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Fernandes MF, Aristizabal-Henao JJ, Marvyn PM, M'Hiri I, Wiens MA, Hoang M, Sebastian M, Nachbar R, St-Pierre P, Diaguarachchige De Silva K, Wood GA, Joseph JW, Doucette CA, Marette A, Stark KD, Duncan RE. Renal tubule-specific Atgl deletion links kidney lipid metabolism to glucagon-like peptide 1 and insulin secretion independent of renal inflammation or lipotoxicity. Mol Metab 2024; 81:101887. [PMID: 38280449 PMCID: PMC10850971 DOI: 10.1016/j.molmet.2024.101887] [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: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 01/29/2024] Open
Abstract
OBJECTIVE Lipotoxic injury from renal lipid accumulation in obesity and type 2 diabetes (T2D) is implicated in associated kidney damage. However, models examining effects of renal ectopic lipid accumulation independent of obesity or T2D are lacking. We generated renal tubule-specific adipose triglyceride lipase knockout (RT-SAKO) mice to determine if this targeted triacylglycerol (TAG) over-storage affects glycemic control and kidney health. METHODS Male and female RT-SAKO mice and their control littermates were tested for changes in glycemic control at 10-12 and 16-18 weeks of age. Markers of kidney health and blood lipid and hormone concentrations were analyzed. Kidney and blood lysophosphatidic acid (LPA) levels were measured, and a role for LPA in mediating impaired glycemic control was evaluated using the LPA receptor 1/3 inhibitor Ki-16425. RESULTS All groups remained insulin sensitive, but 16- to 18-week-old male RT-SAKO mice became glucose intolerant, without developing kidney inflammation or fibrosis. Rather, these mice displayed lower circulating insulin and glucagon-like peptide 1 (GLP-1) levels. Impaired first-phase glucose-stimulated insulin secretion was detected and restored by Exendin-4. Kidney and blood LPA levels were elevated in older male but not female RT-SAKO mice, associated with increased kidney diacylglycerol kinase epsilon. Inhibition of LPA-mediated signaling restored serum GLP-1 levels, first-phase insulin secretion, and glucose tolerance. CONCLUSIONS TAG over-storage alone is insufficient to cause renal tubule lipotoxicity. This work is the first to show that endogenously derived LPA modulates GLP-1 levels in vivo, demonstrating a new mechanism of kidney-gut-pancreas crosstalk to regulate insulin secretion and glucose homeostasis.
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Affiliation(s)
- Maria F Fernandes
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | | | - Phillip M Marvyn
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Iman M'Hiri
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Meghan A Wiens
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | - Manuel Sebastian
- Max Rady College of Medicine, University of Manitoba, Manitoba, Canada
| | - Renato Nachbar
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Philippe St-Pierre
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | | | - Geoffrey A Wood
- Ontario Veterinary College, University of Guelph, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | | | - André Marette
- Québec Heart and Lung Institute, Department of Medicine, Laval University, Québec, Canada
| | - Ken D Stark
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada
| | - Robin E Duncan
- Department of Kinesiology and Health Sciences, University of Waterloo, Ontario, Canada.
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2
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Wright AL, Konen LM, Mockett BG, Morris GP, Singh A, Burbano LE, Milham L, Hoang M, Zinn R, Chesworth R, Tan RP, Royle GA, Clark I, Petrou S, Abraham WC, Vissel B. The Q/R editing site of AMPA receptor GluA2 subunit acts as an epigenetic switch regulating dendritic spines, neurodegeneration and cognitive deficits in Alzheimer's disease. Mol Neurodegener 2023; 18:65. [PMID: 37759260 PMCID: PMC10537207 DOI: 10.1186/s13024-023-00632-5] [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: 01/11/2023] [Accepted: 06/03/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND RNA editing at the Q/R site of GluA2 occurs with ~99% efficiency in the healthy brain, so that the majority of AMPARs contain GluA2(R) instead of the exonically encoded GluA2(Q). Reduced Q/R site editing infcreases AMPA receptor calcium permeability and leads to dendritic spine loss, neurodegeneration, seizures and learning impairments. Furthermore, GluA2 Q/R site editing is impaired in Alzheimer's disease (AD), raising the possibility that unedited GluA2(Q)-containing AMPARs contribute to synapse loss and neurodegeneration in AD. If true, then inhibiting expression of unedited GluA2(Q), while maintaining expression of GluA2(R), may be a novel strategy of preventing synapse loss and neurodegeneration in AD. METHODS We engineered mice with the 'edited' arginine codon (CGG) in place of the unedited glutamine codon (CAG) at position 607 of the Gria2 gene. We crossbred this line with the J20 mouse model of AD and conducted anatomical, electrophysiological and behavioural assays to determine the impact of eliminating unedited GluA2(Q) expression on AD-related phenotypes. RESULTS Eliminating unedited GluA2(Q) expression in AD mice prevented dendritic spine loss and hippocampal CA1 neurodegeneration as well as improved working and reference memory in the radial arm maze. These phenotypes were improved independently of Aβ pathology and ongoing seizure susceptibility. Surprisingly, our data also revealed increased spine density in non-AD mice with exonically encoded GluA2(R) as compared to their wild-type littermates, suggesting an unexpected and previously unknown role for unedited GluA2(Q) in regulating dendritic spines. CONCLUSION The Q/R editing site of the AMPA receptor subunit GluA2 may act as an epigenetic switch that regulates dendritic spines, neurodegeneration and memory deficits in AD.
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Affiliation(s)
- Amanda L Wright
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia
- School of Rural Medicine, Charles Sturt University, Orange, NSW, 2800, Australia
| | - Lyndsey M Konen
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Bruce G Mockett
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Gary P Morris
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, 7005, Australia
| | - Anurag Singh
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Lisseth Estefania Burbano
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Luke Milham
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, ON, N2G 1C5, Canada
| | - Raphael Zinn
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Richard P Tan
- Chronic Diseases, School of Medical Sciences, Faculty of Health and Medicine, University of Sydney, Sydney, NSW, 2050, Australia
- Charles Perkins Centre, University of Sydney, Sydney, NSW, 2006, Australia
| | - Gordon A Royle
- Middlemore Hospital, Counties Manukau DHB, Otahuhu, Auckland, 1062, New Zealand
- Faculty of Medical and Health Sciences, University of Auckland, Grafton, Auckland, 1023, New Zealand
| | - Ian Clark
- Research School of Biology, Australian National University, Canberra, ACT, 0200, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, 3010, Australia
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, Brain Research New Zealand, University of Otago, Box 56, Dunedin, 9054, New Zealand
| | - Bryce Vissel
- St Vincent's Clinical School, St Vincent's Hospital Sydney, Faculty of Medicine, University of New South Wales, Darlinghurst, NSW, 2010, Australia.
- Centre for Neuroscience and Regenerative Medicine, St Vincent's Centre for Applied Medical Research, St Vincent's Hospital Sydney, Darlinghurst, NSW, 2010, Australia.
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Lavrentieva IN, Bichurina MA, Antipova AY, Camara J, Hoang M, Bancevic MD, Zheleznova NV, Egorova SA, Totolian AA. A herd immunity to rubella virus in selected geographical regions. Russian Journal of Infection and Immunity 2022. [DOI: 10.15789/2220-7619-ahi-2015] [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] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Since 2017, the incidence rate of rubella in the Russian Federation has been below 1 case per million total population. In addition, no circulation of endemic strains of the rubella virus is recorded evidencing about achieving infection elimination phase. In modern conditions, it is important to constantly monitor the level of herd immunity to the rubella virus to identify epidemically significant population groups, especially in countries lacking rubella vaccination or featured with insufficient disease control. Purpose: to study herd immunity to the rubella virus in selected countries in Eurasia and Africa. Materials and methods. Between 2018 and 2021, 15,594 samples of blood sera were tested for IgG and IgM antibodies to the rubella virus from subjects of different ages obtained from regional measles and rubella surveillance centers in the Northwestern Federal District (NWFD) of the Russian Federation, the Republic of Serbia, South Vietnam, and the Republic of Guinea. The Anti-Rubella Virus ELISA (IgМ) and Anti-Rubella Virus ELISA (IgG) (Euroimmun, Germany) test kits were used. Statistical data processing was carried out using the MS Excel, Prizm 5.0 (GraphPad Software Inc.), and Statistica 8.0 (StatSoft Inc.) software package. Results. During the observation period (20182020) the population seroprevalence of the to the rubella virus in the NWFD of the Russian Federation was 96.697.7% and fluctuated slightly both in separate years and among individual age groups evidencing about high coverage of rubella vaccination. In the Republic of Serbia conducting two-fold immunization against rubella the overall seroprevalence rate was lower than in the Russian Federation and comprising 86.8%. The minimum number of IgG-positive sera was recorded in the 24-year-old age group pointing to the shortcomings of routine vaccination. In South Vietnam, children aged 13 years (41.9%) predominated among those recovering from rubella, i.e. the age cohort that should be protected by vaccination at the age of 18 months. No rubella vaccination is carried out in Guinea. The total proportion of seropositive individuals was 75%; herd immunity to the rubella virus was established mainly among children and adolescents, reaching 90% only in the older age group. 30% of unprotected subjects of the most active reproductive age were identified among the females surveyed in Guinea. Conclusion. Insufficient herd immunity to the rubella virus, identified in a number of countries, may contribute to the maintenance of the infectious process and the spread of infection. Globalization contributes to the virus importation into regions being at the stage of measles and rubella elimination. The results obtained suggest about a need to continue efforts aimed at maintaining epidemiological wellbeing regarding rubella in diverse countries of the world.
