共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Basic fibroblast growth factor (bFGF) is known to stimulate endosteal bone formation in vivo by a mechanism possibly mediated via osteoblast precursor cells present in the bone marrow. In high density cultures of primary
bone marrow cells, and in the presence of glucocorticoids, bFGF stimulates the formation of a bone-like matrix; however, due
to the dense nature of these cultures, the exact mechanism of action is unclear. In an adaptation of the fibroblastic colony
formation unit assay, in which the bone marrow cells are grown in the presence of dexamethasone, β-glycerophosphate, and ascorbate,
mineralized colonies are formed which stem from single mesenchymal precursor cells and grow in isolation from each other.
Using this system we have been able to investigate the mechanism by which bFGF stimulates the formation of bone like tissue
in vitro. We have shown that bFGF increases the formation of a calcified collagenous matrix in vitro by (1) increasing the total number of fibroblastic colonies formed, (2) increasing the proportion of differentiated colonies
that synthesize collagen and calcify, and (3) stimulating the proliferation and collagen accumulation of the individual colonies.
A maximal increase in total and differentiated colony numbers was seen after only 5 days exposure to bFGF, however, continued
exposure to bFGF continued to increase the size and collagen content of the individual colonies. Bearing in mind the endosteal
location of newly formed bone seen after treatment with bFGF, these processes may well play an active role in this effect.
Received: 17 January 1997 / Accepted: 30 July 1998 相似文献
3.
We have examined the effects of aluminum (Al) on osteoprogenitor proliferation and differentiation, cell survival, and bone
formation in long-term rat calvaria (RC) cell cultures. RC cells were grown in α minimal essential medium containing 10% fetal
bovine serum, 50 μg/ml ascorbic acid, and 10 mM β-glycerophosphate with or without Al added to final concentrations of 1 μM—1
mM. Al caused a dose-dependent increase in the number of bone nodules present at early times (day 11) but had no significant
effect on nodule numbers at later times (day 17). Time course experiments showed that Al increased nodule number beginning
from day 7. Alkaline phosphatase activity, assessed at four stages during the differentiation sequence of RC cell cultures
(from 4 to 13 days) was stimulated by Al at all times. However, Al decreased colony formation, inhibited cell growth in late
log phase, and decreased saturation density of the treated cultures. Al concentrations of 30 μM and above resulted in degeneration
of the cell layer and an increasing fibrillar appearance of the matrix present in between or adjacent to nodules when cultures
were maintained for more than 15 days. The presence of Al significantly decreased the viability of cells obtained from 13–17
days cultures, as determined by plating efficiency and trypan blue exclusion. We frequently observed cellular toxicity (in
8 of 10 experiments) in cultures containing 300 μM Al, and by days 17–19, cells, nodules, and matrix were disintegrating in
these cultures. We conclude that Al accelerates the rate of osteoprogenitor cell differentiation and the formation of bone
nodules while concomitantly inhibiting nodule mineralization. However, concentrations that accelerate differentiation appear
to be cytotoxic in long-term cultures.
Received: 29 April 1997 / Accepted: 9 December 1998 相似文献
4.
C. Kasperk A. Helmboldt I. Börcsök S. Heuthe O. Cloos F. Niethard R. Ziegler 《Calcified tissue international》1997,61(6):464-473
There are obvious sexual differences in adult skeletal morphology which for the most part are related to differences in size.
