Ex vivo pretreatment with melatonin improves survival, proangiogenic/mitogenic activity, and efficiency of mesenchymal stem cells injected into ischemic kidney

Bone marrow mesenchymal stem cells (MSCs) have shown great potential in cell therapy of solid organs. Approaches to improving the ability of grafted MSCs to survive and secrete paracrine factors represent one of the challenges for the further development of this novel therapy. In the present study, we designed a strategy of ex vivo pretreatment with the pineal hormone melatonin to improve survival, paracrine activity, and efficiency of MSCs. Using a rat model of acute renal failure, we showed that melatonin pretreatment strongly increased survival of MSCs after intraparenchymal injection. This effect was concomitant with overstimulation of angiogenesis, proliferation of renal cells, and accelerated recovery of renal function. To gain insight into the mechanisms involved in the effects observed in vivo, melatonin was tested in vitro on cultured MSCs. Our results show that through stimulation of specific melatonin receptors, melatonin induced an overexpression of the antioxidant enzyme catalase and superoxide dismutase-1 and increased the resistance of MSCs to hydrogen peroxide-dependent apoptosis. Compared with untreated cells, MSCs incubated with melatonin displayed a higher expression of basic fibroblast growth factor and hepatocyte growth factor. In addition, conditioned culture media from melatonin-treated MSCs stimulated tube formation by endothelial progenitor cells and proliferation of proximal tubule cells in culture. In conclusion, our results show that melatonin behaves as a preconditioning agent increasing survival, paracrine activity, and efficiency of MSCs. The use of this molecule for pretreatment of stem cells may represent a novel and safe approach to improving the beneficial effects of cell therapy of solid organs.

Vascular endothelial growth factor and basic fibroblast growth factor expression positively correlates with angiogenesis and peritumoural brain oedema in astrocytoma

BACKGROUND

Astrocytoma is the most malignant intracranial neoplasm and is characterized by high neovascularization and peritumoural brain oedema. Angiogenesis is a complicated process in oncogenesis regulated by the balance between angiogenic and antiangiogenic factors.

METHODS

The expression of two angiogenic growth factors, vascular endothelial growth factor and basic fibroblast growth factor were investigated using immunohistochemistry for astrocytoma from 82 patients and 11 normal human tissues.

RESULTS

The expression of vascular endothelial growth factor and basic fibroblast growth factor positively correlate with the pathological grade of astrocytoma, microvessel density numbers and brain oedema, which may be responsible for the increased tumour neovascularization and peritumoural brain oedema.

CONCLUSION

The results support the idea that inhibiting vascular endothelial growth factor and basic fibroblast growth factor are useful for the treatment of human astrocytoma and to improve patient's clinical outcomes and prognosis.

The influence of occlusal stimuli on basic fibroblast growth factor expression in the periodontal healing of replanted teeth

Occlusal stimuli and the periodontal healing of replanted teeth have been reported to be related. However, the mechanism for preventing dentoalveolar ankylosis remains unclear. Basic fibroblast growth factor (bFGF/FGF-2) is considered as a key factor in wound healing. The purpose of this study was to evaluate the relationship between occlusal stimuli, bFGF, and the periodontal healing after tooth replantation. Five-week-old male rats were divided into non-occluded, occluded, and recovery groups. The right maxillary first molars were replanted in all groups, and the left maxillary first molars in the 2-week occluded group without replantation were served as nontreated. An anterior bite plate was attached to the maxillary and mandibular incisors to produce occlusal hypofunction in the non-occluded group and was then removed after 1 week in the recovery group. Histological observations were performed after 1 and 2 weeks of the experimental period. After 2 weeks, the non-occluded group had detectable ankylosis and obvious periodontal tissue stricture. Meanwhile, the occluded and recovery groups showed enlarged and thickened periodontia without ankylosis. The number of bFGF-positive cells in the occluded and recovery groups significantly increased as compared to in the non-occluded group. These results suggest that occlusal stimuli enhance the production of bFGF in the periodontal healing of replanted teeth and prevent dentoalveolar ankylosis.

[Impacts of tetramethylpyrazine on BDNF, bFGF expression and neuron-protection in severe brain injury tissue of rat]

OBJECTIVE

To observe the expression levels of BDNF and bFGF, the variation of superoxide dismutase (SOD) and malondialdehyde (MDA) in serum and injury neuron of rat, and to evaluate the effect of Tetramethylpyrazine (TMP) on neuro-protection finally.

