Partial purification and characterization of hepatocyte growth factor from serum of hepatectomized rats

SNPs of bovine HGF gene and their association with growth traits in Nanyang cattle

Hepatocyte growth factor (HGF) is one of the multifunctional cell factors that regulates cellular proliferation, motility and morphogenesis in mammalians. And its medical research has deep significance. In this paper, polymorphisms of HGF gene were investigated in 1433 health and irrelated Chinese cattle by PCR-RFLP and DNA sequencing approach. Ten novel Single nucleotide polymorphisms (SNPs) were identified, which included one missense mutation, g.72801G>A in the coding region, and the others in the intron. Association analysis between four of them, g.288T>C, g.72801G>A, g.77172G>T, and g.77408T>G, and growth traits in Nanyang, were performed. The results indicated that SNPs within bovine HGF gene were significantly associated with growth traits. Phylogenetic analysis showed that the genetic background of Caoyuan Red cattle was different from the others in the tested breeds. The findings will provide a background for application of bovine HGF gene in the selection program in Chinese cattle.

Up-regulation of cyclin-E(1) via proline-mTOR pathway is responsible for HGF-mediated G(1)/S progression in the primary culture of rat hepatocytes

Hepatocyte growth factor (HGF) is a key ligand that elicits G1/S progression of epithelial cells, including hepatocytes. Proline is also required for DNA synthesis that is induced by growth factors in primary culture of hepatocytes. However, it remains unknown how proline contributes to the G1/S progression of hepatocytes. The primary culture of rat hepatocytes using HGF plus proline can be a conceptual model for elucidating the molecular linkage of amino acids and growth factors during G1/S progression. Using this in vitro model, we provide evidence that not only induction of cyclin-D1 by HGF but also up-regulation of cyclin-E1 by proline is required for hepatocytes to enter the S-phase. Proline-enhanced cyclin-E1 induction, without changing its mRNA level, is associated with the activation of mammalian target of rapamycin (mTOR)-dependent pathways. Indeed, proline enhanced the ribosomal protein S6 phosphorylations (i.e., mTOR target), concomitantly with an increase in cyclin-E1. Inversely, mTOR-inhibitor, rapamycin suppressed the proline-mediated induction of cyclin-E1. As a result, DNA synthesis of hepatocytes, which was induced by HGF in the presence of proline, was largely abolished by mTOR-inhibitor treatment. Such a co-mitogenic effect of proline was also dependent on collagen synthesis: collagen synthesis inhibitors, such as cis-OH-proline, diminished the proline-induced cyclin-E1, and then the G1/S progression of hepatocytes was also suppressed. Overall, proline-mediated mTOR activation and collagen synthesis were found critical for HGF-induced DNA synthesis, partly via the sufficient accumulation of cyclin-E1. This is the first report to demonstrate the molecular bridge between amino acids and growth factors that drive mitogenic outcomes.

HGF percutaneous endocardial injection induces cardiomyocyte proliferation and rescues cardiac function in pigs

OBJECTIVE

To investigate the effect of cardiomyocyte proliferation induced by human hepatocyte growth factor (HGF) in pigs with chronic myocardial infarction (CMI).

METHODS

A steerable, deflectable 7F catheter incorporating a 27-guage needle was advanced percutaneously to the left ventricular myocardium of 18 pigs with CMI. Pigs were randomized (1:1:1) to receive adenoviral vector HGF (total dose, 1×10(10) genome copies), which was administered as five injections into the infarcted myocardium (total, 1.0 mL), or saline, or Ad-null (control groups). Injections were guided by Ensite NavX left ventricular electroanatomical mapping. HGF and cyclin proteins were detected by western blot and immunoprecipitation analysis. Histological and immunohistochemical analysis determined proliferating cardiomyocytes. Myocardial perfusion and cardiac function were estimated by Gated-Single Photon Emission Computed Tomography (G-SPECT).

RESULTS

Western blot analyses showed that HGF were predominantly expressed in the infarct core and border in the myocardium of the infarcted heart. G-SPECT analysis indicated that the HGF group had better cardiac function and myocardial perfusion four weeks after the injection of Ad-HGF than before the injection of Ad-HGF. After treatment there were more proliferating cardiomyocytes in the HGF group compared to either of the control groups. Furthermore, the HGF group myocardial samples expressed higher levels of p-Akt, cyclin A, cyclin E, cyclin D1, cdk2, cdk4 than those in the control groups.

CONCLUSION

The over-expression of HGF activates pro-survival pathways, induces cardiomyocyte proliferation, and improves the perfusion and function of the porcine CMI heart.

HGF as a circulating biomarker of onartuzumab treatment in patients with advanced solid tumors

The objective of this study was to evaluate circulating hepatocyte growth factor (cHGF) as a pharmacodynamic biomarker of Met inhibition for onartuzumab (MetMAb, OA5D5v2) in a phase I trial in patients with advanced cancers and a phase II trial in non-small cell lung cancer (NSCLC). The phase I study was a dose escalation trial with onartuzumab administered i.v. once every three weeks. The phase II study was a randomized two-arm trial in which onartuzumab or placebo was administered in combination with erlotinib in 137 patients with second and third line (2/3L) NSCLC. cHGF levels were evaluated by ELISA at multiple time points over the treatment period. Onartuzumab administration resulted in an acute and sustained rise in cHGF in both the phase I and phase II studies. Elevation in cHGF was independent of dose or drug exposure and was restricted to onartuzumab treatment. Neither higher baseline nor elevated change in cHGF levels upon treatment could simply be attributed to tumor burden or number of liver metastasis. We have shown that elevated cHGF can consistently and reproducibly be measured as a pharmacodynamic biomarker of onartuzumab activity. The elevation in cHGF is independent of tumor type, dose administered, or dose duration. Although these studies were not powered to directly address the contribution of cHGF as a predictive, on-treatment, circulating biomarker, these data suggest that measurement of cHGF in future expanded studies is warranted.

Total synthesis of biotinylated N domain of human hepatocyte growth factor

Hepatocyte growth factor/scatter factor (HGF/SF) is the high affinity ligand of MET tyrosine kinase receptor. We report here the total synthesis of a biotinylated analogue of human HGF/SF N domain. Functionally, N domain is part of the HGF/SF high affinity binding site for MET and also the main HGF/SF binding site for heparin. The 97 Aa linear chain featuring a C-terminal biotin group was assembled in high yield using an N-to-C one-pot three segments assembly strategy relying on a sequential Native Chemical Ligation (NCL)/bis(2-sulfanylethyl)amido (SEA) native peptide ligation process. The folded protein displayed the native disulfide bond pattern and showed the ability to bind heparin.

A novel c-Met inhibitor, MK8033, synergizes with carboplatin plus paclitaxel to inhibit ovarian cancer cell growth

Elevated serum levels of hepatocyte growth factor (HGF) and high tumor expression of c-Met are both indicators of poor overall survival from ovarian cancer (OVCA). In the present study, we evaluated the role of the HGF signaling pathway in OVCA cell line chemoresistance and OVCA patient overall survival as well as the influence of HGF/c-Met signaling inhibition on the sensitivity of OVCA cells to combinational carboplatin plus paclitaxel therapy. The prevalence of the HGF receptor, c-Met, was determined by immunohistochemistry in primary OVCA samples (n=79) and OVCA cell lines (n=41). The influence of the c-Met-specific inhibitor MK8033 on OVCA cell sensitivity to combinations of carboplatin plus paclitaxel was examined in a subset of OVCA cells (n=8) by CellTiter-Blue cell viability assays. Correlation tests were used to identify genes associated with response to MK8033 and carboplatin plus paclitaxel. Identified genes were evaluated for influence on overall survival from OVCA using principal component analysis (PCA) modeling in an independent clinical OVCA dataset (n=218). Immunohistochemistry analysis indicated that 83% of OVCA cells and 92% of primary OVCA expressed the HGF receptor, c-Met. MK8033 exhibited significant anti-proliferative effects against a panel of human OVCA cell lines. Combination index values determined by the Chou-Talalay isobologram equation indicated synergistic activity in combinations of MK8033 and carboplatin plus paclitaxel. Pearson's correlation identified a 47-gene signature to be associated with MK8033-carboplatin plus paclitaxel response. PCA modeling indicated an association of this 47-gene response signature with overall survival from OVCA (P=0.013). These data indicate that HGF/c-Met pathway signaling may influence OVCA chemosensitivity and overall patient survival. Furthermore, HGF/c-Met inhibition by MK8033 represents a promising new therapeutic avenue to increase OVCA sensitivity to carboplatin plus paclitaxel.

Targeting the HGF/c-MET pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a significant cause of cancer-related morbidity and mortality worldwide. Despite improvements in local therapies, including surgical resection, liver transplantation, and transarterial embolization, the prognosis remains poor for the majority of patients who develop recurrence or present with advanced disease. Systemic therapy with the tyrosine kinase inhibitor sorafenib represents a milestone in advanced HCC but provides a limited survival benefit. Ongoing efforts to study hepatocarcinogenesis have identified an important role for c-MET signaling in the promotion of tumor growth, angiogenesis, and metastasis. In this review, we summarize the preclinical data from human tissue, cell lines, and animal models that implicate c-MET in the pathogenesis of HCC. We also evaluate potential biomarkers that may estimate prognosis or predict response to c-MET inhibitors for more rational clinical trial design. Finally, we discuss the latest clinical trials of c-MET inhibitors in advanced HCC.

HGF and c-Met interaction promotes migration in human chondrosarcoma cells

Chondrosarcoma is a type of highly malignant tumor with a potent capacity for local invasion and causing distant metastasis. Chondrosarcoma shows a predilection for metastasis to the lungs. Hepatocyte growth factor (HGF) has been demonstrated to stimulate cancer proliferation, migration, and metastasis. However, the effect of HGF on migration activity of human chondrosarcoma cells is not well known. Here, we found that human chondrosarcoma tissues demonstrated significant expression of HGF, which was higher than that in normal cartilage. We also found that HGF increased the migration and expression of matrix metalloproteinase (MMP)-2 in human chondrosarcoma cells. c-Met inhibitor and siRNA reduced HGF-increased cell migration and MMP-2 expression. HGF treatment resulted in activation of the phosphatidylinositol 3'-kinase (PI3K)/Akt/PKCδ/NF-κB pathway, and HGF-induced expression of MMP-2 and cell migration was inhibited by specific inhibitors or siRNA-knockdown of PI3K, Akt, PKCδ, and NF-κB cascades. Taken together, our results indicated that HGF enhances migration of chondrosarcoma cells by increasing MMP-2 expression through the c-Met receptor/PI3K/Akt/PKCδ/NF-κB signal transduction pathway.

HGF-MET cascade, a key target for inhibiting cancer metastasis: the impact of NK4 discovery on cancer biology and therapeutics

Hepatocyte growth factor (HGF) was discovered in 1984 as a mitogen of rat hepatocytes in a primary culture system. In the mid-1980s, MET was identified as an oncogenic mutant protein that induces malignant phenotypes in a human cell line. In the early 1990s, wild-type MET was shown to be a functional receptor of HGF. Indeed, HGF exerts multiple functions, such as proliferation, morphogenesis and anti-apoptosis, in various cells via MET tyrosine kinase phosphorylation. During the past 20 years, we have accumulated evidence that HGF is an essential conductor for embryogenesis and tissue regeneration in various types of organs. Furthermore, we found in the mid-1990s that stroma-derived HGF is a major contributor to cancer invasion at least in vitro. Based on this background, we prepared NK4 as an antagonist of HGF: NK4 inhibits HGF-mediated MET tyrosine phosphorylation by competing with HGF for binding to MET. In vivo, NK4 treatments produced the anti-tumor outcomes in mice bearing distinct types of malignant cancers, associated with the loss in MET activation. There are now numerous reports showing that HGF-antagonists and MET-inhibitors are logical for inhibiting tumor growth and metastasis. Additionally, NK4 exerts anti-angiogenic effects, partly through perlecan-dependent cascades. This paper focuses on the chronology and significance of HGF-antagonisms in anti-tumor researches, with an interest in NK4 discovery. Tumor HGF–MET axis is now critical for drug resistance and cancer stem cell maintenance. Thus, oncologists cannot ignore this cascade for the future success of anti-metastatic therapy.

Hepatocyte growth factor and lung fibrosis

Idiopathic pulmonary fibrosis is currently believed to be driven by alveolar epithelial cells, with abnormally activated alveolar epithelial cells accumulating in an attempt to repair injured alveolar epithelium (1). Thus, targeting the alveolar epithelium to prevent or inhibit the development of pulmonary fibrosis might be an interesting therapeutic option in this disease. Hepatocyte growth factor (HGF) is a growth factor for epithelial and endothelial cells, which is secreted by different cell types, especially fibroblasts and neutrophils. HGF has mitogenic, motogenic, and morphogenic properties and exerts an antiapoptotic action on epithelial and endothelial cells. HGF has also proangiogenic effect. In vitro, HGF inhibits epithelial-to-mesenchymal cell transition and promotes myofibroblast apoptosis. In vivo, HGF has antifibrotic properties demonstrated in experimental models of lung, kidney, heart, skin, and liver fibrosis. Hence, the modulation of HGF may be an attractive target for the treatment of lung fibrosis.

