胰岛素样生长因子-Ⅰ对兔关节软骨细胞增殖及代谢的影响

目的　探讨胰岛素样生长因子 - (IGF- )对体外生长的关节软骨细胞分裂增殖及功能代谢的影响。方法　采用体外单层培养的方法 ,应用兔关节软骨细胞 ,对照组培养液为 10 %小牛血清 DMEM,实验组在培养液DMEM中加入 IGF- 使其终浓度分别为 3、10、30、10 0及 30 0 ng/ ml,作用细胞 2、4和 6天 ,检测细胞 DNA含量和基质中糖醛酸的含量。结果　 IGF- 在 3～ 30 0 ng/ ml浓度范围能明显增加培养软骨细胞的 DNA及糖醛酸的含量 ,且以30～ 10 0 ng/ ml作用 4天刺激效果最明显 ,与对照组相比 ,有统计学意义 (P<0 .0 1)。结论　 IGF- 对体外培养软骨细胞有刺激 ,并以剂量时间依赖性方式影响增殖及功能代谢。     

FBS对成骨生长肽促进BMSCs增殖分化的影响

目的探讨培养液中不同浓度FBS对成骨生长肽(osteogenic growth peptide,OGP)促进BMSCs增殖和分化的影响。方法取8只5周龄SD大鼠四肢骨,贴壁法分离纯化BMSCs并传代,倒置相差显微镜下观察细胞形态。取第3代BMSCs分组培养:分别采用浓度为1×10-10、1×10-9和1×10-8 mol/L的OGP进行培养,以正常培养细胞作为对照组;同时每组设FBS浓度为0、2%、5%、8%和10%5个梯度。培养后1、3、5、7、9、12 d采用MTT法检测细胞增殖,9 d时采用对硝基苯磷酸二钠法测定早期分化指标细胞内ALP活性。结果倒置相差显微镜下观察BMSCs贴壁生长,增殖迅速,呈纤维状涡旋生长,形态典型。MTT检测示,FBS低于5%时各组细胞不能持续增殖,当FBS浓度为8%以上时细胞可持续增殖;OGP 1×10-8 mol/L和1×10-9 mol/L组在FBS各浓度中促增殖效果均大于对照组(P0.05);FBS浓度低于10%时,OGP 1×10-8 mol/L组促增殖效果显著优于其余OGP浓度组(P0.05),但FBS浓度为10%时OGP 1×10-8 mol/L组无促增殖优势。ALP检测示,各组组内随FBS浓度增加,ALP活性增加(P0.05);当FBS浓度为5%、8%时,各OGP浓度组ALP活性均大于对照组(P0.05),且OGP 1×10-8 mol/L组最高(P0.05);当FBS浓度为10%时,各OGP组ALP活性仍大于对照组(P0.05),但OGP1×10-8 mol/L组与OGP 1×10-9 mol/L组差异无统计学意义(P0.05)。结论 8%FBS浓度为OGP促进BMSCs增殖分化的最佳血清浓度,且OGP促进BMSCs增殖分化的最适浓度为1×10-8 mol/L。     

胰岛素样生长因子对体外培养豚鼠肋软骨细胞的影响

目的：了解胰岛素样生长因子(insulin-1ike growthfactor-1，IGF-1)对体外培养豚鼠肋软骨细胞分裂增殖及功能代谢的影响。方法：体外单层培养豚鼠肋软骨细胞，对照组培养液为无血流清DMEM，实验组在培养液DMEM中加入IGF-1使其终浓度分别为10ng／ml、50ng／ml、100ng／ml，作用6天后，检测细胞DNA含量和培养液中糖醛酸的含量。结果：IGF-1在10～100ng／ml浓度范围能明显增加培养软骨细胞的DNA及糖醛酸的含量，且以50ng／ml作用效果最明显，与对照组相比，有统计擘意义(P＜0．01)。结论：IGF-1对体外培养肋软骨细胞有刺激，并以剂量依赖性方式影响细胞的增殖及功能代谢。     

