Biomaterial Database

Involvement of protein kinase C in the stimulation of sodium-dependent phosphate transport by parathyroid hormone in osteoblast-like cells. 1994

M Arao, and T Yamaguchi, and T Sugimoto, and M Fukase, and K Chihara

Department of Medicine, Kobe University School of Medicine, Japan.

The rat osteosarcoma cell line UMR-106 has an osteoblast-like phenotype and possesses parathyroid hormone (PTH)-responsive dual signal transduction systems [adenosine 3',5'-cyclic monophosphate-dependent protein kinase (PKA) and calcium-protein kinase C (Ca-PKC)]. These cells transport inorganic phosphate (Pi) by a Na(+)-dependent carrier under stimulation by PTH. The present study aimed to clarify PTH-responsive signal transduction mechanisms in the regulation of Na(+)-dependent Pi transport by PTH in UMR-106 cells. Exposure of these cells to 10(-7) mol/l PTH induced a significant increase in Pi uptake within 30 min of incubation and it became maximal after 2 h. Parathyroid hormone (10(-9)-10(-7) mol/l) stimulated Pi uptake dose dependently. Activation of PKC by 12-O-tetradecanoyl phorbol-13-acetate (TPA) also increased Pi uptake in time- and dose-dependent manners similar to PTH. In contrast, neither PKA activation by 10(-4) mol/l forskolin or by 10(-4) mol/l dibutyryladenosine 3',5'-cyclic monophosphate nor calcium ionophore treatment with 10(-7) mol/l A23187 or with 10(-7) mol/l ionomycin during 3-h incubations affect Pi uptake, except its increase by 10(-4) mol/l forskolin at a 3-h incubation. These agents had no influence on Pi uptake even in combined treatments with TPA. The PTH-induced increase in Pi uptake was abolished almost completely by pretreating cells with PKC inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine dihydrochloride (H-7) (50 mumol/l) or staurosporin (10 and 50 nmol/l), and by down-regulating PKC with a prolonged TPA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D010006	Osteoblasts	Bone-forming cells which secrete an EXTRACELLULAR MATRIX. HYDROXYAPATITE crystals are then deposited into the matrix to form bone.	Osteoblast
D010281	Parathyroid Hormone	A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.	Natpara,PTH (1-84),PTH(1-34),Parathormone,Parathyrin,Parathyroid Hormone (1-34),Parathyroid Hormone (1-84),Parathyroid Hormone Peptide (1-34),Hormone, Parathyroid
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D011493	Protein Kinase C	An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.	Calcium Phospholipid-Dependent Protein Kinase,Calcium-Activated Phospholipid-Dependent Kinase,PKC Serine-Threonine Kinase,Phospholipid-Sensitive Calcium-Dependent Protein Kinase,Protein Kinase M,Calcium Activated Phospholipid Dependent Kinase,Calcium Phospholipid Dependent Protein Kinase,PKC Serine Threonine Kinase,Phospholipid Sensitive Calcium Dependent Protein Kinase,Phospholipid-Dependent Kinase, Calcium-Activated,Serine-Threonine Kinase, PKC
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D013755	Tetradecanoylphorbol Acetate	A phorbol ester found in CROTON OIL with very effective tumor promoting activity. It stimulates the synthesis of both DNA and RNA.	Phorbol Myristate Acetate,12-Myristoyl-13-acetylphorbol,12-O-Tetradecanoyl Phorbol 13-Acetate,Tetradecanoylphorbol Acetate, 4a alpha-Isomer,12 Myristoyl 13 acetylphorbol,12 O Tetradecanoyl Phorbol 13 Acetate,13-Acetate, 12-O-Tetradecanoyl Phorbol,Acetate, Phorbol Myristate,Acetate, Tetradecanoylphorbol,Myristate Acetate, Phorbol,Phorbol 13-Acetate, 12-O-Tetradecanoyl,Tetradecanoylphorbol Acetate, 4a alpha Isomer
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured