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Biomedical subjects

O Matsuo

Publications and source records attributed to O Matsuo.

At least 19 recordsLinked to original sources
PubMed2006

Lack of alpha2-antiplasmin improves cutaneous wound healing via over-released vascular endothelial growth factor-induced angiogenesis in wound lesions.

BACKGROUND: The fibrinolytic system is supposed to play an important role in the degradation of extracellular matrices for physiological and pathological tissue remodeling; however, the detailed mechanism regarding how this system affects cutaneous wound healing remains to be clarified. METHODS AND RESULTS: We performed experimental cutaneous wounding in mice with a deficiency of alpha(2)-antiplasmin (alpha(2)AP), which is a potent and specific plasmin inhibitor. We found that an accelerated wound closure was observed in alpha(2)AP-deficient (alpha(2)AP-/-) mice in comparison with wild type (WT) mice. Moreover, we observed that a greater increase of angiogenesis occurred in the process of wound healing in alpha(2)AP-/- mice than in the WT mice. Intriguingly, mRNA expression of vascular endothelial growth factor (VEGF), which is the best characterized positive regulator of angiogenesis, in wound lesions was found to show a greater increase in the early phase of the healing process in alpha(2)AP-/- mice than in WT mice. In addition, the amount of released-VEGF from the explanted fibroblasts of alpha(2)AP-/- mice increased dramatically more than in the WT mice. Finally, the intra-jugular administration of anti-VEGF antibody clearly suppressed the increased angiogenesis and accelerated wound closure in the wound lesion of alpha(2)AP-/- mice. CONCLUSION: The lack of alpha(2)AP markedly causes an over-release of VEGF from the fibroblasts in cutaneous wound lesions, thereby inducing angiogenesis around the area, and thus resulting in an accelerated-wound closure. CONCLUSIONS: This is the first report to describe the crucial role that alpha(2)AP plays following angiogenesis in the process of wound healing. Our results provide new insight into the role of alpha(2)AP on cutaneous wound healing.

Animals↗
PubMed2003

Alpha2-antiplasmin plays a significant role in acute pulmonary embolism.

The importance of pulmonary embolism (PE) due to venous thrombosis is recognized in the treatment of vascular diseases. We have investigated the physiological effects of plasmin generation in experimental acute PE using mice deficient in plasminogen (Plg-/-) or alpha2-antiplasmin (alpha2-AP-/-). PE was induced by continuous induction of venous thrombus in the left jugular vein by endothelial injury due to photochemical reaction. The mortality of wild-type mice was 68.8% at 2 h after the initiation of venous thrombosis and it was significantly reduced in alpha2-AP-/- mice (41.7%). In contrast, Plg-/- mice did not survive. Histological evidence of thromboembolism in the lung was obtained in all mice. However, whereas a strict thromboembolism was observed in Plg-/- mice, only a few thrombi were detected in the lungs of alpha2-AP-/- mice. Plasma fibrinogen levels measured in mice were not different. When alpha2-AP was infused in alpha2-AP-/- mice, the mortality was indistinguishable from wild-type mice. Tissue-type plasminogen activator (tPA) did not reduce the mortality due to acute PE in wild-type mice. However, in alpha2-AP-/- mice, tPA (0.52 mg x kg-1) significantly decreased the mortality compared with that of alpha2-AP-/- mice without tPA. The bleeding time was not significantly prolonged in either type of mice treated with tPA. The lack of plasminogen increases the mortality due to acute PE while a lack of alpha2-AP decreases the mortality rate, which can be further reduced by tPA administration. Therefore, the combination of inhibition of alpha2-AP with thrombolytic therapy could be beneficial in the treatment of acute PE.

Acute Disease↗
PubMed2001

Mechanism of retarded liver regeneration in plasminogen activator-deficient mice: impaired activation of hepatocyte growth factor after Fas-mediated massive hepatic apoptosis.

