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Livingstone JD, Gingras MJ, Leonenko Z, Beazely MA. Search for lithium isotope effects in neuronal HT22 cells. Biochem Biophys Rep 2023; 34:101461. [PMID: 37063814 PMCID: PMC10102007 DOI: 10.1016/j.bbrep.2023.101461] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/11/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Lithium has been used as a treatment for bipolar disorder for over half a century, but there has thus far been no clinical differentiation made between the two naturally occurring stable isotopes (6Li and 7Li). While the natural lithium salts commonly used in treatments are composed of a mixture of these two stable isotopes (approximately 7.59% 6Li and 92.41% 7Li), some preliminary research indicates the above two stable isotopes of lithium may have differential effects on rat behaviour and neurophysiology. Here, we evaluate whether lithium isotopes may have distinct effects on HT22 neuronal cell viability, GSK-3-β phosphorylation in HT22 cells, and GSK-3-β kinase activity. We report no significant difference in lithium isotope toxicity on HT22 cells, nor in GSK-3-β phosphorylation, nor in GSK-3-β kinase activity between the two isotopes of lithium.
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2
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Robinson MJ, Newbury S, Singh K, Leonenko Z, Beazely MA. The Interplay Between Cholesterol and Amyloid-β on HT22 Cell Viability, Morphology, and Receptor Tyrosine Kinase Signaling. J Alzheimers Dis 2023; 96:1663-1683. [PMID: 38073391 DOI: 10.3233/jad-230753] [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] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
BACKGROUND There is a lack of understanding in the molecular and cellular mechanisms of Alzheimer's disease that has hindered progress on therapeutic development. The focus has been on targeting toxic amyloid-β (Aβ) pathology, but these therapeutics have generally failed in clinical trials. Aβ is an aggregation-prone protein that has been shown to disrupt cell membrane structure in molecular biophysics studies and interfere with membrane receptor signaling in cell and animal studies. Whether the lipid membrane or specific receptors are the primary target of attack has not been determined. OBJECTIVE This work elucidates some of the interplay between membrane cholesterol and Aβ42 on HT22 neuronal cell viability, morphology, and platelet-derived growth factor (PDGF) signaling pathways. METHODS The effects of cholesterol depletion by methyl-β-cyclodextrin followed by treatment with Aβ and/or PDGF-AA were assessed by MTT cell viability assays, western blot, optical and AFM microscopy. RESULTS Cell viability studies show that cholesterol depletion was mildly protective against Aβ toxicity. Together cholesterol reduction and Aβ42 treatment compounded the disruption of the PDGFα receptor activation. Phase contrast optical microscopy and live cell atomic force microscopy imaging revealed that cytotoxic levels of Aβ42 caused morphological changes including cell membrane damage, cytoskeletal disruption, and impaired cell adhesion; cell damage was ameliorated by cellular cholesterol depletion. CONCLUSIONS Cholesterol depletion impacted the effects of Aβ42 on HT22 cell viability, morphology, and receptor tyrosine kinase signaling.
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Affiliation(s)
- Morgan J Robinson
- School of Pharmacy, University of Waterloo, Waterloo, ON, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Sean Newbury
- School of Pharmacy, University of Waterloo, Waterloo, ON, Canada
| | - Kartar Singh
- School of Pharmacy, University of Waterloo, Waterloo, ON, Canada
| | - Zoya Leonenko
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
- Department of Physics and Astronomy, University of Waterloo, Waterloo, ON, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Michael A Beazely
- School of Pharmacy, University of Waterloo, Waterloo, ON, Canada
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
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3
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Alkabbani W, Pelletier R, Beazely MA, Labib Y, Quan B, Gamble JM. Drug-Drug Interaction of the Sodium Glucose Co-Transporter 2 Inhibitors with Statins and Myopathy: A Disproportionality Analysis Using Adverse Events Reporting Data. Drug Saf 2022; 45:287-295. [PMID: 35247195 DOI: 10.1007/s40264-022-01166-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2022] [Indexed: 12/12/2022]
Abstract
INTRODUCTION An increased risk of myopathy due to a potential interaction between sodium glucose co-transporter-2 inhibitors (SGLT-2i) and HMG-CoA reductase inhibitors (statins) has been suggested by case reports. OBJECTIVE We aimed to assess if the reporting of myopathy is disproportionally higher among people using both SGLT-2i and statins compared to using either SGLT-2i or statins alone. METHODS We conducted a disproportionality analysis using data from the US Food and Drug Administration Adverse Event Reporting System (FAERS). We included reports with at least one antihyperglycemic agent. We compared the proportion of myopathy cases to non-cases between those not using SGLT-2i or statins, using SGLT-2i only, statins only, or both. We calculated the reporting odds ratio and 95% confidence interval. We further stratified by individual SGLT-2i and selected statins (rosuvastatin or atorvastatin). RESULTS We included 688,388 reports with at least one antihyperglycemic agent recorded, of which 9.80% had at least one SGLT-2i agent. Among all included reports, there were a total of 2202 myopathy cases with the majority, 61.26%, occurring among those using statins alone and only 2.72% of myopathy cases were among those using both SGLT-2i and statins together. Reporting of myopathy was not disproportionally higher among those reporting the use of SGLT-2i with statins (reporting odds ratio 2.95, 95% confidence interval 2.27-3.85) compared to statins alone (reporting odds ratio 6.41, 95% confidence interval 5.86-7.02). CONCLUSIONS Reports of myopathy were not disproportionally higher among those using SGLT-2i with statins compared to SGLT-2i or statins alone at the class level. Further observational studies may be needed to better assess this interaction at the agent level.
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Affiliation(s)
- Wajd Alkabbani
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada
| | - Ryan Pelletier
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada
| | - Michael A Beazely
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada
| | - Youssef Labib
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada
| | - Breanna Quan
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada
| | - John-Michael Gamble
- School of Pharmacy, Faculty of Science, University of Waterloo, 10A Victoria Street S, Kitchener, ON, N2G 1C5, Canada.
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4
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Parihar V, Beazely MA, Katz L, Dhami R, Patterson LL. Assessing the impact of a cannabis course on pharmacy students' understanding, beliefs and preparedness regarding medical and recreational cannabis. Can Pharm J (Ott) 2022; 155:50-59. [PMID: 35035642 DOI: 10.1177/17151635211041041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/29/2020] [Accepted: 11/13/2020] [Indexed: 11/15/2022]
Abstract
Background With the legalization of cannabis in Canada in 2018, pharmacists are increasingly likely to encounter patients using this substance. The primary objective of this pre-post questionnaire study was to evaluate the impact of an accredited cannabis course on the understanding, beliefs, perceptions and knowledge of undergraduate PharmD students. Methods A 38-question, web-based survey generated in REDCap was administered to third-year PharmD students at the University of Waterloo, prior to and right after taking an accredited cannabis course. The pre- and postsurvey data were analyzed using SPSS version 25. Pearson chi-square tests were performed on questions in which answers consisted of qualitative categorical data. Two-sided t tests were performed to test the significance of mean differences of questions measuring continuous variables. Results In a class of 120 students, 110 completed the presurvey and 79 students completed the postsurvey. After the course, students were more likely to report being knowledgeable and prepared for patient encounters dealing with medical and recreational cannabis, understanding that medical cannabis should be prescribed for select (vs all) medical conditions, rating the quality of evidence as poor to moderate for medical use of cannabis, understanding that medical documents should be more prescriptive and understanding that cannabis should not be sold in pharmacies (p < 0.05). Interpretation With cannabis education a part of their curriculum, pharmacy students felt more prepared to engage patients using cannabis both medically and recreationally. Furthermore, students were more cautious regarding the potential use of cannabis therapeutically and indicated that more oversight should be in place. Can Pharm J (Ott) 2021;154:xx-xx.
