Medical Sciences Commons^™

Endothelial Knockdown Of The Tumor Suppressor, Wwox, Increases Inflammation In Ventilator-Induced Lung Injury, Zhenguo Zeng, Eltyeb Abdelwahid, Weiguo Chen, Christian Ascoli, Trinh Pham, Jeffrey R Jacobson, Steven M Dudek, Viswanathan Natarajan, C Marcelo Aldaz, Roberto F Machado, Sunit Singla

Faculty, Staff and Student Publications

Chronic cigarette smoke exposure decreases lung expression of WWOX which is known to protect the endothelial barrier during infectious models of acute respiratory distress syndrome (ARDS). Proteomic analysis of WWOX-silenced endothelial cells (ECs) was done using tandem mass tag mass spectrometry (TMT-MS). WWOX-silenced ECs as well as those isolated from endothelial cell Wwox knockout (EC Wwox KO) mice were subjected to cyclic stretch (18% elongation, 0.5 Hz, 4 h). Cellular lysates and media supernatant were harvested for assays of cellular signaling, protein expression, and cytokine release. These were repeated with dual silencing of WWOX and zyxin. Control and …

Mesenchymal-Specific Alms1 Knockout In Mice Recapitulates Metabolic Features Of Alström Syndrome, Eleanor J Mckay, Ineke Luijten, Xiong Weng, Pablo B Martinez De Morentin, Elvira De Frutos González, Zhanguo Gao, Mikhail G Kolonin, Lora K Heisler, Robert K Semple

Faculty, Staff and Student Publications

OBJECTIVE: Alström Syndrome (AS), caused by biallelic ALMS1 mutations, includes obesity with disproportionately severe insulin resistant diabetes, dyslipidemia, and fatty liver. Prior studies suggest that hyperphagia is accounted for by loss of ALMS1 function in hypothalamic neurones, whereas disproportionate metabolic complications may be due to impaired adipose tissue expandability. We tested this by comparing the metabolic effects of global and mesenchymal stem cell (MSC)-specific Alms1 knockout.

METHODS: Global Alms1 knockout (KO) mice were generated by crossing floxed Alms1 and CAG-Cre mice. A Pdgfrα-Cre driver was used to abrogate Alms1 function selectively in MSCs and their descendants, including preadipocytes. We combined …

Multifactoral Immune Modulation Potentiates Durable Remission In Multiple Models Of Aggressive Malignancy, Matthew M Halpert, Briana A Burns, Spencer R Rosario, Henry G Withers, Akshar J Trivedi, Colby J Hofferek, Benjamin D Gephart, Haotong Wang, Jonathan Vazquez-Perez, Sharon B Amanya, Sean T Hyslop, Jianhua Yang, Jan O Kemnade, Vlad C Sandulache, Vanaja Konduri, William K Decker

Faculty, Staff and Students Publications

Tumors typically lack canonical danger signals required to activate adaptive immunity and also frequently employ substantial immunomodulatory mechanisms that downregulate adaptive responses and contribute to escape from immune surveillance. Given the variety of mechanisms involved in shielding tumors from immune recognition, it is not surprising that single-agent immunomodulatory approaches have been largely unsuccessful in generating durable antitumor responses. Here we report a unique combination of immunomodulatory and cytostatic agents that recondition the tumor microenvironment and eliminate complex and/or poor-prognosis tumor types including the non-immunogenic 4T-1 model of TNBC, the aggressive MOC-2 model of HNSCC, and the high-risk MYCN-amplified model of …

Compensation Between Foxp Transcription Factors Maintains Proper Striatal Function, Newaz I Ahmed, Nitin Khandelwal, Ashley G Anderson, Emily Oh, Rachael M Vollmer, Ashwinikumar Kulkarni, Jay R Gibson, Genevieve Konopka

Faculty, Staff and Students Publications

Spiny projection neurons (SPNs) of the striatum are critical in integrating neurochemical information to coordinate motor and reward-based behavior. Mutations in the regulatory transcription factors expressed in SPNs can result in neurodevelopmental disorders (NDDs). Paralogous transcription factors Foxp1 and Foxp2, which are both expressed in the dopamine receptor 1 (D1) expressing SPNs, are known to have variants implicated in NDDs. Utilizing mice with a D1-SPN-specific loss of Foxp1, Foxp2, or both and a combination of behavior, electrophysiology, and cell-type-specific genomic analysis, loss of both genes results in impaired motor and social behavior as well as increased firing of the D1-SPNs. …

