2017-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/688780摘要：懷孕時期，孕婦會有一連串的代謝變化，以確保母親與胎兒都能夠得到足夠的營養。除了葡萄糖之外，脂肪酸也是母親與胎兒重要的養份之一，孕婦會透過各種荷爾蒙的作用，讓血中三酸甘油脂逐步上升，以提供足夠的lipid substrates 讓母體與胎兒運用。但是，近年來的研究發現，懷孕過程血中三酸甘油脂過高，發生子癲前症(preeclampsia)等問題的機會越高。因此，是否要積極控制孕婦血中三酸甘油脂，是臨床上重要但尚待解決的問題。這問題的其中一個關鍵，就是要更深入了解母體三酸甘油脂對於胎兒代謝與生長的影響。我們在2013-2016 年建立了一個孕婦的世代(cohort)，初步研究的結果顯示，懷孕中期血中三酸甘油脂與胎兒臍帶血中c-peptide、insulin secretion index、insulin resistance index 及出生體重有顯著相關，而此關係獨立於血糖之外。此外，文獻中指出，非懷孕時期的三酸甘油脂與游離脂肪酸會透過free fattyacid receptors (FFARs)來影響胰島β 細胞功能、胰島素敏感性與體重。其中，medium-chain fatty acids(MCFA)以及long-chain fatty acids (LCFA)會透過FFAR1 與FFAR4 作用，short-chain fatty acid (SCFA)則會透過FFAR2 與FFAR3 作用。胰島β 細胞上的FFAR 可直接調控glucose-stimulated insulin secretion；enteroendocrine cells 上的FFAR，也可透過對glucagon-like protein-1 (GLP-1)與gastric inhibitorypolypeptide (GIP)的調控，來間接刺激胰島素分泌。此外，脂肪細胞與巨噬細胞上的FFAR4 可以調節胰島素敏感性；而FFAR 也可透過調控peptide YY 與energy expenditure 等機制，來影響體重。由於目前並沒有文獻探討懷孕期間fatty acid metabolism 對胎兒醣類代謝與生長的影響，因此，我們將透過本計畫來檢視以下假說：懷孕時母體血中的三酸甘油脂與游離脂肪酸會影響 胎兒血中的三酸甘油脂與游離脂肪酸，而胎兒血中的三酸甘油脂與游離脂肪酸會透過FFAR 來影響 胎兒胰島β 細胞的大小、數目與功能，以及胎兒的胰島素敏感性跟生長。本計畫包括3 個specific aims，將透過人類的世代研究(specific aim A 與B)與動物實驗(specific aim C)來進行。Specific aim A 將收錄1000 位孕婦，利用這些孕婦第一孕期、第二孕期與生產時的血液檢體，以及胎兒的臍帶血檢體，測定lipid profile、游離脂肪酸與c-peptide 濃度，並依據胎兒insulin secretion、胰島素敏感性與出生體重，挑選較高與較低的人，以targeted metabolomics 方式測定檢體中LCFA、MCFA 與SCFA 的濃度。本部份將分析(1)母體第一孕期、第二孕期與生產時血中lipid profile、total FFA、LCFA/MCFA/SCFA 濃度，(2)胎兒臍帶血中lipid profile、total FFA、LCFA/MCFA/SCFA 濃度，與(3)胎兒insulin secretion、胰島素敏感性與出生體重，彼此的關係。Specific aim B 將建立華人孕期長期追蹤的cohort，追蹤母親產後1 天、5 天與6-12 週時血中lipidprofile 的變化，同時也將追蹤胎兒出生至3 歲時的成長狀況，包括身高、體重、頭圍與胸圍，並測定臍帶血中IGF-1 濃度。本部份將分析(1)母親產後lipid profile 的變化，(2)母體不同孕期血中lipid profile、total FFA、LCFA/MCFA/SCFA 濃度，與新生兒生長的關係，(3)胎兒臍帶血中lipid profile、total FFA、LCFA/MCFA/SCFA 濃度，與胎兒出生後生長的關係。Specific aim C 為動物實驗，藉由兩種方式造成懷孕母鼠血中游離脂肪酸升高。包括懷孕前餵食high-fat diet、以及懷孕期間直接經由靜脈注射Intralipid + heparin。母鼠將於介入前後，測量血中三酸甘油脂、游離脂肪酸、胰島素及血糖。胎鼠分成兩組，一組為出生後犧牲，另一組為存活4 周後犧牲，記錄體重變化及體組成(脂肪比)、抽取血液檢測三酸甘油脂、游離脂肪酸、胰島素、血糖、c-peptide、GLP-1 與GIP，之後利用HOMA-β 與HOMA-IR 來了解胎鼠的insulin secretion 與胰島素敏感性。此外，也將抽取胎鼠組織，檢測胰島數量及面積，定量胰島β 細胞、intestine 與脂肪組織FFAR 的表現，並分析與胰島β 細胞功能及發展相關的重要基因。<br> Abstract: During pregnancy, there are several hormonal changes to ensure that both the mother and the fetus canhave adequate energy and nutrient supply. Aside from glucose, fatty acids are another important nutrientsource. Maternal plasma triglyceride and free fatty acids (FFA) increase gradually during pregnancy.However, recent reports find that high plasma triglyceride during pregnancy is associated with a higher riskof adverse pregnancy outcomes such as preeclampsia. Therefore, it remains unknown if we should controlhyper-triglyceridemia during pregnancy. A further understanding of maternal plasma triglyceride on fetalmetabolism and growth is a key to this important issue.In 2013-2016, we have established a pregnancy cohort. We found that maternal plasma triglyceride at24-28 gestational week was associated with cord c-peptide, insulin secretion index, insulin resistance indexand birth weight of the newborn. In the literature, plasma triglyceride