Production Of Fibroblast Growth Factor-2 Research Articles

GPR30-mediated non-classic estrogen pathway in mast cells participates in endometriosis pain via the production of FGF2.

Pain is one of the main clinical symptoms of endometriosis, but its underlying mechanism is still not clear. Recent studies have shown that the secretory mediators of mast cells activated by estrogen are involved in the pathogenesis of endometriosis-related pain, but how estrogen-induced mast cell mediators are involved in endometriosis-related pain remains unclear. Here, mast cells were found to be increased in the ovarian endometriotic lesions of patients. They were also closely located closely to the nerve fibers in the ovarian endometriotic lesions from of patients with pain symptoms. Moreover, fibroblast growth factor 2 (FGF2)-positive mast cells were upregulated in endometriotic lesions. The concentration of FGF2 in ascites and the protein level of fibroblast growth factor receptor 1 (FGFR1) were higher in patients with endometriosis than in those without endometriosis, and they were correlated with pain symptoms. In vitro, estrogen could promote the secretion of FGF2 through G-protein-coupled estrogen receptor 30 (GPR30) via the MEK/ERK pathway in rodent mast cells. Estrogen-stimulated mast cells enhanced the concentration of FGF2 in endometriotic lesions and aggravated endometriosis-related pain in vivo. Targeted inhibition of the FGF2 receptor significantly restrained the neurite outgrowth and calcium influx in dorsal root ganglion (DRG) cells. Administration of FGFR1 inhibitor remarkably elevated the mechanical pain threshold (MPT) and prolonged the heat source latency (HSL) in a rat model of endometriosis. These results suggested that the up-regulated production of FGF2 by mast cells through non-classic estrogen receptor GPR30 plays a vital role in the pathogenesis of endometriosis-related pain.

Nanostructured TiC Layer is Highly Suitable Surface for Adhesion, Proliferation and Spreading of Cells

Cell culture is usually performed in 2D polymer surfaces; however, several studies are conducted with the aim to screen functional coating molecules to find substrates more suitable for cell adhesion and proliferation. The aim of this manuscript is to compare the cell adhesion and cytoskeleton organization of different cell types on different surfaces. Human primary fibroblasts, chondrocytes and osteoblasts isolated from patients undergoing surgery were seeded on polystyrene, poly-d-lysine-coated glass and titanium carbide slides and left to grow for several days. Then their cytoskeleton was analyzed, both by staining cells with phalloidin, which highlights actin fibers, and using Atomic Force Microscopy. We also monitored the production of Fibroblast Growth Factor-2, Bone Morphogenetic Protein-2 and Osteocalcin, using ELISA, and we highlighted production of Collagen type I in fibroblasts and osteoblasts and Collagen type II in chondrocytes by immunofluorescences. Fibroblasts, chondrocytes and osteoblasts showed both an improved proliferative activity and a good adhesion ability when cultured on titanium carbide slides, compared to polystyrene and poly-d-lysine-coated glass. In conclusion, we propose titanium carbide as a suitable surface to cultivate cells such as fibroblasts, chondrocytes and osteoblasts, allowing the preservation of their differentiated state and good adhesion properties.

In-office tooth bleaching with 38% hydrogen peroxide promotes moderate/severe pulp inflammation and production of ll-1β, TNF-β, GPX, FGF-2 and osteocalcin in rats.

