Plasma Hepatocyte Growth Factor Research Articles

Abstract 4661: Decreased epidermal growth factor receptor plasma levels as an indicator for head and neck squamous cell carcinoma case status and disease progression

Abstract The epidermal growth factor receptor (EGFR), c-Met and G-protein-coupled receptor signaling pathways contribute to head and neck squamous cell carcinoma (HNSCC) growth. To assess these pathways in HNSCC patients, we measured plasma levels of EGFR, the EGFR ligands transforming growth factor alpha (TGF-α) and amphiregulin (AR), the c-Met ligand hepatocyte growth factor (HGF) and COX-2, a component of prostaglandin production, in HNSCC patients (n=22) and cancer-free controls (n=32) enrolled through an Early Detection Research Network- (EDRN-) sponsored effort. Analytes were measured using a multiplex enzyme-linked immunosorbent assay. Differences in analyte levels between cases and controls and the prognostic potential of each analyte were evaluated. EGFR plasma levels were significantly decreased (P=0.04, rank sum test (RST)) and HGF plasma levels significantly increased (P<0.01, RST) in HNSCC cases compared to cancer-free controls. TGF-α levels tended to be higher in HNSCC cases (P=0.07, RST) while AR and COX-2 levels did not differ between cases and controls (P=0.32 and 0.32, respectively RST). Area under the Receiver Operating Characteristic (ROC) curve for HGF levels in subjects with low EGFR plasma levels was 0.92. EGFR plasma levels were significantly reduced in HNSCC cases who were former or active smokers compared to never smokers (P = 0.009, Kruskal-Wallis test (KWT)), but no difference in EGFR plasma levels by smoking status was observed among cancer-free controls (P = 0.97, KWT). HGF plasma levels tended to be lower in HNSCC cases who were never smokers (P=0.06 KWT) but did not differ by smoking status among cancer-free controls (P=0.16, KWT). Low EGFR plasma levels were associated with significantly reduced progression-free survival (PFS) in EDRN HNSCC cases (P = 0.03, log rank test); no other analyte tested was associated with PFS. We noted a negative correlation between EGFR plasma levels in EDRN HNSCC cases and previously reported EGFR tumor levels assessed by immunohistochemical staining that was not significant (Spearman's rho=-0.41, P=0.10, n=17). Plasma EGFR and HGF levels may provide indications of HNSCC cancer status, and EGFR plasma levels may be a valuable prognostic indicator for patients with HNSCC. Decreased plasma EGFR levels in HNSCC patients were likely not due to general effects related to smoking and instead may reflect tissue characteristics specific to tobacco-related cancers. We found EGFR plasma levels in HNSCC patients were not positively correlated with EGFR tumor levels. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4661.

Impact of acute pulmonary embolism on plasma and tissue hepatocyte growth factor: an experimental study

ABSTRACTThis study was designed to investigate the impact of acute pulmonary embolism (PE) on plasma and tissue hepatocyte growth factor (HGF). PE was established in 16 New Zealand white rabbits by intravenous injection of autologous blood clots. Another 16 sham-operated rabbits were used as control. Plasma HGF levels and tissue HGF expression was measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. The plasma HGF levels in the PE group were elevated 1 hour after PE (P < .01). In the lung tissue samples, the positive HGF expression ratio was 91.7% and 20.8%, respectively, in the PE and the control group (P < .01). The positive HGF expression ratio in the right ventricular tissue samples in the PE group was higher than in the control group (75.0% versus 20.9%; P < .01). The positive HGF expression ratio in the liver samples in the PE and the control groups was 33.3% and 16.7%, respectively (P < .05). In conclusion, acute PE was associated with a significant increase in plasma HGF. Acute PE was also associated with an enhanced HGF expression in the lungs, the right ventricle, and the liver.

