Medical Specialties Commons^™

Deficiency Of Stat1 In Cd11c+ Cells Alters Adipose Tissue Inflammation And Improves Metabolic Dysfunctions In Mice Fed A High-Fat Diet, Antu Antony, Zeqin Lian, Xiaoyuan Dai Perrard, Jerry Perrard, Hua Liu, Aaron R Cox, Pradip Saha, Lothar Hennighausen, Sean M Hartig, Christie M Ballantyne, Huaizhu Wu

Faculty, Staff and Students Publications

CD11c+ macrophages/dendritic cells (MDCs) are increased and display the classically activated M1-like phenotype in obese adipose tissue (AT) and may contribute to AT inflammation and insulin resistance. Stat1 is a key transcription factor for MDC polarization into the M1-like phenotype. Here, we examined the role of Stat1 in obesity-induced AT MDC polarization and inflammation and insulin resistance using mice with specific knockout of Stat1 in MDCs (cKO). Stat1 was upregulated and phosphorylated, indicating activation, early and persistently in AT and AT MDCs of wild-type mice fed a high-fat diet (HFD). Compared with littermate controls, cKO mice fed an HFD (16 …

In Vivo Transplantation Of Human Intestinal Organoids Enhances Select Tight Junction Gene Expression, Mariaelena A Boyle, David J Sequeira, Eoin P Mcneill, Zachary K Criss, Noah F Shroyer, Allison L Speer

Faculty, Staff and Student Publications

BACKGROUND: Short bowel syndrome is a potentially fatal condition with inadequate management options. Tissue-engineered small intestine (TESI) is a promising solution, but confirmation of TESI function will be crucial before human application. We sought to define intestinal epithelial barrier function in human intestinal organoid (HIO)-derived TESI.

MATERIALS AND METHODS: HIOs were generated in vitro from human embryonic stem cells. After 1 mo, HIOs were collected for analysis or transplanted into the kidney capsule of immunocompromised mice. Transplanted HIOs (tHIOs) were harvested for analysis at 4 or 8 wk. Reverse transcription quantitative polymerase chain reaction and immunofluorescent staining were performed for …

Mapk4 Promotes Prostate Cancer By Concerted Activation Of Androgen Receptor And Akt, Tao Shen, Wei Wang, Wolong Zhou, Ilsa Coleman, Qinbo Cai, Bingning Dong, Michael M Ittmann, Chad J Creighton, Yingnan Bian, Yanling Meng, David R Rowley, Peter S Nelson, David D Moore, Feng Yang

Faculty, Staff and Students Publications

Prostate cancer (PCa) is the second leading cause of cancer death in American men. Androgen receptor (AR) signaling is essential for PCa cell growth/survival and remains a key therapeutic target for lethal castration-resistant PCa (CRPC). GATA2 is a pioneer transcription factor crucial for inducing AR expression/activation. We recently reported that MAPK4, an atypical MAPK, promotes tumor progression via noncanonical activation of AKT. Here, we demonstrated that MAPK4 activated AR by enhancing GATA2 transcriptional expression and stabilizing GATA2 protein through repression of GATA2 ubiquitination/degradation. MAPK4 expression correlated with AR activation in human CRPC. Concerted activation of both GATA2/AR and AKT by …

The Rac-Gef Tiam1 Promotes Dendrite And Synapse Stabilization Of Dentate Granule Cells And Restricts Hippocampal-Dependent Memory Functions, Jinxuan Cheng, Federico Scala, Francisco A Blanco, Sanyong Niu, Karen Firozi, Laura Keehan, Shalaka Mulherkar, Emmanouil Froudarakis, Lingyong Li, Joseph G Duman, Xiaolong Jiang, Kimberley F Tolias

Faculty, Staff and Students Publications

The dentate gyrus (DG) controls information flow into the hippocampus and is critical for learning, memory, pattern separation, and spatial coding, while DG dysfunction is associated with neuropsychiatric disorders. Despite its importance, the molecular mechanisms regulating DG neural circuit assembly and function remain unclear. Here, we identify the Rac-GEF Tiam1 as an important regulator of DG development and associated memory processes. In the hippocampus, Tiam1 is predominantly expressed in the DG throughout life. Global deletion of Tiam1 in male mice results in DG granule cells with simplified dendritic arbors, reduced dendritic spine density, and diminished excitatory synaptic transmission. Notably, DG …

Vertical Sleeve Gastrectomy Confers Metabolic Improvements By Reducing Intestinal Bile Acids And Lipid Absorption In Mice, Lili Ding, Eryun Zhang, Qiaoling Yang, Lihua Jin, Kyle M Sousa, Bingning Dong, Yangmeng Wang, Jui Tu, Xiaoxiao Ma, Jingyan Tian, Hongli Zhang, Zhipeng Fang, Ana Guan, Yixin Zhang, Zhengtao Wang, David D Moore, Li Yang, Wendong Huang

Faculty, Staff and Students Publications

Vertical sleeve gastrectomy (VSG) is a highly effective bariatric surgery that sustainably treats obesity and type 2 diabetes (T2D). However, the underlying mechanisms governing its metabolic benefits remain unclear. In this study, we have used four different genetically modified mouse lines to understand the link between bile acid circulation and metabolic effects of VSG. Instead of directly activating the nuclear bile acid receptor farnesoid X receptor (Fxr) in the liver or intestine, VSG reduces intestinal levels of bile acids, thereby decreasing fat absorption in the intestine. Given the rising popularity of bariatric surgeries to treat obesity and associated T2D, the …

Hermansky-Pudlak Syndrome-2 Alters Mitochondrial Homeostasis In The Alveolar Epithelium Of The Lung, Karina Cuevas-Mora, Willy Roque, Hoora Shaghaghi, Bernadette R Gochuico, Ivan O Rosas, Ross Summer, Freddy Romero

Faculty, Staff and Students Publications

BACKGROUND: Mitochondrial dysfunction has emerged as an important player in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a common cause of idiopathic interstitial lung disease in adults. Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder that causes a similar type of pulmonary fibrosis in younger adults, although the role of mitochondrial dysfunction in this condition is not understood.

METHODS: We performed a detailed characterization of mitochondrial structure and function in lung tissues and alveolar epithelial cells deficient in the adaptor protein complex 3 beta 1 (Ap3b1) subunit, the gene responsible for causing subtype 2 of HPS (HPS-2).

RESULTS: We …

Eosinophils Attenuate Hepatic Ischemia-Reperfusion Injury In Mice Through St2-Dependent Il-13 Production, Yaochun Wang, Yang Yang, Meng Wang, Shuhong Wang, Jong-Min Jeong, Long Xu, Yankai Wen, Christoph Emontzpohl, Constance Lynn Atkins, Kevin Duong, Nicolas F Moreno, Xiaoyi Yuan, David R Hall, Wasim Dar, Dechun Feng, Bin Gao, Yong Xu, Zoltan Czigany, Sean P Colgan, J Steve Bynon, Shizuo Akira, Jared M Brown, Holger K Eltzschig, Elizabeth A Jacobsen, Cynthia Ju

Faculty, Staff and Students Publications

Eosinophils are a myeloid cell subpopulation that mediates type 2 T helper cell immune responses. Unexpectedly, we identified a rapid accumulation of eosinophils in 22 human liver grafts after hepatic transplantation. In contrast, no eosinophils were detectable in healthy liver tissues before transplantation. Studies with two genetic mouse models of eosinophil deficiency and a mouse model of antibody-mediated eosinophil depletion revealed exacerbated liver injury after hepatic ischemia and reperfusion. Adoptive transfer of bone marrow-derived eosinophils normalized liver injury of eosinophil-deficient mice and reduced hepatic ischemia and reperfusion injury in wild-type mice. Mechanistic studies combining genetic and adoptive transfer approaches identified …

Lkb1 And Ampk Instruct Cone Nuclear Position To Modify Visual Function, Courtney A Burger, Nicholas E Albrecht, Danye Jiang, Justine H Liang, Ross A Poché, Melanie A Samuel

