Establishment of a Rat Long-Term Culture Expressing the Osteogenic Phenotype: Dependence on Dexamethasone and FGF-2

Rat stromal bone-marrow cells cultured in the presence of dexamethasone, ascorbic acid, &#103 -glycerophosphate, and fibroblast growth factor-2 (FGF-2) express the osteogenic phenotype (Pitaru et al., J. Bone Miner. Res . 8:919-929, 1993). The purpose of this study was to establish a long-term homogeneous culture expressing the osteogenic phenotype. The cultures were routinely passaged every 5 days in the absence or presence of either or both dexamethasone and FGF-2, and the cumulative doubling number and the expression of the osteogenic phenotype were determined. Cultures treated with dexamethasone (10 &#109 7 M) ceased proliferation and only upon addition of FGF-2 (3 ng/ml) was a spontaneous immortalization achieved, as expressed by sustained proliferation for about 1 year, with a doubling time of 22 h and more than 300 doublings in 72 passages. Both FGF-2 and dexamethasone are required and act synergistically to maintain cell propagation, alkaline phosphatase expression, and osteocalcin secretion; however, protein content was FGF-2 dependent and the mineralization was dexamethasone dependent. Repetitive single-cell cloning tested the homogeneity and stability of the cells expressing the osteogenic phenotype in these long-term cultures. It was shown that 25% to 50% of subclones derived from clones with an osteogenic phenotype do not further express the osteogenic phenotype. In conclusion, we have established a spontaneously immortalized dexamethasone- and FGF-2-dependent rat stromal bone-marrow-derived long-term culture expressing the osteogenic phenotype. The cultures tend to lose the osteogenic phenotype, and dexamethasone supports the long-term preservation of the osteogenic phenotype.     

Effects of Applied DC Electric Field on Ligament Fibroblast Migration and Wound Healing

Applied electric fields (static and pulsing) are widely used in orthopedic practices to treat nonunions and spine fusions and have been shown to improve ligament healing in vivo. Few studies, however, have addressed the effect of electric fields (EFs) on ligament fibroblast migration and biosynthesis. In the current study, we applied static and pulsing direct current (DC) EFs to calf anterior cruciate ligament (ACL) fibroblasts. ACL fibroblasts demonstrated enhanced migration speed and perpendicular alignment to the applied EFs. The motility of ligament fibroblasts was further modulated on type I collagen. In addition, type I collagen expression increased in ACL fibroblasts after exposure to pulsing EFs. In vitro wound-healing studies showed inhibitory effects of static EFs, which were alleviated with a pulsing EF. Our results demonstrate that applied EFs augment ACL fibroblast migration and biosynthesis and provide potential mechanisms by which EFs may be used for enhancing ligament healing and repair.     

Controlling Fibroblast Proliferation with Dimensionality-Specific Response by Stiffness of Injectable Gelatin Hydrogels

Abstract

We report an injectable hydrogel system with tunable stiffness for controlling the proliferation rate of human fibroblasts (HFF-1) in both two-dimensional (2D) and three-dimensional (3D) culture environments for potential use as a wound dressing material. The hydrogel composed of gelatin–hydroxyphenylpropionic acid (Gtn–HPA) conjugate was formed by the oxidative coupling of HPA moieties catalyzed by hydrogen peroxide (H₂O₂) and horseradish peroxidase (HRP). The stiffness of the hydrogels was controlled well by varying the H₂O₂ concentration. The effects of hydrogel stiffness on the proliferation rate of HFF-1 in both 2D and 3D were investigated. We found that the proliferation rate of HFF-1 using Gtn–HPA hydrogels was strongly dependent on the hydrogel stiffness, with a dimensionality-specific response. In the 2D studies, the HFF-1 exhibited a higher proliferation rate when the stiffness of the hydrogel was increased. In contrast, the HFF-1 cultured inside the hydrogel remained non-proliferative for 12 days before a stiffness-dependent proliferation profile was shown. The proliferation rate decreased with an increase in stiffness of the hydrogel in a 3D culture environment, unlike in a 2D environment.     