Treatment response to bortezomib in multiple myeloma correlates with plasma hepatocyte growth factor concentration and bone marrow thrombospondin concentration

Multiple myeloma (MM) is associated with increased rate of bone marrow angiogenesis. Increased concentration of hepatocyte growth factor (HGF) is associated with poor prognosis in patients treated with conventional chemotherapy or thalidomide. We have shown previously that decreased level of thrombospondin, an angiogenesis inhibitor, correlates with poor response to high-dose chemotherapy. The aim of our current study was to evaluate association between therapeutic response to bortezomib and thrombospondin and HGF levels. Peripheral blood plasma concentration of HGF and bone marrow plasma concentration of thrombospondin were measured in patients with MM prior to the initiation of bortezomib therapy. Overall, 58 patients were enrolled, 44/58 (76%) of them with relapsed disease. Treatment outcomes were analyzed for possible associations with pretreatment HGF and thrombospondin levels. Patients who achieved complete response had significantly higher pretreatment HGF levels and lower pretreatment thrombospondin levels than others. More than 70% of patients with low pretreatment HGF and high pretreatment thrombospondin concentrations achieved very good partial response or complete response, in contrast to only 20% of patients with high HGF and low thrombospondin levels. High pretreatment thrombospondin and low pretreatment HGF concentrations are associated with therapeutic response to bortezomib in patients with MM.

The discovery of Hepatocyte Growth Factor (HGF) and its significance for cell biology, life sciences and clinical medicine

It has been more than 25 years since HGF was discovered as a mitogen of hepatocytes. HGF is produced by stromal cells, and stimulates epithelial cell proliferation, motility, morphogenesis and angiogenesis in various organs via tyrosine phosphorylation of its receptor, c-Met. In fetal stages, HGF-neutralization, or c-Met gene destruction, leads to hypoplasia of many organs, indicating that HGF signals are essential for organ development. Endogenous HGF is required for self-repair of injured livers, kidneys, lungs and so on. In addition, HGF exerts protective effects on epithelial and non-epithelial organs (including the heart and brain) via anti-apoptotic and anti-inflammatory signals. During organ diseases, plasma HGF levels significantly increased, while anti-HGF antibody infusion accelerated tissue destruction in rodents. Thus, endogenous HGF is required for minimization of diseases, while insufficient production of HGF leads to organ failure. This is the reason why HGF supplementation produces therapeutic outcomes under pathological conditions. Moreover, emerging studies delineated key roles of HGF during tumor metastasis, while HGF-antagonism leads to anti-tumor outcomes. Taken together, HGF-based molecules, including HGF-variants, HGF-fragments and c-Met-binders are available as regenerative or anti-tumor drugs. Molecular analysis of the HGF-c-Met system could provide bridges between basic biology and clinical medicine.

Abstract A11: Lower baseline levels of plasma hepatocyte growth factor, IL-6, and IL-8 are correlated with greater tumor shrinkage in renal cell carcinoma patients treated with pazopanib

