1
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Tallon C, Bell BJ, Malvankar MM, Deme P, Nogueras-Ortiz C, Eren E, Thomas AG, Hollinger KR, Pal A, Mustapic M, Huang M, Coleman K, Joe TR, Rais R, Haughey NJ, Kapogiannis D, Slusher BS. Inhibiting tau-induced elevated nSMase2 activity and ceramides is therapeutic in an Alzheimer's disease mouse model. Transl Neurodegener 2023; 12:56. [PMID: 38049923 PMCID: PMC10694940 DOI: 10.1186/s40035-023-00383-9] [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] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/23/2023] [Indexed: 12/06/2023] Open
Abstract
BACKGROUND Cognitive decline in Alzheimer's disease (AD) is associated with hyperphosphorylated tau (pTau) propagation between neurons along synaptically connected networks, in part via extracellular vesicles (EVs). EV biogenesis is triggered by ceramide enrichment at the plasma membrane from neutral sphingomyelinase2 (nSMase2)-mediated cleavage of sphingomyelin. We report, for the first time, that human tau expression elevates brain ceramides and nSMase2 activity. METHODS To determine the therapeutic benefit of inhibiting this elevation, we evaluated PDDC, the first potent, selective, orally bioavailable, and brain-penetrable nSMase2 inhibitor in the transgenic PS19 AD mouse model. Additionally, we directly evaluated the effect of PDDC on tau propagation in a mouse model where an adeno-associated virus (AAV) encoding P301L/S320F double mutant human tau was stereotaxically-injected unilaterally into the hippocampus. The contralateral transfer of the double mutant human tau to the dentate gyrus was monitored. We examined ceramide levels, histopathological changes, and pTau content within EVs isolated from the mouse plasma. RESULTS Similar to human AD, the PS19 mice exhibited increased brain ceramide levels and nSMase2 activity; both were completely normalized by PDDC treatment. The PS19 mice also exhibited elevated tau immunostaining, thinning of hippocampal neuronal cell layers, increased mossy fiber synaptophysin immunostaining, and glial activation, all of which were pathologic features of human AD. PDDC treatment reduced these changes. The plasma of PDDC-treated PS19 mice had reduced levels of neuronal- and microglial-derived EVs, the former carrying lower pTau levels, compared to untreated mice. In the tau propagation model, PDDC normalized the tau-induced increase in brain ceramides and significantly reduced the amount of tau propagation to the contralateral side. CONCLUSIONS PDDC is a first-in-class therapeutic candidate that normalizes elevated brain ceramides and nSMase2 activity, leading to the slowing of tau spread in AD mice.
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Affiliation(s)
- Carolyn Tallon
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Benjamin J Bell
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Medhinee M Malvankar
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Pragney Deme
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Carlos Nogueras-Ortiz
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Ste 8C228, Baltimore, MD, 21224, USA
| | - Erden Eren
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Ste 8C228, Baltimore, MD, 21224, USA
| | - Ajit G Thomas
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Kristen R Hollinger
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Arindom Pal
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Maja Mustapic
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Ste 8C228, Baltimore, MD, 21224, USA
| | - Meixiang Huang
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Kaleem Coleman
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Tawnjerae R Joe
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Rana Rais
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Norman J Haughey
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Rangos 278, Baltimore, MD, 21205, USA.
- Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Pathology 517, Baltimore, MD, 21287, USA.
| | - Dimitrios Kapogiannis
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Intramural Research Program, Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, 251 Bayview Blvd, Ste 8C228, Baltimore, MD, 21224, USA.
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, 855 N. Wolfe Street, Rangos 278, Baltimore, MD, 21205, USA.
