In the course of pelage hair follicle morphogenesis, cox. To collectively describe the extremely complex expression pattern of human type i and type ii hair keratins in the hair follicle, we have summarized the corresponding expression data schematically ref. Jan 25, 2018 human hair is laminarfibrous tissue and an evolutionarily old keratinization product of follicle trichocytes. Alphakeratins, which are found in the hair, the skin, and the wool of mammals, are primarily fibrous and helical in structure. At stage 1, a few dermal fibroblastlike cells aggregate below the epidermis and the epidermal cells above the aggregation become larger. Human hair proteins were extracted by detergent and detergentfree techniques. During hair follicle development several cell streams are programmed to differentiate from the cell population of the follicle bulb. Studies on the hair proteome can give new insights into hair function and lead to the. Feb 28, 2020 keratin proteins can be subdivided into alpha keratins and beta keratins, on the basis of their secondary structure the geometry of their polypeptide chains, which is influenced by hydrogen bonding.
At the interface between laboratoryand clinic fiona m. Human hair is laminarfibrous tissue and an evolutionarily old keratinization product of follicle trichocytes. Twodimensional polyacrylamide gel electrophoresis of keratins from a sheep wool, b human hair, and c a mixture of human hair and wool. The duration of growth and rest cycles is coordinated by many endocrine, vascular and neural stimuli and depends not only on localization of the hair but also on various factors, like age and nutritional habits.
Similarly, the 26 type ii members comprise 20 epithelial and 6 hair keratins. Human hair keratins journal of investigative dermatology. The viscoelastic properties of chemically modified. The medulla of mammalian hair represents a vertical column of essentially horizontal cells in the center of the hair cortex.
However, hair protein extraction is especially difficult due to extensive cross. At stage 0, before hair follicle development, the epidermis and dermis are uniform. Studies on the hair proteome can give new insights into hair function and lead to the development of novel biomarkers for hair in health and disease. The full text of this article is available as a pdf m. Human hair keratins were among the first to be studied but it is only recently that sufficient information has been obtained to gain. Proliferation and differentiation of cultured human. Hair follicle stem cells can generate hair follicles, sebaceous glands, and interfollicular epidermis 14. Recent discovery of hair follicle keratin 75 krt75 in enamel raises questions about the function of this protein in enamel and the mechanisms of its secretion. One such instructive model is the human healthy or lesional hf or scalp skin organ culture that allows examination of many hf parameters eg, hair growth, pigmentation, hair cycle, mitochondria, stem cells simultaneously and in a reproducible manner, 79, 127 as was already shown with ppar modulators. A homozygous missense variant in type i keratin krt25 causes.
Convergent evolution of cysteinerich proteins in feathers. The follicle is a clubshaped structure in the skin. Read expression pattern of human hair keratin basic 1 hhbl in hair follicle and pilomatricoma, experimental dermatology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. As, however, 9 out of the 37 epithelial keratins are specifically expressed in the hair follicle, the total number of hair folliclespecific keratins 26 almost equals that of those expressed in the various forms of epithelia 28. A hair follicle is a part of the skin, which grows a hair by packing old cells together. The thicker the hair, the more the number of sebaceous glands there are. Thus, by studying human hair keratins and their associated proteins, we have extended the concept of keratinpairs which we originally established based on studies on soft keratins, to include the socalled hard keratins of the hair and nail our immunological data also raise interesting questions regarding the expression of. Being barely detectable in interfollicular epidermis and resting hair follicles of adult mice, cox2 protein appeared in embryonic skin first in epidermal precursor cells and later on in the basal cells and the peridermal layer of the stratified epidermis. Watt mammalian skin research represents the convergence of three complementary disciplines.
Five of the major keratins, the basic keratins nos. Hyperproliferative keratins consistently expressed in outer root sheath cells in vivo and in vitro article pdf available in differentiation 353. Hair keratin pattern in human hair follicles grown in. Hair folliclestructure, functions, and growth phases. Hair follicle differentiation specific keratin expression. Histologically, the epidermis is thickened because of hyperproliferation of transgenic basal cells, whereas the hair follicles are decreased in number, poorly developed, and hypoproliferative. This supports our hypothesis that distinct functional requirements are satisfied by the multiplicity of hair keratins. As, however, 9 out of the 37 epithelial keratins are specifically expressed in the hair follicle, the total number of hair folliclespecific keratins 26. The structure of hair follicles is simple and straightforward, but its functions and its growth cycle are quite complex.
