siRNA potency enhancement via chemical modifications of nucleotide bases at the 5'-end of the siRNA guide strand.

Small interfering RNAs (siRNAs) can be utilized not only as functional biological research tools but also as therapeutic agents. For the clinical use of siRNA as drugs, various chemical modifications have been used to improve the activity of siRNA drugs, and further chemical modifications are expected to improve the utility of siRNA therapeutics. As the 5' nucleobase of the guide strand affects the interaction between an siRNA and AGO2 and target cleavage activity, structural optimization of this specific position may be a useful strategy for improving siRNA activity. Here, using the in silico model of the complex between human AGO2 MID domain and nucleoside monophosphates, we screened and synthesized an original adenine-derived analog, 6-(3-(2-carboxyethyl)phenyl)purine (6-mCEPh-purine), that fits better than the natural nucleotide bases into the MID domain of AGO2. Introduction of the 6-mCEPh-purine analog at the 5'-end of the siRNA guide strand significantly enhanced target knockdown activity in both cultured cell lines and in vivo animal models. Our findings can help expand strategies for rationally optimizing siRNA activity via chemical modifications of nucleotide bases.

Relationship between mortality and use of sodium bicarbonate at the time of dialysis initiation: a prospective observational study.

BACKGROUND: Patients with chronic kidney disease often experience metabolic acidosis. Whether oral sodium bicarbonate can reduce mortality in patients with metabolic acidosis has been debated for years. Hence, this study was conducted to evaluate the utility of sodium bicarbonate in patients who will undergo dialysis therapy. In this study, we investigated the effect of oral sodium bicarbonate therapy on mortality in patients with end-stage kidney disease (ESKD) initiated on dialysis therapy. METHODS: We conducted an observational study of patients when they started dialysis therapy. There were 17 centres participating in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis. Data were available on patients' sex, age, use of sodium bicarbonate, drug history, medical history, vital data, and laboratory data. We investigated whether patients on oral sodium bicarbonate for more than three months before dialysis initiation had a better prognosis than those without sodium bicarbonate therapy. The primary outcome was defined as all-cause mortality. RESULTS: The study included 1524 patients with chronic kidney disease who initiated dialysis between October 2011 and September 2013. Among them, 1030 were men and 492 women, with a mean age of 67.5 ± 13.1 years. Of these, 677 used sodium bicarbonate and 845 did not; 13.6% of the patients in the former group and 21.2% of those in the latter group died by March 2015 (p <  0.001). Even after adjusting for various factors, the use of sodium bicarbonate independently reduced mortality (p <  0.001). CONCLUSIONS: The use of oral sodium bicarbonate at the time of dialysis initiation significantly reduced all-cause mortality in patients undergoing dialysis therapy.

Evaluation of tryptophan-aspartic acid repeat-containing protein 34 as a novel tumor-suppressor molecule in human oral cancer.

Tryptophan-aspartic acid (WD) repeat-containing protein 34 (WDR34), one of the WDR protein superfamilies with five WD40 domains, inhibits a transforming growth factor-beta (TGF-ß) activated kinase 1 (TAK1)-associated NF-κB activation pathway. Nevertheless, little is known about the roles of WDR34 in cancer. The current study sought to elucidate the clinical relevance of WDRsfb34 in oral squamous cell carcinoma (OSCC). We found WDR34 down-regulation in OSCCs compared with normal control tissues using real-time quantitative reverse transcription-polymerase chain reaction, immunoblotting, and immunohistochemistry. Models of overexpression of WDR34 (oeWDR34) showed depressed cellular growth through cell-cycle arrest at the G1 phase. To investigate the inhibitory function of WDR34, we challenged oeWDR34 cells with interleukin (IL)-1, a ligand for activation of the TAK1-NF-κB pathway and assessed the expression of a target gene of the pathway. oeWDR34 strongly inhibited IL-6 expression, which is closely related to tumoral growth, compared with control cells, suggesting that WDR34 would be a critical molecule for control of tumoral progression. In addition to the in vitro experiments, WDR34 negativity was correlated with tumoral growth of OSCCs. Our findings suggested that WDR34 inhibits OSCC progression and might be a potential tumor-suppressor molecule in OSCCs.

