據(jù)《科學(xué) - 轉(zhuǎn)化醫(yī)學(xué)》雜志報道說，研究人員已經(jīng)發(fā)現(xiàn)了如何用生物化學(xué)的方法來加速小鼠斷裂骨頭的愈合方法。

        從增強骨移植到加快患者骨折的修復(fù)，對每年數(shù)百萬因為骨折而需要住院的患者來說，這些發(fā)現(xiàn)在再生醫(yī)學(xué)方面會有廣泛的應(yīng)用。 在人類和小鼠中，正常骨質(zhì)的更新和損傷后的愈合都需要Wnt蛋白。Steven Minear及其同僚發(fā)現(xiàn)，Wnt蛋白是通過激活骨質(zhì)干細(xì)胞而發(fā)揮其作用的，而骨質(zhì)干細(xì)胞的功能是產(chǎn)生新骨。

        研究人員可通過在基因改良小鼠中放大這一自然修復(fù)過程來加速骨質(zhì)的愈合。 與一般的小鼠相比，用基因改良來增強Wnt蛋白的信號使得損傷處的骨干細(xì)胞能夠更加快速地分裂并更快地成熟為成骨細(xì)胞。 接著，研究人員創(chuàng)制了一種叫做脂質(zhì)體Wnt3a的物質(zhì)，這種物質(zhì)可無需基因調(diào)整而產(chǎn)生相同的功效。 給小鼠注射脂質(zhì)體Wnt3a可通過刺激骨干細(xì)胞更多的分裂及更快的成熟而再一次地加快骨質(zhì)的修復(fù)過程，但該功效僅是暫時性的而且只發(fā)生在損傷的部位。 這一發(fā)現(xiàn)非常重要，因為不受控制的Wnt信號可造成諸如骨質(zhì)過度等造成損害的副作用。 研究人員計劃嘗試用一種類似Wnt蛋白的方法來改善皮膚損傷、中風(fēng)和心肌梗塞之后的組織再生。

Sci Transl Med. DOI: 10.1126/scitranslmed.3000231

Wnt Proteins Promote Bone Regeneration
Steven Minear1,*, Philipp Leucht1,2,*, Jie Jiang1,*, Bo Liu1, Arial Zeng3, Christophe Fuerer3, Roel Nusse3,? and Jill A. Helms1,?

The Wnt signaling pathway plays a central role in bone development and homeostasis. In most cases, Wnt ligands promote bone growth, which has led to speculation that Wnt factors could be used to stimulate bone healing. We gained insights into the mechanism by which Wnt signaling regulates adult bone repair through the use of the mouse strain Axin2LacZ/LacZ in which the cellular response to Wnt is increased. We found that bone healing after injury is accelerated in Axin2LacZ/LacZ mice, a consequence of more robust proliferation and earlier differentiation of skeletal stem and progenitor cells. In parallel, we devised a biochemical strategy to increase the duration and strength of Wnt signaling at the sites of skeletal injury. Purified Wnt3a was packaged in liposomal vesicles and delivered to skeletal defects, where it stimulated the proliferation of skeletal progenitor cells and accelerated their differentiation into osteoblasts, cells responsible for bone growth. The end result was faster bone regeneration. Because Wnt signaling is conserved in mammalian tissue repair, this protein-based approach may have widespread applications in regenerative medicine.