Loss Of Lpar6 And Cab39l Dysregulates The Basal-To-Luminal Urothelial Differentiation Program, Contributing To Bladder Carcinogenesis, Sangkyou Lee, Jolanta Bondaruk, Yishan Wang, Huiqin Chen, June Goo Lee, Tadeusz Majewski, Rachel D Mullen, David Cogdell, Jiansong Chen, Ziqiao Wang, Hui Yao, Pawel Kus, Joon Jeong, Ilkyun Lee, Woonyoung Choi, Neema Navai, Charles Guo, Colin Dinney, Keith Baggerly, Cathy Mendelsohn, David Mcconkey, Richard R Behringer, Marek Kimmel, Peng Wei, Bogdan Czerniak

Faculty, Staff and Student Publications

We describe a strategy that combines histologic and molecular mapping that permits interrogation of the chronology of changes associated with cancer development on a whole-organ scale. Using this approach, we present the sequence of alterations around RB1 in the development of bladder cancer. We show that RB1 is not involved in initial expansion of the preneoplastic clone. Instead, we found a set of contiguous genes that we term "forerunner" genes whose silencing is associated with the development of plaque-like field effects initiating carcinogenesis. Specifically, we identified five candidate forerunner genes (ITM2B, LPAR6, MLNR, CAB39L, and ARL11) mapping near RB1. Two …

Astrocytic Slc4a4 Regulates Blood-Brain Barrier Integrity In Healthy And Stroke Brains Via A Ccl2-Ccr2 Pathway And No Dysregulation, Qi Ye, Juyeon Jo, Chih-Yen Wang, Heavin Oh, Jiangshan Zhan, Tiffany J Choy, Kyoung In Kim, Angelo D'Alessandro, Yana K Reshetnyak, Sung Yun Jung, Zheng Chen, Sean P Marrelli, Hyun Kyoung Lee

Faculty, Staff and Student Publications

Astrocytes play vital roles in blood-brain barrier (BBB) maintenance, yet how they support BBB integrity under normal or pathological conditions remains poorly defined. Recent evidence suggests that ion homeostasis is a cellular mechanism important for BBB integrity. In the current study, we investigated the function of an astrocyte-specific pH regulator, Slc4a4, in BBB maintenance and repair. We show that astrocytic Slc4a4 is required for normal astrocyte morphological complexity and BBB function. Multi-omics analyses identified increased astrocytic secretion of CCL2 coupled with dysregulated arginine-NO metabolism after Slc4a4 deletion. Using a model of ischemic stroke, we found that loss of Slc4a4 exacerbates …

Therapeutic Strategies Against Metabolic Imbalance In A Male Mouse Model With 5-Ht2cr Loss-Of-Function, Hailan Liu, Zhaoxun Liu, Hueyxian Kelly Wong, Nathan Xu, Qingzhuo Liu, Yongxiang Li, Yao Liu, Hueyzhong Wong, Megan E Burt, Sanika V Jossy, Junying Han, Yang He

Faculty, Staff and Students Publications

The serotonin 2C receptor (5-HT2CR)-melanocortin pathway plays well-established roles in the regulation of feeding behavior and body weight homeostasis. Dysfunctions in this system, such as loss-of-function mutations in the Htr2c gene, can lead to hyperphagia and obesity. In this study, we aimed to investigate the potential therapeutic strategies for ameliorating hyperphagia, hyperglycemia, and obesity associated with a loss-of-function mutation in the Htr2c gene (Htr2cF327L/Y). We demonstrated that reexpressing functional 5-HT2CR solely in hypothalamic pro-opiomelanocortin (POMC) neurons is sufficient to reduce food intake and body weight in Htr2cF327L/Y mice subjected to a high-fat diet (HFD). In addition, 5-HT2CR expression restores the …