Abstract Introduction: A Phase II RCC study (VEG102616) demonstrated activity with a response rate = 34.7% (CI 95%, 28.4 – 40.9) and disease control rate (CR + PR +SD) = 80% [ASCO 2008, #5046]. An analysis of plasma cytokines and angiogenic factors (CAFs) was undertaken with the objective of identifying patients who were the most likely to respond to pazopanib. Methods: A subset (n=129/217) of available plasma samples were selected based on extremes of tumor shrinkage from baseline. CAF levels were correlated with dichotomized tumor shrinkage (DTS) by logistic regression, with continuous tumor shrinkage (CTS) by linear regression, and with progression-free survival (PFS) by Cox regression. ROC analysis was performed using a stratified random sample of 97 patients in a training set and 32 pts in a test set. Results: Elevated levels of HGF, IL-8, and IL-6 were significantly correlated with less tumor shrinkage. Lower levels of E-Selectin and elevated IL-6 were associated with shorter PFS. ROC curve analysis for HGF resulted in an AUC of 0.668 with an optimal cutoff of 638.5 pg/ml. Using this cutoff, HGF-based predictions in the test set had an overall accuracy of 53%, positive predictive value of 67% and negative predictive value of 50%. Conclusion: CAF profiling showed that lower baseline levels of plasma HGF, IL-6, and IL-8 are correlated with greater tumor shrinkage in renal cell carcinoma pts treated with pazopanib. Also, elevated levels of E-Selectin and lower levels of IL-6 were associated with longer PFS. CAF1 p-value Fold Change2 Dichotomized HGF 0.006 Fold change: 1.3 Tumor Shrinkage IL-8 0.036 Fold change: 3.0 (Logistic regression) IL-6 0.039 Fold change: 1.5 TIMP1 0.047 Fold change: 1.2 Continuous HGF 0.029 Not Applicable - NA Tumor Shrinkage IL-8 0.048 NA (Linear Regression) IL-6 0.031 NA PFS (Cox Proportional E-Selectin 0.017 NA Hazards Model) IL-6 0.005 NA 1 The following CAF analysis were performed: Angio-10 (VEGF, VEGF-R2, ICAM-1, TIE-2, PLGF, TIMP-1, HGF, FGF basic, E-Selectin, and IL-8) and Cyto-8 (IL-1 beta, IL-2, IL-5, IL-6, IL-8, IL-10, IL-12, TNF alpha) BIOCHIPS (Biomarker Workstation, Decision Biomarkers, Inc). Only the significant results were displayed above. 2 Fold change = (median CAF level for group with less tumor shrinkage) / (median CAF level for group with greater tumor shrinkage). Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A11.

Biological Effect of Anaphylatoxin C5a on the Generation of Anti‐inflammatory Substances in Leukocyte Adsorption

Anaphylatoxins, which are involved in both pro-inflammatory processes and a variety of anti-inflammatory effects, are produced during granulocyte and monocyte adsorptive apheresis. We noticed the anti-inflammatory effects of C5a, the strongest anaphylatoxin, in granulocyte and monocyte adsorptive apheresis. The aim of this study was to investigate the effect of C5a on interleukin-1 receptor antagonist (IL-1ra) and hepatocyte growth factor (HGF) generation in granulocyte and monocyte adsorption. Peripheral blood containing nafamostat mesilate as an endogenous complement activation inhibitor was divided into four groups: (1) no recombinant C5a added, no contact with cellulose acetate (CA) beads (control group); (2) no C5a added, contact with CA beads; (3) C5a added, no contact with CA beads; and (4) C5a added, contact with CA beads. After incubation, IL-1ra and HGF in plasma were measured. IL-1ra was significantly higher in group 3, in which only C5a was added in the absence of CA beads, compared to groups 2 (P < 0.01) and 4 (P < 0.05). HGF was significantly higher only in group 4, in which C5a was added in the presence of CA beads (P < 0.05), but did not increase in the absence of CA beads. C5a can directly induce IL-1ra generation without the granulocyte and monocyte adsorption stimuli to CA beads, but can synergistically induce HGF generation with the adsorption stimuli, indicating C5a has different effects on IL-1ra and HGF generation.

Hepatocyte Growth Factor/Activin A/Follistatin System Activation during Hemodialysis with Different Low Molecular Weight Heparins

Hepatocyte growth factor (HGF), activin A (Act A), and follistatin (FS) compose an organotrophic system; interestingly it is modified by heparin. To understand if LMWHs (considered distinct drugs) have different clinical profiles regarding the above growth factors, we studied the effects of enoxaparin, nadroparin, and dalteparin on their plasma levels. Seventeen chronic HD patients completed this prospective, crossover trial. They were randomized into six groups: each patient was administered enoxaparin (effective dose of 0.75 mg/kg), nadroparin (70.4 IU/kg) and dalteparin (78.6 IU/kg) in three time periods of two months each. At the end of this period, the cytokine's plasma levels were measured by immunoassays at the start and at 10 min and 180 min of the HD procedure. At 10 min, we observed a striking increase in plasma HGF (32-fold), Act A (4-fold), and FS (53%), all p = 0.0003. The levels of HGF and Act A remained markedly elevated after 180 min (by 295% and 87%, respectively; both p < 0.002), while those of FS returned to baseline. There were no differences in cytokine profile comparing both their peak concentrations and the areas under the curve. Enoxaparin, dalteparin, and nadroparin are seemingly not different considering the release of HGF/Act A/FS during HD procedures; this may reflect their similar profile in other aspects. Moreover, the concentrations of HGF/Act A/FS are close to therapeutic ones, which may partly explain the mechanisms underlying some of the emerging extra-anticoagulant effects of LMWHs.