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Liu Q, Bell BJ, Kim DW, Lee SS, Keles MF, Liu Q, Blum ID, Wang AA, Blank EJ, Xiong J, Bedont JL, Chang AJ, Issa H, Cohen JY, Blackshaw S, Wu MN. A clock-dependent brake for rhythmic arousal in the dorsomedial hypothalamus. Nat Commun 2023; 14:6381. [PMID: 37821426 PMCID: PMC10567910 DOI: 10.1038/s41467-023-41877-4] [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] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
Circadian clocks generate rhythms of arousal, but the underlying molecular and cellular mechanisms remain unclear. In Drosophila, the clock output molecule WIDE AWAKE (WAKE) labels rhythmic neural networks and cyclically regulates sleep and arousal. Here, we show, in a male mouse model, that mWAKE/ANKFN1 labels a subpopulation of dorsomedial hypothalamus (DMH) neurons involved in rhythmic arousal and acts in the DMH to reduce arousal at night. In vivo Ca2+ imaging reveals elevated DMHmWAKE activity during wakefulness and rapid eye movement (REM) sleep, while patch-clamp recordings show that DMHmWAKE neurons fire more frequently at night. Chemogenetic manipulations demonstrate that DMHmWAKE neurons are necessary and sufficient for arousal. Single-cell profiling coupled with optogenetic activation experiments suggest that GABAergic DMHmWAKE neurons promote arousal. Surprisingly, our data suggest that mWAKE acts as a clock-dependent brake on arousal during the night, when mice are normally active. mWAKE levels peak at night under clock control, and loss of mWAKE leads to hyperarousal and greater DMHmWAKE neuronal excitability specifically at night. These results suggest that the clock does not solely promote arousal during an animal's active period, but instead uses opposing processes to produce appropriate levels of arousal in a time-dependent manner.
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Affiliation(s)
- Qiang Liu
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Benjamin J Bell
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21205, USA
- Danish Research Institute of Translational Neuroscience, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Sang Soo Lee
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Mehmet F Keles
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Qili Liu
- Department of Anatomy, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Ian D Blum
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Annette A Wang
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Elijah J Blank
- Biochemistry, Cellular and Molecular Biology Program, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Jiali Xiong
- Biochemistry, Cellular and Molecular Biology Program, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Joseph L Bedont
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Anna J Chang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Habon Issa
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA
| | | | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, MD, 21205, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, 21205, USA.
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Tallon C, Bell BJ, Malvankar MM, Deme P, Nogueras-Ortiz C, Eren E, Thomas AG, Hollinger KR, Pal A, Mustapic M, Huang M, Coleman K, Joe TR, Rais R, Haughey NJ, Kapogiannis D, Slusher BS. Inhibiting tau-induced elevated nSMase2 activity and ceramides is therapeutic in murine Alzheimer's disease. Res Sq 2023:rs.3.rs-3131295. [PMID: 37502930 PMCID: PMC10371082 DOI: 10.21203/rs.3.rs-3131295/v1] [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] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Background Cognitive decline in Alzheimer's disease (AD) is associated with prion-like tau propagation between neurons along synaptically connected networks, in part via extracellular vesicles (EV). EV biogenesis is triggered by ceramide enrichment at the plasma membrane from neutral sphingomyelinase2(nSMase2)-mediated cleavage of sphingomyelin. We report, for the first time, that tau expression triggers an elevation in brain ceramides and nSMase2 activity. Methods To determine the therapeutic benefit of inhibiting this elevation, we evaluated the efficacy of PDDC, the first potent, selective, orally bioavailable, and brain-penetrable nSMase2 inhibitor, in the PS19 tau transgenic AD murine model. Changes in brain ceramide and sphingomyelin levels, Tau content, histopathology, and nSMase2 target engagement were monitored, as well as changes in the number of brain-derived EVs in plasma and their Tau content. Additionally, we evaluated the ability of PDDC to impede tau propagation in a murine model where an adeno-associated virus(AAV) encoding for P301L/S320F double mutant human tau was stereotaxically-injected unilaterally into the hippocampus and the contralateral transfer to the dentate gyrus was monitored. Results Similar to human AD, PS19 mice exhibited increased brain ceramides and nSMase2 activity; both were completely normalized by PDDC treatment. PS19 mice exhibited elevated tau immunostaining, thinning of hippocampal neuronal cell layers, increased mossy fiber synaptophysin immunostaining, and glial activation, all pathologic features of human AD. PDDC treatment significantly attenuated these aberrant changes. Mouse plasma isolated from PDDC-treated PS19 mice exhibited reduced levels of neuron- and microglia-derived EVs, the former carrying lower phosphorylated Tau(pTau) levels, compared to untreated mice. In the AAV tau propagation model, PDDC normalized the tau-induced increase in brain ceramides and significantly decreased tau spreading to the contralateral side. Conclusions PDDC is a first-in-class therapeutic candidate that normalizes elevated brain ceramides and nSMase2 activity leading to the slowing of tau spread in AD mice.