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Affiliation(s)
- Vikas Parihar
- Faculty of Health Sciences, McMaster University, Hamilton
| | | | - Laura Katz
- Department of Psychiatry and Behavioural Neurosciences, Faculty of Health Sciences, St. Joseph's Healthcare, Hamilton
| | - Rita Dhami
- London Health Sciences, Victoria Hospital and Children's Hospital, London, Ontario
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5
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Cid A, Patten A, Grindrod K, Beazely MA. Frequently asked questions about naloxone: Part 3. Can Pharm J (Ott) 2022; 155:9-11. [PMID: 35035636 DOI: 10.1177/17151635211056571] [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: 11/16/2022]
Affiliation(s)
- Ashley Cid
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Alec Patten
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Kelly Grindrod
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
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6
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Cid A, Patten A, Grindrod K, Beazely MA. Frequently asked questions about naloxone: Part 2. Can Pharm J (Ott) 2021; 154:385-387. [PMID: 34777648 PMCID: PMC8581805 DOI: 10.1177/17151635211045966] [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] [Received: 06/15/2021] [Accepted: 07/27/2021] [Indexed: 11/16/2022]
Affiliation(s)
- Ashley Cid
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Alec Patten
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Kelly Grindrod
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
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7
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Cid A, Patten A, Grindrod K, Beazely MA. Frequently asked questions about naloxone: Part 1. Can Pharm J (Ott) 2021; 154:301-304. [PMID: 34484479 DOI: 10.1177/17151635211034528] [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] [Received: 06/13/2021] [Accepted: 06/28/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Ashley Cid
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Alec Patten
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
| | - Kelly Grindrod
- School of Pharmacy, University of Waterloo, Kitchener, Ontario
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Beazely MA, Tsuyuki RT. The opioid crisis: Naloxone and pharmacists to the rescue. Can Pharm J (Ott) 2021; 154:289-290. [PMID: 34484476 DOI: 10.1177/17151635211035127] [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: 11/15/2022]
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9
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Gondora N, Versteeg SG, Carter C, Bishop LD, Sproule B, Turcotte D, Halpape K, Beazely MA, Dattani S, Kwong M, Nissen L, Chang F. The role of pharmacists in opioid stewardship: A scoping review. Res Social Adm Pharm 2021; 18:2714-2747. [PMID: 34261590 DOI: 10.1016/j.sapharm.2021.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/26/2021] [Accepted: 06/27/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND The opioid epidemic is an international public health concern. Pharmacists are in a strategic position to promote and implement effective opioid stewardship due to both their central role on health care teams and frequent interaction with patients. Despite this integral role, pharmacists do not have harmonized scopes of practice in opioid stewardship. OBJECTIVES This scoping review was conducted to identify and critically review the role of pharmacists in opioid stewardship and identify future areas of study. METHODS The scoping review was conducted according to the methodological framework proposed by Arksey and O'Malley, which was further modified by the Joanna Briggs Institute. Six databases were searched for original, peer-reviewed research; PubMed (MEDLINE), Ovid Embase, Ovid International Pharmaceutical Abstracts, Scopus, Cochrane Library, and APA PsycInfo. RESULTS In 92% of the included studies (n = 77), opioid stewardship interventions led by either a pharmacist or in an interdisciplinary team resulted in improvements in at least one outcome measure, with education and medication therapy adjustments being the most predominant activities. Other areas supported by evidence include community stakeholder education, policy and guideline setting, and risk assessment. CONCLUSION This scoping review provides valuable insight into the various roles pharmacists can have in opioid stewardship. The findings from this review identified opioid stewardship activities that can make significant contributions towards reducing the impact of the opioid crisis. This review informs future research and has the potential to influence pharmacy practice on a national and international scale.
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Affiliation(s)
- Nyasha Gondora
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | | | - Caitlin Carter
- School of Pharmacy, University of Waterloo, Ontario, Canada
| | - Lisa D Bishop
- School of Pharmacy, Memorial University, Newfoundland and Labrador, Canada
| | - Beth Sproule
- Centre for Addiction and Mental Health & Leslie Dan Faculty of Pharmacy, University of Toronto, Ontario, Canada
| | - Dana Turcotte
- College of Pharmacy, University of Manitoba, Manitoba, Canada
| | - Katelyn Halpape
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatchewan, Canada
| | | | - Shelita Dattani
- Neighborhood Pharmacy Association of Canada, Ottawa, Ontario, Canada
| | - Mona Kwong
- British Columbia Centre on Substance Use, British Columbia, Canada
| | - Lisa Nissen
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Feng Chang
- School of Pharmacy, University of Waterloo, Ontario, Canada.
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10
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Gondora N, Pople CB, Tandon G, Robinson M, Solomon E, Beazely MA, Mielke JG. Chronic early-life social isolation affects NMDA and TrkB receptor expression in a sex-specific manner. Neurosci Lett 2021; 760:136016. [PMID: 34111511 DOI: 10.1016/j.neulet.2021.136016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/22/2021] [Accepted: 06/06/2021] [Indexed: 12/27/2022]
Abstract
Exposing mammals to adverse social environments early in life can affect brain development in ways that alter adult behaviour. For example, chronic, early-life social isolation (CELSI) has been found to cause novelty-induced hyperactivity, impaired pre-pulse inhibition, and enhanced anxiety-related behaviour. Although the molecular mechanism(s) underlying the embedding of CELSI have not been fully elucidated, evidence suggests changes in the level of excitatory neurotransmission and neurotrophic factor signalling may be quite important. Since much of the work in this area has focused upon mRNA-level analyses, and has shown variable responses across both brain region and animal sex, our study aimed to explore the impact of CELSI on the expression of two important plasticity-related proteins (Tropomyosin receptor kinase B and the GluN2B subunit of the NMDA receptor) in the pre-frontal cortex and hippocampus of both male and female rats. We observed that the expression of both proteins was clearly changed by CELSI, but that the effect occurred in a sex (but not region) specific manner. Our results support the growing view that early-life adversity can cause structural changes reasonably associated with adult behaviour, and emphasise that the study of such changes benefits from a sex-based analysis.
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Affiliation(s)
- Nyasha Gondora
- School of Pharmacy, University of Waterloo, 10 Victoria Street S, Kitchener, Ontario N2G 1C5, Canada
| | - Christopher B Pople
- Sunnybrook Health Sciences Centre, 2075 Bayview Ave, Toronto, Ontario M4N 3M5, Canada
| | - Gorvie Tandon
- School of Nursing, York University, 400 Keele Toronto, Ontario M3J 1P3, Canada
| | - Morgan Robinson
- School of Pharmacy, University of Waterloo, 10 Victoria Street S, Kitchener, Ontario N2G 1C5, Canada
| | - Eden Solomon
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Michael A Beazely
- School of Pharmacy, University of Waterloo, 10 Victoria Street S, Kitchener, Ontario N2G 1C5, Canada
| | - John G Mielke
- School of Public Health Sciences, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
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11
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Tsuyuki RT, Arora V, Barnes M, Beazely MA, Boivin M, Christofides A, Patel H, Laroche J, Sihota A, So R. Canadian national consensus guidelines for naloxone prescribing by pharmacists. Can Pharm J (Ott) 2020; 153:347-351. [PMID: 33282024 PMCID: PMC7689616 DOI: 10.1177/1715163520949973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ross T Tsuyuki
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Vinita Arora
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Mark Barnes
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Michael A Beazely
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Michael Boivin
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Anna Christofides
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Harsit Patel
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Julie Laroche
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Aaron Sihota
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
| | - Randy So
- University of Alberta (Tsuyuki, So), Edmonton, Alberta.,University of Toronto (Arora), Toronto.,RespectRx (Barnes), Ottawa.,University of Waterloo (Beazely), Waterloo.,CommPharm Consulting (Boivin), Barrie.,IMPACT Medicom Inc. (Christofides), Toronto.,Hamilton General Hospital (Patel), Hamilton Health Sciences, Hamilton, Ontario.,Familiprix (Laroche), St-Lin-Laurentides, Quebec.,University of British Columbia (Sihota), Vancouver, BC
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12
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So R, Al Hamarneh Y, Barnes M, Beazely MA, Boivin M, Laroche J, Patel H, Sihota A, Smith T, Tsuyuki RT. The status of naloxone in community pharmacies across Canada. Can Pharm J (Ott) 2020; 153:352-356. [PMID: 33282025 PMCID: PMC7689620 DOI: 10.1177/1715163520958435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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13
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Gondora N, Sanyal C, Carter C, Nethercott A, Sproule B, Turcotte D, Halpape K, Bishop LD, Nissen L, Beazely MA, Kwong M, Versteeg S, Chang F. The role of pharmacists in opioid stewardship: Protocol. Res Social Adm Pharm 2020; 17:993-996. [PMID: 33773640 DOI: 10.1016/j.sapharm.2020.06.027] [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: 06/30/2020] [Accepted: 06/30/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND The opioid crisis is a worldwide public health concern. In North America, evidence suggests that the increase in opioid prescriptions correlates with the observed increase in opioid-related mortality and morbidity. Pharmacists are in a strategic position to promote effective opioid stewardship as they have a central role on healthcare teams. However, in many contexts, pharmacists do not have a harmonized scope of practice and no standardized opioid stewardship approach has been implemented. OBJECTIVES A scoping review will be conducted to identify and summarize evidence on the role of pharmacists in opioid stewardship and identify areas for future study. METHODS The scoping review will be conducted according to the methodological framework proposed by Arksey and O'Malley, which was further modified by the Joanna Briggs Institute. Six databases will be searched which include PubMed, Embase, International Pharmaceutical Abstracts, Scopus, Cochrane Library, and APA PsycInfo. PROJECT IMPACT The findings of this review will identify opioid stewardship activities that can contribute towards reducing the impact of the opioid crisis. Additionally, it will provide foundational strategies to promote policy level change and foster a harmonized scope of practice. This review has the potential to inform future research, impact pharmacy practice, and drive policy change.
