Pharmaceutical targeting of the cannabinoid type 1 receptor impacts the crosstalk between immune cells and islets to reduce insulitis in humans.

AIMS/HYPOTHESIS: Insulitis, a hallmark of inflammation preceding autoimmune type 1 diabetes, leads to the eventual loss of functional beta cells. However, functional beta cells can persist even in the face of continuous insulitis. Despite advances in immunosuppressive treatments, maintaining functional beta cells to prevent insulitis progression and hyperglycaemia remains a challenge. The cannabinoid type 1 receptor (CB1R), present in immune cells and beta cells, regulates inflammation and beta cell function. Here, we pioneer an ex vivo model mirroring human insulitis to investigate the role of CB1R in this process. METHODS: CD4+ T lymphocytes were isolated from peripheral blood mononuclear cells (PBMCs) from male and female individuals at the onset of type 1 diabetes and from non-diabetic individuals, RNA was extracted and mRNA expression was analysed by real-time PCR. Single beta cell expression from donors with type 1 diabetes was obtained from data mining. Patient-derived human islets from male and female cadaveric donors were 3D-cultured in solubilised extracellular matrix gel in co-culture with the same donor PBMCs, and incubated with cytokines (IL-1ß, TNF-α, IFN-γ) for 24-48 h in the presence of vehicle or increasing concentrations of the CB1R blocker JD-5037. Expression of CNR1 (encoding for CB1R) was ablated using CRISPR/Cas9 technology. Viability, intracellular stress and signalling were assayed by live-cell probing and real-time PCR. The islet function measured as glucose-stimulated insulin secretion was determined in a perifusion system. Infiltration of immune cells into the islets was monitored by microscopy. Non-obese diabetic mice aged 7 weeks were treated for 1 week with JD-5037, then euthanised. Profiling of immune cells infiltrated in the islets was performed by flow cytometry. RESULTS: CNR1 expression was upregulated in circulating CD4+ T cells from individuals at type 1 diabetes onset (6.9-fold higher vs healthy individuals) and in sorted islet beta cells from donors with type 1 diabetes (3.6-fold higher vs healthy counterparts). The peripherally restricted CB1R inverse agonist JD-5037 arrested the initiation of insulitis in humans and mice. Mechanistically, CB1R blockade prevented islet NO production and ameliorated the ATF6 arm of the unfolded protein response. Consequently, cyto/chemokine expression decreased in human islets, leading to sustained islet cell viability and function. CONCLUSIONS/INTERPRETATION: These results suggest that CB1R could be an interesting target for type 1 diabetes while highlighting the regulatory mechanisms of insulitis. Moreover, these findings may apply to type 2 diabetes where islet inflammation is also a pathophysiological factor. DATA AVAILABILITY: Transcriptomic analysis of sorted human beta cells are from Gene Expression Omnibus database, accession no. GSE121863, available at https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSM3448161 .

Au@16-pH-16/miR-21 mimic nanosystem: An efficient treatment for obesity through browning and thermogenesis induction.

Despite the abundance of registered clinical trials worldwide, the availability of effective drugs for obesity treatment is limited due to their associated side effects. Thus, there is growing interest in therapies that stimulate energy expenditure in white adipose tissue. Recently, we demonstrated that the delivery of a miR-21 mimic using JetPEI effectively inhibits weight gain in an obese mouse model by promoting metabolism, browning, and thermogenesis, suggesting the potential of miR-21 mimic as a treatment for obesity. Despite these promising results, the implementation of more advanced delivery system techniques for miR-21 mimic would greatly enhance the advancement of safe and efficient treatment approaches for individuals with obesity in the future. Our objective is to explore whether a new delivery system based on gold nanoparticles and Gemini surfactants (Au@16-ph-16) can replicate the favorable effects of the miR-21 mimic on weight gain, browning, and thermogenesis. We found that dosages as low as 0.2 µg miR-21 mimic /animal significantly inhibited weight gain and induced browning and thermogenic parameters. This was evidenced by the upregulation of specific genes and proteins associated with these processes, as well as the biogenesis of beige adipocytes and mitochondria. Significant increases in miR-21 levels were observed in adipose tissue but not in other tissue types. Our data indicates that Au@16-ph-16 could serve as an effective delivery system for miRNA mimics, suggesting its potential suitability for the development of future clinical treatments against obesity.

