Sugimoto T, Kanatani M, Kaji H, Yamaguchi T, Fukase M, Chihara K
Department of Medicine, Kobe University School of Medicine, Japan.
Am J Physiol. 1993 Sep;265(3 Pt 1):E367-73. doi: 10.1152/ajpendo.1993.265.3.E367.
The second messenger signaling mechanisms of parathyroid hormone (PTH)- and PTH-related peptide (PTHRP)-stimulated osteoclast-like cell formation were investigated in mouse hemopoietic blast cells that possessed PTH binding sites. Human (h) PTH-(1-34) or hPTHRP-(1-34) resulted in a dose-dependent stimulation of tartrate-resistant acid phosphatase-positive multinucleated cells (MNC) formation. Pretreatment with [Nle8,18Tyr34]hPTH-(3-34) significantly blocked hPTH-(1-34)- and hPTHRP-(1-34)-stimulated MNC formation. Dibutyryladenosine 3',5'-cyclic monophosphate (10(-4) M) and forskolin (10(-5) M) as well as the stimulatory diastereoisomer of adenosine 3',5'-cyclic phosphorothioate (Sp-cAMPS), a direct activator of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) (10(-4) M), stimulated MNC formation, and Rp-cAMPS, an inhibitor of PKA activation (10(-4) M), almost completely inhibited MNC formation stimulated by the aforementioned agents but not by 1,25-dihydroxyvitamin D3. Moreover, Rp-cAMPS significantly blocked PTH- and PTHRP-stimulated MNC formation. Treatment with calcium ionophores (10(-8) and 10(-7) M) and phorbol 12-myristate 13-acetate, a protein kinase C (PKC) activator (10(-8) to 10(-6) M), but not 4 alpha-phorbol 12,13-didecanoate, a phorbol incapable of activating PKC, stimulated MNC formation. Two PKC inhibitors [1-(5-isoquinolinylsulfonyl)-2-methylpiperazine dihydrochloride and staurosporine] equally blocked PTH- and PTHRP-stimulated MNC formation. The combined pretreatment with Rp-cAMPS and PKC inhibitors completely blocked PTH- and PTHRP-stimulated MNC formation. Present findings indicate that the activation of PKA and PKC is directly linked to PTH- and PTHRP-stimulated osteoclast-like cell formation from hemopoietic blast cells.
在具有甲状旁腺激素（PTH）结合位点的小鼠造血母细胞中，研究了PTH和PTH相关肽（PTHRP）刺激破骨细胞样细胞形成的第二信使信号传导机制。人（h）PTH-（1-34）或hPTHRP-（1-34）导致抗酒石酸酸性磷酸酶阳性多核细胞（MNC）形成呈剂量依赖性刺激。用[Nle8,18Tyr34]hPTH-（3-34）预处理可显著阻断hPTH-（1-34）和hPTHRP-（1-34）刺激的MNC形成。二丁酰腺苷3'，5'-环磷酸（10^-4 M）、福斯可林（10^-5 M）以及腺苷3'，5'-环磷硫酯的刺激性非对映异构体（Sp-cAMPS），一种腺苷3'，5'-环磷酸（cAMP）依赖性蛋白激酶（PKA）的直接激活剂（10^-4 M），可刺激MNC形成，而PKA激活抑制剂Rp-cAMPS（10^-4 M）几乎完全抑制上述试剂刺激的MNC形成，但不抑制1,25-二羟基维生素D3刺激的MNC形成。此外，Rp-cAMPS显著阻断PTH和PTHRP刺激的MNC形成。用钙离子载体（10^-8和10^-7 M）以及佛波醇12-肉豆蔻酸酯13-乙酸酯（一种蛋白激酶C（PKC）激活剂，10^-8至10^-6 M）处理可刺激MNC形成，但不能激活PKC的佛波醇4α-佛波醇12,13-十二烷酸酯则无此作用。两种PKC抑制剂[1-（5-异喹啉磺酰基）-2-甲基哌嗪二盐酸盐和星形孢菌素]同样可阻断PTH和PTHRP刺激的MNC形成。用Rp-cAMPS和PKC抑制剂联合预处理可完全阻断PTH和PTHRP刺激的MNC形成。目前的研究结果表明，PKA和PKC的激活与PTH和PTHRP刺激造血母细胞形成破骨细胞样细胞直接相关。