血小板衍生性生长因子(PDGF)与胰岛素样生长因子Ⅰ(IGF-Ⅰ)对成骨细胞增殖及分化的影响

目的探讨PDGF与IGF-Ⅰ对体外培养成骨细胞增殖与分化的影响。方法将兔成骨细胞分别与PDGF(10ng/ml),IGF-Ⅰ(100ng/ml),PDGF(10ng/ml)+IGF-Ⅰ(100ng/ml)共同培养,于1、3、5d分别进行3H-TdR、3H-Proline的掺入量以及碱性磷酸酶合成量的检测。结果PDGF与IGF-1联合应用对3H-TdR、3H-Proline的掺入量与单独使用因子组、对照组相比,在各个时段均存在显著性差异(P<0.01);PDGF与IGF-1联合应用对碱性磷酸酶合成量与对照组、PDGF组相比有显著性差异(P<0.01),与IGF-1组相比,未见明显差异(P>0.05)。结论PDGF与IGF-Ⅰ联合应用可显著促进成骨细胞DNA、胶原蛋白、碱性磷酸酶的合成,对促进成骨细胞的增殖与分化功能具有协同作用。     

成骨生长肽（OGP10-14 )在不同微重力条件下生物学活性的研究

目的 成骨生长肽(osteogenic growth peptide,OGP10-14)在不同重力条件下对成骨细胞增殖、分化的影响.方法 利用MTT实验和alkaline phosphatase(ALP)实验分别测定OGP10-14在不同重力条件下对成骨细胞的增殖、分化效应.结果 在正常条件下,10-12 mol/L及10-8 mol/L OGP10-14能够显著促进成骨细胞的增殖(P<0.05),最大效应浓度是10-12 mol/L,而且10-12 mol/L 的OGP10-14显著促进成骨细胞的ALP活性.在微重力条件下,10-8mol/L OGP10-14诱导48h后,促进细胞增殖作用最强.结论 在不同重力条件下,10-8mol/L OGP10-14对成骨细胞的增殖与分化具有促进作用.在正常条件下,10-12 mol/L 的OGP10-14显著促进成骨细胞的ALP活性.     

瘦素对人前脂肪细胞增殖及分化的影响

目的 观察瘦索在体外对人前脂肪细胞增殖和分化的影响,探讨瘦素调节肥胖发生的可能机制.方法 分离并体外培养人腹部皮下前脂肪细胞.采用3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）比色法、细胞计数法、油红O染色提取法及逆转录-聚合酶链式反应（RT-PCR）方法 分析不同浓度（0～1 000 ng/ml）瘦素对人前脂肪细胞增殖、脂质积聚及分化转录因子γ2过氧化物酶体增殖物激活受体（PPAR-γ）、CCAAT增强子α结合蛋白（C/EBP-α）mRNA表达的影响.结果 高浓度（1 000 ng/ml）瘦素能够促进人前脂肪细胞的增殖、脂质积聚以及PPAR-γ2、C/EBP-α mRNA表达（P〈0.05）.低浓度（10 ng/ml）和中浓度（100 ng/ml）瘦素对人前脂肪细胞的增殖及脂质积聚没有明显的促进作用（P〉0.05）.结论 在体外超生理浓度的瘦素能够促进前脂肪细胞的增殖和分化,提示瘦素抵抗、血清高瘦素浓度等病理状态时,瘦素可能促进前脂肪细胞的增殖及分化,影响肥胖发生.     

EGF和IGF对体外培养兔关节软骨细胞的影响

目的　了解表皮生长因子 (EGF)和胰岛素样生长因子 (IGF)对体外培养兔关节软骨细胞存活数目和分裂增殖百分数的影响。方法　体外培养兔关节软骨细胞传至第 2代 ,分别以EGF、IGF ,以及二者不同的浓度组合作用于软骨细胞。通过酶联免疫检测仪 (MTT)测定软骨细胞存活数 ,流式细胞仪测定软骨细胞分裂增殖百分数。结果　不同浓度EGF对兔关节软骨细胞存活和分裂增殖均有促进作用 ,作用浓度强度次序为 :10ng/ml>0 1ng/ml>10 0ng/ml。不同浓度IGF对兔关节软骨细胞的存活和分裂增殖均有较强促进作用 ,浓度为 5 0ng/ml时 ,刺激效果最显著。EGF与IGF联合使用时 ,刺激效果优于任何一种因子单独使用 ,而以EGF 10ng/ml和IGF 5 0ng/ml为最佳浓度组合。 结论　EGF和IGF都可促进兔关节软骨细胞存活和分裂增殖 ,但以协同作用效果最佳。     

