Publications by authors named "Sun Chang Kim"

158 Publications

Pairing of orthogonal chaperones with a cytochrome P450 enhances terpene synthesis in Saccharomyces cerevisiae.

Biotechnol J 2021 Jul 16:e2000452. Epub 2021 Jul 16.

Research Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), Ulsan, Republic of Korea.

The supply of terpenes is often limited by their low extraction yield from natural resources, such as plants. Thus, microbial biosynthesis has emerged as an attractive platform for the production of terpenes. Many strategies have been applied to engineer microbes to improve terpene production capabilities; however, functional expression of heterologous proteins such as cytochrome P450 enzymes (P450s) in microbes is a major obstacle. This study reports the successful pairing of cognate chaperones and P450s for functional heterologous expression in Saccharomyces cerevisiae. This chaperone pairing was exploited to facilitate the functional assembly of the protopanaxadiol (PPD) biosynthesis pathway, which consists of a P450 oxygenase and a P450 reductase redox partner originating from Panax ginseng and Arabidopsis thaliana, respectively. We identified several chaperones required for protein folding in P. ginseng and A. thaliana and evaluated the impact of the coexpression of the corresponding chaperones on the synthesis and activity of PPD biosynthesis enzymes. Expression of a chaperone from P. ginseng (PgCPR5), a cognate of PPD biosynthesis enzymes, significantly increased PPD production by more than 2.5-fold compared with that in the corresponding control strain. Thus, pairing of chaperones with heterologous enzymes provides an effective strategy for the construction of challenging biosynthesis pathways in yeast.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/biot.202000452DOI Listing
July 2021

Transcriptome and translatome of CO fixing acetogens under heterotrophic and autotrophic conditions.

Sci Data 2021 02 9;8(1):51. Epub 2021 Feb 9.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.

Acetogens are anaerobic bacteria that utilise gaseous feedstocks such as carbon monoxide (CO) and carbon dioxide (CO) to synthesise biomass and various metabolites via the energetically efficient Wood-Ljungdahl pathway. Because of this pathway, acetogens have been considered as a novel platform to produce biochemicals from gaseous feedstocks, potentially replacing the conventional thermochemical processes. Despite their advantages, a lack of systematic understanding of the transcriptional and translational regulation in acetogens during autotrophic growth limits the rational strain design to produce the desired products. To overcome this problem, we presented RNA sequencing and ribosome profiling data of four acetogens cultivated under heterotrophic and autotrophic conditions, providing data on genome-scale transcriptional and translational responses of acetogens during CO fixation. These data facilitate the discovery of regulatory elements embedded in their genomes, which could be utilised to engineer strains to achieve better growth and productivity. We anticipate that these data will expand our understanding of the processes of CO fixation and will help in the designing of strains for the desired biochemical production.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41597-021-00837-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7873083PMC
February 2021

Biochemical characterization and molecular docking analysis of novel esterases from Sphingobium chungbukense DJ77.

Int J Biol Macromol 2021 Jan 13;168:403-411. Epub 2020 Dec 13.

School of Biological Sciences, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju 28644, South Korea. Electronic address:

We identified three novel microbial esterase (Est1, Est2, and Est3) from Sphingobium chungbukense DJ77. Multiple sequence alignment showed the Est1 and Est3 have distinct motifs, such as tetrapeptide motif HGGG, a pentapeptide sequence motif GXSXG, and catalytic triad residues Ser-Asp-His, indicating that the identified enzymes belong to family IV esterases. Interestingly, Est1 exhibited strong activity toward classical esterase substrates, p-nitrophenyl ester of short-chain fatty acids and long-chain. However, Est3 did not exhibit any activity despite having high sequence similarity and sharing the identical catalytic active residues with Est1. Est3 only showed hydrolytic degradation activity to polycaprolactone (PCL). MOE-docking prediction also provided the parameters consisting of binding energy, molecular docking score, and molecular distance between substrate and catalytic nucleophilic residue, serine. The engineered mutEst3 has hydrolytic activity for a variety of esters ranging from p-nitrophenyl esters to PCL. In the present study, we demonstrated that MOE-docking simulation provides a valuable insight for facilitating biocatalytic performance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijbiomac.2020.12.077DOI Listing
January 2021

Ginsenoside F2 attenuates chronic-binge ethanol-induced liver injury by increasing regulatory T cells and decreasing Th17 cells.

J Ginseng Res 2020 Nov 10;44(6):815-822. Epub 2020 Apr 10.

Laboratory of Liver Research, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.

Background: Recently, beneficial roles of ginsenoside F2 (GF2), a minor constituent of , have been demonstrated in diverse inflammatory diseases. However, its roles in alcoholic liver inflammation and injury have not been clearly understood. Here, we investigated the underlying mechanism by which GF2 ameliorated alcoholic liver injury.

Methods: To induce alcoholic liver injury, C57BL/6J wild type (WT) or interleukin (IL)-10 knockout (KO) mice were orally administered with ethanol (3 g/kg) or ethanol-containing GF2 (50 mg/kg) for 2 wk. Liver injury and infiltration of macrophages and neutrophils were evaluated by serum biochemistry and immunohistochemistry, respectively. The changes of hepatic immune cells were assessed by flow cytometry and polymerase chain reaction analysis. differentiation of naïve T cells was performed.

Results: GF2 treatment significantly attenuated alcoholic liver injury, in which infiltrations of inflammatory macrophages and neutrophils were decreased. Moreover, the frequencies of Foxp3 regulatory T cells (Tregs) increased but IL-17-producing T (Th17) cells decreased in GF2-treated mice compared to controls. Furthermore, the mRNA expression of IL-10 and Foxp3 was significantly increased, whereas IL-17 mRNA expression was suppressed in GF2-treated mice. However, these beneficial roles of GF2 were not observed in GF2-treated IL-10 KO mice, suggesting a critical role of IL-10. Similarly, GF2 treatment suppressed differentiation of naïve T cells into Th17 cells by inhibiting RORγt expression and stimulating Foxp3 expression.

