• BMB Reports
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• v.29 no.6
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• pp.549-554
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• 1996

Phosphoinositide turnover in response to platelet-derived growth factor, epidermal growth factor, and bradykinin was evaluated in NIH 3T3 cells. Platelet-derived growth factor and bradykinin induced a significant increase in incorporation of $^{32}P$ into phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PIP), and phosphatidylinositol 4.5-bisphosphate ($PIP_2$) in serum-starved NIH 3T3 cells. However, epidermal growth factor increased incorporation of $^{32}P$ into these phosphoinositides by only a small amount. Stimulation with platelet-derived growth factor, not bradykinin, caused a rapid elevation of PI and PIP kinase activities that were maximally activated within 10 min. The maximal levels of their elevation in cells with plateletderived growth factor stimulation were 3.2-fold for PI kinase, and 2.1-fold for PIP kinase. Short term pretreatment of NIH 3T3 cells with phorbol 12-myristate 13-acetate, activator of protein kinase C. caused an approximately 60% decrease in platelet-derived growth factor-induced PI kinase activities, indicating the feedback regulation of phosphoinositide turnover by protein kinase C. These results suggest that although the enhancement of phosphoinositide turnover is a rapidly occurring response in platelet-derived growth factor- or bradykinin-stimulated NIH 3T3 cells, phosphoinositide kinases may be associated with initial signal transduction pathway relevant to platelet-derived growth factor but not to bradykinin.

• BMB Reports
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• v.36 no.1
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• pp.49-59
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• 2003

Platelet-derived growth factor (PDGF) is a critical regulator of mesenchymal cell migration and proliferation. The vital functions of PDGFs for angiogenesis, as well as development of kidney, brain, cardiovascular system and pulmonary alveoli during embryogenesis, have been well demonstrated by gene knock-out approaches. Clinical studies reveal that aberrant expression of PDGF and its receptor is often associated with a variety of disorders including atherosclerosis, fibroproliferative diseases of lungs, kidneys and joints, and neoplasia. PDGF contributes to cancer development and progression by both autocrine and paracrine signaling mechanisms. In this review article, important features of the PDGF isoforms and their cell surface receptor subunits are discussed, with regards to signal transduction, PDGF-isoform specific cellular response, and involvement in angiogenesis, and tumorstromal interactions.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.530-535
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• 2013

Background Platelet-rich plasma (PRP) has more concentrated platelets than normal plasma (approximately 150-400${\times}10^3$ cell/dL). Platelets excrete several growth factors and cytokines that are associated with the healing and regeneration process. However, even though PRP is widely used, the mechanism or actual effect is presently unclear. Therefore, this study was performed to investigate the levels of growth factors and platelet concentration rate. Methods Autologous blood for preparing PRP was obtained from healthy subjects aged 25 to 35 years. The samples were divided into 4 experimental groups (inactivated whole blood, inactivated PRP, activated whole blood with thrombin and calcium chloride, and activated PRP). The platelet counts in the blood were analyzed and the growth factors were quantitatively measured. A statistical analysis was performed by using Dunn's multiple comparison test. Results In the blood cell analysis, the platelet count of the PRP group was approximately 4.25 times higher than that of the whole blood group. In the quantitative analysis of growth factors, the platelet-derived growth factor (PDGF)-AB, PDGF-BB, and transforming growth factor-${\beta}$ of the inactivated and activated PRP groups were higher than those of the inactivated and activated whole blood groups (P<0.05). Conclusions In this study, the platelet count and the levels of PDGF-AB and PDGF-BB in the PRP were determined. Further, more research is required on the bioactivity level of the growth factors secreted during the process of PRP preparation and the potency of growth factors that can be exerted physiologically in vivo.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.518-528
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• 1995

