Hepatocyte growth factor promotes migration of human myeloma cells

Multiple myeloma is characterized by the accumulation and dissemination of malignant plasma cells in the bone marrow. Cell migration is thought to be important for these events. We studied migration in a Transwell two-chamber assay and tested the motogenic effect of various cytokines. In addition to insulin-like growth factor-1 and stromal cell-derived growth factor-1alpha, previously known as chemoattractants for myeloma cells, we identified hepatocyte growth factor as a potent attractant for myeloma cells. Hepatocyte growth factor-mediated migration was dependent on phosphatidylinositol-3-kinase, involved the MAPK/Erk signaling cascade and VLA-4 integrins, but did not involve Akt, mTOR or G proteins.     

Downregulation of transforming growth factor, beta receptor 2 and Notch signaling pathway in human abdominal aortic aneurysm

ObjectiveMutations in FBN1 and TGFBR2 genes are the main causative mutations identified in Marfan syndrome (MFS). The major vascular complication of MFS is aneurysm formation. Abdominal aortic aneurysm (AAA) is an acquired disease of later life of unknown etiology. The aim of this study was to examine if genetic aberrations in MFS-related genes FBN1 and TGFBR2 are present in patients with AAA.MethodsWe assessed the presence of copy number variation (CNV) in FBN1 and TGFBR2 genes in AAA biopsies from twelve patients. We also analyzed the expression of these genes in AAA biopsies compared to control biopsies from six organ donors. In addition we assessed the expression of two members of the Notch signaling pathway NOTCH3 and HEY2 as well as aortic smooth muscle cell (AoSMC) differentiation marker TAGLN in AAA and control biopsies.ResultsLoss of one copy (deletion) of the FBN1 exon 66 sequence and TGFBR2 exon 8 was identified in 7 (58%) and 11 (92%) of the 12 AAA biopsies. No copy number amplifications (duplications) were detected. Patients carrying TGFBR2 exon 8 deletion showed marked downregulation of this gene in AAA biopsies compared to control biopsies (0.699 vs. 1.765, p = 0.038). Notch signaling components NOTCH3 and HEY2 were markedly downregulated in AAA, while expression of the AoSMC differentiation marker TAGLN did not differ between AAA and control biopsies (0.468 vs. 0.486, p = 0.546).ConclusionThis study suggests an acquired impairment in TGF-β signaling that along with downregulation of the Notch signaling pathway may contribute to the pathogenesis of AAA.     

Unusual complications in an inflammatory abdominal aortic aneurysm

An unusual case of an inflammatory abdominal aortic aneurysm (IAAA) associated with coronary aneurysms and pathological fracture of the adjacent lumbar vertebrae. The associated coronary lesions in cases of IAAA are usually occlusions. In the present case, it was concluded that a possible cause of the coronary aneurysm was coronary arteritis and the etiology of the pathological fracture of the lumbar vertebrae was occlusion of the lumbar penetrating arteries due to vasculitis resulting in aseptic necrosis. Inflammatory AAA can be associated with aneurysms in addition to occlusive disease in systemic arteries. The preoperative evaluation of systemic arterial lesions and the function of systemic organs is essential.     

Rapidly growing mural thrombus in an abdominal aortic aneurysm

Summary While mural thrombus accompanied by an abdominal aortic aneurysm (AAA) is not rare, the growth rate of such a thrombus has not yet been adequately documented. We present here a very rare case of a 62-year-old female patient with an AAA in whom the mural thrombus in the aneurysm grew very rapidly over a short period. We could follow the growth of the mural thrombus in the AAA by two-dimensional (2-D) abdominal echography. Patients with an AAA must be closely monitored by this technique which is able to detect the presence of the thrombus and allow evaluation of its growth.     

Hepatocyte growth factor. A cytokine mediating endothelial migration in inflammatory arthritis

