Activation of keratinocyte nicotinic cholinergic receptors stimulates calcium influx and enhances cell differentiation
Activation of keratinocyte nicotinic cholinergic receptors stimulates calcium influx and enhances cell differentiation
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DOI：
10.1111/1523-1747.ep12363399
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发表时间：
1996-09-01
影响因子：
6.5
通讯作者：
Dahl, MV
中科院分区：
文献类型：
--
作者：
Grando, SA;Horton, RM;Dahl, MV
人表皮角质形成细胞合成、分泌和降解乙酰胆碱，并利用其细胞表面烟碱和毒蕈碱胆碱能受体介导乙酰胆碱的自分泌和旁分泌作用。由于乙酰胆碱调节几种类型细胞的跨膜Ca 2+转运和细胞内代谢，我们假设胆碱能药物可能对角质形成细胞具有类似的作用，尼古丁以浓度依赖性方式增加从人新生儿包皮分离的角质形成细胞摄取的Ca-45（2+）的量，这种作用在特异性尼古丁拮抗剂美加明存在下被消除，表明它是由角质形成细胞烟碱乙酰胆碱受体介导的。从分离自培养的角质形成细胞的cDNA扩增编码α 5和α 7烟碱受体亚基的序列。这些亚基，以及α 3，β 2，和先前在角质形成细胞中发现的β 4亚基，可以是Ca 2+渗透性烟碱受体通道的组分。为了了解角质形成细胞烟碱受体的激活如何影响细胞分化的速率，我们测量了烟碱胆碱能对培养的角质形成细胞分化标志物表达的影响。长期孵育与微摩尔浓度的尼古丁显着增加的细胞数量形成皮质包膜和细胞染色的抗体基底上角蛋白10，转氨酶I型，外皮蛋白，和丝聚蛋白的数量。这些分化相关蛋白质的产生增加通过蛋白质印迹法证实，因为烟碱胆碱能刺激引起跨膜Ca 2+转运到角质形成细胞中，并且因为已知细胞内Ca 2+浓度的变化改变各种角质形成细胞功能，包括分化，介导表皮乙酰胆碱对角质形成细胞的自分泌和旁分泌作用的亚细胞机制可能涉及Ca 2+作为第二信使。
Human epidermal keratinocytes synthesize, secrete, and degrade acetylcholine and use their cell-surface nicotinic and muscarinic cholinergic receptors to mediate the autocrine and paracrine effects of acetylcholine, Because acetylcholine modulates transmembrane Ca2+ transport and intracellular metabolism in several types of cells, we hypothesized that cholinergic agents might have similar effects on keratinocytes, Nicotine increased in a concentration-dependent manner the amount of Ca-45(2+) taken up by keratinocytes isolated from human neonatal foreskins, This effect was abolished in the presence of the specific nicotinic antagonist mecamylamine, indicating that it was mediated by keratinocyte nicotinic acetylcholine receptor(s), The sequences encoding the alpha 5 and alpha 7 nicotinic receptor subunits were amplified from cDNA isolated from cultured keratinocytes, These subunits, as well as the alpha 3, beta 2, and beta 4 subunits previously found in keratinocytes, can be components of Ca2+-permeable nicotinic receptor channels. To learn how activation of keratinocyte nicotinic receptors affected the rate of cell differentiation, we measured the nicotinic cholinergic effects on the expression of differentiation markers by cultured keratinocytes. Long-term incubations with micromolar concentrations of nicotine markedly increased the number of cells forming cornified envelopes and the number of cells staining with antibodies to suprabasal keratin 10, transglutaminase type I, involucrin, and filaggrin. The increased production of these differentiation-associated proteins was verified by Western blotting, Because nicotinic cholinergic stimulation causes transmembrane Ca2+ transport into keratinocytes, and because changes in concentrations of intracellular Ca2+ are known to alter various keratinocyte functions, including differentiation, the subcellular mechanisms mediating the autocrine and paracrine actions of epidermal acetylcholine on keratinocytes may involve Ca2+ as a second messenger.