Loss of Smad3 gives rise to poor soft callus formation and accelerates early fracture healing

Smad3 is an intracellular signaling molecule in the transforming growth factor β (TGF-β) pathway that serves as a regulator of chondrogenesis and osteogenesis. To investigate the role of the TGF-β/Smad3 signaling in the process of fracture healing, an open fracture was introduced in mouse tibiae, and the histology of the healing process was compared between wild-type (WT) and Smad3-null (KO) mice. In KO mice, the bone union formed more rapidly with less formation of cartilage in the callus and eventually the fracture was repaired more rapidly than in WT mice. Alkaline phosphatase staining showed that osteoblastic differentiation in the fracture callus was promoted in KO mice. Additionally, TRAP staining and the TUNEL assay revealed that the induction of osteoclasts and apoptotic cells was significantly promoted in the healing callus of KO mice. Sox9 expression clearly decreased at both mRNA and protein levels in the early stage of fracture in KO mice. In contrast, the expression of genes for osteogenesis and osteoclast formation increased from day 5 until day 14 post-fracture in KO mice compared to WT mice. From these results, we concluded that the loss of TGF-β/Smad3 signaling promoted callus formation by promoting osteogenesis and suppressing chondrogenesis, which resulted in faster fracture healing.     

LYVE-1蛋白在小鼠碱烧伤角膜的表达及意义

目的观察淋巴管内皮透明质酸受体(LYVE-1)在小鼠碱烧伤角膜内的表达情况,探讨角膜新生淋巴管形成的时间过程及角膜疾病后新生淋巴管形成的作用。方法应用NaOH溶液制作小鼠角膜碱烧伤模型,分别于角膜碱烧伤后第1d、3d、5d、7d和12d取材。采用免疫组化法,观察正常角膜和碱烧伤后不同时间段角膜内LYVE-1的表达情况。结果在正常角膜组织中,LYVE-1表达于角膜上皮细胞和内皮细胞内。在角膜碱烧伤后1d、3d和5d,LYVE-1主要表达于角膜上皮内及入侵角膜基质的炎性细胞内;碱烧伤后7d,可见大量LYVE-1呈条索样表达于角膜基质中,并可见少量LYVE-1阳性表达于开放状态的淋巴管;碱烧伤后12d,角膜基质内新生淋巴管数量增多。结论正常角膜组织储备LYVE-1生物因子,在炎性角膜中,LYVE-1可能在角膜新生淋巴管运输透明质酸(HA)的过程中发挥重要作用。     

Smad7和组蛋白去乙酰化酶1在小鼠马兜铃酸肾病中的表达

目的 探讨Smad7、组蛋白去乙酰化酶1(HDAC1)在小鼠马兜铃酸肾病(AAN)中的表达及两者在马兜铃酸肾病发生、发展中的作用.方法 将32只体重(20±2)g 的SPF(无菌)雄性昆明小鼠随机分为4组,其中3组为实验组,灌胃给予不同剂量的马兜铃酸(AA)Ⅰ,分别为4 mg/(kg·d)、8 mg/(kg·d)、16mg/(kg·d).另设对照组,PBS灌胃.应用免疫组织化学、免疫印迹法及RT-PCR技术,检测AAN小鼠和正常对照组中Smad7和HDAC1的表达情况.结果 HDAC1阳性着色主要分布于细胞核上,且在AAN中的表达强度明显高于正常对照组.免疫印迹法检测和RT-PCR提示,Smad7在AAN中的表达低于对照组,而HDAC1的表达显著高于对照组.结论 在AAN中Smad7低表达以及HDAC1高表达,提示Smad7和HDAC1可能在AAN的发生、发展中起重要作用.     

