Biomedical subjects

Frank Riedel

Publications and source records attributed to Frank Riedel.

At least 19 recordsLinked to original sources

PubMed2007

Tgf-beta antisense therapy increases angiogenic potential in human keratinocytes in vitro.

BACKGROUND: Transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer exciting prospects for the modulation of wound healing, specifically those targeting TGF-beta. The purpose of this study was to analyze the effect of TGF-beta targeting on the expression of angiogenic vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, and in vitro angiogenic activity. METHODS: Expression of angiogenic VEGF in tissue samples from chronic dermal wounds was investigated by immunohistochemistry. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of VEGF was analyzed by ELISA and RT-PCR in cultured human keratinocytes. Human endothelial cells (EC) were grown in conditioned medium produced from the treated keratinocytes. EC migration was measured using a modified Boyden chamber, EC tube formation was analyzed under the light microscope. RESULTS: Immunohistochemical investigation demonstrated a decreased expression of VEGF protein in tissue samples from chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment upregulated VEGF secretion in vitro. Addition of conditioned medium from TGF-beta antisense-treated keratinocytes resulted in an increase of endothelial cell migration and tube formation. CONCLUSIONS: Our results demonstrate that TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for stimulation of angiogenesis in chronic wounds.

Cell Movement↗

PubMed2006

Ossifying fibromyxoid tumor of the nasal septum.

The fibromyxoid tumor is quite a rare soft tissue tumor and typically presents as an ossifying fibromyxoid tumor (OFMT) in the subcutis of the extremities of adults. Most authors favour schwannian or chondroid origin of this lesion with somehow uncertain biologic dignity. Local recurrence is seen in 27% of patients after primary excision. We present a case of a fibromyxoid tumor of the nasal septum in a 49-year-old female who complained of nasal airway obstruction and enlargement of the right contour of the nose. Endonasal, endoscopic tumor excision was performed. The tumor contained spindle-shaped and polygonal cells, mucoid pseudocysts and a fibromyxoid stroma with local calcifications. The clinical behaviour of OFMT in general is benign but some reports have documented atypical tumors with histologic signs of malignancy. Complete local resection is the treatment of choice. Because of the high rate of local recurrence, clinical follow-up examinations are necessary.

Airway Obstruction↗

PubMed2006

Hereditary hemorrhagic telangiectasia: an update on clinical manifestations and diagnostic measures.

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is an autosomal dominant disorder of the fibrovascular tissue. It is characterized by the classic triad of (muco-)cutaneous telangiectases, arteriovenous malformations with recurrent epistaxis and hemorrhages, and inheritance. A wide variety of clinical manifestations in HHT have been described. In more than 90% of the patients, nosebleeds are the first predominant symptom, therefore ENT physicians often play a key role as far as diagnosis and management of the disease are concerned. In spite of recent diagnostic and therapeutic progress, a cure for this often burdening and handicapping disease is still not available. Apart from affecting the nose, arteriovenous malformations (AVMs) may also affect the skin, lungs, brain, liver and gastrointestinal tract. The two known genes that are implicated in HHT are endoglin (ENG) located on chromosome 9q33-q34 and activin-receptor-like kinase (ALK1) located on chromosome 12q13. Mutations of ENG are observed in HHT type 1 with an incidence up to 40% for pulmonary AVMs, whereas mutations of ALK1 are observed in HHT type 2 with an incidence of only 14% for pulmonary AVMs, which clinically distinguishes these two types of mutation. The emphasis of this paper is mainly on the clinical manifestation, molecular genetics and diagnosis of HHT, taking account of current literature on HHT in order to better understand the complexity of the disease. Recent therapeutic options in the treatment of HHT have been omitted from this paper as they are subject of a following paper. HHT is more common than previously thought and shows a broad range of different clinical organ manifestations that can be sources of substantial morbidity and mortality, making HHT a continuing challenge for many sub-specialties where interdisciplinary diagnostic screening is mandatory in the management of the disease.

Activin Receptors, Type I↗

PubMed2006

In vitro analysis of differential expression of collagens, integrins, and growth factors in cultured human chondrocytes.

