Unsaturated fatty acids enhance the fibrinolytic activity of subtilisin NAT (nattokinase).

Subtilisin NAT (STN), alternatively designated nattokinase, is a serine protease with potent fibrinolytic activity. In this study, we screened several foods to enhance the fibrinolytic potential of STN and identified unsaturated fatty acid-rich ones as candidates. We isolated linoleic acid as a major active compound from one of the most active foods, red pepper. Linoleic acid promoted the STN-mediated fibrin/fibrinogen degradation at >20 µg/ml. STN cleaved three of the fibrinogen polypeptide chains, among which linoleic acid accelerated Bß-chain and γ-chain degradations, but slightly suppressed the degradation of α-chain fragments. Linoleic acid failed to affect small synthetic peptide degradation, suggesting a conformational modulation of fibrin/fibrinogen for the linoleic acid promotion of STN activity. Of the various fatty acids tested, unsaturated ones were active but saturated ones were rather inhibitory to STN-mediated fibrinolysis. Thus, our data shed new light on the dietary promotion of STN activity. PRACTICAL APPLICATIONS: Subtilisin NAT (STN) is a serine protease abundantly contained in natto, a soybean food fermented with Bacillus subtilis var. natto. The use of STN as functional foods to improve blood circulation is getting attention because STN actively degrades fibrin. Our results demonstrate that widely occurring unsaturated fatty acids such as linoleic, eicosapentaenoic, and docosahexaenoic acids enhance the fibrinolytic activity of STN. Thus, the intake of natto or STN supplements in combination with unsaturated fatty acid-containing oil can be a novel way to gain cardiovascular benefits.

Isoprene Side-chain of SMTP is Essential for Soluble Epoxide Hydrolase Inhibition and Cellular Localization.

SMTPs, a family of natural small molecules that effectively treat ischemic stroke, are subject to clinical development. SMTPs enhance plasminogen activation and inhibit soluble epoxide hydrolase (sEH), leading to promotion of endogenous thrombolysis and anti-inflammation. The SMTP molecule consists of atricyclic γ-lactam moiety, an isoprene side-chain, and an N-linked side-chain. Here, we investigate the yet-to-be-characterized function of the isoprene side- chain of SMTPs in sEH inhibition and cellular distribution. The results demonstrated that oxidative modification as well as truncation of the side-chain abolished epoxide hydrolase inhibition. The introduction of a terminal hydroxy group exceptionally unaffected epoxide hydrolase, but led to impaired cellular localization, resulting in diminution of cellular epoxide hydrolase inhibition. Thus, the isoprene side-chain of SMTP is an important pharmacophore for epoxide hydrolase inhibition and cellular localization.

SMTP-7, a novel small-molecule thrombolytic for ischemic stroke: a study in rodents and primates.

SMTP-7 (Stachybotrys microspora triprenyl phenol-7), a small molecule that promotes plasminogen activation through the modulation of plasminogen conformation, has excellent therapeutic activity against cerebral infarction in several rodent models. Detailed evaluations of SMTP-7 in a primate stroke model are needed for effective, safe drug development. Here we evaluated SMTP-7 in a monkey photochemical-induced thrombotic middle cerebral artery (MCA) occlusion model (n=6), in which MCA occlusion was followed by recanalization/reocclusion. SMTP-7 (10 mg/kg, intravenous infusion) significantly increased the postinfusion MCA recanalization rate (32.5-fold, P=0.043) and ameliorated the post-24-h neurologic deficit (by 29%, P=0.02), cerebral infarct (by 46%, P=0.033), and cerebral hemorrhage (by 51%, P=0.013) compared with the vehicle control animals. In normal monkeys, SMTP-7 did not affect general physiologic or hemostatic variables, including coagulation and platelet parameters. Investigations in rodent models of transient and permanent focal cerebral ischemia, as well as arterial thrombosis and bleeding tests, suggest a role for SMTP-7's regulated profibrinolytic action and neuroprotective properties in the monkey MCA occlusion model. In conclusion, SMTP-7 is effective in treating thrombotic stroke in monkeys. SMTP-7 is thus a promising candidate for the development of alternative therapy for ischemic stroke.

Inhibition of NF-kappaB and Akt pathways by an antibody-avidin fusion protein sensitizes malignant B-cells to cisplatin-induced apoptosis.

Multiple myeloma (MM) is an incurable disease of malignant plasma cells. Recent therapeutic advancements have resulted in improved response rates, however, there is no improvement in overall survival, therefore, new therapeutics are needed. Since the transferrin receptor is upregulated on the surface of MM cells, we previously developed an antibody fusion protein consisting of an IgG3 specific for the human transferrin receptor 1 (TfR1, CD71) genetically fused to avidin at its carboxy-terminus (ch128.1Av). We have previously shown that ch128.1Av exhibits intrinsic cytotoxicity against certain malignant B-cells by disrupting the cycling of the TfR and decreasing TfR cell surface expression resulting in lethal iron starvation. In addition, ch128.1Av can sensitize malignant cells to apoptosis induced by gambogic acid, a herbal drug used in Chinese medicine. In this study, we hypothesized that ch128.1Av may also sensitize drug-resistant malignant B-cells to chemotherapeutic agents by inhibiting key survival pathways. In this study we show that ch128.1Av sensitizes malignant B-cells to apoptosis induced by cisplatin (CDDP). The sensitization by ch128.1Av resulted in the inhibition of the constitutively activated Akt and NF-kappaB survival/antiapoptotic pathways and downstream decreased expression of antiapoptotic gene products such as BclxL and survivin. The direct role of the inhibition of the Akt and NF-kappaB pathways by ch128.1Av in CDDP-mediated cytotoxicity was demonstrated by the use of specific chemical inhibitors and siRNA which mimicked the effects of ch128.1Av. Overall, this study provides evidence of the therapeutic potential of ch128.1Av as a chemo-sensitizing agent in drug-resistant tumor cells.

