Differentiation in C2C12 myoblasts depends on the expression of endogenous IGFs and not serum depletion

2002 ◽  
Vol 283 (4) ◽  
pp. C1278-C1286 ◽  
Author(s):  
Yuji Yoshiko ◽  
Keita Hirao ◽  
Norihiko Maeda
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Myogenic Differentiation ◽  
Negative Control ◽  
Mrna Levels ◽  
Rich Medium ◽  
Medium Conditioning ◽  
Serum Components

Myogenic differentiation in vitro has been usually viewed as being negatively controlled by serum mitogens. A depletion of critical serum components from medium has been considered to be essential for permanent withdrawal from the cell cycle and terminal differentiation of myoblasts. Removal of serum mitogens induces the expression of insulin-like growth factors (IGFs), whereas it inhibits that of basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-β in myoblasts. These responses of growth factors to medium conditioning seem to be well matched to their functions in proliferation/differentiation. In the present study, we showed that C2C12 myoblasts differentiated actively, even in mitogen-rich medium, and that this medium offered an advantage over mitogen-poor medium in terms of increasing differentiation. Our attention focused on endogenous growth factors, as described above, especially IGFs in mitogen-rich medium. During differentiation, IGF-I and IGF-II mRNA levels increased, but bFGF and TGF-β1 mRNAs decreased. Differentiation was commensurable with IGF mRNA levels and suppressed by antisense oligodeoxynucleotides and neutralizing monoclonal antibodies against IGFs. These results suggest that an autocrine/paracrine loop of IGFs, bFGF, and TGF-β1 is active in proliferating and differentiating C2C12 cells without a depletion of serum and that endogenous IGFs actively override the negative control of differentiation by serum mitogens.

scholarly journals The Activity of Differentiation Factors Induces Apoptosis in Polyomavirus Large T-Expressing Myoblasts

1998 ◽  
Vol 9 (6) ◽  
pp. 1449-1463 ◽  
Author(s):  
Gian Maria Fimia ◽  
Vanesa Gottifredi ◽  
Barbara Bellei ◽  
Maria Rosaria Ricciardi ◽  
Agostino Tafuri ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Growth Factor ◽  
Cell Cycle Progression ◽  
Transforming Growth Factor ◽  
Myogenic Differentiation ◽  
Transforming Growth Factor Β ◽  
Large Tumor ◽  
Cycle Progression

It is commonly accepted that pathways that regulate proliferation/differentiation processes, if altered in their normal interplay, can lead to the induction of programmed cell death. In a previous work we reported that Polyoma virus Large Tumor antigen (PyLT) interferes with in vitro terminal differentiation of skeletal myoblasts by binding and inactivating the retinoblastoma antioncogene product. This inhibition occurs after the activation of some early steps of the myogenic program. In the present work we report that myoblasts expressing wild-type PyLT, when subjected to differentiation stimuli, undergo cell death and that this cell death can be defined as apoptosis. Apoptosis in PyLT-expressing myoblasts starts after growth factors removal, is promoted by cell confluence, and is temporally correlated with the expression of early markers of myogenic differentiation. The block of the initial events of myogenesis by transforming growth factor β or basic fibroblast growth factor prevents PyLT-induced apoptosis, while the acceleration of this process by the overexpression of the muscle-regulatory factor MyoD further increases cell death in this system. MyoD can induce PyLT-expressing myoblasts to accumulate RB, p21, and muscle- specific genes but is unable to induce G00arrest. Several markers of different phases of the cell cycle, such as cyclin A, cdk-2, and cdc-2, fail to be down-regulated, indicating the occurrence of cell cycle progression. It has been frequently suggested that apoptosis can result from an unbalanced cell cycle progression in the presence of a contrasting signal, such as growth factor deprivation. Our data involve differentiation pathways, as a further contrasting signal, in the generation of this conflict during myoblast cell apoptosis.

