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S-adenosylmethionine (SAMe) is an endogenous methyl donor derived from ATP and methionine that has pleiotropic functions. Most SAMe is synthetized and consumed in the liver, where it acts as the main methylating agent and in protection against the free radical toxicity. Previous studies have shown that the administration of SAMe as a supernutrient exerted many beneficial effects in various tissues, mainly in the liver. In the present study, we aimed to clarify the direct effects of SAMe on fatty acid-induced steatosis and oxidative stress in hepatic and endothelial cells. Hepatoma FaO cells and endothelial HECV cells exposed to a mixture of oleate/palmitate are reliable models for hepatic steatosis and endothelium dysfunction, respectively. Our findings indicate that SAMe was able to significantly ameliorate lipid accumulation and oxidative stress in hepatic cells, mainly through promoting mitochondrial fatty acid entry for β-oxidation and external triglyceride release. SAMe also reverted both lipid accumulation and oxidant production (i.e., ROS and NO) in endothelial cells. In conclusion, these outcomes suggest promising beneficial applications of SAMe as a nutraceutical for metabolic disorders occurring in fatty liver and endothelium dysfunction.

Thyroid hormones play a crucial role in new neuron production and maturation during brain development. However, the knowledge about the involvement of these hormones on adult neurogenesis is still incomplete. Hippocampus is an anatomical region where neurogenesis occurs throughout adulthood and where high levels of thyroid hormone receptors have been found. In this work the possible involvement of thyroid hormones in the regulation of adult neurogenesis in the granule cell layer of rat hippocampus dentate gyrus was investigated using an experimental model of adult-onset pharmacologically-induced hypothyroidism. Neurogenesis was assessed by means of the thymidine analogue 5-bromo-2′-deoxyuridine 24 h and 30 days after its last administration in order to study neural precursor proliferation and newborn cell survival, respectively. Mitotic activity of the neural precursors was not affected by thyroid hormone deficiency; on the contrary, newborn cell survival dramatically decreased under these conditions when compared with controls, leading to a lower number of immature neurons being added to the granule cell layer. Moreover, in conditions of hypothyroidism, new neurons exhibit a delay in neuronal differentiation showing a prolonged expression of the neuritogenesis-associated immature neuron marker TUC-4 and a very immature morphology. Finally, the total number and size of granule cells, and granule cell layer volume decreased in hypothyroid rats. These results suggest that thyroid hormones play a role in regulating new neuron production during adult life in dentate gyrus of rat hippocampus.

Individuals affected by liver steatosis seldom have symptoms of liver injury, but may be particularly vulnerable to oxidative insults. In this study, we evaluated liver redox alterations produced by acute ethanol administration to rats that were fed a high-fat diet (HFD). Adult male Wistar rats were fed HFD or standard diet (controls) for 1 month; a group of animals from each condition were gavaged with 35% (vol/vol) ethanol every 12 h for the last 3 days of the experiment. Total lipid content determined in liver showed lipid accumulation after HFD or HFD combined with ethanol. HFD alone induced a significant rise of seric alanine aminotransferase levels and a marked reduction of antioxidant enzyme activities (catalase, superoxide dismutase, glutathione transferase). Ethanol alone caused a significant rise of seric cholesterol levels and enhanced mitochondrial H 2O 2 production, but without apparent oxidative stress as evaluated by thiobarbituric acid-reactive substances (TBARS) assay. The combination of HFD and acute ethanol caused an increase of TBARS, indicating lipid peroxidation, most likely as a consequence of a decrease in antioxidant defenses induced by HFD and of an increase in reactive oxygen species production induced by ethanol. Principal component analysis, based on all the measured parameters, that is, serum liver function tests, antioxidant enzyme activities, mitochondrial H 2O 2 release, and TBARS, indicated that HFD and ethanol act as two independent factors. In conclusion, our results show that HFD or acute ethanol alone produce, at the most, mild liver injury, whereas their combination triggers oxidative stress, possibly inducing a progression toward liver disease. Hence, our data indicate that a diet too rich in fat is a serious risk factor for the occurrence of liver injury deriving from acute ethanol consumption.