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Ahmed F, Lim R, Moseley I, Hoang M, Wisco O, Robinson-Bostom L, Qureshi A, Cho E. 227 Socioeconomic predictors of melanoma Breslow thickness at a Rhode Island academic center. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.234] [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: 10/17/2022]
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5
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Hoang M, Jentz E, Janssen SM, Nasteska D, Cuozzo F, Hodson DJ, Tupling AR, Fong GH, Joseph JW. Isoform-specific Roles of Prolyl Hydroxylases in the Regulation of Pancreatic β-Cell Function. Endocrinology 2022; 163:6413706. [PMID: 34718519 PMCID: PMC8643417 DOI: 10.1210/endocr/bqab226] [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] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Indexed: 11/19/2022]
Abstract
Pancreatic β-cells can secrete insulin via 2 pathways characterized as KATP channel -dependent and -independent. The KATP channel-independent pathway is characterized by a rise in several potential metabolic signaling molecules, including the NADPH/NADP+ ratio and α-ketoglutarate (αKG). Prolyl hydroxylases (PHDs), which belong to the αKG-dependent dioxygenase superfamily, are known to regulate the stability of hypoxia-inducible factor α. In the current study, we assess the role of PHDs in vivo using the pharmacological inhibitor dimethyloxalylglycine (DMOG) and generated β-cell-specific knockout (KO) mice for all 3 isoforms of PHD (β-PHD1 KO, β-PHD2 KO, and β-PHD3 KO mice). DMOG inhibited in vivo insulin secretion in response to glucose challenge and inhibited the first phase of insulin secretion but enhanced the second phase of insulin secretion in isolated islets. None of the β-PHD KO mice showed any significant in vivo defects associated with glucose tolerance and insulin resistance except for β-PHD2 KO mice which had significantly increased plasma insulin during a glucose challenge. Islets from both β-PHD1 KO and β-PHD3 KO had elevated β-cell apoptosis and reduced β-cell mass. Isolated islets from β-PHD1 KO and β-PHD3 KO had impaired glucose-stimulated insulin secretion and glucose-stimulated increases in the ATP/ADP and NADPH/NADP+ ratio. All 3 PHD isoforms are expressed in β-cells, with PHD3 showing the most distinct expression pattern. The lack of each PHD protein did not significantly impair in vivo glucose homeostasis. However, β-PHD1 KO and β-PHD3 KO mice had defective β-cell mass and islet insulin secretion, suggesting that these mice may be predisposed to developing diabetes.
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Affiliation(s)
- Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Emelien Jentz
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Sarah M Janssen
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
| | - Daniela Nasteska
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - A Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Guo-Hua Fong
- Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, ON, Canada
- Correspondence: Jamie W. Joseph, PhD, Health Science Campus Building A, Room 4008, University of Waterloo, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5.
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Nasteska D, Cuozzo F, Viloria K, Johnson EM, Thakker A, Bany Bakar R, Westbrook RL, Barlow JP, Hoang M, Joseph JW, Lavery GG, Akerman I, Cantley J, Hodson L, Tennant DA, Hodson DJ. Prolyl-4-hydroxylase 3 maintains β cell glucose metabolism during fatty acid excess in mice. JCI Insight 2021; 6:e140288. [PMID: 34264866 PMCID: PMC8409982 DOI: 10.1172/jci.insight.140288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/14/2021] [Indexed: 02/06/2023] Open
Abstract
The α-ketoglutarate–dependent dioxygenase, prolyl-4-hydroxylase 3 (PHD3), is an HIF target that uses molecular oxygen to hydroxylate peptidyl prolyl residues. Although PHD3 has been reported to influence cancer cell metabolism and liver insulin sensitivity, relatively little is known about the effects of this highly conserved enzyme in insulin-secreting β cells in vivo. Here, we show that the deletion of PHD3 specifically in β cells (βPHD3KO) was associated with impaired glucose homeostasis in mice fed a high-fat diet. In the early stages of dietary fat excess, βPHD3KO islets energetically rewired, leading to defects in the management of pyruvate fate and a shift from glycolysis to increased fatty acid oxidation (FAO). However, under more prolonged metabolic stress, this switch to preferential FAO in βPHD3KO islets was associated with impaired glucose-stimulated ATP/ADP rises, Ca2+ fluxes, and insulin secretion. Thus, PHD3 might be a pivotal component of the β cell glucose metabolism machinery in mice by suppressing the use of fatty acids as a primary fuel source during the early phases of metabolic stress.
