Hepatocyte Growth Factor In Response Research Articles

Canine bone marrow peri-adipocyte cells could therapeutically benefit acute spinal cord injury through migration and secretion of hepatocyte growth factor to inflammatory milieu.

Spinal cord injury (SCI) is a common neurological disorder in dogs. A secondary injury that occurs in the acute phase causes expansion of inflammation, resulting in lesion extension and further loss of function. Mesenchymal stem cells (MSCs) have trophic effects and the ability to migrate toward injured tissues; therefore, MSC-based therapy is considered promising for the treatment of canine SCI. We recently reported that bone marrow peri-adipocyte cells (BM-PACs) can be obtained from canine bone marrow and have stem cell potential superior to that of conventional bone marrow MSCs (BMMSCs). However, their therapeutic potential for SCI have been still unknow. Here, we first evaluated the ability of BM-PACs to secrete hepatocyte growth factor (HGF) and their migration ability toward inflammatory milieu in vitro. BM-PACs can secrete HGF in response to pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α and IL-1β, and exhibit migration ability toward these cytokines. Next, BM-PACs were intravenously administered into nude mice with acute SCI to analyze the homing ability and therapeutic effects of HGF secreted by BM-PACs. BM-PACs homed to the injured spinal cord, where the HGF expression level increased 7 days after administration. Intravenous administration of BM-PACs induced functional recovery and pathological improvement, indicated by less demyelinating area, more preserved axons, and less glial scar formation compared with the mice only received vehicle. These findings suggest that the intravenous administration of BM-PACs can be a novel therapeutic intervention for acute canine SCI.

Circulating Hepatocyte Growth Factor Reflects Activation of Vascular Repair in Response to Stress

Hepatocyte growth factor (HGF) is released by stressed human vascular cells and promotes vascular cell repair responses in both autocrine and paracrine ways. Subjects with a low capacity to express HGF in response to systemic stress have an increased cardiovascular risk. Human atherosclerotic plaques with a low content of HGF have a more unstable phenotype. The present study shows that subjects with a low abilityto express HGF in response to metabolic stress have an increased risk to suffer myocardial infarction and stroke.

Anti-inflammatory effect of HGF responses to oral traumatic ulcers using an HGF-Tg mouse model.

Hepatocyte growth factor (HGF) has been implicated in inhibiting diverse types of inflammation. Oral traumatic ulceration (OTU) is a common disease of the oral mucosa, and inflammation is the main process for ulcer healing. This study aimed to explore the expression of HGF in oral ulcers and its role in ulcer inflammation. The saliva of 14 recurrent alphous stomatitis (RAS) patients, 18 OTU patients and 17 healthy controls was collected. Traumatic ulcers of the left mucosa were observed in 42 wild-type (WT) and 42 HGF-overexpressing transgenic (HGF-Tg) mice. Histological scores, inflammatory cell expression and serum cytokine expression were measured and analyzed on the 5th day. The HGF protein level in ulcer-affected human saliva was 9.3-fold higher than that in healthy saliva. The HGF protein levels in RAS and OTU saliva were 14- and 5.7-fold higher, respectively, than those in healthy saliva. Traumatic ulcers enhanced HGF expression in ulcer-affected oral mucosa and in the blood of C57BL/6 mice by 1.21- and 1.40-fold, respectively. In HGF-Tg mouse traumatic ulcers, HGF expression was 1.34-fold higher than that in wild-type mice. HGF-Tg mice had lower weight loss, less ulcer area and lower histopathology scores than WT mice. The results from immunohistochemistry, flow cytometry and serum cytokine analysis showed that HGF-Tg animals presented fewer Ly6G-positive neutrophils and higher levels of circulating inflammatory cytokines. HGF overexpression alleviated weight loss, ulcer area and inflammation, suggesting the role of HGF in promoting the healing of oral ulcers.

Circulating Hepatocyte Growth Factor Reflects Activation of Vascular Repair in Response to Stress

