Cytidine-5'-Diphosphocholine Protects the Liver From Ischemia/Reperfusion Injury Preserving Mitochondrial Function and Reducing Oxidative Stress

Cytoprotection as an Innovative Therapeutic Strategy to Cardiogenic Shock: Exploring the Potential of Cytidine-5-Diphosphocholine to Mitigate Target Organ Damage

BACKGROUND

Preservation of organ function and viability is a crucial factor for survival in cardiogenic shock (CS) patients. There is not information enough on cytoprotective substances that may delay organs damage in CS. We hypothesize that cytidine-5-diphosphocholine (CDP-choline) can act as a cytoprotective pharmacological measure that diminishes the target organ damage. So, we aimed to perform a review of works carried out in our institution to evaluate the effect of therapeutic cytoprotection of the CDP-choline.

SUMMARY

CDP-choline is an intermediate metabolite in the synthesis of phosphatidylcholine. It is also a useful drug for the treatment of acute ischaemic stroke, traumatic brain injury, and neurodegenerative diseases and has shown an excellent pharmacological safety profile as well. We review our institution's work and described the cytoprotective effects of CDP-choline in experimental models of heart, liver, and kidney acute damage, where this compound was shown to diminish reperfusion-induced ventricular arrhythmias, oxidative stress, apoptotic cell death, inflammation, lactic acid levels and to preserve mitochondrial function.

KEY MESSAGES

We propose that additional research is needed to evaluate the impact of cytoprotective therapy adjuvant to mitigate target organ damage in patients with CS.

The emerging role of α7nAChRs/caspase-3/Nrf-2 signaling pathway in citicoline improved autistic behavior induced by thimerosal in mice

AIMS

Autism spectrum disorder (ASD) is a global concern,affecting around 75 million individuals.Various factors contribute to ASD,including mercury-containing preservatives like thimerosal (Thim) found in some vaccines.This study explored whether citicoline could be a therapeutic option for Thim-induced neuronal damage in a mouse model of ASD.Additionally,the study investigated the effects of citicoline on the α7nAChRs/Akt/Nrf2/caspase-3 pathway,which may be involved in the development of ASD.

MATERIALS AND METHODS

The study separated newborn mice into four groups.The control group received saline injections,while the Thim group received intramuscular injections of 3000 μg Hg/kg Thim on days 7,9,11,and 15 after birth.The two citicoline groups were administered Thim followed by intraperitoneal injections of 250 mg/kg or 500 mg/kg citicoline for three weeks.Afterward,various parameters were assessed, including growth,behavior,brain histopathology,oxidative stress,apoptotic,and inflammatory markers.

KEY FINDINGS

Untreated Thim-exposed mice exhibited significant brain damage,which was substantially alleviated by citicoline treatment.This beneficial effect was associated with increased expressions and concentrations of brain α7nAChRs and Akt, increased brain content of Nrf2, and the hippocampus contents of acetylcholine. Citicoline treatment decreased the brain levels of oxidative stress markers (MDA and NO),the apoptotic marker caspase-3,and pro-inflammatory markers (NF-κB,TNF-α,and IL-1β). The drug also increased the brain GPx activity.

SIGNIFICANCE

Based on the results of this study,the α7nAChRs pathway appears to be essential for the therapeutic effectiveness of citicoline in treating Thim-induced ASD in mice.

The effects of CDP-choline treatment in Amanita phalloides mushroom toxicosis

Amanita phalloides poisoning is known to be the most fatal case among mushroom poisoning cases. Its main mechanism of toxicity is that it leads to cell death by the irreversible binding of its toxins to the DNA-dependent RNA polymerase II enzyme. This study was planned to analyze the effects of the CDP-choline molecule on Amanita phalloides mushroom poisoning cases. The extract of the Amanita phalloides mushroom was taken and intraperitoneally administered to male Wistar Albino rats at a dose of 0.3 g/kg. In the experiment phase, the rats were divided into three groups of CDP-choline treatment according to the doses of 100 mg/kg, 250 mg/kg, and 500 mg/kg, and one control group was administered a 1 ml/kg dose of 0.9% isotonic NaCl solution. The treatments were then administered intraperitoneally at the 2nd hour, and at the 6th hour, the rats were sacrificed. The degree of damage in the liver and kidney tissues of the rats was evaluated histopathologically. It was concluded that CDP-choline reduced or prevented the damage that occurred in the liver significantly and dose-dependently in the toxicosis picture caused by Amanita phalloides, and it showed a tendency to lower or prevent the damage in the kidney, albeit not significantly.

