A metalloproteinase inhibitor prevents acute graft-versus-host disease while preserving the graft-versus-leukaemia effect of allogeneic bone marrow transplantation

We examined the effect of a hydroxamic acid-based matrix metalloproteinase inhibitor (KB-R7785), which we previously demonstrated to have a potent ameliorating effect on acute graft-versus-host disease (GVHD), and on the graft-versus-leukaemia (GVL) effect of allogeneic bone marrow transplantation (BMT). KB-R7785 was administered to (C57BL/6 x BALB/c) F1 (CBF1) mice that had been inoculated with IgE-producing B53 hybridoma cells of BALB/c origin as a model tumour, along with or without transplantation of C57BL/6 (B6) bone marrow cells and spleen cells (BMS). Administration of KB-R7785 without BMS significantly prolonged the survival of B53-inoculated CBF1 mice by inhibiting the infiltration of B53 cells into the liver and spleen. Transplantation of B6 BMS without KB-R7785 resulted in the death of most recipients due to acute GVHD while efficiently eliminating B53 cells. Administration of KB-R7785 along with B6 BMS resulted in a 50% survival of B53-inoculated CBF1 mice over 50 d without histological manifestations of acute GVHD or residual B53 cells. These results indicate the beneficial effects of KB-R7785 that inhibit tumour infiltration and prevent acute GVHD while preserving the GVL effect of allogeneic BMT.     

Matrix metalloproteinase inhibitor, CTS-1027, attenuates liver injury and fibrosis in the bile duct-ligated mouse

Aim:  Excessive matrix metalloproteinase (MMP) activity has been implicated in the pathogenesis of acute and chronic liver injury. CTS-1027 is an MMP inhibitor, which has previously been studied in humans as an anti-arthritic agent. Thus, our aim was to assess if CTS-1027 is hepato-protective and anti-fibrogenic during cholestatic liver injury.
Methods:  C57/BL6 mice were subjected to bile duct ligation (BDL) for 14 days. Either CTS-1027 or vehicle was administered by gavage.
Results:  BDL mice treated with CTS-1027 demonstrated a threefold reduction in hepatocyte apoptosis as assessed by the TUNEL assay or immunohistochemistry for caspase 3/7-positive cells as compared to vehicle-treated BDL animals ( P  < 0.01). A 70% reduction in bile infarcts, a histological indicator of liver injury, was also observed in CTS-1027-treated BDL animals. These differences could not be ascribed to differences in cholestasis as serum total bilirubin concentrations were nearly identical in the BDL groups of animals. Markers for stellate cell activation (α-smooth muscle actin) and hepatic fibrogenesis (collagen 1) were reduced in CTS-1027 versus vehicle-treated BDL animals ( P  < 0.05). Overall animal survival following 14 days of BDL was also improved in the group receiving the active drug ( P  < 0.05).
Conclusion:  The BDL mouse, liver injury and hepatic fibrosis are attenuated by treatment with the MMP inhibitor CTS-1027. This drug warrants further evaluation as an anti-fibrogenic drug in hepatic injury.     

基质金属蛋白酶及组织抑制剂在肝癌中的表达及与预后的关系

目的：探讨基质金属蛋白酶（MMPs)及其组织抑制剂（TIMPs）在肝癌中的表达及其意义。方法：应用免疫组化、Northern印迹杂交及图像分析技术对人肝细胞癌（HCC）、肝癌细胞株7721、全反式维甲酸处理的7721细胞（RA－7721）和正常人肝细胞株L－02作MMP－1、2、9和TIMP－2的表达分析。结果;肝癌细胞浆内可表达MMP－1、2和9,但癌内阴性组5年生存率明显高于相应的阳性组（P＜0．05）。体外MMP－9mRNA在7721细胞表达明显高于RA－7721以及L－02细胞,而TIMP－2mRNA的表达与MMP－9相反,MMP－2mRNA在7721细胞中的表达仅略高于L－02细胞。结论：HCC组织内MMP－1和9的表达与患者的预后密切相关;癌细胞高表达MMP－9、低表达TIMP－2,可能是肝癌细胞浸润、转移的主要基础,而MMP-2并无重要作用。     

Plasma matrix metalloproteinase and tissue inhibitor of metalloproteinase in patients with agnogenic myeloid metaplasia or idiopathic primary myelofibrosis