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Affiliation(s)
- Nyasha Gondora
- School of Pharmacy, University of Waterloo, 10 Victoria St S A, Kitchener, Ontario, N2G 1C5, Canada
| | - Chiranjeev Sanyal
- Canadian Pharmacists Association, 1785 Alta Vista Dr, Ottawa, Ontario, K1G 3Y6, Canada
| | - Caitlin Carter
- School of Pharmacy, University of Waterloo, 10 Victoria St S A, Kitchener, Ontario, N2G 1C5, Canada
| | - Ashley Nethercott
- Shoppers Drug Mart, 78 Front St E, Strathroy, Ontario, N7G 1Y7, Canada
| | - Beth Sproule
- Centre for Addiction and Mental Health & Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St, Toronto, Ontario, M5S 3M2, Canada
| | - Dana Turcotte
- College of Pharmacy, University of Manitoba, Apotex Centre, Winnipeg, MB R3E 0T5, Canada
| | - Katelyn Halpape
- College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Rd, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Lisa D Bishop
- School of Pharmacy, Memorial University, 300 Prince Philip Dr, St. John's Newfoundland and Labrador, NL A1B 3V6, Canada
| | - Lisa Nissen
- School of Clinical Sciences, Faculty of Health, Queensland University of Technology, 2 George St, Brisbane City QLD, 4000, Brisbane, Australia
| | - Michael A Beazely
- School of Pharmacy, University of Waterloo, 10 Victoria St S A, Kitchener, Ontario, N2G 1C5, Canada
| | - Mona Kwong
- British Columbia Centre on Substance Use, 1045 Howe St Suite 400, Vancouver, British Columbia, V6Z 2A9, Canada
| | - Sarah Versteeg
- School of Pharmacy, University of Waterloo, 10 Victoria St S A, Kitchener, Ontario, N2G 1C5, Canada
| | - Feng Chang
- School of Pharmacy, University of Waterloo, 10 Victoria St S A, Kitchener, Ontario, N2G 1C5, Canada.
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14
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Liu H, Saffi GT, Vasefi MS, Choi Y, Kruk JS, Ahmed N, Gondora N, Mielke J, Leonenko Z, Beazely MA. Amyloid-β Inhibits PDGFβ Receptor Activation and Prevents PDGF-BBInduced Neuroprotection. Curr Alzheimer Res 2019; 15:618-627. [PMID: 29332578 DOI: 10.2174/1567205015666180110110321] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 11/14/2017] [Accepted: 01/08/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND PDGFβ receptors and their ligand, PDGF-BB, are upregulated in vivo after neuronal insults such as ischemia. When applied exogenously, PDGF-BB is neuroprotective against excitotoxicity and HIV proteins. OBJECTIVE Given this growth factor's neuroprotective ability, we sought to determine if PDGF-BB would be neuroprotective against amyloid-β (1-42), one of the pathological agents associated with Alzheimer's disease (AD). METHODS AND RESULTS In both primary hippocampal neurons and the human-derived neuroblastoma cell line, SH-SY5Y, amyloid-β treatment for 24 h decreased surviving cell number in a concentrationdependent manner. Pretreatment with PDGF-BB failed to provide any neuroprotection against amyloid-β in primary neurons and only very limited protective effects in SH-SY5Y cells. In addition to its neuroprotective action, PDGF promotes cell growth and division in several systems, and the application of PDGFBB alone to serum-starved SH-SY5Y cells resulted in an increase in cell number. Amyloid-β attenuated the mitogenic effects of PDGF-BB, inhibited PDGF-BB-induced PDGFβ receptor phosphorylation, and attenuated the ability of PDGF-BB to protect neurons against NMDA-induced excitotoxicity. Despite the ability of amyloid-β to inhibit PDGFβ receptor activation, immunoprecipitation experiments failed to detect a physical interaction between amyloid-β and PDGF-BB or the PDGFβ receptor. However, G protein-coupled receptor transactivation of the PDGFβ receptor (an exclusively intracellular signaling pathway) remained unaffected by the presence of amyloid-β. CONCLUSIONS As the PDGF system is upregulated upon neuronal damage, the ability of amyloid-β to inhibit this endogenous neuroprotective system should be further investigated in the context of AD pathophysiology.
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Affiliation(s)
- Hui Liu
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Golam T Saffi
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Maryam S Vasefi
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Youngjik Choi
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Jeff S Kruk
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Nawaz Ahmed
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Nyasha Gondora
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - John Mielke
- Faculty of Science, and the School of Public Health and Health Systems, Faculty of Applied Health Science, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Zoya Leonenko
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada.,Physics and Astronomy, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
| | - Michael A Beazely
- The Departments of Biology, University of Waterloo School of Pharmacy, Kitchener, ON, N2G IC5, Canada
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Abstract
Purpose The availability of take home naloxone (THN) was increased for Canadians in 2016, including access to kits via pharmacies. Unlike typical over-the-counter (OTC) and prescription drugs, THN kits may be stored in non-standard conditions, including in vehicles, backpacks, and out of doors. To evaluate whether these non-standard storage conditions affect stability, we investigated the impact of heat and freeze-thaw cycling on naloxone hydrochloride stability. Methods To assess the effect of heat, naloxone hydrochloride ampoules were exposed to 80 °C in a temperature-controlled oven for 8 h followed by 16 h at room temperature. To assess the effect of freeze-thaw cycles, naloxone hydrochloride ampoules were exposed to − 20 °C for 16 h followed by 8 h at 4 °C. The impact of these conditions on naloxone hydrochloride stability was evaluated each day for 1 week and after 2 and 4 weeks. The concentration of remaining naloxone hydrochloride was quantified using high-performance liquid chromatography (HPLC). Naloxone hydrochloride ampoules stored at room temperature served as the experimental control. Results Naloxone hydrochloride ampoules exhibit no changes in drug concentration following exposure to heat or freeze-thaw cycles for up to 28 days compared to ampoules maintained at room temperature (as indicated in the product monograph). Conclusions Naloxone hydrochloride remains chemically stable following exposure to heat or freeze-thaw cycles after 28 days. If THN kits are stored in non-standard conditions (for up to 28 days) the active naloxone is likely to remain stable. Despite this, pharmacists should continue to emphasize the importance of appropriate storage of THN kits to ensure optimal efficacy should naloxone administration be required in an emergency situation. Electronic supplementary material The online version of this article (10.1186/s12954-019-0288-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dulcie Lai
- School of Pharmacy, Faculty of Science, University of Waterloo, 10 Victoria Street South, Kitchener, Ontario, N2G 1C5, Canada
| | - Amy Trinh Pham
- School of Pharmacy, Faculty of Science, University of Waterloo, 10 Victoria Street South, Kitchener, Ontario, N2G 1C5, Canada
| | - Praveen P Nekkar Rao
- School of Pharmacy, Faculty of Science, University of Waterloo, 10 Victoria Street South, Kitchener, Ontario, N2G 1C5, Canada
| | - Michael A Beazely
- School of Pharmacy, Faculty of Science, University of Waterloo, 10 Victoria Street South, Kitchener, Ontario, N2G 1C5, Canada.
