scholarly journals The sulfation of biomimetic glycosaminoglycan substrates controls binding of growth factors and subsequent neural and glial cell growth

2019 ◽  
Vol 7 (10) ◽  
pp. 4283-4298 ◽  
Author(s):  
Waddah Malaeb ◽  
Hisham F. Bahmad ◽  
Wassim Abou-Kheir ◽  
Rami Mhanna
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Cell Growth ◽  
Glial Cell ◽  
Factor Binding ◽  
Control Growth ◽  
Neural Growth

This work shows that alginates can be sulfated to engineer defined substrates that control growth factor binding and neural growth.

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

FGF-18 is a neuron-derived glial cell growth factor expressed in the rat brain during early postnatal development

2002 ◽  
Vol 105 (1-2) ◽  
pp. 60-66 ◽  
Author(s):  
Masamitsu Hoshikawa ◽  
Akiko Yonamine ◽  
Morichika Konishi ◽  
Nobuyuki Itoh
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
Rat Brain ◽  
Postnatal Development ◽  
Glial Cell ◽  
Early Postnatal Development

Glial cell line-derived neurotrophic factor promotes sleep in rats and rabbits

2001 ◽  
Vol 280 (4) ◽  
pp. R1001-R1006 ◽  
Author(s):  
Tetsuya Kushikata ◽  
Takeshi Kubota ◽  
Jidong Fang ◽  
James M. Krueger
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Cell Line ◽  
Glial Cell ◽  
Eye Movement ◽  
Neurotrophic Factor ◽  
Brain Temperature ◽  
Interleukin 1 ◽  
High Dose ◽  
Sleep Regulation

Various growth factors (e.g., growth hormone-releasing hormone, acidic fibroblast growth factor, nerve growth factor, brain-derived neurotrophic factor, and interleukin-1) are implicated in sleep regulation. It is hypothesized that neuronal activity enhances the production of such growth factors, and they in turn form part of the sleep regulatory mechanism. Glial cell line-derived neurotrophic factor (GDNF) promotes development, differentiation, maintenance, and regeneration of neurons, and its production is induced by well-characterized sleep regulatory substances such as interleukin-1 and tumor necrosis factor. Therefore, we investigated whether GDNF would promote sleep. Twenty-six male Sprague-Dawley rats and 30 male New Zealand White rabbits were surgically implanted with electroencephalogram (EEG) and electromyogram (EMG; rats only) electrodes, a brain thermistor, and a lateral intracerebroventricular cannula. The animals were injected intracerebroventricularly with pyrogen-free saline and on a separate day with one of the following doses of GDNF: 5, 50, and 500 ng in rabbits and 50 and 500 ng in rats. The EEG, brain temperature, EMG (in rats), and motor activity (in rabbits) were recorded for 23 h after the intracerebroventricular injection. GDNF (500-ng dose) increased the time spent in nonrapid eye movement sleep in both rats and rabbits. Rapid eye movement sleep was not affected by the lower doses of GDNF but was inhibited in rabbits after the high dose. EEG slow-wave activity was not affected by GDNF. The current results provide further evidence that various growth factors are involved in sleep regulation.

scholarly journals Regulation of Cell Growth

1987 ◽  
Vol 80 (9) ◽  
pp. 591-593
Author(s):  
A J Barrett
Keyword(s):  
Stem Cells ◽  
Growth Factors ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Cell Growth ◽  
Cell Lines ◽  
Growth Regulation ◽  
Platelet Derived Growth Factor ◽  
Haemopoietic Stem Cells

At this meeting of the RSM's Section of Pathology, the regulation of haemopoietic stem cells and growth factors regulating various cell lines were described, and the role of oncogenes, platelet-derived growth factor and nerve growth factor in growth regulation was discussed.

scholarly journals Nutrient-responsive mTOR signalling grows on Sterile ground

2007 ◽  
Vol 403 (1) ◽  
Author(s):  
Simon J. Cook ◽  
Simon J. Morley
Keyword(s):  
Amino Acids ◽  
Growth Factors ◽  
Growth Factor ◽  
Protein Kinase ◽  
Cell Growth ◽  
Cell Size ◽  
Protein Translation ◽  
Small Gtpase ◽  
Mtor Activity ◽  
Mtor Signalling