Urokinase-type plasminogen activator (uPA) is implicated in the regulation of hepatic regeneration by activating hepatocyte growth factor (HGF). Here, we investigated its role in the hepatic regeneration after Fas-mediated massive hepatocyte death employing mice deficient in either uPA or its inhibitor, plasminogen activator inhibitor-1 (PAI-1). We measured kinetics of hepatic levels of proliferating cell nuclear antigen (PCNA)-labeling index, plasmin activity, mature HGF, and its phosphorylated receptor, c-Met. In the genetically targeted and wild-type mice, hepatocytes fell into the same extent of apoptosis 6 to 12 hours after an intraperitoneal injection with anti-Fas antibody, as judged from histologic analysis and a histon-DNA enzyme-linked immunosorbent assay (ELISA). In the wild-type mice, mature HGF emerged in the liver 6 hours following anti-Fas injection, and hepatic PCNA-labeling index started to increase following 24 hours and peaked at 48 hours. In the uPA(-/-) mice, emergence of mature HGF was delayed 12 hours and hepatic regeneration peaked at 96 hours. Supplementation with the uPA gene to the uPA(-/-) mice by in vivo lipofection restored hepatic plasmin levels, and improved a delay in the expression of both mature HGF and phosphorylated c-Met, accompanying a normal rate of liver regeneration. In contrast, PAI-1(-/-) mice showed accelerated liver regeneration; mature HGF emerged as early as 3 hours, and PCNA-labeling index increased at 24 hours. This accelerated regeneration was abolished by administration with anti-HGF antibody. These results strongly suggest a physiologic role of uPA in the proteolytic maturation of HGF, and thereby in hepatic regeneration after Fas-mediated massive hepatocyte death.

Animals↗
PubMed2000

Roles of urokinase type plasminogen activator in a brain stab wound.

Urokinase type plasminogen activator (uPA) may influence brain pathophysiology after injury. We studied disruption of the blood-brain barrier (BBB) and changes in the vasculature after a brain stab wound in uPA-deficient, uPA receptor-deficient, and PA inhibitor-1 (PAI-1) deficient mice. The extravasation of immunoglobulin was greater in PAI-1 deficient mice; less pronounced in uPA-deficient mice; similar to controls in uPA receptor-deficient mice. Vasculatures in the wound proliferated in PAI-1 deficient mice. Our study shows that uPA affects BBB disruption. PA enhances angiogenesis after brain injury.

Animals↗
PubMed2000

A peptide mimic of E-selectin ligand inhibits sialyl Lewis X-dependent lung colonization of tumor cells.

Selectins bind to carbohydrate ligands in a calcium-dependent manner and play critical roles in host defense and possibly in tumor metastasis. To isolate peptides that mimic E-selectin ligands, we screened a phage peptide library using E-selectin as a target molecule. This attempt unexpectedly failed, probably because the binding affinity of E-selectin to its ligand is low. We then took an approach that is analogous to the isolation of anti-idiotype antibodies and were able to isolate peptides that bound to anticarbohydrate antibodies recognizing E-selectin ligands. These peptides, enriched for their binding to anti-Lewis A antibody, were found to bind to E-, P- and L-selectins in a calcium-dependent manner. Phage harboring the identified peptide IELLQAR and synthetic peptides having the same sequence inhibited the binding of sialyl Lewis X or sialyl Lewis A oligosaccharides to E-selectin. The adhesion of HL-60 and B16 melanoma cells expressing sialyl Lewis X to E-selectin was also inhibited by the phage-displaying IELLQAR peptide. Moreover, i.v. injected IELLQAR peptide inhibited the lung colonization of mouse B16 melanoma and human lung tumor cells expressing sialyl Lewis X. These results demonstrate that it is possible to isolate peptides mimicking carbohydrate ligands by screening the peptides for binding to anticarbohydrate antibodies and then using them to inhibit carbohydrate-dependent experimental tumor metastasis.