皮肤老化的几种常见细胞和富血小板血浆治疗进展

皮肤抗老化领域的细胞治疗技术自问世以来,经历多次更新和优化,目前临床上公认安全性和效果较好的细胞治疗制剂包括脂肪干细胞及其培养基提取物、成纤维细胞、皮肤间充质干细胞以及富血小板浓缩物、富血小板血浆制剂等。然而,针对这些制剂的作用机制及优缺点还缺乏系统的总结,本文将对此进行详细阐述。     

机械牵张应力对骨化颈椎后纵韧带成纤维细胞的影响

目的探讨机械牵张应力对体外培养的颈椎后纵韧带骨化症（OPLL）患者颈椎韧带成纤维细胞的影响。方法对2012年1月至2013年12月 OPLL 与颈椎外伤但无后纵韧带骨化（非OPLL）患者（各15例）行前路颈椎手术治疗,术中取韧带标本。采用组织块培养法进行细胞体外培养,免疫细胞化学及免疫荧光技术检测胞质波形蛋白。采用 Flexercell 4000细胞加载培养系统分别对两组患者第3代细胞进行机械牵张应力加载,逆转录-聚合酶链式反应（RT-PCR）方法检测两组成纤维细胞应力刺激前及刺激后12、24 h 成骨特异性指标骨钙素、碱性磷酸酶与Ⅰ型胶原 mRNA 表达。结果免疫细胞化学及免疫荧光检测显示胞质波形蛋白呈阳性表达。OPLL组后纵韧带成纤维细胞经机械牵张应力刺激12 h后,骨钙素、碱性磷酸酶及Ⅰ型胶原 mRNA 表达明显升高,应力刺激前后差异具有统计学意义;而非OPLL组应力刺激前后骨钙素、碱性磷酸酶及Ⅰ型胶原 mRNA 表达无明显变化。结论机械牵张应力可促使OPLL患者后纵韧带成纤维细胞骨钙素、碱性磷酸酶及Ⅰ型胶原mRNA表达增加,促进其骨化,其在OPLL进展中发挥重要作用。     

Fibroblast growth factor-21 is positively associated with atrial fibrosis in atrial fibrillation patients with rheumatic heart disease

Objective: Fibroblast growth factor-21 (FGF-21) has been discovered as a strong hormone, plays an important role in lipid metabolism, glucose metabolism, associated with several diseases such as obesity, metabolic syndrome, diabetes mellitus, and cardiovascular events; however, no evidence is available concerning the relationship of FGF-21 and atrial fibrosis in patients with atrial fibrillation (AF) and rheumatic heart disease (RHD). Methods: Twenty-four rheumatic heart disease patients were divided into two groups, 12 cases with AF and 12 cases with sinus rhythm (SR). Clinical characteristics and blood samples were collected before surgery; right atrial appendage samples were taken in the surgery of valve replacement. HE staining was performed to determine cross-sectional area of atrial myocytes; Masson stained sections and mRNA levels of cardiac fibrosis biomarkers were used to evaluate the degree of cardiac fibrosis; the level of FGF-21 was evaluated via enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and real-time polymerase chain reaction (PCR). Results: Compared with SR group, cross-sectional area of atrial myocytes and collagen volume fraction were significantly increased in the atrial tissue of AF group. The distribution of FGF-21 in the AF group was remarkably higher than SR group. In addition, plasma and mRNA levels of FGF-21 in atrial tissue of AF showed the same trend as the result of immunohistochemistry. Using linear correlation analysis, the expression level of FGF-21 was found to be positively related to the degree of atrial fibrosis. Conclusion: FGF-21 might involve in the development and maintenance of atrial fibrosis in atrial fibrillation with rheumatic heart disease, and FGF-21 could be used as a novel biomarker to evaluate myocardial fibrosis in the future.     

FGFR4蛋白表达与胃癌临床病理特征和预后的关系

背景:许多肿瘤组织中成纤维细胞生长因子受体4(FGFR4)蛋白高表达,且与患者的预后相关,然而关于FGFR4在胃癌中的表达及其作用的研究相对较少。目的:研究FGFR4在胃癌中的表达及其与胃癌临床病理特征和预后的关系。方法:应用免疫组化法检测182例胃癌组织中FGFR4蛋白表达情况,并分析其与不同胃癌临床病理特征的关系,采用Kaplan-Meier生存曲线分析FGFR4蛋白表达与预后的关系。结果:在182例胃癌组织标本中,81例(44.5%)FGFR4蛋白表达阳性,FGFR4蛋白表达与性别、年龄、肿瘤部位、分化程度、TNM分期、神经侵犯、血管侵犯均无关。FGFR4阳性与阴性者的总体5年生存率无明显差异,但在高分化、T1+T2期或伴有远处转移的胃癌中,FGFR4阳性者的预后明显差于FGFR4阴性者(5年生存率:47.0%对62.1%,P=0.036 8;5年生存率:54.5%对78.6%,P=0.041 3;中位生存期:5个月对15个月,P=0.040 5)。结论:FGFR4阳性表达尚不能作为独立指标判断胃癌预后,但在高分化胃癌、T1+T2期胃癌或伴有远处转移的胃癌中,FGFR4阳性表达可能是影响预后的危险因素。     