Background: Acute cardiovascular events arise when the arterial wall fails to repair the damage caused by cardiovascular risk factors. Hepatocyte growth factor (HGF) stimulates growth of vascular cells but has been associated with increased risk of cardiovascular disease (CVD) in epidemiological studies. Here we tested the hypothesis that this association reflects activation of a protective vascular repair response. Methods: Small interfering RNA (siRNA) and recombinant human HGF were used to assess the role of HGF in regulation of human umbilical cord endothelial and coronary artery smooth muscle cell proliferation, migration and viability. Proximity extension assay was used to determine HGF and other biomarkers in 4742 subjects participating in the Malmo Diet and Cancer study and in extracts of 200 human carotid plaques. Findings: HGF promoted migration, proliferation and survival of human endothelial and smooth muscle cells. Human atherosclerotic plaques with a high content of HGF had a more stable phenotype. Cultured vascular cells expressed HGF in response to stress. Plasma HGF correlated with circulating levels of cellular stress biomarkers such as soluble TRAIL receptor-2 and caspase-8. Decreased ability to respond with elevated HGF levels to cellular stress, as assessed by the ratios of HGF to soluble TRAIL receptor-2 and caspase-8, associated with increased risk of cardiovascular events during a follow-up period of 19.4±5.0 years. Interpretations: These findings provide support for a protective role of HGF in CVD and show that subjects with a low ability to express HGF in response to stress have an increased risk of cardiovascular events. Funding Information: The work was supported by the Swedish Society for Medical Research, Emil and Wera Cornell foundation, Hjelt foundation, the Swedish Research Council, the Swedish Foundation for International Cooperation in Research and Higher Education, Crafoord foundation, the Swedish Medical Society, Diabetes foundation, Swedish Heart and Lung Foundation, Diabetes Research and Wellness foundation, Albert Pahlssons foundation, SUS foundations and funds, Lund University Infrastructure grant ”Malmo population-based cohorts” (STYR 2019/2046) and Lund University Diabetes Center (Swedish Research Council - Strategic Research Area Exodiab Dnr 2009-1039 and the Swedish Foundation for Strategic Research Dnr IRC15-006). Declaration of Interests: None. Ethics Approval Statement: All studies were approved by the respective Regional Ethical Review Boards and conducted in accordance with the Helsinki Declaration. All subjects gave written consent.

Transmembrane proteoglycans syndecan-2, 4, receptor candidates for the impact of HGF and FGF2 on semaphorin 3A expression in early-differentiated myoblasts.

Regenerative mechanisms that regulate intramuscular motor innervation are thought to reside in the spatiotemporal expression of axon-guidance molecules. Our previous studies proposed an unexplored role of resident myogenic stem cell (satellite cell)-derived myoblasts as a key presenter of a secreted neural chemorepellent semaphorin 3A (Sema3A); hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGF2) triggered its expression exclusively at the early differentiation phase. In order to advance this concept, the present study described that transmembrane heparan/chondroitin sulfate proteoglycans syndecan-2, 4 may be the plausible receptor candidates for HGF and FGF2 to signal Sema3A expression. Results showed that mRNA expression of syndecan-2, 4 was abundant (two magnitudes higher than syndecan-1, 3) in early-differentiated myoblasts and their in vitro knockdown diminished the HGF/FGF2-induced expression of Sema3A down to a baseline level. Pretreatment with heparitinase and chondroitinase ABC decreased the HGF and FGF2 responses, respectively, in non–knockdown cultures, supporting a possible model that HGF and FGF2 may bind to heparan and chondroitin sulfate chains of syndecan-2, 4 to signal Sema3A expression. The findings, therefore, extend our understanding that HGF/FGF2-syndecan-2, 4 association may stimulate a burst of Sema3A secretion by myoblasts recruited to the site of muscle injury; this would ensure a coordinated delay in the attachment of motoneuron terminals onto fibers early in muscle regeneration, and thus synchronize the recovery of muscle fiber integrity and the early resolution of inflammation after injury with reinnervation toward functional recovery.

Association between circulating hepatocyte growth factor (HGF) and clinical response across five studies with the BRAF inhibitor dabrafenib or MEK inhibitor trametinib.

e20019 Background: To investigate the previously reported association between baseline HGF and clinical response in patients (pts) treated with RAF inhibitors, HGF levels were assessed in pt blood ...

Interferon–β Induces Hepatocyte Growth Factor in Monocytes of Multiple Sclerosis Patients

