Enzyme replacement therapy in two patients with classic Fabry disease from the same family tree: Two case reports.

BACKGROUND: The pathophysiology of Fabry disease (FD)-induced progressive vital organ damage is irreversible. Disease progression can be delayed using enzyme replacement therapy (ERT). In patients with classic FD, sporadic accumulation of globotriaosylceramide (GL-3) in the heart and kidney begins in utero; however, until childhood, GL-3 accumulation is mild and reversible and can be restored by ERT. The current consensus is that ERT initiation during early childhood is paramount. Nonetheless, complete recovery of organs in patients with advanced FD is challenging. CASE SUMMARY: Two related male patients, an uncle (patient 1) and nephew (patient 2), presented with classic FD. Both patients were treated by us. Patient 1 was in his 50s, and ERT was initiated following end-organ damage; this was subsequently ineffective. He developed cerebral infarction and died of sudden cardiac arrest. Patient 2 was in his mid-30s, and ERT was initiated when the patient was diagnosed with FD, during which the damage to vital organs was not overtly apparent. Although he had left ventricular hypertrophy at the beginning of this treatment, the degree of hypertrophy progression was limited to a minimal range after > 18 years of ERT. CONCLUSION: We obtained discouraging ERT outcomes for older patients but encouraging outcomes for younger adults with classic FD.

Apolipoprotein C3 and necrotic core volume are correlated but also associated with future cardiovascular events.

We aimed to clarify the relationship between apolipoprotein C3 (apo-C3) and the vascular composition of lesion plaque in stable coronary disease (SCD) before percutaneous coronary intervention (PCI), and to investigate major adverse cardiovascular events (MACEs) within 4 years. Data of 98 consecutive patients with SCD who underwent PCI between November 1, 2012, and March 10, 2015, were analyzed. Laboratory and virtual histology-intravascular ultrasound (VH-IVUS) examinations of culprit lesions were conducted before PCI. Patients were divided according to median apo-C3 into low apo-C3 (≤ 8.5 mg/dL) and high apo-C3 (> 8.5 mg/dL) groups. VH-IVUS data indicated that the percentage of necrotic core volume (%NC) was significantly higher in the high apo-C3 group than in the low apo-C3 group. Moreover, the %NC significantly correlated with the apo-C3 level (R = 0.2109, P = 0.037). Kaplan-Meier curve analysis revealed that freedom from MACEs exhibited a greater decrease in the high apo-C3 group than in the low apo-C3 group, and in the high %NC group than in the low %NC group. Multivariate Cox hazards analysis showed that the %NC and high apo-C3 were independent predictors of 4 year MACEs. Apo-C3 may be a useful marker of future MACEs in patients with SCD after PCI and contribute to %NC growth.

Dissection of the Mechanisms of Growth Inhibition Resulting from Loss of the PII Protein in the Cyanobacterium Synechococcus elongatus PCC 7942.

In cyanobacteria, the PII protein (the glnB gene product) regulates a number of proteins involved in nitrogen assimilation including PipX, the coactivator of the global nitrogen regulator protein NtcA. In Synechococcus elongatus PCC 7942, construction of a PII-less mutant retaining the wild-type pipX gene is difficult because of the toxicity of uncontrolled action of PipX and the other defect(s) resulting from the loss of PIIper se, but the nature of the PipX toxicity and the PipX-independent defect(s) remains unclear. Characterization of a PipX-less glnB mutant (PD4) in this study showed that the loss of PII increases the sensitivity of PSII to ammonium. Ammonium was shown to stimulate the formation of reactive oxygen species in the mutant cells. The ammonium-sensitive growth phenotype of PD4 was rescued by the addition of an antioxidant α-tocopherol, confirming that photo-oxidative damage was the major cause of the growth defect. A targeted PII mutant retaining wild-type pipX was successfully constructed from the wild-type S. elongatus strain (SPc) in the presence of α-tocopherol. The resulting mutant (PD1X) showed an unusual chlorophyll fluorescence profile, indicating extremely slow reduction and re-oxidation of QA, which was not observed in mutants defective in both glnB and pipX. These results showed that the aberrant action of uncontrolled PipX resulted in an impairment of the electron transport reactions in both the reducing and oxidizing sides of QA.

