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研究生: 賴亭羽
Lai, Ting-Yu
論文名稱: 斑馬魚心臟修復早期過程中Syndecan-4的功能
The characterization of syndecan-4 in early stage of adult zebrafish heart regeneration
指導教授: 莊永仁
Chuang, Yung-Jen
口試委員: 鄭世進
Cheng, Shih-Chin
陳振輝
Chen, Chen-Hui
學位類別: 碩士
Master
系所名稱: 生命科學暨醫學院 - 生物資訊與結構生物研究所
Institute of Bioinformatics and Structural Biology
論文出版年: 2017
畢業學年度: 105
語文別: 英文
論文頁數: 42
中文關鍵詞: 斑馬魚冷凍創傷心臟再生Syndecan-4心電圖
外文關鍵詞: Zebrafish, Cryoinjury, Heart regeneration, Syndecan-4, Electrocardiogram
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  • 心肌梗塞後的組織修復牽涉到複雜的機制,而這些修復的過程中,發炎反應被猜測是關鍵的初始步驟。缺氧壞死的組織誘發細胞介素和趨化介素等因子之表現,調控先天性免疫反應的同時,影響各式生長因子,進而調控血管新生、心肌細胞再生、以及組織重塑等後續反應。大多數哺乳類動物的心臟受損後,再生與組織重塑被認為會互相抗衡,導致受傷的心肌組織由纖維化瘢疤所取代。而這些不具彈性的纖維化組織,會對正常收縮的心肌造成傷害,嚴重時可能造成心臟衰竭而死亡。相較而言,斑馬魚在心肌受損後,具有無疤再生的修復能力,這意味著透過了解斑馬魚心臟再生過程中的調控機制,有助於我們釐清有那些因子參與調控受損心臟傷疤的生成與退減。
    先前在脊椎動物的研究顯示,syndecan-4 (Sdc4)可以調節發炎反應和纖維母細胞的活性。有趣的是,有研究指出剔除Sdc4的小鼠在心肌梗塞後心臟較容易破裂。因此,我們猜測在斑馬魚心臟創傷初期,Sdc4可能透過調控發炎反應及細胞外基質生成,藉以維持心臟功能完整,同時也影響了心臟再生修復的進程。為了驗證這一個假設,我們先進行斑馬魚心臟創傷後的基因表現時序分析。結果顯示,創傷後初期sdc4的表現量果然快速上升,暗示其重要性。接著透過注射接附sdc4 siRNA的奈米磁珠,達成抑制斑馬魚心臟內sdc4基因表現,以進行後續實驗。我們利用轉殖螢光魚標定非淋巴球白血球 (myeloid cells),追蹤白血球聚集於受傷組織的進程。實驗結果顯示減少Sdc4表現可能會阻礙先天免疫細胞的聚集。另外,當sdc4基因被抑制時,col1a1 和tgfb1a的基因表現以及fibronectin蛋白表現量亦隨同下降。透過細胞新生標定結果,我們認為Sdc4可能影響心外膜下層細胞活化與增生。最後,我們透過實驗室先前建立的斑馬魚心電圖測量技術,結合即時錄影,分析心肌收縮狀態與心電圖。由影像可推測sdc4被抑制後,斑馬魚心臟傷口的修復能力下降,以及傷口周邊的心肌組織收縮異常;且同時心電圖中,心肌梗塞指標ST段上升(ST-elevation)持續時間延長。我們假設這些免疫反應、胞外基質調控、以及細胞新生的變化,是抑制sdc4後導致傷口癒合延遲的原因,證實Sdc4在早期心臟修復過程中的重要性。


    Damage repair after myocardial infarction involves a series of complex events, which are thought to be initiated by inflammatory responses. The infarcted necrosis tissue induces production of cytokines and chemokines, which recruit immune cells and lead to the generation of several growth factors to induce and regulate angiogenesis, myocardial proliferation, and tissue remodeling.
    In most mammals, the disproportion of regeneration and tissue remodeling causes the injured tissue to be replaced by fibrotic scars. These non-elastic fibrosis tissues block the contraction of the heart and damage the normal cardiac muscle tissue, which may result in heart failure and death. In contrast, zebrafish has the ability to undertake scar-free healing after cardiac injury. This implies that if we could understand the mechanism of heart regeneration in zebrafish, we may adapt the knowledge to manage heart repair in human myocardial infarction.