Conclusion: The present study suggests that GF2 treatment attenuates alcoholic liver injury by increasing IL-10 expression and Tregs and decreasing IL-17 expression and Th17 cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jgr.2020.03.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655498PMC
November 2020

Novel enzymatic elimination method for the chromatographic purification of ginsenoside Rb in an isomeric mixture.

J Ginseng Res 2020 Nov 17;44(6):784-789. Epub 2019 Aug 17.

Department of Biological Sciences, Hankyong National University, Anseong City, Kyonggi-Do, Republic of Korea.

Background: The separation of isomeric compounds from a mixture is a recurring problem in chemistry and phytochemistry research. The purification of pharmacologically active ginsenoside Rb from ginseng extracts is limited by the co-existence of its isomer Rb. The aim of the present study was to develop an enzymatic elimination-combined purification method to obtain pure Rb from a mixture of isomers.

Methods: To isolate Rb from the isomeric mixture, a simple enzymatic selective elimination method was used. A ginsenoside-transforming glycoside hydrolase (Bgp2) was employed to selectively hydrolyze Rb into ginsenoside Rd. Ginsenoside Rb was then efficiently separated from the mixture using a traditional chromatographic method.

Results: Chromatographic purification of Rb was achieved using this novel enzymatic elimination-combined method, with 58.6-times higher yield and 13.1% less time than those of the traditional chromatographic method, with a lower minimum column length for purification. The novelty of this study was the use of a recombinant glycosidase for the selective elimination of the isomer. The isolated ginsenoside Rb can be used in further pharmaceutical studies.

Conclusions: Herein, we demonstrated a novel enzymatic elimination-combined purification method for the chromatographic purification of ginsenoside Rb. This method can also be applied to purify other isomeric glycoconjugates in mixtures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jgr.2019.08.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7655484PMC
November 2020

Docking Simulation and Sandwich Assay for Aptamer-Based Botulinum Neurotoxin Type C Detection.

Biosensors (Basel) 2020 Aug 12;10(8). Epub 2020 Aug 12.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.

Aptamers are biomaterials that bind to a target molecule through a unique structure, and have high applicability in the diagnostic and medical fields. To effectively utilize aptamers, it is important to analyze the structure of the aptamer binding to the target molecule; however, there are difficulties in experimentally identifying this structure. In the modern pharmaceutical industry, computer-driven docking simulations that predict intermolecular binding models are used to select candidates that effectively bind target molecules. Botulinum toxin (BoNT) is the most poisonous neurotoxin produced from the bacteria, and BoNT/C, one of the eight serotypes, causes paralysis in livestock. In this study, the aptamers that bound to BoNT/C were screened via the systematic evolution of ligands by exponential enrichment, and the binding affinity analysis and binding model were evaluated to select optimal aptamers. Based on surface plasmon resonance analysis and molecular operating environment docking simulation, a pair of aptamers that had high binding affinity to BoNT/C and were bound to different BoNT/C sites were selected. A sandwich assay based on this aptamer pair detected the BoNT/C protein to a concentration as low as ~0.2 ng Ml. These results show that docking simulations are a useful strategy for screening aptamers that bind to specific targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/bios10080098DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7460441PMC
August 2020

SGL 121 Attenuates Nonalcoholic Fatty Liver Disease through Adjusting Lipid Metabolism Through AMPK Signaling Pathway.

Int J Mol Sci 2020 Jun 25;21(12). Epub 2020 Jun 25.

Institute of Pharmaceutical Research and Development, College of Pharmacy, Wonkwang University, Iksan, Jeonbuk 54538, Korea.

A ginsenoside F2-enhanced mixture (SGL 121) increases the content of ginsenoside F2 by biotransformation. In the present study, we investigated the effect of SGL 121 on nonalcoholic fatty liver disease (NAFLD) in vitro and in vivo. High-fat, high-carbohydrate-diet (HFHC)-fed mice were administered SGL 121 for 12 weeks to assess its effect on improving NAFLD. In HepG2 cells, SGL 121 acted as an antioxidant, a hepatoprotectant, and had an anti-lipogenic effect. In NAFLD mice, SGL 121 significantly improved body fat mass; levels of hepatic triglyceride (TG), hepatic malondialdehyde (MDA), serum total cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL); and activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In HepG2 cells, induced by oxidative stress, SGL 121 increased cytoprotection, inhibited reactive oxygen species (ROS) production, and increased antioxidant enzyme activity. SGL 121 activated the Nrf2/HO-1 signaling pathway and improved lipid accumulation induced by free fatty acids (FFA). Sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS) expression was significantly reduced in NAFLD-induced liver and HepG2 cells treated with SGL 121. Moreover, SGL 121 activated adenosine monophosphate-activated protein kinase (AMPK), which plays an important role in the regulation of lipid metabolism. The effect of SGL 121 on the improvement of NAFLD seems to be related to its antioxidant effects and activation of AMPK. In conclusion, SGL 121 can be potentially used for the treatment of NAFLD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21124534DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7352188PMC
June 2020

3D Printed Bioresponsive Devices with Selective Permeability Inspired by Eggshell Membrane for Effective Biochemical Conversion.

ACS Appl Mater Interfaces 2020 Jul 23;12(27):30112-30119. Epub 2020 Jun 23.

School of Mechanical Engineering, Hanyang University, Seoul 04763, Republic of Korea.