Ciliary Tip Actin Dynamics Regulate Photoreceptor Outer Segment Integrity, Roly Megaw, Abigail Moye, Zhixian Zhang, Fay Newton, Fraser Mcphie, Laura C Murphy, Lisa Mckie, Feng He, Melissa K Jungnickel, Alex Von Kriegsheim, Peter A Tennant, Chloe Brotherton, Christine Gurniak, Alecia K Gross, Laura M Machesky, Theodore G Wensel, Pleasantine Mill

Faculty, Staff and Students Publications

As signalling organelles, cilia regulate their G protein-coupled receptor content by ectocytosis, a process requiring localised actin dynamics to alter membrane shape. Photoreceptor outer segments comprise an expanse of folded membranes (discs) at the tip of highly-specialised connecting cilia, into which photosensitive GPCRs are concentrated. Discs are shed and remade daily. Defects in this process, due to mutations, cause retinitis pigmentosa (RP). Whilst fundamental for vision, the mechanism of photoreceptor disc generation is poorly understood. Here, we show membrane deformation required for disc genesis is driven by dynamic actin changes in a process akin to ectocytosis. We show RPGR, a …

Age-Specific Induction Of Mutant P53 Drives Clonal Hematopoiesis And Acute Myeloid Leukemia In Adult Mice, Rasoul Pourebrahim, Rafael Heinz Montoya, Hiroki Akiyama, Lauren Ostermann, Shayuan Khazaei, Muharrem Muftuoglu, Natalia Baran, Ran Zhao, Tom Lesluyes, Bin Liu, Joseph D Khoury, Mihai Gagea, Peter Van Loo, Michael Andreeff

Faculty, Staff and Student Publications

The investigation of the mechanisms behind p53 mutations in acute myeloid leukemia (AML) has been limited by the lack of suitable mouse models, which historically have resulted in lymphoma rather than leukemia. This study introduces two new AML mouse models. One model induces mutant p53 and Mdm2 haploinsufficiency in early development, showing the role of Mdm2 in myeloid-biased hematopoiesis and AML predisposition, independent of p53. The second model mimics clonal hematopoiesis by inducing mutant p53 in adult hematopoietic stem cells, demonstrating that the timing of p53 mutation determines AML vs. lymphoma development. In this context, age-related changes in hematopoietic stem …

Ire1Α Determines Ferroptosis Sensitivity Through Regulation Of Glutathione Synthesis, Dadi Jiang, Youming Guo, Tianyu Wang, Liang Wang, Yuelong Yan, Ling Xia, Rakesh Bam, Zhifen Yang, Hyemin Lee, Takao Iwawaki, Boyi Gan, Albert C Koong

Faculty, Staff and Student Publications

Cellular sensitivity to ferroptosis is primarily regulated by mechanisms mediating lipid hydroperoxide detoxification. We show that inositol-requiring enzyme 1 (IRE1α), an endoplasmic reticulum (ER) resident protein critical for the unfolded protein response (UPR), also determines cellular sensitivity to ferroptosis. Cancer and normal cells depleted of IRE1α gain resistance to ferroptosis, while enhanced IRE1α expression promotes sensitivity to ferroptosis. Mechanistically, IRE1α's endoribonuclease activity cleaves and down-regulates the mRNA of key glutathione biosynthesis regulators glutamate-cysteine ligase catalytic subunit (GCLC) and solute carrier family 7 member 11 (SLC7A11). This activity of IRE1α is independent of its role in regulating the UPR and is …

The Crosstalk Between Macrophages And Cancer Cells Potentiates Pancreatic Cancer Cachexia, Mingyang Liu, Yu Ren, Zhijun Zhou, Jingxuan Yang, Xiuhui Shi, Yang Cai, Alex X Arreola, Wenyi Luo, Kar-Ming Fung, Chao Xu, Ryan D Nipp, Michael S Bronze, Lei Zheng, Yi-Ping Li, Courtney W Houchen, Yuqing Zhang, Min Li

