Brown Algae Dictyopteris divaricata Attenuates Adipogenesis by Modulating Adipocyte Differentiation and Promoting Lipolysis through Heme Oxygenase-1 Activation in 3T3-L1 Cells.

The present study aims to explore the probable anti-adipogenesis effect of Dictyopteris divaricata (D. divaricata) in 3T3-L1 preadipocytes by regulating heme oxygenase-1 (HO-1). The extract of D. divaricata retarded lipid accretion and decreased triglyceride (TG) content in 3T3-L1 adipocytes but increased free glycerol levels. Treatment with the extract inhibited lipogenesis by inhibiting protein expressions of fatty acid synthase (FAS) and lipoprotein lipase (LPL), whereas lipolysis increased by activating phosphorylation of hormone-sensitive lipase (p-HSL) and AMP-activated protein kinase (p-AMPK). The extract inhibited adipocyte differentiation of 3T3-L1 preadipocytes through down-regulating adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1). This is attributed to the triggering of Wnt/ß-catenin signaling. In addition, this study found that treatment with the extract activated HO-1 expression. Pharmacological approaches revealed that treatment with Zinc Protoporphyrin (ZnPP), an HO-1 inhibitor, resulted in an increase in lipid accumulation and a decrease in free glycerol levels. Finally, three adipogenic transcription factors, such as PPARγ, C/EBPα, and SREBP1, restored their expression in the presence of ZnPP. Analysis of chemical constituents revealed that the extract of D. divaricata is rich in 1,4-benzenediol, 7-tetradecenal, fucosterol, and n-hexadecanoic acid, which are known to have multiple pharmacological properties.

The CUL3A-LFH1-UBC15 ubiquitin ligase complex mediates SHORT VEGETATIVE PHASE degradation to accelerate flowering at high ambient temperature.

Ambient temperature affects flowering time in plants, and the MADS-box transcription factor SHORT VEGETATIVE PHASE (SVP) plays a crucial role in the response to changes in ambient temperature. SVP protein stability is regulated by the 26S proteasome pathway and decreases at high ambient temperature, but the details of SVP degradation are unclear. Here, we show that SVP degradation at high ambient temperature is mediated by the CULLIN3-RING E3 ubiquitin ligase (CRL3) complex in Arabidopsis thaliana. We identified a previously uncharacterized protein that interacts with SVP at high ambient temperature and contains a BTB/POZ domain. We named this protein LATE FLOWERING AT HIGH TEMPERATURE 1 (LFH1). Single mutants of LFH1 or CULLIN3A (CUL3A) showed late flowering specifically at 27°C. LFH1 protein levels increased at high ambient temperature. We found that LFH1 interacts with CUL3A in the cytoplasm and is important for SVP-CUL3A complex formation. Mutations in CUL3A and/or LFH1 led to increased SVP protein stability at high ambient temperature, suggesting that the CUL3-LFH1 complex functions in SVP degradation. Screening E2 ubiquitin-conjugating enzymes (UBCs) using RING-BOX PROTEIN 1 (RBX1), a component of the CRL3 complex, as bait identified UBC15. ubc15 mutants also showed late flowering at high ambient temperature. In vitro and in vivo ubiquitination assays using recombinant CUL3A, LFH1, RBX1, and UBC15 showed that SVP is highly ubiquitinated in an ATP-dependent manner. Collectively, these results indicate that the degradation of SVP at high ambient temperature is mediated by a CRL3 complex comprising CUL3A, LFH1, and UBC15.

Ubiquitin ligase RNF20 coordinates sequential adipose thermogenesis with brown and beige fat-specific substrates.

In mammals, brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT) execute sequential thermogenesis to maintain body temperature during cold stimuli. BAT rapidly generates heat through brown adipocyte activation, and further iWAT gradually stimulates beige fat cell differentiation upon prolonged cold challenges. However, fat depot-specific regulatory mechanisms for thermogenic activation of two fat depots are poorly understood. Here, we demonstrate that E3 ubiquitin ligase RNF20 orchestrates adipose thermogenesis with BAT- and iWAT-specific substrates. Upon cold stimuli, BAT RNF20 is rapidly downregulated, resulting in GABPα protein elevation by controlling protein stability, which stimulates thermogenic gene expression. Accordingly, BAT-specific Rnf20 suppression potentiates BAT thermogenic activity via GABPα upregulation. Moreover, upon prolonged cold stimuli, iWAT RNF20 is gradually upregulated to promote de novo beige adipogenesis. Mechanistically, iWAT RNF20 mediates NCoR1 protein degradation, rather than GABPα, to activate PPARγ. Together, current findings propose fat depot-specific regulatory mechanisms for temporal activation of adipose thermogenesis.

Poly(vinyl alcohol)/chitosan hydrogel incorporating chitooligosaccharide-gentisic acid conjugate with antioxidant and antibacterial properties as a potential wound dressing.

The design and development of wound dressing with antioxidant and antibacterial properties to accelerate wound healing remain challenging. In this study, we synthesize a chitooligosaccharide-gentisic acid (COS-GSA) conjugate using the free-radical grafting method, and fabricate a poly(vinyl alcohol) (PVA)/chitosan (CH)/COS-GSA (PVA/CH/CG) hydrogel using a freeze-thaw method. We characterize the synthesized COS-GSA conjugates using through polyphenol assay, absorbance, and 1H NMR spectroscopy and evaluate their antioxidant properties. The COS-GSA conjugates are successfully synthesized and exhibit better antioxidant properties than pristine COSs. Subsequently, the fabricated hydrogel is characterized based on its morphological analysis, rheological properties, water contact angle, swelling, degradation, water retention properties, and COS-GSA release profiles. Finally, the biocompatibility of the fabricated hydrogel is evaluated on HDF and HaCaT cells through indirect and direct cytotoxicity. The PVA/CH/CG hydrogel exhibited significantly higher antioxidant properties (DPPH, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydrogen peroxide (H2O2) scavenging activities) and antibacterial activities (Staphylococcus aureus and Pseudomonas aeruginosa) compared to other fabricated hydrogels such as PVA, PVA/CH, and PVA/CH/COS (PVA/CH/C). These results provide evidence that PVA/CH/CG hydrogels with antioxidant, antibacterial, and non-cytotoxic properties have great potential for wound-dressing applications.

Chemical constituents of the culture broth of Dentipellis fragilis and their anti-inflammatory activities.

Seven undescribed compounds, dentipellinones A‒D (1, 2, 5, and 6), dentipellinol (3), methoxyerinaceolactone B (4), and erinaceolactomer A (7), were isolated from the culture broth of Dentipellis fragilis. Chemical structures of these isolated compounds were determined by analyses of 1D and 2D-NMR and MS data in comparison with data reported in the literature. Absolute configurations of 1‒7 were also determined by Electronic Circular Dichroism calculations. The isolated compounds were evaluated for their anti-inflammatory effects on NO production and pro-inflammatory cytokines levels in LPS-stimulated RAW264.7 cells. Compounds 5 and 7 were evaluated for their anti-inflammatory effects on NO production and pro-inflammatory cytokine levels in LPS-stimulated RAW264.7 cells. They exhibited inhibitory effects on LPS-induced NO production in a dose-dependent manner, and significantly reduced the levels of inflammatory-related cytokines such as IL-1ß and IL-6. TNF-α was not involved in the anti-inflammatory effects of these compounds. Finally, compounds 5 and 7 showed significant anti-inflammatory effects.

Angiotensin I-Converting Enzyme (ACE) Inhibition and Molecular Docking Study of Meroterpenoids Isolated from Brown Alga, Sargassum macrocarpum.

