Spatial and temporal variations in trophic structure of fish assemblages in the Yellow Sea revealed by C and N stable isotopes.

In this study, we assessed spatial and temporal variations in the trophic structure of fish assemblages in the Yellow Sea during spring and summer 2022 and compared their isotopic niches between the Provisional Measure Zone (PMZ) and Korea's west areas (non-PMZ) within the Yellow Sea. Spatial and temporal differences in the diversity and dominant species of fish assemblages were found between the PMZ and non-PMZ areas between the seasons. The mean δ13C values of fish assemblages were relatively higher in the non-PMZ areas than in the PMZ areas. In contrast, no significant differences were found in the mean δ15N values between the areas. Generally, the isotopic niche indices were relatively narrow in the PMZ areas compared to those in the non-PMZ areas. Overall, these spatial differences between the PMZ and non-PMZ areas suggest different trophic diversity of fish assemblages, resulting from site-specific variations in environmental conditions and community composition.

CXCL1 confers a survival advantage in Kaposi's sarcoma-associated herpesvirus-infected human endothelial cells through STAT3 phosphorylation.

Many cytokines produced by Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells have been shown to participate in the pathogenesis of KSHV. Determination of the exact role of cytokines in Kaposi's sarcoma (KS) pathogenesis is limited, however, by the difficulty to manipulate the target genes in human endothelial cells. In this study, we sought to elucidate the role of cytokines in KSHV-infected human immortalized endothelial cell line (HuARLT cells) by knockout (KO) of the corresponding target genes using the CRISPR/Cas9 system. The cytokine production profile of KSHV-infected HuARLT cells was analyzed using a protein array, and several cytokines were found to be highly upregulated following KSHV infection. This study focused on CXCL1, which was investigated by knocked out in HuARLT cells. KSHV-infected CXCL1 KO cells underwent increased cell death compared to KSHV-infected wild-type (WT) cells and mock-infected CXCL1 KO cells. Lytic replication was not observed in KSHV-infected WT nor CXCL1 KO cells. Phosphorylation of STAT3 was significantly suppressed in KSHV-infected CXCL1 KO cells. Additionally, inhibitors of STAT3 and CXCL1 induced cell death in KSHV-infected endothelial cells. Our results show that CXCL1 production is required for the survival of KSHV-infected endothelial cells, and the CXCL1 to STAT3 phosphorylation signaling pathway may be a therapeutic target for KS.

Genetic structure and dispersal in peripheral populations of a marine fish (Pacific cod, Gadus macrocephalus) and their importance for adaptation to climate change.

Small and isolated peripheral populations, which are often remnants of glacial refugia, offer an opportunity to determine the magnitude and direction of fine-scale connectivity in high gene flow marine species. When located at the equatorial edge of a species' range, these populations may also harbor genetic diversity related to survival and reproduction at higher temperatures, a critical resource for marine species facing warming ocean temperatures. Pacific cod (Gadus macrocephalus), a marine fish in the North Pacific, has already experienced major shifts in biomass and distribution linked to climate change. We estimated the magnitude and direction of connectivity between peripheral populations of Pacific cod at the southern edge of the species' range, by conducting restriction site-associated DNA (RAD) sequencing and individual assignment on fish collected around the Korean Peninsula during the spawning season. Three populations on the western, eastern, and southern Korean coasts were highly differentiated (FST  = 0.025-0.042) and relatively small (Ne  = 433-1,777). Ten putative dispersers and estimates of contemporary migration rates revealed asymmetrical, west-to-east movement around the Korean Peninsula, at a higher rate than predicted by indirect estimates of connectivity (FST ). Allele frequencies at 87 RAD loci were decisively correlated with strong marine temperature gradients between the warmer southern coast and the cooler waters of the eastern and western coasts. Despite relatively small sample sizes, our data suggest asymmetrical dispersal and gene flow, potentially involving adaptive alleles, between peripheral populations inhabiting markedly different thermal regimes. Our study emphasizes the conservation value of peripheral populations in high gene flow marine fish species.

HMGB1 Knockout Decreases Kaposi's Sarcoma-Associated Herpesvirus Virion Production in iSLK BAC16 Cells by Attenuating Viral Gene Expression.