Modulation of growth factor incorporation into ECM of human osteoblast-like cells in vitro by 17 beta-estradiol

1994 ◽  
Vol 267 (6) ◽  
pp. E990-E1001 ◽  
Author(s):  
M. Slater ◽  
J. Patava ◽  
K. Kingham ◽  
R. S. Mason
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Bone Growth ◽  
Transforming Growth Factor ◽  
Bone Matrix ◽  
Tgf Beta ◽  
Subsequent Formation ◽  
Igf I

Human fetal osteoblast-like cells formed a regular multilayered structure in vitro with an extensive collagen-based extracellular matrix. With colloidal gold immunocytochemistry, labels for alkaline phosphatase and osteocalcin were distributed in a relatively diffuse pattern, in contrast to the bone growth factors, insulin-like growth factors I and II (IGF-I and IGF-II), transforming growth factor-beta 1 (TGF-beta 1), and basic fibroblast growth factor, which were colocalized in the collagenous matrix of the multilayer. The inclusion of 17 beta-estradiol (10(-11) to 10(-9) M) in the culture medium increased multilayer depths, increased labeling for IGF-I, IGF-II, and TGF-beta 1, and resulted in earlier detection of TGF-beta 1 label. In contrast, the increase in multilayer depth resulting from treatment with human platelets, an exogenous source of growth factors, was not accompanied by an increase in matrix IGF-I, IGF-II, or TGF-beta 1 label, suggesting a particular effect of estradiol to facilitate this process. Because growth factors in bone matrix may act as coupling agents when released during resorption, reduced growth factor incorporation in the presence of reduced sex steroid concentrations may lead to uncoupling of resorption and subsequent formation.

174 EPIDERMAL GROWTH FACTORS AND CALBINDIN-D9k GENE EXPRESSIONS DURING PREGANCY IN THE PORCINE UTERUS

2008 ◽  
Vol 20 (1) ◽  
pp. 167
Author(s):  
Y.-J. Kim ◽  
E.-M. Jung ◽  
G.-S. Lee ◽  
S.-H. Hyun ◽  
E.-B. Jeung
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Expression Patterns ◽  
Negative Control ◽  
Heparin Binding ◽  
Gene Expressions ◽  
Calbindin D9k ◽  
Genes Encoding ◽  
Epidermal Growth

To stably maintain pregnancy, several genes are expressed in the uterus. In particular, the endometrial expression of genes encoding growth factors appears to play a key role in maternal–fetal communication. Previous studies have characterized the endometrial expression kinetics of the genes encoding epidermal growth factor (EGF), its receptor (EGFR), transforming growth factor-alpha (TGF-α), amphiregulin (Areg), heparin-binding (Hb) EGF, and calbindin-D9k (CaBP-9k) in the pig during implantation. Here, we further characterized the expression patterns of these molecules during the entire porcine pregnancy. Porcine (n = 3 per PD) were collected at pregnancy days (PD) 12, 15, 30, 60, 90, and 110 and subjected to semi-quantitative RT-PCR. The data were analyzed with a nonparametric one-way analysis of variance using the Kruskal-Wallis test, followed by Dunnett's test for multiple comparisons to the negative control. EGF and EGFR showed similar expression patterns, being highly expressed around implantation time and then disappearing. TGF-α and Areg expression levels rose steadily until they peaked at PD30, after which they gradually decreased to PD12 levels. The Areg mRNA expression pattern was confirmed by real-time PCR, and similar Areg protein expression patterns were observed. Immunohistochemical analysis of PD60 uteri revealed Areg in the glandular and luminal epithelial cells. Hb-EGF was steadily expressed throughout the entire pregnancy while CaBP-9k was expressed strongly on PD12, and then declined sharply in PD15 before recovering slightly for the remainder of the pregnancy. Thus, the EGF family may play a key role during implantation in pigs. In addition, CaBP-9k may help maintain uterine quiescence during pregnancy by sequestering cytoplasmic Ca2+.

