Ultramicronized palmitoylethanolamide rescues learning and memory impairments in a triple transgenic mouse model of Alzheimer's disease by exerting anti-inflammatory and neuroprotective effects

In an aging society, Alzheimer’s disease (AD) exerts an increasingly serious health and economic burden. Current treatments provide inadequate symptomatic relief as several distinct pathological processes are thought to underlie the decline of cognitive and neural function seen in AD. This suggests that the efficacy of treatment requires a multitargeted approach. In this context, palmitoylethanolamide (PEA) provides a novel potential adjunct therapy that can be incorporated into a multitargeted treatment strategy. We used young (6-month-old) and adult (12-month-old) 3×Tg-AD mice that received ultramicronized PEA (um-PEA) for 3 months via a subcutaneous delivery system. Mice were tested with a range of cognitive and noncognitive tasks, scanned with magnetic resonance imaging/magnetic resonance spectroscopy (MRI/MRS), and neurochemical release was assessed by microdialysis. Potential neuropathological mechanisms were assessed postmortem by western blot, reverse transcription–polymerase chain reaction (RT-PCR), and immunofluorescence. Our data demonstrate that um-PEA improves learning and memory, and ameliorates both the depressive and anhedonia-like phenotype of 3×Tg-AD mice. Moreover, it reduces Aβ formation, the phosphorylation of tau proteins, and promotes neuronal survival in the CA1 subregion of the hippocampus. Finally, um-PEA normalizes astrocytic function, rebalances glutamatergic transmission, and restrains neuroinflammation. The efficacy of um-PEA is particularly potent in younger mice, suggesting its potential as an early treatment. These data demonstrate that um-PEA is a novel and effective promising treatment for AD with the potential to be integrated into a multitargeted treatment strategy in combination with other drugs. Um-PEA is already registered for human use. This, in combination with our data, suggests the potential to rapidly proceed to clinical use

Serotonergic modulation of rat pineal gland activity: In vivo evidence for a 5-hydroxytryptamine(2c) receptor involvement

There are some suggestions that, in the pineal gland, serotonin acts not only as a precursor of melatonin but also plays a role in the modulation of the pineal biosynthetic activity. To corroborate this possible neuromodulatory role of 5-hydroxytryptamine (serotonin) (5-HT) on the pineal gland, the effects of two 5-HT2 receptor agonists meta-chlorophenylpiperazine (m-CPP) and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane were assessed in vivo on pineal N-acetyltransferase (NAT) activity and melatonin content in rats. m-CPP potentiated the enhancement of NAT activity and pineal melatonin content induced by isoproterenol administration during daytime, whereas it did not affect the diurnal basal biosynthetic activity of the gland. At night, m-CPP and 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane enhanced significantly the physiological increases in both pineal NAT activity and melatonin content. This enhancement was prevented by pretreatment with N-(1-methyl-5-indolyl)-N'-(3-pyridyl) urea hydrochloride, an antagonist with higher affinity for 5-HT(2B/C) than for 5-HT(2A) receptor, as well as by pretreatment with 8-[5-(2,4-dimethoxy-5-(4-trifluoromethyl-phenylsulphonamido)-phenyl-5-oxopent hyl]-1,3,8-triazospiro[4,5]decane-2,4-dione, the most specific 5-HT(2C) receptor now available, but not by pretreatment with ketanserin, an antagonist with higher affinity for 5-HT(2A) than for 5-HT(2C) receptor. These results suggest that 5-HT(2C) receptors are likely involved in the mediation of the serotonergic modulation of pineal biosynthetic activity in rats

Astrocyte function is affected by aging and not Alzheimer's disease: A preliminary investigation in hippocampi of 3xTg-AD mice