Establishment of keratinocyte cell lines from human hair follicles. Langbein l, schweitzer j 2005 keratins of the human hair follicle. Dec 01, 1986 although numerous hair proteins have been studied biochemically and many have been sequenced, relatively little is known about their in situ distribution and differential expression in the hair follicle. Hyperproliferativekeratins consistently expressed in outer root sheath cells in vivo and in vitro hans. It is remarkable that, out of the 54 human keratins, almost half of them, that is, 16 hair keratins and 9 epithelial keratins, are specifically expressed in the hair follicle langbein et al.
Any significant alteration to the normal growth cycle of a hair follicle may lead to a hair condition like alopecia areata. Comparative genomics analyses of alphakeratins reveal. In this manuscript, we describe a direct protein extraction method referred as the direct method that can efficiently. Alpha keratins, which are found in the hair, the skin, and the wool of mammals, are primarily fibrous and helical in structure. Keratins and lipids in ethnic hair universidade do minho. Keratin network modifications lead to the mechanical. Jurgen stark division of differentiation and carcinogenesis in vitro, institute of biochemistry, german cancer research center, im neuenheimer feld 280, d. Michael oguin, carolyn hardy, linda mak, and tungtien sun. The expression of these genes in the hair follicle was determined in vivo and a combined catalog of acidic and basic hair keratins was established. Somewhat by design, the direct continuation of the numbering of the six human hair keratins, i. The human type i hair keratin subfamily comprises nine individual members, which can be subdivided into three groups.
Hair keratins and hair folliclespecific epithelial keratins. Expression of keratin k14 in the epidermis and hair. In contrast, out of the 26 hair follicle specific keratins only 5 have, at present, been associated with inherited hair disorders, while one keratin merely acts as a risk factor. A large number of diseases of hair were caused by mutations in hair folliclespecific keratin genes. Specific keratins and their associated proteins as markers. Whereas hhb4 was found in the filiform tongue papilla fig. The large keratin multigene family is made up of the epithelial keratins also designated cytokeratins or soft keratins, which are differentially expressed in the various types of epithelia, and the hair keratins hard keratins, representing the major constituents of hard keratinized structures such as hairs, nails, and claws.
Oct 24, 2017 recent discovery of hair follicle keratin 75 krt75 in enamel raises questions about the function of this protein in enamel and the mechanisms of its secretion. Human hair has an important and undeniable relevance in society. Human hair is composed by approximately 90% proteins and 19% lipids dry weight. Hair keratinassociated proteins kap are a major component of the hair. The group a members hhb1, hhb3, and hhb6 are structurally related, whereas group c members hhb2, hhb4, and hhb5 are rather distinct. To make the method scalable and therefore clinically viable, a team of scientists led by tatsuto kageyama and junji fukuda from yokohama national university proposed a new approach to regenerate hair using mouse and human hair follicle stem cells. The new protocol accelerated the procedure by reducing the extraction time from at least a day to less than two hours and showed a.
Briefly, in this method, human hair was incubated with the. Hair starts growing at the bottom of a hair follicle. Establishment of keratinocyte cell lines from human hair. Keratin, type ii cuticular hb1 is a protein that in humans is encoded by the krt81 gene the protein encoded by this gene is a member of the keratin gene family. Hair folliclespecific keratin genes consisted of 9 hair folliclespecific epithelial keratin genes k71k75, k25k28 and 17 hair keratins k31k40, k81k86 expressed in hair follicle and hair which could directly affect hair growth.
Bertolino hair disease research laboratory, epithelial biology unit, the ronald o. The stiffness of the hair follicle is expected to extend over several orders of magnitude, due to the differentiation of its soft kera. Of all the hair keratins, only type ii hair keratin hhb4 and type i hair keratin hha7 could not be detected by iif in terminal scalp hairs see section ii. We describe the characterization of the type ii keratin intermediate filament if gene family which is expressed early in follicle differentiation. The corneal epithelial cells then gave rise to hair follicle buds, which matured into fully formed hair follicles, and eventually the overlying corneal epitheliumwas transformed into an epidermis, which expressed the k10 keratin ferraris et al, 2000. Hair keratinassociated proteins kap are a major component of the hair fiber, and play crucial roles in forming a strong hair shaft through a crosslinked network with keratin intermediate filaments kif, which are produced from hair keratins. Feathers and hair consist of cornified epidermal keratinocytes in which proteins are crosslinked via disulfide bonds between cysteine residues of structural proteins to establish mechanical resilience. As, however, 9 out of the 37 epithelial keratins are specifically expressed in the hair follicle, the total number of hair follicle specific keratins 26 almost equals that of those expressed in the various forms of epithelia 28. Hyperproliferativekeratins consistently expressed in outer root sheath cells in vivo and in vitro. Ppar signalling as a key mediator of human hair follicle.