Agnogenic myeloid metaplasia (AMM) is characterized by bone marrow fibrosis with abnormal accumulation of extracellular matrix components (ECM), which is dependent on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Twenty-five patients with AMM, 30 with essential thrombocythemia (ET), 12 with polycythemia vera (PV) and 20 normal control subjects were studied. AMM patients had decreased plasma levels of MMP-3 and marked elevated levels of TIMP-1, but MMP-1, MMP-2 and MMP-9 levels were not significantly different from control subjects. Elevated levels of plasma TIMP-1, but not MMPs, were found in ET and PV. Reduced MMP activity together with increased TIMP-1 activity may be essential in fibrosis formation.     

基质金属蛋白酶及其组织抑制剂在胸腔积液诊断中的评价

胸腔积液是最常见的胸膜疾病,病因复杂,诊断困难.近年来,与细胞外基质降解和沉淀有关的基质金属蛋白酶及其组织抑制剂在胸腔积液发生发展过程中的作用得到了更为深入的研究,这也为胸腔积液的诊断和鉴别诊断提供了新的思路.本文对基质金属蛋白酶及其组织抑制剂与各种原因所致胸腔积液的关系作一综述.     

Excessive production of tumor necrosis factor-alpha by bone marrow T lymphocytes is essential in causing bone marrow failure in patients with aplastic anemia

Aplastic anemia (AA) is regarded as an immunological disorder because of the clinical effect of immunosuppressive therapy. Recent studies have reported that cytokines play an important role in the development of AA. In the present study, we measured levels of T-cell derived intracellular cytokine production in peripheral blood and bone marrow (BM) of patients with AA. We demonstrated that BM lymphocytes, particularly CD4(+) and CD8(+) T cells, in patients with AA produced significantly higher amounts of tumor necrosis factor-alpha (TNF-alpha), compared with lymphocytes in normal controls. We have previously reported that expression of TNF receptor (R)1 and TNFR2 in the CD34(+) CD38(-) and CD34(+) CD38(+) fractions of patients with AA is significantly higher than those in normal control. These results indicate that BM stem cells in patients with AA may possess high sensitivity to TNF-alpha. This in turn suggests that TNF-alpha affects hematopoiesis at an earlier stage in AA patients than in normal controls. We strongly support the hypothesis that a simultaneous increase in TNF-alpha production by BM lymphocytes and sensitivity of stem cells to TNF-alpha leads to BM failure in AA.     

Changes in connexin 43, metalloproteinase and tissue inhibitor of metalloproteinase during tachycardia-induced cardiomyopathy in dogs

OBJECTIVE: To study changes in connexin, metalloproteinase and tissue inhibitor of metalloproteinase levels during tachycardia-induced cardiomyopathy (TIC). METHODS: Canine models of TIC were established by rapid right atrial pacing at 350-400 beats per min for 8 weeks in 11 dogs, six dogs acted as a sham operation group. Echocardiography, left ventricular pressure and its first derivation with time (positive and negative maximum, dp/dtmax, -dp/dtmax), and intracardiac electrograms were recorded before and after rapid pacing at 1, 4 and 8 weeks. Data were acquired in sinus rhythm. Ultrastructural changes in left ventricular tissue were observed by transmission electron microscope. Connexin 43 (Cx43) levels in the left ventricular myocardium were measured by confocal laser microscopy. The relative abundance of matrix metalloproteinase (MMP-2) and tissue inhibitor of metalloproteinase (TIMP-2) were studied by immunoblotting. RESULT AND CONCLUSIONS: (1) Ventricular dilatation and systolic dysfunction occurred after 1 week of rapid right atrial pacing. (2) There was structural damage to the myofibrils, mitochondria, and the sarcoplasmic reticulum with intercalated disk discontinuity. (3) Levels of Cx43 decreased significantly and gap junction remodelling occurred during TIC. (4) TIC may result from several mechanisms, such as ultrastructural changes or gap junction and matrix remodelling.     

