title: Immunomodulatory Effects of Alginate Oligosaccharides on Murine Macrophage RAW264.7 Cells and Their Structure-Activity Relationships.
abstract: This study evaluated the immunomodulatory activities, including regulation of nitric oxide (NO), reactive oxygen species (ROS), and tumor necrosis factor (TNF)-α production in RAW264.7 murine macrophages, of alginate oligosaccharides (AOS) and investigated their structure-activity relationships. Our results revealed that unsaturated guluronate oligosaccharide prepared by enzymatic degradation (GOS-ED) induced NO production and inducible nitric oxide synthase (iNOS) expression, dose and time dependently, and stimulated ROS and TNF-α production; however, other AOS prepared by different ways or polymers showed very low and even no such effects. Moreover, GOS-ED induced macrophage activation to release the above-mentioned mediators partly involved in nuclear factor (NF)-κB and mitogen-activated protein (MAP) kinase signaling pathways. We also show that the structural characteristics of AOS, especially the unsaturated terminal structure, molecular size, and M/G ratio, play important roles in determining the macrophage-activating effects. GOS-ED could be applicable for agriculture, drug, and food industry as a potent immune-modulatory agent.
authors.affiliation: College of Life Science, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University , Shenzhen 518060, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Xu
authors.affiliation: College of Life Science, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University , Shenzhen 518060, China.
authors.forename: Xiaoting
authors.initials: X
authors.lastname: Wu
authors.affiliation: College of Life Science, Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen University , Shenzhen 518060, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Life Science, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University , Shenzhen 518060, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Cai
authors.affiliation: College of Life Science, Shenzhen Key Laboratory of Marine Bioresources and Ecology, Shenzhen University , Shenzhen 518060, China.
authors.forename: Hanxue
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Biological Engineering, Jimei University , Jimei, Xiamen 361021, China.|Division of Biochemistry, Faculty of Fisheries, Nagasaki University , Nagasaki 852 8521, Japan.
authors.forename: Zedong
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Division of Physiological Chemistry 2, Department of Medical Biochemistry and Biophysics, Karolinska Institute , Stockholm 17177, Sweden.
authors.forename: Min
authors.initials: M
authors.lastname: Wan
authors.affiliation: Division of Biochemistry, Faculty of Fisheries, Nagasaki University , Nagasaki 852 8521, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Oda
keywords: MAP kinase; NF-κB; ROS; TNF-α; guluronate oligosaccharide; macrophage activation; mannuronate oligosaccharide; nitric oxide