OBJECTIVES: Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation and proliferation of the cells are critical factors that influence the generation of transplants. The aim of our study was to find and characterize markers for cell proliferation and dedifferentiation in cultured chondrocytes. STUDY DESIGN AND SETTING: Human chondrocytes were isolated from septal cartilage and held in primary cell culture. Cells were harvested after 1, 6, and 21 days. The differentiation of the cells was investigated with bright-field microscopy, the expression patterns of various proteins using immunohistochemistry, and the expression of distinct genes with the microarray technique. RESULTS: The chondrocytes showed a strong proliferation. After 6 and 21 days, collagen 9 and 10 were downregulated; collagen 11 was activated. Collagen 1 and 2 were downregulated after 6 days but were reactivated after 21 days. Tumor growth factor beta (TGF-beta)1 was strongly expressed on days 1, 6, and 21, TGF-beta2 was never expressed, and TGF-beta3 and -beta4 were upregulated from day 1 to day 21. The TGF-beta receptor III was expressed on days 1, 6, and 21. Integrin beta1, beta5, and alpha5 were upregulated from day 1 to day 21; integrin beta3 was downregulated. CONCLUSION AND SIGNIFICANCE: Collagens 3, 4, 8, 9, and 11 might be new markers for the dedifferentiation of chondrocytes. Collagen 2 might be a marker for the synthetic activity of the cells rather than the dedifferentiation. TGF-beta3 and -beta4 might influence the dedifferentiation, which is fortified by the expression of TGF-beta receptor III. Integrin beta1, beta5, and alpha5 might be involved in signal transmission for the dedifferentiation.

Biomarkers↗

PubMed2006

The impact of emotions on the perception of dyspnea in pediatric asthma.

Inadequate symptom perception is increasingly recognized as a contributing factor in asthma morbidity. Recent research has shown that psychological factors can influence the perception of asthmatic symptoms such as dyspnea, but little is known, about the impact of emotions on the perception of dyspnea in pediatric asthma. Therefore, we examined the impact of viewing affective film clips of positive, neutral, and negative valence on perceived dyspnea during resistive load breathing in children with stable mild asthma. Perceived dyspnea decreased during the positive film compared to baseline and neutral film whereas the level of respiratory loading and respiratory resistance (R5) remained unchanged across conditions. The results underline the potential impact of psychological factors such as emotions on the perception of dyspnea in children with asthma.

Adult↗

PubMed2006

Perspectives of gene therapy in stem cell tissue engineering.

Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain or improve tissue function. It is hoped that forming tissue de novo will overcome many problems in plastic surgery associated with such areas as wound healing and the immunogenicity of transplanted tissue that lead to dysfunctional repair. Gene therapy is the science of the transfer of genetic material into individuals for therapeutic purposes by altering cellular function or structure at the molecular level. Recently, tissue engineering has been used in conjunction with gene therapy as a hybrid approach. This combination of stem-cell-based tissue engineering with gene therapy has the potential to provide regenerative tissue cells within an environment of optimal regulatory protein expression and would have many benefits in various areas such as the transplantation of skin, cartilage or bone. The aim of this review is to outline tissue engineering and possible applications of gene therapy in the field of biomedical engineering as well as basic principles of gene therapy, vectors and gene delivery.

Animals↗

PubMed2006

[Examination of granuloma of revised cemented or cementless total hip arthroplasties using inductively coupled plasma atomic emission spectrometry (ICP-OES)].

INTRODUCTION: Aseptic loosening is the most common problem in total hip arthroplasty (THA). One main aspect is inflammatory reaction against wear particles of the prosthesis materials. Analysing failure mechanisms in THA analysis of the particles and their element distribution of revised granulomatous tissue is essential to improve materials used in THA. MATERIALS AND METHODS: 23 granulomas of revised THA due to aseptic loosening, 13 of which with metal on metal bearing (M/M), were analysed using inductively coupled plasma atomic emission spectrometry (ICP-OES). RESULTS: Elements Cr, Mn, Ni, Al, Cu, Zn, Cd, Ti, V, Zr, Nb and Fe could be detected. The maximum value of Cr was 23.88 ppb (parts per billion), Al 191.02 ppb, Ni 64.95 ppb and Zr 9.96 ppb. The highest value of Al could be found in cementless implants. The maximum value of the elements Cr and Ni could be detected in M/M. In cemented implants the highest value of Zr was found. DISCUSSION: The origin of Zr was the used bone cement in cemented THA. The elements Cr and Ni were significantly higher in M/M bearings. The highest value of Al was detected in granulomas of revised corund rough blasted cementless implants. The histopathologic findings of the revised M/M bearings have been published recently. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-OES) could not show any differences of the alloying constituents in cases with or without allergic reactions. ICP-OES analysis seems to be not useful examination of histologic sections using SEM with cryotransfer unit.

