1
|
Garcia-Luna GM, Bermudes-Contreras JD, Hernández-Correa S, Suarez-Ortiz JO, Diaz-Urbina D, Garfias-Ramirez SH, Vega AV, Villalobos-Molina R, Vilches-Flores A. Δ9-Tetrahydrocannabinol Treatment Modifies Insulin Secretion in Pancreatic Islets from Prediabetic Mice Under Hypercaloric Diet. Cannabis Cannabinoid Res 2023. [PMID: 37267277 DOI: 10.1089/can.2023.0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
Abstract
Background: The endocannabinoid system over-activation is associated with type-2 diabetes mellitus onset, involving physiological, metabolic, and genetic alterations in pancreatic islets. The use of Δ9-Tetrahydrocannabinol (THC) as treatment is still controversial since its effects and mechanisms on insulin secretion are unclear. The aim of this study was to evaluate the effects of THC treatment in pancreatic islets from prediabetic mice. Methods: Prediabetes was induced in mice by hypercaloric diet, and then treated with THC for 3 weeks. Blood glucose and body weight were determined, after behavior tests. Histological changes were evaluated in whole pancreas; in isolated islets we analyzed the effect of THC exposure in glucose-stimulated insulin secretion (GSIS), gene expression, intracellular cyclic adenosine monophosphate (cAMP), and cytosolic calcium changes. Results: THC treatment in prediabetic mice enhanced anxiety and antidepressive behavior without changes in food ingestion, decreased oral-glucose tolerance test, plasma insulin and weight, with small alterations on pancreatic histology. In isolated islets from healthy mice THC increased GSIS, cAMP, and CB1 receptor (CB1r) expression, meanwhile calcium release was diminished. Small changes were observed in islets from prediabetic mice. Conclusions: THC treatment improves some clinical parameters in prediabetic mice, however, in isolated islets, modifies GSIS, intracellular calcium and gene expression, suggesting specific effects related to diabetes evolution.
Collapse
Affiliation(s)
- Guadalupe M Garcia-Luna
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - J David Bermudes-Contreras
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Samantha Hernández-Correa
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Josue O Suarez-Ortiz
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Daniel Diaz-Urbina
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Sergio H Garfias-Ramirez
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Ana V Vega
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Rafael Villalobos-Molina
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| | - Alonso Vilches-Flores
- FES Iztacala, Department of Medical Research, Universidad Nacional Autónoma de México, Tlalnepantla, Mexico
| |
Collapse
|
2
|
Meah F, Lundholm M, Emanuele N, Amjed H, Poku C, Agrawal L, Emanuele MA. The effects of cannabis and cannabinoids on the endocrine system. Rev Endocr Metab Disord 2022; 23:401-420. [PMID: 34460075 DOI: 10.1007/s11154-021-09682-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/15/2021] [Indexed: 01/24/2023]
Abstract
With the increase in cannabis use due to policy changes and areas of decriminalization, it is important to recognize the potential impact of these substances on endocrine processes. Cannabinoids have many effects by activating the endocannabinoid system. This system plays a role in the normal functioning of nearly every organ and consists of the body's natural endocannabinoids, the cannabinoid receptors, and the enzymes and processes that regulate endocannabinoids. Exogenous cannabinoids such as Δ9-tetrahydrocannabinol (THC) are known to act through cannabinoid type 1 and 2 receptors, and have been shown to mimic endocannabinoid signaling and affect receptor expression. This review summarizes the known impacts of cannabis on thyroid, adrenal, and gonadal function in addition to glucose control, lipids, and bone metabolism, including: reduced female fertility, increased risk of adverse pregnancy outcomes, reduced sperm counts and function, lower thyroid hormone levels with acute use, blunting of stress response with chronic use, increased risk of prediabetes but lower risk of diabetes, suggested improvement of high density lipoproteins and triglycerides, and modest increase in fracture risk. The known properties of endocannabinoids, animal data, population data, and the possible benefits and concerns of cannabinoid use on hormonal function are discussed. The interconnectivity of the endocrine and endocannabinoid systems suggests opportunities for future therapeutic modalities which are an area of active investigation.
Collapse
Affiliation(s)
- Farah Meah
- Endocrinology Section, Medical Service, VA Hospital, Hines, Illinois, USA
| | - Michelle Lundholm
- Department of Internal Medicine, Loyola University Medical Center, Maywood, IL, USA
| | - Nicholas Emanuele
- Endocrinology Section, Medical Service, VA Hospital, Hines, Illinois, USA
| | - Hafsa Amjed
- Department of Medicine, Division of Endocrinology, Loyola University Health Care System, Maywood, Illinois, USA
| | - Caroline Poku
- Department of Medicine, Division of Endocrinology, Loyola University Health Care System, Maywood, Illinois, USA
| | - Lily Agrawal
- Endocrinology Section, Medical Service, VA Hospital, Hines, Illinois, USA
| | - Mary Ann Emanuele
- Department of Medicine, Division of Endocrinology, Loyola University Health Care System, Maywood, Illinois, USA.
| |
Collapse
|
3
|
Mathew B, Harilal S, Musa A, Kumar R, Parambi DGT, Jose J, Uddin MS, Shah MA, Behl T, Unnikrishnan MK. An Agathokakological Tale of Δ 9-THC: Exploration of Possible Biological Targets. Curr Drug Targets 2021; 22:823-834. [PMID: 33001012 DOI: 10.2174/1389450121666201001123515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 11/22/2022]
Abstract
Δ9-Tetrahydrocannabinol (Δ9-THC), the active phytocannabinoid in cannabis, is virtually an adjunct to the endogenous endocannabinoid signaling system. By interacting with G-proteincoupled receptors CB1 and CB2, Δ9-THC affects peripheral and central circulation by lowering sympathetic activity, altering gene expression, cell proliferation, and differentiation, decreasing leukocyte migration, modulating neurotransmitter release, thereby modulating cardiovascular functioning, tumorigenesis, immune responses, behavioral and locomotory activities. Δ9-THC effectively suppresses chemotherapy-induced vomiting, retards malignant tumor growth, inhibits metastasis, and promotes apoptosis. Other mechanisms involved are targeting cell cycle at the G2-M phase in human breast cancer, downregulation of E2F transcription factor 1 (E2F1) in human glioblastoma multiforme, and stimulation of ER stress-induced autophagy. Δ9-THC also plays a role in ameliorating neuroinflammation, excitotoxicity, neuroplasticity, trauma, and stroke and is associated with reliving childhood epilepsy, brain trauma, and neurodegenerative diseases. Δ9-THC via CB1 receptors affects nociception, emotion, memory, and reduces neuronal excitability and excitotoxicity in epilepsy. It also increases renal blood flow, reduces intraocular pressure via a sympathetic pathway, and modulates hormonal release, thereby decreasing the reproductive function and increasing glucose metabolism. Versatile medical marijuana has stimulated abundant research demonstrating substantial therapeutic promise, suggesting the possibilities of first-in-class drugs in diverse therapeutic segments. This review represents the current pharmacological status of the phytocannabinoid, Δ9-THC, and synthetic analogs in cancer, cardiovascular, and neurodegenerative disorders.