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16
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Osman W, Mohamed T, Sit VM, Vasefi MS, Beazely MA, Rao PPN. Structure-activity relationship studies of benzyl-, phenethyl-, and pyridyl-substituted tetrahydroacridin-9-amines as multitargeting agents to treat Alzheimer's disease. Chem Biol Drug Des 2016; 88:710-723. [DOI: 10.1111/cbdd.12800] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 06/03/2016] [Indexed: 01/12/2023]
Affiliation(s)
- Wesseem Osman
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
| | - Tarek Mohamed
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
- Department of Chemistry; University of Waterloo; Waterloo ON Canada
| | - Victor Munsing Sit
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
| | - Maryam S. Vasefi
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
| | - Michael A. Beazely
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
| | - Praveen P. N. Rao
- School of Pharmacy; Health Sciences Campus; University of Waterloo; Waterloo ON Canada
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17
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Kruk JS, Vasefi MS, Gondora N, Ahmed N, Heikkila JJ, Beazely MA. Fluoxetine-induced transactivation of the platelet-derived growth factor type β receptor reveals a novel heterologous desensitization process. Mol Cell Neurosci 2015; 65:45-51. [DOI: 10.1016/j.mcn.2015.02.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/12/2014] [Accepted: 02/06/2015] [Indexed: 10/24/2022] Open
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18
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Tin G, Mohamed T, Gondora N, Beazely MA, Rao PPN. Tricyclic phenothiazine and phenoselenazine derivatives as potential multi-targeting agents to treat Alzheimer's disease. Med Chem Commun 2015. [DOI: 10.1039/c5md00274e] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A group of tricyclic phenothiazines (6a, 6b and 7a–l) and phenoselenazines (12a, 12b and 13a–l) was designed, synthesized and evaluated as multi-targeting ligands aimed at the cholinergic, amyloid and oxidative stress pathways of Alzheimer's disease.
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Affiliation(s)
- Gary Tin
- School of Pharmacy
- Health Sciences Campus
- University of Waterloo
- Waterloo N2L 3G1
- Canada
| | - Tarek Mohamed
- School of Pharmacy
- Health Sciences Campus
- University of Waterloo
- Waterloo N2L 3G1
- Canada
| | - Nyasha Gondora
- School of Pharmacy
- Health Sciences Campus
- University of Waterloo
- Waterloo N2L 3G1
- Canada
| | - Michael A. Beazely
- School of Pharmacy
- Health Sciences Campus
- University of Waterloo
- Waterloo N2L 3G1
- Canada
| | - Praveen P. N. Rao
- School of Pharmacy
- Health Sciences Campus
- University of Waterloo
- Waterloo N2L 3G1
- Canada
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19
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Samarajeewa A, Goldemann L, Vasefi MS, Ahmed N, Gondora N, Khanderia C, Mielke JG, Beazely MA. 5-HT7 receptor activation promotes an increase in TrkB receptor expression and phosphorylation. Front Behav Neurosci 2014; 8:391. [PMID: 25426041 PMCID: PMC4224134 DOI: 10.3389/fnbeh.2014.00391] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [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: 07/22/2014] [Accepted: 10/20/2014] [Indexed: 11/29/2022] Open
Abstract
The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropomyosin-related kinase B (TrkB) receptor is one of the receptors for brain-derived neurotrophic factor (BDNF) and is associated with neurodevelopmental and neuroprotective effects. Application of LP 12 to primary cerebral cortical cultures, SH-SY5Y cells, as well as the retinal ganglion cell line, RGC-5, increased both the expression of full length TrkB as well as its basal phosphorylation state at tyrosine 816. The increase in TrkB expression and phosphorylation was observed as early as 30 min after 5-HT7 receptor activation. In addition to full-length TrkB, kinase domain-deficient forms may be expressed and act as dominant-negative proteins toward the full length receptor. We have identified distinct patterns of TrkB isoform expression across our cell lines and cortical cultures. Although TrkB receptor expression is regulated by cyclic AMP and Gαs-coupled GPCRs in several systems, we demonstrate that, depending on the model system, pathways downstream of both Gαs and Gα12 are involved in the regulation of TrkB expression by 5-HT7 receptors. Given the number of psychiatric and degenerative diseases associated with TrkB/BDNF deficiency and the current interest in developing 5-HT7 receptor ligands as pharmaceuticals, identifying signaling relationships between these two receptors will aid in our understanding of the potential therapeutic effects of 5-HT7 receptor ligands.
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Affiliation(s)
| | | | - Maryam S Vasefi
- School of Pharmacy, University of Waterloo Kitchener, ON, Canada
| | - Nawaz Ahmed
- School of Pharmacy, University of Waterloo Kitchener, ON, Canada
| | - Nyasha Gondora
- School of Pharmacy, University of Waterloo Kitchener, ON, Canada
| | | | - John G Mielke
- School of Public Health and Health Systems, University of Waterloo Waterloo, ON, Canada
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20
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Vasefi MS, Yang K, Li J, Kruk JS, Heikkila JJ, Jackson MF, MacDonald JF, Beazely MA. Acute 5-HT7 receptor activation increases NMDA-evoked currents and differentially alters NMDA receptor subunit phosphorylation and trafficking in hippocampal neurons. Mol Brain 2013; 6:24. [PMID: 23672716 PMCID: PMC3661375 DOI: 10.1186/1756-6606-6-24] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 05/06/2013] [Indexed: 01/16/2023] Open
Abstract
Background N-methyl-D-aspartate (NMDA) receptors are regulated by several G protein-coupled receptors (GPCRs) as well as receptor tyrosine kinases. Serotonin (5-HT) type 7 receptors are expressed throughout the brain including the thalamus and hippocampus. Long-term (2–24 h) activation of 5-HT7 receptors promotes the expression of neuroprotective growth factor receptors, including the platelet-derived growth factor (PDGF) β receptors which can protect neurons against NMDA-induced neurotoxicity. Results In contrast to long-term activation of 5-HT7 receptors, acute (5 min) treatment of isolated hippocampal neurons with the 5-HT7 receptor agonist 5-carboxamidotryptamine (5-CT) enhances NMDA-evoked peak currents and this increase in peak currents is blocked by the 5-HT7 receptor antagonist, SB 269970. In hippocampal slices, acute 5-HT7 receptor activation increases NR1 NMDA receptor subunit phosphorylation and differentially alters the phosphorylation state of the NR2B and NR2A subunits. NMDA receptor subunit cell surface expression is also differentially altered by 5-HT7 receptor agonists: NR2B cell surface expression is decreased whereas NR1 and NR2A surface expression are not significantly altered. Conclusions In contrast to the negative regulatory effects of long-term activation of 5-HT7 receptors on NMDA receptor signaling, acute activation of 5-HT7 receptors promotes NMDA receptor activity. These findings highlight the potential for temporally differential regulation of NMDA receptors by the 5-HT7 receptor.
