Activation of NF-kappaB is involved in the survival of osteoclasts promoted by interleukin-1.
We previously reported that interleukin-1 (IL-1) promoted the survival of murine osteoclast-like cells (OCLs) formed in vitro and activated a transcription factor, NF-kappaB, of OCLs. The present study examined whether the activation of NF-kappaB is directly involved in the survival of OCLs promoted by IL-1. The expression of IL-1 type I receptor mRNA in OCLs was detected by the polymerase chain reaction amplification of reverse-transcribed mRNA. An electrophoretic mobility shift assay showed that IL-1 transiently activated NF-kappaB in the nuclei of the OCLs, and the maximal activation occurred at 30 min. The degradation of IkappaBalpha coincided with the activation of NF-kappaB in the OCLs. The immunocytochemical study revealed that p65, a subunit of NF-kappaB, was translocated from the cytoplasm into almost all of the nuclei of the OCLs within 30 min after IL-1 stimulation. The purified OCLs spontaneously died via apoptosis, and IL-1 promoted the survival of OCLs by preventing their apoptosis. The pretreatment of purified OCLs with proteasome inhibitors suppressed the IL-1-induced activation of NF-kappaB and prevented the survival of OCLs supported by IL-1. When OCLs were pretreated with antisense oligodeoxynucleotides to p65 and p50 of NF-kappaB, the expression of respective mRNAs by OCLs was suppressed, and the IL-1-induced survival of OCLs was concomitantly inhibited. These results indicate that IL-1 promotes the survival of osteoclasts through the activation of NF-kappaB.
Jimi
E
E
Department of Biochemistry, School of Dentistry, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555 Japan.
Nakamura
I
I
Ikebe
T
T
Akiyama
S
S
Takahashi
N
N
Suda
T
T
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D001854:Bone Marrow Cells / Q000166:cytology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003546:Cysteine Endopeptidases / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D017931:DNA Primers; D003609:Dactinomycin / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology*; D051379:Mice; D009097:Multienzyme Complexes / Q000378:metabolism; D016328:NF-kappa B / Q000096:biosynthesis*; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D010006:Osteoblasts / Q000166:cytology; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D046988:Proteasome Endopeptidase Complex; D012333:RNA, Messenger / Q000096:biosynthesis; D017472:Receptors, Interleukin-1 / Q000096:biosynthesis*; D013873:Thionucleotides; D014158:Transcription, Genetic / Q000187:drug effects
D015853:Cysteine Proteinase Inhibitors; D017931:DNA Primers; D007375:Interleukin-1; D009097:Multienzyme Complexes; D016328:NF-kappa B; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1; D013873:Thionucleotides; D003609:Dactinomycin; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex