upregulated in a wide variety of human fibrotic tissues and diseases and was strongly induced by TGF-β, particularly in fibroblasts and fibroblast-related cells. Functional experiments following H19X silencing revealed that H19X was an obligatory factor for TGF-β-induced ECM synthesis as well as differentiation and survival of ECM-producing myofibroblasts. We showed that H19X regulates DDIT4L gene …

Characterization Of Retinal Biomechanical Properties Using Brillouin Microscopy, Yogeshwari S Ambekar, Manmohan Singh, Giuliano Scarcelli, Elda M Rueda, Benjamin M Hall, Ross A Poché, Kirill V Larin

Faculty, Staff and Students Publications

SIGNIFICANCE: The retina is critical for vision, and several diseases may alter its biomechanical properties. However, assessing the biomechanical properties of the retina nondestructively is a challenge due to its fragile nature and location within the eye globe. Advancements in Brillouin spectroscopy have provided the means for nondestructive investigations of retina biomechanical properties.

AIM: We assessed the biomechanical properties of mouse retinas using Brillouin microscopy noninvasively and showed the potential of Brillouin microscopy to differentiate the type and layers of retinas based on stiffness.

APPROACH: We used Brillouin microscopy to quantify stiffness of fresh and paraformaldehyde (PFA)-fixed retinas. As further …

Mtor-Initiated Metabolic Switch And Degeneration In The Retinal Pigment Epithelium, Young-Mi Go, Jing Zhang, Jolyn Fernandes, Christopher Litwin, Rui Chen, Theodore G Wensel, Dean P Jones, Jiyang Cai, Yan Chen

Faculty, Staff and Students Publications

The retinal pigment epithelium (RPE) is a particularly vulnerable tissue to age-dependent degeneration. Over the life span, the RPE develops an expanded endo-lysosomal compartment to maintain the high efficiency of phagocytosis and degradation of photoreceptor outer segments (POS) necessary for photoreceptor survival. As the assembly and activation of the mechanistic target of rapamycin complex 1 (mTORC1) occur on the lysosome surface, increased lysosome mass with aging leads to higher mTORC1 activity. The functional consequences of hyperactive mTORC1 in the RPE are unclear. In the current study, we used integrated high-resolution metabolomic and genomic approaches to examine mice with RPE-specific deletion …

Structure And Mechanism Of A Unique Diiron Center In Mammalian Stearoyl-Coa Desaturase, Jiemin Shen, Gang Wu, Ah-Lim Tsai, Ming Zhou

Faculty, Staff and Students Publications

Stearoyl-CoA desaturase 1 (SCD1) is a membrane-embedded metalloenzyme that catalyzes formation of a double-bond on a saturated acyl-CoA. SCD1 has a diiron center and its proper function requires an electron transport chain composed of NADH (or NADPH), cytochrome b5 reductase (b5R), and cytochrome b5 (cyt b5). Since SCD1 is a key regulator in fat metabolism and is required for survival of cancer cells, there is intense interest in targeting SCD1 for various metabolic diseases and cancers. Crystal structures of human and mouse SCD1 were reported recently, however, both proteins have two zinc ions instead of two iron ions in the …

Metabolism Of Jq1, An Inhibitor Of Bromodomain And Extra Terminal Bromodomain Proteins, In Human And Mouse Liver Microsomes†, Feng Li, Kevin R Mackenzie, Prashi Jain, Conrad Santini, Damian W Young, Martin M Matzuk

Faculty, Staff and Students Publications

JQ1 is a small-molecule inhibitor of the bromodomain and extra terminal (BET) protein family that potently inhibits the bromodomain testis-specific protein (BRDT), which is essential for spermatogenesis. JQ1 treatment produces a reversible contraceptive effect by targeting the activity of BRDT in mouse male germ cells, validating BRDT as a male contraceptive target. Although JQ1 possesses favourable physical properties, it exhibits a short half-life. Because the details of xenobiotic metabolism play important roles in the optimization of drug candidates and in determining the role of metabolism in drug efficacy, we investigated the metabolism of JQ1 in human and mouse liver microsomes. …

A Global Slc7a7 Knockout Mouse Model Demonstrates Characteristic Phenotypes Of Human Lysinuric Protein Intolerance, Bridget M Stroup, Ronit Marom, Xiaohui Li, Chih-Wei Hsu, Cheng-Yen Chang, Luan D Truong, Brian Dawson, Ingo Grafe, Yuqing Chen, Ming-Ming Jiang, Denise Lanza, Jennie Rose Green, Qin Sun, J P Barrish, Safa Ani, Audrey E Christiansen, John R Seavitt, Mary E Dickinson, Farrah Kheradmand, Jason D Heaney, Brendan Lee, Lindsay C Burrage

Faculty, Staff and Students Publications

Lysinuric protein intolerance (LPI) is an inborn error of cationic amino acid (arginine, lysine, ornithine) transport caused by biallelic pathogenic variants in SLC7A7, which encodes the light subunit of the y+LAT1 transporter. Treatments for the complications of LPI, including growth failure, renal disease, pulmonary alveolar proteinosis, autoimmune disorders and osteoporosis, are limited. Given the early lethality of the only published global Slc7a7 knockout mouse model, a viable animal model to investigate global SLC7A7 deficiency is needed. Hence, we generated two mouse models with global Slc7a7 deficiency (Slc7a7em1Lbu/em1Lbu; Slc7a7Lbu/Lbu and Slc7a7em1(IMPC)Bay/em1(IMPC)Bay; Slc7a7Bay/Bay) using CRISPR/Cas9 technology by introducing a deletion of exons …

Profound And Redundant Functions Of Arcuate Neurons In Obesity Development, Canjun Zhu, Zhiying Jiang, Yuanzhong Xu, Zhao-Lin Cai, Qingyan Jiang, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qi Wu, Gang Shu, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic faces a lack of mechanistic insights. It is known that the acute activity changes of a growing number of brain neurons rapidly alter feeding behaviour; however, how these changes translate to obesity development and the fundamental mechanism underlying brain neurons in controlling body weight remain elusive. Here, we show that chronic activation of hypothalamic arcuate GABAergic (GABA

Symmetric Inverse Consistent Nonlinear Registration Driven By Mutual Information, Wen Fury, Keun Woo Park, Zhuhao Wu, Eunhee Kim, Moon-Sook Woo, Yu Bai, Lynn E Macdonald, Susan D Croll, Sunghee Cho

Faculty, Staff and Student Publications

BACKGROUND AND PURPOSE: Stroke is a major cause of chronic neurological disability. There is considerable interest in understanding how acute transcriptome changes evolve into subacute and chronic patterns that facilitate or limit spontaneous recovery. Here we mapped longitudinal changes in gene expression at multiple time points after stroke in mice out to 6 months.

METHODS: Adult C57BL/6 mice were subjected to transient middle cerebral artery occlusion. Longitudinal transcriptome levels were measured at 10 time points after stroke from acute to recovery phases of ischemic stroke. Localization and the number of mononuclear phagocytes were determined in the postischemic brain. Whole-mount brain …

Gut Microbiota-Derived Short-Chain Fatty Acids Promote Poststroke Recovery In Aged Mice, Juneyoung Lee, John D'Aigle, Louise Atadja, Victoria Quaicoe, Pedram Honarpisheh, Bhanu P Ganesh, Ahmad Hassan, Joerg Graf, Joseph Petrosino, Nagireddy Putluri, Liang Zhu, David J Durgan, Robert M Bryan, Louise D Mccullough, Venugopal Reddy Venna

Faculty, Staff and Students Publications

RATIONALE: The elderly experience profound systemic responses after stroke, which contribute to higher mortality and more severe long-term disability. Recent studies have revealed that stroke outcomes can be influenced by the composition of gut microbiome. However, the potential benefits of manipulating the gut microbiome after injury is unknown.

