毛母质细胞研究进展

毛囊作为人体更新最快的组织器官之一,是研究干细胞迁移、分化良好的模型.近年来,关于毛囊干细胞在毛囊的发生和毛囊的更新中所起作用的研究甚多,并取得了一些突破性的进展,如毛囊干细胞的定位,毛囊干细胞的迁移过程等.     

组织工程化皮肤的新种子细胞-毛囊干细胞

以干细胞为种子细胞构建组织工程化皮肤成为当前研究的热点之一。皮肤干细胞主要有表皮干细胞和毛囊干细胞。毛囊干细胞在体内表现为慢周期性,在体外培养时具有高克隆形成能力,毛囊干细胞作为组织工程化皮肤的新种子细胞受到关注。     

毛囊干细胞的生物学特性及意义

毛囊是皮肤重要的附属结构 ,毛囊特定部位存在具有干细胞性质的细胞群 ,其不仅具有巨大的增殖潜能 ,而且能多向分化 ,是表皮、毛囊和皮脂腺细胞补充的来源 ,毛囊干细胞在组织维持与更新以及临床疾病的发生、发展中均起到重要作用     

表皮干细胞与毛囊干细胞生物学特性的比较

背景：获取更合适的组织工程皮肤种子细胞可使皮肤功能得到更好的修复。 目的：分离、培养表皮干细胞和毛囊干细胞,并比较两种细胞的生物学特性。 方法：体外分离培养2月龄新西兰兔表皮干细胞和毛囊干细胞,取生长良好的第2,3,6代细胞观察其生物学特性。 结果与结论：毛囊干细胞较表皮干细胞贴壁快,具有更高的增殖活性。免疫组化及荧光定量PCR检测显示毛囊干细胞β1整合素、角蛋白19蛋白及mRNA表达均明显高于表皮干细胞。提示作为皮肤组织工程的种子细胞,毛囊干细胞较表皮干细胞更具优势。     

组织块法与酶消化法培养大鼠毛囊干细胞的比较

背景：研究证实毛囊干细胞比毛囊间表皮干细胞更有增生能力,近年来受到广泛关注,成为种子细胞的研究热点。 目的：比较组织块法和两步酶法培养大鼠毛囊干细胞的生物学特性。 方法：体式显微镜下分离大鼠触须部的毛囊,分别用组织块法和两步酶法培养毛囊干细胞,利用反复差速贴壁法纯化细胞,定期观察细胞生长状况及形态,流式细胞仪检测第3代毛囊干细胞CD34、β1整合素的表达。 结果与结论：两步酶法获得的细胞生长速度快,获得的细胞量多,而组织块法获得的细胞生长速度较慢,获得的细胞量也少。流式细胞仪分析显示酶消化法培养组PE-CD34、FITC-β1整合素的表达分别为(39.52±19.57)%和(93.46±4.73)%,组织块法培养组相应为(19.20±11.53)%和(363.57±14.42)%,两组间差异有显著性意义(P < 0.05)。总的来说,两种方法均能培养出实验所需毛囊干细胞,可根据不同实验需求选择恰当的培养方法。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

毛囊干细胞在皮肤伤口修复中的促进作用

背景：毛囊干细胞来源于皮肤、毛发,数量极其可观,取材后无严重的并发症和免疫原性,可供自体移植,是最容易获取的干细胞来源之一。目的：综述毛囊干细胞促进皮肤伤口修复的作用因素,以期为该领域研究提供有效的实验依据。方法：应用计算机以“毛囊干细胞、皮肤修复、再生医学、组织工程”或“hair follicle stem cell,skin repairing,regenerative medicine,tissue engineering”为检索词检索CNKI 和 PubMed 数据库1999年1月至2014年12月发表的关于毛囊干细胞促进皮肤伤口修复的文章,最终选择45篇文章进行综述。结果与结论：毛囊干细胞作为一种容易获得、数量可观、使用较为安全以及具有分化潜能的成体干细胞,可以通过皮肤早期血管化、表皮及附属器官的再生、信号通路作用及转录因子调节等方面的影响,促进皮肤伤口的修复,能为再生医学及组织工程研究提供良好的种子细胞。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

