Abstract
Oligodendrocytes are exposed to various cytokines in inflammatory lesions in the central nervous system. In this study, we focused on the direct effects of interferon-γ (IFNG) on highly purified rat oligodendroglial cultures at different developmental stages. Among the three stages tested, IFNG had direct cytotoxic effects on actively proliferating oligodendrocyte progenitors but much less on immature oligodendrocytes and none on mature oligodendrocytes. This stage-specific susceptibility of progenitors to IFNG-induced cytotoxicity consisted of two components, delay in the G1/S transition of the cell cycle and increased cell death at least partly mediated by apoptosis, suggesting that progression of the cell cycle was tightly linked to this toxic mechanism. There was no functional difference in the signal transducers and activators of transcription (STAT) pathways between progenitors and mature oligodendrocytes as determined by induction of IRF1 mRNA in response to IFNG. We found that partial inhibition of the MEK-ERK pathway, one of the mitogen-activated protein kinase phosphorelay modules, by U0126 partially reversed the IFNG-induced cytotoxicity in progenitors. In addition, ERK activity was quickly down-regulated after in vitro differentiation of progenitors to immature oligodendrocytes. Therefore, we concluded that simultaneous activation of the STAT pathway by IFNG and of the ERK pathway by exogenous trophic factors played a role in the stage-specific IFNG-induced cytotoxicity in oligodendroglial progenitors. Our study has implications with respect to the mechanisms of periventricular leukomalacia in infants and of persistent demyelination in multiple sclerosis lesions in adults.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 20095-20106 |
| Number of pages | 12 |
| Journal | Journal of Biological Chemistry |
| Volume | 281 |
| Issue number | 29 |
| DOIs | |
| State | Published - Jul 21 2006 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
MEK-ERK signaling is involved in interferon-γ-induced death of oligodendroglial progenitor cells. / Horiuchi, Makoto; Itoh, Aki; Pleasure, David E; Ito, Takayuki.
In: Journal of Biological Chemistry, Vol. 281, No. 29, 21.07.2006, p. 20095-20106.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - MEK-ERK signaling is involved in interferon-γ-induced death of oligodendroglial progenitor cells
AU - Horiuchi, Makoto
AU - Itoh, Aki
AU - Pleasure, David E
AU - Ito, Takayuki
PY - 2006/7/21
Y1 - 2006/7/21
N2 - Oligodendrocytes are exposed to various cytokines in inflammatory lesions in the central nervous system. In this study, we focused on the direct effects of interferon-γ (IFNG) on highly purified rat oligodendroglial cultures at different developmental stages. Among the three stages tested, IFNG had direct cytotoxic effects on actively proliferating oligodendrocyte progenitors but much less on immature oligodendrocytes and none on mature oligodendrocytes. This stage-specific susceptibility of progenitors to IFNG-induced cytotoxicity consisted of two components, delay in the G1/S transition of the cell cycle and increased cell death at least partly mediated by apoptosis, suggesting that progression of the cell cycle was tightly linked to this toxic mechanism. There was no functional difference in the signal transducers and activators of transcription (STAT) pathways between progenitors and mature oligodendrocytes as determined by induction of IRF1 mRNA in response to IFNG. We found that partial inhibition of the MEK-ERK pathway, one of the mitogen-activated protein kinase phosphorelay modules, by U0126 partially reversed the IFNG-induced cytotoxicity in progenitors. In addition, ERK activity was quickly down-regulated after in vitro differentiation of progenitors to immature oligodendrocytes. Therefore, we concluded that simultaneous activation of the STAT pathway by IFNG and of the ERK pathway by exogenous trophic factors played a role in the stage-specific IFNG-induced cytotoxicity in oligodendroglial progenitors. Our study has implications with respect to the mechanisms of periventricular leukomalacia in infants and of persistent demyelination in multiple sclerosis lesions in adults.
AB - Oligodendrocytes are exposed to various cytokines in inflammatory lesions in the central nervous system. In this study, we focused on the direct effects of interferon-γ (IFNG) on highly purified rat oligodendroglial cultures at different developmental stages. Among the three stages tested, IFNG had direct cytotoxic effects on actively proliferating oligodendrocyte progenitors but much less on immature oligodendrocytes and none on mature oligodendrocytes. This stage-specific susceptibility of progenitors to IFNG-induced cytotoxicity consisted of two components, delay in the G1/S transition of the cell cycle and increased cell death at least partly mediated by apoptosis, suggesting that progression of the cell cycle was tightly linked to this toxic mechanism. There was no functional difference in the signal transducers and activators of transcription (STAT) pathways between progenitors and mature oligodendrocytes as determined by induction of IRF1 mRNA in response to IFNG. We found that partial inhibition of the MEK-ERK pathway, one of the mitogen-activated protein kinase phosphorelay modules, by U0126 partially reversed the IFNG-induced cytotoxicity in progenitors. In addition, ERK activity was quickly down-regulated after in vitro differentiation of progenitors to immature oligodendrocytes. Therefore, we concluded that simultaneous activation of the STAT pathway by IFNG and of the ERK pathway by exogenous trophic factors played a role in the stage-specific IFNG-induced cytotoxicity in oligodendroglial progenitors. Our study has implications with respect to the mechanisms of periventricular leukomalacia in infants and of persistent demyelination in multiple sclerosis lesions in adults.
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UR - http://www.scopus.com/inward/citedby.url?scp=33746017378&partnerID=8YFLogxK
U2 - 10.1074/jbc.M603179200
DO - 10.1074/jbc.M603179200
M3 - Article
C2 - 16728393
AN - SCOPUS:33746017378
VL - 281
SP - 20095
EP - 20106
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 29
ER -