Defective mitochondria and aberrant brain mitochondrial bioenergetics are consistent features in syndromic intellectual disability disorders, such as Rett syndrome (RTT), a rare neurologic disorder that severely affects mainly females carrying mutations in the X-linked MECP2 gene. A pool of CB1 cannabinoid receptors (CB1R), the primary receptor subtype of the endocannabinoid system in the brain, is located on brain mitochondrial membranes (mtCB1R), where it can locally regulate energy production, synaptic transmission and memory abilities through the inhibition of the intra-mitochondrial protein kinase A (mtPKA). In the present study, we asked whether an overactive mtCB1R-mtPKA signaling might underlie the brain mitochondrial alterations in RTT and whether its modulation by systemic administration of the CB1R inverse agonist rimonabant might improve bioenergetics and cognitive defects in mice modeling RTT. Rimonabant (0.3 mg/kg/day, intraperitoneal injections) was administered daily to symptomatic female mice carrying a truncating mutation of the Mecp2 gene and its effects on brain mitochondria functionality, systemic oxidative status, and memory function were assessed. mtCB1R is overexpressed in the RTT mouse brain. Subchronic treatment with rimonabant normalizes mtCB1R expression in RTT mouse brains, boosts mtPKA signaling, and restores the defective brain mitochondrial bioenergetics, abnormal peripheral redox homeostasis, and impaired cognitive abilities in RTT mice. The lack of selectivity of the rimonabant treatment towards mtCB1R does not allow us to exclude that the beneficial effects exerted by the treatment in the RTT mouse model may be ascribed more broadly to the modulation of CB1R activity and distribution among intracellular compartments, rather than to a selective effect on mtCB1R-mediated signaling. The low sample size of few experiments is a further limitation that has been addressed replicating the main findings under different experimental conditions. The present data identify mtCB1R overexpression as a novel molecular alteration in the RTT mouse brain that may underlie defective brain mitochondrial bioenergetics and cognitive dysfunction.
A cutaneous mast cell tumor (cMCT) is among the most common tumors in dogs. Endocannabinoids (eCBs) belong to the endocannabinoid system (ECS), which involves also cannabinoid receptors and an enzymatic system of biosynthesis and degradation. In this study, plasma levels of N-arachidonoylethanolamine (AEA), 2-arachidonoylglycerol (2-AG), N-palmitoylethanolamine (PEA), and N-oleoylethanolamine (OEA) were evaluated in 17 dogs with MCTs of varying histological grades and clinical stages, as well as in a control group of 11 dogs. Dogs affected by cMCT had higher plasma levels of 2-AG (p = 0.0001) and lower levels of AEA (p = 0.0012) and PEA (p = 0.0075) compared to the control group, while no differences were observed at the OEA level between healthy and cMCT dogs (p = 0.9264). The ability of eCBs to help discriminate between healthy and cMCT dogs was interrogated through the area under the ROC curve (AUC). An accuracy of 0.98 (95% confidence interval [CI], 0.94–1.02) was found for 2-AG, of 0.85 (95% CI, 0.71–0.99) for AEA, and of 0.81% for PEA (95% CI, 0.64–0.69). Values > 52.75 pmol/mL for 2-AG showed 94% sensitivity and 90% specificity in distinguishing cMCT. This is the first study to demonstrate alterations in plasmatic levels of eCBs in dogs affected by MCTs, suggesting the significance of these biomarkers in the tumorigenic process and their potential use as biomarkers in the future.
The ability of endocannabinoid (eCB) to change functional microglial phenotype can be explored as a possible target for therapeutic intervention. Since the inhibition of fatty acid amide hydrolase (FAAH), the main catabolic enzyme of anandamide (AEA), may provide beneficial effects in mice model of Alzheimer’s disease (AD)-like pathology, we aimed at determining whether the FAAH inhibitor URB597 might target microglia polarization and alter the cytoskeleton reorganization induced by the amyloid-β peptide (Aβ). The morphological evaluation showed that Aβ treatment increased the surface area of BV-2 cells, which acquired a flat and polygonal morphology. URB597 treatment partially rescued the control phenotype of BV-2 cells when co-incubated with Aβ. Moreover, URB597 reduced both the increase of Rho protein activation in Aβ-treated BV-2 cells and the Aβ-induced migration of BV-2 cells, while an increase of Cdc42 protein activation was observed in all samples. URB597 also increased the number of BV-2 cells involved in phagocytosis. URB597 treatment induced the polarization of microglial cells towards an anti-inflammatory phenotype, as demonstrated by the decreased expression of iNOS and pro-inflammatory cytokines along with the parallel increase of Arg-1 and anti-inflammatory cytokines. Taken together, these data suggest that FAAH inhibition promotes cytoskeleton reorganization, regulates phagocytosis and cell migration processes, thus driving microglial polarization towards an anti-inflammatory phenotype.