Angiotensin I-converting enzyme (ACE) is an important blood pressure regulator. In this study, we aimed to investigate the ACE-inhibitory effects of meroterpenoids isolated from the brown alga, Sargassum macrocarpum, and the molecular mechanisms underlying ACE inhibition. Four fractions of S. macrocarpum were prepared using hexane, chloroform, ethyl acetate, and water as solvents and analyzed for their potential ACE-inhibitory effects. The chloroform fraction showed the strongest ACE-inhibitory effect, with an IC50 value of 0.18 mg/mL. Three meroterpenoids, sargachromenol, 7-methyl sargachromenol, and sargaquinoic acid, were isolated from the chloroform fraction. Meroterpenoids isolated from S. macrocarpum had IC50 values of 0.44, 0.37, and 0.14 mM. The molecular docking study revealed that the ACE-inhibitory effect of the isolated meroterpenoids was mainly attributed to Zn-ion, hydrogen bonds, pi-anion, and pi-alkyl interactions between the meroterpenoids and ACE. These results suggest that S. macrocarpum could be a potential raw material for manufacturing antihypertensive nutraceutical ingredients.

Chloroplasts prevent precocious flowering through a GOLDEN2-LIKE-B-BOX DOMAIN PROTEIN module.

The timing of flowering is tightly controlled by signals that integrate environmental and endogenous cues. Sugars produced by carbon fixation in the chloroplast are a crucial endogenous cue for floral initiation. Chloroplasts also convey information directly to the nucleus through retrograde signaling to control plant growth and development. Here, we show that mutants defective in chlorophyll biosynthesis and chloroplast development flowered early, especially under long-day conditions, although low sugar accumulation was seen in some mutants. Plants treated with the bleaching herbicide norflurazon also flowered early, suggesting that chloroplasts have a role in floral repression. Among retrograde signaling mutants, the golden2-like 1 (glk1) glk2 double mutants showed early flowering under long-day conditions. This early flowering was completely suppressed by constans (co) and flowering locus t (ft) mutations. Leaf vascular-specific knockdown of both GLK1 and GLK2 phenocopied the glk1 glk2 mutants. GLK1 and GLK2 repress flowering by directly activating the expression of B-BOX DOMAIN PROTEIN 14 (BBX14), BBX15, and BBX16 via CCAATC cis-elements in the BBX genes. BBX14/15/16 physically interact with CO in the nucleus, and expression of BBXs hampered CO-mediated FT transcription. Simultaneous knockdown of BBX14/15/16 by artificial miRNA (35S::amiR-BBX14/15/16) caused early flowering with increased FT transcript levels, whereas BBX overexpression caused late flowering. Flowering of glk1/2 and 35S::amiR-BBX14/15/16 plants was insensitive to norflurazon treatment. Taking these observations together, we propose that the GLK1/2-BBX14/15/16 module provides a novel mechanism explaining how the chloroplast represses flowering to balance plant growth and reproductive development.

Antioxidant potential of hydrolysate-derived seahorse (Hippocampus abdominalis) peptide: Protective effects against AAPH-induced oxidative damage in vitro and in vivo.

In this study, seahorse peptide (SHP) was isolated from an alcalase-treated hydrolysate from Hippocampus abdominalis and assessed for its antioxidant potential against AAPH-induced oxidative stress damage. AAPH stimulation significantly decreased cell viability and increased intracellular reactive oxygen species (ROS) production in Vero cells. SHP treatment increased cell viability and remarkably lowered ROS production under AAPH-induced oxidative stress. Furthermore, it protected against AAPH-induced apoptotic DNA damage. Western blot analysis demonstrated that SHP treatment remarkably increased the protein expression levels of catalase and SOD in AAPH-induced Vero cells. A zebrafish study revealed that SHP-treated zebrafish embryos resulted in lower cell death, ROS generation, and lipid peroxidation than the AAPH-treated group. These results suggest that SHP is a potent functional antioxidant that could be developed as a natural antioxidant in the food and functional food industries.

p-Terphenyl glucosides from the culture broth of Phlebiopsis castanea.

A new p-terphenyl derivative, hydroxystrepantibin D (1), was isolated along with two known p-terphenyls (2 and 3) from the culture broth of Phlebiopsis castanea. These compounds were isolated using silica gel column chromatography, reversed-phase medium-pressure liquid chromatography, Sephadex LH-20 column chromatography, and preparative HPLC. Their structures were determined based on spectroscopic methods. These compounds exhibited free radical scavenging activities with IC50 values in the range from 22.2 to 158.4 µM against 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and in the range from 161.1 to 356.1 µM against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.

VLDL-VLDLR axis facilitates brown fat thermogenesis through replenishment of lipid fuels and PPARß/δ activation.

In mammals, brown adipose tissue (BAT) is specialized to conduct non-shivering thermogenesis for survival under cold acclimation. Although emerging evidence suggests that lipid metabolites are essential for heat generation in cold-activated BAT, the underlying mechanisms of lipid uptake in BAT have not been thoroughly understood. Here, we show that very-low-density lipoprotein (VLDL) uptaken by VLDL receptor (VLDLR) plays important roles in thermogenic execution in BAT. Compared with wild-type mice, VLDLR knockout mice exhibit impaired thermogenic features. Mechanistically, VLDLR-mediated VLDL uptake provides energy sources for mitochondrial oxidation via lysosomal processing, subsequently enhancing thermogenic activity in brown adipocytes. Moreover, the VLDL-VLDLR axis potentiates peroxisome proliferator activated receptor (PPAR)ß/δ activity with thermogenic gene expression in BAT. Accordingly, VLDL-induced thermogenic capacity is attenuated in brown-adipocyte-specific PPARß/δ knockout mice. Collectively, these data suggest that the VLDL-VLDLR axis in brown adipocytes is a key factor for thermogenic execution during cold exposure.

Antifibrosis Efficacy of Apo-9-Fucoxanthinone-Contained Sargassum horneri Ethanol Extract on Nasal Polyp: An In Vitro and Ex Vivo Organ Culture Assay.

Sargassum horneri is a seaweed species with diverse bioactivities. However, its antifibrotic effects during nasal polyp (NP) formation are not clearly understood. Therefore, we investigated the inhibitory effect of S. horneri on fibrosis progression in NP-derived fibroblasts (NPDFs) and NP tissues ex vivo. NPDFs were stimulated with TGF-ß1 in the presence or absence of S. horneri ethanol extract (SHE). The extracellular matrix (ECM) protein production levels, myofibroblast differentiation (α-smooth muscle actin, α-SMA), and phosphorylation of Smad 2/3 and -ERK in TGF-ß1-stimulated NPDFs were investigated using western blotting. Further, the contractile activity of SHE was assessed by performing a collagen gel contraction assay. The expression levels of collagen-1, fibronectin, and α-SMA were investigated in NP organ cultures treated with SHE. TGF-ß1 stimulated ECM protein expression, myofibroblast differentiation, and collagen contractile activity while these were attenuated by pretreatment with SHE. We also found antifibrotic effect of SHE on ex vivo NP tissues. The antifibrotic effects of SHE were modulated through the attenuation of Smad 2/3 and ERK signaling pathways in TGF-ß1-stimulated NPDFs. In conclusion, SHE inhibited ECM protein accumulation and myofibroblast differentiation during NP remodeling. Thus, SHE may be helpful as a treatment for NP recurrence after endoscopic sinus surgery.

Sargachromenol Isolated from Sargassum horneri Attenuates Glutamate-Induced Neuronal Cell Death and Oxidative Stress through Inhibition of MAPK/NF-κB and Activation of Nrf2/HO-1 Signaling Pathway.