Loss of HGF activator inhibits foveolar hyperplasia induced by oxyntic atrophy without altering gastrin levels

Spasmolytic polypeptide/trefoil family factor 2 expressing metaplasia (SPEM) is induced by oxyntic atrophy and is known as a precancerous or paracancerous lesion. We now have sought to determine whether hepatocyte growth factor (HGF) influences the development of SPEM and oxyntic atrophy. DMP-777, a parietal cell ablating reagent, was administered to HGF activator (HGFA)-deficient mice and wild-type mice. Gastric mucosal lineage changes were analyzed in the DMP-777 treatment phase and recovery phase. Both wild-type and HGFA knockout mice showed SPEM, and there was no difference in SPEM development. However, after cessation of DMP-777, HGFA-deficient mice showed delayed recovery from SPEM compared with wild-type mice. Foveolar cell hyperplasia and the increase in proliferating cells after parietal cell loss were reduced in HGFA-deficient mice. The HGFA does not affect emergence of SPEM. However, the absence of HGFA signaling causes a delay in the recovery from SPEM to normal glandular composition. HGFA also promotes foveolar cell hyperplasia and mucosal cell proliferation in acute oxyntic injury.

Hepatocyte growth factor increases vascular endothelial growth factor-A production in human synovial fibroblasts through c-Met receptor pathway

Background

Angiogenesis is essential for the progression of osteoarthritis (OA). Hepatocyte growth factor (HGF) is an angiogenic mediator, and it shows elevated levels in regions of OA. However, the relationship between HGF and vascular endothelial growth factor (VEGF-A) in OA synovial fibroblasts (OASFs) is mostly unknown.

Methodology/Principal Findings

Here we found that stimulation of OASFs with HGF induced concentration- and time-dependent increases in VEGF-A expression. Pretreatment with PI3K inhibitor (Ly294002), Akt inhibitor, or mTORC1 inhibitor (rapamycin) blocked the HGF-induced VEGF-A production. Treatment of cells with HGF also increased PI3K, Akt, and mTORC1 phosphorylation. Furthermore, HGF increased the stability and activity of HIF-1 protein. Moreover, the use of pharmacological inhibitors or genetic inhibition revealed that c-Met, PI3K, Akt, and mTORC1 signaling pathways were potentially required for HGF-induced HIF-1α activation.

Conclusions/Significance

Taken together, our results provide evidence that HGF enhances VEGF-A expression in OASFs by an HIF-1α-dependent mechanism involving the activation of c-Met/PI3K/Akt and mTORC1 pathways.

Therapeutic potential of growth factors in pulmonary emphysematous condition

Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease (COPD), which is characterized by progressive destruction of alveolar parenchyma with persistent inflammation of the small airways. Such destruction in the distal respiratory tract is irreversible and irreparable. All-trans-retinoic acid was suggested as a novel therapy for regeneration of lost alveoli in emphysema. However, profound discrepancies were evident between studies. At present, no effective therapeutic options are available that allow for the regeneration of lost alveoli in emphysematous human lungs. Recently, some reports on rodent's models have suggested the beneficial effects of various growth factors toward alveolar maintenance and repair processes.

Change in hepatocyte growth factor concentration promote mesenchymal stem cell-mediated osteogenic regeneration

Mesenchymal stem cells (MSCs) play a crucial role in tissue repair by secretion of tissue nutrient factors such as hepatocyte growth factor (HGF). However, studies examining the effects of HGF on the proliferation and differentiation of MSCs used different concentrations of HGF and reported conflicting conclusions. This study aimed to determine the mechanisms by which different concentrations of HGF regulate MSC proliferation and osteogenic differentiation, and validate the mechanism in an animal model of early stage avascular necrosis of femoral head (ANFH). Our results demonstrate that a low concentration of HGF (20 ng/ml) preferentially promotes MSC osteogenic differentiation through increased c-Met expression and phosphorylation, Akt pathway activation, and increased expression of p27, Runx2 and Osterix. In contrast, a high concentration of HGF (100 ng/ml) strongly induced proliferation by inducing strong activation of the ERK1/2 signalling pathway. As validated by animal experiments, high localized expression of HGF achieved by transplantation of HGF transgenic MSCs into ANFH rabbits increased the number of MSCs. Subsequently, 2 weeks after transplantation, HGF levels decreased and MSCs differentiated into osteoblasts and resulted in efficient tissue repair. Our results demonstrate that sequential concentration changes in HGF control the proliferation and osteogenic differentiation of MSCs in vivo. This phenomenon can be exploited therapeutically to induce bone regeneration and, in turn, improve the efficacy of pharmacological intervention for ANFH treatment.

Hepatocyte Growth Factor Inhibits Lipopolysaccharide-Induced Oxidative Stress via Epithelial Growth Factor Receptor Degradation

Objective—

Lipopolysaccharide (LPS) triggers sepsis and systemic inflammatory response syndrome, which results in multiple organ failure. Our recent reports demonstrated that hepatocyte growth factor (HGF) attenuated angiotensin II–induced oxidative stress via epithelial growth factor receptor (EGFR) degradation in vascular smooth muscle cells. Here, we examined whether HGF can protect against systemic inflammatory response syndrome induced by LPS and investigated the mechanism.

Methods and Results—

HGF inhibited the increase in the expression of vascular cell adhesion molecule-1 and EGFR by LPS in vitro. HGF inhibited colocalization of EGFR and Src homology domain 2–containing inositol 5′-phosphatase 2. Furthermore, HGF inhibited reactive oxygen species production. We also injected LPS into HGF transgenic mice with increased HGF serum concentration and their littermates. HGF transgenic mice reduced LPS-induced vascular cell adhesion molecule-1 and reactive oxygen species compared with control, accompanied by significant EGFR degradation. Furthermore, HGF transgenic mice significantly improved survival in the LPS injection model.

Conclusion—

The present study revealed inhibition of LPS-induced vascular cell adhesion molecule-1 expression by HGF via the degradation of EGFR. We demonstrated that HGF regulated Src homology domain 2–containing inositol 5′-phosphatase 2 recruitment to EGFR and inhibited LPS-induced inflammation via EGFR degradation. This effect of HGF may be useful for the treatment of inflammatory disease.

Growth factors released from gelatin hydrogel microspheres increase new neurons in the adult mouse brain

Recent studies have shown that new neurons are continuously generated by endogenous neural stem cells in the subventricular zone (SVZ) of the adult mammalian brain. Some of these new neurons migrate to injured brain tissues and differentiate into mature neurons, suggesting that such new neurons may be able to replace neurons lost to degenerative disease or injury and improve or repair neurological deficits. Here, we tested whether delivering growth factors via gelatin hydrogel microspheres would support neurogenesis in the SVZ. Insulin-like growth factor-1 (IGF-1)-containing microspheres increased the number of new neurons in the SVZ. Hepatocyte growth factor (HGF)-containing microspheres increased the number of new neurons migrating from the SVZ towards the injured striatum in a stroke model in mouse. These results suggest that the strategy of using gelatin hydrogel microspheres to achieve the sustained release of growth factors holds promise for the clinical regeneration of damaged brain tissues from endogenous neural stem cells in the adult SVZ.