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21
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Beazely MA, Kruk JS. Serotonin transactivation of PDGFβ receptors results in a heterologous desensitization to subsequent transactivation stimuli. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.882.7] [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)
| | - Jeff S Kruk
- BiologyUniversity of WaterlooWaterlooONCanada
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22
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Vasefi MS, Kruk JS, Heikkila JJ, Beazely MA. 5-Hydroxytryptamine type 7 receptor neuroprotection against NMDA-induced excitotoxicity is PDGFβ receptor dependent. J Neurochem 2013; 125:26-36. [PMID: 23336565 DOI: 10.1111/jnc.12157] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 12/20/2012] [Accepted: 01/09/2013] [Indexed: 01/07/2023]
Abstract
The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the hippocampus. Long-term (2-24 h) activation of 5-HT7 receptors regulates growth factor receptor expression, including the expression of platelet-derived growth factor (PDGF) β receptors. Direct activation of PDGFβ receptors in primary hippocampal and cortical neurons inhibits NMDA receptor activity and attenuates NMDA receptor-induced neurotoxicity. Our objective was to investigate whether the 5-HT7 receptor-induced increase in PDGFβ receptor expression would be similarly neuroprotective. We demonstrate that 5-HT7 receptor agonist treatment in primary hippocampal neurons also increases the expression of phospholipase C (PLC) γ, a downstream effector of PDGFβ receptors associated with the inhibition of NMDA receptor activity. To determine if the up-regulation of PDGFβ receptors is neuroprotective, primary hippocampal neurons were incubated with the 5-HT7 receptor agonist, LP 12, for 24 h. Indeed, LP 12 treatment prevented NMDA-induced neurotoxicity and this effect was dependent on PDGFβ receptor kinase activity. Treatment of primary neurons with LP 12 also differentially altered NMDA receptor subunit expression, reducing the expression of NR1 and NR2B, but not NR2A. These findings demonstrate the potential for providing growth factor receptor-dependent neuroprotective effects using small-molecule ligands of G protein-coupled receptors.
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Affiliation(s)
- Maryam S Vasefi
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
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23
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Kruk JS, Vasefi MS, Liu H, Heikkila JJ, Beazely MA. 5-HT1A receptors transactivate the platelet-derived growth factor receptor type beta in neuronal cells. Cell Signal 2013; 25:133-43. [DOI: 10.1016/j.cellsig.2012.09.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 09/07/2012] [Accepted: 09/16/2012] [Indexed: 01/23/2023]
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24
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Mohamed T, Yeung JC, Vasefi MS, Beazely MA, Rao PP. Development and evaluation of multifunctional agents for potential treatment of Alzheimer’s disease: Application to a pyrimidine-2,4-diamine template. Bioorg Med Chem Lett 2012; 22:4707-12. [DOI: 10.1016/j.bmcl.2012.05.077] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Revised: 05/18/2012] [Accepted: 05/18/2012] [Indexed: 12/20/2022]
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25
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Vasefi MS, Kruk JS, Liu H, Heikkila JJ, Beazely MA. Activation of 5-HT7 receptors increases neuronal platelet-derived growth factor β receptor expression. Neurosci Lett 2012; 511:65-9. [DOI: 10.1016/j.neulet.2012.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 01/04/2012] [Accepted: 01/05/2012] [Indexed: 10/14/2022]
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26
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Bartos JA, Ulrich JD, Li H, Beazely MA, Chen Y, MacDonald JF, Hell JW. Postsynaptic clustering and activation of Pyk2 by PSD-95. J Neurosci 2010; 30:449-63. [PMID: 20071509 PMCID: PMC2822408 DOI: 10.1523/jneurosci.4992-08.2010] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2008] [Revised: 11/01/2009] [Accepted: 11/04/2009] [Indexed: 12/24/2022] Open
Abstract
The tyrosine kinase Pyk2 plays a unique role in intracellular signal transduction by linking Ca(2+) influx to tyrosine phosphorylation, but the molecular mechanism of Pyk2 activation is unknown. We report that Pyk2 oligomerization by antibodies in vitro or overexpression of PSD-95 in PC6-3 cells induces trans-autophosphorylation of Tyr402, the first step in Pyk2 activation. In neurons, Ca(2+) influx through NMDA-type glutamate receptors causes postsynaptic clustering and autophosphorylation of endogenous Pyk2 via Ca(2+)- and calmodulin-stimulated binding to PSD-95. Accordingly, Ca(2+) influx promotes oligomerization and thereby autoactivation of Pyk2 by stimulating its interaction with PSD-95. We show that this mechanism of Pyk2 activation is critical for long-term potentiation in the hippocampus CA1 region, which is thought to underlie learning and memory.
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Affiliation(s)
- Jason A. Bartos
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242-1109
| | - Jason D. Ulrich
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242-1109
| | - Hongbin Li
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
| | - Michael A. Beazely
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
| | - Yucui Chen
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242-1109
| | - John F. MacDonald
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada, and
- Robarts Research Institute, University of Western Ontario, London, Ontario N6A 5K8, Canada
| | - Johannes W. Hell
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242-1109
- Department of Pharmacology, University of California, Davis, Davis, California 95616-8636
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27
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Yang K, Trepanier CH, Li H, Beazely MA, Lerner EA, Jackson MF, MacDonald JF. Vasoactive intestinal peptide acts via multiple signal pathways to regulate hippocampal NMDA receptors and synaptic transmission. Hippocampus 2009; 19:779-89. [PMID: 19173226 DOI: 10.1002/hipo.20559] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Vasoactive intestinal peptide (VIP) is a 28-amino acid peptide, which belongs to a superfamily of structurally related peptide hormones including pituitary adenylate cyclase-activating polypeptide (PACAP). Although several studies have identified the involvement of PACAP in learning and memory, little work has been done to investigate such a role for VIP. At least three receptors for VIP have been identified including the PACAP receptor (PAC1-R) and the two VIP receptors (VPAC receptors). VIP can activate the PAC1-R only if it is used at relatively high concentrations (e.g., 100 nM); however, at lower concentrations (e.g., 1 nM) it is selective for the VPAC receptors. Our lab has showed that PAC1-R activation signals through PKC/CAKbeta/Src pathway to regulate NMDA receptors; however, there is little known about the potential regulation of NMDA receptors by VPAC receptors. Our studies demonstrated that application of 1 nM VIP enhanced NMDA currents by stimulating the VPAC receptors as the effect was blocked by VPAC receptor antagonist [Ac-Tyr(1), D-Phe(2)]GRF (1-29). This enhancement of NMDA currents was blocked by both Rp-cAMPS and PKI(14-22) (they are highly specific PKA inhibitors), but not by the specific PKC inhibitor, bisindolylmaleimide I. In addition, the VIP-induced enhancement of NMDA currents was accentuated by inhibition of phosphodiesterase 4, which inhibits the degradation of cAMP. This regulation of NMDA receptors also required the scaffolding protein AKAP. In contrast, the potentiation induced by high concentration of VIP (e.g., 100 nM) was mediated by PAC1-R as well as by Src kinase. Overall, these results show that VIP can regulate NMDA receptors through different receptors and signaling pathways.
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Affiliation(s)
- Kai Yang
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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28
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Beazely MA, Lim A, Li H, Trepanier C, Chen X, Sidhu B, Macdonald JF. Platelet-derived growth factor selectively inhibits NR2B-containing N-methyl-D-aspartate receptors in CA1 hippocampal neurons. J Biol Chem 2008; 284:8054-63. [PMID: 19106110 DOI: 10.1074/jbc.m805384200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Platelet-derived growth factor (PDGF) beta receptor activation inhibits N-methyl-d-aspartate (NMDA)-evoked currents in hippocampal and cortical neurons via the activation of phospholipase Cgamma, PKC, the release of intracellular calcium, and a rearrangement of the actin cytoskeleton. In the hippocampus, the majority of NMDA receptors are heteromeric; most are composed of 2 NR1 subunits and 2 NR2A or 2 NR2B subunits. Using NR2B- and NR2A-specific antagonists, we demonstrate that PDGF-BB treatment preferentially inhibits NR2B-containing NMDA receptor currents in CA1 hippocampal neurons and enhances long-term depression in an NR2B subunit-dependent manner. Furthermore, treatment of hippocampal slices or cultures with PDGF-BB decreases the surface localization of NR2B but not of NR2A subunits. PDGFbeta receptors colocalize to a higher degree with NR2B subunits than with NR2A subunits. After neuronal injury, PDGFbeta receptors and PDGF-BB are up-regulated and PDGFbeta receptor activation is neuroprotective against glutamate-induced neuronal damage in cultured neurons. We demonstrate that the neuroprotective effects of PDGF-BB are occluded by the NR2B antagonist, Ro25-6981, and that PDGF-BB promotes NMDA signaling to CREB and ERK1/2. We conclude that PDGFbetaR signaling, by preferentially targeting NR2B receptors, provides an important mechanism for neuroprotection by growth factors in the central nervous system.