METHODS

120 SD rats were randomly assigned into three groups: pseudo-operation group, severe brain injury model group and TMP treatment group. Every group contained 40 rats. The severe brain injury (SBI) of rat was established according to Feeney' s method. The treatment group was administrated with TMP transperitoneally. Rats were killed at 7 h, 24 h, 72 h, 168 h respectively after SBI. BDNF, bFGF, Nissl body and neurofunction were detected in every group at all the time scales. MDA and SOD of serum were also detected by radical immunoassay.

RESULTS

After rat SBI treated with the administration of TMP, the expression of BDNF and bFGF increased significantly in the injured brain tissue (P<0.05), and the MDA level showed to be decreased but the SOD was increased in serum (P<0.05). The Nissl body and neuro-function were well protected.

CONCLUSION

TMP may protect the rat cerebral neurons from SBI.

Ovine endometrial expression of fibroblast growth factor (FGF) 2 and conceptus expression of FGF receptors during early pregnancy

In ruminants, conceptus development beyond the blastocyst state requires input from uterine-derived factors. Fibroblast growth factor 2 (FGF2) is expressed by the bovine endometrium throughout the estrus cycle and early pregnancy and stimulates trophectoderm expression of interferon-tau, the maternal recognition of pregnancy factor in ruminants. The objective of this study was to examine the expression of FGF2 in ovine endometrium and peri-attachment conceptuses and FGF receptors (FGFR) in conceptuses. FGF2 mRNA was present in the ovine endometrium with specific localization within the luminal and glandular epithelium. No pregnancy-dependent changes in endometrial FGF2 mRNA abundance were detected until placental attachment was well underway. FGF2 protein was detected in the uterine lumen throughout the estrous cycle and early pregnancy. Concentrations of luminal FGF2 protein did not differ based on pregnancy status. However, uterine luminal FGF2 protein levels increased at days 12-13 after estrus in both cyclic and pregnant ewes. Ovine conceptuses collected at days 14-19 after mating contained transcripts for FGF2 and FGFR types 1, 2 and 3. In summary, FGF2 is expressed by the ovine endometrium and conceptus during early pregnancy, and peri-attachment conceptuses possess several FGFR types. Concentrations of FGF2 protein in the uterine lumen increase coincident with the initiation of pregnancy recognition in ewes. These observations support the concept that FGF2 and potentially other FGFs may affect conceptus development and/or gene expression during early pregnancy in ruminants.

Expression of vascular endothelial growth factor and basic fibroblast growth factor in sporadic vestibular schwannomas correlates to growth characteristics

HYPOTHESIS

Expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) may have an impact on the growth characteristics of sporadic vestibular schwannomas (VSs).

BACKGROUND

Vestibular schwannoma is a benign, slow-growing neoplasm that accounts for 6% of all intracranial tumors. The biological backgrounds for neoplastic growth and especially for the various growth patterns of VS remain largely unknown. Because several angiogenic and cytotrophic factors have been described to be involved in the growth of malignant tumors, we initiated this study to examine 2 major representatives of such growth factors in VS and their possible correlation to the growth characteristics of sporadic VSs.

METHODS

Surgical specimens from 17 patients with sporadic VS were examined, and the expression of 2 major angiogenic and neurotrophic factors, bFGF and VEGF, was quantitatively analyzed at the mRNA and protein levels. The microvessel density (MVD) was defined by CD31 staining.

RESULTS

All tumors showed expression of bFGF and VEGF at both the mRNA and protein levels. The mRNA expression and the protein expression of both growth factors correlated positive to tumor volume, to tumor growth index, and to MVD.

CONCLUSION

The bFGF and VEGF mRNA expression and the bFGF and VEGF protein expression in sporadic VS correlates to the tumour volume, to the tumor growth index, and to the MVD. This might indicate an angiogenic and neurotrophic influence of these factors and a possible involvement in the growth of sporadic VS.

Lymphatic microvessel density and the expression of lymphangiogenic factors in oral squamous cell carcinoma

OBJECTIVE

In this study, the expression of several lymphangiogenic growth factors was investigated to determine the mechanism underlying lymphangiogenesis in oral squamous cell carcinoma (OSCCa).

MATERIALS AND METHODS

An immunohistochemical study was performed to determine the lymphatic microvessel density (LMVD) and the expression of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), insulin-like growth factors (IGF-I/II), and hepatocyte growth factor (HGF) in 25 OSCCa and 20 normal oral mucosal tissue samples.

RESULTS

Significantly higher levels of expression of VEGF, PDGF, bFGF, HGF, IGF-I, and IGF-II existed in OSCCa tissue compared to normal oral mucosal tissue (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.01, respectively; Mann-Whitney test). In OSCCa samples, significant positive correlations, based on the Spearman correlation test, existed between the LMVD and VEGF (r = 0.573; p < 0.01), PDGF (r = 0.559; p < 0.01), bFGF (r = 0.516; p < 0.01), HGF (r = 0.448; p < 0.05), and IGF-I (r = 0.6; p < 0.01), but no correlation existed between LMVD and IGF-II (r = 0.380; p > 0.05).

