N-benzyl-N-methyldecan-1-amine and its derivative mitigate 2,4- dinitrobenzenesulfonic acid-induced colitis and collagen-induced rheumatoid arthritis.

As our previous study revealed that N-benzyl-N-methyldecan-1-amine (BMDA), a new molecule originated from Allium sativum, exhibits anti-neoplastic activities, we herein explored other functions of the compound and its derivative [decyl-(4-methoxy-benzyl)-methyl-amine; DMMA] including anti-inflammatory and anti-oxidative activities. Pretreatment of THP-1 cells with BMDA or DMMA inhibited tumor necrosis factor (TNF)-α and interleukin (IL)-1ß production, and blocked c-jun terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), MAPKAP kinase (MK)2 and NF-κΒ inflammatory signaling during LPS stimulation. Rectal treatment with BMDA or DMMA reduced the severity of colitis in 2,4-dinitrobenzenesulfonic acid (DNBS)-treated rat. Consistently, administration of the compounds decreased myeloperoxidase (MPO) activity (representing neutrophil infiltration in colonic mucosa), production of inflammatory mediators such as cytokine-induced neutrophil chemoattractant (CINC)-3 and TNF-α, and activation of JNK and p38 MAPK in the colon tissues. In addition, oral administration of these compounds ameliorated collagen-induced rheumatoid arthritis (RA) in mice. The treatment diminished the levels of inflammatory cytokine transcripts, and protected connective tissues through the expression of anti-oxidation proteins such as nuclear factor erythroid-related factor (Nrf)2 and heme oxygenase (HO)1. Additionally, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels did not differ between the BMDA- or DMMA-treated and control animals, indicating that the compounds do not possess liver toxicity. Taken together, these findings propose that BMDA and DMMA could be used as new drugs for curing inflammatory bowel disease (IBD) and RA.

Types of co-occurring patterns of mental health among the disaster victims in South Korea.

This study examined co-occurring patterns of mental health among disaster victims using latent profile analysis and assessed the difference between sociodemographic factors and protective factors that affect group classification. The data of 2300 disaster victims from 2019 (4th wave) NDMI (National Disaster Management Research Institute) for Long-term Survey on the Change of Life of Disaster Victims were analyzed. The latent profile analysis revealed that three profiles; High comorbid symptom (HCS) (6.2%), Medium comorbid symptom (MCS) (22.6%), and Low symptom (LS) (71.2%). The factors that explain the difference in this divided profile group were the type of disaster, hurt, income, age, elapsed years, resilience, and community resilience in the multinomial logistic regression. When individual resilience and community resilience are high, more effective in making people belong to the low comorbid symptom group. Therefore, there is a need for a strategy that promotes synergy between the two relationships while maintaining a dual focus point of view that fosters resilience at the individual and community level together.

Heating-mediated purification of active FGF21 and structure-based design of its variant with enhanced potency.

Fibroblast growth factor 21 (FGF21) has pharmaceutical potential against obesity-related metabolic disorders, including non-alcoholic fatty liver disease. Since thermal stability is a desirable factor for therapeutic proteins, we investigated the thermal behavior of human FGF21. FGF21 remained soluble after heating; thus, we examined its temperature-induced structural changes using circular dichroism (CD). FGF21 showed inter-convertible temperature-specific CD spectra. The CD spectrum at 100 °C returned to that at 20 °C when the heated FGF21 solution was cooled. Through loop swapping, the connecting loop between ß10 and ß12 in FGF21 was revealed to be associated with the unique thermal behavior of FGF21. According to surface plasmon resonance (SPR) experiments, in vitro cell-based assays, and model high-fat diet (HFD)-induced obesity studies, heated FGF21 maintained biological activities that were comparable to those of non-heated and commercial FGF21s. Based on sequence comparison and structural analysis, five point-mutations were introduced into FGF21. Compared with the wild type, the heated FGF21 variant displayed improved therapeutic potential in terms of body weight loss, the levels of hepatic triglycerides and lipids, and the degree of vacuolization of liver in HFD-fed mice.

Expression and purification of intracrine human FGF 11 and study of its FGFR-dependent biological activity.