PurposePhenolic compounds (PC) of virgin olive oil exert several biochemical and pharmacological beneficial effects. Some dietary PC seem to prevent/improve obesity and metabolic-related disorders such as non-alcoholic fatty liver disease (NAFLD). We investigated the possible effects of PC extracted from olive pomace (PEOP) and of the main single molecules present in the extract (tyrosol, apigenin, oleuropein, p-coumaric and caffeic acid) in protecting hepatocytes and endothelial cells against triglyceride accumulation and oxidative stress.MethodsRat hepatoma and human endothelial cells were exposed to a mixture of oleate/palmitate to mimic the condition of NAFLD and atherosclerosis, respectively. Then, cells were incubated for 24 h in the absence or in the presence of PC or PEOP. Different parameters were evaluated, such as lipid accumulation and oxidative stress-related markers.ResultsIn hepatic cells, expression of peroxisome proliferator-activated receptors (PPARs) and of stearoyl-CoA desaturase 1 (SCD-1) were assessed as index of lipid metabolism. In endothelial cells, expression of intercellular adhesion molecule-1 (ICAM-1), activation of nuclear factor kappa-B (NF-kB), release of nitric oxide (NO), and wound-healing rate were assessed as index of inflammation.ConclusionPEOP extract ameliorated hepatic lipid accumulation and lipid-dependent oxidative imbalance thus showing potential applications as therapeutic agent tuning down hepatosteatosis and atherosclerosis.

Despite some advances in the understanding of amyotrophic lateral sclerosis (ALS) pathogenesis, significant achievements in treating this disease are still lacking. Mesenchymal stromal (stem) cells (MSCs) have been shown to be effective in several models of neurological disease. To determine the effects of the intravenous injection of MSCs in an ALS mouse model during the symptomatic stage of disease, MSCs (1 × 10 6 ) were intravenously injected in mice expressing human superoxide dismutase 1 (SOD1) carrying the G93A mutation (SOD1/G93A) presenting with experimental ALS. Survival, motor abilities, histology, oxidative stress markers and [ 3 H]d-aspartate release in the spinal cord were investigated. MSC injection in SOD1/G93A mice improved survival and motor functions compared with saline-injected controls. Injected MSCs scantly home to the central nervous system and poorly engraft. We observed a reduced accumulation of ubiquitin agglomerates and of activated astrocytes and microglia in the spinal cord of MSC-treated SOD1/G93A mice, with no changes in the number of choline acetyltransferase- and glutamate transporter type 1-positive cells. MSC administration turned around the upregulation of metallothionein mRNA expression and of the activity of the antioxidant enzyme glutathione S-transferase, both associated with disease progression. Last, we observed that MSCs reverted both spontaneous and stimulus-evoked neuronal release of ( 3 H)d-aspartate, a marker of endogenous glutamate, which is upregulated in SOD1/G93A mice. These findings suggest that intravenous administration of MSCs significantly improves the clinical outcome and pathological scores of mutant SOD1/G93A mice, thus providing the rationale for their exploitation for the treatment of ALS.

Overconsumption of fats and sugars is a major cause of development of non-alcoholic fatty liver disease (NAFLD). The main objectives of the present study were to explore the pathways sustaining the interfering metabolic effects of excess fructose and fatty acids in hepatocytes, and to clarify the mechanisms through which the nutraceutical silybin rescues the functional and metabolic alterations that are associated with the NALFD progression. Cultured hepatocytes were exposed to fructose and fatty acids, alone or in combination, to induce different grades of steatosis in vitro. Cell viability, apoptosis, free radical production, lipid content, lipid peroxidation and activity of lipogenic enzymes were assessed by spectrophotometric assays. Oxygen consumption and mitochondrial respiration parameters were measured using a Seahorse analyzer. Expression of markers for liver steatosis and dysfunction were also evaluated by reverse transcription-quantitative polymerase chain reaction. The data revealed that fructose and fatty acid combination in vitro had a positive interference on lipogenic pathways, leading to more severe steatosis and liver dysfunction, reduced cell viability, increased apoptosis, oxidative stress and mitochondrial respiration. Hepatic cell abnormalities were almost completely alleviated by silybin treatment. These findings suggest that silybin may serve as a novel and cost-effective dietary supplement for treatment and/or prevention of hepatosteatosis associated with NAFLD progression.

