天祝白牦牛退行期毛囊细胞亚群鉴定以及特征基因生物信息学分析

从单细胞水平解析天祝白牦牛退行期毛囊发育过程主要细胞类型,旨在对主要细胞类群特异表达基因进行生物功能预测与生物信息学分析,探索退行期毛囊发育调控机制。采用单细胞转录组测序对退行期毛囊进行异质性分析,利用已知标记分子对细胞类群进行筛选鉴定,并对鉴定得到的主要细胞类群进行GO和KEGG分析,同时对毛囊形态发生过程中涉及的关键分子进行免疫组织分析。结果表明,天祝白牦牛退行期涉及IFE-DC细胞、表皮细胞系、黑色素细胞、INFU细胞等细胞类群。其特征基因主要参与表皮发育、上皮细胞分化、超纤维组织发育、组织形态发生以及细胞形态学发生等生物过程。KEGG富集分析发现,特征基因主要富集在黏附连接、细胞周期、RNA转运等与毛囊发育相关的通路中。涉及的不同细胞类型拥有GJA1、FKBP4、KRT1、KRT80、FGFR2等28个共同基因。该研究成功鉴定出天祝白牦牛退行期主要细胞类群,获得了特征基因富集通路,揭示了退行期毛囊发育机制。     

敲除非受体酪氨酸激酶c-Abl促进小鼠毛发循环和再生

c-Abl作为非受体酪氨酸激酶家族的成员,参与调节多个组织器官的发育过程,如神经、血管及骨骼等。c-Abl的异常激活也往往导致神经退行性疾病或肿瘤的发生。到目前为止,c-Abl在皮肤和毛发器官中的研究非常少。本研究首先分析了c-Abl基因在皮肤和毛囊中的动态表达情况,发现在毛囊上皮有丰富的表达,然后利用表皮特异性工具小鼠K14-Cre将c-Abl基因在表皮敲除,发现毛囊由静息期向生长期的转换略有加快。小鼠脱毛实验发现,当所有毛囊都从头开始再生时,突变鼠的毛囊起始比对照小鼠更快。这些结果均表明,在表皮敲除c-Abl基因能够导致毛发循环和毛囊再生的加快。进一步的研究发现,以上表型可能是c-Abl通过调节BMP信号通路造成的。我们的工作首次研究了c-Abl基因在皮肤毛囊中的动态表达,揭示了c-Abl通过BMP信号通路调节毛囊再生的机制。     

睾丸发育和精子生成相关miRNA研究进展

MicroRNA(miRNA)是一类长约22nt的非编码小RNA, 广泛存在于各种生物中, 调节生物体生长、发育和凋亡等过程。研究表明, miRNA在人和动物睾丸发育及精子生成等过程也起着重要的调控作用。但miRNA在不同种属的睾丸组织及其不同发育时间段均存在特异性表达。此外, miRNA在动物精子生成过程中也存在时空特异性。文章综述了睾丸发育和精子生成过程中miRNA的差异性表达、表达调控以及一些miRNA对精子生成的调节作用, 旨在为睾丸miRNA的进一步研究提供参考, 为利用miRNA调控和促进种公畜精液品质提供研究思路。     

青年羊驼耳部和背部皮肤组织中miRNA差异表达研究

羊驼是毛用型经济动物,其耳部和背部的毛发品质和生长速度存在差异.MicroRNA(miRNA)是新发现的一类在转录后水平调控基因表达的非编码RNA分子,为比较miRNA在羊驼耳部和背部皮肤的表达差异,从而探讨miRNA在羊驼皮肤和毛囊发育过程中的调控作用,本实验提取羊驼皮肤总RNA,制备了羊驼皮肤miRNA芯片,通过与Affymetrix多物种miRNA芯片跨物种杂交对耳部和背部皮肤的miRNA进行筛选,并通过实时荧光定量PCR进行了验证,同时利用在线生物信息软件预测miRNA靶基因.结果显示,羊驼耳部和背部皮肤中高表达差异2倍以上的miRNA有39个,实时荧光定量PCR检测let-7b和miR-24在2个部位皮肤中的差异表达量与miRNA基因芯片结果一致;预测到let-7b和miR-24的靶基因中包含有与毛囊生长发育和毛发品质相关的基因,提示这些miRNA可能参与羊驼皮肤和毛囊的生长发育、更新以及毛发品质的调控.     