Apolipoprotein B correlates with intra-plaque necrotic core volume in stable coronary artery disease.

OBJECTIVE: To determine the relationship between plaque composition and low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (Apo-B), and Apo-A1 using virtual-histology intravascular ultrasound (VH-IVUS). METHODS: We assessed plaque composition in patients with stable coronary artery disease (SCD) admitted to our hospital for percutaneous coronary intervention (PCI) between November 1, 2012, and March 10, 2015. Before PCI, fibrous (FI), fibrofatty (FF), necrotic core (NC), and dense calcium (DC) regions were evaluated using VH-IVUS, and the contributions of each to the culprit lesion volume were recorded. Plasma LDL-C, HDL-C, Apo-B, and Apo-A1 levels were assessed before PCI. The relationship between the regions on VH-IVUS and plasma lipid levels was assessed. Patients were categorized into low Apo-B (LAB) and high Apo-B (HAB) groups, based on the overall cohort median Apo-B level. RESULTS: We enrolled 115 patients (median Apo-B, 91 mg/dL, male n = 88) with 57 and 58 patients in the LAB (Apo-B ≤ 90 mg/dL) and HAB (Apo-B ≥ 91 mg/dL) groups, respectively. Vessel, plaque, and %NC volumes were significantly greater in the HAB group than in the LAB group. The %FI, %FF, and %DC volumes were similar in both groups. In all 115 patients, the %NC volume correlated with LDL-C (r = 0.2353, P = 0.0114) and Apo-B (r = 0.2487, P = 0.0074) but not with HDL-C and Apo A-1. The high-sensitivity C-reactive protein level tended to be higher in the HAB group than in the LAB group. Multiple regression analysis showed that being male, Apo-A1, and Apo-B were significant predictors of %NC volume extent. CONCLUSIONS: Elevated Apo-B level was related to the %NC in target coronary artery lesions in SCD patients, suggesting a role of Apo-B as a biomarker of unstable plaque in this population.

Vascular composition data supporting the role of N-3 polyunsaturated fatty acids in the prevention of cardiovascular disease events.

N-3 polyunsaturated fatty acids (PUFAs) are thought to have protective effects against cardiovascular disease. Here, we report the relationship between serum PUFA concentrations and plaque composition, as evaluated by virtual histology-intravascular ultrasound (VH-IVUS). Consecutive patients (n=61) who underwent percutaneous coronary intervention (PCI) were pre-operatively examined using VH-IVUS to assess the composition of culprit plaques. Gray-scale IVUS and VH-IVUS data of fibrous, fibro-fatty, necrotic core, and dense calcium regions of plaques were estimated at the minimal luminal area sites of culprit lesions. Serum levels of high-sensitivity C-reactive protein (hsCRP) and PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA), were compared between patients with (ACS, n=27) and without acute coronary syndrome (non-ACS, n=34) before PCI. Multiple logistic regression analysis of the data showed that EPA/AA under the median was more highly associated with ACS than hsCRP over the median. In addition, EPA/AA was negatively correlated with the percentage of fibrous plaque regions and EPA/AA and DHA/AA were positively correlated with the percentage of dense calcium regions in plaques. Furthermore, the correlation index of EPA/AA was the most highly (R=0.513) correlated with the percentage of dense calcium regions in plaques.

The g.841G>C SNP of FASN gene is associated with fatty acid composition in beef cattle.

The objective of the current study is to evaluate the association between fatty acid composition and fatty acid synthase gene polymorphisms as responsible mutations. For this purpose, we selected seven previously reported single nucleotide polymorphisms (SNPs) in FASN gene, including one within promoter region (g.841G>C) and six non-synonymous SNPs (g.8805C>T, g.13126C>T, g.15532A>C, g.16024A>G, g.16039C>T, g.17924A>G), and genotyped them in Japanese Black cattle. Genotyping results revealed that g.8805 C>T and g.17924 A>G were monomorphic loci. Genome-wide association analysis including the other five SNPs revealed that only g.841G>C showed significant associations with the percentages of C14:0, C14:1, C16:1 and C18:1 at 5% genome-wide significance level. In order to further evaluate the effect, we genotyped g.841G>C using additional three populations, including two Japanese Black populations and a Holstein cattle population. g.16024A>G was also genotyped and included in the analysis because it has been reported to be associated with fatty acid composition in Japanese Black cattle. In the result of analysis of variance, g.841G>C showed stronger effects on fatty acid percentage than those of g.16024A>G in all populations. These results suggested that g.841G>C would be a responsible mutation for fatty acid composition and contribute to production of high-grade beef as a selection marker in beef cattle.

