ThePineapple - Journal Club #48: Cardiotoxicity | GIRK | Fibrosis| Cholesterol Homeostasis

Journal Club #48: Cardiotoxicity, GIRK, Fibrosis, Cholesterol Homeostasis

Week of 07-03-22

Another week goes by and that means we have another selection of cannabis related science papers for you. This week there we have a study on cannabinoid receptor 1 dependent cardiotixicity of antipsychotics. Then we have a paper looking at neuropathic pain mediated through G protein-coupled inwardly-rectifying potassium channels. Followed by a look at CBR2 in the context of bleomycin-induced pulmonary fibrosis. Finally we end on a paper looking at the disruption of cholesterol homeostasis by CBD. Enjoy your journal clubs and don’t eat too much free pizza!

Note: This is a post for cannabis scientists. A weekly curation of fresh papers that help advance our understanding of cannabis and the endocannabinoid system.

CB1R-stabilized NLRP3 inflammasome drives antipsychotics cardiotoxicity.

Li L, Gao P, Tang X, Liu Z, Cao M, Luo R, Li X, Wang J, Lin X, Peng C, Li Z, Zhang J, Zhang X, Cao Z, Zou Y, Jin L. 

Signal Transduct Target Ther. 2022 Jun 24;7(1):190.

Long-term use of antipsychotics is a common cause of myocardial injury and even sudden cardiac deaths that often lead to drug withdrawn or discontinuation. Mechanisms underlying antipsychotics cardiotoxicity remain largely unknown. Herein we performed RNA sequencing and found that NLRP3 inflammasome-mediated pyroptosis contributed predominantly to multiple antipsychotics cardiotoxicity. Pyroptosis-based small-molecule compound screen identified cannabinoid receptor 1 (CB1R) as an upstream regulator of the NLRP3 inflammasome. Mechanistically, antipsychotics competitively bond to the CB1R and led to CB1R translocation to the cytoplasm, where CB1R directly interacted with NLRP3 inflammasome via amino acid residues 177-209, rendering stabilization of the inflammasome. Knockout of Cb1r significantly alleviated antipsychotic-induced cardiomyocyte pyroptosis and cardiotoxicity. Multi-organ-based investigation revealed no additional toxicity of newer CB1R antagonists. In authentic human cases, the expression of CB1R and NLRP3 inflammasome positively correlated with antipsychotics-induced cardiotoxicity. These results suggest that CB1R is a potent regulator of the NLRP3 inflammsome-mediated pyroptosis and small-molecule inhibitors targeting the CB1R/NLRP3 signaling represent attractive approaches to rescue cardiac side effects of antipsychotics.

doi: 10.1038/s41392-022-01018-7. PMID: 35739093; PMCID: PMC9225989.

Involvement of spinal G-protein inwardly rectifying potassium (GIRK) channels in the enhanced antinociceptive effects of the activation of both μ-opioid and cannabinoid CB1 receptors.

Takemura Y, Sudo Y, Saeki T, Kurata S, Suzuki T, Mori T, Uezono Y. 

J Pharmacol Sci. 2022 Jul;149(3):85-92. 

Neuropathic pain is refractory to opioid analgesics. Since there are functional linkages between μ-opioid receptors (MOR) and cannabinoid receptors (CBR), the present study was designed to investigate the interactions between MOR and CB1R based on antinociceptive effects for neuropathic pain mediated through G protein-coupled inwardly-rectifying potassium channels (GIRKs). The antinociceptive effects against pseudonociceptive response or neuropathic pain of MOR and CBR agonists were assessed in mice with or without partial sciatic nerve ligation. To investigate the functional interaction between MOR and CB1R, electrophysiological recording through GIRK was performed using the two-electrode voltage-clamp method in oocytes along with Western blotting in the spinal cord of mice. Co-administration of the MOR agonist DAMGO and the CB1R agonist CP55,940 augmented inwardly rectifying K+ currents in Xenopus oocytes co-expressing MOR, CB1R and GIRK1/2. Further, combination of morphine and the CBR agonist WIN-55,212-2 produced prominent antinociceptive effects in an i.t. GIRK1 inhibitor-reversible manner. Furthermore, CB1R was upregulated under neuropathic pain in the spinal cord, and such upregulation and antinociceptive effects were not altered by repeated treatment with morphine plus WIN-55,212-2. Our findings suggest that co-administration of MOR and CBR agonists could enhance their antinociceptive effects through GIRK1 in the spinal cord of mice.

doi: 10.1016/j.jphs.2022.04.002. Epub 2022 Apr 15. PMID: 35641032.