Recombinant hepatocyte growth factor accelerates cutaneous wound healing in a diabetic mouse model

We examined effects of recombinant hepatocyte growth factor (HGF) on cutaneous wound healing, using a full-thickness cutaneous excision model in diabetic mice. Topical administration of HGF, as well as basic fibroblast growth factor (bFGF), promoted the rate of wound closure and re-epithelialization. Both HGF and bFGF enhanced expansion of the granulation tissue and stimulated neovascularization on day 7 postwounding, wherein the increase in microvessel density in HGF-treated wounds was higher than that in bFGF-treated wounds. Matrix metalloproteinases (MMP-2 and MMP-9) activities involved in cell migration, angiogenesis, and extracellular matrix (ECM) remodeling, were enhanced by HGF-treatment on day 7. On day 28 postwounding (later stages of wound healing), granulation tissue in bFGF-treated wounds remained to a greater extent than that seen in saline- and HGF-treated wounds. Likewise, bFGF- but not HGF-treatment stimulated DNA synthesis of fibroblasts in granulation tissue, suggesting that HGF stimulates wound healing with lesser degree of susceptibility to cutaneous scarring. We propose that supplement of HGF may be a potential therapeutic approach for treatment of cutaneous ulcer.     

血管内皮生长因子D在小鼠碱烧伤后角膜的表达及其作用

目的观察血管内皮生长因子D(VEGF-D)在小鼠角膜碱烧伤后不同时间角膜组织内的表达,探讨VEGF-D在小鼠角膜碱烧伤后新生淋巴管形成过程中的作用。方法制作小鼠角膜碱烧伤模型,分别于碱烧伤后1d、3d、5d、7d、12d和18d取材。应用免疫组化SP法观察VEGF-D在正常角膜和碱烧伤后不同时间角膜内的表达,应用淋巴管内皮透明质酸受体1(LYVE-1)标记淋巴管,观察小鼠碱烧伤角膜内新生淋巴管的形成情况。结果碱烧伤后1d、3d、5d,角膜内VEGF-D表达水平明显高于正常角膜(P<0.01),于碱烧伤后3d,表达达到高峰。碱烧伤后7d,VEGF-D的表达下降至正常水平。在碱烧伤角膜内,可见阳性表达LYVE-1的新生淋巴管。结论 VEGF-D过表达可能参与小鼠角膜碱烧伤后新生淋巴管形成过程。     

辐照灭菌冷冻干燥羊膜修复碱烧伤

背景：经辐照灭菌的冷冻干燥羊膜便于保存和使用,但羊膜经这种方式处理后其活性是否会降低、其临床疗效是否会受到影响至今仍鲜有报道。 目的：观察辐照灭菌后的冷冻干燥羊膜对兔角膜碱烧伤的修复作用。 方法：取健康成年白兔9只,均用1 mol/L 氢氧化钠烧伤角膜后,左侧眼设为羊膜组植入辐照灭菌后的冷冻干燥的羊膜,右侧眼设为对照组不植入羊膜。植入后30 d内裂隙灯显微镜每日观察角膜透明度、角膜新生血管及角膜上皮修复情况。 结果与结论：羊膜植入后30 d,羊膜组角膜透明度、新生血管及角膜上皮修复情况明显优于对照组(P < 0.05),角膜上皮愈合好,基质纤维排列更为整齐,炎细胞浸润程度轻,新生血管更少。结果证实,兔角膜碱烧伤后植入辐照灭菌后的冷冻干燥羊膜可减轻角膜炎性反应,促进角膜上皮修复,减少角膜新生血管形成。     

人Smad7腺病毒表达载体的构建及体外表达

用DNA直接克隆连接的方法,构建人Smad7腺病毒重组质粒,再用293细胞包装。重组腺病毒经扩增、纯化后,感染体外培养的瘢痕疙瘩成纤维细胞,用RT-PCR方法检测细胞中人Smad7mRNA的转录。经酶切和PCR鉴定证实了人Smad7重组腺病毒质粒构建成功,RT-PCR证实瘢痕疙瘩细胞中有腺病毒载体介导的Smad7mRNA的过度表达。结果证实构建的人Smad7腺病毒表达载体可在体外细胞中表达,并可进一步应用于瘢痕疙瘩基因治疗方面的研究。     

Gene expression changes after exposure to six-mix in a mouse model

The exposure of Libby MT residents to amphibole-contaminated vermiculite is well known. To explore the gene-environment interactions in the development of asbestos-related diseases (ARD), a mouse model of asbestos exposure using Six-mix (a combination of amphibole fibers gathered from six sites at the Libby vermiculite mine), crocidolite asbestos, or saline as a negative control was used to determine both gene expression responses by using mouse 10,000 oligonucleotide array and to visualize these changes histologically. Mice were sacrificed and whole lungs harvested for histology and microarray analysis six months following exposure via intratracheal instillation. Using an arbitrary cutoff of 1.25-fold change, genes whose RNA expression levels were specifically altered in response to the different amphibole exposures were grouped into categories by a gene ontology analysis program, GoMiner. Our hypothesis was that assessment of asbestos-responsive genes would provide a better understanding of response mechanisms. These experiments have provided new candidates for genes involved in the asbestos response pathways.     