Arthroplasty, Replacement, Hip↗

PubMed2006

Current status of genetic modulation of growth factors in wound repair.

Growth factors are members of a large functional group of polypeptide regulatory molecules secreted by different cells. They are important players in orchestrating all stages of wound healing exerting their influence through autocrine and paracrine fashions within sites of injury and repair. They are mitogen, chemotactic, they regulate cell-cell interactions and influence synthesis and composition of extracellular matrix components. The use of growth factors to stimulate wound healing is a promising therapeutic approach to repair chronic tissue defects. The delivery of genetic material offers an attractive treatment modality to produce an appropriate amount of growth factor proteins within the wound site. Gene therapy might become a significant treatment modality for those wound healing pathologies refractory to other wound management approaches. This review discusses several methods of growth factor gene transfer into wound tissue.

Animals↗

PubMed2006

In vitro analysis of integrin expression during chondrogenic differentiation of mesenchymal stem cells and chondrocytes upon dedifferentiation in cell culture.

Tissue engineering represents a promising method for generating chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Stem cells, however, displaying unlimited self-renewal and the capacity to differentiate towards chondrocytes, might be usable after further characterization. As the interactions between the extracellular matrix and the cellular compartment can alter the cellular behaviour, we investigated the expression of integrins using microarray analysis during chondrogenic differentiation of human mesenchymal stem cells (MSC) in comparison with de-differentiating human chondrocytes (HC) harvested during septoplasty. During chondrogenic differentiation of MSC, the fibronectin-receptor (Integrin beta1alpha5), fibronectin and the GPIIb/IIIa-receptor were downregulated. The components of the vitronectin-receptor (Integrin alphavbeta3) and CD47 were constantly expressed and ILK was downregulated. Vitronectin and osteopontin were not expressed by the cells. In HC, Integrin beta1alpha5 in conjunction with the ligand fibronectin were upregulated during dedifferentiation, Integrin alphavbeta3 as well as the GBIIb/IIIa-receptor were activated on day 21 but neither vitronectin nor osteopontin were expressed by the cells. The integrins, beta2, beta4, beta6, beta8 and alpha2, alpha4, alpha6, alpha7, alpha11, were not expressed at any time. ILK, CD47, and ICAP were activated with ongoing dedifferentiation. In conclusion, a candidate for signal-transmission is the fibronectin receptor (integrin alpha5beta1) in conjunction with its ligand fibronectin. Other receptors, e.g. for vitronectin and osteopontin (alphavbeta3), or their ligands do not seem to be involved in signal transmission for dedifferentiation. The GPIIb/IIIa-receptor might assist the process of dedifferentiation. Intracellularly, ILK, ICAP1 and CD47 might be involved in the transduction of integrin-dependent signals.

Cell Differentiation↗

PubMed2005

Stability of the replicator equation for a single species with a multi-dimensional continuous trait space.

The replicator equation model for the evolution of individual behaviors in a single species with a multi-dimensional continuous trait space is developed as a dynamics on the set of probability measures. Stability of monomorphisms in this model using the weak topology is compared to more traditional methods of adaptive dynamics. For quadratic fitness functions and initial normal trait distributions, it is shown that the multi-dimensional continuously stable strategy (CSS) of adaptive dynamics is often relevant for predicting stability of the measure-theoretic model but may be too strong in general. For general fitness functions and trait distributions, the CSS is related to dominance solvability which can be used to characterize local stability for a large class of trait distributions that have no gaps in their supports whereas the stronger neighborhood invader strategy (NIS) concept is needed if the supports are arbitrary.

Adaptation, Physiological↗

PubMed2005

Management of radiation-induced tracheocutaneous tissue defects by transplantation of an ear cartilage graft and deltopectoral flap.