Faculty, Staff and Student Publications

With limited treatment options, cachexia remains a major challenge for patients with cancer. Characterizing the interplay between tumor cells and the immune microenvironment may help identify potential therapeutic targets for cancer cachexia. Herein, we investigate the critical role of macrophages in potentiating pancreatic cancer induced muscle wasting via promoting TWEAK (TNF-like weak inducer of apoptosis) secretion from the tumor. Specifically, depletion of macrophages reverses muscle degradation induced by tumor cells. Macrophages induce non-autonomous secretion of TWEAK through CCL5/TRAF6/NF-κB pathway. TWEAK promotes muscle atrophy by activating MuRF1 initiated muscle remodeling. Notably, tumor cells recruit and reprogram macrophages via the CCL2/CCR2 axis …

Regulation Of Cerebral Blood Flow Boosts Precise Brain Targeting Of Vinpocetine-Derived Ionizable-Lipidoid Nanoparticles, Xufei Bian, Ling Yang, Dingxi Jiang, Adam J Grippin, Yifan Ma, Shuang Wu, Linchong Wu, Xiaoyou Wang, Zhongjie Tang, Kaicheng Tang, Weidong Pan, Shiyan Dong, Betty Y S Kim, Wen Jiang, Zhaogang Yang, Chong Li

Faculty, Staff and Student Publications

Despite advances in active drug targeting for blood-brain barrier penetration, two key challenges persist: first, attachment of a targeting ligand to the drug or drug carrier does not enhance its brain biodistribution; and second, many brain diseases are intricately linked to microcirculation disorders that significantly impede drug accumulation within brain lesions even after they cross the barrier. Inspired by the neuroprotective properties of vinpocetine, which regulates cerebral blood flow, we propose a molecular library design centered on this class of cyclic tertiary amine compounds and develop a self-enhanced brain-targeted nucleic acid delivery system. Our findings reveal that: (i) vinpocetine-derived ionizable-lipidoid …

Downregulation Of Mirlet7 Mirna Family Promotes Tc17 Differentiation And Emphysema Via De-Repression Of Rorγt, Phillip A Erice, Xinyan Huang, Matthew J Seasock, Matthew J Robertson, Hui-Ying Tung, Melissa A Perez-Negron, Shivani L Lotlikar, David B Corry, Farrah Kheradmand, Antony Rodriguez

Faculty, Staff and Students Publications

Environmental air irritants including nanosized carbon black (nCB) can drive systemic inflammation, promoting chronic obstructive pulmonary disease (COPD) and emphysema development. The let-7 microRNA (Mirlet7 miRNA) family is associated with IL-17-driven T cell inflammation, a canonical signature of lung inflammation. Recent evidence suggests the Mirlet7 family is downregulated in patients with COPD, however, whether this repression conveys a functional consequence on emphysema pathology has not been elucidated. Here, we show that overall expression of the Mirlet7 clusters, Mirlet7b/Mirlet7c2 and Mirlet7a1/Mirlet7f1/Mirlet7d, are reduced in the lungs and T cells of smokers with emphysema as well as in mice with …

Metaplastic Regeneration In The Mouse Stomach Requires A Reactive Oxygen Species Pathway, Zhi-Feng Miao, Jing-Xu Sun, Xuan-Zhang Huang, Shi Bai, Min-Jiao Pang, Jia-Yi Li, Han-Yu Chen, Qi-Yue Tong, Shi-Yu Ye, Xin-Yu Wang, Xiao-Hai Hu, Jing-Ying Li, Jin-Wei Zou, Wen Xu, Jun-Hao Yang, Xi Lu, Jason C Mills, Zhen-Ning Wang

Faculty, Staff and Students Publications

In pyloric metaplasia, mature gastric chief cells reprogram via an evolutionarily conserved process termed paligenosis to re-enter the cell cycle and become spasmolytic polypeptide-expressing metaplasia (SPEM) cells. Here, we use single-cell RNA sequencing (scRNA-seq) following injury to the murine stomach to analyze mechanisms governing paligenosis at high resolution. Injury causes induced reactive oxygen species (ROS) with coordinated changes in mitochondrial activity and cellular metabolism, requiring the transcriptional mitochondrial regulator Ppargc1a (Pgc1α) and ROS regulator Nf2el2 (Nrf2). Loss of the ROS and mitochondrial control in Ppargc1a-/- mice causes the death of paligenotic cells through ferroptosis. Blocking the cystine transporter SLC7A11(xCT), which …