Overwork accelerates thrombotic reaction: implications for the pathogenesis of Karoshi.

Work-related stressors are potential causes of cardiovascular diseases (CVDs) and stroke; however, the pathophysiological mechanisms by which occupational stress induces and exacerbates CVDs remain unclear. The global thrombosis test (GTT) is a novel in vitro assay for evaluating both thrombotic reactions and subsequent thrombolysis. The time required to form an occlusive thrombus with the GTT, called as the occlusion time (OT), and the time to lyse the thrombus, the lysis time (LT), are markers of thrombotic and thrombolytic reactions, respectively. We investigated the impact of work-related stress on the thrombotic and thrombolytic reactions in 46 healthy medical residents. Off-duty or on-duty blood samples were collected on the mornings of non-work days or after the night duty on the emergent room respectively. The duration of sleep was significantly shorter during night duty than during off-duty nights [2.25 (1.0, 3.0) h vs. 6.0 (5.0, 7.0) h; p < 0.001]. Baseline OT was 310.3 (260.9, 437.7) s. whereas the on-duty OT was significantly shortened [284.2 (230.5, 355.8) s; p < 0.01]. LT was significantly prolonged during overwork conditions compared with off-duty conditions [1547 (1346, 1908) s vs. 1470 (1219, 1692) s; p < 0.05]. Overwork accelerates the thrombotic reactions. These reactions might explain the pathogenesis of overwork-related CVDs. The GTT is a good tool for evaluating of the level of fatigue.

Global Thrombosis Test - a possible monitoring system for the effects and safety of dabigatran.

BACKGROUND: Dabigatran is an alternative to warfarin (WF) for the thromboprophylaxis of stroke in patients with non-valvular atrial fibrillation (NVAF). The advantage of dabigatran over WF is that monitoring is not required; however, a method to monitor the effect and the safety of dabigatran is not currently available. The Global Thrombosis Test (GTT) is a novel method to assess both clot formation and lysis activities under physiological conditions. OBJECTIVE: The aim of this study was to evaluate whether treatment with dabigatran might affect shear-induced thrombi (occlusion time [OT], sec) by the GTT, and to investigate the possibility that the GTT could be useful as a monitoring system for dabigatran. PATIENTS/METHODS: The study population consisted of 50 volunteers and 43 NVAF patients on WF therapy, who were subsequently switched to dabigatran. Using the GTT, the thrombotic status was assessed one day before and 1 month after switching anticoagulation from WF to dabigatran. RESULTS: The OT was 524.9 ± 17.0 sec in volunteers whereas that of NVAF patients on WF therapy was 581.7 ± 26.3 sec. The switch from WF to dabigatran significantly prolonged OT (784.5 ± 19.3 sec). One patient on WF therapy and 12 patients on dabigatran therapy were shown to have OT > 900 sec. CONCLUSION: The GTT could be used to assess the risk of dabigatran-related bleeding complications.

Synthetic studies on mitotic kinesin Eg5 inhibitors: synthesis and structure-activity relationships of novel 2,4,5-substituted-1,3,4-thiadiazoline derivatives.

The 2,4,5-substituted-1,3,4-thiadiazoline derivative 1a has been identified as a new class of mitotic kinesin Eg5 inhibitor. With the aim of enhancement of the mitotic phase accumulation activity, structure optimization of side chains at the 2-, 4-, and 5-positions of the 1,3,4-thiadiazoline ring of 1a was performed. The introduction of sulfonylamino group at the side chain at the 5-position and bulky acyl group at the 2- and 4-position contributed to a significant increase in the mitotic phase accumulation activity and Eg5 inhibitory activity. As a result, a series of optically active compounds exhibited an increased antitumor activity in a human ovarian cancer xenograft mouse model that was induced by oral administration.

