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Publication
Journal: Frontiers in Molecular Neuroscience
October/1/2012
Abstract
At least three forms of signaling between pre- and postsynaptic partners are necessary during synapse formation. First, "targeting" signals instruct presynaptic axons to recognize and adhere to the correct portion of a postsynaptic target cell. Second, trans-synaptic "organizing" signals induce differentiation in their synaptic partner so that each side of the synapse is specialized for synaptic transmission. Finally, in many regions of the nervous system an excess of synapses are initially formed, therefore "refinement" signals must either stabilize or destabilize the synapse to reinforce or eliminate connections, respectively. Because of both their importance in processing visual information and their accessibility, retinogeniculate synapses have served as a model for studying synaptic development. Molecular signals that drive retinogeniculate "targeting" and "refinement" have been identified, however, little is known about what "organizing" cues are necessary for the differentiation of retinal axons into presynaptic terminals. To identify such "organizing" cues, we used microarray analysis to assess whether any target-derived "synaptic organizers" were enriched in the mouse dorsal lateral geniculate nucleus (dLGN) during retinogeniculate synapse formation. One candidate "organizing" molecule enriched in perinatal dLGN was FGF22, a secreted cue that induces the formation of excitatory nerve terminals in muscle, hippocampus, and cerebellum. In FGF22 knockout mice, the development of retinal terminals in dLGN was impaired. Thus, FGF22 is an important "organizing" cue for the timely development of retinogeniculate synapses.
Publication
Journal: European Urology
October/22/2009
Abstract
BACKGROUND
Microsatellite analysis (MA) of voided-urine samples has been promoted as an alternative for cystoscopy surveillance (UCS) of patients with low-grade non-muscle-invasive papillary urothelial carcinoma (UC).
OBJECTIVE
To assess the feasibility and clinical utility of MA on voided-urine samples in a routine setting to detect or predict bladder cancer recurrences.
METHODS
We evaluated 228 patients monitored by MA of voided-urine samples and synchronous UCS who participated in a longitudinal prospective study in 10 hospitals. Follow-up started after diagnosis of a primary or recurrent pTa, pT1, grade 1 or grade 2 papillary UC.
METHODS
Clinico-pathological parameters and fibroblast growth factor receptor 3 (FGFR3) gene mutation status of the inclusion tumour were determined. MA outcome was analysed in 1012 urine samples during a mean follow-up of 41 mo. Poor DNA quality prevented MA in 19% (197/1012) of the samples, leaving 815 visits for a cross-sectional analysis of sensitivity and specificity. We determined the predictive value (PPV) in a longitudinal analysis for 458 series with persistent MA results. Factors influencing diagnostic quality of MA were investigated. Kaplan-Meier analysis was performed to relate MA results to recurrence.
CONCLUSIONS
Cross-sectional sensitivity and specificity of MA for detection of a recurrence were 58% (49/84) and 73% (531/731), respectively. One pT1 grade 3 UC was missed. In a longitudinal analysis, the 2-yr risk to develop a recurrence reached 83% if MA outcome was persistently positive and 22% when MA was persistently negative. PPV of MA was higher with wild-type FGFR3 gene status and smoking habits. All four upper urinary tract tumours detected were preceded by a positive MA test.
CONCLUSIONS
Consecutive positive MA results are a strong predictor for future recurrences, but sensitivity needs to be improved, for example, by patient selection and testing of additional genetic markers in urine samples.
Publication
Journal: BMC Genomics
June/3/2008
Abstract
BACKGROUND
Parent-specific methylation of specific CpG residues is critical to imprinting in eutherian mammals, but its importance to imprinting in marsupials and, thus, the evolutionary origins of the imprinting mechanism have been the subject of controversy. This has been particularly true for the imprinted Insulin-like Growth Factor II (IGF2), a key regulator of embryonic growth in vertebrates and a focal point of the selective forces leading to genomic imprinting. The presence of the essential imprinting effector, DNMT3L, in marsupial genomes and the demonstration of a differentially methylated region (DMR) in the retrotransposon-derived imprinted gene, PEG10, in tammar wallaby argue for a role for methylation in imprinting, but several studies have found no evidence of parent-specific methylation at other imprinted loci in marsupials.
RESULTS
We performed the most extensive search to date for allele-specific patterns of CpG methylation within CpG isochores or CpG enriched segments across a 22 kilobase region surrounding the IGF2 gene in the South American opossum Monodelphis domestica. We identified a previously unknown 5'-untranslated exon for opossum IGF2, which is flanked by sequences defining a putative neonatal promoter, a DMR and an active Matrix Attachment Region (MAR). Demethylation of this DMR in opossum neonatal fibroblasts results in abherrant biallelic expression of IGF2.
CONCLUSIONS
The demonstration of a DMR and an active MAR in the 5' flank of opossum IGF2 mirrors the regulatory features of the 5' flank of Igf2 in mice. However, demethylation induced activation of the maternal allele of IGF2 in opossum differs from the demethylation induced repression of the paternal Igf2 allele in mice. While it can now be concluded that parent-specific DNA methylation is an epigentic mark common to Marsupialia and Eutheria, the molecular mechanisms of transcriptional silencing at imprinted loci have clearly evolved along independent trajectories.
Publication
Journal: Journal of Cellular Physiology
January/29/1998
Abstract
The purpose of this study is to differentiate roles of several <em>growth</em> <em>factors</em> and cytokines in proliferation and differentiation of pulp cells during development and repair. In human pulp cell cultures, laminin and type I collagen levels per cell remained almost constant during the whole culture period (<em>22</em> days). On the other hand, secreted protein, acidic and rich in cysteine (SPARC/osteonectin) and alkaline phosphatase (ALPase) levels markedly increased after the cultures reached confluence. Laminin and type I collagen, as well as fibronectin, stimulated the spreading of pulp cells within 1 h. Adding transforming <em>growth</em> <em>factor</em>-beta (TGF-beta) decreased laminin and ALPase levels, whereas it increased SPARC and fibronectin levels 3- to 10-fold. Western and Northern blots showed that TGF-beta enhanced SPARC synthesis at the protein and mRNA levels. Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) decreased type I collagen, laminin, SPARC, and ALPase levels without changing the fibronectin level. Platelet-derived <em>growth</em> <em>factor</em> (PDGF) selectively decreased laminin, SPARC, and ALPase levels. Epidermal <em>growth</em> <em>factor</em> (EGF) also decreased SPARC and ALPase levels. Tumor necrosis <em>factor</em>-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) decreased type I collagen and laminin levels, and abolished SPARC and ALPase syntheses. Of these peptides, bFGF and PDGF showed the greatest stimulation of [3H]thymidine incorporation into DNA. TGF-beta, EGF, and TNF-alpha had less effect on DNA synthesis, whereas IL-1beta inhibited DNA synthesis. These findings demonstrated that TGF-beta, bFGF, EGF, PDGF, TNF-alpha, and IL-1beta have characteristically different patterns of actions on DNA, laminin, type I collagen, fibronectin, ALPase, and SPARC syntheses by pulp cells.
Publication
Journal: Cancer Research
November/15/2017
Abstract
The tumor microenvironment induces endoplasmic reticulum (ER) stress in tumor cells, an event that can promote progression, but it is unknown how tumor cells adapt to this stress. In this study, we show that the <em>fibroblast</em> <em>growth</em> <em>factor</em> FGF19, a gene frequently amplified in hepatocellular carcinoma (HCC), facilitates a survival response to ER stress. Levels of FGF19 expression were increased in stressed HCC cells in culture and in a mouse xenograft model. Induction of ER stress required the transcription <em>factor</em> ATF4, which directly bound the FGF19 promoter. In cells where ER stress was induced, FGF19 overexpression promoted HCC cell survival and increased resistance to apoptosis, whereas FGF19 silencing counteracted these effects. Mechanistic investigations implicated glycogen synthase kinase-3β (GSK3β) in regulating nuclear accumulation of the stress-regulated transcription <em>factor</em> Nrf2 activated by FGF19. Our findings show how FGF19 provides a cytoprotective role against ER stress by activating a FGFR4-GSK3β-Nrf2 signaling cascade, with implications for targeting this signaling node as a candidate therapeutic regimen for HCC management. Cancer Res; 77(<em>22</em>); 6215-25. ©2017 AACR.
Publication
Journal: Journal of Pediatric Surgery
March/6/2002
Abstract
OBJECTIVE
Transforming growth factor beta (TGF-beta) bioactivity has been implicated as a potential regulator of the transition from scarless healing to scar formation in fetal wounds. Decorin is an extracellular matrix proteoglycan that regulates TGF-beta bioactivity and assists in collagen fibrillogenesis. To determine its role in scarless repair, the authors examined decorin expression in fetal fibroblasts, skin, and wounds.
METHODS
A single, full-thickness, 2-mm open wound was created on the dorsal surface of fetal rats at 16.5 days (E16) and 18.5 days (E18) gestational age (term, 21.5 days [E21]). Wounds were harvested at 24 and 72 hours (n = 12 wounds per time-point). Nonwounded fetal skin at E17, E19, and E21 was harvested for analysis of decorin expression during skin development and as controls for wounds. In addition, fetal (E14, E18) and adult dermal fibroblasts were cultured for in vitro analysis. Reduced-cycle, specific primer, reverse transcriptase polymerase chain reaction was performed to quantitate decorin expression.
RESULTS
Decorin expression increased rapidly with increasing gestational age in both fetal fibroblasts and skin. Expression was increased 22-fold in E18 fibroblasts (P <.002) and 300-fold in adult fibroblasts (P <.001) compared with E14 fibroblasts. In skin, expression increased 74% (P <.01) during the fetal wound healing transition period between E17 and E19. However, in E16 wounds (scarless), decorin expression decreased 59% (P <.006) at 24 hours and 45% (P <.02) at 72 hours. Decorin expression did not change in E18 (scar) wounds at 24 and 72 hours (P>>.05).
CONCLUSIONS
Early gestation fetal fibroblasts and fetal skin express decorin at lower levels than late gestation fetal and adult fibroblasts and skin. Decorin expression is down-regulated in scarless (E16) compared with scar (E18) wounds. Thus, increased decorin expression is associated with both skin development and scar formation. Conversely, decreased decorin expression is associated with scarless repair.
