木瓜蛋白酶酶解鱼鳞提取胶原蛋白的工艺研究

用木瓜蛋白酶水解鱼鳞提取胶原蛋白,对影响酶解过程的的主要因素(酶量、温度、底物浓度)分别作为单因素进行了实验。并通过正交实验得到鱼鳞胶原蛋白提取条件的优化组合,同时对提取物进行了分析检测。结果表明,木瓜蛋白酶对鱼鳞有较好的水解效果,酶用量宜采用4g/L,最佳温度为60℃,底物浓度宜选择20%。     

TNF-α和IL-13对人肺成纤维细胞胶原蛋白生成的影响

以胶原蛋白过量沉积为主要特征的纤维化是临床肺部疾患常见的病理现象。该研究利用RT-PCR技术检测不同剂量TNF-α和IL-13对人肺成纤维细胞IL-13Rα1、IL-13Rα2和Ⅰ型胶原蛋白转录水平的影响;ELISA检测细胞培养上清sIL-13Rα2分泌量;羟脯氨酸法定量分析各组肺成纤维细胞胶原蛋白生成情况。结果发现:在实验剂量条件下,TNF-α和IL-13对人肺成纤维细胞IL-13Rα1的表达无显著影响;两者均能不同程度地上调IL-13Rα2的表达;与对照组相比,TNF-α对胶原蛋白的表达有下调作用,IL-13则无显著影响。     

碱性成纤维细胞生长因子对激光烧伤大兔皮肤愈合的影响分析

摘要 目的：探讨碱性成纤维细胞生长因子对激光烧伤大兔皮肤愈合的影响分析。方法：通过热辐射仪激光灼烧对大兔耳朵进行烧伤处理,根据实验需求,将其随机分为三组：对照组,bFGF组,bFGF + DAPT组。通过ImageJ软件测量伤口面积和疤痕组织的厚度,并定期计算残余伤口面积率和疤痕指数。通过组织学分析大兔伤口愈合的新血管生成量。通过蛋白印迹分析Notch1、Jagged1和Hes1的蛋白表达。通过免疫荧光分析愈合后的皮肤中α-SMA,Col I和Col III的相对蛋白水平。结果：bFGF组较对照组的疤痕指数降低（P<0.05）,bFGF+DAPT组较bFGF组疤痕指数升高（P<0.05）。bFGF组较对照组的愈合面积增加（P<0.05）,bFGF + DAPT组较bFGF组愈合面积降低（P<0.05）。与对照组相比,bFGF组的愈合时间明显缩短,较低的残余伤口面积和较低的疤痕指数（P<0.05）,而bFGF + DAPT组表现出明显的愈合延迟和较高的疤痕指数（P<0.05）。bFGF组较对照组的新血管生成量增加（P<0.05）,bFGF + DAPT组较bFGF组心血管生成量减少（P<0.05）。bFGF组较对照组的肉芽组织平均厚度增加,表皮间隙的闭合百分比升高（P<0.05）,bFGF + DAPT组较bFGF组肉芽组织平均厚度增加、表皮间隙的闭合百分比减少（P<0.05）。H＆E染色进行组织学分析发现,与对照组和bFGF + DAPT组相比,bFGF组出现明显的再上皮化和新血管形成,愈合效率较高（P<0.05）。bFGF组较对照组Notch1、Jagged1和Hes1的蛋白表达升高（P<0.05）,bFGF + DAPT组较bFGF组Notch1、Jagged1和Hes1的蛋白表达降低（P<0.05）。bFGF组较对照组?琢-SMA,Col I和Col III的蛋白表达降低（P<0.05）,bFGF + DAPT组较bFGF组表达升高（P<0.05）。结论：bFGF可以通过促进ESC的增殖并通过激活Notch1 / Jagged1途径抑制其向肌成纤维细胞（Myofibroblasts,MFB）的分化加快伤口愈合,减少疤痕形成。     