Collapse
Affiliation(s)
- Bijo Mathew
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi-682 041, India
| | - Seetha Harilal
- Department of Pharmacy, Kerala University of Health Sciences, Thrissur, Kerala, India
| | - Arafa Musa
- Department of Pharmacogonosy, College of Pharmacy, Jouf University, Sakaka, Al Jouf, 2014, Saudi Arabia
| | - Rajesh Kumar
- Department of Pharmacy, Kerala University of Health Sciences, Thrissur, Kerala, India
| | - Della Grace Thomas Parambi
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jouf University, Sakaka, Al Jouf, 2014, Saudi Arabia
| | - Jobin Jose
- Department of Pharmaceutics, NGSM Institute of Pharmaceutical Science, NITTE Deemed to be University, Manglore, 575018, India
| | - Md Sahab Uddin
- Department of Pharmacy, Southeast University, Dhaka, Bangladesh
| | - Muhammad Ajmal Shah
- Department of Pharmacogonosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Tapan Behl
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | | |
Collapse
|
4
|
Aseer KR, Egan JM. An Autonomous Cannabinoid System in Islets of Langerhans. Front Endocrinol (Lausanne) 2021; 12:699661. [PMID: 34290671 PMCID: PMC8287299 DOI: 10.3389/fendo.2021.699661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/08/2021] [Indexed: 12/31/2022] Open
Abstract
While endocannabinoids (ECs) and cannabis were primarily studied for their nervous system effects, it is now clear that ECs are also produced in the periphery where they regulate several physiological processes, including energy storage, glucose and lipid metabolism, insulin secretion and synthesis, and hepatocyte function. Within islet of Langerhans there is an autonomous EC system (ECS). Beta (β)-cells contain all the enzymes necessary for EC synthesis and degradation; ECs are generated in response to cellular depolarization; their paracrine influence on β-cells is mostly through the cannabinoid 1 receptor (CB1R) that is present on all β-cells; they modulate basal and glucose- and incretin-induced insulin secretion, and β-cell responses to various stressors. Furthermore, there is now accumulating evidence from preclinical studies that the autonomous islet ECS is a key player in obesity-induced inflammation in islets, and β-cell damage and apoptosis from many causes can be mitigated by CB1R blockers. We will thoroughly review the literature relevant to the effects of ECs and their receptors on β-cells and the other cell types within islets. Therapeutic potential of agents targeting EC/CB1R and CB2R is highly relevant because the receptors belong to the druggable G protein-coupled receptor superfamily. Present research in the ECS must be considered preliminary, especially with regards to human islet physiology, and further research is needed in order to translate basic cellular findings into clinical practice and the use of safe, clinically approved CBR modulators with and without glucose lowering combinations presently in therapeutic use for diabetes and obesity needs to be studied.
Collapse
|
5
|
Jourdan T, Godlewski G, Kunos G. Endocannabinoid regulation of β-cell functions: implications for glycaemic control and diabetes. Diabetes Obes Metab 2016; 18:549-57. [PMID: 26880114 PMCID: PMC5045244 DOI: 10.1111/dom.12646] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 02/08/2016] [Accepted: 02/11/2016] [Indexed: 01/11/2023]
Abstract
Visceral obesity is a major risk factor for the development of insulin resistance which can progress to overt type 2 diabetes (T2D) with loss of β-cell function and, ultimately, loss of β-cells. Insulin secretion by β-cells of the pancreatic islets is tightly coupled to blood glucose concentration and modulated by a large number of blood-borne or locally released mediators, including endocannabinoids. Obesity and its complications, including T2D, are associated with increased activity of the endocannabinoid/CB1 receptor (CB1 R) system, as indicated by the therapeutic effects of CB1 R antagonists. Similar beneficial effects of CB1 R antagonists with limited brain penetrance indicate the important role of CB1 R in peripheral tissues, including the endocrine pancreas. Pancreatic β-cells express all of the components of the endocannabinoid system, and endocannabinoids modulate their function via both autocrine and paracrine mechanisms, which influence basal and glucose-induced insulin secretion and also affect β-cell proliferation and survival. The present brief review will survey available information on the modulation of these processes by endocannabinoids and their receptors, with an attempt to assess the contribution of such effects to glycaemic control in T2D and insulin resistance.
Collapse
Affiliation(s)
- T Jourdan
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - G Godlewski
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - G Kunos
- Laboratory of Physiologic Studies, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
6
|
Vilches-Flores A, Delgado-Buenrostro NL, Navarrete-Vázquez G, Villalobos-Molina R. CB1 cannabinoid receptor expression is regulated by glucose and feeding in rat pancreatic islets. ACTA ACUST UNITED AC 2010; 163:81-7. [PMID: 20451564 DOI: 10.1016/j.regpep.2010.04.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 04/01/2010] [Accepted: 04/28/2010] [Indexed: 12/31/2022]
Abstract
Endocannabinoid system is involved in food intake and energy balance. Beside the hypothalamus, pancreatic islet also expresses CB1 cannabinoid receptor, however little is known about its physiological role and regulation. Since gene expression of many specific proteins of the islet depends on the concentration of glucose, we studied CB1 receptor expression in response to fasting and feeding. Whole pancreas or islets were isolated from food-deprived adult Wistar rats, with or without a previous 1.5 g/kg glucose oral-intake. CB1, insulin and glucagon expressions were analyzed by confocal immunofluorescence and PCR. In vitro, rat islets were cultured at different glucose concentrations, in the presence of anandamide, or with Rimonabant analog BAR-1. CB1, insulin, glucagon, glucokinase, and PDX-1 expression were determined by real-time RT-PCR, and insulin secretion and islet content by ELISA. CB1 expression in pancreatic islets is upregulated during food restriction, and decreases in response to glucose intake or feeding. In cultured islets, 16 mmol/l glucose, BAR-1, and anandamide at low glucose reduced CB1 mRNA. Insulin, glucagon, glucokinase and PDX-1 expression increased in islets treated with anandamide at low glucose, while BAR-1 modified PDX-1 and glucagon mRNA at high glucose. Basal insulin secretion and insulin content in islets increased with anandamide, but not the glucose-stimulated response. Our results suggest that the endocannabinoid system has an important role in gene expression on islets and its close relationship with glucose response.