Authors
Publication
Journal: Neuroscience
December/16/1999
Abstract
Axonal regeneration by chronically-injured supraspinal neurons can be enhanced by neurotrophic <em>factor</em> treatment at the site of injury, although the number of regenerating neurons decreases as the interval between spinal cord injury and treatment increases. This study investigated whether this decline in regenerative response could be due to continued loss of neurons during the post-injury period. Adult rats received a cervical hemisection lesion and axotomized neurons were labeled by retrograde transport of True Blue from the lesion site. Animals were killed one, four or eight weeks after injury and surviving neurons (True Blue-labeled) were counted in the red nucleus and lateral vestibular nucleus. The neuron number in the lateral vestibular nucleus was stable for eight weeks after spinal cord injury, while survival in the red nucleus decreased by 25% between four and eight weeks. To test how neurons respond to a second injury with or without trophic <em>factor</em> treatment, at four, eight, 14 or <em>22</em> weeks after injury the lesion cavity was enlarged by 0.5 mm in a rostral direction. Gel foam saturated with ciliary neurotrophic <em>factor</em>, brain-derived neurotrophic <em>factor</em> or basic <em>fibroblast</em> <em>growth</em> <em>factor</em> was placed into the cavity. Animals were killed four weeks later. Re-injury of the spinal cord caused a significant decrease in neuron survival in both the red nucleus and lateral vestibular nucleus, the effects of which were lessened by treatment with ciliary neurotrophic <em>factor</em> or brain-derived neurotrophic <em>factor</em> for the red nucleus and with ciliary neurotrophic <em>factor</em> for the lateral vestibular nucleus, when re-injured at four or eight weeks. Basic <em>fibroblast</em> <em>growth</em> <em>factor</em> did not affect neuron survival at any time post-injury. Ciliary neurotrophic <em>factor</em> was not effective with longer delays (14 or <em>22</em> weeks) between the initial injury and re-injury. These results indicate a delayed pattern of secondary neuronal cell loss after spinal cord injury that is exaggerated by re-injury, but which can be ameliorated by treatment with neurotrophic <em>factors</em>.
Publication
Journal: British Journal of Ophthalmology
May/21/2002
Abstract
BACKGROUND
Tumour microvascularity is a significant determinant of prognosis for a large number of different tumours, including uveal melanoma. The development of blood vessels within these and other tumours is partly controlled by soluble pro-angiogenic cytokines, of which basic fibroblast growth factor (bFGF) and vascular endothelial growth factor-A (VEGF) are the best described.
METHODS
Because VEGF has been inconsistently found within uveal melanomas and bFGF is described as an autocrine growth factor in cutaneous melanoma, the authors looked at the expression of these cytokines in uveal melanomas using immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). The cross talk between uveal melanoma cells and endothelial cells was then assessed in an in vitro co-culture model.
RESULTS
While most tumour cells expressed bFGF at the protein level by immunohistochemistry (89%), relatively few (22%) expressed VEGF, and this was of limited extent. All 20 tumours tested by RT-PCR contained mRNA for both bFGF and VEGF. Co-culture experiments using an ATP based bioassay showed that uveal melanomas could support the growth of a rat brain endothelial cell line (GPNT) and human umbilical vein endothelial cells (HUVEC), and that this could be modulated by cytokines and anti-cytokine antibodies.
CONCLUSIONS
These results suggest that angiogenesis within uveal melanoma may be the result of a complex interplay between endothelial and tumour cells, and that bFGF and VEGF could play a part.
Publication
Journal: Journal of Bone and Mineral Research
July/2/2013
Abstract
Proteoglycan 4 (Prg4), known for its lubricating and protective actions in joints, is a strong candidate regulator of skeletal homeostasis and parathyroid hormone (PTH) anabolism. Prg4 is a PTH-responsive gene in bone and liver. Prg4 null mutant mice were used to investigate the impact of proteoglycan 4 on skeletal development, remodeling, and PTH anabolic actions. Young Prg4 mutant and wild-type mice were administered intermittent PTH(1-34) or vehicle daily from 4 to 21 days. Young Prg4 mutant mice had decreased <em>growth</em> plate hypertrophic zones, trabecular bone, and serum bone formation markers versus wild-type mice, but responded with a similar anabolic response to PTH. Adult Prg4 mutant and wild-type mice were administered intermittent PTH(1-34) or vehicle daily from 16 to <em>22</em> weeks. Adult Prg4 mutant mice had decreased trabecular and cortical bone, and blunted PTH-mediated increases in bone mass. Joint range of motion and animal mobility were lower in adult Prg4 mutant versus wild-type mice. Adult Prg4 mutant mice had decreased marrow and liver <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF-2) mRNA and reduced serum FGF-2, which were normalized by PTH. A single dose of PTH decreased the PTH/PTHrP receptor (PPR), and increased Prg4 and FGF-2 to a similar extent in liver and bone. Proteoglycan 4 supports endochondral bone formation and the attainment of peak trabecular bone mass, and appears to support skeletal homeostasis indirectly by protecting joint function. Bone- and liver-derived FGF-2 likely regulate proteoglycan 4 actions supporting trabeculae formation. Blunted PTH anabolic responses in adult Prg4 mutant mice are associated with altered biomechanical impact secondary to joint failure.
Publication
Journal: Endocrinology
August/2/1993
Abstract
Insulin-like <em>growth</em> <em>factor</em>-I (IGF-I), a prevalent <em>growth</em> <em>factor</em> secreted by bone cells, has important effects on bone remodeling. Hormones are known to regulate the synthesis of skeletal IGF-I, but there is limited information about the actions of <em>growth</em> <em>factors</em> on IGF-I synthesis. We tested the effects of basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), transforming <em>growth</em> <em>factor</em>-beta 1 (TGF beta 1), and platelet-derived <em>growth</em> <em>factors</em> (PDGF) AA and BB on IGF-I mRNA expression and polypeptide concentrations in cultures of osteoblast-enriched (Ob) cells from <em>22</em>-day-old fetal rat calvariae. Steady state IGF-I mRNA levels were determined by Northern blot analysis, and IGF-I concentrations were determined in acidified and fractionated culture medium by a specific RIA. Treatment of Ob cells with bFGF at 0.06-6 nM, TGF beta 1 at 0.04-4 nM, and PDGF BB at 0.3-3.3 nM caused a dose-dependent decrease in steady state IGF-I mRNA. A smaller effect was observed with PDGF AA. The effect was initially observed after 6-8 h of treatment and was maximal after 16 h. Treatment with bFGF at 0.6-6 nM, TGF beta 1 at 0.4-4 nM, and PDGF BB at 0.3-3.3 nM for 24 h decreased IGF-I polypeptide concentrations by 40-80%. The effects of bFGF, TGF beta 1, and PDGF BB and AA on IGF-I mRNA were independent of protein synthesis and cell division, as they were observed in the presence and absence of cycloheximide at 3.6 microM or hydroxyurea at 1 mM. Similarly, their inhibitory actions on immunoreactive IGF-I were not prevented by hydroxyurea. In conclusion, bFGF, TGF beta 1, PDGF BB, and, to a lesser extent, PDGF AA decrease skeletal IGF-I synthesis by reducing IGF-I transcript levels, and this effect may contribute to their actions on selected aspects of Ob cell function.
Publication
Journal: Mechanisms of Development
June/15/1998
Abstract
In an effort to define the roles of bone morphogenic proteins (BMPs) and <em>fibroblast</em> <em>growth</em> <em>factors</em> (FGFs) during chick limb development more closely, we have implanted beads impregnated with these <em>growth</em> <em>factors</em> into chick limb buds between stages 20 and 26. Embryos were sacrificed at the time the bone chondrocyte condensations first appear (stages 27-28). Implantation of beads containing BMPs at the earlier stages (20-<em>22</em>) caused apoptosis to occur, in the most severe cases leading to complete limb degeneration. Application of FGF4, either in the same, or in a different bead, prevented the BMP-induced apoptosis. We argue that the apoptosis observed on removal of the AER prior to stage 23 of development could be brought about by BMPs. The action of epithelial FGF in preventing BMP-mediated apoptosis in the mesenchyme would define a novel aspect of epithelial-mesenchymal interactions. Implanting the BMP4 beads into the core of the limb bud a day later (stages 25-26) caused intense chondrogenesis rather than apoptosis. FGF4 could again nullify this effect and by itself caused a reduction in bone size. This is the reverse of the functional relationship these <em>growth</em> <em>factors</em> have in mouse tooth specification (where it is BMP4 that inhibits the FGF8 function), and suggests that the balance between the effects of FGFs and BMPs could control the size of the chondrocyte precursor cell pool. In this way members of these two <em>growth</em> <em>factor</em> families could control the size of appendages when they are initially formed.
Publication
Journal: Journal of Molecular and Cellular Cardiology
July/16/1997
Abstract
In order to elucidate the effects of the different basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF) isoforms on vascular smooth muscle, we examined aorta-derived vascular smooth muscle cells from transgenic mice expressing the human isoforms of bFGF. Four cell lines were examined from mice in which transgene expression was driven by the ubiquitous phosphoglycerate kinase promoter. Overexpression and cellular localization was confirmed by Western blot analysis in vascular smooth muscle cells from mice expressing: all four human bFGF isoforms (24, <em>22</em>, 21, and 18 kDa); all three nuclear targeted isoforms (24, <em>22</em>, and 21 kDa); only the 24 kDa isoform; and the only secreted/non-nuclear targeted isoform, 18 kDa. All lines showed approximate four-fold increases in bFGF expression, nuclear localization of all nuclear targeted bFGF isoforms, and cytosolic localization of only the 18 kDa bFGF. Measurement of [3H]thymidine incorporation into quiescent cells stimulated with increasing concentrations of serum, showed increased DNA synthesis in cell lines expressing any bFGF isoform when compared to non-transgenic control cells, and a further increase in DNA synthesis in cells expressing the nuclear targeted isoforms (24, <em>22</em>, and 21 kDa) over the 18 kDa bFGF expressing cell line at any concentration of serum. All cells showed equal label incorporation when stimulated with 10 ng/ml of platelet-derived <em>growth</em> <em>factor</em> confirming an equal potential for DNA synthesis. Neutralizing the bFGF antibody markedly decreased serum-stimulated DNA synthesis, but only in the cell lines overexpressing the secreted/non-nuclear targeted 18 kDa isoform. These results suggest amplification of DNA synthesis through synergistic intracrine and autocrine effects of the nuclear targeted and non-nuclear targeted bFGF isoforms in vascular smooth muscle cells.
Publication
Journal: Biology of Reproduction
December/6/1989
Abstract
Experiments were carried out to determine the specificity of <em>growth</em> <em>factor</em> action on maturation of the oocyte-cumulus cell complex in vitro. Cumulus cell-enclosed oocytes (CEO) from primed mice were maintained in meiotic arrest in vitro with hypoxanthine (HX) and treated with one of ten different <em>growth</em>-promoting <em>factors</em>. The percentage of germinal vesicle breakdown (GVB) in the HX controls ranged from 44 to 64.7% after 21-<em>22</em> h. Oocytes responded to treatment with <em>growth</em>-promoting <em>factors</em> in one of three ways: (1) no response; (2) low response; or (3) high response. The nonresponding groups included transforming <em>growth</em> <em>factor</em>-beta, platelet-derived <em>growth</em> <em>factor</em>, bombesin, sodium orthovanadate, nerve <em>growth</em> <em>factor</em>, and insulin-like <em>growth</em> <em>factors</em> I and II, each of which had no statistically significant effect on GVB. Insulin and <em>fibroblast</em> <em>growth</em> <em>factor</em> were members of the low response group and stimulated increases in GVB of 21.2 24.9%. Epidermal <em>growth</em> <em>factor</em> (EGF) was the only <em>factor</em> that produced a high frequency of maturation in the CEO; 100% of the arrested CEO were stimulated to undergo GVB in response to EGF treatment (a 51% increase over controls). No interaction was observed when EGF was tested with follicle-stimulating hormone (FSH) on hormone-induced GVB. When tested for an action on cumulus cell expansion, EGF was the only <em>growth</em>-promoting <em>factor</em> that triggered this response and did so more effectively than FSH. Heparin suppressed cumulus expansion in both EGF- and FSH-treated CEO, but did not prevent GVB stimulated by either hormone.(ABSTRACT TRUNCATED AT 250 WORDS)
Authors
Publication
Journal: Journal of Pathology
April/25/1999
Abstract
Macrophage populations in <em>22</em> biopsies of untreated advanced periodontitis were compared with those in 26 biopsies of clinically healthy (minimally inflamed) gingival tissue. The immunohistochemical investigation used high specificity monoclonal antibodies, including a pan-macrophage marker and probes for acute inflammatory, resident histiocytic, and reparative phenotypes. Macrophage expression of the functional activation markers MHC class II, basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF), acid phosphatase (AP), and tartrate-resistant acid phosphatase (TRAP) was also examined. The study showed that advanced periodontitis and minimally inflamed tissues displayed similar distribution patterns and numbers for the macrophage phenotypic markers: there were, however, regionally-specific differences in the populations. In the advanced periodontitis lesion, there was little evidence of macrophage activation for the expression of HLA-DR, bFGF, and TRAP, although strong expression of HLA-DR and bFGF was observed in association with blood vessels. Macrophages expressing AP showed a distinct regional distribution; this, however, was not associated with foci of degenerate plasma cells. The apparent failure of recruitment and activation of macrophages may in part be both a cause and a consequence of the pathological features of this disease.
Publication
Journal: Developments in Ophthalmology
November/1/1989
Abstract
RPE cell migration and proliferation are believed to play a role in the pathogenesis of PVR. Since PVR develops in situations where vitreous contacts the RPE, we sought to determine whether human vitreous contains <em>factors</em> that stimulate proliferation and migration of RPE cells. We found that postmortem human vitreous stimulates migration but not proliferation of human RPE cells in vitro under serum-free conditions. A significant vitreous <em>growth</em> <em>factor</em> activity for RPE cells and <em>fibroblasts</em>, however, could be released by admixture of albumin with the vitreous. These findings suggest that vitreous contributes modulators that stimulate some functions of RPE cells that are believed to play a role in the pathogenesis of PVR (fig. <em>22</em>). Since macrophages are a ubiquitous component of periretinal membranes, we sought to determine whether they modulate proliferation and/or migration of RPE cells, functions that may be essential for the development of PVR. Using an in vitro assay, we found that macrophage supernatant contains <em>factors</em> that stimulate proliferation and migration of cultured human RPE cells. Since IL-1 is a product of activated macrophages that modulates a number of cellular functions, we also examined its effect on RPE proliferation and migration. We found that IL-1 increased migration but did not affect proliferation, and thus could not duplicate the effect of macrophage supernatant. Injection of activated macrophages into the vitreous of rabbits which had a retinal hole stimulated RPE cell proliferation in the area of the retinal hole, where the RPE cells were exposed. These findings suggest the ability of macrophages to modulate functions of RPE cells that are thought to be critical for the development of PVR (fig. <em>22</em>). We initiated studies to define modulation of cultured RPE cell morphology by exposure to vitreous or to macrophage-conditioned media. Vitreous, serum, and albumin alone had no effect on the epithelial appearance of RPE cells in vitro. However, macrophage-conditioned media and vitreous-serum or vitreous-albumin mixtures induced a reversible <em>fibroblast</em>-like appearance in these cells. These findings show that macrophages produce a morphoplastic substance for RPE cells, and suggest that vitreous also contains a <em>factor</em>(s) that affects RPE cell shape, and that requires mediation by serum components (fig. <em>22</em>).