Objective. Angiogenesis is an integral component of the vasculoproliferative phase of rheumatoid arthritis (RA). Recently, a heparin-binding cytokine termed hepatocyte growth factor (HGF), or scatter factor (due to its ability to disperse cohesive epithelial colonies), was described. We conducted this study to investigate the hypothesis that this cytokine was present in the milieu of the inflamed joint, and that it contributed to the chemotaxis of endothelial cells in the synovial tissue. Methods. We examined synovial fluid, synovial tissue, and peripheral blood from 91 patients with RA and other arthritides. We used 83 total samples in an enzyme-linked immunosorbent assay to quantitate the HGF in synovial fluids and peripheral blood. To determine whether the HGF was biologically active, an epithelial scatter factor assay was performed. Immunohistochemical analysis was used to determine localization in synovial tissues. To define a function for synovial HGF, we preincubated rheumatoid synovial fluids with neutralizing anti-HGF and measured the ability of these synovial fluids to induce endothelial chemotaxis. Results. Synovial fluid from patients with RA contained a mean ± SEM HGF concentration of 2.0 ± 0.3 ng/ml, while synovial fluid from patients with other arthritides (including inflammatory arthritis) contained 2.4 ± 0.7 ng/ml HGF. Osteoarthritis (OA) patient samples contained the smallest quantities of synovial fluid HGF at 0.9 ± 0.1 ng/ml. RA synovial fluid contained significantly more HGF than did RA peripheral blood (1.1 ± 0.2 ng/ml) (P < 0.05). Rheumatoid synovial fluids induced more scattering of cells than did OA synovial fluids, suggesting a role for this cytokine in rheumatoid joint destruction. Interleukin-1β induced expression of rheumatoid synovial tissue fibroblast antigenic HGF and scatter factor activity. Immunohistochemically, HGF, as well as the HGF receptor (the met gene product), localized to significantly more rheumatoid synovial tissue lining cells than normal lining cells (P < 0.05). Both HGF and its receptor immunolocalized to subsynovial macrophages as well. Levels of synovial tissue immunoreactive HGF correlated positively with the number of synovial tissue blood vessels. Anti-HGF neutralized a mean of 24% of the chemotactic activity for endothelial cells found in 10 rheumatoid synovial fluid samples. Conclusion. These results indicate that synovial HGF may contribute to the vasculoproliferative phase of inflammatory arthritides such as RA, by inducing HGF-mediated synovial neovascularization. These findings point to a newly described role for HGF in the fibroproliferative phase of RA-associated synovitis.     

腹主动脉瘤血管内修复治疗术的研究进展

腹主动脉瘤血管内修复治疗近年来不断进步,尤其肾下腹主动脉瘤血管内修复术已具有与开放性外科修补术同等的价值,本文对这一领域的研究进展进行综述如下.     

Coronary disease in patients with an abdominal aortic aneurysm]

The presence of coronary artery disease (CAD) evaluated with coronary angiography and eventual correction of CAD in abdominal aortic aneurysm (AAA) patients has been considered the main determinant of early and late outcome after AAA repair. This study reports our experience in CAD and AAA patients in terms of diagnosis and therapy of CAD. In a population of 126 patients (122 males, 4 females, mean age 67.5 years, range 37-81) who were candidates to elective repair for AAA with a diameter > or = 5 centimeters, we included coronary arteriography in 1) patients who were symptomatic for angina (15.9%); 2) patients with previous myocardial infarction (33.3%); 3) patients with previous coronary artery bypass (4%). We identified a group of 45 patients (35.7%) with significant CAD who had been treated before AAA surgery by coronary artery bypass grafting (CABG) in 37 cases or percutaneous coronary angioplasty (PTCA) in 8 cases. AAA repair was performed during the same hospital stay or at a later date. We did not report any morbidity and mortality related to cardiac or vascular procedures. We believe that among patients reporting cardiac symptoms (previous myocardial infarction, angina) the incidence of surgically-correctable CAD is not negligible (45/67, 67.2%). Therefore, invasive coronary study is strongly suggested in such cases to reveal and treat an eventual coronary artery stenosis prior to AAA repair. The absence of cardiac morbidity and mortality related to cardiac and vascular procedures supports this approach.     

Connective tissue growth factor is overexpressed in human hepatocellular carcinoma and promotes cell invasion and growth

AIM: To determine the expression characteristics of connective tissue growth factor (CTGF/CCN2) in human hepatocellular carcinoma (HCC) in histology and to elucidate the roles of CCN2 on hepatoma cell cycle progression and metastasis in vitro.METHODS: Liver samples from 36 patients (who underwent hepatic resection for the first HCC between 2006 and 2011) and 6 normal individuals were examined for transforming growth factor β1 (TGF-β1) or CCN2 mRNA by in situ hybridization. Computer image analysis was performed to measure integrated optimal density of CCN2 mRNA-positive cells in carcinoma foci and the surrounding stroma. Fibroblast-specific protein-1 (FSP-1) and E-cadherin were examined to evaluate the process of epithelial to mesenchymal transition, α-smooth muscle actin and FSP-1 were detected to identify hepatic stellate cells, and CD34 was measured to evaluate the extent of vascularization in liver tissues by immunohistochemical staining. CCN2 was assessed for its stimulation of HepG2 cell migration and invasion using commercial kits while flow cytometry was used to determine CCN2 effects on HepG2 cell-cycle.RESULTS: In situ hybridization analysis showed that TGF-β1 mRNA was mainly detected in connective tissues and vasculature around carcinoma foci. In comparison to normal controls, CCN2 mRNA was enhanced 1.9-fold in carcinoma foci (12.36 ± 6.08 vs 6.42 ± 2.35) or 9.4-fold in the surrounding stroma (60.27 ± 28.71 vs 6.42 ± 2.35), with concomitant expression of CCN2 and TGF-β1 mRNA in those areas. Epithelial-mesenchymal transition phenotype related with CCN2 was detected in 12/36 (33.3%) of HCC liver samples at the edges between carcinoma foci and vasculature. Incubation of HepG2 cells with CCN2 (100 ng/mL) resulted in more of the cells transitioning into S phase (23.85 ± 2.35 vs 10.94 ± 0.23), and induced a significant migratory (4.0-fold) and invasive (5.7-fold) effect. TGF-β1-induced cell invasion was abrogated by a neutralizing CCN2 antibody showing that CCN2 is a downstream mediator of TGF-β1-induced hepatoma cell invasion.CONCLUSION: These data support a role for CCN2 in the growth and metastasis of HCC and highlight CCN2 as a potential novel therapeutic target.     

