title: Upregulation of mesencephalic astrocyte-derived neurotrophic factor in glial cells is associated with ischemia-induced glial activation.
abstract: BACKGROUND
  Mesencephalic astrocyte-derived neurotrophic factor (MANF), a 20 kDa secreted protein, was originally derived from a rat mesencephalic type-1 astrocyte cell line. MANF belongs to a novel evolutionally conserved family of neurotrophic factors along with conserved dopamine neurotrophic factor. In recent years, ever-increasing evidence has shown that both of them play a remarkable protective role against various injuries to neurons in vivo or in vitro. However, the characteristics of MANF expression in the different types of glial cells, especially in astrocytes, remain unclear.
  
  
  METHODS
  The model of focal cerebral ischemia was induced by rat middle cerebral artery occlusion. Double-labeled immunofluorescent staining was used to identify the types of neural cells expressing MANF. Primarily cultured glial cells were used to detect the response of glial cells to endoplasmic reticulum stress stimulation. Propidium iodide staining was used to determine dead cells. Reverse transcription PCR and western blotting were used to detect the levels of mRNA and proteins.
  
  
  RESULTS
  We found that MANF was predominantly expressed in neurons in both normal and ischemic cortex. Despite its name, MANF was poorly expressed in glial cells, including astrocytes, in normal brain tissue. However, the expression of MANF was upregulated in the glial cells under focal cerebral ischemia, including the astrocytes. This expression was also induced by several endoplasmic reticulum stress inducers and nutrient deprivation in cultured primary glial cells. The most interesting phenomenon observed in this study was the pattern of MANF expression in the microglia. The expression of MANF was closely associated with the morphology and state of microglia, accompanied by the upregulation of BIP/Grp78.
  
  
  CONCLUSIONS
  These results indicate that MANF expression was upregulated in the activated glial cells, which may contribute to the mechanism of ischemia-induced neural injury.
authors.affiliation: Biopharmaceutical Research Institute, Hefei 230032, P R China.
authors.forename: Yujun
authors.initials: Y
authors.lastname: Shen
authors.forename: Aimin
authors.initials: A
authors.lastname: Sun
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Wang
authors.forename: Daqin
authors.initials: D
authors.lastname: Cha
authors.forename: Haiping
authors.initials: H
authors.lastname: Wang
authors.forename: Facai
authors.initials: F
authors.lastname: Wang
authors.forename: Lijie
authors.initials: L
authors.lastname: Feng
authors.forename: Shengyun
authors.initials: S
authors.lastname: Fang
authors.forename: Yuxian
authors.initials: Y
authors.lastname: Shen
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D002478:Cells, Cultured; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3 / Q000378:metabolism; D004195:Disease Models, Animal; D004622:Embryo, Mammalian; D059865:Endoplasmic Reticulum Stress / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005947:Glucose / Q000172:deficiency; D000860:Hypoxia / Q000473:pathology; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology*; D008297:Male; D009414:Nerve Growth Factors / Q000235:genetics / Q000378:metabolism*; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D011247:Pregnancy; D011419:Propidium; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D005904:Glial Fibrillary Acidic Protein; C546826:MANF protein, rat; D009414:Nerve Growth Factors; D011419:Propidium; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D005947:Glucose