T. Miwa et al., LIPOPOLYSACCHARIDE ENHANCES SYNTHESIS OF BRAIN-DERIVED NEUROTROPHIC FACTOR IN CULTURED RAT MICROGLIA, Journal of neuroscience research, 50(6), 1997, pp. 1023-1029
Expression of neurotrophins in pure microglia cultured from embryonic
rat brain and the effects of lipopolysaccharide (LPS) on the expressio
n were investigated. In untreated cultures, nerve growth factor (NGF),
brain-derived neurotrophic factor (BDNF), and neurotrophin (NT)-4/5 m
RNAs were detected by use of reverse transcriptase-polymerase chain re
action but NT-3 mRNA was not. LPS stimulation caused a marked increase
in BDNF mRNA expression in addition to a slight increment of the NT-4
/5 mRNA level; however, the NGF mRNA level was not affected. LPS also
increased BDNF-like immunoreactivity in cultured microglia, an action
consistent with an elevation of BDNF mRNA. These results demonstrate t
hat LPS stimulates synthesis of BDNF and probably NT-4/5, specific lig
ands for tyrosine kinase receptor TrkB, suggesting that activated micr
oglia, which appear in the damaged brain, participate in neuronal rege
neration via production of such neurotrophins. (C) 1997 Wiley-Liss, In
c.