Lack of an effective drug therapy for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) rupture is a common cause of death in adults. Current AAA treatment is by open surgical or endovascular aneurysm repair. Rodent model and human epidemiology, and genetic and observational studies over the last few decades have highlighted the potential of a number of drug therapies, including medications that lower blood pressure, correct dyslipidaemia, or inhibit thrombosis, inflammation or matrix remodelling, as approaches to managing small AAA. This review summarizes prior AAA pathogenesis data from animal and human studies aimed at identifying targets for the development of drug therapies. The review also systematically assesses past randomized placebo‐controlled drug trials in patients with small AAAs. Eleven previously published randomized‐controlled clinical trials testing different drug therapies aimed at slowing AAA progression were identified. Five of the trials tested antibiotics and three trials assessed medications that lower blood pressure. Meta‐analyses of these trials suggested that neither of these approaches limit AAA growth. Allocation to blood pressure‐lowering medication was associated with a small reduction in AAA rupture or repair, compared to placebo (relative risk 0.94, 95% confidence intervals 0.89, 1.00, P = 0.047). Three further trials assessed the effect of a mast cell inhibitor, fibrate or platelet aggregation inhibition and reported no effect on AAA growth or clinical events. Past trials were noted to have a number of design issues, particularly small sample sizes and limited follow‐up. Much larger trials are needed to properly test potential therapeutic approaches if a convincingly effective medical therapy for AAA is to be identified.     

Hepatocyte growth factor promotes growth and lumen formation of fetal lung epithelial cells in primary culture

Abstract Mesenchyme-epithelium interactions are generally considered critical for fetal lung development. Hepatocyte growth factor (HGF), a mesenchyme-derived mitogen active on a variety of epithelial cells, appears to be involved in the morphogenesis of fetal liver and kidney. During lung development, HGF and its receptor, c-Met, are expressed in close proximity in mesenchymal cells and epithelial cells, respectively. To examine the role of HGF in fetal lung development, we investigated the effects of HGF on lung epithelial cells derived from a 15-day-old mouse fetus. First, HGF induces a 45% increase in [³H]thymidine incorporation and a 65% increase in cell number by crystal violet analysis at 10 ng/mL concentration, and the increase is dose dependent. Second, HGF facilitates the formation of an organotypic arrangement of the fetal epithelial cells on a basement membrane extract (Matrigel) that resembles alveolar structures in vivo , and the maximum increase is about twice the control level at 10 ng/mL. These results suggest that HGF may be implicated in fetal lung development through the regulation of mesenchyme-epithelium interactions.     

Differential gene expression in the proximal neck of human abdominal aortic aneurysm

Objective

Abdominal aortic aneurysm (AAA) represents a common cause of morbidity and mortality in elderly populations but the mechanisms involved in AAA formation remain incompletely understood. Previous human studies have focused on biopsies obtained from the center of the AAA however it is likely that pathological changes also occur in relatively normal appearing aorta away from the site of main dilatation. The aim of this study was to assess the gene expression profile of biopsies obtained from the neck of human AAAs.

Methods

We performed a microarray study of aortic neck specimens obtained from 14 patients with AAA and 8 control aortic specimens obtained from organ donors. Two-fold differentially expressed genes were identified with correction for multiple testing. Mechanisms represented by differentially expressed genes were identified using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Some of the differentially expressed genes were validated by quantitative real-time PCR (qPCR) and immunohistochemistry.

Results

We identified 1047 differentially expressed genes in AAA necks. The KEGG analysis revealed marked upregulation of genes related to immunity. These pathways included cytokine–cytokine receptor interaction (P = 8.67*10⁻¹²), chemokine signaling pathway (P = 5.76*10⁻⁰⁷), and antigen processing and presentation (P = 4.00*10⁻⁰⁴). Examples of differentially expressed genes validated by qPCR included the T-cells marker CD44 (2.16-fold upregulated, P = 0.008) and the B-cells marker CD19 (3.14-fold upregulated, P = 0.029). The presence of B-cells in AAA necks was confirmed by immunohistochemistry.

Conclusions

The role of immunity in AAA is controversial. This study suggests that immune pathways are also upregulated within the undilated aorta proximal to an AAA.