CONCLUSION

These findings indicate that several growth factors may promote lymphangiogenesis in OSCCa. Future treatment for OSCCa utilizing antilymphangiogenic agents should target these different growth factor signaling pathways that are involved in lymphangiogenesis in OSCCa.

Up-regulation of platelet-derived growth factor by peripheral-blood leukocytes during experimental allergic encephalomyelitis

In multiple sclerosis (MS) and its animal model, experimental allergic encephalomyelitis (EAE), clinical disease is associated with infiltration of the central nervous system (CNS) by immune cells. Subsequent remission with remyelination has been linked to an increased occurrence of oligodendrocyte progenitor (O2A) cells. Platelet-derived growth factor (PDGF) and fibroblast growth factor-2 (FGF-2) are key growth factors for O2A cells, yet little is known about their relevance in EAE and MS. We analyzed the expression of PDGF, FGF-2, and their receptors by peripheral-blood leukocytes (PBLs) and lymphocyte subsets during MBP-induced EAE. Strong up-regulation of PDGF, but not FGF-2, was observed in PBLs, with the highest expression after the disease maximum. T, NK, and NKT cells expressed PDGF, which is a novel observation because thus far only monocytes/macrophages have been reported to express PDGF. These results extend the idea that growth factors may contribute to improved CNS tissue repair, including PDGF, which is secreted by lesion-homing immune cells. The production of PDGF by lymphocytes may have potential therapeutic value when activating or modulating T-cell responses in demyelinating diseases.

HOXB7, a homeodomain protein, is overexpressed in breast cancer and confers epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is increasingly recognized as a mechanism whereby cells in primary noninvasive tumors acquire properties essential for migration and invasion. Microarray analyses of microdissected epithelial cells from bone metastasis revealed a HOXB7 overexpression that was 3-fold higher than in primary breast carcinomas and 18-fold higher compared with normal breast. This led us to investigate the role of HOXB7 in neoplastic transformation of breast cells. Expression of HOXB7 in both MCF10A and Madin-Darby canine kidney (MDCK) epithelial cells resulted in the acquisition of both phenotypic and molecular attributes typical of EMT. Loss of epithelial proteins, claudin 1 and claudin 7, mislocalization of claudin 4 and E-cadherin, and the expression of mesenchymal proteins, vimentin and alpha-smooth muscle actin, were observed. MDCK cells expressing HOXB7 exhibited properties of migration and invasion. Unlike MDCK vector-transfected cells, MDCK-HOXB7 cells formed highly vascularized tumors in mice. MDCK-HOXB7 cells overexpressed basic fibroblast growth factor (bFGF), had more active forms of both Ras and RhoA proteins, and displayed higher levels of phosphorylation of p44 and p42 mitogen-activated protein kinase (MAPK; extracellular signal-regulated kinases 1 and 2). Effects initiated by HOXB7 were reversed by specific inhibitors of FGF receptor and the Ras-MAPK pathways. These data provide support for a function for HOXB7 in promoting tumor invasion through activation of Ras/Rho pathway by up-regulating bFGF, a known transcriptional target of HOXB7. Reversal of these effects by HOXB7-specific siRNA further suggested that these effects were mediated by HOXB7. Thus, HOXB7 overexpression caused EMT in epithelial cells, accompanied by acquisition of aggressive properties of tumorigenicity, migration, and invasion.

Fibroblast growth factor-2 regulates myocardial infarct repair: effects on cell proliferation, scar contraction, and ventricular function

Fibroblast growth factor-2 (FGF2, bFGF) has been proposed to regulate wound healing and angiogenesis, but skin wound healing in FGF2-knockout (FGF2-KO) animals is only slightly delayed. To determine the role of FGF2 in myocardial infarct repair, we studied the evolution of left ventricular geometry, cell proliferation, matrix content, and cardiac function in mice lacking or overexpressing (FGF2-Tg) FGF2. Despite having no effect on initial infarct size, deletion of FGF2 resulted in reduced fibroblast proliferation and interstitial collagen deposition, decreased endothelial proliferation and vascular density, and decreased cardiomyocyte hypertrophy. Furthermore, FGF2-KO mice demonstrated a complete absence of scar contraction, resulting in increased final infarct size and marked increases in chamber size and infarct expansion. These deficits ultimately impaired left ventricular dP/dt compared with wild-type infarcted mice. Conversely, overexpression of FGF2 increased fibroblast proliferation and collagen deposition, accelerated endothelial proliferation, and enhanced cardiomyocyte hypertrophy after infarction. These changes curbed infarct expansion and preserved left ventricular function. Thus, FGF2 is an important regulator of cell proliferation, angiogenesis, collagen synthesis, myocyte hypertrophy, scar contraction, and, ultimately, left ventricular contractile function during infarct repair. FGF2 may be more important in healing of infarcts compared with skin wounds because of the mechanical stress under which infarcts heal.

