Artificial nerve graft constructed by coculture of activated Schwann cells and human hair keratin for repair of peripheral nerve defects

Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.

TOTAL AND METHYL MERCURY LEVELS IN HUMAN SCALP HAIRS

The contents of total and methyl mercury in scalp hair samples of 1179 fishermenliving at a typical Hg-polluted region in Northeast China and 27 lying-in womenand their new born babies in Beijing have been determined by illstrumental neutronactivation analysis, gas chromatography (electron coupling) and other techniqlles.Only 18 of all fishermen have the Hg contents above 5 ig/g, which indicates that theHg pollution there has been substantially alleviated. The longitudinal Hg patternsof the lying-in women show a gradually lowering tendency during pregnant period.Further, the Hg contents of the new-born babies are generally above or close to those oftheir mothers, confirming the mechanism that the methyl Hg, an organic species of Hgwith high toxicity, is readily able to penetrate the placental barrier and accumulatedin fetus. Thus, the mercury poison hajs occurred at the early stage of pregnancy.

Flavonoids in safflower extract reduce cisplatin-induced damage to human follicle dermal papilla cells by inhibiting DNA damage and Rad17/Chk1/Cdc25C signaling

Background:Cisplatin is a chemotherapeutic agent commonly used clinically for the treatment of various human cancers.Patients often reduce the use of cisplatin due to its side effects,which in turn affects its treatment.This study explored the mechanism of action of safflower extract as an adjuvant traditional Chinese medicine for chemotherapy.Methods:Primary human follicle dermal papilla cells(HFDPCs)were used as target cells for cisplatininduced damage to hair cells.Western blotting was used to investigate the molecular targets of cisplatin and safflower extract in causing HFDPCs damage.Cell survival and cell cycle were analyzed by mitochondrial staining reagent WST-1 and propidium iodide.Results:Cisplatin could reduce the viability of HFDPCs without causing cell death.Cisplatin increased the level of phospho-Rad17 in HFDPCs and activated the Chk1/Cdc25C signaling to reduce the expression of Cdc2 protein,thereby arresting the cells in the G2/M phase.The combination of safflower extract and the flavonoids could effectively inhibit the signal transduction of Rad17/Chk1/Cdc25 in cisplatin-treated cells and reduce the cell population in the G2/M phase.Finally,we also confirmed that safflower extract could effectively inhibit the damage to HFDPCs caused by cisplatin,mainly at the level of reducing the DNA damage caused by cisplatin.Conclusions:Safflower extract can be used as an adjuvant Chinese medicine for chemotherapy to reduce the damage caused by chemotherapy to normal hair follicle cells.

Human hair follicle-derived mesenchymal stem cells:Isolation,expansion,and differentiation

Hair follicles are easily accessible skin appendages that protect against cold and potential injuries.Hair follicles contain various pools of stem cells,such as epithelial,melanocyte,and mesenchymal stem cells(MSCs)that continuously self-renew,differentiate,regulate hair growth,and maintain skin homeostasis.Recently,MSCs derived from the dermal papilla or dermal sheath of the human hair follicle have received attention because of their accessibility and broad differentiation potential.In this review,we describe the applications of human hair follicle-derived MSCs(hHF-MSCs)in tissue engineering and regenerative medicine.We have described protocols for isolating hHF-MSCs from human hair follicles and their culture condition in detail.We also summarize strategies for maintaining hHF-MSCs in a highly proliferative but undifferentiated state after repeated in vitro passages,including supplementation of growth factors,3D suspension culture technology,and 3D aggregates of MSCs.In addition,we report the potential of hHF-MSCs in obtaining induced smooth muscle cells and tissue-engineered blood vessels,regenerated hair follicles,induced red blood cells,and induced pluripotent stem cells.In summary,the abundance,convenient accessibility,and broad differentiation potential make hHF-MSCs an ideal seed cell source of regenerative medical and cell therapy.

