Translational bioengineering strategies for peripheral nerve regeneration:opportunities,challenges,and novel concepts

Peripheral nerve injuries remain a challenging problem in need of better treatment strategies.Despite best efforts at surgical reconstruction and postoperative rehabilitation,patients are often left with persistent,debilitating motor and sensory deficits.There are currently no therapeutic strategies proven to enhance the regenerative process in humans.A clinical need exists for the development of technologies to promote nerve regeneration and improve functional outcomes.Recent advances in the fields of tissue engineering and nanotechnology have enabled biomaterial scaffolds to modulate the host response to tissue repair through tailored mechanical,chemical,and conductive cues.New bioengineered approaches have enabled targeted,sustained delivery of protein therapeutics with the capacity to unlock the clinical potential of a myriad of neurotrophic growth factors that have demonstrated promise in enhancing regenerative outcomes.As such,further exploration of combinatory strategies leveraging these technological advances may offer a pathway towards clinically translatable solutions to advance the care of patients with peripheral nerve injuries.This review first presents the various emerging bioengineering strategies that can be applied for the management of nerve gap injuries.We cover the rationale and limitations for their use as an alternative to autografts,focusing on the approaches to increase the number of regenerating axons crossing the repair site,and facilitating their growth towards the distal stump.We also discuss the emerging growth factor-based therapeutic strategies designed to improve functional outcomes in a multimodal fashion,by accelerating axonal growth,improving the distal regenerative environment,and preventing end-organs atrophy.

沙颍河铅污染对儿童GH-IGF-1轴和体格发育的影响

目的：探讨沙颍河铅污染现状及其对儿童生长激素-胰岛素样生长因子-1（ GH-IGF-1）轴和体格发育的影响。方法：随机选择淮河沙颍河流域S县两个村庄作为调查点（依距河岸距离远近分别定为对照区和污染区）；原子吸收分光光度法检测河水和调查点饮用水及土壤中的铅含量。整群抽取两村庄小学8～13岁在校学生作为研究对象，伏安极谱法测定儿童血清铅含量；ELISA法检测儿童血清胰岛素样生长因子-1（ IGF-1）、胰岛素样生长因子结合蛋白3（IGFBP3）、生长激素（GH）和生长激素结合蛋白（GHBP）水平；电子体重计、身高坐高计、皮褶厚度计及Gulick卷尺分别测量体重、身高、皮褶厚度和胸围。结果：河水3个采样断面铅浓度均超过国家地表水水质标准Ⅴ级。污染区饮用水及土壤铅含量均高于对照区（ t＝2．663和2．300，P＜0．05）。污染区儿童血清铅含量高于对照区儿童（t＝3．227，P＝0．002）。污染区男孩身高、体重、皮褶厚度、胸围与对照区比较差异均无统计学意义（P均＞0．05）。两区女孩身高、体重和胸围差异均无统计学意义（P均＞0．05），但污染区女孩皮褶厚度高于对照区（t＝3．036，P＝0．003）。结论：沙颍河流域的饮用水中铅含量明显升高，污染区儿童血清GH-IGF-1轴相关因子水平受到影响。

