Dietary resveratrol prevents the development of food allergy in mice

Background

Resveratrol is a bioactive polyphenol enriched in red wine that exhibits many beneficial health effects via multiple mechanisms. However, it is unclear whether resveratrol is beneficial for the prevention of food allergy. This study investigated whether resveratrol inhibited the development of food allergy by using a mouse model of the disease.

Methodology/Principal Findings

Mice fed standard diet or standard diet plus resveratrol were sensitized by intragastric administration of ovalbumin (OVA) and mucosal adjuvant cholera toxin (CT). Several manifestations of food allergy were then compared between the mice. The effects of resveratrol on T cells or dendritic cells were also examined by using splenocytes from OVA-specific T cell-receptor (TCR) transgenic DO11.10 mice or mouse bone marrow-derived dendritic cells (BMDCs) in vitro. We found that mice fed resveratrol showed reduced OVA-specific serum IgE production, anaphylactic reaction, and OVA-induced IL-13 and IFN-ã production from the mesenteric lymph nodes (MLNs) and spleens in comparison to the control mice, following oral sensitization with OVA plus CT. In addition, resveratrol inhibited OVA plus CT-induced IL-4, IL-13, and IFN-ã production in splenocytes from DO11.10 mice associated with inhibition of GATA-3 and T-bet expression. Furthermore, resveratrol suppressed the OVA plus CT-induced CD25 expression and IL-2 production in DO11.10 mice-splenocytes in association with decreases in CD80 and CD86 expression levels. Finally, resveratrol suppressed CT-induced cAMP elevation in association with decreases in CD80 and CD86 expression levels in BMDCs.

Conclusions/Significance

Ingestion of resveratrol prevented the development of a food allergy model in mice. Given the in vitro findings, resveratrol might do so by inhibiting DC maturation and subsequent early T cell activation and differentiation via downregulation of CT-induced cAMP activation in mice. These results suggest that resveratrol may have potential for prophylaxis against food allergy.     

LRGUK-1 Is Required for Basal Body and Manchette Function during Spermatogenesis and Male Fertility

Male infertility affects at least 5% of reproductive age males. The most common pathology is a complex presentation of decreased sperm output and abnormal sperm shape and motility referred to as oligoasthenoteratospermia (OAT). For the majority of OAT men a precise diagnosis cannot be provided. Here we demonstrate that leucine-rich repeats and guanylate kinase-domain containing isoform 1 (LRGUK-1) is required for multiple aspects of sperm assembly, including acrosome attachment, sperm head shaping and the initiation of the axoneme growth to form the core of the sperm tail. Specifically, LRGUK-1 is required for basal body attachment to the plasma membrane, the appropriate formation of the sub-distal appendages, the extension of axoneme microtubules and for microtubule movement and organisation within the manchette. Manchette dysfunction leads to abnormal sperm head shaping. Several of these functions may be achieved in association with the LRGUK-1 binding partner HOOK2. Collectively, these data establish LRGUK-1 as a major determinant of microtubule structure within the male germ line.     

Phytoplankton blooms under dim and cold conditions in freshwater lakes of East Antarctica

The seasonal variations of limnological (water temperature, light availability, turbidity, and chlorophyll a concentration) parameters were recorded continuously from January 2004 to February 2005 at two freshwater lakes: Oyako-ike and Hotoke-ike, Sôya Coast, East Antarctica. Water was in a liquid phase throughout the year, with temperatures ranging from 0 to 10°C. The maximum photosynthetically active radiation in Lake Oyako-ike was 23.16 mol m^?2 day^?1 (at 3.8 m) and Hotoke-ike was 53.01 mol m^?2 day^?1 (at 2.2 m) in summer, and chlorophyll a concentration ranged from ca. 0.5 to 2.5 μg L^?1 (Oyako-ike) and from ca. 0.1 to 0.8 μg L^?1 (Hotoke-ike) during the study period. Increase in chlorophyll a fluorescence occurred under dim-light conditions when the lakes were covered with ice in spring and autumn, but the signals were minimum in ice-free summer in both the lakes. During spring and summer, as a result of decreasing snow cover, the chlorophyll a concentration similarly decreased when PAR was relatively high, following periods of heavy winds. The autumnal and spring increase occurred under different PAR levels (ca. 20-fold and 90-fold stronger, respectively, in autumn in both the lakes). Differences in the autumn and spring increases suggest that the spring algal community is more shade-adapted than the autumn algal community. Antarctic phytoplankton appears especially adapted to low-light levels and inhibited by strong light regimes.     