Dynamic changes in the mouse hepatic lipidome following warm ischemia reperfusion injury

Liver failure secondary to metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common cause for liver transplantation in many parts of the world. Moreover, the prevalence of MASLD not only increases the demand for liver transplantation, but also limits the supply of suitable donor organs because steatosis predisposes grafts to ischemia-reperfusion injury (IRI). There are currently no pharmacological interventions to limit hepatic IRI because the mechanisms by which steatosis leads to increased injury are unclear. To identify potential novel mediators of IRI, we used liquid chromatography and mass spectrometry to assess temporal changes in the hepatic lipidome in steatotic and non-steatotic livers after warm IRI in mice. Our untargeted analyses revealed distinct differences between the steatotic and non-steatotic response to IRI and highlighted dynamic changes in lipid composition with marked changes in glycerophospholipids. These findings enhance our knowledge of the lipidomic changes that occur following IRI and provide a foundation for future mechanistic studies. A better understanding of the mechanisms underlying such changes will lead to novel therapeutic strategies to combat IRI.

Food-grade titanium dioxide and zinc oxide nanoparticles induce toxicity and cardiac damage after oral exposure in rats

BACKGROUND

Metallic nanoparticles (NPs) are widely used as food additives for human consumption. NPs reach the bloodstream given their small size, getting in contact with all body organs and cells. NPs have adverse effects on the respiratory and intestinal tract; however, few studies have focused on the toxic consequences of orally ingested metallic NPs on the cardiovascular system. Here, the effects of two food-grade additives on the cardiovascular system were analyzed.

METHODS

Titanium dioxide labeled as E171 and zinc oxide (ZnO) NPs were orally administered to Wistar rats using an esophageal cannula at 10 mg/kg bw every other day for 90 days. We evaluated cardiac cell morphology and death, expression of apoptotic and autophagic proteins in cardiac mitochondria, mitochondrial dysfunction, and concentration of metals on cardiac tissue.

RESULTS

Heart histology showed important morphological changes such as presence of cellular infiltrates, collagen deposition and mitochondrial alterations in hearts from rats exposed to E171 and ZnO NPs. Intracellular Cyt-C levels dropped, while TUNEL positive cells increased. No significant changes in the expression of inflammatory cytokines were detected. Both NPs altered mitochondrial function indicating cardiac dysfunction, which was associated with an elevated concentration of calcium. ZnO NPs induced expression of caspases 3 and 9 and two autophagic proteins, LC3B and beclin-1, and had the strongest effect compared to E171.

CONCLUSIONS

E171 and ZnO NPs induce adverse cardiovascular effects in rats after 90 days of exposure, thus food intake containing these additives, should be taken into consideration, since they translocate into the bloodstream and cause cardiovascular damage.

Efficacy of citicoline as a supplement in glaucoma patients: A systematic review

PURPOSE

Glaucoma is a leading cause of irreversible blindness worldwide. Retinal ganglion cells (RGC), the neurons that connect the eyes to the brain, specifically die in glaucoma, leading to blindness. Elevated intraocular pressure (IOP) is the only modifiable risk factor, however, many patients progress despite excellent IOP control. Thus, alternative treatment strategies to prevent glaucoma progression are an unmet need. Citicoline has demonstrated neuroprotective properties in central neurodegenerative diseases. However, conclusive evidence of the effect of citicoline on glaucoma progression is missing. This systematic review investigates first-time the therapeutic potential of citicoline in glaucoma patients.

METHODS

The present study was conducted according to the PRISMA 2020 statement. PubMed, Web of Science, Google Scholar, and Embase were accessed in July 2023 to identify all clinical studies investigating the efficacy of citicoline on IOP, the mean deviation of the 24-2 visual field testing (MD 24-2), retinal nerve fibre layer (RNFL), and the pattern electroretinogram (PERG) P50-N95 amplitude in glaucoma patients. The risk of bias was assessed using the Review Manager 5.3 software (The Nordic Cochrane Collaboration, Copenhagen) and the Risk of Bias in Non-randomised Studies of Interventions (ROBINS-I) tool.