支气管肺发育不良患儿血浆及支气管肺泡灌洗液中TGF-β_1和KL-6水平变化的意义

目的观察支气管肺发育不良(BPD)患儿机械通气前血浆转化生长因子β1(TGF-β1)、Ⅱ型肺泡细胞表面抗原(KL-6)水平,探讨其与BPD患儿肺发育不成熟度的关联,了解BPD患儿不同机械通气时段血浆及支气管肺泡灌洗液(BALF)TGF-β1、KL-6水平的动态变化在机械通气肺损伤中的意义。方法入选早产患儿90例,分为3组,每组30例,分别为早产非机械通气组(早产儿不予机械通气)、机械通气非BPD组(早产非BPD患儿予机械通气)、机械通气BPD组(早产BPD患儿予机械通气),另选足月健康新生儿30例作为正常对照组。ELISA法测定机械通气早产患儿通气前、非机械通气早产患儿、健康新生儿血浆及机械通气早产患儿通气1、24、48、72 h血浆及BALF中TGF-β1、KL-6水平。结果 (1)机械通气前,机械通气BPD组血浆TGF-β1水平明显高于机械通气非BPD组及早产非机械通气组、正常对照组,差异有统计学意义(P<0.01),通气前血浆TGF-β1水平与胎龄呈显著负相关(r=-0.274,P<0.05),4组患儿KL-6差异无统计学意义(P>0.05)。通气初始(通气1h),机械通气BPD组BALF中TGF-β1明显高于机械通气非BPD组,差异有统计学意义(P<0.01)。通气1 h BALF TGF-β1水平与胎龄呈显著负相关(r=-0.238,P<0.05)。(2)随着通气持续时间的延长,予机械通气的两组患儿血浆及BALF中TGF-β1、KL-6逐渐上升,机械通气BPD组至48 h后TGF-β1、KL-6水平与通气1 h时比较差异有统计学意义(P<0.01),机械通气非BPD组血浆TGF-β1水平至48 h、BALF TGF-β1至72 h后与通气1 h时比较差异有统计学意义(P<0.05),血浆KL-6水平至72 h后与通气1 h时比较差异有统计学意义(P<0.05),BALF KL-6各通气时段变化差异无统计学意义(P>0.05)。(3)不同通气时段机械通气BPD组血浆及BALF TGF-β1水平均高于同时段机械通气非BPD组,差异有统计学意义(P<0.05);KL-6水平,通气1、24 h与非BPD患儿差异无统计学意义(P>0.05),48、72 h均高于非BPD患儿,差异有统计学意义(P<0.05)。(4)血浆中与BALF中TGF-β1水平相关性回归方程为y=0.772 3x+10.664,呈显著正相关(r=0.853,P<0.01);血浆中与BALF中KL-6水平相关性回归方程为y=0.986 3x-16.195,呈显著正相关(r=0.937,P<0.01)。结论机械通气前血浆及机械通气初始BALF高水平的TGF-β1可能与BPD患儿肺发育不成熟度相关。而动态观测机械通气早产患儿血浆及BALF中TGF-β1及KL-6水平,有助于监测机械通气肺损伤的发生发展。血浆与BALF中TGF-β1、KL-6检测具有良好相关性,动态观测BALF中TGF-β1、KL-6水平,对BPD早期诊断、治疗监测具有更为广阔的临床应用前景。

急性脑出血患者血清HIF-1α与VEGF、Hsp70动态表达情况研究

目的:研究分析急性脑出血患者血清低氧诱导因子(hypoxia-inducible factor-1α,HIF-1α)与血管生长因子(vascular endothelial growth factor,VEGF)、热休克蛋白70(heat shock protein 70,Hsp70)动态表达情况。方法:将2014年3月至2015年4月我院急诊收治的35例急性脑出血患者,根据其出血量分为小量组、中量组、大量组,测定比较各分组人员发病后12 h、1 d、3 d、5 d、7 d的静脉血HIF-1α与VEGF、Hsp70差异,同时研究分析这3者与出血量之间的相关关系。结果:大量组患者不同时间点HIF-1α与VEGF、Hsp70指标均明显高于同时间点其他两组患者,P<0.05;单因素方差分析HIF-1α与VEGF、Hsp70与患者出血量间关系,均成正相关(r=0.563,P<0.05;r=0.771,P<0.05;r=0.602,P<0.05)。结论:HIF-1α、VEGF、Hsp70在急性脑出血患者中表达较高,在脑出血12 h后升高,并随着脑出血的发展呈现动态表达,且与出血量成正相关关系。

