转化生长因子β1基因单独转染及与胰岛素样生长因子1基因联合转染治疗兔膝骨关节炎

目的 观察重组大鼠转化生长因子β1(transforming growth factor beta-l,TGF-β1)基因单转染及与胰岛素样生长因子1(insulin-like growth factor-1,IGF-1)基因共转染兔膝关节后对骨关节炎(osteoarthritis,OA)的治疗效果.方法 新西兰白兔24只,随机分为4组,Ⅰ组为空白对照组,Ⅱ组为手术对照组,Ⅲ组为TGF-β1基因转染组,Ⅳ组为TGF-β1和IGF-1双基因转染组.前十字韧带切断法制成兔膝关节OA模型,向膝关节内注射转染不同重组基因的阳性克隆软骨细胞.4、8周后,取关节标本进行Mankin评分,AB-PAS染色,TGF-β1、IGF-1、Ⅱ型胶原原位杂交和免疫组化检测,透射电镜观察.结果 Ⅱ组软骨损伤程度较大,其Mankin评分明显高于Ⅰ组和Ⅲ、Ⅳ组.各因子原位杂交和免疫组化染色,Ⅰ组及Ⅲ、Ⅳ组的灰度值均高于Ⅱ组,Ⅳ组的灰度值较Ⅲ组高;8周时各对应组灰度值较4周有明显下降.透射电镜观察显示,Ⅱ组的超微结构较Ⅰ组明显紊乱,治疗4周后,超微结构逐渐恢复正常,但在8周后紊乱程度又逐渐加重.结论 关节内注射转基因软骨细胞对OA有一定治疗作用;TGF-β1和IGF-1双基因治疗效果优于TGF-β1单基因;基因治疗4周后,基因表达逐渐减弱,基因治疗具时效性.     

胰岛素样生长因子-1基因转染脂肪间充质干细胞向软骨细胞分化的研究

目的 观察胰岛素样生长因子(IGF)-1基因转染的脂肪间充质干细胞(ADSCs)向软骨细胞分化的效果.方法 原代培养兔ADSCs,免疫荧光法检测细胞表面抗原CD44、CIM9;脂质体介导人IGF-1基因转染兔ADSCs联合低浓度血清培养基向软骨细胞分化诱导,RT-PCR及Western blot方法检测IGF-1的表达,MMT法绘制细胞增殖曲线、甲苯胺蓝染色软骨结节、免疫组织化学检测Ⅱ型胶原的表达.结果 脂肪间充质干细胞CD44、CD109表达阳性,基因转染后细胞IGF-1表达阳性,细胞增殖速度增快,出现软骨结节,Ⅱ型胶原表达增高.结论 从脂肪组织中能够分离出增殖旺盛的ADSCs,IGF-1在ADSCs内获得稳定表达,细胞增殖能力增强,促进其向软骨细胞分化.     

转化生长因子-β1基因和胰岛素样生长因子1基因联合转染治疗兔膝骨性关节炎的研究

目的观察重组大鼠转化生长因子(TGF)-β1和胰岛素样生长因子(IGF)-1基因转染兔膝关节后对骨性关节炎(OA)的治疗效果。方法前交叉韧带切断法(ACLT)将新西兰白兔膝关节制成OA模型,分为5组,分别向膝关节内注射转染了不同重组基因的阳性克隆软骨细胞。4 周和8周后,取关节标本进行Mankin’s评分,AB-PAS染色,TGF-β1、IGF-1、Ⅱ型胶原原位杂交和免疫组织化学检测,透射电镜观察。结果手术对照组软骨损伤程度较大,其Mankin’s评分为 9．50±0．96(4周)和12．5±1．71(8周),明显高于空白对照组(P<0．01)和TGF—β1基因转染组、双基因转染组(P<0．05);各因子原位杂交和免疫组织化学染色,空白对照组(P<0．01)及TGF-β1 基因转染组、双基因转染组(P<0．05)的灰度值高于手术对照组;双基因转染组的灰度值较单基因转染组高(P<0．05);8周时各对应组灰度值较4周有明显下降(P<0．05);透射电镜观察显示,手术对照组的超微结构较空白对照组明显紊乱,经基因治疗4周后,超微结构逐渐恢复正常,但在8 周后,其紊乱程度又逐渐加重。结论关节内注射转基因软骨细胞对OA有一定治疗作用;TGF-β1 和IGF-1双基因的治疗效果优于单基因;基因治疗4周后,基因表达逐渐减弱,基因治疗具有时效性。     