Triggering Receptor Expressed On Myeloid Cells 2 (Trem2) Regulates Phagocytosis In Glioblastoma, Mekenzie M Peshoff, Pravesh Gupta, Shivangi Oberai, Rakesh Trivedi, Hiroshi Katayama, Prashanth Chakrapani, Minghao Dang, Simona Migliozzi, Joy Gumin, Divya B Kadri, Jessica K Lin, Nancy K Milam, Mark E Maynard, Brian D Vaillant, Brittany Parker-Kerrigan, Frederick F Lang, Jason T Huse, Antonio Iavarone, Linghua Wang, Karen Clise-Dwyer, Krishna P Bhat

Faculty, Staff and Student Publications

Background: Glioblastomas (GBMs) are central nervous system tumors that resist standard-of-care interventions and even immune checkpoint blockade. Myeloid cells in the tumor microenvironment can contribute to GBM progression; therefore, emerging immunotherapeutic approaches include reprogramming these cells to achieve desirable antitumor activity. Triggering receptor expressed on myeloid cells 2 (TREM2) is a myeloid signaling regulator that has been implicated in a variety of cancers and neurological diseases with contrasting functions, but its role in GBM immunopathology and progression is still under investigation.

Methods: Our reverse translational investigations leveraged single-cell RNA sequencing and cytometry of human gliomas to characterize TREM2 expression across …

Impact Of Sustained Calorie Restriction And Weight Cycling On Body Composition In High-Fat Diet-Fed Male And Female C57bl/6j Mice, Daniel L Smith, Yongbin Yang, Luis M Mestre, Beate Henschel, Erik Parker, Stephanie Dickinson, Amit Patki, David B Allison, Tim R Nagy

Children’s Nutrition Research Center Staff Publications

Objective: The objective of this study was to investigate body composition changes with weight cycling (WC) among adult C57BL/6J mice with diet-induced obesity.

Methods: A total of 555 single-housed mice were fed a high-fat diet ad libitum (AL) from 8 to 43 weeks of age. The 200 heaviest mice of each sex were randomized to the following four groups: ever obese (EO, continued AL feeding); obese weight loser (OWL, calorie-restricted); obese weight loser moderate (OWLM, body weight halfway between EO and OWL); and WC (diet restricted to OWL followed by AL refeeding cycles). Body weight and composition data were collected. …

Piezo1 Regulates Meningeal Lymphatic Vessel Drainage And Alleviates Excessive Csf Accumulation, Dongwon Choi, Eunkyung Park, Joshua Choi, Renhao Lu, Jin Suh Yu, Chiyoon Kim, Luping Zhao, James Yu, Brandon Nakashima, Sunju Lee, Dhruv Singhal, Joshua P Scallan, Bin Zhou, Chester J Koh, Esak Lee, Young-Kwon Hong

Faculty, Staff and Students Publications

Piezo1 regulates multiple aspects of the vascular system by converting mechanical signals generated by fluid flow into biological processes. Here, we find that Piezo1 is necessary for the proper development and function of meningeal lymphatic vessels and that activating Piezo1 through transgenic overexpression or treatment with the chemical agonist Yoda1 is sufficient to increase cerebrospinal fluid (CSF) outflow by improving lymphatic absorption and transport. The abnormal accumulation of CSF, which often leads to hydrocephalus and ventriculomegaly, currently lacks effective treatments. We discovered that meningeal lymphatics in mouse models of Down syndrome were incompletely developed and abnormally formed. Selective overexpression of …

Age-Related Differences In The Mouse Corneal Epithelial Transcriptome And Their Impact On Corneal Wound Healing, Anmar Abu-Romman, Kaitlin K Scholand, Gowthaman Govindarajan, Zhiyuan Yu, Sonali Pal-Ghosh, Mary A Stepp, Cintia S De Paiva

Faculty, Staff and Students Publications

PURPOSE: Aging is a risk factor for dry eye. We sought to identify changes in the aged mouse corneal epithelial transcriptome and determine how age affects corneal sensitivity, re-epithelialization, and barrier reformation after corneal debridement.