microRNA转基因小鼠在心脏发育研究中的应用

microRNA（miRNA）参与调控胚胎心脏的发育,在心脏形态发生、心肌细胞生长及分化过程中发挥着极其重要的作用。通过转基因技术可以实现特异miRNA在心肌组织的过表达与敲除,据此建立的心肌特异性miRNA转基因小鼠模型可以在整体水平揭示miRNA心脏方面的功能。近年,以miRNA为研究对象的心肌特异性转基因小鼠模型数量不断增加。     

小鼠毛囊发育分子遗传学机制研究进展

毛囊作为皮肤的附属器官,具有不断进行组织再生的特点,是研究干细胞的一种理想模型。毛囊发育机制十分复杂,其形态发生与持续终生的再生循环过程涉及表皮(上皮)和真皮(间充质)之间的相互作用。现已有相关的小鼠遗传模型被用于研究毛囊发育及再生的分子机制。该综述介绍最新的小鼠遗传学研究,主要涉及在毛囊发育过程中分别来自表皮和真皮中关键信号分子的敲除或过表达,以描绘一个控制毛囊发育和周期性循环的信号网络,为深入立体地理解毛囊发育机制和临床毛发疾病发病机制提供理论依据。     

Edar信号通路调控毛囊发育的研究进展

Edar信号通路最早发现于人少汗型外胚层发育不良综合征(hypohidrotic ectodermal dysplasia,HED)疾病患者,它是调控胚胎发育早期皮肤附属物——头发、指甲、牙齿、外分泌腺等的形态发生、发育过程的重要信号通路。与人类相同,小鼠皮肤内毛囊于胚胎期发生并发育成熟,出生后进入动态变化的毛囊周期性生长。小鼠模型的相关研究表明,Edar信号通路在早期初级毛囊的发生、成体毛囊周期性生长和被毛纤维直径等方面都发挥重要的调控作用。现综述Edar通路中重要信号分子的结构特点、转导途径及其在皮肤和毛囊早期形态发生中的作用;阐述Edar信号通路对毛囊生长周期的调控,对维持皮肤微环境稳态、促进皮肤损伤修复和表皮再生的作用,以及在临床治疗HED相关疾病方面的潜在应用前景。     

MicroRNAs与疾病和发育

作为模式生物实验系统,线虫可用于研究控制动物发育和人类疾病遗传机制。研究发育缺陷的线虫突变体有助于在动物中发现对发育和生理过程有重要调控作用的基因。其中一些基因编码一类小RNA,如microRNA(miRNA),通过作用于特定基因信使RNA来调控其蛋白质表达。一些在线虫发育过程中有功能的miRNA在人体中也存在。它们参与调控与疾病相关的生物学过程,如癌症、糖尿病和神经退行性疾病。通过分析miRNA在临床样品、哺乳动物细胞和模式生物线虫中的表达,从而揭示miRNA调控途径在相关人类疾病中的功能。     

乳腺发育及泌乳相关miRNA研究进展

MicroRNA(miRNA)是一种重要的转录后调控的非编码RNA, 参与调控哺乳动物乳腺发育和泌乳。文章总结了乳腺发育和泌乳过程中miRNA表达的时空特异性, 综述了个别miRNA对乳腺发育和泌乳的调节作用, 旨在为乳腺miRNA的研究提供指导, 为利用miRNA促进乳腺健康发育和调控高质高效产乳提供理论基础和研究思路。     