1107 Modulation of hepatocyte growth factor plasma levels in relation to the dose of exogenous heparin administered: an experimental study in rats

1107 Modulation of hepatocyte growth factor plasma levels in relation to the dose of exogenous heparin administered: an experimental study in rats

Low‐dose simultaneous delivery of adenovirus encoding hepatocyte growth factor and vascular endothelial growth factor in dogs enhances liver proliferation without systemic growth factor elevation

Hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) gene transfer proved to enhance liver regeneration. However, elevation of their plasma levels may induce potentially serious distant effects such as tumorigenesis or proliferative retinopathy. This study was performed to examine whether simultaneous administration of low-dose adenovirus encoding HGF and VEGF genes in dogs will stimulate liver proliferation but without inducing liver toxicity or systemic elevation of HGF and VEGF levels. Adult dogs received an intravenous injection of low-dose adenoviral vectors encoding human HGF and VEGF (HGF/VEGF), beta-galactosidase (lacZ) or phosphate-buffered saline (PBS). Liver proliferation was measured using the proliferating cell nuclear antigen (PCNA) immunostaining labelling index. HGF and VEGF plasma concentrations and transaminases were repeatedly measured. Transgene expression was evaluated using reverse-transcription polymerase chain reaction. Human HGF and VEGF expressions were detected only in the liver of HGF/VEGF dogs at day 2 after injection but declined at sacrifice (day 7). No expression was detected in the liver of the lacZ or PBS groups. Plasma levels of HGF and VEGF were not statistically different from those in the lacZ group (P=0.81, P=0.22 respectively). The PCNA labelling index was five-fold higher in the HGF/VEGF group compared with the lacZ group (P<0.01). No immunostaining was detected in the PBS group. Transaminases were only elevated (P<0.01) in the lacZ group compared with the other groups. We showed that simultaneous administration of low-dose adenoviral vectors encoding human HGF and VEGF genes can induce transgene expression and liver proliferation without liver toxicity or systemic growth factor elevation.

AS-220: Comparison of the Effect of Different Atorvastatin Therapy Doses on Plasma Hepatocyte Growth Factor Concentration in Patients with Stable Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

AS-220: Comparison of the Effect of Different Atorvastatin Therapy Doses on Plasma Hepatocyte Growth Factor Concentration in Patients with Stable Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

Endogenous Hepatocyte Growth Factor Attenuates Inflammatory Response in Glycerol-Induced Acute Kidney Injury

Background: Hepatocyte growth factor (HGF) is overexpressed after acute kidney injury (AKI). The aim of this study was to evaluate the role of endogenous HGF in the progression of the inflammatory response in glycerol-induced AKI (Gly-AKI) in rats. Methods: Renal and systemic HGF expressions were evaluated during the development of Gly-AKI. Subsequently, the blockade of endogenous HGF was analyzed in rats treated with anti-HGF antibody concomitant to glycerol injection. Apoptosis, cell infiltration and chemokine and cytokine profiles were investigated. Results: We detected an early peak of renal and plasma HGF protein expressions 3 h after glycerol injection. The pharmacological blockade of the endogenous HGF exacerbated the renal impairment, the tubular apoptosis, the renal expression of monocyte chemoattractant protein-1 and the macrophage, CD43+, CD4+ and CD8+ T lymphocytes renal infiltration. The analysis of mRNA expressions of Th1 (t-bet, TNF-α, IL-1β) and Th2 (gata-3, IL-4, IL-10) cytokines showed a Th1-polarized response in Gly-AKI rats that was aggravated with the anti-HGF treatment. Conclusion: Endogenous HGF attenuates the renal inflammatory response, leukocyte infiltration and Th1 polarization after glycerol injection. The control of cellular immune response may partly explain the protective effect of endogenous HGF in the development of Gly-AKI.

