Publications by authors named "Zee-Yong Park"

99 Publications

Integrated Quantitative Phosphoproteomics and Cell-based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-related Phosphorylation Sites.

Mol Cells 2021 Jun 23. Epub 2021 Jun 23.

School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea.

Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser- 98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.
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http://dx.doi.org/10.14348/molcells.2021.4002DOI Listing
June 2021

NSrp70 is a lymphocyte-essential splicing factor that controls thymocyte development.

Nucleic Acids Res 2021 06;49(10):5760-5778

School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea.

Alternative pre-mRNA splicing is a critical step to generate multiple transcripts, thereby dramatically enlarging the proteomic diversity. Thus, a common feature of most alternative splicing factor knockout models is lethality. However, little is known about lineage-specific alternative splicing regulators in a physiological setting. Here, we report that NSrp70 is selectively expressed in developing thymocytes, highest at the double-positive (DP) stage. Global splicing and transcriptional profiling revealed that NSrp70 regulates the cell cycle and survival of thymocytes by controlling the alternative processing of various RNA splicing factors, including the oncogenic splicing factor SRSF1. A conditional-knockout of Nsrp1 (NSrp70-cKO) using CD4Cre developed severe defects in T cell maturation to single-positive thymocytes, due to insufficient T cell receptor (TCR) signaling and uncontrolled cell growth and death. Mice displayed severe peripheral lymphopenia and could not optimally control tumor growth. This study establishes a model to address the function of lymphoid-lineage-specific alternative splicing factor NSrp70 in a thymic T cell developmental pathway.
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http://dx.doi.org/10.1093/nar/gkab389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8191771PMC
June 2021

Cereblon Regulates the Proteotoxicity of Tau by Tuning the Chaperone Activity of DNAJA1.

J Neurosci 2021 Jun 10;41(24):5138-5156. Epub 2021 May 10.

Laboratory of Molecular Neurobiology, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea

Protein aggregation can induce explicit neurotoxic events that trigger a number of presently untreatable neurodegenerative disorders. Chaperones, on the other hand, play a neuroprotective role because of their ability to unfold and refold abnormal proteins. The progressive nature of neurotoxic events makes it important to discover endogenous factors that affect pathologic and molecular phenotypes of neurodegeneration in animal models. Here, we identified microtubule-associated protein tau, and chaperones Hsp70 (heat shock protein 70) and DNAJA1 (DJ2) as endogenous substrates of cereblon (CRBN), a substrate-recruiting subunit of cullin4-RING-E3-ligase. This recruitment results in ubiquitin-mediated degradation of tau, Hsp70, and DJ2. Knocking out CRBN enhances the chaperone activity of DJ2, resulting in decreased phosphorylation and aggregation of tau, improved association of tau with microtubules, and reduced accumulation of pathologic tau across brain. Functionally abundant DJ2 could prevent tau aggregation induced by various factors like okadaic acid and heparin. Depletion of CRBN also decreases the activity of tau-kinases including GSK3α/β, ERK, and p38. Intriguingly, we found a high expression of CRBN and low levels of DJ2 in neuronal tissues of 5XFAD and APP knock-in male mouse models of Alzheimer's disease. This implies that CRBN-mediated DJ2/Hsp70 pathway may be compromised in neurodegeneration. Being one of the primary pathogenic events, elevated CRBN can be a contributing factor for tauopathies. Our data provide a functional link between CRBN and DJ2/Hsp70 chaperone machinery in abolishing the cytotoxicity of aggregation-prone tau and suggest that mice serve as an animal model of resistance against tauopathies for further exploration of the molecular mechanisms of neurodegeneration.
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http://dx.doi.org/10.1523/JNEUROSCI.2494-20.2021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8211538PMC
June 2021

Structural basis for the N-degron specificity of ClpS1 from Arabidopsis thaliana.

Protein Sci 2021 03 30;30(3):700-708. Epub 2020 Dec 30.

Department of Life Sciences, Korea University, Seoul, South Korea.

The N-degron pathway determines the half-life of proteins in both prokaryotes and eukaryotes by precisely recognizing the N-terminal residue (N-degron) of substrates. ClpS proteins from bacteria bind to substrates containing hydrophobic N-degrons (Leu, Phe, Tyr, and Trp) and deliver them to the caseinolytic protease system ClpAP. This mechanism is preserved in organelles such as mitochondria and chloroplasts. Bacterial ClpS adaptors bind preferentially to Leu and Phe N-degrons; however, ClpS1 from Arabidopsis thaliana (AtClpS1) shows a difference in that it binds strongly to Phe and Trp N-degrons and only weakly to Leu. This difference in behavior cannot be explained without structural information due to the high sequence homology between bacterial and plant ClpS proteins. Here, we report the structure of AtClpS1 at 2.0 Å resolution in the presence of a bound N-degron. The key determinants for α-amino group recognition are conserved among all ClpS proteins, but the α3-helix of eukaryotic AtClpS1 is significantly shortened, and consequently, a loop forming a pocket for the N-degron is moved slightly outward to enlarge the pocket. In addition, amino acid replacement from Val to Ala causes a reduction in hydrophobic interactions with Leu N-degron. A combination of the fine-tuned hydrophobic residues in the pocket and the basic gatekeeper at the entrance of the pocket controls the N-degron selectivity of the plant ClpS protein.
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http://dx.doi.org/10.1002/pro.4018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888574PMC
March 2021

Methanol supply speeds up synthesis gas fermentation by methylotrophic-acetogenic bacterium, Eubacterium limosum KIST612.