RESULTS

Ten studies were eligible for this systematic review, including 424 patients. The mean length of the follow-up was 12.1 ± 11.6 months. The overall risk of bias was low to moderate. The mean age of the patients was 56.7 years. There were no significant differences in the IOP, MD 24-2, RNFL, or PERG P50-N95 amplitude between patients receiving citicoline and the control group. There was no improvement from baseline to the last follow-up in IOP, MD 24-2, RNFL, or PERG P50-N95 amplitude.

CONCLUSION

There is a lack of sufficient evidence to support that citicoline slows the progression of glaucoma.

Impact of Feeding Probiotics on Blood Parameters, Tail Fat Metabolites, and Volatile Flavor Components of Sunit Sheep

Sheep crude tail fat has unique nutritional values and is used as a raw material for high-quality natural oil. The purpose of this study was to investigate the effects of probiotics on the metabolites and flavor of sheep crude tail fat. In this study, 12 Sunit sheep were randomly divided into an experimental group (LTF, basal feed + Lactiplantibacillusplantarum powder) and a control group (CTF, basal feed). The results of sheep crude tail fat analysis showed that blood lipid parameters were significantly lower and the expression of fatty acid synthase and stearoyl-CoA desaturase genes higher in the LTF group than in the CTF group (p < 0.05). Metabolomic analysis via liquid chromatography−mass spectrometry showed that the contents of metabolites such as eicosapentaenoic acid, 16-hydroxypalmitic acid, and L-citrulline were higher in the LTF group (p < 0.01). Gas chromatography−mass spectrometry detection of volatile flavor compounds in the tail fat showed that nonanal, decanal, and 1-hexanol were more abundant in the LTF group (p < 0.05). Therefore, Lactiplantibacillus plantarum feeding affected blood lipid parameters, expression of lipid metabolism-related genes, tail fat metabolites, and volatile flavor compounds in Sunit sheep. In this study, probiotics feeding was demonstrated to support high-value sheep crude tail fat production.

Citicoline Modifies the Expression of Specific miRNAs Related to Cardioprotection in Patients with ST-Segment Elevation Myocardial Infarction Subjected to Coronary Angioplasty

Extracellular vesicles are recognized as signaling mediators between cells both in physiological and pathological communication. In this work, we explored the potential effect of citicoline to modify relevant proteins or miRNAs for cardioprotection in the smallest population of such microvesicles; i.e., in exosomes from patients diagnosed with ST-segment elevation myocardial infarction (STEMI) undergoing coronary angioplasty. The plasma-exosome-enriched fraction from these patients was characterized. Their cellular origin was assessed by flow cytometry and Western blot, whereas miRNA expression was evaluated by real-time polymerase chain reaction (qRT-PCR). The content of caveolin-1, caveolin-3, and hnRNPA2B1, which play a relevant role in selective transport of miRNAs into microvesicles, along with the effect on cell viability of the exosomes obtained from citicoline-treated and untreated groups were also analyzed. Our results showed that hypoxic stress increases exosome release into the circulation. Moreover, we found that CD146+ increased in exosomes from citicoline-treated patients, while CD142+ decreased in these patients compared to the placebo group. No changes were detected in the protein levels of caveolin-1, caveolin-3, and hnRNPA2B1. Citicoline administration modified the expression of miR233-3p, miR92, and miR21-5p in exosomes. Cell viability decreased in the presence of exosomes from infarcted patients, while incubation of H9c2 cells with exosomes from patients reperfused with citicoline did not affect cell viability. In conclusion, citicoline administration modifies the expression of specific miRNAs related to cardioprotection in exosomes.

Multicenter, Prospective, Randomized, Single Blind, Cross-Over Study on the Effect of a Fixed Combination of Citicoline 500 mg Plus Homotaurine 50 mg on Pattern Electroretinogram (PERG) in Patients With Open Angle Glaucoma on Well Controlled Intraocular Pressure

Purpose

To evaluate the potential beneficial and synergistic effects of oral intake of a fixed combination of citicoline 500 mg plus homotaurine 50 mg (CIT/HOMO) on retinal ganglion cell (RGC) function in subjects with glaucoma using pattern electroretinogram (PERG) and to investigate the effects on visual field and quality of life.

