TiO2 modified orthocortical and paracortical cells having enhanced photocatalytic degradation and photoreduction properties.

In this study, cortical cells resultant from wool fibers were loaded with TiO2 nanoparticles in a hydrothermal process and were then engineered as organic-nonorganic hybrid composite photocatalysts for both photodegradation of organic dyes and photoreduction of heavy metal ions. The microstructure and photocatalytic properties of TiO2 modified cortical cells (i.e. both orthocortical and paracortical cells) were systematically characterized using a series of analytical techniques including FESEM, TEM, element analysis, Mott-Schottky curve, BET specific surface area, Zeta potentials, as well as XRD, FTIR, XPS, DRS, PL, UPS, EDS and ESR spectra. Their photocatalytic performance and trapping experiments of the TiO2 modified cortical cells were measured in the photodegradation of methylene blue (MB) dye and Congo Red (CR) dye as well as the photoreduction of Cr(VI) ions under visible light irradiation. It was found that anatase TiO2 nanoparticles were chemically grafted on the surface of the two cortical cells via O-Ti4+/O-Ti3+ bonds, and that TiO2 nanoparticles were formed inside the orthocortical cells in the hydrothermal process. The TiO2 modified orthocortical and paracortical cells possessed much higher photocatalytic efficiency than the commercially available TiO2 nanoparticle powder, Degussa P25, in the photodegradation of cationic MB dye and photoreduction of Cr(VI) ions, while their photocatalytic efficiency in the photodegradation of anionic CR dye is smaller because of their greater negative Zeta potentials and photogenerated holes as the main reactive radical species. In comparison with the TiO2 modified paracortical cells, the higher photocatalytic efficiency of the TiO2 modified orthocortical cells was demonstrated in the photodegradation of MB dye solution and this might be due to both the S-doped TiO2 nanoparticles infiltrated into the naturally hydrophilic orthocortical cells and the primary reactive radical species of photogenerated holes being trapped in the cells.

Exploring differentially expressed genes between anagen and telogen secondary hair follicle stem cells from the Cashmere goat (Capra hircus) by RNA-Seq.

Hair follicle stem cells (HFSCs) have been shown to be essential in the development and regeneration of hair follicles (HFs). The Inner Mongolia Cashmere goat (Capra hircus) has two types of HFs, primary and secondary, with cashmere being produced from the secondary hair follicle. To identify the genes associated with cashmere growth, transcriptome profiling of anagen and telogen secondary HFSCs was performed by RNA-Seq. The RNA-Seq analysis generated over 58 million clean reads from each group, with 2717 differentially expressed genes (DEGs) detected between anagen and telogen, including 1500 upregulated and 1217 downregulated DEGs. A large number of DEGs were predominantly associated with cell part, cellular process, binding, biological regulation and organelle. In addition, the PI3K-Akt, MAPK, Ras and Rap1 signaling pathways may be involved in the growth of HFSCs cultured in vitro. The RNA-Seq results showed that the well-defined HFSC signature genes and cell cycle-associated genes showed no significant differences between anagen and telogen HFSCs, indicating a relatively quiescent cellular state of the HFSCs cultured in vitro. These results are useful for future studies of complex molecular mechanisms of hair follicle cycling in cashmere goats.

A somewhat unexpected result from the deconvolution of DSC curves for human hair: There is no apparent relation between cortical cell fractions and hair curliness.

A deconvolution process has been developed for curves obtained by differential scanning calorimetry in water for Merino wool and the main ethnic hair types. This enables estimation of the fractions of ortho- and para-type cell groups. The results also indicate that hair may contain a further, low-sulphur subgroup of ortho-type cells. The sizes of the major cell fractions are in line with expectations from microscopical investigations. The fractions are comparable for hair types, and no consistent association between cell-type fractions and hair curvature is observed.

The degree of acute descending control of spinal nociception in an area of primary hyperalgesia is dependent on the peripheral domain of afferent input.