EXPRESSION OF GROWTH FACTORS AFTER ANGIOPLASTY

Objective To eoplore ulhether or not growth factors are involved in the restenosis afterangioplasty .Methods A rabbit model of atherosclerosis was established with cholesterol feeding after iliacartery injury made with an inflated balloon catheter. Then balloon angioplasty was made. Expression oftransforming growth factor /β1(TGF-β1), epidermal growth factor receptor (EGFR), and basic fibroblast growthfactor (bFGF) mRNA was observed in rabbit iliac artery before and after balloon angioplasty with hybridization ofNorthern blot and reverse transcription polymerase chain reaction. Results Expression of TGF- β1. EGFR andbFGF mRNA in rabbit iliac artery was significantly increased 1 week and 2 weeks after angioplasty in comparisonwith that before angioplasty, Conclusion TGF-β1, EGFR and bFGF may be involved in the restenosis afterangioplasts.

晚期肺癌患者化疗前后血浆转化生长因子β1水平变化

目的：探讨晚期肺癌患者化疗前后血浆转化生长因子β1（TGF-β1）水平变化及其临床意义。方法：采用ELISA法检测37例肺癌患者化疗前、第1周期化疗后、第2周期化疗后及23例健康者血浆TGF-β1水平。结果：肺癌患者化疗前血浆TGF-β1水平明显高于正常对照组（Z＝3．581，P＜0．001）。肺癌患者不同年龄、性别、病理类型、临床分期组间比较，血浆TGF-β1水平差异无统计学意义。肺癌患者化疗2周期后，进展组血浆TGF-β1水平明显升高（t ＝3．067，P＝0．018）；部分缓解组、稳定组血浆TGF-β1水平无明显变化（P＞0．05）。第2周期化疗后，以120．85 ng/L为临界值，血浆TGF-β1水平用于预测疗效的灵敏度为85．71％，特异度为63．64％[AUC（95％CI）＝0．711（05．34～0．875）]。第2周期化疗后，以157．28 ng/L为临界值，血浆TGF-β1水平用于预测病情变化的灵敏度、特异度分别可达81．50％、82．76％[AUC（95％CI）＝0．875（0．737～1．013）]。结论：血浆TGF-β1水平可以对化疗疗效及病情变化起到一定预测作用。

LRG1 promotes corneal angiogenesis and lymphangiogenesis in a corneal alkali burn mouse model

AIM:To investigate the potential effect and mechanism of leucine-richα-2-glycoprotein-1(LRG1)on corneal angiogenesis and lymphangiogenesis.METHODS:Corneal neovascularization and lymphatics were induced by establishing alkali burn mouse model.Immunofluorescence staining was performed to detect the location of LRG1 in cornea tissues and to verify the source of LRG1-positive cells.Corneal whole-mount staining for CD31(a panendothelial cell marker)and lymphatic endothelial hyluronan receptor-1(LYVE-1;lymphatic marker)was performed to detect the growth of blood and lymphatic vessels after local application of exogenous LRG1 protein or LRG1 si RNA.In addition,expressions of the proangiogenic vascular endothelial growth factor(VEGF)related proteins were detected using Western blot analysis.RESULTS:LRG1 was dramatically increased in alkali burned corneal stroma in both the limbal and central areas.LRG1-positive cells in the corneal stroma were mainly derived from Vimentin-positive cells.Local application ofexogenous LRG1 protein not only aggravated angiogenesis but also lymphangiogenesis significantly(P<0.01).LRG1 group upregulated the levels of VEGF and the vascular endothelial growth factor receptor(VEGFR)family when compared with the phosphate-buffered saline(PBS)control group.We also found that LRG1-specific si RNA could suppress corneal angiogenesis and lymphangiogenesis when compared with the scramble si RNA-treated group(P<0.01).CONCLUSION:LRG1 can facilitate corneal angiogenesis and lymphangiogenesis through heightening the stromal expression of VEGF-A,B,C,D and VEGFR-1,2,3;LRG1-specific si RNA can suppress corneal angiogenesis and lymphangiogenesis in corneal alkali burn mice.

