Microtubule-associated Protein 2 Expression Research Articles

Ginsenoside Rb1 increases synaptophysin and microtubule-associated protein 2 mRNA expression in primary cultures of rat hippocampal neurons

Ginsenoside Rb1 has been determined to exert diverse neuromodulatory effects including a stimulatory effect on synaptic formation. Synaptophysin and microtubule-associated protein 2 (MAP2) are synaptic proteins which play vital roles in neurotransmission regulation and synaptic structural stability. The present data revealed that ginsenoside Rb1 enhanced mRNA expression of synaptic markers, synaptophysin and MAP2, in primary cultured rat hippocampal neurons. Our results newly add synaptophysin and MAP2 to the list of genes of which mRNA expression is modulated by ginsenosides. Our finding contributes further understanding of medical usefulness of ginsenoside Rb1 targeting hippocampal network alteration which is commonly observed in aging and neurodegenerative disorders.

Phosphorylation of Akt is involved in protocatechuic acid-induced neurotrophic activity

Objective: To investigate the mechanisms underlying protocatechuic acid (PCA)-induced neurotrophic effects on cultured cortical neurons.Methods: The mRNA expression of microtubule-associated protein 2 (MAP2) and brain-derived neurotrophic factor (BDNF) were measured by real-time quantitative PCR (qPCR). Subsequently, antagonists were used to study the signaling pathways activated by PCA and western blotting was used to detect the phosphorylation level of kinase-related protein.Results: The mRNA expression of MAP2 and BDNF were upregulated in neurons treated with PCA compared with vehicle control. PCA-induced neurite outgrowth and neuronal survival in cultured cortical neurons were significantly inhibited by ZM241385 (an A2A receptor antagonist) and LY294002 (a PI3K inhibitor), but not by K252a (a TrkA receptor antagonist), GÖ6976 (a protein kinase C inhibitor) and PD98059 (a MEK inhibitor). PCA enhanced the phosphorylation of Akt, which could be blocked by LY294002.Conclusion: The PI3K/Akt signaling pathway might play an important role in the neurotrophic activity of PCA.

Neurotrophic effects of 7,8-dihydroxycoumarin in primary cultured rat cortical neurons

Neuronal loss in the central nervous system is central to the occurrence of neurodegenerative diseases. Pharmaceutical companies have devoted much effort to developing new drugs against such diseases, since there are currently no effective drugs for neurodegenerative disease treatment. Promoting the capacity for nerve regeneration is an ideal treatment target. The present study aimed to investigate the neurotrophic effects of 7,8-dihydroxycoumarin (DHC) or daphnetin in primary cultured rat cortical neurons. Cortical neurons were identified by microtubule-associated protein 2 (MAP2) immunostaining. Morphological observation was used to measure the average length of neurite outgrowth. MTT and lactate dehydrogenase assays were used to assess neuronal survival. The mRNA expression of MAP2 and brain-derived neurotrophic factor (BDNF) was measured by RT-PCR. MAP2 immunostaining showed that most of the cultured cells were neurons. Compared with the vehicle control group, DHC promoted neurite outgrowth and prolonged neuronal survival time at concentrations ranging from 2 to 8 μmol/L. Expression of both BDNF mRNA and MAP2 mRNA was increased in the groups treated with 2, 4 and 8 μmol/L DHC. DHC significantly increases neurite outgrowth and promotes neuronal survival in primary cultured rat cortical neurons. The neurotrophic effects of DHC are probably associated with increased BDNF expression.

Human endometrial stem cells as a new source for programming to neural cells.

Human EnSC (endometrial-derived stem cell) is an abundant and easily available source for cell replacement therapy. Many investigations have shown the potency of the cells to differentiate into several mesoderm-derived cell lineages, including osteocytes and adipocytes. Here, the potency of EnSC in neural differentiation has been investigated. Flow cytometric analysis showed that they were positive for CD90, CD105, OCT4, CD44 and negative for CD31, CD34, CD133. The characterized cells were induced into neural differentiation by bFGF (basic fibroblast growth factor), PDGF (platelet-derived growth factor) and EGF (epidermal growth factor) signalling molecules, respectively in a sequential protocol, and differentiated cells were analysed for expression of neuronal markers by RT–PCR (reverse transcription–PCR) and immunocytochemistry, including Nestin, GABA (γ-aminobutyric acid), MAP2 (microtubule-associated protein 2), β3-tub (class III β-tubulin) and NF-L (neurofilament-light) at the level of their mRNAs. The expression of MAP2, β3-tub and NF-L proteins in EnSC was confirmed 28 days PT (post-treatment) by immunocytochemistry. In conclusion, EnSC can respond to signalling molecules that are usually used as standards in neural differentiation and can programme neuronal cells, making these cells worth considering as a unique source for cell therapy in neurodegenerative disease.

Effects of low-dose X-ray on morphology of neuron and expression of microtubule associated protein-2 in hippocampus of young rats

To explore the effects of a continuous low-dose of X-ray upon neuronal morphology and expression of microtubule associated protein-2 (MAP-2) in hippocampus of young rats. A total of 18 Sprague-Dawley rats aged 35 days were randomly divided into two irradiated groups and one control group (n = 6 each). The irradiated groups received different doses of 0.2 mGy/d, 1.0 mGy/d for 7 consecutive days while the control group sham radiation. The hippocampal pyramidal cell was observed by HE staining, the expression of MAP-2 by immunohistochemistry and Western blot, and the morphologies of microtubule and synapse in CA1 by electron microscopy. (1) The phenomenon of neurodegeneration was observed in the 1.0 mGy group while the control and 0.2 mGy groups were normal; (2) the average optical density of positive MAP-2 protein significantly decreased in the 1.0 mGy group (0.242 ± 0.017) in the region of CA1 versus the control group (0.282 ± 0.016) (F = 14.419, P = 0.005). And the average optical density of positive MAP-2 significantly increased in the 0.2 mGy group (0.331 ± 0.017) compared with the control group (F = 21.700, P = 0.002). The expression of total MAP-2 significantly decreased in the 1.0 mGy group (0.332 ± 0.001) versus the control group (0.370 ± 0.012) (F = 28.055, P = 0.000). And the expression of total MAP-2 significantly increased in the 0.2 mGy group (0.455 ± 0.018) versus the control group (F = 61.974, P = 0.002); (3) there were the reduction of microtubule and the damage of postsynaptic density (PSD) in the 1.0 mGy group in hippocampal CA1. Increased microtubule and normal synapses were found in the 0.2 mGy group in hippocampal CA1. The expression of MAP-2 is strongly associated with the integrity of hippocampal neurons in young rats. The 0.2 mGy group may promote the proliferation of hippocampal microtubule in hippocampus and further promote the expression of MAP-2. And the damage of microtubule and PSD on neuron could reduce the expression of MAP-2 in the 1.0 mGy group.

Effects of acupuncture in combination with exercise on learning, memory and the expression of microtubuleassociated protein-2 in the hippocampal CA3 region after experimental focal cerebral infarction in rats

Objective To study the expression of microtubule-associated protein-2 (MAP-2) in the CA3 region of the hippocampus and any effect of acupuncture combined with exercise training on the recovery of learning and memory after experimental cerebral infarction.Methods Eighty Wistar rats were randomly divided into a sham-operation group (n = 8 ) and an operation group (n = 72 ) subdivided randomly and equally into a model group, an exercisetraining group and an acupuncture plus exercise training group, with 24 rats in each group. After right middle cerebral artery occlusion or a mock operation, the expression of MAP-2 in the CA3 region of the hippocampus was detected with immunohistochemistry 1, 3 and 5 weeks after the operation. Learning and memory function was assessed at the 5th week post operation.Results MAP-2- positive fibers were arranged in an orderly way and distributed densely in the shamoperation group. After cerebral infarction, number of MAP-2 positive neurons and dendrite fibers decreased in the CA3 region of the affected side. A week after the operation, MAP-2 positive fibers had increased significantly in the acupuncture plus exercise group compared with the model group and the exercise group. At the 3rd and 5th week post operation, expression of MAP-2 and optical density had increased significantly compared with the model group and the exercise training group. At the 5th week post operation, Y maze discrimination and learning tests showed that learning and memory had improved significantly more in the acupuncture plus exercise training group compared with the model group and the exercise training group.Conclusions Exercise training combined with acupuncture can promote changes in dendritic plasticity and increase MAP-2 expression in the CA3 region after cerebral infarction. This may be correlated positively with the recovery of learning and memory after cerebral infarction, at least in rats. Key words: Cerebral infarction; Learning; Memory; Acupuncture; Exercise training; Microtubule-associated protein-2 ; Hippocampus

Olfactory Neuroblastoma in Dogs and Cats – a Histological and Immunohistochemical Analysis

Olfactory neuroblastoma (ONB) was identified in 13 dogs and nine cats. The tumours were subjected to microscopical examination and were graded using a human pathological grading system. In the canine and feline tumours there was more necrosis and higher mitotic activity (mitotic index and Ki67 labelling index) than reported in human ONB. Rosettes were a common feature of feline ONBs. A significant correlation was observed between the histological grade and the Ki67 labelling index. The histopathological diagnosis of ONB was confirmed immunohistochemically by demonstration of the neuronal marker neuron-specific enolase (NSE). Two other neuron-specific antibodies specific for microtubule-associated protein-2 (MAP-2) and neuronal nuclei antigen (NeuN) were evaluated. MAP-2 expression proved to have higher specificity than labelling for NSE. NeuN expression was less sensitive and of limited practical value.

Expression changes of parvalbumin and microtubule-associated protein 2 induced by chronic constriction injury in rat dorsal root ganglia.

Parvalbumin (PV), as a mobile endogenous calcium buffer, plays an important role in affecting temporospatial characteristics of calcium transients and in modulating calcium homeostasis. PV is expressed in neurons in the dorsal root ganglion (DRG) and spinal dorsal horn and may be involved in synaptic transmission through regulating cytoplasm calcium concentrations. But the exact role of PV in peripheral sensory neurons remains unknown. Microtubule-associated protein 2 (MAP-2), belonging to structural microtubule-associated protein family, is especially vulnerable to acute central nervous system (CNS) injury, and there will be rapid loss of MAP-2 at the injury site. The present study investigated the changes of PV expressing neurons and the MAP-2 neurons in the DRG after an operation for chronic constriction injury to the unilateral sciatic nerve (CCI-SN), in order to demonstrate the possible roles of PV and MAP-2 in transmission and modulation of peripheral nociceptive information. Seventy-two adult male Sprague-Dawley (SD) rats, weighing 180 - 220 g, were randomly divided into two groups (36 rats in each group), the sham operation group and chronic constriction injury (CCI) group. Six rats in each group were randomly selected to receive mechanical and thermal sensitivity tests at one day before operation and 1, 3, 5, 7, and 14 days after surgery. After pain behavioral test, ipsilateral lumbar fifth DRGs were removed and double immunofluorescence staining was performed to assess the expression changes of PV and of MAP2 expressing neurons in the L5 DRG before or after surgery. The animals with CCI-SN showed obvious mechanical allodynia and thermal hyperalgesia (P < 0.05). Both the thermal and mechanical hyperalgesia decreased to their lowest degree at 7 days after surgery compared to the baseline before surgery (P < 0.01). In normal rats before surgery, a large number of neurons were MAP-2 single labeled cells, and just a small number of PV-expressed neurons were found. PV-positive neurons, PV-positive nerve fibers and PV-negative neurons, formed a direct or close contact for cross-talk. We used immunocytochemical staining to quantify the time course of changes to PV and MAP-2 expressing neurons in tissue, and found that the number of PV expressing neurons began to slightly decrease at 3 days after surgery, and had a significant reduction at CCI day 5, day 7 (P < 0.05). But MAP-2 neurons significantly decreased on just the 3rd day after CCI (P < 0.05). No changes in PV and MAP-2 expression were almost found in sham operated rats. The number of PV positive neurons, was positively correlated with the hyperalgesia threshold. A sharp decline in MAP-2 neurons may be the early response to surgical injury, and PV positive neurons were much more effective at affecting the changes of pain behaviors, indicating that the down-regulation of PV protein could participate in, at least in part, the modulation of nociceptive transmission.