Importance of multi-detector computed tomography for percutaneous coronary intervention in a patient with type V dual left anterior descending artery.

A 58-year-old woman came to our hospital because of chest pain. Multi-detector computed tomography (MDCT) showed type V dual left anterior descending artery (LAD) and a 90% stenosis in segment 1 of the right coronary artery. Two days after examination, she was admitted to our hospital because of recurrent chest pain. She was diagnosed with acute myocardial infarction. Coronary angiography showed a 99% stenosis in segment 1 and a dual LAD. She received successful percutaneous coronary intervention (PCI) to segment 1 with a bare metal stent. Type V dual LAD is a rare and complicated coronary anomaly with the short LAD originating from the left sinus of valsalva and the long LAD originating from the right sinus of valsalva. Identifying anatomy of the coronary artery is important when making a strategy for PCI. In types IV-VI dual LAD, the anatomic features can be misinterpreted at coronary angiography. MDCT was useful in understanding the anomaly of dual LAD and performing PCI in the present case.

Site-specific tetrameric streptavidin-protein conjugation using sortase A.

Streptavidin is tetrameric protein which has tight and specific biotin binding affinity, and streptavidin modification of proteins or small molecules is widely used for biotechnology tool. Here, we demonstrate site-specific streptavidin-protein conjugation using enzymes. We focused on sortase A, a transpeptidase from Staphylococcus aureus. A streptavidin-tagged LPETG motif (Stav-LPETG) was expressed in Escherichia coli. We achieved soluble streptavidin expression in E. coli without refolding using a cold shock expression system. Then we successfully conjugated Stav-LPETG with pentaglycine-appended green fluorescence protein (Gly5-GFP) or triglycine-appended glucose oxidase (Gly3-GOD) using sortase A. SDS-PAGE analysis showed site-specific tetrameric streptavidin-protein conjugation with the tagged proteins. In addition, the functions of a Stav-GOD conjugate, i.e., biotin-binding and glucose oxidase activity, were significantly higher compared to those of streptavidin-GOD conjugates prepared by chemical modification.

Involvement of membrane type 1-matrix metalloproteinase (MT1-MMP) in RAGE activation signaling pathways.

An advanced glycation end products (AGE)/a receptor for AGE (RAGE) axis plays a key role in diabetic vascular complications. Membrane type 1-matrix metalloproteinase (MT1-MMP) has been shown to function not only as a proteolytic enzyme but also as a signaling molecule. In this study, we investigated the role of MT1-MMP in the AGE/RAGE-triggered signaling pathways in cultured rabbit smooth muscle cells (SMCs) and the molecular interaction between RAGE and MT1-MMP in vitro and in vivo. In SMCs, AGE-activated Rac1 and p47(phox) within 1 min, NADPH oxidase activity and reactive oxygen species (ROS) generation within 5 min, and NF-κB phosphorylation within 15 min, thereby inducing redox-sensitive molecular expression. Silencing of RAGE by small-interfering RNA (siRNA) blocked the AGE-induced signaling pathways. AGE-induced geranylgeranyl transferase I (GGTase I) activity, Rac1·p47(phox) activation, NADPH oxidase activity, ROS generation, and molecular expression were also markedly attenuated by silencing of MT1-MMP. An inhibitor of GGTase I mimicked the effects of MT1-MMP-specific siRNA. Fluorescent immunohistochemistry revealed that MT1-MMP was partially co-localized with RAGE in SMCs, and RAGE was found to form a complex with MT1-MMP in both cultured SMCs and the aortae of diabetic rats by immunoprecipitation. Furthermore, MT1-MMP and RAGE formed a complex in the aortic atherosclerotic lesions of hyperlipidemic rabbits. We show that MT1-MMP plays a crucial role in RAGE-activated NADPH oxidase-dependent signaling pathways and forms a complex with RAGE in the vasculature, thus suggesting that MT1-MMP may be a novel therapeutic target for diabetic vascular complications.