MiR-221-3p/222-3p Cluster Expression in Human Adipose Tissue Is Related to Obesity and Type 2 Diabetes.

The progression of obesity and type 2 diabetes (T2D) is intricately linked with adipose tissue (AT) angiogenesis. Despite an established network of microRNAs (miRNAs) regulating AT function, the specific role of angiogenic miRNAs remains less understood. The miR-221/222 cluster has recently emerged as being associated with antiangiogenic activity. However, no studies have explored its role in human AT amidst the concurrent development of obesity and T2D. Therefore, this study aims to investigate the association between the miR-221-3p/222-3p cluster in human AT and its regulatory network with obesity and T2D. MiR-221-3p/222-3p and their target gene (TG) expression levels were quantified through qPCR in visceral (VAT) and subcutaneous (SAT) AT from patients (n = 33) categorized based on BMI as normoweight (NW) and obese (OB) and by glycemic status as normoglycemic (NG) and type 2 diabetic (T2D) subjects. In silico analyses of miR-221-3p/222-3p and their TGs were conducted to identify pertinent signaling pathways. The results of a multivariate analysis, considering the simultaneous expression of miR-221-3p and miR-222-3p as dependent variables, revealed statistically significant distinctions when accounting for variables such as tissue depot, obesity, sex, and T2D as independent factors. Furthermore, both miRNAs and their TGs exhibited differential expression patterns based on obesity severity, glycemic status, sex, and type of AT depot. Our in silico analysis indicated that miR-221-3p/222-3p cluster TGs predominantly participate in angiogenesis, WNT signaling, and apoptosis pathways. In conclusion, these findings underscore a promising avenue for future research, emphasizing the miR-221-3p/222-3p cluster and its associated regulatory networks as potential targets for addressing obesity and related metabolic disorders.

Rich oleocanthal and oleacein extra virgin olive oil and inflammatory and antioxidant status in people with obesity and prediabetes. The APRIL study: A randomised, controlled crossover study.

BACKGROUND: Oleocanthal and oleacein are olive oil phenolic compounds with well known anti-inflammatory and anti-oxidant properties. The main evidence, however, is provided by experimental studies. Few human studies have examined the health benefits of olive oils rich in these biophenols. Our aim was to assess the health properties of rich oleocanthal and oleacein extra virgin olive oil (EVOO), compared to those of common olive oil (OO), in people with prediabetes and obesity. METHODS: Randomised, double-blind, crossover trial done in people aged 40-65 years with obesity (BMI 30-40 kg/m2) and prediabetes (HbA1c 5.7-6.4%). The intervention consisted in substituting for 1 month the oil used for food, both raw and cooked, by EVOO or OO. No changes in diet or physical activity were recommended. The primary outcome was the inflammatory status. Secondary outcomes were the oxidative status, body weight, glucose handling and lipid profile. An ANCOVA model adjusted for age, sex and treatment administration sequence was used for the statistical analysis. RESULTS: A total of 91 patients were enrolled (33 men and 58 women) and finished the trial. A decrease in interferon-γ was observed after EVOO treatment, reaching inter-treatment differences (P = 0.041). Total antioxidant status increased and lipid and organic peroxides decreased after EVOO treatment, the changes reaching significance compared to OO treatment (P < 0.05). Decreases in weight, BMI and blood glucose (p < 0.05) were found after treatment with EVOO and not with OO. CONCLUSIONS: Treatment with EVOO rich in oleocanthal and oleacein differentially improved oxidative and inflammatory status in people with obesity and prediabetes.

Efficacy and safety of basal insulin degludec 100 IU/mL versus glargine 300 IU/mL for type 1 diabetes: The single-center INEOX randomized controlled trial.

