Early damage of sympathetic neurons after co-culture with macrophages: a model of neuronal injury in vitro.
Since activated immune cells may damage peripheral nerves during inflammation, we developed a co-culture model that permits the direct study of macrophage-induced neuronal damage. Sympathetic neurons were enzymatically isolated from neonatal mice and co-cultured with increasing numbers of peritoneal macrophages for 24 h. This caused rapid neuronal cell death, reducing neuronal number by 24.1 +/- 4% with the addition of 11.5 x 10(3) macrophages, representing a ratio of 8 macrophages per neuron. Nuclear analysis showed that cell death occurred by both apoptosis and necrosis. These effects were not mimicked by addition of macrophage-conditioned medium, and were prevented by 10 microM dexamethasone. Although no appreciable neuronal death occurred beyond 24 h, the density of neurites was decreased between 1 and 2 days of co-culture (p < 0.05). There is, therefore, a rapid induction of cytotoxicity by macrophages after their addition to the neuronal cultures, followed by axonal damage without neuronal cell death.
Arantes
R M
RM
Gastrointestinal Disease Research Unit, Queen's University, Kingston, Ontario, Canada.
Lourenssen
S
S
Machado
C R
CR
Blennerhassett
M G
MG
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002478:Cells, Cultured; D018920:Coculture Techniques; D003907:Dexamethasone / Q000494:pharmacology; D004594:Electrophysiology; D005456:Fluorescent Dyes; D020287:In Situ Nick-End Labeling; D007249:Inflammation / Q000473:pathology*; D017737:Macrophages, Peritoneal / Q000502:physiology*; D051379:Mice; D009474:Neurons / Q000502:physiology*; D059348:Peripheral Nerve Injuries; D017783:Superior Cervical Ganglion / Q000166:cytology; D013564:Sympathetic Nervous System / Q000166:cytology*
D000893:Anti-Inflammatory Agents; D005456:Fluorescent Dyes; D003907:Dexamethasone