Eggshell membrane has selective permeability that enables gas or liquid molecules to pass through while effectively preventing migration of microbial species. Herein, inspired by the architecture of the eggshell membrane, we employ three-dimensional (3D) printing techniques to realize bioresponsive devices with excellent selective permeability for effective biochemical conversion. The fabricated devices show 3D conductive carbon nanofiber membranes in which precultured microbial cells are controllably deployed. The resulting outcome provides excellent selective permeability between chemical and biological species, which enables acquisition of target responses generated by biological species confined within the device upon input signals. In addition, electrically conductive carbon nanofiber networks provide a platform for real-time monitoring of metabolism of microbial cells in the device. The suggested platform represents an effort to broaden microbial applications by constructing biologically programmed devices for desired responses enabled by designated deployment of engineered cells in a securely confined manner within enclosed membranes using 3D printing methods.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.0c06669DOI Listing
July 2020

Characterization of a Novel Ginsenoside MT1 Produced by an Enzymatic Transrhamnosylation of Protopanaxatriol-Type Ginsenosides Re.

Biomolecules 2020 03 31;10(4). Epub 2020 Mar 31.

Intelligent Synthetic Biology Center, 291 Daehak-Ro, Yuseong-Gu, Daejeon 305-701, Korea.

Background: Ginsenosides, triterpene saponins of species, are considered the main active ingredients responsible for various pharmacological activities. Herein, a new protopanaxatriol-type ginsenoside called "ginsenoside MT1" is described; it was accidentally found among the enzymatic conversion products of ginsenoside Re.

Method: We analyzed the conversion mechanism and found that recombinant β-glucosidase (MT619) transglycosylated the outer rhamnopyranoside of Re at the C-6 position to glucopyranoside at C-20. The production of MT1 by trans-rhamnosylation was optimized and pure MT1 was obtained through various chromatographic processes.

Results: The structure of MT1 was elucidated based on spectral data: (20S)-3β,6α,12β,20-tetrahydroxydammarene-20-O-[-L-rhamnopyranosyl(1→2)-β-D-glucopyranoside]. This dammarane-type triterpene saponin was confirmed as a novel compound.

Conclusion: Based on the functions of ginsenosides with similar structures, we believe that this ginsenoside MT1 may have great potential in the development of nutraceutical, pharmaceutical or cosmeceutical products.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/biom10040525DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7226242PMC
March 2020

Adaptive Laboratory Evolution of ATCC 8486 on Carbon Monoxide.

Front Microbiol 2020 11;11:402. Epub 2020 Mar 11.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.

Acetogens are naturally capable of metabolizing carbon monoxide (CO), a component of synthesis gas (syngas), for autotrophic growth in order to produce biomass and metabolites such as acetyl-CoA via the Wood-Ljungdahl pathway. However, the autotrophic growth of acetogens is often inhibited by the presence of high CO concentrations because of CO toxicity, thus limiting their biosynthetic potential for industrial applications. Herein, we implemented adaptive laboratory evolution (ALE) for growth improvement of ATCC 8486 under high CO conditions. The strain evolved under syngas conditions with 44% CO over 150 generations, resulting in a significant increased optical density (600 nm) and growth rate by 2.14 and 1.44 folds, respectively. In addition, the evolved populations were capable of proliferating under CO concentrations as high as 80%. These results suggest that cell growth is enhanced as beneficial mutations are selected and accumulated, and the metabolism is altered to facilitate the enhanced phenotype. To identify the causal mutations related to growth improvement under high CO concentrations, we performed whole genome resequencing of each population at 50-generation intervals. Interestingly, we found key mutations in CO dehydrogenase/acetyl-CoA synthase (CODH/ACS) complex coding genes, and . To characterize the mutational effects on growth under CO, we isolated single clones and confirmed that the growth rate and CO tolerance level of the single clone were comparable to those of the evolved populations and wild type strain under CO conditions. Furthermore, the evolved strain produced 1.34 folds target metabolite acetoin when compared to the parental strain while introducing the biosynthetic pathway coding genes to the strains. Consequently, this study demonstrates that the mutations in the CODH/ACS complex affect autotrophic growth enhancement in the presence of CO as well as the CO tolerance of ATCC 8486.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2020.00402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7079680PMC
March 2020

Functional cooperation of the glycine synthase-reductase and Wood-Ljungdahl pathways for autotrophic growth of .

Proc Natl Acad Sci U S A 2020 03 13;117(13):7516-7523. Epub 2020 Mar 13.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 34141 Daejeon, Republic of Korea;

Among CO-fixing metabolic pathways in nature, the linear Wood-Ljungdahl pathway (WLP) in phylogenetically diverse acetate-forming acetogens comprises the most energetically efficient pathway, requires the least number of reactions, and converts CO to formate and then into acetyl-CoA. Despite two genes encoding glycine synthase being well-conserved in WLP gene clusters, the functional role of glycine synthase under autotrophic growth conditions has remained uncertain. Here, using the reconstructed genome-scale metabolic model SL771 based on the completed genome sequence, transcriptomics, C isotope-based metabolite-tracing experiments, biochemical assays, and heterologous expression of the pathway in another acetogen, we discovered that the WLP and the glycine synthase pathway are functionally interconnected to fix CO, subsequently converting CO into acetyl-CoA, acetyl-phosphate, and serine. Moreover, the functional cooperation of the pathways enhances CO consumption and cellular growth rates via bypassing reducing power required reactions for cellular metabolism during autotrophic growth of acetogens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1912289117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7132306PMC
March 2020

High-Level Production of Bacteriotoxic Phospholipase A1 in Bacterial Host Pseudomonas fluorescens Via ABC Transporter-Mediated Secretion and Inducible Expression.

Microorganisms 2020 02 11;8(2). Epub 2020 Feb 11.

Korea Science Academy of Korea Advanced Institute of Science and Technology, Busan 47162, Korea.