AIMS: To compare efficacy and safety of degludec 100 IU/mL (Deg-100) and glargine 300 IU/mL (Gla-300) in adults with type 1 diabetes. METHODS: Open-label, single-center, randomized, parallel-group, 24-week trial in adults with type 1 diabetes, on basal-bolus insulin therapy, HbA1c ≤ 10%, using self-monitoring blood glucose. Participants were randomized 1:1 to a basal-bolus insulin regimen with Deg-100 (N = 129) or Gla-300 (N = 131). Primary efficacy endpoint: mean change in HbA1c from baseline to week-24. Main safety outcome: incidence rate of hypoglycemia during the study. Quality of life (DQOL) and satisfaction with diabetes treatment (DTSQ) were assessed. RESULTS: At week 24, after adjusting for baseline HbA1c, the decrease in HbA1c did not differ between groups: Deg-100 (-0.07 ± 0.7%) and Gla-300 (-0.16 ± 0.77%) (P = 0.320). There were no significant differences between groups in HbA1c, nocturnal hypoglycemia, severe hypoglycemia, DQOL, or DTSQ scores. The incidence rates of hypoglycemia < 3.9 mmol/L (Deg-100: 115.24 events/person-year vs Gla-300: 99.01 events/person-year, p < 0.001); and < 3.0 mmol/L (Deg-100: 41.17 events/person-year vs Gla-300: 34.29 events/person-year, p < 0.001) were different between groups. CONCLUSIONS: Deg-100 and Gla-300 have similar metabolic efficacy, incidence ratio of nocturnal and severe hypoglycemia, DQOL and DTSQ scores. Differences in the incidence rate of hypoglycemia < 3.9 mmol/L and < 3.0 mmol/L should be confirmed.

miR-21 mimic blocks obesity in mice: A novel therapeutic option.

MicroRNAs (miRNAs) are promising drug targets for obesity and metabolic disorders. Recently, miRNA mimics are providing a unique mechanism of action that guides the process for drug development and sets out the context of their therapeutic application. miRNA (miR)-21 expression in white adipose tissue (WAT) has been associated with obesity. We aimed to analyze miR-21 expression levels in relation to diabetes and obesity to determine the effect that miR-21 mimic has on processes involved in WAT functionality, to dissect the underlying molecular mechanisms, and to study the potential therapeutic application of the miR-21 mimic against obesity. We found higher miR-21 levels in WAT from non-diabetic obese compared to normoweight humans and mice. Moreover, in 3T3-L1 adipocytes, miR-21 mimic affect genes involved in WAT functionality regulation and significantly increase the expression of genes involved in browning and thermogenesis. Interestingly, in vivo treatment with the miR-21 mimic blocked weight gain induced by a high-fat diet in obese mice, without modifying food intake or physical activity. This was associated with metabolic enhancement, WAT browning, and brown adipose tissue (AT) thermogenic programming through vascular endothelial growth factor A (VEGF-A), p53, and transforming growth factor ß1 (TGF-ß1) signaling pathways. Our findings suggest that miR-21 mimic-based therapy may provide a new opportunity to therapeutically manage obesity and consequently, its associated alterations.

Oxidative and inflammatory effects of pulmonary rehabilitation in patients with bronchiectasis. A prospective, randomized study.