Higher androgen serum levels in males exert potent osteoanabolic effects and therefore may contribute to this sexual dimorphism
of the skeleton. The presence of androgen receptors (AR) in bone cells is a prerequisite for a direct osteoanabolic action
of androgens. To investigate the possibility that, in addition to gender-related differences in androgen serum levels, there
are also gender-related differences in the osteoblastic expression pattern of the androgen receptor, we examined AR mRNA expression,
androgen binding sites, and mitogenic responses to the androgen dihydrotestosterone (DHT) in human osteoblastic cell (HOC)
populations. HOCs were isolated from bone biopsy specimens derived from different skeletal sites of healthy adult males and
females (2–69 years old). We found that male and female HOCs of all examined ages express similar AR mRNA levels and similar
numbers of androgen binding sites. Using whole-cell-binding assays, we observed 3129–8417 androgen binding sites per femoral
HOC with apparent KDs of 1.45–2.83 nM depending on the age of the investigated HOC population. Mandibular and cortical HOC
of both sexes expressed higher AR mRNA levels, significantly more androgen binding sites per cell, and exhibited significantly
greater mitogenic responses to DHT than iliac crest-derived and trabecular HOC of the same skeletal system and the same skeletal-site,
respectively. In early adulthood, HOCs of both sexes appear to express somewhat higher AR mRNA levels and to possess more
androgen binding sites than prepubertal and senescent HOC. Because sex hormone serum levels rise in puberty, we investigated
the regulation of the AR mRNA expression by various steroids. We found that dexamethasone (dexa) and in some experiments also
17β-estradiol (E2) and 1,25-dihydroxyvitamin D3 (D3) increased AR mRNA levels and androgen binding in HOC cultures. A pretreatment
with dexa, E2, and D3 significantly increased the mitogenic response of HOCs to DHT. We conclude that (1) higher androgen
serum levels in males together with a higher AR expression at certain skeletal sites may contribute to the development of
sex-related differences in skeletal morphology, (2) glucocorticoids induce AR gene expression in HOC cultures, and (3) glucocorticoids,
E2, and D3 enhance the mitogenic action of DHT.
Received: 3 June 1996 / Accepted: 30 April 1997 相似文献
5.
Influence of Skeletal Site of Origin and Donor Age on Osteoblastic Cell Growth and Differentiation 总被引:9,自引:0,他引:9
Martínez ME del Campo MT Medina S Sánchez M Sánchez-Cabezudo MJ Esbrit P Martínez P Moreno I Rodrigo A Garcés MV Munuera L 《Calcified tissue international》1999,64(4):280-286
Bone loss with aging may be due, at least in part, to inadequate bone formation. Moreover, the process of bone aging is known
to follow a different pattern throughout the skeleton. In this study, we examined the cell proliferation rate (area under
the cell growth curve, AUC) and the secretion of C-terminal type I procollagen (PICP), alkaline phosphatase (ALP), and osteocalcin
(OC) in primary cultures of osteoblastic cells from human trabecular bone. Osteoblastic cells were obtained for 168 donors
(100 women and 68 men). Ninety-eight bone samples were obtained from subjects undergoing knee arthroplastia, 52 aged 50–70
years (64 ± 5) and 46 over age 70 (73 ± 2). Another 70 bone samples were obtained from subjects undergoing hip arthroplastia;
51 were 50–70 years old (64 ± 4) and 19 were over 70 (75 ± 5). Osteoblastic cells from the older donors had a lower proliferation
rate and OC secretion than those from younger subjects. However, ALP secretion was higher in the former subjects, whereas
PICP secretion was unchanged. Osteoblastic cells from hip had a lower proliferation rate than those from knee. PICP secretion
was also lower and ALP secretion was higher in the former cells. In age-matched cell cultures, osteoblastic cells from the
knee had higher proliferation rate and PICP secretion than osteoblastic cells from the hip. However, ALP secretion was lower
in knee osteoblastic cells than those from hip only in the younger group. With aging, ALP secretion was found to increase
in knee osteoblactic cells, whereas OC secretion decreased in osteoblastic cell cultures from the hip. Our findings suggest
that bone loss with aging may be accounted for, at least in part, by a decreased osteoblastic cell proliferation and an increased
osteoblastic maturation. In addition, our data indicate that these changes with aging do not occur similarly at different
skeletal sites.
Received: 25 March 1998 / Accepted: 1 October 1998 相似文献
6.
探讨表皮生长因子受体(EGFR)和多胺(PA)对人肺癌及正常肺组织生长、分化的影响。方法放射性配体结合法检测EGFR含量;高效液相色谱分析法测PA含量。结果肺癌组织中EGFR的含量(5.62±4.26fmol/mg膜蛋白)高于非癌肺组织(3.905±2.279fmol/mg膜蛋白),有显著性差异(P<0.01);肺癌组织PA的含量亦高于正常肺组织(P<0.01)。结论EGFR和PA可促使肺癌发展,可作为肺癌的肿瘤标记物 相似文献
7.