Multiple host proteins affect the gene expression of Kaposi's sarcoma-associated herpesvirus (KSHV) during latent and lytic replication. High-mobility group box 1 (HMGB1) serves as a highly conserved chromosomal protein inside the cell and a prototypical damage-associated molecular pattern molecule outside the cell. HMGB1 has been shown to play a pathogenic role in viral infectious diseases and to regulate the lytic replication of KSHV. However, its functional effects on the KSHV life cycle in KSHV-infected cells have not been fully elucidated. Here, we explored the role of intracellular and extracellular HMGB1 in KSHV virion production by employing CRISPR/Cas9-mediated HMGB1 knockout in the KSHV-producing iSLK BAC16 cell line. Intracellular HMGB1 formed complexes with various proteins, and the abundance of HMGB1-interacting proteins changed during latent and lytic replication. Moreover, extracellular HMGB1 was found to enhance lytic replication by phosphorylating JNK. Of note, the expression of viral genes was attenuated during lytic replication in HMGB1 knockout iSLK BAC16 cells, with significantly decreased production of infectious virions compared to that of wild-type cells. Collectively, our results demonstrate that HMGB1 is an important cellular cofactor that affects the generation of infectious KSHV progeny during lytic replication. IMPORTANCE The high-mobility group box 1 (HMGB1) protein has many intra- and extracellular biological functions with an intricate role in various diseases. In certain viral infections, HMGB1 affects the viral life cycle and pathogenesis. In this study, we explored the effects of HMGB1 knockout on the production of Kaposi's sarcoma-associated herpesvirus (KSHV). HMGB1 knockout decreased virion production in KSHV-producing cells by decreasing the expression of viral genes. The processes by which HMGB1 affects KSHV production may occur inside or outside infected cells. For instance, several cellular and viral proteins interacted with intracellular HMGB1 in a nucleosomal complex, whereas extracellular HMGB1 induced JNK phosphorylation, thereby enhancing lytic replication. Our results suggest that both intracellular and extracellular HMGB1 are necessary for efficient KSHV replication. Thus, HMGB1 may represent an effective therapeutic target for the regulation of KSHV production.

Rab27b regulates extracellular vesicle production in cells infected with Kaposi's sarcoma-associated herpesvirus to promote cell survival and persistent infection.

Extracellular vesicles (EVs) play a crucial role in cell-to-cell communication. EVs and viruses share several properties related to their structure and the biogenesis machinery in cells. EVs from virus-infected cells play a key role in virus spread and suppression using various loading molecules, such as viral proteins, host proteins, and microRNAs. However, it remains unclear how and why viruses regulate EV production inside host cells. The purpose of this study is to investigate the molecular mechanisms underlying EV production and their roles in Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells. Here, we found that KSHV induced EV production in human endothelial cells via Rab-27b upregulation. The suppression of Rab27b expression in KSHV-infected cells enhanced cell death by increasing autophagic flux and autolysosome formation. Our results indicate that Rab27b regulates EV biogenesis to promote cell survival and persistent viral infection during KSHV infection, thereby providing novel insights into the crucial role of Rab-27b in the KSHV life cycle.

Dimethyl Sulfoxide Enhances Kaposi's Sarcoma-Associated Herpesvirus Production During Lytic Replication.

Kaposi's sarcoma-associated herpesvirus (KSHV) is an etiologic agent of Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman disease. In studies of KSHV, efficient virus production and isolation are essential. Reactivation of KSHV can be initiated by treating latently infected cells with chemicals, such as 12-O-tetradecanoyl-phorbol-13-acetate and sodium butyrate. These chemicals have been used as tools to induce lytic replication and viral production in KSHV-producing cell lines. Dimethyl sulfoxide (DMSO) is an organosulfur compound that is frequently used as an aprotic solvent similar to water. In experiments exploring signaling pathways in KSHV-infected cells, DMSO treatment alone as a vehicle affected the lytic gene expression of KSHV. However, to the best of our knowledge, the effects of DMSO on KSHV-producing cells have not yet been reported. Therefore, in this study, we investigated whether DMSO could be used as a reagent to enhance viral production during lytic replication in KSHV-producing cells and assessed the underlying mechanisms. The effects of DMSO on KSHV production were analyzed in iSLK BAC16 cells, which have been widely used for recombinant KSHV production. We found that the production of KSHV virions was significantly increased by treatment with DMSO during the induction of lytic replication. Mechanistically, lytic genes of KSHV were enhanced by DMSO treatment, which was correlated with virion production. Additionally, DMSO induced the phosphorylation of JNK during lytic replication, and inhibition of JNK abolished the effects of DMSO on lytic replication and virion production. Our findings showed that additional treatment with DMSO during the induction of lytic replication significantly improved the yield of KSHV production.