and FFA during non-pregnant states canbind to free fatty acid receptors (FFARs) and regulate pancreatic β-cell function, insulin sensitivity and bodyweight. Long-chain fatty acids (LCFA) and medium-chain fatty acids (MCFA) can bind to FFAR1 andFFAR4; whereas short-chain fatty acid (SCFA) can bind to FFAR2 and FFAR3. FFAR on pancreas β-cell canregulate glucose-stimulated insulin secretion. Besides, FFAR can also indirectly regulate insulin secretionthrough their effect on glucagon-like protein-1 (GLP-1) and gastric inhibitory polypeptide (GIP) secretion.FFAR4 on adipocytes and macrophages can regulate insulin sensitivity, and FFARs can regulate body weightthrough their effect on peptide YY and energy expenditure.To our best knowledge, there is no report which explore the role of maternal plasma triglyceride andFFA on fetal glucose metabolism and growth. Therefore, we propose this project with the followinghypothesis: 1. maternal plasma triglyceride and FFA will affect fetal plasma triglyceride and FFA. 2. Fetalplasma triglyceride and FFA will affect the size, number and function of their pancreatic β-cells, insulinsensitivity and growth, through the function of FFAR. There are three specific aims in this projects, includinga human cohort study (specific aim A and B) and an animal study (specific aim C).In specific aim A, we will collect cord blood and blood samples at the first trimester, the secondtrimester, and at delivery from 1000 pregnant women/newborn pairs, to measure lipid profile, FFA, andc-peptide concentrations. Besides, we will select mother/fetus pairs with higher and lower values of insulinsecretion index, insulin sensitivity index and birth weight, and measure their LCFA, MCFA and SCFA bytargeted metabolomics. Then, we will analyze the relationship among maternal fatty acid metabolism, cordblood fatty acid metabolism, fetal insulin secretion, fetal insulin sensitivity and birth weight.In specific aim B, we will measure maternal plasma lipid profile 1 day, 5 days and 6-12 weeks afterdelivery, and analyze the change of plasma lipid profile after delivery. We will follow the growth of thenewborn/infants and measure plasma IGF-1 in their cord blood. We will analyze the relationship betweenmaternal plasma fatty acid metabolism, cord blood fatty acid metabolism, and newborn/infant growth.In specific aim C, we will use two animal models for high plasma FFA during pregnancy, includinghigh-fat diet model before pregnancy, and intravenous infusion of Intralipid and heparin, and compare theresults with the control group. Maternal plasma triglyceride, FFA, insulin and glucose will be measuredbefore and after the interventions. Fetal mice will be sacrificed at birth or 4 weeks after delivery. Birth weight,body weight, adiposity, plasma triglyceride, FFA, insulin, glucose, c-peptide, GLP-1 and GIP will bemeasured. Besides, we will measure the number and the area of pancreatic islets, analyze the expression ofFFAR in pancreatic β-cells, intestine and adipose tissue. We will also measure expressions of important genesfor the development and function of pancreas β-cells.