Bacterial phospholipase A1 (PLA1) is used in various industrial fields because it can catalyze the hydrolysis, esterification, and transesterification of phospholipids to their functional derivatives. It also has a role in the degumming process of crude plant oils. However, bacterial expression of the foreign PLA1-encoding gene was generally hampered because intracellularly expressed PLA1 is inherently toxic and damages the phospholipid membrane. In this study, we report that secretion-based production of recombinant PlaA, a bacterial PLA1 gene, or co-expression of PlaS, an accessory gene, minimizes this harmful effect. We were able to achieve high-level PlaA production via secretion-based protein production. Here, TliD/TliE/TliF, an ABC transporter complex of SIK-W1, was used to secrete recombinant proteins to the extracellular medium. In order to control the protein expression with induction, a new strain of , which had the operon repressor gene , was constructed and named ZYAI strain. The bacteriotoxic PlaA protein was successfully produced in a bacterial host, with help from ABC transporter-mediated secretion, induction-controlled protein expression, and fermentation. The final protein product is capable of degumming oil efficiently, signifying its application potential.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/microorganisms8020239DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7074900PMC
February 2020

Iron competition triggers antibiotic biosynthesis in Streptomyces coelicolor during coculture with Myxococcus xanthus.

ISME J 2020 05 28;14(5):1111-1124. Epub 2020 Jan 28.

Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.

Microbial coculture to mimic the ecological habitat has been suggested as an approach to elucidate the effect of microbial interaction on secondary metabolite biosynthesis of Streptomyces. However, because of chemical complexity during coculture, underlying mechanisms are largely unknown. Here, we found that iron competition triggered antibiotic biosynthesis in Streptomyces coelicolor during coculture with Myxococcus xanthus. During coculture, M. xanthus enhanced the production of a siderophore, myxochelin, leading M. xanthus to dominate iron scavenging and S. coelicolor to experience iron-restricted conditions. This chemical competition, but not physical contact, activated the actinorhodin biosynthetic gene cluster and the branched-chain amino acid degradation pathway which imply the potential to produce precursors, along with activation of a novel actinorhodin export system. Furthermore, we found that iron restriction increased the expression of 21 secondary metabolite biosynthetic gene clusters (smBGCs) in other Streptomyces species. These findings suggested that the availability for key ions stimulates specific smBGCs, which had the potential to enhance secondary metabolite biosynthesis in Streptomyces.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41396-020-0594-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7174319PMC
May 2020

Comparative Genome Analysis of Strain PB01, Isolated from an Iceberg.

J Microbiol Biotechnol 2020 Feb;30(2):237-243

Department of Molecular Science and Technology and Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon 16499, Republic of Korea.

A novel psychrotolerant strain PB01, isolated from an Antarctic iceberg, was comparatively analyzed with five related strains. The complete genome of strain PB01 consists of a single circular chromosome (4.3 Mb) and a plasmid (19 Kb). As potential low-temperature adaptation strategies, strain PB01 has four genes encoding cold-shock proteins, two genes encoding DEAD-box RNA helicases, and eight genes encoding transporters for glycine betaine, which can serve as a cryoprotectant, on the genome. The pan-genome structure of the six strains suggests that strain PB01 might have evolved to adapt to extreme environments by changing its genome content to gain higher capacity for DNA repair, translation, and membrane transport. Notably, strain PB01 possesses a complete TCA cycle consisting of eight enzymes as well as three additional pylori-type enzymes: ferredoxin-dependent 2-oxoglutarate synthase, succinyl-CoA/acetoacetyl-CoA transferase, and malate/quinone oxidoreductase. The co-existence of the genes for TCA cycle enzymes has also been identified in the other five strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4014/jmb.1909.09008DOI Listing
February 2020

Ginsenoside Rh2 Ameliorates Atopic Dermatitis in NC/Nga Mice by Suppressing NF-kappaB-Mediated Thymic Stromal Lymphopoietin Expression and T Helper Type 2 Differentiation.

Int J Mol Sci 2019 Dec 4;20(24). Epub 2019 Dec 4.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.

Ginsenosides are known to have various highly pharmacological activities, such as anti-cancer and anti-inflammatory effects. However, the search for the most effective ginsenosides against the pathogenesis of atopic dermatitis (AD) and the study of the effects of ginsenosides on specific cytokines involved in AD remain unclear. In this study, ginsenoside Rh2 was shown to exert the most effective anti-inflammatory action on thymic stromal lymphopoietin (TSLP) and interleukin 8 in tumor necrosis factor-alpha and polyinosinic: polycytidylic acid induced normal human keratinocytes by inhibiting proinflammatory cytokines at both protein and transcriptional levels. Concomitantly, Rh2 also efficiently alleviated 2,4-dinitrochlorobenzene-induced AD-like skin symptoms when applied topically, including suppression of immune cell infiltration, cytokine expression, and serum immunoglobulin E levels in NC/Nga mice. In line with the in vitro results, Rh2 inhibited TSLP levels in AD mice via regulation of an underlying mechanism involving the nuclear factor κB pathways. In addition, in regard to immune cells, we showed that Rh2 suppressed not only the expression of TSLP but the differentiation of naïve CD4+ T-cells into T helper type 2 cells and their effector function in vitro. Collectively, our results indicated that Rh2 might be considered as a good therapeutic candidate for the alternative treatment of AD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms20246111DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6940811PMC
December 2019

Enhanced Production of Fatty Acid Ethyl Ester with Engineered Operon in .

Microorganisms 2019 Nov 11;7(11). Epub 2019 Nov 11.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.

