Digital Commons Network^™

Adipose Tissue-Specific Ablation Of Ces1d Causes Metabolic Dysregulation In Mice, Gang Li, Xin Li, Li Yang, Shuyue Wang, Yulin Dai, Baharan Fekry, Lucas Veillon, Lin Tan, Rebecca Berdeaux, Kristin Eckel-Mahan, Philip L Lorenzi, Zhongming Zhao, Richard Lehner, Kai Sun

Faculty, Staff and Student Publications

Carboxylesterase 1d (Ces1d) is a crucial enzyme with a wide range of activities in multiple tissues. It has been reported to localize predominantly in ER. Here, we found that Ces1d levels are significantly increased in obese patients with type 2 diabetes. Intriguingly, a high level of Ces1d translocates onto lipid droplets where it digests the lipids to produce a unique set of fatty acids. We further revealed that adipose tissue-specific Ces1d knock-out (FKO) mice gained more body weight with increased fat mass during a high fat-diet challenge. The FKO mice exhibited impaired glucose and lipid metabolism and developed exacerbated liver …

Preventing Cholesterol-Induced Perk (Protein Kinase Rna-Like Endoplasmic Reticulum Kinase) Signaling In Smooth Muscle Cells Blocks Atherosclerotic Plaque Formation, Abhijnan Chattopadhyay, Pujun Guan, Suravi Majumder, Kaveeta Kaw, Zhen Zhou, Chen Zhang, Siddharth K Prakash, Anita Kaw, L Maximillian Buja, Callie S Kwartler, Dianna M Milewicz

Faculty, Staff and Student Publications

BACKGROUND: Vascular smooth muscle cells (SMCs) undergo complex phenotypic modulation with atherosclerotic plaque formation in hyperlipidemic mice, which is characterized by de-differentiation and heterogeneous increases in the expression of macrophage, fibroblast, osteogenic, and stem cell markers. An increase of cellular cholesterol in SMCs triggers similar phenotypic changes in vitro with exposure to free cholesterol due to cholesterol entering the endoplasmic reticulum, triggering endoplasmic reticulum stress and activating Perk (protein kinase RNA-like endoplasmic reticulum kinase) signaling.

METHODS: We generated an SMC-specific

RESULTS: SMC-specific deletion of Perk reduces atherosclerotic plaque formation in male hyperlipidemic mice by 80%. Single-cell transcriptomic data identify 2 …

Novel Mitochondria-Targeting Compounds Selectively Kill Human Leukemia Cells, Svetlana B Panina, Jingqi Pei, Natalia Baran, Elissa Tjahjono, Shraddha Patel, Gheath Alatrash, Sergej Konoplev, Leonid A Stolbov, Vladimir V Poroikov, Marina Konopleva, Natalia V Kirienko

Faculty, Staff and Student Publications

Acute myeloid leukemia (AML) is a heterogeneous group of aggressive hematological malignancies commonly associated with treatment resistance, high risk of relapse, and mitochondrial dysregulation. We identified six mitochondria-affecting compounds (PS compounds) that exhibit selective cytotoxicity against AML cells in vitro. Structure-activity relationship studies identified six analogs from two original scaffolds that had over an order of magnitude difference between LD50 in AML and healthy peripheral blood mononuclear cells. Mechanistically, all hit compounds reduced ATP and selectively impaired both basal and ATP-linked oxygen consumption in leukemic cells. Compounds derived from PS127 significantly upregulated production of reactive oxygen species (ROS) in AML …

Advances In Head And Neck Cancer Pain, Y Ye, D D Jensen, C T Viet, H L Pan, W M Campana, M Amit, M D Boada

Faculty, Staff and Student Publications

Head and neck cancer (HNC) affects over 890,000 people annually worldwide and has a mortality rate of 50%. Aside from poor survival, HNC pain impairs eating, drinking, and talking in patients, severely reducing quality of life. Different pain phenotype in patients (allodynia, hyperalgesia, and spontaneous pain) results from a combination of anatomical, histopathological, and molecular differences between cancers. Poor pathologic features (e.g., perineural invasion, lymph node metastasis) are associated with increased pain. The use of syngeneic/immunocompetent animal models, as well as a new mouse model of perineural invasion, provides novel insights into the pathobiology of HNC pain. Glial and immune …