Patients suffering from head and neck cancer often require temporary tracheostomy during therapy. The tracheostomy can usually be closed when postoperative swelling decreases and swallowing ability recovers. However, some patients, especially after adjuvant radiotherapy, may develop severe chronic wounds resulting in persistent tracheocutaneous fistula. Local wound care and plastic reconstruction strategies are required in such cases. We present two patients with head and neck cancer treated with primary surgical regimen including temporary tracheostomy and adjuvant radiotherapy. Both patients developed a persistent, poorly healing wound with persistent tracheocutaneous tissue defect. After local debridement and wound care, the peristomal necrotic tissue was excised down to the level of the trachea. The defect of the anterior tracheal wall was closed with a autogenous ear cartilage graft. The graft was harvested from the cavum conchae and sutured to the tracheal defect. The soft tissue defect was covered by transposition of a well-vascularized, fasciocutaneous deltopectoral flap. In both cases, the flaps healed satisfactorily. The donor defect was closed primarily. Complications were not observed in these two cases. A flexible tracheo-bronchoscopy showed no stenosis of the trachea at the site of cartilage graft transplantation. In conclusion, treatment of persistent radiated tracheocutaneous defects by cartilage graft and deltopectoral flap turned out to be a safe and reliable procedure which can be performed as a one-stage method with low morbidity at the donor site.

Cutaneous Fistula↗

PubMed2005

Targeting TGF-beta1 increases hepatocyte growth factor (HGF/SF) levels in external auditory canal cholesteatoma (EACC) epithelial cell culture.

OBJECTIVE: The transforming growth factor (TGF)-beta 1 is known to have pro- and anti-angiogenic actions. Hepatocyte growth factor/scatter factor (HGF/SF) antagonizes TGF-beta1 by stabilizing SMAD transcriptional co-repressor TGIF. HGF/SF is a multifunctional polypeptide with morphogenic, motogenic, angiogenic, and proliferative capabilities. We assume HGF to be a pivotal factor during the pathogenesis of the external auditory canal cholesteatoma (EACC). In this study, we investigate the effect of antisense targeting TGF-beta1 on HGF/SF levels in the epithelial EACC-culture. MATERIALS: For 48 h, epithelial EACC cell culture was incubated with 3 and 6 mumol antisense targeting TGF-beta1, respectively. Levels of HGF/SF were determined and normalized to cellular protein. Untreated EACC cell culture and scrambled TGF-beta1-antisense served as control. In the second experiment, EACC cells were incubated with rh TGF-beta1 (2 and 4 ng/ml) for 48 h and HGF/SF was determined. RESULTS: After incubation with 3 mumol TGF-beta1-antisense, the average level of HGF/SF was measured at 43.68 pg/ml. Incubation with 6 micromol TGF-beta1-antisense showed 64.95 pg/ml. In untreated EACC (control), the average level of HGF/SF after 48 was 34.55 pg/ml. Incubation with scrambled TGF-beta1 oligonucleotide showed an average HGF/SF level of 34.41 (3 micromol) and 35.66 (6 micromol), respectively. The difference between the scrambled antisense and the targeting antisense TGF-beta1 was significant (p<0.05). After incubation with 2 ng/ml TGF-beta1, the HGF/SF levels were at 22.16 pg/ml. TGF-beta1, 4 ng/ml, resulted in 15.33 pg/ml of HGF/SF. The difference of the levels of HGF/SF after incubation with exogenous TGF-beta1 was significant (p<0.05). CONCLUSION: In this study, levels of HGF/SF increased in the epithelial EACC cell culture after incubation with 3 and 6 mumol antisense TGF-beta1 oligonucleotides depending on the concentration of the antisense. In reverse, TGF-beta1 acted as inhibiting cytokine on HGF/SF levels. In conclusion, TGF-beta1 may be a useful therapeutic agent for managing EACC.

Blotting, Western↗

PubMed2005

Regulation of apoptosis in external auditory canal cholesteatoma by hepatocyte growth factor/scatter factor.

