Model Of Brain Damage Research Articles

Melatonin influences NO/NOS pathway and reduces oxidative and nitrosative stress in a model of hypoxic-ischemic brain damage

In this work, using a rat model combining ischemia and hypobaric hypoxia (IH), we evaluate the relationships between the antioxidant melatonin and the cerebral nitric oxide/nitric oxide synthase (NO/NOS) system seeking to ascertain whether melatonin exerts its antioxidant protective action by balancing this key pathway, which is highly involved in the cerebral oxidative and nitrosative damage underlying these pathologies.The application of the IH model increases the expression of the three nitric oxide synthase (NOS) isoforms, as well as nitrogen oxide (NOx) levels and nitrotyrosine (n-Tyr) impacts on the cerebral cortex. However, melatonin administration before IH makes nNOS expression response earlier and stronger, but diminishes iNOS and n-Tyr expression, while both eNOS and NOx remain unchanged. These results were corroborated by nicotine adenine dinucleotide phosphate diaphorase (NADPH-d) staining, as indicative of in situ NOS activity. In addition, the rats previously treated with melatonin exhibited a reduction in the oxidative impact evaluated by thiobarbituric acid reactive substances (TBARS). Finally, IH also intensified glial fibrillary acidic protein (GFAP) expression, reduced hypoxia-inducible factor-1alpha (HIF-1α), but did not change nuclear factor kappa B (NF-κB); meanwhile, melatonin did not significantly affect any of these patterns after the application of the IH model.The antioxidant melatonin acts on the NO/NOS system after IH injury balancing the release of NO, reducing peroxynitrite formation and protecting from nitrosative/oxidative damage. In addition, this paper raises questions concerning the classical role of some controversial molecules such as NO, which are of great consequence in the final fate of hypoxic neurons.We conclude that melatonin protects the brain from hypoxic/ischemic-derived damage in the first steps of the ischemic cascade, influencing the NO/NOS pathway and reducing oxidative and nitrosative stress.

Thrombopoietin Has Neural Protective Effect in a Neonatal Rat Model of Hypoxic-Ischemic Brain Damage

Objective: The infusion of bone marrow cells into the damaged brain has been proposed as a new clinical practice for this disorder. Alternatively, hematopoietic growth factors may have a direct role on neural protection or have a mobilizing effect on bone marrow stem/progenitor cells to circulation for brain repair. Based on our previous findings, there are many similarities between megakaryocytes and neurons on functions and antigen expression such as neural marker MAP2, GFAP and Tau, 5-HT2A, 2B and 2C receptors (Stem Cells, 2014). Thrombopoietin (TPO) is a growth factor for megakaryocytic lineage. We postulate that TPO may play a role on neural protection or regeneration. The effect of TPO on nervous system has not been well investigated.Methods: To validate this hypothesis, we investigated the expression and role of TPO/TPO receptors in neural cells and a neonatal rat model of hypoxic-ischemic (HIE) brain damage.Results: To investigate the effect of TPO on in-vivo neural protection, a neonatal rat model of HIE brain damage was established. Brain injury was measured by the percentage weight reduction of the ipsilateral cerebral hemisphere as compared to the contralateral hemisphere. There was significantly less brain atrophy in TPO treated animals (12.0±1.2% and 11.5±1.0%) when compared with the saline control (21.0±1.6% and 24.4±2.2%) at 7 and 28 days post-operation (P<0.05, n=12). The percentage of NSE (Neuron-specific enolase) positive cells in the forelimb area of the cortex in the right hemisphere was significantly higher in the TPO group than that of the saline group (P<0.05, n=12). An improvement in sensory motor functions was also demonstrated after TPO treatment. TPO mRNA was also identified in human cerebral hemispheres, cerebellum, and mouse neural stem cell line C17.2 by RT-PCR methods. TPO protein was detected in human cerebrospinal fluids (n=10) by ELISA. Moreover, TPO receptor (c-mpl) mRNA was identified in human cerebral hemispheres and cerebellum, and C17.2 cells using RT-PCR. The expression of c-mpl protein was also confirmed on neurons in the human cerebral hemispheres, hippocampus, cerebellum, brainstem and spinal cord using immune-cytochemical staining. TPO also showed a stimulating effect on the in-vitro growth of C17.2 cells by the MTT assay. TPO activated the phosphoinositide 3-kinase(PI3K)/Akt signaling pathway which was demonstrated by Western blot. The Akt activation by TPO was inhibited by the PI3-kinase inhibitor LY294002.Conclusions: Our study provided the evidences showing the expression of TPO and TPO receptor (c-mpl) in neural cells and this effect may be mediated by c-mpl and Akt signaling. More importantly, our observation further demonstrated the functional role of TPO on neural protection in a rat model. These findings point to the possibility of a new strategy for treating brain damage by hematopoietic growth factors. DisclosuresYang:National Natural Science Foundation of China: Other: National Natural Science Foundation of China(81270580).

Oral Administration of Sitagliptin Activates CREB and Is Neuroprotective in Murine Model of Brain Trauma.

Introduction: Traumatic brain injury is a major cause of mortality and morbidity. We have previously shown that the injectable glucagon-like peptide-1 (GLP-1) analog, liraglutide, significantly improved the outcome in mice after severe traumatic brain injury (TBI). In this study we are interested in the effects of oral treatment of a different class of GLP-1 based therapy, dipeptidyl peptidase IV (DPP-IV) inhibition on mice after TBI. DPP-IV inhibitors reduce the degradation of endogenous GLP-1 and extend circulation of this protective peptide in the bloodstream. This class has yet to be investigated as a potential therapy for TBI.Methods: Mice were administrated once-daily 50 mg/kg of sitagliptin in a Nutella® ball or Nutella® alone throughout the study, beginning 2 days before severe trauma was induced with a stereotactic cryo-lesion. At 2 days post trauma, lesion size was determined. Brains were isolated for immunoblotting for assessment of selected biomarkers for pathology and protection.Results: Sitagliptin treatment reduced lesion size at day 2 post-injury by ~28% (p < 0.05). Calpain-driven necrotic tone was reduced ~2-fold in sitagliptin-treated brains (p < 0.001) and activation of the protective cAMP-response element binding protein (CREB) system was significantly more pronounced (~1.5-fold, p < 0.05). The CREB-regulated, mitochondrial antioxidant protein manganese superoxide dismutase (MnSOD) was increased in sitagliptin-treated mice (p < 0.05). Conversely, apoptotic tone (alpha-spectrin fragmentation, Bcl-2 levels) and the neuroinflammatory markers IL-6, and Iba-1 were not affected by treatment.Conclusions: This study shows, for the first time, that DPP-IV inhibition ameliorates both anatomical and biochemical consequences of TBI and activates CREB in the brain. Moreover, this work supports previous studies suggesting that the effect of GLP-1 analogs in models of brain damage relates to GLP-1 receptor stimulation in a dose-dependent manner.

Feeling, learning from and being aware of inner states: interoceptive dimensions in neurodegeneration and stroke.

Interoception is a complex process encompassing multiple dimensions, such as accuracy, learning and awareness. Here, we examined whether each of those dimensions relies on specialized neural regions distributed throughout the vast interoceptive network. To this end, we obtained relevant measures of cardiac interoception in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal brain damage: behavioural variant fronto-temporal dementia (bvFTD), Alzheimer's disease (AD) and fronto-insular stroke. Neural correlates of the three dimensions were examined through structural and functional resting-state imaging, and online measurements of the heart-evoked potential (HEP). The three patient groups presented deficits in interoceptive accuracy, associated with insular damage, connectivity alterations and abnormal HEP modulations. Interoceptive learning was differentially impaired in AD patients, evidencing a key role of memory networks in this skill. Interoceptive awareness results showed that bvFTD and AD patients overestimated their performance; this pattern was related to abnormalities in anterior regions and associated networks sub-serving metacognitive processes, and probably linked to well-established insight deficits in dementia. Our findings indicate how damage to specific hubs in a broad fronto-temporo-insular network differentially compromises interoceptive dimensions, and how such disturbances affect widespread connections beyond those critical hubs. This is the first study in which a multiple lesion model reveals fine-grained alterations of body sensing, offering new theoretical insights into neuroanatomical foundations of interoceptive dimensions.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Estrogen receptors and estetrol-dependent neuroprotective actions: a pilot study.