INTRODUCTION: Background: systemic inflammation and oxidative stress are important factors in the pathogenesis of bronchiectasis. Pulmonary rehabilitation (PR) is recommended for bronchiectasis, but there is no data about its effect on the inflammatory and REDOX status of these patients. Aims: to investigate the effect of PR in non-cystic-fibrosis bronchiectasis (NCFB) patients, and to compare it with the effect of PR plus a hyperproteic oral nutritional supplement (PRS) enriched with beta-hydroxy-beta-methylbutyrate (HMB) on serum inflammatory and oxidative biomarkers. Materials and methods: this was an open randomized, controlled trial. Thirty individuals (65 years old or younger with a body mass index over 18.5, older than 65 years with a body mass index over 20) were recruited from September 2013 to September 2014, and randomly assigned to receive PR or PRS. Total neutrophils, and inflammatory and oxidative biomarker levels were measured at baseline, and then at 3 and 6 months. Results: in the PRS group neutrophil levels were decreased from baseline at 6 months. A significantly different fold change was found between the PR and PRS groups. In the PR group, IL-6 and adiponectin were increased by the end of the study while TNFα levels were decreased from baseline at 6 months. REDOX biomarkers remained stable throughout the study except for 8-isoprostane levels, which were increased from baseline at 6 months in both groups of patients. Conclusions: a PR program induced a pro-oxidative effect accompanied by changes in circulating inflammatory cytokine levels in NCFB patients. Our results would also suggest a possible beneficial effect of the HMB enriched supplement on neutrophil level regulation in these patients. The information provided in this study could be useful for choosing the right therapeutic approach in the management of bronchiectasis.

INTRODUCCIÓN: Introducción: la inflamación sistémica y el estrés oxidativo son factores importantes en la patogénesis de la bronquiectasia. La rehabilitación pulmonar (PR) está recomendada en los sujetos con bronquiectasias, pero no hay datos sobre sus posibles efectos sobre el estado inflamatorio y REDOX de estos pacientes. Objetivos: investigar el efecto de la PR en pacientes con bronquiectasias no asociadas a fibrosis quística (NCFB) sobre los biomarcadores oxidativos e inflamatorios, y compararlo con los efectos de la PR junto con la suplementación oral de un suplemento hiperproteico (PRS) enriquecido con beta-hidroxi-beta-metilbutirato (HMB). Material y métodos: ensayo clínico abierto, aleatorizado y controlado. Treinta pacientes (de 65 años o menos con un índice de masa corporal por encima de 18,5, y mayores de 65 años con un índice de masa corporal de más de 20) se aleatorizaron para recibir PR o PRS. Los niveles circulantes de neutrófilos totales y los de biomarcadores de estado inflamatorio y oxidativo se determinaron al inicio del estudio y a los 3 y 6 meses. Resultados: los niveles de neutrófilos en el grupo de PRS se redujeron desde el inicio a los 6 meses, presentando una tasa de cambio significativamente diferente según el tratamiento. En el grupo de PR, la IL-6 y la adiponectina aumentaron al final del estudio, mientras que los niveles de TNFα disminuyeron desde el inicio a los 6 meses. Los biomarcadores de estrés oxidativo se mantuvieron estables durante todo el estudio excepto por los niveles de 8-isoprostano, que aumentaron desde el inicio a los 6 meses en ambos grupos de pacientes. Conclusión: el programa de PR indujo un efecto pro-oxidativo acompañado de cambios en los niveles de citoquinas inflamatorias circulantes en pacientes con NCFB. Nuestros resultados también sugieren un posible efecto beneficioso del suplemento nutricional sobre la regulación de los niveles de neutrófilos de estos pacientes.

Inadequate control of thyroid hormones sensitizes to hepatocarcinogenesis and unhealthy aging.

An inverse correlation between thyroid hormone levels and longevity has been reported in several species and reduced thyroid hormone levels have been proposed as a biomarker for healthy aging and metabolic fitness. However, hypothyroidism is a medical condition associated with compromised health and reduced life expectancy. Herein, we show, using wild-type and the Pax8 ablated model of hypothyroidism in mice, that hyperthyroidism and severe hypothyroidism are associated with an overall unhealthy status and shorter lifespan. Mild hypothyroid Pax8 +/- mice were heavier and displayed insulin resistance, hepatic steatosis and increased prevalence of liver cancer yet had normal lifespan. These pathophysiological conditions were precipitated by hepatic mitochondrial dysfunction and oxidative damage accumulation. These findings indicate that individuals carrying mutations on PAX8 may be susceptible to develop liver cancer and/or diabetes and raise concerns regarding the development of interventions aiming to modulate thyroid hormones to promote healthy aging or lifespan in mammals.

miR-20b, miR-296, and Let-7f Expression in Human Adipose Tissue is Related to Obesity and Type 2 Diabetes.

