scholarly journals Electromagnetic Wave Irradiation Promotes Osteoblastic Cell Proliferation and Up-Regulates Growth Factors via Activation of the ERK1/2 and p38 MAPK Pathways

2015 ◽  
Vol 35 (2) ◽  
pp. 601-615 ◽  
Author(s):  
Hiromichi Yumoto ◽  
Kouji Hirao ◽  
Toshihiko Tominaga ◽  
Naoki Bando ◽  
Kanako Takahashi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Electromagnetic Wave ◽  
Growth Factors ◽  
Growth Factor ◽  
P38 Mapk ◽  
Cell Activity ◽  
Specific Inhibitor ◽  
Osteoblastic Cell ◽  
Periodontal Tissues ◽  
Mapk Pathways

Background/Aims: Periodontitis with bone resorption is caused by inflammatory reactions to bacterial infection. We recently reported that electromagnetic wave irradiation (EMWI) has bactericidal effects. However, the effects of EMWI on periodontal tissues remain unclear. This study was aimed to investigate the effects of EMWI on osteoblasts. Methods: Osteoblastic cells MC3T3-E1 were treated with EMWI (500-1,000 kHz, 5 times, 1 sec/time). Cell growth and cytotoxicity were determined by cell proliferation assays and measurement of lactate dehydrogenase release, respectively. Gene expression and protein production of growth factors were analyzed using real-time PCR and ELISA, respectively. EMWI-activated cellular signal transduction pathways were investigated by immunoblotting and blocking assay with specific inhibitors. Results: Osteoblasts proliferation was significantly enhanced 3 days after EMWI and no cytotoxicity was observed. EMWI up-regulated various growth factors, such as vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). EMWI induced ERK1/2, p38 MAPK and SAPK/JNK phosphorylation within 5 min, and the production of PDGF-ΑΑ and VEGF was partially reduced by MAPK-specific inhibitor. Conclusion: These findings demonstrated that EMWI increases osteoblastic cell activity and the expression of growth factors via ERK1/2 and p38 MAPK pathways and suggested that EMWI may be beneficial to bone tissue repair such as periodontitis.

scholarly journals Endostatin: A Promising Drug for Antiangiogenic Therapy

1999 ◽  
Vol 14 (4) ◽  
pp. 263-267 ◽  
Author(s):  
L. Cirri ◽  
S. Donnini ◽  
L. Morbidelli ◽  
P. Chiarugi ◽  
M. Ziche ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Antiangiogenic Therapy ◽  
Specific Inhibitor ◽  
Angiogenesis Inhibitors ◽  
Endothelial Cell Proliferation ◽  
Platelet Factor ◽  
Collagen Xviii ◽  
And Migration

Angiogenesis, the formation of new blood vessels from existing capillaries, is critical for tumors to grow beyond a few in size. Tumor cells produce one or more angiogenic factors including fibroblast growth factor and vascular endothelial growth factor. Surprisingly, antiangiogenic factors or angiogenesis inhibitors have been isolated from tumors. Some angiogenesis inhibitors, such as angiostatin, are associated with tumors while others, such as platelet-factor 4 and interferon-alpha are not. Endostatin, a C-terminal product of collagen XVIII, is a specific inhibitor of endothelial cell proliferation, migration and angiogenesis. The mechanism by which endostatin inhibits endothelial cell proliferation and migration is unknown. Endostatin was originally expressed in a prokaryotic system and, late, in a yeast system, thanks to which it is possible to obtain a sufficient quantity of the protein in a soluble and refolded form to be used in preclincial and clinical trials.

