Monoclonal antibodies against human basic fibroblast growth factor

Efficient proliferation and adipose differentiation of human adipose tissue-derived vascular stromal cells transfected with basic fibroblast growth factor gene

Human vascular stromal (VS) cells obtained from mature adipose tissue were transfected with an adenovirus vector carrying the basic fibroblast growth factor (bFGF) gene. bFGF protein was observed in VS cell nuclei 24 h after transfection and in the cytoplasm and extracellular space 72 h after transfection. Naive VS cells were almost static in vitro and proliferated in a dose-dependent manner on stimulation with recombinant bFGF (rbFGF). However, bFGF-transfected VS cells proliferated spontaneously to the same extent as naive VS cells when stimulated with rbFGF at 100 ng/ml. The former cells started to proliferate on day 3 after transfection and the proliferation pattern was similar to that of the latter cells, although only a slight amount of bFGF protein was detected in the culture medium when the bFGF-transfected cells started to proliferate. The proliferation of bFGF-transfected VS cells was completely inhibited by bFGF neutralizing antibody, which also completely inhibited the proliferation of naive VS cells stimulated with rbFGF. Under conditions favoring differentiation to adipocytes, bFGF-transfected VS cells stopped proliferating and started to accumulate lipid in the cytoplasm. bFGF-transfected VS cells, which spontaneously and efficiently proliferate while preserving their ability to differentiate into adipocytes, may be an adequate cell source for human adipose tissue regeneration.

Effects of basic fibroblast growth factor on human gingival epithelial cells

BACKGROUND

Our previous reports found that basic fibroblast growth factor (FGF-2; bFGF) influences the proliferation and extracellular matrix production of periodontal ligament (PDL) cells. In this study, we examined FGF-2 expression in gingival epithelium and the effect of FGF-2 on proliferative responses by gingival epithelial (GE) cells.

METHODS

Human GE cells were isolated from healthy gingival epithelium, and the mRNA expression of FGF-2 and FGF receptors (FGFRs) was examined by reverse transcription-polymerase chain reaction (RT-PCR). The distribution of FGF-2 in gingival tissues was detected by immunohistological analysis using the monoclonal antibody for human recombinant FGF-2, which was newly established and designated as BF-2. Further, the proliferative responses of GE cells to FGF-2 were investigated by measuring [3H]-thymidine uptake.

RESULTS

RT-PCR revealed that GE cells express FGFR-1, FGFR-2, FGFR-3, and FGFR-4 mRNA; however, not that of FGF-2. Employing immunohistochemical staining with BF-2, FGF-2 was observed localized in the intercellular spaces of gingival epithelium, though not in the cytoplasm of epithelial cells. Interestingly, staining by BF-2 in the intercellular spaces was diminished after treatment of the tissue sections with heparitinase. Further, an in vitro analysis revealed that FGF-2 enhanced the proliferative responses of human GE cells. However, costimulation with fetal calf serum inhibited the FGF-2-induced proliferation of GE cells, whereas the same costimulation synergistically enhanced FGF-2-induced PDL cell proliferation.

CONCLUSIONS

FGF-2 is anchored in the intercellular spaces of gingival epithelium via heparansulfate and may regulate the growth and cytodifferentiation of GE cells via cell-type specific receptors.

Inhibition of cell growth by a fused protein of human ribonuclease 1 and human basic fibroblast growth factor

Pancreatic-type RNases are considered to have cytotoxic potential due to their ability to degrade RNA molecules when they enter the cytosol. However, most of these RNases show little cytotoxicity because cells have no active uptake mechanism for these RNases and because the ubiquitous cytoplasmic RNase inhibitor is considered to play a protective role against the endocytotic leak of RNases from the outside of cells. To study the cytotoxic potential of RNase toward malignant cells targeting growth factor receptors, the C-terminus of human RNase 1 was fused to the N-terminus of human basic fibroblast growth factor (bFGF). This RNase-FGF fused protein effectively inhibited the growth of mouse melanoma cell line B16/BL6 with high levels of cell surface FGF receptor. This effect appeared to result from prolongation of the overall cell cycle rather than the killing of cells or specific arrest in a particular phase of the cell cycle. Thus, human RNase 1 fused to a ligand of cell surface molecules, such as the FGF receptor, is shown to be an effective candidate for a selective cell targeting agent with low toxic effects on normal cell types.

