Involvement of c-Jun NH2-terminal kinase-1 in heat-induced apoptotic cell death of human monoblastic leukaemia U937 cells

Citation
A. Enomoto et al., Involvement of c-Jun NH2-terminal kinase-1 in heat-induced apoptotic cell death of human monoblastic leukaemia U937 cells, INT J RAD B, 77(8), 2001, pp. 867-874
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Experimental Biology
Journal title
INTERNATIONAL JOURNAL OF RADIATION BIOLOGY
ISSN journal
0955-3002 → ACNP
Volume
77
Issue
8
Year of publication
2001
Pages
867 - 874
Database
ISI
SICI code
0955-3002(200108)77:8<867:IOCNKI>2.0.ZU;2-Y
Abstract
Purpose: To determine thee involvement of c-jun NH2-terminal kinase-1 (JNK1 ) and possibly of HSP27 in heat-induced apoptosis of human monoblastic leuk aemia U937 cells. Materials and methods: Dominant negative JNK1 (APF), in which the phosphory lation sites Thr-Pro-Tyr were changed to Ala-Pro-Phe, was overexpressed in UT937 cells. Cell viability and DNA fragmentation were analysed by the eryt hrosin-B dye exclusion test and by agarose gel electrophoresis, respectivel y. Expression of activated caspase-9, phosphorylated JNK1, JNK2, p38 and HS P27 was examined by Western blotting. JNK1 kinase assay was also performed using c-Jun as a substrate. Results: Loss of viability, activated cleavage form of caspase-9 and DNA fr agmentation were rapid in U937 cells after 44 degreesC hyperthermia, while overexpression of dominant negative JNK1 interfered whit phosphorylation or activation of JNK1 Without affecting that of,JNK2 or p38/SAPK, and apparen tly delayed or reduced cleavage and activation of caspase-9, DNA Fragmentat ion and cell death. Heat-induccd phosphorylation of HSP27, observed in pare ntal U937 cells, was suppressed and only slightly detectable in jnk-1 mutan t cells. Conclusions: Prolonged phosphorylation or activation of JNK1 was considered important for heat-induced apoptosis and JNK1 may control the process poss ibly through phosphorylation Of HSP27 and caspase-9 activation in U937 cell s.