Effect of long-term dietary arginyl-fructose (AF) on hyperglycemia and HbA1c in diabetic db/db mice.

We have previously reported that Amadori compounds exert anti-diabetic effects by lowering sucrose-induced hyperglycemia in normal Sprague-Dawley rats. In the present study we extended our recent findings to evaluate whether α-glucosidase inhibitor arginyl-fructose (AF) lowers blood glucose level in diabetic db/db mice, a genetic model for type 2 diabetes. The db/db mice were randomly assigned to high-carbohydrate diets (66.1% corn starch) with and without AF (4% in the diet) for 6 weeks. Changes in body weight, blood glucose level, and food intake were measured daily for 42 days. Dietary supplementation of AF resulted in a significant decrease of blood glucose level (p < 0.001) and body weight (p < 0.001). The level of HbA1c, a better indicator of plasma glucose concentration over prolonged periods of time, was also significantly decreased for 6-week period (p < 0.001). Dietary treatment of acarbose® (0.04% in diet), a positive control, also significantly alleviated the level of blood glucose, HbA1c, and body weight. These results indicate that AF Maillard reaction product improves postprandial hyperglycemia by suppressing glucose absorption as well as decreasing HbA1c level.

Proteomic analysis of human small cell lung cancer tissues: up-regulation of coactosin-like protein-1.

Small cell lung cancer (SCLC) is the leading cause of cancer death, with a high propensity for aggressiveness and metastasis even in an early stage. Thus, identification of biomarkers as early diagnostics and treatment is needed. In this study, we investigated differentially regulated proteins between human SCLC tissues and normal bronchial epithelium by proteomic analysis using two-dimensional electrophoresis (2-DE) and MALDI-TOF mass spectrometry. Seven proteins and protein isoforms, including, γ-actin, tubulin α-1B, laminin B1, coactosin-like protein-1 (COTL-1), ubiquitin carboxyl-terminal esterase L1, ubiquitin-conjugating enzyme E2-25K, and carbonic anhydrase 1, were up-regulated more than 2 fold in SCLC tissues. In particular, up-regulated COTL-1 expression was validated by Western blot analysis, immunohistochemistry, and reverse transcription quantitative polymerase chain reaction (RT-qPCR). Moreover, most SCLC tissues (93%; 28/30) were COTL-1-positive in immunohistochemistry, whereas only 16% (10/64) of nonsmall cell lung cancer (NSLC) tissues were. Taken together, this SCLC proteomic data may help in establishing a human SCLC proteome database. COTL-1 may be a biomarker or a therapeutic target in SCLC patients.

Proteomic identification of overexpressed PRDX 1 and its clinical implications in ovarian carcinoma.

Ovarian carcinoma is the most lethal gynecological malignancy in worldwide. The discovery of reliable marker for early detection of ovarian carcinoma is critical for increasing patient's survival because high mortality rate is associated with late diagnosis of this tumor. In the present study, we performed comparative analysis of whole proteomes between serous borderline tumor and serous carcinoma to identify a useful biomarker for the early diagnosis and progression of ovarian carcinoma. Nine proteins were significantly overexpressed in ovarian serous carcinomas compared to borderline tumors. After validation with Western blotting and immunohistochemical analysis, prdx 1 was found to be the strongest overexpressed protein in malignant ovarian tumors among the selected proteins. In addition, the high level of prdx 1 expression (>50% positive cancer cells) was significantly correlated with poor overall survival in ovarian serous carcinomas. On a multivariate cox analysis, the relative risk of death was 8.74 in patients with serous carcinomas showing >50% of prdx 1-positive cancer cells. Our results suggest that prdx 1 may be a useful diagnostic and prognostic biomarker in ovarian carcinoma, especially serous carcinoma.

Suppressive effect and mechanism of saxatilin, a disintegrin from Korean snake (Gloydius saxatilis), in vascular smooth muscle cells.

