Citicoline increases glutathione redox ratio and reduces caspase-3 activation and cell death in staurosporine-treated SH-SY5Y human neuroblastoma cells

Retinal Protection of New Nutraceutical Formulation

Background/Objectives: Retinal ganglion cell (RGC) protection represents an unmet need in glaucoma. This study assessed the neuroprotective, antioxidant, and anti-inflammatory effect of a new nutraceutical formulation named Epicolin, based on citicoline, homotaurine, epigallocatechin-3-gallate, forskolin, and vitamins, through in vitro and in vivo studies. Methods: The neuroprotective effect of Epicolin or its single components, and Epicolin compared to an untreated control and two marketed formulations [Formulation G (FG) and N (FN)], was evaluated in neuroblastoma cells (SH-SY5Y) challenged with staurosporine. The antioxidant potential and the scavenging activity of Epicolin compared to the untreated control, and FG and FN, was evaluated in SH-SY5Y cells and through oxygen radical absorbance capacity acellular assay, respectively. Moreover, the protective effect against hypoxic damage was evaluated in Muller cells (MIO-M1) subjected to hypoxia. The efficacy of Epicolin was also evaluated in DBA/2J glaucomatous mice through the use of a pattern electroretinogram (PERG), immunostaining, and real-time PCR. Results: Among the nutraceutical formulations tested, only Epicolin showed a significant neuroprotective effect on SH-SY5Y attributable to the synergistic action of its single ingredients. As for antioxidant and scavenging activity, Epicolin showed a higher efficacy compared to FG and FN. Furthermore, Epicolin showed the same protective effect on MIO-M1 cells reducing HIF-1α expression. Finally, Epicolin treatment on DBA/2J mice protected the RGCs from loss of function, as demonstrated by PERG analysis, and attenuated their death by enhancing brain-derived neurotrophic factor (BDNF) and reducing interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) expression. Conclusions: Epicolin, due to its neuroprotective, antioxidant, and anti-inflammatory properties, represents a promising potential treatment for glaucoma.

Novel frontiers in neuroprotective therapies in glaucoma: Molecular and clinical aspects

In the last years, neuroprotective therapies have attracted the researcher interests as modern and challenging approach for the treatment of neurodegenerative diseases, aimed at protecting the nervous system from injuries. Glaucoma is a neurodegenerative disease characterized by progressive excavation of the optic nerve head, retinal axonal injury and corresponding vision loss that affects millions of people on a global scale. The molecular basis of the pathology is largely uncharacterized yet, and the therapeutic approaches available do not change the natural course of the disease. Therefore, in accordance with the therapeutic regimens proposed for other neurodegenerative diseases, a modern strategy to treat glaucoma includes prescription of drugs with neuroprotective activities. With respect to this, several preclinical and clinical investigations on a plethora of different drugs are currently ongoing. In this review, first, the conceptualization of the rationale for the adoption of neuroprotective strategies for retina is summarized. Second, the molecular aspects highlighting glaucoma as a neurodegenerative disease are reported. In conclusion, the molecular and pharmacological properties of most promising direct neuroprotective drugs used to delay glaucoma progression are examined, including: neurotrophic factors, NMDA receptor antagonists, the α2-adrenergic agonist, brimonidine, calcium channel blockers, antioxidant agents, nicotinamide and statins.

Disease Outcome and Brain Metabolomics of Cyclophilin-D Knockout Mice in Sepsis

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction resulting from a systemic inflammatory response to infection, but the mechanism remains unclear. The mitochondrial permeability transition pore (MPTP) could play a central role in the neuronal dysfunction, induction of apoptosis, and cell death in SAE. The mitochondrial isomerase cyclophilin D (CypD) is known to control the sensitivity of MPTP induction. We, therefore, established a cecal ligation and puncture (CLP) model, which is the gold standard in sepsis research, using CypD knockout (CypD KO) mice, and analyzed the disease phenotype and the possible molecular mechanism of SAE through metabolomic analyses of brain tissue. A comparison of adult, male wild-type, and CypD KO mice demonstrated statistically significant differences in body temperature, mortality, and histological changes. In the metabolomic analysis, the main finding was the maintenance of reduced glutathione (GSH) levels and the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio in the KO animals following CLP. In conclusion, we demonstrate that CypD is implicated in the pathogenesis of SAE, possibly related to the inhibition of MPTP induction and, as a consequence, the decreased production of ROS and other free radicals, thereby protecting mitochondrial and cellular function.

Effects of cytidine-5'-diphosphate choline on gray matter volumes in methamphetamine-dependent patients: A randomized, double-blind, placebo-controlled study

BACKGROUND

Cytidine-5'-diphosphate choline (CDP-choline) has been suggested to exert neuroprotective and neuroreparative effects and may be beneficial for patients with stimulant dependence. This randomized, double-blind, placebo-controlled study in methamphetamine (MA) dependence investigated effects of CDP-choline on the brain structures and their associations with craving and MA use.

METHODS

MA users (n = 44) were randomized to receive 2 g/day of CDP-choline (n = 22) or placebo (n = 22) for 8 weeks. Patients underwent brain magnetic resonance imaging (MRI) at baseline and 8-week follow-up. Healthy individuals (n = 27) were also examined using brain MRI at the same interval. Voxel-based morphometry analysis was conducted to examine changes in gray matter (GM) volumes and their associations with craving and MA use.

RESULTS

Craving for MA was significantly reduced after the 8 week-treatment with CDP-choline (p = 0.01), but not with the placebo treatment (p = 0.10). There was no significant difference in the total number of MA-negative urine samples between the two groups (p = 0.19). With CDP-choline treatment, GM volumes in the left middle frontal gyrus (p = 0.001), right hippocampus (p = 0.009), and left precuneus (p = 0.001) were significantly increased compared to the placebo and control groups. Increased GM volumes in the left middle frontal gyrus with CDP-choline treatment were associated with reduced craving for MA (Spearman's ρ = -0.56, p = 0.03). In addition, the right hippocampal volume increases were positively associated with the total number of MA-negative urine results in the CDP-choline group (Spearman's ρ = 0.67, p = 0.006).

CONCLUSION

Our findings suggest that CDP-choline may increase GM volumes of MA-dependent patients, which may be related to decreases in MA use and craving.

Integration of light scattering with machine learning for label free cell detection

Light scattering has been used for label-free cell detection. The angular light scattering patterns from the cells are unique to them based on the cell size, nucleus size, number of mitochondria, and cell surface roughness. The patterns collected from the cells can then be classified based on different image characteristics. We have also developed a machine learning (ML) method to classify these cell light scattering patterns. As a case study we have used this light scattering technique integrated with the machine learning to analyze staurosporine-treated SH-SY5Y neuroblastoma cells and compare them to non-treated control cells. Experimental results show that the ML technique can provide a classification accuracy (treated versus non-treated) of over 90%. The predicted percentage of the treated cells in a mixed solution is within 5% of the reference (ground-truth) value and the technique has the potential to be a viable method for real-time detection and diagnosis.

Citicoline Protects Auditory Hair Cells Against Neomycin-Induced Damage

Aminoglycoside-induced hair cell (HC) loss is one of the most important causes of hearing loss. After entering the inner ear, aminoglycosides induce the production of high levels of reactive oxygen species (ROS) that subsequently activate apoptosis in HCs. Citicoline, a nucleoside derivative, plays a therapeutic role in central nervous system injury and in neurodegenerative disease models, including addictive disorders, stroke, head trauma, and cognitive impairment in the elderly, and has been widely used in the clinic as an FDA approved drug. However, its effect on auditory HCs remains unknown. Here, we used HC-like HEI-OC-1 cells and whole organ explant cultured mouse cochleae to explore the effect of citicoline on aminoglycoside-induced HC damage. Consistent with previous reports, both ROS levels and apoptosis were significantly increased in neomycin-induced cochlear HCs and HEI-OC-1 cells compared to undamaged controls. Interestingly, we found that co-treatment with citicoline significantly protected against neomycin-induced HC loss in both HEI-OC-1 cells and whole organ explant cultured cochleae. Furthermore, we demonstrated that citicoline could significantly reduce neomycin-induced mitochondrial dysfunction and inhibit neomycin-induced ROS accumulation and subsequent apoptosis. Thus, we conclude that citicoline can protect against neomycin-induced HC loss by inhibiting ROS aggregation and thus preventing apoptosis in HCs, and this suggests that citicoline might serve as a potential therapeutic drug in the clinic to protect HCs.