Enhanced pre-operative thrombolytic status is associated with the incidence of deep venous thrombosis in patients undergoing total knee arthroplasty.

BACKGROUND: Deep venous thrombosis (DVT), which is often associated with pulmonary embolism (PE), is a serious complication after total knee arthroplasty (TKA). In the present study, we examined the overall thrombotic and thrombolytic status using Global Thrombosis Test (GTT) in non-anticoagulated blood of patients undergoing TKA to develop the predictable marker for the incidence of DVT. METHODS: DVT was diagnosed using doppler ultrasonography a day after the surgery in 31 patients with osteoarthritis (n = 24), rheumatoid arthritis (n = 6) and ankylosing spondylitis (n = 1) by the well-trained operator. We measured overall thrombotic and thrombolytic status using GTT and other biomarkers, which is associated with blood coagulation and fibrinolysis, before and immediately after the surgery. RESULTS: Newly-generated DVT during the operation was detected in 11 of 31 patients (35.4%) 1 day after TKA. There were no differences in markers of coagulation (PT and APTT), platelet activity (platelet aggregation-induced by ADP and collagen) and fibrinolysis (FDP and D-dimer) between non-DVT and DVT group both before and after the surgery. Both Pre- and Post-operative GTT-occlusion times (OT), an index of platelet reactivity, were tended to be shorter, but not significant, in DVT group compared with non-DVT group. Pre-operative GTT-lysis time (LT), an index of thrombolytic activity, was significantly shorter in DVT group compared with non-DVT group, while there were no differences in post-operative value of this index between DVT group and non-DVT group, suggesting overall thrombolytic activity was enhanced in DVT group before surgery. CONCLUSIONS: Our data suggest that enhancement of pre-operative thrombolytic activity assessed by GTT may be a predictable marker for the incidence of DVT after TKA.

Attenuation of spontaneous thrombolytic activity measured by the global thrombosis test in male habitual smokers.

Smoking is known as one of the major risk factors for atherothrombotic cardiovascular diseases. We investigated the susceptibility to thrombosis in habitual smokers by using the global thrombosis test (GTT), by which both clot formation and clot lysis activities can be evaluated simultaneously in native blood samples in vitro. Subjects were 139 men participating in a periodic health checkup examination, and an informed consent for the subjects was obtained as a document. Using GTT, occlusion time (OT: the time taken for clot formation in the blood sample) and lysis time (LT: the time taken for lysis of the clot that had been formed) were measured. LT was significantly (p = 0.029) longer in smokers [median with range, 1,794 (1,080-6,000) s (n = 76)] than in nonsmokers [median with range, 1,530 (792-3,800) s (n = 63)], while there was no significant difference in OT between smokers and nonsmokers. In smokers, LT was significantly correlated with daily cigarette consumption but not with Brinkman index. LT measured in nine smokers at 3 months after quitting their habitual smoking was significantly shorter than LT measured before the cessation of smoking. Since prolongation of LT implies existence of thrombogenic tendency, smokers are thought to be more susceptible to thrombosis due to decreased fibrinolytic activity, and no smoking for even a short term may be effective for improving fibrinolytic activity in smokers.

Short- and long-term treatment with folic acid suppresses thrombus formation in atherogenic mice in vivo.