转化生长因子-β1对肌腱腱鞘、腱外膜和腱内膜细胞增殖和胶原产生的影响

目的 探讨兔屈趾肌腱腱鞘、腱外膜和腱内膜细胞增殖、胶原产生和转化生长因子（TGF）-β1对细胞的增殖和胶原产生的影响。方法 从兔屈趾肌腱分离腱鞘、腱外膜和腱内膜细胞并培养，在使用TGF-β1培养后，细胞的数量和胶原产生量被测量，并与不使用TGF-β1培养的对照组比较。另外，通过逆转录-聚合酶链反应（RT-PCR）测定使用TGF-β1前后各种细胞Ⅰ型胶原基因的表达。结果 所有3种细胞均可以产生Ⅰ、Ⅱ、Ⅲ型胶原组织，TGF-β1使培养的细胞数量降低，但能显著性地增加Ⅰ、Ⅱ、Ⅲ型胶原组织产生和Ⅰ型胶原基因的表达（P〈0．05）。结论 调节TGF-β1的水平能调节胶原组织的产生，可能为临床上防止肌腱粘连提供新的途径。     

兔髓核细胞体外培养和重组人转化生长因子-β1对其代谢影响的研究

目的：探讨体外单层和立体培养兔髓核细胞时的变化及重组人转化生长因子-β1（rhTGF-β1，10ng／ml）对其代谢的影响。方法：体外培养兔髓核细胞，分为3组。A组，单层培养组；B组，Ⅱ型胶原支架立体培养组；C组，Ⅱ型胶原支架立体培养＋rhTGF-β1（10ng／m1）组。利用倒置显微镜、扫描电镜、RT-PCR、^3H-proline掺入法观察髓核细胞形态学、基因表达水平和总胶原合成的变化。结果：B、C组兔髓核细胞由A组的多角形转为类圆形；与A组相比，B组Ⅱ型胶原、集聚蛋白多糖基因表达水平升高（P〈0．05），总胶原合成升高（P〈0．01）。与B组相比，C组Ⅱ型胶原、集聚蛋白多糖、核心蛋白多糖基因表达水平增高（P〈0．01、P〈0．01、P〈0．05），总胶原合成升高（P〈0．01）。结论：兔髓核细胞由单层培养转到Ⅱ型胶原支架上培养时其基因表达和总胶原合成增强。rhTGF-β1（10ng／ml）增强立体培养的兔髓核细胞基因表达和总胶原合成。     

