Role of extracellular calcium influx in EGF-induced osteoblastic cell proliferation

Loza, J.; Carpio, Lillian; Lawless, George M.; Marzec, N.; Dziak, Rosemary

doi:10.1016/s8756-3282(95)80337-8

Cited by 29 publications

(24 citation statements)

References 42 publications

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“…Thus the decreased trabecular bone mass in the EGFRϪ/Ϫ mice was likely because of decreased osteoblast proliferation. A direct effect of EGFR signaling on osteoblasts is supported by previous studies showing that EGFR was expressed in osteoblasts in vivo (17,43), and that EGF stimulated osteoblast proliferation in vitro (44,45).…”

Section: Egfr Signaling Is Necessary For Normal Osteoclast Recruitmenmentioning

confidence: 61%

Epidermal Growth Factor Receptor-deficient Mice Have Delayed Primary Endochondral Ossification Because of Defective Osteoclast Recruitment

Wang

Yamamoto

Chin

et al. 2004

Journal of Biological Chemistry

101

110

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The epidermal growth factor receptor (EGFR) and its ligands function in diverse cellular functions including cell proliferation, differentiation, motility, and survival. EGFR signaling is important for the development of many tissues, including skin, lungs, intestines, and the craniofacial skeleton. We have now determined the role of EGFR signaling in endochondral ossification. We analyzed long bone development in EGFR-deficient mice. EGFR deficiency caused delayed primary ossification of the cartilage anlage and delayed osteoclast and osteoblast recruitment. Ossification of the growth plates was also abnormal resulting in an expanded area of growth plate hypertrophic cartilage and few bony trabeculae. The delayed osteoclast recruitment was not because of inadequate expression of matrix metalloproteinases, including matrix metalloproteinase-9, which have previously been shown to be important for osteoclast recruitment. EGFR was expressed by osteoclasts, suggesting that EGFR ligands may act directly to affect the formation and/or function of these cells. EGFR signaling regulated osteoclast formation. Inhibition of EGFR tyrosine kinase activity decreased the generation of osteoclasts from cultured bone marrow cells.Skeletal elements develop by two distinct mechanisms: intramembranous and endochondral ossification (1). Endochondral ossification is a process by which a cartilaginous template is first formed and then replaced by bone. During embryogenesis, condensations of mesenchymal cells form, within which chondrocytes develop, proliferate, and differentiate to form a cartilage template that contains distinct zones of resting, proliferative, and hypertrophic chondrocytes. The proliferation and differentiation of chondrocytes within the cartilage template are spatially ordered, with proliferating cells at the two ends of the template and progressively more mature cells forming hypertrophic cartilage in the middle. Hypertrophic chondrocytes secrete a specialized extracellular matrix (ECM) 1 containing collagen X, which becomes calcified. Endochondral ossification begins with the invasion of the calcified hypertrophic cartilage by blood vessels, accompanied by osteoclasts and osteoblasts (primary ossification center). The function of osteoclasts is to remove the hypertrophic cartilage ECM and that of osteoblasts is to replace it with bone ECM. Longitudinal bone growth is accomplished by the continuing proliferation and maturation of chondrocytes at the ends of the cartilage template (the growth plates) to form more hypertrophic cartilage and its continual removal and replacement by bone (growth plate ossification or formation of primary spongiosa). Normal endochondral bone development requires the exquisite coordination of hypertrophic cartilage formation, vascular invasion, and the development and function of osteoclasts and osteoblasts (2, 3).The epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases includes EGFR/ErbB1, HER2/ErbB2, HER3/ErbB3, and HER4/ErbB4 (4, 5). EGFR binds several ligands ...

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Section: Egfr Signaling Is Necessary For Normal Osteoclast Recruitmenmentioning

confidence: 61%

Epidermal Growth Factor Receptor-deficient Mice Have Delayed Primary Endochondral Ossification Because of Defective Osteoclast Recruitment

Wang

Yamamoto

Chin

et al. 2004

Journal of Biological Chemistry

101

110

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“…We have previously shown that EGF increases osteoblastic cell proliferation (16) . We extended this observation by showing that cytosolic calcium increases due to calcium influx through VACCs mediate the EGF‐induced increase in proliferation (17) . The sequence of events triggered by EGF in rat calvarial osteoblasts has been described (18) .…”

Section: Discussionmentioning

confidence: 75%

“…Epidermal growth factor (EGF) is a mitogen for osteoblastic cells (16) . We found that L type VACCs mediate the effect of EGF in cytosolic calcium and in osteoblastic cell proliferation (17,18) . Permeabilization of plasma membrane with Streptolysin O allows introduction of antisense oligonucleotides into a cell with the purpose of blocking specific mRNA translation but still maintaining cell viability (19) .…”