Objectives:To study the intensity of inflammatory infiltrate and production of interleukin-1β (ll-1β), tumor necrosis factor-β (TNF-β), fibroblast growth factor-2 (FGF-2), glutathione peroxidase (GPX), and osteocalcin in response to in-office tooth bleaching in rats.Material and Methods:Twenty male Wistar rats were randomized into four groups (n=5) according to the received treatment (tooth bleaching or no treatment - control) and the period of euthanasia after treatment (24 h or 10 days). We performed tooth bleaching using a 38% hydrogen peroxide gel on maxillary and mandibular incisors. After euthanasia, incisors (20 per group) were processed for histological analysis, immunohistochemistry staining of ll-1β, TNF-β, FGF-2 and GPX and osteocalcin by immunofluorescence. We analyzed data using the Mann-Whitney and Kruskal-Wallis/Dunn tests (p<0.05).Results:The bleached groups presented statistically significant differences regarding the pulp inflammation stage compared with the control groups. Bleached teeth showed moderate/severe inflammatory infiltrate and control groups presented absent inflammatory cells or a negligible number of mononuclear cells (p<0.001) at two times (24 h and 10 days). There was strong staining for ll-1β, TNF-β, and GPX in bleached groups at 24 h and strong staining for ll-1β, TNF-β, GPX and FGF-2 at 10 days. After 10 days of tooth bleaching, the bleached group showed a statistically superior amount of osteocalcin than the other groups (p<0.01).Conclusions:Tooth bleaching with 38% hydrogen peroxide causes severe pulp inflammation, but characteristics of tissue repair after 10 days.

Tracheal Smooth Muscle Cells Stimulated by Stem Cell Factor-c-Kit Coordinate the Production of Transforming Growth Factor-β1 and Fibroblast Growth Factor-2 Mediated by Chemokine (C-C Motif) Ligand 3.

The aim of this study was to evaluate the mechanism involved in the stem cell factor (SCF)-induced production of fibroblast growth factor-2 (FGF-2), transforming growth factor-β1 (TGF-β1), and chemokine (C-C motif) ligand 3 (CCL3) in tracheal smooth muscle cells (tSMCs) and the signaling pathway involved in the process. tSMC primary cultures were stimulated with SCF and evaluated at 24 h. Cells treated with specific antibodies did not show any immunolabeling for cytokeratin or fibroblast activation protein, but were positive for α-smooth muscle actin, indicating the purity of the primary cell line. Western blot analysis showed constitutive phosphorylation of c-Kit, as well as increased total protein and phosphorylated c-Kit levels in tSMCs after SCF stimulation. Flow cytometry analysis also showed an increase in cell-surface c-Kit expression in the presence of SCF. SCF induced TGF-β mRNA expression in tSMCs, as well as the production of TGF-β1, CCL3, and FGF-2. Pretreatment with anti-CCL3 antibody blocked TGF-β1 expression and partially inhibited FGF-2 production. On the other hand, anti-c-Kit antibody blocked TGF-β1 expression and FGF-2 production. Thus, TGF-β1 and FGF-2 production were mediated by CCL3 production through c-Kit. Pretreatment with mitogen-activated protein kinase kinase 1, p38, and Jun N-terminal kinase inhibitors showed that the effects mediated by SCF were involved with the modulation of mitogen-activated protein kinase (MAPK) pathways. Development of inhibitors targeting CCL3 through MAPK activation could thus be an attractive strategy to inhibit tSMC activation during asthma.

House dust mite extract induces growth factor expression in nasal mucosa by activating the PI3K/Akt/HIF-1α pathway

Growing evidence suggests that hypoxia-inducible factor-α (HIF-1α) plays an important role in the progression of allergic airway inflammation and remodeling. However, the biochemical mechanisms leading to the activation of HIF-1α and the effects of HIF-1α on the expression of growth factors, including vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and fibroblast growth factor-2 (FGF-2), in allergic nasal inflammation are not clear. We examined the relationship between HIF-1α activation and production of VEGF, TGF-β1, and FGF-2 in primary cultured nasal epithelial cells (NECs) after stimulation with house dust mite (HDM) extract. Moreover, we evaluated the importance of phosphoinositide3-kinase(PI3K)/Akt signaling in HDM-induced production of these growth factors in vitro and in the nasal mucosa of a murine model of allergic rhinitis (AR). Our results indicate HDM extract induced the expression of VEGF, TGF-β1, and FGF-2 by activating the PI3K/Akt/HIF-1α pathway in human primary cultured NECs and in the nasal mucosa of a murine model. HIF-1α regulated the expression of VEGF, TGF-β1, and FGF-2 in the nasal mucosa through direct and indirect pathways, which suggested that targeting the HIF-1α pathway could be a novel therapeutic approach for reducing nasal airway inflammation and remodeling in AR.