The Combined Effects ofGinkgo BilobaExtracts and Aspirin on Viability of SK-N-MC, Neuroblastoma Cell Line in Hypoxia and Reperfusion Condition

The purpose of this study is to investigate the combined effects of ginkgo biloba extract, ginkgolide A and B and aspirin on SK-N-MC, human neuroblastoma cell viability and mRNA expression of growth associated protein43 (GAP43), Microtubule-associated protein 2 (MAP2), B-cell lymphoma2 (Bcl2) and protein53 (p53) gene in hypoxia and reperfusion condition. SK-N-MC cells were cultured with Dulbecco's Modified Eagle's Medium (DMEM) media in 37℃, 5% CO(2) incubator. The cells were cultured for 8 hours in non-glucose media and hypoxic condition and for 12 hours in normal media and O(2) concentration. Cell survival rate was measured with Cell Counting Kit-8 (CCK-8) reagent assay. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to estimate mRNA levels of GAP43, MAP2, Bcl2, and p53 genes. The ginkgolide A and B increased viable cell number decreased in hypoxic and reperfused condition. The co-treatment of ginkgolide B with aspirin also increased the number of viable cells, however, there was no additive effect. Although there was no increase of mRNA expression of GAP43, MAP2, and Bcl2 in SK-N-MC cells with individual treatment of ginkgolide A, B or aspirin in hypoxic and reperfused condition, the co-treatment of ginkgolide A or B with aspirin significantly increased GAP43 and Bcl2 mRNA levels. In MAP2, only the co-treatment of ginkgolide A and aspirin showed increasing effect. The mRNA expression of p53 had no change in all treating conditions. This study suggests that the combined treatments of Ginkgo biloba extracts and aspirin increase the regeneration of neuroblastoma cells injured by hypoxia and reperfusion.

Inhibition of Na+/H+ Exchanger Isoform 1 Is Neuroprotective in Neonatal Hypoxic Ischemic Brain Injury

We investigated the role of Na(+)/H(+) exchanger isoform 1 (NHE-1) in neonatal hypoxia/ischemia (HI). HI was induced by unilateral ligation of the left common carotid artery in postnatal day 9 (P9) mice, and subsequent exposure of animals to 8% O(2) for 55 min. A pre/posttreatment group received a selective and potent NHE-1 inhibitor HOE 642 (0.5 mg/kg, intraperitoneally) 5 min before HI, then at 24 and 48 h after HI. A posttreatment group received HOE 642 (0.5 mg/kg) at 10 min, 24 h, and 48 h after HI. Saline injections were used as vehicle controls. The vehicle-control brains at 72 h after HI exhibited neuronal degeneration in the ipsilateral hippocampus, striatum, and thalamus, as identified with Fluoro-Jade C positive staining and loss of microtubule-associated protein 2 (MAP2) expression. NHE-1 protein was upregulated in glial fibrillary acidic protein-positive reactive astrocytes. In HOE 642-treated brains, the morphologic hippocampal structures were better preserved and displayed less neurodegeneration and a higher level of MAP2 expression. Motor-learning deficit was detected at 4 weeks of age after HI in the vehicle control group. Inhibition of NHE-1 in P9 mice not only reduced neurodegeneration during the acute stage of HI but also improved the striatum-dependent motor learning and spatial learning at 8 weeks of age after HI. These findings suggest that NHE-1-mediated disruption of ionic homeostasis contributes to striatal and CA1 pyramidal neuronal injury after neonatal HI.

