ADENOSINE-TRIPHOSPHATE STIMULATES PHOSPHOINOSITIDE METABOLISM, MOBILIZES INTRACELLULAR CALCIUM, AND INHIBITS TERMINAL DIFFERENTIATION OF HUMAN EPIDERMAL-KERATINOCYTES
ADENOSINE-TRIPHOSPHATE STIMULATES PHOSPHOINOSITIDE METABOLISM, MOBILIZES INTRACELLULAR CALCIUM, AND INHIBITS TERMINAL DIFFERENTIATION OF HUMAN EPIDERMAL-KERATINOCYTES
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DOI：
10.1172/jci115854
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发表时间：
1992-07-01
影响因子：
15.9
通讯作者：
BIKLE, DD
中科院分区：
文献类型：
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作者：
PILLAI, S;BIKLE, DD
在伤口愈合期间，从血小板释放ATP可能使表皮暴露于已知通过三磷酸肌醇（IP 2）和细胞内钙（Cai）水平的变化来改变介导的细胞功能的ATP浓度。因此，我们确定了角质形成细胞是否对ATP有反应，Cai和IP 3是否增加，以及这种增加是否伴随着它们的增殖和分化的变化。在用细胞外ATP刺激后，在负载Indo-1的新生人包皮角质形成细胞中测量Cai的变化。细胞外ATP诱发的Cai的角质形成细胞在存在和不存在细胞外钙的情况下的短暂和急性增加。ATP还诱导角质形成细胞的磷酸肌醇周转，与其从细胞内来源释放钙的作用一致。ATP没有透化角质形成细胞，也没有促进钙流入细胞。ATP的半最大效应在10 μ M时，在30-100 μ M时观察到饱和。UTP、ITP和ATP-γ-S与ATP一样有效地从细胞内储存中释放Cai，并与ATP竞争其响应，而AMP和腺苷无效，表明P2嘌呤能受体在介导角质形成细胞中的ATP响应中具有特异性。单细胞测量显示钙对ATP的反应具有异质性。这种异质性似乎不是由于初始Cai反应的差异，而是由于这些细胞随后去除了增加的Cai。ATP抑制角质形成细胞的终末分化，通过[S-35]甲硫氨酸掺入到皮质包膜中和适度刺激[H-3]胸苷掺入到DNA中来测量。用双-（邻氨基苯氧基）-N，N，N '，N'-四乙酸螯合Cai，可降低基础Cai，阻断Cai对ATP的反应，抑制基础DNA合成速率，阻断ATP诱导的DNA合成增加。我们的结论是，细胞外ATP可能是一个重要的生理调节表皮生长和分化，通过IP 3和蔡。
During wound healing, release of ATP from platelets potentially exposes the epidermis to concentrations of ATP known to alter cellular functions mediated via changes in inositol trisphosphate (IP2) and intracellular calcium (Cai) levels. Therefore, we determined whether keratinocytes respond to ATP with a rise in Cai and IP3 and whether such increases are accompanied by a change in their proliferation and differentiation. Changes in Cai were measured in Indo-1-loaded neonatal human foreskin keratinocytes after stimulation with extracellular ATP. Extracellular ATP evoked a transient and acute increase in Cai of keratinocytes both in the presence and in the absence of extracellular calcium. ATP also induced the phosphoinositide turnover of keratinocytes, consistent with its effect in releasing calcium from intracellular sources. ATP did not permeabilize keratinocytes, nor did it promote Ca influx into the cells. The half-maximal effect of ATP was at 10-mu-M, and saturation was observed at 30-100-mu-M. UTP, ITP, and ATP-gamma-S were as effective as ATP in releasing Cai from intracellular stores and competed with ATP for their response, whereas AMP and adenosine were ineffective, suggesting the specificity of P2 purinergic receptors in mediating the ATP response in keratinocytes. Single cell measurements revealed heterogeneity in the calcium response to ATP. This heterogeneity did not appear to be due to differences in the initial Cai response but to subsequent removal of increased Cai by these cells. ATP inhibited terminal differentiation of keratinocytes as measured by [S-35]methionine incorporation into cornified envelopes and modestly stimulated incorporation of [H-3]thymidine into DNA. Chelation of Cai by bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid reduced basal Cai, blocked the Cai response to ATP, inhibited the basal rate of DNA synthesis, and blocked the ATP-induced increase in DNA synthesis. We conclude that extracellular ATP may be an important physiological regulator of epidermal growth and differentiation acting via IP3 and Cai.