OBJECTIVE: This study aimed to analyze the potential association of different microRNA (miRNA) molecules with both type 2 diabetes (T2D) and obesity and determine their target genes. METHODS: Quantitative PCR was used to analyze the miR-20b, miR-296, and Let-7f levels in human visceral and subcutaneous adipose tissues (ATs) in relation to obesity and T2D, miRTarBase 4.0 was used for validation of target genes, and the Protein Analysis Through Evolutionary Relationships (PANTHER) Classification System and the Database for Annotation, Visualization and Integrated Discovery (DAVID) were used to annotate the biological processes of the predicted targets. RESULTS: In AT, miR-20b, miR-296, and Let-7f levels were significantly different between normoglycemic subjects and those with T2D. In visceral adipose tissue, miRNA levels were higher in normoglycemic/obesity samples than in T2D/obesity samples. miR-20b-miR-296 and Let-7f target genes that showed significant differences in both ATs in relation to obesity and T2D were CDKN1A, CX3CL1, HIF1A, PPP2R1B, STAT3, and VEGFA. These genes are known to be principally involved in the vascular endothelial growth factor (VEGF) and WNT pathways. CONCLUSIONS: This study provides experimental evidence of the possible correlation between AT miR-20b-miR-296-Let-7f with obesity and T2D, which might involve vascular endothelial growth factor and WNT-dependent pathways that are regulated by six different genes, suggesting a novel signaling pathway that could be important for understanding the mechanisms underlying the AT dysfunction associated with obesity and T2D.

LRH-1 agonism favours an immune-islet dialogue which protects against diabetes mellitus.

Type 1 diabetes mellitus (T1DM) is due to the selective destruction of islet beta cells by immune cells. Current therapies focused on repressing the immune attack or stimulating beta cell regeneration still have limited clinical efficacy. Therefore, it is timely to identify innovative targets to dampen the immune process, while promoting beta cell survival and function. Liver receptor homologue-1 (LRH-1) is a nuclear receptor that represses inflammation in digestive organs, and protects pancreatic islets against apoptosis. Here, we show that BL001, a small LRH-1 agonist, impedes hyperglycemia progression and the immune-dependent inflammation of pancreas in murine models of T1DM, and beta cell apoptosis in islets of type 2 diabetic patients, while increasing beta cell mass and insulin secretion. Thus, we suggest that LRH-1 agonism favors a dialogue between immune and islet cells, which could be druggable to protect against diabetes mellitus.

LH-21 and abnormal cannabidiol improve ß-cell function in isolated human and mouse islets through GPR55-dependent and -independent signalling.

AIMS: To examine the effects of Abn-CBD (GPR55 agonist) and LH-21 (CB1 antagonist) on human and mouse islet function, and to determine signalling via GPR55 using islets from GPR55-/- mice. MATERIALS AND METHODS: Islets isolated from human organ donors and mice were incubated in the absence or presence of Abn-CBD or LH-21, and insulin secretion, [Ca2+ ]i, cAMP, apoptosis, ß-cell proliferation and CREB and AKT phosphorylation were examined using standard techniques. RESULTS: Abn-CBD potentiated glucose-stimulated insulin secretion and elevated [Ca2+ ]i in human islets and islets from both GPR55+/+ and GPR55-/- mice. LH-21 also increased insulin secretion and [Ca2+ ]i in human islets and GPR55+/+ mouse islets, but concentrations of LH-21 up to 0.1 µM were ineffective in islets from GPR55-/- mice. Neither ligand affected basal insulin secretion or islet cAMP levels. Abn-CBD and LH-21 reduced cytokine-induced apoptosis in human islets and GPR55+/+ mouse islets, and these effects were suppressed after GPR55 deletion. They also increased ß-cell proliferation: the effects of Abn-CBD were preserved in islets from GPR55-/- mice, while those of LH-21 were abolished. Abn-CBD and LH-21 increased AKT phosphorylation in mouse and human islets. CONCLUSIONS: This study showed that Abn-CBD and LH-21 improve human and mouse islet ß-cell function and viability. Use of islets from GPR55-/- mice suggests that designation of Abn-CBD and LH-21 as a GPR55 agonist and a CB1 antagonist, should be revised.