Adhaeribacter soli sp. nov., a bacterium isolated from soil in Korea.

Strain MA2T was isolated from a soil sample from Gijang-gun, Busan in Korea. The strain, a Gram-stain-negative aerobic bacterium, is non-motile, ovoid- or rod-shaped, catalase- and oxidase-positive, and grows at NaCl concentrations 1% (w/v), at 15-30 °C (optimum 25 °C) and at pH 6-8.5 (optimum pH 7.5). The 16S rRNA gene sequence indicates that it belongs to the genus Adhaeribacter in the family Hymenobacteraceae. Phylogenetically, its closest relatives are Adhaeribacter terrae HY02T and Adhaeribacter terreus DNG6T, to which the strain shows 16S rRNA gene sequence similarity values of 96.6 and 96.0%, respectively. The major fatty acids (> 5% of the total fatty acids) of strain MA2T are C15:0 iso, C15:0 iso-G and summed feature 4 (anteiso-C17:1 B and/or iso-C17:1 I). The only detected isoprenoid quinone of strain MA2T is MK-7. The major polar lipid was phosphatidylethanolamine. The draft genome sequence of strain MA2T has a size of 4.9 Mkb. The genomic DNA G + C content was 46.9 mol%. Based on the phylogenetic, genotypic, phenotypic and chemotaxonomic data, the strain represents a novel species of the genus Adhaeribacter, for which the name Adhaeribacter soli sp. nov. is proposed. Strain MA2T (= KCTC 72630T = NBRC 114192T) is the type strain.

Effects of different separation methods on the physical and functional properties of extracellular vesicles.

Extracellular vesicles (EVs) are small vesicles secreted from cells. They have crucial biological functions in intercellular communications and may even be biomarkers for cancer. The various methods used to isolate EVs from body fluid and cell culture supernatant have been compared in prior studies, which determined that the component yield and physical properties of isolated EVs depend largely on the isolation method used. Several novel and combined methods have been recently developed, which have not yet been compared to the established methods. Therefore, the purpose of this study is to compare the physical and functional differences in EVs isolated using a differential centrifugation method, the precipitation-based Invitrogen kit, the ExoLutE kit, and the Exodisc, of which the latter two were recently developed. We investigated the properties of EVs isolated from non-infected and Kaposi's sarcoma-associated herpesvirus-infected human umbilical vein endothelial cells using each method and determined the yields of DNA, RNA, and proteins using quantitative polymerase chain reaction and bicinchoninic acid assays. Additionally, we determined whether the biological activity of EVs correlated with the quantity or physical properties of the EVs isolated using different methods. We found that Exodisc was the most suitable method for obtaining large quantities of EVs, which might be useful for biomarker investigations, and that the EVs separated using Exodisc exhibited the highest complement activation activity. However, we also found that the functional properties of EVs were best maintained when differential centrifugation was used. Effective isolation is necessary to study EVs as tools for diagnosing cancer and our findings may have relevant implications in the field of oncology by providing researchers with data to assist their selection of a suitable isolation method.

Effects of Aluminum on the Integrity of the Intestinal Epithelium: An in Vitro and in Vivo Study.

BACKGROUND: Aluminum (Al) is the most abundant and ubiquitous metal in the environment. The main route of human exposure to Al is through food and water intake. Although human exposure to Al is common, the influence of Al on the gastrointestinal tract remains poorly understood. OBJECTIVES: We aimed to further understand the toxic effect of Al and to elucidate the underlying cellular mechanisms in the intestinal barrier. METHODS: The human intestinal epithelial cell line HT-29 and C57BL6 mice were exposed to AlCl3 at 0-16 mM (1-24h) and 5-50mg/kg body weight (13 weeks), respectively. In cell culture experiments, intracellular oxidative stress, inflammatory protein and gene expression, and intestinal epithelial permeability were measured. In animal studies, histological examination, gene expression, and myeloperoxidase (MPO) activity assays were conducted. RESULTS: Cellular oxidative stress level (superoxide production) in AlCl3-treated cells (4 mM, 3h) was approximately 38-fold higher than that of the control. Both protein and mRNA expression of tight junction (TJ) components (occludin and claudin-1) in AlCl3-treated cells (1-4 mM, 24h) was significantly lower than that of the control. Transepithelial electrical resistance (TEER) decreased up to 67% in AlCl3-treated cells (2 mM, 24h) compared with that of the control, which decreased approximately 7%. Al activated extracellular signal-regulated kinase 1/2 and nuclear factor-kappa B (NF-κB), resulting in mRNA expression of matrix metalloproteinase-9, myosin light-chain kinase, and inflammatory cytokines [tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß), and IL-6] in HT-29 cells. Moreover, oral administration of AlCl3 to mice induced pathological alteration, MPO activation, and inflammatory cytokine (TNF-α, IL-1ß, and IL-6) production in the colon. CONCLUSION: Al induced epithelial barrier dysfunction and inflammation via generation of oxidative stress, down-regulation of the TJ proteins, and production of inflammatory cytokines in HT-29 cells. In addition, Al induced toxicity in the colon by increasing the levels of inflammatory cytokines and MPO activity and induced histological damage in a mouse model. Our data suggest that Al may be a potential risk factor for human intestinal diseases. https://doi.org/10.1289/EHP5701.