Basic fibroblast growth factor, its high- and low-affinity receptors, and their relationship to form-deprivation myopia in the chick

Form deprivation myopia in chickens is a widely accepted model to study visually-regulated postnatal ocular growth. Recently we showed that basic fibroblast growth factor-2 provides a "stop" signal for the growing eye. To understand further its action, we have localized basic fibroblast growth factor-2 and its low- and high-affinity receptors in the chicken eye, and determined the localization of basic fibroblast growth factor receptors in the inner plexiform layer with respect to that of neurotransmitter systems known to play a role in form-deprivation myopia. By immunocytochemistry and in situ hybridization, two complementary methods, we found that nearly all cells in the retina, and scleral chondrocytes, contain basic fibroblast growth factor-2 protein and messenger RNA as well as high-affinity basic fibroblast growth factor receptor protein and messenger RNA. Immunocytochemical localization of basic fibroblast growth factor-2 binding sites (a high resolution alternative to autoradiography), combined with N-glycanase and heparitinase treatment or heparin competition, revealed additional binding sites in specific synaptic layers of the inner plexiform layer and low-affinity binding sites in the choroid and optic fibre layer. Some binding sites in the synaptic layers were found to co-stratify with neurites of dopamine-, vasoactive intestinal polypeptide- or enkephalin-containing amacrine cells, suggesting that basic fibroblast growth factor-2 could modulate synaptic transmission to or from these cells. Form deprivation did not affect the levels of basic fibroblast growth factor receptor-1 messenger RNA in retina/retinal pigment epithelium/choroid (Northern blotting), but it abolished the decrease in amount of extractable basic fibroblast growth factor normally observed in the dark (Western blotting). The results are discussed with respect to previous findings on basic fibroblast growth factor-2 and basic fibroblast growth factor receptor-1 localization in the avian and other vertebrate eyes, and their relevance to form-deprivation myopia. The widespread distribution of basic fibroblast growth factor-2 and its receptor makes it impossible to predict which cells might mediate the action of basic fibroblast growth factor-2 in form-deprivation myopia. However, the alteration in amounts of extractable retinal basic fibroblast growth factor-2 in form-deprived, dark-adapted retinas, in which basic fibroblast growth factor-2 probably serves as a "stop" signal for ocular growth, is consistent with a role for basic fibroblast growth factor-2 in the regulation of ocular growth.

Mitogenic activity toward human breast cancer cell line MCF-7 of two bFGFs purified from sera of breast cancer patients: co-operative role of cathepsin D

Mitogenic activity toward MCF-7 cells of two immunoreactive (high-molecular-weight form bFGF, HMW-bFGF; and 16-K bFGF, having the same molecular weight as recombinant bFGF) purified from pooled sera of breast cancer patients by heparin-affinity chromatography and gel filtration was investigated. The mitogenic activity of 16-K bFGF toward the cells was equal to that of recombinant bFGF, whereas the mitogenic effect of HMW-bFGF was weak. Most of the mitogenic activity of these two bFGFs was neutralized by anti-bFGF antibody. Also, the mitogenic activity of both HMW-bFGF and 16-K bFGF was markedly enhanced by aspartyl protease (cathepsin D), which is secreted in excess by breast cancer cells and is responsible for the enzymatic degradation of the extracellular matrix (ECM). By an enzyme immunoassay, we detected cathepsin D-mediated release of recombinant bFGF previously bound to the ECM of MCF-7 cells into the conditioned medium, and also observed cathepsin D-mediated proteolysis of HMW-bFGF to release free 16-K bFGF. These results suggest that 16-K bFGF is the bFGF molecule itself in the blood and that HMW-bFGF is a circulating form of bFGF in blood whose mitogenic activity is regulated by cathepsin D.

Expression patterns of acidic and basic fibroblast growth factor in loach fish embryos

Heparin-binding fractions were taken from the heparin sepharose columns on which extracts of loach fish (Misgurnus anguillicaudatus) embryos from blastula, gastrula, 4-8 and 12-16 somites stages were applied. These heparin-binding fractions, except the fraction derived from 12-16 somite embryos, showed potent mitogenic activity on fibroblast-like cells derived from caudal fin blastema of goldfish. Western blot analysis of these heparin-binding fractions was carried out using monoclonal antibodies against human acidic and basic fibroblast growth factors (FGF-1 and-2). An immunoreactive FGF-1 band at 16 kD was detected in the heparin-binding fraction derived from embryos in each stage of blastula, gastrula and 4-8 somites. An immunoreactive FGF-2 band at 17 kDa was detected exclusively in the heparin-binding fraction derived from 4-8 somite embryos. In the heparin-binding fraction derived from 12-16 somite embryos neither immunoreactive FGF-1 nor-2 member band was detectable.

The role of angiogenic factor bFGF in the development of dural AVFs

PURPOSE

Dural arteriovenous fistulas (dAVFs) are known to be acquired disorders. Angiogenic stimulants, such as basic fibroblast growth factor (bFGF), may be involved in the evolution of this disorder. We examined the appearance and localization of bFGF, in human dAVF sinuses, versus a control using immunohistochemical techniques, to evaluate these qualitative differences.

PATIENTS AND METHODS

Four human dural sinuses from dAVF patients, and one control dural sinus were removed at surgery or autopsy and used for this study. Immunohistochemistry for bFGF was performed in all five specimens to identify its appearance and localization. Immunohistochemistry for alpha smooth muscle actin, factor VII related antigen, and macrophage (CD-68) were done in all tissues to identify the bFGF positive cell types.