Impairment of gastric ulcer healing by alendronate, a nitrogen-containing bisphosphonate, in rats

Bisphosphonates such as alendronate have been developed as antiresorptive agents capable of treating diseases related to bone remodeling. In the present study, we examined the effect of alendronate on the healing of acetic acid-induced gastric ulcers in rats and investigated the mechanism involved in this action both in vivo and in vitro using the rat gastric epithelial cell line (RGM1). Acetic acid-induced gastric ulcers healed spontaneously, with up-regulation of COX-2/prostaglandin E2 production as well as expression of vascular endothelium-derived growth factor (VEGF) and basic fibroblast growth factor (bFGF) in ulcerated mucosa. The healing of ulcers was impaired by indomethacin (2 mg/kg, s.c.) or alendronate (60 mg/kg, p.o.) given once daily for 7 days, starting 3 days after acid application. Indomethacin, but not alendronate, inhibited mucosal prostaglandin E2 production. Alendronate as well as indomethacin decreased the protein expression of both VEGF and bFGF in ulcerated mucosa, resulting in a reduction of angiogenesis in the ulcer base. Supplementation of recombinant bFGF significantly reverted the delay in ulcer healing caused by alendronate. On the other hand, the size of cell-free areas in RGM1 cells in vitro decreased with time after wound induction, and this process was promoted by epidermal growth factor (EGF; 10 ng/ml). Co-incubation with alendronate (1 mM) did not affect the spontaneous healing but significantly suppressed the accelerated wound healing caused by EGF. These results suggest that alendronate impairs the healing of gastric ulcers in rats, and this effect may be related to down-regulation of VEGF and bFGF, the important growth factors for vascularization/granulation, as well as suppression of the stimulatory action of EGF on epithelial proliferation/migration.

Effects of laser irradiation on the release of basic fibroblast growth factor (bFGF), insulin like growth factor-1 (IGF-1), and receptor of IGF-1 (IGFBP3) from gingival fibroblasts

Various studies have shown biostimulation effects of laser irradiation by producing metabolic changes within the cells. Little is known about the biological effect of laser irradiation on the oral tissues. Among the many physiological effects, it is important to recognize that low-level laser therapy (LLLT) may affect release of growth factors from fibroblasts. Therefore, the aim of the present study was to determine whether the laser irradiation can enhance the release of basic fibroblast growth factor (bFGF), insulin-like growth factor-1 (IGF-1), and receptor of IGF-1 (IGFBP3) from human gingival fibroblasts (HGF). The number of all samples in the study were 30, and the samples were randomly divided into three equal groups; In the first group (single dose group), HGF were irradiated with laser energy of 685 nm, for 140 s, 2 J/cm(2) for one time, and in the second group, energy at the same dose was applied for two consecutive days (double dose group). The third group served as nonirradiated control group. Proliferation, viability, and bFGF, IGF-1, IGFBP3 analysis of control and irradiated cultures were compared with each other. Both of the irradiated groups revealed higher proliferation and viability in comparison to the control group. Comparison of the single-dose group with the control group revealed statistically significant increases in bFGF (p < 0.01) and IGF-1 (p < 0.01), but IGFBP3 increased insignificantly (p > 0.05). When the double dose group was compared with the control group, significant increases were determined in all of the parameters (p < 0.01). In the comparison of the differences between the two irradiated groups (one dose and two doses), none of the parameters displayed any statistically significant difference (p > 0.05). In both of the laser groups, LLLT increased the cell proliferation and cell viability. The results of this study showed that LLLT increased the proliferation of HGF cells and release of bFGF, IGF-1, and IGFBP3 from these cells. LLLT may play an important role in periodontal wound healing and regeneration by enhancing the production of the growth factors.

Occurence of stromal myofibroblasts in the invasive ductal breast cancer tissue is an unfavourable prognostic factor

BACKGROUND

Numerous experimental studies have described the capacity of myofibroblasts to stimulate mammary cancer cells in a paracrine manner. Until now, the prognostic significance of myofibroblasts present in breast cancer has not been examined.

