羊驼毛的结构及其特性研究

为研究羊驼毛的特性并评价羊驼的生产性能,观察了羊驼皮肤和毛的显微结构和超微结构。结果表明:皮肤中皮脂腺很少,这决定了羊驼毛易清洗;毛囊由初级毛囊和大部分复合毛囊组成,因此大部分羊驼毛很细;羊驼毛的髓质比例小于皮质所占比例,而且白毛的髓质与皮质的比例大于有色毛,这决定了羊驼毛轻而具有好的保暖性,且白毛重量轻于有色毛;羊驼毛的皮质细胞具有双层结构,上皮细胞有5层,皮质周围有内、外上皮,这些结构可能使毛避免损伤,并可使黑色素颗粒避免丢失以维持其自然色;羊驼毛的鳞片呈锯齿状并形成裂痕,具有疏水性,因此羊驼毛可以防水。所有这些特点决定了羊驼毛在毛纺工业中是理想的原料。     

蒲公英止痘膏的研制

青春痘是痤疮的俗称 ,它是一种毛囊皮脂腺的慢性炎症 ,常发生于面部、前胸及肩胛部位 ,形成丘疹 ,发后大都痊愈 ,有时会留下瘢痕。粉刺在某种程度上可以说是生理症状。青春期雄性激素增多 ,皮脂腺增大 ,皮脂分泌增多 ,同时使毛囊皮脂腺导管角化过度 ,角质层脱落的扁平的死细胞落至毛囊漏斗部与皮脂结合 ,产生混合物。如果这些混合物不能自由地排出至皮肤表面 ,而淤积于毛囊内便形成脂栓。当这些异常角化细胞聚集 ,下部漏斗膨胀时就产生成熟的粉刺。皮脂被毛囊中存在的细菌分解 ,生成脂肪酸 ,后者刺激毛囊产生炎症 ,致使毛囊壁损伤破裂 ,毛囊…     

HGF/c-met在小鼠毛囊生长周期中的表达

目的 HGF及其受体c-met是很多系统中间充质-上皮互相作用的主要的介导者,毛囊周期性生长是典型的间充质-上皮互作模型,为证实HGF/c-met信号在小鼠毛囊周期生长过程中是否发挥作用。方法本实验运用免疫组织化学的方法对HGF/c-met在ICR小鼠毛囊生长期、退化期和休止期进行组织定位。结果 HGF主要位于真毛乳头和皮脂腺,c-met主要位于毛基质、根鞘部和表皮。HGF及其受体在小鼠毛囊生长期表达量达到最高值,在退化期基本不表达,在休止期-生长期过渡时HGF及其受体表达量均上升。结论 HGF/c-met信号在ICR小鼠毛囊生长过程中起调控作用。     

皮肤表皮干细胞的研究进展

成体的皮肤一生都在不断的自我更新,其中的毛囊还是保证毛发进行生长-脱落周期循环的细胞组织学基础。存在于表皮内的干细胞维持了成体皮肤的自我平衡及毛发再生。表皮是由构体分子组成。每个构体分子包含毛皮脂单位（毛囊和皮脂腺）及其周围的毛囊间表皮。毛囊间表皮具有祖细胞,损伤时能自我更新;毛囊具有多能干细胞,在新毛发周期开始或者损伤时能够启动干细胞功能,为毛囊的生长或表皮的修复提供细胞来源。本文概述了当前对表皮干细胞的认识,着重阐明毛囊间表皮内有祖细胞的证据,毛囊间表皮干细胞在体外的自我更新能力,毛囊膨突部内干细胞的特征和一些相关基因的表达等。     

