OBJECTIVETo study the effects of astragalan (AG) on the expression of the neural cell adhesion molecule(NCAM) and c-fos of hippocampus CA1 region after the ischemic brain injury in rats.

METHODSOne hundred male Wistar rats (180-220 g) were divided into ten groups randomly, they were sham operated group (SOG, n = 10), three model group(MG-ld, 3d, 7d, n = 10), as well as three low and high dose astragalan treatment groups (L/H-AGTG-1d, 3d, 7d, n = 10), respectively. And then, middle cerebral artery of MG and AGTG were intercepted by operation inducing brain injured. Their cerebral blood vessel were reperfused on 1, 2, 3 d, respectively, after the L/H-AGTG were treated with the AG (5 mg/kg and 15 mg/kg, ip). After neurologic impairment(NIP) was scored, animals were decapitated to take out hippocampus for counting apoptosis , determining the expression of the NCAM and c-fos by immunohistochemistry method and RT-PCR semiquantitative analysis, respectively.

RESULTSThe NIP scores and apoptotic cell of the L-AGTG and H-AGTG were significantly lower than MG (P < 0.05 or P < 0.01). The expression of NCAM and c-fos were significantly higher than the MG (P < 0.05 or P < 0.01).

CONCLUSIONAstragalan could improve significantly neural function of ischemia brain injury in rats,the mechanism concerned probably with blocking or reversing apoptosis of hippocampus by promoting the expression of the NCAM and c-fos of hippocampus CA1 region.

Animals ; Apoptosis ; drug effects ; Astragalus membranaceus ; chemistry ; Brain Ischemia ; metabolism ; pathology ; CA1 Region, Hippocampal ; cytology ; Kaempferols ; pharmacology ; Male ; Neural Cell Adhesion Molecules ; metabolism ; Neurons ; drug effects ; Neuroprotective Agents ; pharmacology ; Polysaccharides ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVEThis study explored the effects of levetiracetam (LEV) on the expression of nerve cell adhesion molecule (NCAM) and growth-associated protein 43 (GAP-43) mRNA in the hippocampus of rats with epilepsy induced by lithium-pilocarpine (Li-PILO) in order to provide a basis for investigating the antiepileptic mechanism of LEV and its doseresponse.

METHODSForty-eight Wistar rats were randomly divided into a normal control, a Li-PILO model and two LEV treatment groups (LEV: 150 and 300 mg/kg) (n=12 each). The LEV treatment groups received LEV by intragastric administration 6 hrs after status epilepticus (once daily for 2 two weeks). The expressions of NCAM and GAP-43 mRNA in the hippocampus was determined by real-time PCR.

RESULTSThe expression of NCAM and GAP-43 mRNA in the Li-PILO model group was significantly higher than in the normal control group (P<0.05). LEV treatment of 150 and 300 mg/kg significantly decreased the expression of NCAM and GAP-43 mRNA compared with the Li-PILO model group (P<0.05). The LEV treatment group at the dose of 300 mg/kg showed significantly lower expression of NCAM and GAP-43 mRNA than the 150 mg/kg LEV treatment group (P<0.05).

CONCLUSIONSLi-PILO can up-regulate the expressions of NCAM and GAP-43 mRNA in the hippocampus of rats with epilepsy. LEV can inhibit the expression of NCAM and GAP-43 mRNA and the effect is associated with the dose of LEV.

Animals ; Anticonvulsants ; therapeutic use ; Epilepsy ; drug therapy ; metabolism ; GAP-43 Protein ; genetics ; Hippocampus ; metabolism ; Male ; Neural Cell Adhesion Molecules ; genetics ; Piracetam ; analogs & derivatives ; pharmacology ; therapeutic use ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar

Rat hippocampal precursor cells isolated from hippocampi of embryonic day 16.5 (E16.5) rat embryos were found to proliferate in the presence of basic fibroblast growth factor. Addition of soluble neural cell adhesion molecule (NCAM) to these precursor cells reduced cell proliferation in a dose dependent manner and enhanced the induction of precursor cells' differentiation to the neuronal lineage. Given these findings that NCAM induces the differentiation of hippocampal precursor cells, we investigated possible effects of NCAM on the expression of basic helix-loop-helix (bHLH) transcription factors during the differentiation. Soluble NCAM upregulated the transcription of bHLH transcription factors, neurogenin1 and NeuroD, but decreased HES5. Western blot analysis showed that NCAM increased the expression levels of CaMKII, p-MAPK, GluR1 and NR1 but decreased p-STAT3. These results support a role for NCAM in the inhibition of proliferation and the induction of neural differentiation of hippocampal neural precursor cells, and act as developmental regulators of the bHLH families, ultimately leading to the generation of glutamatergic neural cell types in the differentiation of hippocampal precursor cells.
Animals ; Apoptosis/drug effects ; Cell Differentiation/*drug effects ; Cell Division/drug effects ; Cell Lineage/drug effects ; Cells, Cultured ; Helix-Loop-Helix Motifs ; Hippocampus/*cytology/*drug effects ; Neural Cell Adhesion Molecules/*pharmacology ; Neurons/cytology/*drug effects/metabolism ; RNA, Messenger/genetics/metabolism ; Rats ; Receptors, Glutamate/*metabolism ; Signal Transduction ; Stem Cells/cytology/*drug effects ; Transcription Factors/genetics/metabolism

PURPOSE: Cell transplantation of myelin-producing exogenous cells is being extensively explored as a means of remyelinating axons in X-linked adrenoleukodystrophy. We determined whether 3,3',5-Triiodo-L-thyronine (T3) overexpresses the ABCD2 gene in the polysialylated (PSA) form of neural cell adhesion molecule (NCAM)-positive cells and promotes cell proliferation and favors oligodendrocyte lineage differentiation. MATERIALS AND METHODS: PSA-NCAM+ cells from newborn Sprague-Dawley rats were grown for five days on uncoated dishes in defined medium with or without supplementation of basic fibroblast growth factor (bFGF) and/or T3. Then, PSA-NCAM+ spheres were prepared in single cells and transferred to polyornithine/fibronectin-coated glass coverslips for five days to determine the fate of the cells according to the supplementation of these molecules. T3 responsiveness of ABCD2 was analyzed using real-time quantitative polymerase chain reaction, the growth and fate of cells were determined using 5-bromo-2-deoxyuridine incorporation and immunocytochemistry, respectively. RESULTS: Results demonstrated that T3 induces overexpression of the ABCD2 gene in PSA-NCAM+ cells, and can enhance PSA-NCAM+ cell growth in the presence of bFGF, favoring an oligodendrocyte fate. CONCLUSION: These results may provide new insights into investigation of PSA-NCAM+ cells for therapeutic application to X-linked adrenoleukodystrophy.
ATP-Binding Cassette Transporters/*metabolism ; Adrenoleukodystrophy/genetics/*therapy ; Animals ; Animals, Newborn ; Bromodeoxyuridine ; Cell Differentiation ; Fibroblast Growth Factor 2/pharmacology ; Fibronectins/metabolism ; Immunohistochemistry ; Neural Cell Adhesion Molecules/*genetics ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Sialic Acids/metabolism ; Stem Cells ; Thyroid Hormones/*metabolism ; Triiodothyronine/pharmacology

It has been shown that neural cell adhesion molecule (NCAM)-induced neuronal differentiation is extracellular signal-regulated kinase (ERK)-dependent. However, an involvement of the mitogen activated protein kinase (MAPK) kinase (MEK), an upstream kinase of ERK, has not been directly demonstrated in this process. Therefore, we investigated whether the MEK1 plays a critical role in the NCAM-induced neuronal differentiation of hippocampal neural progenitor cells (NPCs). NPCs were transiently transfected with expression plasmids encoding activated or dominant negative (DN) forms of MEK1. The expression of DN MEK1 inhibited neuronal phenotype acquisition and soluble NCAM rescued the defect in the neuronal phenotype acquisition in DN-MEK1-transfected cells, suggesting that NCAM might contribute to the neuronal differentiation via distinct, parallel pathways including the MEK pathway. In cells expressing wild type MEK1 or constitutively active MEK1 on the other hand, the percentage of cells positive for beta-tubulin type III (Tuj1), a marker for early postmitotic neurons, was higher than seen in vector-transfected cells. These results suggest that the activation of MEK1 is required for obtaining neuronal phenotype in NPCs.
Transfection ; Stem Cells/cytology/drug effects/*metabolism ; Solubility ; Rats ; *Phenotype ; Neurons/cytology/drug effects/*metabolism ; Neural Cell Adhesion Molecules/*pharmacology ; Mutation/genetics ; MAP Kinase Kinase 1/genetics/*metabolism ; Hippocampus/cytology/drug effects/*metabolism ; Gene Expression Regulation ; Cells, Cultured ; Cell Differentiation ; Animals