纽约大学Langone医学中心最新研究表明，Wnt信号通路在毛囊细胞和黑素细胞之间控制头发着色，此前，人们已经知道该信号通路调控多种生理过程。
Wnt信号通路异常可导致头发发白
负责这一研究的伊藤真弓（ Mayumi Ito）博士是Langone医学中心皮肤科的副教授，他说：“毛囊干细胞和分泌色素的黑素细胞之间相互作用生成有色头发，我们了解这一联系已达数十年之久，但内在机理却知之甚少。如今，我们又发现，Wnt信号通路在这2种干细胞系协同活动和头发着色方面发挥关键作用。”这一研究表明，对Wnt信号通路的调控可作为白发定向着色的新治疗手段。此外，该研究为组织再生模型提供了线索。
伊藤真弓博士还说：“人体中有许多可以再生其它器官的干细胞种类，在头发更新过程中，毛囊干细胞和黑素干细胞之间的通讯机制为再生多种细胞类型的复杂器官提供线索。”
通过使用老鼠模型，研究人员能够检测Wnt信号通路如何使毛囊和黑素细胞协同活动，进而生成有色头发。毛囊干细胞中Wnt信号通路故障或异常不仅阻止头发的生长，而且抑制了有关色素形成的黑素干细胞的生理功能。而黑素干细胞中Wnt信号通路缺失会产生去色素或灰色头发。
这一研究表明，Wnt信号通路很可能是调控黑素干细胞的关键途径，并能很好地解释黑素干细胞的生理活动如何与头发再生协调一致。这一认识加深了对于一种疾病的理解，在这种疾病中，黑素干细胞要么不正常地凋亡引起头发发白，要么进行不受控制的细胞分裂如黑色素瘤。（生物探索译）
生物探索推荐英文原文
Why Hair Turns Gray: Communication Between Hair Follicles and Melanocyte Stem Cells Key to Mystery
A new study by researchers at NYU Langone Medical Center has shown that, for the first time, Wnt signaling, already known to control many biological processes, between hair follicles and melanocyte stem cells can dictate hair pigmentation.
The research was led by Mayumi Ito, PhD, assistant professor in the Ronald O. Pereleman Department of Dermatology at NYU Langone. "We have known for decades that hair follicle stem cells and pigment-producing melanocycte cells collaborate to produce colored hair, but the underlying reasons were unknown," said Dr. Ito. "We discovered Wnt signaling is essential for coordinated actions of these two stem cell lineages and critical for hair pigmentation." The study suggests the manipulation of Wnt signaling may be a novel strategy for targeting pigmentation such as graying hair. The research study also illustrates a model for tissue regeneration.
"The human body has many types of stem cells that have the potential to regenerate other organs," said Dr. Ito. "The methods behind communication between stem cells of hair and color during hair replacement may give us important clues to regenerate complex organs containing many different types of cells."
Using genetic mouse models, researchers were able to examine how Wnt signaling pathways enabled both hair follicle stem cells and melanocyte stem cells to work together to generate hair growth and produce hair color. Research also showed the depletion (or inhibition or abnormal) Wnt signaling in hair follicle stem cells not only inhibits hair re-growth but also prevents melanocytes stem cell activation required for producing hair color. The lack of Wnt activation in melanocyte stem cells leads to depigmented or gray hair.
The study raises the possibility that Wnt signaling is a key pathway for the regulation of melanocyte stem cells and shows how melanocyte behavior is associated with hair regeneration. This insight provides further understanding of diseases in which melanocytes are either appropriately lost such as hair graying or undergo uncontrolled cell growth as in melanoma.