Old age is a risk factor for Alzheimer's disease (AD), which is characterized by hippocampal impairment together with substantial changes in glial cell functions. Are these alterations due to the disease progression or are they a consequence of aging? To start addressing this issue, we studied the expression of specific astrocytic and microglial structural and functional proteins in a validated transgenic model of AD (3×Tg-AD). These mice develop both amyloid plaques and neurofibrillary tangles, and initial signs of the AD-like pathology have been documented as early as three months of age. We compared male 3×Tg-AD mice at 6 and 12 months of age with their wild-type age-matched counterparts. We also investigated neurons by examining the expression of both the microtubule-associated protein 2 (MAP2), a neuronal structural protein, and the brain-derived neurotrophic factor (BDNF). The latter is indeed a crucial indicator for synaptic plasticity and neurogenesis/ neurodegeneration. Our results show that astrocytes are more susceptible to aging than microglia, regardless of mouse genotype. Moreover, we discovered significant agedependent alterations in the expression of proteins responsible for astrocyte-astrocyte and astrocyte-neuron communication, as well as a significant age-dependent decline in BDNF expression. Our data promote further research on the unexplored role of astroglia in both physiological and pathological aging

Oral Adelmidrol Administration Up-Regulates Palmitoylethanolamide Production in Mice Colon and Duodenum through a PPAR-γ Independent Action

Adelmidrol is a promising palmitoylethanolamide (PEA) analog which displayed up-and-coming anti-inflammatory properties in several inflammatory conditions. Recent studies demonstrated that Adelmidrol is an in vitro enhancer of PEA endogenous production, through the so called “entourage” effect. The present study investigated the ability of Adelmidrol (1 and 10 mg/Kg per os) to increase the endogenous level of PEA in the duodenum and colon of mice after 21-day oral administration in the presence and absence of PPAR-γ inhibitor (1 mg/kg). The level of PEA was analyzed by HPLC-MS. The expression of PEA-related enzymatic machinery was evaluated by western blot and RT-PCR analysis. Our findings demonstrated that Adelmidrol significantly increased PEA levels in the duodenum and colon in a dose/time-dependent manner. We also revealed that Adelmidrol up regulated the enzymatic machinery responsible for PEA metabolism and catabolism. Interestingly, the use of the selective irreversible PPAR-γ antagonist did not affect either PEA intestinal levels or expres-sion/transcription of PEA metabolic enzymes following Adelmidrol administration. The “entourage effect” with Adelmidrol as an enhancer of PEA was thus PPAR-γ-independent. The findings suggest that Adelmidrol can maximize a PEA therapeutic-based approach in several intestinal morbidities

Enteric glia: A new player in inflammatory bowel diseases

In addition to the well-known involvement of macrophages and neutrophils, other cell types have been recently reported to substantially contribute to the onset and progression of inflammatory bowel diseases (IBD). Enteric glial cells (EGC) are the equivalent cell type of astrocyte in the central nervous system (CNS) and share with them many neurotrophic and neuro-immunomodulatory properties. This short review highlights the role of EGC in IBD, describing the role played by these cells in the maintenance of gut homeostasis, and their modulation of enteric neuronal activities. In pathological conditions, EGC have been reported to trigger and support bowel inflammation through the specific over-secretion of S100B protein, a pivotal neurotrophic factor able to induce chronic inflammatory changes in gut mucosa. New pharmacological tools that may improve the current therapeutic strategies for inflammatory bowel diseases (IBD), lowering side effects (i.e. corticosteroids) and costs (i.e. anti-TNFα monoclonal antibodies) represent a very important challenge for gastroenterologists and pharmacologists. Novel drugs capable to modulate enteric glia reactivity, limiting the pro-inflammatory release of S100B, may thus represent a significant innovation in the field of pharmacological interventions for inflammatory bowel diseases

Ultramicronized palmitoylethanolamide inhibits NLRP3 inflammasome expression and pro-inflammatory response activated by SARS-CoV-2 spike protein in cultured murine alveolar macrophages