糖网明目颗粒不同提取部位对缺氧诱导的血管内皮细胞中相关基因表达的影响

目的探讨糖网明目颗粒不同提取部位对缺氧诱导的人脐静脉内皮细胞EA.hy926中相关基因表达的作用机制。方法以COCl2干预细胞复制缺氧模型,人脐静脉内皮细胞EA.hy926分为空白组、缺氧模型组、全方组、部位1组(苷类和黄酮类)、部位2组(有机酸和多糖类)和部位3组(生物碱类)。采用半定量RT-PCR检测糖网明目颗粒不同提取部位对缺氧诱导细胞中血管内皮细胞生长因子(VEGF)及其受体(VEGFR)1、2和细胞间黏附分子(ICAM)-1、白细胞介素(IL)-1α基因表达的变化。结果缺氧导致EA.hy926细胞VEGF、VEGFR-1、VEGFR-2、ICAM-1、IL-1α基因表达上调(P<0.05),VEGFR-1/VEGFR-2比值降低。糖网明目颗粒及其不同提取部位干预细胞后,VEGF、VEGFR-1、VEGFR-2、ICAM-1、IL-1α基因表达降低(P<0.05),VEGFR-1/VEGFR-2比值升高。结论糖网明目颗粒中苷类和黄酮类、生物碱类及有机酸和多糖类调控缺氧诱导的血管内皮细胞基因表达的作用强度依次减弱。

吸入环孢素A对大鼠肺纤维化的干预作用

目的 :研究吸入环孢素A(CsA)对大鼠肺纤维化的干预作用及可能的作用机制。方法 :Wistar大鼠经气管内注入博莱霉素诱导肺纤维化 (M组 ) ,实验组 (A组 )次日雾化吸入CsA进行干预 ,对照组 (C级 )用生理盐水。各组注药后 7d和 2 8d分别处死 5只。测肺系数 ,观察肺泡炎及肺纤维化的程度。检测血及肺泡灌洗液 (BALF)中单核细胞趋化因子 1(MCP 1)和转化生长因子 β(TGF β)。 结果 :M组、A组与C组比较肺系数明显增加 (P <0 .0 5 )。C组肺泡结构正常 ,M组 7d时以肺泡炎改变为主 ,2 8d时广泛性肺纤维化为主。A组病理改变与M组相似 ,但程度较轻。 7d时血清TGF βM组明显高于C组及A组 (P <0 .0 1)。 2 8d时血清及BALF中TGF βM组明显高于C组及A组 (P <0 .0 1) ;MCP 1血清中M组明显高于C组及A组 (P <0 .0 5 ,) ;BALF中M组及A组明显高于C组 (P <0 .0 1)。结论 :雾化吸入CsA能减轻大鼠肺纤维化 ,可能通过抑制TGF β和MCP

生物标志物在口腔鳞癌治疗中的转化研究进展

生物标志物是用以标志某一正常或异常生物现象、健康或者疾病的存在于组织、血液或其他体液中的某种特定生物学分子。它在肿瘤研究中可分为诊断性、预后性和预测性生物标志物,其鉴定及应用对评价肿瘤的诊断、治疗、预后评估及抗药物的生物学效应都具有重要的临床价值,是现今肿瘤转化研究的重点之一。目前生物标志物的转化研究主要涉及肿瘤的诊断与分子分型、靶向治疗、治疗方案的选择与优化、预后预测等方面。本文旨在回顾生物标志物在口腔鳞癌治疗中的转化研究进展,对已上市的针对生物标志物的靶向治疗药物表皮生长因子受体抗体、程序性细胞死亡蛋白-1抑制剂的临床应用,以及作为治疗靶点的潜在生物标志物磷脂酰肌醇3-激酶、WEE1、Wnt/β-catenin通路、Sonic hedgehog通路、细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)通路等抑制剂的临床前试验以及对生物标志物在治疗方案优化的指导作用予以述评并提出未来的发展方向,为实现生物标志物指导口腔鳞癌的个体化治疗研究策略提供参考。