Sasaki H Yukiue H Sekimura A Mizuno K Konishi A Yano M Fukai I Fujii Y 《Surgery today》2004,34(5):477-479
Using the enzyme immunoassay for epidermal growth factor receptor (EGFR), we investigated whether serum EGFR levels could be used as a predictor of the development and extension of thymoma. Serum samples were collected from 31 patients with thymoma and 16 patients with nonmalignant thoracic disease before clinical treatment. There was no difference between the serum EGFR levels of the patients with thymoma and the nonmalignant controls, being 49.1 ± 136.3 and 22.6 ± 7.3fm/ml, respectively (P = 0.11). However, patients with stage IV thymoma had significantly higher EGFR levels than those with stage I or stage II thymoma, the respective values being 127.8 ± 243.9, 10.9 ± 9.2 (P = 0.02), and 19.7 ± 10.6 (P = 0.0433) fm/ml. The serum EGFR levels were similar in the pathological subtypes. These findings suggest that serum EGFR levels may serve as a marker that could be used as a diagnostic indicator of the invasion of thymoma. 相似文献
8.
R. F. Watson R. D. Chernock K. H. Zhang L. S. Michel D. R. Adkins S. K. El-Mofty J. S. Lewis Jr. 《Head and neck pathology》2015,9(3):360-368
Spindle cell carcinoma (SpCC) is an uncommon head and neck squamous cell carcinoma (SCC) variant consisting of spindled and/or pleomorphic cells with epithelial differentiation. Epidermal growth factor receptor (EGFR) is expressed by >90 % of conventional SCC, and high level expression is associated with a poorer prognosis. Anti-EGFR therapies are commonly used to treat head and neck SCC. However, no studies have evaluated EGFR expression in SpCC. Cases of SpCC were retrieved from department files. The diagnosis required either a biphasic lesion with a squamous neoplastic component, or a purely spindle cell or pleomorphic tumor with immunohistochemical positivity for epithelial markers. EGFR immunohistochemistry was performed and was quantified in quartiles. Medical records were reviewed for clinical follow up information. EGFR was expressed in 21/30 (70 %) cases, including in the squamous component in 18/19 (95 %) and the spindle cell component in only 12/30 (40 %). Where the spindle cell component was positive, the intensity and distribution were lower than for the squamous component. Recurrent tumors were predominantly (80–90 %) of the spindle cell component, and had low (or absent) EGFR expression. Kaplan–Meier survival analysis showed no statistically significant differences in overall or disease free survival between the EGFR expressing and non-expressing groups (p = 0.414 and 0.19, respectively). SpCCs of the head and neck have a poor prognosis, and markedly reduced EGFR expression. EGFR-specific therapies may not be ideal for SpCC patients, which may lack EGFR expression, but further studies are needed.
Electronic supplementary material
The online version of this article (doi:10.1007/s12105-014-0604-y) contains supplementary material, which is available to authorized users. 相似文献9.
10.
K. B. Jonsson K. Wiberg S. Ljunghall Ö. Ljunggren 《Calcified tissue international》1996,59(5):366-370
Insulin-like growth factor I (IGF-I) has documented anabolic effects on osteoblasts, whereas its influence on osteoclasts
and on bone resorption is unclear. We have investigated the effects of IGF-I on osteoclast recruitment and bone resorption
in vitro. IGF-I (at and above 1 nM) stimulated the formation of multinucleated tartrate-resistant acid phosphatase positive
cells in murine bone marrow cultures, incubated for 9 days. The number of multinucleated cells increased to 540 ± 160% of
control (mean ± SEM) in cultures treated with 10 nM IGF-I. IGF-I (0.1–100 nM) had no effect by itself on 45Ca-release from prelabelled neonatal mouse calvarial bones. However, IGF-I (100 nM) had an inhibitory effect on bone resorption
induced by prostaglandin E2 and 1,25(OH)2D3. These findings indicate that IGF-I enhances the formation of osteoclasts-like cells in long-term bone marrow cultures. In
bone organ cultures, however, IGF-I has an inhibitory effect on stimulated bone resorption, suggesting that IGF-I inhibits
existing osteoclasts and, alternatively, that IGF-I interferes with the osteoblast-derived factor(s) that stimulate existing
osteoclasts.