In this study, a novel approach was developed to quantify endocannabinoids (eCBs), and was based on the liquid biosensor BIONOTE. This device is composed of a probe that can be immersed in a solution, and an electronic interface that can record a current related to the oxy-reductive reactions occurring in the sample. The two most representative members of eCBs have been analysed in vitro by BIONOTE: anandamide (N-arachidonoylethanolamine, AEA) and 2-arachidonoylglycerol (2-AG). Bovine serum albumin was used to functionalize the probe and improve the sensibility of the whole analytical system. We show that BIONOTE is able to detect both AEA and 2-AG at concentrations in the low nanomolar range, and to discriminate between these eCBs and their moieties arachidonic acid, ethanolamine and glycerol. Notably, BIONOTE distinguished these five different molecules, and it was also able to quantify AEA in human plasma. Although this is just a proof-of-concept study, we suggest BIONOTE as a cheap and user-friendly prototype sensor for high throughput quantitation of eCB content in biological matrices, with an apparent diagnostic potential for tomorrow's medicine.
Chronic enteropathies (CEs) in dogs, according to the treatment response to consecutive trials, are classified as food-responsive (FRE), antibiotic-responsive (ARE), and immunosuppressive-responsive (IRE) enteropathy. In addition to this classification, dogs with loss of protein across the gut are grouped as protein-losing enteropathy (PLE). At present, the diagnosis of CEs is time-consuming, costly and sometimes invasive, also because non-invasive biomarkers with high sensitivity and specificity are not yet available. Therefore, this study aimed at assessing the levels of circulating endocannabinoids in plasma as potential diagnostic markers of canine CEs. Thirty-three dogs with primary chronic gastrointestinal signs presented to Veterinary Teaching Hospitals of Teramo and Bologna (Italy) were prospectively enrolled in the study, and 30 healthy dogs were included as a control group. Plasma levels of N-arachidonoylethanolamine (AEA), 2-arachidonoylglycerol (2-AG), N-palmitoylethanolamine (PEA), and N-oleoylethanolamine (OEA) were measured at the time of the first visit in dogs with different CEs, as well as in healthy subjects. Plasma levels of 2-AG (p = 0.001) and PEA (p = 0.008) were increased in canine CEs compared to healthy dogs. In particular, PEA levels were increased in the FRE group compared to healthy dogs (p = 0.04), while 2-AG was higher in IRE than in healthy dogs (p = 0.0001). Dogs affected by FRE also showed decreased 2-AG (p = 0.0001) and increased OEA levels (p = 0.0018) compared to IRE dogs. Moreover, dogs with PLE showed increased 2-AG (p = 0.033) and decreased AEA (p = 0.035), OEA (p = 0.016) and PEA (p = 0.023) levels, when compared to dogs affected by CEs without loss of proteins. The areas under ROC curves for circulating 2-AG (0.91; 95% confidence interval [CI], 0.79–1.03) and OEA (0.81; 95% CI, 0.65–0.97) showed a good accuracy in distinguishing the different forms of CEs under study (FRE, ARE and IRE), at the time of the first visit. The present study demonstrated that endocannabinoid signaling is altered in canine CEs, and that CE subtypes showed distinct profiles of 2-AG, PEA and OEA plasma levels, suggesting that these circulating bioactive lipids might have the potential to become candidate biomarkers for canine CEs.
Alzheimer's disease (AD) is a neurodegenerative disease that progresses from mild cognitive impairment to severe dementia over time. The main clinical hallmarks of the disease (e.g., beta-amyloid plaques and neurofibrillary tangles) begin during preclinical AD when cognitive deficits are not yet apparent. Hence, a more profound understanding of AD pathogenesis is needed to develop new therapeutic strategies. In this context, the endocannabinoid (eCB) system and the gut microbiome are increasingly emerging as important players in maintaining the general homeostasis and the health status of the host. However, their interaction has come to light just recently with gut microbiota regulating the eCB tone at both receptor and enzyme levels in intestinal and adipose tissues. Importantly, eCB system and gut microbiome, have been suggested to play a role in AD in both animal and human studies. Therefore, the microbiome gut-brain axis and the eCB system are potential common denominators in the AD physiopathology. Hence, the aim of this review is to provide a general overview on the role of both the eCB system and the microbiome gut-brain axis in AD and to suggest possible mechanisms that underlie the potential interplay of these two systems.