Smad2/3与Smad7在大鼠化疗性卵巢早衰卵泡中的表达和意义

目的 探讨顺铂对大鼠卵巢结构和功能损伤的影响及其可能的分子机制。方法 3月龄SD 雌性大鼠随机分为对照组（C组,5只）和化疗组（H组,5只）。H组给予每只大鼠腹腔注射顺铂2 mg/（kg.d）,C组给予腹腔注射等体积生理盐水,连续注射7 d后检测大鼠卵巢指数（卵巢湿重/体重）;酶联免疫吸附法检测血清雌二醇（E₂）和促卵泡刺激素（FSH）水平;苏木素-伊红染色观察卵泡发育并计数各级卵泡;免疫组织化学和Real-time PCR法检测各组Smad2、磷酸化Smad2（p-Smad2）、Smad3、磷酸化Smad3（p-Smad3）、Smad4和Smad7的蛋白和mRNA表达。结果 与C组相比,H组大鼠卵巢体积减小,生长卵泡数明显减少（P<0.05）,大鼠卵巢指数下降（P<0.05）,血清中E2水平降低和FSH水平上升（P<0.05）。免疫组织化学和Real-time PCR结果显示,Smad2（p-Smad2）、Smad3（p-Smad3）、Smad4和Smad7蛋白在卵巢各级卵泡均有表达,H组Smad2蛋白和mRNA表达增加（P<0.05）,Smad2磷酸化水平（p-Smad2）表达增高（P<0.05）;Smad3、Smad4和Smad7蛋白和mRNA表达减少（P<0.05）,p-Smad3 表达降低（P<0.05）。结论 顺铂诱导大鼠卵泡损伤并促进卵巢早衰,引起卵泡细胞内Smad2表达增加,Smad3、Smad7表达降低,Smad细胞内信号通路参与了化疗性卵巢损伤的过程。     

大鼠角膜碱烧伤后热休克蛋白70的表达

背景：角膜碱烧伤后损伤修复受许多因素的影响,热休克蛋白可促进变性、损伤蛋白质的迅速恢复或清除。 目的：观察大鼠角膜碱烧伤后热休克蛋白70的表达及其与角膜损伤修复的关系。 方法：检查大鼠眼无炎症及其他病变后,奥布卡因滴眼液点眼2次,棉签吸除结膜囊液体,将统一规格直径5 mm的滤纸片浸泡于1 mol/L NaOH溶液中10 s,然后置于大鼠角膜中央30 s制作大鼠角膜碱烧伤模型。分别于碱烧伤后6 h,1,3,7,14,21 d取材。 结果与结论：RT-PCR、免疫组织化学染色、Western blot结果均显示热休克蛋白70 mRNA和蛋白在角膜碱烧伤后1 d即开始升高,7 d时达高峰,14 d后开始下降。苏木精-伊红染色及电镜观察显示角膜损伤在烧伤后6 h即较明显,烧伤后7 d逐渐恢复。提示大鼠角膜碱烧伤后热休克蛋白70的表达与碱烧伤后角膜损伤修复过程一致,参与了大鼠角膜碱烧伤后细胞的自我保护及修复过程。     