Regulatory mechanisms of injury and repair after hepatic ischemia/reperfusion

Hepatic ischemia/reperfusion injury is an important complication of liver surgery and transplantation. The mechanisms of this injury as well as the subsequent reparative and regenerative processes have been the subject of thorough study. In this paper, we discuss the complex and coordinated responses leading to parenchymal damage after liver ischemia/reperfusion as well as the manner in which the liver clears damaged cells and regenerates functional mass.

Dissociation of c-Met phosphotyrosine sites in human cells in response to mouse hepatocyte growth factor but not human hepatocyte growth factor: the possible roles of different amino acids in different species

Hepatocyte growth factor (HGF) is essential for embryogenesis, tissue regeneration and tumour malignancy through the activation of its receptor, c-Met. We previously demonstrated that HGF α-chain hairpin-loop, K1 domain and β-chain are required for c-Met signalling. The sequential phosphorylation of tyrosine residues, from c-Met kinase domain to multidocking regions, is required for HGF-signalling transduction. Herein, we provide evidence that the disconcerted activation of c-Met tyrosine regions fails to induce biological functions. When human cells were incubated with 'mouse HGF', kinase domain activation (i.e. phospho-Tyr-1230/34/35) became evident, but the multidocking site (i.e. Tyr-1349) was not phosphorylated, resulting in unsuccessful induction of migration and mitogenesis. The binding ability of mouse HGF α-chain, or of β-chain, to human c-Met was lower than that of human HGF, as evidenced by HGF-chimera assay. Notably, only four amino acid positions in HGF α-chain hairpin-loop and K1 domain and six positions in β-chain differed between human HGF and mouse HGF. The human-specific amino acids (such as Gln-95 in hairpin-loop, Arg-134 in K1 domain and Cys-561 in β-chain) may be important for accurate c-Met assembly and signalling transduction.

Hepatocyte growth factor stimulates neutrophil degranulation but not respiratory burst

Neutrophil function is regulated in part by cytokines with growth factor activities for different cell types. Hepatocyte growth factor (HGF) is a cytokine produced during injury to the liver and other organs. Neutrophils are numerous in such tissue injury sites and may be influenced by HGF. In the present study the effect of HGF on neutrophils was investigated. The data show that HGF at 1-10 ng/ml increased lysosomal enzyme release from both specific and azurophilic granules of cytochalasin-B treated neutrophils. The release of specific granule contents in response to N-formyl-methionyl-leucylphenylalanine was also increased by HGF. In contrast there were no significant effects of HGF on neutrophil respiratory burst, adherence or locomotion. It is concluded that HGF modulates neutrophil granule exocytosis.

Mechanisms of HGF/Met signaling to Brk and Sam68 in breast cancer progression

Signal transduction pathways downstream of receptor tyrosine kinases (RTKs) are often deregulated during oncogenesis, tumor progression, and metastasis. In particular, the peptide growth factor hormone, hepatocyte growth factor (HGF), and its specific receptor, Met tyrosine kinase, regulate cancer cell migration, thereby conferring an aggressive phenotype (Nakamura et al., J Clin Invest 106(12):1511-1519, 2000; Huh et al., Proc Natl Acad Sci U S A 101:4477-4482, 2004). Additionally, overexpression of Met is associated with enhanced invasiveness of breast cancer cells (Edakuni et al., Pathol Int 51(3):172-178, 2001; Jin et al., Cancer 79(4):749-760, 1997; Tuck et al., Am J Pathol 148(1):225-232, 1996). Here, we review the regulation of recently identified novel downstream mediators of HGF/Met signaling, Breast tumor kinase (Brk/PTK6), and Src-associated substrate during mitosis of 68 kDa (Sam68), and discuss their relevance to mechanisms of breast cancer progression.

Attenuation of hepatic fibrosis through ultrasound-microbubble-mediated HGF gene transfer in rats

OBJECTIVE

The objective was to explore the feasibility of ultrasound-microbubble-mediated hepatocyte growth factor (HGF) gene transfer for treating rat hepatic fibrosis induced by CCl(4).

METHODS

Forty-eight male SD rats were divided into ultrasound-microbubble-HGF group (U-M-HGF group), ultrasound-HGF group (U-HGF group), microbubble-HGF group (M-HGF group), HGF group (HGF group), CCl(4) group (control group), and normal group. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), total protein, albumin (ALB), and globulin (GLB) and the ratio of ALB/GLB were determined after treatment. The degree of hepatic fibrosis was evaluated by histopathological numerical scores. The protein expressions of HGF, collagen I, collagen III, and α-smooth muscle antibody (α-SMA) were detected by immunohistochemistry.

RESULTS

Ultrasound-microbubble-mediated HGF therapy significantly reduced the serum level of ALT and AST to 59.88% and 49.18% of the control group, respectively. Ultrasound-microbubble-mediated HGF therapy prevented liver fibrosis, with an obvious decrease in fibrosis areas and extracellular matrix production of collagen I, collagen III, and α-SMA. The gene therapy could induce HGF delivery into the fibrotic liver effectively.

CONCLUSIONS

Ultrasound-microbubble-mediated HGF gene therapy can reduce liver fibrosis, which provides a novel strategy for gene therapy of chronic liver disease.

Hepatocyte growth factor increases osteopontin expression in human osteoblasts through PI3K, Akt, c-Src, and AP-1 signaling pathway

BACKGROUND

Hepatocyte growth factor (HGF) has been demonstrated to stimulate osteoblast proliferation and participated bone remodeling. Osteopontin (OPN) is a secreted phosphoglycoprotein that belongs to the SIBLING family and is present during bone mineralization. However, the effects of HGF on OPN expression in human osteoblasts are large unknown.

METHODOLOGY/PRINCIPAL FINDINGS

Here we found that HGF induced OPN expression in human osteoblasts dose-dependently. HGF-mediated OPN production was attenuated by c-Met inhibitor and siRNA. Pretreatment of osteoblasts with PI3K inhibitor (Ly294002), Akt inhibitor, c-Src inhibitor (PP2), or AP-1 inhibitor (curcumin) blocked the potentiating action of HGF. Stimulation of osteoblasts with HGF enhanced PI3K, Akt, and c-Src activation. In addition, incubation of cells with HGF also increased c-Jun phosphorylation, AP-1-luciferase activity, and c-Jun binding to the AP-1 element on the OPN promoter. HGF-mediated AP-1-luciferase activity and c-Jun binding to the AP-1 element was reduced by c-Met inhibitor, Ly294002, Akt inhibitor, and PP2.

CONCLUSIONS/SIGNIFICANCE

Our results suggest that the interaction between HGF and c-Met increases OPN expression in human osteoblasts via the PI3K, Akt, c-Src, c-Jun, and AP-1 signaling pathway.

