The Effect of Fat Intake with Increased Omega-6-to-Omega-3 Polyunsaturated Fatty Acid Ratio in Animal Models of Early and Late Alzheimer's Disease-like Pathogenesis.

This work aims to clarify the effect of dietary polyunsaturated fatty acid (PUFA) intake on the adult brain affected by amyloid pathology. McGill-R-Thy1-APP transgenic (Tg) rat and 5xFAD Tg mouse models that represent earlier or later disease stages were employed. The animals were exposed to a control diet (CD) or an HFD based on corn oil, from young (rats) or adult (mice) ages for 24 or 10 weeks, respectively. In rats and mice, the HFD impaired reference memory in wild-type (WT) animals but did not worsen it in Tg, did not cause obesity, and did not increase triglycerides or glucose levels. Conversely, the HFD promoted stronger microglial activation in Tg vs. WT rats but had no effect on cerebral amyloid deposition. IFN-γ, IL-1ß, and IL-6 plasma levels were increased in Tg rats, regardless of diet, while CXCL1 chemokine levels were increased in HFD-fed mice, regardless of genotype. Hippocampal 3-nitrotyrosine levels tended to increase in HFD-fed Tg rats but not in mice. Overall, an HFD with an elevated omega-6-to-omega-3 ratio as compared to the CD (25:1 vs. 8.4:1) did not aggravate the outcome of AD regardless of the stage of amyloid pathology, suggesting that many neurobiological processes relevant to AD are not directly dependent on PUFA intake.

Administration of Linoleoylethanolamide Reduced Weight Gain, Dyslipidemia, and Inflammation Associated with High-Fat-Diet-Induced Obesity.

Acylethanolamides (NAEs) are bioactive lipids derived from diet fatty acids that modulate important homeostatic functions, including appetite, fatty acid synthesis, mitochondrial respiration, inflammation, and nociception. Among the naturally circulating NAEs, the pharmacology of those derived from either arachidonic acid (Anandamide), oleic acid (OEA), and palmitic acid (PEA) have been extensively characterized in diet-induced obesity. For the present work, we extended those studies to linoleoylethanolamide (LEA), one of the most abundant NAEs found not only in plasma and body tissues but also in foods such as cereals. In our initial study, circulating concentrations of LEA were found to be elevated in overweight humans (body mass index (BMI, Kg/m2) > 25) recruited from a representative population from the south of Spain, together with AEA and the endocannabinoid 2-Arachidonoyl glycerol (2-AG). In this population, LEA concentrations correlated with the circulating levels of cholesterol and triglycerides. In order to gain insight into the pharmacology of LEA, we administered it for 14 days (10 mg/kg i.p. daily) to obese male Sprague Dawley rats receiving a cafeteria diet or a standard chow diet for 12 consecutive weeks. LEA treatment resulted in weight loss and a reduction in circulating triglycerides, cholesterol, and inflammatory markers such as Il-6 and Tnf-alpha. In addition, LEA reduced plasma transaminases and enhanced acetyl-CoA-oxidase (Acox) and Uncoupling protein-2 (Ucp2) expression in the liver of the HFD-fed animals. Although the liver steatosis induced by the HFD was not reversed by LEA, the overall data suggest that LEA contributes to the homeostatic signals set in place in response to diet-induced obesity, potentially contributing with OEA to improve lipid metabolism after high fat intake. The anti-inflammatory response associated with its administration suggests its potential for use as a nutrient supplement in non-alcoholic steatohepatitis.

Dietary administration of D-chiro-inositol attenuates sex-specific metabolic imbalances in the 5xFAD mouse model of Alzheimer's disease.

