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Sun J, Sepulveda JL, Komissarova EV, Hills C, Seckar TD, LeFevre NM, Simonyan H, Young C, Su G, Del Portillo A, Wang TC, Sepulveda AR. CDKN2A-p16 Deletion and Activated KRAS G12D Drive Barrett's-Like Gland Hyperplasia-Metaplasia and Synergize in the Development of Dysplasia Precancer Lesions. Cell Mol Gastroenterol Hepatol 2024; 17:769-784. [PMID: 38296052 PMCID: PMC10966774 DOI: 10.1016/j.jcmgh.2024.01.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/19/2024]
Abstract
BACKGROUND & AIMS Barrett's esophagus is the precursor of esophageal dysplasia and esophageal adenocarcinoma. CDKN2A-p16 deletions were reported in 34%-74% of patients with Barrett's esophagus who progressed to dysplasia and esophageal adenocarcinoma, suggesting that p16 loss may drive neoplastic progression. KRAS activation frequently occurs in esophageal adenocarcinoma and precancer lesions. LGR5+ stem cells in the squamocolumnar-junction (SCJ) of mouse stomach contribute as Barrett's esophagus progenitors. We aimed to determine the functional effects of p16 loss and KRAS activation in Barrett's-like metaplasia and dysplasia development. METHODS We established mouse models with conditional knockout of CDKN2A-p16 (p16KO) and/or activated KRASG12D expression targeting SCJ LGR5+ cells in interleukin 1b transgenic mice and characterized histologic alterations (mucous-gland hyperplasia/metaplasia, inflammation, and dysplasia) in mouse SCJ. Gene expression was determined by microarray, RNA sequencing, and immunohistochemistry of SCJ tissues and cultured 3-dimensional organoids. RESULTS p16KO mice exhibited increased mucous-gland hyperplasia/metaplasia versus control mice (P = .0051). Combined p16KO+KRASG12D resulted in more frequent dysplasia and higher dysplasia scores (P = .0036), with 82% of p16KO+KRASG12D mice developing high-grade dysplasia. SCJ transcriptome analysis showed several activated pathways in p16KO versus control mice (apoptosis, tumor necrosis factor-α/nuclear factor-kB, proteasome degradation, p53 signaling, MAPK, KRAS, and G1-to-S transition). CONCLUSIONS p16 deletion in LGR5+ cell precursors triggers increased SCJ mucous-gland hyperplasia/metaplasia. KRASG12D synergizes with p16 deletion resulting in higher grades of SCJ glandular dysplasia, mimicking Barrett's high-grade dysplasia. These genetically modified mouse models establish a functional role of p16 and activated KRAS in the progression of Barrett's-like lesions to dysplasia in mice, representing an in vivo model of esophageal adenocarcinoma precancer. Derived 3-dimensional organoid models further provide in vitro modeling opportunities of esophageal precancer stages.
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Affiliation(s)
- Jing Sun
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Jorge L Sepulveda
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Elena V Komissarova
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Caitlin Hills
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Tyler D Seckar
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Narine M LeFevre
- Department of Pharmacology & Physiology, George Washington University, School of Medicine and Health Sciences, Washington, DC
| | - Hayk Simonyan
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Colin Young
- Department of Pharmacology & Physiology, George Washington University, School of Medicine and Health Sciences, Washington, DC
| | - Gloria Su
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Armando Del Portillo
- Department of Pathology and Cell Biology, Columbia University, New York, New York
| | - Timothy C Wang
- Division of Digestive and Liver diseases, Department of Medicine, Columbia University, New York, New York
| | - Antonia R Sepulveda
- Department of Pathology, George Washington University School of Medicine and Health Sciences, Washington, DC.
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Blackmore K, Houchen CJ, Simonyan H, Arestakesyan H, Stark AK, Dow SA, Kim HR, Jeong JK, Popratiloff A, Young CN. A forebrain-hypothalamic ER stress driven circuit mediates hepatic steatosis during obesity. Mol Metab 2024; 79:101858. [PMID: 38141847 PMCID: PMC10809102 DOI: 10.1016/j.molmet.2023.101858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 10/25/2023] [Accepted: 12/19/2023] [Indexed: 12/25/2023] Open
Abstract
OBJECTIVE Non-alcoholic fatty liver disease (NAFLD) affects 1 in 3 adults and contributes to advanced liver injury and cardiometabolic disease. While recent evidence points to involvement of the brain in NAFLD, the downstream neural circuits and neuronal molecular mechanisms involved in this response, remain unclear. Here, we investigated the role of a unique forebrain-hypothalamic circuit in NAFLD. METHODS Chemogenetic activation and inhibition of circumventricular subfornical organ (SFO) neurons that project to the paraventricular nucleus of the hypothalamus (PVN; SFO→PVN) in mice were used to study the role of SFO→PVN signaling in NAFLD. Novel scanning electron microscopy techniques, histological approaches, molecular biology techniques, and viral methodologies were further used to delineate the role of endoplasmic reticulum (ER) stress within this circuit in driving NAFLD. RESULTS In lean animals, acute chemogenetic activation of SFO→PVN neurons was sufficient to cause hepatic steatosis in a liver sympathetic nerve dependent manner. Conversely, inhibition of this forebrain-hypothalamic circuit rescued obesity-associated NAFLD. Furthermore, dietary NAFLD is associated with marked ER ultrastructural alterations and ER stress in the PVN, which was blunted following reductions in excitatory signaling from the SFO. Finally, selective inhibition of PVN ER stress reduced hepatic steatosis during obesity. CONCLUSIONS Collectively, these findings characterize a previously unrecognized forebrain-hypothalamic-ER stress circuit that is involved in hepatic steatosis, which may point to future therapeutic strategies for NAFLD.
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Affiliation(s)
- Katherine Blackmore
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Claire J Houchen
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Hovhannes Arestakesyan
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Alyssa K Stark
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Samantha A Dow
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Han Rae Kim
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Jin Kwon Jeong
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA
| | - Anastas Popratiloff
- Nanofabrication and Imaging Center, George Washington University, Washington, DC, 20037, USA
| | - Colin N Young
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC, 20037, USA.
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Hayashi CTH, Cao Y, Zavala F, Simonyan H, Young CN, Kumar N. Antibodies elicited by Plasmodium falciparum circumsporozoite proteins lacking sequentially deleted C-terminal amino acids reveal mouse strain and epitopes specific differences. Vaccine 2023; 41:S0264-410X(23)01179-9. [PMID: 37827967 PMCID: PMC11004087 DOI: 10.1016/j.vaccine.2023.10.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/14/2023]
Abstract
Malaria affects ∼ ¼ billion people globally and requires the development of additional tools to aid in elimination efforts. The recently approved RTS,S/AS01 vaccine represents a positive step, however, the moderate efficacy necessitates the development of more efficacious vaccines. PfCSP is a key target antigen for pre-erythrocytic vaccines aimed at preventing Plasmodium falciparum malaria infections. Epitopes within the central repeat region and at the junction of the repeat and N-terminal domain are well documented as major protective B cell epitopes. On the other hand, a majority of antibodies against the epitopes in the C-terminal domain, have been shown to be non-protective against sporozoite challenge. The C-terminal domain, however, contains CD4+ and CD8+ T cell epitopes previously shown to be important for regulating immune responses. The present study was designed to further explore the immunomodulatory potential of the C-terminal domain using DNA vaccines encoding PfCSP with sequential C-terminal truncations following known T cell epitopes. Five DNA vaccines encoding different truncations of PfCSP within the C-terminal domain were administered via intramuscular route and in vivo electroporation for effective immunogenicity. Protection in mice was evaluated by challenge with transgenic P. berghei expressing PfCSP. In Balb/c mice, antibody responses and protective efficacy were both affected progressively with sequential deletion of C-terminal amino acid residues. Similar studies in C57Bl/6 mice revealed that immunizations with plasmids encoding truncated PfCSP showed partial protection from sporozoite challenge with no significant differences in antibody titers observed compared to full-length PfCSP DNA immunized mice. Further analysis revealed murine strain-specific differences in the recognition of specific epitopes.
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Affiliation(s)
- Clifford T H Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA
| | - Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA
| | - Fidel Zavala
- Johns Hopkins Malaria Research Institute, Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21215, USA
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington DC 20052, USA
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington DC 20052, USA.