漠河地区养殖的北极狐冬季被毛性状与保温性能的关系

被毛是哺乳动物最主要的特征之一,其保温功能对动物适应寒冷环境意义重大。为了探讨北极狐(Alopex lagopus)在被毛性状上如何适应寒冷的气候条件,对大兴安岭漠河地区人工养殖北极狐的背中部直针毛、上层绒毛、下层绒毛的长度、毛根细度、毛干细度以及毛密度、单个毛束内的毛数量、毛束密度、复合毛囊最大横切面积、1mm2内复合毛囊最大横切面总面积等14个性状因子进行测量分析。结果表明,北极狐绒毛分为上下两层,下层绒毛的长度、毛根细度和毛干细度均小于上层绒毛,上层绒毛长度与直针毛接近,直针毛长度与上层绒毛、下层绒毛长度均不存在显著相关性;毛密度与毛束密度极度正相关(P0.01),但与毛根细度、毛干细度、单个毛束内的毛数量和1mm2内复合毛囊最大横切面总面积不存在显著相关性,且与复合毛囊最大横切面积的相关性较小;复合毛囊最大横切面积受毛根细度、单个毛束内的毛数量和毛束密度的影响较小。北极狐不是通过降低毛细度的方式来增加毛密度以加强保温功能,而是通过改变被毛在皮肤内的分布格局来增加毛密度,以及将有髓质的绒毛分为上下两层来改变被毛空间结构这两种策略提高被毛内静止空气的量以加强保温功能,进而适应高纬度地区的寒冷环境。     

毛囊干细胞

毛囊干细胞被认为是具慢周期性特点,但特定条件下具有较高增殖能力和克隆形成潜能的细胞。它们在形态学和生物化学上处于较原始的状态,常具有多潜能性。利用干细胞标记技术和克隆形成能力检测手段,人们发现毛囊干细胞主要存在于位于毛囊上半部的隆突部位。毛囊干细胞潜在的分子标记包括β1-整合素、α6-整合素、CD71、角蛋白19、p63和CD34,而在体内和体外它们的分子标记也不尽相同。毛囊隆突部位的干细胞能够分化成表皮、上皮性毛根鞘、发杆和皮脂腺。在个体发育过程中,它们具有分化成其他多种细胞系的能力。对于在毛发形态形成和生长周期中毛囊干细胞的行为,研究者们提出了多种假说,包括隆突激活假说和干细胞迁移假说。如今,毛囊干细胞主要应用于制备皮肤的代替品。     

植物疗疖妙法

疖是皮肤和皮下组织的急性化脓性炎症,常在夏秋季因葡萄球菌侵入汗腺、皮脂腺和毛囊而引起。可发生于全身各处,特别是富含汗腺、皮脂腺和毛囊的面部和上背部,以及容易遭受摩擦的后颈部和臀部。患区隆肿,周围皮肤发红。可引起疼痛和发热。严重时细菌的毒素可进入血液,引起全身中毒。眼和鼻周围的疖肿特别危险,因其毒素容易扩散到脑部。     

毛囊干细胞标记物的研究进展

毛囊干细胞是一类位于毛囊隆突区的成体干细胞,对毛囊的周期性生长,表皮和皮脂腺的更新以及皮肤损伤后修复有着至关重要的作用。毛囊干细胞的标记物是对毛囊干细胞进行分离和鉴定的重要依据,对毛囊干细胞的基础研究起着关键作用。因此寻找特异性较高的毛囊干细胞标记物成为了近年的研究热点。本文按毛囊干细胞标记物在细胞中所处部位进行分类,将其分为位于细胞膜、细胞质、细胞核的标记物,综述了目前国内外主要采用的整合素、角蛋白、CD34、CD200等标记物以及新发现的Lgr5、Sox9、Tcf3等基因标记物。     

黄芪、何首乌、女贞子、菟丝子混合提取物对体外培养毛囊生长的影响及药理作用研究

目的:通过体内外实验探讨黄芪、何首乌、女贞子、菟丝子混合中药提取物对毛囊增殖的影响作用以及其作用机理。方法:通过体外培养的C57BL/6小鼠毛囊器官模型观察不同浓度中药提取物对毛囊生长的影响;采用MTT法测定不同浓度中药提取物对毛乳头增殖的影响;蛋白免疫印迹法(Western Blot)和ELISA检测中药提取物对毛乳头细胞分泌肝细胞生长因子(HGF)的影响。结果:中药提取物能够刺激体外培养的小鼠毛囊的生长,800μg/mL浓度的促进作用最强;160μg/mL中药提取物对毛乳头细胞的增殖作用最强,与米诺地尔、齐墩果酸阳性对照存在显著性差异(P0.05)。而且,药提取物促进了毛乳头细胞分泌HGF。结论:黄芪、何首乌、女贞子、菟丝子混合中药提取物在促进毛发生长中起到重要作用,促进毛乳头细胞增殖和分泌HGF是促进毛囊生长的可能性药理机制。     

