Effects of insulin-like growth factor-I (IGF-I) and IGF-II on the growth of antler cells in vitro

1994 ◽  
Vol 143 (3) ◽  
pp. 461-469 ◽  
Author(s):  
M Sadighi ◽  
S R Haines ◽  
A Skottner ◽  
A J Harris ◽  
J M Suttie

Abstract The effects of insulin-like growth factors -I and -II (IGF-I and -II) on the growth of undifferentiated (fibroblast zone) cells from the growing tip of red deer velvet antlers and from cells 1·5 cm distal to the growing tip (cartilage zone) were investigated in primary cell culture. The addition of IGF-I or IGF-II to the medium of cultures preincubated in serum-free medium for 24 h increased the rate of [3H]thymidine uptake in a dose-dependent manner in both cell types, with maximal stimulation occurring when 1 nm–30 nm was added. The addition of IGF-II to the incubation medium containing IGF-I did not cause a further increase in [3H]thymidine uptake in either cell type over and above each growth factor alone, indicating that there were unlikely to be synergistic effects of IGF-II on the mitogenicity of IGF-I. Binding studies were carried out using 3 × 105 fibroblast zone cells and cartilage zone cells after they had been incubated in serum-free medium for 24 h. 125I-Labelled IGF-I (10−9 m) in a final volume of 200 μl was added to each culture and incubation carried out at 4 °C for a further hour. 125I-Labelled IGF-I bound specifically to both fibroblasts and cartilage zone cells; binding was displaced by both unlabelled IGF-I and by IGF-I antibody. These findings indicate that IGF-I and IGF-II are important mediators for antler growth in vitro and suggest that in view of correlations between IGF-I and antler growth, IGF is functionally significant in controlling velvet antler growth in vivo. Journal of Endocrinology (1994) 143, 461–469

1984 ◽  
Vol 103 (2) ◽  
pp. 195-203 ◽  
Author(s):  
D. J. Hill ◽  
R. D. G. Milner

ABSTRACT The actions of partially purified porcine platelet-derived growth factor (PDGF) and highly purified multiplication-stimulating activity (MSA) II and MSA III-2, which are somatomedins, were investigated on the incorporation of [3H]thymidine and [35S]sulphate by fetal rat costal cartilage in vitro. This was compared with their effects in the presence of 1% fetal calf serum (FCS) on the uptake of thymidine by growth-arrested fetal rat fibroblasts. Platelet-derived growth factor at concentrations of 0·21–21 μg/l enhanced the incorporation of both isotopes by fetal cartilage in the presence of 1% FCS, but had an inconsistent action on thymidine uptake and no significant action on sulphate uptake in serum-free medium. Platelet-derived growth factor promoted thymidine uptake by growth-arrested, isolated fetal rat fibroblasts. Multiplication-stimulating activity II (10–100 μg/l) stimulated the uptake of thymidine and sulphate by fetal cartilage in medium containing 1% FCS but had no consistent action in serum-free medium, although MSA II and PDGF had a synergistic effect on thymidine uptake in the absence of serum. Multiplication-stimulating activity III-2 had no consistent action on thymidine or sulphate incorporation by fetal cartilage in either serum-free or serum-supplemented medium. However, the same preparation of MSA III-2 stimulated the uptake of [3H]thymidine into fetal rat fibroblasts with a half-maximal response at a concentration of 5–10 μg/l. The results identify PDGF as a possible mitogenic agent for fetal rat connective tissues in vitro and show a differential sensitivity of fetal cartilage to MSA peptides. J. Endocr. (1984) 103, 195–203


1998 ◽  
Vol 159 (2) ◽  
pp. 313-321 ◽  
Author(s):  
AV Sirotkin ◽  
AV Makarevich ◽  
J Kotwica ◽  
PG Marnet ◽  
HB Kwon ◽  
...  

