Regulation of DNA synthesis in chicken adipocyte precursor cells by insulin-like growth factors, platelet-derived growth factor and transforming growth factor-β

1991 ◽  
Vol 131 (2) ◽  
pp. 203-209 ◽  
Author(s):  
S. C. Butterwith ◽  
C. Goddard
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Transforming Growth Factor ◽  
Precursor Cells ◽  
Igf I ◽  
Tgf Β1 ◽  
Adipocyte Precursor ◽  
Insulin Like Growth Factors

ABSTRACT Adipose tissue growth can occur by both hypertrophy and hyperplasia. The capacity for adipocyte hyperplasia in vivo resides in a population of fibroblast-like adipocyte precursor cells but the regulation of the proliferation of these cells by growth factors has not been well characterized. This study was designed to determine the effects of the insulin-like growth factors (IGF-I and IGF-II), platelet-derived growth factor (PDGF) and transforming growth factor-β1 (TGF-β1) added alone or together on the proliferation of primary adipocyte precursor cells in vitro. Adipocyte precursor cell proliferation measured by [3H]thymidine incorporation into DNA was stimulated by all of these growth factors and was particularly marked with PDGF. IGF-I or IGF-II added together with TGF-β1 produced a greater than additive response and the effect of PDGF was synergistic with that of IGF-I at certain concentrations. Stimulation of proliferation of some cell types by TGF-β has been linked to the secondary production of PDGF but the evidence we have suggests that this is unlikely in chicken adipocyte precursors. DNA synthesis in response to TGF-β1 required only a short exposure to the peptide, and conditioned medium from chicken adipocyte precursor cells previously exposed to TGF-β had no effect on DNA synthesis when added to fresh batches of cells. Addition of TGF-β1 together with PDGF produced a synergistic effect whereas an additive effect would be expected if PDGF mediated the effect of TGF-β1. IGF-I mRNA is expressed in the Ob 1771 preadipocyte cell line during differentiation, in stromalvascular cells from adipose tissue, and TGF-β mRNA is expressed in both proliferating and differentiating 3T3-L1 preadipocytes. Together with the data presented here, this would indicate that these peptides have a role in adipocyte development by an autocrine or paracrine mechanism although the source of PDGF in vivo is at present unknown. Journal of Endocrinology (1991) 131, 203–209

Regulation of adipocyte precursor DNA synthesis by acidic and basic fibroblast growth factors: interaction with heparin and other growth factors

1993 ◽  
Vol 137 (3) ◽  
pp. 369-374 ◽  
Author(s):  
S. C. Butterwith ◽  
C. D. Peddie ◽  
C. Goddard
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Fibroblast Growth Factor ◽  
Transforming Growth Factor ◽  
Fibroblast Growth ◽  
Igf I ◽  
Tgf Β1 ◽  
Adipocyte Precursor ◽  
Stimulation Of

ABSTRACT The development of adipose tissue is dependent on the growth and differentiation of fibroblast-like adipocyte precursor cells. Culture of adipocyte precursor cells in vitro has provided an ideal system for identifying potential regulators of proliferation and differentiation. We have demonstrated that both acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) stimulate chicken adipocyte precursor DNA synthesis in a dose-dependent manner up to a concentration of 100 μg aFGF/l and 1 μg bFGF/l. The effect of bFGF was biphasic, so that in incubations with 25 μg bFGF/l, DNA synthesis was not significantly different from controls. In the presence of heparin, stimulation of DNA synthesis at 25 μg bFGF/l was 1·6-fold greater than at a concentration of 1 μg bFGF/l. Addition of heparin to incubations containing aFGF reduced the concentration required for maximum stimulation of DNA synthesis to 1 μg/l. Cells incubated with aFGF (1–100 μg/l) in combination with insulin-like growth factor-I (IGF-I), platelet-derived growth factor, transforming growth factor-α or transforming growth factor-β1 (TGF-β1) exhibited a marked synergistic increase in DNA synthesis. This was also the case when 1 μg bFGF/l was used, but at a concentration of 25 pg bFGF/l synergy was only seen with IGF-I and TGF-β1. These results suggest that both basic and acidic FGF are potentially important regulators of adipocyte hyperplasia and that their effect is modulated by constituents of the extracellular matrix and the presence of other growth factors. Journal of Endocrinology (1993) 137, 369–374

Effects of transforming growth factor-α on chicken adipocyte precursor cells in vitro