Citicoline protects against lead-induced oxidative injury in neuronal PC12 cells

Lead is a major environmental pollutant that causes serious adverse effects on biological systems and cells. In this study, we examined the effect of citicoline on lead-induced apoptosis in PC12 cells. The PC12 cells were pre-treated with citicoline and then exposed to lead for 48 h. The effect of citicoline on cell survival was examined by MTT assay. In addition, levels of lipid peroxidation (LPO), total thiol groups, total antioxidant power (TAP), catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH) were evaluated. The levels of Bax, Bcl-2, and caspase-3 were also measured, by Western blot analysis. Citicoline significantly increased the cell viability of PC12 cells exposed to lead. Treatment of PC12 cells with lead increased LPO levels, and citicoline effectively decreased LPO. Levels of total thiol groups and TAP, CAT, SOD, and GSH were significantly increased in citicoline-treated PC12 cells compared with the lead-treated group. Citicoline pretreatment significantly reduced Bax expression, and increased the level of Bcl-2 expression. Citicoline also reduced caspase-3 activation in PC12 cells compared with the lead-treated group. Our findings indicate that citicoline exerts a neuroprotective effect against lead-induced injury in PC12 cells through mitigation of oxidative stress and, at least in part, through suppression of the mitochondria-mediated apoptotic pathway.

Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy

Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.

Hypoxic preconditioning potentiates the trophic effects of mesenchymal stem cells on co-cultured human primary hepatocytes

Introduction

Mesenchymal stem/stromal cells (MSCs) improve the metabolic function of co-cultured hepatocytes. The present study aimed to further enhance the trophic effects of co-culture with hepatocytes using hypoxic preconditioning (HPc) of the MSCs and also to investigate the underlying molecular mechanisms involved.

Methods

Human adipose tissue-derived MSCs were subjected to hypoxia (2 % O₂; HPc) or normoxia (20 % O₂) for 24 h and then co-cultured with isolated human hepatocytes. Assays of metabolic function and apoptosis were performed to investigate the hepatotrophic and anti-apoptotic effects of co-culture. Indirect co-cultures and co-culture with MSC-conditioned medium investigated the role of paracrine factors in the hepatotrophic effects of co-culture. Reactive oxygen species (ROS) activity was antagonised with N-acetylcysteine to investigate whether HPc potentiated the effects of MSCs by intracellular ROS-dependent mechanisms. Tumour necrosis factor (TNF)-α, transforming growth factor (TGF)-β1, and extracellular collagen production was determined and CASP9 and BAX/BCL-2 signalling pathways analysed to investigate the role of soluble factors, extracellular matrix deposition, and apoptosis-associated gene signalling in the effects of co-culture.

Results

HPc potentiated the hepatotrophic and anti-apoptotic effects of co-culture by ROS-dependent mechanisms. There was increased MSC TGF-β1 production, and enhanced MSC deposition of extracellular collagen, with reduced synthesis of TNF-α, as well as a downregulation of the expression of pro-apoptotic CASP9, BAX, BID and BLK genes and upregulated expression of anti-apoptotic BCL-2 in hepatocytes.

Conclusions

HPc potentiated the trophic and anti-apoptotic effects of MSCs on hepatocytes via mechanisms including intracellular ROS, autocrine TGF-β, extracellular collagen and caspase and BAX/BCL-2 signalling pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0218-7) contains supplementary material, which is available to authorized users.