Interferon-β is a first-line therapy used to prevent relapses in relapsing-remitting multiple sclerosis. The clinical benefit of interferon-β in relapsing-remitting multiple sclerosis is attributed to its immunomodulatory effects on inflammatory mediators and T cell reactivity. Here, we evaluated the production of hepatocyte growth factor, a neuroprotective and neuroinflammation-suppressive mediator, by peripheral blood mononuclear cells collected from interferon-β−treated relapsing-remitting multiple sclerosis patients, relapsing remitting multiple sclerosis patients not treated with interferon-β, and healthy volunteers. Using intracellular flow cytometry analysis, increased production of hepatocyte growth factor was observed in circulating CD14+ monocytes from patients undergoing long-term treatment with interferon-β versus untreated patients. Complementary in vitro studies confirmed that treatment with interferon-β induced rapid and transient transcription of the hepatocyte growth factor gene in CD14+ monocytes and that intracellular and secreted monocytic hepatocyte growth factor protein levels were markedly stimulated by interferon-β treatment. Additional exploration revealed that “pro-inflammatory” (CD14+CD16+) monocytes produced similar levels of hepatocyte growth factor in response to interferon-β as “classical” (CD14+CD16−) monocytes, and that CD14+ monocytes but not CD4+ T cells express the hepatocyte growth factor receptor c-Met. Our findings suggest that interferon-β may mediate some of its therapeutic effects in relapsing-remitting multiple sclerosis through the induction of hepatocyte growth factor by blood monocytes by coupling immune regulation and neuroprotection.

Trametinib for patients with advanced melanoma – Authors' reply

Gerald Falchook and colleagues show clinical activity of the MEK inhibitor trametinib in patients with either BRAF-mutant or wild-type melanoma. Recently, two essential topics for melanoma have been reported: hepatocyte growth factor (HGF)-dependent resistance to therapy and new driver mutations in melanoma. Stroma-mediated resistance to treatment of BRAF-mutant melanoma is common and HGF secretion from stromal cells seems to be responsible for this drug resistance. Analysis of biopsy samples from patients with BRAF-mutant melanoma suggests that patients with abundant HGF from stromal cells have poor responses to treatment. Furthermore, an inverse relation has been reported between plasma HGF concentration and response to treatment in patients with BRAF-mutant melanoma. HGF secretion leads to activation of the HGF receptor MET, and dual inhibition of RAF and either HGF or MET results in reversal of drug resistance in BRAFmutant melanoma. In Falchook and colleagues’ study, examination by immuno histochemistry of whether HGF expression in melanoma sections correlated with poor responses to the MEK inhibitor trametinib would have been informative, not only in patients with the BRAF mutation, but also in patients with wild-type BRAF. These results would clarify the possibility that a combination of the MEK inhibitor and MET inhibitors have a synergistic eff ect. Moreover, although EGF is less able than HGF to reactivate ERK in most melanoma cell lines, EGF and EGFR mediated resistance might be of interest in melanoma and in colon cancers. For driver mutations, six genes related to melanoma have been newly identifi ed (PPP6C, RAC1, SNX31, TACC1, STK19, and ARID2), with RAC1 mutations also reported. The Illumina platform was used in Falchook and colleagues’ study to analyse the mutational and copy number status of 78 diff erent genes commonly implicated in tumorigenesis. Within these data, is there any information about the six new melanoma genes? If these driver mutations are present, examination of whether they correlate with reduced responses to therapy with trametinib would be interesting, because such examination would not only contribute to drug response predictions but also might help select other treatment options, including combination therapies. Furthermore, data on amplifi cation of BRAF, either with or without mutations, could provide information on whether copy number of this gene plays a role in response to therapy? In the context of treatment with the MEK inhibitor trametinib, an integrated examination including HGF secretion and other gene mutations would open up the possibility of prediction of drug response and combination therapy.

Trametinib for patients with advanced melanoma

Gerald Falchook and colleagues show clinical activity of the MEK inhibitor trametinib in patients with either BRAF-mutant or wild-type melanoma. Recently, two essential topics for melanoma have been reported: hepatocyte growth factor (HGF)-dependent resistance to therapy and new driver mutations in melanoma. Stroma-mediated resistance to treatment of BRAF-mutant melanoma is common and HGF secretion from stromal cells seems to be responsible for this drug resistance. Analysis of biopsy samples from patients with BRAF-mutant melanoma suggests that patients with abundant HGF from stromal cells have poor responses to treatment. Furthermore, an inverse relation has been reported between plasma HGF concentration and response to treatment in patients with BRAF-mutant melanoma. HGF secretion leads to activation of the HGF receptor MET, and dual inhibition of RAF and either HGF or MET results in reversal of drug resistance in BRAFmutant melanoma. In Falchook and colleagues’ study, examination by immuno histochemistry of whether HGF expression in melanoma sections correlated with poor responses to the MEK inhibitor trametinib would have been informative, not only in patients with the BRAF mutation, but also in patients with wild-type BRAF. These results would clarify the possibility that a combination of the MEK inhibitor and MET inhibitors have a synergistic eff ect. Moreover, although EGF is less able than HGF to reactivate ERK in most melanoma cell lines, EGF and EGFR mediated resistance might be of interest in melanoma and in colon cancers. For driver mutations, six genes related to melanoma have been newly identifi ed (PPP6C, RAC1, SNX31, TACC1, STK19, and ARID2), with RAC1 mutations also reported. The Illumina platform was used in Falchook and colleagues’ study to analyse the mutational and copy number status of 78 diff erent genes commonly implicated in tumorigenesis. Within these data, is there any information about the six new melanoma genes? If these driver mutations are present, examination of whether they correlate with reduced responses to therapy with trametinib would be interesting, because such examination would not only contribute to drug response predictions but also might help select other treatment options, including combination therapies. Furthermore, data on amplifi cation of BRAF, either with or without mutations, could provide information on whether copy number of this gene plays a role in response to therapy? In the context of treatment with the MEK inhibitor trametinib, an integrated examination including HGF secretion and other gene mutations would open up the possibility of prediction of drug response and combination therapy.

