PubMed | Kunsan National University, Seoul National University, Marine Biodiversity Institute of Korea and Korean University of Science and Technology
Type: | Journal: Harmful algae | Year: 2017
To investigate interactions between the nematocyst-bearing mixotrophic dinoflagellate Paragymnodinium shiwhaense and different heterotrophic protist and copepod species, feeding by common heterotrophic dinoflagellates (Oxyrrhis marina and Gyrodinium dominans), naked ciliates (Strobilidium sp. approximately 35m in cell length and Strombidinopsis sp. approximately 100m in cell length), and calanoid copepods Acartia spp. (A. hongi and A. omorii) on P. shiwhaense was explored. In addition, the feeding activities of P. shiwhaense on these heterotrophic protists were investigated. Furthermore, the growth and ingestion rates of O. marina, G. dominans, Strobilidium sp., Strombidinopsis sp., and Acartia spp. as a function of P. shiwhaense concentration were measured. O. marina, G. dominans, and Strombidinopsis sp. were able to feed on P. shiwhaense, but Strobilidium sp. was not. However, the growth rates of O. marina, G. dominans, Strobilidium sp., and Strombidinopsis sp. feeding on P. shiwhaense were very low or negative at almost all concentrations of P. shiwhaense. P. shiwhaense frequently fed on O. marina and Strobilidium sp., but did not feed on Strombidinopsis sp. and G. dominans. G. dominans cells swelled and became dead when incubated with filtrate from the experimental bottles (G. dominans+P. shiwhaense) that had been incubated for one day. The ingestion rates of O. marina, G. dominans, and Strobilidium sp. on P. shiwhaense were almost zero at all P. shiwhaense concentrations, while those of Strombidinopsis sp. increased with prey concentration. The maximum ingestion rate of Strombidinopsis sp. on P. shiwhaense was 5.3ngC predator
PubMed | c Mayo Clinic Cancer Center, Marine Biodiversity Institute of Korea, d Robert and Arlene Kogod Center on Aging, Rutgers University and Molecular Therapeutics
Type: | Journal: Epigenetics | Year: 2016
High-fat diet consumption and sedentary life style elevates risk for obesity, non-alcoholic fatty liver disease, and cancer. Exercise training conveys health benefits in populations with or without these chronic conditions. Diet and exercise regulate gene expression by mediating epigenetic mechanisms in many tissues; however, such effects are poorly documented in the liver, a central metabolic organ. To dissect the consequences of diet and exercise on the liver epigenome, we measured DNA methylation, using reduced representation bisulfite sequencing, and transcription, using RNA-seq, in mice maintained on a fast food diet with sedentary lifestyle or exercise, compared to control diet with and without exercise. Our analyses reveal that genome-wide differential DNA methylation and expression of gene clusters are induced by diet and/or exercise. A combination of fast food and exercise triggers extensive gene alterations, with enrichment of carbohydrate/lipid metabolic pathways and muscle developmental processes. Through evaluation of putative protective effects of exercise on diet-induced DNA methylation, we show that hypermethylation is effectively prevented, especially at promoters and enhancers, whereas hypomethylation is only partially attenuated. We assessed diet-induced DNA methylation changes associated with liver cancer-related epigenetic modifications and identified significant increases at liver-specific enhancers in fast food groups, suggesting partial loss of liver cell identity. Hypermethylation at a subset of gene promoters was associated with inhibition of tissue development and promotion of carcinogenic processes. Our study demonstrates extensive reprogramming of the epigenome by diet and exercise, emphasizing the functional relevance of epigenetic mechanisms as an interface between life-style modifications and phenotypic alterations.
