Tissue-non-specific alkaline phosphatase mRNA expression and alkaline phosphatase activity following application of retinoic acid in cultured human dental pulp cells

• Published in: Archives of oral biology 1999-10, Vol.44 (10), p.861-869
• Main Authors: San Miguel, Symone M., Goseki-Sone, Masae, Sugiyama, Eiichi, Watanabe, Hisashi, Yanagishita, Masaki, Ishikawa, Isao
• Format: Article
• Language: English
• Subjects: Alkaline phosphatase; Alkaline Phosphatase - analysis; Alkaline Phosphatase - biosynthesis; Alkaline Phosphatase - drug effects; Alkaline Phosphatase - genetics; Analysis of Variance; Base Sequence; Cell culture; Cells, Cultured; Dental Pulp - cytology; Dental Pulp - drug effects; Dental Pulp - enzymology; Dental pulp cells; Dentistry; DNA Primers; Dose-Response Relationship, Drug; Enzyme Induction - drug effects; Gene Expression Regulation, Enzymologic - drug effects; Gene Expression Regulation, Enzymologic - physiology; Humans; Molecular Sequence Data; mRNA; Reference Values; Retinoic acid; Reverse Transcriptase Polymerase Chain Reaction - methods; Reverse Transcriptase Polymerase Chain Reaction - statistics & numerical data; Reverse transcription-polymerase chain reaction; RNA, Messenger - drug effects; RNA, Messenger - genetics; RNA, Messenger - metabolism; Substrate Specificity - drug effects; Time Factors; Tissue-non-specific alkaline phosphatase gene; Tretinoin - pharmacology
• ISSN: 0003-9969; 1879-1506
• DOI: 10.1016/S0003-9969(99)00072-2

Retinoic acid is a potent inducer of tissue-non-specific alkaline phosphatase (TNSALP) expression in various osteoblastic and fibroblastic cells, and may be involved in morphogenesis, cellular growth and differentiation. This study investigates the effects of retinoic acid on alkaline phosphatase activity and TNSALP gene expression in human dental pulp cells. Cultured cells were treated with various concentrations of retinoic acid (0, 10 −7, 10 −6, 10 −5 M) in 0.5% bovine serum albumin without serum. Alkaline phosphatase activity was determined by the rate of p-nitrophenyl phosphate hydrolysis and was also assayed in the presence of various inhibitors and under thermal inactivation. A set of specific oligonucleotide primers was selected, based on the nucleotide sequences of two human TNSALP mRNA (bone and liver) types, and reverse transcription-polymerase chain reaction (RT-PCR) performed. Inhibitory and thermal inactivation experiments revealed that the elevated alkaline phosphatase activity had properties of the TNSALP type. RT-PCR showed that retinoic acid enhanced the expression of bone-type TNSALP mRNA in pulp cells. However, the liver-type TNSALP mRNA was not detected. These findings suggest that the high alkaline phosphatase activity of retinoic acid-treated dental pulp cells is associated with increased transcription of the bone-type mRNA of the TNSALP gene and not with liver-type.