Collapse
Affiliation(s)
- Alonso Vilches-Flores
- Unidad de Biomedicina, FES Iztacala, Universidad Nacional Autónoma de México, Av. de Los Barrios 1, Los Reyes Iztacala, C.P. 54090, Tlalnepantla, Mexico
| | | | | | | |
Collapse
|
7
|
Role of endocannabinoids and endovanilloids in Ca2+ signalling. Cell Calcium 2009; 45:611-24. [DOI: 10.1016/j.ceca.2009.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 03/03/2009] [Accepted: 03/11/2009] [Indexed: 12/14/2022]
|
8
|
Bermúdez-Silva FJ, Suárez Pérez J, Nadal A, Rodríguez de Fonseca F. The role of the pancreatic endocannabinoid system in glucose metabolism. Best Pract Res Clin Endocrinol Metab 2009; 23:87-102. [PMID: 19285263 DOI: 10.1016/j.beem.2008.10.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The endogenous cannabinoid system participates in the regulation of energy homeostasis, and this fact led to the identification of a new group of therapeutic agents for complicated obesity and diabetes. Cannabinoid receptor antagonists are now realities in clinical practice. The use of such antagonists for reducing body weight gain, lowering cholesterol and improving glucose homeostasis is based on the ability of the endocannabinoids to coordinately regulate energy homeostasis by interacting with central and peripheral targets, including adipose tissue, muscle, liver and endocrine pancreas. In this review we will analyse the presence of this system in the main cell types of the islets of Langerhans, as well as the physiological relevance of the endocannabinoids and parent acylethanolamides in hormone secretion and glucose homeostasis. We will also analyse the impact that these findings may have in clinical practice and the potential outcome of new therapeutic strategies for modulating glucose homeostasis and insulin/glucagon secretion.
Collapse
Affiliation(s)
- Francisco J Bermúdez-Silva
- Laboratorio de Medicina Regenerativa, Fundación IMABIS, Hospital Carlos Haya, Avda. Carlos Haya, Pabellón de Gobierno, sótano, 29010, Málaga, Spain.
| | | | | | | |
Collapse
|
9
|
Aversa A, Rossi F, Francomano D, Bruzziches R, Bertone C, Santiemma V, Spera G. Early endothelial dysfunction as a marker of vasculogenic erectile dysfunction in young habitual cannabis users. Int J Impot Res 2008; 20:566-73. [DOI: 10.1038/ijir.2008.43] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Tharp WG, Lee YH, Maple RL, Pratley RE. The cannabinoid CB1 receptor is expressed in pancreatic delta-cells. Biochem Biophys Res Commun 2008; 372:595-600. [PMID: 18505678 DOI: 10.1016/j.bbrc.2008.05.077] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Accepted: 05/15/2008] [Indexed: 10/22/2022]
Abstract
Antagonists of cannabinoid CB1 receptor (CB1, CNR1) promote weight loss and decrease hyperglycemia in patients with type 2 diabetes. While the endocannabinoid system may modulate islet hormone secretion, the cell-type expressing CB1 receptor in islets has not been fully resolved. In this study, we verified receptor gene expression in rodent islets and cell lines and examined the distribution of CB1 receptor in mouse, rat, and human islets by confocal immunofluorescence (IF) microscopy. IF demonstrated CB1 receptor was present in beta-cell lines, but co-localized solely with somatostatin in the islet delta-cells of Zucker rats, C57BL/6 mice, and humans; no CB1 receptor expression was observed in alpha-, beta-, or pp-cells. Similarly, a rat somatostatinoma cell line, MSL-G2-Tu6, was found to express CB1 receptor. We also found monoacylglycerol lipase (MAGL) to be expressed in delta-cells and fatty acid amide hydrolase (FAAH) to be expressed in alpha-cells. The specific expression of CB1 in delta-cells suggests that the ECS may play a role in modulating islet hormone secretion. As there are some differences between our findings and previous reports, further studies, including detailed physiological studies of the effects of the ECS on islet function, are warranted.
Collapse
Affiliation(s)
- William G Tharp
- Diabetes and Metabolism Translational Medicine Unit, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Vermont College of Medicine, Given C354, 89 Beaumont Avenue, Burlington, VT 05405, USA
| | | | | | | |
Collapse
|
11
|
Li X, Kaminski NE, Fischer LJ. Examination of the immunosuppressive effect of delta9-tetrahydrocannabinol in streptozotocin-induced autoimmune diabetes. Int Immunopharmacol 2001; 1:699-712. [PMID: 11357882 DOI: 10.1016/s1567-5769(01)00003-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
delta9-Tetrahydrocannabinol (delta9-THC) is capable of modulating a variety of immune responses, but has not been evaluated in models of immune-based diabetes. The objectives of the present study were: (a) to investigate the effect of delta9-THC in an established model of multiple low dose streptozotocin (MLDSTZ)-induced autoimmune diabetes; and (b) to determine the contribution of the immune response in the MLDSTZ model. CD-1 mice were treated with 40 mg/kg STZ for 5 days in the presence or absence of delta9-THC treatment. delta9-THC administered orally in corn oil at 150 mg/kg for 11 days attenuated, in a transient manner, the MLDSTZ-induced elevation in serum glucose and loss of pancreatic insulin. MLDSTZ-induced insulitis and increases in IFN-gamma, TNFalpha and IL-12 mRNA expression were all reduced on Day 11 by co-administration of delta9-THC. In separate studies, six doses of delta9-THC, given after completion of STZ treatment, was found equally effective in attenuating mice from MLDSTZ-induced diabetes. Studies performed using B6C3F1 mice showed moderate hyperglycemia and a significant reduction in pancreatic insulin by MLDSTZ in the absence of insulitis. In addition, MLDSTZ produced a less pronounced hyperglycemia compared to CD-1 mice that was not attenuated by delta9-THC. These results suggest that MLDSTZ can initiate direct beta-cell damage, thereby augmenting the destruction of beta-cells by the immune system. Moreover, these results indicate that delta9-THC is capable of attenuating the severity of the autoimmune response in this experimental model of autoimmune diabetes.