细胞因子抑制剂吡非尼酮对体外培养人瘢痕成纤维细胞增殖的影响

背景:有研究表明细胞因子抑制剂吡非尼酮通过调控多种细胞因子,抑制成纤维细胞的生物学活性,其在内脏器官的抗纤维化作用的研究和应用取得了良好的进展,但对于皮肤增生性瘢痕及成纤维细胞是否有影响及其机制尚不清楚。目的:观察细胞因子抑制剂吡非尼酮对人增生性瘢痕成纤维细胞增殖的影响。方法:采用组织块法培养人增生性瘢痕成纤维细胞,实验取第3-6代生长状态良好的对数生长期细胞。根据吡非尼酮不同质量浓度分为对照组(吡非尼酮0 g/L),吡非尼酮0.15,0.3,1 g/L组,共干预12,36,48 h。结果与结论:MTT,反转录-聚合酶链式反应和酶链免疫吸附实验结果显示,与对照组相比,吡非尼酮0.15,0.3,1 g/L组细胞增殖情况、转化生长因子β1 mR NA的表达、Ⅰ、Ⅲ型胶原蛋白的分泌量均降低(P<0.05),其中吡非尼酮1 g/L组降低最明显(P<0.05)。干预24,48,72 h后,吡非尼酮0.15,0.3,1 g/L组间细胞增殖抑制率、Ⅰ、Ⅲ型胶原蛋白的分泌量均差异有显著性意义(P<0.05)。结果证实,细胞因子抑制剂吡非尼酮对体外培养的人增生性瘢痕成纤维细胞胶原蛋白的分泌、转化生长因子β1的表达及细胞增殖活性有明显的抑制作用。

TGF-β1-regulated miR-3691-3p targets E2F3 and PRDM1 to inhibit prostate cancer progression

Transforming growth factor-β1(TGF-β1)acts as a tumor promoter in advanced prostate cancer(PCa).We speculated that microRNAs(miRNAs)that are inhibited by TGF-β1 might exert anti-tumor effects.To assess this,we identified several miRNAs downregulated by TGF-β1 in PCa cell lines and selected miR-3691-3p for detailed analysis as a candidate anti-oncogene miRNA.miR-3691-3p was expressed at significantly lower levels in human PCa tissue compared with paired benign prostatic hyperplasia tissue,and its expression level correlated inversely with aggressive clinical pathological features.Overexpression of miR-3691-3p in PCa cell lines inhibited proliferation,migration,and invasion,and promoted apoptosis.The miR-3691-3p target genes E2F transcription factor 3(E2F3)and PR domain containing 1,with ZNF domain(PRDM1)were upregulated in miR-3691-3p-overexpressing PCa cells,and silencing of E2F3 or PRDM1 suppressed PCa cell proliferation,migration,and invasion.Treatment of mice bearing PCa xenografts with a miR-3691-3p agomir inhibited tumor growth and promoted tumor cell apoptosis.Consistent with the negative regulation of E2F3 and PRDM1 by miR-3691-3p,both proteins were overexpressed in clinical PCa specimens compared with noncancerous prostate tissue.Our results indicate that TGF-β1-regulated miR-3691-3p acts as an anti-oncogene in PCa by downregulating E2F3 and PRDM1.These results provide novel insights into the mechanisms by which TGF-β1 contributes to the progression of PCa.