Faculty, Staff and Students Publications

Cone photoreceptors detect light and are responsible for color vision. These cells display a distinct polarized morphology where nuclei are precisely aligned in the apical retina. However, little is known about the mechanisms involved in cone nuclear positioning or the impact of this organization on retina function. We show that the serine/threonine kinase LKB1 and one of its substrates, AMPK, regulate cone nuclear positioning. In the absence of either molecule, cone nuclei are misplaced along the axon, resulting in altered nuclear lamination. LKB1 is required specifically in cones to mediate this process, and disruptions in nuclear alignment result in reduced …

Conformation-Dependent Blockage Of Activated Vwf Improves Outcomes Of Traumatic Brain Injury In Mice, Xin Xu, Chenyu Wang, Yingang Wu, Katie Houck, Tristan Hilton, Ashley Zhou, Xiaoping Wu, Cha Han, Mengchen Yang, Wei Yang, Fu-Dong Shi, Moritz Stolla, Miguel A Cruz, Min Li, Jianning Zhang, Jing-Fei Dong

Faculty, Staff and Students Publications

Traumatic brain injury-induced coagulopathy (TBI-IC) causes life-threatening secondary intracranial bleeding. Its pathogenesis differs mechanistically from that of coagulopathy arising from extracranial injuries and hemorrhagic shock, but it remains poorly understood. We report results of a study designed to test the hypothesis that von Willebrand factor (VWF) released during acute TBI is intrinsically hyperadhesive because its platelet-binding A1-domain is exposed and contributes to TBI-induced vascular leakage and consumptive coagulopathy. This hyperadhesive VWF can be selectively blocked by a VWF A2-domain protein to prevent TBI-IC and to improve neurological function with a minimal risk of bleeding. We demonstrated that A2 given through …

Spliceosome-Targeted Therapies Trigger An Antiviral Immune Response In Triple-Negative Breast Cancer, Elizabeth A Bowling, Jarey H Wang, Fade Gong, William Wu, Nicholas J Neill, Ik Sun Kim, Siddhartha Tyagi, Mayra Orellana, Sarah J Kurley, Rocio Dominguez-Vidaña, Hsiang-Ching Chung, Tiffany Y-T Hsu, Julien Dubrulle, Alexander B Saltzman, Heyuan Li, Jitendra K Meena, Gino M Canlas, Srinivas Chamakuri, Swarnima Singh, Lukas M Simon, Calla M Olson, Lacey E Dobrolecki, Michael T Lewis, Bing Zhang, Ido Golding, Jeffrey M Rosen, Damian W Young, Anna Malovannaya, Fabio Stossi, George Miles, Matthew J Ellis, Lihua Yu, Silvia Buonamici, Charles Y Lin, Kristen L Karlin, Xiang H-F Zhang, Thomas F Westbrook

Faculty, Staff and Students Publications

Many oncogenic insults deregulate RNA splicing, often leading to hypersensitivity of tumors to spliceosome-targeted therapies (STTs). However, the mechanisms by which STTs selectively kill cancers remain largely unknown. Herein, we discover that mis-spliced RNA itself is a molecular trigger for tumor killing through viral mimicry. In MYC-driven triple-negative breast cancer, STTs cause widespread cytoplasmic accumulation of mis-spliced mRNAs, many of which form double-stranded structures. Double-stranded RNA (dsRNA)-binding proteins recognize these endogenous dsRNAs, triggering antiviral signaling and extrinsic apoptosis. In immune-competent models of breast cancer, STTs cause tumor cell-intrinsic antiviral signaling, downstream adaptive immune signaling, and tumor cell death. Furthermore, RNA …

Agrp Neurons Trigger Long-Term Potentiation And Facilitate Food Seeking, Chunmei Wang, Wenjun Zhou, Yang He, Tiffany Yang, Pingwen Xu, Yongjie Yang, Xing Cai, Julia Wang, Hesong Liu, Meng Yu, Chen Liang, Tingting Yang, Hailan Liu, Makoto Fukuda, Qingchun Tong, Qi Wu, Zheng Sun, Yanlin He, Yong Xu

