Involvement of phosphatidylinositol 3-kinase and insulin-like growth factor-I in YXLST-mediated neuroprotection.
In the present study, we examine the neuroprotective role of the external Qi of YXLST in cultured retinal neurons. Primary retinal neuronal cultures were grown from retinas of 0-2-day-old Sprague-Dawley rats. Cultures were treated directly with external Qi of YXLST 30 min prior to H(2)O(2) exposure in most experiments. Cell viability was measured by 3,(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. Apoptotic cell death was evaluated by the TdT-mediated digoxigenin-dUTP nick-end labeling TUNEL assay, and by DNA laddering analysis. Northern blot analysis was performed to examine the level of insulin-like growth factor-I (IGF-I) gene expression. Phosphatidylinositol 3-kinase (PI3K) assay was performed to study the PI3K activity. The results showed that treatment of external Qi of YXLST significantly attenuated neuronal death that was induced by 24-h exposure to hydrogen peroxide, and greatly inhibited hydrogen peroxide-induced apoptosis. External Qi of YXLST also upregulated IGF-I gene expression and increased PI3K activity. These observations indicate that external Qi-mediated IGF-I expression and PI3K signaling could be one of the mechanisms in neuroprotection by YXLST.
Yan
Xin
X
American New Medicine Institute, New York, NY 10107, USA.
Shen
Hua
H
Zaharia
Marian
M
Wang
Jun
J
Wolf
Delia
D
Li
Feng
F
Lee
Garrick D
GD
Cao
Wei
W
D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern / Q000379:methods; D002452:Cell Count / Q000379:methods; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D006861:Hydrogen Peroxide / Q000633:toxicity; D020287:In Situ Nick-End Labeling / Q000379:methods; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D018696:Neuroprotective Agents; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011247:Pregnancy; D019413:Qi; D012313:RNA / Q000378:metabolism; D051381:Rats; D012160:Retina / Q000166:cytology* / Q000187:drug effects; D013997:Time Factors
D018696:Neuroprotective Agents; D012313:RNA; D007334:Insulin-Like Growth Factor I; D006861:Hydrogen Peroxide; D019869:Phosphatidylinositol 3-Kinases