Involvement of the receptor-associated prorenin system in the pathogenesis of human conjunctival lymphoma.

Extranodal marginal zone B-cell lymphoma (EMZL) is the most common subtype of conjunctival lymphoma, though its molecular mechanisms of pathogenesis are largely unknown. We attempted to explore the association of the renin-angiotensin system (RAS) and (pro)renin receptor ([P]RR) in the pathogenesis of conjunctival lymphoma. Surgically removed conjunctiva EMZL samples were used for gene expression, and immunohistochemical and immunofluorescence analyses of (P)RR and RAS components. Human B-lymphoblast IM-9 cells were treated with prorenin or angiotensin II (Ang II), and gene expression levels were analyzed using real-time quantitative PCR (qPCR). In addition, immunofluorescence analysis of EMZL samples was used to evaluate the in vivo expression of those components. Gene expression and immunohistochemical analyses revealed the expression of RAS components, including (P)RR and angiotensin II type 1 receptor (AT1R), in EMZL tissues. Double-labeling analyses demonstrated that (P)RR and AT1R were detected in cells positive for CD20, a marker for B-cells, where they colocalized with prorenin and angiotensinogen, respectively. Prorenin stimulation of human B-lymphoblast IM-9 cells increased mRNA expression levels of fibroblast growth factor 2 (FGF2), while angiotensin II treatment upregulated the expression levels of basigin (BSG), matrix metallopeptidase (MMP)2, 9, and 14, which were abolished by (P)RR and AT1R blockades, respectively. Immunofluorescence analyses of clinical samples showed colocalizations of (P)RR and AT1R with the products of these upregulated genes. The present study suggests that activation of (P)RR and AT1R is associated with the pathogenesis of conjunctival EMZL by stimulating the production of FGF2 and MMPs.

Growth and Regression in Bovine Corpora Lutea: Regulation by Local Survival and Death Pathways

The bovine corpus luteum (CL) is a transient gland with a life span of only 18 days in the cyclic cow. Mechanisms controlling CL development and secretory function may involve factors produced both within and outside this gland. Although luteinizing hormone (LH) surge is the main trigger of ovulation and granulosa cells luteinization, many locally produced agents such as arachidonic acid (AA) metabolites, growth factors and cytokines were shown to complement gonadotropins action in the process of CL development. Bovine CL is a highly vascular gland, where the very rapid angiogenesis rate (until Day 5 of the cycle) results in the development of a capillary network, endowing this gland with one of the highest blood flow rate per unit mass in the body. Angiogenesis in the developing CL is later followed by either controlled regression of the microvascular tree in the non-fertile cycle or maintenance and stabilization of the blood vessels, as seen during pregnancy. Different luteal cell types (both steroidogenic and accessory luteal cells: immune cells, endothelial cells, pericytes and fibroblasts) are involved in the pro- and/or anti-angiogenic responses. The balance between pro- and anti-angiogenic responses to the main luteolysin - prostaglandin F2α (PGF2α) could be decisive in whether or not PGF2α induces CL regression. Fibroblast growth factor-2 (FGF2) may be one of the factors that modulate the angiogenic response to PGF2α. Manipulation of local production and action of FGF2 will provide new tools for reproductive management of dairy cattle. Luteolysis is characterized by a rapid decrease in progesterone production, followed by structural regression. Factors like endothelin-1, cytokines (tumour necrosis factorα, interferons) and nitric oxide were all shown to play critical roles in functional and structural regression of the CL by inhibiting steroidogenesis and inducting apoptosis.