Children’s Nutrition Research Center Staff Publications

Sufficient feeding is essential for animals' survival, which requires a cognitive capability to facilitate food seeking, but the neurobiological processes regulating food seeking are not fully understood. Here we show that stimulation of agouti-related peptide-expressing (AgRP) neurons triggers a long-term depression (LTD) of spontaneous excitatory post-synaptic current (sEPSC) in adjacent pro-opiomelanocortin (POMC) neurons and in most of their distant synaptic targets, including neurons in the paraventricular nucleus of the thalamus (PVT). The AgRP-induced sEPCS LTD can be enhanced by fasting but blunted by satiety signals, e.g. leptin and insulin. Mice subjected to food-seeking tasks develop similar neural plasticity in AgRP-innervated …

The Effect Of Age On Neurological Inflammation To Acute Sleep Fragmentation In Mice, Molly Taylor

Mahurin Honors College Capstone Experience/Thesis Projects

Obstructive sleep apnea is identified by recurring events of airway collapse during sleep, intermittent hypoxia, and perturbations in sleep continuity, known as sleep fragmentation. There is evidence to suggest that elderly patients are more at risk of developing obstructive sleep apnea. The purpose of this study was to assess whether age affects neurological inflammatory responses to acute sleep fragmentation. This assessment was made by subjecting young (4-5 months old) and old (10-11 months old) male C57BL/6j mice to automated sleep fragmentation, as well as having mice in both age categories as a control with no sleep fragmentation, for twenty-four hours. …

Inhibiting Fatty Acid Binding Protein Family Members Decreases Multiple Myeloma Cell Proliferation Through Effecting The Myc Pathway, Mariah Farrell, Heather Fairfield, Anastasia D'Amico, Carolyne Falank, Connor Murphy, Michaela Reagan

Costas T. Lambrew Research Retreat 2021

FABP inhibition leads to increased survival of myeloma bearing mice and decreased cell growth by inhibiting MYC signaling.

Dietary Phytoestrogens Ameliorate Hydrochloric Acid-Induced Chronic Lung Injury And Pulmonary Fibrosis In Mice, Pavel Solopov, Ruben Manuel Luciano Colunga Biancatelli, Christiana Dimitropoulou, John D. Catravas

Bioelectrics Publications

We previously reported that female mice exhibit protection against chemically induced pulmonary fibrosis and suggested a potential role of estrogen. Phytoestrogens act, at least in part, via stimulation of estrogen receptors; furthermore, compared to residents of Western countries, residents of East Asian countries consume higher amounts of phytoestrogens and exhibit lower rates of pulmonary fibrosis. Therefore, we tested the hypothesis that dietary phytoestrogens ameliorate the severity of experimentally induced pulmonary fibrosis. Male mice placed on either regular soybean diet or phytoestrogen-free diet were instilled with 0.1 N HCl to provoke pulmonary fibrosis. Thirty days later, lung mechanics were measured as …

Ifn-Β Acts On Monocytes To Ameliorate Cns Autoimmunity By Inhibiting Proinflammatory Cross-Talk Between Monocytes And Th Cells., Javad Rasouli, Giacomo Casella, Larissa Ishikawa, Rodolfo Thome, Alexandra Boehm, Adam Ertel, Carolina R Melo-Silva, Elisabeth R. Mari, Patrizia Porazzi, Weifeng Zhang, Dan Xiao, Luis J. Sigal, Paolo Fortina, Guang-Xian Zhang, A M Rostami, Bogoljub Ciric

Department of Neurology Faculty Papers

IFN-β has been the treatment for multiple sclerosis (MS) for almost three decades, but understanding the mechanisms underlying its beneficial effects remains incomplete. We have shown that MS patients have increased numbers of GM-CSF+ Th cells in circulation, and that IFN-β therapy reduces their numbers. GM-CSF expression by myelin-specific Th cells is essential for the development of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. These findings suggested that IFN-β therapy may function via suppression of GM-CSF production by Th cells. In the current study, we elucidated a feedback loop between monocytes and Th cells that amplifies autoimmune neuroinflammation, …

