巨噬细胞移动抑制因子促进肺成纤维细胞增殖和胶原合成

目的： 观察重组巨噬细胞移动抑制因子(rMIF)对人胚肺成纤维细胞（MRC-5）的作用,探讨哮喘气道重塑的发生机制。方法:不同浓度的rMIF (25-100 μg/L)分别作用于MRC-5细胞12 h、24 h或48 h,用CCK-8法测细胞增殖率,羟脯氨酸法检测细胞上清胶原水平,RT-PCR法检测Ⅰ型胶原mRNA表达,Western blotting检测成纤维细胞分泌Ⅰ型胶原。结果: 与对照组比,50 μg/L和100 μg/L的rMIF刺激24 h和48 h,显著促进MRC-5增殖(P<0.05或P<0.01)。刺激48 h后,细胞培养上清中,对照组及实验组均可检测到羟脯氨酸,100 μg/L rMIF显著促进羟脯氨酸分泌(P<0.01); rMIF能够剂量依赖地刺激Ⅰ型胶原mRNA 和蛋白合成(P<0.05或P<0.01)。结论:rMIF通过刺激成纤维细胞增殖及胶原合成,可能在哮喘气道重塑的发病机制中发挥关键作用。     

干扰素γ抑制IL-13对成纤维细胞的纤维化作用

 目的：研究干扰素γ（IFN-γ）抑制白细胞介素13（IL-13）对成纤维细胞纤维化作用的影响。方法：将成纤维细胞分为实验组和空白对照组,实验组加入IFN-γ（4×105 U/L）和IL-13（100 μg/L）,共同作用24、48和72 h后,分别用羟脯氨酸法、RT-PCR和Western blotting检测成纤维细胞分泌胶原蛋白、I型胶原α1(Col 1A1)mRNA表达和I型胶原蛋白的表达水平。另外对比空白对照组、IFN-γ组、IL-13组和IFN-γ+IL-13组72 h后Col1A1 mRNA表达和I型胶原蛋白的表达水平。结果：MTT结果表明IFN-γ浓度增加到4×105 U/L后可显著抑制成纤维细胞的增殖（P<0.01）。羟脯氨酸法检测显示48 h和72 h实验组成纤维细胞分泌的胶原蛋白含量显著低于空白对照组（P<0.05）;RT-PCR分析结果揭示48 h和72 h实验组的Col1A1 mRNA表达水平显著低于空白对照组（P<0.05）;Western blotting检测也进一步证实了48 h和72 h实验组成纤维细胞分泌I型胶原蛋白的水平显著低于空白对照组。另外各因素组对比结果显示, 72 h后IFN-γ组Col1A1 mRNA和蛋白的表达水平显著低于空白对照组（P<0.05）,IL-13组显著高于空白对照组（P<0.05）,而IFN-γ+IL-13组显著低于显著低于其它组（P<0.01）。结论：IFN-γ可抑制IL-13对成纤维细胞的纤维化作用。     

洛沙坦对急性心肌梗塞后大鼠心肌间质金属蛋白酶活性的影响

目的:探讨急性心肌梗塞后,梗塞区心肌间质金属蛋白酶(MMPs)活性的动态变化及洛沙坦对其的影响。方法:结扎SD大鼠冠状动脉前降支复制急性心梗模型,随机分成对照组和用药组。采用MPA-V型多导生物信号分析系统监测血流动力学指标;采用酶谱法测定54kD间质金属蛋白酶1(MMP-1)、58kD和62kD间质金属蛋白酶2(MMP-2)的活性;采用氯氨T法测定胶原蛋白的含量。结果:梗塞区MMPs活性表现出-过性升高,第3d比假手术组高4.5倍,第7d高6.5倍达高峰,然后下降,第14d降至2倍,第42d仍高1.5倍。用药组MMP-1比同时间点对照组降低33%,MMP-2低至50%;左室重量与体重之比(LVW/BW),第14d和第42d明显低于对照组(P<0.01);梗塞区胶原密度第42d显著低于假手术组(P<0.01)。用药组心脏舒张末期压力于第3d一过性高于对照组,第7、14、42d均低于对照组。收缩压最大上升速度高于对照组(P<0.05)。结论:心肌梗塞后梗塞区MMPs被激活,加速胶原分解代谢;洛沙坦降低MMPs活性,降低胶原分解代谢,同时抑制胶原合成代谢,使心梗后期胶原含量降低,具有改善心脏功能,保护心肌的作用更多     