Preventing Cholesterol-Induced Perk (Protein Kinase Rna-Like Endoplasmic Reticulum Kinase) Signaling In Smooth Muscle Cells Blocks Atherosclerotic Plaque Formation, Abhijnan Chattopadhyay, Pujun Guan, Suravi Majumder, Kaveeta Kaw, Zhen Zhou, Chen Zhang, Siddharth K Prakash, Anita Kaw, L Maximillian Buja, Callie S Kwartler, Dianna M Milewicz

Faculty, Staff and Student Publications

BACKGROUND: Vascular smooth muscle cells (SMCs) undergo complex phenotypic modulation with atherosclerotic plaque formation in hyperlipidemic mice, which is characterized by de-differentiation and heterogeneous increases in the expression of macrophage, fibroblast, osteogenic, and stem cell markers. An increase of cellular cholesterol in SMCs triggers similar phenotypic changes in vitro with exposure to free cholesterol due to cholesterol entering the endoplasmic reticulum, triggering endoplasmic reticulum stress and activating Perk (protein kinase RNA-like endoplasmic reticulum kinase) signaling.

METHODS: We generated an SMC-specific

RESULTS: SMC-specific deletion of Perk reduces atherosclerotic plaque formation in male hyperlipidemic mice by 80%. Single-cell transcriptomic data identify 2 …

Hepatic Recruitment Of Eosinophils And Their Protective Function During Acute Liver Injury, Long Xu, Yang Yang, Yankai Wen, Jong-Min Jeong, Christoph Emontzpohl, Constance L Atkins, Zhaoli Sun, Kyle L Poulsen, David R Hall, J Steve Bynon, Bin Gao, William M Lee, Jody Rule, Elizabeth A Jacobsen, Hua Wang, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND & AIMS: Beyond the classical description of eosinophil functions in parasite infections and allergic diseases, emerging evidence supports a critical role of eosinophils in resolving inflammation and promoting tissue remodeling. However, the role of eosinophils in liver injury and the underlying mechanism of their recruitment into the liver remain unclear.

METHODS: Hepatic eosinophils were detected and quantified using flow cytometry and immunohistochemical staining. Eosinophil-deficient (ΔdblGata1) mice were used to investigate the role of eosinophils in 3 models of acute liver injury. In vivo experiments using Il33

RESULTS: Hepatic accumulation of eosinophils was observed in patients with acetaminophen (APAP)-induced liver …

Mir-103-3p Promotes Hepatic Steatosis To Aggravate Nonalcoholic Fatty Liver Disease By Targeting Of Acox1, Jiexia Ding, Caixia Xia, Panpan Cen, Siying Li, Lifei Yu, Jing Zhu, Jie Jin

Faculty, Staff and Student Publications

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a major risk factor for hepatocellular carcinoma, and alterations in miRNA expression are related to the development of NAFLD. However, the role of miRNAs in regulating the development of NAFLD is still poorly understood.

METHODS: We used qRT-PCR to detect the level of miR-103-3p in both cell and mouse models of NAFLD. Biochemical assays, DCF-DA assays, Oil red O staining and HE staining were used to detect the role of miR-103-3p in NAFLD development. Target genes of miR-103-3p were predicted using the TargetScan database and verified by qRT-PCR, western blot and dual-luciferase assays. …

The Role Of Temperature Variation On Macrophage Physiology And Function In Vitro In Mice, Chicken, And Fish, Intisar Abdullah Hassan

Graduate Theses and Dissertations

Fever is an essential component of the immune response. Baseline body temperatures vary in different species, and fever represents increased temperature over baseline. Fever initiates and enhances immune responses as well as creates an environment in which the body has advantages over pathogens. Macrophages are often the first line of cells that come in contact with pathogens, asthey reside in and traffic through tissues. They are important for their engulfment of pathogens that results in the digestion of the pathogen, and they also produce nitric oxide and cytokines that contribute to immune responses in a variety of ways, including initiating …

Spatial Charting Of Single-Cell Transcriptomes In Tissues, Runmin Wei, Siyuan He, Shanshan Bai, Emi Sei, Min Hu, Alastair Thompson, Ken Chen, Savitri Krishnamurthy, Nicholas E Navin

