Eggenberger M, Flühmann B, Muff R, Lauber M, Lichtensteiger W, Hunziker W, Fischer J A, Born W
Department of Orthopedic Surgery, University of Zurich, Switzerland.
Brain Res Mol Brain Res. 1996 Feb;36(1):127-36. doi: 10.1016/0169-328x(95)00253-o.
Cloning and functional expression of a cDNA from the human cerebellum revealed a parathyroid hormone/parathyroid hormone-related peptide (PTH/PTHrP) receptor protein of 593 amino acids, identical in sequence to the PTH/PTHrP receptor of the human kidney and an osteoblast-like cell line (Schipani et al., Endocrinology, 132 (1993) 2157-2165). Expression of mRNA hybridizing with the cloned cDNA, indistinguishable in size on Northern blots from a 2.3 kb transcript in kidney and liver, was detected in eight brain areas. In situ hybridization histochemistry in rat brain tissue sections revealed predominant signals in the Purkinje cell layer of the cerebellum and in the mesencephalic nucleus of the trigeminal nerve. In human neuroblastoma (SK-N-MC) cells, stably transfected with the cloned cDNA, hPTH(1-84) and hPTH(1-34) displaced binding of 125 pM [125I][Tyr36]chPTHrP(1-36) to the PTH/PTHrP receptor with IC50 values of 4.0 +/- 0.6 nM and 2.00 +/- 0.08 nM, and stimulated cyclic AMP accumulation with EC50 values of 0.19 +/- 0.06 nM and 0.09 +/- 0.01 nM, respectively. 16 out of 48 cells responded to 100 nM hPTH(1-34) with a 2-10-fold transient increase of cytosolic free calcium concentrations. In conclusion, a PTH/PTHrP receptor, identified in the human cerebellum, has the primary structure of the corresponding receptors of kidney and bone. Expression in human neuroblastoma SK-N-MC cells revealed functional properties indistinguishable from those of non-neuronal tissues. The widespread distribution of PTHrP and its receptor in brain implies biological functions remaining to be elucidated.
从小脑克隆的一条cDNA及其功能表达，揭示了一种含593个氨基酸的甲状旁腺激素/甲状旁腺激素相关肽（PTH/PTHrP）受体蛋白，其序列与人类肾脏及一种成骨细胞样细胞系的PTH/PTHrP受体相同（希帕尼等人，《内分泌学》，132卷（1993年），2157 - 2165页）。在八个脑区检测到与克隆的cDNA杂交的mRNA表达，其在Northern印迹上的大小与肾脏和肝脏中2.3 kb转录本的大小无法区分。大鼠脑组织切片的原位杂交组织化学显示，在小脑的浦肯野细胞层和三叉神经中脑核有主要信号。在稳定转染了克隆cDNA的人神经母细胞瘤（SK - N - MC）细胞中，hPTH(1 - 84)和hPTH(1 - 34)取代125 pM [125I][Tyr36]chPTHrP(1 - 36)与PTH/PTHrP受体的结合，IC50值分别为4.0±0.6 nM和2.00±0.08 nM，并且刺激环磷酸腺苷积累，EC50值分别为0.19±0.06 nM和0.09±0.01 nM。48个细胞中有16个对100 nM hPTH(1 - 34)有反应，胞质游离钙浓度有2 - 10倍的瞬时升高。总之，在人类小脑中鉴定出的一种PTH/PTHrP受体具有肾脏和骨骼相应受体的一级结构。在人神经母细胞瘤SK - N - MC细胞中的表达揭示了与非神经组织无法区分的功能特性。PTHrP及其受体在脑中的广泛分布意味着其生物学功能有待阐明。