Publication
Journal: Hematological Oncology
November/20/2012
Abstract
Angiogenesis is a complex process essential for the <em>growth</em>, invasion, and metastasis of various malignant tumours, including multiple myeloma (MM). Various angiogenic cytokines have been implicated in the angiogenic process. Among them, platelet-derived <em>growth</em> <em>factor</em>-AB (PDGF-AB) has been reported to be a potent stimulator of angiogenesis in many solid tumours and haematological malignancies, including MM. The aim of the study was to investigate the relationship between PDGF-AB, microvascular density (MVD), and various angiogenic cytokines, such as basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (b-FGF), angiogenin (ANG), and interleukin-6 (IL-6), in MM patients. Forty-seven MM patients before treatment, <em>22</em> of whom were in plateau phase, were studied. We determined the serum levels of the aforementioned cytokines and MVD in bone marrow biopsies before and after treatment. Mean serum values of PDGF-AB, b-FGF, ANG, and MVD were significantly higher in patients compared with controls and with increasing disease stage. Significant positive correlations were observed between serum PDGF-AB, ANG, and IL-6 levels and MVD. Furthermore, we found significant positive correlations between PDGF-AB and b-FGF, IL-6, ANG, and β2 microglobulin. We also found that patients with high MVD had statistically significantly higher serum levels of PDGF-AB when a median MVD value of 7.7 was used as the cutoff point. Furthermore, a significant difference was found in serum levels of PDGF-AB between pre- and post-treatment patients. Finally, survival time was significantly higher in the low MVD group versus the high MVD group (76 vs 51 months). Our results showed that there is a strong positive correlation between PDGF-AB and the studied angiogenic cytokines and MVD. It seems that PDGF-AB plays a role in the complex network of cytokines inducing bone marrow neovascularization in patients with MM.
Publication
Journal: Journal of Cellular Physiology
August/13/1990
Abstract
The human omentum contains a potent, not yet identified angiogenic activity. The omentum is very vascularized. Therefore, we investigated whether human omental microvascular endothelial cells (HOME cells) express the angiogenic peptide basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (bFGF). Cytosol prepared from HOME cells stimulated DNA synthesis in bovine epithelial lens cells (BEL cells). The mitogenic activity could be neutralized by an anti-bFGF antibody. Basic FGF-like material from the HOME cell cytosol was bound onto a heparin-Sepharose column at 0.6 M and was eluted at 3 M NaCl. The 3 M NaCl eluted material reacted with the specific anti-bFGF antibody in an ELISA and stimulated DNA synthesis. It did not react with a specific anti-acidic <em>fibroblast</em> <em>growth</em> <em>factor</em> (aFGF) antibody. Western blotting experiments using the same bFGF antibody showed the presence of a major band of 17 Kd and a doublet of 20-<em>22</em> Kd. Northern blotting of non-stimulated HOME cells using a specific 1.4 kb bFGF probe showed the presence of 5 molecular species of 6.6, 3.7, 2.2, 2.0, and 1.0 kb. No aFGF mRNA was detected with a specific previously characterized 4.04 kb probe. 12-O-tetradecanoylphorbol 13-acetate (TPA) did not influence significantly the expression of bFGF at the protein and mRNA level in HOME cells. Thus, protein kinase C activation by TPA did not appear to modulate significantly the expression of bFGF for that cell type. Contrastingly, human umbilical vein endothelial cells (HUVE cells), which expressed no bFGF and aFGF mRNA at a basal level, were induced to express bFGF but not aFGF mRNA when stimulated by TPA. These results suggest that the described angiogenic activity could be the bFGF-like mitogen contained in HOME cells and that these cells are different from endothelial cells derived from large vessels (HUVE cells) regarding the expression of bFGF.
Publication
Journal: Odontology / the Society of the Nippon Dental University
October/12/2015
Abstract
In this review, we discuss the central role of <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF) signaling in mammalian tooth development. The FGF family consists of <em>22</em> members, most of which bind to four different receptor tyrosine kinases, which in turn signal through a cascade of intracellular proteins. This signaling regulates a number of cellular processes, including proliferation, differentiation, cell adhesion and cell mobility. FGF signaling first becomes important in the presumptive dental epithelium at the initiation stage of tooth development, and subsequently, it controls the invagination of the dental epithelium into the underlying mesenchyme. Later, FGFs are critical in tooth shape formation and differentiation of ameloblasts and odontoblasts, as well as in the development and homeostasis of the stem cell niche that fuels the continuously <em>growing</em> mouse incisor. In addition, FGF signaling is critical in human teeth, as mutations in genes encoding FGF ligands or receptors result in several congenital syndromes characterized by alterations in tooth number, morphology or enamel structure. The parallel roles of FGF signaling in mouse and human tooth development demonstrate the conserved importance of FGF signaling in mammalian odontogenesis.