RGD-peptides can inhibit the binding of ligands to certain beta3 integrins, alphaIIbbeta3 and alphavbeta3, both of which are involved in neointimal hyperplasia that contributes to atherosclerosis and restenosis of arterial walls. Saxatilin, a disintegrin from a Korean snake (Gloydius saxatilis), interacts with integrins alphaIIbbeta3 and alphavbeta3. It suppressed the adhesion of human coronary artery smooth muscle cells (HCASMCs) to vitronectin with an IC(50) of 2.5 microM, and growth factor (PDGF-BB or bFGF)-induced proliferation was inhibited at an IC(50) of 25 microM. Saxatilin disassembled the actin cytoskeleton of focal adhesion and induced cell detachment. This disassembly of focal adhesion in saxatilin-treated HCASMCs involved caspase-induced paxillin degradation. Saxatilin temporally phosphorylated FAK and ERKs and affected the cell cycle of HCASMCs by increasing CDK inhibitors (p21 and p27) and reducing cyclins (D1/2 and E). These results may have significant implications for integrin antagonistic therapy used for the treatment of atherosclerosis and restenosis.

Acute and repeated dose toxicity studies of recombinant saxatilin, a disintegrin from the Korean snake (Gloydius saxatilis).

To examine the toxicological effect of saxatilin, a disintegrin isolated from the venom of a Korean snake (Gloydius saxatilis), recombinant saxatilin was highly expressed as a biologically active form in Pichia pastoris, and was successfully purified to homogeneity from the culture broth supernatant. The molecular and biological properties of the recombinant protein were the same as those of its natural form. Plasma half-life of the protein in rat was determined to 13.8 min. The maximum tolerated dose of the recombinant saxatilin was examined in ICR mice. The determined LD(50) values were 400 and 600 mg/kg of the body weight of a male and female mouse, respectively. To investigate the repeated dose toxicity of saxatilin in mice, the test item was intravenously administered to groups of ICR mice every day for 4 weeks. We observed a decrease in locomotor activity, piloerection, and crouching in clinical findings, a decrease of red blood cells (RBCs) in hematology, and hyperplasia of the spleen in histology related to administration of the test item. These results suggest that the target organ of intravenous administration of the test item is the spleen. The no adverse effect level (NOAEL) in this test for both males and females is considered to be 3mg/kg. Our results also indicate that recombinant saxatilin is non-toxic at an administration dose with an anti-platelet effect, and might be a potential anti-adhesion therapeutic agent for thrombosis, cancer, restenosis, cataract, and osteoporosis.

Design, synthesis and evaluation of 2-phenyl-1H-benzo[d]imidazole-4,7-diones as vascular smooth muscle cell proliferation inhibitors.

A series of 2-phenyl-1H-benzo[d]imidazole-4,7-diones were synthesized and tested for their inhibitory activity on the PDGF-stimulated proliferation of rat aortic vascular smooth muscle cells. Among the tested compounds, 6-arylthio-5-chloro-2-phenyl-1H-benzo[d]imidazole-4,7-diones exhibited an potent antiproliferative activity.

Antiproliferative effects of 6-anilino-5-chloro-1H-benzo[d]imidazole-4,7-dione in vascular smooth muscle cells.

It has been known that benzimidazol-4,7-diones have antiproliferative activity against various cancer cell lines. Recently, we have also reported that these compounds strongly inhibited the proliferation of vascular smooth muscle cell (SMC) and human umbilical vein endothelial cells (HUVECs). Although benzimidazol-4,7-diones have important biological activities, the molecular mechanism of the compounds in these cells remains to be elucidated. In order to investigate the anti-proliferation mechanism of the compounds in smooth muscle cell, we selected 6-anilino-6-chloro-5-chloro-1H-benzo{d}midazole-4,7-dione (BUD-0203) among 12 benzimidazol-4,7-dione derivatives and examined its antiproliferative effects. Phosphorylation of the extracellular-signal regulated kinase (ERK) reached a maximal level at 1h after treatment with BUD-0203 and was sustained during the examined period. We also observed that phosphorylation of p38 reached a maximal level at 4h and decreased to control levels after 8h. These results showed that BUD-0203 sustainedly activated MAP kinase pathways in SMC. However, this compound did not induce cell cycle arrest in G1 or G2 phase in these cells. We also demonstrated that BUD-0203 not only induced apoptosis of SMC, but it also strongly inhibited SMC migration induced by platelet-derived growth factor (PDGF) or serum. Taken together, our experiments indicate that benzimidazol-4,7-diones induce apoptosis of smooth muscle cell via simultaneously prolonged activation of MAP kinase pathways including ERK, p38, and JNK/SAPK, similar with the apoptosis mechanism reported previously.