Increasing evidence shows that hypothalamic dysfunction, insulin resistance, and weight loss precede and progress along with the cognitive decline in sporadic Alzheimer's Disease (AD) with sex differences. This study aimed to determine the effect of oral dietary administration of D-Chiro-inositol (DCI), an inositol used against insulin resistance associated with polycystic ovary, on the occurrence of metabolic disorders in the transgenic 5xFAD mouse model of AD (FAD: Family Alzheimer's Disease). DCI was administered from 6 to 10 months of age to male and female 5xFAD mice and control (non-Tg) littermates. Energy balance and multiple metabolic and inflammatory parameters in the hypothalamus, liver and plasma were evaluated to assess the central and peripheral effects of DCI. Results indicated that weight loss and reduced food intake in 5xFAD mice were associated with decreased neuropeptides controlling food intake and the appearance of a pro-inflammatory state in the hypothalamus. Oral administration of DCI partially restored energy balance and hypothalamic parameters, highlighting an increased expression of Npy and Agrp and female-specific downregulation of Gfap and Igf1. DCI also partially normalized impaired insulin signaling and circulating insulin, GLP-1, and GIP deficiencies in 5xFAD mice. Principal component analysis of metabolic parameters indicated the presence of a female-specific fatty liver in 5xFAD mice: DCI administration reversed hepatic fat accumulation, ß-oxidation, inflammation and increased GOT and GPT levels. Our study depicts that metabolic impairment along with the cognitive decline in a mouse model of AD, which is exacerbated in females, can be ameliorated by oral supplementation with insulin-sensitizing DCI.

Palmitoleoylethanolamide Is an Efficient Anti-Obesity Endogenous Compound: Comparison with Oleylethanolamide in Diet-Induced Obesity.

Obesity is currently a major epidemic in the developed world. However, we lack a wide range of effective pharmacological treatments and therapies against obesity, and those approved are not devoid of adverse effects. Dietary components such as palmitoleic acid have been proposed to improve metabolic disbalance in obesity, although the mechanisms involved are not well understood. Both palmitoleic acid (POA) and oleic acid (OA) can be transformed in N-acylethanolamines (NAEs), mediating the effects of dietary POA and OA. To test this hypothesis, here, we study the effects on food intake and body weight gain of palmitoleylethanolamide (POEA) and the OA-derived NAE analogue, oleoylethanolamide (OEA), in Sprague-Dawley rats with a hypercaloric cafeteria diet (HFD). Plasma biochemical metabolites, inflammatory mediators, and lipogenesis-associated liver protein expression were also measured. The results indicate that POEA is able to improve health status in diet-induced obesity, decreasing weight, liver steatosis, inflammation, and dyslipemia. The action of POEA was found to be almost identical to that of OEA, which is an activator of the nuclear peroxisome proliferator receptor alpha (PPARα), and it is structurally related to POEA. These results suggest that the dietary administration of either POA or POEA might be considered as nutritional intervention as complementary treatment for complicated obesity in humans.

Analysis of Both Lipid Metabolism and Endocannabinoid Signaling Reveals a New Role for Hypothalamic Astrocytes in Maternal Caloric Restriction-Induced Perinatal Programming.

Maternal malnutrition in critical periods of development increases the risk of developing short- and long-term diseases in the offspring. The alterations induced by this nutritional programming in the hypothalamus of the offspring are of special relevance due to its role in energy homeostasis, especially in the endocannabinoid system (ECS), which is involved in metabolic functions. Since astrocytes are essential for neuronal energy efficiency and are implicated in brain endocannabinoid signaling, here we have used a rat model to investigate whether a moderate caloric restriction (R) spanning from two weeks prior to the start of gestation to its end induced changes in offspring hypothalamic (a) ECS, (b) lipid metabolism (LM) and/or (c) hypothalamic astrocytes. Monitorization was performed by analyzing both the gene and protein expression of proteins involved in LM and ECS signaling. Offspring born from caloric-restricted mothers presented hypothalamic alterations in both the main enzymes involved in LM and endocannabinoids synthesis/degradation. Furthermore, most of these changes were similar to those observed in hypothalamic offspring astrocytes in culture. In conclusion, a maternal low caloric intake altered LM and ECS in both the hypothalamus and its astrocytes, pointing to these glial cells as responsible for a large part of the alterations seen in the total hypothalamus and suggesting a high degree of involvement of astrocytes in nutritional programming.