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Affiliation(s)
- Daniela Nasteska
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Federica Cuozzo
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Katrina Viloria
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
| | - Elspeth M Johnson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom.,NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, United Kingdom
| | - Alpesh Thakker
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Rula Bany Bakar
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Rebecca L Westbrook
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Jonathan P Barlow
- Mitochondrial Profiling Centre, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Gareth G Lavery
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Ildem Akerman
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - James Cantley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.,Division of Systems Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, United Kingdom.,NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, United Kingdom
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - David J Hodson
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, United Kingdom
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7
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Abstract
Anaplerosis and the associated mitochondrial metabolite transporters generate unique cytosolic metabolic signaling molecules that can regulate insulin release from pancreatic β-cells. It has been shown that mitochondrial metabolites, transported by the citrate carrier (CIC), dicarboxylate carrier (DIC), oxoglutarate carrier (OGC), and mitochondrial pyruvate carrier (MPC) play a vital role in the regulation of glucose-stimulated insulin secretion (GSIS). Metabolomic studies on static and biphasic insulin secretion, suggests that several anaplerotic derived metabolites, including α-ketoglutarate (αKG), are strongly associated with nutrient regulated insulin secretion. Support for a role of αKG in the regulation of insulin secretion comes from studies looking at αKG dependent enzymes, including hypoxia-inducible factor-prolyl hydroxylases (PHDs) in clonal β-cells, and rodent and human islets. This review will focus on the possible link between defective anaplerotic-derived αKG, PHDs, and the development of type 2 diabetes (T2D).
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Affiliation(s)
- M. Hoang
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - J. W. Joseph
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
- CONTACT J. W. Joseph School of Pharmacy, University of Waterloo, Kitchener, ONN2G1C5, Canada
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8
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Kiuru M, Kriner M, Zhu G, Terrell J, Hoang M, Beechem J, McPherson J. 691 Identification of RNA biomarker candidates in melanocytic tumors using digital spatial profiling. J Invest Dermatol 2020. [DOI: 10.1016/j.jid.2020.03.703] [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: 11/29/2022]
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9
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Hoang M, Paglialunga S, Bombardier E, Tupling AR, Joseph JW. The Loss of ARNT/HIF1β in Male Pancreatic β-Cells Is Protective Against High-Fat Diet-Induced Diabetes. Endocrinology 2019; 160:2825-2836. [PMID: 31580427 PMCID: PMC6846328 DOI: 10.1210/en.2018-00936] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 09/25/2019] [Indexed: 11/19/2022]
Abstract
The transcription factor aryl hydrocarbon receptor nuclear translocator (ARNT)/hypoxia-inducible factor (HIF)-1β (ARNT/HIF1β) plays a key role in maintaining β-cell function and has been shown to be one of the most downregulated transcription factors in islets from patients with type 2 diabetes. We have shown a role for ARNT/HIF1β in glucose sensing and insulin secretion in vitro and no defects in in vivo glucose homeostasis. To gain a better understanding of the role of ARNT/HIF1β in the development of diabetes, we placed control (+/+/Cre) and β-cell-specific ARNT/HIF1β knockout (fl/fl/Cre) mice on a high-fat diet (HFD). Unlike the control (+/+/Cre) mice, HFD-fed fl/fl/Cre mice had no impairment in in vivo glucose tolerance. The lack of impairment in HFD-fed fl/fl/Cre mice was partly due to an improved islet glucose-stimulated NADPH/NADP+ ratio and glucose-stimulated insulin secretion. The effects of the HFD-rescued insulin secretion in fl/fl/Cre islets could be reproduced by treating low-fat diet (LFD)-fed fl/fl/Cre islets with the lipid signaling molecule 1-monoacylglcyerol. This suggests that the defects seen in LFD-fed fl/fl/Cre islet insulin secretion involve lipid signaling molecules. Overall, mice lacking ARNT/HIF1β in β-cells have altered lipid signaling in vivo and are resistant to an HFD's ability to induce diabetes.