TGF-β and CTGF have overlapping and distinct fibrogenic effects on human renal cells

2002 ◽  
Vol 283 (4) ◽  
pp. F707-F716 ◽  
Author(s):  
Elizabeth Gore-Hyer ◽  
Daniel Shegogue ◽  
Malgorzata Markiewicz ◽  
Shianlen Lo ◽  
Debra Hazen-Martin ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Growth Factor ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Tissue Growth ◽  
Mrna Levels ◽  
Potent Inducer ◽  
Collagen Promoter

Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are ubiquitously expressed in various forms of tissue fibrosis, including fibrotic diseases of the kidney. To clarify the common and divergent roles of these growth factors in the cells responsible for pathological extracellular matrix (ECM) deposition in renal fibrosis, the effects of TGF-β and CTGF on ECM expression in primary human mesangial (HMCs) and human proximal tubule epithelial cells (HTECs) were studied. Both TGF-β and CTGF significantly induced collagen protein expression with similar potency in HMCs. Additionally, α2(I)-collagen promoter activity and mRNA levels were similarly induced by TGF-β and CTGF in HMCs. However, only TGF-β stimulated collagenous protein synthesis in HTECs. HTEC expression of tenascin-C (TN-C) was increased by TGF-β and CTGF, although TGF-β was the more potent inducer. Thus both growth factors elicit similar profibrogenic effects on ECM production in HMCs, while promoting divergent effects in HTECs. CTGF induction of TN-C, a marker of epithelial-mesenchymal transdifferentiation (EMT), with no significant induction of collagenous protein synthesis in HTECs, may suggest a more predominant role for CTGF in EMT rather than induction of excessive collagen deposition by HTECs during renal fibrosis.

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.

scholarly journals BMP-4 inhibits follicle-stimulating hormone secretion in ewe pituitary

2005 ◽  
Vol 186 (1) ◽  
pp. 109-121 ◽  
Author(s):  
M-O Faure ◽  
L Nicol ◽  
S Fabre ◽  
J Fontaine ◽  
N Mohoric ◽  
...  
Keyword(s):  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Hormone Secretion ◽  
Inhibitory Effect ◽  
Type I ◽  
Mrna Levels ◽  
Dependent Manner

Activins and inhibins, members of the transforming growth factor-beta family are able to stimulate and inhibit, respectively, FSH synthesis and release. Other members of this superfamily, the bone morphogenetic proteins (BMPs), may also affect FSH synthesis in the mouse. The aim of this work was to determine whether BMPs are expressed in the ovine pituitary and whether they play a role in the regulation of FSH release. The mRNAs encoding BMP-2, BMP-4, BMP-7 and the oocyte-derived growth factor, growth differentiation factor (GDF)-9 were detected in the pituitaries of cyclic ewes by reverse-transcriptase PCR, as well as the mRNAs encoding the BMP type I receptors, BMPR-IA (activin-receptor-like kinase (ALK)-3) and BMPR-IB (ALK-6), and type II receptors (BMPR-II). Immunolabeling of pituitary sections revealed the presence of BMPR-IA (ALK-3) and BMPR-II in gonadotrope cells. To investigate the potential effects of BMPs on FSH secretion, ewe pituitary cell cultures were treated with BMP-4 (10−11 M to 10−9 M) for 48 h. Interestingly, FSH release was decreased in a dose-dependent manner. At 10−9 M BMP-4 both FSH concentration and FSHβ mRNA expression were reduced by 40% of control values. In contrast, there was no inhibitory effect on either LH or LHβ mRNA expression. A similar result was found with BMP-6. BMP-4 triggered the phosphorylation of Smad1, suggesting that the effect of BMP-4 on FSH secretion is due to the activation of the BMPs signaling pathway. Furthermore, BMP-4 blocked the stimulatory effect of activin on both FSH release and FSHβ mRNA and amplified the suppression of FSH release and FSHβ mRNA levels induced by 17β-estradiol. These results indicate that a functional BMP system operates within the sheep pituitary, at least in vitro, to decrease FSH release and to modulate the effect of activin.

scholarly journals High lung inflation increases mRNA levels of ECM components and growth factors in lung parenchyma