Improvement of the survival rate after rat massive hepatectomy due to the reduction of apoptosis by caspase inhibitor

BACKGROUND AND AIM: Acute liver failure after massive hepatectomy is caused by both necrosis and apoptosis in the remnant liver. We investigate the protective effect of the caspase inhibitor on apoptosis after massive hepatectomy in rats. METHODS: Benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (ZVAD-fmk) is a general inhibitor of the caspase. Male Wister rats weighing 200-300 g were divided into three groups: 90Hx group undergoing 90% hepatectomy, 95Hx group undergoing 95% hepatectomy, 95Hx + ZVAD group undergoing 95% hepatectomy and administration of ZVAD-fmk. The 7-day survival rate was studied, and the rats were sacrificed at the 1, 2, 3, 5, and 7th day after hepatectomy. The remnant liver tissues were stained with hematoxylin-eosin, and with proliferating cell nuclear antigen (PCNA) for evaluation of liver regeneration, and with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and in situ oligo ligation method (ISOL) for evaluation of apoptosis. RESULTS: The 7-day survival rates were 100%, 0%, and 30%, in the 90Hx, 95Hx, and 95Hx + ZVAD groups, respectively. There was no significant difference in PCNA labeling index (LI) between the 95Hx and 95Hx + ZVAD groups. TUNEL and ISOL LI of 95Hx + ZVAD group were significantly lower than those of 95Hx group. Fatal liver failure after massive hepatectomy was characterized by more apoptosis and less mitosis of hepatocytes. ZVAD-fmk could significantly attenuate apoptosis of hepatocytes in the remnant liver and improve the survival rate after 95% hepatectomy in rats. CONCLUSION: Caspase inhibitors such as ZVAD-fmk may provide a new adjuvant therapy to treat liver failure after massive hepatectomy.     

Expression of membrane type 1 matrix metalloproteinase, matrix metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 in human cartilaginous tumors with special emphasis on mesenchymal and dedifferentiated chondrosarcoma

Membrane type 1 matrix metalloproteinase (MT1-MMP) has been identified as an activator of the proenzyme of matrix metalloproteinase 2 (MMP-2: gelatinase A), and has also been shown to play a crucial role in tumor invasion by activating proMMP2 in both lung and gastric carcinoma. The tissue inhibitor of metalloproteinase 2 (TIMP-2) plus the MT1-MMP complex also plays an important role in the activation of proMMP-2. In this study, the expressions of MT1-MMP, MMP-2 and TIMP-2 were evaluated in 10 enchondromas, 34 conventional chondrosarcomas, 5 clear-cell chondrosarcomas, 7 mesenchymal chondrosarcomas and 8 dedifferentiated chondrosarcomas. The expressions were immunohistochemically visualized on paraffin sections and the levels of expression were assessed semiquantitatively. The extent of staining was assessed by the extent score in order to determine the overall level of expression. The extent scores of MT1-MMP, MMP-2 and TIMP-2 in grade 2 chondrosarcoma were significantly higher than those in either enchondroma or grade 1 chondrosarcoma (P < 0.05). In conventional chondrosarcoma, significant correlations were found between the extent scores of MT1-MMP and MMP-2 (P < 0.001), MT1-MMP and TIMP-2 (P < 0.01), and MMP-2 and TIMP-2 (P < 0.01). The undifferentiated small round tumor cells of mesenchymal chondrosarcoma showed lower positive rates and extent scores for MT1-MMP (2/7, 0.7 ± 0.5) and MMP-2 (3/7, 0.7 ± 0.4) than for cartilaginous components of mesenchymal chondrosarcoma [MT1-MMP (4/7, 1.3 ± 0.5) and MMP-2 (7/7, 1.9 ± 0.3)] or conventional chondrosarcoma. In dedifferentiated chondrosarcoma, the extent scores of MT1-MMP, MMP-2 and TIMP-2 in low-grade cartilaginous components were not significantly different from those in conventional chondrosarcoma; however, the high-grade anaplastic components showed high extent scores for MT1-MMP, MMP-2 and TIMP-2, compared with the low-grade cartilaginous components of dedifferentiated chondrosarcoma or conventional chondrosarcoma. According to our results, the expression of MT1-MMP as well as that of MMP-2 or TIMP-2 demonstrated a significant correlation with the tumor grade in human cartilaginous tumors. Furthermore, the expressions of MT1-MMP, MMP-2 and TIMP-2 were also found to play a crucial role in invasion in the high-grade components of dedifferentiated chondrosarcoma. Received: 17 February 1999 / Accepted: 21 April 1999     