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Affiliation(s)
- Monica Hoang
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | | | - Eric Bombardier
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
- Correspondence: Jamie W. Joseph, PhD, University of Waterloo, 10 Victoria Street South, Building A, Kitchener, Ontario N2G 1C5, Canada. E-mail:
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10
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Paglialunga S, Simnett G, Robson H, Hoang M, Pillai R, Arkell AM, Simpson JA, Bonen A, Huising M, Joseph JW, Holloway GP. The Rab-GTPase activating protein, TBC1D1, is critical for maintaining normal glucose homeostasis and β-cell mass. Appl Physiol Nutr Metab 2017; 42:647-655. [DOI: 10.1139/apnm-2016-0585] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Tre-2/USP6, BUB2, cdc16 domain family, member 1 (TBC1D1), a Rab-GTPase activating protein, is a paralogue of AS160, and has been implicated in the canonical insulin-signaling cascade in peripheral tissues. More recently, TBC1D1 was identified in rat and human pancreatic islets; however, the islet function of TBC1D1 remains not fully understood. We examined the role of TBC1D1 in glucose homeostasis and insulin secretion utilizing a rat knockout (KO) model. Chow-fed TBC1D1 KO rats had improved insulin action but impaired glucose-tolerance tests (GTT) and a lower insulin response during an intraperitoneal GTT compared with wild-type (WT) rats. The in vivo data suggest there may be an islet defect. Glucose-stimulated insulin secretion was higher in isolated KO rat islets compared with WT animals, suggesting TBC1D1 is a negative regulator of insulin secretion. Moreover, KO rats displayed reduced β-cell mass, which likely accounts for the impaired whole-body glucose homeostasis. This β-cell mass reduction was associated with increased active caspase 3, and unaltered Ki67 or urocortin 3, suggesting the induction of apoptosis rather than decreased proliferation or dedifferentiation may account for the decline in islet mass. A similar phenotype was observed in TBC1D1 heterozygous animals, highlighting the sensitivity of the pancreas to subtle reductions in TBC1D1 protein. An 8-week pair-fed high-fat diet did not further alter β-cell mass or apoptosis in KO rats, suggesting that dietary lipids per se, do not lead to a further impairment in glucose homeostasis. The present study establishes a fundamental role for TBC1D1 in maintaining in vivo β-cell mass.
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Affiliation(s)
- Sabina Paglialunga
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Genevieve Simnett
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Holly Robson
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Renjitha Pillai
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Alicia M. Arkell
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Jeremy A. Simpson
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Arend Bonen
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Mark Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences & Department of Physiology & Membrane Biology, School of Medicine, University of California, Davis, California, USA
| | - Jamie W. Joseph
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Graham P. Holloway
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
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Porter M, Yasuda M, Foreman R, Hoang M, Manatis-Lornell A, Senna M. 838 Histologic and immunohistochemical evaluation of Lichen Planopilaris and correlation with clinical disease severity. J Invest Dermatol 2017. [DOI: 10.1016/j.jid.2017.02.864] [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: 11/28/2022]
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Huang M, Paglialunga S, Wong JMK, Hoang M, Pillai R, Joseph JW. Role of prolyl hydroxylase domain proteins in the regulation of insulin secretion. Physiol Rep 2016; 4:4/5/e12722. [PMID: 26997627 PMCID: PMC4823601 DOI: 10.14814/phy2.12722] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Type 2 diabetes is associated with impaired nutrient‐regulated anaplerosis and insulin secretion in pancreatic β‐cells. One key anaplerotic substrate that may be involved in regulating insulin release is α‐ketoglutarate (αKG). Since prolyl hydroxylase domain proteins (PHDs) can metabolize cytosolic αKG, we sought to explore the role of this enzyme in the regulation of β‐cell function. The oxygen‐sensing PHDs regulate the stability of hypoxia‐inducible factor 1α (HIF1α) as well as other proline‐containing proteins by catalyzing the hydroxylation of proline residues. This reaction is dependent on sufficient levels of oxygen, iron, and αKG. In the present study, we utilized both pharmacological and genetic approaches to assess the impact of inhibiting PHD activity on β‐cell function. We demonstrate that ethyl‐3,4‐dihydroxybenzoate (EDHB), a PHD inhibitor, significantly blunted glucose‐stimulated insulin secretion (GSIS) from 832/13 clonal cells, rat, and human islets. EDHB reduced glucose utilization, ATP/ADP ratio, and key TCA cycle intermediates such as pyruvate, citrate, fumarate, and malate. siRNA‐mediated knockdown of PHD1 and PHD3 inhibited GSIS, whereas siRNA‐mediated knockdown of PHD2 had no effect on GSIS. Taken together, the current results demonstrate an important role for PHDs as mediators of islet insulin secretion.