Evaluation of hepatocyte growth factor in patients with biliary atresia

Background Hepatocyte growth factor (HGF) is a potent mitogen for mature hepatocytes in primary culture and seems to be a trigger factor for liver regeneration and proliferation after liver injury. The aim of this study was to evaluate the expression of HGF in patients with biliary atresia (BA). Methods Plasma levels of HGF were determined using an enzyme-linked immunosorbent assay from 19 patients with BA, 10 at the time of Kasai procedure (KP) and 9 at liver transplantation (LT), and 10 patients with nonicteric choledochal cyst served as control. Hepatic HGF level was quantitatively estimated using enzyme-linked immunosorbent assay and Western blotting. Hepatocyte growth factor messenger RNA (mRNA) expression of liver was measured with quantitative reverse transcriptase polymerase chain reaction. Immunohistochemical study of liver sections was evaluated by HGF staining. Results Plasma HGF levels in LT patients were significantly higher than in KP patients (2977.30 ± 1251.42 vs 960.17 ± 559.82 pg/mL, P < .01). Western blots showed increased hepatic HGF levels in LT group than in KP group (2.02 ± 0.86 vs 1.44 ± 0.72 pg/ μg total protein, P < .05). However, there were no differences in HGF mRNA expression. Immunohistochemical study showed significantly increased HGF staining in hepatocytes of LT livers than of KP livers. Conclusions Elevation of plasma and liver HGF levels could be related to the progression of liver cirrhosis in patients with BA. Hepatocyte growth factor might have a protective role, probably through the induction of hepatocyte proliferation, during the development of BA-associated liver cirrhosis.

Nephromegaly in Children with Kawasaki Disease: New Supporting Evidence for Diagnosis and Its Possible Mechanism

To measure the kidney size in children with Kawasaki disease (KD) and to delineate the condition of nephromegaly, 20 children with KD were enrolled in our study. Kidney sizes were measured during acute stage in these patients. Twenty healthy children and 15 febrile children served as healthy controls and fever controls, respectively. To delineate the possible mechanism, we also evaluated kidney volume (KV) in 13 other patients with KD during the acute phase and after the recovery phase as well as 26 healthy children. Plasma hepatocyte growth factor (HGF) and transforming growth factor-beta1 (TGF-beta1) levels were determined for all children. Kidney lengths and KV in patients with KD during the acute phase were significantly larger than those of healthy children. There was no kidney enlargement in healthy controls and after the recovery phase. The ratio of patient plasma HGF/TGF-beta1 during the acute phase and after the recovery phase correlated positively with the degree of nephromegaly in all patients. These results confirm the presence of large kidneys in children with KD. Our data also suggest that an elevated HGF/TGF-beta1 ratio may be responsible for the transient nephromegaly in these children.

Prognostic significance of hepatocyte growth factor and microvessel bone marrow density in patients with chronic myeloid leukaemia