Publication
Journal: Experimental and Therapeutic Medicine
February/19/2017
Abstract
Tumor necrosis <em>factor</em>-like weak inducer of apoptosis (TWEAK) is a member of the TNF superfamily. It has been suggested that it plays a pivotal role in various physiological and pathological conditions due to its proinflammatory properties. <em>Fibroblast</em> <em>growth</em>-inducible 14 (Fn14) has been identified as a TWEAK receptor. A number of studies have suggested that TWEAK-Fn14 interaction results in the promotion of apoptosis, cell <em>growth</em> as well as angiogenesis. Although recent studies have indicated that TWEAK and Fn14 are expressed in a number of tumor lines and tissues, the therapeutic potential of this pathway has yet to be elucidated. This study investigated the potential of TWEAK and Fn14 in esophageal and pancreatic cancer as novel molecular targets for anti-cancer therapy. TWEAK and Fn14 protein expression was evaluated in 43 patients with esophageal cancer and 51 patients with pancreatic cancer by immunohistochemistry. As a result, either TWEAK or Fn14 expression was observed in 58.1% of the cases with esophageal cancer and 74.5% of the cases with pancreatic cancer. Furthermore, TWEAK/Fn14 gene expression was identified in the majority of the human esophageal and pancreatic cancer cell lines. Therapeutic efficacies of blocking TWEAK and Fn14 were evaluated by tumor <em>growth</em> inhibition assay in TWEAK- and Fn14-expressing human esophageal and pancreatic cancer cell lines. Coculture with anti-TWEAK or -Fn14 mAb was found to induce a <em>22</em>-65% cell <em>growth</em> inhibition of these cells. Finally, the significant therapeutic effect of targeting this pathway under in vivo physiological conditions was confirmed using a murine gastrointestinal cancer model. In conclusion, the TWEAK/Fn14 pathway may be functional and critical in intractable gastrointestinal cancers. Therefore, TWEAK and/or Fn14 may be novel molecular targets for anti-cancer therapy.
Publication
Journal: Journal of Cellular Physiology
December/13/2007
Abstract
<em>Fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF-2) is produced as CUG-initiated, <em>22</em>-34 kDa or AUG-initiated 18 kDa isoforms (hi- and lo-FGF-2, respectively), with potentially distinct functions. We report that expression of hi-FGF-2 in HEK293 cells elicited chromatin compaction preceding cell death with apoptotic features. Nuclear localization of the intact protein was required as expression of a non-nuclear hi-FGF-2 mutant failed to elicit chromatin compaction. Equally ineffective, despite nuclear localization, was the over-expression of the 18 kDa core sequence (lo-FGF-2). Chromatin compaction by hi-FGF-2 was accompanied by increased cytosolic cytochrome C, and was attenuated either by over-expression of Bcl-2 or by a peptide inhibitor of the pro-apoptotic protein Bax. In addition hi-FGF-2 elicited sustained activation of total and nuclear extracellular signal regulated kinase (ERK1/2) by an intracrine route, as it was not prevented by neutralizing anti-FGF-2 antibodies. Inhibition of the ERK1/2 activating pathway by dominant negative upstream activating kinase, or by PD 98059, prevented chromatin compaction by hi-FGF-2. ERK1/2 activation was not affected by the Bax-inhibiting peptide suggesting that it occurred upstream of mitochondrial involvement. We conclude that the hi-FGF-2-induced chromatin compaction and cell death requires its nuclear localization, intracrine ERK1/2 activation and mitochondrial engagement.
Publication
Journal: PLoS ONE
February/10/2016
Abstract
Pharmacological administration of <em>fibroblast</em> <em>growth</em> <em>factor</em> 21 (FGF21) improves metabolic profile in preclinical species and humans. FGF21 exerts its metabolic effects through formation of beta-klotho (KLB)/FGF receptor 1c FGFR1c complex and subsequent signaling. Data from various in vitro systems demonstrate the intact C- and N-terminus of FGF21 is required for binding with KLB, and interaction with FGFR1c, respectively. However the relative roles of the termini for in vivo pharmacological effects are unclear. Here we report PF-05231023, a long-acting FGF21 analogue which is unique in that the half-life and subcutaneous (s.c.) bioavailability of the intact C-terminus are significantly different from those of the intact N-terminus (2 vs. <em>22</em> hr for half-life and 4~7 vs. ~50% SC bioavailability). Therefore, this molecule serves as a valuable tool to evaluate the relative roles of intact C-terminus vs. N-terminus in in vivo pharmacology studies in preclinical species. We determined the effects of PF-05231023 administration on body weight (BW) loss and glucose reduction during an oral glucose tolerance test (OGTT) following SC and intravenous (i.v.) administration in diet-induced obese (DIO) and leptin-deficient obese (ob/ob) mice, respectively. Our data show that the intact N-terminus of FGF21 in PF-05231023 appears to be sufficient to drive glucose lowering during OGTT and sustain BW loss in DIOs. Further, PK/PD modeling suggests that while the intact FGF21 C-terminus is not strictly required for glucose lowering during OGTT in ob/ob mice or for BW reduction in DIO mice, the higher potency conferred by intact C-terminus contributes to a rapid initiation of pharmacodynamic effects immediately following dosing. These results provide additional insight into the strategy of developing stabilized versions of FGF21 analogs to harness the full spectrum of its metabolic benefits.