Collapse
Affiliation(s)
- X Li
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing 48824, USA
| | | | | |
Collapse
|
12
|
Patricia MK, Natarajan R, Dooley AN, Hernandez F, Gu JL, Berliner JA, Rossi JJ, Nadler JL, Meidell RS, Hedrick CC. Adenoviral delivery of a leukocyte-type 12 lipoxygenase ribozyme inhibits effects of glucose and platelet-derived growth factor in vascular endothelial and smooth muscle cells. Circ Res 2001; 88:659-65. [PMID: 11304487 DOI: 10.1161/hh0701.088838] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The lipoxygenase (LO) pathway has been implicated as an important mediator of chronic glucose and platelet-derived growth factor (PDGF)-induced effects in the vascular system. Endothelial cells treated with 12LO products or cultured in high glucose showed enhanced monocyte adhesion, an important step in atherogenesis. We have previously reported that PDGF increased HETE levels in porcine aortic smooth muscle cells. Although several pharmacological inhibitors to the LO pathway are available, most lack specificity and may harbor undesirable side effects. Therefore, we developed a recombinant adenovirus expressing a hammerhead ribozyme (AdRZ) targeted against the porcine leukocyte-type 12LO mRNA to investigate the involvement of LO in glucose- and PDGF-mediated effects in vascular cells. Infection of porcine aortic endothelial cells with AdRZ reduced the level of glucose-enhanced 12LO mRNA expression as determined by quantitative, real-time reverse transcriptase-polymerase chain reaction. Reverse-phase HPLC and RIA analysis also revealed a corresponding decrease in glucose-stimulated 12HETE production in both the cellular and supernatant fractions. In the ribozyme-treated porcine aortic endothelial cells, there was marked inhibition of high glucose-stimulated monocyte adhesion. Infection with AdRZ also reduced PDGF-induced porcine aortic smooth muscle cell migration by approximately 50%. These studies demonstrate the efficacy of recombinant adenovirus expressing 12LO ribozyme in studying the effects of 12LO in vascular wall cells. They document an important role for the 12LO pathway in regulating inflammatory changes in endothelial cells and smooth muscle cells.
Collapse
MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid/metabolism
- Adenoviridae/genetics
- Animals
- Aorta
- Arachidonate 12-Lipoxygenase/genetics
- Arachidonate 12-Lipoxygenase/metabolism
- Cell Adhesion/drug effects
- Cell Movement/drug effects
- Cells, Cultured
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Gene Expression/drug effects
- Gene Transfer Techniques
- Genetic Vectors/genetics
- Genetic Vectors/pharmacology
- Glucose/antagonists & inhibitors
- Glucose/metabolism
- Glucose/pharmacology
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Leukocytes/enzymology
- Lipoxygenase Inhibitors
- Monocytes/drug effects
- Monocytes/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Platelet-Derived Growth Factor/antagonists & inhibitors
- Platelet-Derived Growth Factor/metabolism
- Platelet-Derived Growth Factor/pharmacology
- RNA, Catalytic/genetics
- RNA, Catalytic/metabolism
- RNA, Catalytic/pharmacology
- RNA, Messenger/antagonists & inhibitors
- Substrate Specificity/genetics
- Swine
Collapse
Affiliation(s)
- M K Patricia
- Division of Cardiology, Department of Experimental Pathology, University of California Los Angeles, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Coffey RG, Snella E, Johnson K, Pross S. Inhibition of macrophage nitric oxide production by tetrahydrocannabinol in vivo and in vitro. INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 1996; 18:749-52. [PMID: 9172018 DOI: 10.1016/s0192-0561(97)85557-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
delta 9-Tetrahydrocannabinol (THC, 10 micrograms) was administered intraperitoneally to thioglycollate-treated mice. After 18 h, peritoneal macrophages were harvested and nitric oxide (NO.) production was induced by lipopolysaccharide (LPS, 1 microgram/ml) and interferon-gamma (IFN-gamma, 0.1-10 U/ml). Macrophages from THC-treated mice produced about half as much NO. as controls. THC (1 microgram/ml) added in vitro caused further inhibition. Greater inhibition was observed at the lower (0.1-0.3 U/ml) IFN-gamma concentrations. The results suggest that the use of THC can reduce NO. production and thereby affect host defense mechanisms, inflammation and autoimmune responses.
Collapse
Affiliation(s)
- R G Coffey
- Department of Pharmacology and Therapeutics, University of South Florida College of Medicine, Tampa 33612, USA
| | | | | | | |
Collapse
|
14
|
Coffey RG, Yamamoto Y, Snella E, Pross S. Tetrahydrocannabinol inhibition of macrophage nitric oxide production. Biochem Pharmacol 1996; 52:743-51. [PMID: 8765472 DOI: 10.1016/0006-2952(96)00356-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
delta 9-Tetrahydrocannabinol (THC) inhibited nitric oxide (NO) production by mouse peritoneal macrophages activated by bacterial endotoxin lipopolysaccharide (LPS) and interferon-gamma (IFN)-gamma). Inhibition of NO production was noted at THC concentrations as low as 0.5 microgram/mL, and was nearly total at 7 micrograms/mL. Inhibition was greatest if THC was added 1-4 hr before induction of nitric oxide synthase (NOS) by LPS and IFN-gamma, and declined with time after addition of the inducing agents. This suggested that an early step such as NOS gene transcription or NOS synthesis, rather than NOS activity, was affected by THC. Steady-state levels of mRNA for NOS were not affected by THC. In contrast, protein synthesis was inhibited as indicated by immunoblotting. NOS activity was also decreased in the cytosol of cells pretreated with THC. Addition of excess cofactors did not restore activity. Inhibition of NO production was greater at low levels of IFN-gamma, indicating the ability of the cytokine to overcome inhibition. The effectiveness of various THC analogues, in decreasing order of potency, was delta 8-THC > delta 9-THC > cannabidiol > or = 11-OH-THC > cannabinol. The presumably inactive stereoisomer, (+)delta 9-THC, and the endogenous ligand for cannabinoid receptors, anandamide, were weakly inhibitory. Inhibition may be mediated by a process that depends partly on stereoselective receptors and partly on a nonselective process. LPS, IFN-gamma, hormone receptor agonists, and forskolin increased macrophage cyclic AMP levels. THC inhibited this increase, indicating functional cannabinoid receptors. Addition of 8-bromocyclic AMP increased NO 2-fold, and partially restored NO production that had been inhibited by THC. This occurred only under conditions of limited NOS induction, suggesting that the effect of THC on cyclic AMP was responsible for only a small portion of the inhibition of NO.