Expression of hepatocyte growth factor in the skin of amyotrophic lateral sclerosis

OBJECTIVES

Hepatocyte growth factor (HGF) is one of the most potent survival-promoting factors for motor neurons. Overexpression of neuronal HGF has been shown to result in the attenuation of neuronal cell death and progression of disease in a familial amyotrophic lateral sclerosis (ALS) transgenic mouse model. HGF might be beneficial for motor neuron survival and is a good candidate agent for the treatment of ALS. So far, studies of the skin of ALS have shown unique pathological and biochemical abnormalities. However, there has been no study of HGF in ALS skin.

MATERIALS AND METHODS

We made a quantitative immunohistochemical study of the expression of HGF in the skin from 19 patients with sporadic ALS and 16 controls.

RESULTS

Hepatocyte growth factor immunoreactivity was positive in the epidermis, some dermal blood vessels, and glands in patients with ALS. These findings became more conspicuous as ALS progressed. The optical density for HGF immunoreactivity of the nucleus and the cytoplasm in the epidermis in ALS was significantly higher (P < 0.001 and P < 0.001) than in controls. There was a significant positive relation (r = 0.53, P < 0.02 and r = 0.73, P < 0.001) between HGF immunoreactivity and duration of illness in the nucleus and the cytoplasm in the epidermis in patients with ALS.

CONCLUSIONS

These findings suggest that changes in HGF in ALS skin are related to the disease process and that metabolic alterations of HGF may take place in the skin of patients with ALS.

Ischaemic Preconditioning and Intermittent Clamping Does not Influence Mediators of Liver Regeneration in a Human Liver Sinusoidal Endothelial Cell Model of Ischaemia-Reperfusion Injury

BACKGROUND

The role of surgical technique on liver regeneration following surgery remains inconclusive. The aim of the study was to assess the effect of ischaemic preconditioning (IPC) and intermittent clamping (IC) on mediators of regeneration produced by human liver sinusoidal endothelial cells (SECs), using an in vitro hypoxia-reoxygenation model to mimic ischaemia-reperfusion injury (IRI).

METHODS

Following extraction from samples obtained from liver resection (n = 5), confluent culture flasks of SECs were subjected to IRI (1 hour hypoxia + 1 hour reoxygenation), IPC prior to IRI (10 minutes hypoxia + 10 minutes reoxygenation + 1 hour hypoxia + 1 hour reoxygenation), IC (15 minutes hypoxia + 5 minutes reoxygenation x 3 + 1 hour reoxygenation) and compared to controls. The production of various mediators was determined over 48 hours.

RESULTS

Interleukin (IL)-6, IL-8, granulocyte-colony stimulating factor (G-CSF) and hepatocyte growth factor (HGF) were produced by SECs. Both IPC and IC did not significantly influence the profile of IL-6, IL-8, G-CSF and HGF by SECs compared to IRI over the study period.

CONCLUSION

IPC and IC did not influence the production of pro-regenerative mediators in a SECs model of IRI. The role of surgical technique on liver regeneration remains to be determined.

Serum hepatocyte growth factor and cancer mortality in an apparently healthy Japanese population

Background

In patients with cancer, hepatocyte growth factor (HGF) is elevated and is a predictor of prognosis. We investigated whether serum HGF was a predictive marker for cancer death in a population of community-dwelling Japanese.

Methods

We studied 1492 apparently healthy Japanese adults who underwent health examinations in 1999. Those who reported a history of liver disease or malignancy on a baseline questionnaire were excluded, and plasma HGF was measured in the remaining 1470 participants, who were followed periodically for 10 years. Multivariate proportional hazards regression was used to estimate cancer mortality.

Results

A total of 169 participants died during follow-up (61 from cancer, 32 from cerebrocardiovascular disease, and 76 from other diseases). Mean HGF at baseline was significantly higher among decedents than among survivors (0.26 ± 0.11 vs 0.23 ± 0.09 ng/ml, respectively; P < 0.01). The Cox proportional hazards model showed that age, systolic blood pressure, HGF (hazard ratio, 1.27; 95% CI, 1.06–1.52; P = 0.009), albumin level, smoking status, and creatinine were independent predictors of all-cause death. Age, HGF (hazard ratio, 1.31; 95% CI, 1.04–1.65; P = 0.02), and total cholesterol were independent predictive markers for cancer death.

Conclusions

Serum HGF was a predictor of cancer death in an apparently healthy population of community-dwelling Japanese.

Hepatocyte growth factor overexpression in the nervous system enhances learning and memory performance in mice

Hepatocyte growth factor (HGF) and its receptor, c-Met, play pivotal roles in the nervous system during development and in disease states. However, the physiological roles of HGF in the adult brain are not well understood. In the present study, to assess its role in learning and memory function, we used transgenic mice that overexpress HGF in a neuron-specific manner (HGF-Tg) to deliver HGF into the brain without injury. HGF-Tg mice displayed increased alternation rates in the Y-maze test compared with age-matched wild-type (WT) controls. In the Morris water maze (MWM) test, HGF-Tg mice took less time to find the platform on the first day, whereas the latency to escape to the hidden platform was decreased over training days compared with WT mice. A transfer test revealed that the incidence of arrival at the exact location of the platform was higher for HGF-Tg mice compared with WT mice. These results demonstrate that overexpression of HGF leads to an enhancement of both short- and long-term memory. Western blot analyses revealed that the levels of N-methyl-D-aspartate (NMDA) receptor subunits NR2A and NR2B, but not NR1, were increased in the hippocampus of HGF-Tg mice compared with WT controls, suggesting that an upregulation of NR2A and NR2B could represent one mechanism by which HGF enhances learning and memory performance. These results demonstrate that modulation of learning and memory performance is an important physiological function of HGF that contributes to normal CNS plasticity, and we propose HGF as a novel regulator of higher brain functions.

Hepatocyte growth factor-induced BMP-2 expression is mediated by c-Met receptor, FAK, JNK, Runx2, and p300 pathways in human osteoblasts

Hepatocyte growth factor (HGF) has been demonstrated to stimulate osteoblast proliferation and participated bone remodeling. Bone morphogenetic protein-2 (BMP-2) is a crucial mediator in bone formation during fracture healing. However, the effects of HGF in BMP-2 expression in human osteoblasts are large unknown. Here we found that HGF induced BMP-2 expression in human osteoblasts dose-dependently. HGF-mediated BMP-2 production was attenuated by c-Met inhibitor or siRNA. Pretreatment with FAK inhibitor or JNK inhibitor (SP600125) also blocked the potentiating action of HGF. Stimulation of osteoblasts with HGF enhanced FAK phosphorylation, JNK phosphorylation, and RunX2 translocation from cytosol to the nucleus. HGF-mediated Runx2 binding to BMP-2 promoter was inhibited by c-Met inhibitor, FAK inhibitor, and SP600125. The binding of Runx2 to the BMP-2 promoter, as well as the recruitment of p300 and the enhancement of histones H3 and H4 acetylation on the BMP-2 promoter was enhanced by HGF. Our results suggest that HGF increased BMP-2 production in human osteoblasts via the c-Met receptor/FAK/JNK/Runx2 and p300 signaling pathways.