Methods

Consecutive patients with primary open-angle glaucoma with controlled IOP (<18 mmHg) receiving beta-blockers and prostaglandin analogs alone or as combination therapy (fixed or un-fixed); with stable disease (progression no more than −1 dB/year at the visual field MD); and an early to moderate visual field defect (MD < −12 dB) were randomized to: arm A. topical therapy + CIT/HOMO for 4 months, 2 months of wash out, 4 months of topical therapy alone; arm B. topical therapy alone for 4 months, topical therapy + CIT/HOMO for 4 months, 2 months of wash out. All patients underwent 4 visits: complete ocular examination, visual field, PERG and quality of life assessment (NEI-VFQ25) were performed at each visit.

Results

Fifty-seven patients completed the study: 26 in group A and 31 in group B. At the end of the intake period, PERG's P50 and N95 waves recorded a greater amplitude. The increase was statistically significant in the inferior and superior P50 waves amplitude: 0.47 μV (95%CI, 0.02–0.93; p = 0.04) and 0.65 μV (95% CI, 0.16–1.13; p = 0.009), respectively, and in the inferior N95 wave amplitude 0.63 μV (95% CI, 0.22–1.04; p = 0.002). A significantly shorter peak time of 3.3 μV (95% CI, −6.01– −0.54; p = 0.01) was observed for the superior P50 wave only.

Conclusions

Daily oral intake of the fixed combination CIT/HOMO for 4 months improved the function of inner retinal cells recorded by PERG in the inferior and in the superior quadrants, independently from IOP reduction. This interesting association could represent a valid option for practicing neuromodulation in patients with glaucoma to prevent disease progression.

Reactive Oxygen Species Induce Fatty Liver and Ischemia-Reperfusion Injury by Promoting Inflammation and Cell Death

Liver transplantation is the ultimate method for treating end-stage liver disease. With the increasing prevalence of obesity, the number of patients with non-alcoholic fatty liver, a common cause of chronic liver disease, is on the rise and may become the main cause of liver transplantation in the future. With the increasing gap between the number of donor livers and patients waiting for liver transplantation and the increasing prevalence of non-alcoholic fatty liver, the proportion of steatosis livers among non-standard donor organs is also increasing. Ischemia-reperfusion injury has historically been the focus of attention in the liver transplantation process, and severe ischemia-reperfusion injury leads to adverse outcomes of liver transplantation. Studies have shown that the production of reactive oxygen species and subsequent oxidative stress play a key role in the pathogenesis of hepatic ischemia and reperfusion injury and non-alcoholic fatty liver. Furthermore, the sensitivity of fatty liver transplantation to ischemia-reperfusion injury has been suggested to be related to the production of reactive oxygen species (ROS) and oxidative stress. In ischemia-reperfusion injury, Kupffer cell and macrophage activation along with mitochondrial damage and the xanthine/xanthine oxidase system promote marked reactive oxygen species production and the inflammatory response and apoptosis, resulting in liver tissue injury. The increased levels of ROS and lipid peroxidation products, vicious circle of ROS and oxidative stress along with mitochondrial dysfunction promoted the progress of non-alcoholic fatty liver. In contrast to the non-fatty liver, a non-alcoholic fatty liver produces more reactive oxygen species and suffers more serious oxidative stress when subjected to ischemia-reperfusion injury. We herein review the effects of reactive oxygen species on ischemia-reperfusion injury and non-alcoholic fatty liver injury as well as highlight several treatment approaches.