OBJECTIVES: External auditory canal cholesteatomas (EACC) are characterized by focal invasion of squamous cell epithelium and accumulation of keratin debris in the apical part of the matrix. Apoptosis appears to be important in understanding the pathogenesis of EACC. Here the possible regulatory effect of the apoptosis mediated by hepatocyte growth factor (HGF)/scatter factor (SF)-c-Met-Fas in EACC is discussed. METHODS: We examined 17 EACC specimens for immunohistochemical expression of HGF/SF, c-Met, caspase 3 and Fas. The staining reaction was evaluated semiquantitatively. RESULTS: HGF/SF was detected in mesenchymal tissue below the EACC epithelium. c-Met was expressed throughout the epithelium. Fas and caspase 3 were detected at increasing levels towards the apical layers of the EACC matrix. CONCLUSIONS: High levels of HGF/SF result in binding of HGF/SF to c-Met, releasing Fas to aggregate and bind to its death-inducing signaling complex. The result is apoptosis, marked by formation of dead squamous cells and sequestered keratin debris on the apical side of the cholesteatoma.

Adult↗

PubMed2005

In vitro analysis of matrix proteins and growth factors in dedifferentiating human chondrocytes for tissue-engineered cartilage.

CONCLUSIONS: With ongoing culture and dedifferentiation of chondrocytes, significant changes in the expression patterns of various collagens and the insulin-like growth factor (IGF) receptor were detected. The latter could play an important role in the differentiation of human chondrocytes. OBJECTIVE: Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. So far, little is known about the expression of markers for cell proliferation and differentiation in cultured chondrocytes. MATERIAL AND METHODS: Human chondrocytes were isolated from septal cartilage (n=5) and held in primary cell culture. Cells were harvested after 24 h and 6 days. Proliferation was analyzed using an Alamar Blue assay. The differentiation of the cells was investigated using bright field microscopy, the expression patterns of various proteins using immunohistochemistry and the expression of distinct genes using a microarray technique. RESULTS: The chondrocytes showed strong proliferation (Day 0: 16.7+/-0.7 fluorescent units; Day 5: 52.4+/-2.2 fluorescent units) from the third day of cell culture in medium without growth factors. From this point onwards, a dedifferentiation of the chondrocytes could be observed. In cell culture, the chondrocytes expressed collagen 1 and 10 without expression of collagen 3. After 6 days of cell culture, they expressed collagen 2. The chondrocytes showed constant low expression of the fibroblast growth factor-2 receptor, but constant high expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)2 and MMP9. The cells never expressed the epidermal growth factor receptor. The proportion of IGF receptor-expressing cells diminished significantly during cell culture.

Cartilage↗

PubMed2005

Antiangiogenic therapy of head and neck squamous cell carcinoma by vascular endothelial growth factor antisense therapy.

Angiogenesis is increased in various human cancers, including head and neck squamous cell carcinoma (HNSCC), and correlates with tumor progression and metastasis. Vascular endothelial growth factor (VEGF) has been shown to be a key regulator of angiogenesis. We determined whether VEGF antisense oligonucleotide treatment can decrease the angiogenic activity of HNSCC cell lines in vitro and of HNSCC xenografts in vivo. Established human HNSCC cell lines were screened for VEGF expression at both mRNA and protein levels. By using a 21-mer antisense phosphorothioate oligonucleotide targeting the translation start site of human VEGF mRNA, we examined the modulation of VEGF expression in cell line supernatants by capture ELISA and in cell lysates by Western blotting. Human endothelial cells were grown in conditioned medium produced from the treated tumor cells. Endothelial cell proliferation was determined by cell count, and endothelial cell migration was measured using a modified Boyden chamber. Mice with HNSCC xenografts were treated with PBS, VEGF antisense or sense oligonucleotides (10 mg/kg i.p. injection, 3 times/week), respectively, and tumor volumes were measured for 5 weeks. VEGF antisense oligonucleotide treatment resulted in a significant reduction of VEGF protein expression compared to treatment with the sense control. Although the growth rate of the tumor cell lines was not affected, the addition of conditioned medium from VEGF antisense-treated tumor cells resulted in decreased endothelial cell proliferation and migration. VEGF antisense oligonucleotide treatment of HNSCC xenografts resulted in a significant tumor growth suppression. These results suggest that downmodulation of VEGF using antisense oligonucleotides may be a potential therapy for the inhibition of angiogenesis in HNSCC.

Angiogenesis Inhibitors↗

PubMed2005

Alcohol-related diseases of the mouth and throat.