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Affiliation(s)
- Michael A Beazely
- Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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29
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Thompson RJ, Jackson MF, Olah ME, Rungta RL, Hines DJ, Beazely MA, MacDonald JF, MacVicar BA. Activation of pannexin-1 hemichannels augments aberrant bursting in the hippocampus. Science 2008; 322:1555-9. [PMID: 19056988 DOI: 10.1126/science.1165209] [Citation(s) in RCA: 271] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Pannexin-1 (Px1) is expressed at postsynaptic sites in pyramidal neurons, suggesting that these hemichannels contribute to dendritic signals associated with synaptic function. We found that, in pyramidal neurons, N-methyl-d-aspartate receptor (NMDAR) activation induced a secondary prolonged current and dye flux that were blocked with a specific inhibitory peptide against Px1 hemichannels; knockdown of Px1 by RNA interference blocked the current in cultured neurons. Enhancing endogenous NMDAR activation in brain slices by removing external magnesium ions (Mg2+) triggered epileptiform activity, which had decreased spike amplitude and prolonged interburst interval during application of the Px1 hemichannel blocking peptide. We conclude that Px1 hemichannel opening is triggered by NMDAR stimulation and can contribute to epileptiform seizure activity.
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Affiliation(s)
- Roger J Thompson
- Department of Psychiatry and Brain Research Centre, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada.
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Beazely MA, Weerapura M, MacDonald JF. Abelson tyrosine kinase links PDGFbeta receptor activation to cytoskeletal regulation of NMDA receptors in CA1 hippocampal neurons. Mol Brain 2008; 1:20. [PMID: 19077273 PMCID: PMC2651131 DOI: 10.1186/1756-6606-1-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 12/12/2008] [Indexed: 01/12/2023] Open
Abstract
Background We have previously demonstrated that PDGF receptor activation indirectly inhibits N-methyl-D-aspartate (NMDA) currents by modifying the cytoskeleton. PDGF receptor ligand is also neuroprotective in hippocampal slices and cultured neurons. PDGF receptors are tyrosine kinases that control a variety of signal transduction pathways including those mediated by PLCγ. In fibroblasts Src and another non-receptor tyrosine kinase, Abelson kinase (Abl), control PDGF receptor regulation of cytoskeletal dynamics. The mechanism whereby PDGF receptor regulates cytoskeletal dynamics in central neurons remains poorly understood. Results Intracellular applications of active Abl, but not heat-inactivated Abl, decreased NMDA-evoked currents in isolated hippocampal neurons. This mimics the effects of PDGF receptor activation in these neurons. The Abl kinase inhibitor, STI571, blocked the inhibition of NMDA currents by Abl. We demonstrate that PDGF receptors can activate Abl kinase in hippocampal neurons via mechanisms similar to those observed previously in fibroblasts. Furthermore, PDGFβ receptor activation alters the subcellular localization of Abl. Abl kinase is linked to actin cytoskeletal dynamics in many systems. We show that the inhibition of NMDA receptor currents by Abl kinase is blocked by the inclusion of the Rho kinase inhibitor, Y-27632, and that activation of Abl correlates with an increase in ROCK tyrosine phosphorylation. Conclusion This study demonstrates that PDGFβ receptors act via an interaction with Abl kinase and Rho kinase to regulated cytoskeletal regulation of NMDA receptor channels in CA1 pyramidal neurons.
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Abstract
The direction of plasticity at CA3-CA1 hippocampal synapses is determined by the strength of afferent stimulation. Weak stimuli lead to long-term depression (LTD) and strong stimuli to long-term potentiation (LTP), but both require activation of synaptic N-methyl-D-aspartate receptors (NMDARs). These receptors are therefore necessary and required for the induction of plasticity at CA3-CA1 synapses even though they carry little of the current responsible for the basal excitatory post-synaptic potential (EPSP). The influx of Ca(2+) via NMDARs triggers the subsequent and persistent changes in the expression of alpha-amino-3-hydroxy-5 methylisoxazole-4-proprionic acid receptors (AMPARs) and these receptors are responsible for the major part of the basal EPSP. The degree of activity of NMDARs is determined in part by extracellular Mg(2+) and by the co-agonists for this receptor, glycine and D-serine. During strong stimulation, a relief of the voltage-dependent block of NMDARs by Mg(2+) provides a positive feedback for NMDAR Ca(2+) influx into postsynaptic CA1 spines. In this review, we discuss how the induction of LTP at CA3-CA1 synapses requires further signal amplification of NMDAR activity. We discuss how the regulation of NMDARs by protein kinases and phosphatases is brought into play. Evidence is presented that Src family kinases (SFKs) play a "core" role in the induction of LTP by enhancing the function and expression of NMDARs. At CA3-CA1 synapses, NMDARs are largely composed of NR1 (NMDA receptor subunit 1)-NR2A or NR1-NR2B containing subunits. Recent, but controversial, evidence has correlated NR1-NR2A receptors with the induction of LTP and NR1-NR2B receptors with LTD. However, LTP can be induced by activation of either subtype of NMDAR and the ratio of NR2A:NR2B receptors has been proposed as an alternative determinant of the direction of synaptic plasticity. Many transmitters and signal pathways can modify NMDAR function and expression and, for a given stimulus strength, they can potentially lead to a change in the balance between LTP and LTD. As opposed to the "core" mechanisms of LTP and LTD, the resulting alterations in this balance underlie "meta-plasticity." Thus, in addition to their contribution to core mechanisms, we will also discuss how Src-family kinases could preferentially target NR1-NR2A or NR1-NR2B receptors to alter the relative contribution of these receptor subtypes to synaptic plasticity.
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Affiliation(s)
- John F MacDonald
- Department of Physiology, Medical Sciences Building, 1 King's College, University of Toronto, Toronto Ontario M5S1A8, Canada.
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MacDonald JF, Jackson MF, Beazely MA. G protein-coupled receptors control NMDARs and metaplasticity in the hippocampus. Biochimica et Biophysica Acta (BBA) - Biomembranes 2007; 1768:941-51. [PMID: 17261268 DOI: 10.1016/j.bbamem.2006.12.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 12/06/2006] [Accepted: 12/09/2006] [Indexed: 11/20/2022]
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are the major forms of functional synaptic plasticity observed at CA1 synapses of the hippocampus. The balance between LTP and LTD or "metaplasticity" is controlled by G-protein coupled receptors (GPCRs) whose signal pathways target the N-methyl-D-asparate (NMDA) subtype of excitatory glutamate receptor. We discuss the protein kinase signal cascades stimulated by Galphaq and Galphas coupled GPCRs and describe how control of NMDAR activity shifts the threshold for the induction of LTP.
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Affiliation(s)
- John F MacDonald
- Department of Physiology, University of Toronto, Toronto, ON, Canada.
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33
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Beazely MA, Tong A, Wei WL, Van Tol H, Sidhu B, MacDonald JF. D2-class dopamine receptor inhibition of NMDA currents in prefrontal cortical neurons is platelet-derived growth factor receptor-dependent. J Neurochem 2006; 98:1657-63. [PMID: 16879713 DOI: 10.1111/j.1471-4159.2006.04064.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [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: 12/01/2022]
Abstract
NMDA receptor function is modulated by both G-protein-coupled receptors and receptor tyrosine kinases. In acutely isolated rat hippocampal neurons, direct activation of the platelet-derived growth factor (PDGF) receptor or transactivation of the PDGF receptor by D4 dopamine receptors inhibits NMDA-evoked currents in a phospholipase C (PLC)-dependent manner. We have investigated further the ability of D2-class dopamine receptors to modulate NMDA-evoked currents in isolated rat prefrontal cortex (PFC). We have demonstrated that, similar to isolated hippocampal neurons, the application of PDGF-BB or quinpirole to isolated PFC neurons induces a slow-onset and long-lasting inhibition of NMDA-evoked currents. However, in contrast to hippocampal neurons, the inhibition of NMDA-evoked currents by quinpirole in PFC neurons is dependent upon D2/3, rather than D4, dopamine receptors. In PFC slices, application of both PDGF-BB and quinpirole induced a phosphorylation of the PDGF receptor at the PLCgamma binding and activation site, Tyr1021. The PDGF receptor kinase inhibitor, tyrphostin A9, and the D2/3 dopamine receptor antagonist, raclopride, inhibited quinpirole-induced Tyr1021 phosphorylation. These finding suggest that quinpirole treatment inhibits NMDAR signaling via PDGF receptor transactivation in both the hippocampus and the PFC, and that the effects of quinpirole in these regions are mediated by D4 and D2/3 dopamine receptors, respectively.
