Changes in plasma lipoxin A4, resolvins and CD59 levels after ischemic and traumatic brain injuries in rats

Ischemic and traumatic brain injuries are the major acute central nervous system disorders that need to be adequately diagnosed and treated. To find biomarkers for these acute brain injuries, plasma levels of some specialized pro-resolving mediators (SPMs, i.e., lipoxin A4 [LXA4], resolvin [Rv] E1, RvE2, RvD1 and RvD2), CD59 and interleukin (IL)-6 were measured at 0, 6, 24, 72, and 168 h after global cerebral ischemic (GCI) and traumatic brain injuries (TBI) in rats. Plasma LXA4 levels tended to increase at 24 and 72 h after GCI. Plasma RvE1, RvE2, RvD1, and RvD2 levels showed a biphasic response to GCI; a significant decrease at 6 h with a return to the levels of the sham group at 24 h, and again a decrease at 72 h. Plasma CD59 levels increased at 6 and 24 h post-GCI, and returned to basal levels at 72 h post-GCI. For TBI, plasma LXA4 levels tended to decrease, while RvE1, RvE2, RvD1, and RvD2 showed barely significant changes. Plasma IL-6 levels were significantly increased after GCI and TBI, but with different time courses. These results show that plasma LXA4, RvE1, RvE2, RvD1, RvD2, and CD59 levels display differential responses to GCI and TBI, and need to be evaluated for their usefulness as biomarkers.

Changes in plasma lipoxin A4, resolvins and CD59 levels after ischemic and traumatic brain injuries in rats

Ischemic and traumatic brain injuries are the major acute central nervous system disorders that need to be adequately diagnosed and treated. To find biomarkers for these acute brain injuries, plasma levels of some specialized pro-resolving mediators (SPMs, i.e., lipoxin A4 [LXA4], resolvin [Rv] E1, RvE2, RvD1 and RvD2), CD59 and interleukin (IL)-6 were measured at 0, 6, 24, 72, and 168 h after global cerebral ischemic (GCI) and traumatic brain injuries (TBI) in rats. Plasma LXA4 levels tended to increase at 24 and 72 h after GCI. Plasma RvE1, RvE2, RvD1, and RvD2 levels showed a biphasic response to GCI; a significant decrease at 6 h with a return to the levels of the sham group at 24 h, and again a decrease at 72 h. Plasma CD59 levels increased at 6 and 24 h post-GCI, and returned to basal levels at 72 h post-GCI. For TBI, plasma LXA4 levels tended to decrease, while RvE1, RvE2, RvD1, and RvD2 showed barely significant changes. Plasma IL-6 levels were significantly increased after GCI and TBI, but with different time courses. These results show that plasma LXA4, RvE1, RvE2, RvD1, RvD2, and CD59 levels display differential responses to GCI and TBI, and need to be evaluated for their usefulness as biomarkers.

Increased Poly (ADP-ribose) Polymerase Activation in the 6-Hydroxydopamine Induced Dopaminergic Neuronal Cell Death

BACKGROUND: The pathological hallmark of Parkinson's disease (PD) is dopaminergic cell death in the substantia nigra (SN), but the cause of cell death is unknown. 6-Hydroxydopamine (6-OHDA) is one of the neurotoxins used in experimental models of PD, and its use has led to greater understanding of the pathogenesis of PD. The present study examined the role of poly(ADP-ribose) polymerase (PARP) in 6-OHDA toxicity. METHODS: An in-vitro study was performed using PC12 cells. After treatment with 6-OHDA, the poly(ADP-ribosyl) ation was monitored using a monoclonal antibody to poly(ADP-ribose) (PAR) to examine the PARP activity. To evaluate the effect of the PARP inhibition in 6-OHDA-induced cell death, 3-aminobenzamide or nicotinamide was administered 30 minutes before 6-OHDA treatment. An in-vivo study was performed using a Parkinson rat model. 6-OHDA was stereotactically injected into the unilateral SN of rats. PAR immunolabeling was used to examine the time-dependent activation of PARP. The dopaminergic cell death in the SN was quantified using apomorphine-induced rotations and tyrosine hydroxylase- immunoreactive cell numbers in the SN 2 weeks after lesioning. RESULTS: Poly(ADP-ribosyl)ation of nuclear proteins was maximal at 6 hr, and was still present 24 hr after 6-OHDA treatment. Pretreatment of 3-aminobenzamide or nicotinamide significantly attenuated the 6-OHDA-induced PC12 cell death. In 6-OHDA injected rats, PAR formation was seen 6 hr after 6-OHDA injection, peaked at 12 hr, and was still detectable at 24 hr. The dopaminergic cell death in the SN was significantly decreased by intraperitoneal injection of nicotinamide in 6-OHDA injected rats. CONCLUSIONS: These results provide evidence suggesting an involvement of the PARP in 6-OHDA-induced dopaminergic cell death, and inhibitors of PARP may have a protective benefit in PD.

