Introduction: MSCs are multipotent progenitor cells that can differentiate into various cell lineages, such as osteoblasts, chondrocytes and adipocytes. MSCs synthesize abundant secretion factors to extracellular matrix which contain a variety of growth factors, cytokines and microRNAs. Secretion factors could stimulate the regeneration and differentiation of surrounding cells, but their underlying mechanism still remains elusive. We hypothesized that secretion factors from different tissues derived MSCs had potential to promote MSCs differentiation and musculoskeletal tissue regeneration. We also suggested that microRNAs played an essential role in the effects of secretion factors. In present study, we investigated the effects of secretion factors obtained from different tissues derived MSCs (umbilical cord, dental pulp, gingiva and adipose tissue) on multi-differentiation potentials of MSCs, including osteogenesis, chondrogenesis, tenogenesis, neurogenesis and adipogenesis. Moreover, we illustrated the effects of umbilical cord derived MSC (UCMSC) secretion on bone, cartilage and tendon tissue repair. We further revealed that microRNAs may impact the effect of secretion factors on MSCs osteogenic differentiation. / Methods: Human bone marrow MSCs (hBMSCs) were incubated with various differentiation induction media. Secretion factors were used as supplement. Different animal models of tissue repair (bone, cartilage and tendon) were employed for study of the effects of secretion factors on tissue healing. miRNA microarray was performed to find the potential effective miRNAs in secretion factors. Real time qRT-PCR, microCT, mechanical test, immunohistological analysis and various staining methods were employed as outcome measurements. / Results: We found that both UCMSC and dental pulp derived MCS secretion could initiate osteogenic differentiation of hBMSCs without osteogenic induction medium. UCMSC secretion had positive effect on chondrogenic and tenogenic differentiation of MSCs and inhibitory effect on adipogenesis of hBMSCs. Our results showed that UCMSC secretion in HA/TCP scaffolds with hBMSCs promoted ectopic bone formation in nude mice. UCMSC secretion with rat BMSCs in hyaluronic hydrogel significantly enhanced the bone repair of rat calvarial bone critical defect. To reveal the underlying mechanism, secretion factors were analyzed by miRNA microarray. Among the differentially expressed microRNAs, we found miR-1237 could promote osteogenesis while miR-3676 could inhibit osteogenic differentiation of MSCs. / Conclusions: This study indicated that among secretion factors from MSCs form four types tissues, UCMSC secretion could initiate osteogenesis of MSCs and promote bone repair. We also demonstrated that microRNAs from secretion had impact on osteogenic differentiation of MSCs. Our study showed clinical potential of UCMSC secretion in bone regeneration, and more research are needed for optimizing the preparation and delivery of the MSCs secretive factors, as well as to understand their mechanisms of action. / 前言：間充質幹細胞是具有強大分化潛能的始祖細胞。間充質幹細胞可以分化為多種細胞系，例如成骨細胞，軟骨細胞和脂肪細胞。間充質幹細胞合成并釋放大量分泌素到細胞外基質中。這些分泌素包括多種生長因子，細胞因子和微小核糖核酸。分泌素能夠刺激周圍細胞的再生和分化，但是分泌素的作用機理還不是很清楚。我們認為，不同組織來源的間充質幹細胞分泌素有可能會促進間充質幹細胞的多系分化和骨骼肌肉組織的再生，並且微小核糖核酸在分泌素的效應中發揮了重要作用。我們首先研究了臍帶，牙髓，牙齦和脂肪來源的間充質幹細胞分泌素對于間充質幹細胞的分化能力的作用。我們還對臍帶幹細胞分泌素在骨，軟骨和肌腱修復的效果做了進一步的研究。另外，我們還發現分泌素中的微小核糖核酸在間充質幹細胞的成骨分化方面有一定的效果。 / 方法：我們用人間充質幹細胞來進行誘導分化實驗。臍帶，牙髓，牙齦和脂肪來源的間充質幹細胞的分泌素用於細胞培養基的補充。在體內實驗中我們用了不同的動物模型，把填充物和分泌素一起種植在動物體內。我們利用微小核糖核酸陣列技術來檢測分泌素中的有效微小核糖核酸。我們使用了定量聚合酶鏈反應技術，微型計算機斷層掃描成像，力學測試，免疫組織分析和多種染色方法。 / 結果：我們發現臍帶和牙髓間充質幹細胞分泌素可以在沒有成骨誘導培養基的情況下啟動骨髓間充質幹細胞的成骨分化。臍帶間充質幹細胞對成軟骨和成肌腱分化起到積極作用，而且可以抑制脂肪分化。我們發現在羥基磷灰石/磷酸三鈣材料中，臍帶間充質幹細胞分泌素與人骨髓間充質幹細胞可以共同促進裸鼠的異位成骨。臍帶間充質幹細胞分泌素與鼠骨髓間充質幹細胞一起用於透明質酸水凝膠中能夠加快大鼠頭骨缺損的修復。為了揭示分泌素的作用機理，我們用微小核糖核酸陣列技術來檢測分泌素。在表達不同的微小核糖核酸之中，我們發現miR-1237可以促進間骨髓間充質幹細胞的成骨分化，而miR-3676能夠抑制骨髓間充質幹細胞成骨分化。 / 結論：本研究表明，在四種不同來源的分泌素中，臍帶間充質幹細胞分泌素可以啟動骨髓間充質幹細胞的成骨分化，同時加快骨組織修復。我們發現微小核糖核酸在分泌素的促進間骨髓間充質幹細胞成骨分化的效果中發揮了一定的作用。我們的研究表明，使用臍帶間充質幹細胞分泌素修復骨組織具有廣泛的臨床應用前景。間充質幹細胞分泌素的生產，使用過程和作用機理還有待于進一步的優化和研究。 / Wang, Kuixing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 131-147). / Abstracts also in Chinese. / Title from PDF title page (viewed on 01, November, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_1290687 |
| Date | January 2014 |
| Contributors | Wang, Kuixing (author.), Li, Gang (thesis advisor.), Chinese University of Hong Kong Graduate School. Division of Biomedical Sciences. (degree granting institution.) |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography, text |
| Format | electronic resource, electronic resource, remote, 1 online resource (xvi, 147 leaves) : illustrations, computer, online resource |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons "Attribution-NonCommercial-NoDerivatives 4.0 International" License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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