Hair Follicle Transcriptome Analysis Reveals Differentially Expressed Genes That Regulate Wool Fiber Diameter in Angora Rabbits.

Wool fiber diameter (WFD) is an important index of wool traits and the main determinant of wool quality and value. However, the genetic determinants of fiber diameter have not yet been fully elucidated. Here, coarse and fine wool of Wan strain Angora rabbits and their hair follicle traits were characterized. The results indicated significant differences in the diameters of wool fibers and their hair follicles. The RNA sequencing (RNA-Seq) technique was used to identify differences in gene expression in hair follicles between coarse and fine wool. In total, 2574 differentially expressed genes (DEGs) were found between the two hair follicle groups. Transcription factors, keratin-associated protein (KAP) and keratin (KRT) families, and ECM-related genes may control the structure of fine fibers in rabbits. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that skin development, epidermal cell and keratinocyte differentiation, epithelium development, and Notch and ribosome signaling pathways were significantly enriched, respectively. GSEA further filtered six important pathways and related core genes. PPI analysis also mined functional DEGs associated with hair structure, including LEF1, FZD3, SMAD3, ITGB6, and BMP4. Our findings provide valuable information for researching the molecular mechanisms regulating wool fiber and could facilitate enhanced selection of super-fine wool rabbits through gene-assisted selection in the future.

On Hair Care Physicochemistry: From Structure and Degradation to Novel Biobased Conditioning Agents.

Hair is constantly exposed to various adverse external stimuli, such as mechanical or thermal factors, that may cause damage or cause it to lose its shine and smooth appearance. These undesirable effects can be minimized by using hair conditioners, which repair the hair and restore the smooth effect desired by the consumer. Some of the currently used conditioning agents present low biodegradability and high toxicity to aquatic organisms. Consumers are also becoming more aware of environmental issues and shifting their preferences toward natural-based products. Therefore, developing novel, sustainable, natural-based derivatives that can act as conditioning agents in hair care products and thus compete with the traditional systems obtained from non-renewable sources is highly appealing. This paper presents the key physicochemical aspects of the hair conditioning process, including hair structure and degradation, and reviews some of the new alternative conditioning agents obtained from natural resources.

A highly resistant structure between the cuticle and the cortex of human hair III: Characterzation of the structure CARB.

OBJECTIVE: It was previously reported that a highly resistant structure, which functions as a barrier against the penetration of dyes, is present at the interface between the cuticle and the cortex of human hair. That structure was named CARB, cuticle anchored resistant base. The goal of this study was to clarify the formation and composition of the structure CARB. METHODS: Cuticular substructures were observed from the keratinized area of each hair to its root end. The positions where the CARB structure appeared were isolated, and the barrier ability before and after that structure was evaluated. The distributions of glycolipid and cystine were measured using a nano-IR and a transmission electron microscope (TEM). RESULTS: Cuticular substructures were fully constructed several mm from the hair bulb of the hairs observed. The results show that keratinization at the distal side of the cuticle cell precedes that of the proximal side, and CARB is fully constructed last among the substructures. Glycolipid was preferentially distributed at CARB in the keratinized area. The cystine content of CARB is lower than that of the A-layer; however, it is slightly higher than that of the exocuticle and the inner layer. CONCLUSION: These results demonstrate that CARB is produced in the final stage of keratinization of the cuticle layers. The rich contents of glycolipid and cystine might contribute to its resistant property.

OBJECTIF: Il a été précédemment rapporté qu'une structure hautement résistante, qui fonctionne comme une barrière contre la pénétration des colorants, est présente à l'interface entre la cuticule et le cortex des cheveux humains. Cette structure a été baptisée « CARB ¼ pour cuticle anchored resistant base (base résistante ancrée dans la cuticule). L'objectif de cette étude était de clarifier la formation et la composition de la structure CARB. MÉTHODES: Des sous-structures cuticulaires ont été observées à partir de la zone kératinisée de chaque cheveu jusqu'à sa racine. Les positions où apparaissait la structure CARB ont été isolées et la capacité de barrière avant et après cette structure a été évaluée. Les distributions des glycolipides et de la cystine ont été mesurées à l'aide d'un spectromètre infrarouge nanométrique (nano-IR) et d'un microscope électronique à transmission (MET). RÉSULTATS: Les sous-structures cuticulaires étaient entièrement construites à plusieurs mm du bulbe capillaire des cheveux observés. Les　résultats montrent que la kératinisation du côté distal de la cellule cuticulaire précède celle du côté proximal, et la structure CARB est entièrement construite en dernier dans les sous-structures. Les glycolipides étaient distribués de préférence dans la structure CARB dans la zone kératinisée. La teneur en cystine de la structure CARB est inférieure à celle de la couche A ; cependant, elle est légèrement supérieure à celle de l'exocuticule et de la couche interne. CONCLUSION: Ces résultats démontrent que la structure CARB est produite à l'étape finale de la kératinisation des couches cuticulaires. Le riche contenu en glycolipides et cystine pourrait contribuer à sa propriété résistante.

A highly resistant structure between the cuticle and the cortex of human hair. II. CARB, a penetration barrier.