The immunohistochemical study has been performed on the distribution of receptors for various growth factors in the newly forming granulation tissues following the guided tissue regeneration procedures. Two specimens from 2 different patients were collected from the newly forming granulation tissues at 2 weeks following GTR procedures using Gore-tex menbrane and rubber dam, respectively. For immunohistochemical localization of each recptor, anti-platelet-derived growth factor $receptor-{\alpha}$, anti-platelet-derived growth factor $receptor-{\beta}$. anti-insulin-like growth factor receptor, anti-basic fibroblast growth factor receptor, anti-transforming growth $factor-{\beta}$ receptor and anti-fibronectin receptor were incubated onto the specimens as primary antibodies. After the reaction, FITC-conjugated second antibodies have been applied. When the total numbers of immunoreactive cells and the true positive cells were counted, there were high variability among receptors tested in the present study. The mean number of immunoreactive cells were highest in the case for anti-IFG-1 receptor. However the number of true positive cells were highest in the case for $TGF-{\beta}$ receptor. The present investigation indicated that the receptor for $TGF-{\beta}$ were stongly expressed in the newly forming granulation tissues following the guided tissue regeneration therapy.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.732-736
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• 2006

Purpose: The purpose of this pilot study was to investigate a potential of platelet concentrate obtained from blood bank(PCBB) in accelerating wound healing and to determine an effective treatment protocol by quantifying levels of platelet derived growth factor (PDGF)-BB in PCBB in vitro. Methods: The first study was designed to investigate quantity of PDGF-BB over stored time of the PCBB. The stored times for each PCBB were 1, 3, 5, 7, 9, 11 and 13 days. The second study was designed to determine efficacy of adding thrombin to stimulate release of PDGF-BB from the platelets of PCBB. The platelets were suspended and incubated in either with or without thrombin. On 30 minutes and days 1, 3, 5, 7 after incubation, the levels of PDGF-BB were measured. Results: PDGF-BB level showed a linear decrease over stored time of PCBB from the first day to the 13th day. Addition of thrombin increased PDGF-BB release from 30 minute through the 5th day. Conclusion: The results indicate that PCBB can provide sufficient amount of growth factors to stimulate wound healing and adding thrombin accelerate it.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.229-236
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• 1995

The experiments reported here take advantage of the large number of in vitro matured and in vitro fertilized(IVM /IVF) bovine oocytes which can be produced, permitting the design of controlled experiments to establish a simple defined medium for the study of early embryo requirements. A total of 1,386 IVM /IVF oocytes were used to compare a simple defined medium(KSOM) with more complex culture conditions used successfully for culture of bovine embryos but do not permit study of specific requirements. All experiments were extensively replicated factorials. In Experiment 1, KSOM was superior to Menezo B$_2$ medium in producing morulae plus blastocysts from IVM /IVF oocytes(33 vs 20%, P<0.()5). The yield of morulae plus blastocysts with KSOM was 22% and with BRLC added was 30%. In Experiment 2, (a 2x2 factorial of KSOM with or without BRLC and 0, 1 ng /ml of platelet derived growth factor, PDGF) more morulae plus blastocysts (40%) were produced in KSOM-BRLC co-culture containing 1 ng /ml PDGF than in the control KSOM(12%). In Experiment 3, there was no dose response when 0, 1 and 5 ng /ml of PDGF were added. The results with simple defined KSOM medium are sufficiently promising to indicate that specific requirements of the embryo may be examined in future studies with KSOM as a base.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.158-164
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• 2013