1992 ◽  
Vol 134 (2) ◽  
pp. 163-168 ◽  
Author(s):  
S. C. Butterwith ◽  
C. D. Peddie ◽  
C. Goddard
Keyword(s):  
Adipose Tissue ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Transforming Growth Factor ◽  
Precursor Cells ◽  
Transforming Growth Factor Α ◽  
Igf I ◽  
Factor Α ◽  
Adipocyte Precursor

ABSTRACT The hyperplastic capacity of adipose tissue resides in a group of fibroblast-like adipocyte precursor cells. There is evidence to suggest that their proliferation and differentiation is regulated by insulin-like growth factor-I (IGF-I) and transforming growth factor-β (TGF-β) but there is less information about other growth factors which may also participate in adipocyte precursor cell hyperplasia. Transforming growth factor-α (TGF-α) is a 50 amino acid polypeptide which has been shown to stimulate proliferation in both neoplastic and normal cell types acting through the epidermal growth factor (EGF) receptor. We have studied the regulation of DNA synthesis and the activity of lipoprotein lipase by TGF-α in chicken adipocyte precursor cells in vitro. Both TGF-α and EGF stimulated incorporation of [3H]thymidine into DNA in a dose-dependent manner. TGF-α was approximately 180-fold more potent than EGF. Addition of TGF-α in combination with IGF-I, TGF-β1 or platelet-derived growth factor produced a synergistic increase in DNA synthesis. Short-term incubation with TGF-α reduced lipoprotein lipase activity by 23%. These results show that TGF-α is a potent mitogen in these adipocyte precursor cells and can inhibit their differentiation in vitro and may participate in the regulation of adipose tissue development in vivo. Journal of Endocrinology (1992) 134, 163–168

Comparison of Release Profiles of Various Growth Factors from Biodegradable Carriers

1998 ◽  
Vol 530 ◽  
Author(s):  
Y. Tabata ◽  
M. Yamamoto ◽  
Y. Ikada
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
The Body ◽  
Bone Morphogenetic Protein 2 ◽  
Biodegradable Hydrogel ◽  
Tgf Β1

AbstractA biodegradable hydrogel was prepared by glutaraldehyde crosslinking of acidic gelatin with an isoelectric point (IEP) of 5.0 as a carrier to release basic growth factors on the basis of polyion complexation. Basic fibroblast growth factor (bFGF), transforming growth factor β1 (TGF-β1), and bone morphogenetic protein-2 (BMP-2) were sorbed from their aqueous solution into the dried gelatin hydrogels to prepare respective growth factor-incorporating hydrogels. Under an in vitro non-degradation condition, approximately 20 % of incorporated bFGF and TGF-β1 was released from the hydrogels within initial 40 min, followed by no further release, whereas a large initial release of BMP-2 was observed. After subcutaneous implantation of the gelatin hydrogels incorporating 125I-labeled growth factor in the mouse back, the remaining radioactivity was measured to estimate the in vivo release profile of growth factors. Incorporation into gelatin hydrogels enabled bFGF and TGF-β1 to retain in the body for about 15 days and the retention period well correlated with that of the gelatin hydrogel. Taken together, it is likely that the growth factors ionically complexed with acidic gelatin were released in vivo as a result of hydrogel biodegradation. On the contrary, basic BMP-2 did not ionically interact with acidic gelatin, resulting in no sustained released by the present biodegradable carrier system.

Effects of hormones and growth factors on TGF-β1 expression in bovine mammary epithelial cells

2005 ◽  
Vol 72 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Joanna Zarzyńska ◽  
Małgorzata Gajewska ◽  
Tomasz Motyl
Keyword(s):  
Cell Cycle ◽  
Mammary Gland ◽  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Mammary Epithelial ◽  
Inhibition Of Proliferation ◽  
Igf I ◽  
Induction Of Apoptosis ◽  
Tgf Β1

The decline of mammary epithelial cell (MEC) number during mammary gland involution in the cow is due to inhibition of proliferation and induction of apoptosis. Transforming growth factor-beta 1 (TGF-β1) belongs to a group of intramammary auto/paracrine inhibitors of bovine MEC growth and inducers of apoptosis. However, the mechanism responsible for the regulation of TGF-β1 expression in MEC is not known. The present study examined the effect of the hormones, growth hormone (GH), somatostatin (STS), 17-β oestradiol (E2), progesterone (P4), as well as the growth factors, insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF), on TGF-β1 expression in the bovine MEC lines, BME-UV1 and MAC-T. The model of apoptosis in bovine mammary gland in vitro was applied by reduction of fetal bovine serum (FBS) (from 10% to 2% or 0·5% FBS) in the cell environment to show the relationship between TGF-β1 expression and apoptosis in bovine MEC. RT-PCR, Western blot and laser scanning cytometry (LSC) were used for analysis of TGF-β1 transcript and protein level as well as apoptosis and cell cycle in examined MEC. In this model of apoptosis, FBS deficiency (mimicking the naturally occurring decline in the access of bioactive compounds and nutrients at the end of lactation and dry period) was associated with increased TGF-β1 expression at the level of transcript and protein, induction of apoptosis and inhibition of cell cycle. Exogenous TGF-β1, IGF-I, EGF and GH inhibited FBS-deficiency-stimulated TGF-β1 expression. The suppressive effect of GH was reversed when cells were maintained longer in FBS-deficient medium. In general, STS, E2 and P4 increased TGF-β1 expression. However, this effect was dependent on hormone concentration and cell line. BME-UV1 cells were much more responsive to the peptides, GH, STS, IGF-I and EGF, whereas MAC-T cells were more responsive to the steroid sex hormones: E2 and P4.

scholarly journals Transforming growth factor-beta1 stimulates the production of insulin-like growth factor-I and insulin-like growth factor-binding protein-3 in human bone marrow stromal osteoblast progenitors

2001 ◽  
Vol 169 (3) ◽  
pp. 549-561 ◽  
Author(s):  
M Kveiborg ◽  
A Flyvbjerg ◽  
EF Eriksen ◽  
M Kassem
Keyword(s):  
Growth Factors ◽  
Steady State ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Mrna Level ◽  
Precursor Cells ◽  
Time Dependent ◽  
Transforming Growth Factor Beta1 ◽  
Igf I ◽  
Steady State Mrna Level

While transforming growth factor-beta1 (TGF-beta1) regulates proliferation and differentiation of human osteoblast precursor cells, the mechanisms underlying these effects are not known. Several hormones and locally acting growth factors regulate osteoblast functions through changes in the insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs). Thus, we studied the effects of TGF-beta1 on IGFs and IGFBPs in human marrow stromal (hMS) osteoblast precursor cells. TGF-beta1 increased the steady-state mRNA level of IGF-I up to 8.5+/-0.6-fold (P<0.001) in a dose- (0.1-10 ng/ml), and time-dependent (12-72 h) manner. No significant effects on IGF-II gene expression were detectable. Employing RNase protection and nuclear run-on assays, these effects on IGF-I were found to take place at the transcriptional level and were not dependent on de novo protein synthesis. Using the transient transfection of various fragments of the IGF-I promoter 1, we found that TGF-beta responsive elements were present in a promoter fragment ranging from-65 bp to+55 bp relative to the major transcription start site in exon 1. In addition, TGF-beta1 treatment resulted in a dose- and time-dependent increase (2-fold) in the IGFBP-3 steady-state mRNA level as well as in protein production but did not affect IGFBP-2 or IGFBP-4 at mRNA or protein levels. Our results indicate that TGF-beta1 exerts significant effects on stimulatory components of the IGF-system and that may represent a mechanism mediating TGF-beta effects on the biological functions of osteoblasts.

Metanephric transforming growth factor-beta 1 regulates nephrogenesis in vitro

1993 ◽  
Vol 264 (6) ◽  
pp. F996-F1002 ◽  
Author(s):  
S. A. Rogers ◽  
G. Ryan ◽  
A. F. Purchio ◽  
M. R. Hammerman
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Rat Embryos ◽  
Igf I ◽  
Metanephric Blastema

Development of the metanephric kidney during embryogenesis is regulated by a number of polypeptide growth factors of renal origin. We have defined previously a role for insulin-like growth factors (IGF) I and II and for transforming growth factor (TGF)-alpha. To delineate the effect of TGF-beta 1, on renal organogenesis, we cultured metanephroi surgically dissected from 13-day-old rat embryos in serum-free chemically defined media. TGF-beta 1 mRNA was present in kidneys from 13-day-old rat embryos, and positive immunostaining for TGF-beta 1 could be demonstrated in cultured metanephroi. However, TGF-beta bioactivity could not be detected in media obtained from the metanephroi. Addition of 10(-9) M TGF-beta 1 to cultures inhibited tubulogenesis, but had no effect on synthesis of IGF-I or -II. Addition of anti-TGF-beta 1 antibodies to cultures accelerated tubulogenesis within the metanephric blastema. These findings establish the potential for TGF-beta 1 production within the rat metanephros during development in vivo. It is possible that this peptide exerts a negative control on the process of tubulogenesis within metanephric blastema and in this manner acts to shape the architecture of mature kidney.

