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111.
Tina B McKay Akhee Sarker‐Nag Desiree' Lyon John M Asara Dimitrios Karamichos 《Cell biochemistry and function》2015,33(5):341-350
Corneal scarring is the result of a disease, infection or injury. The resulting scars cause significant loss of vision or even blindness. To‐date, the most successful treatment is corneal transplantation, but it does not come without side effects. One of the corneal dystrophies that are correlated with corneal scarring is keratoconus (KC). The onset of the disease is still unknown; however, altered cellular metabolism has been linked to promoting the fibrotic phenotype and therefore scarring. We have previously shown that human keratoconus cells (HKCs) have altered metabolic activity when compared to normal human corneal fibroblasts (HCFs). In our current study, we present evidence that quercetin, a natural flavonoid, is a strong candidate for regulating metabolic activity of both HCFs and HKCs in vitro and therefore a potential therapeutic to target the altered cellular metabolism characteristic of HKCs. Targeted mass spectrometry‐based metabolomics was performed on HCFs and HKCs with and without quercetin treatment in order to identify variations in metabolite flux. Overall, our study reveals a novel therapeutic target OF Quercetin on corneal stromal cell metabolism in both healthy and diseased states. Clearly, further studies are necessary in order to dissect the mechanism of action of quercetin. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The role of ungulates in nowadays temperate forests. A response to Fløjgaard et al. (DOI:10.1111/gcb.14029) 下载免费PDF全文
114.
Annelie Eklund Sarron Randall‐Demllo Sergey Shabala Nuri Guven Anthony L Cook Rajaraman D Eri 《Cell biochemistry and function》2013,31(7):603-611
Endoplasmic reticulum (ER) stress and oxidative stress have recently been linked to the pathogenesis of inflammatory bowel diseases. Under physiological conditions, intestinal epithelial cells are exposed to ER and oxidative stress affecting the cellular ionic homeostasis. However, these altered ion flux ‘signatures’ during these stress conditions are poorly characterized. We investigated the kinetics of K+, Ca2+ and H+ ion fluxes during ER and oxidative stress in a colonic epithelial cell line LS174T using a non‐invasive microelectrode ion flux estimation technique. ER and oxidative stress were induced by cell exposure to tunicamycin (TM) and copper ascorbate (CuAsc), respectively, from 1 to 24 h. Dramatic K+ efflux was observed following acute ER stress with peak K+ efflux being ?30·6 and ?138·7 nmolm?2 s?1 for 10 and 50 µg ml?1, respectively (p < 0·01). TM‐dependent Ca2+ uptake was more prolonged with peak values of 0·85 and 2·68 nmol m?2 s?1 for 10 and 50 µg ml?1 TM, respectively (p < 0·02). Ion homeostasis was also affected by the duration of ER stress. Increased duration of TM treatment from 0 to 18 h led to increases in both K+ efflux and Ca2+ uptake. While K+ changes were significantly higher at each time point tested, Ca2+ uptake was significantly higher only after prolonged treatment (18 h). CuAsc also led to an increased K+ efflux and Ca2+ uptake. Functional assays to investigate the effect of inhibiting K+ efflux with tetraethylammonium resulted in increased cell viability. We conclude that ER/oxidative stress in colonic epithelial cells cause dramatic K+, Ca2+ and H+ ion flux changes, which may predispose this lineage to poor stress recovery reminiscent of that seen in inflammatory bowel diseases. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
115.