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Affiliation(s)
- Michael A Beazely
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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34
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Macdonald DS, Weerapura M, Beazely MA, Martin L, Czerwinski W, Roder JC, Orser BA, MacDonald JF. Modulation of NMDA receptors by pituitary adenylate cyclase activating peptide in CA1 neurons requires G alpha q, protein kinase C, and activation of Src. J Neurosci 2006; 25:11374-84. [PMID: 16339032 PMCID: PMC6725893 DOI: 10.1523/jneurosci.3871-05.2005] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [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: 11/21/2022] Open
Abstract
At CA1 synapses, activation of NMDA receptors (NMDARs) is required for the induction of both long-term potentiation and depression. The basal level of activity of these receptors is controlled by converging cell signals from G-protein-coupled receptors and receptor tyrosine kinases. Pituitary adenylate cyclase activating peptide (PACAP) is implicated in the regulation of synaptic plasticity because it enhances NMDAR responses by stimulating Galphas-coupled receptors and protein kinase A (Yaka et al., 2003). However, the major hippocampal PACAP1 receptor (PAC1R) also signals via Galphaq subunits and protein kinase C (PKC). In CA1 neurons, we showed that PACAP38 (1 nM) enhanced synaptic NMDA, and evoked NMDAR, currents in isolated CA1 neurons via activation of the PAC1R, Galphaq, and PKC. The signaling was blocked by intracellular applications of the Src inhibitory peptide Src(40-58). Immunoblots confirmed that PACAP38 biochemically activates Src. A Galphaq pathway is responsible for this Src-dependent PACAP enhancement because it was attenuated in mice lacking expression of phospholipase C beta1, it was blocked by preventing elevations in intracellular Ca2+, and it was eliminated by inhibiting either PKC or cell adhesion kinase beta [CAKbeta or Pyk2 (proline rich tyrosine kinase 2)]. Peptides that mimic the binding sites for either Fyn or Src on receptor for activated C kinase-1 (RACK1) also enhanced NMDAR in CA1 neurons, but their effects were blocked by Src(40-58), implying that Src is the ultimate regulator of NMDARs. RACK1 serves as a hub for PKC, Fyn, and Src and facilitates the regulation of basal NMDAR activity in CA1 hippocampal neurons.
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Affiliation(s)
- D S Macdonald
- Department of Pharmacology, Faculty of Medicine, University of Toronto, Mount Sinai Hospital, Toronto, Ontario, M5S 1A8, Canada
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35
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Abstract
Adenylate cyclases (AC) type 5 and 6 comprise the calcium-inhibited family of adenylate cyclase isoforms. Here we review recent discoveries in the regulation of AC5 and AC6 with a focus on posttranslational modifications including glycosylation, nitrosylation, and phosphorylation by the cyclic AMP-dependent protein kinase (PKA), protein kinase C (PKC), and Raf1. We also describe novel signaling interactions such as Galpha(q)-mediated potentiation of AC6 activation. Novel regulators of AC5 and AC6, including small molecules and proteins that physically interact with AC5 and AC6 such as snapin, regulator of G protein signaling 2 (RGS2), protein associated with myc (PAM), and caveolin peptides are discussed. We also describe several recent studies that demonstrate the usefulness of transgenic or adenoviral overexpression of AC5 and AC6 in models for disease states such as cardiovascular hypertrophy. The discovery of novel regulatory mechanisms for AC5 and AC6 and their potential role in crucial physiological processes provide new avenues for research into therapeutic interventions targeting the cyclic AMP pathway.
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Affiliation(s)
- Michael A Beazely
- Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Canada, ON M5S 1A8.
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Beazely MA, Watts VJ. Galphaq-coupled receptor signaling enhances adenylate cyclase type 6 activation. Biochem Pharmacol 2005; 70:113-20. [PMID: 15885660 DOI: 10.1016/j.bcp.2005.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 04/13/2005] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
Calcium signaling robustly inhibits AC6 activity in membrane preparations and in intact cells via capacitative calcium entry (CCE). However, the release of intracellular calcium has not been demonstrated to robustly alter AC6 signaling and activation of Galpha(q)-coupled receptors in tissues that express AC6 enhances cyclic AMP accumulation. To specifically examine the ability of Galpha(q)-coupled receptors to modulate AC6 signaling in intact cells, we used stably transfected HEK-AC6 cells. We demonstrate that AC6 activation is potentiated by activation of endogenous muscarinic receptors expressed in HEK293 cells. Muscarinic receptor activation failed to potentiate the activation of the closely related AC5 isoform. Expression of recombinant Galpha(q)-coupled muscarinic or serotonin receptors, or constitutively active Galpha(q), also potentiated drug-stimulated cyclic AMP accumulation in HEK-AC6 cells. Muscarinic receptor-mediated potentiation of AC6 activation was not due to activation of PKC or modulation of Galpha(i/o)-mediated inhibition of AC6. We demonstrate that calcium chelation or inhibition of calmodulin attenuates the effect of carbachol on AC6 activation. These data support the hypothesis that Galpha(q)-coupled receptor-mediated calcium signaling potentiates AC6 activation in intact cells.
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Affiliation(s)
- Michael A Beazely
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-2091, USA
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37
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Beazely MA, Watts VJ. Activation of a novel PKC isoform synergistically enhances D2L dopamine receptor-mediated sensitization of adenylate cyclase type 6. Cell Signal 2005; 17:647-53. [PMID: 15683739 DOI: 10.1016/j.cellsig.2004.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Accepted: 10/13/2004] [Indexed: 11/23/2022]
Abstract
Despite acutely inhibiting adenylate cyclase, prolonged activation of Galpha(i/o)-coupled receptors leads to a subsequent heterologous sensitization of adenylate cyclase responsiveness. Recently, protein kinase signaling and phosphorylation have been implicated in the sensitization of adenylate cyclase type 6 (AC6). To examine the sensitization specifically of AC6, we constructed human embryonic kidney cells (HEK293) cells stably expressing AC6 and the Galpha(i/o)-coupled D2L dopamine receptor. In contrast to observations in delta-opioid-expressing Chinese hamster ovary (CHO) cells that express endogenous AC6 and AC7, neither protein kinase C (PKC) nor tyrosine kinase inhibitors attenuated D2L receptor-mediated sensitization of AC6. Inhibition of Raf1 modestly inhibited the magnitude of D2L receptor-induced sensitization of AC6; however, activation of PKC robustly enhanced D2L receptor-mediated AC6 sensitization in a Raf1-dependent manner. These data indicate that, although PKC and Raf1 are not required for sensitization, activation of the PKC-Raf1 pathway robustly potentiated D2L receptor-mediated sensitization of AC6.