Dietary supplementation with combined extracts from garlic (Allium sativum), brown seaweed (Undaria pinnatifida), and pinecone (Pinus koraiensis) improves milk production in Holstein cows under heat stress conditions.

OBJECTIVE: This study was conducted to examine the effects of a mixture of pinecone oil, garlic, and brown seaweed extracts (PGBE) on milk production traits as well as physiological and ethological parameters in Holstein cows during the summer season (24 May to 03 July 2015, Korea). METHODS: Among the extract combinations tested, we found that the level of 2,2'-azino-bis (3-ethylberzothiazoline-6-sulphonic acid) cation radical scavenging activity of the 0.16% PBGE complex at ratio of 1:1:1 (vol/vol) was comparable to that of the control (ascorbic acid; 1 mg/mL). Additionally, the PBGE complex reduced lipopolysaccharide-induced COX-2 expression in bovine mammary epithelial cells. Based on these findings, 40 lactating Holstein cows were used to measure the effects of PBGE complex at ratio of 1:1:1 (vol/vol) on milk production, immune response, metabolites, and behavior patterns by dividing the cows into two groups fed diets containing PGBE complex (n = 20; 0.016%/kg feed dry matter basis) or not containing PGBE complex (control, n = 20) for 40 d. RESULTS: Results showed that PGBE complex did not influence milk composition, eating and ear surface temperature patterns, immune response, or metabolic parameters but promoted average milk yield throughout the experimental period. Additionally, a tendency of higher total antioxidant capacity and glutathione in the PGBE group was observed compared to the those in the control. When the temperature-humidity index (THI) exceeded 72 (average THI = 73.8), PGBE complex-fed cows experiencing heat stress showed increased milk yield and a tendency of increased rumination compared to the control. CONCLUSION: We suggest that incorporation of a combined mixture of 0.016% PGBE (1:1:1 ratio, vol/vol) to diet has the potential to improve milk yield and health status of cows under mild to moderate heat stress, denoting that it might be useful as an alternative anti-stressor in the diet of dairy cows under hot conditions.

Piperlongumine Induces Cell Cycle Arrest via Reactive Oxygen Species Accumulation and IKKß Suppression in Human Breast Cancer Cells.

Piperlongumine (PL), a natural product derived from long pepper (Piper longum L.), is known to exhibit anticancer effects. However, the effect of PL on cell cycle-regulatory proteins in estrogen receptor (ER)-positive breast cancer cells is unclear. Therefore, we investigated whether PL can modulate the growth of ER-positive breast cancer cell line, MCF-7. We found that PL decreased MCF-7 cell proliferation and migration. Flow cytometric analysis demonstrated that PL induced G2/M phase cell cycle arrest. Moreover, PL significantly modulated the mRNA levels of cyclins B1 and D1, cyclin-dependent kinases 1, 4, and 6, and proliferating cell nuclear antigen. PL induced intracellular reactive oxygen species (hydrogen peroxide) accumulation and glutathione depletion. PL-mediated inhibition of IKKß expression decreased nuclear translocation of NF-κB p65. Furthermore, PL significantly increased p21 mRNA levels. In conclusion, our data suggest that PL exerts anticancer effects in ER-positive breast cancer cells by inhibiting cell proliferation and migration via ROS accumulation and IKKß suppression.

Extracellular Vesicles From KSHV-Infected Cells Stimulate Antiviral Immune Response Through Mitochondrial DNA.