Section: Introductionmentioning

confidence: 99%

Molecular Characterization of the α1 Subunit of the L Type Voltage Calcium Channel Expressed in Rat Calvarial Osteoblasts

Loza

Carpio

Bradford

et al. 1999

Journal of Bone and Mineral Research

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Voltage-activated calcium channels (VACCs) regulate extracellular calcium influx in many cells. VACCs are composed of five subunits. The ␣ 1 subunit is considered the most important in regulating channel function. Three isoforms of this subunit have been described: skeletal, cardiac, and neuroendocrine. It was the purpose of the present study to determine the molecular identity of the ␣ 1 subunit of the VACCs in rat calvarial osteoblasts and to study the nature of the regulation of these channels as a function of cellular growth. We also attempted to identify which isoform of the ␣ 1 subunit of the VACCs mediates the effects of epidermal growth factor (EGF) on osteoblastic cell proliferation. Reverse transcription-polymerase chain reaction was used to detect the isoforms of the VACCs that are expressed in osteoblastic cells. These analyses showed that the proliferative state of the cell and the time in culture influence RNA expression. The only ␣ 1 subunit detected in osteoblasts corresponds to the cardiac isoform. In additional experiments, the effects of EGF on cytosolic calcium and osteoblast proliferation were determined. For these experiments, the synthesis of the different isoforms of the VACCs was selectively blocked by antisense oligonucleotides prior to EGF stimulation. These studies showed that the cardiac isoform mediates the effects of EGF on cytosolic calcium and cellular proliferation in rat calvarial osteoblasts. (J Bone Miner Res 1999;14:386-395)

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“…Previous reports indicate that the calcium concentration at the interfacial layer between cells and composite samples favorably supports the growth of osteoblastic cells 12. Extracellular calcium concentration has been considered to be a significant factor affecting the proliferation and differentiation of osteoblastic cells 13. In previous studies, it has been demonstrated that the high solubility of the surfaces and high release rate of PO 4 and Ca components into the medium are crucial factors in stimulating the growth of osteoblastic cells 14–16.…”

Section: Discussionmentioning

confidence: 99%

Effect of reinforcement particle size on in vitro behavior of β‐tricalcium phosphate‐reinforced high‐density polyethylene: A novel orthopedic composite

Homaeigohar

Shokrgozar

Javadpour

et al. 2006

J Biomedical Materials Res

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Beta-tricalcium phosphate-reinforced high-density polyethylene (beta-TCP/HDPE) is a new biomaterial, which was made to simulate bone composition and study its capacity to act like bony tissues. This material was produced by replacing mineral component and collagen soft tissue of bone with beta-TCP and HDPE, respectively. The biocompatibility of composite samples with different volume fractions of TCP (20, 30, and 40 vol %) and two different particle sizes (80-100 and 120-140 mesh size) was examined in vitro using the osteoblast cell line G-292 by proliferation, alkaline phosphatase (ALP) production, and cell adhesion assays. Cell-material interaction on the surface of the composites was observed by scanning electron microscopy (SEM). The effect of beta-TCP particle size on behavior of the osteoblast cell line was compared between two groups of the composite samples containing smaller and larger reinforcement particle sizes as well as with those of a negative control. In general, results showed that the composite samples containing larger particles supported a higher rate of proliferation and ALP production by osteoblast cells after 3, 7, and 14 days of incubation compared to the composite samples with smaller particle size and control. Furthermore, more cells were attached to the surface of composite samples containing larger particle size when compared to the smaller particle size composites (p<0.05). This number was nearly equal with numbers adhered on negative control [tissue culture polystyrene (TPS)] and significantly higher in comparison with composite control [polyethylene (PE)] (p<0.05). Adhered cells presented a normal morphology by SEM and many of the cells were seen to be undergoing cell division. These findings indicate that beta-TCP/HDPE composites are biocompatible, nontoxic, and in some cases, act to stimulate proliferation of the cells, ALP production, and cell adhesion when compared to the control counterparts. Furthermore, beta-TCP/HDPE samples with larger reinforcement particle size were shown to possess better biological properties.

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Role of extracellular calcium influx in EGF-induced osteoblastic cell proliferation

Cited by 29 publications

References 42 publications

Epidermal Growth Factor Receptor-deficient Mice Have Delayed Primary Endochondral Ossification Because of Defective Osteoclast Recruitment

Epidermal Growth Factor Receptor-deficient Mice Have Delayed Primary Endochondral Ossification Because of Defective Osteoclast Recruitment

Molecular Characterization of the α1 Subunit of the L Type Voltage Calcium Channel Expressed in Rat Calvarial Osteoblasts

Effect of reinforcement particle size on in vitro behavior of β‐tricalcium phosphate‐reinforced high‐density polyethylene: A novel orthopedic composite

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