老年人钙化主动脉瓣中基质金属蛋白酶和细胞凋亡的表达及意义

目的研究基质金属蛋白酶2(MMP-2)及基质金属蛋白酶组织抑制剂2(TIMP-2)和细胞凋亡在主动脉瓣钙化病理过程中的作用。方法选择行主动脉瓣置换术、且主动脉瓣钙化的患者15例作为钙化组,同期选择相同手术、且主动脉瓣正常的患者10例作为非钙化组。术中取主动脉瓣组织,免疫组织化学染色检测MMP-2和TIMP-2表达、TUNEL检测细胞凋亡。结果与非钙化组比较,钙化组主动脉瓣MMP 2、TIMP-2为中、重度着色,阳性细胞显著增多,差异有统计学意义(P<0.01)。钙化组主动脉瓣细胞凋亡指数较非钙化组明显增多(0.71±9.07 vs0.21±6.83,P<0.05)。结论老年钙化主动脉瓣MMP 2和TIMP 2表达异常增高,细胞凋亡数明显增多。     

慢性间断性缺氧对小鼠肾组织结构、基质金属蛋白酶及其组织抑制因子表达的影响

目的 观察慢性间断性缺氧（chronic intermittent hypoxia，CIH）对小鼠肾脏结构，基质金属蛋白酶-1、9（matrixmetallo-proteinase-1、9，MMP-1、9）及其组织抑制因子-1（tissue inhibitor of metalloproteinase-1，TIMP-1）表达变化的影响，探讨其在睡眠呼吸暂停综合征（sAs）肾损害中的作用。方法 将30只ICR小鼠随机分为4组，空气模拟对照组（10只）、CIH2周组（5只）、CIH4周组（5只）、CIH8周组（10只）。采用光镜下病理检查和免疫组织化学方法观察实验小鼠肾组织结构变化和MMP-1、MMP-9及TIMP-1在肾脏的表达。结果 ①CIH各组见肾小管上皮细胞肿胀、空泡、颗粒变性，随缺氧时间延长，变性范围扩大，主要表现为近曲小管的病理改变，其中8周组可见部分肾小管坏死。②MMP-1、MMP-9及TIMP-1主要表达于肾小管上皮细胞。③与对照组比较，CIH各组MMP-1表达均明显减少（P均d0．01），2周时降至最低，随后MMP-1表达略有回升；CIH组间两两比较差异无显著性（P〉0．05）。MMP-9在2周组的表达水平与对照组相比均显著升高（P〈0．01），而在4、8周两组则显著降低（P均d0．01）。CIH各组TIMP-1均呈高表达（P均〈0．01），其中高峰表达在2周缺氧组。CIH各组MMP-1／TIMP-1均显著降低（P均〈0．05），其中2周组达最低（P〈0．01），CIH各组间两两比较差异无显著性（P〉0．05）。MMP-9／TIMP-1随间断缺氧时间的延长呈下降趋势，CIH4周、8周两组均低于对照组（P〈0．05），最低表达在8周组（P〈0．01）。④随间断缺氧时间延长，TIMP-1与MMP-1之间存在负相关关系（r=-0．769，Pd0．01）；TIMP-1与MMP-9之间存在正相关关系（r=0．392，PdO．05）。结论 CIH可引起实验小鼠肾小管变性、坏死等病理变化；同时肾小管上皮细胞MMP-1、MMP-9、TIMP-1表达异常；MMP-1／TIMP-1与MMP-9／TIMP-1下降，这可能参与了SAS肾损害的发生发展过程。     

基质金属蛋白酶9及其抑制剂与老年高血压患者颈动脉粥样硬化程度的相关性

目的探讨基质金属蛋白酶9(mctalloprotemase-9,MMP-9)及组织基质金属蛋白酶抑制剂1(TIMP-1)与老年高血压患者颈动脉粥样硬化程度的相关性。方法选择老年高血压患者330例,应用高分辨超声测量颈动脉内膜中层厚度(IMT)及斑块情况,将患者分为4组:IMT正常组(26例)、IMT增厚组(80例)、稳定性斑块组(135例)和不稳定性斑块组(89例),测定血清生化指标、MMP-9、TIMP-1水平,进行组间比较。结果 IMT正常组、IMT增厚组、稳定性斑块组和不稳定性斑块组血清MMP-9、TIMP-1水平逐渐增高,不稳定性斑块组MMP-9/TIMP-1比值明显高于其他3组,差异有统计学意义(P<0.01)。取所有高血压患者进行多元线性逐步回归分析,颈动脉IMT与年龄、收缩压、LDL-C、空版(?)(?)相关(P<0.05,P<0.01);logistic回归分析显示,颈动脉是否存在斑块与体重指数、收缩压、LDL-C、logMMP-9相关(P<0.05,P<0.01)。取颈动脉斑块患者进行logistic回归分析,斑块是否稳定与收缩压、LDL-C、logMMP-9(模型1,P<0.05,P<0.01)或收缩压、LDL-C、logMMP-9/TIMP-1比值(模型2,P<0.05)相关。结论老年高血压患者血清MMP-9水平、MMP 9/TIMP-1比值与颈动脉是否存在斑块及其稳定性密切相关。     

靶向X染色体连锁凋亡抑制蛋白的短发夹状RNA诱导肝癌细胞凋亡

X染色体连锁凋亡抑制蛋白（XIAP）是凋亡抑制蛋白家族中最具有caspase抑制能力的成员，具有较强的抗凋亡能力。有研究表明XIAP在肿瘤中高表达可能是肿瘤进展及导致肿瘤对化疗药物耐药的一个重要机制。我们通过构建以XIAP为靶的短发夹状RNA（shRNA）重组质粒，观察下调XIAP表达对HepG2细胞生长及凋亡的影响。     

MyD88 is involved in the signalling pathway for Taxol-induced apoptosis and TNF-alpha expression in human myelomonocytic cells

Taxol is an effective anti-tumour drug against a variety of tumour cells. Taxol directly induces apoptosis in addition to a G2/M cell cycle arrest. However, it remains poorly understood how Taxol induces apoptosis in tumour cells. Taxol induces the secretion of inflammatory cytokines in murine macrophages in a toll-like receptor-4 (TLR-4)-dependent manner in addition to its anti-tumour effects, but the effect of Taxol on human macrophages is controversial. In this study, we demonstrated that low doses (less than 1000 nmol/l) of Taxol induced the expression of tumour necrosis factor (TNF)-alpha in human myelomonocytic cells and that the induction of TNF-alpha mRNA was inhibited by dominant-negative myeloid differentiation protein (dnMyD88). Furthermore, we demonstrated that the same doses of Taxol induced apoptosis of the same myelomonocytic cells and that the Taxol-induced apoptosis was also inhibited by dnMyD88. In accordance with the previous reports, Taxol induced the expression of TNF-alpha and apoptosis in a TLR4-independent manner. These results suggest that TNF-alpha expression and apoptosis, both induced by Taxol in human myelomonocytic cells, share the signal transduction molecule MyD88.     

Effect of PGE1 on TNF-alpha status and hepatic D-galactosamine-induced apoptosis in rats

Prostaglandin E1 has hepatoprotective properties in several clinical and experimental models of liver dysfunction. Hepatotoxicity induced by D-galactosamine (D-GalN) is a suitable animal model of human acute hepatic failure. The aim of the study was to investigate if prostaglandin E1 (PGE1) protection against hepatic D-GalN-induced apoptosis was related to tumour necrosis factor-alpha (TNF-alpha) content in serum. This cytokine is associated with in vitro apoptosis and general inflammatory disorders. In this study, PGE1 was administered 30 min before D-GalN to rats. In other experiments, several doses of TNF-alpha were administered 15min after PGE1 to D-Ga1N-treated rats. Several parameters related to apoptosis and necrosis were measured by flow cytometry, gel electrophoresis, biochemical analysis, and optical and electron microscopy. Tumour necrosis factor-alpha was quantified by competitive enzyme-linked immunosorbent assay (ELISA). PGE1 by itself did not modify the cell cycle of hepatocytes and liver toxicity, but increased TNF-alpha in serum in comparison with the control group. D-Galactosamine increased the percentage of hepatocytes in apoptosis and in the S phase of the cell cycle, and decreased those in G0/G1. Such an increase of hepatocytes in apoptosis was correlated with a higher number of apoptotic bodies and DNA fragmentation in liver than control samples. Also, D-GalN increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase and TNF-alpha in serum compared with the control group. Pre-administration of PGE1 to D-GalN-treated rats reduced all the parameters of apoptosis and necrosis in liver, and increased additionallyTNF-alpha content in serum. In those experiments where low doses of TNF-alpha were administered to PGE1 and D-GalN-treated rats an inverse relationship appeared between TNF-alpha and ALT content in serum. In conclusion, the protective effects of PGE1 on D-GalN-induced apoptosis may be linked to its capacity to modulate cell division and/or its immunomodulatory activity. In this sense, our experimental results suggest that TNF-alpha could be involved in protection or exacerbation of liver damage in relation to the pathophysiological status of the liver.     