TNF-α对体外培养的人牙囊细胞增殖特性及碱性磷酸酶的影响

目的:检测不同浓度TNF-对体外培养人牙囊细胞增殖活性和碱性磷酸酶活性的影响。方法:第5代人牙囊细胞接种于96孔培养板上,分别与不同浓度的TNF-共同孵育,检测TNF-对人牙囊细胞的增殖活性和碱性磷酸酶活性的影响。结果:TNF-在浓度为10～50ng/ml,时间为3天时促进人牙囊细胞的增殖,浓度为10～200ng/ml时抑制碱性磷酸酶活性。结论:TNF-在特定的浓度和时间促进人牙囊细胞的增殖,抑制牙囊细胞的成骨特性。     

重组人胰岛素样生长因子Ⅰ对大鼠成骨细胞增殖、凋亡及Ⅰ型胶原蛋白合成的影响

目的 观察胰岛素样生长因子Ⅰ（IGF-Ⅰ）对体外培养的大鼠成骨细胞的增殖、凋亡及Ⅰ型胶原蛋白合成的影响，探讨IGF-Ⅰ对骨代谢影响的可能机制。方法 不同浓度rhIGF-Ⅰ刺激体外培养的大鼠成骨细胞，采用噻唑蓝（MTT）法测定细胞增殖能力；肿瘤坏死因子α（TNF-α单独或与rhIGF-Ⅰ共同刺激成骨细胞，流式细胞仪检测细胞周期和凋亡率；rhIGF-Ⅰ刺激成骨细胞，免疫细胞化学结合计算机图像分析系统检测Ⅰ型胶原蛋白的表达。结果 一定浓度IGF-Ⅰ能明显增加成骨细胞数量（P〈0．05），在0．1～100ng／ml这种作用与IGF-Ⅰ的浓度呈正相关；TNF-α在0．1～100ng/ml浓度范围内呈剂量依赖性地促进成骨细胞凋亡（P〈0．05），并使S期细胞减少（P〈0．05），而IGF-Ⅰ能抑制，TNF-α对成骨细胞的促凋亡作用（P〈0．05）；经IGF-Ⅰ的刺激，成骨细胞Ⅰ型胶原蛋白的表达明显高于对照组（P〈0．05）。结论 IGF-Ⅰ对大鼠成骨细胞有明显的促增殖作用，在0．1～100ng/ml之间呈浓度依赖性，IGF-Ⅰ能抑制，TNF-α诱导的大鼠成骨细胞凋亡，IGF-Ⅰ能促进大鼠成骨细胞Ⅰ型胶原蛋白的合成。     

rhBMP-2对骨骼肌卫星细胞增殖与粘附的影响

目的探讨人重组骨形态发生蛋白(rhBMP)-2对骨骼肌卫星细胞增殖与粘附的影响.方法体外分离与培养骨骼肌卫星细胞,分别用0、50、100、500、1000 ng/ml的rhBMP-2诱导培养基培养48h.利用MTT法测定细胞增殖能力的变化,通过荧光法测定接种后1h的粘附细胞率.结果rhBMP-2可促进骨骼肌卫星细胞的增殖,这种作用从BMP浓度为500ng/ml即可表现出来,并随着浓度的增加而越发明显.在rhBMP-2作用下骨骼肌卫星细胞的粘附率增高,在500ng/ml的浓度时达最高,但当BMP浓度进一步增大时,细胞粘附率却不再增加.结论rhBMP-2可促进骨骼肌卫星细胞的增殖,增强其粘附特性.     