Combined Targeting of the MET and FGF Receptor Tyrosine Kinases Induces Sustained AML Cell Death by Preventing Compensatory Upregulation of HGF in Response to MET Kinase Inhibition

Abstract 1405▪▪This icon denotes a clinically relevant abstractDespite improvements in the treatment of AML, high-risk disease including 8p11 myeloproliferative syndrome/stem cell leukemia remains largely refractory to current therapy, and is mostly fatal. Identification of effective therapeutic targets by using candidate gene approaches has been limited by the number and variety of genetic defects associated with AML. Based on the results of a genome-wide functional screen in AML using a retroviral library of short hairpin RNAs (shRNAs), we discovered that hepatocyte growth factor (HGF) is aberrantly expressed in about 40% of patients with AML, leading to activation of its receptor MET. Autocrine activation of MET is required for survival of AML cells, as genetic and pharmacologic inhibition of HGF or MET induces apoptosis and inhibits cell growth. However, AML cells treated for more than one week with the MET kinase inhibitor crizotinib develop resistance as a result of 13-fold upregulation of HGF expression, leading to restoration of MET pathway activity, and emphasizing autocrine HGF production as the basis for MET signaling addiction. Using simple thermodynamic models, we find that ligand-mediated receptor activation due to increased ligand expression effectively antagonizes the effects of targeted kinase inhibitors, causing complete restoration of aberrant signaling activity. Here we show that this mechanism of resistance can be overcome by combining MET kinase inhibition with depletion of HGF or targeting of pathways required for compensatory HGF upregulation. In the case of KG-1 cells derived from a patient with 8p11 myeloproliferative syndrome AML with chromosomal translocation mediated activation of FGFR1, we find that signaling downstream of the FGFR is required for the upregulation of HGF that occurs in response to MET kinase inhibition. Sustained MET inhibition due to the blockade of compensatory HGF upregulation leads to durable logarithmic cell kill as a result of combined treatment with the MET kinase inhibitor crizotinib and FGFR kinase inhibitor PD173074. In addition, we find that aberrant expression of HGF is highly correlated with expression of FGF2 (Pearson’s correlation = 0.79, p < 0.001), with 10% of all patients exhibiting co-expression of HGF and FGF2. This co-expression leads to autocrine co-activation of MET and FGFR1, which can be effectively targeted using combined treatment with MET and FGFR kinase inhibitors. In all, these findings suggest a therapeutic strategy for patients with co-activation of MET and FGFR, including patients with 8p11 myeloproliferative syndrome AML, establish a paradigm of effective therapeutic targeting of aberrant HGF/MET signaling in AML, and emphasize the importance of targeting compensatory ligand-dependent receptor tyrosine kinase activation, as required for the development of rational combination therapy. Disclosures:Christensen:Pfizer: Employment. Kung:Novartis Pharmaceuticals: Consultancy, Research Funding.

Possible implication of satellite cells in regenerative motoneuritogenesis: HGF upregulates neural chemorepellent Sema3A during myogenic differentiation