Animals↗
PubMed2000

Effect of hyperthermia on the viability and the fibrinolytic potential of human cancer cell lines.

The effects of heat treatment on the viability and fibrinolytic potential of four cultured human carcinoma cell lines, fibrosarcoma cells (HT-1080), lung adenocarcinoma cells with highly metastatic potential (HAL-8), melanoma cells (Bowes) and osteosarcoma cells (NY), determined by measuring their levels of urokinase-type plasminogen activator (u-PA) and its specific receptor (u-PAR), were investigated by comparing them with those of human umbilical vein endothelial cells (HUVECs). HUVECs incubated at 43 degrees C for 120 min exhibited no decrease in viability but exhibited an increase in both u-PA and u-PAR. HT-1080 and HAL-8 showed a moderately high heat-resistance (viability, 60-90%) that correlated with the reduction of u-PAR but not u-PA. On the other hand, Bowes and NY cells, with poor heat-resistance (viability, 20-50%), exhibited stronger cell-associated u-PA activity when they survived at 43 degrees C for 120 min. Since the u-PA/u-PAR system is directly involved in the invasiveness and metastatic potential of carcinoma cells, hyperthermia would alter the biological activity of these carcinoma cells.

Adenocarcinoma↗
PubMed2000

Binding of mutant tissue-type plasminogen activators to human endothelial cells and their extracellular matrix.

We previously demonstrated that tissue-type plasminogen activator (t-PA) specifically bound to its receptor (t-PAR) on human umbilical vein endothelial cells (HUVEC). In addition to analyses of t-PA binding to plasminogen activator inhibitor-1 (PAI-1) in the extracellular matrix (ECM) and to the t-PAR, we further evaluated the binding of three t-PA mutants, deltaFE1X t-PA lacking finger (F), epidermal growth factor-like (E) domains and one sugar chain at Asn177 thus comprising two kringles (K1 and K2) and protease (P) domains, deltaFE3X t-PA with three glycosylation sites deleted at Asn117, 184, and 448, and deltaFEK1 t-PA comprising K2 and P domains without glycosylation. Wild-type t-PA bound to ECM with high affinity, which was completely blocked by anti-PAI-1 IgG. Wild-type t-PA, deltaFE1X t-PA and deltaFEK1 t-PA bound to two classes of binding sites with high and low affinities on monolayer HUVEC. However, all t-PAs bound to a single class of binding site in the presence of anti-PAI-1 IgG. DeltaFEK1 t-PA bound t-PAR maximally among these t-PAs. These results suggested that the high affinity binding of t-PA mainly occurred with PAI-1 on ECM while the low affinity binding was with t-PAR. The deletion of F, E domains and sugar chains had no effect on binding with t-PAR. However, since only K1-missing t-PA (deltaFEK1) exhibited significantly increased binding sites among these t-PAs, it was suggested that the binding to t-PAR was mediated mainly by K2 domain and that the increase of binding was due to direct exposure of K2 domain.

Aminocaproic Acid↗
PubMed2000

The interaction between components of the fibrinolytic system and GPIb/V/IX of platelets thrombus formation in mice.