SD大鼠皮肤组织病理学观察

目的观察不同日龄SD大鼠皮肤组织学结构。方法10％甲醛固定,行石蜡切片,HE染色。结果新生大鼠皮肤较薄,透明层缺乏,皮脂腺发育良好。6月龄时表皮、真皮和皮下组织明显增厚,毛囊增粗,生长旺盛,毛囊深入皮下脂肪层。24月龄时,大鼠皮脂腺及汗腺萎缩,表皮变薄,真皮成纤维细胞、血管数量减少,弹力纤维变细。结论不同日龄SD大鼠皮肤组织学结构有差异。     

Development and homeostasis of the skin epidermis

The skin epidermis is a stratified epithelium that forms a barrier that protects animals from dehydration, mechanical stress, and infections. The epidermis encompasses different appendages, such as the hair follicle (HF), the sebaceous gland (SG), the sweat gland, and the touch dome, that are essential for thermoregulation, sensing the environment, and influencing social behavior. The epidermis undergoes a constant turnover and distinct stem cells (SCs) are responsible for the homeostasis of the different epidermal compartments. Deregulation of the signaling pathways controlling the balance between renewal and differentiation often leads to cancer formation.     

Comparative responsiveness of supracaudal and other sebaceous glands in male and female guinea pigs to hormones

Different types of sebaceous glands in guinea pigs were chosen to study their comparative responsiveness to steroid hormones. Glands selected were (1) Sebaceous glands associated with rudimentary hair in the supracaudal gland; (2) Free sebaceous glands of the nipple; (3) Sebaceous glands associated with the hair. The results showed distinct differences in sensitivity among these different sebaceous glands and according to the sex of the experimental animal. The most responsive of the glands in males was the supracaudal gland; in the female the most responsive glands were the sebaceous glands of the nipple. Sebaceous glands associated with normal hair were relatively insensitive to changes in hormonal level. In all cases testosterone propionate was more potent in stimulating any of the sebaceous glands than progesterone. After gonadectomy, various sebaceous glands showed unequal states of depletion due to the different rates of differentiation and disintegration of their cells into sebum.     

Endogenous retinoids in the hair follicle and sebaceous gland

Vitamin A and its derivatives (retinoids) are critically important in the development and maintenance of multiple epithelial tissues, including skin, hair, and sebaceous glands, as shown by the detrimental effects of either vitamin A deficiency or toxicity. Thus, precise levels of retinoic acid (RA, active metabolite) are needed. These precise levels of RA are achieved by regulating several steps in the conversion of dietary vitamin A (retinol) to RA and RA catabolism. This review discusses the localization of RA synthesis to specific sites within the hair follicle and sebaceous gland, including their stem cells, during both homeostasis and disease states. It also discusses what is known about the specific roles of RA within the hair follicle and sebaceous gland. This article is part of a Special Issue entitled: Retinoid and Lipid Metabolism.     

Cellular dynamics of the outer layers of the hair follicle of fine-wool sheep during the phase of stable hair growth

The structure, origin, and migration of outer sheath cells of the hair follicles of domestic sheep were studied by electron microscopic, autoradiographic, and histochemical (glycogen) methods in order to understand the role of this layer in hair morphogenesis. We demonstrated that the cells of the outer layers of the outer sheath interpose into the inner “companion” layer of the outer sheath. Although this process takes place all along the hair follicle from the lower bulb up to the sebaceous glands orifices, it mainly takes place over the bulb. Labeled cells interposed into the companion layer reach sebaceous glands orifices more than 24 h faster than labeled cells of the inner sheath and hair, because these cells included the label not in the bulb cambium (as hair and inner sheath) but over the bulb, and from this point they start movement. Interposition of cells into the companion layer must cause increase of its volume and additional volume supposed to be led away into the pillar canal around the hair near the sebaceous glands orifices. This can provide the mechanism of the hair and inner sheath promotion to sebaceous gland orifices.     