    Previous studies have reported that syndecan-4 (Sdc4) regulates the inflammatory response and fibroblast activity in the vertebrates. Interestingly, Sdc4 knockout mice have higher mortality rate after myocardial infarction due to heart wall rupture. Therefore, we hypothesized that in early stage of zebrafish heart repair, Sdc4 may be a key regulator of inflammatory response and the production of extracellular matrix supportive proteins to protect heart from further damage and to promote tissue regeneration. To test this hypothesis, we first conducted a time-lapsed gene expression analysis to identify the gene expression profile of sdc4 after heart injury in zebrafish. As expected, we found the sdc4 expression increased rapidly after cryoinjury, which implies its importance in the early phase of heart regeneration. Then, we injected nano-magnetic beads coupled with sdc4 siRNA to inhibit sdc4 expression in zebrafish heart under an external magnetic field. We used the Lyz:DsRed zebrafish line to label myeloid cells to track the movement of immune cells. The results showed that loss of Sdc4 blocked the accumulation of innate immune cells in the lesion. In addition, when sdc4 was knocked down, we found the gene expression of col1a1a and tgfb1a and the protein expression of fibronectin were all down-regulated. Moreover, loss of Sdc4 might also affect the cell activation and proliferation around subepicardium. Finally, we measured the electrocardiogram in post-heart injury zebrafish with integrated video recording of ex vivo heart. After sdc4 knockdown, we observed the reduced capacity of wound repair and abnormal ventricular contraction around the cryoinjury lesion, meanwhile, the electrocardiogram showed sustained ST-elevation, the marker of myocardial infarction, in sdc4 knockdown group. In conclusion, Sdc4 might mediate the innate immune cells’ movement, the production of ECM proteins, the cell proliferation, the heart’s contractility, and the cardiac repair in the early stage of zebrafish heart repair. Sdc4 could be a critical regulator for scar-free healing in zebrafish heart regeneration.

    中文摘要 I Abstract III 致謝 V List of Tables VIII List of Figures VIII Abbreviations IX 1. Introduction 1 1.1 Current status of myocardial infarction 1 1.1.1 Myocardial infarction 1 1.1.2 Diagnosis and treatment of MI 1 1.1.3 Recent research strategies in MI 3 1.2 Syndecan-4 4 1.2.1 Syndecan-4 is a multi-functional protein 4 1.2.2 Implications of syndecan-4 in heart diseases 5 1.3 Zebrafish model for cardiac tissue repair research 5 1.4 The aim of this study: to investigate the role of syndecan-4 in early stage of zebrafish heart regeneration 6 2. Material and methods 7 2.1 Zebrafish husbandry 7 2.2 Zebrafish anesthetization and sacrifice 7 2.3 Cryoinjury MI model in zebrafish 7 2.4 Adult zebrafish retro-orbital injection 8 2.5 Inducing sdc4 knockdown of the heart in adult zebrafish 8 2.6 RNA isolation and Real-time quantitative PCR analysis 8 2.7 Fixation and cryosection 9 2.8 Immunofluorescence staining 9 3. Results 11 3.1 The SilenceMag sdc4 siRNA inhibited sdc4 gene expression in post-MI heart of adult zebrafish 11 3.2 Sdc4-dependent recruitment of innate immune cells 11 3.3 Sdc4 stimulated the expression of marker genes involved in ECM remodeling 12 3.4 sdc4 regulated the expression of fibronectin in and around the injury site 13 3.5 Dynamic expression of fibronectin was regulated by Sdc4 during cardiac repair 14 3.6 Cell proliferation 15 3.7 Assessing the heart function by electrocardiography and video recording during regeneration 16 3.8 Combined analysis of electrocardiography and video recording on ST-elevation and ventricular aneurysm under sdc4 knockdown 17 4. Conclusion and Discussion 19 4.1 Sdc4 regulates early immune response during heart regeneration 19 4.2 Sdc4-dependent mechanism in heart regeneration 19 4.3 The improved ECG for adult zebrafish 21 5. Reference 22 List of Tables Table. 1 The zebrafish siRNA sequences 27 Table. 2 Primer list of Real Time-quantitative PCR analysis 27 List of Figures Figure. 1 Protocol for gene knockdown experiment and the sdc4 gene expression profile in post-injury heart of zebrafish 28 Figure. 2 Sdc4 knockdown reduced the recruitment of innate immune cells in the lesion site following cryoinjury 29 Figure. 3 Target gene expression profiles during cardiac repair 30 Figure. 4 Cryoinjury-induced sdc4 expression co-localized with fibronectin expression around and within the injury site 31 Figure. 5 sdc4 knockdown inhibited fibronectin expression in the lesion zone at 1 dpci 32 Figure. 6 Fibronectin expression in the epicardium and the lesion site was affected by sdc4 knockdwon at 3 dpci 33 Figure. 7 sdc4 knockdown disrupted the cardiac repair process at 7 dpci 34 Figure. 8 Cell proliferation pattern at 3 and 7 dpci 35 Figure. 9 The design of electrocardiography setting and video record 36 Figure. 10 Cryoinjury immediately induces ST-elevation 37 Figure. 11 ST-elevation was persistence under sdc4 knockdown 38 Figure. 12 Video recordings of post-cryoinjury heart 39 Figure. 13 Proposed scheme on the effects of sdc4 knockdown in zebrafish heart repair 40 Figure. S1 Cryoinjury tool and cryoinjury procedure 41 Figure. S2 Inducing sdc4 knockdown of the heart in adult zebrafish. 42

    1. World Health Organization: The top 10 causes of death. Health topics: Mortality. 2017.
    2. World Health Organization: Global health estimates summary tables: projection of deaths by cause, age and sex, by world bank income group and who region. Projections of mortality and causes of death, 2015 and 2030. 2013.