CDP-choline Corrects Alveolar Type II Cell Mitochondrial Dysfunction in Influenza-infected Mice

Development of ARDS in influenza A virus (IAV)-infected mice is associated with inhibition of alveolar type II (ATII) epithelial cell de novo phosphatidylcholine synthesis and administration of the phosphatidylcholine precursor CDP-choline attenuates IAV-induced ARDS in mice. We hypothesized inhibition of phosphatidylcholine synthesis would also impact the function of ATII cell mitochondria. To test this hypothesis, adult C57BL/6 mice of both sexes were inoculated intranasally with 10,000 p.f.u./mouse influenza A/WSN/33 (H1N1). Controls were mock-infected with virus diluent. Mice were treated with saline vehicle or CDP-choline (100 μg/mouse, i.p.) once daily from 1-5 days post-inoculation (dpi). ATII cells were isolated by a standard lung digestion protocol at 6 dpi for analysis of mitochondrial function. IAV infection increased uptake of the glucose analog 18F-FDG by the lungs and caused a switch from oxidative phosphorylation to aerobic glycolysis as a primary means of ATII cell ATP synthesis by 6 dpi. Infection also induced ATII cell mitochondrial depolarization and shrinkage, upregulation of PGC-1α, decreased cardiolipin content, and reduced expression of mitofusin 1, OPA1, DRP1, Complexes I and IV of the electron transport chain, and enzymes involved in cardiolipin synthesis. Daily CDP-choline treatment prevented the declines in oxidative phosphorylation, mitochondrial membrane potential, and cardiolipin synthesis resulting from IAV infection but did not fully reverse the glycolytic shift. CDP-choline also did not prevent the alterations in mitochondrial protein expression resulting from infection. Taken together, our data show ATII cell mitochondrial dysfunction following IAV infection results from impaired de novo phospholipid synthesis, but the glycolytic shift does not.

Citicoline and COVID-19-Related Cognitive and Other Neurologic Complications

With growing concerns about COVID-19’s hyperinflammatory condition and its potentially damaging impact on the neurovascular system, there is a need to consider potential treatment options for managing short- and long-term effects on neurological complications, especially cognitive function. While maintaining adequate structure and function of phospholipid in brain cells, citicoline, identical to the natural metabolite phospholipid phosphatidylcholine precursor, can contribute to a variety of neurological diseases and hypothetically toward post-COVID-19 cognitive effects. In this review, we comprehensively describe in detail the potential citicoline mechanisms as adjunctive therapy and prevention of COVID-19-related cognitive decline and other neurologic complications through citicoline properties of anti-inflammation, anti-viral, neuroprotection, neurorestorative, and acetylcholine neurotransmitter synthesis, and provide a recommendation for future clinical trials.

[Molecular and clinical aspects of the effect of cytidyndiphosphocholine on cognitive functions]

OBJECTIVE

Systematization of the array of publications on cytidyldiphosphocholine (CDP-choline).

MATERIAL AND METHODS

Systematic computer analysis of all currently available publications on CDP-choline (1750 publications in PUBMED) using the topological theory of big data analysis.

RESULTS

CDP-choline is essential for acetylcholine biosynthesis, phospholipid metabolism, and DNA methylation. The article describes the effects of CDP-choline on acetylcholinergic and other types of neurotransmission, anti-inflammatory, neuroprotective and neurotrophic effects of CDP-choline. Also, the paper presents the effects of the molecule on lipid metabolism and gene expression within the post-genomic paradigm (in particular, an increase in the expression of nicotinic and muscarinic acetylcholine receptors). The results of fundamental and clinical studies of CDP-choline in the treatment of cognitive impairments associated with cerebral ischemia and neurodegeneration are presented.

CONCLUSION

The pharmacological effects of CDP-choline are mediated through multiple molecular mechanisms that contribute to the nootropic action of this molecule.

Protective effects of citicoline-containing eye drops against UVB-Induced corneal oxidative damage in a rat model