转化生长因子β1和胰岛素样生长因子1对体外培养人退变髓核细胞生物学活性的影响

目的：观察在体外培养条件下转化生长因子β1（TGF-β1）和胰岛素样生长因子1（IGF—1）对人退变髓核细胞生物学活性的影响。方法：体外培养人退变髓核细胞，台盼蓝染色法测定活细胞率。将每份髓核细胞样本分为对照组、TGF-β1组和TGF-β1＋IGF—1组。采用考马斯亮蓝法测定TGF—β1和IGF—1干预后第0、2、4、6天细胞内总蛋白含量。采用免疫组织化学和免疫荧光化学染色方法测定细胞在TGF-β1和IGF-1干预后0～6d合成Ⅱ型胶原的情况。结果：体外培养人退变髓核细胞的活细胞率为90％～95％。干预后第4、6天TGF-β1组和TGF-β1＋IGF—1组与对照组比较、TGF-β1＋IGF—1组与TGF-β1组比较细胞内总蛋白含量均显著增加（P〈0.05），TGF—β1＋IGF—1组Ⅱ型胶原的合成较对照组显著增加（P〈0．05）；干预后第6天TGF—β1组和TGF-β1＋IGF—1组与对照组比较、TGF-β1＋IGF—1组与TGF-β1组比较Ⅱ型胶原均显著增加（P〈0.05）。结论：一定浓度的TGF-β1能够促进人退变髓核细胞合成Ⅱ型胶原，改善其生物学活性，合用TGF-β1和IGF—1上述作用更加明显。     

转IL-1Ra和TGF-β1基因治疗兔骨性关节炎的体外实验研究

目的 探讨重组人IL-1Ra和TGF-β1双基因在体外对兔骨性关节炎软骨退变的治疗效果.方法 取新西兰大白兔关节软骨,经消化分离,软骨细胞以1.5×105/ml浓度培养于6孔培养板.软骨细胞分为5组,转染IL-1Ra组、转染TGF-β1组、转染IL-1Ra＋TGF-β1双基因组、未转染组、空白组.上述转染组均以LipofectamineTM 2000 Reagent脂质体为转染媒介.各组加入软骨块,除空白组外,其余各组均加入20 ng IL-1β.于第6天后每组各取4孔1.5 ml培养基,ELISA法检测TGF-β1和IL-1Ra的含量,RIA法检测IL-1β和TNF-α的含量.收集软骨块做HE染色、阿尔新蓝染色及Ⅱ型胶原免疫组化检测等组织学观察.结果 转染组IL-1Ra或TGF-β1有较高的表达水平;转染组IL-1β和TNF-α的表达水平降低,在双基因组降低最明显,与单基因组之间有显著性差异（P〈0.05）.转基因组基质染色均比未转染组着色较深.在双基因组软骨细胞排列尚整齐,细胞数量多,基质深染.结论 联合基因治疗效果优于单基因,为体外骨性关节炎的基因治疗提供实验基础.     

TGF—β1基因修饰诱导脂肪干细胞成软骨分化的实验研究

[目的]本研究通过选择对软骨细胞ECM合成具有促进作用的TGF-β1转染脂肪干细胞(ADSCs),观察转染后目的基因的稳定表达和对软骨细胞外基质(ECM)的两种重要组分:Ⅱ型胶原(type Ⅱ collage,ColⅡ)和aggrecan的合成,为构建新型的组织工程软骨提供实验依据.[方法]TGF-β1基因转染脂肪干细胞及阳性细胞克隆株的筛选;RT-PCR检测TGF-β1、纤连蛋白(fibronectin,FiN)、ColⅡ、Aggrecan的表达;Western-blot检测TGF-β1.[结果]RT-PCR结果显示:实验组(TGF-β1稳定转染组)的TGF-β1、FN、Col Ⅱ、Aggrecan的表达较空染组和正常对照组均明显增多(P＜0.01);Western blot检测实验组(TGF-β1稳定转染组)TGF-β1蛋白的表达较空染组和正常对照组均明显增多(P＜0.01).[结论]成功分离培养脂肪干细胞;以脂质体介导法将TGF-β1目的基因成功转染ADSCs,转染后成软骨分化的特异性细胞外基质增多,表明转染TGF-β1基因可以促使ADSCs向软骨细胞方向分化,从而为软骨组织工程提供新的思路和方法.     