Descending controls of spinal nociceptive processing play a critical role in the development of inflammatory hyperalgesia. Acute peripheral nociceptor sensitization drives spinal sensitization and activates spino-supraspinal-spinal loops leading to descending inhibitory and facilitatory controls of spinal neuronal activity that further modify the extent and degree of the pain state. The afferent inputs from hairy and glabrous skin are distinct with respect to both the profile of primary afferent classes and the degree of their peripheral sensitization. It is not known whether these differences in afferent input differentially engage descending control systems to different extents or in different ways. Injection of complete Freund's adjuvant resulted in inflammation and swelling of hairy hind foot skin in rats, a transient thermal hyperalgesia lasting <2 h, and longlasting primary mechanical hyperalgesia (≥7 days). Much longer lasting thermal hyperalgesia was apparent in glabrous skin (1 h to >72 h). In hairy skin, transient hyperalgesia was associated with sensitization of withdrawal reflexes to thermal activation of either A- or C-nociceptors. The transience of the hyperalgesia was attributable to a rapidly engaged descending inhibitory noradrenergic mechanism, which affected withdrawal responses to both A- and C-nociceptor activation and this could be reversed by intrathecal administration of yohimbine (α-2-adrenoceptor antagonist). In glabrous skin, yohimbine had no effect on an equivalent thermal inflammatory hyperalgesia. We conclude that acute inflammation and peripheral nociceptor sensitization in hind foot hairy skin, but not glabrous skin, rapidly activates a descending inhibitory noradrenergic system. This may result from differences in the engagement of descending control systems following sensitization of different primary afferent classes that innervate glabrous and hairy skin.

Study of wool characteristics in the aranese ovine breed / Estudio de las características de la lana en la raza ovina aranesa

To date, no ethnological study on the wool characteristics of the Spanish Aranese ovine breed has been published. Fifty three animals belonging to this breed are tested as fleece samples. Each sample is analyzed for fleece type and length, yield by isoalcohol scouring, fiber length for each kind of fiber, variation in fiber diameter, and proportions of non-medullated and medullated or kemp fibers. Fiber length appears shorter than that previously reported for the breed by other authors. Fleeces of the Aranese sheep breed can be described as square, simple, "semi-open" and short with a relatively high yield by isoalcohol scouring and low medullation levels, thus indicating good potential quality and greater suitability for potential processing than other similar meat breeds.

Hasta el momento, ningún estudio etnológico sobre las características de la lana de la variedad española ovina Aranesa ha sido publicado. Cincuenta y tres animales de esta raza han sido analizados a partir de muestras de su vellón. Cada muestra se analizó para el tipo de vellón y longitud, su rendimiento mediante isoalcohol desgrasado, longitud de las fibras para cada tipo de fibra, variación en el diámetro de la fibra, y las proporciones de fibras no meduladas y meduladas o fibras kemp. La longitud de las fibras parece más corta que la reportada para esta raza por otros autores. El vellón de la raza ovina Aranesa se puede describir como cuadrado, simple, "semi-abierto" y corto, con un rendimiento relativamente alto por desengrasado mediante isoalcohol y bajos niveles de medulación, lo que indica la buena calidad potencial y mayor oportunidad para el procesamiento potencial que otras razas similares de carne.

Cytotoxicity study of high temperature wool (HT wool) by cell magnetometric evaluation.