PATIENTS AND METHODS

In paraffin sections, originating from 45 patients with primary invasive breast cancer, immunohistochemical reactions were performed using antibodies directed against smooth muscle actin, Ki-67, VEGF, bFGF and UPA.

RESULTS

The cases with higher content of myofibroblasts in the tumour tissue manifested higher grade, more pronounced expression of Ki-67, VEGF and bFGF and shorter overall survival and relapse-free survival.

CONCLUSION

The present study for the first time documents the unfavourable prognostic significance of myofibroblasts in tissues of invasive ductal mammary carcinomas.

A homeobox gene related to Drosophila distal-less promotes ovarian tumorigenicity by inducing expression of vascular endothelial growth factor and fibroblast growth factor-2

Homeobox genes control developmental patterning and are increasingly being found to be deregulated in tumors. The DLX4 homeobox gene maps to the 17q21.3-q22 region that is amplified in some epithelial ovarian cancers. Because amplification of this region correlates with poor prognosis, we investigated whether DLX4 overexpression contributes to aggressive behavior of this disease. DLX4 was not detected in normal ovary and cystadenomas, whereas its expression in ovarian carcinomas was strongly associated with high tumor grade and advanced disease stage. Overexpression of DLX4 in ovarian cancer cells promoted growth in low serum and colony formation. Imaging of mice bearing intraperitoneal tumors revealed that DLX4 overexpression substantially increased tumor burden. Tumors that overexpressed DLX4 were more vascularized than vector-control tumors. Conditioned medium of DLX4-overexpressing tumor cells was more effective than medium conditioned by vector-control cells in stimulating endothelial cell growth. These observations were associated with the ability of DLX4 to induce expression of vascular endothelial growth factor as well as intracellular and secreted isoforms of fibroblast growth factor-2. Moreover, increased levels of these fibroblast growth factor-2 isoforms induced vascular endothelial growth factor expression in tumor cells. This study reveals a novel role for a homeobox gene in ovarian tumorigenicity by its induction of a proangiogenic, growth-stimulatory molecular program.

Combination therapy with IFN-alpha plus bortezomib induces apoptosis and inhibits angiogenesis in human bladder cancer cells

In a recent study, we showed that the proteasome inhibitor bortezomib sensitizes human bladder cancer cells to IFN-induced cell death. Here, we characterized the molecular mechanisms underlying the antitumoral effects of the combination in more detail. Bortezomib synergized with IFN-alpha to promote apoptosis via a tumor necrosis factor-related apoptosis-inducing ligand-associated mechanism but did not inhibit production of proangiogenic factors (vascular endothelial growth factor, basic fibroblast growth factor, and interleukin-8) in human UM-UC-5 cells. In contrast, exposure to the combination did not increase the levels of apoptosis in human UM-UC-3 cells but did inhibit the production of basic fibroblast growth factor and vascular endothelial growth factor. Studies with tumor xenografts confirmed that combination therapy with bortezomib plus IFN-alpha was effective in both models but that the effects were associated with differential effects on tumor necrosis factor-related apoptosis-inducing ligand-associated apoptosis (predominant in UM-UC-5) versus inhibition of angiogenesis (predominant in UM-UC-3). Together, our results show that combination therapy with IFN-alpha plus bortezomib is effective but can work via different mechanisms (apoptosis versus angiogenesis inhibition) in preclinical models of human bladder cancer.

Magnolia ovovata extract and its active component magnolol prevent skin photoaging via inhibition of nuclear factor κB

Transcriptional activity of nuclear factor kappaB (NF-kappaB) is induced by environmental signals including inflammation, UV irradiation and oxidative stress. It was shown that the NF-kappaB activity greatly contributes to the skin photoaging process. Thus, it is plausible that NF-kappaB inhibitors could directly prevent skin photoaging. In this study, we found that Magnolia ovovata extract inhibited NF-kappaB-mediated gene expression and demonstrated that external swabbing with Magnolia extract preventing skin photoaging processes through keratinocyte hyperproliferation and degradation of collagen fibers in mice skin. We have identified magnolol as the solely responsible active compound in Magnolia extract. Magnolol effectively inhibited the NF-kappaB-dependent transcription, but no effect was observed with other inducible transcription factors such as activator protein-1 (AP-1) and cyclic-AMP responsive element-binding protein (CREB). In addition, magnolol was effective in inhibiting the production of basic fibroblast growth factor (bFGF) and matrix metalloprotease-1 (MMP-1) from the cells overexpressing p65, a major subunit of NF-kappaB. Although magnolol did not affect the phosphorylation and degradation of IkappaBalpha, it inhibited the nuclear translocation of the activated NF-kappaB. These findings suggest that Magnolia extract and its active component magnolol can be used to prevent the skin photoaging via inhibiting NF-kappaB by external topical application.