Collapse
Affiliation(s)
- R G Coffey
- Department of Pharmacology, University of South Florida College of Medicine, Tampa 33612-4799, USA
| | | | | | | |
Collapse
|
15
|
Kempe K, Hsu FF, Bohrer A, Turk J. Isotope dilution mass spectrometric measurements indicate that arachidonylethanolamide, the proposed endogenous ligand of the cannabinoid receptor, accumulates in rat brain tissue post mortem but is contained at low levels in or is absent from fresh tissue. J Biol Chem 1996; 271:17287-95. [PMID: 8663381 DOI: 10.1074/jbc.271.29.17287] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Arachidonylethanolamide (AEA) isolated from porcine brain binds to cannabinoid receptors, mimics cannabinoid pharmacologic effects, and has been proposed as an endogenous cannabinoid receptor ligand. Demonstration of co-distribution of AEA and cannabinoid receptors in various brain regions could provide supportive evidence for this role. We have performed isotope dilution mass spectrometric measurements of AEA and have demonstrated AEA production by rat tissue homogenates in vitro from exogenous arachidonate and ethanolamine. No detectable endogenous AEA (<3.5 pmol/g of tissue) was observed in fresh rat brain, whether or not inhibitors of AEA hydrolysis were present during tissue processing. AEA (>1 nmol/g) was produced during saponification of brain phospholipid extracts. This appears not to reflect hydrolysis of N-arachidonylethanolamine phospholipid precursors of AEA, because Streptomyces chromfucsis phospholipase D, which is active against NAPE, failed to generate AEA from brain phospholipids despite substantial conversion of phospholipids to phosphatidic acid. Such experiments suggested that the abundance of N-arachidonylethanolamine phospholipid in fresh rat brain may be less than 1 in 10(6) phospholipid molecules. AEA generated during saponification of tissue phospholipids appears to arise from base-catalyzed aminolysis of arachidonate-containing glycerolipids, because AEA was produced from synthetic (1-stearoyl, 2-arachidonoyl)-phosphatidylethanolamine under saponification conditions, and the amount produced increased 300-fold when free ethanolamine was included in the hydrolysis solution. Although AEA was not detectable (<0.17 pmol/mg of protein) in fresh rat brain, AEA accumulated post mortem to levels of 126 pmol/mg of brain protein. These findings do not exclude the possibility that AEA is rapidly synthesized and degraded locally in vivo, but they indicate that the AEA content of fresh rat brain and of NAPE precursors from which AEA might be derived are exceedingly low and that AEA can be produced artifactually from biological materials.
Collapse
Affiliation(s)
- K Kempe
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | | | | | | |
Collapse
|
16
|
Chang MC, Berkery D, Schuel R, Laychock SG, Zimmerman AM, Zimmerman S, Schuel H. Evidence for a cannabinoid receptor in sea urchin sperm and its role in blockade of the acrosome reaction. Mol Reprod Dev 1993; 36:507-16. [PMID: 8305215 DOI: 10.1002/mrd.1080360416] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Delta-9-tetrahydrocannabinol ((-)delta 9 THC), the primary psychoactive cannabinoid in marihuana, reduces the fertilizing capacity of sea urchin sperm by blocking the acrosome reaction that normally is stimulated by a specific ligand in the egg's jelly coat. The bicyclic synthetic cannabinoid [3H]CP-55,940 has been used as a ligand to demonstrate the presence of a cannabinoid receptor in mammalian brain. We now report that [3H]CP-55,940 binds to live sea urchin (Strongylocentrotus purpuratus) sperm in a concentration, sperm density, and time-dependent manner. Specific binding of [3H]CP-55,940 to sperm, defined as total binding displaced by (-)delta 9THC, was saturable: KD 5.16 +/- 1.02 nM; Hill coefficient 0.98 +/- 0.004. This suggests a single class of receptor sites and the absence of significant cooperative interactions. Sea urchin sperm contain 712 +/- 122 cannabinoid receptors per cell. Binding of [3H]CP-55,940 to sperm was reduced in a dose-dependent manner by increasing concentrations of CP-55,940, (-)delta 9THC, and (+)delta 9THC. The rank order of potency to inhibit binding of [3H]CP-55,940 to sperm and to block the egg jelly stimulated acrosome reaction was: CP-55,940 > (-)delta 9THC > (+)delta 9THC. These findings show that sea urchin sperm contain a stereospecific cannabinoid receptor that may play a role in inhibition of the acrosome reaction. The radioligand binding data obtained with live sea urchin sperm are remarkably similar to those previously published by other investigators using [3H]CP-55,940 on mammalian brain and nonneural tissues. The cannabinoid binding properties of this receptor appear to have been highly conserved during evolution. We postulate that the cannabinoid receptor may modulate cellular responses to stimulation.
Collapse
Affiliation(s)
- M C Chang
- Department of Anatomical Sciences, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York 14214
| | | | | | | | | | | | | |
Collapse
|
17
|
Felder CC, Briley EM, Axelrod J, Simpson JT, Mackie K, Devane WA. Anandamide, an endogenous cannabimimetic eicosanoid, binds to the cloned human cannabinoid receptor and stimulates receptor-mediated signal transduction. Proc Natl Acad Sci U S A 1993; 90:7656-60. [PMID: 8395053 PMCID: PMC47201 DOI: 10.1073/pnas.90.16.7656] [Citation(s) in RCA: 339] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Arachidonylethanolamide (anandamide), a candidate endogenous cannabinoid ligand, has recently been isolated from porcine brain and displayed cannabinoid-like binding activity to synaptosomal membrane preparations and mimicked cannabinoid-induced inhibition of the twitch response in isolated murine vas deferens. In this study, anandamide and several congeners were evaluated as cannabinoid agonists by examining their ability to bind to the cloned cannabinoid receptor, inhibit forskolin-stimulated cAMP accumulation, inhibit N-type calcium channels, and stimulate one or more functional second messenger responses. Synthetic anandamide, and all but one congener, competed for [3H]CP55,940 binding to plasma membranes prepared from L cells expressing the rat cannabinoid receptor. The ability of anandamide to activate receptor-mediated signal transduction was evaluated in Chinese hamster ovary (CHO) cells expressing the human cannabinoid receptor (HCR, termed CHO-HCR cells) and compared to control CHO cells expressing the muscarinic m5 receptor (CHOm5 cells). Anandamide inhibited forskolin-stimulated cAMP accumulation in CHO-HCR cells, but not in CHOm5 cells, and this response was blocked with pertussis toxin. N-type calcium channels were inhibited by anandamide and several active congeners in N18 neuroblastoma cells. Anandamide stimulated arachidonic acid and intracellular calcium release in both CHOm5 and CHO-HCR cells and had no effect on the release of inositol phosphates or phosphatidylethanol, generated after activation of phospholipase C and D, respectively. Anandamide appears to exhibit the essential criteria required to be classified as a cannabinoid/anandamide receptor agonist and shares similar nonreceptor effects on arachidonic acid and intracellular calcium release as other cannabinoid agonists.
Collapse
Affiliation(s)
- C C Felder
- Laboratory of Cell Biology, National Institute of Mental Health, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|
18
|
Badiani K, Lu X, Arthur G. Effect of delta 9-tetrahydrocannabinol and merthiolate on acyltransferase activities in guinea pig liver microsomes. Lipids 1993; 28:299-303. [PMID: 8387622 DOI: 10.1007/bf02536314] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
delta 9-Tetrahydrocannabinol (THC) and merthiolate have been utilized as lysophospholipid acyltransferase inhibitors in metabolic studies. However, their effects on acyltransferases other than lysophosphatidylcholine:acyl-CoA acyltransferase (LPCAT) are not known. We have therefore investigated the effectiveness of THC and merthiolate in inhibiting the acylation of lysophosphatidylcholine, lysophosphatidylethanolamine, lysophosphatidylserine, lysophosphatidylinositol (LPI) and lysophosphatidic acid (LPA) in guinea pig liver microsomes using oleoyl-CoA and arachidonoyl-CoA as acyl donors. THC inhibited LPCAT and lysophosphatidylethanolamine:acyl-CoA acyltransferase (LPEAT) by 40-50%, but had no effect or only slightly increased the activities of the other acyltransferases when assayed with oleoyl-CoA as the acyl donor. The results obtained with arachidonoyl-CoA were similar to those with oleoyl-CoA, with the exception of a 40% inhibition of lysophosphatidylserine:acyl-CoA acyltransferase (LPSAT) at concentrations of 50 microM or higher. At similar concentrations, merthiolate was more effective than THC in inhibiting the acyltransferases examined. Selective effects on the acyltransferases were observed at low concentrations of merthiolate (20 microM or less). Thus, LPCAT was most susceptible, followed by LPI acyltransferases, LPSAT, LPEAT and lysophosphatidic acid:acyl-CoA acyltransferases (LPAAT). The presence of LPA did not affect the inhibition of LPCAT by merthiolate. Thus the resilience of LPAAT to merthiolate inhibition was not due to chelation of the compound by the acidic lysolipid. Thiol reagents including N-ethyl-maleiamide, 5,5'-dithio-bis-nitrobenzoic acid, iodoacetate, beta-mercaptoethanol and dithiothreitol had little or no effect on the acyltransferases relative to equimolar concentrations of merthiolate.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- K Badiani
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
| | | | | |
Collapse
|
19
|
Bakken AM, Farstad M. The activities of acyl-CoA:1-acyl-lysophospholipid acyltransferase(s) in human platelets. Biochem J 1992; 288 ( Pt 3):763-70. [PMID: 1471991 PMCID: PMC1131952 DOI: 10.1042/bj2880763] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The activities of acyl-CoA:1-acyl-lysophospholipid acyltransferases (EC 2.3.1.23) have been studied in human platelet lysates by using endogenously formed [14C]acyl-CoA from [14C]fatty acid, ATP and CoA in the presence of 1-acyl-lysophosphatidyl-choline (lysoPC), -ethanolamine (lysoPE), -serine (lysoPS) or -inositol (lysoPI). Linoleic acid as fatty acid substrate had the highest affinity to acyl-CoA:1-acyl-lysophospholipid acyltransferase with lysoPC as variable substrate, followed by eicosapentaenoic acid (EPA) and arachidonic acid (AA). The activity at optimal conditions was 7.4, 7.3 and 7.2 nmol/min per 10(9) platelets with lysoPC as substrate, with linoleic acid, AA and EPA respectively. EPA and AA were incorporated into all lyso-forms. Linoleic acid was also incorporated into lysoPE at a high rate, but less into lysoPS and lysoPI. DHA was incorporated into lysoPC and lysoPE, but only slightly into lysoPI and lysoPS. Whereas incorporation of all fatty acids tested was maximal for lysoPC and lysoPI at 200 and 80 microM respectively, maximal incorporation needed over 500 microM for lysoPE and lysoPS. The optimal concentration for [14C]fatty acid substrates was in the range 15-150 microM for all lysophospholipids. Competition experiments with equimolar concentrations of either lysoPC and lysoPI or lysoPE resulted in formation of [14C]PC almost as if lysoPI or lysoPE were not added to the assay medium.