核酸锁修饰的NF-κB诱捕寡核甘酸对肺泡巨噬细胞源性基质金属蛋白酶9表达的影响

目的：研究核酸锁（LNA）修饰的NF-κB诱捕寡核甘酸(ODNs)对TNF-α诱导的慢性阻塞性肺疾病(COPD)患者肺泡巨噬细胞（AM）源性MMP-9、MMP-2表达以及NF-κB活性的影响。方法:从COPD患者支气管肺泡灌洗液中分离与培养AM，脂质体转染NF-κB 诱捕 (decoy) ODNs和NF-κB 错配ODNs，接着以TNF-α刺激AM。以半定量逆转录-聚合酶链反应（RT-PCR）法检测MMP-9、MMP-2 mRNA的表达；以Western blotting检测MMP-9蛋白的表达；以凝胶阻滞分析实验（EMSA）检测NF-κB活性。结果:NF-κB decoy ODNs显著抑制TNF-α诱导的AM源性MMP-9、MMP-2 mRNA及MMP-9蛋白的表达（P<0.05）；错配ODNs则对TNF-α诱导的AM源性MMP-9、MMP-2 mRNA以及MMP-9蛋白的表达无显著影响（P>0.05）。NF-κB decoy ODNs显著降低TNF-α刺激所致的NF-κB活性水平（P<0.05），而错配ODNs则对TNF-α刺激所致的NF-κB活性水平无显著影响（P>0.05）。结论:LNA修饰的NF-κB decoy ODNs能够抑制TNF-α诱导的AM源性MMP-9和MMP-2的表达；LNA修饰和decoy ODNs为COPD的治疗提供了新的思路。     

咪达普利拉对人心脏成纤维细胞基质金属蛋白酶-2和抑制剂-2的作用及机制研究

目的：研究血管紧张素转化酶抑制剂（angiotensin converting enzyme inhibitor，ACEI）咪达普利活性代谢物咪达普利拉对白细胞介素－1β（interleukin -1β，IL-1β）诱导的心脏成纤维细胞基质金属蛋白酶（matrix metalloproteinases，MMPs）和基质金属蛋白酶2型抑制剂（type 2 tissue inhibitor of matrix metalloproteinase，TIMP-2）表达的影响及其可能机制。方法:原代人心脏成纤维细胞从美国细胞应用所购买。用RT-PCR检测心脏成纤维细胞MMP-2、MMP-9和TIMP-2 mRNA水平的变化；用凝胶酶谱法分析心脏成纤维细胞中MMP-2、MMP-9的活性；用Griess方法检测培养上清一氧化氮（nitric oxide，NO）水平。结果:通过凝胶酶谱分析，RT-PCR和Griess方法发现IL-1β能显著增加MMP-2基因转录以及活性(P<0.05)，同时也显著增加了细胞培养上清中NO的产生(P<0.05)。IL-1β的这些效应可以被咪达普利拉和外源性NO合酶抑制剂L-单甲基精氨酸（NG-methyl L-Arginine，L-NMMA）所抑制(P<0.05)，而外源性NO供体亚硝基铁氰化钠(sodium nitroprusside，SNP）可以取消咪达普利拉对于NO、MMP-2的有效作用(P<0.05)。实验中发现IL-1β以及咪达普利拉对TIMP-2基因转录无明显作用(P>0.05)。结论:咪达普利拉能通过NO途径抑制IL-1β诱导的心脏成纤维细胞MMP-2的合成和活性；提示ACEI抗心肌重塑以及心力衰竭的部分作用可能是通过MMPs途径实现的。     