Dendritic Cell-Based Immunotherapy for Solid Tumors.

As a treatment for solid tumors, dendritic cell (DC)-based immunotherapy has not been as effective as expected. Here, we review the reasons underlying the limitations of DC-based immunotherapy for solid tumors and ask what can be done to improve immune cell-based cancer therapies. Several reports show that, rather than a lack of immune induction, the limited efficacy of DC-based immunotherapy in cases of renal cell carcinoma (RCC) likely results from inhibition of immune responses by tumor-secreted TGF-ß and an increase in the number of regulatory T (Treg) cells in and around the solid tumor. Indeed, unlike DC therapy for solid tumors, cytotoxic T lymphocyte (CTL) responses induced by DC therapy inhibit tumor recurrence after surgery; CTL responses also limit tumor metastasis induced by additional tumor-challenge in RCC tumor-bearing mice. Here, we discuss the mechanisms underlying the poor efficacy of DC-based therapy for solid tumors and stress the need for new and improved DC immunotherapies and/or combination therapies with killer cells to treat resistant solid tumors.

Acute and repeated dose (28 days) toxicity studies in rats and dogs of recombinant batroxobin, a snake venom thrombin-like enzyme expressed from Pichia pastoris.

Recombinant batroxobin is a thrombin-like enzyme of Bothrops atrox moojeni venom. To evaluate its toxicological effect, it was highly expressed in Pichia pastorisand successfully purified to homogeneity from culture broth supernatant following Good Manufacturing Practice (GMP). The maximum tolerated dose of the recombinant batroxobin was examined in Sprague-Dawley (SD) rat and Beagle dogs following Good Laboratory Practice (GLP) regulations. The approximate lethal dose of recombinant batroxobin was 10 National Institute of Health (NIH) u/kg in male and female rats. Slight test substance-related effects were clearly in male and female dogs at more than 10 NIH u/kg. The maximum tolerated dose (MTD) was considered to be greater than 30 NIH u/kg in dogs. To investigate the repeated dose toxicity of batroxobin, the test item was intravenously administered to groups of SD rat and Beagle dog every day for 4 weeks. We observed that all animals survived the duration of the study without any effects on their mortality. There were no effects in both rats and dogs regarding their clinical signs, body weight, food consumption, ophthalmological examination, urinalysis, hematology, clinical chemistry, organ weightand gross post mortem examinations. The no adverse effect level (NOAEL) of recombinant batroxobin for both males and females is considered to be greater than 2.5 NIH u/kgin rats and 1 NIH u/kg in dogs, respectively. No toxic effects were noted in target organs. In conclusion, these results show a favorable preclinical profile and may contribute clinical development of recombinant batroxobin.

Functional fusion proteins and prevention of electrode fouling for a sensitive electrochemical immunosensor.

A highly sensitive electrochemical immunosensor was developed by preventing electrode fouling and using a novel fusion protein of silica binding polypeptides (SBP)-protein G (ProG) created by recombinant DNA technology as a functional crosslinker for rapid and self-oriented immobilization of antibodies onto silica nanoparticles (SiNPs). Antibody immobilization onto the SiNPs by the SBP-ProG could rapidly be achieved without any chemical treatment. The immunosensor was fabricated through bonding of a partially gold-deposited cyclic olefin copolymer (COC) (top substrate) and gold patterned interdigitated array COC electrode (bottom substrate). To prevent electrode fouling, human immunoglobulin G (hIgG) was immobilized onto the ceiling inside the microchannel, instead of the bottom electrode. Alkaline phosphatase (AP)-labeled anti-hIgG was allowed to immunoreact with hIgG on the ceiling, followed by addition of an enzyme to generate an oxidative peak current. A three-fold increase in current was observed from the immunosensor without any electrode fouling compared with a control with the protein functionalized electrode. Also, the SiNPs facilely coated with AP-anti-hIgG via the SBP-ProG could increase the electrochemical signal up to 20% larger than that of the AP-anti-hIgG alone. Furthermore, this immunosensor was ultrasensitive with a detection limit of 0.68 pg/mL of a biomarker associated with prostate cancer.