大鼠毛囊神经嵴干细胞分离培养及鉴定

目的:采用显微分离+组织块贴壁法培养大鼠毛囊神经嵴干细胞(hf NCSC)。方法:显微分离SD大鼠触须部毛囊膨凸部(bugle),采用组织块贴壁法培养毛囊神经嵴干细胞,倒置显微镜下观察细胞形态。采用免疫荧光多重标记法检测Nestin和神经营养素受体p75(p75NTR)的表达。结果:用显微分离+组织块贴壁法可成功获得毛囊神经嵴干细胞,倒置显微镜下观察细胞活性好,形态多样,以梭形为主,也可见三角形、椭圆形细胞,核大而明显,多居于胞质一侧。免疫荧光鉴定显示细胞Nestin和p75NTR双阳性。结论:从SD大鼠触须部毛囊bugle区成功分离到毛囊神经嵴干细胞。     

毛囊干细胞的研究进展

毛囊干细胞不仅对毛囊的形态发生和毛发的周期性生长和主导作用，同时还是表皮和皮脂腺更新的细胞来源。毛囊外根鞘隆突部的细胞具有干细胞的多种特征，包括慢周期性生长和自我更新能力等，因而被认为是毛囊干细胞的所在。毛囊干细胞的增殖分化受周围环境的诱导。研究者相继提出多种假说，包括隆突激活假说和干细胞迁移假说，解释干细胞在毛囊形态发生和周期性生长中的作用。其分子机制涉及Wnt、BMP、Shh等多种信号途径的相互作用，β-catenin和LEF1／TCF是其中的重要环节。     

毛囊真皮鞘细胞的生物学特性研究进展

真皮鞘包绕于毛囊外周,是维持和再生毛乳头的重要物质基础,是毛囊再生的必要条件。近年研究表明,毛囊真皮鞘细胞不但参与皮肤创伤修复,而且具有成体干细胞特性,有望为皮肤创伤愈合研究和组织工程学研究提供新的思路。本文就毛囊真皮鞘细胞生物学特性研究进展作一综述。     

氯化锂诱导毛囊干细胞定向分化中Wnt信号通路介导基因的调控

背景：研究发现氯化锂有促进毛囊干细胞向毛囊上皮定向分化的作用,但其分子调节机制仍不清楚。 目的：通过外源性因子氯化锂干预人毛囊干细胞,观察Wnt信号通路中主要下游分子及目的基因的改变,探讨氯化锂对毛囊干细胞定向分化的诱导作用。 方法：取正常成人除皱术后的头皮,采用两步酶消化法结合手术显微镜分选毛囊干细胞,采用角蛋白10抗体-异硫氰酸荧光素鉴定毛囊干细胞。以外源性因子氯化锂干预人毛囊干细胞。 结果与结论：氯化锂干预5 d后可发现毛囊干细胞体积变大,核浆比减小,Wnt信号通路中β-catenin、cyclinD1表达增强,GSK3β、Tcf3表达减弱,c-myc在氯化锂浓度低时增强浓度高时减弱。提示氯化锂可影响毛囊干细胞中Wnt信号通路β-catenin、GSK3β、Tcf3、c-myc和cyclinD1的表达水平,可能对毛囊干细胞的分化起到重要作用。     

毛囊干细胞对坐骨神经损伤修复的影响

背景：毛囊干细胞具有多分化潜能,可分化成神经细胞,极有希望成为治疗周围神经损伤的种子细胞。 目的：观察毛囊干细胞对坐骨神经损伤修复的影响。 方法：体外分离培养SD大鼠乳鼠胡须处的毛囊干细胞,经鉴定备用。36只SD大鼠随机分为实验组和对照组,建立坐骨神经损伤模型后,实验组于坐骨神经损伤处的上方注入浓度约10⁶ L^-1的毛囊干细胞50 μL,对照组注射等量的磷酸盐缓冲液。 结果与结论：各组坐骨神经功能指数均随观察时间进行性增加,其中实验组大鼠神经功能恢复早于对照组;免疫组织化学检测移植后的毛囊干细胞大量存活并分化成神经细胞。结果提示毛囊干细胞能够有效的促进损伤的坐骨神经修复。     