Biodiesel, or fatty acid ethyl ester (FAEE), is an environmentally safe, next-generation biofuel. Conventionally, FAEE is produced by the conversion of oil/fats, obtained from plants, animals, and microorganisms, by transesterification. Recently, metabolic engineering of bacteria for ready-to-use biodiesel was developed. In , it is produced by fatty acyl-carrier proteins and ethanol, with the help of thioesterase (TesB) and wax synthase (WS) enzymes. One of the foremost barriers in microbial FAEE production is the feedback inhibition of the fatty acid (FA) operon (. Here, we studied the effect of biodiesel biosynthesis in with an engineered operon. With a basic FAEE producing BD1 strain harboring and genes, biodiesel of 32 mg/L were produced. Optimal FAEE biosynthesis was achieved in the BD2 strain that carries an overexpressed operon ( and genes) and achieved up to 1291 mg/L of biodiesel, a 40-fold rise compared to the BD1 strain. The composition of FAEE obtained from the BD2 strain was 65% (C10:C2, decanoic acid ethyl ester) and 35% (C12:C2, dodecanoic acid ethyl ester). Our findings indicate that overexpression of the native FA operon, along with FAEE biosynthesis enzymes, improved biodiesel biosynthesis in .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/microorganisms7110552DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6920873PMC
November 2019

Development of a novel hybrid antimicrobial peptide for targeted killing of Pseudomonas aeruginosa.

Eur J Med Chem 2020 Jan 25;185:111814. Epub 2019 Oct 25.

Research Institute of Life Science, Gyeongsang National University, Jinju, 52828, South Korea; Division of Life Science, Gyeongsang National University, Jinju, 52828, South Korea. Electronic address:

The emergence of multidrug-resistant (MDR) Pseudomonas aeruginosa, coupled with shrinking antibiotic pipelines, has increased the demand for new antimicrobials with novel mechanisms of action. As the indiscriminate nature of broad-spectrum antimicrobial toxicity may have negative clinical consequences and increase the incidence of resistance, we have developed a P. aeruginosa-selective antimicrobial peptide capable of preferentially killing P. aeruginosa relative to benign microorganisms. A targeting peptide (PA2) that binds specifically to OprF porin on P. aeruginosa was identified by phage display peptide library screening, and a hybrid peptide was constructed by addition of the targeting peptide to GNU7, a potent antimicrobial peptide. The resulting hybrid peptide PA2-GNU7 exhibited potent antimicrobial activity against P. aeruginosa without causing host toxicity. Confocal laser scanning microscopy analysis and time-kill experiments demonstrated that PA2-GNU7 exhibited a high degree of specificity for P. aeruginosa, and rapidly and selectively killed P. aeruginosa cells in mixed cultures. In addition, in vivo treatment efficacy of PA2-GNU7 was significantly greater than that of conventional antibiotics in a mouse model of MDR P. aeruginosa infection. Taken together, the data suggest that PA2-GNU7 may be a promising template for further development as a novel anti-MDR P. aeruginosa therapeutic agent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmech.2019.111814DOI Listing
January 2020

Minor ginsenoside F1 improves memory in APP/PS1 mice.

Mol Brain 2019 09 5;12(1):77. Epub 2019 Sep 5.

Department of Biological Sciences, KAIST Institute for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea.

Ginseng has been shown to produce a cognitive improvement effect. The key molecular components in ginseng that produce pharmacological effects are ginsenosides. Previous studies reported a memory improvement effect of a few major ginsenosides. However, the identity of specific minor ginsenosides mediating such function remains unknown. Here, we report that a minor ginsenoside F1 improves memory function in APPswe/PSEN1dE9 (APP/PS1) double-transgenic Alzheimer's disease (AD) model mice. After 8-wk oral administration of F1 jelly, we observed that spatial working memory, but not context-dependent fear memory, was restored in AD mice. To search for a possible underlying molecular and cellular mechanism, we investigated the effect of F1 on Aβ plaque. We observed F1 administration reduced the Aβ plaque area and density in the cortex, but not in the hippocampus of AD mice. Next, we tested for the effect of F1 on the expression level of key molecules involved in learning and memory. Results from Western blot assay revealed that an abnormally reduced level of a phosphorylated form of CREB in the hippocampus of AD mice was restored to a normal level by F1 administration. Moreover, in the same animals, BDNF level was augmented in the cortex. Our results, therefore, suggest that minor ginsenoside F1 constitutes a promising target to develop therapeutic agents for AD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13041-019-0495-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6728944PMC
September 2019

Inactivation of a Mismatch-Repair System Diversifies Genotypic Landscape of During Adaptive Laboratory Evolution.

Front Microbiol 2019 16;10:1845. Epub 2019 Aug 16.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.

Adaptive laboratory evolution (ALE) is used to find causal mutations that underlie improved strain performance under the applied selection pressure. ALE studies have revealed that mutator populations tend to outcompete their non-mutator counterparts following the evolutionary trajectory. Among them, inactivated mutator cells, characterize d by a dysfunctional methyl-mismatch repair system, are frequently found in ALE experiments. Here, we examined inactivation as an approach to facilitate ALE of The wild-type MG1655 and knock-out derivative (Δ) were evolved in parallel for 800 generations on lactate or glycerol minimal media in a serial-transfer experiment. Whole-genome re-sequencing of each lineage at 100-generation intervals revealed that (1) mutations emerge rapidly in the Δ compared to in the wild-type strain; (2) mutations were more than fourfold higher in the Δ strain at the end-point populations compared to the wild-type strain; and (3) a significant number of random mutations accumulated in the Δ strains. We then measured the fitness of the end-point populations on an array of non-adaptive carbon sources. Interestingly, collateral fitness increases on non-adaptive carbon sources were more pronounced in the Δ strains than the parental strain. Fitness measurement of single mutants revealed that the collateral fitness increase seen in the mutator lineages can be attributed to a pool of random mutations. Together, this study demonstrates that short-term mutator ALE extensively expands possible genotype space, resulting in versatile bacteria with elevated fitness levels across various carbon sources.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2019.01845DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6706779PMC
August 2019

Tailoring the Saccharomyces cerevisiae endoplasmic reticulum for functional assembly of terpene synthesis pathway.

