IL-1alpha affects mineralized nodule formation by rat osteoblasts.
The present study was conducted to determine the effect of the inflammatory mediator interleukin 1alpha (IL-1alpha) on osteogenesis using rat osteoblasts. We examined the effect of IL-1alpha on cell proliferation, alkaline phosphatase (ALPase) activity, mineralized nodule formation, and the expression of extracellular matrix proteins in rat osteosarcoma cell lines. The cells were cultured with alpha-minimum essential medium containing 10% fetal bovine serum with and without 0, 1, 10, and 100 units/ml of IL-1alpha for up to 14 days. The mineralized nodule formation was examined by alizarin red staining, and the calcium content in mineralized nodules was determined using a Calcium C-Test kit. The expression of extracellular matrix proteins was estimated by determining levels of mRNAs using the semiquantitative reverse transcription-polymerase chain reaction. The mineralized nodule formation and the calcium content in mineralized nodules were remarkably suppressed by IL-1alpha after 5 days of culture. The ALPase activity decreased in a dose-dependent manner in the presence of IL-1alpha after 7 days of culture. The expression of type I collagen was decreased after 3 days of culture with IL-1alpha. The expression of bone sialoprotein was slightly decreased at days 3 and 5, and the expression of osteopontin was increased at days 3, 5, and 7 of culture with IL-1alpha. These results suggest that IL-1alpha suppresses osteogenesis through a decrease in ALPase and type I collagen production by osteoblasts.
Tanabe
Natsuko
N
Department of Endodontics, Nihon University School of Dentistry, 1-8-13, Kanda Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
Ito-Kato
Emi
E
Suzuki
Naoto
N
Nakayama
Atsushi
A
Ogiso
Bunnai
B
Maeno
Masao
M
Ito
Koichi
K
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001859:Bone Neoplasms / Q000473:pathology; D002113:Calcification, Physiologic / Q000502:physiology; D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D017931:DNA Primers; D004305:Dose-Response Relationship, Drug; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000096:biosynthesis; D007375:Interleukin-1 / Q000494:pharmacology*; D010006:Osteoblasts / Q000187:drug effects*; D012516:Osteosarcoma / Q000473:pathology; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D007375:Interleukin-1; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D000469:Alkaline Phosphatase; D002118:Calcium