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Cao Y, Hayashi CTH, Zavala F, Tripathi AK, Simonyan H, Young CN, Clark LC, Usuda Y, Van Parys JM, Kumar N. Effective Functional Immunogenicity of a DNA Vaccine Combination Delivered via In Vivo Electroporation Targeting Malaria Infection and Transmission. Vaccines (Basel) 2022; 10:1134. [PMID: 35891298 PMCID: PMC9323668 DOI: 10.3390/vaccines10071134] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 11/16/2022] Open
Abstract
Plasmodium falciparum circumsporozoite protein (PfCSP) and Pfs25 are leading candidates for the development of pre-erythrocytic and transmission-blocking vaccines (TBV), respectively. Although considerable progress has been made in developing PfCSP- and Pfs25-based vaccines, neither have elicited complete protection or transmission blocking in clinical trials. The combination of antigens targeting various life stages is an alternative strategy to develop a more efficacious malaria vaccine. In this study, female and male mice were immunized with DNA plasmids encoding PfCSP and Pfs25, administered alone or in combination via intramuscular in vivo electroporation (EP). Antigen-specific antibodies were analyzed for antibody titers, avidity and isotype by ELISA. Immune protection against sporozoite challenge, using transgenic P. berghei expressing PfCSP and a GFP-luciferase fusion protein (PbPfCSP-GFP/Luc), was assessed by in vivo bioluminescence imaging and blood-stage parasite growth. Transmission reducing activity (TRA) was evaluated in standard membrane feeding assays (SMFA). High levels of PfCSP- and Pfs25-specific antibodies were induced in mice immunized with either DNA vaccine alone or in combination. No difference in antibody titer and avidity was observed for both PfCSP and Pfs25 between the single DNA and combined DNA immunization groups. When challenged by PbPfCSP-GFP/Luc sporozoites, mice immunized with PfCSP alone or combined with Pfs25 revealed significantly reduced liver-stage parasite loads as compared to mice immunized with Pfs25, used as a control. Furthermore, parasite liver loads were negatively correlated with PfCSP-specific antibody levels. When evaluating TRA, we found that immunization with Pfs25 alone or in combination with PfCSP elicited comparable significant transmission reduction. Our studies reveal that the combination of PfCSP and Pfs25 DNAs into a vaccine delivered by in vivo EP in mice does not compromise immunogenicity, infection protection and transmission reduction when compared to each DNA vaccine individually, and provide support for further evaluation of this DNA combination vaccine approach in larger animals and clinical trials.
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Affiliation(s)
- Yi Cao
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
| | - Clifford T. H. Hayashi
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
| | - Fidel Zavala
- Department of Molecular Microbiology & Immunology, Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.Z.); (A.K.T.)
| | - Abhai K. Tripathi
- Department of Molecular Microbiology & Immunology, Johns Hopkins Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.Z.); (A.K.T.)
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington, DC 20052, USA; (H.S.); (C.N.Y.)
| | - Colin N. Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, George Washington University, Washington, DC 20052, USA; (H.S.); (C.N.Y.)
| | - Leor C. Clark
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
| | - Yukari Usuda
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
| | - Jacob M. Van Parys
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
| | - Nirbhay Kumar
- Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC 20052, USA; (Y.C.); (C.T.H.H.); (L.C.C.); (Y.U.); (J.M.V.P.)
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Blackmore K, Simonyan H, Young CN. Estrogen Receptor‐a in the Subfornical Organ Controls Glucose Homeostasis During Obesity in Males. FASEB J 2022. [DOI: 10.1096/fasebj.2022.36.s1.r5932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Katherine Blackmore
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin N. Young
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
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Wu B, Zhang X, Chiang HC, Pan H, Yuan B, Mitra P, Qi L, Simonyan H, Young CN, Yvon E, Hu Y, Zhang N, Li R. RNA polymerase II pausing factor NELF in CD8 + T cells promotes antitumor immunity. Nat Commun 2022; 13:2155. [PMID: 35444206 PMCID: PMC9021285 DOI: 10.1038/s41467-022-29869-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/31/2022] [Indexed: 11/15/2022] Open
Abstract
T cell factor 1 (TCF1) is required for memory and stem-like CD8+ T cell functions. How TCF1 partners with other transcription factors to regulate transcription remains unclear. Here we show that negative elongation factor (NELF), an RNA polymerase II (Pol II) pausing factor, cooperates with TCF1 in T cell responses to cancer. Deletion of mouse Nelfb, which encodes the NELFB subunit, in mature T lymphocytes impairs immune responses to both primary tumor challenge and tumor antigen-mediated vaccination. Nelfb deletion causes more exhausted and reduced memory T cell populations, whereas its ectopic expression boosts antitumor immunity and efficacy of chimeric antigen receptor T-cell immunotherapy. Mechanistically, NELF is associated with TCF1 and recruited preferentially to the enhancers and promoters of TCF1 target genes. Nelfb ablation reduces Pol II pausing and chromatin accessibility at these TCF1-associated loci. Our findings thus suggest an important and rate-limiting function of NELF in anti-tumor immunity. Negative elongation factor B (NELFB) is one of the four subunits of the NELF complex that controls RNA polymerase II pausing. Here the authors show that, by associating with the key T cell transcription factor TCF1, NELFB is required for eliciting CD8 + T cell memory and anti-tumor immune responses.