Prenatal growth restriction and postnatal growth restriction followed by accelerated growth independently program reduced bone growth and strength

Low birth weight increases the risk of developing adult onset cardiovascular and metabolic diseases. Recently being born small has also been identified as a risk factor for adverse bone growth, development and adult fracture risk. Evidence also suggests that accelerated growth in offspring of normal birth weight, following periods of slowed growth, can also independently program adult diseases. The aim of this study was to determine the relative roles of prenatal and postnatal growth restriction on adult bone characteristics and strength. Bilateral uterine vessel ligation (Restricted) or sham surgery (Control) was performed on gestational day 18 in WKY rats to induce fetal growth restriction. Control, Reduced (reduced Control litter size to match Restricted) and Restricted pups were cross-fostered onto different Control (normal lactation) or Restricted (impaired lactation) mothers 1 day after birth. Femur length, dimensions, strength, mineral content and density were quantified using DXA and pQCT analysis. Markers of bone turnover were measured in offspring at 6 months. Restricted pups were born lighter than Controls with males, not females, remaining smaller than Control-on-Control at 6 months (P < 0.05). Pups born of normal weight from a reduced litter suckling on a Restricted mother (Reduced-on-Restricted) grew slowly during lactation then quicker after weaning compared to Controls (P < 0.05). Cortical bone mineral content, dimensions and strength were lower in Restricted-on-Restricted and Reduced-on-Restricted offspring compared to Controls with lower density in Reduced-on-Restricted females (P < 0.05). The stress strain index of bone bending strength remained lower in the Restricted male offspring when body weight adjustments were made. Cross-fostering Restricted females, but not males, onto mothers with normal lactation (Restricted-on-Control) restored growth and bone parameters to Controls (P < 0.05). Being born small, or postnatal growth restriction for normal birth weight offspring followed by accelerated growth, programs bone content and strength deficits. Deficits were corrected by improving postnatal nutrition for females born small, highlighting sex specific programming outcomes and impact of postnatal nutrition. These findings suggest a link between growth restriction and adult bone health with additional studies needed to further explore this link in humans.     

Organic control of growth and new growth

Each part of the body is transmitted from parent to offspring by genes. The growth and size of each part is dependent upon stimulation by hormones derived from ductless glands. If certain endocrine factors are absent or withdrawn, dwarfing or hypoplasia results; if the stimulating hormone is in excess, giantism or overgrowth may follow. Normally the body is cast in a chemical mold, each cell and part being held to rigid limits as to size and shape by specific chemical compounds circulating in the blood. Thus an epithelial cell, the nose, an arm, the liver, maintain a definite individual size from birth to death. Physiologic new growths of limited duration depend upon new or modified ductless glands of transient existence. For pregnancy a special gland, the corpus luteum, of short life, is called into being. If one attempts to add to the size of the body or of its individual parts by transplantation, cytolysins remove the alien elements. For successful grafting the tissue must come from the individual's own body—an iso-graft. Abnormal new growths may be called into being by the dysfunction of ductless glands and these pathological overgrowths may involve the entire body, a system, a member, an organ, a tissue, a cell or group of cells. New growths which have long been considered as benign or malignant tumors have been proved to result from endocrine dysfunction. We can no longer believe that tumors are always autogenous new growths for pathological new growths clearly arise and progress as a result of endocrine dysfunction.     

Influence of growth hormone and insulin-like growth factor-I on kidney function and kidney growth