Novel monoclonal antibody that recognizes new neoantigenic determinant of D-dimer.

Our novel monoclonal antibody (mAb) B4 reacted with only D-dimer but not intact fibrinogen, or fibrinogen degradation products (FgDP) such as D-monomer, E fragment on ELISA. B4 didn't react with denatured D-dimer, while it reacted well with denatured D-monomer rather than the native form, indicating that B4 recognizes some neoconformational epitope in D-dimer. In our epitope study, B4 recognized the N-terminal (Bbeta134-142) of D-dimer, which corresponds to the most flexible segment of coiled coil backbone. It was confirmed by inhibition assay of B4 binding to D-dimer using the synthesized peptides with this sequence. As the other evidence, B4 didn't bind to some D-dimer species produced from a particular fibrinogen variant. This fibrinogen variant is mutated BbetaLys133 residue to Gln133 thus it doesn't produce the particular N-terminal epitope of D134 approximately by plasmin. Finally, our mAb was useful for clinical application. ELISA using our mAbs was well correlated with other commercial D-dimer ELISAs and in some clinical samples it was preferable to them. These results suggest that the epitope for B4 is another neoantigenic determinant in native D-dimer as distinct from native D-monomer.

Expression, purification and transduction of PEP-1-botulinum neurotoxin type A (PEP-1-BoNT/A) into skin.

Botulinum neurotoxin A (BoNT/A) has been used therapeutically to treat muscular hypercontractions and sudomotor hyperactivity and it has been reported that BoNT/A might have analgesic properties in headache. PEP-1 peptide is a known carrier peptide that delivers full-length native proteins in vitro and in vivo. In this study, a BoNT/A gene were fused with PEP-1 peptide in a bacterial expression vector to produce a genetic in-frame PEP-1-BoNT/A fusion protein. The expressed and purified PEP-1-BoNT/A fusion proteins were efficiently transduced into cells in a time- and dose-dependent manner when added exogenously in a culture medium. In addition, immunohistochemical analysis revealed that PEP-1-BoNT/A fusion protein efficiently penetrated into the epidermis as well as the dermis of the subcutaneous layer, when sprayed on mice skin. These results suggest that PEP-1-BoNT/A fusion protein provide an efficient strategy for therapeutic delivery in various human diseases related to this protein.

Fibrinogen Seoul (FGG Ala341Asp): a novel mutation associated with hypodysfibrinogenemia.

Dysfibrinogenemia is a coagulation disorder caused by a variety of structural abnormalities in the fibrinogen molecule that result in fibrinogen function. The molecular basis of hypodysfibrinogenemia was investigated in a 66-year-old woman with peripheral artery obstructive disease and in her family members. Plasma level of functional fibrinogen determined using the Clauss method was lower (75 mg/dL; normal, 140-460 mg/dL) than that measured with immunologic nephelometric assay (137 mg/dL; normal, 180-400 mg/dL). Similar results were also observed in two family members through two generations. DNA was extracted from whole blood, and the coding regions and intron/exon boundaries of gamma chain gene (FGG) were amplified. A novel (Fibrinogen Seoul) heterozygous FGG mutation (GCT->GAT, Ala341Asp) was identified in all three affected family members. Thrombin-catalyzed polymerization was found to be defective on the analysis of purified fibinogen from the propositus. Molecular modeling also showed a conformational change of fibrinogen structure.

Inhibitory effect of the salmosin gene transferred by cationic liposomes on the progression of B16BL6 tumors.