OBJECTIVE: We previously reported that a chemically resistant structure is present at the interface between the cuticle and the cortex of human hair. The goal of this study was to identify the position of that structure and to clarify its barrier ability. METHODS: Untreated, partially and completely decuticled hair fibres were characterized. The correlation between the number of cuticle layers and the penetration depth of a dye into the cortex was microscopically investigated. In addition, similar measurements were performed using hair with a denatured cell membrane complex. RESULTS: The penetration depth of the dye into the cortex showed no statistically significant correlation with the number of cuticle layers in the case of partially decuticled hair fibres (the number of cuticle layers ranged from one to four). Penetration of the dye proceeded drastically just when the last cuticle layer was lost, but denaturation of the cell membrane complex did not affect the depth of penetration. That suggested that the penetration barrier at the interface between the cuticle and the cortex is not the cell membrane complex, but rather is the resistant structure previously reported. It was observed that a thin layer structure is located beneath the endocuticle of the innermost cuticle cell layer, only in the range where the cuticle borders the cortex. It is thought that this is the structure in question. CONCLUSION: These results demonstrate that a highly resistant structure located at the interface between the cuticle and the cortex of human hair acts as a penetration barrier. We propose that structure be named CARB, cuticle anchored resistant base.

OBJECTIF: nous avions fait état, précédemment, de la présence d'une structure chimiquement résistante, située à l'interface entre la cuticule et le cortex des cheveux humains. L'objectif de cette étude était d'identifier la position de cette structure et de clarifier sa capacité à former une barrière. MÉTHODES: des fibres capillaires non traitées, dont on a retiré partiellement ou totalement la cuticule, ont été caractérisées. La corrélation entre le nombre de couches de cuticule et la profondeur de pénétration d'une coloration dans le cortex capillaire a été étudiée au microscope. Des mesures similaires ont également été effectuées sur des cheveux dont le complexe membranaire cellulaire est dénaturé. RÉSULTATS: la profondeur de pénétration de la coloration dans le cortex capillaire n'a pas montré de corrélation statistiquement significative avec le nombre de couches de cuticule dans le cas de fibres capillaires dont la cuticule a été partiellement retirée (nombre de couches de cuticule compris entre un et quatre). La pénétration de la coloration se poursuivait considérablement au moment même où la dernière couche de cuticule a été perdue, mais la dénaturation du complexe membranaire cellulaire n'a pas affecté la profondeur de pénétration. Cela suggère que la barrière de pénétration située à l'interface entre la cuticule et le cortex capillaires n'est pas le complexe membranaire cellulaire, mais plutôt la structure résistante susmentionnée. On a observé la présence d'une fine structure composée de couches, située sous l'endocuticule de la couche cellulaire de la cuticule la plus intérieure, uniquement à l'endroit où la cuticule borde le cortex capillaire. On pense qu'il s'agit de la structure en question. CONCLUSION: ces résultats montrent qu'une structure très résistante située à l'interface entre la cuticule et le cortex des cheveux humains fait office de barrière contre la pénétration. Nous proposons de nommer cette structure «base résistante ancrée dans la cuticule¼ (cuticle anchored resistant base, CARB).

The physical and chemical disruption of human hair after bleaching - studies by transmission electron microscopy and redox proteomics.

OBJECTIVE: To understand the structural and chemical effects of cosmetic peroxide bleaching on human hair. METHODS: Human hair was progressively bleached using alkaline peroxide-persulphate treatment. Proteins lost through leaching were examined using amino acid analysis and mass spectrometric sequencing. Fibre damage was assessed using transmission electron microscopy, amino acid analysis and redox proteomics. RESULTS: Protein loss through leaching increased with bleaching severity. Leached proteins were not limited to the cuticle, but also included cortical intermediate filaments and matrix keratin-associated proteins. The leached proteins were progressively oxidized as bleaching severity increased. Bleached fibres demonstrated substantial damage to the cuticle layers and to the cortex. Extensive melanin granule degradation was present after the mildest bleach treatment. Protein oxidation in bleached fibres was principally in cortical intermediate filaments - the most abundant hair proteins - and targeted the sulphur-containing amino acids, particularly the conversion of cystine disulphide bonds to cysteic acid. CONCLUSION: Peroxide chemical treatments quickly access the cortex, causing untargeted oxidative damage across the fibre in addition to the desired loss of melanin. Peroxide ingress is likely facilitated by the considerable structural degradation caused to the cuticle layers of hair fibres. The consequences of the peroxide action within the cuticle and cortex are oxidation of the proteins, and subsequent protein loss from the fibre that correlates to bleaching severity.

A highly resistant structure between cuticle and cortex of human hair.

