ABSTRACT
OBJECTIVE: To investigate microRNA (miRNA) expression profiles before and after pilocarpine-induced status epilepticus (SE) in the cornu ammonis (CA) and dentated gyrus (DG) areas of the mouse hippocampus, and to predict the downstream proteins and related pathways based on bioinformatic analysis. METHODS: An epileptic mouse model was established using a pilocarpine injection. Brain tissues from the CA and DG were collected separately for miRNA analysis. The miRNAs were extracted using a kit, and the expression profiles were generated using the SurePrint G3 Mouse miRNA microarray and validated. The intersecting genes of TargetScan and miRanda were selected to predict the target genes of each miRNA. For gene ontology (GO) studies, the parent-child-intersection (pci) method was used for enrichment analysis, and Benjamini-Hochberg was used for multiple test correction. The Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to detect disease-related pathways among the large list of miRNA-targeted genes. All analyses mentioned above were performed at the time points of control, days 3, 14, and 60 post-SE. RESULTS: Control versus days 3, 14, and 60 post-SE: in the CA area, a total of 131 miRNAs were differentially expressed; 53, 49, and 26 miRNAs were upregulated and 54, 10, and 22 were downregulated, respectively. In the DG area, a total of 171 miRNAs were differentially expressed; furthermore, 36, 32, and 28 miRNAs were upregulated and 78, 58, and 44 were downregulated, respectively. Of these, 92 changed in both the CA and DG, 39 only in the CA, and 79 only in the DG area. The differentially expressed miRNAs target 11-1630 genes. Most of these proteins have multiple functions in epileptogenesis. There were 15 common pathways related to altered miRNAs: nine different pathways in the CA and seven in the DG area. CONCLUSIONS: Stage- and subfield-associated hippocampal miRNA expression patterns are closely related to epileptogenesis, although the detailed mechanisms need to be explored in the future.
ABSTRACT
We analyzed the expression pattern of transforming growth factor-beta isoforms (TGF-beta1, TGF-beta2 and TGF-beta3) in the developing brain of embryos derived from the normal and diabetic mice exposed to cyclophosphamide (CP), a cytotoxic teratogen. The CP-treated diabetic embryos showed significantly more TGF-beta1 and TGF-beta2 immunoreactive cells in the regions of telencephalon and diencephalon in comparison to that of CP-treated non-diabetic embryos. Moreover, no cells expressing TGF-beta isoforms were detectable in the developing brain of normal and diabetic embryos. The mRNA expression levels of TGF-beta isoforms were found to be significantly increased in the developing brain of CP-treated diabetic embryos compared to that of CP-treated non-diabetic embryos as measured by quantitative real time reverse transcription-polymerase chain reaction. The enhanced expression levels of TGF-beta isoforms appear to be associated with the increased frequency of neural tube defects observed in the diabetic embryos exposed to CP.
Subject(s)
Central Nervous System/metabolism , Cyclophosphamide/toxicity , Diabetes Mellitus, Experimental/metabolism , Pregnancy in Diabetics/metabolism , Teratogens/toxicity , Transforming Growth Factor beta/biosynthesis , Animals , Central Nervous System/embryology , Embryo, Mammalian/drug effects , Embryo, Mammalian/metabolism , Female , Immunohistochemistry , Mice , Pregnancy , Protein Isoforms/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Transforming Growth Factor beta1 , Transforming Growth Factor beta2 , Transforming Growth Factor beta3ABSTRACT
The qualitative and quantitative changes in acetylcholine receptor distribution were studied in the gracilis muscle of the Wistar rat following free neurovascular transfer. Even at 30 weeks after transfer, the morphology of the neuromuscular junction failed to return to the presurgical state. The number of acetylcholine receptors at the reinnervated neuromuscular junction also remained lower than the control. The persistent weakness following free neurovascular muscle transfer may be attributed to these qualitative and quantitative changes at the neuromuscular junction.
