title: Selective ablation of an astroglial subset by toxic gene expression driven by tenascin promoter.
abstract: OBJECTIVE
  In vitro culture, one of the astroglia-derived extracellular matrix proteins, tenascin, expressed highly in fibrous astrocytes, whereas it expressed only low levels in protoplasmic astrocytes. We devised a method of selectively altering the population of astroglial subsets in primary culture of astrocytes derived from embryonic mouse brains using toxic gene expression driven by the tenascin promoter.
  
  
  METHODS
  We have identified that the segment of 512-bases of 5'-flanking plus 243-bases leader sequences of the mouse tenascin gene contains maximum promoter activity in primary culture of astrocytes by deletion analysis of 5'-upstream region. This promoter element was used to specifically express the herpes simplex virus thymidine kinase (HSV-TK) gene in tenascin-positive astrocytes.
  
  
  RESULTS
  This strategy allowed us to selectively decrease tenascin-positive astrocytes at the optimal concentration of ganciclovir, which is cytotoxic in HSV-TK-expressing cells.
  
  
  CONCLUSIONS
  This approach should be useful for examining the role of the tenascin-negative astroglial subset in the development and regeneration of the central nervous system.
authors.affiliation: Department of Neuroanatomy, Keio University School of Medicine, Tokyo, Japan. ikeshima@jikei.ac.jp
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ikeshima-Kataoka
authors.forename: Shigeki
authors.initials: S
authors.lastname: Yuasa
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D001253:Astrocytes / Q000145:classification / Q000166:cytology / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D002469:Cell Separation; D002478:Cells, Cultured; D003603:Cytotoxins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance / Q000187:drug effects / Q000235:genetics; D015774:Ganciclovir / Q000494:pharmacology; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D018139:Simplexvirus / Q000235:genetics; D019063:Tenascin / Q000235:genetics* / Q000378:metabolism*; D013937:Thymidine Kinase / Q000235:genetics*; D014162:Transfection / Q000379:methods*
chemical_list: D000998:Antiviral Agents; D003603:Cytotoxins; D005904:Glial Fibrillary Acidic Protein; D019063:Tenascin; D013937:Thymidine Kinase; D015774:Ganciclovir