Role Of Astrocyte In The Aetiology Of Neurodegeneration Diseases Involving Inflammation

Objectiv:To investigate the role of astrocyte in aetiology of the neurodegeneration disease involving inflammation and the influence to neuron.Methods:Part I: Lipopolysaccharide (LPS) was applied to rat astrocytes for 30min, 24h, 48h and 72h, and the cell viability, free calcium concentration and reactive oxygen species (ROS) released by astrocytes, nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) secreted by astrocytes, glutathione peroxidase (GPx) activity and glutathione (GSH) in astrocytes were detected. Glial fibrillary acidic protein (GFAP), heme oxygenase-1 (HO-1), nuclear factor kappa Bp65 (NF-κBp65),phospho-p38, phospho-JNK1/2 and phospho-ERK1/2 protein expressed in astrocytes were assayed in astrocytes both with western-blot and fluoresent immunocytochemistry.Part II: PC12 cells were treated with the astrocyte conditioned medium (ACM) which was dealt with LPS over 24h. Icariin, oleanolic acid (OA), camptothecin (CPT), gardenoside or 4,6,7-trihydroxy-1,3-dimethoxyxanthone (TDX) were co-cultured with PC12 1h prior to LPS. The LPS positive control were set as well as the blank control. The cell viability, lactate dehydrogenase (LDH) activity and TNF-αconcentration in the cell culture medium was detected. The early apoptosis ratio of PC12 was assayed by Annexin V-PI method. NF-κBp65, phospho-p38, phospho-JNK1/2 and phospho-ERK1/2 protein expressed by PC12 were assayed with western-blot.Results:Part I: 1. LPS could promote the proliferation of astrocytes and increase the cell viability〔P<0.05 vs control).2. LPS could increase the NO release from astrocyte〔P<0.05 vs control).3. The calcium concentration and ROS amount stimulated by all different dose group of LPS increased within 15-30s and 300-400s respectively. 4. Among all the different time group of LPS, the GPx activity and GSH amount only...