全身放射损伤对皮肤伤口成纤维细胞参与组织修复能力的影响

合并全身放射损伤的创伤（放创复合伤）是一种重要而有代表性的难愈性创伤,其难愈机制尚未完全阐明,成纤维细胞是最为重要的组织修复细胞,其辐射敏感性较低,为了明确放创复合伤时合并的放射损伤是否对伤口成纤维细胞有直接损伤作用,以及这些损伤作用对创伤愈合的影响,实验检测了分离,培养的放创复合伤和单纯创伤大鼠皮肤伤口成纤维细胞的增殖,凋亡及其他反映其参与组织修复能力的指标变化,结果发现,在去除全身因素和局部因素,特别是创伤局部细胞因子和细胞外基质对成纤维细胞的反馈作用后,放创复合伤组伤口成纤维细胞增殖力,贴壁力和粘附力均显著弱于单纯创伤组,而成纤维细胞的凋亡率则显著增加,这些细胞表明,全身放射损伤对伤口成纤维细胞有直接损伤作用,使其参与组织修复能力显著受抑,这是合并全身放射损伤时创伤难愈的重要原因。     

转染Smad7基因的人Tenon囊成纤维细胞Smad2及Ⅰ型胶原蛋白表达的改变(简报)

大量研究表明,TGF-β作为一种具有多种功能的生长因子,是全身瘢痕愈合的重要刺激因素.在人眼部参与多种眼部纤维化的过程。尤其在促进青光眼滤过术后结膜瘢痕形成中起重要作用。Smad蛋白家族在TGF-β超家族的信号转导中具有重要的作用。Smad7主要通过抑制TGF书受体介导的Smad2、Smad3磷酸化来拮抗TGF-β的信号转导,被认为是TGF-β超家族信号转导自我调节的一种负反馈信号。     

鱼鳞中胶原蛋白的提取纯化及应用

总结了鱼鳞中胶原蛋白的提取、分离和纯化方法及其结构特点、生物学功能,并探讨了其在食品、生物、医学、造纸、饲料等方面的应用及发展前景。     

星虫胶原蛋白的生物学特性研究

本文研究了胶原蛋白的生物学特性.结果显示,胶原蛋白溶液的粘度随浓度的增大而增大,随着温度的升高而下降;酸性条件下,粘度总体呈下降趋势,碱性时粘度变化不大;外加中低浓度的电解质与非电解质对胶原蛋白溶液粘度的影响不显著,溶液的流变学特性相对稳定.星虫胶原蛋白对小鼠皮肤无致敏反应,对创面愈合有明显的促进作用,该胶原蛋白不仅可以应用于食品与化妆品行业,还可以进一步应用于生物医学材料等领域.     

成纤维细胞生长因子的研究

成纤维细胞生长因子的研究崔亚东（阜阳师范学院生物系,安徽阜阳２３６０３２）关键词成纤维细胞生长因子早在１９４０年,人们发现脑和垂体提取液中含有一种能促进成纤维细胞生长的活性物质。直到１９７４年,该物质才被分离纯化,命名为成纤维细胞生长因子（ＦＧＦ）。...     

SAHA对TGF-β诱导人胚肺成纤维细胞α-SMA蛋白及前胶原蛋白mRNA表达的影响

目的:探讨在转化生长因子-β 1(TGF-β1)刺激下,组蛋白去乙酰化酶抑制剂辛二酰苯胺异羟肟酸(SAHA)对人胚肺成纤维细胞系HELF向肌成纤维细胞(MF)分化时,α-SMA蛋白及前胶原蛋白mRNA表达的影响.方法:体外培养人胚肺成纤维细胞系HELF,并根据不同的实验目的分为空白对照组,TGF-β1处理组以及SAHA干预组.细胞处理结束后,用Western blot检测α-SMA表达,RT-PCR检测Ⅰ、Ⅲ型前胶原的mRNA表达水平.结果:空白对照组中几乎无α-SMA蛋白表达,TGF-β1处理后α-SMA水平显著增高,而SAHA能有效降低α-SMA的水平.SAHA孵育24h后,能够明显抑制TGF-βl刺激后的细胞表达Ⅰ型和Ⅲ型前胶原蛋白mRNA,并且具有明显的剂量依赖性.结论:SAHA能降低TGF-βl诱导HELF细胞向MF转化时α-SMA表达以及前胶原蛋白表达.     