The most frequently encountered problems at fixture-implantation sites are lack of adequate bone and proximity to anatomic structures. It is generally accepted that growth factors play an essential role in the healing process and tissue formation, and they have become the focus of grafting materials research. The granules in platelets contain high concentrations of various growth factors. In particular, platelet-rich fibrin (PRF) is a second-generation platelet concentrate that allows the production of fibrin membranes enriched with platelets and growth factors from an anticoagulant-free blood harvest. This study investigated the in vitro effects of PRF on osteoblasts, in terms of the key cellular functions, and especially the effects on two growth factors, the homodimer of platelet-derived growth factor subunit B (BPDGF-BB) and transforming growth factor (TGF)-${\beta}1$, which are associated with wound healing and regeneration (i.e., proliferation and differentiation). The following parameters were investigated: PDGF-BB and TGF-${\beta}1$ levels in PRF, cell viability, alkaline phosphatase (ALP) activity, type 1 collagen synthesis, and the expressions of osteoblast differentiation markers (ALP and runt-related transcription factor 2) and bone matrix proteins (type 1 collagen). The release of autologous growth factors from PRF was maintained for a reasonable period of time, and exerted positive effects on the proliferation and differentiation of osteoblasts. The use of PRF thus appears to be a promising method for enhancing bone healing and remodeling.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.785-804
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• 1999

The cell activities of bone metabolism is affected by growth factor rather than by hormone. The affects of growth factors on the bone activity were observed using various culture methods. Platelet-derived growth factor(PDGF) is produced from the well differentiated bone cell. It stimulates cell mitosis, synthesizes collagen in bone tissue and plays a role in healing response. The purpose of this study is to evaluate the effects that PDGF has on the activity and the proliferation of osteoblast by measuring the activity of alkaline phosphatase, the growth formation of calcified nodules, and osteocalcin production. In this study, HOS and ROS 17/2.8 osteoblastic cell line was used, along with variable concentrations of PDGF the were measured with osteoblastic proliferation. The cell proliferation of HOS and ROS 17/2.8 cells was stimulated dose- depentdently. Alakline phosphatase activity was significantly decreased by PDGF in osteoblastic cells. A number of small calcified nodules were observed in HOS cell treated with low concentrations(0.1, 0.4 ng/ml) of PDGF-BB and no significant difference from control group was found. High concentrations(10, 50 ng/ml) of PDGF suppressed calcified nodule formation. And osteocalcin production was inhibited with PDGF. These results suggest that PDGF stimulates the osteoblastic proliferation, whereas suppresses the individual cellular functions.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.108.2-108.2
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• 2003

Kaempferol, a flavonol compound, has been reported as the anti-oxidant and anti-angiogenic agent and it has been found to inhibit cell growth in vitro. Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays an important role in development of atherosclerosis. In this study, we examined the anti-proliferative effect and its mechanism on rat aortic VSMCs treated by kaempferol. kaempferol significantly inhibited the platelet-derived growth factor (PDGF)-BB-induced proliferation of rat aortic VSMCs in concentration-dependent manner by cell count and ［$^3$H］-thymidine incorporation assay. (omitted)

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.2
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• pp.140-150
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• 2005

Maxillary sinus lifting procedure and bone grafting are used to reconstruct atrophic maxillae. These procedure are usually followed by the placement of endosseous dental implants. Different materials and techniques can be used for sinus bone grafting. Platelets are known to contain various growth factors involved in the repair of the vasculature and tissues, and it is known that the specialized platelet secretory granules, the alpha granules, contain platelet derived growth factor(PDGF), transforming growth factor-beta(TGF-beta), insuline like growth factor-I(IGF-I), epidermoid growth factor(EGF), and others. This study was to evaluate the effect of PRP on bone formation in a sinus bone grafting. Twelve rabbits were included in this randomized, blinded, prospective pilot study. In experimental group, sinus bone grafting with autobone and platelet rich plasma. In control group, sinus bone grafting with only autobone. Rabbits were sacrificed at 2nd, 4th, 8th, 12th weeks postoperatively. Clinical and radiographic tests, histological analysis were conducted to compare both sides. In clinical examination, there in no significant difference between experimental group and control group. But, in radiographic examination, a distinct incresed in the radiopaque of the PRP experimental group at 2nd and 4th weeks. The histologic examination revealed that more new bone formation and osteoblast activity were seen in experimental group at 2nd and 4th weeks. In conclusion, PRPs action in sinus bone grafting had a capacity of increased new bone formation in a early bone healing stage.