角蛋白15在大鼠皮肤发育中表达的研究

目的研究角蛋白15(K15)在大鼠皮肤发育中的表达状况,定位表皮干细胞.方法以不同年龄大鼠背部皮肤为标本,用组织学方法,观察出生后大鼠皮肤的形态发育变化;以K15单克隆抗体为一抗,进行免疫组织化学染色,观察K15在大鼠皮肤中的表达状况.结果(1)组织学方法显示,随着年龄的增长,大鼠背部表皮细胞层数逐渐变少;在毛囊的生长周期中,以隆突区为界,毛囊上段为恒定区,下段呈周期性变化(2)免疫组化染色显示,毛囊隆突区细胞胞浆表达K15,随年龄的增长,K15阳性细胞出现在毛母质细胞区、毛囊外根鞘和表皮基底层.结论表皮干细胞位于毛囊隆突区,与表皮的更新和毛囊的周期性变化有关.     

小鼠皮肤及其毛囊早期发育的组织学观察

目的探讨小鼠皮肤及其毛囊的早期发育规律。方法采用常规石蜡切片和H-E染色技术,观察昆明系小鼠出生前后皮肤及其毛囊的形态发育。结果(1)孕龄16 d胎鼠的皮肤表面形成凹凸不平的深褶皱,但在生后3 d~5 d不仅皱褶的数量减少,而且凹陷变浅;(2)胎鼠孕龄16 d至19 d,其皮肤的表皮、真皮及皮肤总厚度呈现平稳增厚。但是,出生后,其表皮、真皮和皮肤总厚度急剧降低;在生后第1天至第9天,表皮呈现平稳增厚,而真皮则在生后快速厚度,第7天达到最高值(1861.50μm);(3)孕龄16 d的胎鼠皮肤中可观察到初级毛囊,至生后第7天其密度呈现平稳增长;与其相比,次级毛囊从18 d胎鼠开始出现,其密度增长非常迅速,出生后第7天达到1257.14/mm;毛囊的总密度与次级毛囊呈现相似的变化趋势。出生第7天后,由于毛囊的数量急剧增加,无法观察初级毛囊和次级毛囊的变化规律;(4)初级毛囊和次级毛囊的长度与深度变化在出生前后的相对缓慢,与其相比在第3天以后至第7天呈现迅速变化趋势。结论小鼠皮肤及其毛囊的生长性发育发生在胎儿晚期和生后的早期,而其周期性变化可能从出生后的第9天以后开始出现;在孕期16 d至生后第7天可能是检测毛囊特异性基因表达的最佳期。     

A subset of skin-expressed microRNAs with possible roles in goat and sheep hair growth based on expression profiling of mammalian microRNAs

The microRNAs (miRNAs) are an extensive class of small noncoding RNAs (18-25 nucleotides) with probable roles in the regulation of gene expression. Due to the fact that miRNAs are conserved in closely related eukaryotes and some are also conserved across a larger evolutionary distance, their potential functions in mammalian development are under active study. In order to identify mammalian miRNAs that might function in hair growth, we characterized the expression of 159 miRNAs in adult body side skin and ear skin from goat and sheep using microarray analysis. Of these, 19 miRNAs were specifically expressed or greatly enriched in body side skin in goats and sheep. This suggests hair growth-specific functions for miRNAs. Of the coexpressed 105 miRNAs, the degree of correlation within species is higher than interspecies. Nine of the expressed miRNAs were detected exclusively in the goat body side skin area where more cashmere was grown than coat hair; mmu-miR-720 and mmu-miR-199b were expressed primarily in goat skin. The identification of 105 of skin-expressed miRNAs whose expression behavior is conserved in goats and sheep differentiating hair follicles implicates these miRNAs have functions in mammalian hair follicles growth and development. We demonstrate that miRNAs previously associated with hair follicles in the mouse are also expressed in the adult skin of goats and sheep. In addition, 69 more conserved miRNAs cross-species were discerned in the study. Of them, the let-7, mir-17, mir-30, mir-15, and mir-8 gene families were expressed in high frequency. These results reveal critical roles of them in skin and hair follicle development and function.     