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Affiliation(s)
| | | | | | | | | | - Erden Eren
- National Institute on Aging Laboratory of Clinical Investigation
| | | | | | | | - Maja Mustapic
- National Institute on Aging Laboratory of Clinical Investigation
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4
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Tallon C, Bell BJ, Malvankar M, Thomas AG, Yoo SW, Pal A, Wu Y, Coleman K, Joe TR, Sharma A, Eren E, Zhu X, Kannan RM, Kapogiannis D, Haughey NJ, Rais R, Slusher BS. nSMase2 inhibition reduces tau propagation in Alzheimer’s Disease mouse models. Alzheimers Dement 2022. [DOI: 10.1002/alz.063639] [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: 12/24/2022]
Affiliation(s)
- Carolyn Tallon
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Benjamin J Bell
- Johns Hopkins University School of Medicine Baltimore MD USA
| | | | - Ajit G Thomas
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Seung Wan Yoo
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Arindom Pal
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Ying Wu
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Kaleem Coleman
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Tawnjerae R Joe
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Anjali Sharma
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Erden Eren
- National Institute on Aging/National Institutes of Health Baltimore MD USA
| | - Xiaolei Zhu
- Johns Hopkins University School of Medicine Baltimore MD USA
| | | | | | | | - Rana Rais
- Johns Hopkins University School of Medicine Baltimore MD USA
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5
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Tallon C, Bell BJ, Sharma A, Pal A, Malvankar MM, Thomas AG, Yoo SW, Hollinger KR, Coleman K, Wilkinson EL, Kannan S, Haughey NJ, Kannan RM, Rais R, Slusher BS. Dendrimer-Conjugated nSMase2 Inhibitor Reduces Tau Propagation in Mice. Pharmaceutics 2022; 14:pharmaceutics14102066. [PMID: 36297501 PMCID: PMC9609094 DOI: 10.3390/pharmaceutics14102066] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 08/23/2022] [Revised: 09/11/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by the progressive accumulation of amyloid-β and hyperphosphorylated tau (pTau), which can spread throughout the brain via extracellular vesicles (EVs). Membrane ceramide enrichment regulated by the enzyme neutral sphingomyelinase 2 (nSMase2) is a critical component of at least one EV biogenesis pathway. Our group recently identified 2,6-Dimethoxy-4-(5-Phenyl-4-Thiophen-2-yl-1H-Imidazol-2-yl)-Phenol (DPTIP), the most potent (30 nM) and selective inhibitor of nSMase2 reported to date. However, DPTIP exhibits poor oral pharmacokinetics (PK), modest brain penetration, and rapid clearance, limiting its clinical translation. To enhance its PK properties, we conjugated DPTIP to a hydroxyl-PAMAM dendrimer delivery system, creating dendrimer-DPTIP (D-DPTIP). In an acute brain injury model, orally administered D-DPTIP significantly reduced the intra-striatal IL-1β-induced increase in plasma EVs up to 72 h post-dose, while oral DPTIP had a limited effect. In a mouse tau propagation model, where a mutant hTau (P301L/S320F) containing adeno-associated virus was unilaterally seeded into the hippocampus, oral D-DPTIP (dosed 3× weekly) significantly inhibited brain nSMase2 activity and blocked the spread of pTau to the contralateral hippocampus. These data demonstrate that dendrimer conjugation of DPTIP improves its PK properties, resulting in significant inhibition of EV propagation of pTau in mice. Dendrimer-based delivery of DPTIP has the potential to be an exciting new therapeutic for AD.
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Affiliation(s)
- Carolyn Tallon
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Benjamin J. Bell
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Anjali Sharma
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
| | - Arindom Pal
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | | | - Seung-Wan Yoo
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Kaleem Coleman
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Elizabeth L. Wilkinson
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Moser Center for Leukodystrophies at Kennedy Krieger, Kennedy Krieger Institute, Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Sujatha Kannan
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Hugo W. Moser Research Institute at Kennedy-Krieger Inc., Baltimore, MD 21205, USA
- Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Norman J. Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Center for Nanomedicine at the Wilmer Eye Institute, Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rangaramanujam M. Kannan
- Center for Nanomedicine, Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21231, USA
- Moser Center for Leukodystrophies at Kennedy Krieger, Kennedy Krieger Institute, Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rana Rais
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Correspondence: (R.R.); (B.S.S.); Tel.: +1-410-800-8049 (R.R.); +1-410-960-6162 (B.S.S.)
| | - Barbara S. Slusher
- Johns Hopkins Drug Discovery, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Center for Nanomedicine at the Wilmer Eye Institute, Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Correspondence: (R.R.); (B.S.S.); Tel.: +1-410-800-8049 (R.R.); +1-410-960-6162 (B.S.S.)