FT-IR Microspectroscopic Imaging of Cross-Sectioned Human Hair during a Bleaching Process

We investigated bleached human hair by FT-IR microspectroscopy and chemical imaging. The cross sectioned hair is approximately 90 μm in diameter, showed cuticle and cortex in chemical imaging. Differential amide I/II absorbance ratio and broadening amide I band between in the cortex and cuticle were confirmed in FT-IR microspectroscopy and chemical imaging. The cystine monoxide band from the products of disulfide oxidation of the amino acid cystine is associated with hair damaging during bleaching process. With increase bleaching time, the band for cystine monoxide shows more intense and larger area in chemical image. The spatially chemical change was investigated in detail by FT-IR microspectroscopy and chemical imaging during the bleached process.

Ultrastructural analysis shows persistence of adhesion and tight junction proteins in mature human hair

The differentiation of cells composing mature human hairs produces layers with different corneous characteristics that would tend to flake away one from another,as in the corneous layer of the epidermis,without anchoring junctions.It is likely that cell junctions established in the forming cells of the hair bulb are not completely degraded like in the corneous layer of the epidermis but instead remain in the hair shaft to bind mature cuticle,cortex,and medulla cells into a compact hair shaft.During cell differentiation in hairs,cell junctions seem to disappear,and little is known about the fate of junctional proteins present in the mature human hair shaft.The present ultrastructural immunogold study has detected some marker proteins of adhesion junction(cadherin and beta-catenin)and tight junctions(occludin and cingulin)that are still present in cornified hairs where numerous isopeptide bonds are detected,especially in the medulla.This qualitative ultrastructural study indicates that aside from the cell membrane complex,a long corneo-desmosome bonding cortex and cuticle cells,also sparse adherens and tight junction remnants are present.It is suggested that the cornification of these junctions with the incorporation of their proteins within the mature corneous material of the hair shaft likely contributes to maintaining the integrity of the mature hair.This information will also allow us to evaluate the effects of different chemical components present in hair formulations and stains on these junctional proteins and the consequent integrity of the hair shaft.

Degradation of human hair keratin scaffold material used to repair injured skeletal muscles of rabbits

Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (composed of 3 different types of HHK material with varied degradation speed) after musclectomy were divided into 3 groups (2 in each group) to observe the degradation of the material at 1, 3, 6weeks after operation. Another rabbit without operation was used as the control group. The degradation of HHK was observed with light microscopy, histochemistry of ubiquitin and electron microscopy. Results:Light microscopy showed that human hair cuticles fell off from the HHK material and emerged, and the macrophagocytes and multinucleate giant cells were attached onto the surface of the material, which became homogeneous at the first postoperative week. The HHK scaffold material was degraded into particles that was phagocytosed by macrophagocytes and multinucleate giant cells at the third week. Ubiquitin enzymatic histochemistry showed that the macrophagocytes and the multinucleate giant cells were positive at the first week. Under electron microscope, HHK scaffold material was degraded into particles, and at the sixth week,part of HHK scaffold material was further degraded. Conclusion: Large mass of the HHK scaffold material is degraded via ubiquitin system, and the resultant particles are phagocytosed and degraded with the cooperation of lysosome and ubiquitin.

Peripheral nerve repair by conduits made of human hair keratin: An experimental study

Objective: To explore the method to repair injured peripheral nerve using conduits made of human hair keratin (HHK). Methods: The tibial nerves of rabbits were transected leaving a gap 10 mm in length between the 2 severed ends, which were either routinely sutured or bridged using HHK nerve conduits. Electro-physiological , anatomical and histological examinations were performed at different time postoperatively. Results: Electrophysiological study showed more obvious improvement in the neural function recovery in rabbits with HHK conduits bridging as compared with that in rabbits with routine suture. In the former group, HHK conduits were gradually degraded and absorbed with large amount of myelinated nerve fibers and Schwann cells regenerated around HHK conduits. In the latter group, however, the nerve tissues around the suture were degenerated and replaced by connective tissues. Conclusion: HHK may induce the regeneration of the nerve fibers and provides an ideal approach to repair nerve damages.