The aim of our in vitro experiments with isolated porcine ovarian follicles was to study the effects of gonadotropins, GH, IGF-I and oxytocin (OT) on release of ovarian steroid, OT, IGF-I, insulin-like growth factor-binding protein-3 (IGFBP-3), prostaglandin F (PGF), prostaglandin E (PGE) and cAMP. It was found that quarters of ovarian follicles cultured for 8 days produced significant amounts of progesterone, estradiol-17 beta, OT and IGFBP-3 with peaks of accumulation from the 3rd to the 8th day of culture. Addition of serum promoted progesterone, estradiol and OT release, whilst accumulation of IGFBP-3 was maintained to a greater extent in serum-free medium. GH (10 ng/ml or above) was able to inhibit androstenedione, OT, PGF and IGFBP-3, to stimulate IGF-I and cAMP, and to alter testosterone and PGE release by follicles cultured in serum-supplemented and/or serum-free medium. IGF-I (10 ng/ml or more) inhibited androstenedione and PGF secretion, stimulated testosterone, estradiol, OT and cAMP production, but did not influence progesterone, IGFBP-3 or PGE output in these conditions. OT (100 ng/ml) was able to inhibit androstenedione and to stimulate testosterone, IGF-I, PGF and PGE, but not estradiol or IGFBP-3 release. A stimulatory effect of LH on progesterone and OT and an inhibitory influence of LH on estradiol secretion in the serum-supplemented medium were observed. FSH in these conditions stimulated OT, but not progesterone or estradiol secretion. The use of this experimental model suggests the involvement of gonadotropins, OT, GH and IGF-I in the control of ovarian steroid and nonapeptide hormone, growth factor, growth factor-binding protein, prostaglandin and cyclic nucleotide production. The stimulatory effect of GH on IGF-I, and the stimulatory influence of IGF-I on OT, as well as coincidence of the majority of effects of IGF-I and OT, suggest the existence of a GH-IGF-I-OT axis. On the other hand, the different patterns of action of GH and IGF-I on OT, estrogen and IGFBP-3 suggest that part of the GH effect on ovarian cells is IGF-I independent.


1989 ◽  
Vol 3 (3) ◽  
pp. 183-190 ◽  
Author(s):  
K. A. Freed ◽  
A. C. Herington

ABSTRACT Human MCF-7 breast cancer cells have been studied to determine their suitability as an autocrine model for the synthesis, secretion and action of insulin-like growth factor-I (IGF-I). Secretion of immunoreactive (ir-) IGF-I into serum-free medium was very low (<500 pg/106 cells per day). Northern blot hybridization detected at least two IGF-I messenger RNA transcripts (∼4·6 and ∼1·8 kb) which were similar in size to those reported in other human and rat tissues. IGF-II mRNA was also detected but at low abundance. Cell proliferation was stimulated in a dose-responsive manner by exogenous IGF-I (10–30 ng/ml). Addition of a monoclonal antibody against IGF-I to MCF-7 cells in serum-free medium caused an inhibition of cell proliferation, suggesting that endogenous locally produced IGF-I does play an autocrine/paracrine role in MCF-7 cell growth. Proliferation of MCF-7 cells was sensitive to oestradiol (10 nm) in the absence but not in the presence of the weakly oestrogenic pH indicator phenol red. Neither IGF-I secretion nor IGF-I mRNA synthesis, however, was affected by addition of oestradiol. Similarly, GH, dexamethasone or dexamethasone plus oestradiol had no effect on either parameter. These data indicate that MCF-7 cells synthesize, secrete and respond to IGF-I. The very low levels of ir-IGF-I produced and their apparent lack of hormonal modulation suggest, however, that further studies are required to establish whether IGF-I plays a major physiological role in growth and development of MCF-7 cells.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Naoki Ishiuchi ◽  
Ayumu Nakashima ◽  
Shigehiro Doi ◽  
Ryo Kanai ◽  
Satoshi Maeda ◽  
...  