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Affiliation(s)
- Mei Huang
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Julia M-K Wong
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
| | - Renjitha Pillai
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Waterloo, Ontario, Canada
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Pillai R, Paglialunga S, Hoang M, Cousteils K, Prentice KJ, Bombardier E, Huang M, Gonzalez FJ, Tupling AR, Wheeler MB, Joseph JW. Deletion of ARNT/HIF1β in pancreatic beta cells does not impair glucose homeostasis in mice, but is associated with defective glucose sensing ex vivo. Diabetologia 2015; 58:2832-42. [PMID: 26409461 PMCID: PMC6338330 DOI: 10.1007/s00125-015-3768-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [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: 05/12/2015] [Accepted: 09/01/2015] [Indexed: 01/24/2023]
Abstract
AIMS/HYPOTHESIS It has been suggested that the transcription factor ARNT/HIF1β is critical for maintaining in vivo glucose homeostasis and pancreatic beta cell glucose-stimulated insulin secretion (GSIS). Our goal was to gain more insights into the metabolic defects seen after the loss of ARNT/HIF1β in beta cells. METHODS The in vivo and in vitro consequences of the loss of ARNT/HIF1β were investigated in beta cell specific Arnt/Hif1β knockout mice (β-Arnt (fl/fl/Cre) mice). RESULTS The only in vivo defects found in β-Arnt (fl/fl/Cre) mice were significant increases in the respiratory exchange ratio and in vivo carbohydrate oxidation, and a decrease in lipid oxidation. The mitochondrial oxygen consumption rate was unaltered in mouse β-Arnt (fl/fl/Cre) islets upon glucose stimulation. β-Arnt (fl/fl/Cre) islets had an impairment in the glucose-stimulated increase in Ca(2+) signalling and a reduced insulin secretory response to glucose in the presence of KCl and diazoxide. The glucose-stimulated increase in the NADPH/NADP(+) ratio was reduced in β-Arnt (fl/fl/Cre) islets. The reduced GSIS and NADPH/NADP(+) levels in β-Arnt (fl/fl/Cre) islets could be rescued by treatment with membrane-permeable tricarboxylic acid intermediates. Small interfering (si)RNA mediated knockdown of ARNT/HIF1β in human islets also inhibited GSIS. These results suggest that the regulation of GSIS by the KATP channel-dependent and -independent pathways is affected by the loss of ARNT/HIF1β in islets. CONCLUSIONS/INTERPRETATION This study provides three new insights into the role of ARNT/HIF1β in beta cells: (1) ARNT/HIF1β deletion in mice impairs GSIS ex vivo; (2) β-Arnt (fl/fl/Cre) mice have an increased respiratory exchange ratio; and (3) ARNT/HIF1β is required for GSIS in human islets.
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Affiliation(s)
- Renjitha Pillai
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5
| | - Sabina Paglialunga
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5
| | - Katelyn Cousteils
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5
| | - Kacey J Prentice
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Eric Bombardier
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Mei Huang
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, MD, USA
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Michael B Wheeler
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Jamie W Joseph
- School of Pharmacy, University of Waterloo, Health Science Campus building A, room 4008, 10A Victoria Street South, Kitchener, ON, Canada, N2G 1C5.
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Hoang M, Nguyen P, Hajeebhoy N, Menon P, Rawat R. Willingness to Pay for Nutrition Counseling Services in Vietnam. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.584.28] [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)
- M Hoang
- Health EconomicsHanoi Medical Univ.Viet Nam
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Hwang K, Illerstam F, Torfeh T, Maier J, Shave S, Hoang M. SU-E-J-146: Spatial Accuracy QA of An MR System. Med Phys 2014. [DOI: 10.1118/1.4888199] [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: 11/07/2022] Open
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Bakaysa SL, Potter JA, Hoang M, Han CS, Guller S, Norwitz ER, Abrahams VM. Single- and double-stranded viral RNA generate distinct cytokine and antiviral responses in human fetal membranes. Mol Hum Reprod 2014; 20:701-8. [PMID: 24723465 DOI: 10.1093/molehr/gau028] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
There has been growing interest in the role of viral infections and their association with adverse pregnancy outcomes. However, little is known about the impact viral infections have on the fetal membranes (FM). Toll-like receptors (TLR) are thought to play a role in infection-associated inflammation at the maternal-fetal interface. Therefore, the objective of this study was to characterize the cytokine profile and antiviral response in human FMs exposed to viral dsRNA, which activates TLR3, and viral ssRNA, which activates TLR8; and to determine the mechanisms involved. The viral dsRNA analog, Poly(I:C), induced up-regulated secretion of MIP-1α, MIP-1β, RANTES and TNF-α, and down-regulated interleukin (IL)-2 and VEGF secretion. In contrast, viral ssRNA induced a broader panel of cytokines in the FMs by up-regulating the secretion of IL-1β, IL-2, IL-6, G-CSF, MCP-1, MIP-1α, MIP-1β, RANTES, TNF-α and GRO-α. Using inhibitory peptides against TLR adapter proteins, FM secretion of MIP-1β and RANTES in response to Poly(I:C) was MyD88 dependent; MIP-1α secretion was dependent on MyD88 and TRIF; and TNF-α production was independent of MyD88 and TRIF. Viral ssRNA-induced FM secretion of IL-1β, IL-2, IL-6, G-CSF, MIP-1α, RANTES and GRO-α was dependent on MyD88 and TRIF; MIP-1β was dependent upon TRIF, but not MyD88; and TNF-α and MCP-1 secretion was dependent on neither. Poly(I:C), but not ssRNA, induced an FM antiviral response by up-regulating the expression of IFNβ, myxovirus-resistance A, 2',5'-oligoadenylate synthetase and apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like 3G. These findings demonstrate that human FMs respond to two viral signatures by generating distinct inflammatory cytokine/chemokine profiles and antiviral responses through different mechanisms.