TGF-β2转染关节软骨细胞的实验研究

目的 观察人关节软骨细胞在体外单层培养过程中的去分化，以及转染TGF-β2在关节软骨细胞内的表达和对去分化的抑制作用。方法 从手术中切除的软骨组织中分离培养成人关节软骨细胞，通过脂质体介导的方法将已构建的pcDNA3.1( )/TGF-β2转染到体外单层培养的软骨细胞中，采用RT-PCR，ELISA、组织学染色、免疫组化和原位杂交的方法．分别对转染组和未转染组的第1、6、9代细胞进行检测，比较目的基因表达、软骨细胞形态以及胶原和多糖生物合成的差异．结果 经多次传代后，未转染软骨细胞在体外单层培养过程中逐渐走向去分化．TGF-β2、Ⅱ型胶原和蛋白多糖聚糖体的表达逐渐减低．而Ⅰ型胶原的表达增高，目的基因在转染组各代软骨细胞内均得到表达，转染后细胞保持软骨细胞的形态，Ⅱ型胶原和蛋白多糖聚糖体表达虽有降低．但均高于未转染的同代细胞，而Ⅰ型胶原表达增高的程度低于未转染细胞。结论 人关节软骨细胞在体外单层培养中有去分化趋势；pcDNA3.1( )/TGF-β2真核表达载体转染人关节软骨细胞获得成功．在转染后关节软骨细胞内稳定表达．并对软骨细胞的去分化有抑制作用。     

重组PGL3-转化生长因子β1基因转染兔骨髓基质干细胞体外诱导向软骨细胞分化的实验研究

目的探讨将编码细胞转化生长因子β1(transforming growth factor β1,TGF-β1)的重组PGL3-TGF-β1质粒转染兔骨髓基质干细胞(marrow stromal stem cells,MSCs),体外通过自分泌、诱导作用向软骨细胞方向分化的可行性,为基因加强组织工程学修复软骨损伤提供体外实验依据.方法兔MSCs体外密度梯度离心及贴壁筛选法分离培养,脂质体法转染重组PGL3-TGF-β1,转染后绘制不同时期细胞生长曲线,MTT法分析转染后细胞(实验组)生长活性,以未转染空载体细胞为实验对照组,未转染细胞为空白对照组;转染后第2、7天,分别进行抗TGF-β1和抗Ⅱ型胶原蛋白的免疫组织化学染色(SABC法),以未转染细胞为实验对照组,PBS作为一抗为空白对照组,进行图像定量分析.结果 MSCs体外分离培养,脂质体法转染后,生长曲线显示转染后细胞生长活性较对照组降低,MTT法显示实验组及实验对照组吸光度(A)值较空白对照组低,差异有统计学意义(P＜0.01);实验组转染细胞第2天,抗TGF-β1免疫组织化学染色可见细胞内阳性颗粒,实验对照组及空白对照组均为阴性;转染细胞第7天,抗Ⅱ型胶原免疫组织化学染色实验组可见细胞内阳性颗粒,实验对照组及空白对照组均为阴性.图像分析示,实验组抗TGF β1及抗Ⅱ型胶原免疫组织化学染色阳性值与实验对照组及空白对照组相比,差异均有统计学意义(P＜0.01).结论脂质体法重组PGI3-TGF-β1基因可成功转染兔MSCs,但对细胞生长有一定影响,转染细胞表达TGF β1,通过其自分泌、诱导作用,细胞分泌Ⅱ型胶原蛋白,表现出软骨细胞样生理特征,并向软骨细胞方向分化.     