成纤维细胞生长因子21对载脂蛋白E基因敲除小鼠动脉粥样硬化病变中内质网应激诱导的凋亡的影响

目的　探讨成纤维细胞生长因子21（FGF-21）对载脂蛋白E基因敲除（ApoE^-/-）小鼠主动脉中内质网应激诱导的凋亡的影响。方法　将24只ApoE^-/-小鼠随机分为动脉粥样硬化模型组（简称模型组）和FGF-21组（n12）,另选12只C57BL/6J小鼠作为正常对照组,三组小鼠都给予高胆固醇饮食4周,同时FGF-21组皮下给予FGF-21［0.1　mg　/（kg·d）］4周,而模型组和正常对照组给予等量生理盐水。4周后处死小鼠进行主动脉病理学检测,观察斑块面积,采用放射免疫法检测血浆中FGF-21的水平,采用免疫组织化学染色和Western　Blot检测主动脉成纤维细胞生长因子受体1（FGFR-1）的表达水平,采用Tunel染色检测主动脉斑块中的细胞凋亡水平,采用Western　Blot检测主动脉中剪切后Caspase-12和C/EBP　同源蛋白（CHOP）的表达水平。结果　与正常对照组比较,模型组血浆中的FGF-21水平及主动脉中FGFR1蛋白表达显著升高　（P<0.05）,模型组主动脉根部斑块面积、细胞凋亡数量、剪切后Caspase-12及CHOP蛋白的表达水平增加（P<0.05）;与模型组比较,FGF-21组主动脉根部斑块面积、细胞凋亡数量、剪切后Caspase-12及CHOP蛋白的表达水平减少（P<0.05）。结论　FGF-21可能通过抑制剪切后Caspase-12及CHOP相关促凋亡蛋白表达,抑制ApoE^-/-小鼠主动脉斑块病变中细胞的凋亡及斑块进展。     

中晚期慢性肾脏病患者成纤维细胞生长因子23水平与颈动脉粥样硬化的关系

目的　探讨中晚期慢性肾脏病（CKD）患者成纤维细胞生长因子23（FGF23）水平与颈动脉粥样硬化的相关性。方法　收集我院中晚期慢性肾脏病患者共计120例,分为3组,其中CKD非透析组患者（3～5期）30例、腹膜透析组患者30例、血液透析组患者60例;另外选择年龄、性别匹配的20例健康体检者为健康对照组。比较中晚期慢性肾脏病患者与健康人群FGF23水平的差别,以及3组之间的差别。同时将中晚期CKD患者分为颈动脉粥样硬化组和无颈动脉粥样硬化组,比较两组临床有关参数及FGF23水平的变化,探讨FGF23水平与颈动脉粥样硬化的相关性,分析其临床意义。结果　中晚期CKD患者颈动脉粥样硬化发生率较高（59/120,49.2%）。颈动脉粥样硬化组血清FGF23水平明显高于无颈动脉粥样硬化组（P<0.01）;中晚期CKD患者血清FGF23水平显著高于健康对照组（P<0.01）;中晚期CKD患者3组人群比较,透析患者FGF23水平高于非透析的CKD　3～5期患者（P<0.05）;血液透析患者的FGF23水平又显著高于腹膜透析患者（P<0.01）。中晚期CKD患者FGF23水平与颈动脉内膜中层厚度呈正相关（r＝0.68,P<0.05）,多因素分析显示,FGF23水平是中晚期慢性肾脏病患者发生颈动脉粥样硬化的独立危险因素。结论　血清FGF23水平与中晚期CKD患者颈动脉粥样硬化的发生相关,FGF23在颈动脉粥样硬化的发生发展中可能起着重要作用。FGF23可能成为预测CKD患者发生心血管疾病和死亡风险性增高的更敏感的标志物之一。