OBJECTIVES: We performed a cytotoxicity study by cell magnetometry, measured lactate dehydrogenase (LDH) activity by enzyme assay, detected DNA ladder formation, and performed morphological examination by electron microscopy in order to evaluate the safety of high temperature wool (HT wool), an asbestos substitute, using long and short chrysotile fibers (CF) as positive controls and phosphate buffered saline (PBS) as a negative control. METHODS: Alveolar macrophages were isolated from male Fisher rats. Following the addition of iron oxide particles (Fe(3)O(4)) to macrophages, HT wool, long or short CF was added. Then, the remanence strength was measured for 20 min after magnetization by an external field. Percent LDH release was calculated after determining LDH activity. DNA was detected using an apoptosis detection kit. Morphological observation was performed by taking electron micrographs of macrophages in the groups treated with HT wool and long- and short-CF. RESULTS: Rapid relaxation, an indicator of decay of cytotoxicity, was observed by cell magnetometry immediately after magnetization was ended in the groups treated with HT wool and PBS, showing that HT wool causes no harmful effect on the cytoskeleton. The CF-treated groups had higher LDH activity than the PBS- and HT wool-treated groups. No fragmentation of DNA was observed in any group. In morphological observation, cytotoxicity in macrophages was lower in the HT wool-treated groups than in the CF-treated groups. CONCLUSIONS: The results suggest that HT wool has no cytotoxicity, as evaluated by cell magnetometry, enzyme assay, DNA ladder detection and morphological examination.

Protein expression in orthocortical and paracortical cells of merino wool fibers.

Crimp and bulk, important wool fiber properties, are thought to be related to differences in the protein composition of the orthocortex and paracortex. Fiber morphological studies have demonstrated that the paracortex has a higher proportion of matrix and cysteine than the orthocortex. While there is some evidence for the differential expression of genes between these cell types in the follicle, this has not been demonstrated satisfactorily in the mature fiber. Using proteolytic digestion of wool fibers, followed by ultrasonic disruption to obtain relatively pure fractions of both cell types, the KAP3 high sulfur protein family was found to be present in higher concentrations in the paracortex. This significant finding provides an explanation for the higher cysteine content reported in the paracortex. This represents an advance in our understanding of protein expression variation in the orthocortex and paracortex, and how this relates to key physical and mechanical properties of wool fibers.

Cortical cell types and intermediate filament arrangements correlate with fiber curvature in Japanese human hair.

Naturally straight and curved human scalp hairs were examined using fluorescence and electron microscopy techniques to determine morphological and ultrastructural features contributing to single fiber curvature. The study excluded cuticle and medulla, which lack known bilateral structural asymmetry and therefore potential to form curved fibers. The cortex contained four classifiable cell types, two of which were always present in much greater abundance than the remaining two types. In straight hair, these cell types were arranged annularly and evenly within the cortex, implying that the averaging of differing structural features would maintain a straight fiber conformation. In curved fibers, the cell types were bilaterally distributed approximately perpendicular to fiber curvature direction with one dominant cell type predominantly located closest to the convex fiber side and the other, closest to the concave side. Electron tomography confirmed that the dominant cell type closest to the convex fiber side contained discrete macrofibrils composed of helically arranged intermediate filaments, while the dominant cell type closest to the concave side contained larger fused macrofibrils composed of intermediate filament arrangements varying from helical to hexagonal arrays approximately parallel to the longitudinal fiber axis. These findings concur with the current hypothesis of hair curvature formation and behavior.

Characterization of the exocuticle a-layer proteins of wool.

The outermost protein layer of wool cuticle cells is known as the exocuticle a-layer. This layer is a resistant barrier to the degradation of the fibre and, as a result, little is known of its proteinaceous composition. Merino wool fibres were subjected to both proteolytic and chemical digestion and the resulting material was found by transmission electron microscopy to be highly enriched in a-layer. Amino acid analysis revealed a high cysteine and glycine content, with a close, but not exact, match to the Allwörden membrane. Subsequent digestion of the a-layer preparation by 2-nitro-5-thiocyano-benzoic acid produced a large number of short peptides, and analysis by mass spectrometry revealed peptides with strong homologies to cuticular ultra-high sulphur proteins of sheep wool and cuticular ultra-high and high-sulphur proteins of human hair, thus supporting other evidence for the presence of these sulphur-rich proteins in the a-layer.

The differential expression of proteins in the cortical cells of wool and hair fibres.