Estetrol (E4) has strong antioxidative, neurogenic and angiogenic effects in neural system resulting in the attenuation of neonatal hypoxic–ischemic encephalopathy. We aimed to define the role of estrogen receptors in E4-dependent actions in neuronal cell cultures and prove the promyelinating effect of E4. In vitro the antioxidative and cell survival/proliferating effects of E4 on H2O2-induced oxidative stress in primary hippocampal cell cultures were studied using different combinations of specific inhibitors for ERα (MPP dihydrochloride), ERβ (PHTTP), GPR30 (G15) and palmytoilation (2-BR). LDH activity and cell survival assays were performed. In vivo the promyelinating role of different concentrations of E4 (1 mg/kg/day, 5 mg/kg/day, 10 mg/kg/day, 50 mg/kg/day) was investigated using the hypoxic–ischemic brain damage model in the 7-day-old immature rats before/after the induction of hypoxic–ischemic insult. Myelin basic protein (MBP) immunostaining was performed on brain coronal sections. Our results show that LDH activity is significantly upregulated in cell cultures where the E4’s effect was completely blocked by concomitant treatment either with ERα and ERβ inhibitors (MPP and PHTPP, respectively), or ERα and ERβ inhibitors combined with 2-BR. Cell survival is significantly downregulated in cell cultures where the effect of E4 was blocked by ERβ inhibitor (PHTTP) alone. The blockage of GRP30 receptor did affect neither LDH activity nor cell survival. MBP immunostaining is significantly upregulated in E4-pretreated groups at a concentration of 5 mg/kg/day and 50 mg/kg/day E4, whereas the MBP-positive area OD ratio is significantly increased in all the E4-treated groups. E4’s antioxidative actions mostly depend on ERα and ERβ, whereas neurogenesis and possibly promyelinating activities might be realized through ERβ.

P.7.a.005 - Long-term consequences in model of mild perinatal hypoxic brain damage in albino rat pups

P.7.a.005 - Long-term consequences in model of mild perinatal hypoxic brain damage in albino rat pups

Ammonium accumulation is a primary effect of 2-methylcitrate exposure in an in vitro model for brain damage in methylmalonic aciduria.

Using 3D organotypic rat brain cell cultures in aggregates we recently identified 2-methylcitrate (2-MCA) as the main toxic metabolite for developing brain cells in methylmalonic aciduria. Exposure to 2-MCA triggered morphological changes and apoptosis of brain cells. This was accompanied by increased ammonium and decreased glutamine levels. However, the sequence and causal relationship between these phenomena remained unclear. To understand the sequence and time course of pathogenic events, we exposed 3D rat brain cell aggregates to different concentrations of 2-MCA (0.1, 0.33 and 1.0mM) from day in vitro (DIV) 11 to 14. Aggregates were harvested at different time points from DIV 12 to 19. We compared the effects of a single dose of 1mM 2-MCA administered on DIV 11 to the effects of repeated doses of 1mM 2-MCA. Pan-caspase inhibitors Z-VAD FMK or Q-VD-OPh were used to block apoptosis. Ammonium accumulation in the culture medium started within few hours after the first 2-MCA exposure. Morphological changes of the developing brain cells were already visible after 17h. The highest rate of cleaved caspase-3 was observed after 72h. A dose-response relationship was observed for all effects. Surprisingly, a single dose of 1mM 2-MCA was sufficient to induce all of the biochemical and morphological changes in this model. 2-MCA-induced ammonium accumulation and morphological changes were not prevented by concomitant treatment of the cultures with pan-caspase inhibitors Z-VAD FMK or Q-VD-OPh: ammonium increased rapidly after a single 1mM 2-MCA administration even after apoptosis blockade. We conclude that following exposure to 2-MCA, ammonium production in brain cell cultures is an early phenomenon, preceding cell degeneration and apoptosis, and may actually be the cause of the other changes observed. The fact that a single dose of 1mM 2-MCA is sufficient to induce deleterious effects over several days highlights the potential damaging effects of even short-lasting metabolic decompensations in children affected by methylmalonic aciduria.