RESULTS

In the control dural sinus, there was negative staining by bFGF immunohistochemistry. However, in all four sinuses of the dAVF patients, smooth muscle cells, endothelial cells, and meningeal cells were stained positively in various degrees by bFGF immunohistochemistry.

CONCLUSION

bFGF may be significant in the development of dAVFs, judging from its strong immunoreactivity in the sinuses of dAVF patients.

Expression of basic fibroblast growth factor and fibroblast growth factor receptor in advanced gastric carcinoma

The expression of basic fibroblast growth factor (bFGF) and fibroblast growth factor receptor (FGFR) mRNA was examined in gastric carcinomas by immunohistochemistry and in situ hybridization, respectively. In the 20 advanced carcinomas examined, bFGF was found in 14 (70.0 per cent) and was confined to the tumour cells, whereas FGFR mRNA was demonstrated in 12 (60.0 per cent) and seen in both tumour cells and endothelial cells. The bFGF and FGFR mRNA-positive carcinomas were larger, were more frequently classified as undifferentiated adenocarcinoma, more frequently invaded the serosal layer, and had a higher rate of lymph node metastases than the bFGF and FGFR mRNA-negative carcinomas. Patients with bFGF and FGFR mRNA-positive carcinomas appear to die earlier than those with bFGF and FGFR mRNA-negative tumours. The values for the carcinomas that were positive for either bFGF or FGFR mRNA fell between these two groups. The findings suggest that the autocrine/paracrine bFGF/FGFR channel is associated with undifferentiated gastric carcinomas and may lead to a poorer prognosis.

Brief exposure to hypoxia induces bFGF mRNA and protein and protects rat cortical neurons from prolonged hypoxic stress

We examined the hypoxic tolerance phenomenon in vitro. Brief exposure to hypoxia induced the production of basic fibroblast growth factor (bFGF) mRNA and protein in rat cortical neurons and protected them from hypoxic injury. Cortical neurons were cultured from 18th-day rat embryos in a serum-free medium and subjected to brief (4 h) and/or prolonged (24 h) hypoxia. Neuronal damage was assessed by quantifying lactate dehydrogenase (LDH) activity in the medium. After brief hypoxia, LDH release was identical to that of the controls, whereas prolonged hypoxia caused a significant increase in LDH release, indicating neuronal death. However, if brief hypoxia was applied 2 days prior to the prolonged hypoxia, no increase in LDH release was observed. The bFGF mRNA expression was assessed with Northern blot and protein immunoreactivity with Western blot analysis. The brief period of hypoxia caused a 2.5-fold increase in bFGF mRNA and considerable bFGF protein expression 1 day later, but prolonged hypoxia caused increase in the expression of bFGF mRNA at 2 days and no protein expression until 3 days after the start of the hypoxia. When cells were subjected to prolonged hypoxia 2 days after brief hypoxia, however, no increase in bFGF mRNA was observed, while bFGF protein was expressed continuously. We also observed that exogenously applied bFGF reduced neuronal injury produced by prolonged hypoxia. The results obtained with this model suggest that brief hypoxia induces bFGF protein and thus tolerance to subsequent lethal hypoxia. Basic FGF might play a role as a tolerance-associated factor in this process. Thus, an in vitro model is useful for assessing the response of cortical neurons to hypoxic stress and for researching new factors related to ischemic tolerance.

Pick's disease immunohistochemistry: new alterations and Alzheimer's disease comparisons

Pick's disease (PD) brains were examined immunohistochemically for the expression of antigens known to be associated with Alzheimer's disease (AD) lesions. Most antibodies which label intracellular neurofibrillary tangles (NFTs) in AD were found to stain Pick bodies (PBs). Among them was the monoclonal antibody A2B5, which is known to recognize neuronal surface gangliosides. This result indicates that membrane proteins are probably incorporated into PBs as into NFTs. However, PBs, in contrast to NFTs, showed a paucity of staining for heparan sulfate glycosaminoglycan and basic fibroblast growth factor (bFGF). Staining for midkine, seen in senile plaques in AD, was not seen in PD. The relative lack of staining for these two neurotrophic factors in PD brain may reflect underlying mechanisms which are distinct from those in AD. We also describe two glial abnormalities in PD: glial fibrillary tangles and clusters of granules positive for the complement protein C4d in the hippocampal dentate fascia. These are presumably related to complement-activated oligodendroglia, and both pathological structures are more abundant in advanced cases, suggesting that they may be hallmarks of the disease progression.