Regulation of Myelopoiesis by Differentiation Stage-Specific Activities of HOXA9 and HOXA10

Abstract SCI-29HOXA9 and HOXA10 are homeodomain (HD) transcription factors that are implicated in control of myelopoiesis and contribute to myeloid leukemogenesis. These proteins are expressed coordinately during hematopoiesis, with maximal expression in granulocyte/monocyte progenitor (GMP) cells. Engineered overexpression of Hoxa9 or Hoxa10 in primary bone marrow cells expands the GMP population in vitro, and results in myeloproliferation in murine bone marrow transplant experiments. Mice transplanted with Hoxa9- or Hoxa10-overexpressing bone marrow develop acute myeloid leukemia (AML) over time. Consistent with this, increased and sustained expression of a set of HD proteins, including HOXA9 and HOXA10, is found in a subset of human AML, including AML with MLL gene translocations (11q23-AML). Since the DNA-binding HDs of HOXA9 and HOXA10 are highly conserved, we hypothesize that they recognize a common set of target genes. However, since HOXA9 and HOXA10 diverge outside the HD, we considered the unexplored possibility that they perform different functions in regulating such genes. To identify molecular mechanisms for HOX-induced GMP expansion and leukemogenesis, we performed a chromatin immunoprecipitation-based screen for HOXA10 target genes. Gene ontology studies determined that the identified set is enriched for genes encoding growth factors and receptors, including fibroblast growth factor 2 (FGF2). We found that production of FGF2 by Hoxa10-overexpressing GMP stabilizes β-catenin and induces proliferation in an autocrine manner. We also found that HOXA9 and HOXA10 activate common FGF2 cis elements. The Hoxa10-target-gene set is also enriched for HD-transcription factors, including CDX4. We determined that Cdx4 transcription is activated by HOXA10 in GMP, but repressed by HOXA9 in differentiating myeloid cells. CDX4 activates transcription of both Hoxa9 and Hoxa10, identifying a HOX-CDX cross-regulatory mechanism. This mechanism may be influenced by Fgf2, since Hoxa10 and Cdx4 are β-catenin target genes, but β-catenin activity decreases Hoxa9 expression. Gene expression profiling studies indicate that HOXA9, HOXA10, CDX4, and FGF2 are increased in 11q23-AML, suggesting clinical relevance. Arih2 (encoding the E3 ligase Triad1) is another common HOXA9 and HOXA10 target gene that may influence Fgf2 activity. We found that Arih2 transcription is repressed by HOXA9 in myeloid progenitors, but activated by HOXA10 in differentiating phagocytes. FGF receptors are destabilized by ubiquitination, and we found increased FGF-R ubiquitination in Hoxa10-overexpressing cells. Therefore, Triad1-dependent regulation of FGF-R stability is another mechanism for control of FGF2 activity and myeloproliferation by HOXA9 and HOXA10. Therefore, HOXA9 and HOXA10 regulate a common set of target genes that control GMP expansion in a manner that is antagonistic for some genes and cooperative for others. Clinical correlative studies suggest that coordinate control of these genes by HOXA9 and HOXA10 is dysregulated in HOX-overexpressing leukemia. Understanding HOX-regulated gene networks may identify therapeutic targets for HOX-overexpressing leukemias. For example, blocking FGF-related signaling pathways may ameliorate cytokine hypersensitivity in such leukemias, and would be a topic of interest for additional studies. Disclosures:No relevant conflicts of interest to declare.

Chlamydia trachomatis Co-opts the FGF2 Signaling Pathway to Enhance Infection

The molecular details of Chlamydia trachomatis binding, entry, and spread are incompletely understood, but heparan sulfate proteoglycans (HSPGs) play a role in the initial binding steps. As cell surface HSPGs facilitate the interactions of many growth factors with their receptors, we investigated the role of HSPG-dependent growth factors in C. trachomatis infection. Here, we report a novel finding that Fibroblast Growth Factor 2 (FGF2) is necessary and sufficient to enhance C. trachomatis binding to host cells in an HSPG-dependent manner. FGF2 binds directly to elementary bodies (EBs) where it may function as a bridging molecule to facilitate interactions of EBs with the FGF receptor (FGFR) on the cell surface. Upon EB binding, FGFR is activated locally and contributes to bacterial uptake into non-phagocytic cells. We further show that C. trachomatis infection stimulates fgf2 transcription and enhances production and release of FGF2 through a pathway that requires bacterial protein synthesis and activation of the Erk1/2 signaling pathway but that is independent of FGFR activation. Intracellular replication of the bacteria results in host proteosome-mediated degradation of the high molecular weight (HMW) isoforms of FGF2 and increased amounts of the low molecular weight (LMW) isoforms, which are released upon host cell death. Finally, we demonstrate the in vivo relevance of these findings by showing that conditioned medium from C. trachomatis infected cells is enriched for LMW FGF2, accounting for its ability to enhance C. trachomatis infectivity in additional rounds of infection. Together, these results demonstrate that C. trachomatis utilizes multiple mechanisms to co-opt the host cell FGF2 pathway to enhance bacterial infection and spread.