OBJECTIVE: To determine if restoring youthful gut microbiota after stroke aids in recovery in aged subjects, we altered the gut microbiome through young fecal transplant gavage in aged mice after experimental stroke. Further, the effect of direct enrichment of selective bacteria producing short-chain fatty acids (SCFAs) was tested as a more targeted …

Paraventricular Hypothalamus Mediates Diurnal Rhythm Of Metabolism, Eun Ran Kim, Yuanzhong Xu, Ryan M Cassidy, Yungang Lu, Yongjie Yang, Jinbin Tian, De-Pei Li, Rachel Van Drunen, Aleix Ribas-Latre, Zhao-Lin Cai, Mingshan Xue, Benjamin R Arenkiel, Kristin Eckel-Mahan, Yong Xu, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

Defective rhythmic metabolism is associated with high-fat high-caloric diet (HFD) feeding, ageing and obesity; however, the neural basis underlying HFD effects on diurnal metabolism remains elusive. Here we show that deletion of BMAL1, a core clock gene, in paraventricular hypothalamic (PVH) neurons reduces diurnal rhythmicity in metabolism, causes obesity and diminishes PVH neuron activation in response to fast-refeeding. Animal models mimicking deficiency in PVH neuron responsiveness, achieved through clamping PVH neuron activity at high or low levels, both show obesity and reduced diurnal rhythmicity in metabolism. Interestingly, the PVH exhibits BMAL1-controlled rhythmic expression of GABA-A receptor γ2 subunit, and dampening …

Disrupted Hypothalamic Crh Neuron Responsiveness Contributes To Diet-Induced Obesity, Canjun Zhu, Yuanzhong Xu, Zhiying Jiang, Jin Bin Tian, Ryan M Cassidy, Zhao-Lin Cai, Gang Shu, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qingyan Jiang, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic mainly results from high-fat high-caloric diet (HFD) feeding and may also be contributed by chronic stress; however, the neural basis underlying stress-related diet-induced obesity remains unknown. Corticotropin-releasing hormone (CRH) neurons in the paraventricular hypothalamus (PVH), a known body weight-regulating region, represent one key group of stress-responsive neurons. Here, we found that HFD feeding blunted PVH CRH neuron response to nutritional challenges as well as stress stimuli and dexamethesone, which normally produce rapid activation and inhibition on these neurons, respectively. We generated mouse models with the activity of these neurons clamped at high or low levels, both …

C1q/Tnf-Related Protein 5 Contributes To Diabetic Vascular Endothelium Dysfunction Through Promoting Nox-1 Signaling., Jing Liu, Zhijun Meng, Lu Gan, Rui Guo, Jia Gao, Caihong Liu, Di Zhu, Demin Liu, Ling Zhang, Zhen Zhang, Dina Xie, Xiangying Jiao, Wayne Bond Lau, Bernard L. Lopez, Theodore A. Christopher, Xin-Liang Ma, Jimin Cao, Yajing Wang

Department of Emergency Medicine Faculty Papers

OBJECTIVE: Dysregulated adipokine profiles contribute to the pathogenesis of diabetic cardiovascular complications. Endothelial cell (EC) dysfunction, a common pathological alteration in cardiovascular disorders, is exaggerated in diabetes. However, it is unclear whether and how dysregulated adipokines may contribute to diabetic EC dysfunction.

METHODS AND RESULTS: Serum C1q/TNF-Related Protein 5 (CTRP5) were determined in control/diabetes patients, and control/diabetic mice (high-fat diet, HFD). We observed for the first time that serum total CTRP5 was increased, high molecular weight (HMW) form was decreased, but the globular form (gCTRP5) was significantly increased in diabetic patients. These pathological alterations were reproduced in diabetic mice. To …

Atrx Deletion In Neurons Leads To Sexually Dimorphic Dysregulation Of Mir-137 And Spatial Learning And Memory Deficits., Renee J. Tamming, Vanessa Dumeaux, Yan Jiang, Sarfraz Shafiq, Luana Langlois, Jacob Ellegood, Lily R. Qiu, Jason P. Lerch, Nathalie G. Bérubé

