Beneficial metabolic effects of CB1R anti-sense oligonucleotide treatment in diet-induced obese AKR/J mice

The intervention of cannabinoid receptor in chronic and acute kidney disease animal models: a systematic review and meta-analysis

AIM

Cannabinoid receptors are components of the endocannabinoid system that affect various physiological functions. We aim to investigate the effect of cannabinoid receptor modulation on kidney disease.

METHODS

PubMed, Web of Science databases, and EMBASE were searched. Articles selection, data extraction and quality assessment were independently performed by two investigators. The SYRCLE's RoB tool was used to assess the risk of study bias, and pooled SMD using a random-effect model and 95% CIs were calculated. Subgroup analyses were conducted in preselected subgroups, and publication bias was evaluated. We compared the effects of CB1 and CB2 antagonists and/or knockout and agonists and/or genetic regulation on renal function, blood glucose levels, body weight, and pathological damage-related indicators in different models of chronic and acute kidney injury.

RESULTS

The blockade or knockout of CB1 could significantly reduce blood urea nitrogen [SMD,- 1.67 (95% CI - 2.27 to - 1.07)], serum creatinine [SMD, - 1.88 (95% CI - 2.91 to - 0.85)], and albuminuria [SMD, - 1.60 (95% CI - 2.16 to - 1.04)] in renal dysfunction animals compared with the control group. The activation of CB2 group could significantly reduce serum creatinine [SMD, - 0.97 (95% CI - 1.83 to - 0.11)] and albuminuria [SMD, - 2.43 (95% CI - 4.63 to - 0.23)] in renal dysfunction animals compared with the control group.

CONCLUSIONS

The results suggest that targeting cannabinoid receptors, particularly CB1 antagonists and CB2 agonists, can improve kidney function and reduce inflammatory responses, exerting a renal protective effect and maintaining therapeutic potential in various types of kidney disease.

Expanding Research on Cannabis-Based Medicines for Liver Steatosis: A Low-Risk High-Reward Way Out of the Present Deadlock?

Obesity and nonalcoholic fatty liver disease (NAFLD) constitute global and growing epidemics that result in therapeutic dead ends. There is an urgent need for new and accessible treatments to improve and widen both preventive and curative approaches against NAFLD. The endocannabinoid system (ECS) is recognized as a complex signaling apparatus closely related to metabolic disorders and is a key target for treating NAFLD. Despite a lack of conclusive clinical trials, observational and pre-clinical studies highlight putative benefits of phytocannabinoids on liver steatosis through multiple pathways. Owing to both its safety profile and its diversity of active compounds acting primarily (although not exclusively) on the ECS-and its expanded version, the endocannabinoidome, the Cannabis plant should be considered a major prospect in the treatment of NAFLD. However, seizing this opportunity, and intensifying clinical research in this direction, will require overcoming both scientific and nonscientific barriers.

Controversies surrounding peripheral cannabinoid receptor 1 in fatty liver disease

Cannabinoid receptor 1 (CB-1) antagonists are potential candidates for treating obesity and metabolic complications. Despite clear metabolic benefits, unwanted side effects in the brain pose issues for patients. With the hope of overcoming this obstacle, CB-1 in peripheral tissues has become a potential drug target. Previous studies had suggested that liver CB-1 would be an excellent target to prevent development of nonalcoholic steatohepatitis (NAFLD). However, in this issue of the JCI, Wang et al. showed that CB-1 was barely detectable in the liver and deletion of CB-1 in hepatocytes provided no metabolic benefits against NAFLD. These contradictory results raise substantial concerns about the potential benefits of peripheral CB-1 blockers against NAFLD.

Tart cherry (Prunus cerasus L.) dietary supplement modulates visceral adipose tissue CB1 mRNA levels along with other adipogenesis-related genes in rat models of diet-induced obesity

PURPOSE

There is increasing evidence for the involvement of dietary bioactive compounds in the cross-talk modulation of endocannabinoid system and some of the key regulators of transcriptional control for adipogenesis.

METHODS

We aimed to characterize the expression of cannabinoid CB1/CB2 receptors and fatty acid amide hydrolase (FAAH) along with selected adipogenesis-related genes (PPARγ, SREBP-1c and PREF-1), adipocyte-secreted factors (leptin and adiponectin), mitochondrial bioenergetic modulators (PGC-1A and UCP-2), and transient receptor potential vanilloid subtype 1 (TRPV1) and 2 (TRPV2) channels in visceral adipose tissue of rats fed with a high-fat diet (HFD) containing either tart cherry seeds alone or tart cherry seeds and juice for 17 weeks. The visceral adipose tissue was weighed and checked the expression of different markers by qRT-PCR, Western blot and immunohistochemistry.

