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.

Close-loop recyclable and flexible halide perovskite@wool keratin sensor with piezoelectric property

Halide perovskites with excellent piezoelectric properties,but their poor stability hinders their largescale application.Herein,a sandwich-structured halide perovskite flexible sensor with good stability was developed according to a three-step procedure as follows:(ⅰ) in-situ growth of wool keratinCsPbBr_(3)(WK-CsPbBr_(3)) using wool keratin in interfacial passivation and coating,(ⅱ) electrospinning of a wool keratin-CsPbBr_(3)/polyacrylonitrile(WCP) nanofiber film,and(ⅲ) coating of the WCP nanofiber with polydimethylsiloxane(PDMS) to obtain a sensor(WCPP).The sensor could generate a piezoelectric voltage of 7.8 V at a pressure of 6 kPa in the stages of pressing and releasing,and the output characteristics did not decline even after 10,000 cycles.Compared to the 4-month stability of the perovskite sensor,WCPP sensor exhibited the output performance even after 16 months,which indicated that wool keratin as a multidentate improved the stability of the halide perovskite.Additionally,the sensor displayed a self-cleaning property and could also light up 14 commercial LEDs.The close-loop recycling of the lead halide perovskite was achieved by dissolving the WCP nanofiber film in DMF and then reelectrospinning.Therefore,the method proposed is a step forward for achieving the commercialization of WK-CsPbBr_(3) and providing new avenues for further utilization of wool waste.

慢性异体肾移植病人肾纤维化组织中MMP-2、TIMP-1、Vimentin、Keratin免疫组化定量分析

目的:探讨慢性异体肾移植病人肾纤维化组织中基质金属蛋白酶-2(MMP-2)、金属蛋白酶抑制物(TIMP-1)、波形蛋白(Vimentin)和角蛋白(Keratin)的表达与肾纤维化间的关系。方法:收集我院18例肾移植后不同程度肾纤维化病人及10例正常肾组织,进行MMP-2、TIMP-1、Vimentin及Keratin的免疫组化定量检测分析。结果:肾纤维化早期,与正常肾组织对比,抗MMP-2和Keratin呈显较强免疫阳性反应,且量增加;随肾纤维化程度增加,抗MMP-2和Keratin免疫染色阳性反应减弱,量减少,甚至出现阴性;抗TIMP-1和Vimentin免疫染色阳性增强,并随着纤维化进展而量增加。结论:由肾纤维化组织局部Vimentin阳性与相关细胞产生并分泌的细胞因子以诱导MMP-2、TIMP-1的活性改变在慢性肾移植肾病患者的肾纤维化过程中具有关键性作用。

人细胞角蛋白Keratin 14的生物信息学分析

人细胞角蛋白Keratin 14是I型中间丝蛋白家族的亚群,参与形成上皮细胞的细胞骨架。利用生物信息学分析Keratin 14基因的启动子区、CpG岛及其所编码的蛋白质的理化性质、结构特点和功能特征。结果表明,Keratin 14基因存在两个启动子区,启动子区不存在CpG岛;Keratin 14全长472个氨基酸,其等电点为5.09,是一个无跨膜结构的亲水性蛋白质;角蛋白Keratin 14二级结构具7个α螺旋和5个β折叠,预测三级结构的拉曼图分析显示其结构稳定;与Keratin 14相互作用的蛋白质主要是角蛋白,而且Keratin 14还参与细胞的生长和分裂,有促进细胞分化的作用;此外,Keratin 14的氨基酸序列在哺乳动物间的同源性较高。上述对角蛋白Keratin 14的表达、结构和功能的预测可以为研究其在生命过程中的作用提供重要的信息。

Keratin和CEA在前列腺病变组织的分布

本文用CEA和Keratin单克隆抗体,对前列腺正常组织、结节性增生和癌各15例进行标记,其中15例前列腺癌随访2年以上,标记方法为BA法。结果,CEA在正常前列腺组织、结节性增生和癌中含量低,阳性率低,提示CEA非识别前列腺癌的理想标记物。Keratin在正常前列腺组织、结节性增生和癌的所有病例中均为阳性。三者在染色强度上无显著差异。不同分化程度的癌在染色强度上也无显著差异。Keratin广泛分布于前列腺癌的上皮细胞内,间质标记均为阴性,对鉴别前列腺上皮性和非上皮性肿瘤是有意义的。