Objective. The aims of the study were: (1) to perform a complex angiogenic assessment in chronic myeloid leukaemia (CML) patients using multiple parameters: bone marrow microvessel density (MVD), bone marrow immunohistochemical cellular expressions of vascular endothelial growth factor (VEGF) and its receptor KDR, as well as hepatocyte growth factor (HGF) and its receptor MET, and the plasma VEGF and HGF; and (2) to determine the clinical significance of these factors for patients with CML. Material and methods. The VEGF and HGF plasma levels were analysed by ELISA in 38 newly diagnosed CML patients. Immunohistochemical methods were used to visualize the MVD as well as the cellular VEGF/KDR and HGF/MET expression. Results. We found an increased MVD, cellular VEGF/KDR and HGF/MET expression and elevated plasma VEGF and HGF in CML patients. The plasma HGF, cellular HGF and MET expression correlated with the CML phase. The plasma HGF correlated with all markers reflecting the tumour burden (leucocytes, blast percentage, splenomegaly and LDH) as well as with the phase of CML and overall survival of the patients. Cox regression analysis determined the prognostic relevance of HGF and MVD parameters, but not for the plasma VEGF and cellular VEGF and KDR. Conclusions. Using a complex angiogenic assessment we determined an increased angiogenesis in CML patients. No prognostic relevance was found for VEGF plasma levels or VEGF/KDR cellular bone marrow expression. The increased cellular HGF and MET expressions could be considered high‐risk factors for these patients. Plasma HGF and MVD were shown to be independent prognostic parameters for patients' survival.

Angiotensin II Regulates Liver Regeneration via Type 1 Receptor Following Partial Hepatectomy in Mice

Angiotensin II (Ang II) is an important mediator stimulating liver fibrosis after liver injury. However, it is not known whether Ang II plays a role in liver regeneration. Here, we investigate the effects of Ang II type 1 (AT(1)) receptor blocker (ARB), angiotensin-converting enzyme inhibitor (ACEI), systemic infusion of Ang II, and genetic deficiency of the AT(1a) receptor (AT1a-KO) on the hepatic regenerative response to partial hepatectomy (PH) in mice. Administration of ARB (candesartan cilexetil and losartan) or ACEI (enarapril and lisinopril) enhanced 5-bromo-2'-deoxyuridine (BrdU) incorporation into hepatocyte nuclei in remnant liver as well as the restoration of liver weight after PH. Systemic infusion of Ang II (100 ng/kg/min) suppressed the PH-induced BrdU incorporation and the restoration of liver weight. In contrast to Ang II infusion, these hepatic responses to PH were significantly greater in AT1a-KO mice than in wild-type mice. The PH-induced increases in hepatic levels of hepatocyte growth factor (HGF) mRNA and plasma HGF concentrations were greater in candesartan- and enarapril-treated mice or in AT1a-KO mice than in vehicle-treated mice or wild-type mice, respectively, whereas they were less in Ang II-infused mice than in vehicle-infused mice. In contrast to HGF, blockades of the renin-angiotensin system or Ang II infusion produced opposite effects on the PH-induce increases in hepatic transforming growth factor (TGF)-beta 1 mRNA and plasma TGF-beta 1 levels. These studies suggest that Ang II plays a role in the liver regeneration as a suppressor of hepatocyte proliferation via the AT(1) receptor-mediated control of growth factor production.

Genetic and environmental determinants of hepatocyte growth factor levels and their association with obesity and blood pressure

Background: Hepatocyte growth factor (HGF) is a member of the adipocytokine family; it is implicated in tissue repair, regeneration, and angiogenesis. Several studies have reported that the HGF plays important role in obesity and cardiovascular disease.Aim: This study examines whether HGF and its phenotypic correlations with obesity and blood pressure (BP), in healthy individuals, are due to shared genetic or common environmental factors.Subjects and methods: Body mass index (BMI), waist-to-hip ratio (WHR), BP, and HGF plasma concentrations were measured in a sample of 733 individuals belonging to 248 pedigrees.Results: The most significant phenotypic correlations were found among HGF, WHR, and systolic BP (p < 0.001). Analysis of the familial aggregation revealed that parent–offspring and sibling correlations in HGF levels, adjusted for age, age2, and sex, were statistically highly significant (p < 0.001). Variance decomposition analysis showed that when adjusted for potential covariates, 48.4% of the HGF variation was due to putative genetic factors. The genetic correlations between all pairs of studied traits (HGF, WHR, and SBP) were statistically significant (p < 0.02) and ranged between 0.23 ± 0.07 and 0.40 ± 0.07. However, correlation between WHR and BP becomes non-significant after adjustment for HGF.Conclusions: The results provide evidence that putative genetic factors involved in regulation of HGF variation contribute also significantly to variation of the obesity and BP. It is possible that the familial resemblance for WHR and the SBP correlation in the studied sample is affected substantially by genetic factors regulating circulating HGF levels.