Metab Eng 2019 12 21;56:50-59. Epub 2019 Aug 21.

Research Center for Bio-based Chemistry, Korea Research Institute of Chemical Technology (KRICT), 406-30, Jongga-ro, Jung-gu, Ulsan, 44429, Republic of Korea. Electronic address:

The endoplasmic reticulum (ER) is a dynamic organelle that synthesizes and folds proteins. An imbalance between the ER protein synthesis load and its folding capacity triggers the unfolded protein response, thereby restoring normal ER functions via size adjustment. Inspired by such inherent genetic programming events, we engineered Saccharomyces cerevisiae to expand the ER by overexpressing a key ER size regulatory factor, INO2. ER space expansion enhanced ER protein synthesis and folding capacity, and relieved metabolic constraints imposed by the limited enzyme abundance. Harnessing the yeast ER for metabolic engineering, we ultimately increased the production of squalene and cytochrome P450-mediated protopanaxadiol by 71-fold and 8-fold, compared to their respective control strains without overexpression of INO2. Furthermore, genome-wide transcriptome analysis of the ER-expanded strain revealed that the significant improvement in terpene production was associated with global rewiring of the metabolic network. Therefore, the yeast ER can be engineered as a specialized compartment for enhancing terpene production, representing new possibilities for the high-level production of other value-added chemicals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ymben.2019.08.013DOI Listing
December 2019

Genome Engineering of Using Expanded Genetic Tools and the CRISPR-Cas9 System.

ACS Synth Biol 2019 09 12;8(9):2059-2068. Epub 2019 Aug 12.

Department of Biological Sciences and KI for the BioCentury , KAIST , Daejeon , 305-701 , Republic of Korea.

is one of the important bacteria in C feedstock utilization as well as in human gut microbiota. Although has recently garnered much attention and investigation on a genome-wide scale, a bottleneck for systematic engineering in is the lack of available genetic tools and an efficient genome editing platform. To overcome this limitation, we here report expanded genetic tools and the CRISPR-Cas9 system. We have developed an inducible promoter system that enables implementation of the CRISPR-Cas9 system to precisely manipulate target genes of the Wood-Ljungdahl pathway with 100% efficiency. Furthermore, we exploited the effectiveness of CRISPR interference to reduce the expression of target genes, exhibiting substantial repression of several genes in the Wood-Ljungdahl pathway and fructose-PTS system. These expanded genetic tools and CRISPR-Cas9 system comprise powerful and widely applicable genetic tools to accelerate functional genomic study and genome engineering in .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acssynbio.9b00150DOI Listing
September 2019

Application of antihelix antibodies in protein structure determination.

Proc Natl Acad Sci U S A 2019 09 1;116(36):17786-17791. Epub 2019 Aug 1.

Department of Life Sciences, Pohang University of Science and Technology, Nam-gu, Pohang 37673, Korea;

Antibodies are indispensable tools in protein engineering and structural biology. Antibodies suitable for structural studies should recognize the 3-dimensional (3D) conformations of target proteins. Generating such antibodies and characterizing their complexes with antigens take a significant amount of time and effort. Here, we show that we can expand the application of well-characterized antibodies by "transplanting" the epitopes that they recognize to proteins with completely different structures and sequences. Previously, several antibodies have been shown to recognize the alpha-helical conformation of antigenic peptides. We demonstrate that these antibodies can be made to bind to a variety of unrelated "off-target" proteins by modifying amino acids in the preexisting alpha helices of such proteins. Using X-ray crystallography, we determined the structures of the engineered protein-antibody complexes. All of the antibodies bound to the epitope-transplanted proteins, forming accurately predictable structures. Furthermore, we showed that binding of these antihelix antibodies to the engineered target proteins can modulate their catalytic activities by trapping them in selected functional states. Our method is simple and efficient, and it will have applications in protein X-ray crystallography, electron microscopy, and nanotechnology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1910080116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6731670PMC
September 2019

High-density immobilization of a ginsenoside-transforming β-glucosidase for enhanced food-grade production of minor ginsenosides.

Appl Microbiol Biotechnol 2019 Sep 9;103(17):7003-7015. Epub 2019 Jul 9.

Intelligent Synthetic Biology Center, 291 Daehak-Ro, Yuseong-Gu, Daejeon, 305-701, Korea.

Use of recombinant glycosidases is a promising approach for the production of minor ginsenosides, e.g., Compound K (CK) and F, which have potential applications in the food industry. However, application of these recombinant enzymes for food-grade preparation of minor ginsenosides are limited by the lack of suitable expression hosts and low productivity. In this study, Corynebacterium glutamicum ATCC13032, a GRAS strain that has been used extensively for the industrial-grade production of additives for foodstuffs, was employed to express a novel β-glucosidase (MT619) from Microbacterium testaceum ATCC 15829 with high ginsenoside-transforming activity. A cellulose-binding module was additionally fused to the N-terminus of MT619 for immobilization on cellulose, which is an abundant and safe material. Via one-step immobilization, the fusion protein in cell lysates was efficiently immobilized on regenerated amorphous cellulose at a high density (maximum 984 mg/g cellulose), increasing the enzyme concentration by 286-fold. The concentrated and immobilized enzyme showed strong conversion activities against protopanaxadiol- and protopanaxatriol-type ginsenosides for the production of CK and F. Using gram-scale ginseng extracts as substrates, the immobilized enzyme produced 7.59 g/L CK and 9.42 g/L F in 24 h. To the best of our knowledge, these are the highest reported product concentrations of CK and F, and this is the first time that a recombinant enzyme has been immobilized on cellulose for the preparation of minor ginsenosides. This safe, convenient, and efficient production method could also be effectively exploited in the preparation of food-processing recombinant enzymes in the pharmaceutical, functional food, and cosmetics industries.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00253-019-09951-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6690934PMC
September 2019

mRNA Engineering for the Efficient Chaperone-Mediated Co-Translational Folding of Recombinant Proteins in .