Despite its possible therapeutic potential against COVID-19, the exact mechanism(s) by which palmitoylethanolamide (PEA) exerts its beneficial activity is still unclear. PEA has demonstrated analgesic, anti-allergic, and anti-inflammatory activities. Most of the anti-inflammatory properties of PEA arise from its ability to antagonize nuclear factor-κB (NF-κB) signalling pathway via the selective activation of the PPARα receptors. Acting at this site, PEA can downstream several genes involved in the inflammatory response, including cytokines (TNF-α, Il-1β) and other signal mediators, such as inducible nitric oxide synthase (iNOS) and COX2. To shed light on this, we tested the anti-inflammatory and immunomodulatory activity of ultramicronized(um)-PEA, both alone and in the presence of specific peroxisome proliferator-activated receptor alpha (PPAR-α) antagonist MK886, in primary cultures of murine alveolar macrophages exposed to SARS-CoV-2 spike glycoprotein (SP). SP challenge caused a significant concentration-dependent increase in proinflammatory markers (TLR4, p-p38 MAPK, NF-κB) paralleled to a marked upregulation of inflammasome-dependent inflammatory pathways (NLRP3, Caspase-1) with IL-6, IL-1β, TNF-α over-release, compared to vehicle group. We also observed a significant concentration-dependent increase in ACE-2 following SP challenge. um-PEA concentration-dependently reduced all the analyzed proinflammatory markers fostering a parallel downregulation of ACE-2. Our data show for the first time that um-PEA, via PPAR-α, markedly inhibits the SP induced NLRP3 signalling pathway outlining a novel mechanism of action of this lipid against COVID-19

S100B‑p53 disengagement by pentamidine promotes apoptosis and inhibits cellular migration via aquaporin‑4 and metalloproteinase‑2 inhibition in C6 glioma cells

S100 calcium‑binding protein B (S100B) is highly expressed in glioma cells and promotes cancer cell survival via inhibition of the p53 protein. In melanoma cells, this S100B‑p53 interaction is known to be inhibited by pentamidine isethionate, an antiprotozoal agent. Thus, the aim of the present study was to evaluate the effect of pentamidine on rat C6 glioma cell proliferation, migration and apoptosis in vitro. The change in C6 cell proliferation following treatment with pentamidine was determined by performing a 3‑[4,5‑dimethylthiazol‑2‑yl]‑2,5 diphenyltetrazolium bromide‑formazan assay. Significant dose‑dependent decreases in proliferation were observed at pentamidine concentrations of 0.05 μM (58.5±5%; P<0.05), 0.5 μM (40.6±7%; P<0.01) and 5 μM (13±4%; P<0.001) compared with the control (100% viability). Furthermore, treatment with 0.05, 0.5 and 5 μM pentamidine was associated with a significant increase in apoptosis versus the untreated cells, as determined by DNA fragmentation assays, immunofluorescence analysis of C6 chromatin using Hoechst staining, and immunoblot analysis of B‑cell lymphoma‑2 (Bcl‑2)‑associated X protein (100%, P<0.05; 453%, P<0.01; and 1000%, P<0.001, respectively) and Bcl‑2 (‑60%, P<0.001; ‑80.13%, P<0.001; ‑95%, P<0.001, respectively). In addition, the administration of 0.05, 0.5 and 5 μM pentamidine significantly upregulated the protein expression levels of p53 (681±87.5%, P<0.05; 1244±94.3%, P<0.01; and 2244±111%, P<0.001, respectively), and significantly downregulated the expression levels of matrix metalloproteinase‑2 (42±2.3%, P<0.05; 71±2.5%, P<0.01; and 95.8±3.3%, P<0.001, respectively) and aquaporin 4 (38±2.5%, P<0.05; 69±2.6%, P<0.01; and 88±3.0%, P<0.001, respectively), compared with the untreated cells. The wound healing assay demonstrated that cell migration was significantly impaired by treatment with 0.05, 0.5 and 5 μM pentamidine compared with untreated cells (88±4.2%, P<0.05; 64±2%, P<0.01; and 42±3.1%, P<0.001, respectively). Although additional in vivo studies are required to clarify the current in vitro data, the present study indicates that pentamidine and S100B‑p53 inhibitors may represent a novel approach for the treatment of glioma

S100B and APP Promote a Gliocentric Shift and Impaired Neurogenesis in Down Syndrome Neural Progenitors

Down syndrome (DS) is a developmental disorder associated with mental retardation (MR) and early onset Alzheimer's disease (AD). These CNS phenotypes are attributed to ongoing neuronal degeneration due to constitutive overexpression of chromosome 21 (HSA21) genes. We have previously shown that HSA21 associated S100B contributes to oxidative stress and apoptosis in DS human neural progenitors (HNPs). Here we show that DS HNPs isolated from fetal frontal cortex demonstrate not only disturbances in redox states within the mitochondria and increased levels of progenitor cell death but also transition to more gliocentric progenitor phenotypes with a consequent reduction in neuronogenesis. HSA21 associated S100B and amyloid precursor protein (APP) levels are simultaneously increased within DS HNPs, their secretions are synergistically enhanced in a paracrine fashion, and overexpressions of these proteins disrupt mitochondrial membrane potentials and redox states. HNPs show greater susceptibility to these proteins as compared to neurons, leading to cell death. Ongoing inflammation through APP and S100B overexpression further promotes a gliocentric HNPs phenotype. Thus, the loss in neuronal numbers seen in DS is not merely due to increased HNPs cell death and neurodegeneration, but also a fundamental gliocentric shift in the progenitor pool that impairs neuronal production