Enzyme-mediated site-specific antibody-protein modification using a ZZ domain as a linker.

A ZZ domain (ZZ) and alkaline phosphatase (AP), luciferase (Luc), or glucose oxidase (GOD) were conjugated using Sortase A (SrtA) from Staphylococcus aureus. The specific peptidyl linker for SrtA was genetically fused to the C-terminus of ZZ, and the other linker was fused to the N-terminus of AP, Luc, or GOD, respectively. The resultant proteins were obtained separately by bacterial expression. The recombinant peptide-tagged ZZ and AP, Luc, or GOD were site-specifically conjugated by SrtA through the extra peptidyl linkers in vitro. The SrtA reaction had little influence on either the antibody-binding activity of the ZZ moiety or the enzymatic activity of AP, Luc, or GOD moieties of the conjugates. Additionally, antibody-ZZ-proteins were yielded easily by mixing antibody with ZZ-AP, ZZ-Luc, or ZZ-GOD, allowing their use in an enzyme-linked immunosorbent assay. These results suggest that the enzymatic approach with SrtA facilitates the construction of ZZ-proteins. Furthermore, mixing antibody and ZZ-proteins produces a wide variety of antibody-ZZ-proteins.

LOX-1-MT1-MMP axis is crucial for RhoA and Rac1 activation induced by oxidized low-density lipoprotein in endothelial cells.

AIMS: RhoA and Rac1 activation plays a key role in endothelial dysfunction. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a major receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells (ECs). Membrane type 1 matrix metalloproteinase (MT1-MMP) has been shown to be involved in atherogenesis. This study was conducted to investigate the role of the LOX-1-MT1-MMP axis in RhoA and Rac1 activation in response to ox-LDL in ECs. METHODS AND RESULTS: Ox-LDL induced rapid RhoA and Rac1 activation as well as MT1-MMP activity in cultured human aortic ECs. Inhibition of LOX-1 prevented ox-LDL-dependent RhoA and Rac1 activation. Knockdown of MT1-MMP by small interfering RNA prevented ox-LDL-induced RhoA and Rac1 activation, indicating that MT1-MMP is upstream of RhoA and Rac1. Fluorescent immunostaining revealed the colocalization of LOX-1 and MT1-MMP, and the formation of a complex of LOX-1 with MT1-MMP was detected by immunoprecipitation. Blockade of LOX-1 or MT1-MMP prevented RhoA-dependent endothelial NO synthase protein downregulation and cell invasion, Rac1-mediated NADPH oxidase activity, and reactive oxygen species generation. CONCLUSION: The present study provides evidence that the LOX-1-MT1-MMP axis plays a crucial role in RhoA and Rac1 activation signalling pathways in ox-LDL stimulation, suggesting that this axis may be a promising target for treating endothelial dysfunction.

Role of LOX-1 in monocyte adhesion-triggered redox, Akt/eNOS and Ca2+ signaling pathways in endothelial cells.

This study was conducted to examine the role of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in monocyte adhesion-induced redox-sensitive, Akt/eNOS and Ca2+ signaling pathways in endothelial cells (ECs). LOX-1 was blocked by an antibody-neutralizing LOX-1 TS92 or small interfering RNA. In cultured human aortic ECs, monocyte adhesion activated Rac1 and p47(phox), and increased NADPH oxidase activity and reactive oxygen species (ROS) generation within 30 min and NF-kappaB phosphorylation within 1 h, resulting in redox-sensitive gene expression. Akt and eNOS phosphorylation was induced 15 min after adding monocytes and returned to control level after 30 min, whereas NO production was not altered by monocyte adhesion. Blockade of LOX-1 blunted the monocyte adhesion-triggered redox-sensitive signaling pathway and Akt/eNOS phosphorylation in ECs. Both endothelial intracellular Ca2+ mobilization and Ca2+ influx caused by monocyte attachment were markedly attenuated by pretreatment of ECs with TS92. This suggests that LOX-1 is involved in redox-sensitive, Akt/eNOS and Ca2+ signaling pathways in monocyte adhesion to ECs independent of oxidized low-density lipoprotein (ox-LDL). Furthermore, blockade of Ca2+ inhibited monocyte adhesion-triggered Rac1 and p47(phox) activation and ROS generation in ECs, whereas Ca2+ signaling was suppressed by blockade of NADPH oxidase and ROS generation. Finally, TS92 blocked the monocyte adhesion to ECs stimulated with or without tumor necrosis factor-alpha or ox-LDL. We provide evidence that LOX-1 plays a role in redox-sensitive, Akt/eNOS and Ca2+ signaling pathways in monocyte adhesion to ECs independent of the ox-LDL-LOX-1 axis.