Glial response to 17β-estradiol in neonatal rats with excitotoxic brain injury

White-matter injury is the most common cause of the adverse neurodevelopmental outcomes observed in preterm infants. Only few options exist to prevent perinatal brain injury associated to preterm delivery. 17β-estradiol (E2) is the predominant estrogen in circulation and has been shown to be neuroprotective in vitro and in vivo. However, while E2 has been found to modulate inflammation in adult models of brain damage, how estrogens influence glial cells response in the developing brain needs further investigations. Using a model of ibotenate-induced brain injury, we have refined the effects of E2 in the developing brain. E2 provides significant neuroprotection both in the cortical plate and the white matter in neonatal rats subjected to excitotoxic insult mimicking white matter and cortical damages frequently observed in very preterm infants. E2 promotes significant changes in microglial phenotypes balance in response to brain injury and the acceleration of oligodendrocyte maturation. Maturational effects of E2 on myelination process were observed both in vivo and in vitro. Altogether, these data demonstrate that response of glial cells to E2 could be responsible for its neuroprotective properties in neonatal excitotoxic brain injury.

Effect of hyperbaric oxygen on lipid peroxidation and visual development in neonatal rats with hypoxia-ischemia brain damage.

The aim of the present study was to investigate the effect of hyperbaric oxygen (HBO) on lipid peroxidation and visual development in a neonatal rat model of hypoxic-ischemic brain damage (HIBD). The rat models of HIBD were established by delayed uterus dissection and were divided randomly into two groups (10 rats each): HIBD and HBO-treated HIBD (HIBD+HBO) group. Another 20 rats that underwent sham-surgery were also divided randomly into the HBO-treated and control groups. The rats that underwent HBO treatment received HBO (0.02 MPa, 1 h/day) 24 h after the surgery and this continued for 14 days. When rats were 4 weeks old, their flash visual evoked potentials (F-VEPs) were monitored and the ultrastructures of the hippocampus were observed under transmission electron microscope. The levels of superoxide dismutase (SOD) and malonyldialdehyde (MDA) in the brain tissue homogenate were detected by xanthine oxidase and the thiobarbituric acid colorimetric method. Compared with the control group, the ultrastructures of the pyramidal neurons in the hippocampal CA3 area were distorted, the latencies of F-VEPs were prolonged (P<0.01) and the SOD activities were lower while the MDA levels were higher (P<0.01) in the HIBD group. No significant differences in ultrastructure, the latency of F-VEPs or SOD/MDA levels were identified between the HBO-treated HIBD group and the normal control group (P>0.05). HBO enhances antioxidant capacity and reduces the ultrastructural damage induced by hypoxic-ischemia, which may improve synaptic reconstruction and alleviate immature brain damage to promote the habilitation of brain function.

Application of Cortexin for correcting the consequences of hypoxic-ischemic damage in the brain of infant rats