Oxidative stress-induced neuronal cell loss is considered to be the major mechanism underlying the pathogenesis of neurodegenerative diseases, which could be induced by a high concentration of glutamate. In this study, sargachromenol (SC) was isolated from a marine brown seaweed Sargassum horneri (S. horneri) and its neuroprotective effects against glutamate-induced oxidative stress in HT22 cells were investigated. An MTT assay was applied to assess the cytotoxicity of the SC, and the efficacies of SC were determined by flow cytometry, an analysis of ROS production, quantitative Real-Time PCR, and the Western blot assay. Our results showed that the pretreatment of SC reduced glutamate-induced apoptosis in HT22 cells via inhibiting the sub-G1 population, DNA fragmentation, and nuclear condensation, as well as up-regulating anti-apoptotic protein (Bcl-2) and down-regulating apoptotic proteins (Bax, p53, cleaved-PARP, caspase-3, caspase-9, and cytochrome c). Additionally, SC attenuated glutamate-induced oxidative stress by suppressing mitogen-activated protein kinases (MAPKs;ERK, JNK, and p38) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling (IκBα and NF-κB p65), while activating nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) signaling (Nrf2; HO-1, and NQO-1). Our results suggest that SC could be used as a pharmacological candidate for the prevention and treatment of neurodegenerative diseases.

Isolation and Characterization of Efficient Active Compounds Using High-Performance Centrifugal Partition Chromatography (CPC) from Anti-Inflammatory Activity Fraction of Ecklonia maxima in South Africa.

Ecklonia maxima is a brown seaweed, which is abundantly distributed in South Africa. This study investigated an efficient approach using high-performance centrifugal partition chromatography (HPCPC), which has been successfully developed for the isolation and purification of phlorotannins, eckmaxol, and dieckol from the ethyl acetate fraction of E. maxima (EEM). We evaluated EEM for its inhibitory effect against lipopolysaccharide (LPS)-induced inflammatory responses in zebrafish embryos. The separation of eckmaxol and dieckol from samples of EEM using HPCPC was found to be of high purity and yield under an optimal solvent system composed of n-hexane:ethyl acetate:methanol:water (2:7:3:7, v/v/v/v). To evaluate the anti-inflammatory efficacy of EEM containing active compounds, zebrafish embryos exposed to LPS were compared with and without EEM treatment for nitric oxide (NO) production, reactive oxygen species (ROS) generation, and cell death two days after fertilization. These evaluations indicate that EEM alleviated inflammation by inhibiting cell death, ROS, and NO generation induced by LPS treatment. According to these results, eckmaxol and dieckol isolated from brown seaweed E. maxima could be considered effective anti-inflammatory agents as pharmaceutical and functional food ingredients.

Antihypertensive Effects of IGTGIPGIW Peptide Purified from Hippocampus abdominalis: p-eNOS and p-AKT Stimulation in EA.hy926 Cells and Lowering of Blood Pressure in SHR Model.

The aim of this study was to assess the potential hypertensive effects of the IGTGIPGIW peptide purified from Hippocampus abdominalis alcalase hydrolysate (HA) for application in the functional food industry. We investigated the antihypertensive effects of IGTGIPGIW in vitro by assessing nitric oxide production in EA.hy926 endothelial cells, which is a major factor affecting vasorelaxation. The potential vasorelaxation effect was evaluated using 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate, a fluorescent stain. IGTGIPGIW significantly increased the expression of endothelial-derived relaxing factors, including endothelial nitric oxide synthase and protein kinase B, in EA.hy926 cells. Furthermore, oral administration of IGTGIPGIW significantly lowered the systolic blood pressure (183.60 ± 1.34 mmHg) and rapidly recovered the diastolic blood pressure (143.50 ± 5.55 mmHg) in the spontaneously hypertensive rat model in vivo. Our results demonstrate the antihypertensive activity of the IGTGIPGIW peptide purified from H. abdominalis and indicate its suitability for application in the functional food industry.

Distinct properties of adipose stem cell subpopulations determine fat depot-specific characteristics.

