A novel bioactive peptide derived from enzymatic hydrolysis of Ruditapes philippinarum: Purification and investigation of its free-radical quenching potential

We purified a novel antioxidant peptide from Ruditapes philippinarum (R. philippinarum) and investigated its free radical scavenging activities. To prepare the peptide, eight proteases were tested for enzymatic hydrolysis. α-chymotrypsin hydrolysate, which showed clearly superior hydroxyl radical scavenging activity (p < 0.05), were further purified using a flow filtration system and consecutive chromatographic methods. Finally, a novel antioxidant peptide was obtained, and the sequence was identified as Ser-Val-Glu-Ile-Gln-Ala-Leu-Cys-Asp-Met. The peptide from R. philippinarum effectively scavenged hydroxyl, DPPH, alkyl and superoxide radicals, with observed IC₅₀ values of 0.042, 0.091, 0.107 and 0.372 mg/ml, respectively. This is the first report of an antioxidant peptide derived from the hydrolysates of R. philippinarum which, further, possesses competitive free radical quenching potential.     

Characterization and immunostimulating activity of a water-soluble polysaccharide isolated from <Emphasis Type="Italic">Haematococcus lacustris</Emphasis>

A water-soluble polysaccharide was isolated and purified from the culture filtrate of the photosynthetic green microalgae Haematococcus lacustris by 75% ethanol precipitation and Sepharose CL-6B column chromatography. The molecular mass of the purified polysaccharide (named HCP) was estimated to be approximately 135 kDa by size-exclusion HPLC and its monosaccharide composition was galactose, glucose and mannose at a relative molar ratio of 2.0, 1.0, and 4.1, respectively, suggesting that HCP is a galactomannan. Fourier-transform infrared and elemental analysis revealed that the purified HCP contains sulfate esters by 1.08% (in mass) and no detectable level of protein. The HCP significantly stimulated murine macrophage RAW264.7 cells to secrete the pro-inflammatory cytokine, TNF-α, in a dose-dependent manner and also enhanced the expression of COX-2 and iNOS genes at a concentration of lower than 10 μg/mL HCP. These results indicated that the sulfated HCP of H. lacustris has potent early innate immune stimulating activities.     

Development of inactivated trivalent vaccine for the teratogenic Aino,Akabane and Chuzan viruses

Aino, Akabane and Chuzan viruses are arthropod-borne (arbo) viruses transmitted by blood-sucking insects like mosquitoes and Culicoides biting midges. These arbovirus infections are mainly associated with abortion, stillbirth and congenital defects in pregnant cattle, sheep and goats, which induces a considerable economic loss in livestock industry. The viruses seem to be widely distributed in Southeast Asia and Australia. As a control strategy, an inactivated trivalent vaccine against Aino, Akabane and Chuzan virus was developed by using binary ethylenimine or formalin as an inactivating agent. The newly developed trivalent vaccine is evaluated for its safety and immunogenicity in animals such as mice, guinea pigs and cattle. The immune responses were significantly detected within 2-weeks after second vaccination without any side effects. Since the field application of experimental vaccine also revealed increased antibodies in inoculated cattle, we demonstrated that these trivalent vaccines could be used as a vaccine to control the arboviral infections in ruminants.     

Type I interferon signaling regulates Ly6C(hi) monocytes and neutrophils during acute viral pneumonia in mice

Type I interferon (IFN-I) plays a critical role in the homeostasis of hematopoietic stem cells and influences neutrophil influx to the site of inflammation. IFN-I receptor knockout (Ifnar1 ^−/−) mice develop significant defects in the infiltration of Ly6C^hi monocytes in the lung after influenza infection (A/PR/8/34, H1N1). Ly6C^hi monocytes of wild-type (WT) mice are the main producers of MCP-1 while the alternatively generated Ly6C^int monocytes of Ifnar1 ^−/− mice mainly produce KC for neutrophil influx. As a consequence, Ifnar1 ^−/− mice recruit more neutrophils after influenza infection than do WT mice. Treatment of IFNAR1 blocking antibody on the WT bone marrow (BM) cells in vitro failed to differentiate into Ly6C^hi monocytes. By using BM chimeric mice (WT BM into Ifnar1 ^−/− and vice versa), we confirmed that IFN-I signaling in hematopoietic cells is required for the generation of Ly6C^hi monocytes. Of note, WT BM reconstituted Ifnar1 ^−/− chimeric mice with increased numbers of Ly6C^hi monocytes survived longer than influenza-infected Ifnar1 ^−/− mice. In contrast, WT mice that received Ifnar1 ^−/− BM cells with alternative Ly6C^int monocytes and increased numbers of neutrophils exhibited higher mortality rates than WT mice given WT BM cells. Collectively, these data suggest that IFN-I contributes to resistance of influenza infection by control of monocytes and neutrophils in the lung.     