Role of Ca(2+)influx in tissue factor expression in monocyte adhesion to endothelial cells.

Tissue factor (TF) is the primary initiator of the coagulation cascade. Ca(2+) signaling is involved in TF gene expression. Monocyte chemoattractant protein-1 (MCP-1) and its receptor (CCR2) play a pivotal role in the inflammation of atherosclerosis. Although nitric oxide (NO) impairment appears to promote thrombogenicity in monocyte adhesion to endothelial cells (ECs), little is known about its mechanism. N(omega)-nitro-L-arginine methyl ester (L-NAME) promoted MCP-1 expression in EC culture. In response to monocyte adhesion, increased TF expression accompanied by NF-kappaB p65 activation was observed in L-NAME-treated ECs compared with non-treated ECs. This increased TF expression was prevented by BAPTA-AM, an intracellular Ca(2+) chelator. Monocyte attachment to L-NAME- treated ECs increased Ca(2+) influx compared with non-treated ECs, which was prevented by the blockade of MCP1/CCR2. These findings suggest that increased production of MCP-1 caused by L-NAME contributes to the enhancement of Ca(2+) influx only when monocytes adhered to ECs and that this may accelerate TF expression in ECs triggered by monocyte adhesion. We demonstrate the role of Ca(2+) influx via MCP-1/CCR2 under NO impairment in TF expression in monocyte-EC interaction.

RhoA-dependent PAI-1 gene expression induced in endothelial cells by monocyte adhesion mediates geranylgeranyl transferase I and Ca2+ signaling.

We investigated the role of RhoA activation and its mechanism in plasminogen activator inhibitor-1 (PAI-1) gene expression induced in endothelial cells by monocyte adhesion. Isolated human peripheral blood monocytes were added to cultured human coronary endothelial cells. Monocyte adhesion to endothelial cells increased PAI-1 expression at the transcriptional level and activated RhoA which was accompanied by an increase in the activity of geranylgeranyl transferase I (GGTase I), an enzyme responsible for geranylgeranylation, and actin stress fiber formation. Inhibition of RhoA by C3 exoenzyme or by adenovirus-mediated expression of N19RhoA, as well as by pravastatin, prevented the upregulation of PAI-1 induced by monocyte adhesion. GGTI-286, an inhibitor of GGTase I, prevented the monocyte-induced RhoA activation and PAI-1 expression in endothelial cells. Monocyte attachment induced an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in endothelial cells and Ca(2+) chelation prevented the increased promoter activity and expression of PAI-1 induced by monocyte adhesion. C3 exoenzyme and GGTI-286 also suppressed endothelial intracellular Ca(2+) mobilization and Ca(2+) entry induced by monocytes. The present study shows that GGTase I plays a role in the RhoA activation in endothelial cells induced by monocyte adhesion and that GGTase I-mediated Ca(2+) signaling may contribute to RhoA-dependent PAI-1 gene expression.

Endogenous NO blockade enhances tissue factor expression via increased Ca2+ influx through MCP-1 in endothelial cells by monocyte adhesion.