1997 ◽  
Vol 83 (1) ◽  
pp. 120-128 ◽  
Author(s):  
John T. Berg ◽  
Zhenxing Fu ◽  
Ellen C. Breen ◽  
Hung-Cuong Tran ◽  
Odile Mathieu-Costello ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Wall Stress ◽  
Lung Parenchyma ◽  
Control Group ◽  
High Peep ◽  
Mrna Levels ◽  
Lung Inflation ◽  
Pulmonary Capillaries

Berg, John T., Zhenxing Fu, Ellen C. Breen, Hung-Cuong Tran, Odile Mathieu-Costello, and John B. West. High lung inflation increases mRNA levels of ECM components and growth factors in lung parenchyma. J. Appl. Physiol. 83(1): 120–128, 1997.—Remodeling of pulmonary capillaries occurs after chronic increases in capillary pressure (e.g., mitral stenosis). Also, remodeling of pulmonary arteries begins within 4 h of increased wall stress and is endothelium dependent. We have previously shown that high lung inflation increases wall stress in pulmonary capillaries. This study was designed to determine whether high lung inflation induces remodeling of the extracellular matrix (ECM) in lung parenchyma. Open-chest rabbits were ventilated for 4 h with 9-cmH2O positive end-expiratory pressure (PEEP) on one lung and 1-cmH2O PEEP on the other (High-PEEP group), or with 2-cmH2O PEEP on both lungs (Low-PEEP group). An additional untreated control group was also included. We found increased levels of mRNA in both lungs of High-PEEP rabbits (compared with both the Low-PEEP and untreated groups) for α1(III) and α2(IV) procollagen, fibronectin, basic fibroblast growth factor, and transforming growth factor-β1. In contrast, α2(I) procollagen and vascular endothelial growth factor mRNA levels were not changed. We conclude that high lung inflation for 4 h increases mRNA levels of ECM components and growth factors in lung parenchyma.

Growth factor and somatic cell regulation of mouse gonocyte-derived colony formation in vitro

Reproduction ◽  
2000 ◽  
pp. 85-91 ◽  
Author(s):  
S Hasthorpe ◽  
S Barbic ◽  
PJ Farmer ◽  
JM Hutson
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Colony Formation ◽  
Inhibitory Action ◽  
Transforming Growth Factor ◽  
Epidermal Growth ◽  
Growth Factor Beta

At birth, the mouse gonocyte does not resume mitotic activity for several days in vivo but, in an in vitro clonogenic system, cell division commences soon after culture. Somatic testis cell underlays had potent inhibitory activity on gonocyte-derived colony formation (23 +/- 15% compared with 84 +/- 1% in controls; P = 0.0001) when added to cultures of gonocytes in vitro. A Sertoli cell line, TM4B, had an even more pronounced effect on gonocyte clonogenic capacity, with 1 +/- 1% compared with 72 +/- 17% colony formation in controls (P = 0.0003). Testis cells appeared to have a direct inhibitory effect since testis-conditioned medium did not show a significant reduction in the number of colonies. The observed reduction in colony formation with the testis cell underlay was not accounted for by decreased attachment of gonocytes as simultaneous addition of a single cell suspension of testis cells was still effective in significantly reducing colony number when compared with controls (P = 0.01). Therefore, the observed inhibition exerted by testis cells appears to be a consequence of decreased proliferation of gonocytes. Growth factors belonging to the transforming growth factor beta superfamily which are known to be expressed in testis, such as transforming growth factor beta and epidermal growth factor, did not exert any inhibitory action on gonocyte-derived colony formation when added together or alone. However, a shift to a smaller colony size occurred in the presence of transforming growth factor beta and transforming growth factor beta plus epidermal growth factor, indicating a reduction in colony cell proliferation. Evidence for the expression of the Mullerian inhibiting substance receptor on newborn gonocytes using in situ hybridization was inconclusive. This finding was in agreement with the lack of a direct action of Mullerian inhibiting substance on the formation of gonocyte-derived colonies in vitro. Leukaemia inhibitory factor, alone or in combination with forskolin, had neither an inhibitory nor an enhancing effect on gonocyte-derived colony formation. An in vitro clonogenic method to assay for the proliferation of gonocytes in the presence of specific growth factors, cell lines, testis cell underlays and cell suspensions was used to identify a somatic cell-mediated inhibitor which may be responsible for the inhibitory action on gonocyte proliferation in vivo shortly after birth.