RESULTS

Tart cherry supplements were able to downregulate the HFD-induced mRNA expression of CB1 receptor, SREBP-1c, PPARγ, leptin, TRPV1 and TRPV2 resulting in potential anti-adipogenic effects.

CONCLUSION

The present study points out that the intake of bioactive constituents of tart cherry may attenuate the effect of adipogenesis by acting directly on the adipose tissue and modulating the interplay between CB1, PPARγ and TRPV channel gene transcription.

Natriuretic peptide receptor C contributes to disproportionate right ventricular hypertrophy in a rodent model of obesity-induced heart failure with preserved ejection fraction with pulmonary hypertension

Heart failure with preserved ejection fraction (HFpEF) currently has no therapies that improve mortality. Right ventricular dysfunction and pulmonary hypertension are common in HFpEF, and thought to be driven by obesity and metabolic syndrome. Thus, we hypothesized that an animal model of obesity-induced HFpEF with pulmonary hypertension would provide insight into the pathogenesis of right ventricular failure in HFpEF. Two strains of mice, one susceptible (AKR) and one resistant (C3H) to obesity-induced HFpEF, were fed high fat (60% fat) or control diet for 0, 2, or 20 weeks and evaluated by cardiac catheterization and echocardiography for development of right ventricular dysfunction, pulmonary hypertension, and HFpEF. AKR, but not C3H, mice developed right ventricular dysfunction, pulmonary hypertension, and HFpEF. NPRC, which antagonizes beneficial natriuretic peptide signaling, was found in RNA sequencing to be the most differentially upregulated gene in the right ventricle, but not left ventricle or lung, of AKR mice that developed pulmonary hypertension and HFpEF. Overexpression of NPRC in H9C2 cells increased basal cell size and increased expression of hypertrophic genes, MYH7 and NPPA. In conclusion, we have shown that NPRC contributes to right ventricular modeling in obesity-induced pulmonary hypertension-HFpEF by increasing cardiomyocyte hypertrophy. NPRC may represent a promising therapeutic target for right ventricular dysfunction in pulmonary hypertension-HFpEF.

Inhibition of Cannabinoid Receptor 1 Can Influence the Lipid Metabolism in Mice with Diet-Induced Obesity

A growing number of evidences accumulated about critical metabolic role of cannabinoid type 1 receptor (CB1), carnitine palmitoyltransferase-1 (CPT1) and peroxisome proliferator-activated receptors (PPARs) in some peripheral tissues, including adipose tissue, liver, skeletal muscle and heart. To better understand the interactions of CB1, CPT1 and PPARs in these tissues, 30 diet-induced obese (DIO) C57BL/6J male mice were obtained, weight-matched and divided into two groups (15 in each group): (i) DIO/vehicle mice (D-Veh) and (ii) DIO/SR141716 mice (D-SR) treated with SR141716 (or rimonabant, a selective CB1 receptor blocker) administered orally (10 mg/kg daily). Another 15 mice fed standard diet (STD) formed the STD/vehicle group (S-Veh). At the end of 3-week treatment, mean body weight was 28.4 ± 0.5, 36.5 ± 0.8, and 30.3 ± 1.2 g for the S-Veh, D-Veh, and D-SR group, respectively (p < 0.05; D-Veh vs. D-SR). Liver weight in the D-SR group was also decreased significantly compared to the D-Veh group (p < 0.05). Serum levels of total cholesterol, high-density lipoprotein cholesterol, leptin and adiponectin in the D-SR group were ameliorated compared to the D-Veh group (p < 0.05). Both qRT-PCR and Western blot assay revealed that CB1 expression levels were efficiently blocked by SR141716 in subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), skeletal muscles and liver (D-SR vs. D-Veh; p < 0.05), whereas there was no significant difference between S-Veh and D-Veh mice (p > 0.05). Simultaneously with the reduction of CB1 expression in the D-SR group, the expression levels of CPT1A isoform (protein) in the liver and heart and CPT1B isoform (protein) in the SAT, VAT, liver and skeletal muscles were significantly increased (p < 0.05; D-SR vs. D-Veh). Interestingly, the CPT1A and CPT1B expression levels in heart were detected slightly. The expression levels of PPARα in the SAT, VAT, liver and skeletal muscles and PPARγ in the SAT and skeletal muscles in the D-SR group were significantly increased compared to the D-Veh mice (p < 0.05). However, the PPARβ expression level differed from that of PPARα and PPARγ. Taken together, these data indicate that the inhibition of CB1 could ameliorate lipid metabolism via the stimulation of the CPT1A and CPT1B expression in vivo. Simultaneously, the PPARα and PPARγ expression levels significantly differed compared to that of PPARβ in obesity and lipid metabolism-related disorders under blockade of CB1. Both the mechanism of the influence of CB1 inhibition on lipid metabolism in the examined tissues and the specific mechanism of PPARα, PPARγ and PPARβ involvement in lipid exchange under these conditions remain to be further elucidated.