435 REDUCTION OF CELL CYCLE LENGTH AND INCREASE IN S-PHASE BY GROWTH FACTORS IN PIG FETAL FIBROBLASTS

2010 ◽  
Vol 22 (1) ◽  
pp. 374
Author(s):  
S. Waghmare ◽  
B. Mir
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Growth Factors ◽  
Growth Factor ◽  
Cycle Length ◽  
S Phase ◽  
Proliferation Rate ◽  
Fetal Fibroblasts ◽  
Cell Cycle Length ◽  
Number Of Cells

Gene targeting in primary somatic cells is inefficient compared with embryonic stem cells. This is because of a slow rate of cell proliferation, fewer cells in S-phase at a given time point under normal culture conditions, and low rate of homologous recombination. Homologous recombination occurs mainly in late S-phase and increase in gene targeting efficiency has been reported in S-phase synchronized cells in bovine and rhesus macaque fetal fibroblasts. In this study we tested several growth factors: platelet-derived growth factor (PDGF), tumor necrosis factor a (TNFα), epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor β1 (TGFβ1), insulin-like growth factor 1 (ILGF-1) and insulin-like growth factor II (ILGF-II) individually and in various combinations to see the effect on cell proliferation rate. Each experimental set consisted of 3 replicates. TGFβ1-, ILGF1-, ILGFII-, and FGF-treated cells grew very slowly compared with untreated cells. However, a combination of 3 growth factors: PDGF (15 ng mL-1), EGF (50 ng mL-1) and TNFa (100 pg mL-1), herein referred to as the cocktail, accelerated cell proliferation rate and reduced cell cycle length on average from 24.5 ± 0.2 to 20.4 ± 0.5 h with no significant change in number of cells in S-phase. Further, cells grown in the presence of the cocktail showed changes in morphology. The cells became spindle-shaped and occupied less surface area per cell compared with untreated cells. Importantly, cocktail-treated cells maintained a normal karyotype without any chromosomal abnormality. Thymidine has been used successfully to block various cell types in S-phase but it failed to synchronize these cells in S-phase in the concentration range of 2 to 10 mM for 24 to 48 h. However, serum starvation (0.2% fetal bovine serum) for 48 h blocked the cell proliferation rate effectively and synchronized cells in G0 phase (80-82% cells). After releasing from the block, cells were grown in the absence or presence of cocktail and cell cycle analysis was done at different time points by flow cytometry. Each time point was repeated 3 times. We observed the maximum number of cells in S-phase at 22 to 23 h (61.33% ± 7.77 in cocktail-treated cells v. 41.7% ± 3.28 in untreated cells). In summary, the cocktail-treated cells showed changes in cell morphology, higher proliferation rate, reduction in cell cycle length by 16.7%, and maximum percentage of cells in S-phase following serum starvation but maintained normal karyotypes. This high proliferation rate, reduction in cell cycle length, and maximum number of cells in S-phase should be very helpful in increasing the efficiency of gene-targeting in pig fetal fibroblasts.

Thrombopoietin Enhances Expression of Vascular Endothelial Growth Factor (VEGF) in Primitive Hematopoietic Cells through Hif-1α.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2170-2170
Author(s):  
Keita Kirito ◽  
Norma Fox ◽  
Kenneth Kaushansky
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factors ◽  
Growth Factor ◽  
Hematopoietic Cells ◽  
Specific Inhibitor ◽  
Hematopoietic Cell ◽  
Vascular Endothelial ◽  
Vegf Expression ◽  
Endothelial Growth Factor ◽  
Marrow Cells

