Central role of fibroblast α3 nicotinic acetylcholine receptor in mediating cutaneous effects of nicotine
Central role of fibroblast α3 nicotinic acetylcholine receptor in mediating cutaneous effects of nicotine
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DOI：
10.1097/01.lab.0000053917.46614.12
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发表时间：
2003-02-01
影响因子：
5
通讯作者：
Grando, SA
中科院分区：
文献类型：
--
作者：
Arredondo, J;Hall, LL;Grando, SA
吸烟与异常的皮肤组织重塑有关，如皮肤过早老化和伤口愈合受损。其机制尚不完全清楚。真皮成纤维细胞（DF）是真皮的主要细胞成分，可能为烟草制品的病理作用提供靶点。本研究旨在探讨尼古丁（Nic）对DF生长和组织重塑功能的影响机制。我们假设，Nic对DF的影响是由于其与这些细胞表达的特定尼古丁乙酰胆碱受体（nachr）结合，并且来自受体的下游信号改变了正常的细胞功能，导致皮肤稳态的变化。通过RT-PCR和Western blotting，我们发现人DF暴露于10 mum Nic 24小时会导致细胞周期调节因子p21、cyclin D1、Ki-67和PCNA的mRNA和蛋白水平增加1.9- 28倍，凋亡调节因子Bcl-2和caspase 3的mRNA和蛋白水平增加1.7- 2倍。Nic暴露也上调真皮基质蛋白lalpha1型胶原蛋白和弹性蛋白以及基质金属蛋白酶-1的表达。nAChRs的特异性拮抗剂甲胺（Mec）可以消除nic诱导的改变，表明它们是由DF表达的nAChRs的药理刺激引起的。为了确定这些发现与特定烟碱能途径的相关性，我们研究了转染了抗α 3反义寡核苷酸的人DF和α 3 nAChR敲除小鼠的小鼠DF。在这两种情况下，缺乏alpha3与成纤维细胞生长和功能的改变有关，这与Nic处理的DF相反，这表明尼古丁对DF的影响主要是由alpha3 nAChR介导的。除alpha3外，在人DF中检测到的nAChR亚基还有alpha5、alpha7、beta2和beta4。DF暴露于Nic改变了这些亚基的相对数量，导致[H-3]表贝替丁结合动力学的相互变化。因此，烟草制品对皮肤细胞外基质转换的一些病理效应可能源于尼古丁诱导的生理控制的改变，这些生理控制是由遗传决定的生长程序的展开和DF的组织重塑功能，以及成纤维细胞nachr的结构和功能的改变。
Smoking is associated with aberrant cutaneous tissue remodeling, such as precocious skin aging and impaired wound healing. The mechanism is not fully understood. Dermal fibroblasts (DF) are the primary cellular component of the dermis and may provide a target for pathobiologic effects of tobacco products. The purpose of this study was to characterize a mechanism of nicotine (Nic) effects on the growth and tissue remodeling function of DF. We hypothesized that the effects of Nic on DF result from its binding to specific nicotinic acetylcholine receptors (nAChRs) expressed by these cells and that downstream signaling from the receptors alters normal cell functioning, leading to changes in skin homeostasis. Using RT-PCR and Western blotting, we found that a 24-hour exposure of human DF to 10 mum Nic causes a 1.9- to 28-fold increase of the mRNA and protein levels of the cell cycle regulators p21, cyclin D1, Ki-67, and PCNA and a 1.7- to 2-fold increase of the apoptosis regulators Bcl-2 and caspase 3. Nic exposure also up-regulated expression of the dermal matrix proteins collagen type lalpha1 and elastin as well as matrix metalloproteinase-1. Mecamylamine (Mec), the specific antagonist of nAChRs, abolished Nic-induced alterations, indicating that they resulted from a pharmacologic stimulation of nAChRs expressed by DF. To establish the relevance of these findings to a specific nicotinergic pathway, we studied human DF transfected with anti-alpha3 antisense oligonucleotides and murine DF from alpha3 nAChR knockout mice. In both cases, lack of alpha3 was associated with alterations in fibroblast growth and function that were opposite to those observed in DF treated with Nic, suggesting that the nicotinic effects on DF were mostly mediated by alpha3 nAChR. In addition to alpha3, the nAChR subunits detected in human DF were alpha5, alpha7, beta2, and beta4. The exposure of DF to Nic altered the relative amounts of each of these subunits, leading to reciprocal changes in [H-3]epibatidine-binding kinetics. Thus, some of the pathobiologic effects of tobacco products on extracellular matrix turnover in the skin may stem from Nic-induced alterations in the physiologic control of the unfolding of the genetically determined program of growth and the tissue remodeling function of DF as well as alterations in the structure and function of fibroblast nAChRs.