In the present study, we examined the effects of short- and long-term treatment with folic acid (FA) on thrombus formation in vivo in atherogenic mice to explore a novel agent for the prevention of atherothrombotic disease. Apolipoprotein E and low-density lipoprotein receptor double deficient (ApoE(-/-)LDLR(-/-)) mice were orally administrated a single bolus of FA (20mg/kg) or fed an atherogenic diet with or without FA (0.02, 0.5, and 1.5mg/kg) for 12 weeks. Thrombus formation and endothelial function were assessed in vivo using the He-Ne laser-induced carotid artery thrombus formation test and the flow-mediated vasodilation method. Platelet reactivity was assessed ex vivo using haemostatometry. Short-term treatment with FA markedly increased plasma folate levels and significantly suppressed laser-induced thrombus formation in apoE(-/-)LDLR(-/-) mice. Short-term treatment with FA suppressed platelet reactivity in apoE(-/-)LDLR(-/-) mice, but FA treatment did not affect endothelial function or plasma homocysteine levels. Long-term treatment with FA increased plasma folate levels dose-dependently. Thrombus formation and endothelial dysfunction were suppressed by treatment with 0.5 and 1.5mg/kg of FA, respectively, but not with 0.02mg/kg of FA, whereas platelet reactivity was not altered by treatment with any dose of FA. Long-term treatment with all doses of FA decreased the plasma homocysteine levels in apoE(-/-)LDLR(-/-) mice, although this result was not consistent with its anti-thrombotic action. In conclusion, our data showed that short- and long-term treatment with FA could suppress in vivo thrombus formation in an atherogenic setting, independent of its hypohomocysteinemic action.

Crocetin, a carotenoid from Gardenia jasminoides Ellis, protects against hypertension and cerebral thrombogenesis in stroke-prone spontaneously hypertensive rats.

Crocetin is a natural carotenoid dicarboxylic acid that is found in the fruit of Gardenia jasminoides Ellis (Cape Jasmine) and in the stamen and pistil of Crocus sativus L. (saffron). It is used worldwide as an important spice, food colorant, and herbal medicine. In the current investigation, we have examined the cardiovascular effects of crocetin using stroke-prone spontaneously hypertensive rats (SHRSPs). Male SHRSPs (6 weeks old) were classified into three groups: a control group and two crocetin groups (25 and 50 mg/kg/day). The animals were given crocetin for 3 weeks. Body weights in each group were not significantly different during the treatment period, but the increase in systolic blood pressures observed with age was significantly moderated by crocetin. Thrombogenesis, assessed using a He-Ne laser technique in pial vessels, was significantly decreased. Antioxidant activity, assessed by measuring urinary 8-hydroxy-2'-deoxyguanosine levels, together with urinary nitric oxide (NO) metabolite levels, was increased significantly after treatment. Acetylcholine-induced vasodilation was measured using the aorta and indicated that endothelial function was significantly improved by crocetin. These results strongly suggest that the antihypertensive and antithrombotic effects of crocetin were related to an increase in bioavailable NO, possibly mediated by decreased inactivation of NO by reactive oxygen species.

Successful treatment with granulocyte and monocyte adsorption apheresis for plaque-type skin lesions in patients with psoriatic arthritis.

INTRODUCTION: Granulocyte and monocyte adsorption apheresis (GMA) is usually performed weekly for refractory skin diseases, such as generalized pustular psoriasis and psoriatic arthritis (PsA). METHODS: Four patients with PsA who were refractory to previous treatments were enrolled. They received five or ten sessions of GMA. We assessed the clinical conditions of each patient and laboratory findings before and after GMA. RESULTS: GMA was effective in plaque-type skin eruptions in all four patients with PsA. It was also effective in joint symptoms in three patients with PsA with mild symptoms, but was ineffective in one patient with severe joint symptoms. CONCLUSION: GMA may be recommended to PsA patients with skin eruptions and mild joint symptoms.

Distribution of hydrogen sulfide (H2S)-producing enzymes and the roles of the H2S donor sodium hydrosulfide in diabetic nephropathy.