It has been reported that citicoline increases antioxidant activity in some tissues. However, the effect of citicoline on corneal wound-healing has not yet been demonstrated. The aim was to investigate the protective effects of citicoline on ultraviolet B (UVB) radiation-induced corneal oxidative damage in a rat model. Four groups (eight animals each) were investigated: controls; UVB only; UVB/citicoline; and citicoline only. Corneal oxidative damage was induced by exposure to UVB radiation at 560 μW/cm² for five days in the UVB-exposed groups and 1% citicoline eye drops were applied (3xday) for eight days in the two citicoline groups. Corneal surface damage was evaluated by opacity and fluorescein staining. Corneal injury was assessed biochemically by measuring the concentrations of glutathione (GSH) and malondialdehyde (MDA) and the activity of corneal superoxide dismutase (SOD) and catalase. Matrix metalloproteinase (MMP) -2 and -9 and caspase-3 were evaluated by immunofluorescent staining and microscopic examination and by Western blot analysis. Corneal gene expression analysis was performed for vascular endothelial growth factor (VEGF), interleukin-1 beta (IL-1β) and transforming growth factor-beta (TGF-β). UVB radiation caused significant epithelial damage and evident opacity in the cornea, together with a local decrease in SOD, catalase and GSH activity. Corneal MDA concentrations increased with UVB exposure. The UVB/Citicoline group had significantly less corneal damage, greater SOD, catalase and GSH activity, and decreased MDA concentrations compared to the UVB only group (p < 0.05). Expression of TGF-β, IL-1β and VEGF was significantly lower in the citicoline/UVB group compared to the UVB group (p < 0.05). Interestingly, TGF-β expression was lower in the citicoline only group compared with controls. Immunfluorescent staining and Western blot analysis showed increased MMP-2, -9 and caspase-3 in the UVB only group compared with the UVB/citicoline group. It was shown that citicoline treatment may be effective in suppressing oxidative stress and controlling inflammation in UVB corneal injury.

[The role of citicoline in glaucoma]

Hintergrund

In den letzten Jahren wurde in vielen experimentellen und klinischen Studien gezeigt, dass bei der Glaukomerkrankung die neuronale Degeneration nicht nur auf der Höhe von Netzhaut und Sehnerv, sondern im Verlauf der gesamten Sehbahn und des Gehirns erfolgt.

Fragestellung

Dargestellt werden die neuroprotektive Wirkung und ihre Mechanismen von Citicolin bei der Glaukomerkrankung.

Material und Methode

Vor dem Hintergrund der Neuroanatomie, des Neuroimaging und der Pathogenese der Glaukomerkrankung wird die Relevanz erläutert. Die Daten der experimentellen und klinischen Studien werden dargelegt und ein Fazit für die klinische Anwendung gezogen.

Ergebnisse

Citicolin wirkt neuroprotektiv über glaukomrelevante Mechanismen. Die neuroprotektive Wirkung von Citicolin bei Offenwinkelglaukomen ist funktionell und morphologisch nachweisbar. Sie ist unabhängig vom Glaukomschaden und Augeninnendruck und tritt i. d. R. erst nach einem Jahr auf. Die Effekte von oralem Citicolin treten bei einer Tagesdosis von 500–1000 mg auf. Die Einnahme von Citicolin kann dauerhaft oder in Zyklen erfolgen. In den Studien traten bei der Einnahme von Citicolin keine Nebenwirkungen auf. Citicolin kann kognitive Leistungen und somit Therapieadhärenz sowie die Lebensqualität bei Glaukompatienten verbessern

Schlussfolgerung

Diese relativ alte nootrope Substanz, welche jetzt als Nahrungsergänzungsmittel vertrieben wird, scheint eine wertvolle Ergänzung zur konventionellen Therapie der Glaukomerkrankung und eine rationale Option zur Neuroprotektion und Prophylaxe zu sein.

Metabolomics analysis of annual killifish (Austrofundulus limnaeus) embryos during aerial dehydration stress

The annual killifish, Austrofundulus limnaeus, survives in ephemeral ponds in the coastal deserts of Venezuela. Persistence through the dry season is dependent on drought-resistant eggs embedded in the pond sediments during the rainy season. The ability of these embryos to enter drastic metabolic dormancy (diapause) during normal development enables A. limnaeus to survive conditions lethal to most other aquatic vertebrates; critical to the survival of the species is the ability of embryos to survive months and perhaps years without access to liquid water. Little is known about the molecular mechanisms that aid in survival of the dry season. This study aims to gain insight into the mechanisms facilitating survival of dehydration stress due to aerial exposure by examining metabolite profiles of dormant and developing embryos. There is strong evidence for unique metabolic profiles based on developmental stage and length of aerial exposure. Actively developing embryos exhibit more robust changes; however, dormant embryos respond in an active manner and significantly alter their metabolic profile. A number of metabolites accumulate in aerial-exposed embryos that may play an important role in survival, including the identification of known antioxidants and neuroprotectants. In addition, a number of unique metabolites not yet discussed in the dehydration literature are identified, such as lanthionine and 2-hydroxyglutarate. Despite high oxygen availability, embryos accumulate the anaerobic end product lactate. This paper offers an overview of the metabolic changes occurring that may support embryonic survival during dehydration stress due to aerial incubation, which can be functionally tested using genetic and pharmacological approaches.