scholarly journals Long-term effects of local growth factor (IGF-I and TGF-β1) treatment on fracture healing. A safety study for using growth factors

2004 ◽  
Vol 22 (3) ◽  
pp. 514-519 ◽  
Author(s):  
Gerhard Schmidmaier ◽  
Britt Wildemann ◽  
Daniel Ostapowicz ◽  
Frank Kandziora ◽  
Richard Stange ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Fracture Healing ◽  
Long Term Effects ◽  
Local Growth ◽  
Safety Study ◽  
Igf I ◽  
Tgf Β1

Influence of insulin-like growth factor-binding protein-2 on plasma clearance and transfer of insulin-like growth factors-I and -II from plasma into mammary-derived lymph and milk of goats

1996 ◽  
Vol 150 (1) ◽  
pp. 121-127 ◽  
Author(s):  
C G Prosser ◽  
J Schwander
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Plasma Clearance ◽  
Binding Protein ◽  
Plasma Concentrations ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Lactating Goats ◽  
Igf I ◽  
Insulin Like Growth Factors

Abstract Plasma clearance of insulin-like growth factors-I and -II (IGF-I and -II) and insulin-like growth factor-binding protein-2 (IGFBP-2) from lactating goats (n=4) was determined following a single intravenous injection of the corresponding 125I-labelled human protein. Transfer of these proteins out of the vascular space was monitored by their subsequent appearance in mammary-derived lymph and milk. Clearance of 125I-IGFBP-2 from circulation was 0·37 ± 0·06 ml/min/kg, which is markedly greater than that of 125I-IGF-I or -II (0·11 ± and 0·12 ± 0·01 ml/min/kg respectively). This was also reflected in longer elimination half-lives for IGF-I (353 ± 6 min) and -II (254 ± 8 min) compared with IGFBP-2 (110 ± 9 min). Three hours after injection of the 125I-labelled protein, the plasma:lymph ratio of trichloroacetic acid-precipitable radioactivity was 1·54 ±0·04, 3·3 ±0·6 and 4·1 ±0·4 for IGFBP-2, IGF-I and -II respectively. The form of 125I-IGFBP-2 in lymph was not different from that of plasma. Elevation of plasma concentrations of IGFBP-2 by its intravenous infusion significantly decreased plasma half-life of both IGF-I and -II (251 ± 8 and 198 ±7 min respectively). Although the amount and rate of transfer of IGF into mammary-derived lymph was decreased slightly by IGFBP-2, concentrations eventually obtained were not different from control. However, secretion of IGFs into milk was significantly reduced by IGFBP-2, particularly in the case of IGF-I. These results are consistent with the ability of all three compounds to cross the vascular endothelium intact and of IGFBP-2 to decrease the uptake of IGF by mammary epithelium and subsequent secretion into milk. IGFBP-2 may well have acted to target plasma IGF towards non-mammary tissues, thus explaining the more rapid plasma clearance of IGFs in the presence of elevated IGFBP-2. Journal of Endocrinology (1996) 150, 121–127

Platelet-Rich Plasma Powder: A New Preparation Method for the Standardization of Growth Factor Concentrations

2016 ◽  
Vol 45 (4) ◽  
pp. 954-960 ◽  
Author(s):  
Matthias Kieb ◽  
Frank Sander ◽  
Cornelia Prinz ◽  
Stefanie Adam ◽  
Anett Mau-Möller ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Clinical Application ◽  
Whole Blood ◽  
Sports Medicine ◽  
Transforming Growth Factor ◽  
Platelet Rich Plasma ◽  
Transforming Growth Factor Β1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tgf Β1