190 Sorafenib effectively controls early-stage hepatocellular carcinoma but not visceral metastases in a preclinical orthotopic transplant model

The aim of this study was to examine the effects of fibroblast growth factor-2 (FGF-2) on cancer cell invasion on fibroblast proliferation in an in vitro model of invasion. Three kinds of human oral squamous cell carcinoma cell lines with different invasive activity were used: OSC-20, OSC-19 (lower invasive type), HOC313 (higher invasive type). FGF-2 its high-affinity receptors FGFR-1 FGFR-2 were detected by western blotting. The expression of FGF-2 FGFRs mRNA was examined in cultured human oral squamous cell carcinoma cells by reverse transcriptase polymerase chain reaction (RT-PCR). Furthermore, recombinant human FGF-2 (rhFGF-2) was reacted with each cell line, the invasion rate was determined by invasion assay. We also observed the behavior of cancer cell invasion in the collagen gel invasion model in the presence or absence of FGF-2-neutralizing antibody (anti-FGF-2). HOC313 cells showed higher expression of FGF-2 than OSC-20 OSC-19 cells. The addition of rhFGF-2 promoted not only the proliferation of fibroblasts, but also the invasion of all cancer cell lines. In contrast, the addition of anti-FGF-2 completely inhibited the invasion of OSC-20 OSC-19 cells. These results suggest that a higher invasiveness of squamous carcinoma cells is associated with higher production of FGF-2, which acts in an autocrine fashion to promote cancer cell invasion, in a paracrine fashion to promote fibroblast proliferation.

RAAV-mediated overexpression of FGF-2 promotes cell proliferation, survival, and α-SMA expression in human meniscal lesions

Meniscal tears are a common problem in sports medicine. Direct application of therapeutic vectors derived from the adeno-associated virus might be beneficial to enhance meniscal repair. We tested the hypothesis that overexpression of fibroblast growth factor 2 (FGF-2) through recombinant adeno-associated virus (rAAV) vectors leads to detectable metabolic changes in human meniscal fibrochondrocytes and in human meniscal defects. rAAV-mediated gene transfer was investigated for its ability to promote FGF-2 secretion in human meniscal fibrochondrocytes in vitro, in intact human meniscal explants in situ, and in experimentally created human meniscal lesions. Effects of the treatment on cell proliferation and survival, extracellular matrix synthesis, and expression of the alpha-smooth muscle actin (alpha-SMA) contractile marker were monitored using biochemical, immunohistochemical, histological, and histomorphometric analyses. Efficient production of FGF-2 through rAAV could be achieved in vitro and in situ, both in the intact and injured meniscus. Application of the candidate FGF-2 vector allowed for enhanced cell proliferation and survival compared with control transduction, in particular in areas with poor healing capacity and in sites of injury, consistent with the mitogenic activities of the growth factor. Remarkably, a significant reduction of the amplitude of meniscal tears was noted after FGF-2 treatment, with increased levels of alpha-SMA expression. In contrast, there was no significant stimulation of synthesis of the major extracellular matrix components when the candidate vector was applied and instead, a decrease in the matrix/DNA contents was reported, in good agreement with the properties of FGF-2. Such a direct gene-based approach may have value in options aiming at treating human meniscal defects.