Effects of pre-germinated brown rice treatment high-fat diet-induced metabolic syndrome in C57BL/6J mice

To investigate using pre-germinated brown rice (PGBR) to treat metabolic syndrome, we fed one group of mice standard-regular-diet (SRD) for 20 weeks and another group of mice high-fat-diet (HFD) for 16 weeks. We subdivided them into HFD group and HFD + PGBR group whose dietary carbohydrate was replaced with PGBR for 4 weeks. The HFD group gained more weight, had higher blood pressure, heart rate, blood glucose and lipids, liver levels of TG, feces TG and bile acid, lower adipose levels of adipocytokine, lower skeletal muscle IR, IRS-1, IRS-2, PI3 K, Akt/PKB, GLUT-1, GLUT-4, GCK and PPAR-γ; higher liver SREBP-1, SCD-1, FAS, HMGCR, LDLR, CYP7α1 and PPAR-α, and higher adipose SREBP-1, SCD-1, FAS, and lower adipose PPAR-α and adiponectin. The HFD + PGBR group had clearly improved blood pressure, biochemical parameters and above proteins expressions. PGBR successful treatment of metabolic syndrome was achieved through improvements in glucose and lipid synthesis and metabolism.

Endocannabinoid regulation of β-cell functions: implications for glycaemic control and diabetes

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.

Lack of Interactions Between an Antisense Oligonucleotide with 2'-O-(2-Methoxyethyl) Modifications and Major Drug Transporters

ISIS 141923 is a model compound of 2'-O-(2-methoxyethyl) (2'-MOE) modified antisense oligonucleotides (ASOs). The purpose of this study is to determine whether ISIS 141923 is a substrate or an inhibitor against a panel of nine major uptake or efflux drug transporters, namely breast cancer resistance protein (BCRP), P-glycoprotein (P-gp), organic anion transporter (OAT)1, OAT3, organic cation transporter (OCT)1, OCT2, organic anion transporting polypeptide 1B (OATP1B)1, OATP1B3, and bile salt export pump (BSEP), in vitro. The uptake test system for transporters in the solute carrier (SLC) family (OAT1, OAT3, OCT1, OCT2, OATP1B1, and OATP1B3) was studied in Madin-Darby canine kidney (MDCK)-II cells transfected to express the transporters of interest. BCRP was studied using carcinoma colon-2 (Caco-2) cells with endogenously expressed BCRP. P-gp transporter was studied in MDCK-multi-drug resistance 1 (MDR1) cells, while BSEP was studied using Spodoptera frugiperda 9 (Sf9) membrane vesicles containing human BSEP. The ISIS 141293 concentrations evaluated were 10 and 100 μM for the substrate and inhibition study, respectively. Cellular uptake of ISIS 141923 was analyzed using a high performance liquid chromatography-mass spectrometry method, while concentrations of known substrates (used as positive controls) of each transporters evaluated were determined by radiometric detection. At 10 μM ISIS 141923, there was no significant transporter-mediated uptake of ISIS 141923 (P > 0.05) in the SLC family, and the efflux ratios were not above 2.0 for either BCRP or P-gp. Therefore, no transporter-mediated uptake of ISIS 141923 was observed by any of the nine transporters studied. At 100 μM ISIS 141923, the % inhibition was in the range of -16.0% to 19.0% for the nine transporters evaluated. Therefore, ISIS 141923 is not considered as an inhibitor of the nine transporters studied. Overall, the results from this study suggest that it is unlikely that ISIS 141923 or similar 2'-MOE ASOs would interact with small molecule drugs either as a victim (substrate) or perpetrator (inhibitor) of major transporters in humans. The results from available clinical drug-drug interaction studies conducted with this class of compounds to date are also supportive of this conclusion.

New perspectives on the development of antiobesity drugs

After many years of research, obesity is still a disease with an unmet medical need. Very few compounds have been approved, acting mainly on neuromediators; researches, in recent years, pointed toward compounds potentially safer than first-generation antiobesity drugs, able to interact with one or more (multitarget therapy) receptors for substances produced by the gut, adipose tissue and other targets outside CNS. Other holistic approaches, such as those involving gut microbiota and plant extracts, appeared recently in the literature, and undoubtedly will contribute to the discovery of a valuable therapy for this disease. This review deals with the positive results and the pitfalls obtained following these approaches, with a view on their clinical trial studies.