Anti-oxidative neuroprotection by estrogens in mouse cortical cultures

Estrogen replacement therapy in postmenopausal women may reduce the risk of Alzheimer's disease, possibly by ameliorating neuronal degeneration. In the present study, we examined the neuroprotective spectrum of estrogen against excitotoxicity, oxidative stress, and serum-deprivation-induced apoptosis of neurons in mouse cortical cultures. 17beta-estradiol as well as 17alpha-estradiol and estrone attenuated oxidative neuronal death induced by 24 hr exposure to 100 microM FeCl2, excitotoxic neuronal death induced by 24 hr of exposure to 30 microM N-methyl-D-aspartate (NMDA) and serum-deprivation induced neuronal apoptosis. Furthermore, estradiol attenuated neuronal death induced by Abeta25-35. However, all these neuroprotective effects were mediated by the anti-oxidative action of estrogens. When oxidative stress was blocked by an antioxidant trolox, estrogens did not show any additional protection. Addition of a specific estrogen receptor antagonist ICI182,780 did not reverse the protection offered by estrogens. These findings suggest that high concentrations of estrogen protect against various neuronal injuries mainly by its anti-oxidative effects as previously shown by Behl et al. Our results do not support the view that classical estrogen receptors mediate neuroprotection.

Anti-oxidative neuroprotection by estrogens in mouse cortical cultures

Estrogen replacement therapy in postmenopausal women may reduce the risk of Alzheimer's disease, possibly by ameliorating neuronal degeneration. In the present study, we examined the neuroprotective spectrum of estrogen against excitotoxicity, oxidative stress, and serum-deprivation-induced apoptosis of neurons in mouse cortical cultures. 17beta-estradiol as well as 17alpha-estradiol and estrone attenuated oxidative neuronal death induced by 24 hr exposure to 100 microM FeCl2, excitotoxic neuronal death induced by 24 hr of exposure to 30 microM N-methyl-D-aspartate (NMDA) and serum-deprivation induced neuronal apoptosis. Furthermore, estradiol attenuated neuronal death induced by Abeta25-35. However, all these neuroprotective effects were mediated by the anti-oxidative action of estrogens. When oxidative stress was blocked by an antioxidant trolox, estrogens did not show any additional protection. Addition of a specific estrogen receptor antagonist ICI182,780 did not reverse the protection offered by estrogens. These findings suggest that high concentrations of estrogen protect against various neuronal injuries mainly by its anti-oxidative effects as previously shown by Behl et al. Our results do not support the view that classical estrogen receptors mediate neuroprotection.

A Case of Internal Carotid Artery Dissection Presenting with Isolated Hypoglossal Nerve Palsy

Neurological manifestations of internal carotid aretry (ICA) dissection include amaurosis fugax, cerebral ischemia, oculosympathetic paresis, and various cranial nerve palsies. Isolated hypoglossal nerve palsy is a rare manifestation of ICA dissection. A 55-year-old man developed dysarthria following sudden pain in the left retroauricular area. His tongue was paralysed on the left side. Magnetic resonance image and carotid angiogram showed characteristic features of left ICA dissection, which may be the most plausible cause of hypoglossal nerve palsy in this patient. Expanding hematoma of dissecting aneurysm of ICA seems to have compressed the nutrient artery of the hypoglossal nerve, although the possibility of direct compression of the hypoglossal nerve itself is not completely ruled out.

Zinc translocation and heat shock protein induction in rat brains following kainate seizures / 대한해부학회지

Translocation of synaptic zinc may mediate neuronal death in pathological conditions. In this study, we examined the possible correlation between zinc translocation and heat shock protein (HSP)72 induction in rat brains following kainate seizures. Zinc accumulation, visualized by Timm's method, occurred in degenerating neurons in hippocampus, amygdala, and cortex 6~24 h after kainate injection. Immunohistochemistry with anti-HSP72 antibody revealed HSP induction largely in areas where zinc accumulation occurred. At the cellular level, however, most HSP72 immunoreac-tive neurons were found to be Timm (-) and morphologically intact. Present results suggest that intense zinc translocation may induce neuronal death before possible HSP induction. However, we could not rule out the possibility that sublethal zinc translocation, below the detection limit by Timm's method, may play a role in HSP72 induction.

Proton Nuclear MR Spectroscopy (H-MRS) in Adult Onset Hallervorden-Spatz Disease

Background & Significance : Hallervorden-Spatz disease (HSD) is a rare neurologic disorder characterized by progressive dystonia, retinal degeneration, pyramidal sign, and mental deterioration. The neuropathological findings include preferential deposition of iron within the extrapyramidal nuclei, including globus pallidus, substantia nigra, and red nuclei. The final diagnosis depends on the typical pathologic findings. MRI brain imaging study commonly shows so-called "eye-of-the-tiger" in the globus pallidus. However 1H-MRS findings of HSD have not been reported. We experienced a case with clinically suspicious HSD whose diagnosis was further supported by 1H-MRS. Case : A forty four year-old man presented with slowly progressive dystonia for six years. He had been well until age of thirty eight, when he noticed clumsy hand-writing. Three years later, he developed difficulty in chewing. Clumsiness of his hands and arm movements progressed to the point of difficulty in using spoon and chopsticks. While walking, arm swing was decreased and both arms and neck took more dystonic posture. Brain MRI (T2Wl) showed symmetric high signal intensity lesions in the globus pallidus, surrounded by a peripheral zone of exaggerated low signal. On 1H-MRS of basal ganglia, although choline, creatine and N-acetyl-aspartate (NAA) peaks were detected, marked noise probably due to paramagnetic substance (iron), made quantitative analysis difficult. Conclusion : 1H-MRS of HSD is characterized by "noise", which may be suggestive of HSD.