Comparison of the Effects of Goat Dairy and Cow Dairy Based Breakfasts on Satiety, Appetite Hormones, and Metabolic Profile.

The satiating effects of cow dairy have been thoroughly investigated; however, the effects of goat dairy on appetite have not been reported so far. Our study investigates the satiating effect of two breakfasts based on goat or cow dairy and their association with appetite related hormones and metabolic profile. Healthy adults consumed two breakfasts based on goat (G-Breakfast) or cow (C-Breakfast) dairy products. Blood samples were taken and VAS tests were performed at different time points. Blood metabolites were measured and Combined Satiety Index (CSI) and areas under the curves (AUC) were calculated. Desire to eat rating was significantly lower (breakfast & time interaction p < 0.01) and hunger rating tended to be lower (breakfast & time interaction p = 0.06) after the G-breakfast. None of the blood parameters studied were different between breakfasts; however, AUCGLP-1 was inversely associated with the AUChunger and AUCdesire-to-eat after the G-Breakfast, whereas triglyceride levels were directly associated with AUCCSI after the C-Breakfast. Our results suggest a slightly higher satiating effect of goat dairy when compared to cow dairy products, and pointed to a potential association of GLP-1 and triglyceride levels with the mechanisms by which dairy products might affect satiety after the G-Breakfast and C-Breakfast, respectively.

RPL13A and EEF1A1 Are Suitable Reference Genes for qPCR during Adipocyte Differentiation of Vascular Stromal Cells from Patients with Different BMI and HOMA-IR.

Real-time or quantitative PCR (qPCR) is a useful technique that requires reliable reference genes for data normalization in gene expression analysis. Adipogenesis is among the biological processes suitable for this technique. The selection of adequate reference genes is essential for qPCR gene expression analysis of human Vascular Stromal Cells (hVSCs) during their differentiation into adipocytes. To the best of our knowledge, there are no studies validating reference genes for the analyses of visceral and subcutaneous adipose tissue hVSCs from subjects with different Body Mass Index (BMI) and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index. The present study was undertaken to analyze this question. We first analyzed the stability of expression of five potential reference genes: CYC, GAPDH, RPL13A, EEF1A1, and 18S ribosomal RNA, during in vitro adipogenic differentiation, in samples from these types of patients. The expression of RPL13A and EEF1A1 was not affected by differentiation, thus being these genes the most stable candidates, while CYC, GAPDH, and 18S were not suitable for this sort of analysis. This work highlights that RPL13A and EEF1A1 are good candidates as reference genes for qPCR analysis of hVSCs differentiation into adipocytes from subjects with different BMI and HOMA-IR.

Leucine supplementation modulates fuel substrates utilization and glucose metabolism in previously obese mice.

OBJECTIVE: High-protein diets favor weight loss and its maintenance. Whether these effects might be recapitulated by certain amino acids is unknown. Therefore, the impact of leucine supplementation on energy balance and associated metabolic changes in diet-induced obese (DIO) mice during and after weight loss was investigated. METHODS: DIO C57BL/6J mice were fed a normocaloric diet to induce weight loss while receiving or not the amino acid leucine in drinking water. Body weight, food intake, body composition, energy expenditure, glucose tolerance, insulin, and leptin sensitivity were evaluated. Q-PCR analysis was performed on muscle, brown and white adipose tissues. RESULTS: DIO mice decreased body weight and fat mass in response to chow, but supplementation with leucine did not affect these parameters. During weight maintenance, mice supplemented with leucine had improved glucose tolerance, increased leptin sensitivity, and lower respiratory quotient. The latter was associated with changes in the expression of several genes modulating fatty acid metabolism and mitochondrial activity in the epididymal white and the brown adipose tissues, but not muscle. CONCLUSIONS: Leucine supplementation might represent an adjuvant beneficial nutritional therapy during weight loss and maintenance, because it improves lipid and glucose metabolism and restores leptin sensitivity in previously obese animals.