Faculty, Staff and Student Publications

Single-cell RNA sequencing methods can profile the transcriptomes of single cells but cannot preserve spatial information. Conversely, spatial transcriptomics assays can profile spatial regions in tissue sections, but do not have single-cell resolution. Here, we developed a computational method called CellTrek that combines these two datasets to achieve single-cell spatial mapping through coembedding and metric learning approaches. We benchmarked CellTrek using simulation and in situ hybridization datasets, which demonstrated its accuracy and robustness. We then applied CellTrek to existing mouse brain and kidney datasets and showed that CellTrek can detect topological patterns of different cell types and cell states. We …

Plasma Metabolomics Analysis Of Aspirin Treatment And Risk Of Colorectal Adenomas, Elizabeth L Barry, Veronika Fedirko, Yutong Jin, Ken Liu, Leila A Mott, Janet L Peacock, Michael N Passarelli, John A Baron, Dean P Jones

Faculty, Staff and Student Publications

Despite substantial observational and experimental evidence that aspirin use can provide protection against the development of colorectal neoplasia, our understanding of the molecular mechanisms involved is inadequate and limits our ability to use this drug effectively and safely for chemoprevention. We employed an untargeted plasma metabolomics approach using liquid chromatography with high-resolution mass spectroscopy to explore novel metabolites that may contribute to the chemopreventive effects of aspirin. Associations between levels of metabolic features in plasma and aspirin treatment were investigated among 523 participants in a randomized placebo-controlled clinical trial of two doses of aspirin (81 or 325 mg/day) and were …

Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 Regulates Hepatic Fuel Metabolism, Brittany A Stork, Adam Dean, Andrea R Ortiz, Pradip Saha, Nagireddy Putluri, Maricarmen D Planas-Silva, Iqbal Mahmud, Kimal Rajapakshe, Cristian Coarfa, Stefan Knapp, Philip L Lorenzi, Bruce E Kemp, Benjamin E Turk, John W Scott, Anthony R Means, Brian York

Faculty, Staff and Students Publications

OBJECTIVE: The liver is the primary internal metabolic organ that coordinates whole body energy homeostasis in response to feeding and fasting. Genetic ablation or pharmacological inhibition of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) has been shown to significantly improve hepatic health and peripheral insulin sensitivity upon overnutrition with high fat diet. However, the precise molecular underpinnings that explain this metabolic protection have remained largely undefined.

METHODS: To characterize the role of CaMKK2 in hepatic metabolism, we developed and challenged liver-specific CaMKK2 knockout (CaMKK2

RESULTS: Consistent with previous findings, we show that hepatic CaMKK2 ablation significantly improves indices of peripheral insulin …

Sex-Specific Phenotypes In The Aging Mouse Heart And Consequences For Chronic Fibrosis, Aude Angelini, Jesus Ortiz-Urbina, Joann Trial, Anilkumar K Reddy, Anna Malovannaya, Antrix Jain, Mark L Entman, George E Taffet, Katarzyna A Cieslik

Faculty, Staff and Students Publications

The incidence of diastolic dysfunction increases with age in both humans and mice. This is characterized by increased passive stiffness and slower relaxation of the left ventricle. The stiffness arises at least partially from progressively increased interstitial collagen deposition because of highly secretory fibroblasts. In the past, we demonstrated that AMPK activation via the drug 5-aminoimidazole-4-carboxamide riboside (AICAR) in middle-aged mice reduced adverse remodeling after myocardial infarction. Therefore, as an attempt to normalize the fibroblast phenotype, we used 21-mo-old male and female mice and treated them with AICAR (0.166 mg/g body wt) where each mouse was followed in a functional …

Il-34 Deficiency Impairs Foxp3+ Treg Function In A Model Of Autoimmune Colitis And Decreases Immune Tolerance Homeostasis, Antoine Freuchet, Marco Colonna, Et Al

2020-Current year OA Pubs

BACKGROUND: Immune homeostasis requires fully functional Tregs with a stable phenotype to control autoimmunity. Although IL-34 is a cytokine first described as mainly involved in monocyte cell survival and differentiation, we recently described its expression by CD8

METHODS: We generated Il34

RESULTS: Here we report that the absence of expression of IL-34 in Il34

CONCLUSION: Altogether, our data emphasize on the crucial necessity of IL-34 for immune homeostasis and for CD4

HIGHLIGHTS: -Absence of expression of IL-34 in Il34

Impaired Mitophagy In Sanfilippo A Mice Causes Hypertriglyceridemia And Brown Adipose Tissue Activation, Miguel Tillo, Patricia I Dickson, Et Al.