Fibroblast growth factor 11 (FGF11) is one of intracrine FGFs (iFGFs), which function within cells. Unlike canonical FGFs, FGF11 remains intracellularly and plays biological roles in FGF receptor (FGFR)-independent manner. Here, we established an expression system of recombinant FGF11 proteins in E. coli and investigated whether the extracellular administration of FGF11 can activate cellular signaling. Human FGF11 has two isoforms, FGF11a and FGF11b, depending on the presence of nuclear localization sequences (NLSs) in the N-terminus. Because these two isoforms are unstable, we prepared an FGF11a-Mut by substituting three cysteine residues in the NLS with serine and FGF11b-ΔC with C-terminal truncation. The introduction of mutation in the NLS improved the solubility of FGF11 prepared from E. coli. Exogenous addition of FGF11b and FGF11b-ΔC to BALB3T3 increased cell proliferation, while FGF11a-Mut exerted no effect. FGF11b-ΔC showed higher cell proliferation activity and FGFR signaling than FGF11b. The cell-proliferating activities of FGF11b and FGF11b-ΔC were blocked by an FGFR1 inhibitor or a recombinant FGFR1, confirming the FGFR1-dependent extracellular activity of FGF11b. The analysis of circular dichroism suggested that the C-terminus of FGF11 has an α-helical structure, which may affect its interaction with FGFR1. These results suggest that the N-and C-terminus of recombinant FGF11 are involved in the activation of FGFR1. The above results provide novel insights into the function and mechanism of FGF11 that may aid the development of useful ligands for FGFR regulation.

The Analyses of Cetacean Virus-Responsive Genes Reveal Evolutionary Marks in Mucosal Immunity-Associated Genes.

Viruses are the most common and abundant organisms in the marine environment. To better understand how cetaceans have adapted to this virus-rich environment, we compared cetacean virus-responsive genes to those from terrestrial mammals. We identified virus-responsive gene sequences in seven species of cetaceans, which we compared with orthologous sequences in seven terrestrial mammals. As a result of evolution analysis using the branch model and the branch-site model, 21 genes were selected using at least one model. IFN-ε, an antiviral cytokine expressed at mucous membranes, and its receptor IFNAR1 contain cetacean-specific amino acid substitutions that might change the interaction between the two proteins and lead to regulation of the immune system against viruses. Cetacean-specific amino acid substitutions in IL-6, IL-27, and the signal transducer and activator of transcription (STAT)1 are also predicted to alter the mucosal immune response of cetaceans. Since mucosal membranes are the first line of defense against the external environment and are involved in immune tolerance, our analysis of cetacean virus-responsive genes suggests that genes with cetacean-specific mutations in mucosal immunity-related genes play an important role in the protection and/or regulation of immune responses against viruses.

α-Poly-L-lysine functions as an adipogenic inducer in 3T3-L1 preadipocytes.

α-Poly-L-lysine (PLL) has been used for various purposes such as cell attachment, immunization, and molecular delivery, and is known to be cytotoxic to several cell lines. Here, we studied the effect of PLL on the adipogenesis of 3T3-L1 cells and investigated the underlying mechanism. Differentiation media containing PLL with a molecular weight (MW) greater than 4 kDa enhanced lipid droplet formation and increased adipogenic marker levels, indicating an increase in adipocyte differentiation. PLL with a molecular weight between 30 and 70 kDa was more effective than PLL of other sizes in 3T3-L1 cell differentiation. Moreover, PLL induced 3T3-L1 adipogenesis in insulin-free adipocyte differentiation medium. Incubation with insulin and PLL exhibited greater adipogenesis than insulin treatment only even at a high concentration. PLL stimulated insulin signaling and augmented the signaling pathway when it was added with insulin. While PLL did not activate the glucocorticoid receptor, which is phosphorylated by dexamethasone (DEX), it showed a positive effect on the cAMP signal pathway when preadipocytes were treated with PLL and 3-isobutyl-1-methylxanthine (IBMX). Consistent with these results, incubation with PLL and DEX without IBMX induced adipocyte differentiation. We also observed that the mitotic clonal expansion phase was the critical stage in adipogenesis for inducing the effects of PLL. These results suggest that PLL functions as an adipogenic inducer in 3T3-L1 preadipocytes and PLL has a direct effect on insulin signaling, one of the main regulatory pathways.