Nitric oxide mediates cytotoxicity and basic fibroblast growth factor release in cultured vascular smooth muscle cells. A possible mechanism of neovascularization in atherosclerotic plaques

To define the pathophysiological role of nitric oxide (NO) released from vascular smooth muscle cells (VSMC), we examined whether NO released from VSMC induces cytotoxicity in VSMC themselves and adjacent endothelial cells (EC) using a coculture system. Prolonged incubation with interleukin-1 (IL-1) induced large amounts of NO release and cytotoxicity in VSMC. NG-Monomethyl-L-arginine, an inhibitor of NO synthesis, inhibited both NO release and cytotoxicity induced by IL-1. In contrast, DNA synthesis in cocultured EC was not inhibited but rather stimulated by prolonged incubation with IL-1 or sodium nitroprusside (SNP), a NO donor. However, IL-1 and SNP did not stimulate but inhibited DNA synthesis in EC alone. On the other hand, conditioned medium from VSMC incubated for a long period with IL-1 or SNP stimulated DNA synthesis in EC alone. Furthermore, the concentration of basic fibroblast growth factor in the conditioned medium was increased and correlated with the degree of cytotoxicity in VSMC. These results indicate that NO released from VSMC induces VSMC death, which results in release of basic fibroblast growth factor, which then stimulates adjacent EC proliferation. Thus, NO released from VSMC may participate in the mechanism of neovascularization in atherosclerotic plaques.

Improvement of an EIA system for basic fibroblast growth factor by use of biotinylated antibody prepared with NHS-LC-biotin

We improved our previously devised enzyme immunoassay (FIA) system for basic fibroblast growth factor (bFGF) using biotinylated antibody prepared with sulfosuccinimidyl-6-(biotinamido)hexanoate (NHS-LC-Biotin, Pierce), a water-soluble biotin analogue, with an extended spacer arm. The discriminatory detection limit of the improved EIA was found to be 5 pg/ml (0.5 pg/assay tube), sixfold more sensitive than that of the previous system. The reproducibility of within- and between-assay series was 5.10-8.61% and 5.99-8.69%, respectively; and recovery of exogenous bFGF from serum was approximately 102%. Employing the improved EIA system, we investigated by chromatofocusing chromatography the isoelectric points of two immunoreactive bFGFs (high-molecular-weight bFGF-like immunoreactive substance, designated as HMW-bFGF-LI and 16-kd bFGF-LI, having the same molecular weight as recombinant bFGF) detected in serum from a breast cancer patient. As a result, the pI value of HMW-bFGF-LI was estimated to be 7.13, and that of 16 kd bFGF-LI, 9.58.

Retention of basic fibroblast growth factor immunoreactivity in dopaminergic neurons of the substantia nigra during normal aging in humans contrasts with loss in Parkinson's disease

A count of pigmented neurons per mm3 in sections of the substantia nigra at the level where the oculomotor nerve emerges in 11 neurologically normal controls aged 15-82 showed the expected slow loss of such neurons with age. Most (82 +/- 3.8%) of the pigmented neurons showed immunoreactivity for basic fibroblast growth factor (bFGF) and this percentage was unaffected by age. This is in marked contrast to the case in Parkinson's disease where only some 12.7 +/- 2.6% of the remaining dopaminergic neurons showed bFGF-like immunoreactivity, providing further evidence against the hypothesis that Parkinson's disease is due to some early insult followed by age-related attrition of the remaining neurons.

Cellular markers that distinguish the phases of hemangioma during infancy and childhood

Hemangiomas, localized tumors of blood vessels, appear in approximately 10-12% of Caucasian infants. These lesions are characterized by a rapid proliferation of capillaries for the first year (proliferating phase), followed by slow, inevitable, regression of the tumor over the ensuing 1-5 yr (involuting phase), and continual improvement until 6-12 yr of age (involuted phase). To delineate the clinically observed growth phases of hemangiomas at a cellular level, we undertook an immunohistochemical analysis using nine independent markers. The proliferating phase was defined by high expression of proliferating cell nuclear antigen, type IV collagenase, and vascular endothelial growth factor. Elevated expression of the tissue inhibitor of metalloproteinase, TIMP 1, an inhibitor of new blood vessel formation, was observed exclusively in the involuting phase. High expression of basic fibroblast growth factor (bFGF) and urokinase was present in the proliferating and involuting phases. There was coexpression of bFGF and endothelial phenotypic markers CD31 and von Willebrand factor in the proliferating phase. These results provide an objective basis for staging hemangiomas and may be used to evaluate pharmacological agents, such as corticosteroids and interferon alfa-2a, which accelerate regression of hemangiomas. By contrast, vascular malformations do not express proliferating cell nuclear antigen, vascular endothelial growth factor, bFGF, type IV collagenase, and urokinase. These data demonstrate immunohistochemical differences between proliferating hemangiomas and vascular malformations which reflect the biological distinctions between these vascular lesions.

Stable and strong expression of basic fibroblast growth factor in naevus cell naevus contrasts with aberrant expression in melanoma

It has been proposed that basic fibroblast growth factor (bFGF) is an autocrine growth factor of melanoma cells, in contrast with normal melanocytes where bFGF acts as a paracrine growth factor. As this notion is mostly based on the different requirements for bFGF in cultures of benign and malignant pigment cells in vitro, we performed an immunohistochemical study to examine bFGF expression in vivo, using paraffin sections from naevus cell naevi (NCN) and malignant melanoma (MM). All the NCN (n = 7) showed strong and homogeneous expression of bFGF protein, whereas the primary MMs (n = 5) showed heterogeneous expression, with a population of negative cells. Metastatic MMs (n = 5) also showed heterogeneous expression, and had a greater population of negative cells. These results suggest that bFGF has some, as yet unidentified, role in the growth of benign NCN, and that overexpression of bFGF is neither a prerequisite for melanoma genesis nor for progression to metastatic MM.