OBJECTIVE: To clarify the presence and properties of a unique structure which is located between the cuticle and cortex of human hair. METHODS: Whole hair fibre and longitudinally split hair were used. Treated with a mixture of urea, reductant and alkaline, hair was split at the interface between cuticle and cortex. The residues in the solution were observed by microscope, and the distribution of lipids and protein was determined. RESULTS: From the treated longitudinally split hair, a membrane-like structure which was located at the interface between cuticle and cortex was obtained. This structure showed especially high resistance against chemical treatment and was thought to be the region into which the proximal roots of the cuticle cells are embedded. It was supposed that some steryl glucoside-like lipid, of which the presence in the cuticle and cortex interface was previously reported, is located in this structure. CONCLUSION: This study proposed the presence of a membrane-like structure, which is highly resistant against chemical treatment, at the region between cuticle and cortex of human hair. This may protect cortex from external stimuli more firmly than the surface part of cuticle.

Towards a body hair atlas of women of caucasian ethnicity.

OBJECTIVE: A preliminary study was conducted in 17 female volunteers (mean age 29.8 years) to gain deeper insights into the characteristics of terminal Caucasian female body hair of different body parts. The focus on Caucasian women was driven by the high number of different scalp hair phenotypes in this ethnicity and intended to identify relevant differences between body areas to improve body hair removal approaches. METHODS: Multiple growth parameters and structural parameters were assessed for hair on the upper arm, forearm, upper leg, lower leg, axilla and intimate area and compared to scalp data. RESULTS: In particular, macroscopic and much less microscopic or hair surface properties differ strikingly in the investigated body areas. Hair density on the body is much lower than on scalp with the highest hair density in the axilla and intimate area. Multihair follicular units are described for scalp but were also found to a smaller proportion in the axilla and the intimate area. Substantial percentages of hair triplets are only found on the scalp and intimate area. Hair diameter is highest in the intimate area, followed by axillary and lower leg hair and correlates with a faster hair growth rate. The angle of emerging hair is smallest in the intimate area, axilla and on the lower leg. Hair shafts on the lower leg and in the axilla have most overlapping cuticle layers, but independent of body region, no significant differences in the mean thickness of cuticle layers were detectable. In addition, no differences were found in the mean distance between cuticle layer edges along the hair shaft and the hair surface roughness. Hair on the scalp, forearm, upper arm and upper leg had an almost round shape, whereas hair of the lower leg, intimate area and axilla had more elliptical shape. Hairs on the arm showed the highest luminance values and no visible medulla. The darkest hairs were in the axilla and intimate area containing the highest level of visible medulla in hair shafts. CONCLUSION: To our knowledge, this is the first systematic study comparing terminal hair properties in all cosmetically relevant body regions in Caucasian women.

Synchrotron nanoscopy imaging study of scalp hair in breast cancer patients and healthy individuals: Difference in medulla loss and cortical membrane enhancements.

Nanoscopic synchrotron X-ray imaging was performed on scalp hair samples of patients with breast cancer and healthy individuals to investigate any structural differences as diagnostic tool. Hair strands were divided into 2-3 segments along the strands from root to tip, followed by imaging either in projection or in CT scanning with a monochromatic 6.78-keV X-ray using zone-plate optics with a resolving power of 60 nm. All the examined cancer hairs exhibited medulla loss with cancer stage-dependent pattern; complete loss, discontinuous or trace along the strands. In contrast, medullas were well retained without complete loss in the healthy hair. In the CT-scanned axial images, the cortical spindle compartments had no contrast in the healthy hair, but appeared hypointense in contrast to the surrounding hyperintense cortical membrane complex in the cancer hair. In conclusion, observation of medulla loss and cortical membrane enhancements in the hair strands of breast cancer patients demonstrated structural variations in the cancer hair, providing a new platform for further synchrotron X-ray imaging study of screening breast cancer patients.

Optical coherence tomography using images of hair structure and dyes penetrating into the hair.

BACKGROUND/PURPOSE: Hair dyes are commonly evaluated by the appearance of the hair after dyeing. However, this approach cannot simultaneously assess how deep the dye has penetrated into hair. METHODS: For simultaneous assessment of the appearance and the interior of hair, we developed a visible-range red, green, and blue (RGB) (three primary colors)-optical coherence tomography (OCT) using an RGB LED light source. We then evaluated a phantom model based on the assumption that the sample's absorbability in the vertical direction affects the tomographic imaging. RESULTS: Consistent with theory, our device showed higher resolution than conventional OCT with far-red light. In the experiment on the phantom model, we confirmed that the tomographic imaging is affected by absorbability unique to the sample. Furthermore, we verified that permeability can be estimated from this tomographic image. We also identified for the first time the relationship between penetration of the dye into hair and characteristics of wavelength by tomographic imaging of dyed hair. CONCLUSION: We successfully simultaneously assessed the appearance of dyed hair and inward penetration of the dye without preparing hair sections.

A Case of Hair Structure Abnormality Associated with Iron Deficiency Anaemia

Iron deficiency has been discussed as an etiologic factor in diffuse alopecia. Although the mechanism of alopecia related to iron deficiency remains unknown, the diagnosis is confirmed if hair loss ceases with iron administration. However, hair structure abnormalities due to iron deficiency are less known. We report a case of hair structure abnormality associated with iron deficiency anaemia. The hair structure abnormality was a fusiform and expanded node of the hair shaft. The hair loss ceased and the abnormality was corrected with iron administration.