Chronic consumption of alcoholic beverages is an accepted social custom worldwide. In the upper aerodigestive tract, local morphologic, metabolic and functional alterations are present due to alcohol consumption. A clinical link between the chronic consumption of alcohol and head and neck cancer has been observed for decades. While alcohol was described initially as a risk enhancer only in smokers, a number of epidemiological studies have now provided sufficient evidence that chronic alcohol consumption increases the risk of head and neck cancer independent of exposure to tobacco smoke. The systemic effects of alcohol interact with local changes in the morphology and function of the salivary glands. In addition, alcohol leads to accumulation of pathologic microbes within the mucosa, leading to chronic infection. Susceptibility to carcinogens and cell proliferation in the mucosa are increased, resulting in genetic changes with the development of dysplasia, leukoplacia and carcinoma. Chronic alcohol consumption is correlated with an increased risk of cancer and an increased mortality in a dose-effect relationship. A number of biologically plausible mechanisms exist by which alcohol may cause cancer. These mechanisms are discussed in this article.

Alcohol Drinking↗

PubMed2005

Angiogenesis in hereditary hemorrhagic telangiectasia: VEGF165 plasma concentration in correlation to the VEGF expression and microvessel density.

Angiogenesis defines the physiologic process of capillary blood vessel formation. It is a multistep process, which is controlled by a large number of pro- and anti-angiogenic factors. Vascular endothelial growth factors (VEGF) are the best characterized pro-angiogenic factors, which play a key role in angiogenesis. Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant, multi-systemic disorder of angiogenesis, clinically characterized by severe and recurrent hemorrhages. We assume in HHT patients with increased VEGF plasma levels a high VEGF expression also correlates with the degree of microvesssel density (MVD). In 41 HHT patients and 47 healthy patients, the VEGF165 plasma concentration was determined by standard ELISA technique. Cryostat sections of 13 HHT patients were immunostained for VEGF and endothelial cells by an anti-vWF monoclonal antibody using a standard streptavidinbiotin complex procedure. The degree of vessel density was quantified by light microscopy (x200) within 'hot spot' areas of the HHT-tissue. All HHT cryostat sections showed a medium to strong staining for VEFG compared to healthy control tissue. The VEGF expression correlated with the VEGF165 plasma concentration and the mean MVD in HHT patients. HHT patients with medium VEGF staining revealed significantly lower VEGF165 plasma concentrations and a lower mean MVD (204+/-12 vessels/per microscopic field) than HHT patients with strong VEGF staining (327+/-76 vessels/per microscopic field). High VEGF expression in patients with HHT in correlation to their VEGF165 plasma levels and the microvessel density may support the theory that VEGF functions as an important regulator and key protein of angiogenesis, even in HHT.

Adult↗

PubMed2005

Hepatocyte growth factor/scatter factor induces VEGF in human external auditory canal cholesteatoma cell culture.

Human external auditory canal cholesteatoma (EACC) is not often seen in otolaryngology. Some authors have noted circulatory disorders of the local blood vessels as the etiologic factor for establishing EACC. Diminished oxygen supply results in the attempt to establish angiogenesis. Hepatocyte growth factor/scatter factor (HGF/SF) and vascular endothelial growth factor (VEGF) are the most important angiogenic factors in this process. In a recent study we described strong expression of VEGF and HGF in EACC. All EACC and normal AMS cell cultures were obtained from 5 patients undergoing surgery and used at passage 3. After 16 to 72 h of incubation with 20 ng/ml HGF/SF, the expression of the VEGF protein in the supernants of the HGF/SF-treated and untreated culture was analyzed. EACC-culture cells showed a stronger baseline expression of VEGF. After 72 h of incubation with 20 ng/ml HGF/SF of HGF/SF, the expression of VEGF in normal keratinocytes was 173.4 pg/ml. The expression level of VEGF in the EACC culture was 275.73 pg/ml. We observed a 2.5-fold induction of VEGF in EACC after 72 h, which started with 1.5-fold baseline VEGF concentrations of normal keratinocytes. Our analysis showed that, in the EACC culture, VEGF was elevated after treatment with HGF/SF. HGF/SF appears to activate cellular pathways inducing release of VEGF. After purification, no fibroblasts were present in our EACC culture so as to exclude possible paracrine effects by fibroblasts.

Cells, Cultured↗