Overexpression of HGF attenuates the degeneration of Purkinje cells and Bergmann glia in a knockin mouse model of spinocerebellar ataxia type 7

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disorder associated with cerebellar neurodegeneration caused by expansion of a CAG repeat in the ataxin-7 gene. Hepatocyte growth factor (HGF), a pleiotrophic growth factor, displays highly potent neurotrophic activities on cerebellar neurons. A mutant c-met/HGF receptor knockin mouse model has revealed a role for HGF in the postnatal development of the cerebellum. The present study was designed to elucidate the effect of HGF on cerebellar neurodegeneration in a knockin mouse model of SCA7 (SCA7-KI mouse). SCA7-KI mice were crossed with transgenic mice overexpressing HGF (HGF-Tg mice) to produce SCA7-KI/HGF-Tg mice that were used to examine the phenotypic differences following HGF overexpression. The Purkinje cellular degeneration is thought to occur via cell-autonomous and non-cell autonomous mechanisms mediated by a reduction of glutamate transporter levels in Bergmann glia. The Purkinje cellular degeneration and reduced expression of glutamate transporters in the cerebellum of SCA7-KI mice were largely attenuated in the SCA7-KI/HGF-Tg mice. Moreover, phenotypic impairments exhibited by SCA7-KI mice during rotarod tests were alleviated in SCA7-KI/HGF-Tg mice. The bifunctional nature of HGF on both Purkinje cells and Bergmann glia highlight the potential therapeutic utility of this molecule for the treatment of SCA7 and related disorders.

The first clinical trial in Tohoku University Hospital after the Great East Japan Earthquake: the heroic efforts of my friend, Professor Masashi Aoki

The Great East Japan Earthquake of 2011 seriously jeopardized our collaborative research with Professor Masashi Aoki (Tohoku University School of Medicine) on the development of new therapies for amyotrophic lateral sclerosis (ALS) using hepatocyte growth factor. After the earthquake struck, Professor Aoki made a tremendous contribution to saving patients' lives and to recovering from the disastrous situation. Thanks to his strong leadership and support from many reliable colleagues, we could finally start new clinical trials for ALS patients. In this article, I wish to introduce Professor Aoki's heroic efforts.

Review: The skeletal muscle extracellular matrix: Possible roles in the regulation of muscle development and growth

Velleman, S. G., Shin, J., Li, X. and Song, Y. 2012. Review: The skeletal muscle extracellular matrix: Possible roles in the regulation of muscle development and growth. Can. J. Anim. Sci. 92: 1–10. Skeletal muscle fibers are surrounded by an extrinsic extracellular matrix environment. The extracellular matrix is composed of collagens, proteoglycans, glycoproteins, growth factors, and cytokines. How the extracellular matrix influences skeletal muscle development and growth is an area that is not completely understood at this time. Studies on myogenesis have largely been directed toward the cellular components and overlooked that muscle cells secrete a complex extracellular matrix network. The extracellular matrix modulates muscle development by acting as a substrate for muscle cell migration, growth factor regulation, signal transduction of information from the extracellular matrix to the intrinsic cellular environment, and provides a cellular structural architecture framework necessary for tissue function. This paper reviews extracellular matrix regulation of muscle growth with a focus on secreted proteoglycans, cell surface proteoglycans, growth factors and cytokines, and the dynamic nature of the skeletal muscle extracellular matrix, because of its impact on the regulation of muscle cell proliferation and differentiation during myogenesis.

Improvement of sepsis by hepatocyte growth factor, an anti-inflammatory regulator: emerging insights and therapeutic potential

Sepsis-induced multiple organ failure (MOF) is the most frequent lethal disease in intensive care units. Thus, it is important to elucidate the self-defensive mechanisms of sepsis-induced MOF. Hepatocyte growth factor (HGF) is now recognized as an organotrophic factor, which is essential for organogenesis during embryonic growth and regeneration in adulthood. HGF production is enhanced in response to infectious challenges, but the increase in endogenous HGF levels is transient and insufficient, with a time lag between tissue injuries and HGF upregulation, during progression of septic MOF. Thus, administration of active-formed HGF might be a new candidate for therapeutic development of MOF. HGF has an ability to target endotoxin-challenged macrophages and inhibits the upregulation of inflammatory cytokines through nuclear factor-κB-inactivated mechanisms. HGF also targets the endothelium and epithelium of various organs to suppress local inflammation, coagulation, and apoptotic death. This paper summarizes the novel mechanisms of HGF for attenuating sepsis-related pathological conditions with a focus on sepsis-induced MOF.

Identification of mannose receptor as receptor for hepatocyte growth factor β-chain: novel ligand-receptor pathway for enhancing macrophage phagocytosis

Hepatocyte growth factor (HGF), a heterodimer composed of the α-chain and β-chain, exerts multifunctional actions for tissue repair and homeostasis via its receptor, MET. HGF is cleaved by proteases secreted from inflammatory cells, and NK4 and β-chain remnant (HGF-β) are generated. Here, we provide evidence that HGF-β binds to a new receptor other than MET for promoting a host cell clearance system. By an affinity cross-linking, radiolabeled HGF-β was bound to liver non-parenchymal cells, particularly to Kupffer cells and sinusoidal endothelial cells, but not to parenchymal hepatocytes. The cross-linked complex was immunoprecipitated by anti-HGF antibody, but not anti-MET antibody, implying that HGF-β binds to non-parenchymal cells at a site distinct from MET. Mass spectrometric detection of the ligand receptor complex revealed that the binding site of HGF-β was the mannose receptor (MR). Actually, an ectopic expression of MR in COS-7 cells, which express no endogenous MR or MET, enabled HGF-β to bind these cells at a K(D) of 89 nM, demonstrating that MR is the new receptor for HGF-β. Interaction of HGF-β and MR was diminished by EGTA, and by an enzymatic digestion of HGF-β sugar chains, suggesting that MR may recognize the glycosylation site(s) of HGF-β in a Ca(2+)-dependent fashion. Notably, HGF-β, but not other MR ligands, enhanced the ingestion of latex beads, or of apoptotic neutrophils, by Kupffer cells, possibly via an F-actin-dependent pathway. Thus, the HGF-β·MR complex may provide a new pathway for the enhancement of cell clearance systems, which is associated with resolution of inflammation.