Dissecting Growth Factors Production in Patients with Agnogenic Myeloid Metaplasia (AMM).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4749-4749
Author(s):  
Jen-Chin Wang ◽  
Kirugaval Hemavathy ◽  
Amit Goldberg ◽  
Tsong S. Chang ◽  
Allan D. Novetsky ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Prior History ◽  
Mrna Levels ◽  
Myeloid Metaplasia ◽  
Number Of Patients ◽  
History Of ◽  
Tgf Β1 ◽  
Marrow Fibrosis

Abstract Growth factors including Transforming Growth Factor-β 1 ( TGF- β1), Platelet Derived Growth Factor (PDGF) and Fibroblast Growth Factor (FGF) have been implicated as responsible for bone marrow fibrosis in AMM. Although TGF-β1 and FGF have been demonstrated to be increased in blood hematopoietic progenitor cells, a direct measurement of the production of these growth factors by megakaryocytes has not been performed. The current study was devised to study the production of these growth factors production directly in megakaryocytes and monocytes of AMM patients and correlate these with the clinical features. Twelve patients with AMM and 11 normal healthy volunteers used as controls, were studied. CD 34 + cells and CD 14+ cells were obtained from blood mononuclear cells by MACS Progenitor cell isolation kits ( Miltenyi Biotec, CA). The megakaryocytic (CD41+) cells were then obtained by growing the isolated blood CD34 + for 10 days in Iscove Modified Dulbecco Medium with Stem Cell Growth Factor and Thrombopoietin. The mRNA levels of TGF-β1, FGF and PDGF in the isolated megakaryocytes and blood monocytes were assayed by Real-Time RT-PCR. The results were as shown in Table 1. Among the AMM patients, a patient with prior history of Polycythemia Vera (PV) and a patient with Essential Throbocythemia (ET) were found to have elevated PDGF and FGF expression in their monocytes but the expression of growth factors was not elevated in their megakaryocytes.. These results demonstrate that megakaryocytes are the main source of growth factors responsible for marrow fibrosis. The study also suggests that growth factors produced by monocytes may be responsible for fibrosis in AMM patients with a prior history of PV or ET. Table-1 Megakaryocytes Monocytes * Denotes number of patients with elevated growth factor levels as compared with controls. ** Denotes numbers of patients tested. TGF- β 1 8*/10* 0/10 PDGF 8/10 3/7 FGF 6/10 2/7

Angiogenic Growth Factors: Their Effects and Potential in Soft Tissue Wound Healing

1992 ◽  
Vol 101 (4) ◽  
pp. 349-354 ◽  
Author(s):  
David B. Hom ◽  
Robert H. Maisel
Keyword(s):  
Wound Healing ◽  
Growth Factors ◽  
Growth Factor ◽  
Soft Tissue ◽  
Transforming Growth Factor Beta ◽  
Animal Studies ◽  
Transforming Growth Factor ◽  
Therapeutic Potential ◽  
Angiogenic Growth Factors

Since their discovery 30 years ago, angiogenic growth factors have been demonstrated to stimulate neovascularization in vitro and in animal studies. Over the last decade, knowledge gained in the field of angiogenic growth factors has grown immensely. These angiogenic growth factors exist in four major families: fibroblast growth factor (FGF), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). Each has the ability to induce soft tissue vascularization in microgram quantities. In animal models, FGF, TGF-β, PDGF, and EGF have been shown to enhance soft tissue wound healing. In human clinical trials, EGF and a mixture of PDGFs have been demonstrated to accelerate epidermal regeneration in cutaneous wounds. These factors have considerable therapeutic potential in the areas of soft tissue wound healing and otolaryngology. This article reviews important aspects of angiogenic growth factors and discusses their future potential in soft tissue wound healing.

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