Molecular function of microtubule-associated protein 2 for filial imprinting in domestic chicks ( Gallus gallus domesticus)

RNA interference (RNAi)-mediated gene-silencing can be a tool for elucidating the role of genes in the neural basis of behavioral plasticity. Previously, we reported that exogenous DNA could be successfully delivered into newly-hatched chick brains via electroporation. Here, we used this in vivo gene-transfer technique and showed that transfected microRNA vectors preferentially silence exogenous DNA expression in neuronal cells. Using this system, the up-regulation of microtubule-associated protein 2 (MAP2) accompanying filial imprinting was suppressed in vivo, which impaired the filial imprinting in chicks. In addition, the phosphorylation of MAP2 was found to increase in parallel with filial imprinting, and lithium chloride, an inhibitor of glycogen synthase kinase 3 (GSK3), was found to impair filial imprinting. Our results suggest that the regulation of MAP2 expression and its phosphorylation are required for filial imprinting and may modify microtubule stability, thereby leading to cytoskeletal reorganization during imprinting. This in vivo RNAi-mediated gene-silencing system will facilitate the analysis of gene function in the living chick brain and provides further clues regarding the molecular mechanisms underpinning avian learning.

Potential therapeutic effects of curcumin: Relationship to microtubule-associated proteins 2 in Aβ1–42 insult

Curcumin can bind senile plaques and promote disaggregation of existing amyloid deposits and prevent aggregation of new amyloid deposits. Curcumin can also reverse distorted and curvy neurites around senile plaques and repair the neuritic abnormalities. We hypothesized whether altered neurite morphologies resulting from Aβ production had anything to do with the changes of expression of microtubule-associated protein 2 (MAP2), but curcumin could reverse damaged neurites by upregulation of MAP2 expression. In present study we designed and chemically synthesized curcumin and its six derivatives. After screening the protective effect of curcumin and derivatives, we found that the viability of SK-N -SH cell model induced by Aβ1–42 was significantly increased by curcumin and Cur1, and the expression of MAP-2 protein was obviously up-regulated in immunocytochemical staining and Western blot. The cell morphologies, including the number of neurites, neurite growth and neurite extension, were significantly improved. Cur1 showed more significant protective effect on SK-N -SH cells than curcumin. Our study revealed for the first time that the neuroprotective effect of curcumin and curcumin derivatives not only directly depends on their special chemical constitution, but they can resist to Aβ damage by up-regulation of MAP-2 expression. In view of the special advantages of curcumin and Cur1, we reasonably believe that curcumin and Cur1 may be considered as an ideal therapeutic agent for the treatment of AD.

Role of Acetylated p53 in Regulating the Expression of map2 in Retinoic Acid-induced P19 Cells

To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2 (MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid (RA). Neuronal differentiation of P19 cells was initiated with 4-day RA treatment. Immunofluorescence, real-time reverse transcription-polymerase chain reaction (RT-PCR) assay, and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells. Real-time PCR-based chromatin immunoprecipitation assay (ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter. The expression of MAP2 was markedly increased in RA-induced P19 cells. The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment, compared with the cells without RA treatment (control). p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity. p300/CBP associated factor (PCAF) was found induced in RA-treated cells and enriched in the nucleus, which might contribute to the acetylation of p53 in the regulation of map2 gene. Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells. PCAF is possibly involved in this process by mediating the acetylation of p53.

PHOSPHO1 is essential for mechanically competent mineralization and the avoidance of spontaneous fractures

Patients suffering from the rare hereditary disease hypophosphatasia (HPP), which is based on mutations in the ALPL gene, tend to develop central nervous system (CNS) related issues like epileptic seizures and neuropsychiatric illnesses such as anxiety and depression, in addition to well-known problems with the mineralization of bones and teeth. Analyses of the molecular role of tissue-nonspecific alkaline phosphatase (TNAP) in transgenic SH-SY5YTNAPhigh neuroblastoma cells compared to SH-SY5YTNAPlow cells indicate that the enzyme influences the expression levels of neuronal marker genes like RNA-binding protein, fox-1 homolog 3 (NEUN) and enolase 2, gamma neuronal (NSE) as well as microtubule-binding proteins like microtubule-associated protein 2 (MAP2) and microtubule-associated protein tau (TAU) during neurogenic differentiation. Fluorescence staining of SH-SY5YTNAPhigh cells reveals TNAP localization throughout the whole length of the developed projection network and even synapsin Ι co-localization with strong TNAP signals at some spots at least at the early time points of differentiation. Additional immunocytochemical staining shows higher MAP2 expression in SH-SY5YTNAPhigh cells and further a distinct up-regulation of tau and MAP2 in the course of neurogenic differentiation. Interestingly, transgenic SH-SY5YTNAPhigh cells are able to develop longer cellular processes compared to control cells after stimulation with all-trans retinoic acid (RA). Current therapies for HPP prioritize improvement of the bone phenotype. Unraveling the molecular role of TNAP in extraosseous tissues, like in the CNS, will help to improve treatment strategies for HPP patients. Taking this rare disease as a model may also help to dissect TNAP's role in neurodegenerative diseases and even improve future treatment of common pathologies.