Human hair follicle-derived mesenchymal stem cells promote tendon repair in a rabbit Achilles tendinopathy model

Background:Hair follicles are easily accessible and contain stem cells with different developmental origins,including mesenchymal stem cells(MSCs),that consequently reveal the potential of human hair follicle(hHF)-derived MSCs in repair and regeneration.However,the role of hHF-MSCs in Achilles tendinopathy(AT)remains unclear.The present study investigated the effects of hHF-MSCs on Achilles tendon repair in rabbits.Methods:First,we extracted and characterized hHF-MSCs.Then,a rabbit tendinopathy model was constructed to analyze the ability of hHF-MSCs to promote repair in vivo.Anatomical observation and pathological and biomechanical analyses were performed to determine the effect of hHF-MSCs on AT,and quantitative real-time polymerase chain reaction,enzyme-linked immunosorbent assay,and immunohistochemical staining were performed to explore the molecular mechanisms through which hHF-MSCs affects AT.Furthermore,statistical analyses were performed using independent sample t test,one-way analysis of variance(ANOVA),and one-way repeated measures multivariate ANOVA as appropriate.Results:Flow cytometry,a trilineage-induced differentiation test,confirmed that hHF-derived stem cells were derived from MSCs.The effect of hHF-MSCs on AT revealed that the Achilles tendon was anatomically healthy,as well as the maximum load carried by the Achilles tendon and hydroxyproline proteomic levels were increased.Moreover,collagen I and III were upregulated in rabbit AT treated with hHF-MSCs(compared with AT group;P<0.05).Analysis of the molecular mechanisms revealed that hHF-MSCs promoted collagen fiber regeneration,possibly through Tenascin-C(TNC)upregulation and matrix metalloproteinase(MMP)-9 downregulation.Conclusions:hHF-MSCs can be a treatment modality to promote AT repair in rabbits by upregulating collagen I and III.Further analysis revealed that treatment of AT using hHF-MSCs promoted the regeneration of collagen fiber,possibly because of upregulation of TNC and downregulation of MMP-9,thus suggesting that hHF-MSCs are more promising for AT.

Mercury in soil,vegetable and human hair in a typical mining area in China:Implication for human exposure

Concentrations of total mercury（T-Hg） and methylmercury（MeHg） in soil, vegetables, and human hair were measured in a mercury mining area in central China. T-Hg and MeHg concentrations in soil ranged from 1.53 to 1054.97 mg/kg and 0.88 to 46.52 μg/kg, respectively.T-Hg concentrations was correlated with total organic carbon（TOC） content（R^2= 0.50, p〈0.01）and pH values（R^2= 0.21, p〈0.05）. A significant linear relationship was observed between MeHg concentrations and the abundance of sulfate-reducing bacteria（SRB）（R^2= 0.39, p〈0.05） in soil.Soil incubation experiments amended with specific microbial stimulants and inhibitors showed that Hg methylation was derived from SRB activity. T-Hg and MeHg concentrations in vegetables were 24.79 – 781.02 μg/kg and 0.01 – 0.18 μg/kg, respectively; levels in the edible parts were significantly higher than in the roots（T-Hg： p〈0.05; MeHg： p〈0.01）. Hg species concentrations in rhizosphere soil were positively correlated to those in vegetables（p〈0.01）, indicating that soil was an important source of Hg in vegetables. Risk assessment indicated that the consumption of vegetables could result in higher probable daily intake（PDI） of T-Hg than the provisional tolerable daily intake（PTDI） for both adults and children. In contrast, the PDI of MeHg was lower than the reference dose. T-Hg and MeHg concentrations in hair samples ranged from 1.57 to 12.61 mg/kg and 0.04 to 0.94 mg/kg, respectively, and MeHg concentration in hair positively related to PDI of MeHg via vegetable consumption（R^2= 0.39, p〈0.05）, suggesting that vegetable may pose health risk to local residents.