FGF11 influences 3T3-L1 preadipocyte differentiation by modulating the expression of PPARγ regulators.

Fibroblast growth factor 11 (FGF11) is a member of the intracellular fibroblast growth factor superfamily. Here, we identified FGF11 as a novel mediator of adipogenesis. During 3T3-L1 adipocyte differentiation, the expression of FGF11 decreased at the mitotic clonal expansion stage and increased at the terminal differentiation stage. FGF11 knockdown reduced the expression of peroxisome proliferator-activated receptor gamma (PPARγ), a master regulator of adipogenesis, resulting in the inhibition of adipocyte differentiation. Treatment with the PPARγ agonist rosiglitazone restored the inhibition of adipogenesis caused by FGF11 knockdown. We also report that the expression of the PPARγ regulators CCAAT/enhancer-binding protein α, sterol regulatory element-binding protein 1, KLF9, KLF2, GATA binding factor 2, and GATA binding factor 3 was influenced by FGF11. These results suggest that FGF11 indirectly controls the expression of PPARγ through modifying the expression of multiple PPARγ regulators, thereby mediating adipogenesis.

MD001, a Novel Peroxisome Proliferator-activated Receptor α/γ Agonist, Improves Glucose and Lipid Metabolism.

Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have been developed to treat metabolic diseases; however, most of them exhibit side effects such as body weight gain and oedema. Therefore, we developed a novel PPARα/γ dual agonist that modulates glucose and lipid metabolism without adverse effects. We synthesised novel compounds composed of coumarine and chalcone, determined their crystal structures, and then examined their binding affinity toward PPARα/γ. We investigated the expression of PPARα and PPARγ target genes by chemicals in HepG2, differentiated 3T3-L1, and C2C12 cells. We examined the effect of chemicals on glucose and lipid metabolism in db/db mice. Only MD001 functions as a PPARα/γ dual agonist in vitro. MD001 increased the transcriptional activity of PPARα and PPARγ, resulting in enhanced expression of genes related to ß-oxidation and fatty acid and glucose uptake. MD001 significantly improved blood metabolic parameters, including triglycerides, free fatty acids, and glucose, in db/db mice. In addition, MD001 ameliorated hepatic steatosis by stimulating ß-oxidation in vitro and in vivo. Our results demonstrated the beneficial effects of the novel compound MD001 on glucose and lipid metabolism as a PPARα/γ dual agonist. Consequently, MD001 may show potential as a novel drug candidate for the treatment of metabolic disorders.

iMGEins: detecting novel mobile genetic elements inserted in individual genomes.

BACKGROUND: Recent advances in sequencing technology have allowed us to investigate personal genomes to find structural variations, which have been studied extensively to identify their association with the physiology of diseases such as cancer. In particular, mobile genetic elements (MGEs) are one of the major constituents of the human genomes, and cause genome instability by insertion, mutation, and rearrangement. RESULT: We have developed a new program, iMGEins, to identify such novel MGEs by using sequencing reads of individual genomes, and to explore the breakpoints with the supporting reads and MGEs detected. iMGEins is the first MGE detection program that integrates three algorithmic components: discordant read-pair mapping, split-read mapping, and insertion sequence assembly. Our evaluation results showed its outstanding performance in detecting novel MGEs from simulated genomes, as well as real personal genomes. In detail, the average recall and precision rates of iMGEins are 96.67 and 100%, respectively, which are the highest among the programs compared. In the testing with real human genomes of the NA12878 sample, iMGEins shows the highest accuracy in detecting MGEs within 20 bp proximity of the breakpoints annotated. CONCLUSION: In order to study the dynamics of MGEs in individual genomes, iMGEins was developed to accurately detect breakpoints and report inserted MGEs. Compared with other programs, iMGEins has valuable features of identifying novel MGEs and assembling the MGEs inserted.