    3. Thygesen K, Alpert J and White H: Universal definition of myocardial infarction. European Heart Journal 2007, 28:2525–2538.
    4. Matsui Y, Morimoto J and Uede T: Role of matricellular proteins in cardiac tissue remodeling after myocardial infarction. World J Biol Chem 2010, 1(5):69-80.
    5. Shah A, Anand A, Sandoval Y, et al.: High-sensitivity cardiac troponin I at presentation in patients with suspected acute coronary syndrome: a cohort study. The Lancet 2016, 386(10012):2481-2488.
    6. Pandie S, Hellenberg D, Heilig F, et al.: Approach to chest pain and acute myocardial infarction. South African Medical Journal 2016, 106(3).
    7. Windecker S, Kolh P, Alfonso F, et al.: 2014 ESC/EACTS Guidelines on myocardial revascularization. European Heart Journal 2014, 35:2541–2619.
    8. Cahill T, Choudhury R and Riley P: Heart regeneration and repair after myocardial infarction: translational opportunities for novel therapeutics. Nature Reviews Drug Discovery 2017.
    9. Bergmann O, Bhardwaj R, Bernard S, et al.: Evidence for Cardiomyocyte Renewal in Humans. SCIENCE 2009 324(5923):98-102.
    10. Struthers A: Pathophysiology of heart failure following myocardial infarction. Heart 2005, 91(2):14-16.
    11. Travers J, Kamal F, Robbins J, et al.: Cardiac Fibrosis: The Fibroblast Awakens. Circulation Research 2015, 2016(118):1021-1040.
    12. Xin M, Olson E and Bassel-Duby R: Mending broken hearts: cardiac development as a basis for adult heart regeneration and repair. Nature Reviews Molecular Cell Biology 2013, 14:529–541.
    13. Leask A: Potential Therapeutic Targets for Cardiac Fibrosis: TGF , Angiotensin, Endothelin, CCN2, and PDGF, Partners in Fibroblast Activation. Circulation Research 2010, 2010(106):1675-1680.
    14. Lin Z and Pu W-T: Strategies for cardiac regeneration and repair. Science Translational Medicine 2014, 6(239).
    15. Annex B and Simons M: Growth factor-induced therapeutic angiogenesis in the heart: protein therapy. Cardiovascular Research 2005, 65:649 – 655.
    16. Passier R, van Laake L and Mummery C: Stem-cell-based therapy and lessons from the heart. Insight review 2008, 453(15).
    17. Zlatanova I, Pinto C and Silvestre J-S: Immune Modulation of Cardiac Repair and Regeneration: The Art of Mending Broken Hearts. Frontiers in Cardiovascular Medicine 2016, 3(40).
    18. Liehn E, Postea O, Curaj A, et al.: Repair After Myocardial Infarction, Between Fantasy and Reality: The Role of Chemokines. Journal of the American College of Cardiology 2011, 58(23).
    19. Tkachenko E, Rhodes J and Simons M: Syndecans: New Kids on the Signaling Block. Circulation Research 2005, 96:488-500.
    20. Chakravarti R and Adams J: Comparative genomics of the syndecans defines an ancestral genomic context associated with matrilins in vertebrates. BioMed Central Genomics 2006, 7(83).
    21. Elfenbein A and Simons M: Syndecan-4 signaling at a glance. Journal of Cell Science 2013, 126(17):3799–3804.
    22. Strand M, Aronsen J, Braathen B, et al.: Shedding of syndecan-4 promotes immune cell recruitment and mitigates cardiac dysfunction after lipopolysaccharide challenge in mice. Journal of Molecular and Cellular Cardiology 2015, 88:133–144.
    23. Herum K, Lunde I, Skrbic B, et al.: Syndecan-4 signaling via NFAT regulates extracellular matrix production and cardiac myofibroblast differentiation in response to mechanical stress. Journal of Molecular and Cellular Cardiology 2013, 54:73–81.
    24. Cornelison D, Filla M, Stanley H, et al.: Syndecan-3 and Syndecan-4 Specifically Mark Skeletal Muscle Satellite Cells and Are Implicated in Satellite Cell Maintenance and Muscle Regeneration. Developmental Biology 2001, 239:79–94.