Three different cell types have been identified in the cortex of wool: orthocortex, mesocortex and paracortex. Fine wool fibres, particularly Merino sheep, are noted for their bilateral distribution of orthocortical and paracortical cells, with the latter following the concave side of the crimp wave. Furthermore, studies have indicated that the paracortex has a higher concentration of cysteine than the orthocortex. This has been supported by in situ hybridization studies in the follicle that have shown that sulphur-rich proteins are initially expressed on the paracortical side of the fibre, with some becoming more uniformly spread, laterally, over the entire fibre as the keratinization process progresses. In contrast, proteins high in glycine and tyrosine tend to be expressed initially on the orthocortical side of the follicle. While these in vitro studies have pointed to where specific proteins are located in the follicle, elucidating the situation for the mature fibre has been less easy. A range of approaches have been used to separate orthocortical and paracortical cells and these have only been able to provide evidence for a higher level of cysteine in the latter. Electrophoretic studies have found a number of differences in protein expression between the two sides but have not specifically identified which proteins. Thus, there appears to be good evidence for the paracortex containing a higher proportion of proteins in the ultra-high sulphur class but there is some uncertainty regarding the exact distribution of proteins high in glycine and tyrosine.

The three-dimensional arrangement of intermediate filaments in Romney wool cortical cells.

The three-dimensional orientation and arrangement of intermediate filaments in Romney wool ortho-, meso-, and paracortical cells has been revealed using single axis high voltage electron tomography. Modelled tomograms confirm that intermediate filaments in orthocortical cells are arranged helically, with the helical angle progressively increasing from the centre to the periphery of macrofibrils. Intermediate filaments in meso- and paracortical cells display parallel arrangements differing mainly in packing density, with the mesocortex packed more tightly than the paracortex. The intermediate filament arrangements observed confirm expectations based on earlier two-dimensional transmission electron microscopy observations by the authors and other researchers. It is expected that these findings will contribute to a better understanding of the biological and structural basis of wool fibre curvature.

In vitro assembly and structure of trichocyte keratin intermediate filaments: a novel role for stabilization by disulfide bonding.

Intermediate filaments (IF) have been recognized as ubiquitous components of the cytoskeletons of eukaryotic cells for 25 yr. Historically, the first IF proteins to be characterized were those from wool in the 1960s, when they were defined as low sulfur keratins derived from "microfibrils." These proteins are now known as the type Ia/type IIa trichocyte keratins that constitute keratin IF of several hardened epithelial cell types. However, to date, of the entire class of >40 IF proteins, the trichocyte keratins remain the only ones for which efficient in vitro assembly remains unavailable. In this paper, we describe the assembly of expressed mouse type Ia and type IIa trichocyte keratins into IF in high yield. In cross-linking experiments, we document that the alignments of molecules within reduced trichocyte IF are the same as in type Ib/IIb cytokeratins. However, when oxidized in vitro, several intermolecular disulfide bonds form and the molecular alignments rearrange into the pattern shown earlier by x-ray diffraction analyses of intact wool. We suggest the realignments occur because the disulfide bonds confer substantially increased stability to trichocyte keratin IF. Our data suggest a novel role for disulfide bond cross linking in stabilization of these IF and the tissues containing them.

Wool follicle matrix cells: culture conditions and keratin expression in vitro.

Wool follicle matrix cell cultures were initiated as explants from Tukidale (carpet wool) sheep primary follicle bulbs after removal of the outer root sheath. Successful explantation required coculture on collagen with intact dermal papillae. Cells had a typical epidermal morphology (pavements of flattened. polyhedral cells). Extracellular matrix from dermal papillae, conditioned media, separation of dermal papilla from bulb matrices by tissue culture inserts and feeder layers were unable to support matrix cell explantation. Cultures could be maintained for up to 14 passages during which time the cells became larger with an increased cytoplasmic/nuclear ratio and irregular outline. Proliferation of matrix cells was greater on laminin than with either collagen type I or type IV. Proliferation was considerably reduced under serum-free conditions. This was most apparent at low calcium (0.09 mmol/L). By Northern hybridization matrix cells were found to express keratin K18 at all stages of culture. Keratin K 1.15 expression was evident by the tenth passage. The wool-specific keratin K2.10 was not detected. The data demonstrate that successful wool matrix cell culture is achievable. Keratin gene expression occurs in these cells and varies with the stage of culture.