METHODS: Corneal epithelium of female C57BL/6J (B6) mice of different ages (2, 12, 18, and 24 months) was collected, RNA extracted, and bulk RNA sequencing performed. Cornea sensitivity was measured with an esthesiometer in 2- to 3-month-old, 12- to 13-month-old, 18- to 19-month-old, and 22- to 25-month-old female and male mice. The 2-month-old and 18-month-old female and male mice underwent unilateral corneal debridement using a …

Sialic Acid-Siglec-E Interactions Regulate The Response Of Neonatal Macrophages To Group B Streptococcus, Sean J Lund, Pamela G B Del Rosario, Asami Honda, Kaitlin J Caoili, Marten A Hoeksema, Victor Nizet, Kathryn A Patras, Lawrence S Prince

Faculty, Staff and Students Publications

The mammalian Siglec receptor sialoadhesin (Siglec1, CD169) confers innate immunity against the encapsulated pathogen group B Streptococcus (GBS). Newborn lung macrophages have lower expression levels of sialoadhesin at birth compared with the postnatal period, increasing their susceptibility to GBS infection. In this study, we investigate the mechanisms regulating sialoadhesin expression in the newborn mouse lung. In both neonatal and adult mice, GBS lung infection reduced Siglec1 expression, potentially delaying acquisition of immunity in neonates. Suppression of Siglec1 expression required interactions between sialic acid on the GBS capsule and the inhibitory host receptor Siglec-E. The Siglec1 gene contains multiple STAT binding …

Impact Of Obesity And Age On Mouse Corneal Innervation At The Epithelial-Stromal Interface, Justin A Courson, Rolando E Rumbaut, Alan R Burns

Faculty, Staff and Students Publications

PURPOSE: The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age.

METHODS: Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the …

Stat3 Protects Hematopoietic Stem Cells By Preventing Activation Of A Deleterious Autocrine Type-I Interferon Response, Bhakti Patel, Yifan Zhou, Rachel L Babcock, Feiyang Ma, M Anna Zal, Dhiraj Kumar, Yusra B Medik, Laura M Kahn, Josué E Pineda, Elizabeth M Park, Sarah M Schneider, Ximing Tang, Maria Gabriela Raso, Collene R Jeter, Tomasz Zal, Karen Clise-Dwyer, Khandan Keyomarsi, Filippo G Giancotti, Simona Colla, Stephanie S Watowich

Faculty, Staff and Student Publications

Hematopoietic stem and progenitor cells (HSPCs) maintain blood-forming and immune activity, yet intrinsic regulators of HSPCs remain elusive. STAT3 function in HSPCs has been difficult to dissect as Stat3-deficiency in the hematopoietic compartment induces systemic inflammation, which can impact HSPC activity. Here, we developed mixed bone marrow (BM) chimeric mice with inducible Stat3 deletion in 20% of the hematopoietic compartment to avoid systemic inflammation. Stat3-deficient HSPCs were significantly impaired in reconstitution ability following primary or secondary bone marrow transplantation, indicating hematopoietic stem cell (HSC) defects. Single-cell RNA sequencing of Lin-ckit+Sca1+ BM cells (LSKs) revealed aberrant activation of cell cycle, p53, …

Synthetic Cationic Helical Polypeptides For The Stimulation Of Antitumour Innate Immune Pathways In Antigen-Presenting Cells, Daeyong Lee, Kristin Huntoon, Yifan Wang, Minjeong Kang, Yifei Lu, Seong Dong Jeong, Todd M Link, Thomas D Gallup, Yaqing Qie, Xuefeng Li, Shiyan Dong, Benjamin R Schrank, Adam J Grippin, Abin Antony, Jonghoon Ha, Mengyu Chang, Yi An, Liang Wang, Dadi Jiang, Jing Li, Albert C Koong, John A Tainer, Wen Jiang, Betty Y S Kim