Hepatocyte Growth Factor Expression in Bone Marrow Microenvironment Is Critical for Progression of MGUS to Myeloma.

Hepatocyte growth factor (HGF) augments proliferation, survival and increases migration of plasma cells in vitro and in addition it induces haemangiogeneis and lymphangiogenesis. C-met (HGF receptor) is expressed on plasma cells and HGF is constitutively elevated in serum of patients with myeloma (MM) and MGUS patients. We investigated the distribution of HGF in bone marrow biopsies to better understand its role in progression of monoclonal gammopathy.Materials and methods: Bone marrow trephines were analysed by immunohistochemistry of paraffin embedded bone marrow (BM) trephine specimens. Trephines were dewaxed without antigen retrieval. Plasma cell enumeration was done using CD38 staining (Novocastra, UK). HGF (Goat antihuman IgG, R&D systems) staining was performed using Vectastain® ABC kit with DAB reactivity. Slides were analysed using an Optical microscope (Zeiss Standard 20, Germany).Results: Archived BM specimens of MM (n= 7), MGUS (n= 5) and normal controls (n=6) were stained in duplicate. Trephines were graded from Grade 1–3 (weak, moderate, strong) based on the intensity of staining. The localisation of staining to paratrabecular, perivascular and intertrabecular areas was analysed. Interstitial and cytoplasmic staining patterns were analysed. HGF staining localised to paratrabecular regions was observed in all normal individuals with staining intensity of Grade 1–2 in 3/6(50%) and Grade 3 in 3/6(50%). In 4/5(80%) patients with MGUS a distinct intertrabecular pattern of staining was observed in discrete regions, where plasma cells were localised. Intensity of staining was Grade 2 in 3/5(60%) and Grade 3 in 2/5(40%) MGUS patients. Plasma cell percentages were between 5–20% in MGUS patients. In MM patients we found a correlation between the plasma cell counts and the degree of HGF staining. In 2/7 (28.5%) patients plasma cell percentages ranged between 5% and 15% and Grade 1–2 discrete paratrabecular staining was observed with none or low perivascular staining. In 5/7 (71.5%) MM patients plasma cell percentages were >20% and Grade 3 confluent staining with interstitial and cytoplasmic location of HGF was observed. In addition, patients with Grade 3 staining presented a strong perivascular localisation of HGF.Conclusion: HGF distribution in bone marrow microenvironment of MGUS and MM patients is non random. We observed that MGUS patients have a discrete intertrabecular pattern and MM patients have a confluent interstitial pattern of staining with strong perivascular localisation. Other groups have shown that high HGF levels increase angiogenesis. We hypothesise that HGF localisation and pattern of distribution in BM microenvironment leads to neo angiogenesis and progression from MGUS to MM. Ongoing studies are evaluating this hypothesis.

Impairment of the antifibrotic effect of hepatocyte growth factor in lung fibroblasts from African Americans: possible role in systemic sclerosis.