In mammals, white adipose tissues are largely divided into visceral epididymal adipose tissue (EAT) and subcutaneous inguinal adipose tissue (IAT) with distinct metabolic properties. Although emerging evidence suggests that subpopulations of adipose stem cells (ASCs) would be important to explain fat depot differences, ASCs of two fat depots have not been comparatively investigated. Here, we characterized heterogeneous ASCs and examined the effects of intrinsic and tissue micro-environmental factors on distinct ASC features. We demonstrated that ASC subpopulations in EAT and IAT exhibited different molecular features with three adipogenic stages. ASC transplantation experiments revealed that intrinsic ASC features primarily determined their adipogenic potential. Upon obesogenic stimuli, EAT-specific SDC1+ ASCs promoted fibrotic remodeling, whereas IAT-specific CXCL14+ ASCs suppressed macrophage infiltration. Moreover, IAT-specific BST2high ASCs exhibited a high potential to become beige adipocytes. Collectively, our data broaden the understanding of ASCs with new insights into the origin of white fat depot differences.

Daldinans D‒G, new isoindolinone antioxidants isolated from the ascomycete Daldinia concentrica.

Four new isoindolinone derivatives, daldinans D‒G (3‒6), together with two known compounds, daldinans A and B (1 and 2), were isolated from the stroma of the ascomycete Daldinia concentrica. Chemical structures of the isolated compounds were determined by spectroscopic methods. All of these compounds exhibited antioxidant activities with IC50 values of 3.21 to 39.67 µM in the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay.

Increasing Transfection Efficiency of Lipoplexes by Modulating Complexation Solution for Transient Gene Expression.

Transient gene expression is a suitable tool for the production of biopharmaceutical candidates in the early stage of development and provides a simple and rapid alternative to the generation of stable cell line. In this study, an efficient transient gene expression methodology using DC-Chol/DOPE cationic liposomes and pDNA in Chinese hamster ovary suspension cells was established through screening of diverse lipoplex formation conditions. We modulated properties of both the liposome formation and pDNA solution, together called complexation solutions. Protein expression and cellular cytotoxicity were evaluated following transfection over the cell cultivation period to select the optimal complexation solution. Changes in hydrodynamic size, polydispersity index, and ζ potential of the liposomes and lipoplexes were analyzed depending on the various pH ranges of the complexation solutions using dynamic light scattering. The transfer of lipoplexes to the cytosol and their conformation were traced using fluorescence analysis until the early period of transfection. As a result, up to 1785 mg/L and 191 mg/L of human Fc protein and immunoglobulin G (bevacizumab), respectively, were successfully produced using acidic liposome formation and alkaline pDNA solutions. We expect that this lipoplex formation in acidic and alkaline complexation solutions could be an effective methodology for a promising gene delivery strategy.

Spatial Regulation of Reactive Oxygen Species via G6PD in Brown Adipocytes Supports Thermogenic Function.

Reactive oxygen species (ROS) are associated with various roles of brown adipocytes. Glucose-6-phosphate dehydrogenase (G6PD) controls cellular redox potentials by producing NADPH. Although G6PD upregulates cellular ROS levels in white adipocytes, the roles of G6PD in brown adipocytes remain elusive. Here, we found that G6PD defect in brown adipocytes impaired thermogenic function through excessive cytosolic ROS accumulation. Upon cold exposure, G6PD-deficient mutant (G6PDmut) mice exhibited cold intolerance and downregulated thermogenic gene expression in brown adipose tissue (BAT). In addition, G6PD-deficient brown adipocytes had increased cytosolic ROS levels, leading to extracellular signal-regulated kinase (ERK) activation. In BAT of G6PDmut mice, administration of antioxidant restored the thermogenic activity by potentiating thermogenic gene expression and relieving ERK activation. Consistently, body temperature and thermogenic execution were rescued by ERK inhibition in cold-exposed G6PDmut mice. Taken together, these data suggest that G6PD in brown adipocytes would protect against cytosolic oxidative stress, leading to cold-induced thermogenesis.

Consoramides A-C, New Zwitterionic Alkaloids from the Fungus Irpex consors.

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C18 cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A-C (1-3).