Effect of transfection strategy on growth factor overexpression by articular chondrocytes

Articular cartilage damage remains an unsolved problem in orthopaedics. Insulin-like growth factor I (IGF-I) and fibroblast growth factor-2 (FGF-2) are anabolic and mitogenic for articular chondrocytes, and are candidates for the application of gene therapy to articular cartilage repair. We tested the hypothesis that the production of IGF-I and FGF-2 can be augmented by modulating vector designs and delivery methods used for gene transfer to articular chondrocytes. We developed a novel adeno-associated virus (AAV)-based plasmid (pAAV) to overexpress IGF-I and FGF-2 cDNAs in adult bovine articular chondrocytes. We found that the pAAV-based vectors generated significantly more growth factor than pcDNA vectors carrying the same cDNAs. Chondrocytes cotransfected with both IGF-I and FGF-2 cDNAs in two separate pAAV plasmids produced significantly more IGF-I and FGF-2 than cells transfected by a single pAAV plasmid carrying both cDNAs in a dicistronic cassette. These data indicate that pAAV vectors are more effective than pcDNA vectors for transfer of IGF-I and FGF-2 genes to articular chondrocytes. They further suggest that cotransfection may be an effective strategy for multiple gene transfer to these cells. These findings may be important in applying growth factor gene transfer to cell-based articular cartilage gene therapy.

Fibroblast Growth Factor-2 Accelerates Invasion of Oral Squamous Cell Carcinoma

The aim of this study was to examine the effects of fibroblast growth factor-2 (FGF-2) on cancer cell invasion on fibroblast proliferation in an in vitro model of invasion. Three kinds of human oral squamous cell carcinoma cell lines with different invasive activity were used: OSC-20, OSC-19 (lower invasive type), HOC313 (higher invasive type). FGF-2 its high-affinity receptors FGFR-1 FGFR-2 were detected by western blotting. The expression of FGF-2 FGFRs mRNA was examined in cultured human oral squamous cell carcinoma cells by reverse transcriptase polymerase chain reaction (RT-PCR). Furthermore, recombinant human FGF-2 (rhFGF-2) was reacted with each cell line, the invasion rate was determined by invasion assay. We also observed the behavior of cancer cell invasion in the collagen gel invasion model in the presence or absence of FGF-2-neutralizing antibody (anti-FGF-2). HOC313 cells showed higher expression of FGF-2 than OSC-20 OSC-19 cells. The addition of rhFGF-2 promoted not only the proliferation of fibroblasts, but also the invasion of all cancer cell lines. In contrast, the addition of anti-FGF-2 completely inhibited the invasion of OSC-20 OSC-19 cells. These results suggest that a higher invasiveness of squamous carcinoma cells is associated with higher production of FGF-2, which acts in an autocrine fashion to promote cancer cell invasion, in a paracrine fashion to promote fibroblast proliferation.

Retinoids induce fibroblast growth factor-2 production in endothelial cells via retinoic acid receptor alpha activation and stimulate angiogenesis in vitro and in vivo.

The effect of retinoic acid (RA) on endothelial cells is still controversial and was examined in the present study. In bovine aortic endothelial cells (BAECs), all-trans RA (ATRA) and 9-cis RA (9CRA), but not 13-cis RA (13CRA), induced fibroblast growth factor-2 (FGF-2) production and exhibited a biphasic dose-dependent effect to enhance BAEC proliferation and differentiation into tubular structures on reconstituted basement membrane proteins (Matrigel); both processes were inhibited by FGF-2-neutralizing antibody. The pan RA receptor (RAR)-selective ligand (E)-4-[2-(5,5,8,8,-tetramethyl-5,6,7,8-tetrahydro-2-naphtalenyl)-1-propenyl] benzoic acid and the RARalpha-selective ligand 4-[1-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydro-2-naphtyl)-ethenyl] benzoic acid stimulated the production of FGF-2, whereas the addition of the RARalpha-antagonist RO 41-5253 inhibited this effect. In BAECs, the forced expression of RARalpha, but not RARbeta or RARgamma, enhanced FGF-2 production, whereas the RARalpha-dominant negative, Delta403, blocked this effect. Furthermore, RARalpha overexpression directly stimulated BAEC differentiation on Matrigel and potentiated the effects of ATRA in this assay. Finally, ATRA-treated BAECs coinjected with Matrigel subcutaneously in mice induced neovascularization within the Matrigel plug, and ATRA also enhanced angiogenesis in the chicken chorioallantoic membrane assay. In conclusion, RA can stimulate endothelial cell proliferation and differentiation in vitro via enhanced RARalpha-dependent FGF-2 production, and it can also induce angiogenesis in vivo. The full text of this article is available at http://www.circresaha.org.