Increased circulating sclerostin and accumulation of advanced glycation end‐products (AGEs) are two potential mechanisms underlying low bone turnover and increased fracture risk in type 2 diabetes (T2D). Whether the expression of the sclerostin‐encoding SOST gene is altered in T2D, and whether it is associated with AGEs accumulation or regulation of other bone formation‐related genes is unknown. We hypothesized that AGEs accumulate and SOST gene expression is upregulated in bones from subjects with T2D, leading to downregulation of bone forming genes (RUNX2 and osteocalcin) and impaired bone microarchitecture and strength. We obtained bone tissue from femoral heads of 19 T2D postmenopausal women (mean glycated hemoglobin [HbA1c] 6.5%) and 73 age‐ and BMI‐comparable nondiabetic women undergoing hip replacement surgery. Despite similar bone mineral density (BMD) and biomechanical properties, we found a significantly higher SOST (p = .006) and a parallel lower RUNX2 (p = .025) expression in T2D compared with non‐diabetic subjects. Osteocalcin gene expression did not differ between T2D and non‐diabetic subjects, as well as circulating osteocalcin and sclerostin levels. We found a 1.5‐fold increase in total bone AGEs content in T2D compared with non‐diabetic women (364.8 ± 78.2 versus 209.9 ± 34.4 μg quinine/g collagen, respectively; p < .001). AGEs bone content correlated with worse bone microarchitecture, including lower volumetric BMD (r = −0.633; p = .02), BV/TV (r = −0.59; p = .033) and increased trabecular separation/spacing (r = 0.624; p = .023). In conclusion, our data show that even in patients with good glycemic control, T2D affects the expression of genes controlling bone formation (SOST and RUNX2). We also found that accumulation of AGEs is associated with impaired bone microarchitecture. We provide novel insights that may help understand the mechanisms underlying bone fragility in T2D. © 2020 American Society for Bone and Mineral Research (ASBMR).
Although the primordial concept of lipids is associated with the role they play as key components of the cell membrane, growing research in the field of bioactive lipids and lipidomic technologies proves the prominent role of these molecules in other biological functions [...].
There is robust evidence indicating that enhancing the endocannabinoid (eCB) tone has therapeutic potential in several brain disorders. The inhibition of eCBs degradation by fatty acid amide hydrolase (FAAH) blockade, is the best-known option to increase N-acyl-ethanolamines-(NAEs)-mediated signaling. Here, we investigated the hypothesis that intranasal delivery is an effective route for different FAAH inhibitors, such as URB597 and PF-04457845. URB597 and PF-04457845 were subchronically administered in C57BL/6 male mice every other day for 20 days for overall 10 drug treatment, and compared for their ability to inhibit FAAH activity by the way of three different routes of administration: intranasal (i.n.), intraperitoneal (i.p.) and oral (p.o.). Lastly, we compared the efficacy of the three routes in terms of URB597-induced increase of NAEs levels in liver and in different brain areas. Results: We show that PF-04457845 potently inhibits FAAH regardless the route selected, and that URB597 was less effective in the brain after p.o. administration while reached similar effects by i.n. and i.p. routes. Intranasal URB597 delivery always increased NAEs levels in brain areas, whereas a parallel increase was not observed in the liver. By showing the efficacy of intranasal FAAH inhibition, we provide evidence that nose-to-brain delivery is a suitable alternative to enhance brain eCB tone for the treatment of neurodegenerative disorders and improve patients’ compliance.
