Differential hepatoprotective role of the cannabinoid CB1 and CB2 receptors in paracetamol-induced liver injury.
Received: 15 April 2019
Revised: 19 February 2020
Accepted: 2 March 2020
DOI: 10.1111/bph.15051
RESEARCH PAPER
Differential hepatoprotective role of the cannabinoid CB1 and
CB2 receptors in paracetamol-induced liver injury
Patricia Rivera1,2
| Antonio Vargas2 | Antoni Pastor3
Antonio Jesús López-Gambero2
| Laura Sánchez-Marín2
| Anna Boronat3
|
2
| Dina Medina-Vera
|
| Francisco Javier Pavón2,4
| Rafael de la Torre3
|
Antonia Serrano2
5
6
Ekaitz Agirregoitia
| María Isabel Lucena
| Fernando Rodríguez de Fonseca2 |
Juan Decara2
|
Juan Suárez2
1
Department of Endocrinology, Fundación
Investigación Biomédica del Hospital Infantil
Universitario Niño Jesús, Instituto de
Investigación Biomédica la Princesa, Madrid,
Spain
2
UGC Salud Mental, Hospital Regional
Universitario de Málaga, Instituto de
Investigación Biomédica de Málaga (IBIMA),
Universidad de Málaga, Málaga, Spain
3
Farmacología Integrada y Neurociencia de
Sistemas, Institut Hospital del Mar
d'Investigacions Mèdiques (IMIM), Barcelona,
Spain
4
UGC Corazón, Hospital Universitario Virgen
de la Victoria, IBIMA, Universidad de Málaga,
Málaga, Spain
5
Department of Physiology, Faculty of
Medicine and Nursing, UPV/EHU, Leioa, Spain
6
Servicio de Farmacología Clínica, Hospital
Universitario Virgen de la Victoria, IBIMA,
Universidad de Málaga, Málaga, Spain
Correspondence
Dr Juan Suárez and Dr Juan Decara, UGC
Salud Mental, Hospital Regional Universitario
de Málaga, Instituto de Investigación
Biomédica de Málaga (IBIMA), Universidad de
Málaga, Avenida Carlos Haya 82, Pabellón de
Gobierno, 29010 Málaga, Spain.
Email: ;
Background and Purpose: Protective mechanisms of the endogenous cannabinoid
system against drug-induced liver injury (DILI) are actively being investigated regarding the differential regulatory role of the cannabinoid CB1 and CB2 receptors in liver
fibrogenesis and inflammation.
Experimental Approach: The 2-arachidonoylglycerol (2-AG)-related signalling receptors and enzymatic machinery, and inflammatory/fibrogenic factors were investigated in the liver of a mouse model of hepatotoxicity induced by acute and repeated
overdoses (750 mgkg−1day−1) of paracetamol (acetaminophen), previously treated
with selective CB1 (ACEA) and CB2 (JWH015) agonists (10 mgkg−1), or lacking CB1
and CB2 receptors.
Key Results: Acute paracetamol increased the expression of CB2, ABHD6 and COX2, while repeated paracetamol increased that of CB1 and COX-2 and decreased that
of DAGLβ. Both acute paracetamol and repeated paracetamol decreased the liver
content of acylglycerols (2-AG, 2-LG and 2-OG). Human liver samples from a patient
suffering APAP hepatotoxicity confirmed CB1 and CB2 increments. Acute
paracetamol-exposed CB2 KO mice had higher expression of the fibrogenic αSMA
and the cytokine IL-6 and lower apoptotic cleaved caspase 3. CB1 deficiency
enhanced the repeated APAP-induced increases in αSMA and cleaved caspase 3 and
blocked those of CYP2E1, TNF-α, the chemokine CCL2 and the circulating
γ-glutamyltransferase (γGT). Although JWH015 reduced the expression of αSMA and
TNF-α in acute paracetamol, ACEA increased the expression of cleaved caspase
3 and CCL2 in repeated paracetamol.