Interleukin-12 deficiency is permissive for angiogenesis in UV radiation-induced skin tumors

We have shown previously that endogenous deficiency of interleukin (IL)-12 promotes photocarcinogenesis in mice. To characterize the role of IL-12 deficiency in tumor angiogenesis, we developed IL-12p35 knockout (IL-12 KO) mice on a C3H/HeN background. IL-12 KO mice and their wild-type (WT) counterparts were subjected to a photocarcinogenesis protocol. When tumor yield was stabilized, samples of tumor and tumor-uninvolved UVB-exposed skin were collected and subjected to immunohistochemistry, gelatinolytic zymography, real-time PCR, and Western blot analysis of angiogenic factors. We found that the protein, mRNA expression and/or activity of the matrix metalloproteinases (MMP)-2, MMP-3, MMP-7, and MMP-9, and basic fibroblast growth factor, which play crucial roles in tumor growth, were significantly higher in UVB-exposed skin and tumors of IL-12 KO mice compared with WT mice. With respect to the tumor vasculature, the expression of CD31-positive cells and the expression of vascular endothelial growth factor were higher in the tumors of IL-12 KO mice than WTs. The proliferative capacity of tumor cells of the IL-12 KO mice was significantly higher than their WT counterparts when determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and by analyzing the expression of cyclin D1. The level of the proinflammatory cytokine IL-6 and the expression of IL-23 in tumors of IL-12 KO mice were markedly higher than in the tumors of WT mice. IL-23 has been shown to promote tumor growth. Together, these data indicate for the first time that IL-12 deficiency promotes proangiogenic stimuli in UVB-induced skin tumors and suggest that endogenous enhancement of IL-12 levels may be effective in the prevention and treatment of UV-induced skin cancers.

[Effect of panax quinquefolius saponin on angiogenesis and expressions of VEGF and bFGF in myocardium of rats with acute myocardial infarction]

OBJECTIVE

To study the effect of Panax quinquefolius Saponin (PQS), an extraction from stem and leaf of American ginseng, on vascular regeneration in infarcted area, and expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in myocardium of rats with acute myocardial infarction (AMI).

METHODS

Fifty male Wistar rats were established into AMI model successfully and randomly divided into 5 groups equally, i.e. the model group, the high, middle and low dose PQS groups and the metoprolol group. They were treated with saline, different doses of PQS (54 mg/kg x d, 27 mg/kg x d, 13.5 mg/kg x d)and metoprolol (4.5 mg/kg x d) respectively, by gavage once a day for 14 days. Besides, a sham operated group and a normal control group were set up for control with 10 rats in each group. All rats were killed on the 15th day. Six samples of heart were chosen from each group for examining expressions of VEGF, bFGF and the VIII coagulation factor under light microscopy by immunohistochemical staining, and the quantitative analysis on positive responsive intensity of VEGF and bFGF was conducted on the other 4 heart samples using the image analysing system, then mean micro-vessel density (MMVD) was calculated.

RESULTS

The expressions of VEGF and MMVD were higher in the high and the middle dose PQS groups than those in the model group (P < 0.05) and the expression of bFGF was higher in the three PQS groups than that in the model group (P < 0.05).

CONCLUSION

PQS can protect myocardium from ischemic injury in rats after AMI by way of promoting angiogenesis in the infarcted or ischemic area of myocardium and up-regulating expressions of VEGF and bFGF in myocardial cells.

Mammalian tumor xenografts induce neovascularization in zebrafish embryos

The zebrafish (Danio rerio)/tumor xenograft model represents a powerful new model system in cancer. Here, we describe a novel exploitation of the zebrafish model to investigate tumor angiogenesis, a pivotal step in cancer progression and target for antitumor therapies. Human and murine tumor cell lines that express the angiogenic fibroblast growth factor (FGF) 2 and/or vascular endothelial growth factor (VEGF) induce the rapid formation of a new microvasculature when grafted close to the developing subintestinal vessels of zebrafish embryos at 48 h postfertilization. Instead, no angiogenic response was exerted by related cell clones defective in the production of these angiogenic growth factors. The newly formed blood vessels sprout from the subintestinal plexus of the zebrafish embryo, penetrate the tumor graft, and express the transcripts for the zebrafish orthologues of the early endothelial markers Fli-1, VEGF receptor-2 (VEGFR2/KDR), and VE-cadherin. Accordingly, green fluorescent protein-positive neovessels infiltrate the graft when tumor cells are injected in transgenic VEGFR2:G-RCFP zebrafish embryos that express green fluorescent protein under the control of the VEGFR2/KDR promoter. Systemic exposure of zebrafish embryos immediately after tumor cell injection to prototypic antiangiogenic inhibitors, including the FGF receptor tyrosine kinase inhibitor SU5402 and the VEGFR2/KDR tyrosine kinase inhibitor SU5416, suppresses tumor-induced angiogenesis without affecting normal blood vessel development. Accordingly, VE-cadherin gene inactivation by antisense morpholino oligonucleotide injection inhibits tumor neovascularization without affecting the development of intersegmental and subintestinal vessels. These data show that the zebrafish/tumor xenograft model represents a novel tool for investigating the neovascularization process exploitable for drug discovery and gene targeting in tumor angiogenesis.