Introduction Systemic delivery of bone marrow-derived mesenchymal stem cells (MSC) seems to be of benefit in the treatment of multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) sustained by migration of T cells across the brain blood barrier (BBB) and subsequent induction of inflammatory lesions into CNS. MSC have been found to modulate several effector functions of T cells. In this study, we investigated the effects of MSC on adhesion molecules and receptors on T cell surface that sustain their transendothelial migration. Methods We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate the expression both at the mRNA and at the plasma-membrane level of α4 integrin, β2 integrin, ICAM-1 and CXCR3. In parallel, we assessed if MSC are able to modulate expression of adhesion molecules on the endothelial cells that interact with T cells during their transendothelial migration. Results Our in vitro analyses revealed that MSC: (i) inhibit proliferation and activation of both peripheral blood mononuclear cells (PBMC) and CD3 + -selected lymphocytes through the release of soluble factors; (ii) exert suppressive effects on those surface molecules highly expressed by activated lymphocytes and involved in transendothelial migration; (iii) inhibit CXCL10-driven chemotaxis of CD3 + cells; (iv) down-regulated expression of adhesion molecules on endothelial cells. Conclusions Taken together, these data demonstrate that the immunosuppressive effect of MSC does not exclusively depends on their anti-proliferative activity on T cells, but also on the impairment of leukocyte migratory potential through the inhibition of the adhesion molecules and receptors that are responsible for T cell trafficking across BBB. This could suggest a new mechanism through which MSC modulate T cell responses.

Transgenic mice overexpressing spermine oxidase (SMO) in the cerebral cortex (Dach-SMO mice) showed increased vulnerability to excitotoxic brain injury and kainate-induced epileptic seizures. To investigate the mechanisms by which SMO overexpression leads to increased susceptibility to kainate excitotoxicity and seizure, in the cerebral cortex of Dach-SMO and control mice we assessed markers for astrocyte proliferation and neuron loss, and the ability of kainate to evoke glutamate release from nerve terminals and astrocyte processes. Moreover, we assessed a possible role of astrocytes in an in vitro model of epileptic-like activity in combined cortico-hippocampal slices recorded with a multi-electrode array device. In parallel, as the brain is a major metabolizer of oxygen and yet has relatively feeble protective antioxidant mechanisms, we analyzed the oxidative status of the cerebral cortex of both SMO-overexpressing and control mice by evaluating enzymatic and non-enzymatic scavengers such as metallothioneins. The main findings in the cerebral cortex of Dach-SMO mice as compared to controls are the following: astrocyte activation and neuron loss; increased oxidative stress and activation of defense mechanisms involving both neurons and astrocytes; increased susceptibility to kainate-evoked cortical epileptogenic activity, dependent on astrocyte function; appearance of a glutamate-releasing response to kainate from astrocyte processes due to activation of Ca 2+ -permeable AMPA receptors in Dach-SMO mice. We conclude that reactive astrocytosis and activation of glutamate release from astrocyte processes might contribute, together with increased reactive oxygen species production, to the vulnerability to kainate excitotoxicity in Dach-SMO mice. This mouse model with a deregulated polyamine metabolism would shed light on roles for astrocytes in increasing vulnerability to excitotoxic neuron injury.

Excess fat accumulation renders the liver more vulnerable to ethanol, but it is still unclear how alcohol enhances lipid dysmetabolism and oxidative stress in a pre-existing steatosis condition. The effects produced by binge ethanol consumption in the liver of male Wistar rats fed a standard (Ctrl) or a high-fat diet HFD were compared. The liver status was checked through tissue histology and standard serum parameters. Alteration of hepatic lipid homeostasis and consequent oxidative unbalance were assessed by quantifying the mRNA expression of the lipid-regulated peroxisome proliferator-activated receptors (PPARs), of the cytochromes CYP2E1 and CYP4A1, and of some antioxidant molecules such as the metallothionein isoforms MT1 and MT2 and the enzymes catalase and superoxide dismutase. The number of adipose differentiation-related protein (ADRP)-positive lipid droplets (LDs) was evaluated by immunohistochemical staining. As a response to the double insult of diet and ethanol the rat liver showed: (1) a larger increase in fat accumulation within ADRP-positive LDs; (2) stimulation of lipid oxidation in the attempt to limit excess fat accumulation; (3) induction of antioxidant proteins (MT2, in particular) to protect the liver from the ethanol-induced overproduction of oxygen radicals. The data indicate an increased susceptibility of fatty liver to ethanol and suggest that the synergistic effect of diet and ethanol on lipid dysmetabolism might be mediated, at least in part, by PPARs and cytochromes CYP4A1 and CYP2E1.