Background: Platelet-rich plasma (PRP) is widely used in sports medicine. Available PRP preparations differ in white blood cell, platelet, and growth factor concentrations, making standardized research and clinical application challenging. Purpose: To characterize a newly standardized procedure for pooled PRP that provides defined growth factor concentrations. Study Design: Controlled laboratory study. Methods: A standardized growth factor preparation (lyophilized PRP powder) was prepared using 12 pooled platelet concentrates (PCs) derived from different donors via apheresis. Blood samples and commercially available PRP (SmartPrep-2) served as controls (n = 5). Baseline blood counts were analyzed. Additionally, single PCs (n = 5) were produced by standard platelet apheresis. The concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), insulin-like growth factor 1 (IGF-1), interleukin (IL)–1α, IL-1β, and IL-1 receptor agonist (IL-1RA) were analyzed by enzyme-linked immunosorbent assay, and statistical analyses were performed using descriptive statistics, mean differences, 95% CIs, and P values (analysis of variance). Results: All growth factor preparation methods showed elevated concentrations of the growth factors VEGF, bFGF, PDGF-AB, and TGF-β1 compared with those of whole blood. Large interindividual differences were found in VEGF and bFGF concentrations. Respective values (mean ± SD in pg/mL) for whole blood, SmartPrep-2, PC, and PRP powder were as follows: VEGF (574 ± 147, 528 ± 233, 1087 ± 535, and 1722), bFGF (198 ± 164, 410 ± 259, 151 ± 99, and 542), PDGF-AB (2394 ± 451, 17,846 ± 3087, 18,461 ± 4455, and 23,023), and TGF-β1 (14,356 ± 4527, 77,533 ± 13,918, 68,582 ± 7388, and 87,495). IGF-1 was found in SmartPrep-2 (1539 ± 348 pg/mL). For PC (2266 ± 485 pg/mL), IGF-1 was measured at the same levels of whole blood (2317 ± 711 pg/mL) but was not detectable in PRP powder. IL-1α was detectable in whole blood (111 ± 35 pg/mL) and SmartPrep-2 (119 ± 44 pg/mL). Conclusion: Problems with PRP such as absent standardization, lack of consistency among studies, and black box dosage could be solved by using characterized PRP powder made by pooling and lyophilizing multiple PCs. The new PRP powder opens up new possibilities for PRP research as well as for the treatment of patients. Clinical Relevance: The preparation of pooled PRP by means of lyophilization may allow physicians to apply a defined amount of growth factors by using a defined amount of PRP powder. Moreover, PRP powder as a dry substance with no need for centrifugation could become ubiquitously available, thus saving time and staff resources in clinical practice. However, before transferring the results of this basic science study to clinical application, regulatory issues have to be cleared.

Post-transcriptional control of the onset of DNA synthesis by an insulin-like growth factor

1984 ◽  
Vol 4 (9) ◽  
pp. 1807-1814
Author(s):  
J Campisi ◽  
A B Pardee
Keyword(s):  
Cell Cycle ◽  
Growth Factors ◽  
Growth Factor ◽  
Dna Synthesis ◽  
Transcriptional Control ◽  
S Phase ◽  
G1 Phase ◽  
Insulin Like Growth Factor ◽  
Igf I ◽  
Translational Inhibition

The control of eucaryotic cell proliferation is governed largely by a series of regulatory events which occur in the G1 phase of the cell cycle. When stimulated to proliferate, quiescent (G0) 3T3 fibroblasts require transcription, rapid translation, and three growth factors for the growth state transition. We examined exponentially growing 3T3 cells to relate the requirements for G1 transit to those necessary for the transition from the G0 to the S phase. Cycling cells in the G1 phase required transcription, rapid translation, and a single growth factor (insulin-like growth factor [IGF] I) to initiate DNA synthesis. IGF I acted post-transcriptionally at a late G1 step. All cells in the G1 phase entered the S phase on schedule if either insulin (hyperphysiological concentration) or IGF I (subnanomolar concentration) was provided as the sole growth factor. In medium lacking all growth factors, only cells within 2 to 3 h of the S phase were able to initiate DNA synthesis. Similarly, cells within 2 to 3 h of the S phase were less dependent on transcription and translation for entry into the S phase. Cells responded very differently to inhibited translation than to growth factor deprivation. Cells in the early and mid-G1 phases did not progress toward the S phase during transcriptional or translational inhibition, and during translational inhibition they actually regressed from the S phase. In the absence of growth factors, however, these cells continued progressing toward the S phase, but still required IGF at a terminal step before initiating DNA synthesis. We conclude that a suboptimal condition causes cells to either progress or regress in the cell cycle rather than freezing them at their initial position. By using synchronized cultures, we also show that in contrast to earlier events, this final, IGF-dependent step did not require new transcription. This result is in contrast to findings that other growth factors induce new transcription. We examined the requirements for G1 transit by using a chemically transformed 3T3 cell line (BPA31 cells) which has lost some but not all ability to regulate its growth. Early- and mid-G1-phase BPA31 cells required transcription and translation to initiate DNA synthesis, although they did not regress from the S phase during translational inhibition. However, these cells did not need IGF for entry into the S phase.

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