Crucial Role Of Mammalian Glutaredoxin 3 In Cardiac Energy Metabolism In Diet-Induced Obese Mice Revealed By Transcriptome Analysis, Ninghui Cheng, Qianxing Mo, Jimmonique Donelson, Lingfei Wang, Ghislain Breton, George G Rodney, Jin Wang, Kendal D Hirschi, Xander H T Wehrens, Paul A Nakata

Children’s Nutrition Research Center Staff Publications

Obesity is often associated with metabolic dysregulation and oxidative stress with the latter serving as a possible unifying link between obesity and cardiovascular complications. Glutaredoxins (Grxs) comprise one of the major antioxidant systems in the heart. Although Grx3 has been shown to act as an endogenous negative regulator of cardiac hypertrophy and heart failure, its metabolic impact on cardiac function in diet-induced obese (DIO) mice remains largely unknown. In the present study, analysis of Grx3 expression indicated that Grx3 protein levels, but not mRNA levels, were significantly increased in the hearts of DIO mice. Cardiac-specific Grx3 deletion (Grx3 CKO) mice …

Tph2 In The Dorsal Raphe Nuclei Regulates Energy Balance In A Sex-Dependent Manner, Hailan Liu, Chunmei Wang, Meng Yu, Yongjie Yang, Yang He, Hesong Liu, Chen Liang, Longlong Tu, Nan Zhang, Lina Wang, Julia Wang, Feng Liu, Fang Hu, Yong Xu

Children’s Nutrition Research Center Staff Publications

AbstractCentral 5-hydroxytryptamine (5-HT), which is primarily synthesized by tryptophan hydroxylase 2 (TPH2) in the dorsal Raphe nuclei (DRN), plays a pivotal role in the regulation of food intake and body weight. However, the physiological functions of TPH2 on energy balance have not been consistently demonstrated. Here we systematically investigated the effects of TPH2 on energy homeostasis in adult male and female mice. We found that the DRN harbors a similar amount of TPH2+ cells in control male and female mice. Adult-onset TPH2 deletion in the DRN promotes hyperphagia and body weight gain only in male mice, but not in female …

Small-Molecule Inhibitor Of Af9/Enl-Dot1l/Af4/Aff4 Interactions Suppresses Malignant Gene Expression And Tumor Grow, Fangrui Wu, Shenyou Nie, Yuan Yao, Tong Huo, Xin Li, Xiaowei Wu, Jidong Zhao, Yi-Lun Lin, Yinjie Zhang, Qianxing Mo, Yongcheng Song

Faculty, Staff and Students Publications

Chromosome translocations involving mixed lineage leukemia (MLL) gene cause acute leukemia with a poor prognosis. MLL is frequently fused with transcription cofactors AF4 (~35%), AF9 (25%) or its paralog ENL (10%). The AHD domain of AF9/ENL binds to AF4, its paralog AFF4, or histone-H3 lysine-79 (H3K79) methyltransferase DOT1L. Formation of AF9/ENL/AF4/AFF4-containing super elongation complexes (SEC) and the catalytic activity of DOT1L are essential for MLL-rearranged leukemia. Protein-protein interactions (PPI) between AF9/ENL and DOT1L/AF4/AFF4 are therefore a potential drug target.