PubMed | Kosin University, Inje University, Korea University, Marine Biodiversity Institute of Korea and Jeju National University
Type: | Journal: International journal of molecular medicine | Year: 2016
In the present study, we investigated the cytoprotective efficacy of morin, a natural flavonoid, against oxidative stress and elucidated the underlying mechanisms in C2C12 myoblasts. Our results indicated that morin treatment prior to hydrogen peroxide (H2O2) exposure significantly increased cell viability and prevented the generation of reactive oxygen species. H2O2-induced comet-like DNA formation and H2AX phosphorylation were also markedly suppressed by morin with a parallel inhibition of apoptosis in C2C12 myoblasts, suggesting that morin prevented H2O2-induced cellular DNA damage. Furthermore, morin markedly enhanced the expression of heme oxygenase-1(HO-1) associated with the induction and phosphorylation of nuclear factor-erythroid2-related factor2(Nrf2) and the inhibition of Kelch-like ECH-associated protein1 (Keap1) expression. Notably, these events were eliminated by transient transfection with Nrf2specific small interfering RNA. Additional experiments demonstrated that the activation of the Nrf2/HO-1 pathway by morin was mediated by the extracellular signalregulated kinase(ERK) signaling cascade. This phenomenon was confirmed with suppressed Nrf2 phosphorylation and consequently diminished HO-1 expression in cells treated with a pharmacological inhibitor of ERK. Collectively, these results demonstrated that morin augments the cellular antioxidant defense capacity through the activation of Nrf2/HO1 signaling, which involves the activation of the ERK pathway, thereby protecting C2C12 myoblasts from H2O2-induced oxidative cytotoxicity.
Caffeic acid phenethyl ester reduces the secretion of vascular endothelial growth factor through the inhibition of the ROS, PI3K and HIF-1α signaling pathways in human retinal pigment epithelial cells under hypoxic conditions
PubMed | Korea University, Marine Biodiversity Institute of Korea, Inje University, Jeju National University and 2 more.
Type: Journal Article | Journal: International journal of molecular medicine | Year: 2015
Choroidal neovascularization (CNV) can lead to progressive and severe visual loss. Vascular endothelial growth factor (VEGF) promotes the development of CNV. Caffeic acid phenethyl ester (CAPE), a biologically active component of the honeybee (Apis mellifera) propolis, has been demonstrated to have several interesting biological regulatory properties. The objective of this study was to determine whether treatment with CAPE results in the inhibition of the production of vascular endothelial growth factor (VEGF) in retinal pigment epithelial cells (RPE cells) under hypoxic conditions and to explore the possible underlying mechanisms. An in vitro experimental model of hypoxia was used to mimic an ischemic microenvironment for the RPE cells. Human RPE cells (ARPE-19) were exposed to hypoxia with or without CAPE pre-treatment. ARPE-19 cells were used to investigate the pathway involved in the regulation of VEGF production under hypoxic conditions, based on western blot analysis, enzyme-linked immunosorbent assay (ELISA) and electrophoretic mobility shift assay (EMSA). The amount of VEGF released from the hypoxia-exposed cells was significantly higher than that of the normoxic controls. Pre-treatment with CAPE suppressed the hypoxia-induced production of VEGF in the ARPE-19 cells, and this effect was inhibited through the attenuation of reactive oxygen species (ROS) production, and the inhibition of phosphoinositide 3-kinase (PI3K)/AKT and hypoxia-inducible factor-1 (HIF-1) expression. These in vitro findings suggest that CAPE may prove to be a novel anti-angiogenic agent for the treatment of diseases associated with CNV.
PubMed | Korea University, Marine Biodiversity Institute of Korea, Kosin University, Inje University and 4 more.