The cerebrospinal fluid in patients with moyamoya disease (spontaneous occlusion of the circle of Willis) contains high level of basic fibroblast growth factor

The level of basic fibroblast growth factor (bFGF) in cerebrospinal fluid (CF) was measured by an EIA in 15 patients with moyamoya disease, in 11 patients with atherosclerotic occlusive disease, and in 8 patients with spinal disc disease. In the moyamoya patients, bFGF was found in 13 out of 15 CF samples with a mean value of 101 pg/ml. However, bFGF was detected in only 4 out of 11 patients with atherosclerotic disease with a mean of 8 pg/ml. In all the patients with disc disease, bFGF was not detected. The elevated level of bFGF may play a crucial role in the pathogenesis of moyamoya disease.

Loss of cytoplasmic basic fibroblast growth factor from physiologically wounded myofibers of normal and dystrophic muscle

Using muscle as an in vivo model system, we have tested the hypothesis that basic fibroblast growth factor is released from a cytoplasmic storage site into the extra-cellular environment via diffusion through survivable, mechanically-induced plasma membrane disruptions. Normal and dystrophic (mdx) mouse muscle were studied. Strong immunostaining for bFGF was detected in the cytoplasm of myofibers of uninjured muscle fixed in situ by perfusion. By contrast, myofibers did not stain cytoplasmically for bFGF after suffering lethal disruptions of their plasma membranes caused by freezing and thawing followed by sectioning. Sub-lethal, transient disruptions of myofiber plasma membranes--termed plasma membrane ‘wounds’--were shown to be induced by needle puncture or exercise of muscle. Quantitative image analysis revealed that these wounded fibers contained significantly reduced levels of bFGF. Dystrophic exercised and unexercised muscle was found to possess an approximately 6-fold higher proportion of wounded myofibers than does normal muscle under equivalent conditions. Release of bFGF at a rate that is a direct function of the frequency of myofiber wounding may explain in part how a muscle adjusts its growth to meet changing mechanical demand as well as the pathological hypertrophy characteristic of certain stages of muscular dystrophy.

Restitution of frog gastric mucosa in vitro: effect of basic fibroblast growth factor

BACKGROUND

Rapid re-epithelialization after superficial gastric mucosal injury is caused by migration of persisting viable epithelial cells. Basic fibroblast growth factor (bFGF) has been reported to enhance the healing of experimental duodenal ulcer, but its mode of action is unclear. The present experiments examine whether an effect of bFGF on restitution might contribute to such healing.

METHODS

Paired halves of bullfrog fundic gastric mucosa in Ussing chambers were injured by luminal exposure to 1 mol/L NaCl for 10 minutes.

RESULTS

Luminal protamine or suramin, both known to interfere with endogenous bFGF, significantly inhibited electrophysiological recovery at neutral luminal pH (pHL). Luminal sucrose octasulfate, which prevents acid degradation of bFGF, and an exogenous, acid-resistant form of bFGF allowed electrophysiological recovery at a pHL of 3.0 that completely prevented restitution in control tissues. Electrophysiological recovery correlated well with morphological restitution. The presence of endogenous bFGF in normal and restituting bullfrog mucosa was confirmed by positive staining with a monoclonal antibody.

CONCLUSIONS

It is concluded that rapid epithelial repair after surface injury is at least in part mediated by bFGF.

Acidic and basic fibroblast growth factor-like immunoreactivity in the striatum and midbrain in Huntington's disease

The immunohistochemical localizations of acidic and basic fibroblast growth factor (aFGF and bFGF) were investigated in the striatum and midbrain of Huntington's disease (HD) and control cases using specific antibodies. In the striatum of control cases, the ependymal cell layer was stained for aFGF and bFGF. In addition, a few subependymal astrocytes were positive for aFGF, and some neurons stained weakly for bFGF. In HD striatum, many astrocytes and remaining neurons were strongly stained for aFGF. aFGF-positive astrocytes were particularly conspicuous in the subependymal region of the caudate but appeared throughout the caudate and putamen. The number of bFGF-positive astrocytes was slightly increased. In contrast to the caudate/putamen, the globus pallidus, nucleus of the oculomotor nerve and substantia nigra showed very similar patterns for both aFGF and bFGF in control and most HD brains. Reports that FGF can protect against glutamate neurotoxicity, and that the FGF receptor (FGFR3), with its gene located in the HD region on chromosome 4, appears in striatal neurons, make it tempting to speculate on a possibly important role for FGF-FGFR3 interactions in HD pathology.