Effect of Miscanthus sinensis var.purpurascens Flower Extract on Proliferation and Molecular Regulation in Human Dermal Papilla Cells and Stressed C57BL/6 Mice

Objective： To investigate the hair growth-promoting effect of Miscanthus sinensis var.purpurascens（MSP） flower extracton on in vitro and in vivo models.Methods： MSP flower extract was extracted in 99.9% methanol and applied to examine the proliferation of human dermal papilla cells（h DPCs） in vitro at the dose of 3.92-62.50 μg/m L and hair growth of C57 BL/6 mice in vivo at the dose of 1000 μg/m L.The expression of transforming growth factor β1（TGF-β1）,hepatocyte growth factor（HGF）,β-catenin,substance P was measured by relative quantitative realtime polymerase chain reaction.Histopathological and immunohistochemical analysis were performed.Results： MSP（7.81 μg/m L） down-regulated TGF-β1 and up-regulated HGF and β-catenin in h DPCs（P〈0.01）.MSP（1000 μg/m L）-treated mice showed the earlier transition of hair follicles from the telogen to the anagen phase.The number of mast cells was lower in the MSP-treated mice than in other groups（P〈0.05 vs.NCS group）.Substance P and TGF-β1 were expressed in hair follicles and skin of the MSP group lower than that in negative control.Stem cell factor in hair follicles was up-regulated in the MSP-treated mice（P〈0.01）.Conclusion： The MSP flower extract may have hair growth-promotion activities.

Identification of adrafinil and its main metabolite modafinil in human hair.Self-administration study and interpretation of an authentic case

For several years,the misuse of stimulant substances is increasingly observed both in the field of sport,to improve the functions of the body and therefore to be more performant,and also by non-athletes to make life more tolerable on a daily basis.Adrafinil,2-((diphenylmethyl)sulfinyl)-N-hydroxyacetamide,is a drug designed for the treatment of narcolepsy by promoting an awakened state,and to treat alertness and neurological symptoms in the elderly.It is primarily metabolized in vivo to an active form,i.e.modafinil,2-((diphenylmethyl)sulfinyl)acetamide.The World Anti-Doping Agency(WADA)banned these two drugs in sports in 2004.The authors report an authentic case involving adrafinil and modafinil.The laboratory was requested to test for adrafinil in a hair strand collected from a woman found in posses-sion of vials of adrafinil and suspected of trafficking.A specific method was developed by liquid chromatography tandem mass spectrometry(LC-MS/MS).Unlike modafinil(varying from 6.8 to 13.9ng/mg),adrafinil was not identified in the strand.The interpretation of the results was difficult because this is the first case describing human hair analysis.In order to be able to interpret the results,a self-administration study was conducted after an oral administration to a volunteer(200 mg)whose beard hair was collected 10days after adminis-tration.The analysis of this specimen highlighted the presence of adrafinil at 0.8ng/mg and modafinil at 0.5 ng/mg.These results demonstrate the dual identification of both compounds after a single consumption,even after administration of a low dose.According to these results,the analysis of the hair strand from the authentic case does not match with a con-sumption of adrafinil,in accordance with abuse of modafinil alone.Intelligence considered that this was a trafficking case of adrafinil,with no self-consumption.

Relationship between selenium concentration in child hair and the distribution of Kashin-Beck Disease in Tibet, China

The focus of this study is to determine the relationship between selenium(Se)concentrations in child hair and the distribution of Kashin-Beck disease(KBD)in Tibet.The hair of children in typical KBD-affected areas and non-disease areas was collected,and its Se concentrations were measured by atomic fluorescent spectrometry.The Se concentrations in child hair were(0.13±0.04)and(0.18±0.07)μg/g respectively in KBD areas and non-disease areas respectively,which are significantly different.In areas supplemented with Se in Tibet,the Se concentration of hair in KBD-affected areas was higher than that in non-diseased areas,being(0.28±0.03)and(0.18±0.04)μg/g respectively.There is a close relationship between the Se concentrations in hair and KBD distribution.Se supplement increase the Se concentrations in the human body.Appropriate Se supplementation is important to prevent KBD in Tibet.