The interaction of fibrinolytic components with GPIb/V/IX of platelets on thrombus formation, was investigated in mice deficient in tissue type (tPA-/-), urokinase type plasminogen activator (uPA-/-) or plasminogen activator inhibitor-1 (PAI-1-/-) and in their wild type control (tPA+/+, uPA+/+, PAI-1+/+). A thrombus was induced in the murine carotid artery using a photochemical reaction. The times to occlusion after the initiation of endothelial injury in all wild type mice was within 12 min, and no significant changes in occlusion delay were observed in uPA-/- and tPA-/- mice compared to wild type mice, whereas that of PAI-1 mice were significantly prolonged (16.9+/-2.9 min, P<0.05). When high molecular weight aurintricarboxylic acid (ATA), an inhibitor of platelet glycoprotein Ib/V/IX, was administered, the time to occlusion was prolonged in a dose-dependent manner in all types of mice. However, when this compound was injected in tPA-/- mice, the most significant changes were observed: i.e. the estimated ED(50) was 20.2 times higher than that in tPA+/+ mice, but the estimated ED(50) in uPA-/- mice was not changed as compared with that of wild type mice. On the other hand, when ATA was injected in PAI-1-/- mice, the estimated ED(50) was significantly decreased (P<0.05). Platelet aggregation induced by botrocetin was not significantly different among all types of mice. The bleeding time was prolonged in a dose dependent-manner when ATA was injected in all types of mice. In conclusion, the antithrombotic effect of inhibition of platelet GPIb/V/IX is severely affected by the absence or presence of tPA-production on thrombus formation and the inhibition of PAI-1 could enhance this antithrombotic effect.

Animals↗
PubMed2000

Antithrombotic regulation in human endothelial cells by fibrinolytic factors.

Vascular endothelial cells (ECs) modulate the blood fibrinolytic system by secreting tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA), and their inhibitor, type-1 plasminogen activator inhibitor (PAI-1). ECs also express t-PA receptors (t-PAR) and u-PA receptors (u-PAR) on their cell surfaces, assembling both enzymes to regulate the cellular fibrinolytic activity. In addition, ECs modulate these factors in response to several stimuli. Fibrin clots on ECs induce the up- and downregulation of t-PA and PAI-1 production, respectively, thus causing an effective lysis of the fibrin clot. Heat shock (43 degrees C) increases the expression of u-PA, t-PA, PAI-1, and u-PAR by which ECs become more fibrinolytic around the cells. Furthermore, because ECs possess t-PAR and u-PAR on their cell surfaces, the binding of t-PA and u-PA is a critical event, which affords ECs the localized and condensed fibrinolytic potential. Therefore, ECs play a central role in antithrombotic activity by regulating the levels of these fibrinolytic factors.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

The effect of argatroban on injured endothelial cells by thrombin.

When endothelial cells are exposed to thrombin, they become perturbed and acquire thrombogenic properties. Argatroban is an arginine derivative, synthetic small molecule that binds to the active site of thrombin and inhibits its catalytic activity. Therefore, the effects of argatroban on endothelial cells, which had been injured by thrombin, were investigated. The established endothelial cell line, TKM-33, which had been cloned from human umbilical vein endothelial cells, was used. Endothelial cells produce plasminogen activator (PA) to prevent thrombosis and maintain the blood flow. When the endothelial cells were injured by thrombin, secretion of plasminogen activator inhibitor-1 (PAI-1) increased and then the PA activity proportionally decreased. The treatment of endothelial cells with argatroban after thrombin injury did not restore their reduced PA activity. However, the treatment of endothelial cells with argatroban prior to thrombin injury resulted in inhibiting the induction of PAI-1 secretion. Thus, pretreatment of endothelial cells with argatroban suppresses the inhibition of their PA activity by thrombin. Since the effect of thrombolytic agent may be modified by the fibrinolytic factors produced by the endothelial cells, the activity of staphylokinase (SAK) was measured in the presence of endothelial cells that had been injured by thrombin. SAK is a newly developed thrombolytic agent. SAK activity in the presence of injured endothelial cells by thrombin was lower than that in the presence of endothelial cells without thrombin injury. However, treatment of endothelial cells with argatroban prior to thrombin injury revealed higher SAK activity than that after thrombin injury. These findings indicate that argatroban pretreatment prevents thrombin injury of endothelial cells, which may then maintain their physiological function.

Arginine↗
PubMed2000

Analysis of plasminogen activation by the plasmin-staphylokinase complex in plasma of alpha2-antiplasmin-deficient mice.