Heparan Sulfate Regulates Hair Follicle and Sebaceous Gland Morphogenesis and Homeostasis

Hair follicle (HF) morphogenesis and cycling are a result of intricate autonomous epithelial-mesenchymal interactions. Once the first HF cycle is complete it repeatedly undergoes cyclic transformations. Heparan sulfate (HS) proteoglycans are found on the cell surface and in the extracellular matrix where they influence a variety of biological processes by interacting with physiologically important proteins, such as growth factors. Inhibition of heparanase (an HS endoglycosidase) in in vitro cultured HFs has been shown to induce a catagen-like process. Therefore, this study aimed to elucidate the precise role of HS in HF morphogenesis and cycling. An inducible tetratransgenic mouse model was generated to excise exostosin glycosyltransferase 1 (Ext1) in keratin 14-positive cells from P21. Interestingly, EXT1^{StEpiΔ/StEpiΔ} mice presented solely anagen HFs. Moreover, waxing the fur to synchronize the HFs revealed accelerated hair regrowth in the EXT1^{StEpiΔ/StEpiΔ} mice and hindered cycling into catagen. The ablation of HS in the interfollicular epidermal cells of mature skin led to the spontaneous formation of new HFs and an increase in Sonic Hedgehog expression resembling wild-type mice at P0, thereby indicating that the HS/Sonic Hedgehog signaling pathway regulates HF formation during embryogenesis and prevents HF formation in mature skin. Finally, the knock-out of HS also led to the morphogenesis and hyperplasia of sebaceous glands and sweat glands in mature mice, leading to exacerbated sebum production and accumulation on the skin surface. Therefore, our findings clearly show that an intricate control of HS levels is required for HF, sebaceous gland, and sweat gland morphogenesis and HF cycling.     

Normal fur development and sebum production depends on fatty acid 2-hydroxylase expression in sebaceous glands

2-Hydroxylated fatty acid (HFA)-containing sphingolipids are abundant in mammalian skin and are believed to play a role in the formation of the epidermal barrier. Fatty acid 2-hydroxylase (FA2H), required for the synthesis of 2-hydroxylated sphingolipids in various organs, is highly expressed in skin, and previous in vitro studies demonstrated its role in the synthesis of HFA sphingolipids in human keratinocytes. Unexpectedly, however, mice deficient in FA2H did not show significant changes in their epidermal HFA sphingolipids. Expression of FA2H in murine skin was restricted to the sebaceous glands, where it was required for synthesis of 2-hydroxylated glucosylceramide and a fraction of type II wax diesters. Absence of FA2H resulted in hyperproliferation of sebocytes and enlarged sebaceous glands during hair follicle morphogenesis and anagen (active growth phase) in adult mice. This was accompanied by a significant up-regulation of the epidermal growth factor receptor ligand epigen in sebocytes. Loss of FA2H significantly altered the composition and physicochemical properties of sebum, which often blocked the hair canal, apparently causing a delay in the hair fiber exit. Furthermore, mice lacking FA2H displayed a cycling alopecia with hair loss in telogen. These results underline the importance of the sebaceous glands and suggest a role of specific sebaceous gland or sebum lipids, synthesized by FA2H, in the hair follicle homeostasis.     