Abstract Background Mesenchymal stem cells (MSCs) repair injured tissue in a paracrine manner. To enhance their therapeutic properties, preconditioning with various factors has been researched. We have previously showed that MSCs cultured in serum-free medium (SF-MSCs) promote their immunosuppressive ability, thereby enhancing their anti-fibrotic effect. Here, we examined whether serum-free medium and hypoxic preconditioning synergistically enhance the therapeutic effects of MSCs on renal fibrosis in rats with ischemia–reperfusion injury (IRI). Methods SF-MSCs were incubated under 1% O2 conditions (hypo-SF-MSCs) or 21% O2 conditions (normo-SF-MSCs) for 24 h before collection. After IRI procedure, hypo-SF-MSCs or normo-SF-MSCs were injected through the abdominal aorta. At 7 or 21 days post-injection, the rats were killed and their kidneys were collected to evaluate inflammation and fibrosis. In in vitro experiments, we investigated whether hypo-SF-MSCs enhanced secretion of anti-fibrotic humoral factors using transforming growth factor (TGF)-β1-stimulated HK-2 cells incubated with conditioned medium from hypo-SF-MSCs or normo-SF-MSCs. Results Normo-SF-MSCs showed attenuation of senescence, which increased their proliferative capacity. Although no significant difference in cellular senescence was found between normo-SF-MSCs and hypo-SF-MSCs, hypo-SF-MSCs further increased their proliferative capacity compared with normo-SF-MSCs. Additionally, administration of hypo-SF-MSCs more strongly ameliorated renal fibrosis than that of normo-SF-MSCs. Moreover, although hypo-SF-MSCs strongly attenuated infiltration of inflammatory cells compared with the control rats, which were treated with PBS, this attenuation was almost equal between normo-SF-MSCs and hypo-SF-MSCs. In vitro experiments revealed that hypo-SF-MSCs more significantly inhibited transforming growth factor (TGF)-β/Smad signaling compared with normo-SF-MSCs. Moreover, hypoxic preconditioning increased hepatocyte growth factor (HGF) secretion even under serum-free conditions, whereas knockdown of HGF in hypo-SF-MSCs attenuated inhibition of TGF-β/Smad signaling. Conclusions These results indicate that administration of ex vivo-expanded, hypoxia-preconditioned SF-MSCs may be a useful cell therapy to prevent renal fibrosis.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3607-3607
Author(s):  
Jen-Chin Wang ◽  
Tsong H Chang ◽  
Amit Goldberg ◽  
Allan D. Novetsky ◽  
Steven Lichter ◽  
...  

Abstract Currently, the prevailing concept concerning the etiology of bone marrow fibrosis in patients with idiopathic myelofibrosis (IMF) is that it results from excessive production of fibrosing growth factors including transforming growth factor beta (TGF-B1), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF) from megakaryocytes and monocytes. Since megakaryocytes are difficult to isolate from bone marrow in IMF patients, this concept remains speculative. We obtained megakaryocytes (CD41+ cells) from 10-day in vitro culture of blood CD34+ cells in serum-free medium with thrombopoietin and stem cell factors as described and cultured monocytes from isolating blood CD14+ cells. Then quantitative analyses of fibrosing growth factors at the mRNA and protein levels were obtained. mRNA levels were obtained from real-time RT-PCR technique, and protein levels were obtained from ELISA analysis of the supernatant of CD41+ cells cultured 4 h in serum-free medium. The results showed 1) mRNA levels of TGF-B1, PDGF, and FGF produced by the megakaryocytes were significantly elevated in agnogenic myeloid metaplasia (AMM) compared with those in normal controls (p<0.05). While these growth factors were elevated several-fold in AMM compared with other myeloproliferative disorders (MPD) including essential thrombocythemia and polycythemia vera, they were not statistically significant. 2) mRNA levels of TGF-B1 were higher than levels of PDGF or FGF. 3) The mRNA levels of these growth factors produced from CD14+ cells were not significantly elevated in AMM compared with other MPDs or controls; the AMM mRNA levels were significantly elevated only in some patients. 4) The correlation of mRNA levels of these growth factors with the degree of myelofibrosis in AMM was significant with megakaryocytes (r=0.73) but not with monocytes (r=0.23). 5) ELISA analysis of the growth factors from the cultured megakaryocytes showed that, in most of the patients with AMM and other MPDs and in volunteer controls, the growth factors were undetectable, and only a few patients with AMM had significantly elevated protein levels of these growth factors. We conclude thatin IMF, megakaryocytes but not monocytes are the predominant cells producing fibrosing growth factors, andthe failure of finding increased protein levels of these growth factors in the in vitro system suggest that other factors are necessary to initiate translation of these growth factors in the megakaryoctes, and neutrophil emperipolesis with releasing factors may be important in this process.