High molecular weight basic fibroblast growth factor-like protein is localized to a subpopulation of mesencephalic dopaminergic neurons in the rat brain

A rabbit antiserum (R917) was raised to a purified fraction of bovine brain basic fibroblast growth factor (bFGF). On Western blots of rat midbrain extract, the antiserum did not recognize low molecular weight forms of bFGF. Instead, it recognized a single band of 27-28 kDa. Immunohistochemically, the antiserum preferentially stained a subpopulation of calbindin-negative mesencephalic dopaminergic neurons. The positive somata were mainly packed in a ventral portion of the tegmentum including the A10 region, the ventral tegmental area and the pars compacta of the medial substantia nigra, but were also scattered in both the pars compacta and reticulata portions of the lateral substantia nigra. Processes of dendrites and axons were clearly visible. Terminal fields were located in striosomes, the dorsolateral rim of the neostriatum, the anterodorsal aspect of the nucleus accumbens shell, the infralimbic cortex, and the medial prefrontal cortex. These results suggest that trophic specialization in subpopulations may occur in all three of these dopaminergic projection systems, i.e. the nigrostriatal, mesolimbic and mesocortical pathways.

Inhibitory effects of magnoshinin and magnosalin, compounds from "Shin-i" (Flos magnoliae), on the competence and progression phases in proliferation of subcultured rat aortic endothelial cells

Anti-proliferative effects of magnoshinin and magnosalin derived from "Shin-i" (Flos magnoliae) were investigated using subcultured endothelial cells (EC) of rat aorta. The inhibitory effects of magnoshinin were 2-fold greater at 10 micrograms/ml than that of magnosalin on the increase in cell number when EC were stimulated by 5% fetal bovine serum. In the 3H-thymidine incorporation monitored at 3 hr-intervals, magnoshinin (0.1-3 micrograms/ml) prolonged the starting time of DNA synthesis and reduced the rate of incorporation into EC. Magnosalin (0.3-3 micrograms/ml) reduced only the incorporation rate. These results suggest that magnoshinin inhibits both the competence phase and progression phase, but magnosalin preferentially inhibits the progression phase in EC proliferation.

Correlation of basic fibroblast growth factor expression levels with the degree of malignancy and vascularity in human gliomas

Basic fibroblast growth factor (FGF) is a mitogen, a differentiation factor for neuroectoderm-derived cells, and a potent angiogenic factor. The authors have previously demonstrated that the messenger ribonucleic acid of basic FGF is expressed in more than 90% of human gliomas. In the present study, they examined the expression of basic FGF in human glioma tissues using immunohistochemical techniques with a mouse monoclonal antibody against human basic FGF. They also correlated the basic FGF level with the histological grades of malignancy assessed by the number of nucleolar organizer regions (NOR's). Basic FGF was detected in 18 of 19 gliomas, whereas it was undetectable in two normal brains. The expression level of basic FGF peptide increased proportionally with the degree of malignancy. There was also a tendency for the number of NOR's in glioma cells to increase in glioma samples with a high level of basic FGF expression. Furthermore, most of the cases with increased vascularity demonstrated on cerebral angiograms showed a relatively high level of basic FGF expression of tumor cells and a large number of NOR's in endothelial cells in tumor tissues. These results suggest that basic FGF is actually produced in most gliomas and is involved in tumorigenesis and malignant progression as an autocrine growth factor. Moreover, basic FGF may play an important role in tumor neovascularization as a paracrine angiogenic factor.

Acidic fibroblast growth factor in the developing rat embryo

Compared to basic fibroblast growth factor (bFGF), a widely distributed, broad spectrum mitogen and mesoderm inducer, acidic fibroblast growth factor (aFGF) is reported to have an essentially neural distribution and to be undetectable in the early embryo. In the present investigation, we used immunoblotting and immunochemistry to assess the cellular and tissue distributions of aFGF and bFGF in 11-20-d rat embryos. Immunoblotting of crude and heparin-bound embryo extracts revealed faint bands at the expected 17-18-kD and predominant bands at an apparent molecular mass of 26 to 28-kD (despite reducing conditions) using multiple specific antibodies for aFGF and bFGF. Pretreatment with 8 M urea yielded 18-20-kD aFGF and bFGF and some 24-26-kD bFGF. Immunoreactivity for both aFGF and bFGF was positive and similar in the cytoplasm, nuclei, and extracellular matrix of cells of neuroectodermal and mesodermal origin, while it was negative in endoderm-derived cells. The distribution of immunoreactive aFGF and bFGF also showed changes during development that were associated with the process of cellular and tissue differentiation. For example, intensity and extent of immunoreactivity for both peptides progressively increased in the middle layer of the spinal cord with increasing differentiation of the neural cells. The immunostaining patterns were very similar for aFGF and bFGF for each organ and at each stage. In conclusion, high molecular mass forms of immunoreactive aFGF and bFGF are present in the rat embryo. Acidic FGF and bFGF are both widely distributed in tissues of neuroectodermal and mesodermal origin, and their distribution was very similar.