Endocannabinoid signalling/cannabinoid receptor 2 is involved in icariin-mediated protective effects against bleomycin-induced pulmonary fibrosis.

Du W, Zhang T, Yang F, Gul A, Tang Z, Zhang H, Jiang S, Wang S, Dong J. 

Phytomedicine. 2022 Aug;103:154187. 

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic disease of unknown aetiology with limited effective treatment options. It is important to explore novel therapeutic targets and develop potential drugs for IPF. The aim of the present study was to analyse nontargeted plasma metabolites in patients with IPF and investigate whether cannabinoid receptor (CB2) activation mediates the antifibrotic effect of icariin (ICA). We used an untargeted metabolomics method to detect the global metabolic profiles in the plasma of stable IPF patients and patients with stable chronic obstructive pulmonary disease (COPD), as well as healthy subjects. The untargeted liquid chromatography-mass spectrometry (LC-MS) analysis revealed that IPF showed differential metabolites and perturbed signalling pathways. ICA is pharmacologically bioactive and possesses extensive therapeutic capacities such as osteoprotective, neuroprotective, cardiovascular protective, anti-cancer, anti-inflammation and reproductive function. Therefore, ICA was administered to a pulmonary fibrosis rat model for 4 weeks and then the effect of ICA on pulmonary fibrosis was examined by dissection and histology. The metabolites in the plasma were determined by untargeted LC-MS. An unsupervised principal component analysis (PCA) was used to observe the distribution of each sample, and a supervised partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) results showed that there was significant separation between any two groups. ROC curve analyses revealed that 8 metabolites with high AUCs above 0.7 between the three groups of plasma samples. Pathway enrichment analysis revealed that 3 metabolites are involved in retrograde endocannabinoid signalling. Meanwhile, Retrograde endocannabinoid signalling was identified significantly different in IPF group from other groups by Kyoto encyclopedia of Genes and Genomes (KEGG) pathway analysis, and then we further confirmed the endocannabinoid signalling by detecting the expression of the main receptors in bleomycin-induced pulmonary fibrosis, COPD rat model and normal rats. Consistent with previous studies, we found that the elevation of CB1 and CB2 in the lung tissues could be a signature of the pulmonary fibrosis rat model. Importantly, ICA may alleviate bleomycin-induced lung injury by decreasing CB1 and CB2 expression in the bleomycin-induced rat model. Taken together, we measured the global metabolic profile of IPF patients and identified CB2 as a novel potential target. ICA treatment demonstrated outstanding therapeutic effects on bleomycin-induced pulmonary fibrosis and targeting on CB2 may be the main underlying mechanism. ICA is a promising drug candidate to cure pulmonary fibrosis and mediate antagonists of the CB2 receptor.

doi: 10.1016/j.phymed.2022.154187. Epub 2022 May 21. PMID: 35667261.

Multi-Omic Analysis Reveals Disruption of Cholesterol Homeostasis by Cannabidiol in Human Cell Lines. 

Guard SE, Chapnick DA, Poss ZC, Ebmeier CC, Jacobsen J, Nemkov T, Ball KA, Webb KJ, Simpson HL, Coleman S, Bunker E, Ramirez A, Reisz JA, Sievers R, Stowell MHB, D'Alessandro A, Liu X, Old WM. 

Mol Cell Proteomics. 2022 Jun 23:100262. 

The non-psychoactive cannabinoid, cannabidiol (CBD), is FDA-approved for treatment of two drug-resistant epileptic disorders, and is seeing increased use among the general public, yet the mechanisms that underlie its therapeutic effects and side-effect profiles remain unclear. Here, we report a systems-level analysis of CBD action in human cell lines using temporal multi-omic profiling. FRET-based biosensor screening revealed that CBD elicits a sharp rise in cytosolic calcium, and activation of AMPK in human keratinocyte and neuroblastoma cell lines. CBD treatment leads to alterations in the abundance of metabolites, mRNA transcripts, and proteins associated with activation of cholesterol biosynthesis, transport and storage. We found that CBD rapidly incorporates into cellular membranes, alters cholesterol accessibility, and disrupts cholesterol-dependent membrane properties. Sustained treatment with high concentrations of CBD induces apoptosis in a dose-dependent manner. CBD-induced apoptosis is rescued by inhibition of cholesterol synthesis and potentiated by compounds that disrupt cholesterol trafficking and storage. Our data point to a pharmacological interaction of CBD with cholesterol homeostasis pathways, with potential implications in its therapeutic use.

doi: 10.1016/j.mcpro.2022.100262. Epub ahead of print. PMID: 35753663.