Hypoxic and ischemic effects on gene and protein expression levels of paracrine factors by human olfactory mucosa mesenchymal-like stem cells

Ting Yuan,1* Yi Zhuo,1* Chaying Su,2 Xuan Li,1 Da Duan,1 Lite Ge,1 Pei Wu,1 Hao Wang,1 Yujia Deng,1 Ming Lu1 1Department of Neurosurgery, Second Affiliated Hospital of Hunan Normal University (163 Hospital of the People’s Liberation Army), Changsha, 2Department of Pediatrics, 169 Hospital of the People’s Liberation Army, Hengyang, Peoples’ Republic ofChina * These authors contributed equally to this work Abstract: Human olfactory mucosa mesenchymal-like stem cells (hOM-MSCs) secrete paracrine factors that may exert a protective effect on the cerebral ischemia. This study was done to determine the hypoxic and ischemic effects on the mRNA and protein expression level of paracrine factors by hOM-MSCs. The hOM-MSCs were cultured with 5% or 20% serum and under either normoxic (21% O2) or hypoxic (3% O2) conditions. Expression levels of mRNA and protein for vascular endothelial growth factor (VEGF), nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and matrix metalloproteinase-2 (MMP-2) were determined by quantitative reverse transcription polymerase chain reaction and Western blot, respectively. Hypoxia reduced gene expression for VEGF (5% serum), GDNF, BDNF (5% serum) and NGF (5% serum) and increased it for BDNF (20% serum), MMP-2 (5% serum) and NGF (20% serum). Ischemia lowered gene expression for VEGF (hypoxia), GDNF, BDNF (hypoxia), MMP-2 (normoxia) and NGF (hypoxia) and increased it for VEGF (normoxia), BDNF (normoxia), MMP-2 (hypoxia) and NGF (normoxia).The protein level of these factors was almost in line with the gene level. These data demonstrate that serum and oxygen levels have a significant effect on the gene and protein expression levels of paracrine factors by hOM-MSCs, which will affect how hOM-MSCs interact in vivo during cerebral ischemia. Keywords: human olfactory mucosa mesenchymal-like stem cells, paracrine factors, hypoxia, ischemia, cerebral ischemia