Regenerative coordination and remodeling of the intramuscular motoneuron network and neuromuscular connections are critical for restoring skeletal muscle function and physiological properties. The regulatory mechanisms of such coordination remain unclear, although both attractive and repulsive axon guidance molecules may be involved in the signaling pathway. Here we show that expression of a neural secreted chemorepellent semaphorin 3A (Sema3A) is remarkably upregulated in satellite cells of resident myogenic stem cells that are positioned beneath the basal lamina of mature muscle fibers, when treated with hepatocyte growth factor (HGF), established as an essential cue in muscle fiber growth and regeneration. When satellite cells were treated with HGF in primary cultures of cells or muscle fibers, Sema3A message and protein were upregulated as revealed by reverse transcription-polymerase chain reaction and immunochemical studies. Other growth factors had no inductive effect except for a slight effect of epidermal growth factor treatment. Sema3A upregulation was HGF dose dependent with a maximum (about 7- to 8-fold units relative to the control) at 10-25 ng/ml and occurred exclusively at the early-differentiation stage, as characterized by the level of myogenin expression and proliferation (bromodeoxyuridine incorporation) of the cells. Neutralizing antibody to the HGF-specific receptor, c-met, did not abolish the HGF response, indicating that c-met may not mediate the Sema3A expression signaling. Finally, in vivo Sema3A was upregulated in the differentiation phase of satellite cells isolated from muscle regenerating following crush injury. Overall, the data highlight a heretofore unexplored and active role for satellite cells as a key source of Sema3A expression triggered by HGF, hence suggesting that regenerative activity toward motor innervation may importantly reside in satellite cells and could be a crucial contributor during postnatal myogenesis.

Hepatocyte growth factor activator is a serum activator of single‐chain precursor macrophage‐stimulating protein

Macrophage-stimulating protein (MSP) is a plasma protein that circulates as a single-chain proform. It acquires biological activity after proteolytic cleavage at the Arg483-Val484 bond, a process in which serum and cell surface serine proteinases have been implicated. In this article, we report that hepatocyte growth factor activator (HGFA), a serum proteinase which activates hepatocyte growth factor in response to tissue injury, may have a critical role in the activation of pro-MSP. In vitro analysis has revealed that human HGFA efficiently cleaves human pro-MSP at the physiological activation site without further degradation, resulting in biologically active MSP, as measured by the chemotactic response and MSP-induced morphological change of peritoneal macrophages. The processing of pro-MSP by HGFA is 10-fold more efficient than processing by factor XIa. To search for a role of HGFA in pro-MSP activation, we analyzed the processing of mouse pro-MSP in sera from HGFA-knockout (HGFA(-/-)) mice. The proform of MSP was the predominant molecular form in the plasma of both wild-type and HGFA(-/-) mice. In wild-type sera, endogenous pro-MSP was progressively converted to the mature two-chain form during incubation at 37 degrees C. However, this conversion was significantly impaired in sera from HGFA(-/-) mice. The addition of recombinant HGFA to HGFA-deficient serum restored pro-MSP convertase activity in a dose-dependent manner, and a neutralizing antibody to HGFA significantly reduced the conversion of pro-MSP in wild-type serum. Moreover, initial infiltration of macrophages into the site of mechanical skin injury was delayed in HGFA(-/-) mice. We suggest that HGFA is a major serum activator of pro-MSP.

Hepatocyte growth factor (HGF) and the satellite cell response following muscle lengthening contractions in humans

The time-courses of satellite cell (SC) activation and protein expression of hepatocyte growth factor (HGF), HGF activator (HGFA), HGFA inhibitor-1 (HAI-1), and HGFA inhibitor-2 (HAI-2) in human skeletal muscle, as well as serum HGF following a single bout of muscle lengthening contractions, were determined. Eight recreationally active participants were recruited for the study. Subjects performed 300 lengthening contractions involving the quadriceps femoris muscles of a single leg at a fixed velocity of 180 degrees/s. Percutaneous muscle biopsies were taken before (PRE) and at 4 h (T4), 24 h (T24), 72 h (T72), and 120 h (T120) following the exercise. The protocol resulted in an increase in the number of SCs [neural cell adhesion molecule (NCAM)-labeled cells] expressed relative to total myonuclei, at T24, compared with both PRE and T4 (P<0.05), and peaked at T72 (approximately 80% increase vs. PRE, P<0.05). HGF protein increased significantly in serum from baseline (PRE) to T4 (P<0.05). Active HGF protein was detected in skeletal muscle at rest [14.4+/-1.3 average integrated density value (IDV)/actin average IDV] and tended to increase at early time-points (P=0.12). HGFA protein increased significantly from PRE to T24 (P<0.05). HAI-1 protein increased significantly from PRE to T24 (P<0.05). HAI-2 (32 kDa) increased significantly from baseline (PRE) by T24 (P<0.05), and also by T72 and T120 (P<0.05). We conclude that a single bout of lengthening muscle contractions is sufficient to activate SCs, which may involve both a local and systemic HGF response to contraction-induced injury.