Collapse
Affiliation(s)
- A M Bakken
- Laboratory of Clinical Biochemistry, University of Bergen, University Hospital Haukeland, Norway
| | | |
Collapse
|
20
|
Husain S, Anwer J. Characteristics of cocaine interaction with delta-9-tetrahydrocannabinol on glucose metabolism in the rat testis. Pharmacol Biochem Behav 1991; 40:625-8. [PMID: 1666922 DOI: 10.1016/0091-3057(91)90373-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this study, the characteristics of cocaine (COC) interaction with delta-9-tetrahydrocannabinol (THC) on glucose metabolism in the rat testis were investigated at different time points. Rats receiving 20 mg/kg IP COC at 0830 h and sacrificed at 15 min, 30 min and 60 min posttreatment showed no change in glucose metabolism. Moreover, 5 mg/kg, IV, COC treatment at 0900 h to rats and sacrificed 60 min postexposure, also produced no change in glucose metabolism. However, at 1300 h, the same protocol with IV COC treatment resulted in a significant increase in glucose utilization by the testis. Furthermore, a THC dose of 10 mg/kg, PO to the rats at 0830 or at 1130 h, followed by sacrifice 90 min later caused a significant decrease in glucose utilization at both time points. Similarly, when rats were given both THC and COC (THC at 0830 h, COC 90 min later) and sacrificed 60 min post-COC, it resulted in a further decrease in testicular glucose metabolism as compared to the rats treated by THC alone. On the other hand, concurrent exposure of rats to these drugs at 1300 h with same protocol, ended up with no change in glucose utilization in the testis. These data suggest that not only the route of administration but also the time of exposure plays an important role in defining the nature of the effects of COC/THC interaction on rat testicular glucose metabolism.
Collapse
Affiliation(s)
- S Husain
- Department of Pharmacology, School of Medicine, University of North Dakota, Grand Forks 58203
| | | |
Collapse
|
21
|
Chang MC, Berkery D, Laychock SG, Schuel H. Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. III. Activation of phospholipase A2 in sperm homogenate by delta 9-tetrahydrocannabinol. Biochem Pharmacol 1991; 42:899-904. [PMID: 1651081 DOI: 10.1016/0006-2952(91)90051-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Inhibition of the egg jelly induced acrosome reaction by delta 9-tetrahydrocannabinol (THC) is associated with the localized disruption of the nuclear envelope and the formation of lipid deposits in sea urchin sperm. This suggests that THC may activate phospholipase(s) within the sperm. We now report effects of THC on phospholipase A2 activity in homogenates of sea urchin sperm using 1-stearoyl-2-[1-14C]arachidonyl phosphatidylcholine as substrate. The release of radioactive arachidonic acid was measured after a 30-min incubation with the enzyme. In the absence of exogenous Ca2+, 100 microM THC produced a significant (P less than 0.001) increase in phospholipase A2 activity. THC activated phospholipase A2 in a concentration (1-100 microM) and time-dependent (0-30 min) manner. Exogenous calcium (10 mM) significantly augmented basal (P less than 0.001) and THC-stimulated (P less than 0.005) phospholipase A2 activity. Calcium chelators [ethylene glycol bis(beta-aminoethyl ether)N,N,N',N'-tetraacetic acid (EGTA) and 1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)] inhibited the basal level of phospholipase A2 activity in the sperm homogenate, and prevented the activation of phospholipase A2 by THC. Submicromolar levels of free calcium ions were required for THC stimulation of phospholipase A2. Cannabinol which mimics the effects of THC on the acrosome reaction also activated phospholipase A2 in sperm homogenate. These results suggest that THC may alter lipid metabolism in sperm by activating calcium-dependent phospholipase A2. Putative metabolites derived from this process may inhibit the acrosome reaction and thereby reduce the fertilizing capacity of sea urchin sperm.
Collapse
Affiliation(s)
- M C Chang
- Department of Anatomical Sciences, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York 14214
| | | | | | | |
Collapse
|
22
|
Chang MC, Schuel H. Reduction of the fertilizing capacity of sea urchin sperm by cannabinoids derived from marihuana. II. Ultrastructural changes associated with inhibition of the acrosome reaction. Mol Reprod Dev 1991; 29:60-71. [PMID: 1647173 DOI: 10.1002/mrd.1080290110] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pretreatment of Strongylocentrotus purpuratus sperm with delta 9-tetrahydrocannabinol (THC) prevents the triggering of the acrosome reaction by egg jelly. Examination of THC-treated sperm by transmission electron microscopy reveals that the membrane fusion reaction between the sperm plasma membrane and the acrosomal membrane is completely blocked. Electron-dense deposits are present in the subacrosomal fossa and in the centriolar fossa. The nuclear envelope is fragmented in close proximity to the electron-dense deposits. The electron-dense deposits are not bound by a limiting membrane, stain positively for lipid with thymol and farnesol, and disappear from THC-treated sperm that are extracted with chloroform:methanol (2:1) after glutaraldehyde fixation. The electron-dense deposits are lipid in nature and may be a hydrolytic product of the nuclear envelope. Electron-dense deposits are seen in sperm after 1-10 min treatment with 5-100 microM THC. The electron-dense deposits disappear after removal of THC from the sperm by washing, but the fragmented nuclear envelope in the subacrosomal fossa persists. Cannabidiol (CBD) and cannabinol (CBN) also inhibit the triggering of the acrosome reaction by egg jelly and produce ultrastructural changes in the sperm identical to those elicited by THC. Enhanced phospholipase activity stimulated by THC, CBD, and CBN may be the cause of the accumulation of lipid deposits in the sperm. Metabolites derived from this modification of membrane phospholipids may prevent triggering of the acrosome reaction by egg jelly and thereby inhibit fertilization.
Collapse
Affiliation(s)
- M C Chang
- Department of Anatomical Sciences, School of Medicine and Biomedical Sciences, State University of New York at Buffalo 14214
| | | |
Collapse
|
23
|
Specter S, Lancz G. Effects of marijuana on human natural killer cell activity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 288:47-56. [PMID: 1659137 DOI: 10.1007/978-1-4684-5925-8_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S Specter
- Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa 33612
| | | |
Collapse
|
24
|
Rubin RP, Thompson RH, Laychock SG. Characterization of phospholipase A2 and acyltransferase activities in purified zymogen granule membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1045:245-51. [PMID: 2386797 DOI: 10.1016/0005-2760(90)90127-j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Phospholipase A2 and acyltransferase activities were identified in membranes associated with purified pancreatic zymogen granules. In homogenate and granule membranes, phospholipase activity was linearly related to protein concentration and was Ca2(+)-dependent with an alkaline pH optimum. The Ca2+ sensitivity was observed over the range of concentrations through which intracellular ionic Ca2+ is elevated by physiological stimuli in intact cells. Intact zymogen granules and granule membranes also demonstrated reacylating activity in the presence and absence of an exogenous acceptor. Reacylating activity was related to the concentration of lyosphospholipid added and was optimally activated at alkaline pH. A more rapid rate of reacylation was observed when [14C]arachidonoyl CoA was employed as the donor molecule rather than [3H]arachidonate (plus coenzyme A); this suggests the absence of acyl-CoA synthetase in the purified granule membranes. We conclude that granule membrane phospholipase A2 and acyltransferases may be involved in arachidonic acid turnover in exocrine pancreas and perhaps in membrane fusion events associated with exocytosis.