Paediatrics Publications

ATRX gene mutations have been identified in syndromic and non-syndromic intellectual disabilities in humans. ATRX is known to maintain genomic stability in neuroprogenitor cells, but its function in differentiated neurons and memory processes remains largely unresolved. Here, we show that the deletion of neuronal Atrx in mice leads to distinct hippocampal structural defects, fewer presynaptic vesicles, and an enlarged postsynaptic area at CA1 apical dendrite-axon junctions. We identify male-specific impairments in long-term contextual memory and in synaptic gene expression, linked to altered miR-137 levels. We show that ATRX directly binds to the miR-137 locus and that the enrichment of the …

Nuclear Localization Of A Novel Calpain-2 Mediated Junctophilin-2 C-Terminal Cleavage Peptide Promotes Cardiomyocyte Remodeling, Satadru K Lahiri, Ann P Quick, Benoit Samson-Couterie, Mohit Hulsurkar, Ies Elzenaar, Ralph J Van Oort, Xander H T Wehrens

Faculty, Staff and Students Publications

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Patients with HF exhibit a loss of junctophilin-2 (JPH2), a structural protein critical in forming junctional membrane complexes in which excitation-contraction takes place. Several mechanisms have been proposed to mediate the loss of JPH2, one being cleavage by the calcium-dependent protease calpain. The downstream mechanisms underlying HF progression after JPH2 cleavage are presently poorly understood. In this study, we used Labcas to bioinformatically predict putative calpain cleavage sites on JPH2. We identified a cleavage site that produces a novel C-terminal JPH2 peptide (JPH2-CTP) using several domain-specific antibodies. Western …

Effects Of A Postnatal Atrx Conditional Knockout In Neurons On Autism-Like Behaviours In Male And Female Mice., Nicole Martin-Kenny, Nathalie G Bérubé

Paediatrics Publications

BACKGROUND: Alpha-thalassemia/mental retardation, X-linked, or ATRX, is an autism susceptibility gene that encodes a chromatin remodeler. Mutations of ATRX result in the ATR-X intellectual disability syndrome and have been identified in autism spectrum disorder (ASD) patients. The mechanisms by which ATRX mutations lead to autism and autistic-like behaviours are not yet known. To address this question, we generated mice with postnatal Atrx inactivation in excitatory neurons of the forebrain and performed a battery of behavioural assays that assess autistic-like behaviours.

METHODS: Male and female mice with a postnatal conditional ablation of ATRX were generated using the Cre/lox system under the …

Acute Tubular Injury In A Patient On A Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor, June K Pickett, Maulin Shah, Michael Gillette, Peter Jones, Salim Virani, Christie Ballantyne, Vijay Nambi

Faculty, Staff and Students Publications

A 72-year-old man with coronary artery disease, statin intolerance, and chronic kidney disease stage IIIa was initiated on alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, and developed acute kidney injury. A kidney biopsy was performed and suggested acute tubular injury. The serum creatinine returned to baseline after discontinuation of alirocumab. (Level of Difficulty: Intermediate.)

Aav-Crispr Gene Editing Is Negated By Pre-Existing Immunity To Cas9, Ang Li, Mark R Tanner, Ciaran M Lee, Ayrea E Hurley, Marco De Giorgi, Kelsey E Jarrett, Timothy H Davis, Alexandria M Doerfler, Gang Bao, Christine Beeton, William R Lagor

Faculty, Staff and Students Publications

Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by …

Discovery Of A Selective Inhibitor Of Doublecortin Like Kinase 1, Fleur M Ferguson, Behnam Nabet, Srivatsan Raghavan, Yan Liu, Alan L Leggett, Miljan Kuljanin, Radha L Kalekar, Annan Yang, Shuning He, Jinhua Wang, Raymond W S Ng, Rita Sulahian, Lianbo Li, Emily J Poulin, Ling Huang, Jost Koren, Nora Dieguez-Martinez, Sergio Espinosa, Zhiyang Zeng, Cesear R Corona, James D Vasta, Ryoma Ohi, Taebo Sim, Nam Doo Kim, Wayne Harshbarger, Jose M Lizcano, Matthew B Robers, Senthil Muthaswamy, Charles Y Lin, A Thomas Look, Kevin M Haigis, Joseph D Mancias, Brian M Wolpin, Andrew J Aguirre, William C Hahn, Kenneth D Westover, Nathanael S Gray