2020-Current year OA Pubs

Lysosomal storage diseases result in various developmental and physiological complications, including cachexia. To study the causes for the negative energy balance associated with cachexia, we assessed the impact of sulfamidase deficiency and heparan sulfate storage on energy homeostasis and metabolism in a mouse model of type IIIa mucopolysaccharidosis (MPS IIIa, Sanfilippo A syndrome). At 12-weeks of age, MPS IIIa mice exhibited fasting and postprandial hypertriglyceridemia compared with wildtype mice, with a reduction of white and brown adipose tissues. Partitioning of dietary [

The Lupus Susceptibility Allele Drb1*03:01 Encodes A Disease-Driving Epitope, Bruna Miglioranza Scavuzzi, Vincent Van Drongelen, Bhavneet Kaur, Jennifer Callahan Fox, Jianhua Liu, Raquel A Mesquita-Ferrari, J Michelle Kahlenberg, Evan A Farkash, Fernando Benavides, Frederick W Miller, Amr H Sawalha, Joseph Holoshitz

Faculty, Staff and Student Publications

The HLA-DRB1*03:01 allele is a major genetic risk factor in systemic lupus erythematosus (SLE), but the mechanistic basis of the association is unclear. Here we show that in the presence of interferon gamma (IFN-γ), a short DRB1*03:01-encoded allelic epitope activates a characteristic lupus transcriptome in mouse and human macrophages. It also triggers a cascade of SLE-associated cellular aberrations, including endoplasmic reticulum stress, unfolded protein response, mitochondrial dysfunction, necroptotic cell death, and production of pro-inflammatory cytokines. Parenteral administration of IFN-γ to naïve DRB1*03:01 transgenic mice causes increased serum levels of anti-double stranded DNA antibodies, glomerular immune complex deposition and histopathological renal …

Targeting De Novo Lipogenesis And The Lands Cycle Induces Ferroptosis In Kras-Mutant Lung Cancer, Caterina Bartolacci, Cristina Andreani, Gonçalo Vale, Stefano Berto, Margherita Melegari, Anna Colleen Crouch, Dodge L Baluya, George Kemble, Kurt Hodges, Jacqueline Starrett, Katerina Politi, Sandra L Starnes, Daniele Lorenzini, Maria Gabriela Raso, Luisa M Solis Soto, Carmen Behrens, Humam Kadara, Boning Gao, Ignacio I Wistuba, John D Minna, Jeffrey G Mcdonald, Pier Paolo Scaglioni

Faculty, Staff and Student Publications

Mutant KRAS (KM), the most common oncogene in lung cancer (LC), regulates fatty acid (FA) metabolism. However, the role of FA in LC tumorigenesis is still not sufficiently characterized. Here, we show that KMLC has a specific lipid profile, with high triacylglycerides and phosphatidylcholines (PC). We demonstrate that FASN, the rate-limiting enzyme in FA synthesis, while being dispensable in EGFR-mutant or wild-type KRAS LC, is required for the viability of KMLC cells. Integrating lipidomic, transcriptomic and functional analyses, we demonstrate that FASN provides saturated and monounsaturated FA to the Lands cycle, the process remodeling oxidized phospholipids, such as PC. Accordingly, …

Slc12a8 In The Lateral Hypothalamus Maintains Energy Metabolism And Skeletal Muscle Functions During Aging, Naoki Ito, Ai Takatsu, Hiromi Ito, Yuka Koike, Kiyoshi Yoshioka, Yasutomi Kamei, Shin-Ichiro Imai

2020-Current year OA Pubs

Sarcopenia and frailty are urgent socio-economic problems worldwide. Here we demonstrate a functional connection between the lateral hypothalamus (LH) and skeletal muscle through Slc12a8, a recently identified nicotinamide mononucleotide transporter, and its relationship to sarcopenia and frailty. Slc12a8-expressing cells are mainly localized in the LH. LH-specific knockdown of Slc12a8 in young mice decreases activity-dependent energy and carbohydrate expenditure and skeletal muscle functions, including muscle mass, muscle force, intramuscular glycolysis, and protein synthesis. LH-specific Slc12a8 knockdown also decreases sympathetic nerve signals at neuromuscular junctions and β2-adrenergic receptors in skeletal muscle, indicating the importance of the LH-sympathetic nerve-β2-adrenergic receptor axis. LH-specific overexpression …

