Laboratory StudyEffects of citicoline used alone and in combination with mild hypothermia on apoptosis induced by focal cerebral ischemia in rats
Introduction
Neuronal cell death during stroke occurs, particularly in the central zone, by necrotic and apoptotic mechanisms.1 Apoptosis following cerebral ischemia/reperfusion is a major pathway leading to cell death; the presence of apoptotic cells in the penumbra suggests that apoptosis may contribute to the final infarct size.2 Proapoptotic protein translocation during cerebral ischemia/reperfusion is controlled by the family of Bcl-2 proteins. The anti-apoptotic protein Bcl-2 has been implicated following brain injury, and is thought to provide protection after transient focal ischemia.3
In this study, we tested the effects of the combination of hypothermia, which has elicited neuroprotective effects in experimental and clinical studies,[4], [5], [6], [7] and citicoline, an endogenous compound that stabilizes membrane function and reduces free radical generation, during cerebral ischemia.[8], [9], [10] Krupinski et al.11 showed that citicoline may directly interact with the apoptotic cascade by inhibiting pro-caspase expression and caspase activation, and suggested that this effect was probably due to the interaction of citicoline with phosphatidylcholine metabolism. Study of the combination of hypothermia and citicoline on cerebral ischemia seems rational, since these agents act through different mechanisms and may therefore have a synergistic effect.
We investigated the neuroprotective effects of citicoline and mild hypothermia (34 ± 1 °C), used either alone or in combination, on apoptotic processes using the middle cerebral artery occlusion (MCAo) model. The purpose of the study was to determine whether the combination treatment showed additive benefit in reducing apoptosis.
Section snippets
Materials and methods
The experimental procedures and protocols used in this study were reviewed and approved by our Institutional Committee on Animal Research, and were carried out in accordance with its guidelines.
Results
There were no differences in body weight of the rats in any of the groups. Body temperatures (mean ± standard deviation) of Group 4 and Group 5 rats were significantly reduced due to hypothermia (Group 1: 37.08 ± 0.03; Group 2: 37.22 ± 0.01; Group 3: 36.98 ± 0.03; Group 4: 33.96 ± 0.26; Group 5: 33.95 ± 0.03) (p > 0.05).
Immediately after MCAo, LCBF measurements (mL LD/100 g per minute) decreased sharply by over 50% compared to controls. All groups exhibited significant decreases in LCBF after MCAo. The
Discussion
There is increasing evidence that some neuronal death after brain ischemia is mediated by the action of cysteine-requiring aspartate directed proteases (caspases), the proteases responsible for apoptosis in mammals.18 Caspase-mediated neuronal death is more extensive after transient than permanent focal brain ischemia, and may contribute to delayed loss of neurons in the penumbral region of infarcts. The intracellular processes that contribute to caspase-mediated neuronal death following
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Late treatment with choline alfoscerate (L-alpha glycerylphosphorylcholine, α-GPC) increases hippocampal neurogenesis and provides protection against seizure-induced neuronal death and cognitive impairment
2017, Brain ResearchCitation Excerpt :This result is similar to that of a previous study using another choline precursor, citicoline (CDP-choline; cytidine 5′-diphosphocholine) (Kim et al., 2015). High doses of CDP-choline actually aggravated neuronal death, suggesting that CDP-choline or possibly also α-GPC may have negligible neuroprotective effects in pilocarpine-induced seizure, distinct from studies in other brain injury settings such as ischemia and traumatic brain injury (TBI) studies (Adibhatla and Hatcher, 2005; Sahin et al., 2010; Schabitz et al., 1996). The exact mechanism for why CDP-choline showed adverse effects in pilocarpine seizure-induced neuronal death is not clear.
Cytidine 5-diphosphocholine (CDP-choline) adversely effects on pilocarpine seizure-induced hippocampal neuronal death
2015, Brain ResearchCitation Excerpt :Citicoline (CDP-choline; cytidine 5′-diphosphocholine), a naturally occurring endogenous compound, is an important intermediate in the biosynthesis of cell membrane phospholipids (Kennedy and Weiss, 1956). The ability of citicoline to reverse or prevent neuronal injury has been previously tested in animal models of cerebral ischemia (Adibhatla and Hatcher, 2005; Sahin et al., 2010; Schabitz et al., 1996). Citicoline improved the outcome in a randomized, double-blind, placebo-controlled, multicenter clinical Phase III trial (International Citicoline Trial on Acute Stroke [ICTUS]), but provided inconclusive results in recent clinical trials (Davalos et al., 2012).
CDP-choline treatment induces brain plasticity markers expression in experimental animal stroke
2012, Neurochemistry InternationalCitation Excerpt :Additionally, CDP-choline is able to produce antinociception in different models of acute or chronic pain in rats by potentiating endogenous cholinergic activity without impairing motor coordination (Hamurtekin and Gurun, 2006) through the activation of neuronal nicotinic acetylcholine receptors (nAChRs) (Flores, 2000; Decker et al., 2004). Preclinical studies have shown that CDP-choline decreases infarct volume, edema and apoptosis, and limits neurological deficits, either alone or in combination with other agents (Schabitz et al., 1996, 1999; Alonso de Leciñana et al., 2006; Gutiérrez et al., 2006; Sahin et al., 2010). What is more, CDP-choline is a safe and well-tolerated drug in the treatment of stroke (Dávalos et al., 2002).
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