Faculty, Staff and Students Publications

Doublecortin like kinase 1 (DCLK1) is an understudied kinase that is upregulated in a wide range of cancers, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about its potential as a therapeutic target. We used chemoproteomic profiling and structure-based design to develop a selective, in vivo-compatible chemical probe of the DCLK1 kinase domain, DCLK1-IN-1. We demonstrate activity of DCLK1-IN-1 against clinically relevant patient-derived PDAC organoid models and use a combination of RNA-sequencing, proteomics and phosphoproteomics analysis to reveal that DCLK1 inhibition modulates proteins and pathways associated with cell motility in this context. DCLK1-IN-1 will serve as a versatile tool …

Hypoxia-Inducible Factor (Hif)-2Α Reprograms Liver Macrophages To Protect Against Acute Liver Injury Via The Production Of Interleukin-6, Rachel Y Gao, Meng Wang, Qihui Liu, Dechun Feng, Yankai Wen, Yang Xia, Sean P Colgan, Holger K Eltzschig, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND AND AIMS: Acetaminophen (APAP) overdose represents the most frequent cause of acute liver failure, resulting in death or liver transplantation in more than one third of patients in the United States. The effectiveness of the only antidote, N-acetylcysteine, declines rapidly after APAP ingestion, long before patients are admitted to the clinic with symptoms of severe liver injury. The direct hepatotoxicity of APAP triggers a cascade of innate immune responses that may exacerbate or limit the progression of tissue damage. A better understanding of this complex mechanism will help uncover targets for therapeutic interventions.

APPROACH AND RESULTS: We observed that …

Myeloma Cells Shift Osteoblastogenesis To Adipogenesis By Inhibiting The Ubiquitin Ligase Murf1 In Mesenchymal Stem Cells, Zhiqiang Liu, Huan Liu, Jin He, Pei Lin, Qiang Tong, Jing Yang

Faculty, Staff and Students Publications

The suppression of bone formation is a hallmark of multiple myeloma. Myeloma cells inhibit osteoblastogenesis from mesenchymal stem cells (MSCs), which can also differentiate into adipocytes. We investigated myeloma-MSC interactions and the effects of such interactions on the differentiation of MSCs into adipocytes or osteoblasts using single-cell RNA sequencing, in vitro co-culture, and subcutaneous injection of MSCs and myeloma cells into mice. Our results revealed that the α4 subunit of integrin on myeloma cells stimulated vascular cell adhesion molecule 1 (VCAM1) on MSCs, leading to the activation of protein kinase C β1 (PKCβ1) signaling and repression of the muscle ring-finger …

Age-Dependent Involvement Of Gut Mast Cells And Histamine In Post-Stroke Inflammation, Maria Pilar Blasco, Anjali Chauhan, Pedram Honarpisheh, Hilda Ahnstedt, John D'Aigle, Arunkumar Ganesan, Sriram Ayyaswamy, Frank Blixt, Susan Venable, Angela Major, David Durgan, Anthony Haag, Julia Kofler, Robert Bryan, Louise D Mccullough, Bhanu Priya Ganesh

Faculty, Staff and Students Publications

BACKGROUND: Risk of stroke-related morbidity and mortality increases significantly with age. Aging is associated with chronic, low-grade inflammation, which is thought to contribute to the poorer outcomes after stroke seen in the elderly. Histamine (HA) is a major molecular mediator of inflammation, and mast cells residing in the gut are a primary source of histamine.

METHODS: Stroke was induced in male C57BL/6 J mice at 3 months (young) and 20 months (aged) of age. Role of histamine after stroke was examined using young (Yg) and aged (Ag) mice; mice underwent MCAO surgery and were euthanized at 6 h, 24 h, …