Role Of Trail-R In Primary And Secondary Genital And Respiratory Chlamydia Muridarum Infections In Mice, Sukumar Pal, Sydni Sheff, Mufadhal Al-Kuhlani, David M. Ojcius, Luis M. De La Maza

Pacific Faculty Work

The tumor necrosis factor (TNF)-related apoptosis-inducing ligand receptor (TRAIL-R) suppresses inflammation and could therefore affect the course of Chlamydia infections and their long-term sequelae. Wild-type (WT) and TRAIL-R^2/2 C57BL/6 mice were inoculated vaginally with Chlamydia muridarum; the course of the infection was followed with vaginal cultures and the presence of hydrosalpinx determined. To evaluate the role of TRAIL-R following a secondary infection, the mice were vaginally reinfected. WT and TRAIL-R^2/2 male mice were also infected and reinfected in the respiratory tract, and the course of the diseases and the infections were followed. Following the primary and secondary vaginal …

Myt1l In The Making: Emerging Insights On Functions Of A Neurodevelopmental Disorder Gene, Jiayang Chen, Allen Yen, Colin P Florian, Joseph D Dougherty

2020-Current year OA Pubs

Large scale human genetic studies have shown that loss of function (LoF) mutations in MYT1L are implicated in neurodevelopmental disorders (NDDs). Here, we provide an overview of the growing number of published MYT1L patient cases, and summarize prior studies in cells, zebrafish, and mice, both to understand MYT1L's molecular and cellular role during brain development and consider how its dysfunction can lead to NDDs. We integrate the conclusions from these studies and highlight conflicting findings to reassess the current model of the role of MYT1L as a transcriptional activator and/or repressor based on the biological context. Finally, we highlight additional …

Sirpα Mediates Igf1 Receptor In Cardiomyopathy-Induced By Chronic Kidney Disease, Sandhya S Thomas, Jiao Wu, Giovanni Davogustto, Michael W Holliday, Kristin Eckel-Mahan, Daniela Verzola, Giacomo Garibotto, Zhaoyong Hu, William E Mitch, Heinrich Taegtmeyer

Faculty, Staff and Student Publications

BACKGROUND: Chronic kidney disease (CKD) is characterized by increased myocardial mass despite near-normal blood pressure, suggesting the presence of a separate trigger. A potential driver is SIRPα (signal regulatory protein alpha)-a mediator impairing insulin signaling. The objective of this study is to assess the role of circulating SIRPα in CKD-induced adverse cardiac remodeling.

METHODS: SIRPα expression was evaluated in mouse models and patients with CKD. Specifically, mutant, muscle-specific, or cardiac muscle-specific SIRPα KO (knockout) mice were examined after subtotal nephrectomy. Cardiac function was assessed by echocardiography. Metabolic responses were confirmed in cultured muscle cells or cardiomyocytes.

RESULTS: We demonstrate that …

A Phospholipid Mimetic Targeting Lrh-1 Ameliorates Colitis, Suzanne G Mays, Emma H D'Agostino, Autumn R Flynn, Xiangsheng Huang, Guohui Wang, Xu Liu, Elizabeth J Millings, C Denise Okafor, Anamika Patel, Michael L Cato, Jeffery L Cornelison, Diana Melchers, René Houtman, David D Moore, John W Calvert, Nathan T Jui, Eric A Ortlund

Faculty, Staff and Students Publications

Phospholipids are ligands for nuclear hormone receptors (NRs) that regulate transcriptional programs relevant to normal physiology and disease. Here, we demonstrate that mimicking phospholipid-NR interactions is a robust strategy to improve agonists of liver receptor homolog-1 (LRH-1), a therapeutic target for colitis. Conventional LRH-1 modulators only partially occupy the binding pocket, leaving vacant a region important for phospholipid binding and allostery. Therefore, we constructed a set of molecules with elements of natural phospholipids appended to a synthetic LRH-1 agonist. We show that the phospholipid-mimicking groups interact with the targeted residues in crystal structures and improve binding affinity, LRH-1 transcriptional activity, …