Activation of PI3K/Akt Signaling Pathway in Rat Hypothalamus Induced by an Acute Oral Administration of D-Pinitol.

D-Pinitol (DPIN) is a natural occurring inositol capable of activating the insulin pathway in peripheral tissues, whereas this has not been thoroughly studied in the central nervous system. The present study assessed the potential regulatory effects of DPIN on the hypothalamic insulin signaling pathway. To this end we investigated the Phosphatidylinositol-3-kinase (PI3K)/Protein Kinase B (Akt) signaling cascade in a rat model following oral administration of DPIN. The PI3K/Akt-associated proteins were quantified by Western blot in terms of phosphorylation and total expression. Results indicate that the acute administration of DPIN induced time-dependent phosphorylation of PI3K/Akt and its related substrates within the hypothalamus, indicating an activation of the insulin signaling pathway. This profile is consistent with DPIN as an insulin sensitizer since we also found a decrease in the circulating concentration of this hormone. Overall, the present study shows the pharmacological action of DPIN in the hypothalamus through the PI3K/Akt pathway when giving in fasted animals. These findings suggest that DPIN might be a candidate to treat brain insulin-resistance associated disorders by activating insulin response beyond the insulin receptor.

A Negative Energy Balance Is Associated with Metabolic Dysfunctions in the Hypothalamus of a Humanized Preclinical Model of Alzheimer's Disease, the 5XFAD Mouse.

Increasing evidence links metabolic disorders with neurodegenerative processes including Alzheimer's disease (AD). Late AD is associated with amyloid (Aß) plaque accumulation, neuroinflammation, and central insulin resistance. Here, a humanized AD model, the 5xFAD mouse model, was used to further explore food intake, energy expenditure, neuroinflammation, and neuroendocrine signaling in the hypothalamus. Experiments were performed on 6-month-old male and female full transgenic (Tg5xFAD/5xFAD), heterozygous (Tg5xFAD/-), and non-transgenic (Non-Tg) littermates. Although histological analysis showed absence of Aß plaques in the hypothalamus of 5xFAD mice, this brain region displayed increased protein levels of GFAP and IBA1 in both Tg5xFAD/- and Tg5xFAD/5xFAD mice and increased expression of IL-1ß in Tg5xFAD/5xFAD mice, suggesting neuroinflammation. This condition was accompanied by decreased body weight, food intake, and energy expenditure in both Tg5xFAD/- and Tg5xFAD/5xFAD mice. Negative energy balance was associated with altered circulating levels of insulin, GLP-1, GIP, ghrelin, and resistin; decreased insulin and leptin hypothalamic signaling; dysregulation in main metabolic sensors (phosphorylated IRS1, STAT5, AMPK, mTOR, ERK2); and neuropeptides controlling energy balance (NPY, AgRP, orexin, MCH). These results suggest that glial activation and metabolic dysfunctions in the hypothalamus of a mouse model of AD likely result in negative energy balance, which may contribute to AD pathogenesis development.

Sex-specific Associations of Alcohol Withdrawal in Patients Admitted for the Treatment of Alcohol Use Disorder.

OBJECTIVES: There are sex differences in the pattern of alcohol consumption and in the complications of alcohol use disorder (AUD). We aimed to identify sex-specific differences in the factors associated with alcohol withdrawal syndrome (AWS) among patients that requested a first treatment for AUD. METHODS: We enrolled 313 patients (75% men) with a Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) AUD diagnosis that started treatment between 2014 and 2016. We collected socio-demographics, the type and amount of alcohol and other substances consumed, and clinical and laboratory parameters. According to Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) AUD criteria, AWS occurred when patients experienced 2 or more clinical signs/symptoms and/or consumed alcohol to relieve symptoms. Logistic regression models were used to determine factors associated with AWS according to sex. RESULTS: The median age of participants was 50 years (interquartile range [IQR]: 43-54 years). The median age of starting alcohol consumption was 16 years (IQR: 14-18 years). Notably, 69% of participants smoked tobacco, and 61% had a family history of AUD; 18% currently used cannabis, and 7.7% used cocaine. Overall, 73% of patients exhibited AWS criteria, and men (76.5%) were more likely than women (64.6%) to report AWS (P = 0.038). In the adjusted analysis, factors associated with AWS were the age at starting alcohol consumption (odds ratio [OR] for every 5 years = 1.89, 95% confidence interval [CI]: 1.69-2.08), and cannabis use (OR = 2.8, 95% CI: 1.04-7.7) in men, and a family history of AUD in women (OR = 2.85 95% CI: 1.07-7.54). CONCLUSIONS: factors associated with AWS differ by sex which may have clinical implications for proactive management of AWS during treatment for AUD.

