Inhibiting CB1 receptors improves lipogenesis in an in vitro non-alcoholic fatty liver disease model

Shi, Dongmei; Zhan, Xi; Yu, Xiaofeng; Jia, Minglei; Zhang, Ying; Hu, Xiaona; Bao, Zhijun

doi:10.1186/1476-511x-13-173

Cited by 37 publications

(27 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…ECs mediate their effects on energy and lipid metabolism by activating CB1 or CB2 receptors. Several studies using genetic deletion mutants or pharmacological antagonization of CB1 receptor have demonstrated anorectic effects that improved obesity as well as hepatic steatosis and metabolic disturbances [39]. It has been shown that CB1 −/− protects from steatosis in alcoholic liver injury, which provoked the suggestion that CB1 receptor activation aggravates SREBP-1c-mediated steatosis after ethanol intake [40].…”

Section: Discussionmentioning

confidence: 99%

Cannabinoid receptor 1 knockout alleviates hepatic steatosis by downregulating perilipin 2

Irungbam

Churin

Matono

et al. 2020

Laboratory Investigation

View full text Add to dashboard Cite

The endocannabinoid (EC) system has been implicated in the pathogenesis of several metabolic diseases, including nonalcoholic fatty liver disease (NAFLD). With the current study we aimed to verify the modulatory effect of endocannabinoid receptor 1 (CB1)-signaling on perilipin 2 (PLIN2)-mediated lipophagy. Here, we demonstrate that a global knockout of the cannabinoid receptor 1 gene (CB1−/−) reduced the expression of the lipid droplet binding protein PLIN2 in the livers of CB1−/− and hepatitis B surface protein (HBs)-transgenic mice, which spontaneously develop hepatic steatosis. In addition, the pharmacologic activation and antagonization of CB1 in cell culture also caused an induction or reduction of PLIN2, respectively. The decreased PLIN2 expression was associated with suppressed lipogenesis and triglyceride (TG) synthesis and enhanced autophagy as shown by increased colocalization of LC3B with lysosomal-associated membrane protein 1 (LAMP1) in HBs/CB1−/− mice. The induction of autophagy was further supported by the increased expression of LAMP1 in CB1−/− and HBs/CB1−/− mice. LAMP1 and PLIN2 were co-localized in HBs/CB1−/− indicating autophagy of cytoplasmic lipid droplets (LDs) i.e., lipophagy. Lipolysis of lipid droplets was additionally indicated by elevated expression of lysosomal acid lipase. In conclusion, these results suggest that loss of CB1 signaling leads to reduced PLIN2 abundance, which triggers lipophagy. Our new findings about the association between CB1 signaling and PLIN2 may stimulate translational studies analyzing new diagnostic and therapeutic options for NAFLD.

show abstract

Section: Discussionmentioning

confidence: 99%

Cannabinoid receptor 1 knockout alleviates hepatic steatosis by downregulating perilipin 2

Irungbam

Churin

Matono

et al. 2020

Laboratory Investigation

View full text Add to dashboard Cite

show abstract

“…Recent studies have shown that CBR inverse agonists may have potential therapeutic relevance in many disease states, including cancer, osteoporosis, alcoholism, liver cirrhosis and cardiovascular toxicity [52, 67–69]. Specifically, cannabinoid agonists including Δ 9 -THC and CP-55,940 have been studied for decades and shown to induce cancer cell death, inhibit angiogenesis and block tumor invasion and metastasis of numerous cancer cell types [70].…”

Section: Discussionmentioning

confidence: 99%

Tamoxifen Isomers and Metabolites Exhibit Distinct Affinity and Activity at Cannabinoid Receptors: Potential Scaffold for Drug Development

et al. 2016

View full text Add to dashboard Cite

Tamoxifen (Tam) is a selective estrogen receptor (ER) modulator (SERM) that is an essential drug to treat ER-positive breast cancer. Aside from known actions at ERs, recent studies have suggested that some SERMs like Tam also exhibit novel activity at cannabinoid subtype 1 and 2 receptors (CB1R and CB2Rs). Interestingly, cis- (E-Tam) and trans- (Z-Tam) isomers of Tam exhibit over a 100-fold difference in affinity for ERs. Therefore, the current study assessed individual isomers of Tam and subsequent cytochrome P450 metabolic products, 4-hydroxytamoxifen (4OHT) and 4-hydroxy-N-desmethyl tamoxifen (End) for affinity and activity at CBRs. Results showed that Z-4OHT, but not Z-Tam or Z-End, exhibits higher affinity for both CB1 and CB2Rs relative to the E-isomer. Furthermore, Z- and E-isomers of Tam and 4OHT show slightly higher affinity for CB2Rs, while both End isomers are relatively CB1R-selective. When functional activity was assessed by G-protein activation and regulation of the downstream effector adenylyl cyclase, all isomers examined act as full CB1 and CB2R inverse agonists. Interestingly, Z-Tam appears to be more efficacious than the full inverse agonist AM630 at CB2Rs, while both Z-Tam and Z-End exhibit characteristics of insurmountable antagonism at CB1 and CB2Rs, respectively. Collectively, these results suggest that the SERMs Tam, 4OHT and End elicit ER-independent actions via CBRs in an isomer-specific manner. As such, this novel structural scaffold might be used to develop therapeutically useful drugs for treatment of a variety of diseases mediated via CBRs.