Anti-obesity efficacy of LH-21, a cannabinoid CB(1) receptor antagonist with poor brain penetration, in diet-induced obese rats.

BACKGROUND AND PURPOSE: Peripheral blockade of cannabinoid CB(1) receptors has been proposed as a safe and effective therapy against obesity, putatively devoid of the adverse psychiatric side effects of centrally acting CB(1) receptor antagonists. In this study we analysed the effects of LH-21, a peripherally acting neutral cannabinoid receptor antagonist with poor brain penetration, in an animal model of diet-induced obesity. EXPERIMENTAL APPROACH: To induce obesity, male Wistar rats were fed a high-fat diet (HFD; 60 kcal% fat) whereas controls received a standard diet (SD; 10 kcal% fat). Following 10 weeks of feeding, animals received a daily i.p. injection of vehicle or 3 mg·kg(-1) LH-21 for 10 days. Plasma and liver samples were used for biochemical analyses whereas visceral fat-pad samples were analysed for lipid metabolism gene expression using real-time RT-PCR. In addition, the potential of LH-21 to interact with hepatic cytochrome P450 isoforms and cardiac human Ether-à-go-go Related Gene (hERG) channels was evaluated. KEY RESULTS: LH-21 reduced feeding and body weight gain in HFD-fed animals compared with the control group fed SD. In adipose tissue, this effect was associated with decreased gene expression of: (i) leptin; (ii) lipogenic enzymes, including SCD-1; (iii) CB(1) receptors; and (iv) both PPARα and PPARγ. Although there were no significant differences in plasma parameters between HFD- and SD-fed rats, LH-21 did not seem to induce hepatic, cardiac or renal toxicity. CONCLUSIONS AND IMPLICATIONS: These results support the hypothesis that treatment with the peripherally neutral acting CB(1) receptor antagonist, LH-21, may promote weight loss through modulation of visceral adipose tissue.

The role of the endocannabinoid system in the neuroendocrine regulation of energy balance.

Animal and human studies carried out so far have established a role for the endocannabinoid system (ECS) in the regulation of energy balance. Here we critically discuss the role of the endocannabinoid signalling in brain structures, such as the hypothalamus and reward-related areas, and its interaction with neurotransmitter and neuropeptide systems involved in the regulation of food intake and body weight. The ECS has been found to interact with peripheral signals, like leptin, insulin, ghrelin and satiety hormones and the resulting effects on both central and peripheral mechanisms affecting energy balance and adiposity will be described. Furthermore, ECS dysregulation has been associated with the development of dyslipidemia, glucose intolerance and obesity; phenomena that are often accompanied by a plethora of neuroendocrine alterations which might play a causal role in determining ECS dysregulation. Despite the withdrawal of the first generation of cannabinoid type 1 receptor (CB1) antagonists from the pharmaceutical market due to the occurrence of psychiatric adverse events, new evidence suggests that peripherally restricted CB1 antagonists might be efficacious for the treatment of obesity and its associated metabolic disorders. Thus, a perspective on new promising strategies to selectively target the ECS in the context of energy balance regulation is given.

Endocannabinoid system and psychiatry: in search of a neurobiological basis for detrimental and potential therapeutic effects.