2000 ◽  
Vol 28 (2) ◽  
pp. 199-202 ◽  
Author(s):  
J. D. Aplin ◽  
H. Lacey ◽  
T. Haigh ◽  
C. J. P. Jones ◽  
C.-P. Chen ◽  
...  

At the periphery of the human placenta, trophoblast attaches to the uterine wall. The tissue interface contains many anchoring sites, with cytotrophoblast columns that form bridges between the overlying extraembryonic (villous) mesenchyme and the maternal decidual stroma beneath. From the periphery of these columns, large numbers of trophoblast cells detach, migrate through the decidua and eventually colonize and transform maternal arteries. In this way the placenta increases and gives priority to the maternal blood supply to the conceptus. We have shown that when early villous tissue is explanted on a collagen gel in serum-free medium, anchoring-site morphogenesis occurs. Thus, in the presence of placental mesenchyme but in the absence of maternal cells, contact with a permissive extracellular matrix (ECM) is necessary and sufficient for cytotrophoblast column development. Proliferation of trophoblast occurs, followed by differentiation into a columnar cell phenotype in which cells remain attached to one another and to the ECM. At this stage, interaction between fibronectin and integrin α5β1 at the cell surface stabilizes the column and the cells remain as a contiguous multilayered sheet. However, the addition of serum-free conditioned medium from first-trimester placental fibroblasts stimulates cytotrophoblast to detach from the distal column and migrate in streams across the ECM. The removal of insulin-like growth factor I (IGF-I) from the fibroblast medium decreases streaming activity, whereas the addition of exogenous IGF-I (10 ng/ml) to serum-free medium produces a streaming phenotype. In contrast, transforming growth factor β1 (10 ng/ml) maintains the cells in a tight sheet. These results suggest the possibility of a paracrine interaction between villous mesenchyme and cytotrophoblast in anchoring sites to stimulate the infiltration of the maternal ECM by trophoblast. Such a mechanism would be self-limiting because the signal diminishes with distance from the placenta.


1996 ◽  
Vol 76 (02) ◽  
pp. 258-262 ◽  
Author(s):  
Robert I Roth

SummaryHuman endothelial cells, when incubated with bacterial endotoxin (lipopolysaccharide, LPS), modify their surface in association with prominent production of procoagulant tissue factor (TF) activity. This deleterious biological effect of LPS has been shown previously to be enhanced approximately 10-fold by the presence of hemoglobin (Hb), a recently recognized LPS binding protein that causes disaggregation of LPS and increases the biological activity of LPS in a number of in vitro assays. The present study was performed to test the hypothesis that Hb enhances the LPS-induced procoagulant activity of human umbilical vein endothelial cells (HUVEC) by increasing LPS binding to the cells. The binding of 3H-LPS to HUVEC was determined in the absence or presence of Hb or two other known LPS-binding proteins, human serum albumin (HSA) and IgG. LPS binding was substantially increased in the presence of Hb, in a Hb concentration-dependent manner, but was not increased by HSA or IgG. Hb enhancement of LPS binding was observed in serum-free medium, indicating that there was no additional requirement for any of the serum factors known to participate in the interaction of LPS with cells (e.g., lipopolysaccharide (LPS)-binding protein (LBP) and soluble CD14 (sCD14)). Hb enhancement of LPS binding also was observed in the more physiologic condition of 100% plasma. LPS-induced TF activity was stimulated by Hb, but not by HSA or IgG. In serum-free medium, TF activity was not stimulated under any of the conditions tested. Ultrafiltration of LPS was dramatically increased after incubation with Hb but not with HSA or IgG, suggesting that LPS disaggregation by Hb was responsible for the enhanced binding of LPS to HUVEC and the subsequent stimulation of TF activity.


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