Hepatocyte growth factor (HGF) regulates blood-testis barrier (BTB) in adult rats

We have studied the effects of HGF on BTB dynamics in adult rats. We demonstrate that, at stages VII-VIII of the epithelium wave when germ cells traverse the BTB, HGF reduces the levels of occludin and influences its distribution pattern and assembling. Moreover, we report that, at stages VII-VIII, HGF significantly increases the amount of active TGF-β and the amount of uPA present in the tubules. For the first time we report that, in the same stages, HGF reduces the amount of actin present in the BTB region, in which occludin levels are highest, and modifies the morphology of the actin cytoskeleton network. At the level of maximal intensity of occludin fluorescence, we report that HGF also modifies the colocalization of occludin and actin. Lastly, we demonstrate that HGF is maximally expressed at stages VII-VIII, whereas its levels fall in the subsequent stages.

Hepatocyte growth factor and omega-3-enriched feeds have a synergistic effect on mucosal mass in an animal model of inflammatory bowel disease

BACKGROUND

Hepatocyte growth factor (HGF) decreases intestinal inflammation and cytokine levels in an animal model of inflammatory bowel disease (IBD). Luminal omega-3 (OM-3) is anti-angiogenic, reduces inflammation, and may decrease symptoms in patients with Crohn's disease. This study evaluates the synergism of HGF and OM-3.

METHODS

Twenty adult female transgenic HLA-B27 rats were divided into 4 groups: group 1: regular feeds, IV saline; group 2: OM-3-enriched feeds, IV saline; group 3: regular feeds, IV HGF (150 µg/kg per day); and group 4: OM-3-enriched feeds, IV HGF(150 µg/kg per day). Rats were killed at 14 days after pump placement. Small and large bowel mucosa was harvested, and DNA and protein were extracted and quantified. Statistical analysis was done by analysis of variance with post-hoc Tukey's HSD test.

RESULTS

Content of protein and DNA in the ileum were significantly increased by supplementation of HGF (P < .001, P < .01, respectively) alone. OM-3 significantly increased protein content but not DNA (P = .02, P = 0.3, respectively). Combined, they had a synergistic effect greater than either supplement alone (P = .0001, P = .002, respectively). In the colon, HGF and OM-3 did not significantly increase protein or DNA content individually or together.

CONCLUSIONS

This is the first demonstration of the synergistic effect of a growth factor (HGF) and a dietary supplement (OM-3) in an immunologic model of IBD.

Migration and fate of therapeutic stem cells in different brain disease models

Stem cells have a number of properties, which make them excellent candidates for the treatment of various neurologic disorders, the most important of which being their ability to migrate to and differentiate predictably at sites of pathology in the brain. The disease-directed migration and well-characterized differentiation patterns of stem cells may eventually provide a powerful tool for the treatment of both localized and diffuse disease processes within the human brain. A thorough understanding of the molecular mechanisms governing their migratory properties and their choice between different differentiation programs is essential if these cells are to be used therapeutically in humans. This review focuses on summarizing the migration and differentiation of therapeutic neural and mesenchymal stem cells in different disease models in the brain and also discusses the promise of these cells to eventually treat various forms of neurologic disease.

Human hepatocyte growth factor promotes functional recovery in primates after spinal cord injury

Many therapeutic interventions for spinal cord injury (SCI) using neurotrophic factors have focused on reducing the area damaged by secondary, post-injury degeneration, to promote functional recovery. Hepatocyte growth factor (HGF), which is a potent mitogen for mature hepatocytes and a mediator of the inflammatory responses to tissue injury, was recently highlighted as a potent neurotrophic factor in the central nervous system. We previously reported that introducing exogenous HGF into the injured rodent spinal cord using a herpes simplex virus-1 vector significantly reduces the area of damaged tissue and promotes functional recovery. However, that study did not examine the therapeutic effects of administering HGF after injury, which is the most critical issue for clinical application. To translate this strategy to human treatment, we induced a contusive cervical SCI in the common marmoset, a primate, and then administered recombinant human HGF (rhHGF) intrathecally. Motor function was assessed using an original open field scoring system focusing on manual function, including reach-and-grasp performance and hand placement in walking. The intrathecal rhHGF preserved the corticospinal fibers and myelinated areas, thereby promoting functional recovery. In vivo magnetic resonance imaging showed significant preservation of the intact spinal cord parenchyma. rhHGF-treatment did not give rise to an abnormal outgrowth of calcitonin gene related peptide positive fibers compared to the control group, indicating that this treatment did not induce or exacerbate allodynia. This is the first study to report the efficacy of rhHGF for treating SCI in non-human primates. In addition, this is the first presentation of a novel scale for assessing neurological motor performance in non-human primates after contusive cervical SCI.

Clinical correlations and prognostic relevance of tissue angiogenic factors in patients with gastric cancer

AIMS

To evaluate the relationship between vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) levels in gastric cancer tissue and clinicopathological features and to determine whether these factors were correlated with survival.

MATERIALS AND METHODS

We analysed tissue samples from 58 patients with gastric cancer and used 24 normal gastric mucosae as controls. Tissue levels of VEGF and HGF were measured in tissue extracts by enzyme-linked immunosorbent assay.

RESULTS

HGF and VEGF levels were significantly higher in gastric cancer tissue than in matched normal gastric mucosa. VEGF levels were significantly increased in cancer tissue from cases involving lymphatic invasion. HGF levels were significantly increased according to the disease stage. Patients with high levels of VEGF or HGF showed significantly worse survival rates than patients with low levels. Using multivariate analysis, a high level of VEGF or HGF was an independent factor predicting poor survival.

CONCLUSIONS

Intratumoral levels of HGF and VEGF are an important prognostic determinant in gastric cancer. The current findings suggest that high concentrations of HGF and VEGF may induce aggressive tumour growth and metastasis.

Human hepatocyte growth factor promotes functional recovery in primates after spinal cord injury

Many therapeutic interventions for spinal cord injury (SCI) using neurotrophic factors have focused on reducing the area damaged by secondary, post-injury degeneration, to promote functional recovery. Hepatocyte growth factor (HGF), which is a potent mitogen for mature hepatocytes and a mediator of the inflammatory responses to tissue injury, was recently highlighted as a potent neurotrophic factor in the central nervous system. We previously reported that introducing exogenous HGF into the injured rodent spinal cord using a herpes simplex virus-1 vector significantly reduces the area of damaged tissue and promotes functional recovery. However, that study did not examine the therapeutic effects of administering HGF after injury, which is the most critical issue for clinical application. To translate this strategy to human treatment, we induced a contusive cervical SCI in the common marmoset, a primate, and then administered recombinant human HGF (rhHGF) intrathecally. Motor function was assessed using an original open field scoring system focusing on manual function, including reach-and-grasp performance and hand placement in walking. The intrathecal rhHGF preserved the corticospinal fibers and myelinated areas, thereby promoting functional recovery. In vivo magnetic resonance imaging showed significant preservation of the intact spinal cord parenchyma. rhHGF-treatment did not give rise to an abnormal outgrowth of calcitonin gene related peptide positive fibers compared to the control group, indicating that this treatment did not induce or exacerbate allodynia. This is the first study to report the efficacy of rhHGF for treating SCI in non-human primates. In addition, this is the first presentation of a novel scale for assessing neurological motor performance in non-human primates after contusive cervical SCI.