酪氨酸激酶抑制剂A771726阻断IL-13对成纤维细胞的促胶原合成作用

目的:观察酪氨酸激酶抑制剂A77 1726对白细胞介素13(IL-13)促成纤维细胞胶原合成作用的影响.方法:MTF法观察不同浓度的A77 1726对成纤维细胞的增殖作用的影响.成纤维细胞分为实验组和实验对照组,实验对照组加入IL-13(100 μg/L),实验组加入A77 1726(50 μmol/L)和IL-13(100μg/L),作用24、48、72 h后,羟脯氨酸(Hyp)检测A77 1726对IL-13促进成纤维细胞分泌胶原蛋白的影响,RTPCR观察A77 1726对IL-13促进成纤维细胞Ⅰ型胶原α1基因mRNA水平表达的影响,Western blot观察A77 1726对IL-13促进成纤维细胞分泌Ⅰ型胶原蛋白的影响.结果:A77 1726可抑制成纤维细胞的增殖.羟脯氨酸检测实验组48 h组和72 h组成纤维细胞分泌胶原蛋白的含量显著低于实验对照组(P＜0.05),RT-PCR观察到实验组48 h组和72 h组成纤维细胞Ⅰ型胶原α1基因(COLIA1)mRNA表达水平显著低于实验对照组(P＜0.05),Western blot观察到实验组48 h组和72 h组成纤维细胞分泌Ⅰ型胶原蛋白的水平显著低于空白对照组(P＜0.05).结论:酪氨酸酶抑制剂A77 1726阻断IL-13对成纤维细胞的促胶原蛋白合成作用,阻断IL-13促成纤维细胞Ⅰ型胶原α1基因mRNA水平和蛋白水平的表达.     

缬沙坦对阿霉素心肌病大鼠的心脏保护作用及机制研究

目的： 探讨AT1受体阻滞剂缬沙坦对阿霉素心肌病(ADR-DCM)大鼠的心脏保护作用及其机制。方法: 雄性Wistar大鼠分3组：(1)阿霉素心肌病组(ADR-DCM，n=25)，阿霉素 2.5 mg/kg，尾静脉注射，每周1次，连续10周；(2)阿霉素心肌病+缬沙坦治疗组(ARB，n=10)， 缬沙坦 30 mg/kg，每天1次，灌胃治疗；(3)正常对照组(CON，n=10)。12周时进行超声和血流动力学检测，氯胺T法检测羟脯氨酸及胶原含量， Western印迹分析检测MMP-2、MMP-9及TIMP-1的表达，明胶酶谱法检测MMPs活性。结果: ARB组死亡率明显低于ADR-DCM组(20% vs 40%，P<0.01)。ADR-DCM组大鼠左室内径大于CON组，心功能明显低于CON组， ARB组左室内径增加程度及心功能各项指标变化低于ADR-DCM组。ADR-DCM组心肌羟脯氨酸及胶原含量高于CON组， ARB组显著低于ADR-DCM组(P<0.01)。ADR-DCM组左室心肌MMP-2、MMP-9蛋白表达及MMPs明胶酶活性明显高于CON组 (P<0.01)，ARB组MMP-2、MMP-9表达及活性明显低于ADR-DCM组(P<0.01)，而TIMP-1的表达在3组间均无显著差异(P>0.05)。结论: 缬沙坦部分通过抑制MMPs表达及活性逆转ADR-DCM左室重构，改善心功能。     

百合水溶液对麻黄素致损伤小鼠肺组织的影响

目的 探讨百合水溶液对麻黄素致损伤肺组织的影响。方法 选出生10 d的小鼠72只,随机分为空白对照组、实验对照组和百合组3组。实验对照组和百合组采用递增剂量连续（1-5,5-10,11-15d）腹腔注射（2.0、4.0、6.0 g/L）麻黄素溶液15 d（每次0.2 mL,每天两次）,百合组注射麻黄素1 h后,再灌胃0.2 mL百合水溶液,实验对照组灌胃等量的生理盐水,空白对照组腹腔注射和灌胃等量的生理盐水。用比色法检测肺组织SOD、CAT和GSH-Px活性及血浆MPO活性的变化,用石蜡包埋法和HE染色法观察小鼠肺组织结构的病理变化,用免疫组织化学法检测小鼠肺组织Bax、NF-κB蛋白表达的变化。结果 实验对照组肺组织SOD、CAT和GSH-Px活性显著降低(P<0.01或P<0.05),血浆MPO活性显著升高(P<0.01或P<0.05),肺组织出现明显病理性损伤,肺泡上皮细胞局部降解、脱落,肺泡直径和肺泡隔厚度增大 (P<0.01),肺组织Bax、NF-κB蛋白的阳性表达明显增强 (P<0.01或P<0.05)。与实验对照组相比较,百合组肺组织SOD、CAT和GSH-Px活性又升高 (P<0.01或P<0.05),血浆MPO活性又显著降低（P<0.05),肺组织损伤明显改善,肺泡上皮脱落减少,肺泡直径和肺泡隔厚度均又减小(P<0.01或P<0.05),肺组织Bax、NF-κB蛋白的阳性表达明显减弱 (P<0.01或P<0.05)。结论 百合水溶液能增强机体抗氧化能力,提高机体免疫力,抑制肺组织Bax、NF-κB蛋白的阳性表达和肺组织细胞凋亡,对麻黄素致损伤肺组织有一定的保护作用。     