Staphylokinase (SAK) expresses plasminogen activator (PA) activity by forming a complex with plasmin; this PA activity is inhibited by alpha2-antiplasmin (alpha2-AP) in plasma. However, SAK's activity is protected against inhibition by alpha2-AP in the presence of fibrin because the plasmin-SAK complex binds to fibrin. In the present study, the interaction between SAK and murine plasminogen was investigated in the plasma of alpha2-AP-deficient (alpha2-AP-/-) mice or plasminogen-deficient (Plg-/-) mice. Although the human plasmin-SAK complex was formed in equimolar mixtures of plasmin and SAK, the murine plasmin-SAK complex was not formed. Human plasminogen was activated by the human plasmin-SAK complex, although equimolar mixtures of murine plasmin and SAK did not activate murine plasminogen. These findings suggest that SAK does not react with murine plasmin. However, the murine plasminogen was activated by the human plasmin-SAK complex, although this activation was approximately 100-fold weaker than human plasminogen. Human and wild-type mouse plasminogens were not activated by the human plasmin-SAK complex in their plasma. In alpha2-AP-/- mouse plasma, murine plasminogen was activated by the human plasmin-SAK complex. Human or murine plasminogen, which had been added to Plg-/- mouse plasma, was not activated by the human plasmin-SAK complex. However, plasma clot lysis by the human plasmin-SAK complex was observed in both human and murine plasma. These findings indicate that: (1) murine plasmin does not react with SAK, (2) human plasmin-SAK complex activates murine plasminogen, (3) this activation is inhibited by murine alpha2-AP, but (4) this activation is not inhibited by murine alpha2-AP in the presence of fibrin.

Animals↗
PubMed2000

tPA, but not uPA, significantly affects antithrombotic therapy by a glycoprotein IIb/IIIa antagonist, but not by a factor Xa inhibitor.

To define the interaction of fibrinolytic components with platelets or coagulation factors on thrombus formation, we investigated mouse deficient in tissue plasminogen activator (tPA -/-) or urokinase plasminogen activator (uPA -/-) and in their wild-type control (tPA +/+, uPA +/+). A thrombus was induced in the murine carotid artery using photochemical reaction. Blood flow was monitored and the time needed before the vessel became completely obstructed was within 12 min in all types of mice. When DX-9065a, a selective factor Xa inhibitor, or GR144053, a platelet glycoprotein (GP) complex IIb/IIIa antagonist was applied, the time required to occlusion was prolonged in a dose-dependent manner in all types of mice. When a factor Xa inhibitor was injected in tPA -/- mice, the estimated ED50 was not changed. However, when GR144053 was injected in tPA -/- mice, the most significant changes were observed: the estimated ED51 was 19.6 times higher than the one in tPA +/+ mice. Platelet aggregation, hemostasis tests, and bleeding times were not significantly different among the different types of mice. In conclusion, the antithrombotic effect of platelet inhibition by a GPIIb/IIIa antagonist, is severely affected by the absence or presence of tPA production. On the contrary, the inhibition of factor Xa shows a stable antithrombotic effect with or without tPA. Thus the lack of tPA, but not of uPA, significantly affects antithrombotic efficacy.

Animals↗
PubMed2000

Lack of tPA significantly affects antithrombotic therapy by a GPIIb/IIIa antagonist, but not by a thrombin inhibitor in mice.

The interaction of fibrinolytic components with platelets or coagulation factors after endothelial injury, was investigated in mouse deficient in tissue type plasminogen activator (tPA -/-), or urokinase (uPA -/-) and in their wild type control (tPA +/+, uPA +/+). A thrombus was induced in the murine carotid artery using the photochemical reaction. Blood flow was continuously monitored and the time needed before the vessel became completely obstructed was within 11 min in all types of mice. When GR144053, a platelet glycoprotein IIb/IIIa antagonist, or argatroban, a thrombin inhibitor, was applied, the time required to occlusion was prolonged in a dose-dependent manner in all types of mice. However, when GR144053 was injected in tPA -/- mice, the most significant changes were observed: that is the estimated ED50 was 14.8 times higher than the one in tPA +/+ mice. On the other hand, when argatroban was injected in tPA -/- mice, the estimated ED50 was not changed. Platelet aggregation, haemostasis tests and bleeding times were not significantly different among the different types of mice. In conclusion, the antithrombotic effect of platelet inhibition by a GPIIb/IIIa antagonist, is severely affected by the absence or presence of tPA-production. Thus, the lack of tPA significantly reduces the antithrombotic efficacy.