Public concern on mental health has noticeably increased given the high prevalence of neuropsychiatric disorders. Cognition and emotionality are the most affected functions in neuropsychiatric disorders, i.e., anxiety disorders, depression, and schizophrenia. In this review, most relevant literature on the role of the endocannabinoid (eCB) system in neuropsychiatric disorders will be presented. Evidence from clinical and animal studies is provided for the participation of CB1 and CB2 receptors (CB1R and CB2R) in the above mentioned neuropsychiatric disorders. CBRs are crucial in some of the emotional and cognitive impairments reported, although more research is required to understand the specific role of the eCB system in neuropsychiatric disorders. Cannabidiol (CBD), the main non-psychotropic component of the Cannabis sativa plant, has shown therapeutic potential in several neuropsychiatric disorders. Although further studies are needed, recent studies indicate that CBD therapeutic effects may partially depend on facilitation of eCB-mediated neurotransmission. Last but not least, this review includes recent findings on the role of the eCB system in eating disorders. A deregulation of the eCB system has been proposed to be in the bases of several neuropsychiatric disorders, including eating disorders. Cannabis consumption has been related to the appearance of psychotic symptoms and schizophrenia. In contrast, the pharmacological manipulation of this eCB system has been proposed as a potential strategy for the treatment of anxiety disorders, depression, and anorexia nervosa. In conclusion, the eCB system plays a critical role in psychiatry; however, detrimental consequences of manipulating this endogenous system cannot be underestimated over the potential and promising perspectives of its therapeutic manipulation.

Obesity-dependent cannabinoid modulation of proliferation in adult neurogenic regions.

Endocannabinoid signalling participates in the control of neurogenesis, especially after brain insults. Obesity may explain alterations in physiology affecting neurogenesis, although it is unclear whether cannabinoid signalling may modulate neural proliferation in obese animals. Here we analyse the impact of obesity by using two approaches, a high-fat diet (HFD, 60% fat) and a standard/low-fat diet (STD, 10% fat), and the response to a subchronic treatment with the cannabinoid receptor type 1 (CB1) inverse agonist AM251 (3 mg/kg) on cell proliferation of two relevant neurogenic regions, namely the subventricular zone in the striatal wall of the lateral ventricle (SVZ) and the subgranular zone of the dentate gyrus (SGZ), and also in the hypothalamus given its role in energy metabolism. We found evidence of an interaction between diet-induced obesity and CB1 signalling in the regulation of cell proliferation. AM251 reduced caloric intake and body weight in obese rats, as well as corrected plasma levels of cholesterol and triglycerides. AM251 is shown, for the first time, to modulate cell proliferation in HFD-obese rats only. We observed an increase in the number of 5-bromo-2-deoxyuridine-labelled (BrdU+) cells in the SGZ, but a decrease in the number of BrdU+ cells in the SVZ and the hypothalamus of AM251-treated HFD rats. These BrdU+ cells expressed the neuron-specific ßIII-tubulin. These results suggest that obesity may impact cell proliferation in the brain selectively, and provide support for a role of CB1 signalling regulation of neurogenesis in response to obesity.

Estradiol decreases cortical reactive astrogliosis after brain injury by a mechanism involving cannabinoid receptors.

The neuroactive steroid estradiol reduces reactive astroglia after brain injury by mechanisms similar to those involved in the regulation of reactive gliosis by endocannabinoids. In this study, we have explored whether cannabinoid receptors are involved in the effects of estradiol on reactive astroglia. To test this hypothesis, the effects of estradiol, the cannabinoid CB1 antagonist/inverse agonist AM251, and the cannabinoid CB2 antagonist/inverse agonist AM630 were assessed in the cerebral cortex of male rats after a stab wound brain injury. Estradiol reduced the number of vimentin immunoreactive astrocytes and the number of glial fibrillary acidic protein immunoreactive astrocytes in the proximity of the wound. The effect of estradiol was significantly inhibited by the administration of either CB1 or CB2 receptor antagonists. The effect of estradiol may be in part mediated by alterations in endocannabinoid signaling because the hormone increased in the injured cerebral cortex the messenger RNA levels of CB2 receptors and of some of the enzymes involved in the synthesis and metabolism of endocannabinoids. These findings suggest that estradiol may decrease reactive astroglia in the injured brain by regulating the activity of the endocannabinoid system.