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Affiliation(s)
- S L Bakaysa
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - J A Potter
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - M Hoang
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - C S Han
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - S Guller
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
| | - E R Norwitz
- Department of Obstetrics & Gynecology, Tufts Medical Center, Boston, MA, USA
| | - V M Abrahams
- Department of Obstetrics, Gynecology & Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA
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Pépin D, Hoang M, Nicolaou F, Hendren K, Benedict LA, Al-Moujahed A, Sosulski A, Marmalidou A, Vavvas D, Donahoe PK. An albumin leader sequence coupled with a cleavage site modification enhances the yield of recombinant C-terminal Mullerian Inhibiting Substance. Technology 2013; 1:63-71. [PMID: 24729676 PMCID: PMC3980489 DOI: 10.1142/s2339547813500076] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Mullerian Inhibiting Substance (MIS) has been shown to inhibit ovarian cancer cells both in-vitro and in-vivo. Furthermore, recent evidence suggests that MIS may effectively target a putative ovarian cancer progenitor cell population enriched by a panel of CD44+, CD24+, Ep-CAM+, and E-cadherin-cell surface markers. In order to accommodate clinical testing of MIS in ovarian cancer patients, the production of recombinant human MIS must be optimized to increase yield and purity. Here we show that, compared to wild type, the substitution of the MIS leader sequence to that of human serum albumin, combined with a modification of the endogenous cleavage site from RAQR/S to a furin/kex2 RARR/S consensus site results in high expression, increased C-terminus cleavage and a reduction in unwanted cryptic internal cleavage products when produced in CHO cells. Purified MIS containing these alterations retains its capacity to induce regression of the Mullerian duct in fetal rat embryonic urogenital ridge assays.
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Affiliation(s)
- D Pépin
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital ; Harvard Medical School
| | - M Hoang
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital ; Harvard Medical School ; Massachusetts Eye-Ear Infirmary
| | - F Nicolaou
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital
| | - K Hendren
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital
| | - L A Benedict
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital ; Harvard Medical School
| | - A Al-Moujahed
- Harvard Medical School ; Massachusetts Eye-Ear Infirmary
| | - A Sosulski
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital ; Harvard Medical School
| | - A Marmalidou
- Harvard Medical School ; Massachusetts Eye-Ear Infirmary
| | - D Vavvas
- Harvard Medical School ; Massachusetts Eye-Ear Infirmary
| | - P K Donahoe
- Pediatric Surgical Research Laboratories, Massachusetts General Hospital ; Harvard Medical School
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Hoang M, Mathews JF, Pratt KC, Xie Z. A kinetic study of oxidative dehydrogenation of isobutane to isobutylene over chromium oxide supported on lanthanum carbonate. Kinet Catal 2010. [DOI: 10.1134/s0023158410030122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Reutter JC, Hoang M, Vollmer RT, Groben PA, Thomas DB, Selim MA. The Role of Ki-67 in Predicting Prognosis of Malignant Melanoma of the Vulva. J Cutan Pathol 2008. [DOI: 10.1111/j.0303-6987.2005.320gc.x] [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: 11/28/2022]
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Hussey S, Gander R, Southern P, Hoang M. Subcutaneous Phaeohyphomycosis Caused by Cladophialophora Bantiana. J Cutan Pathol 2008. [DOI: 10.1111/j.0303-6987.2005.320cy.x] [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: 11/30/2022]
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Abstract
Objective: To develop a comprehensive conceptual framework of tobacco industry tactics in four countries in South East Asia for the purpose of: (1) generating consensus on key areas of importance and feasibility for regional and cross country tobacco industry monitoring and surveillance; (2) developing measures to track and monitor the effects of the tobacco industry and to design counterstrategies; and (3) building capacity to improve tobacco control planning in the participating countries. Design: A structured conceptualisation methodology known as concept mapping was used. The process included brainstorming, sorting and rating of statements describing industry activities. Statistical analyses used multidimensional scaling and cluster analysis. Interpretation of the maps was participatory, using regional tobacco control researchers, practitioners, and policy makers during a face to face meeting. Participants: 31 participants in this study come from the four countries represented in the project along with six people from the Johns Hopkins Blomberg School of Public Health. Conclusions: The map shows eight clusters of industry activities within the four countries. These were arranged into four general sectors: economics, politics, public relations and deception. For project design purposes, the map indicates areas of importance and feasibility for monitoring tobacco industry activities and serves as a basis for an initial discussion about action planning. Furthermore, the development of the map used a consensus building process across different stakeholders or stakeholder agencies and is critical when developing regional, cross border strategies for tracking and surveillance.