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Bell BJ, Hollinger KR, Deme P, Sakamoto S, Hasegawa Y, Volsky D, Kamiya A, Haughey N, Zhu X, Slusher BS. Glutamine antagonist JHU083 improves psychosocial behavior and sleep deficits in EcoHIV-infected mice. Brain Behav Immun Health 2022; 23:100478. [PMID: 35734753 PMCID: PMC9207540 DOI: 10.1016/j.bbih.2022.100478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/02/2022] [Accepted: 05/30/2022] [Indexed: 10/31/2022] Open
Abstract
Combined antiretroviral therapy ushered an era of survivable HIV infection in which people living with HIV (PLH) conduct normal life activities and enjoy measurably extended lifespans. However, despite viral control, PLH often experience a variety of cognitive, emotional, and physical phenotypes that diminish their quality of life, including cognitive impairment, depression, and sleep disruption. Recently, accumulating evidence has linked persistent CNS immune activation to the overproduction of glutamate and upregulation of glutaminase (GLS) activity, particularly in microglial cells, driving glutamatergic imbalance with neurological consequences. Our lab has developed a brain-penetrant prodrug of the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON), JHU083, that potently inhibits brain GLS activity in mice following oral administration. To assess the therapeutic potential of JHU083, we infected mice with EcoHIV and characterized their neurobehavioral phenotypes. EcoHIV-infected mice exhibited decreased social interaction, suppressed sucrose preference, disrupted sleep during the early rest period, and increased sleep fragmentation, similar to what has been reported in PLH but not yet observed in murine models. At doses shown to inhibit microglial GLS, JHU083 treatment ameliorated all of the abnormal neurobehavioral phenotypes. To explore potential mechanisms underlying this effect, hippocampal microglia were isolated for RNA sequencing. The dysregulated genes and pathways in EcoHIV-infected hippocampal microglia pointed to disruptions in immune functions of these cells, which were partially restored by JHU083 treatment. These findings suggest that upregulation of microglial GLS may affect immune functions of these cells. Thus, brain-penetrable GLS inhibitors like JHU083 could act as a potential therapeutic modality for both glutamate excitotoxicity and aberrant immune activation in microglia in chronic HIV infection.
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Tallon C, Bell BJ, Malvankar M, Hollinger KR, Thomas AG, Yoo SW, Chaudhuri AD, Wu Y, Rais R, Haughey NJ, Slusher BS. The neutral sphingomyelinase 2 inhibitor PDDC reduces tau burden in Alzheimer’s disease mice. Alzheimers Dement 2021. [DOI: 10.1002/alz.054502] [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: 11/09/2022]
Affiliation(s)
- Carolyn Tallon
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Benjamin J Bell
- Johns Hopkins University School of Medicine Baltimore MD USA
| | | | | | - Ajit G Thomas
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Seung Wan Yoo
- Johns Hopkins University School of Medicine Baltimore MD USA
| | | | - Ying Wu
- Johns Hopkins University School of Medicine Baltimore MD USA
| | - Rana Rais
- Johns Hopkins University School of Medicine Baltimore MD USA
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Tallon C, Hollinger KR, Pal A, Bell BJ, Rais R, Tsukamoto T, Witwer KW, Haughey NJ, Slusher BS. Nipping disease in the bud: nSMase2 inhibitors as therapeutics in extracellular vesicle-mediated diseases. Drug Discov Today 2021; 26:1656-1668. [PMID: 33798648 DOI: 10.1016/j.drudis.2021.03.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [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: 02/21/2021] [Revised: 03/04/2021] [Accepted: 03/24/2021] [Indexed: 12/11/2022]
Abstract
Extracellular vesicles (EVs) are indispensable mediators of intercellular communication, but they can also assume a nefarious role by ferrying pathological cargo that contributes to neurological, oncological, inflammatory, and infectious diseases. The canonical pathway for generating EVs involves the endosomal sorting complexes required for transport (ESCRT) machinery, but an alternative pathway is induced by the enrichment of lipid membrane ceramides generated by neutral sphingomyelinase 2 (nSMase2). Inhibition of nSMase2 has become an attractive therapeutic strategy for inhibiting EV biogenesis, and a growing number of small-molecule nSMase2 inhibitors have shown promising therapeutic activity in preclinical disease models. This review outlines the function of EVs, their potential role in disease, the discovery and efficacy of nSMase2 inhibitors, and the path to translate these findings into therapeutics.