BACKGROUND: Hydrogen sulfide (H(2)S) has recently been found to play beneficial roles in ameliorating several diseases, including hypertension, atherosclerosis and cardiac/renal ischemia-reperfusion injuries. Cystathionine ß-synthase (CBS) and cystathionine γ-lyase (CSE), the main enzymes in the transsulfuration pathway, catalyze H(2)S production in mammalian tissues. However, the distributions and precise roles of these enzymes in the kidney have not yet been identified. METHODS: The present study examined the localization of both enzymes in the normal kidney and the effect of the H(2)S donor sodium hydrosulfide (NaHS) in the renal peritubular capillary (PTC) under conditions of diabetic nephropathy, using pancreatic ß-cell-specific calmodulin-overexpressing transgenic mice as a model of diabetes. RESULTS: In the normal kidney, we detected expression of both CBS and CSE in the brush border and cytoplasm of the proximal tubules, but not in the glomeruli, distal tubules and vascular endothelial cells of renal PTCs. Administration of NaHS increased PTC diameter and blood flow. We further evaluated whether biosynthesis of H(2)S was altered in a spontaneous diabetic model that developed renal lesions similar to human diabetic nephropathy. CSE expression was markedly reduced under diabetic conditions, whereas CBS expression was unaffected. Progressive diabetic nephropathy showed vasoconstriction and a loss of blood flow in PTCs that was ameliorated by NaHS treatment. CONCLUSION: These findings suggest that CSE expression in the proximal tubules may also regulate tubulointerstitial microcirculation via H(2)S production. H(2)S may represent a target of treatment to prevent progression of ischemic injury in diabetic nephropathy.

Preventive effects of hesperidin, glucosyl hesperidin and naringin on hypertension and cerebral thrombosis in stroke-prone spontaneously hypertensive rats.

The effects of hesperidin, glucosyl hesperidin (G-hesperidin), a water-soluble derivative of hesperidin, and naringin on blood pressure and cerebral thrombosis were investigated using stroke-prone spontaneously hypertensive rats (SHRSP). Hesperidin, G-hesperidin and naringin were mixed with diet and fed to the animals for 4 weeks. No effect was evident on body weight, but the supplements significantly suppressed the age related increase in blood pressure. Thrombotic tendency, as assessed using a He-Ne laser technique in the cerebral blood vessels, was significantly decreased in the treated animals compared with the control animals. Measurements of 8-hydroxy-2'-deoxyguanosine (8-OHdG) demonstrated that the supplements had strong antioxidant activity. Furthermore, these supplements significantly increased the production of nitric oxide (NO) metabolites in urine measured with Griess reagent. Vasodilation induced by acetylcholine-mediated NO production in the endothelium was assessed using thoracic aortic ring preparations and indicated that endothelial function was significantly improved by the administration of these supplements. These findings suggest that the strong antioxidant properties of hesperidin, G-hesperidin and naringin could modulate the inactivation of NO and protect endothelial function from reactive oxygen species (ROS). In this manner, the flavonoids could contribute beneficial effects on the mechanisms of hypertension and thrombosis by increasing the bioavailability of NO.

Global thrombosis test for assessing thrombotic status and efficacy of antithrombotic diet and other conditions.

Because of the high mortality from myocardial infarction and stroke, there is a great demand for finding novel methods of diagnosis, prevention and treatment of these diseases. Most of the current tests measure important determinants of thrombosis such as platelet function, coagulation and fibrinolysis in isolation; therefore, a global test measuring the actual thrombotic status would be more useful in clinical conditions. We obtained considerable experience by using the global thrombosis test, which determines the actual thrombotic status by taking into account the measured platelet reactivity, coagulation and fibrinolytic activities. In animal experiments, we found significant correlation between the ex vivo global thrombosis test measurements and the in vivo thrombotic status. The published evidence for the benefit of an antithrombotic diet with regular physical exercise is also described.

Engineered exosomes delivering specific tumor-suppressive RNAi attenuate oral cancer progression.