To compare the composition of cytokines in African American and Caucasian patients with systemic sclerosis (SSc; scleroderma) and in healthy individuals, particularly the expression and function of hepatocyte growth factor (HGF). Bronchoalveolar lavage (BAL) fluid samples were analyzed using cytokine array techniques. HGF in plasma and cell culture medium samples was measured by enzyme-linked immunosorbent assay. Connective tissue growth factor (CTGF), type I collagen expression, and c-Met receptor phosphorylation were studied by immunoblotting. Overall greater expression of cytokines in BAL fluid from African American patients as compared with Caucasian patients was observed. Significant increases in HGF concentrations were detected in BAL fluid, plasma, and fibroblast culture medium from Caucasian SSc patients. In contrast, African American SSc patients did not demonstrate an increase in HGF. Recombinant HGF readily abolished CTGF expression and collagen accumulation in lung fibroblasts isolated from Caucasian SSc patients. Pretreatment of lung fibroblasts with neutralizing anti-c-Met antibody abolished the effects of HGF on CTGF expression and collagen accumulation, suggesting that the antifibrotic activity of HGF is mediated via c-Met receptor tyrosine kinase. Whereas recombinant HGF rapidly induced c-Met receptor phosphorylation in lung fibroblasts from Caucasian patients, c-Met receptor phosphorylation was significantly reduced in lung fibroblasts from African American subjects. Moreover, recombinant HGF failed to prevent CTGF expression and collagen accumulation in lung fibroblasts derived from African American subjects. Ethnic differences exist in terms of antifibrotic HGF expression in lung fibroblasts derived from Caucasian and African American subjects. Reduced levels of HGF as well as a deficiency in c-Met receptor function appear to be present in African American patients with SSc. These findings may explain in part the greater disease severity and worse prognosis observed in African Americans with SSc.

Sulodexide induces hepatocyte growth factor release in humans

Heparin influences numerous pleiotropic growth factors, including hepatocyte growth factor (HGF), partially by their release from endothelial and extracellular matrix stores. The effects of sulodexide, a heparin-like glycosaminoglycan medication of growing importance in medicine, on HGF liberation are not known. We performed a 2-week open-label sulodexide trial in healthy male volunteers. The drug was initially administered intravenously (i.v.) in a single dose of 1200 Lipoprotein Lipase Releasing Units (LRU), then – orally for 12 days (500 LRU twice a day), and – again by i.v. route (1200 LRU) on day 14. Intravenous sulodexide injections were repeatedly found to induce marked and reproducible increases in immunoreactive plasma HGF levels (more than 3500% vs baseline after 10 min, and more than 1200% after 120 min), and remained unchanged when measured 120 min following oral sulodexide administration. The percentage increments in plasma HGF evoked by i.v. sulodexide at both time points and on both days inversely correlated with baseline levels of the growth factor. On day 14, the HGF levels after 120 min and their percentage increase vs baseline were strongly and directly dependent on i.v. sulodexide dose per kg of body weight. This study shows that sulodexide has a novel, remarkable and plausibly biologically important stimulating effect on the release of pleiotropic hepatocyte growth factor in humans.

Intravascular Ultrasound Evidence of Angiographically Silent Allograft Vasculopathy Inversely Correlates With Circulating Level of Hepatocyte Growth Factor

Cardiac allograft vasculopathy (CAV) is the major determinant of long-term survival after heart transplantation. The characteristic diffuse concentric intimal thickening of CAV detected by intravascular ultrasound (IVUS) imaging may not be perceivable on coronary angiogram. Previous studies of hepatocyte growth factor (HGF) in murine models suggested the protective effects on vascular endothelium and allograft survival. However, the possible role of circulating HGF that contributes to the development of CAV in human is unclear. IVUS was used to assess the left anterior descending coronary arteries of 47 patients who had survived cardiac transplantation for more than 1 year and had no angiographically detectable CAV. The IVUS measurements for the extent of intimal hyperplasia, including volume index (calculated as [total plaque volume/total vessel volume] x 100) and maximum area stenosis, were compared with plasma levels of HGF by linear regression analyses. The volume index significantly correlated with maximum area stenosis in the IVUS measurements (r = 0.90, p < 0.0001). Both volume index and maximum area stenosis inversely correlated with plasma HGF levels (r = -0.39, p = 0.007 and r = -0.42, p = 0.003, respectively). In angiographically silent CAV, circulating HGF may have a protective effect on vascular endothelium and thus attenuate the severity of intimal hyperplasia.