探讨使用表达荧光蛋白的ES胚胎干细胞验证中医经络学说——干细胞巢及其群落就是经络系统的腧穴

An Insight into the Verification of TCM Meridians Using Embryonic Stem Cells Expressing Fluorescent Proteins—The Acupoints of the Meridian System: Stem Cell Niches and Their Communities

摘要: 经络是各种干细胞活动交流、协同进化的巨系统，主要表现为干细胞巢的出现以及不同种类干细胞巢的有序分布。近百年来，以肉眼观察和解剖操作为主的大体解剖学，不可能将微小的干细胞巢从细胞组织中鉴别和分离出来；即使是以电子显微镜等来观察细胞组织，也难以判断干细胞巢内的干细胞组成。只有以ES胚胎干细胞、EG胚胎干细胞乃至造血干细胞等不同种类的干细胞为探针，运用干细胞示踪和单细胞测序等足够先进的科学技术，才能逐步验证中医经络学说。《黄帝内经•上古天真论》将在经络中流注运行的ES胚胎干细胞称为真气，本文初步探讨了在一些重要腧穴附近注射能够表达荧光蛋白的ES胚胎干细胞，观察实验动物体内督脉(如斑马鱼的督脉)和十二经脉(如微型猪的手厥阴心包经)的循行分布，以及研究ES胚胎干细胞在相应经脉中的增殖分化。同样，使用表达荧光蛋白的造血干细胞，观察研究造血干细胞归巢、冲脉的循行分布以及造血干细胞的增殖分化。潘巍峻等人2018年在Nature上报告称，VCAM-1⁺巨噬细胞亚群能够引导造血干细胞归巢；作者认为红系细胞中应该存在与VCAM-1⁺巨噬细胞一样功能的引导细胞(usher cells)，能够识别和引导造血干细胞进入冲脉的诸干细胞巢中。希望这些实验设想能够引起一些专家学者的研究兴趣，尽快地寻找确认腧穴的解剖学基础。

Abstract: Meridians are a giant system for the exchange and coevolution of various stem cells, which are mainly manifested as the emergence of stem cell niches and the orderly distribution of different types of stem cell niches. In the past 100 years, gross anatomy, mainly based on naked eye observation and anatomical manipulation, is incapable to identify and separate tiny stem cell niches from cells and tissues. Composition of stem cells in the stem cell niche is also difficult to determine even under an electron microscope. If stem cells, such as embryonic stem cells, embryonic germ cells, and hematopoietic stem cells, act as probes, there may be an opportunity to verify the theory of TCM meridians using advanced scientific technologies such as stem cell tracing and single-cell sequencing. In the Inner Canon of Yellow Emperor∙Ancient Theory about Genuine Qi, embryonic stem cells distributing in the meridians are defined as Genuine Qi. In this study, embryonic stem cells that can express fluorescent proteins were preliminarily injected around some important acupoints to observe the running and distribution of the Governor vessel (such as the Governor vessel of the zebrafish) and the twelve meridians (such as the pericardium meridian of Hand-Jueyin of the miniature pig), as well as the proliferation and differentiation of embryonic stem cells in the corresponding meridians. Similarly, hematopoietic stem cells expressing fluorescent proteins were injected to observe the homing of hematopoietic stem cells, the running and distribution of the Chong meridian (the thoroughfare vessel), and the proliferation and differentiation of hematopoietic stem cells. In 2018, a study by Pan Weijun et al. published in Nature indicated that VCAM-1⁺ macrophage subsets can guide the homing of hematopoietic stem cells. Therefore, we believe that there should be a kind of usher cells in erythroid cells that share similar functions with VCAM-1⁺ macrophage subsets, which can identify and guide the homing of hematopoietic stem cells into stem cell niches of the Chong meridian. These experimental assumptions are hoped to arouse much scholarly concern on finding and identifying the anatomical basis of acupoints.