Methods: Compound screening followed by medicinal chemistry was used to find inhibitors of such PPIs, which were examined for their biological …

The Bile Acid Induced Hepatokine Orosomucoid Suppresses Adipocyte Differentiation, Sung Ho Lee, Jong Min Choi, Sung Yun Jung, Aaron R Cox, Sean M Hartig, David D Moore, Kang Ho Kim

Faculty, Staff and Students Publications

Bile acids have recently emerged as key metabolic hormones with beneficial impacts in multiple metabolic diseases. We previously discovered that hepatic bile acid overload distally modulates glucose and fatty acid metabolism in adipose tissues to exert anti-obesity effects. However, the detailed mechanisms that explain the salutary effects of serum bile acid elevation remain unclear. Here, proteomic profiling identified a new hepatokine, Orosomucoid (ORM) that governs liver-adipose tissue crosstalk. Hepatic ORMs were highly induced by both genetic and dietary bile acid overload. To address the direct metabolic effects of ORM, purified ORM proteins were administered during adipogenic differentiation of 3T3-L1 cells …

Intrapulmonary Administration Of Purified Neil2 Abrogates Nf-Κb-Mediated Inflammation, Nisha Tapryal, Shandy Shahabi, Anirban Chakraborty, Koa Hosoki, Maki Wakamiya, Gobinda Sarkar, Gulshan Sharma, Victor J Cardenas, Istvan Boldogh, Sanjiv Sur, Gourisankar Ghosh, Tapas K Hazra

Faculty, Staff and Students Publications

Aberrant or constitutive activation of nuclear factor kappa B (NF-κB) contributes to various human inflammatory diseases and malignancies via the upregulation of genes involved in cell proliferation, survival, angiogenesis, inflammation, and metastasis. Thus, inhibition of NF-κB signaling has potential for therapeutic applications in cancer and inflammatory diseases. We reported previously that Nei-like DNA glycosylase 2 (NEIL2), a mammalian DNA glycosylase, is involved in the preferential repair of oxidized DNA bases from the transcriptionally active sequences via the transcription-coupled base excision repair pathway. We have further shown that Neil2-null mice are highly sensitive to tumor necrosis factor α (TNFα)- and lipopolysaccharide-induced …

Lrrtm4 Is A Member Of The Transsynaptic Complex Between Rod Photoreceptors And Bipolar Cells, Melina A Agosto, Theodore G Wensel

Faculty, Staff and Students Publications

Leucine rich repeat transmembrane (LRRTM) proteins are synaptic adhesion molecules with roles in synapse formation and signaling. LRRTM4 transcripts were previously shown to be enriched in rod bipolar cells (BCs), secondary neurons of the retina that form synapses with rod photoreceptors. Using two different antibodies, LRRTM4 was found to reside primarily at rod BC dendritic tips, where it colocalized with the transduction channel protein, TRPM1. LRRTM4 was not detected at dendritic tips of ON-cone BCs. Following somatic knockout of LRRTM4 in BCs by subretinal injection and electroporation of CRISPR/Cas9, LRRTM4 was abolished or reduced in the dendritic tips of transfected …

Mir-9-1 Suppresses Cell Proliferation And Promotes Apoptosis By Targeting Uhrf1 In Lung Cancer, Cheng-You Jia, Wei Xiang, Ji-Bin Liu, Geng-Xi Jiang, Feng Sun, Jian-Jun Wu, Xiao-Li Yang, Rui Xin, Yi Shi, Dan-Dan Zhang, Wen Li, Zavuga Zuberi, Jie Zhang, Gai-Xia Lu, Hui-Min Wang, Pei-Yao Wang, Fei Yu, Zhong-Wei Lv, Yu-Shui Ma, Da Fu

Faculty, Staff and Student Publications

Lung cancer is listed as the most common reason for cancer-related death all over the world despite diagnostic improvements and the development of chemotherapy and targeted therapies. MicroRNAs control both physiological and pathological processes including development and cancer. A microRNA-9 to 1 (miR-9 to 1) overexpression model in lung cancer cell lines was established and miR-9 to 1 was found to significantly suppress the proliferation rate in lung cancer cell lines, colony formation in vitro, and tumorigenicity in nude mice of A549 cells. Ubiquitin-like containing PHD and RING finger domains 1 (UHRF1) was then identified to direct target of miR-9 …