生长因子与老年性骨质疏松症相关性的临床研究

目的观察老年性骨质疏松患者转化生长因子β1(TGF-β1)、胰岛素样生长因子-1(IGF-1),表皮生长因子(EGF)血清水平以及与骨质疏松的相关性.方法采用双能X线骨密度仪测量了86例在本院老年病门诊和住院的老年人腰椎正位以及股骨颈、ward三角区、大粗隆部位的骨密度(BMD),受试者均为老年男性,平均年龄为69.97±5.73岁,按照WHO推荐的诊断标准,参考中国人骨质疏松症建议诊断标准(第二稿),将其分为非骨质疏松组(NOP)、腰椎骨质疏松组(OP1)和股骨上段骨质疏松组(OP2),测定所有受试者血清TGF-β1,IGF-1,EGF水平.结果腰椎骨质疏松组和股骨上段骨质疏松组血清IGF-1浓度值均低于非骨质疏松组((P＜0.01)).腰椎骨质疏松组血清TGF-β1浓度值与非骨质疏松组无明显差异((P>0.05)),股骨上段骨质疏松组血清TGF-β1浓度值低于非骨质疏松组(0.01<P<0.05),骨质疏松组血清EGF值与非骨质疏松组无差异(P>0.5).腰椎骨密度值与血清IGF-1值呈正相关(相关系数分别为0.212、0.325、0.228),腰椎骨密度值与血清TGF-β1值呈显著正相关(相关系数分别为0.373、0.328、0.341、P<0.05).股骨颈、Ward三角、大粗隆的骨密度值与IGF-1和TGF-β1无显著相关性.骨密度值与表皮生长因子无显著相关性.结论老年骨质疏松患者血清TGF-1含量低而血清TGF-β1浓度值差异较大,但从相关分析结果看,骨密度值与IGF-1和TGF-β1有较密切关系,为进一步探讨骨质疏松的发病机理,需做生长因子的骨组织表达.血清表皮生长因子(EGF)可能与骨重建无明显相关性.     

Improvement of fracture healing by systemic administration of growth hormone and local application of insulin-like growth factor-1 and transforming growth factor-beta1

Fracture healing is influenced by numerous hormones, growth factors, and cytokines. The systemic administration of growth hormone (GH) has shown to accelerate bone regeneration. Local application of growth factors, such as insulin-like growth factor-1 (IGF-1) and transforming growth factor-beta-1 (TGF-beta1), are known to stimulate bone metabolism. Until now, the exact local and systemic mechanisms that lead to improved bone regeneration remain unclear. In addition, the effect of systemic administration of GH as compared with locally delivered growth factors on fracture healing in rats is not known. A midshaft fracture of the right tibia of 5-month-old female Sprague-Dawley rats (n = 80) was intramedullary stabilized with IGF-1 and TGF-beta1 coated vs. uncoated titanium K-wires. The growth factors were incorporated in a poly(D,L-lactide) (PDLLA) coating and released continuously throughout the experiment. Recombinant species-specific (rat) GH was applied systemically (2 mg/kg body weight) by daily subcutaneous injection and compared with a placebo group. The healing process was radiologically monitored. Twenty-eight days after fracture biomechanical torsional testing was performed. The consolidation and callus composition, including quantification of cartilage and mineralized tissue, was traced in histomorphometrical investigations using an image analysis system. Both methods, the systemic administration of GH and the local application of growth factors, showed significant biomechanical and histological effects on fracture healing. The local growth factor application showed a stronger effect on fracture healing than the systemic GH injection. The combined application of both methods did not accelerate the effect on bone healing compared with the single application. It is therefore concluded that combining local and systemic stimulating methods does not provide further additive effects with regard to fracture healing.     

Serum levels of insulin-like growth factor-1 and insulin-like growth factor-1 binding proteins after radical prostatectomy