OBJECTIVE: Ca2+ plays an important role in tissue factor (TF) gene expression. We investigated the role of endogenous nitric oxide (NO) in the induction of TF expression in endothelial cells (ECs) by monocyte adhesion and the mechanisms of NO action. METHODS AND RESULTS: Inhibition of endogenous NO by Nomega-nitro-L-arginine methyl ester (L-NAME) enhanced TF promoter activity and protein expression induced in human coronary ECs by monocyte adhesion, as well as EC surface TF activity. L-NAME also induced monocyte chemoattractant protein-1 (MCP-1) expression, which was blocked by an NO donor, NOC18. Exogenous MCP-1 enhanced TF expression induced by monocyte adhesion, whereas adenovirus-mediated expression of the mutant MCP-1, 7ND, abolished the L-NAME enhancement of TF expression induced by monocyte adhesion. Monocyte attachment to L-NAME-treated ECs increased Ca2+ influx, which was prevented by NOC18, anti-MCP-1 antibody or 7ND. These results indicate that the binding of increased MCP-1 induced by endogenous NO blockade to CCR2 mediated the enhancement of Ca2+ influx only when monocytes adhered to ECs, which upregulated TF expression in ECs triggered by monocyte adhesion. CONCLUSIONS: MCP-1/CCR2 may play a role in Ca2+ influx-dependent TF regulation in the monocyte-EC interaction in the impairment of NO synthesis.

Thrombin-induced rapid geranylgeranylation of RhoA as an essential process for RhoA activation in endothelial cells.

RhoA plays a critical signaling role in thrombin-induced endothelial dysfunction. The possible thrombin regulation of geranylgeranylation, a lipid modification, of unprocessed RhoA and the significance of the geranylgeranylation in RhoA activation in endothelial cells (ECs) are not well understood. The amounts of the unprocessed and geranylgeranylated forms of RhoA in non-stimulated cultured human aortic ECs were 31 +/- 8 and 69 +/- 8% total cellular RhoA, respectively (n = 6, p < 0.0001), as determined by the Triton X-114 partition method. Thrombin-induced rapid conversion of most of the unprocessed RhoA into the geranylgeranylated form within 1 min through stimulating geranylgeranyltransferase I (GGTase I) activity. Thrombin-induced rapid geranylgeranylation was inhibited by acute short term (3 min) pretreatment with atorvastatin as well as by an inhibitor of GGTase I (GGTI-286). Thrombin also rapidly stimulated GTP loading of RhoA, which was blocked by acute pretreatment with either atorvastatin or GGTI-286. These observations indicate the dependence of thrombin stimulation of RhoA on the rapid geranylgeranylation of unprocessed RhoA. Importantly, the addition of geranylgeranylpyrophosphate to ECs pretreated with atorvastatin quickly reversed the atorvastatin inhibition of thrombin stimulation of RhoA. These results suggest that geranylgeranylation of unprocessed RhoA may limit thrombin-induced full activation of RhoA in ECs. Cytoskeleton analysis demonstrated that atorvastatin and GGTI-286 inhibited thrombin-induced stress fiber formation. We provide the evidence that, in thrombin-stimulated ECs, the unprocessed form of RhoA is rapidly geranylgeranylated to become the mature form, which then is converted into GTP-bound active RhoA.

Evaluation of aroma compounds contributing to muskmelon flavor in Porapak Q extracts by aroma extract dilution analysis.

The flavor of the Miyabi variety of Japanese muskmelon was extracted according to the Porapak Q column method (PQM) and evaluated by using aroma extract dilution analysis (AEDA) method. The overall odor of the PQM extracts was perceived as having a natural muskmelon-like odor, suggesting that the PQM was able to extract volatile compounds in muskmelon fruit without degradation of original flavor. Forty-six odorant compounds [Kovats index (KI), 961 < or = KI < or = 2605] were found by GC-sniffing in PQM extracts, confirming the effectiveness of PQM in trapping a wide range of volatile compounds in muskmelon flavor. The 46 odorants could be divided into three groups on the basis of their odor attributes: fruity note (KI < 1300); green, grassy, or cucumber-like note (1300 < KI < 2020); and sweet note (KI > 2020). When the original extracts were diluted in AEDA analysis, seven odorants could still be detected by GC-sniffing at a flavor diluation (FD) factor of 128 or above: one had a fruity note (compound 3); four had a cucumber-like, green, or grassy note (compounds 12, 17, 21, and 23); and two had a sweet note (caramel-like or yakitori-like) (compounds 32 and 34).

Integral role of RhoA activation in monocyte adhesion-triggered tissue factor expression in endothelial cells.