To verify if the peptide preparation Cortexin can be used to correct pathological processes in the CNS during perinatal ontogenesis, a set of physiological parameters (EMG, ECG, respiration, vagosympathetic balance) were recorded and analyzed in a rat perinatal hypoxic-ischemic brain damage (PHIBD) model and control infant rats. In experimental 7-day-old animals, PHIBD was modeled under inhalation ether anesthesia by ligation of the left common carotid artery and subsequent exposure to a gas mixture of 8% oxygen and 92% nitrogen. 1 h after exposure, animals were first injected intraperitoneally with cortexin (1 mg/kg); the preparation was then injected at a daily basis for 10 days. Both control animals and those after surgery but non-treated were injected with physiological solution. After 10 and 30 days after surgery, animals exhibited a delayed body weight gain versus control and significant differences in EMG intensity and spectral structure. Cortexin treatment induced on day 10 a transient improvement in EMG spectral structure but not amplitude; by day 30, the positive effect of cortexin was no longer observed. The respiration rate both in treated and non-treated animals was higher than in control. No significant changes in the heart rate were revealed in animals with PHIBD, but non-treated animals exhibited on day 30 a tendency towards its decrease. The heart rate variability (HRV) analysis showed that 10 days after trauma both non-treated and cortexin-treated animals exhibited a statistically significant shift in the vagosympathetic balance towards a parasympathetic prevalence. On day 30, cortexin treatment yields positive effects, while in non-treated animals the vagosympathetic balance shifts towards a humoral-metabolic and sympathetic prevalence. Cortexin injection to intact rats leads to significant disturbances in the vagosympathetic balance, cardiac and, to a lesser extent, respiratory rhythms, and can cause stable disturbances in activity of the somatic and vegetative nervous systems.

TLR2/NFκB signalling regulates endogenous IL-6 release from marrow-derived mesenchymal stromal cells to suppress the apoptosis of PC12cells injured by oxygen and glucose deprivation.

Two previous studies published by our group identified that mesenchymal stromal cells (MSCs) conferred neuroprotection in a rat model of hypoxic-ischaemic brain damage (HIBD), and that MSCs secreted abundant interleukin-6 (IL‑6) when co‑cultured with oxygen and glucose deprivation (OGD)‑injured PC12cells. The present study has further investigated the role of IL‑6, and explored potential signalling pathways invitro. Invitro models were established by co‑culturing OGD‑injured PC12cells with MSCs. Subsequently, the expression levels of the signalling molecules, Toll‑like receptor2 (TLR2)/nuclear factorκB (NFκB), and IL‑6 were altered separately in this invitro model by treatment with an agonist, antagonist, siRNA or overexpression adenovirus. The expression levels of Bcell lymphoma‑associated X (Bax), TLR2, NFκB and IL‑6 were detected by western blot analysis, real‑time polymerase chain reaction or ELISA. The resting membrane potential (RMP) of the PC12cells was analysed by whole‑cell patch‑clamp recordings. Compared with controls or the PC12 co‑culture group, the MSC co‑cultured group induced less expression of Bax, but more IL‑6 secretion. Up- or down-regulation of the TLR2/NFκB signalling pathway resulted in a corresponding increase or decrease in the IL‑6 expression level in the MSCs. Co‑culture with siIL‑6‑MSCs increased the expression levels of Bax and increased the RMP in the OGD PC12cells. In conclusion, the release of IL‑6 from MSCs was regulated via the TLR2/NFκB signalling pathway. Endogenous IL‑6 reduced apoptosis and protected OGD‑injured PC12cells when they were co‑cultured with MSCs. The present study has reported a novel immunomodulatory effect of the microenvironment of neural damage during MSC cytotherapy.

The Impact of Previous Physical Training on Redox Signaling after Traumatic Brain Injury in Rats: A Behavioral and Neurochemical Approach.

Throughout the world, traumatic brain injury (TBI) is one of the major causes of disability, which can include deficits in motor function and memory, as well as acquired epilepsy. Although some studies have shown the beneficial effects of physical exercise after TBI, the prophylactic effects are poorly understood. In the current study, we demonstrated that TBI induced by fluid percussion injury (FPI) in adult male Wistar rats caused early motor impairment (24 h), learning deficit (15 days), spontaneous epileptiform events (SEE), and hilar cell loss in the hippocampus (35 days) after TBI. The hippocampal alterations in the redox status, which were characterized by dichlorofluorescein diacetate oxidation and superoxide dismutase (SOD) activity inhibition, led to the impairment of protein function (Na(+), K(+)-adenosine triphosphatase [ATPase] activity inhibition) and glutamate uptake inhibition 24 h after neuronal injury. The molecular adaptations elicited by previous swim training protected against the glutamate uptake inhibition, oxidative stress, and inhibition of selected targets for free radicals (e.g., Na(+), K(+)-ATPase) 24 h after neuronal injury. Our data indicate that this protocol of exercise protected against FPI-induced motor impairment, learning deficits, and SEE. In addition, the enhancement of the hippocampal phosphorylated nuclear factor erythroid 2-related factor (P-Nrf2)/Nrf2, heat shock protein 70, and brain-derived neurotrophic factor immune content in the trained injured rats suggests that protein expression modulation associated with an antioxidant defense elicited by previous physical exercise can prevent toxicity induced by TBI, which is characterized by cell loss in the dentate gyrus hilus at 35 days after TBI. Therefore, this report suggests that previous physical exercise can decrease lesion progression in this model of brain damage.