MicroRNA-449b-5p targets HMGB1 to attenuate hepatocyte injury in liver ischemia and reperfusion

MicroRNAs (miRNAs) participate in the pathological process of liver ischemia/reperfusion (I/R) injury. MiR-449b-5p is the target miRNA of high mobility group box 1 (HMGB1). Its role and molecular mechanism in liver I/R injury remain unidentified. In this study, we found a protective effect of miR-449b-5p against hepatic I/R injury. HMGB1 expression significantly increased, whereas miR-449b-5p dramatically decreased in patients after liver transplant and in L02 cells exposed to hypoxia/reoxygenation (H/R). A dual-luciferase reporter assay confirmed the direct interaction between miR-449b-5p and the 3' untranslated region of HMGB1 messenger RNA. We also found that overexpression of miR-449b-5p significantly promoted cell viability and inhibited cell apoptosis of L02 cells exposed to H/R. Moreover, miR-449b-5p repressed HMGB1 protein expression and nuclear factor-κB (NF-κB) pathway activation in these L02 cells. In an in vivo rat model of hepatic I/R injury, overexpression of miR-449b-5p significantly decreased alanine aminotransferase and aspartate aminotransferase and inhibited the HMGB1/NF-κB pathway. Our study thus suggests that miR-449b-5p alleviated hepatic I/R injury by targeting HMGB1 and deactivating the NF-κB pathway, which may provide a novel and promising therapeutic target for hepatic I/R injury.

Cholinergic nervous system and glaucoma: From basic science to clinical applications

The cholinergic system has a crucial role to play in visual function. Although cholinergic drugs have been a focus of attention as glaucoma medications for reducing eye pressure, little is known about the potential modality for neuronal survival and/or enhancement in visual impairments. Citicoline, a naturally occurring compound and FDA approved dietary supplement, is a nootropic agent that is recently demonstrated to be effective in ameliorating ischemic stroke, traumatic brain injury, Parkinson's disease, Alzheimer's disease, cerebrovascular diseases, memory disorders and attention-deficit/hyperactivity disorder in both humans and animal models. The mechanisms of its action appear to be multifarious including (i) preservation of cardiolipin, sphingomyelin, and arachidonic acid contents of phosphatidylcholine and phosphatidylethanolamine, (ii) restoration of phosphatidylcholine, (iii) stimulation of glutathione synthesis, (iv) lowering glutamate concentrations and preventing glutamate excitotoxicity, (v) rescuing mitochondrial function thereby preventing oxidative damage and onset of neuronal apoptosis, (vi) synthesis of myelin leading to improvement in neuronal membrane integrity, (vii) improving acetylcholine synthesis and thereby reducing the effects of mental stress and (viii) preventing endothelial dysfunction. Such effects have vouched for citicoline as a neuroprotective, neurorestorative and neuroregenerative agent. Retinal ganglion cells are neurons with long myelinated axons which provide a strong rationale for citicoline use in visual pathway disorders. Since glaucoma is a form of neurodegeneration involving retinal ganglion cells, citicoline may help ameliorate glaucomatous damages in multiple facets. Additionally, trans-synaptic degeneration has been identified in humans and experimental models of glaucoma suggesting the cholinergic system as a new brain target for glaucoma management and therapy.

Propofol alleviates oxidative stress via upregulating lncRNA-TUG1/Brg1 pathway in hypoxia/reoxygenation hepatic cells