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Affiliation(s)
- F Stillman
- Institute for Global Tobacco Control, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe Street, W6027, Baltimore, MD 21205, USA.
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Malouin F, Blais J, Chamberland S, Hoang M, Park C, Chan C, Mathias K, Hakem S, Dupree K, Liu E, Nguyen T, Dudley MN. RWJ-54428 (MC-02,479), a new cephalosporin with high affinity for penicillin-binding proteins, including PBP 2a, and stability to staphylococcal beta-lactamases. Antimicrob Agents Chemother 2003; 47:658-64. [PMID: 12543674 PMCID: PMC151748 DOI: 10.1128/aac.47.2.658-664.2003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RWJ-54428 (MC-02,479) is a new cephalosporin active against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The potency of this new cephalosporin against MRSA is related to a high affinity for penicillin-binding protein 2a (PBP 2a), as assessed in a competition assay using biotinylated ampicillin as the reporter molecule. RWJ-54428 had high activity against MRSA strains COL and 67-0 (MIC of 1 micro g/ml) and also showed affinity for PBP 2a, with a 50% inhibitory concentration (IC(50)) of 0.7 micro g/ml. RWJ-54428 also displayed excellent affinity for PBP 5 from Enterococcus hirae R40, with an IC(50) of 0.8 micro g/ml and a MIC of 0.5 micro g/ml. The affinity of RWJ-54428 for PBPs of beta-lactam-susceptible S. aureus (MSSA), enterococci (E. hirae), and Streptococcus pneumoniae showed that the good affinity of RWJ-54428 for MRSA PBP 2a and E. hirae PBP 5 does not compromise its binding to susceptible PBPs. RWJ-54428 showed stability to hydrolysis by purified type A beta-lactamase isolated from S. aureus PC1. In addition, RWJ-54428 displayed low MICs against strains of S. aureus bearing the four classes of staphylococcal beta-lactamases, including beta-lactamase hyperproducers. The frequency of isolation of resistant mutants to RWJ-54428 from MRSA strains was very low. In summary, RWJ-54428 has high affinity to multiple PBPs and is stable to beta-lactamase, properties that may explain our inability to find resistance by standard methods. These data are consistent with its excellent activity against beta-lactam-resistant gram-positive bacteria.
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Affiliation(s)
- Francois Malouin
- Essential Therapeutics, Inc., Mountain View, California 94043, USA
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Chamberland S, Blais J, Hoang M, Dinh C, Cotter D, Bond E, Gannon C, Park C, Malouin F, Dudley MN. In vitro activities of RWJ-54428 (MC-02,479) against multiresistant gram-positive bacteria. Antimicrob Agents Chemother 2001; 45:1422-30. [PMID: 11302805 PMCID: PMC90483 DOI: 10.1128/aac.45.5.1422-1430.2001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC(90)) of 2 microg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC(90) of 2 microg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, < or = 0.0625 to 1 microg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC(90), 0.5 microg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC(90) of 0.125 microg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between < or = 0.0625 and 1 microg/ml for ampicillin-susceptible strains and 0.125 and 8 microg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains of Streptococcus pneumoniae (MIC(90)s, 0.25, 0.125, and < or = 0.0625 microg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae and Moraxella catarrhalis (MIC(90)s, 0.25 and 0.5 microg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.
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Affiliation(s)
- S Chamberland
- Microcide Pharmaceuticals Inc, Mountain View, California 94043, USA
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Abstract
The morphology observed by transmission electron microscopy of rare earth oxides, prepared by two different routes, has been related to adsorption characteristics for nitrogen at 77 K. The most common morphology was that of thin sheets, then small equiaxed particles, and, more rarely, rod-like particles. The presence of small equiaxed particles was found to be a prerequisite for adsorption hysteresis. Evaluation of linear 't' plots indicated freedom from micropores in all samples, but positive deviations in the presence of sheet morphology at high relative pressures left open the possibility of wedge-like pores in these samples.
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