GLP-1R激动剂抗肥胖和FPRL1激动剂抗肺纤维化药理学研究(硕士)(论文57000字)
中文摘要
过去十几年间，肥胖已经逐渐发展成为全球范围的流行趋势。尽管饮食节制和运动是防治肥胖的基本方法，药物治疗则是使病人获得长期减重效果的重要手段。胰高血糖素样肽-1（Glucagon-like peptide-1, GLP-1）作为一种胃肠激素可通过多种途径调节机体的能量平衡，因此成为抗肥胖治疗的重要潜在药物。我们在前期工作中发现非肽类GLP-1受体（Glucagon-like peptide-1 receptor，GLP-1R）激动剂Boc5对db/db糖尿病小鼠除具有抗糖尿病作用外，也显示了一定的减肥效果。本课题中我们选取更接近人类肥胖发病特征的高脂饮食诱导的肥胖（Diet-induced obesity, DIO）小鼠模型，重点研究Boc5的减肥作用及相关减肥机制。实验结果表明，一周三次、持续12周腹腔注射Boc5能剂量依赖性地减轻DIO小鼠的体重、减少身体质量指数和摄食量；同时能降低体脂，减轻脂肪细胞肥大和外周组织脂肪沉积；Boc5也能显著改善肥胖小鼠的血糖、糖耐量、胰岛素抵抗，提高胰岛素敏感性；Boc5（3 mg）治疗后小鼠脂肪细胞胰岛素刺激的葡萄糖摄取能力和脂质降解活性也得到一定恢复；Boc5还能改善血清脂肪因子（瘦素、脂联素）、谷丙转氨酶、谷草转氨酶、甘油三酯、总胆固醇、游离脂肪酸、高密度脂蛋白胆固醇与低密度脂蛋白胆固醇的比值等生化指标。研究还发现限制摄食（Pair-fed）的减肥作用不及Boc5。我们的实验结果提示，Boc5可以通过多种机制发挥减肥效应，并能纠正肥胖伴随的各种代谢紊乱，因此具有重要的药用开发价值。
特发性肺纤维化（Idiopathic pulmonary fibrosis, IPF）是一种以肺功能障碍为主要特征的间质性肺疾病。尽管近二十年来IPF的药物治疗取得了极大的进展，但仍然缺乏有效的干预手段。博莱霉素（Bleomycin, BLM）诱导的肺纤维化动物模型能模拟人类IPF的病理特点，因此广泛用于实验室研究。Quin-C1是本研究组通过高通量筛选，首次发现的特异性甲酰肽样受体1（Formyl peptide receptor-like 1, FPRL1）小分子激动剂，初期的体外实验证实它具有活化中性粒细胞的作用。本课题旨在观察Quin-C1对BLM诱导的肺纤维化小鼠是否具有抗炎和抗纤维化作用。实验结果发现，与模型组相比，Quin-C1（0.2 mg）能明显减少小鼠肺灌流液中性粒细胞和淋巴细胞数量，抑制肺组织细胞因子（肿瘤坏死因子、白介素-1β、转化生长因子-β1和角质细胞起源趋化因子）的生成，并能降低肺中羟脯氨酸的含量。这些成果提示Quin-C1具有一定的体内抗炎和抗纤维化活性，是治疗IPF的潜在药物。
此外，本论文工作还包括基于甲状旁腺激素1型受体（Parathyroid hormone receptor type-1, PTHR1）的细胞水平药物筛选模型的建立。甲状旁腺激素（Parathyroid hormone, PTH）可与PTHR1（G蛋白偶联受体B家族）结合，发挥骨组织重塑和调节血钙稳态的作用，因此PTH(1-34)成为目前重要的抗骨质疏松药物。由于PTHR1肽类激动剂具有一定的临床应用限制，科研人员开始积极寻找有效的小分子激动剂。本课题的研究目的是建立以PTHR1为靶点的细胞水平的高通量筛选模型。实验中，我们将PTHR1表达载体和pCRE-Luc荧光素酶报告基因质粒共转染HEK293细胞，测得PTH(1-34)的EC50为7.75 nM，与文献报道相当。在优化实验条件（细胞密度、DMSO浓度等）后，评价了各项筛选参数，认为该模型符合高通量筛选要求，可以用于高通量药物筛选。
关键词：肥胖；胰高血糖素样肽-1；胰高血糖素样肽-1受体激动剂；特发性肺纤维化；甲酰肽样受体1；甲酰肽样受体1激动剂；甲状旁腺激素1型受体
Pharmacological studies on the anti-obesity effect of GLP-1R agonistand the anti-fibrotic property of FPRL1 agonist
He min (Pharmacology)
Directed by Professor Ming-Wei Wang
Abstract
Obesity has become a worldwide epidemic in the past two decades. Although diet control and exercise remain the first steps in obesity management, the use of pharmacological agents may sometimes be indispensable for long-term treatment of obesity. Glucagon-like peptide-1 (GLP-1), an important gastrointestinal hormone, plays an essential role at multiple levels in the regulation of energy homeostasis and has been regarded as a potential therapeutic agent for weight loss. Our previous work has demonstrated that Boc5, a non-peptidic glucagon-like peptide-1 receptor agonist, could simultaneously elicit antidiabetic and antiobesity effects in diabetic db/db mice. The objective of the current work was to investigate if Boc5 is capable of treating over weight and metabolic abnormities observed in diet-induced obesity (DIO) mice, which resemble the pathological features of human obesity. Our results indicate that a 12-week t.i.w. Boc5 injection regimen dose-dependently induced durable reductions in body weight, body mass index (BMI) and food intake, associated with decreases in fat mass, adipocyte hypertrophy and peripheral tissue lipid accumulation. Boc5 also provided glycemic control through significantly improvement of insulin sensitivity in DIO mice. In addition, chronic administration of Boc5 (3 mg/mouse) apparently reduced basal while