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Affiliation(s)
- Carolyn Tallon
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kristen R Hollinger
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Arindom Pal
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Benjamin J Bell
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Rana Rais
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Takashi Tsukamoto
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Kenneth W Witwer
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Norman J Haughey
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Barbara S Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychiatry and Behavioral Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Pharmacology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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9
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Bell BJ, Wang AA, Kim DW, Xiong J, Blackshaw S, Wu MN. Characterization of mWake expression in the murine brain. J Comp Neurol 2020; 529:1954-1987. [PMID: 33140455 DOI: 10.1002/cne.25066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 08/07/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 01/24/2023]
Abstract
Structure-function analyses of the mammalian brain have historically relied on anatomically-based approaches. In these investigations, physical, chemical, or electrolytic lesions of anatomical structures are applied, and the resulting behavioral or physiological responses assayed. An alternative approach is to focus on the expression pattern of a molecule whose function has been characterized and then use genetic intersectional methods to optogenetically or chemogenetically manipulate distinct circuits. We previously identified WIDE AWAKE (WAKE) in Drosophila, a clock output molecule that mediates the temporal regulation of sleep onset and sleep maintenance. More recently, we have studied the mouse homolog, mWAKE/ANKFN1, and our data suggest that its basic role in the circadian regulation of arousal is conserved. Here, we perform a systematic analysis of the expression pattern of mWake mRNA, protein, and cells throughout the adult mouse brain. We find that mWAKE labels neurons in a restricted, but distributed manner, in multiple regions of the hypothalamus (including the suprachiasmatic nucleus, dorsomedial hypothalamus, and tuberomammillary nucleus region), the limbic system, sensory processing nuclei, and additional specific brainstem, subcortical, and cortical areas. Interestingly, mWAKE is also observed in non-neuronal ependymal cells. In addition, to describe the molecular identities and clustering of mWake+ cells, we provide detailed analyses of single cell RNA sequencing data from the hypothalamus, a region with particularly significant mWAKE expression. These findings lay the groundwork for future studies into the potential role of mWAKE+ cells in the rhythmic control of diverse behaviors and physiological processes.
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Affiliation(s)
- Benjamin J Bell
- McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Annette A Wang
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Dong Won Kim
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jiali Xiong
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University, Baltimore, Maryland, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mark N Wu
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland, USA
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Abstract
The propagation of pathological proteins throughout the brain is the primary physiological hallmark of the progression of Alzheimer's Disease (AD). A growing body of evidence indicates that hyperphosphorylated Tau proteins are spread transcellularly between neurons in a prionlike fashion, inducing misfolding and aggregation into neurofibrillary tangles which accumulate along specific connectivity pathways. Earlier transgenic rodent AD models did not capture this disease-relevant spread, and therefore, seeded Tau-propagation models have been developed. Here, mutant human Tau (as isolated protein or packaged into an adeno-associated virus (AAV) viral vector) is stereotaxically injected into select brain regions and its histopathological propagation to downstream neurons quantified. These models offer a faster and more direct mechanism to evaluate genetic components and therapeutic approaches which attenuate Tau spreading in vivo. Recently, these Tau-seeding models have revealed several new targets for AD drug discovery, including nSMase2, SIRT1, p300/CBP, LRP1, and TYROBP, as well as the potential therapeutics based on melatonin and chondroitinase ABC. Importantly, these Tau-propagation rodent models more closely phenocopy the progression of AD in humans and are therefore likely to improve preclinical studies and derisk future moves into clinical trials.