A Steroid Receptor Coactivator Stimulator (Mcb-613) Attenuates Adverse Remodeling After Myocardial Infarction, Lisa K Mullany, Aarti D Rohira, John P Leach, Jong H Kim, Tanner O Monroe, Andrea R Ortiz, Brittany Stork, M Waleed Gaber, Poonam Sarkar, Andrew G Sikora, Todd K Rosengart, Brian York, Yongcheng Song, Clifford C Dacso, David M Lonard, James F Martin, Bert W O'Malley

Faculty, Staff and Students Publications

Progressive remodeling of the heart, resulting in cardiomyocyte (CM) loss and increased inflammation, fibrosis, and a progressive decrease in cardiac function, are hallmarks of myocardial infarction (MI)-induced heart failure. We show that MCB-613, a potent small molecule stimulator of steroid receptor coactivators (SRCs) attenuates pathological remodeling post-MI. MCB-613 decreases infarct size, apoptosis, hypertrophy, and fibrosis while maintaining significant cardiac function. MCB-613, when given within hours post MI, induces lasting protection from adverse remodeling concomitant with: 1) inhibition of macrophage inflammatory signaling and interleukin 1 (IL-1) signaling, which attenuates the acute inflammatory response, 2) attenuation of fibroblast differentiation, and 3) promotion …

Mouse Models To Study The Pathophysiology Of Combined Methylmalonic Acidemia And Homocystinuria, Cblc Type, Tiffany Chern, Annita Achilleos, Xuefei Tong, Chih-Wei Hsu, Leeyean Wong, Ross A Poché

Faculty, Staff and Students Publications

Combined methylmalonic acidemia and homocystinuria, cblC type, is the most common inherited disorder of cobalamin metabolism and is characterized by severe fetal developmental defects primarily impacting the central nervous system, hematopoietic system, and heart. CblC was previously shown to be due to mutations in the MMACHC gene, which encodes a protein thought to function in intracellular cobalamin trafficking and biosynthesis of adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl). These coenzymes are required for the production of succinyl-CoA and methionine, respectively. However, it is currently unclear whether additional roles for MMACHC exist outside of cobalamin metabolism. Furthermore, due to a lack of sufficient …

Depletion Of Essential Isoprenoids And Er Stress Induction Following Acute Liver-Specific Deletion Of Hmg-Coa Reductase, Marco De Giorgi, Kelsey E Jarrett, Jason C Burton, Alexandria M Doerfler, Ayrea Hurley, Ang Li, Rachel H Hsu, Mia Furgurson, Kalyani R Patel, Jun Han, Christoph H Borchers, William R Lagor

Faculty, Staff and Students Publications

HMG-CoA reductase (Hmgcr) is the rate-limiting enzyme in the mevalonate pathway and is inhibited by statins. In addition to cholesterol, Hmgcr activity is also required for synthesizing nonsterol isoprenoids, such as dolichol, ubiquinone, and farnesylated and geranylgeranylated proteins. Here, we investigated the effects of Hmgcr inhibition on nonsterol isoprenoids in the liver. We have generated new genetic models to acutely delete genes in the mevalonate pathway in the liver using AAV-mediated delivery of Cre-recombinase (AAV-Cre) or CRISPR/Cas9 (AAV-CRISPR). The genetic deletion of Hmgcr by AAV-Cre resulted in extensive hepatocyte apoptosis and compensatory liver regeneration. At the biochemical …

Stat1 Dissociates Adipose Tissue Inflammation From Insulin Sensitivity In Obesity, Aaron R Cox, Natasha Chernis, David A Bader, Pradip K Saha, Peter M Masschelin, Jessica B Felix, Robert Sharp, Zeqin Lian, Vasanta Putluri, Kimal Rajapakshe, Kang Ho Kim, Dennis T Villareal, Reina Armamento-Villareal, Huaizhu Wu, Cristian Coarfa, Nagireddy Putluri, Sean M Hartig

Faculty, Staff and Students Publications

Obesity fosters low-grade inflammation in white adipose tissue (WAT) that may contribute to the insulin resistance that characterizes type 2 diabetes. However, the causal relationship of these events remains unclear. The established dominance of STAT1 function in the immune response suggests an obligate link between inflammation and the comorbidities of obesity. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. STAT1 expression in WAT inversely correlated with fasting plasma glucose in both obese mice and humans. Metabolomic and gene expression profiling established STAT1 deletion in adipocytes (STAT1a-KO) enhanced mitochondrial function …