Cerebellar and cortical TLR4 activation and behavioral impairments in Wernicke-Korsakoff Syndrome: Pharmacological effects of oleoylethanolamide.

Wernicke-Korsakoff Syndrome (WKS) is a neuropsychiatric disorder whose etiology is a thiamine deficiency (TD), with alcoholism being the main underlying cause. Previous evidence suggests the presence of initial neuroinflammation and oxidative/nitrosative stress in the physiopathology, although the specific molecular mechanisms underlying TD-induced brain damage and behavioral disabilities are unknown. We explored the specific role of the innate immune receptor TLR4 in three murine models of WKS, based on the combination of a thiamine-deficient diet and pyrithiamine injections (0.25 mg/kg, i.p.) over time. The Symptomatic Model (SM) allowed us to describe the complete neurological/neurobehavioral symptomatology over 16 days of TD. Animals showed an upregulation of the TLR4 signaling pathway both in the frontal cortex (FC) and cerebellum and clear motor impairments related with cerebellar dysfunction. However, in the Pre-Symptomatic Model (PSM), 12 days of TD induced the TLR4 pathway upregulation in the FC, which correlated with disinhibited-like behavior, but not in the cerebellum, and no motor impairments. In addition, we tested the effects of the biolipid oleoylethanolamide (OEA, 10 mg/kg, i.p., once daily, starting before any symptom of the pathology is manifested) through the Glucose-Precipitated Model (GPM), which was generated by glucose loading (5 g/kg, i.v., last day) in thiamine-deficient animals to accelerate damage. Pretreatment with OEA prevented the TLR4-induced signature in the FC, as well as an underlying incipient memory disability and disinhibited-like behavior. This study suggests a key role for TLR4 in TD-induced neuroinflammation in the FC and cerebellum, and it reveals different vulnerability of these brain regions in WKS over time. Pre-treatment with OEA counteracts TD-induced TLR4-associated neuroinflammation and may serve as co-adjuvant therapy to prevent WKS-induced neurobehavioral alterations.

DSM-5 in patients seeking their first treatment for alcohol use disorder. Sex differences in the multicenter CohRTA study. / DSM-5 en pacientes que solicitan el primer tratamiento del trastorno por uso de alcohol. Diferencias de sexo en el estudio multicéntrico CohRTA.

OBJECTIVE: We aimed to analyze sex differences in the DSM-5 criteria among patients admitted to  their first treatment of alcohol use disorder (AUD). METHODS: Assessment of AUD was carried out using DSM-5 diagnostic criteria in a multicenter study (CohRTA) within the Spanish Network on Addictive Disorders. Further, baseline questionnaires including socio-demographics, family history, lifetime alcohol consumption and other substance use, as well as clinical and laboratory parameters were obtained during admission. RESULTS: 313 patients (74.8%M) were eligible; mean age at first AUD treatment was 48.8 years (standard deviation (SD): 9.9 years). Age at onset of alcohol use was 15.9 years (SD: 3.3 years) and age at starting regular alcohol consumption was 25.6 years (SD: 9.6 years). Almost 69.3% of patients were tobacco smokers and 61% had family history of AUD. Regarding other substance use, 7.7% were current cocaine users and 18.2% were cannabis users. Women started regular alcohol consumption later than men (p<,001) and used benzodiazepines more frequently (p=.013). According to DSM-5, 89.5% of cases had severe AUD (≥6 criteria). In the adjusted analysis (logistic regression), men were more likely to neglect major rules (OR=1.92, 95%CI: 1.06-3.48) and to have hazardous alcohol use (OR=3.00, 95%CI: 1.65-5.46). DISCUSSION: DSM-5 detects sex differences in patients seeking their first AUD treatment. Social impairment and risky alcohol use are significantly more frequent in men.