Antisense-overexpression of the MsCOMT gene induces changes in lignin and total phenol contents in transgenic tobacco plants

Initially, we isolated the caffeic acid O-methyltransferase (COMT) gene from Miscanthus sinensis (accession number HM062766.1). Next, we produced transgenic tobacco plants with down-regulated COMT gene expression to study its control of total phenol and lignin content and to perform morphological analysis. These transgenic plants were found to have reduced PAL and ascorbate peroxidases expression, which are related to the phenylpropanoid pathway and antioxidant activity. The MsCOMT-down-regulated plants had decreased total lignin in the leaves and stem compared with control plants. Reduced flavonol concentrations were confirmed in MsCOMT-down-regulated transgenic plants. We also observed a morphological difference, with reduced plant cell number in transgenic plants harboring antisense MsCOMT. The transgenic tobacco plants with down-regulated COMT gene expression demonstrate that COMT plays a crucial role related to controlling lignin and phenol content in plants. Also, COMT activity may be related to flavonoid production in the plant lignin pathway.     

Incidence,Predictive Factors,and Clinical Outcomes of Acute Kidney Injury after Gastric Surgery for Gastric Cancer

Background

Postoperative acute kidney injury (AKI), a serious surgical complication, is common after cardiac surgery; however, reports on AKI after noncardiac surgery are limited. We sought to determine the incidence and predictive factors of AKI after gastric surgery for gastric cancer and its effects on the clinical outcomes.

Methods

We conducted a retrospective study of 4718 patients with normal renal function who underwent partial or total gastrectomy for gastric cancer between June 2002 and December 2011. Postoperative AKI was defined by serum creatinine change, as per the Kidney Disease Improving Global Outcomes guideline.

Results

Of the 4718 patients, 679 (14.4%) developed AKI. Length of hospital stay, intensive care unit admission rates, and in-hospital mortality rate (3.5% versus 0.2%) were significantly higher in patients with AKI than in those without. AKI was also associated with requirement of renal replacement therapy. Multivariate analysis revealed that male gender; hypertension; chronic obstructive pulmonary disease; hypoalbuminemia (<4 g/dl); use of diuretics, vasopressors, and contrast agents; and packed red blood cell transfusion were independent predictors for AKI after gastric surgery. Postoperative AKI and vasopressor use entailed a high risk of 3-month mortality after multiple adjustments.

Conclusions

AKI was common after gastric surgery for gastric cancer and associated with adverse outcomes. We identified several factors associated with postoperative AKI; recognition of these predictive factors may help reduce the incidence of AKI after gastric surgery. Furthermore, postoperative AKI in patients with gastric cancer is an important risk factor for short-term mortality.     

Mucosa-associated epithelial chemokine/CCL28 expression in the uterus attracts CCR10+ IgA plasma cells following mucosal vaccination via estrogen control

Previous studies demonstrated cross talk between mucosal and reproductive organs during secretory IgA Ab induction. In this study, we aimed to clarify the underlying mechanisms of this cross talk. We found significantly higher titers of Ag-specific secretory IgA Ab in the vaginal wash after mucosal vaccination by both the intranasal (i.n.) and the intravaginal routes but not by the s.c. route. Interestingly, Ag-specific IgA Ab-secreting cells (ASCs) were found mainly in the uterus but not in the cervix and vaginal canal after i.n. vaccination. The fact that most Ag-specific IgA ASCs isolated from the uteri of vaccinated mice migrated toward mucosa-associated epithelial chemokine (MEC)/CCL28 suggests dominant expression of CCR10 on the IgA ASCs. Further, IgA ASCs in the uteri of vaccinated mice were reduced drastically in mice treated with neutralizing anti-MEC/CCL28 Ab. Most intriguingly, the female sex hormone estrogen directly regulated MEC/CCL28 expression and was augmented by i.n. vaccination with cholera toxin or stimulators for innate immunity. Further, blockage of estrogen function in the uterus by oral administration of the estrogen antagonist raloxifene significantly inhibited migration of Ag-specific IgA ASCs after i.n. vaccination with OVA plus cholera toxin. Taken together, these data strongly suggest that CCR10(+) IgA ASCs induced by mucosal vaccination via the i.n. route migrate into the uterus in a MEC/CCL28-dependent manner and that estrogen might have a crucial role in the protection against genital infection by regulating MEC/CCL28 expression in the uterus.