A highyield twohour protocol for extraction of human hair. A total of 54 functional keratin genes were identified in the human genome, which can be divided into 28 type i and 26 type ii genes 10, 11. Distinctive anatomy and physiology of hair follicle are. Keratins in human hair a thesis submitted to the university of manchester for the degree of doctor of philosophy ph. Aug 23, 2018 the family of keratin genes in human contains 54 functional genes. The term hair follicle is derived from the latin word follis. It is the key structural material making up hair, nails, feathers, horns, claws, hooves, calluses, and the outer layer of skin among vertebrates. Conclusions our findings implicate a novel gene involved in human hair abnormality, and are consistent with the curled, fragile hair found in mice with krt25 mutations, and further support the role of irsspecific type i keratins in hair follicle development and maintenance of hair texture. Based on previous, although controversial claims of the occurrence in the irs of various classical epithelial keratins, we undertook a systematic study using antibodies against the presently described human epithelial and hair keratins and show that the type i keratins k25k28 k25irs1k25irs4 and the type ii keratins k71k74. In addition, our results suggest that hair keratins may be effective in moderating the microenvironment sufficiently to enrich hmscs with high colonyforming efficiency ex vivo, for clinical applications. Cultivation of keratinocytes from the outer root sheath of. Keratins are best known for providing strength and resilience to cells that form the hair, skin, and nails.
During woundhealing, keratinocyte migration enables rapid wound closure and reepithelialization of injured skin to regenerate the bodys barrier. In this study, we investigated the expression and localization of most of the human hair keratin members of. For the sake of a comprehensive interpretation of these data, in both schemes. According the consensus nomenclature for mammalian keratins, the keratin family include three categories. New consensus nomenclature for mammalian keratins journal.
As a type ii hair keratin, it is a basic protein which heterodimerizes with type i keratins to form hair and nails. It is composed of several different cell types which form the medulla, cortex and outer cuticle of the hair shaft and the surrounding inner and outer root sheaths. Expression of keratin k14 in the epidermis and hair follicle. Group a hha1, hha3i, hha3ii, hha4 and b hha7, hha8 each contains structurally related hair keratins, whereas group c members hha2, hha5, and hha6 represent structurally rather unrelated hair keratins.
It is also not clear how this protein with a very specific and narrow expression pattern, limited to the inner root sheath of the hair follicle, became associated with enamel. Recently, the study of human kap has advanced significantly. Hair keratins provide shape, strength, and integrity to the hair fiber. As, however, 9 out of the 37 epithelial keratins are specifically expressed in the hair follicle, the total number of hair follicle specific keratins 26 almost equals. To study this problem, we have prepared several mouse monoclonal antibodies that recognize different classes of human hair proteins. In contrast, out of the 26 hair folliclespecific keratins only 5 have, at present, been associated with inherited hair disorders, while one keratin merely acts as a risk factor.
In the human genome, the keratin genes are clustered at two diverent chromosomal sites. Human hair keratins were among the first to be studied but it is only recently that sufficient information has been obtained to gain a basic biologic perspective of these proteins. Hair follicle article about hair follicle by the free. Their colocalization in upper cortical and cuticle cells of the human hair follicle and their relationship to soft keratins marion h. Cysteinerich keratinassociated proteins krtaps are important components of hair whereas the molecular components of feathers have remained incompletely known. Human hair keratins are abundant and might constitute a feasible replacement for other biomaterials that are of animal origin. Keratin proteins can be subdivided into alphakeratins and betakeratins, on the basis of their secondary structure the geometry of their polypeptide chains, which is influenced by hydrogen bonding. Keratins are also involved in several other critical cell functions, including cell movement migration, regulation of cell. Sensitive method for the confident identification of. The hair follicle is a specialised epithelial structure derived from the epidermis.
The root of the hair is made up of protein cells and. Modulating mesenchymal stem cell behavior using human hair. All in all, out of the 54 human keratin genes, at least 26. Keratins, in general, are fibrous structural proteins that belong to the intracellular intermediate filament if superfamily. A large number of diseases of hair were caused by mutations in hair follicle specific keratin genes. The hair shaft, the part of the hair seen above the skin, has a thickness of. In the present study, we have developed a rapid extraction protocol for hair shaft protein using alkalinebased buffer. Out of the 28 type i keratins, 17 are epithelial and 11 are hair keratins. A homozygous missense variant in type i keratin krt25. The majority of the hair strand is composed of keratins that make up the outer protective cuticle and the inner cortical cell units.