透明质酸含量在浓烟吸入所致大鼠急性肺损伤中的变化

观察浓烟吸入所致大鼠急性肺损伤与透明质酸(Hyaluronic Acid,HA)、层粘蛋白（Laminin, LN）含量的关系。将SD大鼠随机分成正常对照组和吸烟后不同时间观察组。分别测定血清、肺组织和支气管肺泡灌洗液中HA及LN含量，支气管肺泡灌洗液中炎性细胞数及比例，并用光镜和电镜观察肺组织病变。结果显示，吸烟后血清和肺组织中HA含量升高，12h达到高峰。血清和肺组织中HA含量分别为（470.4±97.5）μg/L和（697.5±115.1）μg/L；对照组分别是（186.4±31.5）μg/L和（202.6±39.4）μg/L。支气管肺泡灌洗液HA在18h显著升高，而LN各组无明显变化。支气管肺泡灌洗液中细胞数在12h最多，主要是中性粒细胞。提示HA升高似可作为浓烟吸入急性肺损伤的病理指标。     

转化生长因子β1对香烟诱导的大鼠肺泡巨噬细胞γ-谷氨酰半胱氨酸合酶表达的影响

目的：探讨转化生长因子（TGF）-β1对香烟诱导的大鼠肺泡巨噬细胞γ-谷氨酰半胱氨酸合酶（γ-GCS）和活化蛋白(AP)-1亚单位c-fos mRNA及其蛋白表达的影响。方法:通过支气管肺泡灌洗获取大鼠肺泡巨噬细胞，随机分为对照组、香烟组和TGF-β1组。TGF-β1组加入终浓度为3 μg/L的TGF-β1,2 h后除对照组外，余2组均加入香烟烟雾提取物,对照组加入磷酸盐缓冲液。分别用逆转录聚合酶链式反应（RT-PCR）和免疫细胞化学方法检测肺泡巨噬细胞中γ-GCSh(重链亚单位)及c-fos mRNA和蛋白的表达。结果:香烟组γ-GCSh和c-fos mRNA及其蛋白表达水平显著高于对照组(分别P<0.05,P<0.01)。TGF-β1组γ-GCSh mRNA及其蛋白表达水平明显低于香烟组(均P<0.01)；而c-fos mRNA及其蛋白表达水平明显高于香烟组(均P<0.01)。结论:转化生长因子-β1参与香烟所致慢性阻塞性肺疾病肺氧化/抗氧化失衡的发病机制。     

Short collagen fibers provide control of contraction and permeability in fibroblast-seeded collagen gels

Tissue engineering may allow for the reconstruction of breast, facial, skin, and other soft tissue defects in the human body. Cell-seeded collagen gels are a logical choice for creating soft tissues because they are biodegradable, mimic the natural tissue, and provide a three-dimensional environment for the cells. The main drawback associated with this approach, however, is the subsequent contraction of the gel by the constituent cells, which severely reduces permeability, initiates apoptosis, and precludes control of the resulting shape and size of the construct. In this study, type I collagen gels were seeded with fibroblasts and cast either with or without the addition of short collagen fibers. Gel contraction was monitored and permeability was assessed after 7 and 14 days in culture. The addition of short collagen fibers both significantly limited contraction and increased permeability of fibroblast-seeded collagen gels. The addition of short collagen fibers had no detrimental effect on cell proliferation, and there were a high number of viable fibroblasts in gels with fibers and gels without fibers. Gels containing short collagen fibers demonstrated permeabilities that were 100 to 1000 times greater than controls and also closely maintained their casting dimensions (never less than 96% of original). By limiting contraction and maintaining permeability, the incorporation of short collagen fibers should enable the creation of larger constructs by allowing for greater nutrient diffusion, and permit the creation of more complicated shapes during gel casting.     