Salmosin is a novel disintegrin containing the Arg-Gly-Asp sequence that significantly inhibits platelet aggregation, basic fibroblast growth factor-induced endothelial cell proliferation, and tumor progression by antagonizing integrin-mediated cell interactions. Previously, it was shown that daily administration of salmosin was able to inhibit tumor-derived angiogenesis and adherence and proliferation of tumor cells, resulting in suppression of tumor progression. However, it is very difficult to maintain a therapeutic level of salmosin in the blood by systemic administration of the protein. Hence, an alternative strategy for antiangiogenic cancer therapy, based on the in vivo expression of the salmosin gene administered with cationic liposomes, was investigated. The salmosin peptides expressed in vitro inhibited the proliferation of bovine capillary endothelial cells in a dose-dependent manner, presumably as a result of inhibition of cell adhesion mediated via alpha(v)beta(3) integrin. Subcutaneous administration of the salmosin gene resulted in systemic expression of the gene product and concomitant inhibition of the growth of B16BL6 melanoma cells. Suppression of pulmonary metastases, verified by experimental and spontaneous metastasis models in mice, also resulted from salmosin gene treatment. These results suggest that administration of the salmosin gene complexed to cationic liposomes is effective in maintaining antiangiogenic salmosin at an effective therapeutic level and may be clinically applicable to anticancer gene therapy.

Antihyperglycemic effect of short-term arginyl-fructose supplementation in subjects with prediabetes and newly diagnosed type 2 diabetes: randomized, double-blinded, placebo-controlled trial.

BACKGROUND: A previous study reported that arginyl-fructose may have great value as a functional food with antioxidant and antidiabetic activities. However, there have been few clinical studies on the efficacy of arginyl-fructose supplementation for blood glucose control. METHODS: In this double-blind, placebo-controlled study, 60 Korean subjects with prediabetes or type 2 diabetes mellitus were randomly assigned to placebo or test groups. The test group subjects received 1500 mg/day arginyl-fructose. Fasting serum levels of glucose, hemoglobin A1c, insulin, and free fatty acids were measured by 2-hour oral glucose tolerance tests at baseline and after the 6-week intervention. Eleven subjects dropped out or were excluded during the trial. The data for the remaining 49 were statistically analyzed using Student's t-test and paired t-test. RESULTS: After the 6-week intervention, the test group showed significant reductions in serum glucose levels at 30 minutes (-19.4 ± 5.62 mg/dL) and 60 minutes (-15.4 ± 7.01 mg/dL) and reduced glucose area under the curve (-27.4 ± 8.59 mg/dL) compared with those of the placebo control group. The changes (differences from baseline) in serum glucose levels at 60 minutes and glucose area under the curve in the test group differed significantly from those in the control group even after adjusting for baseline values. In contrast, glucose-related biomarkers including hemoglobin A1c, insulin, and C-peptide levels were not significantly improved by the dietary intervention with arginyl-fructose. CONCLUSIONS: Arginyl-fructose supplementation (1500 mg/day) may be beneficial for reducing postprandial blood glucose levels in patients with prediabetes or type 2 diabetes mellitus. TRIAL REGISTRATION: ClinicalTrials.gov NCT02285231 . Registered 11 May 2014.

Factor Xa induces mitogenesis of coronary artery smooth muscle cell via activation of PAR-2.

Factor Xa-induced stimulation of coronary artery smooth muscle cells (CASMC) was investigated by analyzing [(3)H]thymidine incorporation, cell proliferation, and ERK-1/2 activation. Exposure of the cells to factor Xa evoked a time-dependent activation of ERK-1/2 with increased [(3)H]thymidine incorporation and cell proliferation. The factor Xa-induced ERK-1/2 activation was not desensitized by preincubation of the cells with thrombin. However, ERK-1/2 activation was markedly attenuated by prior exposure of the cells to protease-activated receptor-2 (PAR-2) activating peptide, SLIGKV. The mitogenic effect of factor Xa was significantly reduced in the presence of anti-PAR-2 monoclonal antibody. Several lines of experimental evidence indicate that factor Xa-induced mitogenesis of CASMC is a cellular process mediated by PAR-2 activation.

Functional characterization of recombinant batroxobin, a snake venom thrombin-like enzyme, expressed from Pichia pastoris.

A thrombin-like enzyme of Bothrops atrox moojeni venom, batroxobin, specifically cleaves fibrinogen alpha chain, resulting in the formation of non-crosslinked fibrin clots. The cDNA encoding batroxobin was cloned, expressed in Pichia pastoris and the molecular function of purified recombinant protein was also characterized. The recombinant batroxobin had an apparent molecular weight of 33 kDa by SDS-PAGE analysis and biochemical activities similar to those of native batroxobin. The purified recombinant protein strongly converted fibrinogen into fibrin clot in vitro, and shortened bleeding time and whole blood coagulation time in vivo. However, it did not make any considerable alterations on other blood coagulation factors. Several lines of experimental evidence in this study suggest that the recombinant batroxobin is a potent pro-coagulant agent.