[Effect of hypoxia inducible factor-1alpha on cells of hair follicle]

OBJECTIVE

To investigate the feasibility of stable transfection of human hypoxia inducible factor-1alpha (HIF-1alpha) gene into fibroblasts cells and the effects of supernatant from the transfected cell culture on hair follicle cells.

METHODS

PcDNA-HIF1alpha was stably transfected into fibroblasts cells with lipofectamine 2000. Expression of HIF-1alpha was observed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The supernatant was obtained to detect the expression of vascular endothelial growth factor (VEGF) by ELISA. The mRNA expression of basic fibroblast growth factor (bFGF) was detected by RT-PCR. MTT was used to detect the activity of fibroblasts cells and dermal sheath cells added with supernatant.

RESULTS

PcDNA-HIF1alpha was successfully transfected into fibroblasts cells. HIF-1alpha could be detected by RT-PCR and Western blot. The expression of VEGF in the supernatant of cells transfected with PcDNA-HIF1alpha was detected. The mRNA expression of bFGF was significantly higher than in the control group (P < 0.01). MTT showed the activity of cells added with supernatant was enhanced (P < 0.05).

CONCLUSION

PcDNA-HIF1alpha can stably transfected into fibroblasts cells, and the expressed HIF-1alpha induces the expression of VEGF and bFGF, and the expressed VEGF enhances the activity of cells.

Frequent immunoexpression of TGF-beta1, FGF-2 and BMP-2 in fibroblast-like cells in osteofibrous dysplasia

Osteofibrous dysplasia (OFD) and fibrous dysplasia (FD) are both benign bone lesions which comprise the proliferation of fibroblast-like cells with bone formation, and these fibroblast-like cells have the phenotype of osteoprogenitor cells. The roentgenograph of OFD shows a heterogeneous osteolytic lesion with surrounding osteosclerosis, whereas FD is typically characterized by a rather homogeneous osteolytic lesion, or 'ground-glass appearance', with a smaller amount of surrounding osteosclerosis. Growth factors of transforming growth factor-beta1 (TGF-beta1), fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2) modulate bone differentiation. Expression of these growth factors was examined in the fibroblast-like cells of 16 cases of OFD and 16 cases of FD, immunohistochemically. TGF-beta1 in fibroblast-like cells was frequently expressed both in the OFD (16/16) and the FD (15/16) cases. The frequency of FGF-2 (16/16) expression and BMP-2 (13/16) expression in the fibroblast-like cells of OFD was higher than that of those [FGF-2 (8/16) and BMP-2 (6/16)] in the fibroblast-like cells of FD, with a statistical significance. These results seem to suggest that fibroblast-like cells of OFD have greater bone-forming ability than those of FD, and may explain the roentgenographic difference between OFD and FD and a difference in the nature of fibroblast-like cells between these two types of lesions.

The effects of indomethacin on angiogenic factors mRNA expression in renal cortex of healthy rats

Indomethacin is a nonsteroidal anti-inflammatory drug used frequently to control chronic or temporary pain. In the kidney, indomethacin decreases medullary and cortical perfusion, resulting in hypoxia. Kidney hypoxia has many effects, including changes in gene expression, and is a strong stimulus for angiogenesis. Other angiogenic factors include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF-2), transforming growth factor beta 1 (TGFbeta1), and platelet-derived growth factor (PDGF). Our goal was to examine the influence of indomethacin on mRNA expression of these factors and their selected receptors in the renal cortex of healthy rats. Groups of 8 healthy, male, six-week-old Wistar rats received either indomethacin (5 mg/kg/day) or placebo orally for three months. RNA from renal cortex biopsies was analyzed by real-time polymerase chain reaction to quantify the mRNA levels of each cytokine. We observed significantly higher mRNA levels for VEGF (1.73-fold), FGF-2 (5.6-fold) and TGFbeta receptor III (2.93-fold), PDGF receptor alpha (2.93-fold) and receptor beta (2.91-fold) in rats receiving indomethacin compared to rats given placebo (p < 0.05). Amounts of mRNA for TGFbeta1, PDGF, FGF receptors 1 and 2 and TGFbeta receptor I did not differ between analysed groups. Our data indicates that indomethacin may regulate the expression of potent angiogenic factors VEGF and FGF-2.