Type: | Journal: Drug development research | Year: 2016
Preclinical Research Fucoidan, a sulfated polysaccharide, is a compound found in various species of seaweed that has anti-viral, anti-bacterial, anti-oxidant, anti-inflammatory, and immunomodulatory activities; however, the underlying relationship between apoptosis and anti-telomerase activity has not been investigated. Here, we report that fucoidan-induced apoptosis in 5637 human bladder cancer cells was associated with an increase in the Bax/Bcl-2 ratio, the dissipation of the mitochondrial membrane potential (MMP, m), and cytosolic release of cytochrome c from the mitochondria. Under the same experimental conditions, fucoidan-treatment decreased hTERT (human telomerase reverse transcriptase) expression and the transcription factors, c-myc and Sp1. This was accompanied by decreased telomerase activity. Fucoidan-treatment also suppressed activation of the PI3K/Akt signaling pathway. Inhibition of PI3K/Akt signaling enhanced fucoidan-induced apoptosis and anti-telomerase activity. Meanwhile, fucoidan treatment increased the generation of intracellular ROS, whereas the over-elimination of ROS by N-acetylcysteine, an anti-oxidant, attenuated fucoidan-induced apoptosis, inhibition of hTERT, c-myc, and Sp1 expression, and reversed fucoidan-induced inactivation of the PI3K/Akt signaling pathway. Collectively, these data indicate that the induction of apoptosis and the inhibition of telomerase activity by fucoidan are mediated via ROS-dependent inactivation of the PI3K/Akt pathway.
Park H.,Korea Advanced Institute of Science and Technology |
Kwon S.-J.,Marine Biodiversity Institute of Korea |
Hadi S.,Bandung Institute of Technology
Journal of Coastal Research | Year: 2016
The coastal flooding caused by land subsidence is one of major social problems in the coastal area of Jakarta bay, Indonesia. To develop a land subsidence response planning, 3D topographic survey is conducted by using the Terrestrial LIDAR and GPS in Pantai Mutiara. The Terrestrial LIDAR survey results show that the survey site has mean elevation of -0.31m with the highest elevation of 0.31m and lowest -0.99m. Considering that A.H.H.W. (Approximate Highest High Water) is 0.51m, many areas of the survey site are lying below the A.H.H.W. The subsidence happened from 1994 to 2012, subsided about 1.8m and the average rate of about 0.095m. The last stand which keeps the area from flooding and inundation is the dikes built around the area. Although the dikes are still functioning, the heights of the dikes are getting lower and uneven due to subsidence and partial reconstruction. We can conclude that flooding vulnerability of this area depends on the height of the dikes. In order to develop practical policies, we make the distribution maps, expected time of dike flooding, height and cost of dike heightening, through considering land subsidence rate, sea level rising rate, storm surge height and A.H.H.W. © Coastal Education and Research Foundation, Inc. 2016.
Back J.,Marine Biodiversity Institute of Korea |
Lee W.,Hanyang University
Journal of Natural History | Year: 2013
Three new species of Paramesochridae are described from the subtidal zone off Pungdo Island, west coast of Korea. Paramesochra parasimilis sp. nov. is closely related to Paramesochra similis. However, the new species is clearly distinguished by the characteristic seta IV of the caudal rami. Paramesochra pungdoensis sp. nov is characterized by five setae in antennary exopod and seta IV, which is longer than the caudal ramus. Paramesochra mirabilis sp. nov. has a laterally bent caudal seta V in the female. These three new species are placed in the dubia-group by the inner seta on the endopod of leg 3 and leg 4. Also, a redescription of Paramesochra similis Kunz, 1936 is provided, and an updated key to the species of Paramesochra is suggested. http://www.zoobank.org/urn:lsid:zoobank.org:pub:F017D873-6A34-4976-A7EA-589038E1A9A3. © 2013 Copyright Taylor and Francis Group, LLC.
Back J.,Hanyang University |
Lee W.,Marine Biodiversity Institute of Korea
Zootaxa | Year: 2012
A study of harpacticoid copepods from the intertidal zone of Jeju Island in the South Sea of Korea resulted in the discovery of two new paramesochrid species. They are placed in the genus Apodopsyllus Huys, 2009 on account of the following combination of characters: the absence of P2-P4 endopods, the poorly defined body segmentation, the two-segmented P1 endopod and exopod, and the fusion of the P2-P4 coxae with the respective body somites. Apodopsyllus gwakjiensis sp. nov. is most closely related to A. bermudensis (Coull & Hogue, 1978), but clearly distinguishable from it by the following characters: the concave shape of the baseoendopod with two bare setae, P4 basis without endopodal seta, and certain detailed characteristics of the mouthparts. Apodopsyllus unisetosus sp. nov. is easily distinguished from its congeners by the antennary exopod, which is armed with a single apical seta. In addition, A. unisetosus has the baseoendopod of P5 fused with somite, the P1 armed with one inner and one outer basal seta, and the unique shape of the male P6. Keys to genera of the family Paramesochridae Lang, 1944, as well as to species of the genus Apodopsyllus Huys, 2009 are provided. Copyright © 2012 Magnolia Press.