Purification and molecular cloning of a novel serine protease from the centipede, Scolopendra subspinipes mutilans.

A novel serine protease, named as scolonase, was purified and characterized from the tissue of the Korean centipede, Scolopendra subspinipes mutilans. Purified scolonase showed an apparent molecular weight of 25 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and an isoelectric point of 4.8 on isoelectric focusing gel. Scolonase was able to preferentially hydrolyze arginine over lysine at the cleavage site among the several synthetic peptide substrates. Scolonase has also a potent fibrinolytic activity by converting human Glu-plasminogen to activated plasmin due to the specific cleavage of the molecule at the peptide bond Arg(561)-Val(562). The enzyme activity of scolonase was completely inhibited by phenylmethanesulfonyl fluoride and difluorophosphate. The cDNA encoding scolonase was cloned from the cDNA library of the centipede constructed with oligonucleotide probe, which was designed on the basis of the N-terminal amino acid sequence of scolonase. The deduced complete amino acid sequence of scolonase demonstrated that the protein is composed of 277 amino acids including 33 amino acids as a leader sequence, and that it has significant sequence homology with other serine proteases.

A novel metalloprotease from Gloydius halys venom induces endothelial cell apoptosis through its protease and disintegrin-like domains.

A novel hemorrhagic metalloprotease, halysase, isolated from the snake venom of Gloydius halys induces apoptosis in endothelial cells. The purified metalloprotease is a monomeric glycoprotein with an isoelectric point of 4.8. Analysis of the cDNA sequence encoding halysase revealed that the enzyme consists of multifunctional domains including a proprotein domain, a protease domain, a disintegrin-like domain and a cysteine-rich domain. The metalloprotease has a DECD sequence in the disintegrin-like domain instead of the typical RGD sequence. Halysase strongly inhibits proliferation of human umbilical vein endothelial cells in a dose-dependent manner as well as adhesion of the cells to extracellular matrix proteins. The enzyme specifically hydrolyzes not only extracellular matrix proteins such as fibronectin, vitronectin, and type IV collagen, but also integrins alpha1beta1 and alpha5beta1. The apoptosis of endothelial cells induced by halysase is closely associated with activation of caspase-3 and decreased level of Bcl-X(L)/Bax. Apohalysase, which lacks metalloprotease activity, is also able to induce the apoptosis. Several lines of experimental evidence suggest that the protease domain and the disintegrin-like domain of halysase cooperatively contribute to the induction of endothelial cell apoptosis.

Phospholipase C-delta1 rescues intracellular Ca2+ overload in ischemic heart and hypoxic neonatal cardiomyocytes.

Ischemia and simulated ischemic conditions cause intracellular Ca2+ overload in the myocardium. The relationship between ischemia injury and Ca2+ overload has not been fully characterized. The aim of the present study was to investigate the expression and characteristics of PLC isozymes in myocardial infarction-induced cardiac remodeling and heart failure. In normal rat heart tissue, PLC-delta1 (about 44 ng/mg of heart tissue) was most abundant isozymes compared to PLC-gamma1 (6.8 ng/mg) and PLC-beta1 (0.4 ng/mg). In ischemic heart and hypoxic neonatal cardiomyocytes, PLC-delta1, but not PLC-beta1 and PLC-gamma1, was selectively degraded, a response that could be inhibited by the calpain inhibitor, calpastatin, and by the caspase inhibitor, zVAD-fmk. Overexpression of the PLC-delta1 in hypoxic neonatal cardiomyocytes rescued intracellular Ca2+ overload by ischemic conditions. In the border zone and scar region of infarcted myocardium, and in hypoxic neonatal cardiomyocytes, the selective degradation of PLC-delta1 by the calcium sensitive proteases may play important roles in intracellular Ca2+ regulations under the ischemic conditions. It is suggested that PLC isozyme-changes may contribute to the alterations in calcium homeostasis in myocardial ischemia.