Establishment and identification of a hypoxia-ischemia brain damage model in neonatal rats.

The present study was designed to set up a reliable model of severe hypoxia-ischemia brain damage (HIBD) in neonatal rats and several methods were used to identify whether the model was successful. A total of 40 healthy 7-day-old Sprague-Dawley rats were randomly divided into 2 groups: The sham-surgery group (n=18) and the HIBD model group (n=22). The HIBD model was produced according to the traditional Rice method. The rats were anesthetized with ethyl ether. The left common carotid artery (CCA) was exposed, ligated and cut. Following this, the rats were exposed to hypoxia in a normobaric chamber filled with 8% oxygen and 92% nitrogen for 2 h. In the sham-surgery group, the left CCA was exposed but was not ligated, cut or exposed to hypoxia. The neurobehavioral changes of the rats were observed in the 24 h after HIBD. The brains were collected after 72 h to observe the pathological morphological changes of the brain tissue. The behavioral ability and neurobehavioral changes were studied in each group. The water maze test was used for evaluating the learning-memory ability when the rats were 28 days old. Compared with the sham-surgery group, all the HIBD model rats had a lag of motor development. The rats had evident changes in anatomy and Nissl staining, and cognitive impairment was shown through the result of the water maze. Therefore, the model of HIBD in neonatal rats is feasible and provides a reliable model for subsequent studies.

A microRNA-152 that targets the phosphatase and tensin homolog to inhibit low oxygen induced-apoptosis in human brain microvascular endothelial cells.

Brain damage caused by perinatal asphyxia is dangerous for neonatal infants, but the mechanism by which it occurs remains elusive. In this study, microRNA-152 (miR-152) expression was induced by low oxygen levels in rat models of hypoxia brain damage, as well as in human brain microvascular endothelial cells (HBMECs) cultured in vitro. Analysis of the sequence of miR-152 revealed that the phosphatase and tensin homolog gene (PTEN) is probably the target of miR-152 both in humans and rats. When HBMECs were transfected with miR-152 mimics, PTEN expression was inhibited at both the mRNA and protein levels. Moreover, transfection with the miR-152 mimic also inhibited apoptosis induced by hypoxia. Furthermore, expression of the pro-apoptotic gene Bax was downregulated while the anti-apoptotic gene Bcl2 was upregulated after miR-152 mimic transfection. Taken together, these results indicate that miR-152 induced by hypoxia suppresses cell apoptosis and acts as a protective factor during hypoxia by repressing PTEN.

Zebrafish (Danio rerio) Developed as an Alternative Animal Model for Focal Ischemic Stroke.

Thrombotic cerebral ischemia is one of the leading causes of mortality and chronic disability. Animal models provide an essential tool for understanding the complex cellular and molecular pathophysiology of ischemia and for improving treatment and testing novel neuroprotective drugs in the preclinical setting. In this study, we tested zebrafish as a novel model for thrombotic ischemic brain damage. Zebrafish were intraperitoneally injected with Rose Bengal and light exposure was directed onto the optic tectum region of the brain to induce photothrombosis. After full recovery from anesthesia, zebrafish consistently exhibited abnormal swimming patterns, indicating brain injury from the procedure. The staining of 2,3,5-triphenyltetrazolium chloride (TTC) 24 h after the treatment showed lack of staining of the exposed area of the brain, which further confirmed the ischemic injury. Application of Activase®-tPA improved viability of the brain. The tPA treatment also reduced the occurrence of moving disability as well as the mortality rate, demonstrating that the zebrafish model not only showed focal ischemic injury but also responded well to tPA therapy. Our results suggest that the current photothrombotic method induced focal ischemia in zebrafish and produced consistent brain damage that can be measured by behavioral changes and quantified by histological staining.