Aging, Graying and Loss of Melanocyte Stem Cells

Hair graying is one of the prototypical signs of human aging. Maintenance of hair pigmentation is dependent on the presence and functionality of melanocytes, neural crest derived cells which synthesize pigment for growing hair. The melanocytes, themselves, are maintained by a small number of stem cells which reside in the bulge region of the hair follicle. The recent characterization of the melanocyte lineage during aging has significantly accelerated our understanding of how age-related changes in the melanocyte stem cell compartment contribute to hair graying. This review will discuss our current understanding of hair graying, drawing on evidence from human and mouse studies, and consider the contribution of melanocyte stem cells to this process. Furthermore, using the melanocyte lineage as an example, it will discuss common theories of tissue and stem cell aging.     

Characterization of Rat Hair Follicle Stem Cells Selected by Vario Magnetic Activated Cell Sorting System

Hair follicle stem cells (HfSCs) play crucial roles in hair follicle morphogenesis and hair cycling. These stem cells are self-renewable and have the multi-lineage potential to generate epidermis, sebaceous glands, and hair follicle. The separation and identification of hair follicle stem cells are important for further research in stem cell biology. In this study, we report on the successful enrichment of rat hair follicle stem cells through vario magnetic activated cell sorting (Vario MACS) and the biological characteristics of the stem cells. We chose the HfSCs positive surface markers CD34, α6-integrin and the negative marker CD71 to design four isolation strategies: positive selection with single marker of CD34, positive selection with single marker of α6-integrin, CD71 depletion followed by CD34 positive selection, and CD71 depletion followed by α6-integrin positive selection. The results of flow cytometry analysis showed that all four strategies had ideal effects. Specifically, we conducted a series of researches on HfSCs characterized by their high level of CD34, termed CD34^bri cells, and low to undetectable expression of CD34, termed CD34^dim cells. CD34^bri cells had greater proliferative potential and higher colony-forming ability than CD34^dim cells. Furthermore, CD34^bri cells had some typical characteristics as progenitor cells, such as large nucleus, obvious nucleolus, large nuclear:cytoplasmic ratio and few cytoplasmic organelles. Our findings clearly demonstrated that HfSCs with high purity and viability could be successfully enriched with Vario MACS.     

Dynamic signals for hair follicle development and regeneration

Hair follicles form during embryonic development and, after birth, undergo recurrent cycling of growth, regression, and relative quiescence. As a functional mini-organ, the hair follicle develops in an environment with dynamic and alternating changes of diverse molecular signals. Over the past decades, genetically engineered mouse models have been used to study hair follicle morphogenesis and significant advances have been made toward the identification of key signaling pathways and the regulatory genes involved. In contrast, much less is understood in signals regulating hair follicle regeneration. Like hair follicle development, hair follicle regeneration probably relies on populations of stem cells that undergo a highly coordinated and stepwise program of differentiation to produce the completed structure. Here, we review recent advances in the understanding of the molecular signals underlying hair follicle morphogenesis and regeneration, with a focus on the initiation of the primary hair follicle structure placode. Knowledge about hair follicle morphogenesis may help develop novel therapeutic strategies to enhance cutaneous regeneration and improve wound healing.     

毛囊细胞--一种新的皮肤组织工程种子细胞

毛囊的上皮细胞和真皮细胞与皮肤的表皮角朊细胞和真皮成纤维细胞具有很大的相似性,但其具有更强的增殖分化能力和更多的生物学特性,并且毛囊真皮细胞具有干细胞的一些特性,作为皮肤组织工程的种子细胞具有更独特的优势,在构建带有皮肤附属器的组织工程皮肤上有潜在的前景.     