Differences In Gynecologic Tumor Development In Amhr2-Cre Mice With Krasg12d Or Krasg12v Mutations, Eucharist H S Kun, Yvonne T M Tsang, Sophia Lin, Sophia Pan, Tejas Medapalli, Anais Malpica, Joanne S Richards, David M Gershenson, Kwong-Kwok Wong

Faculty, Staff and Students Publications

How different KRAS variants impact tumor initiation and progression in vivo has not been thoroughly examined. We hypothesize that the ability of either KRASG12D or KRASG12V mutations to initiate tumor formation is context dependent. Amhr2-Cre mice express Cre recombinase in tissues that develop into the fallopian tubes, uterus, and ovaries. We used these mice to conditionally express either the KRASG12V/+ or KRASG12D/+ mutation. Mice with the genotype Amhr2-Cre Pten(fl/fl) KrasG12D/+(G12D mice) had abnormal follicle structures and developed low-grade serous ovarian carcinomas with 100% penetrance within 18 weeks. In contrast, mice with …

Role For Carbohydrate Response Element-Binding Protein (Chrebp) In High Glucose-Mediated Repression Of Long Noncoding Rna Tug1, Jianyin Long, Daniel L Galvan, Koki Mise, Yashpal S Kanwar, Li Li, Naravat Poungavrin, Paul A Overbeek, Benny H Chang, Farhad R Danesh

Faculty, Staff and Students Publications

Long noncoding RNAs (lncRNAs) have been shown to play key roles in a variety of biological activities of the cell. However, less is known about how lncRNAs respond to environmental cues and what transcriptional mechanisms regulate their expression. Studies from our laboratory have shown that the lncRNA Tug1 (taurine upregulated gene 1) is crucial for the progression of diabetic kidney disease, a major microvascular complication of diabetes. Using a combination of proximity labeling with the engineered soybean ascorbate peroxidase (APEX2), ChIP-qPCR, biotin-labeled oligonucleotide pulldown, and classical promoter luciferase assays in kidney podocytes, we extend our initial observations in the current …

Social And Leisure Activities Predict Transitions In Cognitive Functioning In Older Mexican Adults: A Latent Transition Analysis Of The Mexican Health And Aging Study, Heather Mary Brown, Stephen A Murray, Hope Northrup, Kit Sing Au, Lee A Niswander

Faculty, Staff and Student Publications

Disruptions in neural tube (NT) closure result in neural tube defects (NTDs). To understand the molecular processes required for mammalian NT closure, we investigated the role of Snx3, a sorting nexin gene. Snx3−/− mutant mouse embryos display a fully-penetrant cranial NTD. In vivo, we observed decreased canonical WNT target gene expression in the cranial neural epithelium of the Snx3−/− embryos and a defect in convergent extension of the neural epithelium. Snx3−/− cells show decreased WNT secretion, and live cell imaging reveals aberrant recycling of the WNT ligand-binding protein WLS and mis-trafficking to the lysosome for degradation. The importance …

Myosight-Semi-Automated Image Analysis Of Skeletal Muscle Cross Sections, Lyle W Babcock, Amy D Hanna, Nadia H Agha, Susan L Hamilton

Faculty, Staff and Students Publications

BACKGROUND: Manual analysis of cross-sectional area, fiber-type distribution, and total and centralized nuclei in skeletal muscle cross sections is tedious and time consuming, necessitating an accurate, automated method of analysis. While several excellent programs are available, our analyses of skeletal muscle disease models suggest the need for additional features and flexibility to adequately describe disease pathology. We introduce a new semi-automated analysis program, MyoSight, which is designed to facilitate image analysis of skeletal muscle cross sections and provide additional flexibility in the analyses.

RESULTS: We describe staining and imaging methods that generate high-quality images of immunofluorescent-labelled cross sections from mouse …