Prevention of chemotherapy-induced peripheral neuropathy by the small-molecule inhibitor pifithrin-μ.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment. It is the most frequent cause of dose reduction or treatment discontinuation in patients treated for cancer with commonly used drugs including taxanes and platinum-based compounds. No FDA-approved treatments for CIPN are available. In rodents, CIPN is represented by peripheral mechanical allodynia in association with retraction of intraepidermal nerve fibers. The mechanism of chemotherapy-induced neurotoxicity is unclear, but it has been established that mitochondrial dysfunction is an important component of the dysregulation in peripheral sensory neurons. We have shown earlier that inhibition of mitochondrial p53 accumulation with the small compound pifithrin-μ (PFT-μ) prevents cerebral neuronal death in a rodent model of hypoxic-ischemic brain damage. We now explore whether PFT-μ is capable of preventing neuronal mitochondrial damage and CIPN in mice. We demonstrate for the first time that PFT-μ prevents both paclitaxel- and cisplatin-induced mechanical allodynia. Electron microscopic analysis of peripheral sensory nerves revealed that PFT-μ secured mitochondrial integrity in paclitaxel-treated mice. In addition, PFT-μ administration protects against chemotherapy-induced loss of intraepidermal nerve fibers in the paw. To determine whether neuroprotective treatment with PFT-μ would interfere with the antitumor effects of chemotherapy, ovarian tumor cells were cultured in vitro with PFT-μ and paclitaxel. Pifithrin-μ does not inhibit tumor cell death but even enhances paclitaxel-induced tumor cell death. These data are the first to identify PFT-μ as a potential therapeutic strategy for prevention of CIPN to combat one of the most devastating side effects of chemotherapy.

Prevention of chemotherapy-induced peripheral neuropathy by the small-molecule inhibitor Pifithrin-mu in a mouse model

Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of cancer treatment and a frequent cause of treatment discontinuation. No FDA-approved treatments for CIPN are available. In rodents CIPN is represented by peripheral mechanical hyperalgesia in association with retraction of intra-epidermal nerve fibers (IENFs). The mechanism of chemotherapy-induced neurotoxicity is unclear but it has been established that mitochondrial dysfunction is an important component of the dysregulation. We have shown earlier that inhibition of mitochondrial p53 accumulation with the small compound pifithrin-mu (PFT-mu) prevents cerebral neuronal death in a rodent model of hypoxic-ischemic brain damage. We now explored whether PFT- mu is capable of preventing neuronal mitochondrial damage and CIPN in mice. We demonstrate for the first time that PFT-mu prevents both paclitaxel- and cisplatin-induced mechanical hyperalgesia. Electron microscopic analysis of peripheral sensory nerves revealed that PFT-mu secured mitochondrial integrity in paclitaxel-treated mice. In addition, PFT-mu administration protected against chemotherapy-induced loss of IENFs in the paw. To determine whether neuroprotective treatment with PFT-mu would interfere with the anti-tumor effects of chemotherapy, ovarian tumor cells were cultured in vitro with PFT-mu and paclitaxel. The results showed that PFT-mu does not inhibit tumor cell death but even enhances paclitaxel-induced tumor cell death. These data are the first to identify PFT-mu as a potential therapeutic strategy for prevention of CIPN to combat the devastating side effects of chemotherapy.