The effects of fibroblast growth factors 1 and 2 on fibre growth of wool follicles in culture.

The effects of fibroblast growth factor-1 (FGF-1) and FGF-2 on fibre growth and follicle function were examined using a previously described procedure to culture wool follicles. Because the FGFs bind to glycosaminoglycan components of the extra-cellular matrix, we also investigated interactions between FGF-1 and FGF-2 with heparin on wool fibre growth. Individual follicles were microdissected from Merino sheepskin and transferred to culture. Follicles increased in length for 6 days, and in all groups, no significant differences in follicle length were observed. Increase in follicle length was associated with fibre growth, follicles maintained normal anagen morphology and incorporated [3H]thymidine into the bulb and outer root sheath cells. Follicles in all treatments continued to produce fibre keratins, as detected by immunohistochemistry. However, the patterns of fibre and cytoskeletal proteins incorporating [35S]methionine in control and treated follicles were significantly different. We found a considerable decrease in the intermediate filament keratins or low sulphur proteins in follicles cultured in the presence of FGF-1 and FGF-2 compared to controls. The majority of proteins detected in these samples were acidic high sulphur proteins. These studies provide evidence for a specific role for the fibroblast growth factors in the regulation of fibre differentiation.

A continuum mechanics approach to determining the cellular velocity field with a wool follicle.

A model, based on the principles of continuum mechanics, is presented for the analysis of cell-velocity fields within wool follicles. The model requires specification of three follicle characteristics in the form of spatially varying fields: viscosity, cell density and cell production rate. The viscosity is introduced as an attempt to model both complex intercellular interactions and individual cell deformation as the cells move. It is demonstrated that the distribution of cell production is more important than axial variation in viscosity in determining the overall flow pattern.

Effects of epidermal growth factor and transforming growth factor alpha on the function of wool follicles in culture.

The development of a procedure to culture wool follicles from Merino sheep in serum-free conditions has enabled us to investigate the actions of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) on follicle function, including fibre growth. Follicles grown in the absence of growth factors maintained their anagen morphology for 6 days as determined by light microscopy. During this time they incorporated [3H]thymidine into the DNA of the bulb matrix and outer root sheath (ORS) cells and produced fibre keratins as detected by immunohistochemistry. In the presence of EGF and TGF alpha, fibre production ceased after 4 days, as it does following the administration of EGF in vivo. Cessation of fibre growth was not accompanied by regression of the follicle bulb which occurs in vivo. Follicle length growth did not differ significantly from controls and cells in the bulb continued to proliferate. Usually, the structure of the dermal papillae resembled that in control follicles, which was also in marked contrast to changes reported in vivo. In EGF- and TGF alpha-treated follicles, [3H]thymidine continued to be incorporated into DNA of the ORS and bulb after fibre growth ceased. Although wool keratin synthesis ceased, cytokeratins of the epidermis and ORS continued to be produced in the bulb as detected by immunochemistry. These bulb cells were also positive for the periodic acid-Schiff (PAS) reaction indicating the presence of glycogen, a normal component of ORS cells. The observations that cell proliferation continued in the bulb, that glycogen was present and that soft keratins were expressed in these cells suggest that the bulb cell population was induced to differentiate into an ORS phenotype by EGF and TGF alpha.

Dietary cysteine regulates the levels of mRNAs encoding a family of cysteine-rich proteins of wool.