Abstract The development of hematopoietic stem cells (HSCs) is orchestrated by numerous hematopoietic cytokines, growth factors and chemokines. For the most part these proteins are secreted from bone marrow microenviromental cells, including fibroblasts, endothelial cells and stromal cells, or are displayed on their cell surfaces. HSCs have also been shown to produce numerous cytokines and growth factors. Interestingly, secreted cytokines have also been reported to induce the production of additional cytokines from neighboring cells, suggesting that cytokines drive networks of other cytokines to support hematopoietic cell development. Vascular endothelial growth factor (VEGF), a major regulator of angiogenesis and vasculogenesis, also plays an important role in HSC development, where it acts in an intracellular autocrine fashion to promote cell survival. The secretion of VEGF from endothelial or smooth muscle cells is regulated by extracellular stimuli, inflammatory cytokines and hypoxia. In contrast, it is not clear whether synthesis of VEGF in HSCs is regulated by extracellular signals. Because several early acting cytokines, including TPO, affect VEGF-A expression in hematopoietic cell lines, we hypothesized that TPO could be a regulator of a HSC VEGF autocrine loop. We found that TPO induces VEGF transcripts in primitive marrow derived sca-1+/c-kit+/Gr-1− hematopoietic cells, and that VEGF transcripts are reduced in these cells when derived from Tpo−/− mice. Additional studies determined that TPO induces VEGF expression by increasing the nuclear levels of its primary transcription factor, both in the TPO-dependent primitive hematopoietic cell line UT-7/TPO and in purified sca-1+/c-kit+/Gr-1−marrow cells. Elevation of HIF-1α by TPO is achieved by two different mechanisms; augmented protein synthesis and enhanced stabilization. The latter mechanism is dependent on heat shock protein 90 (Hsp90), as inhibition of Hsp90 function by the specific inhibitor geldanamycin inhibited the TPO-dependent stabilization of HIF-1α. In additional studies we also established that VEGF expression was important for the favorable TPO effect on primitive hematopoietic cells, as blockade of the VEGF receptor with a specific inhibitor, SU5416 (0.1mM), substantially blunted TPO induced growth of sorted single sca-1+/c-kit+/Gr-1−marrow cells in serum-free cultures. Importantly, this inhibitor does not affect TPO induced phosphorylation of Jak2, ERK and AKT in UT-7/TPO cells even at a 100-fold higher concentration. Along with our previous findings that TPO affects Hox transcription factors that regulate HSC proliferation, these data contribute to our growing understanding of the mechanisms by which a hormone can influence HSC development.

Growth factor stimulated cell proliferation is accompanied by an elevated labile intracellular pool of zinc in 3T3 cells

2002 ◽  
Vol 80 (8) ◽  
pp. 790-795 ◽  
Author(s):  
Shirley C Paski ◽  
Zhaoming Xu
Keyword(s):  
Cell Proliferation ◽  
Growth Factors ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Cell Number ◽  
3T3 Cells ◽  
Intracellular Pool ◽  
Igf I ◽  
Epidermal Growth ◽  
Number Counts

Growth factors such as platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and insulin-like growth factor-I (IGF-I) are required for quiescent 3T3 cells to proliferate, but zinc deprivation impairs IGF-I-induced DNA synthesis. We recently showed that labile intracellular pool of zinc is involved in cell proliferation. Our objective was to determine whether the labile intracellular pool of zinc plays a role in growth factor (PDGF, EGF, and IGF-I) - stimulated proliferation of 3T3 cells. Quiescent 3T3 cells were cultured in DMEM with or without growth factors. Labile intracellular pool of zinc, DNA synthesis, and cell proliferation were assessed using fluorescence microscopy, 3H-thymidine incorporation, and total cell number counts, respectively. After 24 h, growth factors stimulated DNA synthesis (24%) but not cell proliferation. After 48 h, growth factors stimulated both DNA synthesis (37%) and cell proliferation (89%). In response to growth factor stimulation, the labile intracellular pool of zinc was also elevated after 24 or 48 h of treatment. In summary, growth factor (PDGF, EGF, and IGF-I) - stimulated increase in DNA synthesis and cell proliferation were accompanied by an elevated labile intracellular pool of zinc in 3T3 cells. Since elevation of the labile intracellular pool of zinc occurred along with increased DNA synthesis, but cell proliferation remained unchanged, the elevation of the labile intracellular pool of zinc likely occurred during the S phase to provide the zinc needed to support DNA synthesis and ultimately cell proliferation.Key words: PDGF, EGF, IGF-I, labile intracellular pool of zinc, cell proliferation, DNA synthesis, 3T3 cells.