Abnormal maturation of non-dysmorphic neurons in focal cortical dysplasia: Immunohistochemical considerations

Aim Dysmorphic neurons and balloon cells in focal cortical dysplasia (FCD) reportedly show immaturity and abnormal differentiation with neuronal and glial components. Although normal-looking neurons (NL-neurons) in FCD are major constituent elements, their biological characteristics have never been identified. The aim of this study was to investigate maturation of NL-neurons with the focus on neuronal developmental lineage. Methods Eighteen FCD surgical specimens and controls were examined immunohistochemically using the antibodies for nestin, mammalian achaete-scute complex homolog 1 (Mash1), prospero-related homeobox 1 (Prox1), neuron-specific beta-III tubulin (Tuj1) and microtubule-associated protein 2 (MAP2) of neuronal lineage, glutamic acid decarboxylase (GAD), calretinin (CR) and calbindin (CB) of interneuron markers, and glial fibrillary-acidic protein (GFAP) of glial cell marker. Additionally, we performed fluorescent-double staining with these markers, and semi-quantitative analysis. Results NL-neurons in FCD had both mature and immature components, without interneuron components. NL-neurons in FCD showed abnormal maturation with the combined expression of MAP2 and Mash1/Prox1. Prox1-containing cell distribution in the deep layer was different from that of Mash1-containing cells in the superficial area. The MAP2-containing cell concentration decreased in the order of type I-A, I-B, II-A and II-B, but the Tuj1-containing cell concentration increased. Conclusion These findings may reflect differences in neuronal function and expression timing in developmental stages. From the standpoint of molecular expression, abnormal maturation of NL-neurons may initiate synaptic dysfunction, resulting in intractable seizures of FCD.

A tumor-specific cellular environment at the brain invasion border of adamantinomatous craniopharyngiomas

Craniopharyngiomas (CP) are benign epithelial tumors of the sellar region and can be clinicopathologically distinguished into adamantinomatous (adaCP) and papillary (papCP) variants. Both subtypes are classified according to the World Health Organization grade I, but their irregular digitate brain infiltration makes any complete surgical resection difficult to obtain. Herein, we characterized the cellular interface between the tumor and the surrounding brain tissue in 48 CP (41 adaCP and seven papCP) compared to non-neuroepithelial tumors, i.e., 12 cavernous hemangiomas, 10 meningiomas, and 14 metastases using antibodies directed against glial fibrillary acid protein (GFAP), vimentin, nestin, microtubule-associated protein 2 (MAP2) splice variants, and tenascin-C. We identified a specific cell population characterized by the coexpression of nestin, MAP2, and GFAP within the invasion niche of the adamantinomatous subtype. This was especially prominent along the finger-like protrusions. A similar population of presumably astroglial precursors was not visible in other lesions under study, which characterize them as distinct histopathological feature of adaCP. Furthermore, the outer tumor cell layer of adaCP showed a distinct expression of MAP2, a novel finding helpful in the differential diagnosis of epithelial tumors in the sellar region. Our data support the hypothesis that adaCP, unlike other non-neuroepithelial tumors of the central nervous system, create a tumor-specific cellular environment at the tumor-brain junction. Whether this facilitates the characteristic infiltrative growth pattern or is the consequence of an activated Wnt signaling pathway, detectable in 90% of these tumors, will need further consideration.