Expression of fibroblast growth factor-2 in the nucleus ambiguus following recurrent laryngeal nerve injury in the rat.

To examine fibroblast growth factor-2 (FGF-2) immunoreactivity in the nucleus ambiguus (NA) after three different recurrent laryngeal nerve (RLN) injuries. Immunohistochemical analysis of FGF-2. Thirty adult rats underwent left-sided RLN crush (group A). The left RLN was transected in groups B (n = 30) and C (n = 30); in group C, both nerve stumps were covered with silicone caps. FGF-2 in the NA was assessed as the ratio of the positive areas on the left (operated [O]) and right (unoperated [U]) sides. The ratio (O/U) was measured 1, 3, 7, 14, and 28 days after the procedure. Three rats underwent left-sided RLN exposure and were killed 7 days later (control). Left-sided RLN paralysis occurred until day 28 in group A. In the control group, O/U was approximately 1. In group A, O/U was significantly elevated on day 7; in group B, on days 3, 7, and 14; and in group C, on day 3. O/U in group B was significantly greater than that in group A on days 14 and 28. Maximal FGF-2 immunoreactivity was significantly lower in group C than in groups A and B. We demonstrated elevated production of FGF-2 in the NA after RLN injury. This endogenous FGF-2 might contribute to preventing lesion-induced neuronal death. Blockage of axonal regeneration might suppress FGF-2 production in the NA. Further understanding of the roles of FGF-2 after RLN injury may contribute to the prevention of neuronal death and facilitation of axonal regeneration.

Fibroblast growth factor-2-producing fibroblasts protect the nigrostriatal dopaminergic system from 6-hydroxydopamine

We tested the hypothesis that fibroblasts, which had been genetically engineered to produce fibroblast growth factor-2 (FGF-2), can protect nigrostriatal dopaminergic neurons. Three groups of rats received either a burr hole only ( n=5) or implantation of fibroblasts, which had been genetically engineered to produce β-galactosidase (β-gal) ( n=8) or FGF-2 ( n=8), at two sites in the right striatum. Two weeks later, the animals received an injection of 25 μg of 6-hydroxydopamine hydrobromide (6-OHDA) midway between the two implant sites. The group that received FGF-2-fibroblasts had significantly fewer apomorphine-induced rotations than the groups that received a burr hole only or β-gal-fibroblasts at weeks 2 and 3 following lesioning with 6-OHDA. Testing for amphetamine-induced rotation revealed a mild reduction in rotation in the β-gal-fibroblast group compared to the burr hole only group, but a striking attenuation of amphetamine-induced rotation in the FGF-2-fibroblast group. There was also preservation of TH-IR neurons on the lesioned side relative to both control groups. The size of the grafts and the gliosis surrounding the injection sites did not differ between the FGF-2-fibroblast and β-gal-fibroblast groups. To further characterize the production of FGF-2 by the FGF-2-fibroblasts, we implanted FGF-2-fibroblasts and β-gal-fibroblast into the striatum of rats but did not lesion the animals with 6-OHDA. The animals were then sacrificed at 1, 2 and 5 weeks following implantation. Prior to implantation the FGF-2 fibroblasts contained 148 ng/mg of FGF-2-immunoreactive (FGF-2-IR) material per mg of protein of cell lysate. After implantation FGF-2-IR material was noted in the grafts of FGF-2-fibroblasts, most conspicuously at 1 and 2 weeks following implantation. We also noted FGF-2-IR material in the nuclei of reactive astrocytes adjacent to the implants, and OX-42-immunoreactive (OX-42-IR) cells adjacent and occasionally within the implants. Our work indicates that fibroblasts genetically engineered to produce FGF-2 and implanted in the striatum can protect the nigrostriatal dopaminergic system and may be useful in the treatment of Parkinson’s disease.