BINDING OF LEUKOTRIENE-C4 TO RAT LUNG FIBROBLASTS AND STIMULATION OF COLLAGEN-SYNTHESIS INVITRO
BINDING OF LEUKOTRIENE-C4 TO RAT LUNG FIBROBLASTS AND STIMULATION OF COLLAGEN-SYNTHESIS INVITRO
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DOI：
10.1021/bi00408a028
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发表时间：
1988-04-19
期刊：
影响因子：
2.9
通讯作者：
KUNKEL, SL
中科院分区：
文献类型：
--
作者：
PHAN, SH;MCGARRY, BM;KUNKEL, SL
花生四烯酸代谢产物是影响多种细胞功能的有效生物介体。虽然E系列前列腺素是环氧合酶途径的产物，已被认为是成纤维细胞增殖和胶原合成的抑制剂或下调因子，但最近发现的5-脂氧合酶途径产物在成纤维细胞功能方面还没有得到广泛的研究。本研究检测了脂氧合酶途径的硫多肽产物白三烯C4(LTC4)在体外对大鼠肺成纤维细胞胶原合成和增殖的调节作用。数据显示，LTC4和较小程度的白三烯D4(LTD4)以剂量依赖的方式(10-11-10-8M)刺激胶原合成，而不影响放射性标记胸苷掺入测定的细胞增殖：1 nM LTC4引起85%(P<；白三烯受体拮抗剂FPL55712(10微米)可阻断LTC4对胶原蛋白的掺入，放线菌素D和放线菌素D可抑制LTC4对胶原蛋白合成的抑制作用。LTC4对胶原蛋白合成的促进作用略高于非胶原蛋白合成，但不伴随胶原类型的任何改变。[~3H]LTC4与这些细胞的结合是特异的、可逆的和可饱和的，Kd值为1.8.+-。0.95海里。在均衡条件下，估计为2.39倍。每个细胞104个受体。这种结合也被10µM FPL55712抑制。竞争结合研究表明，LTC4与LTD4和FPL55712的这种结合具有特异性。此外，在结合研究中没有发现LTC4向LTD4或白三烯E4的显著转化。这些结果表明，这些细胞上存在特异的LTC4受体，这可能介导了细胞对蛋白质和胶原合成的影响。
Arachidonate metabolites are potent biological mediators affecting multiple cellular functions. Although prostaglandins of the E series, which are products of the cyclooxygenase pathway, have been known as inhibitors or down-regulators of fibroblast proliferation and collagen synthesis, the more recently discovered products of the 5-lipoxygenase pathway have not been as extensively investigated with regard to fibroblast function. In this study, a sulfidopeptide product of the lipoxygenase pathway, leukotriene C4 (LTC4), was examined for its ability to modulate rat lung fibroblast collagen synthesis and proliferation in vitro. The data revealed the ability of LTC4 and to a lesser extent leukotriene D4 (LTD4) to stimulate collagen synthesis in a dose-dependent (10-11-10-8 M) manner without affecting cellular proliferation as determined by radiolabeled thymidine incorporation; 1 nM LTC4 caused an 85% (p < 0.02) increase above untreated controls in [3H]proline incorporation into collagenous protein in the media, which was blocked by the putative leukotriene receptor antagonist FPL55712 (10 .mu.M) and inhibited by cycloheximide and actinomycin D. This LTC4 stimulatory effect was slightly more specific for collagen synthesis vs noncollagenous protein synthesis but was not accompanied with any change in the collagen type composition. Binding of [3H]LTC4 to these cells was specific, reversible, and saturable, with a Kd of 1.8 .+-. 0.95 nM. Under equilibrium conditions, there was an estimated 2.39 .times. 104 receptors per cell. This binding was also inhibited by 10 .mu.M FPL55712. Competitive binding studies show specificity of this binding for LTC4 relative to LTD4 and FPL55712. Furthermore, no significant conversion of LTC4 to LTD4 or leukotriene E4 was noted during the binding studies. These results indicate the presence of specific LTC4 receptors on these cells which may mediate the cellular effects on protein and collagen synthesis.