In the present work, mice overexpressing mutant amyloid precursor protein (Tg2576), a transgenic model of Alzheimer's disease (AD), are used to investigate a specific lipid profile over the course of disease progression. Using a targeted lipidomic approach, plasma levels of N‐acylethanolamines with different length and unsaturation at presymptomatic, mild‐symptomatic, and symptomatic disease stages are measured. Moreover, N‐acylethanolamines are also assessed in the brain areas most affected in AD. The ethanolamides of palmitic, oleic, arachidonic, eicosapentaenoic, and docosahexaenoic acids do not show any significant alteration in blood of Tg2576 mice at the different stages analyzed, as compared to wild‐type. Except for N‐docosahexaenoylethanolamine, a general tendency to decrease is instead detected for all measured N‐acylethanolamines in the cortex, hippocampus, striatum, and cerebellum of symptomatic Tg2576 mice. Together, the data can help to redefine the range of lipid‐associated signals in Alzheimer pathophysiology.Practical Application: The development of novel therapies for AD is strongly narrowed not only by the lack of a full comprehension of underlying pathophysiological mechanisms but also by the absence of affordable, reliable, and noninvasive biomarkers. Hence, there is the practical necessity to acquire accessible blood biomarkers to provide rapid, cost‐effective, and critical information to timely identify disease stage and implement preventive strategies aimed at slowing down cognitive decline. In this study, a targeted lipidomics investigation of N‐acylethanolamines at different stages of disease progression, clearly indicates that the discovery of innovative blood biomarkers should be refocused on different indices of deranged lipid metabolism for a realistic prediction of the risk of AD.It is investigated that potential alterations of N‐acylethanolamines content during disease development in a transgenic mouse model of Alzheimer's disease (AD). Circulating and central N‐acylethanolamine levels did not show any alteration in Tg2576 mice at different disease stages.
Fragility fractures are major complications in type 2 diabetes (T2D), but mechanisms underlying bone fragility are still poorly clarified. Bone mineral density (BMD) underestimates T2D fracture incidence, since a normal or even higher BMD is associated with a greater fracture risk than healthy population. We hypothesized that bone fragility in T2D results from poor bone microarchitecture and bone quality caused by WNT signaling impairment and lower bone formation. We aimed to evaluate the association between bone gene expression of WNT pathway and features of bone microarchitecture and strength. We enrolled T2D (n=13) and nondiabetic (controls, n=75) postmenopausal women undergoing standard hip arthroplasty. Serum and proximal femur samples from recruited subjects were collected at the moment of surgical procedure. Gene expression of sclerostin (SOST), WNT5a, WNT10b, SFRP5, GSK3β, osteocalcin and RUNX2 was analyzed by real-time PCR. Total-body, lumbar and femoral BMD were assessed by bone densitometry. A trabecular core from bone samples was analyzed by Micro X-ray computed tomography and by compression tests. Age (75.23 ± 8.47 vs. 73.24 ± 5.77) and BMI (29.92 ± 5.38 vs. 27.68 ± 5.62 Kg/m2) did not differ between T2D and controls respectively. Glycated hemoglobin was 6.48 ± 1.7 mmol/mol. We found that T2D subjects had no differences in BMD and in bone microarchitecture parameters compared to controls. Neither bone turnover nor WNT serum markers differed among groups. SOST gene expression was increased (p=0.003) whereas RUNX2 expression was decreased in T2D vs. controls (p=0.017), independently by BMI and age. Osteocalcin and other WNT related genes expression did not differ among groups. Compression tests did not show impairment in bone strength in T2D vs. controls. In conclusion, although a good glycemic control and no alterations in bone density, microarchitecture and strength, we found an increase in SOST and a decrease in RUNX2 gene expression, implying a lower bone formation in T2D. Disclosure A. Piccoli: None. F. Cannata: None. F. Russo: None. V.L. Greto: None. C. Isgrò: None. G. Leanza: None. R. Strollo: None. C. Massaroni: None. C. Pedone: None. S. Silvestri: None. G. Vadalà: None. V. Denaro: None. T. Bisogno: None. R. Papalia: None. P. Pozzilli: None. M. Maccarrone: None. N. Napoli: None. Funding Campus Bio-Medico University
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OBJECTIVE Despite the growing knowledge on the functional relationship between an altered endocannabinoid (eCB) system and development of anorexia nervosa (AN), to date no studies have investigated the central eCB tone in the activity-based anorexia (ABA) model that reproduces key aspects of human AN. METHOD We measured levels of two major eCBs, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), those of two eCB-related lipids, oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), and the cannabinoid type-1 receptor (CB1R) density in the brain of female ABA rats, focusing on areas involved in homeostatic and rewarding-related regulation of feeding behavior (i.e., prefrontal cortex, nucleus accumbens, caudato putamen, amygdala, hippocampus and hypothalamus). Analysis was carried out also at the end of recovery from the ABA condition. RESULTS At the end of the ABA induction phase, 2-AG was significantly decreased in ABA rats in different brain areas but not in the caudato putamen. No changes were detected in AEA levels in any region, whereas the levels of OEA and PEA were decreased exclusively in the hippocampus and hypothalamus. Furthermore, CB1R density was decreased in the dentate gyrus of hippocampus and in the lateral hypothalamus. After recovery, both 2-AG levels and CB1R density were partially normalized in some areas. In contrast, AEA levels became markedly reduced in all the analyzed areas. DISCUSSION These data demonstrate an altered brain eCB tone in ABA rats, further supporting the involvement of an impaired eCB system in AN pathophysiology that may contribute to the maintenance of some symptomatic aspects of the disease.