Vitamin E succinate induced apoptosis and enhanced chemosensitivity to paclitaxel in human bladder cancer cells in vitro and in vivo.

There have been several studies on the antitumor activities of vitamin E succinate (alpha-TOS) as complementary and alternative medicine. In the present study, we investigated the cytotoxic effect of alpha-TOS and the enhancement of chemosensitivity to paclitaxel by alpha-TOS in bladder cancer. KU-19-19 and 5637 bladder cancer cell lines were cultured in alpha-TOS and/or paclitaxel in vitro. Cell viability, flow cytometric analysis, and nuclear factor-kappa B (NF-kappaB) activity were analyzed. For in vivo therapeutic experiments, pre-established KU-19-19 tumors were treated with alpha-TOS and/or paclitaxel. In KU-19-19 and 5637 cells, the combination treatment resulted in a significantly higher level of growth inhibition, and apoptosis was significantly induced by the combination treatment. NF-kappaB was activated by paclitaxel; however, the activation of NF-kappaB was inhibited by alpha-TOS. Also, the combination treatment significantly inhibited tumor growth in mice. In the immunostaining of the tumors, apoptosis was induced and proliferation was inhibited by the combination treatment. Combination treatment of alpha-TOS and paclitaxel showed promising anticancer effects in terms of inhibiting bladder cancer cell growth and viability in vitro and in vivo. One of the potential mechanisms by which the combination therapy has synergistic cytotoxic effects against bladder cancer may be that alpha-TOS inhibits NF-kappaB induced by chemotherapeutic agents.

Preparation of conophylline affinity nano-beads and identification of a target protein.

Conophylline, a vinca alkaloid extracted from the tropical plant Ervatamia microphylla, has been shown to induce the differentiation of insulin-producing beta-cells in cultured cells and in animals. However, its mechanism of action and the molecular target have remained unclear. Therefore, we prepared a fishing probe with conophylline to identify the target protein by using latex nano-beads, which are newly innovated tools for affinity-purification. With these conophylline-linked nano-beads, we found that conophylline directly interacted with ARL6IP. ARL6IP may thus be involved in the mechanism of cellular differentiation of beta-cells, and this probe should be useful to find other target proteins.

Inhibition of Yin Yang 1-dependent repressor activity of DR5 transcription and expression by the novel proteasome inhibitor NPI-0052 contributes to its TRAIL-enhanced apoptosis in cancer cells.

TRAIL promotes apoptotic tumor cell death; however, TRAIL-resistant tumors need to be sensitized to reverse resistance. Proteasome inhibitors potentiate TRAIL apoptosis in vitro and in vivo and correlate with up-regulation of death receptor 5 (DR5) via an unknown mechanism. We hypothesized that the proteasome inhibitor NPI-0052 inhibits the transcription repressor Yin Yang 1 (YY1) which regulates TRAIL resistance and negatively regulates DR5 transcription. Treatment of PC-3 and Ramos cells with NPI-0052 (

Preoperative steroid pulse therapy for invasive thymoma: clinical experience and mechanism of action.

BACKGROUND: Glucocorticoid was used in thymomas. The purpose of the study was to evaluate the efficacy of intravenous high-dose glucocorticoid (steroid pulse) therapy in patients with previously untreated advanced thymoma. Causes were also sought for a possible underlying mechanism of the effect of steroid on thymoma. METHODS: Seventeen patients with invasive thymoma who had not received previous chemotherapy or radiation therapy were enrolled in the study. All cases were treated with 2 courses of glucocorticoid therapy before surgery. Tumor response was assessed by computed tomography (CT) scan 1 week after the steroid pulse therapy. Lymphocytes associated with thymoma were analyzed for their CD4/CD8 phenotype and glucocorticoid receptor (GR). TdT-mediated dUTP-biotin nick-end labeling (TUNEL) staining was used to analyze the apoptotic lymphocytes and epithelial cells. RESULTS: The overall response rate to the steroid pulse therapy was 47.1% (8 of 17). The reduction in tumor size was most prominent in type B1 thymomas; there were significant differences between type AB and type B1 thymomas (P = .0234) and type B1 and type B3 thymomas (P = .0068). The reduction in tumor size was accompanied with a marked reduction in the CD4+8+ double-positive immature thymocytes that expressed higher levels of glucocorticoid receptor. Apoptotic changes were observed in both neoplastic epithelial cell and lymphocyte components after glucocorticoid therapy. CONCLUSIONS: The efficiency of preoperative steroid pulse therapy in type B1 thymoma was most prominent, which is probably related to the specific effect on GR-rich CD4+8+ double-positive immature lymphocytes, which are abundant in this type of thymoma.