Induction of cellular stress and chaperone activation in organotypic slice cultures of hippocampus.
Neurodegenerative diseases are often associated with the occurrence of misfolded proteins preceding neuronal cell death. Accumulation of misfolded proteins in the endoplasmic reticulum induces ER stress, which in consequence enhances chaperone expression to restore protein homeostasis. Here we used organotypic hippocampal slice cultures to analyze the time course of chaperone expression and neuronal death after induction of ER stress by tunicamycin treatment. Shortly after explantation many cells stain positive for Fluoro Jade B demonstrating neuronal cell death. While in control cultures the number of Fluoro Jade B labeled cells remarkably decrease over the total period of cultivation, neuronal death remains elevated in ER-stressed slice cultures. Caspase-3 staining revealed that neuronal death is primarily due to apoptosis in tunicamycin-treated slice cultures. The chaperone GRP78/BiP is expressed at low levels in control sections. Its expression is largely restricted to hippocampal neurons. Tunicamycin treatment resulted in upregulation of GRP78/BiP in the neuronal cells. Double-immunolabeling for GFAP shows a concomitant de novo expression of GRP78/BiP in astrocytes. The astrocytic GRP78/BiP upregulation might reflect an early, neuroprotective response. The increase of GRP78/BiP in neurons and astrocytes show successful induction of the ER stress response. The hippocampal slice cultures are, thus, a useful tool to examine the process of neurodegeneration and to investigate neuroprotective devices in an ER stress paradigm.
Institute of Anatomy & Cell Biology, University of Freiburg, Germany.
Philipp
P
Lacour
Bernd
B
Heimrich
Felicitas
F
Pröls
D000818:Animals; D000831:Animals, Newborn; D000998:Antiviral Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D005452:Fluoresceins; D006360:Heat-Shock Proteins / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism* / Q000503:physiopathology; D006706:Homeostasis / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018832:Molecular Chaperones / Q000378:metabolism*; D009410:Nerve Degeneration / Q000378:metabolism* / Q000503:physiopathology; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009924:Organ Culture Techniques / Q000379:methods; D009930:Organic Chemicals; D017510:Protein Folding; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013312:Stress, Physiological / Q000378:metabolism* / Q000503:physiopathology; D014415:Tunicamycin / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
D000998:Antiviral Agents; D000091342:Endoplasmic Reticulum Chaperone BiP; D005452:Fluoresceins; D006360:Heat-Shock Proteins; C000717248:Hspa5 protein, mouse; D018832:Molecular Chaperones; D009930:Organic Chemicals; C435731:fluoro jade; D014415:Tunicamycin; D053148:Caspase 3