Back J.,Marine Biodiversity Institute of Korea |
Lee W.,Hanyang University
ZooKeys | Year: 2014
A survey on the harpacticoid copepods from an intertidal zone in Hyeopjae sandy beach, Jeju Island, Korea, resulted in the discovery of an unusual laophontid, Jejulaophonte hyeopjaeensis sp. n., which cannot be placed in any extant genus within the family. To accommodate the species, a new genus of the family Laophontidae T. Scott, 1905 is proposed and fully described here. The new species is closely related to the lineage of the five primitive genera, Carraroenia McCormack, 2006, Coullia Hamond, 1973, Hemilaophonte Jakubisiak 1933, Psammoplatypus Lee & Huys, 1999, and Robustunguis Fiers, 1992 (the CCHPR-lineage) by the reduced P2 endopod, ovate shape of the female P5 exopod and sexual dimorphism in the P3 endopod. However, it displays discrepancies from the species of the CCHPR-lineage in the presence of an inner seta on P3 and P4 exp-2, four setae on P4 enp-2, and an inner seta on P3 and P4 enp-2 in the female. Furthermore, no other species within the family Laophontidae has three setae on P2 exp-3 and a seta on P2 enp-2 at the same time. The new species has sexual dimorphism in the antennule, genital segmentation and the legs from P2 to P5. The terminal seta on the second endopodal segment of P2 in the male is longer than that in the female. The endopod of P3 is 3-segmented and displays a short inner apophysis on the second segment in the male. The outer setae on the exopod of P3 and P4 are distinctly thicker and stronger in the male than in the female. Mitochondrial cytochrome oxidase subunit I (mt-COI) sequencing of the new species has been realized in order to be used in future phylogenetic analysis. © 2014, Jinwook Back, Wonchoel Lee.
PubMed | Marine Biodiversity Institute of Korea and Hanyang University
Type: | Journal: ZooKeys | Year: 2014
A survey on the harpacticoid copepods from an intertidal zone in Hyeopjae sandy beach, Jeju Island, Korea, resulted in the discovery of an unusual laophontid, Jejulaophontehyeopjaeensis sp. n., which cannot be placed in any extant genus within the family. To accommodate the species, a new genus of the family Laophontidae T. Scott, 1905 is proposed and fully described here. The new species is closely related to the lineage of the five primitive genera, Carraroenia McCormack, 2006, Coullia Hamond, 1973, Hemilaophonte Jakubisiak 1933, Psammoplatypus Lee & Huys, 1999, and Robustunguis Fiers, 1992 (the CCHPR-lineage) by the reduced P2 endopod, ovate shape of the female P5 exopod and sexual dimorphism in the P3 endopod. However, it displays discrepancies from the species of the CCHPR-lineage in the presence of an inner seta on P3 and P4 exp-2, four setae on P4 enp-2, and an inner seta on P3 and P4 enp-2 in the female. Furthermore, no other species within the family Laophontidae has three setae on P2 exp-3 and a seta on P2 enp-2 at the same time. The new species has sexual dimorphism in the antennule, genital segmentation and the legs from P2 to P5. The terminal seta on the second endopodal segment of P2 in the male is longer than that in the female. The endopod of P3 is 3-segmented and displays a short inner apophysis on the second segment in the male. The outer setae on the exopod of P3 and P4 are distinctly thicker and stronger in the male than in the female. Mitochondrial cytochrome oxidase subunit I (mtCOI) sequencing of the new species has been realized in order to be used in future phylogenetic analysis.