Autocrine stimulation of human hepatocytes triggers late DNA synthesis and stabilizes long-term differentiation in vitro

Isolated human hepatocytes are of great value in investigating cell transplantation, liver physiology, pathology, and drug metabolism. Though hepatocytes possess a tremendous proliferative capacity in vivo, their ability to grow in culture is severely limited. We postulated that repeated medium change, common to most in vitro systems, may prevent long-term maintenance of hepato-specific functions and growth capacity. To verify our hypotheses we compared the DNA synthesis and differentiation status of isolated human hepatocytes, cultured in medium which was renewed every day or was not changed for 3 weeks ('autocrine' setting). Daily medium change led to rapid hepatocellular de-differentiation without any signs of DNA replication. In contrast, the autocrine setting allowed hepatocytes to become highly differentiated, demonstrated by an elevated ASGPr expression level, and increased albumin and fibrinogen synthesis and release. Cytokeratin 18 filaments were stably expressed, whereas cytokeratin 19 remained undetectable. Hepatocytes growing in an autocrine fashion were activated in the presence of hepatocyte growth factor (HGF), evidenced by c-Met phosphorylation. However, HGF response was not achieved when the culture medium was renewed daily. Furthermore, the autocrine setting evoked a late but strong interleukin 6 release into the culture supernatant, reaching maximum values after a 10-day cultivation period, and intense BrdU incorporation after a further 5-day period. Our data suggest that preservation of the same medium creates environmental conditions which allow hepatocytes to control their differentiation status and DNA synthesis in an autocrine fashion. Further studies are necessary to identify the key mediators involved in autocrine communication and to design the optimal culture configuration for clinical application.

Met-Independent Hepatocyte Growth Factor-mediated regulation of cell adhesion in human prostate cancer cells

BackgroundProstate cancer cells communicate reciprocally with the stromal cells surrounding them, inside the prostate, and after metastasis, within the bone. Each tissue secretes factors for interpretation by the other. One stromally-derived factor, Hepatocyte Growth Factor (HGF), was found twenty years ago to regulate invasion and growth of carcinoma cells. Working with the LNCaP prostate cancer progression model, we found that these cells could respond to HGF stimulation, even in the absence of Met, the only known HGF receptor. The new HGF binding partner we find on the cell surface may help to clarify conflicts in the past literature about Met expression and HGF response in cancer cells.MethodsWe searched for Met or any HGF binding partner on the cells of the PC3 and LNCaP prostate cancer cell models, using HGF immobilized on agarose beads. By using mass spectrometry analyses and sequencing we have identified nucleolin protein as a novel HGF binding partner. Antibodies against nucleolin (or HGF) were able to ameliorate the stimulatory effects of HGF on met-negative prostate cancer cells. Western blots, RT-PCR, and immunohistochemistry were used to assess nucleolin levels during prostate cancer progression in both LNCaP and PC3 models.ResultsWe have identified HGF as a major signaling component of prostate stromal-conditioned media (SCM) and have implicated the protein nucleolin in HGF signal reception by the LNCaP model prostate cancer cells. Antibodies that silence either HGF (in SCM) or nucleolin (on the cell surfaces) eliminate the adhesion-stimulatory effects of the SCM. Likewise, addition of purified HGF to control media mimics the action of SCM. C4-2, an LNCaP lineage-derived, androgen-independent human prostate cancer cell line, responds to HGF in a concentration-dependent manner by increasing its adhesion and reducing its migration on laminin substratum. These HGF effects are not due to shifts in the expression levels of laminin-binding integrins, nor can they be linked to expression of the known HGF receptor Met, as neither LNCaP nor clonally-derived C4-2 sub-line contain any detectable Met protein. Even in the absence of Met, small GTPases are activated, linking HGF stimulation to membrane protrusion and integrin activation. Membrane-localized nucelolin levels increase during cancer progression, as modeled by both the PC3 and LNCaP prostate cancer progression cell lines.ConclusionWe propose that cell surface localized nucleolin protein may function in these cells as a novel HGF receptor. Membrane localized nucleolin binds heparin-bound growth factors (including HGF) and appears upregulated during prostate cancer progression. Antibodies against nucleolin are able to ameliorate the stimulatory effects of HGF on met-negative prostate cancer cells. HGF-nucleolin interactions could be partially responsible for the complexity of HGF responses and met expression reported in the literature.