Preparation and Characteristics of Wool Keratin Aqueous Solution and Sponge

Wool keratin has broad application prospects in biomedical materials, tissue engineering, and other fields. To obtain porous wool keratin membrane with good performance, and lay the foundation for its application in biological fields in the future, wool keratin aqueous solution and sponge were prepared and their characters were discussed. Wool fiber was dissolved with a mixture of urea, β-mercapitoethanol, sodium dodecyl sulfate(SDS) and water, and stable keratin aqueous solution was prepared through filtration and dialysis. Dissolution rate under different conditions was discussed. The results show that dissolution rate increases with the increase of dissolving temperature, reduction β-mercaptoethanol and assistant agent urea concentration and the addition of SDS. SDS polyacrylamide gel electrophoresis (SDS PAGE) shows the major molecular weight of the aqueous keratin solution is between 44300 u and 66400 u. Amino acid analysis shows the cysteine acid content of the keratin solution decreases obviously. Wool keratin sponge was made from the keratin solution with freeze drying method and its structure and characters were studied with scanning electron microscopy(SEM) and Fourier transform infrared spectrometer (FTIR). The results indicate that keratin sponge has evident pores structure, and the conformation of the sponge is β-sheet.

Keratin的分类及表达规律

中等纤维(Intermediate Filaments,IF)是细胞骨架的主要成分之一。根据IF的免疫学和生化特性可将其分为五种类型:(1)角蛋白纤维(Keratin filament):存在于上皮及上皮源性细胞;(2)波形蛋白纤维(Vimentin filament):存在于间质源性细胞;结蛋白纤维(Desmin filament):存在于肌肉细胞;(4)神经原纤维(Neurofilament):存在于中枢和周围神经系统的神经细胞;(5)胶质原纤维(Glialfilament):存在于中枢神经系统的胶质细胞中。

结直肠癌中Keratin 17的表达及其临床预后价值

目的分析角蛋白17(Keratin 17,KRT17)在结直肠癌(colorectal cancer,CRC)中的表达及其临床预后价值。方法采用生物信息学方法分析KRT17在CRC数据库中的表达及预后价值;进一步,采用免疫组织化学技术检测KRT17蛋白在95对CRC临床样本组织中的表达水平,并分析其表达与患者临床病理特征及预后的相关性。结果生物信息分析发现,KRT17在CRC组织中的表达水平显著高于正常组织,其表达与肿瘤病理类型、淋巴结转移及TNM分期相关,并预示较差的总生存期(P均<0.05)。免疫组化验证显示,与癌旁组织相比,蛋白在CRC组织中的表达显著上调(t=45.704,P<0.001),与生物信息学分析结果保持一致;KRT17高表达与肿瘤分化程度、浸润深度、淋巴结转移、TNM分期、淋巴脉管浸润及神经侵犯显著相关(P_(均 )0.05);生存分析显示,KRT17高表达组CRC患者的总生存期显著低于低表达组(χ^(2)=8.510,P=0.004);进一步的单因素和多因素分析结果表明,KRT17高表达是影响CRC患者总生存期的一个独立危险因素(HR=2.015,95%CI:1.219~4.457,P=0.018)。结论KRT17在CRC组织中表达显著上调,且其高表达预示着肿瘤进展及不良预后,有望成为CRC患者预后评估的生物标志物。

Keratin13基因在喉癌发生中的作用

目的 探讨keratin 13基因在喉癌发生中的作用。方法 在keratin 13基因内部及附近选择 5个微卫星引物进行LOH分析 ,于DNA水平间接检测 10 0例喉癌患者中该基因的缺失情况。结果 5个STR位点均存在LOH ,其中D17S196 4E、D17S2 0 92、D17S791、D17S16 6 5及D17S80 8位点的LOH频率分别为 30 4 8%、2 6 0 2 %、2 1 6 2 %、37 6 6 %和 2 1 5 1%,以D17S16 6 5位点的LOH频率最高 ,杂合性丢失与临床分期无显著相关。结论 Keratin 13基因在喉癌的发生中具有重要作用 ,具体机制有待进一步研究。

低温冷冻对皮肤α-tubulin、β-tubulin和cytoskeratin表达的影响

目的:探讨低温冷冻对皮肤骨架蛋白中α-微管蛋白(α-tubu lin)、β-微管蛋白(β-tubu lin)和高分子量角蛋白(cytoskeratin)表达的影响,从而进一步揭示皮肤低温损伤的机制。方法:用-αtubu lin、β-tubu lin、cytoskeratin抗体对5种储存条件下的皮肤作免疫组化染色,采用计算机图像分析技术进行定量分析。并进一步采用透射电镜观察-αtubu lin、β-tubu lin、cytoskeratin的超微结构的变化。结果:α-tubu lin、β-tubu lin、cytoskeratin在4℃组、-20℃组、-80℃组均表达显著下降,且超微形态结构及分布改变明显。在-196℃组储存时三种成分含量下降较少,形态改变亦不显著。结论:皮肤的低温损伤与骨架蛋白-αtubu lin、β-tubu lin、cytoskeratin的破坏有关。

