Trophic niche overlap in coralline algae- and coral-dominated rocky-bottom subtidal communities.

We investigated trophic structures in rocky subtidal ecosystems transitioning from canopy-forming to barren states across coastlines with varying oceanographic conditions. We examined stable isotopes and functional traits of common invertebrate and fish taxa to understand the food-web consequences. We hypothesized that resource exploitation patterns of functional guilds would result in distinct isotopic niches, defining trophic diversity and niche.

Factors controlling massive green tide blooms on the coasts of Jeju Island, Korea.

To determine the driving mechanisms between submarine groundwater discharge (SGD) and massive blooms of the green alga Ulva, we examined the magnitude of SGD and SGD-derived nutrient fluxes from November 2019 to July 2020 in Ihotewoo (north) and Bangdu (east) bays, Jeju Island, Korea. The variability of SGD flux at both the sites, where the hydraulic gradient is low, closely followed the daily variability of the tidal range, indicating that SGD flux is primarily driven by tidal pumping. Although the average annual SGD-driven nutrient fluxes were 24-37 % lower in Bangdu Bay than in Ihotewoo Bay, massive Ulva blooms only occurred in Bangdu Bay.

Dominance of the scleractinian coral Alveopora japonica in the barren subtidal hard bottom of high-latitude Jeju Island off the south coast of Korea assessed by high-resolution underwater images.

Coastal benthic communities in temperate regions have been influenced by climate change, including increasing sea-surface temperature. Nevertheless, scleractinian coral Alveopora japonica Eguchi, 1968, is thriving in shallow subtidal hard bottoms around Jeju Island, off the southern coast of Korea. The presence of this corals has negatively impacted subtidal kelp populations in Jeju Island.

Bisphenol A inhibits osteogenic activity and causes bone resorption via the activation of retinoic acid-related orphan receptor α.

Bisphenol A (BPA) has deleterious effects on bone metabolism; however, its underlying mechanism has not yet been comprehensively understood. Here, we investigated whether RORα plays an important role in BPA-induced bone resorption both in vitro and in vivo. We found that BPA (0.

A comparison of physiological responses between attached and pelagic populations of Sargassum horneri under nutrient and light limitation.

Large-scale Sargassum blooms have been increasingly observed in coastal zones in recent years. Sargassum horneri (Turner) C. Agardh blooms (pelagic) have been observed in Jeju Island (Korea) and the southwest of the Korean Peninsula, causing serious problems for seaweed and abalone farms as well as for fisheries, tourism and recreational industries.

Spatiotemporal change in coastal waters caused by land-based fish farm wastewater-borne nutrients: Results from Jeju Island, Korea.

We investigated spatiotemporal distributions of dissolved inorganic nutrients and organic carbon (DOC) and nitrogen (DON) in coastal waters and land-based fish farm wastewater to determine effects of wastewater on seawater of Jeju Island, Korea. The nutrient concentrations in seawater were lower than in wastewater with negative correlations against salinity, indicating a terrestrial source. Wastewater-derived DOC and DON were transported offshore while wastewater-derived inorganic nutrients were effectively removed, likely via biological production, and this was closely linked to decline in N:P ratios.

The Anti-Oxidative and Anti-Neuroinflammatory Effects of by Heme Oxygenase-1 Induction in BV2 and HT22 Cells.

is used as a traditional medicinal agent and exhibits various pharmacological effects. In this study, we found that the 70% EtOH extract contained 34.37 ± 0.

UVB protective effects of Sargassum horneri through the regulation of Nrf2 mediated antioxidant mechanism.

The present study aimed to evaluate the protective effect of a methanol extract of Sargassum horneri (SHM), which contains 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one (HTT) and apo-9'-fucoxanthinone, against ultraviolet B (UVB)-induced cellular damage in human keratinocytes and its underlying mechanism. SHM significantly improved cell viability of UVB-exposed human keratinocytes by reducing the generation of intracellular reactive oxygen species (ROS). Moreover, SHM inhibited UVB exposure-induced apoptosis by reducing the formation of apoptotic bodies and the populations of the sub-G hypodiploid cells and the early apoptotic cells by modulating the expression of the anti- and pro-apoptotic molecules, Bcl-2 and Bax, respectively.

Bisphenol A: A potential Toll-like receptor 4/myeloid differentiation factor 2 complex agonist.

In addition to endocrine disruption, bisphenol A (BPA) is known to induce inflammation through the activation of nuclear factor-κB (NF-κB). However, detailed studies on the mechanism of NF-κB activation by BPA have not been sufficiently conducted. In the present study, we observed that low concentrations of BPA (≤1 μM) upregulated the release of proinflammatory mediators, including nitric oxide (NO) and prostaglandin E (PGE), as well as proinflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-12, and IL-6.

Factors controlling the distributions of dissolved organic matter in the East China Sea during summer.

To determine the distribution of dissolved organic matter (DOM) in the East China Sea (ECS) during the summer, we measured the dissolved organic carbon (DOC) and nitrogen (DON), fluorescent dissolved organic matter (FDOM), and chlorophyll a (Chl. a) in the upper 100-m layer of this region during July and September 2015. The DOC (r = 0.

Human Keratinocyte UVB-Protective Effects of a Low Molecular Weight Fucoidan from Purified by Step Gradient Ethanol Precipitation.

Ultraviolet B (UVB) radiation-induced oxidative skin cell damage is a major cause of photoaging. In the present study, a low molecular weight fucoidan fraction (SHC4) was obtained from by Celluclast-assisted extraction, followed by step gradient ethanol precipitation. The protective effect of SHC4 was investigated in human keratinocytes against UVB-induced oxidative stress.

Factors controlling the vertical zonation of the intertidal seagrass, Zostera japonica in its native range in the northwestern Pacific.

The desiccation tolerance of the intertidal seagrass Zostera japonica has been demonstrated in a number of studies; however, the factors limiting expansion of intertidal seagrass species into subtidal zones remain controversial. We transplanted Z. japonica shoots from the intermediate intertidal zone into the plots with and without Z.

GSK-3β-Targeting Fisetin Promotes Melanogenesis in B16F10 Melanoma Cells and Zebrafish Larvae through β-Catenin Activation.

Fisetin is found in many fruits and plants such as grapes and onions, and exerts anti-inflammatory, anti-proliferative, and anticancer activity. However, whether fisetin regulates melanogenesis has been rarely studied. Therefore, we evaluated the effects of fisetin on melanogenesis in B16F10 melanoma cell and zebrafish larvae.

Composition and structure of the marine benthic community in Terra Nova Bay, Antarctica: Responses of the benthic assemblage to disturbances.

The community structure and assemblages of marine benthic organisms were investigated in coastal areas near the Jang Bogo Antarctic Research Station in Terra Nova Bay during the 2012-2018 summer seasons. We also examined the recovery pattern of marine benthic organisms following disturbance due to the construction of the Jang Bogo Station. A total of 26 taxa were identified in the study area during the experimental period.

Anthocyanins from L. Inhibit Melanogenesis by Activating the ERK Signaling Pathway.

L. exhibited promising potential as a new source of food and colorants containing various anthocyanins. However, the function of anthocyanins from L.

Species composition, diversity, and distribution of the genus Ulva along the coast of Jeju Island, Korea based on molecular phylogenetic analysis.

Species diversity in the genus Ulva remains understudied worldwide. Using molecular analyses we investigated the species composition, diversity, distribution, and relative frequencies of the genus Ulva along the entire coast of Jeju Island, off the southern tip of Korea. Species identification was performed for 215 samples collected from 23 sites, based on comprehensive phylogenetic and model-based species delimitation analyses using the sequences of two molecular markers, chloroplast elongation factor Tu (tufA) and nuclear rDNA internal transcribed spacer (ITS).

The origin and population genetic structure of the 'golden tide' seaweeds, Sargassum horneri, in Korean waters.

In recent years, drifting and inundating brown seaweed (Sargassum horneri) biomass, called 'golden tides', has frequently drifted and accumulated along the southern coastlines of Korea, causing devastating impacts on the local economy and coastal ecosystems. In this study, based on combined analyses of mitochondrial DNA cox3 gene and seven microsatellites, we investigated the genetic makeup of the floating S. horneri populations (N = 14) in comparison to Korean benthic populations (N = 5), and tracked their genetic sources.

Camptothecin induces G/M phase arrest through the ATM-Chk2-Cdc25C axis as a result of autophagy-induced cytoprotection: Implications of reactive oxygen species.