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Affiliation(s)
- Benjamin J. Bell
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Medhinee M. Malvankar
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Carolyn Tallon
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Barbara S. Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
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Bell BJ, Nauman E, Voytik-Harbin SL. Multiscale strain analysis of tissue equivalents using a custom-designed biaxial testing device. Biophys J 2012; 102:1303-12. [PMID: 22455913 DOI: 10.1016/j.bpj.2012.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 12/21/2011] [Accepted: 02/03/2012] [Indexed: 01/13/2023] Open
Abstract
Mechanical signals transferred between a cell and its extracellular matrix play an important role in regulating fundamental cell behavior. To further define the complex mechanical interactions between cells and matrix from a multiscale perspective, a biaxial testing device was designed and built. Finite element analysis was used to optimize the cruciform specimen geometry so that stresses within the central region were concentrated and homogenous while minimizing shear and grip effects. This system was used to apply an equibiaxial loading and unloading regimen to fibroblast-seeded tissue equivalents. Digital image correlation and spot tracking were used to calculate three-dimensional strains and associated strain transfer ratios at macro (construct), meso, matrix (collagen fibril), cell (mitochondria), and nuclear levels. At meso and matrix levels, strains in the 1- and 2-direction were statistically similar throughout the loading-unloading cycle. Interestingly, a significant amplification of cellular and nuclear strains was observed in the direction perpendicular to the cell axis. Findings indicate that strain transfer is dependent upon local anisotropies generated by the cell-matrix force balance. Such multiscale approaches to tissue mechanics will assist in advancement of modern biomechanical theories as well as development and optimization of preconditioning regimens for functional engineered tissue constructs.
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Affiliation(s)
- B J Bell
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA
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Kreger ST, Bell BJ, Bailey J, Stites E, Kuske J, Waisner B, Voytik-Harbin SL. Polymerization and matrix physical properties as important design considerations for soluble collagen formulations. Biopolymers 2010; 93:690-707. [PMID: 20235198 DOI: 10.1002/bip.21431] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Despite extensive use of type I collagen for research and medical applications, its fibril-forming or polymerization potential has yet to be fully defined and exploited. Here, we describe a type I collagen formulation that is acid solubilized from porcine skin collagen (PSC), quality controlled based upon polymerization potential, and well suited as a platform polymer for preparing three-dimensional (3D) culture systems and injectable/implantable in vivo cellular microenvironments in which both relevant biochemical and biophysical parameters can be precision-controlled. PSC is compared with three commercial collagens in terms of composition and purity as well as polymerization potential, which is described by kinetic parameters and fibril microstructure and mechanical properties of formed matrices. When subjected to identical polymerization conditions, PSC showed significantly decreased polymerization times compared to the other collagens and yielded matrices with the greatest mechanical integrity and broadest range of mechanical properties as characterized in oscillatory shear, uniaxial extension, and unconfined compression. Compositional and intrinsic viscosity analyses suggest that the enhanced polymerization potential of PSC may be attributed to its unique oligomer composition. Collectively, this work demonstrates the importance of standardizing next generation collagen formulations based upon polymerization potential and provides preliminary insight into the contribution of oligomers to collagen polymerization properties.
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Affiliation(s)
- S T Kreger
- Weldon School of Biomedical Engineering, College of Engineering, Purdue University, West Lafayette, IN 47907, USA
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Bell BJ, Bour ES, Scott JD, Cobb WS, Carbonell AM. Management of complications after laparoscopic Roux-en-Y gastric bypass. MINERVA CHIR 2009; 64:265-276. [PMID: 19536052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Obesity has become an increasing problem in developed countries and laparoscopic Roux-en-Y gastric bypass (LRYGB) is one of the leading treatments for this disease. Although studies show that it is effective in reducing weight and lessening comorbidities, both early and late complications can occur. Early complications include venous thromboembolism, anastomotic leak, and hemorrhage. Late complications include obstruction, anastomotic stenosis, fistula, ulcer, cholelithiasis and nutritional deficiencies. Diagnosis of these complications is often challenging due to the lack of specificity of the presenting signs and symptoms. A high index of suspicion for detecting these complications is universally advocated. Fortunately, mortality from this procedure is rare. Management of the complications is generally consistent with basic surgical principles and surgical reinterventions can often be performed either endoscopically or laparoscopically depending on the situation and the surgeon's expertise. The available literature is confounded by mixing of results between open and laparoscopic techniques as well as the substantial differences in technique between authors reporting their outcomes. Although there is no consensus for managing the reported complications of LRYGB surgery, this article reviews the current literature and describes the presentation, diagnosis, and management of each of the early and late complications associated with the procedure.