    25. Woods A, Longley R, Tumova S, et al.: Syndecan-4 binding to the high affinity heparin-binding domain of fibronectin drives focal adhesion formation in fibroblasts. Archives of Biochemistry and Biophysics 2000, 374(1):66-72.
    26. Strand M, Herum K and Rana Z: Innate immune signaling induces expression and shedding of the heparan sulfate proteoglycan syndecan-4 in cardiac fibroblasts and myocytes, affecting inflammation in the pressure-overloaded heart. Federation of European Biochemical Societies Journal 2013, 280:2228–2247.
    27. Takahashi R, Negishi K, Watanabe A, et al.: Serum syndecan-4 is a novel biomarker for patients with chronic heart failure. Journal of Cardiology 2011, 57: 325—332.
    28. Xie J, Wang J, Li R, et al.: Syndecan-4 over-expression preserves cardiac function in a rat model of myocardial infarction. Journal of Molecular and Cellular Cardiology 2012, 53:250–258.
    29. Tzahor E and Poss K: Cardiac regeneration strategies: Staying young at heart. Science 2017, 356:1035–1039.
    30. Bednarek D, González-Rosa J, Guzmán-Martínez G, et al.: Telomerase Is Essential for Zebrafish Heart Regeneration. Cell Reports 2015, 12(10):1691–1703.
    31. Nakada Y, Canseco D, Thet S, et al.: Hypoxia induces heart regeneration in adult mice. Nature 2017, 541(12).
    32. Torr E, Ngam C, Bernau K, et al.: Myofibroblasts exhibit enhanced fibronectin assembly that is intrinsic to their contractile phenotype. The Journal of Biological Chemistry 2015.
    33. Jaźwińska A and Sallin P: Regeneration versus scarring in vertebrate appendages and heart. Journal of Pathology 2016, 238:233–246.
    34. Chablais F, Veit J, Rainer G, et al.: The zebrafish heart regenerates after cryoinjury-induced myocardial infarction. BMC Developmental Biology 2011, 11(21).
    35. Pugach E, Li P, White R, et al.: Retro-orbital Injection in Adult Zebrafish. Journal of Visualized Experiments 2009(34):e1645.
    36. Knorr M, Münzel T and Wenzel P: Interplay of NK cells and monocytes in vascular inflammation and myocardial infarction. Frontiers in physiology 2014, 5(295).
    37. de Preux Charles A-S, Bise T, Baier F, et al.: Distinct effects of inflammation on preconditioning and regeneration of the adult zebrafish heart. Open Biology 2016, 6(160102).
    38. Matsui Y, Ikesue M, Danzaki K, et al.: Syndecan-4 Prevents Cardiac Rupture and Dysfunction After Myocardial Infarction. Circulation Research 2011, 2011(108):1328-1339.
    39. Wang. J, Karra R, Dickson A, et al.: Fibronectin is deposited by injury-activated epicardial cells and is necessary for zebrafish heart regeneration. Developmental Biology 2013, 382(2):427-435.
    40. Pataki CA, Couchman JR and Brábek J: Wnt Signaling Cascades and the Roles of Syndecan Proteoglycans. Journal of Histochemistry & Cytochemistry 2015, 63(7):465–480.
    41. Gopal S, Multhaupt HAB, Pocock R, et al.: Cell-extracellular matrix and cell-cell adhesion are linked by syndecan-4. Matrix Biology 2017, 60-61:57-69.
    42. de Preux Charles A-S, Bise T, Baier F, et al.: Preconditioning boosts regenerative programmes in the adult zebrafish heart. Open Biology 2016, 6(160101).
    43. Wang J-P and Hielscher A: Fibronectin: How Its Aberrant Expression in Tumors May Improve Therapeutic Targeting. Journal of Cancer 2017, 8(4):674-682.
    44. Pie´rard L: ST elevation after myocardial infarction: what does it mean? Heart 2007, 93:1329–1330.
    45. Huang W-C, Yang C-C, Chen I-H, et al.: Treatment of Glucocorticoids Inhibited Early Immune Responses and Impaired Cardiac Repair in Adult Zebrafish. PLoS ONE 2013, 8(6):e66613.
    46. Wang J, Karra R, Dickson A, et al.: Fibronectin is deposited by injury-activated epicardial cells and is necessary for zebrafish heart regeneration. Developmental Biology 2013, 382(2).
    47. Konstandin M, Toko H, Gastelum G, et al.: Fibronectin is essential for reparative cardiac progenitor cell response after myocardial infarction. Circulation Research 2013, 113(2):115-125.
    48. Moerkamp A, Lodder K, van Herwaarden T, et al.: Human fetal and adult epicardial-derived cells: a novel model to study their activation. Stem Cell Research & Therapy 2016, 7(174).

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