Publication
Journal: Vox Sanguinis
February/3/2014
Abstract
OBJECTIVE
Clinical use of plasma rich in growth factors requires biochemical product control. We aimed to measure and modulate concentrations of growth factors in solutions deriving from platelet apheresis or whole blood.
METHODS
Growth factor concentrations were measured 5', 10', 20', 30', 60' after CaCl2 was added at 40°C to platelet-apheresis products (n = 39) or after 60' in platelet concentrates from whole blood (n = 13). Growth factor release was also obtained in platelet apheresis a) by incubation at 22°C or 40°C for 10' or 30' (n = 4); b) by repeated freeze-thaw (n = 9).
RESULTS
Fibroblast growth factor (FGF), platelet-derived growth factor (PDGF) isoforms AA and AB and transforming growth factor beta (TGF-β) concentrations (pg/10(9 ) plt) were 25-60% higher in growth factors solutions from whole blood compared to platelet apheresis. Vascular endothelial growth factor (VEGF), TGF-β and PDGF isoforms were released early (5-10') during incubation: TGF-β concentration increased also at 30'. FGF and epidermal growth factor (EGF) were released only after 30'. Incubation at 40°C/10' increased VEGF (+70%) and decreased EGF (-30%) and PDGF-BB (-50%) versus 22°C/30'. Shock significantly increased TGF-β (1.6-fold), EGF (1.5-fold), FGF (4.5-fold) and lowered PDGF isoforms (0.2- to 0.5-fold) versus prolonged incubation at 40°C.
CONCLUSIONS
Platelets from platelet apheresis and whole-blood release all investigated growth factors. The release can be regulated controlling incubation time and/or temperature and performing cell lysis.
Publication
Journal: Biochemical and Biophysical Research Communications
November/12/2017
Abstract
Increasing evidences have revealed the important role of circular RNAs (circRNAs) in cardiovascular system disease. Whereas, the expression profiles and in-depth regulation of circRNAs on vascular smooth muscle cells (VSMCs) is still undetermined. In present study, our research team performed circRNAs microarray analysis to present the circRNAs expression profiles in high glucose induced VSMCs in vitro. Results showed that total of 983 circRNAs were discovered to be differentially expressed, and of these, 458 were upregulated and 525 were downregulated. Moreover, 31 circRNAs were up-regulated and <em>22</em> circRNAs were down-regulated with 2 fold change (P < 0.05). One of an up-regulated circRNA, circWDR77, was identified. In vitro cell assay, circWDR77 silencing significantly inhibited the proliferation and migration. Bioinformatics methods discovered that miR-124 and <em>fibroblast</em> <em>growth</em> <em>factor</em> 2 (FGF-2) were downstream targets of circWDR77. The RNA sequence complementary binding was validated by RNA immunoprecipitation (RIP) and/or luciferase reporter assay. Further function validation experiments revealed that circWDR77 regulated VSMCs proliferation and migration via targeting miR-124/FGF2. Taken together, present study firstly reveals the circRNAs expression profiles in high glucose induced VSMCs and identifies the role of circWDR77-miR-124-FGF2 regulatory pathway in VSMCs proliferation and migration, which might provide a new theoretical basis for diabetes mellitus correlated vasculopathy.
Publication
Journal: Neuroscience
November/25/2002
Abstract
Brief experimentally induced seizures have been shown to increase the expression of mRNA encoding basic <em>fibroblast</em> <em>growth</em> <em>factor</em> (FGF-2) in specific brain regions. However, the extent to which this change in mRNA affects the expression of FGF-2 protein in these brain regions has not been examined. In the present study, we exposed rats to brief non-injurious seizures to determine whether this treatment would lead to an increase in FGF-2 protein expression in selected brain regions. Because initial results indicated that the elevation of FGF-2 protein was not significant following acute seizure exposure, we examined both acute and chronic seizure treatment to determine whether FGF-2 protein expression could be increased under conditions of repeated seizures. Brief limbic seizures were induced by minimal electroconvulsive shock (ECS) given as daily treatments for 1 (acute) or 7 (chronic) days. FGF-2 protein was measured in hippocampus, rhinal cortex, frontal cortex, and ol<em>factor</em>y bulb at 20, 48, and 72 h following the last seizure. No significant increases in FGF-2 protein were observed in any region following acute ECS. In the chronic ECS-treated groups, significantly elevated FGF-2-like immunoreactivity was found in the frontal and rhinal cortex as compared with the same regions from both control and acute ECS animals. Increases after chronic ECS were maximal at 20 h, and remained significantly elevated as long as 72 h. These increases were predominantly observed for the 24-kDa and <em>22</em>/<em>22</em>.5-kDa FGF-2 isoforms. Because chronic ECS, which has been shown to be protective against neuronal cell death, induced significantly more FGF-2 immunoreactivity than did acute ECS, we suggest that FGF-2 expression may be an important substrate for the neuroprotective action of non-injurious seizures. A prolonged induction of the high molecular weight isoforms of FGF-2, as occurs after chronic ECS, may selectively reduce the vulnerability of certain brain regions to a variety of neurodegenerative insults.
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