The abomasal or intravenous infusion of sulphur-containing amino acids such as cysteine or methionine into sheep on low-quality diets increases the sulphur content of the wool by increasing the synthesis of proteins containing a cysteine content of approximately 30 mol %. To investigate the molecular and cellular basis of this nutritional effect, quantitative analyses of wool keratin mRNA and protein levels, and follicle cortical cell type, were undertaken in sheep intravenously infused with cysteine. Northern blot analyses revealed that the mRNA levels of one gene family encoding cysteine-rich keratin-associated proteins (KAP4 family) expressed in the wool follicle cortex, increased approximately 5-6 times. Furthermore, the response was rapid as the mRNA levels increased approximately 3.5 times after 1 d of the cysteine infusion and, by 1 d post-infusion, they had fallen, approaching their basal level. No changes in the mRNA levels encoding the intermediate filament or the other keratin-associated protein families of lower cysteine content were observed. Concomitantly, two-dimensional polyacrylamide gel electrophoresis analysis of wool proteins showed a striking increase in the abundance of a group of cysteine-rich keratin-associated proteins in the wool by the end of the infusion period, returning to basal levels by 3 weeks later. At the cellular level, KAP4 expression was localized to the follicle paracortical cells, and the proportion of paracortical cells and the extent of KAP4 expression paralleled the changes in the cysteine infusion status of the sheep.

Differential lectin binding to presumptive cortical cells of the wool follicle bulb.

An alpha-D-galactoside-specific lectin from Bandeiraea simplicifolia (BSLI) showed differential binding to cortical cells of the wool follicle bulb. The lectin bound to cells on one side only of the bulb and was completely blocked by alpha-D-galactose. The region of lectin binding extended from presumptive cortical cells at the base of the bulb to cortical cells at the top of the bulb, disappearing as cortical cells entered the fibre cortex. An orthocortex-specific monoclonal antibody was used to show that cortical cells recognised by the lectin lie directly below the fibre orthocortex and presumably give rise to the orthocortex. The results suggest that two distinct populations of presumptive cortical cells are present only two to three cell layers from the base of the bulb in a region where no morphological differences are detectable. The lectin-bound pre-cortical cells appear to give rise to orthocortical cells while cells not bound by lectin presumably give rise to paracortical cells. Electron microscopy showed that the lectin bound to sites on the plasma membrane, probably on the extracellular surface. This suggests that the lectin target may be a membrane glycoprotein or glycolipid. Two polypeptides recognised by BSLI were separated from wool follicle extracts by SDS-gel electrophoresis. These polypeptides migrated at approximately 69 kDa and 17 kDa. However, only the 69 kDa molecule showed the expected loss of binding by BSLI in the presence of alpha-D-galactose. Further work will be required to determine if this glycoprotein is the bulb cell molecule recognised by BSLI.(ABSTRACT TRUNCATED AT 250 WORDS)

Apoptosis in wool follicles during mouse epidermal growth factor (mEGF)-induced catagen regression.

Depilatory infusions of mouse epidermal growth factor (mEGF) induced regressive involution (catagen) in the wool follicles of Merino sheep. The follicles were examined by transmission electron microscopy prior to infusion and at intervals during catagen regression in order to determine the mechanism(s) involved in follicle involution. Cell deletion by apoptosis occurred in all cell types in the proximal region of catagen follicles between 12 h and 6 days after the beginning of infusion. Apoptosis also occurred in the basal layer of involuting sebaceous glands at 2 and 3 days, following earlier mEGF-induced proliferation. This process involved nuclear chromatin condensation and margination in single, scattered cells which subsequently fragmented and were ultimately phagocytosed and degraded by adjacent unaffected cells. It was concluded that during mEGF-induced catagen, wool follicle involution was accomplished largely through cell death and deletion by apoptosis.

Localization of low-sulfur keratin proteins in the wool follicle using monoclonal antibodies.

Monoclonal antibodies that recognize components of the low-sulfur keratin proteins extracted from Merino wool have been used to locate these components within the wool follicle. Immunoblotting procedures showed that all of the monoclonal antibodies bound more than one of the eight low-sulfur protein components, indicating that these proteins have antigenic determinants in common. Immunofluorescence studies showed that those antibodies specific for the component 7 family of the low-sulfur proteins bound to the developing wool fiber, whereas those antibodies recognizing the component 8 family bound to areas throughout the wool follicle, particularly the inner and outer root sheaths, but also to the fiber, the cuticle, and the epidermis. One of the monoclonal antibodies also bound to intermediate filament networks of cultured human epithelial cells.