MicroRNA对皮肤毛囊发育的调控机制

MicroRNA是参与转录后水平表达调控的重要因子, 在病理上成为药物作用的潜在靶点, 在生理上成为表型调控的潜在位点。目前, 对于microRNA的功能已有一定了解, 但其在皮肤毛囊发育中的作用机制还不完全清楚。近年来, 高通量测序技术为microRNA的鉴定提供了更准确、快速的途径, 研究发现一些microRNA能够影响皮肤毛囊细胞的分化和增殖, 其相关靶基因在调控毛囊周期性生长的过程中充当重要角色。文章综述了近年来microRNA在皮肤毛囊生长发育调控机制研究领域所取得的成果, 以期为后续开展绒山羊毛囊生长相关microRNA作用机制研究提供借鉴。     

Hoxc12 expression pattern in developing and cycling murine hair follicles

We examine the Hoxc12 RNA expression pattern during both hair follicle morphogenesis and cycling in direct comparison to its only upstream neighbor, Hoxc13. Expression of both genes is restricted to the epidermal part of the follicle excluding the outer root sheath and interfollicular epidermis in a distinct stage-dependent and cyclical manner. During the progressive growth phase (anagen) of developing and cycling follicles, the distinct proximo-distal expression domain of Hoxc12 overlaps only proximally, at the upper-most region of the bulb, with the more proximally restricted Hoxc13 domain. This arrangement of the expression domains of the two genes along the proximal-toward-distal axis of increasing follicular differentiation correlates with the sequential expression of first Hoxc13 and then Hoxc12. This indicates a reversal of the typical temporal colinearity of Hox gene activation otherwise observed along the anterior-posterior morphogenetic axis of the embryo (review: Cell 78 (1994) 191).     

Targeted inactivation of integrin-linked kinase in hair follicle stem cells reveals an important modulatory role in skin repair after injury

Integrin-linked kinase (ILK) is key for normal epidermal morphogenesis, but little is known about its role in hair follicle stem cells and epidermal regeneration. Hair follicle stem cells are important contributors to newly formed epidermis following injury. We inactivated the Ilk gene in the keratin 15--expressing stem cell population of the mouse hair follicle bulge. Loss of ILK expression in these cells resulted in impaired cutaneous wound healing, with substantially decreased wound closure rates. ILK-deficient stem cells produced very few descendants that moved toward the epidermal surface and into the advancing epithelium that covers the wound. Furthermore, those few mutant cells that homed in the regenerated epidermis exhibited a reduced residence time. Paradoxically, ILK-deficient bulge stem cells responded to anagen growth signals and contributed to newly regenerated hair follicles during this phase of hair follicle growth. Thus ILK plays an important modulatory role in the normal contribution of hair follicle stem cell progeny to the regenerating epidermis following injury.     

Hoxa4 expression in developing mouse hair follicles and skin

We have examined the expression of the Hoxa4 gene in embryonic vibrissae and developing and cycling postnatal pelage hair follicles by digoxigenin-based in situ hybridization. Hoxa4 expression is first seen in E13.5 vibrissae throughout the follicle placode. From E15.5 to E18.5 its expression is restricted to Henle's layer of the inner root sheath. Postnatally, Hoxa4 expression is observed at all stages of developing pelage follicles, from P0 to P4. Sites of expression include both inner and outer root sheaths, matrix cells, and the interfollicular epidermis. Hoxa4 is not expressed in hair follicles after P4. Hoxb4, however, is expressed both in developing follicles at P2 and in catagen at P19, suggesting differential expression of these two paralogous genes in the hair follicle cycle.