碱性成纤维细胞生长因子对培养的瘢痕成纤维细胞FN合成的调控作用

目的探讨碱性成纤维细胞生长因子（bFGF）对成纤维细胞纤维连结蛋白（FN）合成的调控作用。方法采用细胞培养、ELISA法、RT-PCR方法观察bFGF在不同剂量下对瘢痕来源的成纤维细胞FN合成的影响。结果FN的表达在低bFGF浓度组与对照组无明显差异,随着浓度的升高表现为增高趋势,以50、100、500ng／ml最显著,与对照组之间有显著性差异（P〈0．05）。FN mRNA表达在50-100ng／ml组明显升高,与对照组间有显著性差异（P〈0．05）。mRNA表达趋势与上清中蛋白的表达具有一致性。结论高浓度bFGF刺激FN合成可能是bFGF促进创面愈合的重要原因。     

Effect of PGE2 and indomethacin on human fibroblast collagen production

Fibroblasts can synthetize prostaglandins (particularly PGE2) "in vitro" but it still remains unclear what role they play in the regulation of fibroblast proliferation and collagen production. We report here the effect of PGE2 and indomethacin on collagen synthesis by cultured human dermal fibroblasts. PGE2 (range: 1-300 pmoles/ml) and indomethacin (range: 0.0025-1.0 micrograms/ml) did not significantly affect fibroblast collagen production, when added for 24 hours at 37 degrees C to the cultures, in comparison to controls (fibroblasts incubated for 24 hours at 37 degrees C in medium only). Prostaglandins probably modulate collagen synthesis, as described in a previous report, by means their effect on cell proliferation. It appears they do not affect the intracellular mechanism of collagen production.     

Effect of FXIII on monocyte and fibroblast function.

Factor XIII is a plasma transglutaminase that participates in the final stage of the coagulation cascade. Thrombin-activated FXIII (FXIIIa) catalyzes the formation of covalent crosslinks between gamma-glutamyl and epsilon-lysyl residues on fibrin molecules to yield the mature clot. In addition to its role in hemostasis, FXIIIa was previously shown by us to stimulate endothelial cells to exhibit pro-angiogenic activity. In this work, we studied the effect of FXIIIa on other cells that participate in angiogenesis and tissue repair, such as monocytes and fibroblasts. FXIIIa significantly enhanced migration and proliferation, and inhibited apoptosis of monocytes and fibroblasts. Similar to our previous observations with endothelial cells, the stimulating effect of FXIIIa on monocytes and fibroblasts was elicited via its binding to alpha (v)beta (3) integrin leading to cJun upregulation and TSP-1 downregulation. Since monocytes and fibroblasts are essential components of the tissue repair process, the results of this study, together with the proangiogenic activity of FXIIIa, further substantiate a significant role of FXIII in tissue repair.     

Stable isotope analyses of collagen in fish scales: limitations set by scale architecture

Comparisons between the stable isotope composition of carbon in collagen excized from juvenile (freshwater) and adult (marine) portions of scales from Atlantic salmon Salmo salar demonstrated that c. 75% of carbon analysed in the 'juvenile' portion of the scale derives from later formed collagen. Scale collagen analyses were effectively restricted to the last season of growth.     

Studies on fish scale formation and resorption

Summary Electron microscopic investigation of scales of the goldfish Carassius auratus revealed that the lamellae of fibrillary plates contain sheet-like structures composed of vertically oriented collagen fibers embedded in an organic matrix. The fibers (TC fibers) are smaller in diameter (35–45 nm) than those of the lamellae and the matrix is stained intensely with lead citrate.The sheet-like structures as well as the lamellae are formed by fibroblasts located beneath the lamellae. The orientation of the collagen fibers of the sheets and the lamellae seems to be controlled by the orientation of the ridges and invaginations of the surface of the fibroblasts.The fibrillary plate of C. auratus was found to be partially calcified. Calcification was initiated by the deposition of needle-like or flaky crystals of hydroxyapatite in the organic matrix of the sheet-like structure and proceeded into the TC fibers and the matrix region of the lamellae. The potassium pyroantimonate-osmium tetroxide method showed a heavy concentration of calcium in the osteoblasts, fibroblasts, and in the matrix regions of the fibrillary plate. Calcium-containing precipitates were also present in the hole zone of the collagen fibers in the lamellae, but the significance of this location in calcification remains to be elucidated.Contribution No. 285, Belle W. Baruch Institute for Marine Biology and Coastal Research, University of South Carolina, Columbia, South Carolina, 29208, USA     

Large scale purification of human fibroblast interferon

Human fibroblast interferon was partially purified, about 4,000-fold, on a chromatographic tandem of columns: concanavalin A-agarose leads to phenyl-agarose, to a specific activity of ca 4 x 10(7). The overall recovery of interferon activity was ca 60%.     