Anecdotal evidence that cannabis preparations have medical benefits together with the discovery of the psychotropic plant cannabinoid Δ 9 -tetrahydrocannabinol (THC) initiated efforts to develop cannabinoid-based therapeutics. These efforts have been marked by disappointment, especially in relation to the unwanted central effects that result from activation of cannabinoid receptor 1 (CB1), which have limited the therapeutic use of drugs that activate or inactivate this receptor. The discovery of CB2 and of endogenous cannabinoid receptor ligands (endocannabinoids) raised new possibilities for safe targeting of this endocannabinoid system. However, clinical success has been limited, complicated by the discovery of an expanded endocannabinoid system — known as the endocannabinoidome — that includes several mediators that are biochemically related to the endocannabinoids, and their receptors and metabolic enzymes. The approvals of nabiximols, a mixture of THC and the non-psychotropic cannabinoid cannabidiol, for the treatment of spasticity and neuropathic pain in multiple sclerosis, and of purified botanical cannabidiol for the treatment of otherwise untreatable forms of paediatric epilepsy, have brought the therapeutic use of cannabinoids and endocannabinoids in neurological diseases into the limelight. In this Review, we provide an overview of the endocannabinoid system and the endocannabinoidome before discussing their involvement in and clinical relevance to a variety of neurological disorders, including Parkinson disease, Alzheimer disease, Huntington disease, multiple sclerosis, amyotrophic lateral sclerosis, traumatic brain injury, stroke, epilepsy and glioblastoma.
The lipid signal is becoming increasingly crowded as increasingly fatty acid amide derivatives are being identified and considered relevant therapeutic targets. The identification of N-arachidonoyl-ethanolamine as endogenous ligand of cannabinoid type-1 and type-2 receptors as well as the development of different-omics technologies have the merit to have led to the discovery of a huge number of naturally occurring N-acyl-amines. Among those mediators, N-acyl amino acids, chemically related to the endocannabinoids and belonging to the complex lipid signaling system now known as endocannabinoidome, have been rapidly growing for their therapeutic potential. Here, we review the current knowledge of the mechanisms for the biosynthesis and inactivation of the N-acyl amino acids, as well as the various molecular targets for some of the N-acyl amino acids described so far.
Growing evidence suggests that endocannabinoid levels are modulated during pathological conditions affecting both central and peripheral nervous system. In the present study, a novel approach (patent pending) based on an innovative liquid biosensor has been used to analyze two relevant endocannabinoid molecules with calibration purposes: N-arachidonoylethanolamine and 2-arachidonoylglycerol. The system was able to predict both compound concentrations with a Root Mean Square Error in Cross Validation (RMSECV) of 6.61 nM and 23.50 nM, respectively.
SIGNIFICANCE:Under physiological conditions, neurons and glia are in a healthy, redox-balanced environment; when injury perturbs this equilibrium, a neuroinflammatory state is established by activated microglia that triggers pro-inflammatory responses and alters the oxidant/antioxidant balance, thus leading to neuronal loss and neurodegeneration. In neurodegenerative diseases (such as Alzheimer's disease, Parkinson's disease, amyothrophic lateral sclerosis, and multiple sclerosis), the brain is in a constitutively self-sustaining cycle of inflammation and oxidative stress that prompts and amplifies brain damage. Recent Advances: Recently, an increasing amount of scientific data highlight the ability of specific nutrients to cross the blood-brain barrier, and to modulate inflammatory and oxidative pathways. Therefore, nutritional approaches may contribute to restore the lost equilibrium among factors accounting for neurodegeneration.CRITICAL ISSUES:Herein, we critically examine how essential lipids (including fatty acids, liposoluble vitamins and phytosterols) might contribute to accelerate or prevent the onset and progression of such pathologies. In particular, we highlight that experimental and clinical findings, although promising, are still inadequate to draw definitive conclusions.FUTURE DIRECTIONS:More research is warranted in order to establish the real impact of lipid intake on brain health, especially when redox balance and inflammatory responses have been already compromised. In the future, it would be hoped to gain a detailed knowledge of chemical modifications and dynamic properties of such nutrients, before planning to exploit them as potential therapeutics. Antioxid. Redox Signal. 29, 37-60.