Glutamate transporter Slc1a3 mediates inter‐niche stem cell activation during skin growth

Tissues contain distinct stem cell niches, but whether cell turnover is coordinated between niches during growth is unknown. Here, we report that in mouse skin, hair growth is accompanied by sebaceous gland and interfollicular epidermis expansion. During hair growth, cells in the bulge and outer root sheath temporarily upregulate the glutamate transporter SLC1A3, and the number of SLC1A3⁺ basal cells in interfollicular epidermis and sebaceous gland increases. Fate mapping of SLC1A3⁺ cells in mice revealed transient expression in proliferating stem/progenitor cells in all three niches. Deletion of slc1a3 delays hair follicle anagen entry, uncouples interfollicular epidermis and sebaceous gland expansion from the hair cycle, and leads to reduced fur density in aged mice, indicating a role of SLC1A3 in stem/progenitor cell activation. Modulation of metabotropic glutamate receptor 5 activity mimics the effects of SLC1A3 deletion or inhibition. These data reveal that stem/progenitor cell activation is synchronized over distinct niches during growth and identify SLC1A3 as a general marker and effector of activated epithelial stem/progenitor cells throughout the skin.     

Hair growth in mouse mutants affecting coat texture

The genetic control of hair growth has been studied in mice carrying the following coat texture genes: fz (fuzzy), soc (soft coat), hid (hair interior defect), sa (satin), It (lustrous), Ve (velvet), wa-1 (waved-1), Re (rex), Re ^wc (wavy coat) and pk (plucked).
A general effect on cells of epidermal origin, found in soc/soc and Ve /+ skin samples illustrates how common factors control developmental potential in both the stratum germinativum and the follicle bulb. A direct influence on follicle bulb development is also seen in fz/fz homozygotes in which the dermal papilla functions abnormally. The role of the bulb cells and the dermal papilla in the control of hair shaft calibre is discussed.
hid is a new gene, found in homozygous condition in all mice of the AKR inbred strain. hid and sa appear primarily to be concerned in the differentiation of the medulla.
In the hair waving mutants, waved-1, rex and wavy coat, the processes controlling hair movement within the follicle are disturbed. These genes appear to regulate internal root sheath function. When the normal relationship between internal root sheath and developing hair shaft is disturbed, shaft movement slows, with the subsequent development of shaft calibre abnormalities.
pk acts at the level of the sebaceous gland, disturbing the normal process of hair eruption. The roles of the internal root sheath, external root sheath and the sebaceous gland in hair eruption are discussed.
The abnormal epidermal layer in soc/soc and Ve /+ skin also disturbs hair eruption to a small extent. The resulting abnormalities this causes in hair shaft formation are compared with those found pk/pk samples and also with the similar effects of faulty hair movement in the hair waving mutants. An effect on pigmentation is also described.
The chemistry of keratinization appears to be normal in all these mutants.     

CELL KINETICS IN THE SEBACEOUS GLANDS OF THE MOUSE. II. THE GLANDS DURING HAIR GROWTH

The sebaceous glands of the mouse have been studied during hair growth initiated either spontaneously or artificially. The labelling index of the glands increases early in the spontaneous hair growth period. That of the epidermis is much lower and hardly changes during the growth period. After the initiation of hair growth by plucking, changes in cell proliferation in the sebaceous glands appear to follow those in the epidermis. The size of the gland and the number of cells in it also change after plucking. These variations can be related to the stages of hair growth.     

Cidea Control of Lipid Storage and Secretion in Mouse and Human Sebaceous Glands

Sebaceous glands are skin appendages that secrete sebum onto hair follicles to lubricate the hair and maintain skin homeostasis. In this study, we demonstrated that Cidea is expressed at high levels in lipid-laden mature sebocytes and that Cidea deficiency led to dry hair and hair loss in aged mice. In addition, Cidea-deficient mice had markedly reduced levels of skin surface lipids, including triacylglycerides (TAGs) and wax diesters (WDEs), and these mice were defective in water repulsion and thermoregulation. Furthermore, we observed that Cidea-deficient sebocytes accumulated a large number of smaller-sized lipid droplets (LDs), whereas overexpression of Cidea in human SZ95 sebocytes resulted in increased lipid storage and the accumulation of large LDs. Importantly, Cidea was highly expressed in human sebaceous glands, and its expression levels were positively correlated with human sebum secretion. Our data revealed that Cidea is a crucial regulator of sebaceous gland lipid storage and sebum lipid secretion in mammals and humans.