Objetivo: Analizar las diferencias de sexo en los criterios diagnósticos del DSM-5 de los pacientes que solicitan un tratamiento para el trastorno por uso de alcohol (TUA) por primera vez. Métodos: Pacientes incluidos entre enero 2014 y marzo 2016 en el estudio multicéntrico CohRTA de la Red de Trastornos Adictivos. El diagnóstico del TUA se realizó mediante el DSM-5. Además, se recogieron datos sociodemográficos, sobre el consumo de alcohol y otras sustancias, variables clínicas y una analítica general. Resultados: se incluyeron 313 pacientes (74,8% hombres); la edad al inicio del primer tratamiento fue de 48,8 años (desviación estándar (DE): 9,9 años), la edad al inicio del consumo de alcohol de 15,9 años (DE: 3,3 años) y la de inicio del consumo regular de 25,6 años (DE: 9,6 años). Un 69,3% de los pacientes eran fumadores y un 61% tenían antecedentes familiares de TUA. Un 7,7% eran consumidores de cocaína y un 18,2% de cannabis. Las mujeres iniciaron el consumo regular de alcohol más tarde que los hombres (p<,001) y usaban benzodiacepinas con mayor frecuencia (p=,013). Según el DSM-5, el 89,5% de los pacientes presentaban un TUA grave (≥6 criterios). En el análisis ajustado (regresión logística), los hombres tenían mayor probabilidad de presentar el criterio diagnóstico relacionado con el incumplimiento de los deberes fundamentales en el trabajo o en el hogar (OR=1,92, IC95%: 1,06-3,48) y el criterio diagnóstico de consumir alcohol en situaciones de riesgo físico (OR=3,00, IC95%: 1,65-5,46). Discusión: El DSM-5 detecta diferencias de sexo en pacientes que solicitan el primer tratamiento del TUA. El deterioro social y el consumo de alcohol de riesgo son significativamente más frecuentes en hombres.

Sex-Dimorphic Behavioral Alterations and Altered Neurogenesis in U12 Intron Splicing-Defective Zrsr1 Mutant Mice.

Mutant mice with respect to the splicing factor Zrsr1 present altered spermatogenesis and infertility. To investigate whether Zrsr1 is involved in the homeostatic control that the hypothalamus exerts over reproductive functions, we first analyzed both differential gene and isoform expression and alternative splicing alterations in Zrsr1 mutant (Zrsr1mu) hypothalamus; second, we analyzed the spontaneous and social behavior of Zrsr1mu mice; and third, we analyzed adult cell proliferation and survival in the Zrsr1mu hypothalamus. The Zrsr1mu hypothalamus showed altered expression of genes and isoforms related to the glutathione metabolic process, synaptonemal complex assembly, mRNA transport, and altered splicing events involving the enrichment of U12-type intron retention (IR). Furthermore, increased IR in U12-containing genes related with the prolactin, progesterone, and gonadotropin-releasing hormone (GnRH) reproductive signaling pathway was observed. This was associated with a hyperactive phenotype in both males and females, with an anxious phenotype in females, and with increased social interaction in males, instead of the classical aggressive behavior. In addition, Zrsr1mu females but not males exhibited reduced cell proliferation in both the hypothalamus and the subventricular zone. Overall, these results suggest that Zrsr1 expression and function are relevant to organization of the hypothalamic cell network controlling behavior.

Perinatal free-choice of a high-calorie low-protein diet affects leptin signaling through IRS1 and AMPK dephosphorylation in the hypothalami of female rat offspring in adulthood.

AIM: We aimed to investigate whether a dysregulated maternal diet during gestation and lactation induces long-lasting changes in the hypothalamic control of feeding behavior in the offspring and whether this effect is sex specific. METHODS: The study included an analysis of appetite-regulating metabolic hormones and hypothalamic signaling in male and female offspring in adulthood after exposure to a free-choice high-calorie palatable low-protein (P) diet or standard chow (C) during (pre)gestation/lactation (maternal) and/or postweaning (offspring). RESULTS: Maternal exposure to the P diet resulted in decreased protein intake and body weight gain in dams and decreased body weight gain in offspring during lactation. The maternal P diet (PC) specifically increased feed efficacy and decreased body weight and cholesterol levels in the female offspring in adulthood, but no changes in adiposity or leptin levels were found. In contrast, P diet exposure after weaning (CP and PP) increased caloric intake, adiposity and circulating levels of leptin in the male and female offspring in adulthood. The hypothalami of the female offspring exposed to the maternal P diet (PC and PP) expressed high levels of the phospho-leptin receptor and low levels of SOCS3, phospho-IRS1 and phospho-AMPK, regardless of the postweaning diet. The hypothalami of the female rats in the PC group also showed increased levels of STAT3 and the orexigenic neuropeptide Agrp. CONCLUSIONS: Maternal exposure to a free-choice high-calorie low-protein diet induces a long-term feed efficacy associated with changes in leptin signaling through IRS-1 and AMPK dephosphorylation in the hypothalami of female offspring in adulthood.

The adiponectin promoter activator NP-1 induces high levels of circulating TNFα and weight loss in obese (fa/fa) Zucker rats.

Chronic NP-1 administration reduces body weight and hepatic steatosis despite induction of tolerance in adiponectin gene transcription with respect to the acute actions of this drug. This study explored the hypothesis that NP-1 could exert these effects through mechanisms independent of adiponectin. To this aim, we took advantage of the Zucker (fa/fa) rat model, which exhibits obesity, fatty liver and elevated leptin and adiponectin levels. Body weight and food intake were reduced after chronic NP-1 treatment. Plasma TNFα concentrations were elevated but no increase in adiponectin was found. Even so, NP-1 ameliorated fatty liver and corrected dyslipidemia by mechanisms probably associated with reduced feeding, transcription of Cpt1 and down-regulation of Hmgcr-CoA expression. In brown fat tissue NP-1 increased Dnmt1 (inhibitor of Adipoq) while it reduced Ucp1 expression and heat production, which excludes thermogenesis as a mechanism of the NP-1 slimming effect. The anti-obesity action of chronic NP-1 administration might be mediated by TNFα, which is known to have anorectic actions in the hypothalamus and to regulate both Dmnt1 and Ucp1 expression in adipose tissues. This finding opens up the possibility of using NP-1-mediated TNFα-induced weight loss as an innovative treatment of complicated obesity under strict pharmacologic control.

A moderate diet restriction during pregnancy alters the levels of endocannabinoids and endocannabinoid-related lipids in the hypothalamus, hippocampus and olfactory bulb of rat offspring in a sex-specific manner.

Undernutrition during pregnancy has been associated to increased vulnerability to develop metabolic and behavior alterations later in life. The endocannabinoid system might play an important role in these processes. Therefore, we investigated the effects of a moderate maternal calorie-restricted diet on the levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), arachidonic acid (AA) and the N-acylethanolamines (NAEs) anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the brain of newborn rat offspring. We focused on brain structures involved in metabolism, feeding behavior, as well as emotional and cognitive responses. Female Wistar rats were assigned during the entire pregnancy to either control diet (C) or restriction diet (R), consisting of a 20% calorie-restricted diet. Weight gain and caloric intake of rat dams were monitored and birth outcomes were assessed. 2-AG, AA and NAE levels were measured in hypothalamus, hippocampus and olfactory bulb of the offspring. R dams displayed lower gain weight from the middle pregnancy and consumed less calories during the entire pregnancy. Offspring from R dams were underweight at birth, but litter size was unaffected. In hypothalamus, R male offspring displayed decreased levels of AA and OEA, with no change in the levels of the endocannabinoids 2-AG and AEA. R female exhibited decreased 2-AG and PEA levels. The opposite was found in the hippocampus, where R male displayed increased 2-AG and AA levels, and R female exhibited elevated levels of AEA, AA and PEA. In the olfactory bulb, only R female presented decreased levels of AEA, AA and PEA. Therefore, a moderate diet restriction during the entire pregnancy alters differentially the endocannabinoids and/or endocannabinoid-related lipids in hypothalamus and hippocampus of the underweight offspring, similarly in both sexes, whereas sex-specific alterations occur in the olfactory bulb. Consequently, endocannabinoid and endocannabinoid-related lipid signaling alterations might be involved in the long-term and sexual dimorphism effects commonly observed after undernutrition and low birth weight.

Antiobesity efficacy of GLP-1 receptor agonist liraglutide is associated with peripheral tissue-specific modulation of lipid metabolic regulators.

To investigate the role of glucagon-like-peptide-1 receptor (GLP-1R) in peripheral lipid metabolism. Both lean and high-fat diet (HFD)-induced obesity (DIO) rats were used to compare the peripheral effects of the subcutaneous and repeated administration of the GLP-1R agonist liraglutide on the expression of key regulators involved in lipid metabolism, ß-oxidation and thermogenesis in liver, abdominal muscle, and epididymal white adipose tissue (eWAT). We observed that liraglutide reduced caloric intake, body weight, and plasma levels of triglycerides and VLDL in a diet-independent manner. However, changes in liver fat content and the expression of lipid metabolism regulators were produced in a diet and tissue-dependent manner. In lean rats, liraglutide increased the gene/protein expression of elements involved in lipogenesis (ChREBP, Acaca/ACC, Fasn/FAS, Scd1/SCD1, PPARα/γ), ß-oxidation (CPT1b), and thermogenesis (Cox4i1, Ucp1/UCP1) in eWAT and muscle, which suggest an increase in fatty-acid flux and utilization to activate energy expenditure. Regarding DIO rats, the specific reduction of liver lipid content by liraglutide was associated with a decreased expression of main elements involved in lipogenesis (phospho-ACC), peroxisomal ß-oxidation (ACOX1), and lipid flux/storage (Pparγ/PPARγ) in liver, which suggest a recovery of lipid homeostasis. Interestingly, the muscle of DIO rats treated with liraglutide showed a decreased expression of PPARγ and the thermogenic factor UCP1. These results help us to better understand the peripheral mechanisms regulating lipid metabolism that underlay the effectiveness of GLP-1 analogues for the treatment of diabetes and obesity. © 2016 BioFactors, 42(6):600-611, 2016.

Mediterranean diet and the Spanish paradox. A hypothesis.

The Spanish paradox is a phenomenon observed in Spain and some other Mediterranean countries by which the cardiovascular morbidity and mortality levels are dissociated from their cardiovascular risk factors. The Mediterranean diet has been proposed as the main reason for this dissociation, but dietary changes themselves are not enough to explain this situation. It has been recently discovered that Stearoil-CoA desaturase (SCD) is involved in the dissociation between a favourable atherogenic metabolic profile and the risk for arteriosclerosis. We propose a hypothesis that attempts to clarify the Spanish paradox. This hypothesis contemplates the essential role of dietary olive oil and its interaction with different SCD genetic patterns. Confirmation of this hypothesis could provide the basis for the design of clinical and preventive strategies against cardiovascular morbidity and mortality, as well as certain metabolic risk factors.

Maternal deprivation has sexually dimorphic long-term effects on hypothalamic cell-turnover, body weight and circulating hormone levels.