Faculty, Staff and Student Publications

Intracellular DNA sensors regulate innate immunity and can provide a bridge to adaptive immunogenicity. However, the activation of the sensors in antigen-presenting cells (APCs) by natural agonists such as double-stranded DNAs or cyclic nucleotides is impeded by poor intracellular delivery, serum stability, enzymatic degradation and rapid systemic clearance. Here we show that the hydrophobicity, electrostatic charge and secondary conformation of helical polypeptides can be optimized to stimulate innate immune pathways via endoplasmic reticulum stress in APCs. One of the three polypeptides that we engineered activated two major intracellular DNA-sensing pathways (cGAS-STING (for cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes) …

Dlk-Mapk Signaling Coupled With Dna Damage Promotes Intrinsic Neurotoxicity Associated With Non-Mutated Tau, Sanming Li, Ethan R Roy, Yanyu Wang, Trent Watkins, Wei Cao

Faculty, Staff and Student Publications

Alzheimer's disease (AD) is the most prevalent form of neurodegeneration. Despite the well-established link between tau aggregation and clinical progression, the major pathways driven by this protein to intrinsically damage neurons are incompletely understood. To model AD-relevant neurodegeneration driven by tau, we overexpressed non-mutated human tau in primary mouse neurons and observed substantial axonal degeneration and cell death, a process accompanied by activated caspase 3. Mechanistically, we detected deformation of the nuclear envelope and increased DNA damage response in tau-expressing neurons. Gene profiling analysis further revealed significant alterations in the mitogen-activated protein kinase (MAPK) pathway; moreover, inhibitors of dual leucine …

The Hepatokine Orosomucoid 2 Mediates Beneficial Metabolic Effects Of Bile Acids, Sung Ho Lee, Ji Ho Suh, Mi Jeong Heo, Jong Min Choi, Yang Yang, Hyun-Jung Jung, Zhanguo Gao, Yongmei Yu, Sung Yun Jung, Mikhail G Kolonin, Aaron R Cox, Sean M Hartig, Holger K Eltzschig, Cynthia Ju, David D Moore, Kang Ho Kim

Faculty, Staff and Student Publications

Bile acids (BAs) are pleiotropic regulators of metabolism. Elevated levels of hepatic and circulating BAs improve energy metabolism in peripheral organs, but the precise mechanisms underlying the metabolic benefits and harm still need to be fully understood. In the current study, we identified orosomucoid 2 (ORM2) as a liver-secreted hormone (i.e., hepatokine) induced by BAs and investigated its role in BA-induced metabolic improvements in mouse models of diet-induced obesity. Contrary to our expectation, under a high-fat diet (HFD), our Orm2 knockout (Orm2-KO) exhibited a lean phenotype compared with C57BL/6J control, partly due to the increased energy expenditure. However, when challenged …

Interaction Of High-Fat Diet And Brain Trauma Alters Adipose Tissue Macrophages And Brain Microglia Associated With Exacerbated Cognitive Dysfunction, Rebecca J Henry, James P Barrett, Maria Vaida, Niaz Z Khan, Oleg Makarevich, Rodney M Ritzel, Alan I Faden, Bogdan A Stoica

Faculty, Staff and Student Publications

Obesity increases the morbidity and mortality of traumatic brain injury (TBI). Detailed analyses of transcriptomic changes in the brain and adipose tissue were performed to elucidate the interactive effects between high-fat diet-induced obesity (DIO) and TBI. Adult male mice were fed a high-fat diet (HFD) for 12 weeks prior to experimental TBI and continuing after injury. High-throughput transcriptomic analysis using Nanostring panels of the total visceral adipose tissue (VAT) and cellular components in the brain, followed by unsupervised clustering, principal component analysis, and IPA pathway analysis were used to determine shifts in gene expression patterns and molecular pathway activity. Cellular …

Histone Proteoform Analysis Reveals Epigenetic Changes In Adult Mouse Brown Adipose Tissue In Response To Cold Stress, Bethany C Taylor, Loic H Steinthal, Michelle Dias, Hari Krishna Yalamanchili, Scott A Ochsner, Gladys E Zapata, Nitesh R Mehta, Neil J Mckenna, Nicolas L Young, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

BACKGROUND: Regulation of the thermogenic response by brown adipose tissue (BAT) is an important component of energy homeostasis with implications for the treatment of obesity and diabetes. Our preliminary analyses of RNA-Seq data uncovered many nodes representing epigenetic modifiers that are altered in BAT in response to chronic thermogenic activation. Thus, we hypothesized that chronic thermogenic activation broadly alters epigenetic modifications of DNA and histones in BAT.

RESULTS: Motivated to understand how BAT function is regulated epigenetically, we developed a novel method for the first-ever unbiased top-down proteomic quantitation of histone modifications in BAT and validated our results with a …

Dopamine Release Neuroenergetics In Mouse Striatal Slices, Msema Msackyi, Yuanxin Chen, Wangchen Tsering, Ninghan Wang, Hui Zhang

Department of Neuroscience Faculty Papers

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Dopamine (DA) neurons in the substantia nigra pars compacta, which have axonal projections to the dorsal striatum (dSTR), degenerate in PD. In contrast, DA neurons in the ventral tegmental area, with axonal projections to the ventral striatum, including the nucleus accumbens (NAcc) shell, are largely spared. This study aims to uncover the relative contributions of glycolysis and oxidative phosphorylation (OxPhos) to DA release in the striatum. We measured evoked DA release in mouse striatal brain slices using fast-scan cyclic voltammetry applied every two minutes. Blocking OxPhos resulted in a greater …

Ccr2+ Monocytes Replenish Border-Associated Macrophages In The Diseased Mouse Brain, Lingxiao Wang, Jiaying Zheng, Shunyi Zhao, Yushan Wan, Meijie Wang, Dale B Bosco, Chia-Yi Kuan, Jason R Richardson, Long-Jun Wu

Faculty, Staff and Student Publications

Border-associated macrophages (BAMs) are tissue-resident macrophages that reside at the border of the central nervous system (CNS). Since BAMs originate from yolk sac progenitors that do not persist after birth, the means by which this population of cells is maintained is not well understood. Using two-photon microscopy and multiple lineage-tracing strategies, we determine that CCR2+ monocytes are significant contributors to BAM populations following disruptions of CNS homeostasis in adult mice. After BAM depletion, while the residual BAMs possess partial self-repopulation capability, the CCR2+ monocytes are a critical source of the repopulated BAMs. In addition, we demonstrate the existence of CCR2+ …

An Estrogen Receptor Α-Derived Peptide Improves Glucose Homeostasis During Obesity, Wanbao Yang, Wen Jiang, Wang Liao, Hui Yan, Weiqi Ai, Quan Pan, Wesley A Brashear, Yong Xu, Ling He, Shaodong Guo

Faculty, Staff and Students Publications

Estrogen receptor α (ERα) plays a crucial role in regulating glucose and energy homeostasis during type 2 diabetes mellitus (T2DM). However, the underlying mechanisms remain incompletely understood. Here we find a ligand-independent effect of ERα on the regulation of glucose homeostasis. Deficiency of ERα in the liver impairs glucose homeostasis in male, female, and ovariectomized (OVX) female mice. Mechanistic studies reveal that ERα promotes hepatic insulin sensitivity by suppressing ubiquitination-induced IRS1 degradation. The ERα 1-280 domain mediates the ligand-independent effect of ERα on insulin sensitivity. Furthermore, we identify a peptide based on ERα 1-280 domain and find that ERα-derived peptide …

Transposable Elements Regulate Thymus Development And Function, Jean-David Larouche, Céline M Laumont, Assya Trofimov, Krystel Vincent, Leslie Hesnard, Sylvie Brochu, Caroline Côté, Juliette F Humeau, Éric Bonneil, Joel Lanoix, Chantal Durette, Patrick Gendron, Jean-Philippe Laverdure, Ellen R Richie, Sébastien Lemieux, Pierre Thibault, Claude Perreault

Faculty, Staff and Student Publications

Transposable elements (TEs) are repetitive sequences representing ~45% of the human and mouse genomes and are highly expressed by medullary thymic epithelial cells (mTECs). In this study, we investigated the role of TEs on T-cell development in the thymus. We performed multiomic analyses of TEs in human and mouse thymic cells to elucidate their role in T-cell development. We report that TE expression in the human thymus is high and shows extensive age- and cell lineage-related variations. TE expression correlates with multiple transcription factors in all cell types of the human thymus. Two cell types express particularly broad TE repertoires: …