OBJECTIVE: The role of Rho activation in the regulation of tissue factor (TF) is not clear. This study was undertaken to investigate this in endothelial cells induced by monocyte adhesion. METHODS AND RESULTS: Isolated human peripheral blood monocytes were added to cultured human coronary endothelial cells. Monocyte adhesion to endothelial cells increased the levels of TF antigen in the endothelial cells. The results of transient transfection of the human TF promoter/luciferase gene into endothelial cells indicated that the increase in endothelial expression of the TF gene caused by monocyte adhesion occurred at the transcriptional level. The upregulation of TF was inhibited by statins, and the suppressive effect of statins was reversed by geranylgeranylpyrophosphate. Monocyte adhesion rapidly upregulated the membrane translocation and GTP/GDP exchange of RhoA, but not of Cdc42 or Rac, in endothelial cells. Rho inhibition by C3 exoenzyme or adenovirus-mediated expression of N19RhoA prevented the endothelial upregulation of TF caused by monocyte adhesion, and this was mimicked by Rho-kinase inhibitors. Moreover, monocyte adhesion increased the phosphorylation of nuclear factor-kappaB p65 in endothelial cells, and this was prevented by statins and Rho inhibition. CONCLUSIONS: Our study shows that RhoA activation plays an integral role in TF expression in endothelial cells.

Different contribution of apoptosis to the antiproliferative effects of L-arginine, enalapril and losartan on neointimal growth inhibition after balloon arterial injury.

It remains to be clarified how angiotensin-converting enzyme inhibitor-induced function (ie, increased NO related action or the inhibition of angiotensin II AT1 receptor dependent action) affects apoptosis of smooth muscle cells in the neointima following arterial injury. Saline (control), enalapril, L-arginine, combined enalapril and L-arginine, or losartan was administered for 14 days to Sprague-Dawley rats after balloon carotid injury and the ratio of intima to media areas (I/M), inducible NO synthase (iNOS) concentrations and %TUNEL were measured. I/M decreased similarly in the enalapril, L-arginine and losartan groups, and the combination of enalapril and L-arginine resulted in the largest I/M decrease. TUNEL positivity was increased compared with controls in the following order: losartan, L-arginine, enalapril and combination of enalapril and L-arginine. The intensity of immunostaining for iNOS was increased approximately 1.9-fold compared with the control in the combined enarapril and L-arginine group as well as in the enalapril group. These data suggest that the apoptosis in the neointima is different for L-arginine, losartan and enalapril under similar conditions and was higher under treatment with enalapril, not only via the action of NO or blocking of the AT1, but also by upregulation of iNOS.

Inhibition of Rho/Rho-kinase signaling downregulates plasminogen activator inhibitor-1 synthesis in cultured human monocytes.

Increased production of plasminogen activator inhibitor-1 (PAI-1) in plaques plays a role in the pathogenesis of atherosclerosis. This study was conducted to investigate the effect of blockade of Rho/Rho-kinase signaling on the synthesis of PAI-1 in cultured human peripheral blood monocytes. HMG-CoA reductase inhibitors (statins) and inhibitors of Rho and Rho-kinase were added to monocyte cultures. The levels of PAI antigen and mRNA were determined by Western blotting and RT-PCR, respectively, and PAI-1 expression was assessed by immunohistochemistry. We performed pull-down assays to determine the activity of Rho by measuring the GTP-bound form of Rho A. In unstimulated and lipopolysaccharide (LPS)-stimulated cultured monocytes, statins reduced the levels of PAI-1 antigen and mRNA. The suppressive effects of statins on PAI-1 synthesis were reversed by geranylgeranylpyrophosphate (GGPP) and were mimicked by C3 exoenzyme. Immunohistochemistry confirmed the role of lipid modification by GGPP in suppressive effect of statins in PAI-1 synthesis. Pull-down assays demonstrated that statins decreased the levels of the GTP-bound form of Rho A. Our findings suggest that statins decrease the activity of Rho by inhibiting geranylgeranylation. Moreover, Rho-kinase inhibitors, Y-27632 and fasudil, suppressed the synthesis of PAI-1 in this culture system. We show that inhibition of Rho/Rho-kinase signaling downregulates the synthesis of PAI-1 in human monocytes.