Avastin对小鼠角膜碱烧伤后新生淋巴管形成的影响

目的观察小鼠角膜碱烧伤后新生淋巴管形成情况,探讨Avastin对小鼠角膜碱烧伤后新生淋巴管形成的影响及其机制。方法制作小鼠角膜碱烧伤模型,随机分为治疗组和烧伤组,烧伤组连续两周内每日左氧氟沙星滴眼液滴眼3次,治疗组连续两周内应用25mg/ml Avastin结膜下隔日注射5μl+每日左氧氟沙星滴眼液滴眼3次,分别于碱烧伤后3d、5d、7d、12d和18d取材。采用免疫组化法,观察VEGF-C在碱烧伤后不同时间段角膜组织内的表达;应用淋巴管内皮透明质酸受体(LYVE-1)标记淋巴管内皮,观察小鼠角膜内新生淋巴管的形成情况。结果在正常小鼠角膜组织内,VEGF-C表达于角膜上皮层和内皮层。在烧伤组碱烧伤角膜内,VEGF-C主要表达于角膜上皮细胞和角膜基质内入侵的炎性细胞,于碱烧伤后3d,VEGF-C的表达达到高峰(0.05),碱烧伤后12d,VEGF-C的表达恢复至正常水平。在治疗组碱烧伤角膜内,VEGF-C的表达在碱烧伤后3d低于烧伤组。Avastin治疗组角膜内,碱烧伤后12d见LYVE-1阳性表达开放状态的新生淋巴管,淋巴管出现的时间较烧伤组明显延迟。结论 Avastin能减少小鼠碱烧伤后角膜新生淋巴管的形成,其机制可能与抑制角膜组织内淋巴管生成因子VEGF-C的表达相关。     

重组人粒细胞集落刺激因子促进兔手术联合化疗后的切口愈合

目的 评价重组人粒细胞集落刺激因子(rhG-CSF)对手术同时使用化疗的兔切口感染程度及血管内皮生长因子(VEGF)和肿瘤坏死因子(TNF-α)的影响.方法 新西兰大白兔24只,随机分为3组,空白组单纯进行手术,常规换药;对照组和治疗组均于手术前当日给予表阿霉素静脉输注,常规换药,治疗组换药时涂抹重组人粒细胞集落刺激因子.于手术后第7天观察切口愈合等级,进行病理检查,通过免疫组化检测各组VEGF表达水平,酶联免疫吸附法检测TNF-α水平.结果 使用重组人集落刺激因子后切口愈合情况及等级均优于对照组(P＜0.05),VEGF表达水平升高,而TNF-α与对照组相比无明显差别.结论 重组人粒细胞集落刺激因子可以提高切口部位VEGF表达水平,对手术同时使用化疗的切口有促进愈合作用.     

Smad交互蛋白1在增生性瘢痕组织中的表达及其对纤维化相关因子的影响

目的研究Smad交互蛋白1（SIP1）在人增生性瘢痕组织中的表达及其对纤维化相关因子的影响。方法收集临床整形手术切取的9例患者增生性瘢痕标本及其自体正常皮肤标本。分离培养原代人增生性瘢痕成纤维细胞（HSFBs）,取第3-5代细胞用于实验。（1）免疫组织化学法检测增生性瘢痕组织标本及其自体正常皮肤组织标本中SIP1的表达情况。（2）真核表达质粒pcDNA3.1（＋）/SIP1转染HSFBs。按照随机数字表法将细胞分为6组：对照组;pcDNA3.1（＋）组（空载体组）;pcDNA3.1（＋）/SIP1组;对照＋TGF-β1组;pcDNA3.1（＋）＋TGF-β1组;pcDNA3.1（＋）/SIP1＋TGF-β1组。于转染后第48 h和72 h分别提取细胞总RNA和细胞总蛋白。应用实时荧光定量PCR法检测各组细胞α平滑肌肌动蛋白（α-SMA）及结缔组织生长因子（CTGF）的mRNA表达水平;采用Western-blotting检测α-SMA的蛋白表达水平。结果 （1）免疫组织化学染色结果显示：增生性瘢痕组织中SIP1表达明显低于自体正常皮肤组织。（2）pcDNA3.1（＋）/SIP1转染HSFBs后纤维化相关因子的表达：①α-SMA的mRNA和蛋白表达水平：与对照组和pcDNA3.1（＋）组相比,pcDNA3.1（＋）/SIP1组在mRNA和蛋白表达水平均显著下调,差异有统计学意义（P〈0.05）。当细胞给予TGF-β1刺激后,各组α-SMA表达均上调,但pcDNA3.1（＋）/SIP1＋TGF-β1组mRNA和蛋白表达水仍低于对照＋TGF-β1组,差异有统计学意义（P〈0.05）。②CTGF的mRNA表达水平：与对照组和pcDNA3.1（＋）组相比,pcDNA3.1（＋）/SIP1组在mRNA表达水平显著下调,差异有统计学意义（P〈0.05）。当细胞给予TGF-β1刺激后,各组CTGF表达均显著上调,但pcDNA3.1（＋）/SIP1＋TGF-β1组mRNA表达水仍低于对照＋TGF-β1组,差异有统计学意义（P〈0.05）。结论与正常皮肤组织相比较,SIP1在增生性瘢痕组织中低表达。SIP1基因转染HSFBs可降低纤维化相关因?     