Animals↗
PubMed1999

Nigral degeneration following striato-pallidal lesion in tissue type plasminogen activator deficient mice.

Tissue type plasminogen activator (tPA) has been suggested as a key factor in excitotoxic neuronal death in the hippocampus. Transneuronal degeneration of the substantia nigra pars reticulata (SNR) neurons after striato-pallidal lesions is attributable to excess excitatory glutamatergic inputs into the SNR following inhibitory GABAergic deafferentation and tPA may contribute to the mechanism of transneuronal degeneration of the SNR. To examine this possibility, we studied pathological changes in the SNR following striato-pallidal lesions produced by electrocoagulation in tPA-deficient mice. There was no difference in the degree of SNR degeneration, or in microglial activation and proliferation in the degenerating SNR of tPA-deficient and control mice. Our results indicate that tPA does not contribute to transneuronal degeneration in the SNR following striato-pallidal lesions in mice.

Animals↗
PubMed1999

Alpha2-antiplasmin gene deficiency in mice is associated with enhanced fibrinolytic potential without overt bleeding.

alpha2-antiplasmin (alpha2-AP) is the main physiologic plasmin inhibitor in mammalian plasma. Inactivation of the murine alpha2-AP gene was achieved by replacing, through homologous recombination in embryonic stem cells, a 7-kb genomic sequence encoding the entire murine protein (exon 2 through part of exon 10, including the stop codon) with the neomycin resistance expression cassette. Germline transmission of the mutated allele was confirmed by Southern blot analysis. Mendelian inheritance of the inactivated alpha2-AP allele was observed, and homozygous deficient (alpha2-AP-/-) mice displayed normal fertility, viability, and development. Reverse transcription-polymerase chain reaction confirmed the absence of alpha2-AP mRNA in kidney and liver from alpha2-AP-/- mice, in contrast to wild-type (alpha2-AP+/+) mice. Immunologic and functional alpha2-AP levels were undetectable in plasma of alpha2-AP-/- mice, and were about half of wild-type in heterozygous littermates (alpha2-AP+/-). Other hemostasis parameters, including plasminogen activator inhibitor-1, plasminogen, fibrinogen, hemoglobin, hematocrit, and blood cell counts were comparable for alpha2-AP+/+, alpha2-AP+/-, and alpha2-AP-/- mice. After amputation of tail or toe tips, bleeding stopped spontaneously in alpha2-AP+/+, as well as in alpha2-AP+/- and alpha2-AP-/- mice. Spontaneous lysis after 4 hours of intravenously injected 125I-fibrin-labeled plasma clots was significantly higher in alpha2-AP-/- than in alpha2-AP+/+ mice when injecting clots prepared from alpha2-AP+/+ plasma (78% +/- 5% v 46% +/- 9%; mean +/- SEM, n = 6 to 7; P =.02) or from alpha2-AP-/- plasma (81% +/- 5% v 46% +/- 5%; mean +/- SEM, n = 5; P =.008). Four to 8 hours after endotoxin injection, fibrin deposition in the kidneys was significantly reduced in alpha2-AP-/- mice, as compared with alpha2-AP+/+ mice (P </=.005). Thus, alpha2-AP-/- mice develop and reproduce normally; they have an enhanced endogenous fibrinolytic capacity without overt bleeding.

Alleles↗