The control of cell growth, that is cell size, is largely controlled by mTOR (the mammalian target of rapamycin), a large serine/threonine protein kinase that regulates ribosome biogenesis and protein translation. mTOR activity is regulated both by the availability of growth factors, such as insulin/IGF-1 (insulin-like growth factor 1), and by nutrients, notably the supply of certain key amino acids. The last few years have seen a remarkable increase in our understanding of the canonical, growth factor-regulated pathway for mTOR activation, which is mediated by the class I PI3Ks (phosphoinositide 3-kinases), PKB (protein kinase B), TSC1/2 (the tuberous sclerosis complex) and the small GTPase, Rheb. However, the nutrient-responsive input into mTOR is important in its own right and is also required for maximal activation of mTOR signalling by growth factors. Despite this, the details of the nutrient-responsive signalling pathway(s) controlling mTOR have remained elusive, although recent studies have suggested a role for the class III PI3K hVps34. In this issue of the Biochemical Journal, Findlay et al. demonstrate that the protein kinase MAP4K3 [mitogen-activated protein kinase kinase kinase kinase-3, a Ste20 family protein kinase also known as GLK (germinal centre-like kinase)] is a new component of the nutrient-responsive pathway. MAP4K3 activity is stimulated by administration of amino acids, but not growth factors, and this is insensitive to rapamycin, most likely placing MAP4K3 upstream of mTOR. Indeed, MAP4K3 is required for phosphorylation of known mTOR targets such as S6K1 (S6 kinase 1), and overexpression of MAP4K3 promotes the rapamycin-sensitive phosphorylation of these same targets. Finally, knockdown of MAP4K3 levels causes a decrease in cell size. The results suggest that MAP4K3 is a new component in the nutrient-responsive pathway for mTOR activation and reveal a completely new function for MAP4K3 in promoting cell growth. Given that mTOR activity is frequently deregulated in cancer, there is much interest in new strategies for inhibition of this pathway. In this context, MAP4K3 looks like an attractive drug target since inhibitors of this enzyme should switch off mTOR, thereby inhibiting cell growth and proliferation, and promoting apoptosis.

scholarly journals Growth Factors Can Influence Cell Growth and Survival through Effects on Glucose Metabolism

2001 ◽  
Vol 21 (17) ◽  
pp. 5899-5912 ◽  
Author(s):  
Matthew G. Vander Heiden ◽  
David R. Plas ◽  
Jeffrey C. Rathmell ◽  
Casey J. Fox ◽  
Marian H. Harris ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Cell Growth ◽  
Glucose Uptake ◽  
Fixed Dose ◽  
Glucose Limitation ◽  
Growth And Survival ◽  
Glucose Levels ◽  
Dependent Cell ◽  
High Concentrations

ABSTRACT Cells from multicellular organisms are dependent upon exogenous signals for survival, growth, and proliferation. The relationship among these three processes was examined using an interleukin-3 (IL-3)-dependent cell line. No fixed dose of IL-3 determined the threshold below which cells underwent apoptosis. Instead, increasing growth factor concentrations resulted in progressive shortening of the G1 phase of the cell cycle and more rapid proliferative expansion. Increased growth factor concentrations also resulted in proportional increases in glycolytic rates. Paradoxically, cells growing in high concentrations of growth factor had an increased susceptibility to cell death upon growth factor withdrawal. This susceptibility correlated with the magnitude of the change in the glycolytic rate following growth factor withdrawal. To investigate whether changes in the availability of glycolytic products influence mitochondrion-initiated apoptosis, we artificially limited glycolysis by manipulating the glucose levels in the medium. Like growth factor withdrawal, glucose limitation resulted in Bax translocation, a decrease in mitochondrial membrane potential, and cytochromec redistribution to the cytosol. In contrast, increasing cell autonomous glucose uptake by overexpression of Glut1 significantly delayed apoptosis following growth factor withdrawal. These data suggest that a primary function of growth factors is to regulate glucose uptake and metabolism and thus maintain mitochondrial homeostasis and enable anabolic pathways required for cell growth. Consistent with this hypothesis, expression of the three genes involved in glucose uptake and glycolytic commitment, those for Glut1, hexokinase 2, and phosphofructokinase 1, was found to rapidly decline to nearly undetectable levels following growth factor withdrawal.

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