基于细胞穿透机理闽产太子参抗肺气虚证COPD环肽活性研究

Pseudostellaria heterophylla (Miq.) Pax (Taizishen, TZS) produced by Zherong County is the genuine medicinal materials of Fujian Province. TZS has such as stimulated saliva and Runfei effectiveness. We previous study showed that the ethyl acetate extract of TZS named as No.2 Zhe-Shen exhibited an antitussive effects, enhance immunity ability, anti model rat with Lung-Qi deficiency syndrome related to its improvement in lung function via attenuation of airway inflammation by adjustment of multi-cytokine levels. We have identified ethyl acetate extract of TZS contains three main classes that are amino acids, cyclic peptides and free fatty acids. HPLC fingerprint-oriented preparative separation of major cyclic peptides from ethyl acetate extract of TZS by preparative pressurized liquid chromatography. The pharmacological test showed that cyclic peptides extract can reduce lung airway resistance (RL) but increase lung compliance (Cdyn) of COPD rat with Lung-Qi deficiency syndrome. In this project, we will isolate cyclic peptide compounds and characterized the structures by Mass and NMR spectroscopy. To choose alveolar macrophage and T lymphocytes as the subject investigated, cyclic peptides are conjugated with Alexa-488 and the cell membrane is conjugated.with WGA-Alexa-647 for cellular uptake studies. The cellular uptake visualization is analyzed by confocal laser scanning microscopy and cell uptake quantification is analyzed by flow cytometry. Cells are treated at deferent macropinocytosis inhibitors to explore the mode and approach cellular uptake cyclic peptides. Peptide interact with phosphatidylinositols and phosphatidic serine (POPC、PI) using nitrocellulose membranes. Peptide-lipid interaction studies by surface plasmon resonance (SPR) and peptide heparan sulfate proteoglycan (HSPG、HS) interaction studies by SPR, too. The expressions of TLR4 and MyD88 mRNA tested by RT-PCR and JNK、p38、IKK and IκB protein phosphorylation tested by western blotting methods. To explore the activity mechanism of cell-permeable cyclic peptides reducing the secretion of inflammatory cytokines anti COPD, what the theoretic foundation to activate lung defensive immune response.

太子参生津润肺，止肺燥干咳。课题前期研究，闽产柘荣太子参乙酸乙酯提取物，是抗肺气虚证大鼠润肺止咳有效部位；鉴别其主要含有氨基酸、环肽和游离脂肪酸三类物质。加压制备色谱结合指纹图谱导向分离制备目标环肽提取物（CPE），可降低肺气虚证COPD大鼠气道阻力，增加肺动态顺应性，改善咳嗽、气急等症状。本项目采用高压制备色谱分离CPE环肽单体，Mass、NMR等多种谱学方法，表征结构。以大鼠肺泡巨噬细胞和T淋巴细胞为对象，Alexaλ1标记环肽、WGA-Alexaλ2细胞膜染色，激光共聚焦显微镜活细胞成像、流式细胞定量，评价环肽细胞穿透性；硝酸纤维素膜印迹和表面等离子共振技术（SPR），研究环肽与细胞膜磷脂（POPC、PI）、细胞表面糖蛋白受体（HSPG、HS）结合动力学；筛选细胞穿透性环肽（CPCP）。进而探讨CPCP抗COPD活性，从TLR4/MyD88信号转导通路，激活机体防御性免疫应答的机制。

太子参生津润肺，止肺燥干咳。闽产柘荣太子参乙酸乙酯提取物，是抗肺气虚证大鼠润肺止咳有效部位。本项目建立太子参环肽的提取方法，经乙酸乙酯提取、石油醚脱脂、除氨基酸、醇沉及冻干的步骤，获得的提取物中含有11种环肽成分，纯度可达92.94%。本项目采用高压制备色谱分离获得太子参环肽A（Heterophyllin A，HA）、太子参环肽B（Heterophyllin B，HB）、太子参环肽乙（Pseudosetlarin B，PB）、太子参环肽丙（Pseudosetlarin C，PC）、太子参环肽庚（Pseudosetlarin G，PG）、太子参环肽戊（Pseudostellarin E，PE），6种环肽单体。以大鼠肺泡巨噬细胞和T淋巴细胞为对象，FITC标记太子参环肽A（HA）、WGA-Alexa Fluor-594细胞膜染色，激光共聚焦显微镜活细胞成像，HA具有细胞穿透性；硝硝酸纤维素膜印迹和表面等离子共振技术（SPR），研究环肽与细胞膜磷脂（POPC、PI）、细胞表面糖蛋白受体（HSPG、HS）结合动力学、分子动力学，筛选细胞穿透性环肽（CPCP）。太子参环肽能够穿透细胞膜；但不同结构的环肽，穿膜能力不尽相同。本项目的研究结果为阐释太子参环肽的生物活性奠定了基础。药理实验表明，可降低肺气虚证COPD大鼠气道阻力，增加肺动态顺应性，改善咳嗽、气急等症状。进而探讨环肽抗COPD活性，从TLR4/MyD88信号转导通路，探讨了激活机体防御性免疫应答的机制。本项目以COPD为对象，验证了太子参环肽的药理活性，并进一步深入探讨其作用机制。制备COPD大鼠模型，以高中低剂量环肽提取物（200 mg/kg、400 mg/kg、500mg/kg），每天1次，灌胃15天。结果表明，灌胃400mg/kg的大鼠，肺气道阻力显著降低，但动态肺顺应性上升。肺组织病理提示太子参环肽可降低肺泡破坏程度，减轻肺部炎症，增加肺泡间隙，改善浸润炎症细胞；环肽可降低大鼠血清中TNF-α水平，但增加IL-10，以调节大鼠血清中的多种细胞因子。分离肺气虚证COPD大鼠模型肺泡巨噬细胞，分别用环肽干预12h 、24h、48h，细胞上清液中TNF-α和IL-8降低，IL-10含量升高；TLR4mRNA、MyD88mRNA和AP-1mRNA水平、p-JNK、p-p38和p-TAK1蛋白表达水平均显著降低。表