Collapse
Affiliation(s)
- R P Rubin
- Division of Cellular Pharmacology, Medical College of Virginia, Richmond
| | | | | |
Collapse
|
25
|
Laychock SG. Coordinate interactions of cyclic nucleotide and phospholipid metabolizing pathways in calcium-dependent cellular processes. CURRENT TOPICS IN CELLULAR REGULATION 1989; 30:203-42. [PMID: 2559830 DOI: 10.1016/b978-0-12-152830-0.50009-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It is hoped that his review enables the reader to appreciate the complexities implicit in the interactions among Ca2+, cyclic nucleotides, and phospholipid-metabolizing pathways in cell signal transduction. The interactions are varied and intricate, often involving several levels of cell amplification mechanisms. Upsetting the balance of fatty acids in membrane phospholipids can have detrimental effects on adenylate cyclase. Thus, n - 3 fatty acid enrichment of phospholipids suppresses adenylate cyclase activity. The effects of significant alterations in dietary fatty acids, such as might occur with the current vogue for n - 3 eicosapentaenoic acid and docosahexaenoic acid (fish oil) dietary enrichment regimens, will need to be assessed more fully with regard to stimulus-induced changes in cyclic nucleotide production in various tissues. Since the n - 3 fatty acids have not been demonstrated to affect guanylate cyclase activity, dietary changes in certain of these fatty acids would not be expected to contribute to changes in cGMP generation as much as in cAMP production. Moreover, the ingestion of large quantities of these n - 3 fatty acids can alter the profile of cyclooxygenase and lipoxygenase products produced in cells. According to the paradigm developed in this article, changes in the metabolism of fatty acids are amplified by alterations in cyclic nucleotide production and phospholipase activities, with the eventual physiological impact predicated on the tissue type and the specific stimulus response. There appears to be a rather clear distinction between the regulatory properties of eicosanoids regarding adenylate and guanylate cyclase activities. Whereas prostaglandins often stimulate adenylate cyclase activity, they have little effect on guanylate cyclase activity. On the other hand, the HETE compounds seem to play an important role in guanylate cyclase regulation in certain cells. Moreover, arachidonic acid affects adenylate cyclase activity without prior peroxidation, whereas endoperoxides and hydroperoxides are more effective than arachidonic acid with regard to guanylate cyclase stimulation. However, in the intact cell there is a strong implication that the dual stimulation of guanylate cyclase by Ca2+ and fatty acid evokes optimal enzyme activity. An advantage of multidimensional response mechanisms in cells includes the ability to recognize different stimuli and to respond with specific, coordinated responses modulated in their intensity and/or duration by messenger interaction. Few cell types respond to receptor stimulation in an all-or-none fashion, and the "milieu interior" depends on specific, graded responses to the autonomic nervous system and endocrine stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- S G Laychock
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298
| |
Collapse
|
26
|
Metz SA. Membrane phospholipid turnover as an intermediary step in insulin secretion. Putative roles of phospholipases in cell signaling. Am J Med 1988; 85:9-21. [PMID: 3057898 DOI: 10.1016/0002-9343(88)90393-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
One or more phospholipases of the C and A2 types exist in rodent islets and may play a pivotal role in the cell signaling cascade culminating in exocytotic insulin release. Phospholipase C generates myo-inositol-1,4,5-trisphosphate, which mobilizes a "pool" of calcium in the endoplasmic reticulum and which may also secondarily facilitate calcium (Ca++) influx from the extracellular space to replenish that pool. Diacylglycerol is also generated by phospholipase C action and activates protein kinase C; it may thereby potentiate the cellular response to elevations in cytosolic free Ca++ concentration. Arachidonic acid may be released during the degradation of diacylglycerol and may also contribute to islet activation. Phospholipase C is activated by glucose, cholinergic agonists, and probably by Ca++ fluxes. Phospholipase A2 action generates arachidonic acid and lysophospholipids. Certain lysophospholipids mobilize cellular Ca++, at least in part from superficial, plasmalemmal stores. Native (unoxygenated) arachidonic acid also has the capability of mobilizing cellular Ca++ from membrane-bound stores; it may, in addition, activate protein kinase C, as suggested by recent indirect studies. The further metabolism of arachidonic acid via lipoxygenase and cyclo-oxygenase appears to provide positive and negative modulation, respectively, of stimulated insulin secretion. Many pieces of the puzzle remain, however, to be supplied. For example, it has not yet been unequivocally demonstrated that phospholipase A2 is activated by physiologic stimuli in intact islets. Furthermore, the absence of truly specific pharmacologic stimulators or inhibitors of these processes currently precludes precise delineation of the respective physiologic roles of each potential mediator in stimulus-secretion coupling. When such roles are elucidated, it can be asked whether the defects in insulin secretion in diabetes mellitus may be due in part to abnormalities in the turnover of beta-cell membrane phospholipids and the generation of intracellular lipid-derived signals.
Collapse
Affiliation(s)
- S A Metz
- Denver Veterans Administration Medical Center, Colorado
| |
Collapse
|
27
|
Metz SA. Arachidonic acid and its metabolites: evolving roles as transmembrane signals for insulin release. Prostaglandins Leukot Essent Fatty Acids 1988; 32:187-202. [PMID: 3137586 DOI: 10.1016/0952-3278(88)90170-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- S A Metz
- Denver Veterans Administration Medical Center, Colorado 80220
| |
Collapse
|
28
|
Affiliation(s)
- A A Spector
- Department of Biochemistry, University of Iowa, Iowa City 52242
| | | | | |
Collapse
|