Peritoneal fluid and serum levels of hepatocyte growth factor may predict the activity of endometriosis

The suitable parameter in PF as well as in serum that may predict the activity of endometriosis is not well described. Therefore, we tried to examine the peritoneal fluid (PF) and serum concentrations of hepatocyte growth factor (HGF) in different revised American Society of Reproductive Medicine (r-ASRM) staging and morphologic appearances of endometriosis in an attempt to determine whether HGF can be clinically useful to predict the activity of pelvic endometriosis. Peritoneal fluid was collected from 137 women with endometriosis and 57 women without endometriosis during laparoscopy and blood sampling was collected from 37 women with endometriosis and 21 women without endometriosis before laparoscopy. The concentration of HGF in PF and serum was measured by enzyme-linked immunosorbent assay. The ability of isolated macrophages and stroma to secrete HGF in response to lipopolysaccharide (LPS) was evaluated. A significantly increased concentration of HGF in PF was found in women with endometriosis (1451.75 +/- 90.7 pg/mL) than that in non-endometriosis (1120.5 +/- 77.3 pg/mL, p < 0.01) without any remarkable difference in HGF levels between women with stage I-/II endometriosis and stage III-/IV endometriosis. When we distributed serum and PF levels of HGF according to different color appearances of endometriosis, we found a significantly higher serum and PF levels of HGF in women containing dominant red peritoneal lesions in pelvic cavity (740 +/- 109.3 pg/mL for serum; 1685 +/- 183.4 pg/mL for PF) than those having other pigmented lesions (649 +/- 79.5 pg/mL, p < 0.05 for serum; 1224 +/- 67.8 pg/mL, p < 0.05 for PF) or chocolate cysts (485 +/- 43.1 pg/mL, p < 0.05 for serum; 1118 +/- 83.1 pg/mL, p < 0.01 for PF). Exogenous stimulation with LPS significantly increased the production of HGF in the culture media by macrophages and stroma derived from women with endometriosis than that in women without endometriosis. These results suggest that women with early or advanced endometriosis as measured by r-ASRM scoring system are not associated with an increase in either serum or PF concentrations of HGF. Rather HGF levels in serum and PF were significantly increased in women harboring blood-filled red peritoneal lesions and may be clinically useful to predict the activity of pelvic endometriosis.

Estrogen and progesterone receptor expression in macrophages and regulation of hepatocyte growth factor by ovarian steroids in women with endometriosis

Information regarding macrophage-mediated regulation of hepatocyte growth factor (HGF) by ovarian steroid hormones in women with endometriosis is limited. Therefore, we investigated the regulation of HGF by steroid hormones in isolated macrophages and stromal cells derived from women with or without endometriosis. We isolated CD68 immunoreactive adherent macrophages in vitro from 46 women with endometriosis and 30 women without endometriosis. Estrogen receptor (ER) and progesterone receptor (PR) expression in macrophages was demonstrated by immunohistochemistry and RT-PCR. Production of HGF in the culture media of basal and ovarian steroid-stimulated macrophages was examined by enzyme-linked immunosorbent assay. Expression of mRNA for HGF and its receptor, c-Met in macrophages and stromal cells in response to ovarian steroid was investigated by RT-PCR. The single and combined effect of HGF and estrogen on the growth of macrophages and stromal cells was analysed by bromodeoxyuridine (BrdU) incorporation. ER and PR were expressed in isolated macrophages and intact tissue at the protein and mRNA levels. Macrophages derived from women with endometriosis produced significantly higher concentration of HGF (352.2 +/- 4.9 pg/ml) in conditioned media after treatment with estradiol (10(-8) mol/l) than that of basal macrophages (221.5 +/- 32.8 pg/ml, P<0.05) or women without endometriosis (170.6 +/- 2.6 pg/ml, P<0.05). These effects were less evident after treatment with progesterone. Treatment with tamoxifen (10(-6) mol/l) reversed the production of HGF and other macromolecules. Secretion of HGF in response to ovarian steroids was further enhanced after activation with lipopolysaccharide. The mRNA expressions of HGF and its receptor, c-Met, were also detected in macrophages and stroma in response to estrogen, suggesting an autocrine regulation. HGF mRNA expression was higher in cells of women with endometriosis than non-endometriosis women. Bromodeoxyuridine incorporation indicated that exogenous stimulation with HGF and estrogen, either alone or in combination, significantly increased the cell proliferation of both endometrial stroma and macrophages compared to that of non-endometriosis or non-treated cells. These results suggest that besides other inflammatory mediators, ovarian steroids also participate in the production of HGF by peritoneal macrophages which may be involved in the growth of endometriosis either alone or in combination with estrogen.