Decreased glomerular filtration rate (GFR) in hypopituitarism and increased GFR in acromegaly suggest that growth hormone (GH) has a substantial effect on renal haemodynamics. Extractive and recombinant human (rh) GH in healthy volunteers increased effective renal plasma flow (ERPF) and GFR by 10% and 15% respectively. Renal response to GH was delayed and occurred at the same time as an increase in plasma insulin-like growth factor (IGF)-I values, whereas infusion of rhIGF-I promptly increased GFR and ERPF, indicating that the haemodynamic response of the kidney to GH is mediated by IGF-I. In chronic renal failure (CRF), the acute effect of GH on GFR is obliterated. This might protect the diseased kidney against the undesired consequences of hyperfiltration. Indeed, rhGH treatment for 1 year in children with CRF did not lead to an accelerated decline in GFR compared with the year before treatment. GH and IGF-I also effect renal growth. Exposure to excessive GH in transgenic mice causes renomegaly and progressive glomerular selerosis. In acromegalic humans, increased renal size and weight and increased glomerular diameter are well known, whereas renal failure is not a long-term hazard. At least in normal and hypophysectomized rats treated with doses comparable with the therapeutic regimens used in stunted children, rhGH increased renal weight but in proportion to the increase in body weight indicating an isometric effect of GH on renal growth. From these data, major renal longterm side effects of rhGH treatment in children with CRF appear unlikely.     

Compensatory renal growth: role of growth hormone and insulin-like growth factor-I

Recent experimental evidence suggests that insulin-like growth factor-I (IGF-I) may be involved in compensatory renal growth (CRG). This study was designed to determine the relative contribution of IGF-I and growth hormone (GH) to the CRG that takes place in rats following uninephrectomy (UNx). We also studied the respective role of GH and IGF-I in the stimulation of CRG induced by a high protein diet (HPD). CRG was studied 7 days after UNx in Wistar rats and in a new mutant strain of dwarf rats, selectively deficient in GH. Prior to UNx, rats of both strains were pre-fed (14 days) either a medium-protein diet (MPD, casein 18%) or a HPD (54%). On MPD, CRG was comparable in Wistar (17.6 +/- 3.1%, M +/- SD) and dwarf (14.4 +/- 4.8%) rats. The HPD enhanced CRG in the Wistars (27 +/- 3.9%, P less than 0.005) but not in the dwarfs (14.9 +/- 2%). CRG in both experimental groups involved renal hypertrophy and hyperplasia. Control (baseline) serum, liver and kidney IGF-I were significantly less in dwarf rats. However, following UNx, on a MPD, kidney IGF-I increased significantly in both Wistar and dwarf rats: Wistar, pre-UNx, 310 +/- 46 ng/g tissue; post-UNx, 405 +/- 54 ng/g, P less than 0.005; dwarfs, pre-UNx, 205 +/- 35 ng/g; post-UNx 426 +/- 90 ng/g, P less than 0.001. On a HPD a further significant increase in renal IGF-I was only observed in Wistar rats (505 +/- 46 ng/g). No change in serum or liver IGF-I was observed after UNx in either strain.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regulation of cartilage growth by growth hormone and insulin-like growth factor I

A number of studies have shown that growth hormone (GH) and insulin-like growth factor-I (IGF-I) have important regulatory roles for skeletal growth. However, it has been a matter of controversy whether GH acts directly on cells in the growth plate or if the growth-promoting effects of GH are mediated by liver-derived (endocrine-acting) IGF-I. With the recognition that GH regulates the production of IGF-I in multiple extra-hepatic tissues, autocrine and paracrine functions of IGF-I have been suggested as important components of GH action. This review focuses on recent developments in our understanding of the cellular mechanisms by which GH promotes longitudinal bone growth and the inter-relationship between GH and IGF-I in the growth plate.     

The role of growth hormone and insulin-like growth factor-I in experimental renal growth and scarring

Recent evidence suggests a causal link between early renal/glomerular hypertrophy and late kidney scarring and glomerular sclerosis. Insulin-like growth factor-I (IGF-I) is a growth-promoting peptide likely to play a role in the development of kidney growth. We observed an increased renal IGF-I content in two experimental models of accelerated kidney growth in the rat. By contrast, diabetic renal hypertrophy is abolished in the absence of growth hormone (GH). Dietary protein manipulations affect the expression of compensatory renal growth (CRG), as well as renal IGF-I content. The renotrophic effect of a high-protein diet on CRG seems GH-dependent and IGF-I-mediated. GH also appears to have a permissive role on the development of progressive renal scarring following extensive renal ablation in rats, as dwarf rats seem somewhat resistant to the development of accelerated scarring and renal failure.     