Effects of combination of ischemic postconditioning and remote ischemic postconditioning on focal cerebral ischemia-reperfusion injury in rats

Objective To investigate the effects of combination of ischemic postconditioning (IPC) and remote IPC on the focal cerebral ischemia-reperfusion (I/R) injury in rats. Methods Eighty-six adult male SD rats were randomly divided into 5 groups: sham operation group (group Ⅰ, n = 19) , I/R group (group Ⅱ, n=19) , IPC group (group Ⅳ, n = 16) , remote>IPC group (group Ⅳ, n = 16), and IPC + remote IPC group (group V , n = 16) . Focal cerebral I/R was produced by occlusion of the right middle cerebral artery (MCA) for 1.5 h followed by 24 h of reperfusion. In group Ⅰ, operation was performed but focal cerebral I/R was not produced. In group Ⅲ , the rats were subjected to 3 episodes of 30 s ischemia at 30 s intervals before 24 h of reperfusion. In group Ⅳ, after 1.5 h of the right MCA occlusion, remote IPC was performed by occluding the right femoral artery for 5 min before 24 h of reperfusion. In group Ⅴ, IPC and remote IPC were performed as described in group Ⅲ and Ⅳ respectively before 24 h of reperfusion. The neurologic deficit scores (NDSs) were measured at 2 and 24 h of reperfusion. Ten rats in each group were decapitated at 24 h of reperfusion and brains rapidly . removed for measuring the cerebral infarct size (IS). The expression of microtubule-associated protein 2 (MAP2) were detected. The animals received iv injection of fluorescein isothiocyanate (FICT)-dextran via the femoral vein 1 min before decapitation, for laser confocal scanning. The contralateral side was served as control. Results As compared with group Ⅰ, the NDSs and cerebral IS on the ischemic side were significantly increased, and the cerebral expression of MAP2, plasma volume of the cerebral tissues, and diameter and length of the cerebral microvessel on the ischemic side significantly decreased in group Ⅱ, Ⅲ , Ⅳ and Ⅴ ( P < 0.05 ) . As compared with group Ⅱ, the NDSs and cerebral IS on the ischemic side were significantly decreased, and the cerebral expression of MAP2, plasma volume of the cerebral tissues, and diameter and length of the cerebral microvessel on the ischemic side significantly increased in group ID , Ⅳ and Ⅴ( P < 0.05). Conclusion Although the combination of IPC and remote IPC can attenuate the focal cerebral I/R injury in rats, the efficacy is similar to that of either of them alone. Key words: Reperfusion injury; Brain; Ischemia postconditioning

Microtubule-associated Protein-2 is a Sensitive Marker of Primary and Metastatic Neuroblastoma

Microtubule-associated protein-2 (MAP-2) is a protein expressed in high levels in cells derived from the neural crest. To the best of our knowledge, MAP-2 expression has not been thoroughly evaluated in tissues outside of the central nervous tissue. We examined the diagnostic utility of MAP-2 as a marker of neuroblastoma and attempted to characterize the expression of this protein in other tumors in the morphologic differential diagnosis of neuroblastoma. MAP-2 showed significant cytoplasmic reactivity in 95% of primary and 100% of metastatic neuroblastomas. Included within this set of tumors were 3 undifferentiated neuroblastomas, all of which showed strong staining. MAP-2 did not show significant staining in the majority of other small round blue cell tumors within the morphologic differential. Additionally, MAP-2 showed comparable sensitivity in staining primary neuroblastomas as compared with synaptophysin, chromogranin, CD56, and beta-catenin. In contrast to other markers of neuroblastoma, MAP-2 did not show significant cross reactivity to native bone marrow precursors, thus eliminating a potential source of confusion. In normal tissues, MAP-2 staining was essentially restricted to organs derived from the neural crest (adrenal medulla, endocrine organs). Variant patterns of staining were seen in exocrine organs, monocyte/macrophages and solitary fibrous tumor/hemangiopericytoma family of tumors. Rarely, high-grade adult sarcomas exhibiting strong cytoplasmic MAP-2 staining were seen. MAP-2 is a sensitive and specific marker of neuroblastoma, both in the primary tumor and bone marrow biopsy settings. We think that MAP-2, in conjunction with synaptophysin, is a very powerful immunohistochemical marker in differentiating neuroblastoma from its morphologic mimics.