TGF-beta 1 accelerates wound healing: reversal of steroid-impaired healing in rats and rabbits.

TGF-beta modulates events of normal wound healing through multiple pathways that influence cell infiltration, proliferation, angiogenesis, extracellular matrix synthesis and remodeling. The effects of topically applied TGF-beta 1 on wound healing in two models of healing were evaluated when the healing response was impaired by the administration of methylprednisolone to rats or rabbits. TGF-beta 1 increased the healing of linear incision wounds on rats, as measured by breaking strength, to that of normal rats. Full thickness open wounds were also created on the inner ears of rabbits to simulate a non-contracting wound with limited blood supply. Healing was further impaired by the administration of methylprednisolone. The single application of TGF-beta 1 improved the healing of open wounds. TGF-beta 1 stimulated increased granulation tissue formation, as well as reepithelialization. The amount of granulation tissue and epithelialization were similar to wounds from normal-healing control rabbits. The delayed healing caused by methylprednisolone permitted the evaluation of multiple applications of TGF-beta 1 to wounds. Two applications of TGF-beta 1 spaced 7 days apart further improved the healing response when compared to a single application. Thus, single or multiple topical applications of TGF-beta 1 reversed impaired healing conditions secondary to methylprednisolone when used on incisional or open wounds. These observations support the hypothesis that growth factors, such as TGF-beta 1, may be useful as accelerators of wound repair in patients with impaired healing conditions.     

The response of healing corneal epithelium to grooved polymer surfaces

Corneal epithelial wounds heal rapidly by the inwards growth of tissue with a contracting wound front. A synthetic polymer lens to correct refractive error (an implantable contact lens) could be incorporated into the cornea using this wound healing process. Topographical cues on the polymer surface may facilitate epithelial tissue migration over the anterior device surface. Here, silicone discs with a defined surface geometry of parallel grooves (groove and ridge widths of 1, 2, 5 and 10 microm; groove depths of 1 and 5 microm) were implanted into corneas and maintained in organ culture. The nature and rate of epithelial tissue migration over the test surfaces was monitored for 8 days and evaluated using microscopy and histology. Irrespective of the pitch, deep groove geometries directed tissue migration laterally along the grooves but this prevented contraction of the wound front and retarded migration rates. No guidance occurred on any of the shallow groove geometries but these allowed inwards radial migration with a contracting wound front and supported migration rates equivalent to a flat surface. None of the geometries tested promoted tissue migration above a flat polymer surface and data suggested that parallel grooves may not be optimal for this application.     

Fetal abnormalities produced after preimplantation exposure of mouse embryos to ammonium chloride

BACKGROUND: The aims of this study were to determine whether preimplantation exposure of mouse embryos to ammonium resulted in abnormal fetal development and to evaluate similar risks to the outcome of human assisted conception. METHODS: Mouse embryos cultured from the 1-cell stage were exposed to 0.3 mmol/l ammonium chloride for 3 days. Embryos cultured from the 2-cell stage were exposed to 0.3 or 0.6 mmol/l ammonium for 2 days. After transfer to the uteri of pseudopregnant recipient females, post-implantation development was evaluated on embryonic day 15.5 (E15.5) or E18.5. RESULTS: There was no consistent effect of preimplantation exposure to ammonium chloride on fetal or placental weights. All 101 E18.5 fetuses were normal but 5/217 E15.5 fetuses were abnormal (three exencephalic and two polydactylous), which was significantly higher than the 0/363 for the pooled groups of E15.5 control fetuses (P = 0.007). The combined E15.5 and E18.5 frequency was also significantly higher than the controls (5/318 versus 0/433; P = 0.013). CONCLUSIONS: These results support the conclusion that abnormal preimplantation culture conditions can cause fetal abnormalities in mice, but the risks may be lower than previously suggested. Further work is needed to evaluate the risk more fully but this risk should be considered when designing new strategies for human assisted conception.