Exosomes are involved in a wide range of biological processes in human cells. Considerable evidence suggests that engineered exosomes (eExosomes) containing therapeutic agents can attenuate the oncogenic activity of human cancer cells. Despite its biomedical relevance, no information has been available for oral squamous cell carcinoma (OSCC), and therefore the development of specific OSCC-targeting eExosomes (octExosomes) is urgently needed. We demonstrated that exosomes from normal fibroblasts transfected with Epstein-Barr Virus Induced-3 (EBI3) cDNA were electroporated with siRNA of lymphocyte cytoplasmic protein 1 (LCP1), as octExosomes, and a series of experiments were performed to evaluate the loading specificity/effectiveness and their anti-oral cancer cell activities after administration of octExosomes. These experiments revealed that octExosomes were stable, effective for transferring siLCP1 into OSCC cells and LCP1 was downregulated in OSCC cells with octExosomes as compared with their counterparts, leading to a significant tumor-suppressive effect in vitro and in vivo. Here we report the development of a new valuable tool for inhibiting tumor cells. By engineering exosomes, siLCP1 was transferred to specifically suppress oncogenic activity of OSCC cells. Inhibition of other types of human malignant cells merits further study.

Platelet function and spontaneous thrombolytic activity of patients with cerebral infarction assessed by the global thrombosis test.

Measurements of platelet reactivity and assessment of the efficacy of antiplatelet drugs are widely recognized as pre-requisite for the diagnosis and treatment of stroke patients. A recently established shear-induced platelet reactivity test using non-anticoagulated blood (the Global Thrombosis Test) has facilitated measurements of physiologically relevant platelet function and thrombolytic activity. 195 healthy volunteers, not taking antiplatelet drugs or anticoagulants, and 185 patients with acute cerebrovascular diseases were enrolled. The effect of antiplatelet drugs on platelet function and thrombolytic activity was assessed using the Global Thrombosis Test after 14 days of medication. The occlusion time (OT), an index of platelet reactivity, in healthy controls was 284.9 ± 92.2 s. The lysis time (LT), an index of thrombolytic activity, in healthy controls was 2,231 ± 1,223 s. Both times had no significant difference between males and females. The OT of all stroke patients was 210.3 ± 140.8 s and was shorter than that of the healthy controls (284.9 ± 92.2, p < 0.0001). The LT of all stroke patients was 3,159 ± 1,549 s and was longer than that of the controls (2,231 ± 1,223, p < 0.0001). Medication significantly prolonged the OT from 184.5 ± 150.6 s (before) to 295.3 ± 208.1 s (after) in all patients, indicating a reversal of the hyper-platelet reactivity. In addition, medication shortened the LT from 3,924 ± 1,718 s (before) to 3,107 ± 1,794 s (after) in all patients. A prothrombotic state exists in stroke patients due to enhanced platelet function and suppressed thrombolytic activity. Medication improved these physiological parameters of haemostasis.

Are all wines made from various grape varieties beneficial in the prevention of myocardial infarction and stroke?

AIM: Epidemiologic studies support the assumption (French paradox hypothesis) that drinking red wine is beneficial in the prevention of cardiovascular diseases. Our recent works however cast doubt on such claim. Earlier we have shown that the antithrombotic activity of various fruits and vegetables mainly depends on their varieties. For this reason, several varieties of red and white grapes were tested for antithrombotic effect in animal experiments. RESULTS: Antithrombotic effect of 45 red and white grape varieties were assessed in the present study. Out of the 45, one red grape variety showed antithrombotic effect, while the majority of red and white grape varieties enhanced thrombosis. CONCLUSION: Most red and white grape varieties enhanced thrombotic activity of blood.