Burdens of disease in southern Africa

20 Ross DJ, Moudgil A, Bagga A, et al. Lung allograft dysfunction correlates with gamma-interferon gene expression in bronchoalveolar lavage. J Heart Lung Transplant 1999; 18: 627–36. 21 Tsubouchi H, Niitani Y, Hirono S, et al. Levels of the human hepatocyte growth factor in serum of patients with various liver diseases determined by an enzyme-linked immunosorbent assay. Hepatology 1991; 13: 1–5. 22 Maeda J, Ueki N, Hada T, Higashino K. Elevated serum hepatocyte growth factor/scatter factor levels in inflammatory lung disease. Am J Respir Crit Care Med 1995; 152: 1587–91. 23 Valantine HA, Luikart H, Doyle R, et al. Impact of cytomegalovirus hyperimmune globulin on outcome after cardiothoracic transplantation: a comparative study of combined prophylaxis with CMV hyperimmune globulin plus ganciclovir versus ganciclovir alone. Transplantation 2001; 72: 1647–52. 24 Weill D, Lock BJ, Wewers DL, et al. Combination prophylaxis with ganciclovir and cytomegalovirus (CMV) immune globulin after lung transplantation: effective CMV prevention following daclizumab induction. Am J Transplant 2003; 3: 492–96. 25 Defrances MC, Wolf HK, Michalopoulos GK, Zarnegar R. The presence of hepatocyte growth factor in the developing rat. Development 1992; 116: 387–95. 26 Matsumoto K, Tajima H, Hamanoue M, Kohno S, Kinoshita T, Nakamura T. Identification and characterization of “injurin,” an inducer of expression of the gene for hepatocyte growth factor. Proc Natl Acad Sci USA 1992; 89: 3800–04. 27 Yanagita K, Nagaike M, Ishibashi H, Niho Y, Matsumoto K, Nakamura T. Lung may have an endocrine function producing hepatocyte growth factor in response to injury of distal organs. Biochem Biophys Res Commun 1992; 182: 802–09. 28 Hall SM, Odom N, McGregor CG, Haworth SG. Transient ultrastructural injury and repair of pulmonary capillaries in transplanted rat lung: effect of preservation and reperfusion. Am J Respir Cell Mol Biol 1992; 7: 49–57. ARTICLES

Portal and systemic serum growth factor and acute-phase response after laparotomy or partial hepatectomy in patients with colorectal liver metastases: a prognostic role for C-reactive protein and hepatocyte growth factor

Background: Growth factors play a role in wound healing and tumour growth. The aim of this study was to compare the effect of partial hepatectomy (PH) and laparotomy on serum levels of growth factors and acute-phase proteins in patients with colorectal liver metastases and to correlate these levels with prognosis after PH. Methods: Epidermal growth factor (EGF), hepatocyte growth factor (HGF), insulin like growth factor-I (IGF-I), insulin, interleukin-6 (IL-6), C-reactive protein (CRP) and serum amyloid-A (SAA) were determined in portal and systemic serum in 24 PH patients and 9 laparotomy patients. Results: No differences were found in the clinicopathological characteristics of PH and laparotomy patients with the exception of the number of metastases, blood loss and operation time. The response of SAA, CRP and IGF-I was lower in PH patients than in laparotomy patients (P < 0.02). PH was associated with a higher IL-6 (P = 0.02) and HGF (P = 0.055) response than laparotomy. A higher HGF and CRP response was associated with a poorer prognosis. Total IGF-I was negatively correlated with the resected liver volume (r = −0.48, P < 0.05). Conclusions: PH is associated with a lower acute-phase and total IGF-I response and a higher HGF and IL-6 response compared with laparotomy. HGF and CRP responses had an influence on the prognosis.

A differentiation switch for genetically modified hepatocytes.

The hepatocyte growth factor (HGF) receptor mediates a two-sided response-cell proliferation and differentiation. This process, defined as "branching morphogenesis," involves cell scatter and redistribution to form ramified hollow tubules within the extracellular matrix, and protection from apoptosis. We have fused the intracellular domain of the HGF receptor (HGFR) with three FK506-binding protein (FKBP) domains and a membrane-targeting signal. This molecule (FKBP-HGFR) dimerizes after administration of a bifunctional ligand specific for FKBP domains. We show that, in mouse hepatocyte progenitors, FKBP-HGFR dimerization elicits the differentiative side of the HGF response, including cell scatter, morphogenesis, and protection from apoptosis. Surprisingly, FKBP-HGFR does not induce cell proliferation. We could correlate the segregation of the differentiative response with a distinctive signaling kinetic of FKBP-HGFR: a) reduced and prolonged tyrosine kinase activation; and b) low early peak of MAP kinase activation (a log lower than the peak induced by the wild-type receptor), followed by a sustained activation over 6 h. These data show that the biological response triggered by the HGFR can be dissected on the basis of the quantitative signaling profile, and that FKBP-HGFR may be used to control selectively the differentiation of hepatocytes, without promoting cell expansion.