Experimental diabetic renal growth: role of growth hormone and insulin-like growth factor-I

We have compared the kidneys of two inbred strains of rats (Lewisand Lewis-Dwarf) 7 days after the induction of diabetes mellituswith streptozotocin, in order to examine the influence of aselective growth hormone (GH) deficiency on diabetic renal growthand insulin-like growth factor-I (IGF-I) content of the kidneys.Insulin-like growth factor-I was measured by radioimmunoassayand its distribution within the kidney by immunohistochemicalstaining. We detected a significant increase in both the wetweight (32.9±5.3%, P=0.0085) and dry weight (16.3±6.3%,P=0.046) of the kidneys of diabetic Lewis rats but dwarf rats,selectively deficient in GH, did not show a significant increasein either parameter. Extractable IGF-I increased within thekidneys of diabetic rats of both strains but to a lesser extentin the dwarf rats (+105±28% and +65±21% respectively,P<0.0l). In diabetic Lewis rats a positive correlation wasnoted between the severity of glycaemia and kidney IGF-I content(r=0.604, P<0.05) but no such correlation was noted in dwarfrats. Insulin-like growth factor-I immunostaining increased in diabeticrats of both strains, mainly within cells of the thick ascendinglimb of the loop of Henle including damaged and vacuolated cells.However, morphometric analysis of the staining showed that itwas significantly less widespread in the diabetic dwarf rats(P=0.026). We conclude that growth hormone deficiency bluntsexperimental diabetic renal growth and restricts the increasein the kidney IGF-I content. These findings raise further questionsconcerning the contribution of GH and IGF-I to the early stagesof experimental diabetic renal disease.     

Epidermal growth factor and keratinocyte growth factor differentially regulate epidermal migration, growth, and differentiation

Various growth factors such as epidermal growth factor and keratinocyte growth factor have been reported to promote wound closure and epidermal regeneration. In the present study epidermis reconstructed on de-epidermized dermis was used to investigate the effects of epidermal growth factor and keratinocyte growth factor on keratinocyte proliferation, migration and differentiation. Our results show that epidermal growth factor supplemented cultures share many of the features which are observed during regeneration of wounded epidermis: a thickening of the entire epidermis, an enhanced rate of proliferation and migration, and an increase in keratin 6, keratin 16, skin-derived antileukoproteinase, involucrin and transglutaminase 1 expression. The increase in transglutaminase 1 protein is accompanied by an increase in the amount of active transglutaminase 1 enzyme. Surprisingly no increase in keratin 17 is observed. Prolonging the culture period for more than two weeks results in rapid senescence and aging of the cultures. In contrast, keratinocyte growth factor supplemented cultures have a tissue architecture that is similar to healthy native epidermis and remains unchanged for at least 4 weeks of air-exposure. The rate of proliferation and the expression of keratins 6, 16 and 17, skin-derived antileukoproteinase, involucrin and transglutaminase 1 is similar to that found in healthy epidermis and furthermore keratinocyte migration does not occur. When the culture medium is supplemented with a combination of keratinocyte growth factor and a low concentration of epidermal growth factor, skin-derived antileukoproteinase, involucrin and keratins 6, 16 and 17 expression is similar to that found in cultures supplemented with keratinocyte growth factor alone and in healthy epidermis. Only high transglutaminase 1 expression remains similar to that observed in cultures supplemented with epidermal growth factor alone. Our results show that the regulation of keratinocyte growth, migration and differentiation depends on the availability of these growth factors. Epidermal growth factor may play a dominant early role in wound healing by stimulating keratinocyte proliferation and migration while keratinocyte growth factor may play a role later in the repair process by stabilizing epidermal turnover and barrier function.     

Normal growth and growth predictions in the upper extremity

The study consisted of 102 children, 50 boys and 52 girls, who were randomly selected. Measurements of their extremities were obtained from orthoroentgenograms with the method described by Anderson and Green. On the basis of this information, growth prediction charts were developed for the individual bones (humerus, ulna, and radius), as well as for the entire upper extremeity. These charts can be a valuable tool in the correction of growth inequality, particularly in the treatment of differential bone growth of the distal forearm.