Kaposi's Sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma, which is the most common cancer in acquired immune deficiency syndrome patients. KSHV contains a variety of immunoregulatory proteins. There have been many studies on the modulation of antiviral response by these immunoregulatory proteins of KSHV. However, the antiviral effects of extracellular vesicles (EVs) during de novo KSHV infection have not been investigated to our best knowledge. In this study, we showed that KSHV-infected cells induce interferon-stimulated genes (ISGs) response but not type I interferon in uninfected bystander cells using EVs. mRNA microarray analysis showed that ISGs and IRF-activating genes were prominently activated in EVs from KSHV-infected cells (KSHV EVs)-treated human endothelial cells, which were validated by RT-qPCR and western blot analysis. We also found that this response was not associated with cell death or apoptosis by virus infection. Mechanistically, the cGAS-STING pathway was linked with these KSHV EVs-mediated ISGs expressions, and mitochondrial DNA on the surface of KSHV EVs was one of the causative factors. Besides, KSHV EVs-treated cells showed lower infectivity for KSHV and viral replication activity than mock EVs-treated cells. Our results indicate that EVs from KSHV-infected cells could be an initiating factor for the innate immune response against viral infection, which may be critical to understanding the microenvironment of virus-infected cells.

Klotho plays a protective role against glomerular hypertrophy in a cell cycle-dependent manner in diabetic nephropathy.

There are few studies on the effect of klotho on podocytes in diabetic nephropathy. Thus, we tested whether klotho exerts a protective effect against glomerular injury in diabetes. Mouse podocytes were cultured in media containing 5.6 or 30 mM glucose(HG) with or without 200 pM of recombinant klotho (rKL). Additionally, 32 mice were injected intraperitoneally with either diluent( n = 16, C) or with streptozotocin ( n = 16, DM). Control and diabetic mice underwent sham operation and unilateral nephrectomy, respectively. Eight mice from each control and DM group were treated daily with 10 µg·kg-1·day-1 of rKL, using an osmotic minipump. Klotho was expressed in podocytes, and its expression was dependent on peroxisome proliferator-activateed receptor-γ (PPARγ). HG treatment increased the expression of cell cycle-related and apoptotic markers, and these were significantly attenuated by rKL; rKL inhibited the extracellular signal-regulated protein kinase-1/2 and p38 signaling pathways in HG-induced podocyte injury. However, siRNA against klotho gene in HG-treated podocytes failed to aggravate cell cycle arrest and apoptosis. When HG-treated podocytes were incubated in the high-klotho-conditioned medium from tubular epithelial cells, cell injury was significantly attenuated. This effect was not observed when klotho was inhibited by siRNA. In vivo, the expressions of cell cycle-related and apoptotic markers were increased in diabetic mice compared with controls, which were significantly decreased by rKL. Glomerular hypertrophy (GH) and increased profibrotic markers were significantly alleviated after rKL administration. These results showed that klotho was expressed in glomerular podocytes that and its expression was regulated by PPARγ. Additionally, administration of rKL attenuated GH via a cell cycle-dependent mechanism and decreased apoptosis.

Phytoncide Extracted from Pinecone Decreases LPS-Induced Inflammatory Responses in Bovine Mammary Epithelial Cells.

Mastitis is a prevalent inflammatory disease that remains one of the main causes of poor quality of milk. Phytoncides are naturally occurring anti-inflammatory compounds derived from plants and trees. To determine if treatment with phytoncide could decrease the severity of lipopolysaccharide (LPS)-induced inflammatory responses, mammary alveolar epithelial cells (MAC-T) were pretreated with phytoncide (0.02% and 0.04% (v/v)) followed by LPS treatment (1 and 25 µg/ml). The results demonstrated that phytoncide downregulated LPS-induced pro-inflammatory cyclooxygenase-2 (COX-2) expression. Additionally, LPS-induced activation of ERK1/2, p38, and Akt was attenuated by phytoncide. Treatment of cells with known pharmacological inhibitors of ERK1/2 (PD98059), p38 (SB203580), and Akt (LY294002) confirmed the association of these signaling pathways with the observed alterations in COX-2 expression. Moreover, phytoncide attenuated LPS-induced NF-κB activation and superoxide production, and, finally, treatment with phytoncide increased Nrf2 activation. Results suggest that phytoncide can decrease LPS-induced inflammation in MAC-T cells.