Novel therapeutic target for head and neck squamous cell carcinoma: HGF-MET signaling pathway

Head and neck squamous cell carcinoma (HNSCC) represents a devastating type of malignancy characterized by its high incidence of regional and distant metastases at the time of diagnosis. Vital physiological functions in the upper aerodigestive tract are often impaired as a result of the disease and treatment for the disease, giving rise to severe morbidity in patients suffering from this type of cancer. It is crucial to delineate the aberrant growth signaling pathways in HNSCC cells and develop specific target therapies for the disease to improve the treatment outcome. Although the epidermal growth factor receptor pathway has been extensively studied in HNSCC and anti-epidermal growth factor receptor therapy has already shown promise in treating HNSCC in phase III clinical trials, the signaling pathway that accounts for the highly invasive phenotype of HNSCC needs to be defined and also therapeutically targeted. The hepatocyte growth factor-MET signaling pathway has been studied extensively over the past two decades and it is now clear that it plays an important role in mediating invasive growth of many types of cancer. Here, we review comprehensively the evidence on hepatocyte growth factor-MET cascade being a key in the signaling pathway in mediating invasive growth of HNSCC and the potential of this signaling pathway to be a therapeutic target for the treatment of HNSCC.

CXC chemokine signaling in the liver: impact on repair and regeneration

The process of liver repair and regeneration following hepatic injury is complex and relies on a temporally coordinated integration of several key signaling pathways. Pathways activated by members of the CXC family of chemokines play important roles in the mechanisms of liver repair and regeneration through their effects on hepatocytes. However, little is known about the signaling pathways used by CXC chemokine receptors in hepatocytes. Here we review our current understanding of the pathways involved in both CXC chemokine receptor signaling in other cell types, most notably neutrophils, and similar pathways operant during hepatocyte proliferation/liver regeneration to formulate a basis for the function of CXC chemokine receptor signaling in hepatocytes.

Diminished met signaling in podocytes contributes to the development of podocytopenia in transplant glomerulopathy

Transplant glomerulopathy (TxG) can show secondary focal and segmental glomerulosclerosis (FSGS). FSGS in native kidneys is caused by podocytopenia. This study examines podocytopenia and the role of decreased paracrine Met activation on podocytes by decreased glomerular hepatocyte growth factor (HGF) levels in the development of podocytopenia in TxG. Podocytes were counted in 10 zero-hour biopsies and 10 specimens each with and without TxG. HGF/Met was examined with immunostains and quantitative RT-PCR in a set of three consecutive biopsies from 10 patients with TxG, including the diagnostic biopsy (DiagnBx) and the two previous biopsies (1stPrevBx and 2ndPrevBx). Antiapoptotic effects of HGF on podocytes were examined in vitro. Mean podocyte numbers per glomerulus were lower and glomerular volume higher in TxG. Fewer of the two preceding biopsies of the patients than of the controls contained phospho-Met(Tyr1349)-positive podocytes (2 of 8 versus 7 of 7, P = 0.0070; 4 of 9 versus 9 of 9, P = 0.0294). Glomerular HGF mRNA levels were lower in the 1stPrevBx of the patients (0.049 ± 0.083 versus 0.284 ± 0.331; P = 0.0155). In vitro, HGF stimulation of podocytes resulted in antiapoptotic phosphorylation of AKT and extracellular signal-regulated kinase (ERK) and induction of X-linked inhibitor of apoptosis protein (XIAP). Decreased antiapoptotic Met signaling in podocytes, probably due to decreased HGF secretion by glomerular epithelial cells, could contribute to podocyte loss and FSGS in TxG.

Proliferation of Hepatic Oval Cells via Cyclooxygenase-2 and Extracellular Matrix Protein Signaling during Liver Regeneration Following 2-AAF/Partial Hepatectomy in Rats

BACKGROUND/AIMS

In the 2-acetylaminofluorene (2-AAF)/70% partial hepatectomy (PHx) model, the mechanism underlying the differentiation of activated hepatic oval cells (HOCs) into hepatocytes and bile ductile cells is unclear. We investigated the role of cyclooxygenase-2 (COX-2) in HOCs and the relationship between COX-2 and extracellular matrix proteins in cellular proliferation.

METHODS

Reverse transcription-polymerase chain reaction, immunohistochemical staining, and Western blotting were used to assess COX-2 expression. The co-localization of COX-2 with Thy1, c-Met, epithelial cell adhesion molecule, and α-smooth muscle actin was also examined. Additionally, we investigated whether connective tissue growth factor (CTGF), fibronectin (FN), extracellular signal-regulated kinase 1/2 (P-ERK1/2), and AKT were expressed in HOCs.

RESULTS

The expression of COX-2, prostaglandin E2 receptors, and c-Met was upregulated in HOCs. However, HOCs treated with the COX-2 inhibitor NS398 showed decreased COX-2, CTGF, FN, and AKT expression, whereas P-ERK1/2 was unaffected. Additionally, NS398 inhibited HOC proliferation, but not the proliferation of HOCs cultured on FN-coated dishes. Furthermore, the proliferative response of HOCs treated with NS398 was reversed by hepatic growth factor treatment.

CONCLUSIONS

These results suggest that HOC proliferation is mediated through COX-2, extracellular FN expression, and AKT activation. Thus, COX-2 plays an important role in HOC proliferation following acute injury.

A novel herbal formulation "LiverCare" differentially regulates primary rat hepatocyte and hepatocarcinoma cell proliferation in vitro

Hepatocyte growth factor (HGF) plays an important role in hepatocyte proliferation. HGF expression is regulated by various signaling molecules and nuclear receptors. In the present study, LiverCare(®) (LC), a novel polyherbal formulation (The Himalaya Drug Company, Bangalore, India), was evaluated for its efficacy, using co-cultures of primary rat hepatocytes-non-parenchymal cells (NPCs) and human hepatocellular carcinoma cells (HepG2). The rate of primary hepatocyte co-culture proliferation was significantly and dose-dependently increased by LC as determined by [(3)H]thymidine incorporation into newly synthesized DNA and cell proliferation assay. LC also increased HGF expression in primary hepatocyte co-culture. Albumin and urea content remained constant during proliferation of hepatocyte co-cultures in the presence of LC with decreased activity of alanine aminotransferase. It is interesting that LC inhibited incorporation of [(3)H]thymidine into DNA in HepG2 cells. LC enhanced peroxisome proliferator-activated receptor-α expression during hepatocyte proliferation, whereas tumor necrosis factor-α expression remained unaffected. In conclusion, our study clearly showed that LC differentially regulates primary rat hepatocytes and human hepatocarcinoma cell proliferation. LC may be a promising candidate for treating degenerative liver diseases by enhancing liver regeneration.