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Affiliation(s)
- B J Bell
- Department of Surgery, University of South Carolina School of Medicine, Greenville, SC, USA
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Bell BJ, Watanabe L, Rios-Steiner JL, Tulinsky A, Lebioda L, Arni RK. Structure of 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase from Pseudomonas putida. Acta Crystallogr D Biol Crystallogr 2003; 59:1454-8. [PMID: 12876349 DOI: 10.1107/s0907444903013192] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2003] [Accepted: 06/12/2003] [Indexed: 11/10/2022]
Abstract
2-Keto-3-deoxy-6-phosphogluconate (KDPG) aldolase from Pseudomonas putida is a key enzyme in the Entner-Doudoroff pathway which catalyses the cleavage of KDPG via a class I Schiff-base mechanism. The crystal structure of this enzyme has been refined to a crystallographic residual R = 17.1% (R(free) = 21.4%). The N-terminal helix caps one side of the torus of the (betaalpha)(8)-barrel and the active site is located on the opposite, carboxylic side of the barrel. The Schiff-base-forming Lys145 is coordinated by a sulfate (or phosphate) ion and two solvent water molecules. The interactions that stabilize the trimer are predominantly hydrophobic, with the exception of the cyclically permuted bonds formed between Glu132 OE1 of one molecule and Thr129 OG1 of a symmetry-equivalent molecule. Except for the N-terminal helix, the structure of KDPG aldolase from P. putida closely resembles the structure of the homologous enzyme from Escherichia coli.
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Affiliation(s)
- B J Bell
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
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O'Connell BM, Abel EA, Nickoloff BJ, Bell BJ, Hunt SA, Theodore J, Shumway NE, Jacobs PH. Dermatologic complications following heart transplantation. J Heart Transplant 1986; 5:430-6. [PMID: 2956400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A total of 107 consecutive heart transplant recipients at Stanford University Medical Center were prospectively screened for dermatologic disease as part of their routine postoperative evaluation over a 6-month period. The incidence of nonmelanotic skin tumors and premalignant lesions was approximately 25-fold greater than expected in a normal population. Skin infections were seen in 55% of the patients and dermatologic drug side effects were almost universal including xerosis, hypertrichosis, and steroid acne. Successful excision or cryotherapy of all neoplastic lesions was achieved with no evidence of recurrence to date, a mean of 11 months. The skin infections responded to appropriate antiviral, antibacterial, and antifungal agents and the xerotic and acneiform lesions were successfully treated with emollients and topical retinoic acid, respectively. In addition, patients were instructed in preventive measures including the use of sunscreen agents and protective clothing. We conclude that heart transplant recipients have a significantly increased incidence of neoplastic, infectious, and drug-induced skin diseases. Routine dermatologic screening resulted in early identification and successful treatment of these lesions. We suggest that dermatologic screening is both feasible and valuable in this setting.
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Abstract
A study has been conducted on infants under six months of age during induction and anaesthesia to compare the effect on heat loss when a warming blanket, a humidifier and an overhead heater were used. The combination of all three was associated with significantly less heat loss than when the blanket was used alone. The particular benefit of the overhead heater during prolonged preparation for neurosurgery was also demonstrated. It is recommended that overhead heaters should be used during induction of anaesthesia in infants.
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Mayberger HW, Bell BJ. FDA proposes patient package inserts for most drugs. J Asthma Res 1979; 17:1-5. [PMID: 262454 DOI: 10.3109/02770907909105674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Mayberger HW, Bell BJ. FDA proposes patient package inserts for most drugs. Leg Aspects Med Pract 1979; 7:42-4. [PMID: 263192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Bean MR, Bell BJ. Nursing intervention in the care of the physically handicapped, severely retarded child. Nurs Clin North Am 1975; 10:353-9. [PMID: 124425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Bell BJ. Account of a Varioloid Epidemic Which Occurred in George Watson's Hospital in the Summer of 1835, with Remarks in Illustration of the Antivariolous Power of Vaccination. Edinb Med Surg J 1836; 45:28-38. [PMID: 30330458 PMCID: PMC5781178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Benjamin J. Bell
- Fellow of the Royal College of Surgeons, Edinburgh, Member of the College of Surgeons, London, late House-Surgeon to St Bartholomew's Hospital
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