Pre-germinated brown rice prevents high-fat diet induced hyperglycemia through elevated insulin secretion and glucose metabolism pathway in C57BL/6J strain mice

This study investigated the effect and mechanism of pre-germinated brown rice (PGBR) prevented hyperglycemia in C57BL/6J mice fed high-fat-diet (HFD). Normal six-week-old mice were randomly divided into three groups. Group 1 was fed standard-regular-diet (SRD) and group 2 was fed HFD for 16 weeks. In group 3, the mice were fed a HFD with its carbohydrate replaced with PGBR for 16 weeks. Comparing the SRD and HFD groups, we found the HFD group had higher blood pressure, higher concentrations of blood glucose and HbA1c. The HFD group had less protein expression of insulin receptor (IR), insulin receptor substrate-1 (IRS-1), phosphatidylinositol-3-kinase (PI3K), glucose transporter-4 (GLUT-4) and glucokinase (GCK) and greater expression of glucogen synthase kinase (GSK) in skeletal muscle. The HFD group also had less expression of IR, serine/threonine kinase PI3K-linked protein kinase B (Akt/PKB), AMP-activated protein kinase (AMPK), GCK and peroxisome proliferator-activated receptor γ (PPARγ) in liver. In the HFD + PGBR group, the PGBR could reverse the disorders of blood pressure, blood glucose, HbA1c and increase insulin concentration. PGBR increased the IR, IRS-1, PI3K, Akt, GLUT-1 and GLUT-4 proteins, and ameliorated AMPK, GCK, GSK and PPARγ proteins. Together, PGBR prevented HFD-induced hyperglycemia through improving insulin levels, insulin receptor, glucose transporters and enhancing glucose metabolism.

Selective depletion of factor XI or factor XII with antisense oligonucleotides attenuates catheter thrombosis in rabbits

Central venous catheter thrombosis can cause venous obstruction and pulmonary embolism. To determine the extent to which catheter thrombosis is triggered by the contact or extrinsic pathway of coagulation, we used antisense oligonucleotides (ASOs) to selectively knock down factor (f)XII, fXI, or high-molecular-weight kininogen (HK), key components of the contact pathway, or fVII, which is essential for the extrinsic pathway. Knockdown of contact pathway components prolonged the activated partial thromboplastin time and decreased target protein activity levels by over 90%, whereas fVII knockdown prolonged the prothrombin time and reduced fVII activity to a similar extent. Using a rabbit model of catheter thrombosis, catheters implanted in the jugular vein were assessed daily until they occluded, up to a maximum of 35 days. Compared with control, fXII and fXI ASO treatment prolonged the time to catheter occlusion by 2.2- and 2.3-fold, respectively. In contrast, both HK and fVII knockdown did not significantly prolong the time to occlusion, and dual treatment with fVII- and fXI-directed ASOs produced a time to occlusion similar to that with the fXI ASO alone. These findings suggest that catheter thrombosis is triggered via the contact pathway and identify fXII and fXI as potential targets to attenuate this complication.

Activation of the Nlrp3 inflammasome in infiltrating macrophages by endocannabinoids mediates beta cell loss in type 2 diabetes

Type 2 diabetes mellitus (T2DM) progresses from compensated insulin resistance to beta cell failure resulting in uncompensated hyperglycemia, a process replicated in the Zucker diabetic fatty (ZDF) rat. The Nlrp3 inflammasome has been implicated in obesity-induced insulin resistance and beta cell failure. Endocannabinoids contribute to insulin resistance through activation of peripheral CB1 receptors (CB₁Rs) and also promote beta cell failure. Here we show that beta cell failure in adult ZDF rats is not associated with CB₁R signaling in beta cells, but rather in M1 macrophages infiltrating into pancreatic islets, and that this leads to activation of the Nlrp3-ASC inflammasome in the macrophages. These effects are replicated in vitro by incubating wild-type human or rodent macrophages, but not macrophages from CB₁R-deficient (Cnr1(-/-)) or Nlrp3(-/-) mice, with the endocannabinoid anandamide. Peripheral CB₁R blockade, in vivo depletion of macrophages or macrophage-specific knockdown of CB₁R reverses or prevents these changes and restores normoglycemia and glucose-induced insulin secretion. These findings implicate endocannabinoids and inflammasome activation in beta cell failure and identify macrophage-expressed CB₁R as a therapeutic target in T2DM.