Silencing endothelin-3 expression attenuates the malignant behaviors of human melanoma cells by regulating SPARC levels / 华中科技大学学报（医学）（英德文版）

Endothelin-3 (ET-3) is aberrantly expressed in both metastatic melanoma tissues and cultured melanoma cells. Our previous work showed that ET-3 could promote survival of metastatic melanoma cells via its altered expression. In this study, we investigated the mechanisms responsible for these gene-induced phenotypes in melanoma cells. An ET-3 gene sequence-specific shRNA vector pLVTHM-ET3-RNAi was constructed and transfected into human malignant melanoma cells A375 and MMRU, and the resultant molecular events and cellular changes were examined. As compared with the empty-vector group, cell proliferation was slowed down, and the growth inhibition rates were 38.9% in A375 cells and 38.4% in MMRU cells after transfection. In addition, cell invasion capability was also inhibited, with a reduction of 62.2% in A375 cells and 54.3% in MMRU cells. The percentage of apoptotic cells was found to increase. Meanwhile, in both cell lines, secreted protein acidic and rich in cysteine (SPARC) levels were down-regulated together with inhibition of its upstream signaling molecule, NF-κB. Thus, the current results suggested that down-regulated expression of ET3 attenuates the malignant behaviors of human melanoma cells partially by decreasing the expression of SPARC and NF-κB.

Endothelin 1 protects HN33 cells from serum deprivation-induced neuronal apoptosis through Ca2+-PKCalpha-ERK pathway

Endothelins (ETs), which were originally found to be potent vasoactive transmitters, were known to be implicated in nervous system, but the mode of mechanism remains unclear. ETs (ET-1, ET-2, and ET-3) were added to HN33 (mouse hippocampal neuron chi neuroblastoma) cells. Among the three types of ET, only ET-1 increased the intracellular calcium levels in a PLC dependent manner with the induction of ERK 1/2 activation. As the result of ET-1 exposure, the survival rate of HN33 cells and the PKCalpha translocation into the plasma membrane were increased. We suggest that ET-1 participated in the neuroprotective effect involving the calcium-PKCalpha-ERK1/2 pathway.

The expression of endothelin receptor B in melanoma cells A375 and Sk-mel-1 and the proliferative effects of endothelin 3 on A375 cells / 华中科技大学学报（医学）（英德文版）

In order to investigate the expression of endothelin receptor B (ETR-B) in human malignant melanoma (MM) cells A375 and SK-mel-1 and the proliferative effects of endothelin 3 (ET3) on A375 cells, RT-PCR was applied to detect the expression of ETR-B gene in human MM cells A375 and SK-mel-1. MTT method was used to evaluate the growth enhancing effects of ET3 on A375 cell line in vitro. The results showed that ETR-B gene was expressed in both MM A375 and SK-mel-1 cells. ET3 had stronger ability to enhance the proliferation of A375 cells in vitro in a concentration-dependent manner. It was suggested that ET3/ETR-B might play an important proliferative role in MM.

Endothelin-1, Endothelin-2 and Endothelin-3 Induced Expression of Monocyte Chemoattractant Protein-1 in Rat Mesangial Cells / 대한신장학회잡지

BACKGROUND: Monocyte chemoattractant protein- 1 (MCP-1) is an important mediator for monocyte/ macrophage infiltration in various inflammatory renal diseases and is produced by renal cells. In the process of renal diseases, endothelin-1 (ET-1) is known to play an active role in cell growth, inflammation and fibrosis. The aim of this study was to investigate whether three isoforms of endothelin regulate MCP-1 expression in cultured mesangial cells. METHODS: Mesangial cells were incubated with or without various doses of ET-1, ET-2 or ET-3. To determine the monocyte chemotactic activity, chemotaxis assay was performed in modified Boyden chambers using freshly isolated human monocytes. MCP-1 mRNA expression in mesangial cells was measured by Northern blot analysis. RESULTS: ET-1, ET-2 and ET-3 stimulated monocyte chemotactic activity released from mesangial cells in a dose-dependent manner. ET-1, ET-2 and ET-3 also stimulated MCP-1 mRNA expression in a time-dependent manner, which was seen as early as 4 hours and was maintained up to 24 hours. CONCLUSION: These data suggest that ET-1, ET- 2 and ET-3 stimulate MCP-1 expression in mesangial cells and may contribute to the monocyte/ macrophage infiltration in inflammatory renal diseases.

Hirschsprung's Disease: Etiology and Pathophysiology

Abnormal distribution of the enteric nerves such as adrenergic, cholinergic and peptidergic nerves may cause the functional obstruction in Hirschsprung's disease (HD). Although the sustained contraction of the aganglionic segment is the main pathophysiology of HD, the etiology and pathogenesis is not thoroughly understood. With the recent progress of molecular biology and genetics,a more detailed approach to the pathogenesis of the HD can be undertaken. In this review, the roles of the nitric oxide, nitric oxide synthase and interstitial cells of Cajal on smooth muscle relaxation, the effects of extracellular matrix, cell adhesion molecules, neurotrophic factors on the migration and maturation of the neural crest cells are described. In the section of genetic factors, familial occurrences, association of chromosomal abnormalities, RET gene, glial cell line-derived neurotrophic factor gene, endothelin-3 gene and endothelin-B receptor gene and their relationships to HD is briefly reviewed.

The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3

How the considerable diversity of neural crest (NC)-derived cell types arises in the vertebrate embryo has long been a key question in developmental biology. The pluripotency and plasticity of differentiation of the NC cell population has been fully documented and it is well-established that environmental cues play an important role in patterning the NC derivatives throughout the body. Over the past decade, in vivo and in vitro cellular approaches have unravelled the differentiation potentialities of single NC cells and led to the discovery of NC stem cells. Although it is clear that the final fate of individual cells is in agreement with their final position within the embryo, it has to be stressed that the NC cells that reach target sites are pluripotent and further restrictions occur only late in development. It is therefore a heterogenous collection of cells that is submitted to local environmental signals in the various NC-derived structures. Several factors were thus identified which favor the development of subsets of NC-derived cells in vitro. Moreover, the strategy of gene targeting in mouse has led at identifying new molecules able to control one or several aspects of NC cell differentiation in vivo. Endothelin peptides (and endothelin receptors) are among those. The conjunction of recent data obtained in mouse and avian embryos and reviewed here contributes to a better understanding of the action of the endothelin signaling pathway in the emergence and stability of NC-derived cell phenotypes

Endothelial-dependent and independent vasodiatation; an index for endothelial dysfunction in women with previous gestational diabetes mellitus

Aim: This work was intended to assess whether healthy women with a history of gestational diabetes mellitus [GDM] may have abnormalities in endothelial function at a very early stage before glucose intolerance occurs. Subjects and the work included 45 subjects classified into 3 groups; I] included 15 obese women with previous GDM, II] included 15 nonobese women with previous GDM and III] included 15 nonobese healthy women as controls. All women were subjected to the following: thorough history taking, full clinical examination, laboratory investigations including serum uric acid, glycosylated haemoglobin, plasma endothelin-1 and complete lipid profile "total cholesterol, triglycerides, HDL-C and LDL-C". Oral glucose tolerance test [OGTT] was done using 75g glucose. Insulin sensitivity index and relative resistance for insulin were estimated during OGTT. The vasodilatory responses of the brachial artery during reactive hyperemia [endothelium-dependent Vasodilatation], and after nitroglycerine administration [endothelium-independent Vasodilatation] were measured using high-resolution echo-Doppler ultrasound 3-6 months after the last delivery. Flow mediated dilatation [FMD] was significantly and equally decreased in both groups of women with previous GDM, compared with control subjects [1.6 +/- 3.7% in the nonobese GDM group and 1.6 +/- 2.5% in the obese GDM group versus 10.3 +/- 4.4% in control subjects, P <0.05]. FMD correlated inversely and significantly with serum uric acid levels, BMI, serum total cholesterol, plasma endothelin-1 and relative resistance for insulin. Nitrate-induced dilatation [NID] was significantly decreased only in the obese GDM group compared with controls [21.4 +/- 5.1% versus 27.9 +/- 9.5%, P < 0.05]. OGTT was within normal range in all groups, although glucose concentrations at 30 and 60 min were significantly higher in both GDM groups, and glucose at fasting time, 90 and 120 min were significantly higher only in obese GDM women. Insulin levels at fasting, 30, 60, 90 and 120 min during the OGTT were significantly higher in obese GDM group. The relative resistance for insulin was significantly higher in the obese GDM group when compared with both the normal and nonobese GDM groups. Glycosylated haemoglobin levels were similar in all groups. Serum uric acid and plasma endothelin-1 were significantly higher in both obese and nonobese GDM women. Total cholesterol, triglycerides and LDL-cholesterol were significantly higher in obese GDM women. Conclusions: Our results suggest that endothelial dysfunction, which is considered as a very early index of atherogenesis, is already present in both obese and nonobese women with a history of GDM, even when they have normal glucose tolerance