Effect of glycosides of Cistanche on the expression of mitochondrial precursor protein and keratin type Ⅱ cytoskeletal 6A in a rat model of vascular dementia

Glycosides of Cistanche（GC）is a preparation used extensively for its neuroprotective effect against neurological diseases,but its mechanisms of action remains incompletely understood.Here,we established a bilateral common carotid artery occlusion model of vascular dementia in rats and injected the model rats with a suspension of GC（10 mg/kg/day,intraperitoneally）for 14 consecutive days.Immunohistochemistry showed that GC significantly reduced p-tau and amyloid beta（Aβ）immunoreactivity in the hippocampus of the model rats.Proteomic analysis demonstrated upregulation of mitochondrial precursor protein and downregulation of keratin type II cytoskeletal6A after GC treatment compared with model rats that had received saline.Western blot assay confirmed these findings.Our results suggest that the neuroprotective effect of GC in vascular dementia occurs via the promotion of neuronal cytoskeleton regeneration.

A mutation in the type Ⅱ hair keratin KRT86 gene in a Han family with monilethrix

Monilethrix, a congenital disease of hair, is usually associated with mutations in keratin genes, like KRT81, KRT83 and KRT86. We conducted this study to investigate the mutation of type Ⅱ human basic hair keratin hHb/ KRT gene in a Han family with monilethrix and obtain information for potential pathogenic mechanism study of monilethrix. Peripheral blood samples were drawn for genomic DNA detection. Exon 1 and exon 7 of the KRT81, KRT83 and KRT86 genes were amplified by PCR. All PCR products were sequenced directly using an ABI 310 DNA sequencer. These sequences were aligned with the standard sequences in GenBank using the BLAST software. PCR products were digested with restriction endonuclease and restriction fragment length polymorphism （RFLP） analysis was performed. In this study, we identified one novel mutation, which is a heterozygous transitional mutation of G→A at position 1,289 in exon 7 of the KRT86 gene [R430Q （KRT86）]. RFLP assays for the novel mutation excluded the possibility of polymorphism. The R430Q mutation of the KRT86 gene may be pathogenic for monilethrix. Meanwhile, we did not find any novel mutation or recurrent mutation in exons 1 and 7 of KRT81 and KRT83 and exon 1 of KRT86. There is a potential pathogenic gene in the subjects and our results expand the spectrum of mutations in the hHb6 gene.

Tailoring the Meso-Structure of Gold Nanoparticles in Keratin-Based Activated Carbon Toward High-Performance Flexible Sensor

Flexible biosensors with high accuracy and reliable operation in detecting pH and uric acid levels in body fluids are fabricated using well-engineered metaldoped porous carbon as electrode material.The gold nanoparticles@N-doped carbon in situ are prepared using wool keratin as both a novel carbon precursor and a stabilizer.The conducting electrode material is fabricated at 500℃ under customized parameters,which mimics A-B type(two different repeating units) polymeric material and displays excellent deprotonation performance(pH sensitivity).The obtained pH sensor exhibits high pH sensitivity of 57 mV/pH unit and insignificant relative standard deviation of 0.088%.Conversely,the composite carbon material with sp^2 structure prepared at 700℃ is doped with nitrogen and gold nanoparticles,which exhibits good conductivity and electrocatalytic activity for uric acid oxidation.The uric acid sensor has linear response over a range of 1-150 μM and a limit of detection 0.1 μM.These results will provide new avenues where biological material will be the best start,which can be useful to target contradictory applications through molecular engineering at mesoscale.

Peri-implant keratinized gingiva augmentation using xenogeneic collagen matrix and platelet-rich fibrin:A case report

BACKGROUND Keratinized gingival insufficiency is a disease attributed to long-term tooth loss,can severely jeopardizes the long-term health of implants.A simple and effective augmentation surgery method should be urgently developed.CASE SUMMARY A healthy female patient,45-year-old,requested implant restoration of the her left mandibular first molar and second molar.Before considering a stage II,as suggested from the probing depth measurements,the widths of the mesial,medial,and distal buccal keratinized gingiva of second molar(tooth#37)were measured and found to be 0.5 mm,0.5 mm,and 0 mm,respectively.This suggested that the gingiva was insufficient to resist damage from bacterial and mechanical stimulation.Accordingly,modified apically repositioned flap(ARF)surgery combined with xenogeneic collagen matrix(XCM)and platelet-rich fibrin(PRF)was employed to increase the width of gingival tissue.After 1 mo of healing,the widths of mesial,medial,and distal buccal keratinized gingiva reached 4 mm,4 mm,and 3 mm,respectively,and the thickness of the augmented mucosa was 4.5 mm.Subsequently,through the second-stage operation,the patient obtained an ideal soft tissue shape around the implant.CONCLUSION For cases with keratinized gingiva widths around implants less than 2mm􀀀the soft tissue width and thickness could be increased by modified ARF surgery combined with XCM and PRF.Moreover,this surgery significantly alleviated patients’pain and ameliorated oral functional comfort.