Hair follicles and hair are seen all over the body except some regions like our palms, soles, and lips. Thus, there are 28 type i keratin genes 17 epithelial keratins and 11 hair keratins and 26 type ii keratin genes 20 epithelial keratins and 6 hair keratins. Jul 10, 2006 somewhat by design, the direct continuation of the numbering of the six human hair keratins, i. Intermediate filament proteins resource hair keratins. The skin provides a paradigm for current research in cell adhesion, inflammation, and tissue stem cells. Using reverse transcription pcr with total human hair follicle rna, we demonstrated transcripts of the major tale proteins pbx14, meis1, 2 and prep1, 2 in the human hair follicle. In the hair cells, a number of keratin gene families are transcriptionally activated. Characterization of the human hair shaft cuticlespecific. Specific antisera against the individual hair keratins were used to establish the twodimensional catalog of human type ii hair keratins. Therefore, we investigated the effects of low and high concentrations of biotin on proliferation and differentiation of cultured outer root sheath cells from human hair follicles as an in vitro model for skin. The very first stages of hair follicle embryogenesis are shown in the pictures above. The hair follicle is a structure which appears like a bag or sac and the hair grows from it. Hair follicle has a continuous growth and rest sequence named hair cycle. The outer root sheath ors of hair follicles is a multilayered tissue made up predominantly by undifferentiated keratinocytes it1, it2 although the functions of the ors cells for hair growth are not established, it is known that the ors cells can contribute to the regeneration of the epidermis, as during healing of superficial wounds where the ors cells.
Hair follicle differentiation specific keratin expression in. Follicle, associated structures and growth a persons hair is often considered as a remnant of the animal mane and continues to have both a social role as a symbol of youth, health and fertility and a biological role by protecting the top of the head from the sun and by the sequestration and excretion of unwanted biochemical substances. Proteome analysis of the human hair remains challenging due to the poor solubility of hair proteins and the difficulty in their extraction. Attached inside the top of the follicle are sebaceous glands, which are tiny sebum producing glands in almost all skin except on the palms, lips and soles of the feet. Jun 10, 2007 the human keratin family comprises 54 members, 28 type i and 26 type ii. K25 k25irs1, k26 k25irs2, k27 k25irs3, and k28 k25irs4. A novel purification procedure for keratinassociated. These proteins allow tissues to resist damage from friction and minor trauma, such as rubbing and scratching. Hair keratins are members of the intermediate filament family of proteins, yet are sufficiently divergent from epidermal keratins to warrant separate classification. The expression of individual keratins, regulatory pathways and proliferative states were analysed using reverse transcription.
Oct 31, 2019 to detect them, we first need an efficient method to extract proteins from human hair shafts. A hair follicle is a tunnelshaped structure in the epidermis outer layer of the skin. The inconsistent regulation of hoxc on different keratins. Hair follicle specific keratin genes consisted of 9 hair follicle specific epithelial keratin genes k71k75, k25k28 and 17 hair keratins k31k40, k81k86 expressed in hair follicle and hair which could directly affect hair growth. Studies on the proteome of human hair identification of. This is the largest number of hair follicles a human will ever have. They have a very distinct expression pattern in different epithelial layers and organs.
Jun 10, 2007 similarly, the 26 type ii members comprise 20 epithelial and 6 hair keratins. Nov 15, 2005 hox specificity is generally thought to be enhanced by the interaction with members of the tale superclass of homeodomain proteins pbx, meis, and prep. Specific antisera against the individual hair keratins were used to establish the twodimensional catalog of human type ii. The structure of hair a hair consists of two parts.
The human keratin family comprises 54 members, 28 type i and 26 type ii. Regulation of a hair follicle keratin intermediate. High doses of biotin may also have beneficial effects on skin, hair and fingernails in humans and animals with normal biotin status. The human hair follicle was used here as a model system to show how the local, microscopic network architecture is connected to local mechanical properties in a tridimensional tissue. All in all, out of the 54 human keratin genes, at least 26 50% are specifically expressed in the hair follicle. Jun 17, 20 a novel mutation in the lipase h gene underlies autosomal recessive hypotrichosis and woolly hair.