宫颈阴道分泌物非磷酸化胰岛素样生长因子结合蛋白1与残余羊水指数监测在未足月胎膜早破中的诊断价值

目的：通过对疑似未足月胎膜早破（PPROM）孕妇进行宫颈阴道分泌物非磷酸化胰岛素样生长因子结合蛋白1（IGFBP-1）与残余羊水指数（AFI）监测，探讨快速诊断 PPROM的方法，以及残余羊水对母儿预后的影响。方法采用快速层析法对96例疑似 PPROM孕妇进行宫颈阴道分泌物 IGFBP-1检测，腹部 B超监测 AFI，分析病因，比较妊娠结局及新生儿预后情况。结果92例宫颈阴道分泌物 IGFBP-1阳性者均确诊为 PPROM，导致 PPROM的危险因素主要为：生殖道感染，流产、引产史，原因不明（包括无证据的感染、胎膜发育不良或其他不明确因素），双胎、多胎、巨大儿，臀位或头盆不称，妊娠期高血压疾病，子宫肌瘤或畸形，营养不良及羊水过多。92例 PPROM孕妇，破膜至分娩时间为（105．7±13．9）h，剖宫产率为51．1％，孕妇发热率为7．6％，胎盘早剥率为4．3％，胎儿宫内窘迫发生率为14．1％，围产期感染率为21．7％，新生儿窒息率为7．6％，新生儿死亡率为7．6％。AFI≤40 mm 组与 AFI ＞40 mm 组比较，破膜至分娩时间显著缩短（t ＝10.904，P ＜0．05），新生儿死亡率显著升高（χ^2＝4．359，P ＜0．05）。结论宫颈阴道分泌物 IGFBP-1与 AFI监测，可快速诊断 PPROM，也可评估妊娠结果及新生儿预后。

Down-regulation of eIF5A-2 prevents epithelial-mesenchymal transition in non-small-cell lung cancer cells

Background:Epithelial-mesenchymal transition(EMT) is believed to be the critical process in malignant tumor invasion and metastases,and has a great influence on improving the survival rate in non-small-cell lung cancer(NSCLC) patients.Recent studies suggested that eukaryotic initiation factor 5A-2(eIF5A-2) might serve as an adverse prognostic marker of survival.We detected eIF5A-2 in NSCLC A549 cells,and found that the invasive capability correlates with the eIF5A-2 expression.Methods:Transforming growth factor(TGF)-β1 was used to induce EMT in A549 cells.Western blotting,immunofluorescence,wound healing assay,and transwell-matrigel invasion chambers were used to identify phenotype changes.Western blotting was also used to observe changes of the expression of eIF5A-2.We down-regulated the eIF5A-2 expression using an eIF5A-2 siRNA and identified the phenotype changes by western blotting and immunofluorescence.We tested the change of migration and invasion capabilities of A549 cells by the wound healing assay and transwell-matrigel invasion chambers.Results:After stimulating with TGF-β1,almost all A549 cells changed to the mesenchymal phenotype and acquired more migration and invasion capabilities.These cells also had higher eIF5A-2 protein expression.Down-regulation of eIF5A-2 expression with eIF5A-2 siRNA transfection could change the cells from mesenchymal to epithelial phenotype and decrease tumor cell migration and invasive capabilities significantly.Conclusions:The expression of eIF5A-2 was up-regulated following EMT phenotype changes in A549 cells,which correlated with enhanced tumor invasion and metastatic capabilities.Furthermore,in the A549 cell line,the process of EMT phenotype change could be reversed by eIF5A-2 siRNA,with a consequent weakening of both invasive and metastatic capabilities.

Phototropism in land plants： Molecules and mechanism from light perception to response

BACKGROUND： Phototropism is the response a plant exhibits when it is faced with a directional blue light stimulus. Though a seemingly simple differential cell elongation response within a responding tissue that results in organ curvature, phototropism is regulated through a complex set of signal perception and transduction events that move from the plasma membrane to the nucleus. In nature phototropism is one of several plant responses that have evolved to optimize photosynthesis and growth. OBJECTIVE： In the present work we will review the state of the field with respect to the molecules and mechanisms associated with phototropism in land plants. METHODS： A systematic literature search was done to identify relevant advances in the field. Though we tried to focus on literature within the past decade （1998-present）, we have discussed and cited older literature where appropriate because of context or its significant impact to the present field. Several previous review articles are also cited where appropriate and readers should seek those out. RESULTS： A total of 199 articles are cited that fulfill the criteria listed above. CONCLUSIONS： Though important numerous and significant advances have been made in our understanding of the molecular, biochemical, cell biological and physiologic mechanisms underlying phototropism in land plants over the past decade, there are many remaining unanswered questions. The future is indeed bright for researchers in the field and we look forward to the next decade worth of discoveries.