弹力蛋白酶和基质金属蛋白酶在肺组织破坏中协同作用的实验研究

目的：采用肺成纤维细胞三维立体培养技术，直接观察弹力蛋白酶和基质金属蛋白酶对肺的主要成分之一胶原组织的降解作用。方法： 用明胶酶谱法和Western blotting法测定MMP-1、2、 3、9和TIMP-1和2 (金属蛋白酶抑制因子), 同时测定胶原含量。结果： TNF-α和IL-1β诱导培养在立体胶原内的肺成纤维细胞产生MMP-1、3和9, 但是只引起少量胶原降解（2.8%±1.5%, P＞0.05），同时加入中性粒细胞弹力蛋白酶(NE), 结果导致胶原完全降解（Ｐ＜0.01）。NE 使MMP-1、2、3和9由非活化的形式转化为较小分子量的活化分子，同时，清除TIMP-1和2。胶原降解后基质发生强烈收缩。结论： 基质金属蛋白酶可直接降解肺内胶原和其它间质组织，导致肺组织破坏，中性粒细胞弹力蛋白酶通过活化基质金属蛋白酶引起或加速细胞外基质的破坏。基质金属蛋白酶与弹力蛋白酶的协同作用可能是肺气肿等肺组织破坏的机理。     

Modification of type I collagenous gels by alveolar epithelial cells

Contraction of type I collagen gels is an in vitro model of tissue remodeling. In addition to fibroblasts, some epithelial cells can mediate this process. We therefore hypothesized that alveolar epithelial cells might contract extracellular matrices and have the potential to directly participate in the remodeling of the lung after alveolar injury. A549 cells were plated on top of collagen gels, and the gels were floated in culture medium. A549 cells contracted the gels in a time- and cell density-dependent manner. A549 cells, as well as human bronchial epithelial cells (HBEC) and rat alveolar epithelial cells (RalvEC) contracted collagen gels more when they were plated on top of the gel than when they were embedded inside, in contrast to human fetal lung fibroblast (HFL1), which contracted more when cast inside. The amount of hydroxyproline in the collagen gels remained unchanged throughout the contraction. Anti-beta(1) integrin antibody inhibited A549 cell-mediated contraction. Transforming growth factor beta augmented the contraction by A549 cells as well as that by HBEC and HFL1. Prostaglandin E(2) inhibited the contraction by HFL1 but did not affect the contraction by A549 cells, HBEC, or RalvEC. Cytomix (a mixture of tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma) inhibited the contraction by HFL1 but strongly enhanced the contraction by A549 cells. Cytomix also caused a morphologic change of A549 cells from a polygonal to a spindle shape. Immunocytochemistry showed that cytomix induced alpha-tubulin expression in A549 cells, whereas cytokeratin, vimentin, smooth muscle actin, beta(1) integrin, and paxillin expressions were not changed. This study thus demonstrates that alveolar epithelial cells can cause contraction of extracellular matrices and that this process is modulated by exogenous mediators, which also modify the microtubular system. Such an activity might contribute to alveolar remodeling after injury.     

Thrombin and TNF-alpha/IL-1beta synergistically induce fibroblast-mediated collagen gel degradation

Degradation of preexisting and newly synthesized extracellular matrix is thought to play an important role in tissue remodeling. The current study evaluated whether thrombin and TNF-alpha/IL-1beta could collaboratively induce collagen degradation by human fetal lung fibroblasts (HFL-1) and adult bronchial fibroblasts cultured in three-dimensional collagen gels. TNF-alpha/IL-1beta alone induced production of matrix metalloproteinases (MMPs)-1, -3, and -9, which were released in latent form. With the addition of thrombin, the latent MMPs were converted into active forms and this resulted in collagen gel degradation. Part of the activation of MMPs by thrombin resulted from direct activation of MMP-1, MMP-2, MMP-3, and MMP-9 in the absence of cells. In addition, tissue inhibitor of metalloproteinase-1 production was inhibited by the combination of thrombin and TNF-alpha/IL-1beta. These results suggest that thrombin and TNF-alpha/IL-1beta synergize to induce degradation of three-dimensional collagen gels through increasing the production and activation of MMPs, and that this effect is mediated through both direct activation of MMPs by thrombin and indirectly by thrombin activation of fibroblasts. Through such mechanisms, thrombin could contribute to many chronic lung disorders characterized by tissue remodeling.     

Co-Cultured Human Mast Cells Stimulate Fibroblast-Mediated Contraction of Collagen Gels

In the current study, we asked whether mast cells might modulate remodeling of extracellular matrix by affecting fibroblast-mediated contraction of three-dimensional collagen gels. Mast cells and human lung fibroblasts were co-cultured in floating type I collagen gels. The area of the gels was measured by an image analyzer. Mast cells in co-culture augmented fibroblast contractility (P < 0.001) in a timeand concentration dependent manner. The tryptase inhibitor bis(5-amidino-2-benzimidazo-lyl)methane (BABIM) were unable to block the augmented fibroblast contractility induced by co-cultured mast cells and tryptase added alone in the culture system had no effect on contractility, suggesting that other mediators besides tryptase might be involved. The amount of collagen in dissolved gels, measured as hydroxyproline, did not change after co-culture indicating that degradation of collagen may not be a major mechanism. Our findings support the hypothesis that the activity of mast cells may drive rearrangement of extracellular matrix and this and could subsequently lead to fibrosis and tissue dysfunction.     