Activity of the prothoracic gland and its sensitivity to prothoracicotropic hormone in the penultimate and last-larval instar of Bombyx mori

The time course of secretion of ecdysone in vitro by the prothoracic glands of Bombyx mori was studied through the penultimate and last-larval instars. Ecdysone was produced by the glands in high amounts by the penultimate instar at 72 and 84 h while the glands in the last instar exhibited a high activity over 4 days around the time of gut purge and thereafter. The glands in the penultimate instar produced ecdysone at a low level throughout the instar before the sharp peak of activity, when they became inactive and remained so for the first 3 days of the last instar after when they regained secretory activity. Sensitivity of the glands to prothoracicotropic hormone varied in accord with the changes in their secretory activity. Inactive glands were not stimulated by 22K-prothoracicotropic hormone. In addition, glands with maximal activity in the penultimate instar were insensitive to 22K-prothoracicotropic hormone. These results suggest that the prothoracic glands in the penultimate and last-instar larvae are physiologically different.     

Platelet-rich plasma provides nucleus for mineralization in cultures of partially differentiated periodontal ligament cells

Summary Platelet-rich plasma (PRP) has been used to promote periodontal regeneration following the premise that constituent transforming growth factor-β1 (TGF-β1) and platelet-derived growth factor-AB will stimulate cell proliferation at the site of application. In previous studies, we demonstrated that PRP mimics TGF-β1 to modulate proliferation in a cell type-specific manner, that fibrin clot formation by PRP upregulates type I collagen, and that an unidentified factor(s) in PRP increases alkaline phosphatase (ALP) activity in human periodontal ligament (PDL) cell cultures. We have now examined the effects of PRP on in vitro mineralization. Platelet-rich plasma and PDL cells were prepared from human adult volunteers or rats. After 20 d of continuous treatment with PRP in dexamethazone (Dex)-containing osteogenic medium, PRP time dependently promoted mineralization by rat PDL cells but failed to fully induce the osteoblastic phenotype. Furthermore, when human PDL cells were induced to increase ALP activity in osteogenic medium that lacked Dex, a condition that should delay (or suppress) osteoblastic differentiation, transmission electron microscopy revealed that mineralized spicules were initially deposited onto PRP-derived platelet aggregates. Taken together with our previous data, these findings suggest that PRP provides platelet aggregates as nuclei to initiate mineralization while stimulating PDL cell proliferation, differentiation, and collagen production. The combination of these effects may effectively mediate PRP's ability to promote regeneration of periodontal tissue, including skeletal tissue, at the site of injury.     

Effects of dehydration rate on physiological responses and survival after rehydration in larvae of the anhydrobiotic chironomid

Strategies to combat desiccation are critical for organisms living in arid and semi-arid areas. Larvae of the Australian chironomid Paraborniella tonnoiri resist desiccation by reducing water loss. In contrast, larvae of the African species Polypedilum vanderplanki can withstand almost complete dehydration, referred to as anhydrobiosis. For successful anhydrobiosis, the dehydration rate of P. vanderplanki larvae has to be controlled. Here, we desiccated larvae by exposing them to different drying regimes, each progressing from high to low relative humidity, and examined survival after rehydration. In larvae of P. vanderplanki, reactions following desiccation can be categorized as follows: (I) no recovery at all (direct death), (II) dying by unrepairable damages after rehydration (delayed death), and (III) full recovery (successful anhydrobiosis). Initial conditions of desiccation severely affected survival following rehydration, i.e. P. vanderplanki preferred 100% relative humidity where body water content decreased slightly. In subsequent conditions, unfavorable dehydration rate, such as more than 0.7 mg water lost per day, resulted in markedly decreased survival rate of rehydrated larvae. Slow dehydration may be required for the synthesis and distribution of essential molecules for anhydrobiosis. Larvae desiccated at or above maximum tolerable rates sometimes showed temporary recovery but died soon after.     

Cell wall extensibility during branch formation in the xanthophycean alga Vaucheria terrestris

In the tip-growing filamentous cell of the xanthophycean alga Vaucheria terrestris sensu Götz, a new growing tip develops in the non-growing, cylindrical region of the cell that was exposed by local illumination. The present study examined changes in the strength and extensibility of the cell wall of the new growing tip and in the matrix components of the inner surface of the cell wall. The internal pressure required to rupture the cell walls decreased remarkably during the early to middle stages of growing tip development, but the cell wall hardly extended before rupture. In contrast, during the middle and late stages of development, cell walls were extended by internal pressure. Atomic force microscopy revealed that protease-resistant, fine granular matrix components were present only at the apical portion of a normal growing tip, and were absent in the non-growing cylindrical region. In the early and middle stages of new growing tip development, these matrix components appeared in the cell walls in patches. These results suggest that first cell wall strength decreases and then cell wall extensibility increases in the development of new growing tips, and that protease-resistant, fine granular matrix components may be involved in rendering a cell wall extensible.