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HGF Activator (hgf + activator)
Selected AbstractsHepatocyte Growth Factor Contributes to Fracture Repair by Upregulating the Expression of BMP Receptors,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 10 2005Yuuki Imai MD Abstract Hepatocyte growth factor (HGF) is activated and the expression of BMP receptors (BMPRs) is induced around the fracture site during the early phase of fracture repair. HGF facilitates the expression of BMPRs in mesenchymal cells. This study suggests that HGF contributes to fracture repair by inducing the expression of BMPRs. Introduction: The precise mechanisms that control the upregulation of BMP, BMPRs, and other molecules involved in bone repair are not completely understood. In this study, we hypothesized that HGF, activated through the action of thrombin on the HGF activator, may enhance BMP action through the local induction of BMP or BMPRs. Materials and Methods: Callus samples from tibial fractures in mice were harvested for immunohistochemical analysis of HGF and phosphorylated c-Met, for in situ hybridization of BMPRs, and for real-time RT-PCR analysis for the expression of HGF, c-Met, and BMPRs. To study the changes in gene expression of BMPRs in response to HGF, C3H10T1/2 cells were cultured with or without HGF and harvested for real-time RT-PCR and for Western blot analysis. To evaluate the contribution of HGF to the biological action of BMP2, C3H10T1/2 cells and primary muscle-derived mesenchymal cells were precultured with HGF and cultured with BMP2. In addition, the expression of the luciferase gene linked to the Id1 promoter containing the BMP responsive element and alkaline phosphatase (ALP) activity were assayed. Results: Positive immunostaining of HGF and phosphorylated c-Met was detected around the fracture site at 1 day after the fracture was made. mRNA expression of BMPRs was increased 1 day after fracture and localized in mesenchymal cells at the fracture site. From an in vitro study, the expression of mRNA for BMPRs was elevated by treatment with HGF, but the expression of BMP4 did not change. Western blot analysis also showed the upregulation of BMPR2 by HGF treatment. The results from the luciferase and ALP assays indicated increased responsiveness to BMPs by treating with HGF. Conclusions: This study indicates that HGF is activated and expressed at the fracture site and that HGF induces the upregulation of BMPRs in mesenchymal cells. Furthermore, HGF may facilitate BMP signaling without altering the expression of BMP molecules. [source] Serum active hepatocyte growth factor (AHGF) in benign prostatic disease and prostate cancerTHE PROSTATE, Issue 4 2009Kenji Yasuda Abstract BACKGROUND Hepatocyte growth factor (HGF) is secreted as an inactive single-chain precursor called pro-HGF. Pro-HGF is converted to an active two-chain form by HGF activator and matriptase. We attempted to clarify whether serum levels of active HGF (AHGF) could be used as a marker of prostate cancer. METHODS Serum levels of AHGF and total HGF (THGF; pro-HGF,+,AHGF) were measured by enzyme-linked immunosorbent assay in 38 patients with benign prostatic disease and 160 patients with prostate cancer. RESULTS Serum levels of AHGF in patients with untreated prostate cancer (0.37,± 0.12 ng/ml) were significantly higher than those in patients with benign prostatic disease (0.28,±,0.08 ng/ml) (P,=,0.0001). Serum AHGF levels were increased in patients with stage D or D3 compared with stage B. In addition, there were significant differences in serum AHGF levels between patients with well-differentiated and poorly differentiated adenocarcinoma. Furthermore, the mean serum AHGF/THGF ratio in patients with stage D3 prostate cancer was significantly higher than that in patients with stage B. CONCLUSIONS AHGF may be a potential tumor marker for prostate cancer. Further studies in large groups of patients are needed to define the clinical value of AHGF. Prostate 69:346,351, 2009. © 2008 Wiley-Liss, Inc. [source] Production of Functional Hepatocyte Growth Factor (HGF) in Insect Cells Infected with an HGF-Recombinant Baculovirus in a Serum-Free MediumBIOTECHNOLOGY PROGRESS, Issue 2 2000Min-Ying Wang Three insect cell lines, SL-7B cells derived from Spodoptera litura, Sf9, and High Five (Hi-5) cells, were used for the production of pro-hepatocyte growth factor (pro-HGF). Cells were cultured and then infected with a recombinant HGF-containing baculovirus in a serum-free medium. In SL-7B cells, pro-HGF is synthesized and excreted from the cells and late in infection is converted to a heterodimeric form of HGF even when the cells are grown in serum free medium. Conversion of a single-chain form of HGF (pro-HGF) into an HGF heterodimer was unexpected, as pro-HGF is normally cleaved by a serum protease called HGF activator. The proliferation activity of heparin-affinity-purified HGF from serum-free culture supernatant of SL-7B cells is comparable to that obtained from HGF converted by serum proteases, suggesting that SL-7B cells produce a functionally analogous protease to correctly process pro-HGF. This work reports, for the first time, on the feasibility of properly processing pro-HGF to form functional HGF by proteases from invertebrate cells in serum-free media. Avoiding the supplementation of sera provides the advantages of a low production cost, zero contamination of infectious agents from sera, and simple downstream product purification. Experimental results further demonstrate that the conversion of pro-HGF by insect cells is cell-line-dependent, because proteases in Hi-5 or Sf9 cells could not process pro-HGF as efficiently and properly as those in SL-7B cells. [source] Vascular and Biology 03BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue S1 2002C. Parr Background: Hepatocyte growth factor (HGF) elicits a number of functions that are tumourigenic and known to enhance the metastatic potential of tumour cells. HGF is produced as pro-HGF and requires proteolytic activation, by HGF activator, to evoke a biological response. The HGF inhibitors, HAI-1 and HAI-2, suppress the conversion of pro-HGF, through their interaction with HGF activator. This study quantitated the expression of HGF, its receptor and its inhibitors in breast cancer. Methods: Breast cancer tissues from patients (n = 97) were obtained with background normal tissues. RNA was extracted from these tissues, and HGF, c-Met, HAI-1 and HAI-2 expression was quantified using a real-time quantitative PCR (RTQ-PCR) techniques. Results: Levels of HGF and its receptor were found to be significantly higher in breast cancer than normal background tissues. The level of HAI-1 and 2 was also seen to be higher in tumour tissues. The mean results (copy number mL,1) are given in the Table below: In addition, patients with progressive diseases had a higher level of HGF (62.7 copies mL,1), than those with stable disease (43.8 copies mL,1), over a 5-year follow-up period. Furthermore, tumour tissues from node-positive patients expressed lower HAI-2 levels (341.3 copies mL,1), than the node-negative breast cancer tissues (1021.5 copies mL,1). Conclusions: This study has shown that the quantity of HGF, c-Met, HAI-1 and HAI-2 expressed in breast cancer tissues was significantly higher than that of background breast samples, and that the level of HGF is associated with progressive disease. [source] | ||||||||||