Received: 15 August 1995 / Accepted: 1 April 1996 相似文献
11.
Stimulation of Bone Formation by Recombinant Fibroblast Growth Factor-2 in Callotasis Bone Lengthening of Rabbits 总被引:19,自引:0,他引:19
H. Okazaki T. Kurokawa K. Nakamura T. Matsushita K. Mamada H. Kawaguchi 《Calcified tissue international》1999,64(6):542-546
Bone lengthening by callotasis is one of the most useful methods not only for the treatment of short extremities but also
for extensive bone defects; however, the procedure takes a long time especially for the consolidation of the distracted callus.
In this study, effects of a single local injection of recombinant human fibroblast growth factor-2 (FGF-2 or basic FGF) on
callotasis bone lengthening were examined in rabbits. Ten days after the osteotomy at the middle of the tibia and the installment
of an external fixator, the osteotomized site was distracted at a rate of 1.4 mm/day for 7 days, resulting in 9.8 mm lengthening.
On the final day of distraction, 200 μg of FGF-2 in 150 μl of saline solution or vehicle alone was injected into the center
of the distracted callus. Injection of FGF-2 increased bone formation at the distracted callus radiologically and histologically.
A significant effect on bone mineral content (BMC) at the callus was observed as early as 2 weeks, and FGF-2 increased the
BMC about twofold at 5 weeks after a normal remodeling process. We conclude that the callotasis method in combination with
FGF-2 injection at the consolidation step could be clinically beneficial to shorten the bone lengthening period.
Received: 6 May 1997 / Accepted: 1 November 1998 相似文献
12.
M. Miyao T. Hosoi S. Inoue S. Hoshino M. Shiraki H. Orimo Y. Ouchi 《Calcified tissue international》1998,63(4):306-311
13.
Clinical Significance of the Epidermal Growth Factor Receptor and HER2 Receptor in Resectable Gastric Cancer 总被引:8,自引:0,他引:8
García I Vizoso F Martín A Sanz L Abdel-Lah O Raigoso P García-Muñiz JL 《Annals of surgical oncology》2003,10(3):234-241
Background: Epidermal growth factor receptor (EGFR or HER1) and its homolog c-erbB-2 (HER2) are membrane receptors. Both EGFR and HER2 genes are overexpressed in a variety of solid human cancers and are related to poor prognosis of the patients. The objective of this work was to evaluate the EGFR and HER2 contents in resectable gastric cancer, their possible relationship with clinicopathologic parameters of tumors, and their prognostic significance.Methods: This was a prospective analysis of 63 patients with resectable gastric carcinomas, with a mean follow-up period of 40.7 months. Membranous EGFR levels were examined by radioligand binding assays, and cytosolic HER2 levels were examined by means of an immunoenzymatic assay.Results: There was a wide variability of EGFR (1–1,239 fmol/mg of protein) and HER2 (7–20,863 NHU/mg of protein) levels in tumors. There was no significant correlation between these levels and patient or tumor characteristics. However, high levels of EGFR and HER2 were significantly associated with a shorter overall survival period (P = .03 and P = .02, respectively).Conclusions: There is a wide variability in membranous EGFR levels and in cytosolic HER2 levels in gastric cancer, which seems to be related to the biological heterogeneity of these tumors. In addition, high tumor EGFR and HER2 levels were associated with an unfavorable outcome in patients with resectable gastric cancer. 相似文献
14.