Mast cells enhance contraction of three-dimensional collagen lattices by fibroblasts by cell-cell interaction: role of stem cell factor/c-kit

Reorganization of the extracellular matrix is important in many biological and pathophysiological processes, including tissue remodelling, wound healing, or cancer metastasis. The ability of cultured fibroblasts to reorganize and contract three-dimensional type I collagen gels is regarded as an in vitro model for this process. In tissue fibrosis, complex interactions among fibroblasts, inflammatory cells and the extracellular matrix are taking place. Mast cells have often been discussed to play a role in several fibrotic conditions including scleroderma, scar formation, or wound healing. In this study, we examined the effects of mast cells on contraction of collagen lattices. The results demonstrate that co-culture of dermal fibroblasts with a human mast cell line (HMC-1) significantly enhanced contraction of the three-dimensional collagen lattices, whereas mast cells alone failed to contract the gel. Addition of culture supernatants of mast cells did not enhance the speed of gel contraction, indicating the importance of cell-cell contact. Morphological analysis showed that mast cells were incorporated into the lattices. Histological examination also demonstrated that within the lattices, mast cells were localized in close contact to, or attached to, fibroblasts. As fibroblasts and mast cells are known to attach via stem cell factor (SCF)/c-kit interaction when co-cultured in monolayers, we also examined the effect of antibodies against SCF and c-kit in this system. Addition of both antibodies inhibited gel contraction up to 70%. In contrast, antibodies against interleukin-4 (IL-4) and IL-4 receptor did not affect gel contraction. These results indicate that mast cells enhance fibroblast-mediated contraction of collagen lattices via direct cell-cell contact, mediated in part by SCF/c-kit interactions.     

Red blood cells stimulate fibroblast-mediated contraction of three dimensional collagen gels in co-culture

OBJECTIVE AND DESIGN: Following injury, red blood cells (RBC) may interact with extracellular matrix (ECM). In the present study we hypothesised that RBC, and soluble factors from RBC, might mediate remodelling of ECM by affecting fibroblast-mediated contraction of three dimensional collagen gels. MATERIALS AND METHODS: Human lung fibroblasts (HFL-1), were cultured together with isolated RBC, conditioned medium from RBC (RBC-CM) and hemolysed RBC in type I collagen gels. Gel contraction was determined by an image analyser. RESULTS: Both RBC, RBC-CM and hemolysed RBC stimulated gel contraction by fibroblasts (P < 0.001), compared to fibroblasts alone. The RBC-CM stimulated (P < 0.01) gel contraction in a time and concentration dependent manner. A similar effect was observed when supernatant from hemolysed RBC was tested. The production of fibronectin was increased (P < 0.01) in the co-culture system, compared to fibroblasts cultured alone. CONCLUSIONS: The present study shows that RBC can interact with mesenchymal cells in vitro. The ability of RBC to modulate fibroblast-mediated contraction in vitro, might therefore be an important mechanism regulating repair processes after injury.     

Healing and Normal Fibroblasts Exhibit Differential Proliferation, Collagen Production, α-SMA Expression, and Contraction

This study determines the differences in proliferation, collagen production, α-smooth muscle actin (α-SMA) expression, and contraction between healing and normal fibroblasts. Transected and sham-operated rat medial collateral ligaments (MCL) were used to obtain healing and normal fibroblasts, respectively. It was found that healing fibroblasts in monolayer culture proliferated 1.4-fold faster at 48 h and had 1.7-fold greater protein expression of α-SMA than normal fibroblasts. In addition, it was noted that the proliferation of healing fibroblasts in collagen gels was not significantly different from that of normal fibroblasts at 24 h, but it was at 48 h. Furthermore, in collagen gels, healing fibroblasts produced more type I collagen than normal fibroblasts and generated 1.6- and 1.7-fold larger contractile forces at 15 and 20 h, respectively, than their normal counterparts. Taken together, the results of this study show that healing fibroblasts possess a differential proliferation, α-SMA protein expression, and contraction than normal fibroblasts.