Advantages of anchoring growth factors to materials for neural stem/progenitor cell proliferation

2016 ◽  
Vol 4 (37) ◽  
pp. 6213-6220 ◽  
Author(s):  
T. Nakaji-Hirabayashi ◽  
K. Fujimoto ◽  
Y. Kato ◽  
H. Kitano ◽  
Y. Inoue ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Growth Factors ◽  
Growth Factor ◽  
Cell Biology ◽  
Progenitor Cell ◽  
Materials Science ◽  
Progenitor Cell Proliferation

We tried to clarify the mechanisms underlying immobilized-growth factor in NSPC regulation using approaches from materials science and cell biology.

IL-6 induces neuroendocrine dedifferentiation and cell proliferation in non-small cell lung cancer cells

2005 ◽  
Vol 289 (3) ◽  
pp. L446-L453 ◽  
Author(s):  
Kuo-Ting Chang ◽  
Chun-Ming Tsai ◽  
Yih-Chy Chiou ◽  
Chao-Hua Chiu ◽  
King-Song Jeng ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Proliferation ◽  
Small Cell Lung Cancer ◽  
P38 Mapk ◽  
Cell Lung Cancer ◽  
Specific Inhibitor ◽  
Small Cell ◽  
Small Cell Lung ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway

Interleukin-6 (IL-6) has been identified as an important growth regulator of lung cancer cells. Elevation of serum levels of IL-6 has been found in a subpopulation of lung cancer patients, but rarely in patients with benign lung diseases. Approximately 15% of non-small cell lung cancer (NSCLC) tumors exhibit neuroendocrine (NE) properties (NSCLC-NE) and have been suggested to have the biological characteristics similar to small cell lung cancer (SCLC) with early metastasis and initial responsiveness to chemotherapy. We recently showed that IL-6 promotes cell proliferation and downregulates the expression of neuron-specific enolase (NSE, one of the major NE markers) in NSCLC-NE cells. In this study, we show that IL-6 stimulates a transient increase of tyrosine phosphorylation of STAT3 in a dose-dependent fashion. Inhibition of STAT3 signaling pathway by either AG-490 (JAK2-specific inhibitor) or overexpression of STAT3Y705F (a dominant-negative STAT3) reverses NSE expression in IL-6- treated NSCLC-NE cells. In addition, IL-6 induces phosphorylation and activation of p38 MAPK. SB-203580, a p38 MAPK-specific inhibitor, inhibits IL-6-induced p38 MAPK phosphorylating activity and suppresses IL-6-stimulated cell proliferation. Together, our results indicate that STAT3 signaling pathway is involved in IL-6-induced NE differentiation and that p38 MAPK is associated with IL-6-stimulated growth regulation in NSCLC-NE cells. These data suggest that both kinase pathways play critical roles in the pathogenesis of NSCLC-NE malignancies, providing new molecular targets for future therapeutic approaches.

Salivary Growth Factors in Health and Disease

2000 ◽  
Vol 14 (1) ◽  
pp. 99-102 ◽  
Author(s):  
H. Kagami ◽  
Y. Hiramatsu ◽  
S. Hishida ◽  
Y. Okazaki ◽  
K. Horie ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Salivary Gland ◽  
Growth Factors ◽  
Growth Factor ◽  
Submandibular Gland ◽  
Cultured Cells ◽  
Healing Process ◽  
Physiological Role ◽  
Gland Cells ◽  
Salivary Gland Cells

The salivary gland is considered to be a reservoir of many growth factors in rodents. In humans, the epidermal growth factor, basic fibroblast growth factor, and insulin and insulin-like growth factor family have also been detected in this gland, but their physiological role remains unclear. In this study, we focused on bFGF, which is a well-known mitogen for various types of cells, and is present in the salivary gland as well as in saliva. The roles of bFGF in the salivary gland were investigated by three different procedures. First, the effects of bFGF on the salivary gland cells were investigated with a monolayer culture of normal submandibular gland cells. The effects of different concentrations of bFGF on the second passage of these cultured cells were examined. In both human and rat cultured submandibular gland cells, bFGF accelerated the cell proliferation at a concentraion of 100 ng/mL or higher. Next, an atrophic model of the rat submandibular gland was used to examine the ability of bFGF to accelerate tissue repair. Two weeks after ductal ligation, the ligature was removed, and various amounts of bFGF, isoproterenol, or saline were administered via a retrograde duct instillation. Both isoproterenol and bFGF increased acinar and ductal cell proliferation significantly. To determine the role of bFGF in saliva, we investigated its effect on the healing process of oral mucosal defects. Four-millimeter mucosal defects were made to the depth of the periosteum in the rat palate under anesthesia. bFGF or vehicle alone was applied once only at the time of surgery as a suspension. At days 3, 5, and 7 in the bFGF group, significant increases in the degree of re-epithelialization were found in treated groups. These results indicate that its action as a mitogen stimulus is the major effect of bFGF on salivary gland cells and mucosal epithelium.