目的探讨膜表面核仁素(nucleiolin,NCL)在表皮生长因子受体(epidermal growth factor receptor,EGFR)信号启动中的作用。方法采用免疫组化法检测NCL及EGFR在甲状腺乳头状癌组织中的表达;Western blot法检测甲状腺乳头状癌细胞TPC-1中磷酸化EGFR(phosphorylation EGFR,p-EGFR)的表达水平;Transwell小室试验检测TPC-1细胞的迁移能力。结果免疫组化染色结果显示,甲状腺乳头状癌组织中NCL及EGFR的表达阳性率分别为100%(56/56)和80.4%(45/56);NCL及EGFR的表达与淋巴结转移有关(P〈0.05),且NCL的表达与EGFR的表达呈正相关关系(r=0.635,P〈0.01)。Western blot法检测结果显示,拮抗甲状腺乳头状癌TPC-1细胞的NCL或EGFR后,其p-EGFR表达水平均明显下调(P〈0.01)。Transwell小室试验发现,拮抗NCL和EGFR后,可明显减少TPC-1细胞的穿膜细胞数(P〈0.01)。结论膜表面NCL可能是EGFR受体信号启动的必要成分,可能通过EGFR参与肿瘤的生长与转移。以NCL为靶点将开拓肿瘤新的治疗领域。 相似文献
15.
M. E. Martínez S. Medina M. T. del Campo M. J. Sánchez-Cabezudo M. Sánchez L. Munuera 《Calcified tissue international》1998,62(5):453-456
We have studied the direct effects of polyethylene particles on osteoblastic function in primary human bone cell cultures.
The cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. When the cells
reached confluency, they were subcultured into two flasks, one untreated (control culture) and the other treated with polyethylene
particles, and incubated until confluency. Osteoblastic function was evaluated by assaying osteocalcin, alkaline phosphatase,
and C-terminal procollagen type I, with and without 1,25(OH)2D stimulation, in the cell-conditioned medium. We found that addition of polyethylene to these osteoblastic cell cultures
induced higher levels of secreted osteocalcin after 1,25(OH)2D stimulation. Alkaline phosphatase levels increased whereas C-terminal procollagen type I levels decreased in the cell conditioned
medium after polyethylene was added to the cultures. Treatment of the control cultures with 1,25(OH)2D stimulated alkaline phosphatase levels and decreased C-terminal procollagen type I. However, these osteoblastic markers
in 1,25(OH)2D-treated cells did not change in cultures with polyethylene. This study demonstrates that polyethylene particles have a direct
effect on osteoblastic markers in human bone cells in culture.
Received: 2 May 1996 / Accepted: 17 June 1997 相似文献
16.
R. W. Keen P. Egger C. Fall P. J. Major J. S. Lanchbury T. D. Spector C. Cooper 《Calcified tissue international》1997,60(3):233-235
Family and twin studies have demonstrated a strong genetic component to the development of peak bone mass. Early fetal and
infant environment has also been shown to influence bone mass through an effect on skeletal size and mineral content. We report
a retrospective study that has examined whether early infant growth is regulated by genetic factors shown to be associated
with bone mass. We have determined the vitamin D receptor (VDR) gene alleles for 66 women (mean age 65.5 years) on whom detailed
birth records were available. There was a statistically significant trend (P= 0.04) for VDR genotype against weight at the age of 1 year, with the ``tt' homozygote group having 7% higher weight. We
conclude that early fetal or infant environment may interact with an individual's underlying genotype to program early skeletal
growth, and that this may track through later life to influence adult characteristics. Further prospective studies are required,
however, to fully clarify the precise environmental and genetic mechanisms underlying these findings.
Received: 5 June 1996 / Accepted: 21 August 1996 相似文献
17.
In this study, we demonstrated that type I collagen matrix induced the expression of osteoblastic phenotypes of bone marrow
cells, and that antibone sialoprotein (BSP) monoclonal antibody suppressed the expression of these phenotypes. On the other
hand, BSP accelerated the expression of osteoblastic phenotypes of bone marrow cells. The adherent bone marrow cells were
harvested from rat femur and cultured on type I collagen matrix gels in medium containing 15% fetal calf serum, neither β-glycerophosphate
nor glucocorticoid. Cells showed osteoblastic phenotypes (high alkaline phosphatase activity, osteocalcin synthesis, and responsiveness
against parathyroid hormone) on collagen matrix gels at week 3 after the inoculation, and simultaneously, BSP was detected
in the conditioned medium by Western blotting using an anti-BSP monoclonal antibody. However, cells in the conventional culture
dishes did not show osteoblastic phenotypes during the experimental period. To investigate the physiological function of BSP
in osteoblastic differentiation, bone marrow cells were cultured on collagen matrix with an anti-BSP monoclonal antibody for
3 weeks. This treatment suppressed the expression of the osteoblastic phenotypes, and the effect of the antibody was abolished
by the addition of bovine bone BSP. Furthermore, bovine bone BSP stimulated the expression of osteoblastic phenotypes of bone
marrow cells. Our results indicate that BSP plays a crucial role in the expression of osteoblastic phenotypes of bone marrow
cells.