An ultrasonic-ionic liquid process for the efficient acid catalyzed hydrolysis of feather keratin

A novel efficient method for hydrolyzing feather keratin using an ultrasonic-ionic liquid coupling process has been developed, with reaction conditions optimized using response surface analysis of data obtained from single factor optimization studies. Ultrasonic irradiation(225 W power) of feathers in 8.4 mol·L^(-1) hydrochloric acid containing 1-butyl-3-methylimidazolium chloride as a cosolvent at 80 °C for 1.4 h, followed by heating at 110 °C for 8.3 h, resulted in hydrolysis of their keratin component in an excellent 83.1% yield. Compared with previous methods, this new method employs reduced amounts of hydrochloric acid, shorter reaction time, and affords amino acid hydrolysis products in higher yield.

Festosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling

Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor （AR） protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B （Krt33b）. Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.

Fabrication and Evaluation of Porous Keratin/chitosan(KCS) Scaffolds for Effectively Accelerating Wound Healing

Objective To develop a dressing with desired antibacterial activity, good water maintaining ability and mechanical properties for wound healing and skin regeneration. Methods The chitosan with different concentrations were added in keratin solution to form porous keratin/chitosan（KCS） scaffolds. The morphological characteristics, chemical composition, wettability, porosity, swelling ratio and degradation of the scaffolds were evaluated. The antibacterial activity was tested by using S. aureus and E. coli suspension for 2 h. And L929 fibroblast cells culture was used to evaluate the cytotoxicity of the KCS scaffolds. Results The adding of chitosan could increase the hydrophobicity, decrease porosity, swelling ratio and degradation rate of the KCS porous scaffolds. Mechanical properties of KCS scaffolds could be enhanced and well adjusted by chitosan. KCS scaffolds could obviously decrease bacteria number. The proliferation of fibroblast cells in porous KCS patch increased firstly and then decreased with the increase of chitosan concentration. It was appropriate to add 400 μg/m L chitosan to form porous KCS scaffold for achieving best cell attachment and proliferation compared with other samples. Conclusion The porous KCS scaffold may be used as implanted scaffold materials for promoting wound healing and skin regeneration.

Robust Waterborne Polyurethane/Wool Keratin/Silk Sericin Freeze-Drying Composite Membrane for Heavy Metal Ions Adsorption

Wool keratin(WK)and silk sericin(SS)have the ability to interact with metal ions.In order to take advantage of this potential,a novel environmentally friendly waterborne polyurethane(WPU)/WK/SS membrane named as WPU&WK&SS membrane with crosslinked structure was constructed by freeze-drying via self-assembly style.Surface morphology and chemical structure characterization were investigated by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).In addition,the adsorption experiments of Cu2+and Cr6+were performed to evaluate the adsorption of WPU&WK&SS membrane,including adsorption kinetics,adsorption isotherm models and various factors affecting adsorption.Further investigation indicates that the maximum adsorption capacity of Cu2+and Cr6+can reach 54.21 mg·g-1and 85.21 mg·g-1,respectively,which are higher than most of the reported adsorbents.Through adsorption kinetics and thermodynamic analysis,it is find that the pseudo-second-order kinetic equation and the Langmuir adsorption isotherm model are more suitable for the static adsorption of Cu2+and Cr6+by WPU&WK&SS membrane.

Pleomorphic Adenoma with Exuberant Squamous Metaplasia and Keratin Cysts Mimicking Squamous Cell Carcinoma in Minor Salivary Gland

Salivary gland tumors, the second most common neoplasm of the mouth after squamous cell carcinoma, account for a significant proportion of tumors of the oral and perioral regions. An unusual case of adenoma presented as a solitary intraoral palatine mass in a 32-year-old woman is reported here. The tumor was interpreted as an unusual pleomorphic adenoma because of the presence of exuberant squamous metaplasia, clinically mimicking squamous cell carcinoma. Moreover, the presence of cystic structures filled with keratinized material was also salient feature. Pleomorphic adenomas may occasionally display focal squamous metaplastic changes;when extensive, it presents the potential for misinterpretation of the histology as indicative of well-differentiated squamous cell carcinoma.