Palmitoylethanolamide exerts neuroprotective effects in mixed neuroglial cultures and organotypic hippocampal slices via peroxisome proliferator-activated receptor-α

<p>Abstract</p> <p>Background</p> <p>In addition to cytotoxic mechanisms directly impacting neurons, β-amyloid (Aβ)-induced glial activation also promotes release of proinflammatory molecules that may self-perpetuate reactive gliosis and damage neighbouring neurons, thus amplifying neuropathological lesions occurring in Alzheimer's disease (AD). Palmitoylethanolamide (PEA) has been studied extensively for its anti-inflammatory, analgesic, antiepileptic and neuroprotective effects. PEA is a lipid messenger isolated from mammalian and vegetable tissues that mimics several endocannabinoid-driven actions, even though it does not bind to cannabinoid receptors. Some of its pharmacological properties are considered to be dependent on the expression of peroxisome proliferator-activated receptors-α (PPARα).</p> <p>Findings</p> <p>In the present study, we evaluated the effect of PEA on astrocyte activation and neuronal loss in models of Aβ neurotoxicity. To this purpose, primary rat mixed neuroglial co-cultures and organotypic hippocampal slices were challenged with Aβ_1-42and treated with PEA in the presence or absence of MK886 or GW9662, which are selective PPARα and PPARγ antagonists, respectively. The results indicate that PEA is able to blunt Aβ-induced astrocyte activation and, subsequently, to improve neuronal survival through selective PPARα activation. The data from organotypic cultures confirm that PEA anti-inflammatory properties implicate PPARα mediation and reveal that the reduction of reactive gliosis subsequently induces a marked rebound neuroprotective effect on neurons.</p> <p>Conclusions</p> <p>In line with our previous observations, the results of this study show that PEA treatment results in decreased numbers of infiltrating astrocytes during Aβ challenge, resulting in significant neuroprotection. PEA could thus represent a promising pharmacological tool because it is able to reduce Aβ-evoked neuroinflammation and attenuate its neurodegenerative consequences.</p

Factors associated with lifetime suicide attempts in bipolar disorder: results from an Italian nationwide study

The purpose of the present study was to detect demographic and clinical factors associated with lifetime suicide attempts in Bipolar Disorder (BD). A total of 1673 bipolar patients from different psychiatric departments were compared according to the lifetime presence of suicide attempts on demographic/clinical variables. Owing to the large number of variables statistically related to the dependent variable (presence of suicide attempts) at the univariate analyses, preliminary multiple logistic regression analyses were realized. A final multivariable logistic regression was then performed, considering the presence of lifetime suicide attempts as the dependent variable and statistically significant demographic/clinical characteristics as independent variables. The final multivariable logistic regression analysis showed that an earlier age at first contact with psychiatric services (odds ratio [OR] = 0.97, p &lt; 0.01), the presence of psychotic symptoms (OR = 1.56, p &lt; 0.01) or hospitalizations (OR = 1.73, p &lt; 0.01) in the last year, the attribution of symptoms to a psychiatric disorder (no versus yes: OR = 0.71, partly versus yes OR = 0.60, p &lt; 0.01), and the administration of psychoeducation in the last year (OR = 1.49, p &lt; 0.01) were all factors associated with lifetime suicide attempts in patients affected by BD. In addition, female patients resulted to have an increased association with life-long suicidal behavior compared to males (OR: 1.02, p &lt; 0.01). Several clinical factors showed complex associations with lifetime suicide attempts in bipolar patients. These patients, therefore, require strict clinical monitoring for their predisposition to a less symptom stabilization. Future research will have to investigate the best management strategies to improve the prognosis of bipolar subjects presenting suicidal behavior