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Affiliation(s)
- Bogang Wu
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Xiaowen Zhang
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Huai-Chin Chiang
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Haihui Pan
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Bin Yuan
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA
| | - Payal Mitra
- Department of Anatomy & Cell Biology, The George Washington University, Washington, DC, 20037, USA
| | - Leilei Qi
- Department of Anatomy & Cell Biology, The George Washington University, Washington, DC, 20037, USA
| | - Hayk Simonyan
- Department of Pharmacology & Physiology, The George Washington University, Washington, DC, 20037, USA
| | - Colin N Young
- Department of Pharmacology & Physiology, The George Washington University, Washington, DC, 20037, USA
| | - Eric Yvon
- Department of Medicine, The George Washington University Cancer Center School of Medicine & Health Sciences, The George Washington University, Washington, DC, 20037, USA
| | - Yanfen Hu
- Department of Anatomy & Cell Biology, The George Washington University, Washington, DC, 20037, USA
| | - Nu Zhang
- Department of Microbiology, Immunology & Molecular Genetics, University of Texas Health San Antonio, San Antonio, TX, 78229, USA
| | - Rong Li
- Department of Biochemistry & Molecular Medicine, The George Washington University, Washington, DC, 20037, USA.
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7
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Soni V, Adhikari M, Simonyan H, Lin L, Sherman JH, Young CN, Keidar M. In Vitro and In Vivo Enhancement of Temozolomide Effect in Human Glioblastoma by Non-Invasive Application of Cold Atmospheric Plasma. Cancers (Basel) 2021; 13:4485. [PMID: 34503293 PMCID: PMC8430547 DOI: 10.3390/cancers13174485] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 01/21/2023] Open
Abstract
Glioblastoma (GBM) is one of the most aggressive forms of adult brain cancers and is highly resistant to treatment, with a median survival of 12-18 months after diagnosis. The poor survival is due to its infiltrative pattern of invasion into the normal brain parenchyma, the diffuse nature of its growth, and its ability to quickly grow, spread, and relapse. Temozolomide is a well-known FDA-approved alkylating chemotherapy agent used for the treatment of high-grade malignant gliomas, and it has been shown to improve overall survival. However, in most cases, the tumor relapses. In recent years, CAP has been used as an emerging technology for cancer therapy. The purpose of this study was to implement a combination therapy of CAP and TMZ to enhance the effect of TMZ and apparently sensitize GBMs. In vitro evaluations in TMZ-sensitive and resistant GBM cell lines established a CAP chemotherapy enhancement and potential sensitization effect across various ranges of CAP jet application. This was further supported with in vivo findings demonstrating that a single CAP jet applied non-invasively through the skull potentially sensitizes GBM to subsequent treatment with TMZ. Gene functional enrichment analysis further demonstrated that co-treatment with CAP and TMZ resulted in a downregulation of cell cycle pathway genes. These observations indicate that CAP can be potentially useful in sensitizing GBM to chemotherapy and for the treatment of glioblastoma as a non-invasive translational therapy.
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Affiliation(s)
- Vikas Soni
- Department of Mechanical and Aerospace Engineering, MPNL, The George Washington University, Washington, DC 20052, USA; (V.S.); (M.A.); (L.L.); (J.H.S.)
| | - Manish Adhikari
- Department of Mechanical and Aerospace Engineering, MPNL, The George Washington University, Washington, DC 20052, USA; (V.S.); (M.A.); (L.L.); (J.H.S.)
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20052, USA;
| | - Li Lin
- Department of Mechanical and Aerospace Engineering, MPNL, The George Washington University, Washington, DC 20052, USA; (V.S.); (M.A.); (L.L.); (J.H.S.)
| | - Jonathan H. Sherman
- Department of Mechanical and Aerospace Engineering, MPNL, The George Washington University, Washington, DC 20052, USA; (V.S.); (M.A.); (L.L.); (J.H.S.)
| | - Colin N. Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20052, USA;
| | - Michael Keidar
- Department of Mechanical and Aerospace Engineering, MPNL, The George Washington University, Washington, DC 20052, USA; (V.S.); (M.A.); (L.L.); (J.H.S.)
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Dow S, Arestakesyan H, Simonyan H, Young C. Brain Cellular Senescence as a Potential Mediator of Angiotensin II‐Induced Hypertension. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.03919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Samantha Dow
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hovhannes Arestakesyan
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin Young
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
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Kim HR, Simonyan H, Young C. Forebrain microglia involvement in non‐alcoholic fatty liver disease during obesity. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.04140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Han Rae Kim
- Department of Pharmacology & PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Department of Pharmacology & PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin Young
- Department of Pharmacology & PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
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10
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Banik D, Noonepalle S, Hadley M, Palmer E, Gracia-Hernandez M, Zevallos-Delgado C, Manhas N, Simonyan H, Young CN, Popratiloff A, Chiappinelli KB, Fernandes R, Sotomayor EM, Villagra A. HDAC6 Plays a Noncanonical Role in the Regulation of Antitumor Immune Responses, Dissemination, and Invasiveness of Breast Cancer. Cancer Res 2020; 80:3649-3662. [PMID: 32605998 PMCID: PMC7484424 DOI: 10.1158/0008-5472.can-19-3738] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/27/2020] [Accepted: 06/24/2020] [Indexed: 12/24/2022]
Abstract
Despite the outstanding clinical results of immune checkpoint blockade (ICB) in melanoma and other cancers, clinical trials in breast cancer have reported low responses to these therapies. Current efforts are now focused on improving the treatment efficacy of ICB in breast cancer using new combination designs such as molecularly targeted agents, including histone deacetylase inhibitors (HDACi). These epigenetic drugs have been widely described as potent cytotoxic agents for cancer cells. In this work, we report new noncanonical regulatory properties of ultra-selective HDAC6i over the expression and function of epithelial-mesenchymal transition pathways and the invasiveness potential of breast cancer. These unexplored roles position HDAC6i as attractive options to potentiate ongoing immunotherapeutic approaches. These new functional activities of HDAC6i involved regulation of the E-cadherin/STAT3 axis. Pretreatment of tumors with HDAC6i induced critical changes in the tumor microenvironment, resulting in improved effectiveness of ICB and preventing dissemination of cancer cells to secondary niches. Our results demonstrate for the first time that HDAC6i can both improve ICB antitumor immune responses and diminish the invasiveness of breast cancer with minimal cytotoxic effects, thus departing from the cytotoxicity-centric paradigm previously assigned to HDACi. SIGNIFICANCE: Ultraselective HDAC6 inhibitors can reduce tumor growth and invasiveness of breast cancer by noncanonical mechanisms unrelated to the previously cytotoxic properties attributed to HDAC inhibitors.
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Affiliation(s)
| | | | | | - Erica Palmer
- The George Washington University, Washington, DC
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11
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Blackmore K, Simonyan H, Young CN. Inhibition of a Forebrain‐Hypothalamic Circuit Ameliorates Hepatic Steatosis During Obesity. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.04828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Hayk Simonyan
- George Washington University School of Medicine and Health Sciences
| | - Colin N. Young
- George Washington University School of Medicine and Health Sciences
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12
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Jeong JK, Simonyan H, Young CN. Pre‐hypertensive molecular alterations in the paraventricular nucleus of the hypothalamus during angiotensin‐II hypertension. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.03462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jin Kwon Jeong
- George Washington University School of Medicine and Health Sciences
| | - Hayk Simonyan
- George Washington University School of Medicine and Health Sciences
| | - Colin N. Young
- George Washington University School of Medicine and Health Sciences
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Jeong JK, Simonyan H, Young C. Abstract P2026: Involvement of Subfornical Organ Insulin Receptor Signaling in the Development of Angiotensin-II Hypertension. Hypertension 2019. [DOI: 10.1161/hyp.74.suppl_1.p2026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neurocardiovascular dysfunction due to angiotensin-II (Ang-II) signaling within the brain has emerged as a key mechanism in hypertension development. Interestingly, the hormone insulin is also closely associated with multiple forms of hypertension. Emerging evidence suggests interactions between insulin receptor and Ang-II type 1a receptor (AT
1a
R) signaling, although the extent to which this contributes to hypertension development remains unclear. Based on this, we hypothesized that brain insulin receptor signaling is involved in Ang-II hypertension. Male C57Bl/6J mice were instrumented with intracerebroventricular cannula (ICV) and radiotelemeters for conscious cardiovascular measurements. Subsequently, administration of Ang-II (600 ng/kg/min) over 2 wk resulted in the development of hypertension in control animals; daily ICV insulin receptor antagonism with the pharmacological agent S961 (3.5 nM) prevented hypertension development (e.g. day 14 mean arterial pressure 118±6 vs 110±6 mmHg, ICV vehicle vs ICV S961, p=0.05). Given the well-known role for the subfornical organ, a forebrain region that lacks a blood-brain-barrier, in this model of hypertension, we next focused our attention on this nucleus. Insulin receptor immunohistochemistry in AT
1a
R eGFP reporter mice (GENSAT NZ44) revealed that insulin receptors were present on 69% of AT
1a
R cells (42 of 62, n=3) in the SFO. Acute insulin administration (i.p. 5U) was also used to explore SFO insulin receptor-associated intracellular signaling including phosphorylation of AKT [pAkt; phosphatidylinositol 3-kinase (PI3K) signaling] and ERK1/2 [pERK; mitogen-activated protein kinase (MAPK) signaling]. Analysis of over 4000 SFO cells indicated that insulin resulted in activation of the PI3K pathway as demonstrated by an increase in the percentage of cells with medium to high pAKT expression (5±1 vs 14±1% per section, vehicle vs insulin, n=3-4, 5-10 sections/animal). In contrast, acute insulin administration did not influence SFO pERK. Collectively, these findings indicate that brain insulin receptor signaling is necessary for the development of Ang-II hypertension, and that this response may be mediated by interactions between Ang-II and insulin and/or PI3K signaling in the SFO.
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Hurr C, Simonyan H, Morgan DA, Rahmouni K, Young CN. Liver sympathetic denervation reverses obesity-induced hepatic steatosis. J Physiol 2019; 597:4565-4580. [PMID: 31278754 DOI: 10.1113/jp277994] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 06/26/2019] [Indexed: 01/05/2023] Open
Abstract
KEY POINTS Non-alcoholic fatty liver disease, characterized in part by elevated liver triglycerides (i.e. hepatic steatosis), is a growing health problem. In this study, we found that hepatic steatosis is associated with robust hepatic sympathetic overactivity. Removal of hepatic sympathetic nerves reduced obesity-induced hepatic steatosis. Liver sympathetic innervation modulated hepatic lipid acquisition pathways during obesity. ABSTRACT Non-alcoholic fatty liver disease (NAFLD) affects 1 in 3 Americans and is a significant risk factor for type II diabetes mellitus, insulin resistance and hepatic carcinoma. Characterized in part by excessive hepatic triglyceride accumulation (i.e. hepatic steatosis), the incidence of NAFLD is increasing - in line with the growing obesity epidemic. The role of the autonomic nervous system in NAFLD remains unclear. Here, we show that chronic hepatic sympathetic overactivity mediates hepatic steatosis. Direct multiunit recordings of hepatic sympathetic nerve activity were obtained in high fat diet and normal chow fed male C57BL/6J mice. To reduce hepatic sympathetic nerve activity we utilized two approaches including pharmacological ablation of the sympathetic nerves and phenol-based hepatic sympathetic nerve denervation. Diet-induced NAFLD was associated with a nearly doubled firing rate of the hepatic sympathetic nerves, which was largely due to an increase in efferent nerve traffic. Furthermore, established high fat diet-induced hepatic steatosis was effectively reduced with pharmacological or phenol-based removal of the hepatic sympathetic nerves, independent of changes in body weight, caloric intake or adiposity. Ablation of liver sympathetic nerves was also associated with improvements in liver triglyceride accumulation pathways including free fatty acid uptake and de novo lipogenesis. These findings highlight an unrecognized pathogenic link between liver sympathetic outflow and hepatic steatosis and suggest that manipulation of the liver sympathetic nerves may represent a novel therapeutic strategy for NAFLD.
