Analysis of hippocampal gene expression profile of Alzheimer's disease model rats using genome chip bioinformatics

In this study, an Alzheimer＇s disease model was established in rats through stereotactic injection of condensed amyloid beta 1-40 into the bilateral hippocampus, and the changes of gene expression profile in the hippocampus of rat models and sham-operated rats were compared by genome expression profiling analysis. Results showed that the expression of 50 genes was significantly up-regulated （fold change 〉 2）, while 21 genes were significantly down-regulated in the hippocampus of Alzheimer＇s disease model rats （fold change 〈 0.5） compared with the sham-operation group. The differentially expressed genes are involved in many functions, such as brain nerve system development, neuronal differentiation and functional regulation, cellular growth, differentiation and apoptosis, synaptogenesis and plasticity, inflammatory and immune responses, ion channels/transporters, signal transduction, cell material/energy metabolism. Our findings indicate that several genes were abnormally expressed in the metabolic and signal transduction pathways in the hippocampus of amyloid beta 1 40-induced rat model of Alzheimer＇s disease, thereby affecting the hippocampal and brain functions.

Gene expression in rat mesenchymal stem cells following treatment with natural cerebrolysin-containing serum Validation of a whole genome microarray technique

BACKGROUND： Natural cerebrolysin （NC）, a Chinese herbal drug for the treatment of Alzheimer＇s disease （AD）, induces mesenchymal stem cell （MSC） differentiation into neuron-like cells, with low toxicity. But the mechanisms involved in NC effects on MSCs remain poorly understood. OBJECTIVE： We used a whole genome microarray technique to further investigate the molecular, genetic, and pharmacodynamic mechanisms of NC on MSC gene expression profiles. DESIGN, TIME AND SETTING： A parallel, controlled, in vitro experiment was performed at the First Affiliated Hospital of Shenzhen University, Shenzhen Institute of Integrated Chinese and Western Medicine, China, between September 2006 and October 2008. MATERIALS： NC was provided by Shenzhen Institute of Integrated Chinese and Western Medicine China. It was predominantly composed of Renshen （Radix Ginseng）, Tianma （Rhizoma Gastrodiae） and Yinxingye （Ginkgo Leaf） and prepared by conventional water extractJon technology. Twelve adult, male, New Zealand rabbits were included, six of which underwent intragastric administration of NC extract for 1 month to create NC-containing serum. METHODS： Bone marrow was collected from the tibia and femur of Sprague Dawley rats, aged 6 8 months old. Rat MSCs were isolated and purified by the whole bone marrow adherence method. After in vitro culture, MSCs from passage 4 were treated with NC-containing serum for 48 hours, and total RNA was extracted. Gene expression in MSCs was analyzed using Affymetrix whole genome microarray analysis. MAIN OUTCOME MEASURES： Differentially expressed genes in NC serum-treated MSCs. RESULTS： NC treated MSCs displayed 46 differentially expressed genes, 22 with upregulated expression （fold change 〉 2） and 24 with downregulated expression （fold change 〈 -2）. Differentially expressed genes participated in neuronal growth, differentiation, and function, cell growth, differentiation, proliferation, apoptosis, signal transduction, substance/energy metabolism, ion transport, and immune responses. NC treatment changed levels of transforming growth factor β/ bone morphogenetic proteins, Hedgehog, Bmp, and Wntsignaling pathways, which regulate nerve cell differentiation, development and function, as well as learning and memory; Ras, G protein- coupled receptor signal pathways that are related to cell growth, proliferation, and apoptosis; and mitogen-activated protein kinase kinase kinase signaling cascades. CONCLUSION： NC can regulate gene expression for many signal transduction pathways related to nerve cell differentiation, development and function, learning and memory function, as well as regulation of cell growth, differentiation, proliferation, or apoptosis to mediate the genetic effects of NC treatment on AD.