Optimizing T4 DNA polymerase conditions enhances the efficiency of one-step sequence- and ligation-independent cloning.

Previously, we developed a one-step sequence- and ligation-independent cloning (SLIC) method that is simple, fast, and cost-effective. However, although one-step SLIC generally works well, its cloning efficiency is occasionally poor, potentially due to formation of stable secondary structures within the single-stranded DNA (ssDNA) region generated by T4 DNA polymerase during the 2.5 min treatment at room temperature. To overcome this problem, we developed a modified thermo-regulated one-step SLIC approach by testing shorter T4 DNA polymerase treatment durations (5 s-2.5 min) over a wide range of temperatures (25-75°C). The highest cloning efficiency resulted when inserts with homology lengths <20 bases were treated with T4 DNA polymerase for 30 s at 50°C. This briefer T4 polymerase treatment at a higher temperature helps increase cloning efficiency for inserts with strong secondary structures at their ends, increasing the utility of one-step SLIC for the cloning of short fragments.

Analysis of the FGF gene family provides insights into aquatic adaptation in cetaceans.

Cetacean body structure and physiology exhibit dramatic adaptations to their aquatic environment. Fibroblast growth factors (FGFs) are a family of essential factors that regulate animal development and physiology; however, their role in cetacean evolution is not clearly understood. Here, we sequenced the fin whale genome and analysed FGFs from 8 cetaceans. FGF22, a hair follicle-enriched gene, exhibited pseudogenization, indicating that the function of this gene is no longer necessary in cetaceans that have lost most of their body hair. An evolutionary analysis revealed signatures of positive selection for FGF3 and FGF11, genes related to ear and tooth development and hypoxia, respectively. We found a D203G substitution in cetacean FGF9, which was predicted to affect FGF9 homodimerization, suggesting that this gene plays a role in the acquisition of rigid flippers for efficient manoeuvring. Cetaceans utilize low bone density as a buoyancy control mechanism, but the underlying genes are not known. We found that the expression of FGF23, a gene associated with reduced bone density, is greatly increased in the cetacean liver under hypoxic conditions, thus implicating FGF23 in low bone density in cetaceans. Altogether, our results provide novel insights into the roles of FGFs in cetacean adaptation to the aquatic environment.

FGF11 induced by hypoxia interacts with HIF-1α and enhances its stability.

Fibroblast growth factor 11 (FGF11) is an intracellular FGF. Although induction of FGF11 by hypoxia has been observed in several cell types, the molecular function of FGF11 is not clearly understood yet. Here, we investigated the role of FGF11 under hypoxia. We identified hypoxia-inducible factor-1α (HIF-1α) as an interacting protein of FGF11 using immunoprecipitation and mass spectrometry. FGF11 knockdown decreased HIF-1α protein, while FGF11 overexpression increased it, without affecting HIF-1α mRNA. Protein stability test and ubiquitination assay showed that FGF11 increased HIF-1α stability by acting upstream of proteasomal degradation. Altogether, these results suggest a cross-regulation between HIF-1α and FGF11, through which hypoxia-induced FGF11 reinforces hypoxia responses by enhancing the stability of HIF-1α.

Light-induced negative differential resistance in graphene/Si-quantum-dot tunneling diodes.

One of the interesing tunneling phenomena is negative differential resistance (NDR), the basic principle of resonant-tunneling diodes. NDR has been utilized in various semiconductor devices such as frequency multipliers, oscillators, relfection amplifiers, logic switches, and memories. The NDR in graphene has been also reported theoretically as well as experimentally, but should be further studied to fully understand its mechanism, useful for practical device applications. Especially, there has been no observation about light-induced NDR (LNDR) in graphene-related structures despite very few reports on the LNDR in GaAs-based heterostructures. Here, we report first observation of LNDR in graphene/Si quantum dots-embedded SiO2 (SQDs:SiO2) multilayers (MLs) tunneling diodes. The LNDR strongly depends on temperature (T) as well as on SQD size, and the T dependence is consistent with photocurrent (PC)-decay behaviors. With increasing light power, the PC-voltage curves are more structured with peak-to-valley ratios over 2 at room temperature. The physical mechanism of the LNDR, governed by resonant tunneling of charge carriers through the minibands formed across the graphene/SQDs:SiO2 MLs and by their nonresonant phonon-assisted tunneling, is discussed based on theoretical considerations.