enhancing insulin-stimulated glucose incorporation and noradrenaline-stimulated lipolysis in isolated adipocytes. Furthermore, circulating leptin, adiponectin, alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, free fatty acid and high-density lipoprotein/low density lipoprotein cholesterol ratio were normalized by Boc5 treatment. The effects in in pair-fed animals were comparatively less pronounced. Our findings suggest that Boc5 may evoke metabolic benefits via multi-facet mechanisms and represent an attractive therapeutic intervention counteracting obesity and associated metabolic disorders.
Idiopathic pulmonary fibrosis (IPF) is a disease condition that leads to a reduced blood oxygen exchange capability of the affected lungs. Despite significant research progress made in the past two decades, effective therapies for IPF are still limited. Bleomycin (BLM)-induced pulmonary fibrosis is a frequently used and well-characterized model for laboratory investigations of the pathogenesis of lung fibrosis. Quin-C1, a highly specific formyl peptide receptor-like 1 (FPRL1) agonist, identified through a high-throughput screening (HTS) campaign. Our initial pharmacological characterization identified Quin-C1 with neutrophil-activating functions. The objective of the present work was to investigate if Quin-C1 could exert anti-inflammatory and anti-fibrotic effects in BLM-induced lung fibrosis mice. The results show that mice receiving Quin-C1 (0.2 mg/mouse, q.d.) following BLM challenge had significantly reduced neutrophil and lymphocyte counts in the bronchoalveolar lavage fluid (BALF), diminished expression of the proinflammatory cytokines (TNF-α、IL-1β、TGF-β1 and KC), and decreased collagen deposition in lung tissue, compared to mice receiving BLM plus vehicle. Quin-C1 treatment also reduced the content of hydroxyproline in the mouse lung tissue. These data demonstrate an anti-inflammatory and anti-fibrotic function of Quin-C1 in vivo, suggesting its therapeutic potential in the control of IPF.
Finally, a functional HTS assay targeting parathyroid hormone receptor type-1 (PTHR1) was developed. Parathyroid hormone (PTH), a principal regulator of bone remodeling and calcium ion homeostasis, exerts its effects by binding and activating PTHR1, a family member of the class B G protein-coupled receptors (GPCRs). PTH(1-34) that stimulates bone formation is an approved drug for osteoporosis. Since all PTHR1 agonists currently under development are of peptidic nature and subject to limitations for clinical use, there is growing interest to find small molecule agonists of this receptor. The objective of our work was to establish a cell-based HTS assay targeting PTHR1. HEK293 cell stably transfected with a PTHR1 expression vector and a reporter plasmid pCRE-Luc were used to develop this assay. EC50 value of the positive peptide, PTH(1-34)，was measured at 7.75 nM, consistent with that reported in the literature. Factors including cell density and DMSO concentrations were evaluated to obtain an optimal assay condition. A series of assay parameters were systematically studied within the context of this assay and the results indicate its suitability for HTS.
Key words: Obesity, glucagon-like peptide-1, GLP-1R agonist, idiopathic pulmonary fibrosis, formyl peptide receptor-like 1, FPRL1 agonist, parathyroid hormone receptor type-1
目 录
缩略词 III
中文摘要 V
英文摘要 VII
第一章 GLP-1受体激动剂Boc5抗肥胖作用的药理学研究 1
第一节 前言 1
第二节 GLP-1受体激动剂Boc5抗肥胖作用的药理学研究 12
一、材料与方法 12
二、实验结果 23
三、讨论与总结 42
参考文献 52
第二章 FPRL1激动剂Quin-C1抗炎和抗纤维化作用的药理学研究 60
第一节 前言 60
第二节 FPRL1激动剂Quin-C1抗炎和抗纤维化作用的药理学研究 69
一、材料与方法 69
二、实验结果 75
三、讨论与总结 83
参考文献 86
第三章 基于PTHR1的细胞水平药物筛选模型的建立 91
第一节 前言 91
第二节 基于PTHR1的细胞水平药物筛选模型的建立 95
一、材料与方法 95
二、实验结果 98
三、讨论与总结 102
参考文献 105
在学期间发表文章目录 108
致谢 109
附录. 111
缩略词
AgRP Agouti-related protein 刺鼠相关蛋白
ALT Alanine aminotransferase 谷丙转氨酶
AST Aspartate aminotransferase 谷草转氨酶
cAMP Adenosine cyclophosphate 环磷酸腺苷
BAT Brown adipose tissue (Brown fat) 棕色脂肪
BSA Bovine serum albumin 牛血清白蛋白
BLM Bleomycin 博莱霉素
BALF Bronchoalveolar lavage fluid 肺泡灌洗液
CART Cocaine-amphetamine-regulated transcript 可卡因—苯丙胺调节转录肽
CV Coefficient of variation 变异系数
DPP-IV Dipeptidyl peptidase IV 二肽酶-IV
FPR Formyl peptide receptor 甲酰肽受体
FPRL1 Formyl peptidereceptor like-1 甲酰肽样受体1
FFA Free fatty acid 游离脂肪酸
GLP-1 Glucagon-like peptide-1 胰高血糖素样肽-1
GLP-1R Glucagon-like peptide-1 receptor 胰高血糖素样肽-1受体
GPCR G protein-coupled receptor G蛋白偶联受体
HDL-C High-density lipoprotein cholesterol 高密度脂蛋白胆固醇
HYP Hydroxyproline 羟脯氨酸
HTS High-throughput screening 高通量药物筛选
ITT Insulin tolerance test 胰岛素耐量实验
IPF Idiopathic pulmonary fibrosis 特发性肺纤维化
IL-1β Interleukin-1β 白介素-1β
LDL-C Low-density lipoprotein cholesterol 低密度脂蛋白胆固醇
NA L-noradrenaline, NA L-去甲肾上腺素
PKA Protein kinase A 蛋白激酶A
PLC Phospholipase C 磷脂酶C
PKC Protein kinase C 蛋白激酶C
PTH Parathyroid hormone 甲状旁腺激素
PTHrP Parathyroid hormone related peptide PTH相关蛋白
RLU Relative luminescence unit 相对冷光单位
RFU Relative fluorescence unit 相对荧光单位
S/B Signal/Background ratio 信号本底比
S/N Signal/Noise ratio 信噪比
TC Total cholesterol 总胆固醇
TG Triglycerides 甘油三酯
TNF-α Tumor necrosis factor-α 肿瘤坏死因子-α
TGF-β1 Transforming growth factor-β1 转化生长因子-β1
WAT White adipose tissue (White fat) 白色脂肪 |