Hair loss as a result of cutaneous autoimmunity: frontiers in the immunopathogenesis of primary cicatricial alopecia

Primary cicatricial alopecias (PCA) represent uncommon inflammatory disorders that result in permanent loss of scalp hair. Cutaneous autoimmunity, most prominently chronic cutaneous lupus erythematosus (CCLE), can result in this kind of scarring hair loss. The cosmetic disfigurement caused by PCA and the very unsatisfactory therapeutic options available to date all demand a better understanding of the obscure pathobiology of PCA so as to define new therapeutic targets and strategies. Hair follicle (HF) cycling and regeneration are abolished in PCA due to irreversible, epithelial hair follicle stem cell (eHFSC) damage, triggered by major, yet unclear pro-inflammatory events (e.g. type I interferon-associated cytotoxic inflammation, loss of HF immune privilege, loss of immunosuppressive "no danger" signals). Therefore, immuno-protection of eHFSC and restitution of their immune privilege are attractive future therapeutic strategies in PCA. Chronic cutaneous lupus erythematosus-associated PCA may serve as a model system for other diseases where epithelial stem cells undergo immuno-destruction.     

角质细胞无血清培养基促进大鼠毛囊干细胞的增殖

背景：以往研究培养毛囊干细胞多使用DMEM/F12+体积分数10%胎牛血清培养基,而进年来开发出的角质细胞无血清培养基也可应用于毛囊干细胞的培养。 目的：观察3种不同培养基对大鼠毛囊干细胞增殖情况及干细胞纯度的影响。 方法：取大鼠触须部皮肤组织,体式显微镜下分离出毛囊组织,中性蛋白酶Ⅱ与胰蛋白酶和乙二胺四乙酸混合液“两步酶法”消化。所得细胞悬液按细胞数平均分为3份,分别使用角质细胞无血清培养基、DMEM/F12+体积分数10%胎牛血清及角质细胞无血清培养基+体积分数10%胎牛血清共3种培养基培养,Ⅳ型胶原差速贴壁法筛选毛囊干细胞,进行传代培养。 结果与结论：培养毛囊干细胞传至第3代,锥虫蓝染色计数法检测结果显示,此3组间细胞活率差异无显著性意义(P > 0.05)。CCK8比色法检测细胞生长曲线显示,培养前2 d,此3组细胞生长均较缓慢;培养4 d,细胞生长进入对数生长期,3种培养基培养的细胞增殖活性：角质细胞无血清培养基+10%胎牛血清组>DMEM/F12+10%胎牛血清>角质细胞无血清培养基(P < 0.05)。流式细胞仪检测显示,角质细胞无血清培养基组CD34的表达高于角质细胞无血清培养基+10%胎牛血清组(P < 0.05)。DMEM/F12+10%胎牛血清组中CD34、β1-整合素(CD29)及CK15标记物的表达低于其他2组(P < 0.05)。结果表明,角质细胞无血清培养基较DMEM/F12+体积分数10%胎牛血清能培养出纯度更高的毛囊干细胞,并且在此培养基培养的基础上加入血清,能够促进毛囊干细胞的增殖。     

Embryonic development of hair follicle pluripotent stem (hfPS) cells

Our laboratory discovered nestin-expressing hair follicle stem cells and demonstrated their pluripotency. We have shown that nestin-positive and K15-negative multipotent hair follicle stem cells are located above the hair follicle bulge, and we termed these cells hair follicle pluripotent stem (hfPS) cells. We have previously shown that hair follicle stem cells can regenerate peripheral nerve and spinal cord. In the present study, we describe the embryonic development of the hair follicle stem cell area (hfPSCA), which is located above the bulge and below the sebaceous glands in the adult mouse. At embryonic day 16.5 (E16.5) of nestindriven GFP (ND-GFP) transgenic mice, which express nestin in hfPS cells, the ND-GFP hair follicle stem cells are located in mesenchymal condensates. At postnatal day 0 (P0), the ND-GFP-expressing cells are migrating to the upper part of the hair follicle from the dermal papilla. At P3, keratin 15 (K15)-positive cells, derived from ND-GFP dermal papilla cells, are located in the outer-root sheath and basal layer of the epidermis. By P10, the ND-GFP have formed the K15-positive outer-root sheath as well as the ND-GFP hfPSA. These results suggest that ND-GFP hfPS cells in the dermal papilla form nestin-expressing hair follicle stem cells in the first hair cycle. These observations provide new insight into the origins of hfPS cells and the hfPSCA.