Int J Mol Sci 2019 Jun 28;20(13). Epub 2019 Jun 28.

KAIST Institute for BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.

The production of soluble, functional recombinant proteins by engineered bacterial hosts is challenging. Natural molecular chaperone systems have been used to solubilize various recombinant proteins with limited success. Here, we attempted to facilitate chaperone-mediated folding by directing the molecular chaperones to their protein substrates before the co-translational folding process completed. To achieve this, we either anchored the bacterial chaperone DnaJ to the 3' untranslated region of a target mRNA by fusing with an RNA-binding domain in the chaperone-recruiting mRNA scaffold (CRAS) system, or coupled the expression of DnaJ and a target recombinant protein using the overlapping stop-start codons 5'-TAATG-3' between the two genes in a chaperone-substrate co-localized expression (CLEX) system. By engineering the untranslated and intergenic sequences of the mRNA transcript, bacterial molecular chaperones are spatially constrained to the location of protein translation, expressing selected aggregation-prone proteins in their functionally active, soluble form. Our mRNA engineering methods surpassed the in-vivo solubilization efficiency of the simple DnaJ chaperone co-overexpression method, thus providing more effective tools for producing soluble therapeutic proteins and enzymes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms20133163DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6651523PMC
June 2019

Cytochrome P450 Monooxygenase-Mediated Metabolic Utilization of Benzo[]Pyrene by Species.

mBio 2019 05 28;10(3). Epub 2019 May 28.

Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, Madison, Wisconsin, USA

Soil-dwelling fungal species possess the versatile metabolic capability to degrade complex organic compounds that are toxic to humans, yet the mechanisms they employ remain largely unknown. Benzo[]pyrene (BaP) is a pervasive carcinogenic contaminant, posing a significant concern for human health. Here, we report that several species are capable of degrading BaP. Exposing cells to BaP results in transcriptomic and metabolic changes associated with cellular growth and energy generation, implying that the fungus utilizes BaP as a growth substrate. Importantly, we identify and characterize the conserved gene encoding a cytochrome P450 monooxygenase that is necessary for the metabolic utilization of BaP in We further demonstrate that the fungal NF-κB-type regulators VeA and VelB are required for proper expression of in response to nutrient limitation and BaP degradation in Our study illuminates fundamental knowledge of fungal BaP metabolism and provides novel insights into enhancing bioremediation potential. We are increasingly exposed to environmental pollutants, including the carcinogen benzo[]pyrene (BaP), which has prompted extensive research into human metabolism of toxicants. However, little is known about metabolic mechanisms employed by fungi that are able to use some toxic pollutants as the substrates for growth, leaving innocuous by-products. This study systemically demonstrates that a common soil-dwelling fungus is able to use benzo[]pyrene as food, which results in expression and metabolic changes associated with growth and energy generation. Importantly, this study reveals key components of the metabolic utilization of BaP, notably a cytochrome P450 monooxygenase and the fungal NF-κB-type transcriptional regulators. Our study advances fundamental knowledge of fungal BaP metabolism and provides novel insight into designing and implementing enhanced bioremediation strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/mBio.00558-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538779PMC
May 2019

Triterpenoid-biosynthetic UDP-glycosyltransferases from plants.

Biotechnol Adv 2019 11 9;37(7):107394. Epub 2019 May 9.

Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 17104, Republic of Korea. Electronic address:

Triterpenoid saponins are naturally occurring structurally diverse glycosides of triterpenes that are widely distributed among plant species. Great interest has been expressed by pharmaceutical and agriculture industries for the glycosylation of triterpenes. Such modifications alter their taste and bio-absorbability, affect their intra-/extracellular transport and storage in plants, and induce novel biological activities in the human body. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyze glycosylation using UDP sugar donors. These enzymes belong to a multigene family and recognize diverse natural products, including triterpenes, as the acceptor molecules. For this review, we collected and analyzed all of the UGT sequences found in Arabidopsis thaliana as well as 31 other species of triterpene-producing plants. To identify potential UGTs with novel functions in triterpene glycosylation, we screened and classified those candidates based on similarity with UGTs from Panax ginseng, Glycine max, Medicago truncatula, Saponaria vaccaria, and Barbarea vulgaris that are known to function in glycosylate triterpenes. We highlight recent findings on UGT inducibility by methyl jasmonate, tissue-specific expression, and subcellular localization, while also describing their catalytic activity in terms of regioselectivity for potential key UGTs dedicated to triterpene glycosylation in plants. Discovering these new UGTs expands our capacity to manipulate the biological and physicochemical properties of such valuable molecules.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biotechadv.2019.04.016DOI Listing
November 2019

Hierarchical Macroporous Particles for Efficient Whole-Cell Immobilization: Application in Bioconversion of Greenhouse Gases to Methanol.

ACS Appl Mater Interfaces 2019 May 14;11(21):18968-18977. Epub 2019 May 14.

Department of Chemical Engineering , Konkuk University , 1 Hwayang-Dong , Gwangjin-Gu, Seoul 05029 , Republic of Korea.