Neurochemical alterations in methamphetamine-dependent patients treated with cytidine-5'-diphosphate choline: a longitudinal proton magnetic resonance spectroscopy study

Cytidine-5'-diphosphate choline (CDP-choline), as an important intermediate for major membrane phospholipids, may exert neuroprotective effects in various neurodegenerative disorders. This longitudinal proton magnetic resonance spectroscopy ((1)H-MRS) study aimed to examine whether a 4-week CDP-choline treatment could alter neurometabolite levels in patients with methamphetamine (MA) dependence and to investigate whether changes in neurometabolite levels would be associated with MA use. We hypothesized that the prefrontal levels of N-acetyl-aspartate (NAA), a neuronal marker, and choline-containing compound (Cho), which are related to membrane turnover, would increase with CDP-choline treatment in MA-dependent patients. We further hypothesized that this increase would correlate with the total number of negative urine results. Thirty-one treatment seekers with MA dependence were randomly assigned to receive CDP-choline (n=16) or placebo (n=15) for 4 weeks. Prefrontal NAA and Cho levels were examined using (1)H-MRS before medication, and at 2 and 4 weeks after treatment. Generalized estimating equation regression analyses showed that the rate of change in prefrontal NAA (p=0.005) and Cho (p=0.03) levels were greater with CDP-choline treatment than with placebo. In the CDP-choline-treated patients, changes in prefrontal NAA levels were positively associated with the total number of negative urine results (p=0.03). Changes in the prefrontal Cho levels, however, were not associated with the total number of negative urine results. These preliminary findings suggest that CDP-choline treatment may exert potential neuroprotective effects directly or indirectly because of reductions in drug use by the MA-dependent patients. Further studies with a larger sample size of MA-dependent patients are warranted to confirm a long-term efficacy of CDP-choline in neuroprotection and abstinence.

Citicoline reduces upregulated clusterin following kainic acid injection in the rat retina

PURPOSE

To investigate the effects of citicoline on upregulated clusterin and retinal damage induced by kainic acid (KA).

METHODS

KA was injected into the vitreous of rats. Effects of systemic citicoline treatments were estimated by measuring the thickness of the various retinal layers, immunoblotting, and immunohistochemical techniques.

RESULTS

One day after KA injection, the immunoreactivity of clusterin increased significantly. In rats treated with KA plus citicoline, clusterin immunoreactivity was markedly reduced compared to KA-treated rats. Western blot analysis showed that clusterin protein levels were increased in KA-treated rats, but decreased in KA plus citicoline-treated rats. Apoptotic cell death was determined by TUNEL method. Citicoline reduced the expression of clusterin, as well as the expression of TUNEL after KA injection in the rat retina.

CONCLUSION

The increased expression of clusterin following KA injection in the rat retina suggests the presence of neurodegenerative events; citicoline may provide neuroprotection against neuronal cell damage.

CDP-choline reduces dopaminergic cell loss induced by MPP(+) and glutamate in primary mesencephalic cell culture

Cytidine-5'-diphosphocholine (citicoline or CDP-choline) is an essential endogenous intermediate in the biosynthesis of phosphatidylcholine. In the present study, primary dopaminergic cultures from mouse mesencephala were treated with citicoline to investigate its neuroprotective potential on the survival of dopaminergic neurons exposed to MPP(+) and glutamate. Treatment with citicoline alone significantly increased the survival of dopaminergic neurons compared to controls. MPP(+) or glutamate decreased the total number of dopaminergic neurons whereas citicoline afforded significant protection against either toxicity. Moreover, citicoline significantly decreased propidium iodide uptake by cultured cells. The study concludes that citicoline exerts stimulant and neuroprotective actions on cultured dopaminergic neurons.