Development of Prodrug Type Circular siRNA for In Vivo Knockdown by Systemic Administration.

siRNAs are being developed as a novel therapeutic modality; however, problems impeding their application in extrahepatic tissues persist, including inadequate stability in biological environments and inefficient drug delivery system to target tissues. Thus, technological improvements that enable robust silencing of target messenger RNA (mRNA) in extrahepatic tissues are necessary. We developed prodrug type covalently closed siRNA (circular siRNA) as a novel nucleic acid agent to knockdown target genes in extrahepatic tissues by systemic administration without drug delivery components. Circular siRNA, which is chemically synthesizable, can assume optimal structures for efficient knockdown using its cleavable linker; namely, circular and linear structure in extracellular and intracellular environment, respectively. In this study, we investigated circular siRNA physicochemical properties, knockdown mechanism, and characteristics in vitro, as well as pharmacokinetics, accumulation, knockdown activity, and safety in vivo. Our circular siRNA exhibited higher stability against serum and exonucleases, increased cellular uptake, and stronger knockdown activity without transfection reagent in vitro than linear siRNA. Furthermore, after systemic administration to mice, circular siRNA showed prolonged circulation and improved knockdown activity in the liver, kidney, and muscle, without causing adverse effects. Circular siRNA may represent an additional platform for RNAi therapeutics, providing alternate solutions for disease treatment.

Tissue-type plasminogen activator deficiency attenuates peritoneal fibrosis in mice.

Peritoneal fibrosis (PF) is an important complication of peritoneal dialysis therapy. The present study was performed to examine the mechanisms of PF in view of the plasminogen activator (PA)/plasmin/matrix metalloproteinase (MMP) cascade. PF was induced in tissue-type PA (tPA) deficient mice and wild-type mice by intraperitoneal injection of chlorhexidine gluconate. Mice were killed on day 21, and tissue samples were taken. Histopathological studies were performed. Plasmin activity, gelatinases activity, and the levels of tPA, transforming growth factor-beta1 (TGF-beta1), and MMP-2 mRNA were determined. Protein levels of MMP-3, tissue inhibitor of metalloproteinases (TIMP)-1, -2, and -3, phospho-Smad3, membrane-type 1 (MT1)-MMP, and MT3-MMP were also studied. On day 21, tPA +/+ mice showed severe PF, whereas tPA -/- mice showed milder change. Submesothelial basement membranes were dissolved in tPA +/+ mice while they were relatively preserved in tPA -/- mice. The levels of macrophage infiltration, staining for alpha-smooth muscle actin (alpha-SMA) and collagen type III, and vascular density were all significantly lower in tPA -/- mice than in tPA +/+ mice. The levels of plasmin activity, pro- and active MMP-2, mRNA expression of tPA and TGF-beta1, and phospho-Smad3 protein were also lower in tPA -/- mice. No difference was observed between the two groups concerning the protein levels of MMP-3, TIMP-1, TIMP-2, TIMP-3, MT1-MMP, or MT3-MMP. These results indicate that the presence of tPA enhances inflammation, angiogenesis, and fibrogenesis in the peritoneum of the PF model mice. Activation of the PA/plasmin/MMP cascade may play a pivotal role in the pathogenesis of PF.

Antithrombotic papain-hydrolyzed peptides isolated from pork meat.

INTRODUCTION: Atherothrombotic disease such as coronary artery disease and stroke is one of major causes of death. Platelets play important role in these arterial diseases. Suppression of platelet activity by materials may decrease incidence of the disease. The present study aimed to examine the peptides from pork meat with antithrombotic activity. MATERIAL AND METHODS: Peptide fraction or hydrolyzate of defatted pork meat by papain was used as the starting material. Antithrombotic activity of the fraction was assessed by a share-induced platelet function test in vitro (haemostatometry) using non-anticoagulated rat blood, followed by a helium-neon laser-induced mouse carotid artery thrombosis test in vivo. RESULTS AND DISCUSSION: The starting peptide fraction with mean molecular weight 2500 showed antithrombotic activity in vivo after oral administration to mice at 210 mg/kg body weight. The fraction with mean molecular weight 2517 further purified by cation exchange chromatography showed antithrombotic activity after oral administration at 70 mg/kg body weight. Antithrombotic activity of the purified peptide fraction was equivalent to that of aspirin at 50 mg/kg body weight. It is possible this pork peptide could be beneficial to prevent atherothrombosis.