A peptide inhibitor of cytochrome c/inositol 1,4,5-trisphosphate receptor binding blocks intrinsic and extrinsic cell death pathways

Apoptotic stimuli augment intracellular calcium concentration through inositol 1,4,5-trisphosphate receptors (IP3R) on endoplasmic reticulum calcium stores. We previously discovered an apoptotic cascade wherein cytochrome c binds to IP3R early in apoptosis, resulting in dysregulated calcium release. Here we show that cytochrome c binding to IP3R depends on a cluster of glutamic acid residues within the C terminus of the channel. A cell permeant peptide derived from this sequence displaces cytochrome c from IP3R and abrogates cell death induced by staurosporine treatment of HeLa cells and Fas ligand stimulation of Jurkat cells. Small-molecule inhibitors of cytochrome c/IP3R interactions may prove useful in treating disorders associated with inappropriate intrinsic and extrinsic apoptotic signaling.     

幽门螺杆菌对胃上皮细胞株GES-1凋亡及XIAP表达的影响

目的观察幽门螺杆菌（Hp）慢性感染对胃上皮细胞凋亡及X凋亡抑制蛋白（XIAP）表达的影响。方法通过Hp SS1与人非肿瘤性胃上皮细胞株GES-1共培养,建立GES-1模型细胞,检测模型细胞凋亡率及胃上皮细胞XIAP mRNA的表达。结果Hp感染8周、12周、16周模型细胞凋亡率分别为64．55％、60．58％、45．52％,模型胃上皮细胞的XIAP mRNA实时定量PCR的CT值分别为0．901、0．842、0．796,明显低于对照组细胞凋亡率75．52％（P〈0．05）及XIAP mRNA的CT值1．030（P〈0．01）。结论Hp慢性感染能抑制胃上皮细胞凋亡,其机制可能与上调XIAP mRNA表达有关。     

Matrix metalloproteinase regulation of sphingosine-1-phosphate-induced angiogenic properties of bone marrow stromal cells

OBJECTIVE: Bone marrow-derived stromal cells (MSC) are able to acquire histological and immunophenotypic characteristics consistent with endothelial cells (EC). In this study we examined the effect of sphingosine-1-phosphate (S1P), a platelet-derived bioactive lysophospholipid that is believed to specifically stimulate EC migration and tube formation, on the angiogenic properties of MSC. METHODS: MSC were isolated from murine bone marrow and cultured in the presence of diverse angiogenic growth factors. Using a chemotaxis chamber and Matrigel tubulogenesis assay, we measured the extent of MSC migration and capillary-like structure formation. Western blots and zymography were used to assess the levels and activation states of soluble and membrane-bound matrix metalloproteinase (MMP). RESULTS: We found that S1P strongly induced MSC migration and in vitro capillary-like structure formation. Ilomastat, a broad-spectrum MMP inhibitor, antagonized several angiogenic and S1P-mediated events in MSC. These included 1) the inhibition of S1P-induced tube formation, 2) the inhibition of concanavalin-A (Con-A)-mediated proMMP-2 activation, and 3) the inhibition of S1P- and Con-A-induced caspase-3 activity. Moreover, S1P induced membrane type-1 (MT1)-MMP mRNA and protein expression, but paradoxically antagonized its cell surface proteolytic processing. In addition, anti-angiogenic agents such as Ilomastat, Neovastat, and green tea polyphenol epigallocatechin-3-gallate antagonized the S1P-induced migration of MSC as well as that of transfected COS-7 cells overexpressing the recombinant receptor for S1P, EDG-1. CONCLUSION: Collectively, our results indicate a crucial role for S1P/EDG-1-mediated angiogenic and survival events in the regulation of microvascular network remodeling by MSC, and may provide a new molecular link between hemostasis and angiogenesis processes.