Kathryn V. Holmes: A Career Of Contributions To The Coronavirus Field, Aurelio Bonavia, Samuel R Dominguez, Gabriela Dveksler, Sara Gagneten, Megan Howard, Scott Jeffers, Zhaohui Qian, Mary Kathryn Smith, Larissa B Thackray, Dina B Tresnan, David E Wentworth, David R Wessner, Richard K Williams, Tanya A Miura

2020-Current year OA Pubs

Over the past two years, scientific research has moved at an unprecedented rate in response to the COVID-19 pandemic. The rapid development of effective vaccines and therapeutics would not have been possible without extensive background knowledge on coronaviruses developed over decades by researchers, including Kathryn (Kay) Holmes. Kay's research team discovered the first coronavirus receptors for mouse hepatitis virus and human coronavirus 229E and contributed a wealth of information on coronaviral spike glycoproteins and receptor interactions that are critical determinants of host and tissue specificity. She collaborated with several research laboratories to contribute knowledge in additional areas, including coronaviral pathogenesis, …

Hippo-Taz Signaling Is The Master Regulator Of The Onset Of Triple-Negative Basal-Like Breast Cancers, Hirotoshi Soyama, Miki Nishio, Junji Otani, Toshiko Sakuma, Shintaro Takao, Shigeo Hara, Takaaki Masuda, Koshi Mimori, Shinya Toyokuni, John P Lydon, Kazuwa Nakao, Hiroshi Nishina, Takumi Fukumoto, Tomohiko Maehama, Akira Suzuki

Faculty, Staff and Students Publications

A universal oncogenic driver of basal-like breast cancer (BLBC) has resisted identification. We show that continuous transcriptional coactivator with PDZ-binding motif (TAZ) activation in precancerous murine luminal cells generates luminal cancers that later become BLBCs. Subsequent TP53 alteration, a feature of invasive human BLBCs, accelerates tumor progression. Because BLBC development is inhibited by TAZ inactivation in vivo, our work provides a sound rationale for targeting Hippo-TAZ signaling as therapy for human BLBC. Our mouse model of BLBC represents a powerful tool for evaluating such drugs.

Sox9 Directs Divergent Epigenomic States In Brain Tumor Subtypes, Debosmita Sardar, Hsiao-Chi Chen, Amanda Reyes, Srinidhi Varadharajan, Antrix Jain, Carrie Mohila, Rachel Curry, Brittney Lozzi, Kavitha Rajendran, Alexis Cervantes, Kwanha Yu, Ali Jalali, Ganesh Rao, Stephen C Mack, Benjamin Deneen

Duncan NRI Faculty and Staff Publications

Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations; however, the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here, we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). Using our autochthonous mouse models, we found that Sox9 suppresses HGG growth and expands associated H3K27ac states, while promoting ZFTA-RELA (ZR

Cranial Base Synchondrosis Lacks Pthrp-Expressing Column-Forming Chondrocytes, Shawn A Hallett, Annabelle Zhou, Curtis Herzog, Ariel Arbiv, Wanida Ono, Noriaki Ono

Faculty, Staff and Student Publications

The cranial base contains a special type of growth plate termed the synchondrosis, which functions as the growth center of the skull. The synchondrosis is composed of bidirectional opposite-facing layers of resting, proliferating, and hypertrophic chondrocytes, and lacks the secondary ossification center. In long bones, the resting zone of the epiphyseal growth plate houses a population of parathyroid hormone-related protein (PTHrP)-expressing chondrocytes that contribute to the formation of columnar chondrocytes. Whether PTHrP+ chondrocytes in the synchondrosis possess similar functions remains undefined. Using Pthrp-mCherry knock-in mice, we found that PTHrP+ chondrocytes predominantly occupied the lateral wedge-shaped area of the synchondrosis, unlike …

Slitrk2 Variants Associated With Neurodevelopmental Disorders Impair Excitatory Synaptic Function And Cognition In Mice, Salima El Chehadeh, Dorothy K Grange, Et Al