Funding information
Consejería de Salud, Junta de Andalucía,
Grant/Award Numbers: PI-0139-2018, PI0337-2012, C1-0049-2019; Instituto de Salud
Carlos III, Grant/Award Numbers:
Conclusion and Implications: The differential role of CB1 versus CB2 receptors on
inflammatory/fibrogenic factors related to paracetamol-induced hepatotoxicity
should be considered for designing alternative therapies against DILI.
Abbreviations: 2-AG, 2-arachidonoylglycerol; 2-LG, 2-linoleoylglycerol; 2-OG, 2-oleoylglycerol; Abhd6, α/β-hydrolase domain-containing 6 or 2-arachidonoylglycerol hydrolase; AGs,
acylglycerols; AILI, paracetamol-induced liver injury; ALT, alanine aminotransferase; APAP, paracetamol or acetaminophen; AST, aspartate aminotransferase; Cnr1, cannabinoid receptor 1 gene;
Cnr2, cannabinoid receptor 2 gene; Cox-2 (Ptgs2), PG-endoperoxide synthase 2; Cyp2e1, cytochrome P450 2E1 gene; Daglα, DAG lipase α gene; Daglβ, DAG lipase β gene; DILI, drug-induced
liver injury; Faah, fatty acid amide hydrolase; MAGL/Mgll, monoacylglycerol lipase/ gene; Nape-pld, N-acylphosphatidylethanolamine PLD; αSma/Acta2, α-smooth muscle actin; γGT,
γ-glutamyltransferase.
Br J Pharmacol. 2020;177:3309–3326.
wileyonlinelibrary.com/journal/bph
© 2020 The British Pharmacological Society
3309
3310
RIVERA ET AL.
CP19/00068, CPII17/00024, PI16/01374,
PI16/01698, CP14/00173, CPII19/00022,
PI17/02026, PI16/01953; Departament
d'Innovació, Universitats i Empresa, Generalitat
de Catalunya, Grant/Award Number: 2014
SGR 680; Agencia de Innovación y Desarrollo
de Andalucía, Grant/Award Number: CTS8221
1
|
I N T RO DU CT I O N
What is already known
Paracetamol (acetaminophen in the U.S.A.; APAP) is a common drug
used for its analgesic and antipyretic actions. Only a minimal amount
• Cannabinoid receptors play a role in liver fibrogenesis
and inflammation.
of the paracetamol that is consumed as a therapeutic doses (approximately 4 gday−1) and converted to N-acetyl-4-benzoquinoneimine
What this study adds
(napqi) by the cytochrome P450 and is in fact detoxified by conjuga-
• Acute and repeated oral overdose of paracetamol altered
tion with glutathione (GSH). An acute overdose or repeated doses of
paracetamol can lead to drug-induced liver injury (DILI) as a result of
the liver 2-AG-related signalling system.
• CB1
and
CB2
the liver accumulation of N-acetyl-4-benzoquinoneimine, a reactive
hepatoprotective
metabolite that induces hepatotoxicity (Jollow et al., 1973). Practi-
hepatotoxicity.
receptors
functions
in
exert
differential
paracetamol-induced
cally, paracetamol is the only drug that causes dose-dependent liver
injury (Andrade, Robles, Ulzurrun, & Lucena, 2009). Moreover,
What is the clinical significance
paracetamol-induced liver injury (AILI) is a common cause of acute
• Pharmacotherapies involving the 2-AG/CB2-related sig-
liver failure characterized by elevated levels of serum aminotransfer-
nalling system should be considered for treating
ases, low levels of serum bilirubin and often renal insufficiency
paracetamol-induced liver injury.
(Davern, 2012).
Despite being poorly understood, the pathogenesis of druginduced liver injury is thought to involve the endogenous cannabinoid
system. Cumulated evidences point to the endogenous cannabinoid
system as a key player in the pathophysiology of hepatic diseases
Experimental evidence suggests the potential antifibrogenic prop-
such as fatty liver, hepatitis, fibrosis and cirrhosis (Alswat, 2013;
erties of CB2 stimulation, while CB1 activation has been proposed as a
Caraceni, Domenicali, Giannone, & Bernardi, 2009). The endogenous
profibrogenic mechanism (Teixeira-Clerc et al., 2006, 2010). Thus,
cannabinoid system is a lipid signalling system involved in the modula-
CB1 receptor a (...truncated)