A viable approach for methanol production under ambient physiological conditions is to use greenhouse gases, methane (CH) and carbon dioxide (CO), as feed for immobilized methanotrophs. In the present study, unique macroporous carbon particles with pore sizes in the range of ∼1-6 μm were synthesized and used as support for the immobilization of Methylocella tundrae. Immobilization was accomplished covalently on hierarchical macroporous carbon particles. Maximal cell loading of covalently immobilized M. tundrae was 205 mg g of particles. Among these particles, the cells immobilized on 3.6 μm pore size particles showed the highest reusability with the least leaching and were chosen for further study. After immobilization, M. tundrae showed up to 2.4-fold higher methanol production stability at various pH and temperature values because of higher stability and metabolic activity than free cells. After eight cycles of reuse, the immobilized cells retained 18.1-fold higher relative production stability compared to free cells. Free and immobilized cells exhibited cumulative methanol production of 5.2 and 9.5 μmol mg under repeated batch conditions using simulated biogas [CH and CO, 4:1 (v/v)] as feed, respectively. The appropriate pore size of macroporous particles favors the efficient M. tundrae immobilization to retain better biocatalytic properties. This is the first report concerning the covalent immobilization of methanotrophs on the newly synthesized macroporous carbon particles and its subsequent application in repeated methanol production using simulated biogas as a feed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.9b03420DOI Listing
May 2019

Gypenoside LXXV Promotes Cutaneous Wound Healing In Vivo by Enhancing Connective Tissue Growth Factor Levels Via the Glucocorticoid Receptor Pathway.

Molecules 2019 Apr 23;24(8). Epub 2019 Apr 23.

Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.

Cutaneous wound healing is a well-orchestrated event in which many types of cells and growth factors are involved in restoring the barrier function of skin. In order to identify whether ginsenosides, the main active components of , promote wound healing, the proliferation and migration activities of 15 different ginsenosides were tested by MTT assay and scratched wound closure assay. Among ginsenosides, gypenoside LXXV (G75) showed the most potent wound healing effects. Thus, this study aimed to investigate the effects of G75 on wound healing in vivo and characterize associated molecular changes. G75 significantly increased proliferation and migration of keratinocytes and fibroblasts, and promoted wound closure in an excision wound mouse model compared with madecassoside (MA), which has been used to treat wounds. Additionally, RNA sequencing data revealed G75-mediated significant upregulation of connective tissue growth factor (CTGF), which is known to be produced via the glucocorticoid receptor (GR) pathway. Consistently, the increase in production of CTGF was confirmed by western blot and ELISA. In addition, GR-competitive binding assay and GR translocation assay results demonstrated that G75 can be bound to GR and translocated into the nucleus. These results demonstrated that G75 is a newly identified effective component in wound healing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules24081595DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6515290PMC
April 2019

Pro-angiogenic Ginsenosides F1 and Rh1 Inhibit Vascular Leakage by Modulating NR4A1.

Sci Rep 2019 03 14;9(1):4502. Epub 2019 Mar 14.

Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Korea.

Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis, but VEGF-induced angiogenesis is often accompanied by a vascular permeability response. Ginsenosides are triterpenoid saponins from the well-known medicinal plant, ginseng, and have been considered a candidate for modulating angiogenesis. Here, we systemically investigated the effects of 10 different ginsenosides on human umbilical vein endothelial cells and newly identified that two PPT-type ginsenosides, F1 and Rh1 induce the migration and proliferation of endothelial cells. Interestingly, RNA transcriptome analysis showed that gene regulation induced by VEGF in endothelial cells is distinct from that of ginsenoside F1 and Rh1. In addition, F1 and Rh1 significantly inhibited vascular leakage both in vitro and in vivo, which are induced by vascular endothelial growth factor. Furthermore, comparative transcriptome analysis revealed that these effects of F1 and Rh1 on vascular leakage restoration are mainly caused by changes in VEGF-mediated TNFα signaling via NFκB, particularly by the suppression of expression and transcriptional activity of NR4A1 by F1 and Rh1, even in the presence of VEGF. These findings demonstrate that ginsenosides F1 and Rh1 can be a promising herbal remedy for vessel normalization in ischemic disease and cancer and that NR4A1 is the key target.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-019-41115-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6418182PMC
March 2019

Ginsenoside Rh2 Ameliorates Doxorubicin-Induced Senescence Bystander Effect in Breast Carcinoma Cell MDA-MB-231 and Normal Epithelial Cell MCF-10A.

Int J Mol Sci 2019 Mar 12;20(5). Epub 2019 Mar 12.

Intelligent Synthetic Biology Center, Daejeon 34141, Korea.

The anthracycline antibiotic doxorubicin is commonly used antineoplastic drug in breast cancer treatment. Like most chemotherapy, doxorubicin does not selectively target tumorigenic cells with high proliferation rate and often causes serve side effects. In the present study, we demonstrated the cellular senescence and senescence associated secretory phenotype (SASP) of both breast tumor cell MDA-MB-231 and normal epithelial cell MCF-10A induced by clinical dose of doxorubicin (100 nM). Senescence was confirmed by flattened morphology, increased level of beta galactose, accumulating contents of lysosome and mitochondrial, and elevated expression of p16 and p21 proteins. Similarly, SASP was identified by highly secreted proteins IL-6, IL-8, GRO, GM-CSF, MCP-1, and MMP1 by antibody array assay. Reciprocal experiments, determined by cell proliferation and apoptosis assays and cell migration and cell invasion, indicated that SASP of MDA-MB-231 cell induces growth arrest of MCF-10A, whereas SASP of MCF-10A significantly stimulates the proliferation of MDA-MB-231. Interestingly, SASP from both cells powerfully promotes the cell migration and cell invasion of MDA-MB-231 cells. Treatment with the natural product ginsenoside Rh2 does not prevent cellular senescence or exert senolytic. However, SASP from senescent cells treated with Rh2 greatly attenuated the above-mentioned bystander effect. Altogether, Rh2 is a potential candidate to ameliorate this unwanted chemotherapy-induced senescence bystander effect.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms20051244DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6429443PMC
March 2019
-->