F-box only protein 9 is an E3 ubiquitin ligase of PPARγ.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a critical regulator of carbohydrate and lipid metabolism, adipocyte differentiation and inflammatory response. Post-translational modification of PPARγ and its degradation involve several pathways, including the ubiquitin-proteasome system. Here, we identified F-box only protein 9 (FBXO9) as an E3 ubiquitin ligase of PPARγ. We screened interacting partners of PPARγ using immunoprecipitation and mass spectrometric analysis and identified FBXO9 as an E3 ubiquitin ligase of PPARγ. FBXO9 directly interacted with PPARγ through the activation function-1 domain and ligand-binding domain. FBXO9 decreased the protein stability of PPARγ through induction of ubiquitination. We found that the F-box motif of FBXO9 was required for its ubiquitination function. The activity of PPARγ was significantly decreased by FBXO9 overexpression. Furthermore, FBXO9 overexpression in 3T3-L1 adipocytes resulted in decreased levels of endogenous PPARγ and suppression of adipogenesis. These results suggest that FBXO9 is an important enzyme that regulates the stability and activity of PPARγ through ubiquitination.

Hypoxia-induced fibroblast growth factor 11 stimulates capillary-like endothelial tube formation.

Low oxygen or hypoxia can be observed in the central region of solid tumors. Hypoxia is a strong stimulus for new blood vessel formation or angiogenesis, which is essential for tumor growth and progression. Fibroblast growth factor 11 (FGF11) is an intracellular non-secretory FGF whose function has not yet been fully characterized. In the present study, we demonstrated that FGF11 expression is upregulated under hypoxic conditions in human umbilical vein endothelial cells (HUVECs). FGF11 overexpression stimulated capillary-like tube formation, yet did not affect cell migration. Notably, FGF11 markedly increased the levels of tight junction proteins including occludin, zonula occludens-1 (ZO-1) and claudin-5 in HUVECs. The FGF11 promoter contains hypoxia response elements (HREs), and hypoxia-inducible factor-1 (HIF-1) binds to HREs to activate hypoxia-related genes. We demonstrated that hypoxia or HIF-1 expression under normoxic conditions increased the luciferase activity driven by the FGF11 promoter. However, deletion of the HREs from the FGF11 promoter rendered reporter gene activity unresponsive to hypoxia or HIF-1. Taken together, we propose that FGF11 may be involved in the stabilization of capillary-like tube structures associated with angiogenesis and may act as a modulator of hypoxia-induced pathological processes such as tumorigenesis.

Graphene/Si-quantum-dot heterojunction diodes showing high photosensitivity compatible with quantum confinement effect.

Graphene/Si quantum dot (QD) heterojunction diodes are reported for the first time. The photoresponse, very sensitive to variations in the size of the QDs as well as in the doping concentration of graphene and consistent with the quantum-confinement effect, is remarkably enhanced in the near-ultraviolet range compared to commercially available bulk-Si photodetectors. The photoresponse proves to be dominated by the carriertunneling mechanism.

Near-ultraviolet-sensitive graphene/porous silicon photodetectors.

Porous silicon (PSi) is recognized as an attractive building block for photonic devices because of its novel properties including high ratio of surface to volume and high light absorption. We first report near-ultraviolet (UV)-sensitive graphene/PSi photodetectors (PDs) fabricated by utilizing graphene and PSi as a carrier collector and a photoexcitation layer, respectively. Thanks to high light absorption and enlarged energy-band gap of PSi, the responsivity (Ri) and quantum efficiency (QE) of the PDs are markedly enhanced in the near-UV range. The performances of PDs are systemically studied for various porosities of PSi, controlled by varying the electroless-deposition time (td) of Ag nanoparticles for the use of Si etching. Largest gain is obtained at td = 3 s, consistent with the maximal enhancement of Ri and QE in the near UV range, which originates from the well-defined interface at the graphene/PSi junction, as proved by atomic- and electrostatic-force microscopies. Optimized response speed is ∼10 times faster compared to graphene/single-crystalline Si PDs. These and other unique PD characteristics prove to be governed by typical Schottky diode-like transport of charge carriers at the graphene/PSi junctions, based on bias-dependent variations of the band profiles, resulting in novel dark- and photocurrent behaviors.