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Affiliation(s)
- Michael A Beazely
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-2091, USA
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38
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Beazely MA, Alan JK, Watts VJ. Protein kinase C and epidermal growth factor stimulation of Raf1 potentiates adenylyl cyclase type 6 activation in intact cells. Mol Pharmacol 2004; 67:250-9. [PMID: 15470083 DOI: 10.1124/mol.104.001370] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenylyl cyclase type 6 (AC6) activity is inhibited by protein kinase C (PKC) in vitro; however, in intact cells, PKC activation does not inhibit the activity of transiently expressed AC6. To investigate the effects of PKC activation on AC6 activity in intact cells, we constructed human embryonic kidney (HEK) 293 cells that stably express wild-type AC6 (AC6-WT) or an AC6 mutant lacking a PKC and cyclic AMP-dependent protein kinase (PKA) phosphorylation site, Ser674 (AC6-S674A). In contrast to in vitro observations, we observed a PKC-mediated enhancement of forskolin- and isoproterenol-stimulated cyclic AMP accumulation in HEK-AC6 cells. Phorbol 12-myristate 13-acetate also potentiated cyclic AMP accumulation in cells expressing endogenous AC6, including Chinese hamster ovary cells and differentiated Cath.a differentiated cells. In HEK-AC6-S674A cells, the potentiation of AC6 stimulation was significantly greater than in cells expressing AC6-WT. The positive effect of PKC activation on AC6 activity seemed to involve Raf1 kinase because the Raf1 inhibitor 3-(3,5-dibromo-4-hydroxybenzylidene-5-iodo-1,3-dihydro-indol-2-one (GW5074) inhibited the PKC potentiation of AC6 activity. Furthermore, the forskolin-stimulated activity of a recombinant AC6 in which the putative Raf1 regulatory sites have been eliminated was not potentiated by activation of PKC. The ability of Raf1 to regulate AC6 may involve a direct interaction because AC6 and a constitutively active Raf1 construct were coimmunoprecipitated. In addition, we report that epidermal growth factor receptor activation also enhances AC6 signaling in a Raf1-dependent manner. These data suggest that Raf1 potentiates drug-stimulated cyclic AMP accumulation in cells expressing AC6 after activation of multiple signaling pathways.
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Affiliation(s)
- Michael A Beazely
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-2091, USA
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39
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Johnston CA, Beazely MA, Bilodeau ML, Andrisani O, Watts VJ. Differentiation-induced alterations in cyclic AMP signaling in the Cath.a differentiated (CAD) neuronal cell line. J Neurochem 2004; 88:1497-508. [PMID: 15009651 DOI: 10.1046/j.1471-4159.2004.02285.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Regulation of intracellular cyclic AMP is critical to the modulation of many cellular activities, including cellular differentiation. Moreover, morphological differentiation has been linked to subsequent alterations in the cAMP signaling pathway in various cellular models. The current study was designed to explore the mechanism for the previously reported enhancement of adenylate cyclase activity in Cath.a differentiated cells following differentiation. Differentiation of Cath.a differentiated cells stably expressing the D2L dopamine receptor markedly potentiated both forskolin- and A2-adenosine receptor-stimulated cAMP accumulation. This enhancement was accompanied by a twofold increase in adenylate cyclase 6 (AC6) expression and a dramatic loss in the expression of AC9. The ability of Ca2+ to inhibit drug-stimulated cAMP accumulation was enhanced following differentiation, as was D2L dopamine receptor-mediated inhibition of Galphas-stimulated cAMP accumulation. Differentiation altered basal and drug-stimulated phosphorylation of the cAMP-response element-binding protein, which was independent of changes in protein kinase A expression. The current data suggest that differentiation of the neuronal cell model, Cath.a differentiated cells induces significant alterations in the expression and function of both the proximal and distal portions of the cAMP signaling pathway and may impact cellular operations dependent upon this pathway.
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Affiliation(s)
- Christopher A Johnston
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, USA
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40
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Johnston CA, Beazely MA, Vancura AF, Wang JKT, Watts VJ. Heterologous sensitization of adenylate cyclase is protein kinase A-dependent in Cath.a differentiated (CAD)-D2L cells. J Neurochem 2002; 82:1087-96. [PMID: 12358756 DOI: 10.1046/j.1471-4159.2002.01033.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Persistent activation of Galphai/o-coupled receptors results in a paradoxical enhancement of subsequent drug-stimulated adenylate cyclase activity. The exact mechanism of this up-regulation in the cyclic AMP signaling pathway, known as heterologous sensitization, remains undefined. The present study was designed to investigate the involvement of cyclic AMP-dependent protein kinase in D2L receptor-mediated sensitization in a neuronal cellular environment. The current studies were conducted in the Cath.a differentiated (CAD) cell line transfected stably with the D2L dopamine receptor (CAD-D2L). Long-term 18 h treatment with the D2 receptor agonist, quinpirole, resulted in a two-fold enhancement of forskolin-stimulated cyclic AMP accumulation. Similarly, long-term treatment with the PKA inhibitors, H89 or Rp-8Br-cAMP, also enhanced adenylate cyclase activity. In contrast, long-term activation of protein kinase A (PKA) by forskolin, isobutylmethylxanthine (IBMX), or dibutyryl cyclic AMP caused a significant reduction in subsequent forskolin-stimulated cyclic AMP accumulation and reduced both quinpirole- and H89-induced heterologous sensitization. The effects of PKA inhibitors and activators did not involve changes in PKA subunit expression. RT-PCR analysis of adenylate cyclase isoform expression patterns revealed the expression of mRNA for ACVI and ACIX in CAD-D2L cells. The ability of ACVI to be negatively regulated by PKA is consistent with the observation that inhibition of PKA results in heterologous sensitization of adenylate cyclase activity in CAD-D2L cells.
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Affiliation(s)
- Christopher A Johnston
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907, USA
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41
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Dimmock JR, Kumar P, Nazarali AJ, Motaganahalli NL, Kowalchuk TP, Beazely MA, Wilson Quail J, Oloo EO, Allen TM, Szydlowski J, DeClercq E, Balzarini J. Cytotoxic 2,6-bis(arylidene)cyclohexanones and related compounds. Eur J Med Chem 2000; 35:967-77. [PMID: 11137225 DOI: 10.1016/s0223-5234(00)01173-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [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: 11/30/2022]
Abstract
A number of 2-arylidenecyclohexanones 1, 2, 6-bis(arylidene)cyclohexanones 2 and related Mannich bases 3-5 were prepared. Various torsion angles as well as atomic charges on olefinic carbon atoms were determined by molecular modelling on all compounds. These molecules showed cytotoxicity towards murine P388 and L1210 cells as well as to human Molt 4/C8 and CEM T-lymphocytes. The average cytotoxicity of the dienones 2 was more than three times greater than was found with the monoarylidene analogues 1, and, in general, were slightly more cytotoxic than the Mannich bases 3-5. A number of the compounds displayed potency towards a panel of human tumour cell lines and most of the representative compounds in series 2-5 were selectively toxic to colon cancers and leukaemic cells.
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Affiliation(s)
- J R Dimmock
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatchewan, S7N 5C9, Saskatoon, Canada.
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42
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Dimmock JR, Elias DW, Beazely MA, Kandepu NM. Bioactivities of chalcones. Curr Med Chem 1999; 6:1125-49. [PMID: 10519918] [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: 02/14/2023]
Abstract
This review outlines the different bioactivities of a variety of chalcones. The cytotoxic, anticancer, chemopreventative and mutagenic properties of a number of chalcones are described followed by an account of various of these unsaturated ketones as antimicrobial agents. The antiviral, antiprotozoal and insecticidal activities of a variety of chalcones are reviewed as well as the enzyme-inhibitory properties and miscellaneous activities of some of these molecules.
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Affiliation(s)
- J R Dimmock
- College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9, Canada.
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43
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Dimmock JR, Semple HA, John S, Beazely MA, Abrams GD. Isolation and identification of the major urinary metabolite of 4-(4-fluorophenoxy)benzaldehyde semicarbazone after oral dosing to rats. Pharmazie 1999; 54:260-2. [PMID: 10234738] [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] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
4-(4-Fluorophenoxy)benzaldehyde semicarbazone (1) is a novel anticonvulsant affording excellent protection in the rat oral maximal electroshock (MES) screen as well as having an apparent protection index of over 300. The metabolism of this compound was studied by examining the urine or rats dosed orally with 50 mg/kg of 1 which revealed that most of the drug was converted into one metabolite 2. The structure of 2 was shown by mass spectrometry to be 1-[4-(4-fluoro-phenoxy)benzoyl]semicarbazide which was confirmed by an independent synthesis. Compound 2 was bereft of activity in the rat oral MES screen when nine times the ED50 dose of 1 was administered. This datum provided strong evidence that the anticonvulsant activity of 1 and related compounds is due to the intact molecules and is not produced by breakdown products in vivo.
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Affiliation(s)
- J R Dimmock
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
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