Effects of fibroblast growth factors and platelet-derived growth factor on food intake in rats

In the present study, the relations between acidic and basic fibroblast growth factors (aFGF and bFGF, respectively), platelet-derived growth factor (PDGF), and food intake were studied. When aFGF-, bFGF-, and PDGF-like activity in cerebrospinal fluid (CSF) was examined by bioassay, the activity of those factors significantly increased in postfeeding CSF, compared to prefeeding CSF. Injections of aFGF, bFGF, aFGF (synthetic amino-terminal peptide of aFGF), and PDGF into the third cerebral ventricle decreased food intake, and injections of anti-aFGF, anti-bFGF, and anti-aFGF antibodies into the lateral hypothalamus (LHA) increased food intake. The activity of LHA glucose-sensitive neurons was inhibited by electrophoretic application of aFGF. These results suggest that aFGF, bFGF and PDGF have in vivo physiological roles in the central nervous system, distinct from those as mitogens.

Possible roles of basic fibroblast growth factor in the pathogenesis of moyamoya disease: an immunohistochemical study

Prominent features of moyamoya disease are fibrocellular thickening of the intima and enhanced angiogenesis. The pathogenesis of moyamoya disease is, however, unknown. Basic fibroblast growth factor (FGF) is an angiogenic factor as well as a potent mitogen for a number of cell types including vascular endothelial and smooth-muscle cells. In order to test the possibility that basic FGF takes part in the pathogenesis of moyamoya disease, the authors tested for the presence of this factor using a mouse monoclonal antibody against human recombinant basic FGF. The surgical specimens studied included two sections of the superficial temporal artery (STA) and four samples of dura mater from four patients with moyamoya disease. Surgical specimens were obtained from three patients with other diseases as control tissue. Sections of the STA obtained from the patients with moyamoya disease showed strong basic FGF immunoreactivity in endothelial and smooth-muscle cells, while control sections had only faint and scattered immunoreactivity. All sections of the dura mater obtained from the patients with moyamoya disease also revealed more intense immunohistochemical staining of basic FGF in meningeal and vascular cells than did control sections. These observations indicate that the amount of basic FGF is increased in the tissues of patients with moyamoya disease; thus, basic FGF may play an important role in the pathogenesis of moyamoya disease.

Immunohistochemical localization of basic and acidic fibroblast growth factors in the developing rat heart

BACKGROUND

We used biochemical and immunohistochemical techniques to investigate the expression and distribution of immunoreactive basic and acidic fibroblast growth factors (bFGF and aFGF, respectively) in the hearts of rat embryos (11-20 days of gestation) and of postnatal rats (1-35 days after birth). Our purpose was to assess the relation between the cellular distribution of these growth factors and histogenetic and morphogenetic events in the developing heart.

METHODS AND RESULTS

Western-blot analysis of heparin-bound material from neonatal heart extracts identified a single band with a molecular weight of approximately 18 kD for both bFGF and aFGF. Five antibodies for bFGF and three for aFGF showed superimposable distribution of immunoreactive bFGF and aFGF in the heart at each stage examined. At the cellular level, these peptides were localized in the cytoplasm and extracellular matrix. In the myocytes, immunostaining was positive throughout the embryonic and neonatal periods. In the majority of the mesenchymal cells of the cushions and endothelial cells of endocardium and vessels, staining was also positive. In the smooth muscle cells of the aorta, other large arteries, and coronary arteries, immunostaining was intensely positive at early stages of development but became faint or negative with increasing cell differentiation.

CONCLUSIONS

The wide distribution of immunoreactive bFGF and aFGF that we identified in the developing rat heart suggests that these growth factors play an important role in heart cytodifferentiation and morphogenesis. Their superimposable distribution may reflect functional interaction. The progressive changes in their distribution suggest a changing role for these peptides during organogenesis.

Increase in basic fibroblast growth factor-like immunoreactivity in rat brain after forebrain ischemia

Using immunohistochemical techniques, a study was conducted to determine whether basic fibroblast growth factor (bFGF) is generated as one of the 'self-repair' responses in rat brain following transient forebrain ischemia. In normal brain, slight bFGF-like immunoreactivity was observed. However, in rats exposed to 20 min of forebrain ischemia, intense bFGF-like immunoreactivity was observed in the CA1 subfield of the hippocampus and the caudate putamen, and marked activity was evident in the temporal cortex, corpus callosum and the CA4 subfield of the hippocampus. Marked neuronal degeneration was also observed in these brain regions following forebrain ischemia. These results suggest that induction of bFGF-like immunoreactivity may be related to the healing which follows brain ischemia.