PURPOSE: Elevated serum levels of insulin-like growth factor-1 (IGF-1) have been consistently shown to be a risk factor for prostate cancer. Alterations in serum IGF-1 binding proteins 1 to 3 have also been associated with prostate cancer risk. A potentially important complication in these studies is that prostate tissue, perhaps especially malignant prostate tissue, may secrete IGF-1 and its binding proteins into serum. In fact, it is possible that altered levels of these proteins observed in subjects at risk for prostate cancer are the result of prostate cancer rather than related to its cause. MATERIALS AND METHODS: The contribution of prostate cancer to serum levels of IGF-1 and IGF-1 binding proteins was determined by analyzing serum samples from 86 patients with prostate cancer 2 weeks before and 8 weeks after radical prostatectomy. Preoperative and postoperative values for IGF-1 and its 3 major binding proteins were analyzed using univariate and multivariate analysis models. RESULTS: On univariate analysis significant increases and not decreases in IGF-1, IGF binding protein-1 and 3 were observed after prostatectomy. On multivariate analysis a significant post-prostatectomy increase was observed for IGF-1 binding proteins 1 and 3 but the increase in IGF-1 was not significant. CONCLUSIONS: Increased levels of IGF-1 and IGF-1 binding proteins were unexpected after prostatectomy. This result makes it extremely unlikely that secretion from the prostate, even if it contains cancer, affects serum levels of these proteins. The implication of these findings is that endocrine production of IGF-1 is a factor in prostate cancer risk. Therefore, strategies to lower serum IGF-1 may be potentially useful.     

Hepatocyte nuclear factor-1alpha modulates pancreatic beta-cell growth by regulating the expression of insulin-like growth factor-1 in INS-1 cells

Maturity-onset diabetes of the young type 3 (MODY3) is characterized by impaired insulin secretion. Heterozygous mutations in the gene encoding hepatocyte nuclear factor (HNF)-1alpha are the cause of MODY3. Transgenic mice overexpressing dominant-negative HNF-1alpha mutant in pancreatic beta-cells and HNF-1alpha knockout mice are animal models of MODY3. These mice exhibit defective glucose-stimulated insulin secretion and have reduced beta-cell mass and beta-cell proliferation rate. Here we examined the effect of HNF-1alpha on beta-cell proliferation by overexpressing a human naturally occurring dominant- negative mutation P291fsinsC in INS-1 cells under the control of doxycycline-induction system. INS-1 cells overexpressing P291fsinsC showed apparent growth impairment. The proliferation rate estimated by [(3)H]thymidine incorporation was significantly reduced in P291fsinsC-expressing INS-1 cells compared with noninduced or wild-type HNF-1alpha-overexpressing INS-1 cells. Growth inhibition occurred at the transition from G1 to S cell cycle phase, with reduced expression of cyclin E and upregulation of p27. cDNA array analysis revealed that the expression levels of IGF-1, a major growth factor for beta-cells, and macrophage migration inhibitory factor (MIF), a cytokine expressed in pancreatic beta-cells, were reduced in P291fsinsC-HNF-1alpha-expressing INS-1 cells. Although MIF seemed to have proliferative function, blockade of MIF action by anti-MIF antibody stimulated INS-1 cell proliferation, excluding its direct role in the growth impairment. However, addition of IGF-1 to P291fsinsC-expressing INS-1 cells rescued the growth inhibition. Our data suggest that HNF-1alpha is critical for modulating pancreatic beta-cell growth by regulating IGF-1 expression. IGF-1 might be a potential therapeutic target for the treatment of MODY3.     

Insulin-like growth factor-1 suppresses pyrophosphate elaboration by transforming growth factor beta1-stimulated chondrocytes and cartilage

Our objective was to examine the effect of insulin-like growth factor-1 (IGF-1) on extracellular pyrophosphate (ePPi) elaboration by porcine cartilage. These studies further define the factors influencing ePPi accrual, a key step in calcium pyrophosphate dihydrate (CPPD) crystal formation. ePPi was measured in adult porcine organ and monolayer culture media in the presence of IGF-1, transforming growth factor beta-1 (TGFbeta-1), IGF-1 antibody and synovial fluid (SF). As previously shown, TGFbeta-1 stimulated ePPi elaboration by cartilage and chondrocytes. IGF-1 significantly inhibited the stimulatory effect of TGFbeta-1 on ePPi elaboration by both cartilage explants and chondrocytes. Anti-IGF-1 antibody blocked this inhibition. Anti-IGF-1 antibody also decreased the inhibitory effect of SF on ePPi elaboration, suggesting the presence of active IGF-1. These results support an important regulatory role for IGF-1 in cartilage ePPi elaboration. IGF-1 inhibited the effects of the ePPi-stimulatory factor TGFbeta-1 and thus may protect normal joints from excess accumulation of ePPi and subsequent CPPD crystal formation.     