One-dimensional viscoelastic behavior of fibroblast populated collagen matrices

Bio-artificial tissues are being developed as replacements for damaged biologic tissues. Their mechanical properties are critical for load bearing applications. Current testing protocols for bio-artificial tissues vary widely and often do not consider viscoelasticity. Uniaxial stretch tests were performed on fibroblast populated collagen matrices (FPCMs) to determine the influence of specific test protocols on the mechanical behavior. The peak force, hysteresis and shape of the force-stretch curve are affected by the stretch rate, rest period, stretch amplitude and the number and magnitude of preconditioning cycles.     

Human fibroblast culture on a crosslinked dermal porcine collagen matrix

The use of a novel porcine-derived collagen biomaterial as a dermal tissue engineering matrix was examined. The matrix is derived from porcine dermis, and is processed to retain the native collagen (Type 1) and elastin structure. Human primary fibroblasts were cultured on the matrix to examine its potential for creating a dermal replacement. Attachment of fibroblasts on the collagen was compared to tissue culture plastic and PET membranes. Cell proliferation was assessed using the MTT assay and DAPI staining. For seeding densities of 5×10⁴ and 1×10⁵ cells cm⁻², PET and plastic demonstrated >95% attachment of seeded numbers after 3 h. The collagen matrix reached levels >80% after 3–4 h with no influence of the seeding density. Matrix samples with perforating pores of 40 μm diameter were also studied. After 216 h culture in static culture, with media replacement every 3 days, the final cell numbers reached 2.1×10⁵ (perforated) and 2.0×10⁵ cells cm⁻² (unperforated). In comparison fibroblast culture in a perfusion bioreactor, with continuous media replacement, reached 2.3×10⁵ (unperforated) and 2.5×10⁵ cells cm⁻² (perforated) after 216 h.     

Effects of collagen density on cardiac fibroblast behavior and gene expression

Interactions between cells and the extracellular matrix (ECM) play essential roles in modulating cell behavior during development and disease. The myocardial ECM is composed predominantly of interstitial collagen type I and type III. The composition, organization, and accumulation of these collagens are altered concurrent with cardiovascular development and disease. Changes in these parameters are thought to play significant roles in myocardial function. While a number of studies have examined how changes in the ECM affect myocardial function as a whole, much less is known regarding the response at the cellular level to changes in the collagenous ECM. Experiments were carried out to determine the effects of alterations in collagen density and ECM stiffness on the behavior of isolated heart fibroblasts. In vitro bioassays were performed to measure the effects of changes in collagen concentration (0.75-1.25 mg/ml) on adhesion, migration, spreading, and gene expression by heart fibroblasts. Increased density of collagen in 3-dimensional gels resulted in more efficient adhesion, spreading, and migration by heart fibroblasts. These experiments indicated that the density of the collagen matrix has a significant impact on fibroblast function. These studies begin to elucidate the effects of ECM density at the cellular level in the myocardium.     

Influence of cell density on collagen biosynthesis in fibroblast cultures.

Characteristic features of collagen metabolism in human skin fibroblasts were studied in relation to cell density. Measuring peptide-bound hydroxyproline we found that collagen synthesis per cell decreased when cultures approached confluency. On the other hand, the relative rate of collagen synthesis (collagen/total protein) was higher in quiescent than in proliferating cultures. With increasing cell density the proportion of type III collagen in comparison with type I was found to be slightly increased. In addition, in low-density cultures [alpha I(I)]3 collagen trimers were produced in considerable amounts, whereas they were no longer detected in cultures with a high cell density. Although hydroxylation of proline residues was normal in all cell stages, conversion of procollagen into collagen was found to depend strongly on the density at which the cells were investigated. Almost no cleavage of procollagen peptides was observed in rapidly growing cells, whereas highly confluent cell cultures converted most of the newly synthesized procollagen molecules.