Caspase inhibition by cardiotrophin‐1 prevents neuronal death in vivo and in vitro

Our previous studies showed that cardiotrophin-1 (CT-1), a cytokine in the interleukin-6 family, protected the developing rat brain against focal cerebral ischemia (FCI) in vivo and prevented cortical neuron death in vitro. However, the mechanisms by which CT-1 prevents neuronal death are not clearly understood. This in vivo study focused on whether CT-1 treatment prevented FCI-induced brain injuries in the postnatal day 7 (P7) rat through modulating activation of the initiator caspase-8 (C-8) and the downstream effector caspase-3 (C-3). FCI caused a significant increase in expressions of cleaved C-8 and C-3 and, meanwhile, a significant decrease in expression of microtubule-associated protein-2 (MAP2) in the left ischemic cortex of the P7 rat brain after FCI. Exogenous treatment of CT-1 significantly reduced the expression of cleaved C-8 or C-3 and attenuated the decline in MAP2 expression in the ischemic cortex from 12 to 24 hr after FCI. Subsequent in vitro experiments demonstrated that CT-1 treatment inhibited sodium nitroprusside (SNP)-induced activation of C-8 and C-3 and loss of MAP2-positive neurons in cortical neuron cultures. More importantly, CT-1 activated several pathways, including Janus kinase 2, signal transducers and activators of transcription 3, nuclear factor kappa B, mitogen-activated protein kinase (MAPK), and MAPK kinase in the cultures exposed to SNP. This is the first suggestion that CT-1 prevents neuronal injury in the developing central nervous system possibly through mediating multiple signal pathways, inhibiting activation of C-8 and C-3.

Effects of electrical stimulation on motor function and the expressions of microtubule-associated protein-2 and survivin after cerebral infarction in rats

Objective To investigate the effects of unilateral and bilateral electrical stimulation of the upper and lower limbs on motor function following cerebral infarction and the expressions of microtubule-associated protein-2 (MAP-2) and survivin in the infarction border zone of rats. Methods Adult male Sprague-Dawley (SD) rats were randomly divided into sham operation, control, impaired limb and bilateral limbs electrical stimulation groups (each group included 32 rats). Acute cerebral infarction was mimicked using a middle cerebral artery occlusion tech-nique. After cerebral infarction for 24 h, the rats were treated daily with or without electrical stimulation. A beam walking test (BWT) was used to measure limbs motor function and immunohistochemistry and HE staining were used to detect the expressions of MAP-2 and survivin in the border zone of infarcted area after electrical stimulation treat-ment for 3, 7, 14 and 21 d. Results Comparet with the control group treatment with electric stimulation led to BWT scores increasing significantly, and bilateral stimulation was more potent in ameliorating motor function thanstimulating the impaired limb only. The expression of MAP-2 was significantly higher in eleetrieal stimulation groups than in control group from the 7th of treatment, and it was higher in bilateral stimulation group than that in unilateral stimulation group from tbe 14th day of treatment. There was no significant difference in MAP-2 expression between bi-lateral stimulation group and sham operation group at the 21st day of treatment. In electrical stimulation groups, at every time point the expressions of survivin were obviously higher than that in sham operation group, and it was higher than that in control group and peaked at the 7tb and 14th day of treatment and in bilateral stimulation group it was no-tably higher than that in unilateral stimulation group. At the 21st d of treatment the level of survivin expression drop-per; however, there was no significant difference between unilateral and bilateral electrical stimulation groups. Con-clusions Treatment with electrical stimulation, particularly in bilateral limbs stimulation, could induce MAP-2 and survivin expressions in the infarction border zone of rats. It also could promote the recovery of motor function in para-lyzed limbs after cerebral infarction of rats. The improvement might involve the up-regulation of MAP-2 and survivin expressions. Key words: Motor function; Cerebral infarction; Electrical stimulation; Microtubule-assoeiated protein-2; Survivin