Insulin-like growth factor-1, growth hormone-dependent insulin-like growth factor-binding protein and growth in children with chronic renal failure

Insulin-like growth factor-binding protein-3 (IGFBP-3) and insulin-like growth factor-1 (IGF-1) levels were measured by specific radioimmunoassays in children with all degrees of chronic renal failure (CRF). Study group 1 comprised 29 children (10 on dialysis) who had been studied one to four times over 2 years to determine whether IGF-1 and IGFBP-3 levels differed from those in age-matched healthy children and to examine the relationship between these levels and heights. IGF-1 and IGFBP-3 levels did not differ from those in normal children. IGF-1 and IGFBP-3 were significantly correlated, increased with pubertal stage in all children and with age in non-dialysis patients. IGF-1, but not IGFBP-3, correlated with age in dialysis patients. There was no correlation between IGF-1 or IGFBP-3 levels (corrected for age) and height standard deviation score (SDS) in either non-dialysis or dialysis patients. Study group 2 comprised 19 children (7 on dialysis) who were studied prospectively for 1–2 years to examine the relationship between IGF-1 and IGFBP-3 levels, growth rates and nutritional parameters. Mean values of IGF-1 and IGFBP-3 (corrected for age) did not change over 1-year periods, while height SDS fell by –0.38 ±0.21 SD/year in dialysis patients and by –0.11 ±0.29 SD/year in non-dialysis patients. No significant correlations were found between IGF-1 or IGFBP-3 levels and growth rates or nutritional parameters. Thus growth retardation in children with CRF is not related to circulating levels of IGF-1 or IGFBP-3.     

Insulin-like growth factor 1 (IGF-1) and growth hormone (hGH) as the markers of osteoarthritis

AIM OF STUDY: The aim of study was evaluation of diagnostic usefulness of IGF-1 and hGH serum level in osteoarthritis. MATERIAL AND METHODS: IGF-1 and hGH concentration were measured in serum collected from 25 patients with coxarthrosis and 16 healthy persons. IGF-1 and hGH serum level were assayed by ELISA. RESULTS: There was no statistics difference in growth hormone serum level between osteoarthritis patients and healthy persons. The ROC curve for hGH concentration confirmed low discriminatory value of this test. There was no significant correlation between hGH and IGF-1 in serum. IGF-1 concentration in patients serum was significant lower then in control grupe. The ROC curve for serum level of IGF-1 confirmed significant usefulness this test in laboratory diagnostic of osteoarthritis. CONCLUSIONS: Serum concentration of IGF-1 seems to be usefull laboratory marker of osteoarthritis.     

Activation of latent transforming growth factor beta1 by stromelysin 1 in extracts of growth plate chondrocyte-derived matrix vesicles.