Maternal deprivation (MD) has numerous outcomes, including modulation of neuroendocrine functions. We previously reported that circulating leptin levels are reduced and hypothalamic cell-turnover is affected during MD, with some of these effects being sexually dimorphic. As leptin modulates the development of hypothalamic circuits involved in metabolic control, we asked whether MD has long-term consequences on body weight, leptin levels and the expression of neuropeptides involved in metabolism. Rats were separated from their mother for 24h starting on postnatal day (PND) 9 and sacrificed at PNDs 13, 35 and 75. In both sexes MD reduced body weight, but only until puberty, while leptin levels were unchanged at PND 35 and significantly reduced at PND 75. Adiponectin levels were also reduced at PND 75 in females, while testosterone levels were reduced in males. At PND 13, MD modulated cell-turnover markers in the hypothalamus of males, but not females and increased nestin, a marker of immature neurons, in both sexes, with males having higher levels than females and a significantly greater rise in response to MD. There was no effect of MD on hypothalamic mRNA levels of the leptin receptor or metabolic neuropeptides or the mRNA levels of leptin and adiponectin in adipose tissue. Thus, MD has long-term effects on the levels of circulating hormones that are not correlated with changes in body weight. Furthermore, these endocrine outcomes are different between males and females, which could be due to the fact that MD may have sexually dimorphic effects on hypothalamic development.

Implication of the endocannabinoid system in the locomotor hyperactivity associated with congenital hypothyroidism.

Alterations in motor functions are well-characterized features observed in humans and experimental animals subjected to thyroid hormone dysfunctions during development. Here we show that congenitally hypothyroid rats display hyperactivity in the adult life. This phenotype was associated with a decreased content of cannabinoid receptor type 1 (CB(1)) mRNA in the striatum and a reduction in the number of binding sites in both striatum and projection areas. These findings suggest that hyperactivity may be the consequence of a thyroid hormone deficiency-induced removal of the endocannabinoid tone, normally acting as a brake for hyperactivity at the basal ganglia. In agreement with the decrease in CB(1) receptor gene expression, a lower cannabinoid response, measured by biochemical, genetic and behavioral parameters, was observed in the hypothyroid animals. Finally, both CB(1) receptor gene expression and the biochemical and behavioral dysfunctions found in the hypothyroid animals were improved after a thyroid hormone replacement treatment. Thus, the present study suggests that impairment in the endocannabinoid system can underlay the hyperactive phenotype associated with hypothyroidism.

Antiobesity effects of the novel in vivo neutral cannabinoid receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-hexyl-1H-1,2,4-triazole--LH 21.

The present study evaluates the pharmacological profile of the new neutral cannabinoid CB1 receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-hexyl-1H-1,2,4-triazole -LH-21- on feeding behavior and alcohol self-administration in rats, two behaviors inhibited by cannabinoid CB1 receptor antagonists. Administration of LH-21 (0.03, 0.3 and 3 mg/kg) to food-deprived rats resulted in a dose-dependent inhibition of feeding. Subchronic administration of LH-21 reduced food intake and body weight gain in obese Zucker rats. Acute effects on feeding were not associated with anxiety-like behaviors, or induction of complex motor behaviors such as grooming or scratching sequences, usually observed after central administration of cannabinoid receptor blockers with inverse agonist properties. LH-21 did not markedly reduce alcohol self-administration (30% reduction observed only at a high dose of 10 mg/kg). This pharmacological pattern partially overlaps that of the reference cannabinoid CB1 receptor antagonist N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide, SR141716A, (0.3, 1 and 3 mg/kg) that reduced feeding and alcohol self-administration with similar efficacy. In vitro analysis of blood-brain barrier permeability using a parallel artificial membrane permeation assay demonstrated that LH-21 has lower permeation through membranes than SR141716A. That was confirmed in vivo by studies showing lower potency of peripherally injected LH-21 when compared to SR141716A to antagonize motor depression induced by intracerebroventricular administration of the CB1 agonist CP55,940. The neutral antagonist profile and the lower penetration into the brain of LH-21 favour this class of antagonists with respect to reference inverse agonists for the treatment of obesity because they potentially will display reduced side effects.