Hanafin N M, Chen T C, Heinrich G, Segre G V, Holick M F
Vitamin D, Skin, and Bone Research Laboratory, Boston University Medical Center, Massachusetts, 02118, USA.
J Invest Dermatol. 1995 Jul;105(1):133-7. doi: 10.1111/1523-1747.ep12313466.
There is increasing evidence that parathyroid hormone (PTH) and PTH-related peptides (PTHrP) are involved in normal skin cell growth; therefore, we investigated whether the PTH/PTHrP receptor was expressed in cultured human keratinocytes and dermal fibroblasts. Northern analyses of poly (A)+ RNA isolated from cultured fibroblasts revealed two PTH/PTHrP receptor transcripts with one major band at 2.5 kb and one minor band at 2.3 kb. These transcripts were consistent with those found in human osteosarcoma cells, which are known to express PTH/PTHrP-R mRNAs. In contrast, after repeated Northern analyses no PTH/PTHrP receptor transcripts were found in poly (A)+ RNA isolated from cultured keratinocytes. Reverse-transcriptase/nested polymerase chain reaction analyses of total RNA isolated from cultured keratinocytes and fibroblasts confirmed the Northern analyses data that the PTH/PTHrP receptor was expressed in cultured fibroblasts but not in cultured keratinocytes. When cultured fibroblasts and keratinocytes were exposed to 10(-7) M PTH (1-34) there was a twofold increase in cAMP levels in the fibroblasts and no demonstrable increase was noted in keratinocytes. These results suggest that skin fibroblasts possess the classical PTH/PTHrP receptor and are target cells for PTH and PTHrP whereas keratinocytes do not have the receptor and are unresponsive to its N-terminal agonist in the stimulation of cAMP formation.
越来越多的证据表明，甲状旁腺激素（PTH）和甲状旁腺激素相关肽（PTHrP）参与正常皮肤细胞的生长；因此，我们研究了PTH/PTHrP受体是否在培养的人角质形成细胞和真皮成纤维细胞中表达。对从培养的成纤维细胞中分离的聚腺苷酸（poly (A)+）RNA进行的Northern分析显示，有两种PTH/PTHrP受体转录本，一条主要条带在2.5 kb处，一条次要条带在2.3 kb处。这些转录本与在人骨肉瘤细胞中发现的转录本一致，已知人骨肉瘤细胞表达PTH/PTHrP-R mRNA。相比之下，经过反复的Northern分析，在从培养的角质形成细胞中分离的聚腺苷酸（poly (A)+）RNA中未发现PTH/PTHrP受体转录本。对从培养的角质形成细胞和成纤维细胞中分离的总RNA进行逆转录/巢式聚合酶链反应分析，证实了Northern分析数据，即PTH/PTHrP受体在培养的成纤维细胞中表达，但在培养的角质形成细胞中不表达。当培养的成纤维细胞和角质形成细胞暴露于10^(-7) M的PTH（1-34）时，成纤维细胞中的环磷酸腺苷（cAMP）水平增加了两倍，而角质形成细胞中未观察到明显增加。这些结果表明，皮肤成纤维细胞具有经典的PTH/PTHrP受体，是PTH和PTHrP的靶细胞，而角质形成细胞没有该受体，在cAMP形成的刺激中对其N端激动剂无反应。