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Affiliation(s)
- Chansol Hurr
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA.,Department of Physical Education, Chonbuk National University, Jeonju, South Korea
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
| | - Donald A Morgan
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
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15
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Jeong JK, Horwath JA, Simonyan H, Blackmore KA, Butler SD, Young CN. Subfornical organ insulin receptors tonically modulate cardiovascular and metabolic function. Physiol Genomics 2019; 51:333-341. [PMID: 31172876 DOI: 10.1152/physiolgenomics.00021.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Insulin acts within the central nervous system through the insulin receptor to influence both metabolic and cardiovascular physiology. While a major focus has been placed on hypothalamic regions, participation of extrahypothalamic insulin receptors in cardiometabolic regulation remains largely unknown. We hypothesized that insulin receptors in the subfornical organ (SFO), a forebrain circumventricular region devoid of a blood-brain barrier, are involved in metabolic and cardiovascular regulation. Immunohistochemistry in mice revealed widespread insulin receptor-positive cells throughout the rostral to caudal extent of the SFO. SFO-targeted adenoviral delivery of Cre-recombinase in insulin receptorlox/lox mice resulted in sufficient ablation of insulin receptors in the SFO. Interestingly, when mice were maintained on a normal chow diet, deletion of SFO insulin receptors resulted in greater weight gain and adiposity, relative to controls, independently of changes in food intake. In line with this, ablation of insulin receptors in the SFO was associated with marked hepatic steatosis and hypertriglyceridemia. Selective removal of SFO insulin receptors also resulted in a lower mean arterial blood pressure, which was primarily due to a reduction in diastolic blood pressure, whereas systolic blood pressure remained unchanged. Cre-mediated targeting of SFO insulin receptors did not influence heart rate. These data demonstrate multidirectional roles for insulin receptor signaling in the SFO, with ablation of SFO insulin receptors resulting in an overall deleterious metabolic state while at the same time maintaining blood pressure at low levels. These novel findings further suggest that alterations in insulin receptor signaling in the SFO could contribute to metabolic syndrome phenotypes.
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Affiliation(s)
- Jin Kwon Jeong
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Julie A Horwath
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Katherine A Blackmore
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Scott D Butler
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
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16
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Jeong JK, Simonyan H, Young C. Investigation of Insulin Receptor‐Associated Neuronal Phenotypes in the Subfornical Organ of the Brain. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.554.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jin Kwon Jeong
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin Young
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
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17
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Houchen CJ, Blackmore K, Simonyan H, Young CN. Activation of a Forebrain‐Hypothalamic Circuit Disrupts Hepatic Lipid Regulatory Pathways. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.869.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Claire J. Houchen
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Katherine Blackmore
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin N. Young
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
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18
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Blackmore K, Simonyan H, Young C. A Subfornical Organ→Paraventricular Nucleus Neuronal Network Contributes to Non‐Alcoholic Fatty Liver Disease via Hepatic Sympathetic Outflow. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.850.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Katherine Blackmore
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin Young
- Pharmacology and PhysiologyGeorge Washington University School of Medicine and Health SciencesWashingtonDC
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19
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Hurr C, Ritchie BJ, Simonyan H, Young CN. Hypertensive Actions of Long Chain Fatty Acids are Paralleled by Toll‐Like Receptor 4 Upregulation and Nuclear Factor‐kB (NFkB) Activation in the Subfornical Organ. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.591.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chansol Hurr
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
| | | | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
| | - Colin N. Young
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
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20
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Hurr C, Simonyan H, Young CN. Hepatic Sympathetic Denervation Reduces Hepatic Steatosis and Blunts Liver Lipid Acquisition Pathways in Diet‐Induced Obese Mice. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.873.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chansol Hurr
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
| | - Colin N. Young
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
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21
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Blackmore KA, Houchen CJ, Simonyan H, Young CN. A Forebrain‐Hypothalamic Circuit Mediates Hepatic Steatosis. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.885.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Katherine A. Blackmore
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Claire J. Houchen
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Hayk Simonyan
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
| | - Colin N. Young
- Department of Pharmacology and PhysiologyThe George Washington University School of Medicine and Health SciencesWashingtonDC
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Simonyan H, Chen Z, Sherman J, Cheng X, Keidar M, Young CN. INTRACRANIAL TARGETING OF GLIOBLASTOMA MULTIFORME WITH COLD ATMOSPHERIC PLASMA. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.599.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hayk Simonyan
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
| | - Zhitong Chen
- Mechanical and Aerospace EngineeringGeorge Washington UniversityWashingtonDC
| | | | - Xiaoqian Cheng
- Mechanical and Aerospace EngineeringGeorge Washington UniversityWashingtonDC
| | - Michael Keidar
- Mechanical and Aerospace EngineeringGeorge Washington UniversityWashingtonDC
| | - Colin N. Young
- Pharmacology and PhysiologyGeorge Washington UniversityWashingtonDC
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23
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Jeong JK, Simonyan H, Young CN. Insulin receptor signaling in the subfornical organ protects against the development of metabolic syndrome. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.923.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jin Kwon Jeong
- Pharmacology and PhysiologyThe George Washington UniversityWashington DCDC
| | - Hayk Simonyan
- Pharmacology and PhysiologyThe George Washington UniversityWashington DCDC
| | - Colin N. Young
- Pharmacology and PhysiologyThe George Washington UniversityWashington DCDC
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Simonyan H, Sargsyan A, Balalian A. Model for fighting undernutrition among 0-6 yo children in rural communities in Armenia. Eur J Public Health 2016. [DOI: 10.1093/eurpub/ckw172.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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25
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Simonyan H, Hurr C, Young CN. A synthetic luciferin improves in vivo bioluminescence imaging of gene expression in cardiovascular brain regions. Physiol Genomics 2016; 48:762-770. [PMID: 27614203 PMCID: PMC5243229 DOI: 10.1152/physiolgenomics.00055.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/02/2016] [Indexed: 12/18/2022] Open
Abstract
Bioluminescence imaging is an effective tool for in vivo investigation of molecular processes. We have demonstrated the applicability of bioluminescence imaging to spatiotemporally monitor gene expression in cardioregulatory brain nuclei during the development of cardiovascular disease, via incorporation of firefly luciferase into living animals, combined with exogenous d-luciferin substrate administration. Nevertheless, d-luciferin uptake into the brain tissue is low, which decreases the sensitivity of bioluminescence detection, particularly when considering small changes in gene expression in tiny central areas. Here, we tested the hypothesis that a synthetic luciferin, cyclic alkylaminoluciferin (CycLuc1), would be superior to d-luciferin for in vivo bioluminescence imaging in cardiovascular brain regions. Male C57B1/6 mice underwent targeted delivery of an adenovirus encoding the luciferase gene downstream of the CMV promoter to the subfornical organ (SFO) or paraventricular nucleus of hypothalamus (PVN), two crucial cardioregulatory neural regions. While bioluminescent signals could be obtained following d-luciferin injection (150 mg/kg), CycLuc1 administration resulted in a three- to fourfold greater bioluminescent emission from the SFO and PVN, at 10- to 20-fold lower substrate concentrations (7.5-15 mg/kg). This CycLuc1-mediated enhancement in bioluminescent emission was evident early following substrate administration (i.e., 6-10 min) and persisted for up to 1 h. When the exposure time was reduced from 60 s to 1,500 ms, minimal signal in the PVN was detectable with d-luciferin, whereas bioluminescent images could be reliably captured with CycLuc1. These findings demonstrate that bioluminescent imaging with the synthetic luciferin CycLuc1 provides an improved physiological genomics tool to investigate molecular events in discrete cardioregulatory brain nuclei.
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Affiliation(s)
- Hayk Simonyan
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Chansol Hurr
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
| | - Colin N Young
- Department of Pharmacology and Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, District of Columbia
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26
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Balalian A, Simonyan H, Hekimian K. A New Approach: Qualitative Evaluation of Continuing medical education Nagorno Karabagh, March 2013. Eur J Public Health 2013. [DOI: 10.1093/eurpub/ckt124.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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