Occlusal stimuli regulate interleukin-1 beta and FGF-2 expression in rat periodontal ligament

While many studies reported the structural changes in the periodontal ligament (PDL) under hypofunctional conditions, the associations of cytokine growth factors are still unclear. They are known to take part in inflammation, and may affect the biological properties of hypofunctional tooth. To investigate the hypofunctional PDL and the recovery from this condition, we focused on interleukin-1 beta (IL-1beta) and basic fibroblast growth factor (FGF-2). Male Wistar rats were divided into occluded, non-occluded, and recovery groups. An anterior bite plate was used to eliminate the occlusal contact of molars in the non-occluded group, and was then removed for the recovery group. After occlusal stimuli were eliminated for 7 and 14 days, and after 3 and 7 days of recovery from 7 days in the hypofunctional condition, the PDLs of the lower first molars were investigated immunohistochemically. The lack of occlusal stimuli caused atrophic changes in the PDL with the upregulation of IL-1beta and decreased expression of FGF-2, while decreased IL-1beta and enhanced FGF-2 expression were observed in the recovery process. These results suggest that occlusal stimuli regulate IL-1beta and FGF-2 expression, and the nature of this regulation may differ from that in the healing process of an inflammatory reaction.

Immunohistochemical expression of heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) as an angiogenic factor in head and neck tumorigenesis

Heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) is a secreted protein that releases immobilized fibroblast growth factor-2 (FGF-2) from the extracellular matrix and plays a critical role in FGF bioactivation. In the present study co-localization of FGF-2 and HBp17/FGFBP-1 was observed in oral tissues including normal mucosa, hyperplasia, dysplasia of different degrees and oral squamous cell carcinoma (OSCC). The expression score for HBp17/FGFBP-1, FGF-2 as well as vascular endothelial growth factor A (VEGF-A) became higher with the severity of epithelial dysplasia and was highest in severe dysplasia. The expression of HBp17/FGFBP-1, FGF-2 and VEGF-A showed significant association with microvessel density, but no correlation with TNM stages or OSCC recurrence interval. Our results demonstrated that HBp17/FGFBP-1, like VEGF-A and FGF-2, might also promote the induction of tumor angiogenesis. The strongest expression of angiogenic factors in severe dysplasia suggests a potential point for targeting novel anti-angiogenic therapeutic strategies.

Fibroblast growth factor (FGF)-2 and FGF receptor 3 are required for the development of the substantia nigra, and FGF-2 plays a crucial role for the rescue of dopaminergic neurons after 6-hydroxydopamine lesion

Basic fibroblast growth factor (FGF-2) is involved in the development and maintenance of the nervous system. Exogenous administration of FGF-2 increased dopaminergic (DA) graft survival in different animal models of Parkinson's disease. To study the physiological function of the endogenous FGF-2 system, we analyzed the nigrostriatal system of mice lacking FGF-2, mice overexpressing FGF-2, and FGF-receptor-3 (FGFR3)-deficient mice both after development and after 6-hydroxydopamine lesion. FGFR3-deficient mice (+/-) displayed a reduced number of DA neurons compared with the respective wild type. Whereas absence of FGF-2 led to significantly increased numbers of DA neurons, enhanced amount of the growth factor in mice overexpressing FGF-2 resulted in less tyrosine hydroxylase expression and a reduced DA cell density. The volumes of the substantia nigra were enlarged in both FGF-2(-/-) and in FGF-2 transgenic mice, suggesting an important role of FGF-2 for the establishment of the proper number of DA neurons and a normal sized substantia nigra during development. In a second set of experiments, the putative relevance of endogenous FGF-2 after neurotoxin application was investigated regarding the number of rescued DA neurons after partial 6-OHDA lesion. Interestingly, the results after lesion were directly opposed to the results after development: significantly less DA neurons survived in FGF-2(-/-) mice compared with wild-type mice. Together, the results indicate that FGFR3 is crucially involved in regulating the number of DA neurons. The lack of FGF-2 seems to be (over)compensated during development, but, after lesion, compensation mechanisms fail. The transgenic mice showed that endogenous FGF-2 protects DA neurons from 6-OHDA neurotoxicity.