scholarly journals Osteocalcin Induces Proliferation via Positive Activation of the PI3K/Akt, P38 MAPK Pathways and Promotes Differentiation Through Activation of the GPRC6A-ERK1/2 Pathway in C2C12 Myoblast Cells

2017 ◽  
Vol 43 (3) ◽  
pp. 1100-1112 ◽  
Author(s):  
Suifeng Liu ◽  
Feng Gao ◽  
Lei Wen ◽  
Min Ouyang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
P38 Mapk ◽  
C2c12 Cell ◽  
C2c12 Cells ◽  
Myoblast Differentiation ◽  
C2c12 Myoblast ◽  
C2c12 Myoblasts ◽  
Mapk Phosphorylation ◽  
Mapk Pathways ◽  
Myoblast Cells

Background/Aims: Sarcopenia is characterized by an age-related decline in skeletal muscle plus low muscle strength and/or physical performance. Despite the clinical significance of sarcopenia, the molecular pathways underlying sarcopenia remain elusive. The recent demonstration that undercarboxylated osteocalcin (ucOC) favours muscle function related to insulin sensitivity and glucose metabolism raises the question of whether this hormone may also regulate muscle mass. The present study explored the promotive effects of ucOC in proliferation and differentiation processes of C2C12 myoblasts as well as the possible signalling pathways involved. Methods: The effects of exogenous ucOC on C2C12 myoblasts proliferation were assessed using CCK8 and immunohistological staining assays. C2C12 cells were pretreated with PI3K/Akt or P38 MAPK inhibitors to investigate the possible involvement of the PI3K/Akt and P38 MAPK pathways in proliferation. The levels of Akt, phosphorylated-Akt (p-Akt), P38, and phosphorylated-P38 (p-P38) were measured by Western Blotting. The effects of ucOC on myoblast differentiation were quantified by morphological analysis. A silencing experiment was conducted in which the expression of GPRC6A in C2C12 myoblasts was modified. The expression of GPRC6A, myosin heavy chain (MyHC) and the related ERK1/2 signalling pathway in C2C12 myoblasts were monitored by qRT-PCR and Western Blotting. Results: We showed that treatment with exogenous ucOC stimulated the priming of C2C12 myoblasts proliferation. Inhibition of Akt phosphorylation by wortmannin or inhibition of P38 MAPK phosphorylation by SB203580 decreased C2C12 cell proliferation. Wortmannin also reduced P38 MAPK phosphorylation, whereas SB203580 did not affect Akt activation. Furthermore, ucOC promoted C2C12 myoblast differentiation. Inhibition of ERK1/2 phosphorylation with U0126 decreased C2C12 cell differentiation. Finally, GPRC6A expression was substantially increased after ucOC treatment of C2C12 cells. GPRC6A silencing inhibited Akt, P38 MAPK phosphorylation in C2C12 cells, and ERK1/2 phosphorylation in C2C12 myotubes; GPRC6A silencing also decreased cell proliferation, decreased cell differentiation, and downregulated MyHC expression. Conclusions: The present data suggest that ucOC induces myoblast proliferation via sequential activation of the PI3K/Akt and p38 MAPK pathways in C2C12 myoblast cells. Moreover, ucOC enhances myogenic differentiation via a mechanism involving GPRC6A-ERK1/2 signalling.

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