Previous studies have shown that matrix vesicles isolated from cultures of costochondral growth zone chondrocytes and treated with 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] can activate recombinant human latent transforming growth factor beta1 (rhTGF-beta1). It is unknown what enzyme or other factor in the extracellular organelles is responsible for the activation. This study tested the hypothesis that enzymes present in matrix vesicles can activate latent TGF-beta1 and that this is regulated by 1alpha,25(OH)2D3. To do this, we examined the ability of matrix vesicle extracts to activate small latent rhTGF-beta1. In addition, enzymes previously determined to be present in matrix vesicles were screened for their ability to activate small latent rhTGF-beta1. Recombinant human matrix metalloproteinase 2 (rhMMP-2; 72 kDa gelatinase), rhMMP-3 (stromelysin 1), purified human plasminogen, and purified urokinase (plasminogen activator) were each tested at varying concentrations. To assess the role of cell maturation, we used a cell culture model in which chondrocytes are derived from two distinct zones of rat costochondral cartilage, the resting zone and the growth zone. Matrix vesicles were isolated from these cultures and then tested. The results showed that extracts of matrix vesicles produced by both growth zone and resting zone chondrocytes were able to activate small latent rhTGF-beta1. The effects were dose and time dependent, with greater activity being found in extracts of matrix vesicles from the growth zone chondrocyte cultures. Only rhMMP-3 was able to activate small latent rhTGF-beta1, indicating that stromelysin-1, but not MMP-2, plasminogen, or urokinase, was involved. As observed in the extracts, the effect of rhMMP-3 was time and dose dependent. When anti-MMP-3 antibody was added to matrix vesicle extracts from both cell types, activation of small latent rhTGF-beta1 was dose-dependently blocked. Neither 1alpha,25(OH)2D3 nor 24R,25(OH)2D3 had a direct effect on activation of small latent rhTGF-beta1 by the extracts. However, when intact matrix vesicles were treated with 1alpha,25(OH)2D3, their ability to activate small latent rhTGF-beta1 was increased. Inhibition of phospholipase A2 with quinacrine blocked the 1alpha,25(OH)2D3-dependent effect. These results suggest that the ability of 1alpha,25(OH)2D3-treated matrix vesicles to activate small latent TGF-beta1 is via action of the secosteroid on the matrix vesicle membrane, not on the enzymes responsible for activating latent TGF-beta1. Because matrix vesicles isolated from growth zone chondrocytes have been shown to contain increased phospholipase A2 activity after treatment with 1alpha,25(OH)2D3, it is likely that this secosteroid promotes loss of membrane integrity through phospholipase A2-dependent formation of lysophospholipids, resulting in the release of MMP-3 into the matrix, where latent TGF-beta1 is stored. Taken together, the results of the current study show that matrix vesicles produced by growth plate chondrocytes contain MMP-3, that this enzyme is at least partially responsible for activation of small latent TGF-beta1 in the matrix, and that 1alpha,25(OH)2D3 regulates MMP release from matrix vesicles.     

Transforming growth factor-β1 and fibroblast growth factors in rat growth plate

Chondrocytes in the growth plate progress in an orderly fashion from resting through proliferating to hypertrophic cells. In the region of hypertrophic chondrocytes, the cartilage is invaded by capillary loops and endochondral ossification is initiated. It is currently believed that growth factors may regulate the proliferation and maturation of chondrocytes and the synthesis of extracellular matrix in the growth plate. The ordered sequence of proliferation and differentiation observed in the growth plate provides a unique opportunity to study the role of acidic fibroblast growth factor, basic fibroblast growth factor, and transforming growth factor-β1 in the regulation of these processes. In this study, expression of the mRNA of these growth factors was examined using total RNA extracted from the physis and epiphysis of rat tibias. Transforming growth factor-β1 mRNA was detected by Northern hybridization. Expression of the genes encoding acidic and basic fibroblast growth factors was demonstrated by polymerase chain reaction amplification. In addition, using polyclonal antibodies against these growth factors, we localized them by immunohistochemical analysis. Strong intracellular staining with a predominantly nuclear pattern was observed in chondrocytes from the proliferating and upper hypertrophic zones. In contrast, chondrocytes in the resting zone stained only faintly for the presence of these growth factors. Some chondrocytes in the resting zone adjacent to the proliferating zone stained with these antibodies, and the antibodies also stained cells in the zone of Ranvier, which regulates latitudinal bone growth. Lastly, the location of transforming growth factor-β1 was examined further with use of a polyclonal antipeptide antibody specific for its extracellular epitope. Interestingly, extracellular staining for transforming growth factor-β1 was observed only around chondrocytes in the hypertrophic zone. These results suggest a role for these growth factors in the regulation of proliferation and maturation of chondrocytes and in endochondral ossification.