Received: 17 February 1999 / Accepted: 14 December 1999 相似文献
18.
Osteoporosis is a well-known side effect of long-term treatment with glucocorticoids. The hepatocyte growth factor (HGF)
receptor is expressed by human osteoclasts and osteoblasts, and mouse osteoblasts also express HGF, indicating that HGF may
regulate bone metabolism. Because HGF could be a candidate factor in the local paracrine signaling between osteoblasts and
osteoclasts in bone, we decided to study whether human osteoblasts secrete HGF and whether glucocorticoids regulate the expression
of HGF. HGF was easily detectable in the culture medium from human osteoblast-like cells (hOB). The HGF protein released into
the culture medium was increased with increasing confluency. Hydrocortisone decreased the amount of HGF released into the
culture medium from hOB in a dose-dependent manner with a maximal effect at 10− M. Time-course studies revealed that hydrocortisone decreased the amount of HGF released into the culture medium significantly
after 16 hours of stimulation (65 ± 2% of control culture). This effect of hydrocortisone was maximal after 24 hours of stimulation
(52 ± 8% of control culture). In conclusion, HGF is produced by primary cultured hOB cells. Furthermore, the amount of HGF
released into the culture medium is decreased by glucocorticoids. The biological significance of this finding remains to be
demonstrated.
Received: 29 December 1998 / Accepted: 13 August 1999 相似文献
19.
Fluid Shear Stress Increases Transforming Growth Factor Beta 1 Expression in Human Osteoblast-like Cells: Modulation by Cation Channel Blockades 总被引:7,自引:0,他引:7
Mechanical stress is an important regulator of bone metabolism. Fluid shear stress caused by mechanical load in bone tissue
has been shown to be important to both the bone structure and function through its effects on osteocytes and osteoblasts.
We explored the effects of the fluid shear stress on the expression of growth factors and cytokines in human osteoblast-like
SaOS-2 cells with a purpose-built cone-plate viscometer. We showed that the physiological level (1.7–2.0 Pascal) of fluid
shear stress increased the mRNA expression of TGF-β1 about threefold after 3 hours and also increased TGF-β1 protein about
threefold after 24 hours in the SaOS-2 cells. However, no mRNA expression of PDGF-A, IGF-I, IGF-II, or IL-6 was detected.
To explore the mechanism of up-regulation of TGF-β1 expression, we examined the effects of a stretch activated cation nonselective
(SA-cat) channel blockade with gadolinium and a voltage-dependent L-type Ca2+ channel blockade with verapamil on the TGF-β1 expression at the mRNA levels. The fluid shear stress-induced increase in the
TGF-β1 mRNA levels was significantly inhibited by both gadolinium and verapamil. These findings suggest that the physiological
level of fluid shear stress induces the production of TGF-β1 by the SaOS-2 cells via the cation channel function and, as a
result, may therefore promote bone formation.
Received: 15 October 1997 / Accepted: 8 April 1998 相似文献
20.
M. Ishibe T. Ishibashi K. Kaneda T. Koda R. N. Rosier J. E. Puzas 《Calcified tissue international》1998,63(1):36-38
Insulin-like growth factor-II (IGF-II) plays an important role in skeletal remodeling, however, little is known about its
effect on bone formation in vivo. In our study of the stimulation of bone formation in vivo by IGF II we injected recombinant human IGF-II into the parietal bones of neonatal rats once a day for 12 days. The bone
mineral density measured by dual energy X-ray absorptiometry and the thickness of IGF-II-injected parietal bones increased
in a dose-dependent manner. The layers of osteoblasts were observed along the IGF-II-injected side.
Received: 12 June 1997 / Accepted: 8 January 1998 相似文献