Mitochondrial isocitrate dehydrogenase protects human neuroblastoma SH-SY5Y cells against oxidative stress

The neuroprotective effect of mitochondrial isocitrate dehydrogenase (IDPm), an enzyme involved in the reduction of NADP(+) to NADPH and the supply of glutathione (GSH) in mitochondria, was examined using SH-SY5Y cells overexpressing IDPm (S1). S1 cells showed higher NADPH and GSH levels than vector transfectant (V) cells and were more resistant to staurosporine-induced cell death than controls. Staurosporine-induced cytochrome c release, caspase-3 activation, and production of reactive oxygen species (ROS) were significantly attenuated in S1 cells as compared to V cells and reduced by antioxidants, trolox and GSH-ethyl ester (GSH-EE). Staurosporine-induced the release of Mcl-1 from mitochondria that formed a complex with Bim. Mcl-1 was then cleaved to a shortened form in a caspase-3 dependent manner; its release was attenuated far more in S1 than in V cells after staurosporine treatment. Finally, the staurosporine-induced decrease in mitochondrial membrane potential (Deltapsi(m)) was correlated with the time of mitochondrial Mcl-1 release; the loss of Deltapsi(m) was attenuated significantly in S1 cells as compared to that in V cells. These results suggest that the neuroprotective effect of IDPm may result from increases in NADPH and GSH levels in the mitochondria. This, in turn, inhibits mitochondrial ROS production after cytochrome c release, which seems to be mediated through Mcl-1 release.

Cytidine 5'-diphosphocholine (CDP-choline) in stroke and other CNS disorders

Brain phosphatidylcholine (PC) levels are regulated by a balance between synthesis and hydrolysis. Pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1alpha/beta) activate phospholipase A(2) (PLA(2)) and PC-phospholipase C (PC-PLC) to hydrolyze PC. PC hydrolysis by PLA(2) releases free fatty acids including arachidonic acid, and lyso-PC, an inhibitor of CTP-phosphocholine cytidylyltransferase (CCT). Arachidonic acid metabolism by cyclooxygenases/lipoxygenases is a significant source of reactive oxygen species. CDP-choline might increase the PC levels by attenuating PLA(2) stimulation and loss of CCT activity. TNF-alpha also stimulates proteolysis of CCT. TNF-alpha and IL-1beta are induced in brain ischemia and may disrupt PC homeostasis by increasing its hydrolysis (increase PLA(2) and PC-PLC activities) and inhibiting its synthesis (decrease CCT activity). The beneficial effects of CDP-choline may result by counteracting TNF-alpha and/or IL-1 mediated events, integrating cytokine biology and lipid metabolism. Re-evaluation of CDP-choline phase III stroke clinical trial data is encouraging and future trails are warranted. CDP-choline is non-xenobiotic, safe, well tolerated, and can be considered as one of the agents in multi-drug treatment of stroke.

Enteropathogenic Escherichia coli infection triggers host phospholipid metabolism perturbations

Enteropathogenic Escherichia coli (EPEC) specifically recognizes phosphatidylethanolamine (PE) on the outer leaflet of host epithelial cells. EPEC also induces apoptosis in epithelial cells, which results in increased levels of outer leaflet PE and increased bacterial binding. Consequently, it is of interest to investigate whether EPEC infection perturbs host cell phospholipid metabolism and whether the changes play a role in the apoptotic signaling. Our findings indicate that EPEC infection results in a significant increase in the epithelial cell PE level and a corresponding decrease in the phosphatidylcholine (PC) level. PE synthesis via both the de novo pathway and the serine decarboxylation pathway was enhanced, and de novo synthesis of phosphatidylcholine via CDP-choline was reduced. The changes were transitory, and the maximum change was noted after 4 to 5 h of infection. Addition of exogenous PC or CDP-choline to epithelial cells prior to infection abrogated EPEC-induced apoptosis, suggesting that EPEC infection inhibits the CTP-phosphocholine cytidylyltransferase step in PC synthesis, which is reportedly inhibited during nonmicrobially induced apoptosis. On the other hand, incorporation of exogenous PE by the host cells enhanced EPEC-induced apoptosis and necrosis without increasing bacterial adhesion. This is the first report that pathogen-induced apoptosis is associated with significant changes in PE and PC metabolism, and the results suggest that EPEC adhesion to a host membrane phospholipid plays a role in disruption of host phospholipid metabolism.