Activating mitochondrial function and haemoglobin expression with EH‐201, an inducer of erythropoietin in neuronal cells, reverses memory impairment

Background and PurposeMemory impairment can be progressive in neurodegenerative diseases, and physiological ageing or brain injury, mitochondrial dysfunction and oxidative stress are critical components of these issues. An early clinical study has demonstrated cognitive improvement during erythropoietin treatment in patients with chronic renal failure. As erythropoietin cannot freely cross the blood–brain barrier, we tested EH-201 (2,3,5,4′-tetrahydroxystilbene-2-O-β-d-glucoside, also known as TSG), a low MW inducer of erythropoietin, for its therapeutic effects on memory impairment in models of neurodegenerative diseases, physiological ageing or brain injury.Experimental ApproachThe effects of EH-201 were investigated in astrocytes and PC12 neuronal-like cells. In vivo, we used sleep-deprived (SD) mice as a stress model, amyloid-β (Aβ)-injected mice as a physiological ageing model and kainic acid (KA)-injected mice as a brain damage model to assess the therapeutic effects of EH-201.Key ResultsEH-201 induced expression of erythropoietin, PPAR-γ coactivator 1α (PGC-1α) and haemoglobin in astrocytes and PC12 neuronal-like cells. In vivo, EH-201 treatment restored memory impairment, as assessed by the passive avoidance test, in SD, Aβ and KA mouse models. In the hippocampus of mice given EH-201 in their diet, levels of erythropoietin, PGC-1α and haemoglobin were increasedConclusions and ImplicationsThe induction of endogenous erythropoietin in neuronal cells by inducers such as EH-201 might be a therapeutic strategy for memory impairment in neurodegenerative disease, physiological ageing or traumatic brain injury.

The Effects of Thymoquinone on Nitric Oxide and Superoxide Dismutase Levels in a Rat Model of Diazinon-induced Brain Damage

Diazinon (DI) is an organophosphate. Thymoquinone (TQ) is produced from Nigella sativa. This study was a biochemical investigation of the protective properties of TQ as a supportive treatment in brain damage caused by diazinon. Rats were divided into four groups of eight, as follows: Group 1, control; group 2, DI; group 3, DI + TQ; and group 4, TQ. Groups 2 and 3 received DI. Groups 3 and 4 received TQ. In group 2, NO levels were higher and SOD levels were lower compared to the control group. In groups 3 and 4, NO levels were lower and SOD levels were higher than in either the control or group 2. In group 4, DNA damage was lower than in group 2, but the difference between groups 2 and 3 was not significant. The results suggest that TQ, because of its antioxidant properties, can be used to treat oxidative stress caused by DI intoxication.

Effect of transplantation of adipose-derived multipotent mesenchymal stromal cells on the nervous tissue and behavioral responses in a mouse model of periventricular leukomalacia

The study of opportunities to use stem cells of different origins in the treatment and rehabilitation of patients with perinatal pathology of the central neural system (CNS) is important.The aim of our study was to evaluate the effects of transplantation of multipotent mesenchymal stromal cells (MMSСs) from adipose tissue in mice with experimental model of cerebral palsy – periventricular leukomalacia (PVL).Materials and methods. PVL was modeled by unilateral coagulation of common carotid artery in mice line FVB on sixth day after birth followed by exposure to hypoxia (6 % O2) with intraperitoneal injection of the endotoxin lipopolysaccharide 1 mg/kg. For transplantation we used MMSСs from adipose tissue of the 2nd passage derived from mice FVB-Cg-Tg(GFPU)5Nagy/J. Syngeneic transplantation of GFP-positive MMSСs suspension into seven-day-old (P7) animals with a model of perinatal brain damage was performed stereotactically into right hemisphere in 24 hours after PVL. Corticospinal function of the control animals and the mice with PVL was assessed by testing reaching and retrieval of food rewards.Results. After modeling PVL operated animals lagged in development, had less weight, height and disorders of static and kinetic reflex compared to non-operated control mice. Animals with PVL had lower rates of successful attempts at obtaining food: the percentage of successful attempts in control animals was 58 ± 3 % and in animals with PVL – 23 ± 4 %. In the group of animals with MMSСs transplantation after PVL modeling corticospinal function recovery was observed and the number of successful attempts was 43 ± 4 %.Conclusions. Syngeneic stereotactic transplantation of multipotent mesenchymal stromal cells from adipose tissue contributes to the restoration of behavioral responses in animals after PVL and improves cytoarchitectonics in the focus of brain damage