2020-Current year OA Pubs

SLITRK2 is a single-pass transmembrane protein expressed at postsynaptic neurons that regulates neurite outgrowth and excitatory synapse maintenance. In the present study, we report on rare variants (one nonsense and six missense variants) in SLITRK2 on the X chromosome identified by exome sequencing in individuals with neurodevelopmental disorders. Functional studies showed that some variants displayed impaired membrane transport and impaired excitatory synapse-promoting effects. Strikingly, these variations abolished the ability of SLITRK2 wild-type to reduce the levels of the receptor tyrosine kinase TrkB in neurons. Moreover, Slitrk2 conditional knockout mice exhibited impaired long-term memory and abnormal gait, recapitulating a subset of …

Cd11b Suppresses Tlr Activation Of Nonclassical Monocytes To Reduce Primary Graft Dysfunction After Lung Transplantation, Melissa Querrey, Stephen Chiu, Emilia Lecuona, Qiang Wu, Haiying Sun, Megan Anderson, Megan Kelly, Sowmya Ravi, Alexander V. Misharin, Daniel Kreisel, Ankit Bharat, G. R. Scott Budinger

2020-Current year OA Pubs

Primary graft dysfunction (PGD) is the leading cause of postoperative mortality in lung transplant recipients and the most important risk factor for development of chronic lung allograft dysfunction. The mechanistic basis for the variability in the incidence and severity of PGD between lung transplant recipients is not known. Using a murine orthotopic vascularized lung transplant model, we found that redundant activation of Toll-like receptors 2 and 4 (TLR2 and -4) on nonclassical monocytes activates MyD88, inducing the release of the neutrophil attractant chemokine CXCL2. Deletion of Itgam (encodes CD11b) in nonclassical monocytes enhanced their production of CXCL2 and worsened PGD, …

Infiltration Of Peripheral Immune Cells Into The Olfactory Bulb In A Mouse Model Of Acute Nasal Inflammation, Hinami Asano, Sanae Hasegawa-Ishii, Ken Arae, Aki Obara, Geoffroy Laumet, Robert Dantzer, Atsuyoshi Shimada

Faculty, Staff and Student Publications

Chronic nasal inflammation induces robust olfactory bulb (OB) atrophy in mice. Here we examined initial events that occur in the OB after bilateral intranasal administration of lipopolysaccharide, focusing on the olfactory nerve fibers and meninges. We analyzed the time course of OB and meninges inflammation using histological and biochemical approaches. Within 12 h, we observed increased chemokine expression and transient infiltration of peripheral immune cells into the OB, resulting in the development of pro-inflammatory status in the OB. Meningeal immunity was activated. Resident microglia produced anti-inflammatory cytokines within 24 h. These could be the initial events that lead to OB …

Cd11bhigh B Cells Increase After Stroke And Regulate Microglia: Cd11bhigh B Cells Increase After Stroke And Regulate Mg, Janelle M Korf, Pedram Honarpisheh, Eric C Mohan, Anik Banerjee, Maria P Blasco-Conesa, Parisa Honarpisheh, Gary U Guzman, Romeesa Khan, Bhanu P Ganesh, Amy L Hazen, Juneyoung Lee, Aditya Kumar, Louise D Mccullough, Anjali Chauhan

Faculty, Staff and Student Publications

Recent studies have highlighted the deleterious contributions of B cells to post-stroke recovery and cognitive decline. Different B cell subsets have been proposed based on expression levels of transcription factors (e.g. T-bet) as well as specific surface proteins. CD11b (α-chain of integrin) is expressed by several immune cell types and is involved in regulation of cell motility, phagocytosis, and other essential functions of host immunity. Although B cells express CD11b, the CD11b^high subset of B cells has not been well characterized, especially in immune dysregulation seen with aging and after stroke. Here, we investigate the role of CD11b^{high …}

Gut Bacterial Isoamylamine Promotes Age-Related Cognitive Dysfunction By Promoting Microglial Cell Death, Yun Teng, Jingyao Mu, Fangyi Xu, Xiangcheng Zhang, Mukesh K Sriwastva, Qiaohong M Liu, Xiaohong Li, Chao Lei, Kumaran Sundaram, Xin Hu, Lifeng Zhang, Juw Won Park, Jae Yeon Hwang, Eric C Rouchka, Xiang Zhang, Jun Yan, Michael L Merchant, Huang-Ge Zhang

Faculty, Staff and Student Publications

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. …