Responses of pre‐dispersal seed predators to sequential flowering of Dipterocarps in Malaysia 下载免费PDF全文
Tetsuro Hosaka Takakazu Yumoto Yu‐Yun Chen I‐Fang Sun S. Joseph Wright Shinya Numata Noor Md Nur Supardi 《Biotropica》2017,49(2):177-185
Many species of Dipterocarpaceae and other plant families reproduce synchronously at irregular, multi‐year intervals in Southeast Asian forests. These community‐wide general flowering events are thought to facilitate seed survival through satiation of generalist seed predators. During a general flowering event, closely related Shorea species (Dipterocarpaceae) stagger their flowering times by several weeks, which may minimize cross pollination and interspecific competition for pollinators. Generalist, pre‐dispersal seed predators might also track flowering hosts and influence predator satiation. We addressed the question of whether pre‐dispersal seed predation differed between early and late flowering Shorea species by monitoring flowering, fruiting and seed predation intensity over two general flowering events at the Pasoh Research Forest, Malaysia. Pre‐dispersal insect seed predators killed up to 63 percent of developing seeds, with Nanophyes shoreae, a weevil that feeds on immature seeds being the most important predator for all Shorea species. This weevil caused significantly greater pre‐dispersal seed predation in earlier flowering species. Long larval development time precluded oviposition by adults that emerged from the earliest flowering Shorea on the final flowering Shorea. In contrast, larvae of weevils that feed on mature seeds before seed dispersal (Alcidodes spp.), appeared in seeds of all Shorea species almost simultaneously. We conclude that general flowering events have the potential to satiate post‐dispersal seed predators and pre‐dispersal seed predators of mature fruit, but are less effective at satiating pre‐dispersal predators of immature fruit attacking early flowering species. 相似文献
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117.
Yun‐Zhen Xu Ni‐Ni Guo Zong‐Ming Zheng Xian‐Jin Ou Hong‐Juan Liu De‐Hua Liu 《Biotechnology and bioengineering》2009,104(5):965-972
Klebsiella pneumoniae HR526, a new isolated 1,3‐propanediol (1,3‐PD) producer, exhibited great productivity. However, the accumulation of lactate in the late‐exponential phase remained an obstacle of 1,3‐PD industrial scale production. Hereby, mutants lacking D ‐lactate pathway were constructed by knocking out the ldhA gene encoding fermentative D ‐lactate dehydrogenase (LDH) of HR526. The mutant K. pneumoniae LDH526 with the lowest LDH activity was studied in aerobic fed‐batch fermentation. In experiments using pure glycerol as feedstock, the 1,3‐PD concentrations, conversion, and productivity increased from 95.39 g L?1, 0.48 and 1.98 g L?1 h?1 to 102. 06 g L?1, 0.52 mol mol?1 and 2.13 g L?1 h?1, respectively. The diol (1,3‐PD and 2,3‐butanediol) conversion increased from 0.55 mol mol?1 to a maximum of 0.65 mol mol?1. Lactate would not accumulate until 1,3‐PD exceeded 84 g L?1, and the final lactate concentration decreased dramatically from more than 40 g L?1 to <3 g L?1. Enzymic measurements showed LDH activity decreased by 89–98% during fed‐batch fermentation, and other related enzyme activities were not affected. NADH/NAD+ enhanced more than 50% in the late‐exponential phase as the D ‐lactate pathway was cut off, which might be the main reason for the change of final metabolites concentrations. The ability to utilize crude glycerol from biodiesel process and great genetic stability demonstrated that K. pnemoniae LDH526 was valuable for 1,3‐PD industrial production. Biotechnol. Bioeng. 2009; 104: 965–972. © 2009 Wiley Periodicals, Inc. 相似文献
118.
Gerald Brandacher Johanna Grahammer Robert Sucher Wei‐Ping Andrew Lee 《Birth defects research. Part C, Embryo today : reviews》2012,96(1):39-50
Reconstructive transplantation represents a bona fide option for select patients with devastating tissue loss, which could better restore the appearance, anatomy, and function than any other conventional treatment currently available. Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the potential side effects of chronic multidrug immunosuppression. Thus, any reconstructive measures to improve these non‐life‐threatening conditions must address a delicate balance of risks and benefits. Today, several exciting novel therapeutic strategies, such as the implementation of cellular therapies including bone marrow or stem cells that integrate the concepts of immune regulation with those of nerve regeneration, are on the horizon. The development of reliable and reproducible small andlarge animal models is essential for the study of the unique immunological and biological aspects of vascularized composite allografts and to translate such novel immunoregulatory and tolerance‐inducing strategies and therapeutic concepts from the bench to bedside. This review provides an overview of the multitude of small and largeanimal models that have been particularly designed for basicand translational research related to reconstructive transplantation. (Part C) 96:39–50, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
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Exposure to Bordetella pertussis adenylate cyclase toxin affects integrin‐mediated adhesion and mechanics in alveolar epithelial cells 下载免费PDF全文