In the present study, we report that camptothecin (CPT) caused irreversible cell cycle arrest at the G/M phase, and was associated with decreased levels of cell division cycle 25C (Cdc25C) and increased levels of cyclin B1, p21, and phospho-H3. Interestingly, the reactive oxygen species (ROS) inhibitor, glutathione, decreased CPT-induced G/M phase arrest and moderately induced S phase arrest, indicating that the ROS is required for the regulation of CPT-induced G/M phase arrest. Furthermore, transient knockdown of nuclear factor-erythroid 2-related factor 2 (Nrf2), in the presence of CPT, increased the ROS' level and further shifted the cell cycle from early S phase to the G/M phase, indicating that Nrf2 delayed the S phase in response to CPT.

Silibinin sensitizes TRAIL-mediated apoptosis by upregulating DR5 through ROS-induced endoplasmic reticulum stress-Ca-CaMKII-Sp1 pathway.

In this study, we addressed how silibinin enhances tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in various cancer cells. Combined treatment with silibinin and TRAIL (silibinin/TRAIL) induced apoptosis accompanied by the activation of caspase-3, caspase-8, caspase-9, and Bax, and cytosolic accumulation of cytochrome c. Anti-apoptotic proteins such as Bcl-2, IAP-1, and IAP-2 were inhibited as well.

Green tide development associated with submarine groundwater discharge in a coastal harbor, Jeju, Korea.

We measured the magnitude of submarine fresh groundwater discharge (SFGD) and associated nutrient inputs to Jocheon harbor, on Jeju Island, Korea, during four sampling periods, in order to determine the link between SFGD and Ulva sp. green tide development. Good correlations among salinity, Rn, and dissolved inorganic nitrogen (DIN) in harbor seawater suggest that SFGD is the major source of DIN and fresh water since there are no surface runoffs.

Population genetic structure of eelgrass (Zostera marina) on the Korean coast: Current status and conservation implications for future management.

Seagrasses provide numerous ecosystem services for coastal and estuarine environments, such as nursery functions, erosion protection, pollution filtration, and carbon sequestration. Zostera marina (common name "eelgrass") is one of the seagrass bed-forming species distributed widely in the northern hemisphere, including the Korean Peninsula. Recently, however, there has been a drastic decline in the population size of Z.

Glutamine deprivation sensitizes human breast cancer MDA-MB-231 cells to TRIAL-mediated apoptosis.

Tumor cell metabolism is a promising target for various cancer treatments. Apart from aerobic glycolysis, cancer cell growth is dependent on glutamine (Gln) supply, leading to their survival and differentiation. Therefore, we examined whether treatment with TNF-related apoptosis-inducing ligand (TRAIL) sensitizes MDA-MB-231 cells to apoptosis under Gln deprivation condition (TRAIL/Gln deprivation).

Exploring the Impacts of Anthropogenic Disturbance on Seawater and Sediment Microbial Communities in Korean Coastal Waters Using Metagenomics Analysis.

The coastal ecosystems are considered as one of the most dynamic and vulnerable environments under various anthropogenic developments and the effects of climate change. Variations in the composition and diversity of microbial communities may be a good indicator for determining whether the marine ecosystems are affected by complex forcing stressors. DNA sequence-based metagenomics has recently emerged as a promising tool for analyzing the structure and diversity of microbial communities based on environmental DNA (eDNA).

Caffeic acid phenethyl ester enhances TRAIL-mediated apoptosis via CHOP-induced death receptor 5 upregulation in hepatocarcinoma Hep3B cells.

Caffeic acid phenethyl ester (CAPE) exhibits various pharmaceutical properties, including anti-bacterial, anti-inflammatory, anti-viral, anti-cancer, and anti-oxidative activity. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been a promising anti-cancer agent that preferentially induces cancer cell apoptosis with negligible cytotoxicity toward normal cells. Therefore, the present study investigated whether CAPE promotes TRAIL-mediated cytotoxicity in hepatocarcinoma Hep3B cells.

Photoacclimatory Responses of Zostera marina in the Intertidal and Subtidal Zones.

Photoacclimatory responses of the seagrass Zostera marina in the intertidal and subtidal zones were investigated by measuring chlorophyll a fluorescence parameters, photosynthetic pigments, leaf δ13C values, and shoot morphology in two bay systems. Intertidal plants had higher carotenoid concentrations than subtidal plants to avoid photodamage under excess light conditions during the day. The maximum relative electron transport rate (rETRmax) and minimum saturation irradiance (Ek) of the intertidal plants were higher than those of the subtidal plants, whereas photosynthetic efficiency (α) and maximum quantum yield (Fv/Fm) were higher in subtidal plants.