show abstract

“…Stock solutions of 50 mmol/L sodium oleate and 50 mmol/L sodium palmitate were mixed at five different ratios (oleate/palmitate, at 3:0, 2:1,1:1, 1:2 and 0:3 ratios) and were then conveniently diluted in culture medium containing 1% BSA to obtain the desired final concentrations (0.25 mmol/L, 0.5 mmol/L, 0.75 mmol/L, 1.0 mmol/L and 1.5 mmol/L) (Shi et al, 2014;Gomez-Lechon et al, 2007). To induce fat-overloading in cells, the L-02 cells were serum-starved overnight and were then incubated with different permutations of the concentrations and ratios of the FFA mixture for 24 hours.…”

Section: Establishment Of L-02 Fatty Liver Cell Modelmentioning

confidence: 99%

Peer Review #1 of "Huperzine A attenuates nonalcoholic fatty liver disease by regulating hepatocyte senescence and apoptosis: an in vitro study (v0.2)"

Zhou¹

2018

View full text Add to dashboard Cite

This study was undertaken to detect if free fatty acids (FFA) induce hepatocyte senescence in L-02 cells and if huperzine A has an anti-aging effect in fatty liver cells. Methods: L-02 cells were treated with a FFA mixture (oleate/palmitate, at 3:0, 2:1, 1:1, 1:2 and 0:3 ratios) at different concentrations. Cell viability and fat accumulation rate were assessed by a Cell Counting Kit 8 (CCK8) kit and Nile Red staining, respectively. The Objective: This study was undertaken to detect if free fatty acids (FFA) induce hepatocyte senescence in L-02 cells and if huperzine A has an anti-aging effect in fatty liver cells. Methods: L-02 cells were treated with a FFA mixture (oleate/palmitate, at 3:0, 2:1, 1:1, 1:2 and 0:3 ratios) at different concentrations. Cell viability and fat accumulation rate were assessed by a Cell Counting Kit 8 (CCK8) and Nile Red staining, respectively. The mixture with the highest cell viability and fat accumulation rate was selected to continue with the following experiment. The L-02 cells were divided into five groups, including the control group, FFA group, FFA+0.1 μmol/L huperzine A (LH) group, FFA+1.0 μmol/L huperzine A (MH) group and FFA+10 μmol/L huperzine A (HH) group, and were cultured for 24 h. The expression of senescence-associated β-galactosidase (SA-β-gal) was detected by a SA-β-gal staining kit. The expression levels of aging genes were measured by qRT-PCR. The expression levels of apoptosis proteins were detected by a Western blot. ELISA kits were used to detect inflammatory factors and oxidative stress products. The expression of NF-κB and IκBα were detected by immunofluorescence. Results: The FFA mixture (oleate/palmitate, at a 2:1 ratio) of 0.5 mmol/L had the highest cell viability and fat accumulation rate, which was preferable for establishing an in vitro fatty liver model. The expression of inflammatory factors (TNFα, IL-6, and IL-10) and oxidants (MDA, HNE and ROS) also increased in the L-02 fatty liver cells. The expression levels of aging markers and aging genes, such as SA-β-gal, p16, p21, p53 and pRb, increased more in the L-02 fatty liver cells than in the L-02 cells. The total levels of the apoptosisassociated proteins Bcl2, Bax, Bax/Bcl-2, CyCt, and cleaved caspase 9 were also upregulated in the L-02 fatty liver cells. All of the above genes and proteins were downregulated in the huperzine A and FFA co-treatment group. In the L-02 fatty liver cells, the expression of IκBα decreased, while the expression of NF-κB increased. After the huperzine A and FFA co-treatment, the expression of IκBα increased, while the expression of NF-κB decreased. Conclusion: Fatty liver cells showed an obvious senescence and apoptosis phenomenon. Huperzine A suppressed hepatocyte senescence, and it might exert its anti-aging effect via the NF-κB pathway.

show abstract

Inhibiting CB1 receptors improves lipogenesis in an in vitro non-alcoholic fatty liver disease model

Cited by 37 publications

References 23 publications

Cannabinoid receptor 1 knockout alleviates hepatic steatosis by downregulating perilipin 2

Cannabinoid receptor 1 knockout alleviates hepatic steatosis by downregulating perilipin 2

Tamoxifen Isomers and Metabolites Exhibit Distinct Affinity and Activity at Cannabinoid Receptors: Potential Scaffold for Drug Development

Peer Review #1 of "Huperzine A attenuates nonalcoholic fatty liver disease by regulating hepatocyte senescence and apoptosis: an in vitro study (v0.2)"

Contact Info

Product

Resources

About