High-performance graphene-quantum-dot photodetectors.

Graphene quantum dots (GQDs) have received much attention due to their novel phenomena of charge transport and light absorption/emission. The optical transitions are known to be available up to ~6 eV in GQDs, especially useful for ultraviolet (UV) photodetectors (PDs). Thus, the demonstration of photodetection gain with GQDs would be the basis for a plenty of applications not only as a single-function device in detecting optical signals but also a key component in the optoelectronic integrated circuits. Here, we firstly report high-efficient photocurrent (PC) behaviors of PDs consisting of multiple-layer GQDs sandwiched between graphene sheets. High detectivity (>10(11) cm Hz(1/2)/W) and responsivity (0.2 ~ 0.5 A/W) are achieved in the broad spectral range from UV to near infrared. The observed unique PD characteristics prove to be dominated by the tunneling of charge carriers through the energy states in GQDs, based on bias-dependent variations of the band profiles, resulting in novel dark current and PC behaviors.

Enhancement of the effectiveness of graphene as a transparent conductive electrode by AgNO3 doping.

Single-layer graphene sheets have been synthesized by using chemical vapor deposition, and subsequently doped with AgNO3 at various doping concentrations (n(D)) from 5 to 50 mM. Atomic force microscopy and field emission scanning electron microscopy images reveal the formation of ∼10-100 nm Ag particles on the graphene surface after doping. The type of n doping is confirmed by analyzing the n(D)-dependent behaviors of Raman scattering and the work function of the doped graphene films. The sheet resistance monotonically decreases to ∼173 Ω/sq with the increase of n(D) to 50 mM, and the transmittance is reduced by only about 3% for the highest n(D). At n(D) = 10 mM optimized doped graphene layers with a sheet resistance of 202 Ω/sq and a transmittance of 96% are obtained, resulting in a maximum DC conductivity/optical conductivity ratio (σ(DC)/σ(OP)) of ∼45.5, much larger than the minimum industry standard (σ(DC)/σ(OP) = ∼35) for transparent conductive electrodes.

Herpesvirus-associated ubiquitin-specific protease (HAUSP) modulates peroxisome proliferator-activated receptor γ (PPARγ) stability through its deubiquitinating activity.

The peroxisome proliferator-activated receptor γ (PPARγ) is a central regulator of adipogenesis and modulates glucose and lipid metabolism. In this study, herpesvirus-associated ubiquitin-specific protease (HAUSP) was isolated as a binding partner of PPARγ. Both endogenous and exogenous PPARγ associated with HAUSP in co-immunoprecipitation analysis. HAUSP, but not the catalytically inactive HAUSP C223S mutant, increased the stability of both endogenous and exogenous PPARγ through its deubiquitinating activity. Site-directed mutagenesis experiments showed that the Lys(462) residue of PPARγ is critical for ubiquitination. HBX 41,108, a specific inhibitor of HAUSP, abolished the increase in PPARγ stability induced by HAUSP. In addition, knockdown of endogenous HAUSP using siRNA decreased PPARγ protein levels. HAUSP enhanced the transcriptional activity of both exogenous and endogenous PPARγ in luciferase activity assays. Quantitative RT-PCR analysis showed that HAUSP increased the transcript levels of PPARγ target genes in HepG2 cells, resulting in the enhanced uptake of glucose and fatty acids, and vice versa, upon siRNA knockdown of HAUSP. In vivo analysis using adenoviruses confirmed that HAUSP, but not the HAUSP C223S mutant, decreased blood glucose and triglyceride levels, which are associated with the increased expression of endogenous PPARγ and lipid accumulation in the liver. Our results demonstrate that the stability and activity of PPARγ are modulated by the deubiquitinating activity of HAUSP, which may be a target for the development of anti-diabetic drugs.