Establishment of monoclonal antibodies against human acidic fibroblast growth factor

Four kinds of hybridomas secreting monoclonal antibodies (MAbs) against human acidic fibroblast growth factor (haFGF) were established using recombinant haFGF as an immunogen. The recognition sites of four MAbs designated AF1-52, 81, 114 and 1C10 for the haFGF molecule were examined by binding studies with synthetic polypeptides and with amino-terminal truncated forms of haFGF. These experiments suggested that AF1-52, 114, and 1C10 MAbs recognize epitopes within the 1-5, 44-132 and 6-43 amino acid sequences, respectively. However, the epitope recognized by the AF1-81 MAb could not be determined. The sandwich EIA method constructed with these MAbs was sensitive to 1.5 pg/well of haFGF and had no cross-reactivity with human basic FGF, bovine aFGF or the hst-1 gene product.

A sensitive enzyme immunoassay for human basic fibroblast growth factor

A sensitive sandwich enzyme immunoassay for human basic fibroblast growth factor (HbFGF) was developed employing three monoclonal antibodies (MAb3H3, MAb98 and MAb52). The Fab' fragment of MAb3H3 which inhibits HbFGF biological activity was conjugated to horseradish peroxidase. A mixture of MAb52 and MAb98 was used in the solid phase. Neither human acidic fibroblast growth factor, hst-1/KS3 product nor acid denatured HbFGF was cross-reactive in this assay system. The detection limit of this assay system was 1 pg/well. Using this assay, some tumor cell lines were revealed to produce a higher level of bFGF than a normal one. Serum samples from normal volunteers were also assayed, and immuno-reactive HbFGF could be detected in 16 out of 57 samples at range 30 approximately 206 pg/ml.

Gene expression of fibroblast growth factors in human gliomas and meningiomas: demonstration of cellular source of basic fibroblast growth factor mRNA and peptide in tumor tissues

The growth autonomy of human tumor cells is considered due to the endogenous production of growth factors. Transcriptional expression of candidates for autocrine stimulatory factors such as basic fibroblast growth factor (FGF), acidic FGF, and transforming growth factor type beta were determined in human brain tumors. Basic FGF was expressed abundantly in 17 of 18 gliomas, 20 of 22 meninglomas, and 0 of 5 metastatic brain tumors. The level of mRNA expression of acidic FGF in gliomas was significant. In contrast, transforming growth factor type beta 1 was expressed in all the samples investigated. The mRNA for basic FGF and its peptide were localized in tumor cells in vivo by in situ hybridization and immunohistochemistry, showing that basic FGF is actually produced in tumor cells. Our results suggest that tumor-derived basic FGF is involved in the progression of gliomas and meningiomas in vivo, whereas acidic FGF is expressed in a tumor origin-specific manner, suggesting that acidic FGF works in tandem with basic FGF in glioma tumorigenesis.

Carboxyl-terminal structure of basic fibroblast growth factor significantly contributes to its affinity for heparin

The carboxyl-terminal sequence of basic fibroblast growth factor (bFGF) is rich in basic amino acid residues, a common characteristic amongst fibroblast growth factors, and is considered to contribute greatly to the binding to negatively charged extracellular matrixes such as heparin. To study the relationship between the affinity for heparin and the carboxyl-terminal structure of bFGF, amino- or carboxyl-terminal truncated molecules were produced in Escherichia coli using recombinant DNA techniques. These terminally truncated bFGFs were applied to a heparin-affinity HPLC column. Truncation of more than six amino acid residues from the carboxyl-terminal made the bFGF produced in E. coli markedly difficult to solubilize and weakened its affinity for heparin, though bFGF having up to 46 amino acids removed showed significant stimulation of the DNA synthesis of BALB/c3T3 cells. This stimulation of the DNA synthesis was also recognized by the bFGF having 40 amino acids removed from its amino-terminal, while the affinity of this peptide for heparin has been shown to be equal to that of the mature bFGF (146 amino acids). These results show that the affinity of bFGF for heparin depends significantly on its carboxyl-terminal structure and that the essential part for receptor binding is present between Asp41 and Ser100. Moreover, it suggests that the Phe139Leu140Pro141, present in all members of the FGF family, contributes greatly to the stable structure of the intact molecule.

Monoclonal antibodies directed against basic fibroblast growth factor which inhibit its biological activity in vitro and in vivo

A panel of four murine monoclonal IgG1 antibodies (mAbs) to a recombinant form of basic fibroblast growth factor (bFGF) was produced using somatic cell fusion techniques. Non-linear regression analysis of radioimmunoassay data for each mAb yielded the following dissociation constants (nM) for their interactions with bFGF: DE6 (0.822); AF11 (2.0); FE8 (2.31); and DG2 (20.0). One of the mAbs, DG2, was identified as a bFGF neutralizing antibody on the basis of its ability to inhibit, in vitro, the binding of [125I]-bFGF to high and low affinity bFGF sites on cultured baby hamster kidney cells and bFGF-induced [3H]-thymidine incorporation in cultured 3T3 cells, and in vivo, the angiogenic response to bFGF in a rat kidney capsule model of angiogenesis. The other mAbs displayed varying inhibitory activities in these assays. These mAbs, particularly DG2, may be well suited for a number of applications in bFGF research including immunoassays, immunohistochemical studies, and as functional antagonists of bFGF for examining its role in physiological processes such as reproduction, growth, and development.