Reducing oxidative stress is an effective method to prevent hepatic ischaemia/reperfusion injury (HIRI). This study focuses on the role of propofol on the oxidative stress of hepatic cells and the involved lncRNA-TUG1/Brahma-related gene 1 (Brg1) pathway in HIRI mice. The mouse HIRI model was established and was intraperitoneally injected with propofol postconditioning. Hepatic injury indexes were used to evaluate HIRI. The oxidative stress was indicated by increasing 8-isoprostane concentration. Mouse hepatic cell line AML12 was treated with hypoxia and subsequent reoxygenation (H/R). The targeted regulation of lncRNA-TUG1 on Brg1 was proved by RNA pull-down, RIP (RNA-binding protein immunoprecipitation) and the expression level of Brg1 responds to silencing or overexpression of lncRNA-TUG1. Propofol alleviates HIRI and induces the upregulation of lncRNA-TUG1 in the mouse HIRI model. Propofol increases cell viability and lncRNA-TUG1 expression level in H/R-treated hepatic cells. In H/R plus propofol-treated hepatic cells, lncRNA-TUG1 silencing reduces cell viability and increased oxidative stress. LncRNA-TUG1 interacts with Brg1 protein and keeps its level via inhibiting its degradation. Brg1 overexpression reverses lncRNA-TUG1 induced the reduction of cell viability and the increase in oxidative stress. LncRNA-TUG1 silencing abrogates the protective role of propofol against HIRI in the mouse HIRI model. LncRNA-TUG1 has a targeted regulation of Brg1, and thereby affects the oxidative stress induced by HIRI. This pathway mediates the protective effect of propofol against HIRI of hepatic cell.

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.

Switching obese mothers to a healthy diet improves fetal hypoxemia, hepatic metabolites, and lipotoxicity in non-human primates

Objective

Non-alcoholic fatty liver disease (NAFLD) risk begins in utero in offspring of obese mothers. A critical unmet need in this field is to understand the pathways and biomarkers underlying fetal hepatic lipotoxicity and whether maternal dietary intervention during pregnancy is an effective countermeasure.

Methods

We utilized a well-established non-human primate model of chronic, maternal, Western-style diet induced obesity (OB-WSD) compared with mothers on a healthy control diet (CON) or a subset of OB-WSD mothers switched to the CON diet (diet reversal; OB-DR) prior to and for the duration of the next pregnancy. Fetuses were studied in the early 3rd trimester.

Results

Fetuses from OB-WSD mothers had higher circulating triglycerides (TGs) and lower arterial oxygenation suggesting hypoxemia, compared with fetuses from CON and OB-DR mothers. Hepatic TG content, oxidative stress (TBARs), and de novo lipogenic genes were increased in fetuses from OB-WSD compared with CON mothers. Fetuses from OB-DR mothers had lower lipogenic gene expression and TBARs yet persistently higher TGs. Metabolomic profiling of fetal liver and serum (umbilical artery) revealed distinct separation of CON and OB-WSD groups, and an intermediate phenotype in fetuses from OB-DR mothers. Pathway analysis identified decreased tricarboxylic acid cycle intermediates, increased amino acid (AA) metabolism and byproducts, and increased gluconeogenesis, suggesting an increased reliance on AA metabolism to meet energy needs in the liver of fetuses from OB-WSD mothers. Components in collagen synthesis, including serum protein 5-hydroxylysine and hepatic lysine and proline, were positively correlated with hepatic TGs and TBARs, suggesting early signs of fibrosis in livers from the OB-WSD group. Importantly, hepatic gluconeogenic and arginine related intermediates and serum levels of lactate, pyruvate, several AAs, and nucleotide intermediates were normalized in the OB-DR group. However, hepatic levels of CDP-choline and total ceramide levels remained high in fetuses from OB-DR mothers.

Conclusions

Our data provide new metabolic evidence that, in addition to fetal hepatic steatosis, maternal WSD creates fetal hypoxemia and increases utilization of AAs for energy production and early activation of gluconeogenic pathways in the fetal liver. When combined with hyperlipidemia and limited antioxidant activity, the fetus suffers from hepatic oxidative stress and altered intracellular metabolism which can be improved with maternal diet intervention. Our data reinforce the concept that multiple “first hits” occur in the fetus prior to development of obesity and demonstrate new biomarkers with potential clinical implications for monitoring NAFLD risk in offspring.

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Maternal WSD increases fetal hypoxemia and utilization of AAs for gluconeogenesis.

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Maternal WSD increases fetal oxidative stress and precursors to liver fibrosis.

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Carnosine and l-proline uniquely correlated with fetal TG and oxidative stress.

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Fetal TGs were correlated with fetal arterial oxygen saturation.

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Diet reversal in obese WSD mothers prevents fetal hypoxemia and oxidative stress.