Bioresour Technol 2021 Feb 10;321:124521. Epub 2020 Dec 10.

School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea.

This study analyzed the effect of methanol on the metabolism of syngas components (i.e., H and CO) by the syngas fermenting acetogenic strain E. limosum KIST612. The culture characteristics and relevant proteomic expressions (as fold changes) were carefully analyzed under CO/CO and H/CO conditions with and without methanol addition, as well as, under methanol/CO conditions. The culture characteristics (specific growth rate and H consumption rate) under H/CO conditions were greatly enhanced in the presence of methanol, by 4.0 and 2.7 times, respectively. However, the promoting effect of methanol was not significant under CO/CO conditions. Proteomic fold changes in most enzyme expression levels in the Wood-Ljungdahl pathway and chemiosmotic energy conservation also exhibited high correspondence between methanol and H/CO but not between methanol and CO/CO. These findings suggest the advantages of methanol addition to H/CO for biomass enhancement and faster consumption of gaseous substrates during syngas fermentation.
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http://dx.doi.org/10.1016/j.biortech.2020.124521DOI Listing
February 2021

Correction to: Cinnamon extract induces tumor cell death through inhibition of NFκB and AP1.

BMC Cancer 2019 11 14;19(1):1113. Epub 2019 Nov 14.

School of Life Sciences and Immune Synapse Research Center, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Puk-ku, Gwangju, 500-712, Republic of Korea.

Following publication of the original article [1], the authors have re-evaluated the authorship for this article. The updated author group is.
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http://dx.doi.org/10.1186/s12885-019-6342-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6857335PMC
November 2019

A host dTMP-bound structure of T4 phage dCMP hydroxymethylase mutant using an X-ray free electron laser.

Sci Rep 2019 11 8;9(1):16316. Epub 2019 Nov 8.

Department of Life Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea.

The hydroxymethylation of cytosine bases plays a vital role in the phage DNA protection system inside the host Escherichia coli. This modification is known to be catalyzed by the dCMP hydroxymethylase from bacteriophage T4 (T4dCH); structural information on the complexes with the substrate, dCMP and the co-factor, tetrahydrofolate is currently available. However, the detailed mechanism has not been understood clearly owing to a lack of structure in the complex with a reaction intermediate. We have applied the X-ray free electron laser (XFEL) technique to determine a high-resolution structure of a T4dCH D179N active site mutant. The XFEL structure was determined at room temperature and exhibited several unique features in comparison with previously determined structures. Unexpectedly, we observed a bulky electron density at the active site of the mutant that originated from the physiological host (i.e., E. coli). Mass-spectrometric analysis and a cautious interpretation of an electron density map indicated that it was a dTMP molecule. The bound dTMP mimicked the methylene intermediate from dCMP to 5'-hydroxymethy-dCMP, and a critical water molecule for the final hydroxylation was convincingly identified. Therefore, this study provides information that contributes to the understanding of hydroxymethylation.
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http://dx.doi.org/10.1038/s41598-019-52825-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6841964PMC
November 2019

Extra domain A-containing fibronectin expression in Spin90-deficient fibroblasts mediates cancer-stroma interaction and promotes breast cancer progression.

J Cell Physiol 2020 05 21;235(5):4494-4507. Epub 2019 Oct 21.

Cell Logistics and Silver Health Research Center, School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play major roles in supporting cancer progression. A previous report showed that SPIN90 downregulation is correlated with CAF activation and that SPIN90-deficient CAFs promote breast cancer progression. However, the mechanisms that mediate cancer-stroma interaction and how such interactions regulate cancer progression are not well understood. Here, we show that extra domain A (EDA)-containing fibronectin (FN), FN(+)EDA, produced by mouse embryonic fibroblasts (MEFs) derived from Spin90-knockout (KO) mice increases their own myofibroblast differentiation, which facilitates breast cancer progression. Increased FN(+)EDA in Spin90-KO MEFs promoted fibril formation in the extracellular matrix (ECM) and specifically interacted with integrin α4β1 as the mediating receptor. Moreover, FN(+)EDA expression by Spin90-KO MEFs increased proliferation, migration, and invasion of breast cancer cells. Irigenin, a specific inhibitor of the interaction between integrin α4β1 and FN(+)EDA, significantly blocked the effects of FN(+)EDA, such as fibril formation by Spin90-KO MEFs and proliferation, migration, and invasion of breast cancer cells. In orthotopic breast cancer mouse models, irigenin injection remarkably reduced tumor growth and lung metastases. It was supported by that FN(+)EDA in assembled fibrils was accumulated in cancer stroma of human breast cancer patients in which SPIN90 expression was downregulated. Our data suggest that SPIN90 downregulation increases FN(+)EDA and promotes ECM stiffening in breast cancer stroma through an assembly of long FN(+)EDA-rich fibrils; moreover, engagement of the Integrin α4β1 receptor facilitates breast cancer progression. Inhibitory effects of irigenin on tumor growth and metastasis suggest the potential of this agent as an anticancer therapeutic.
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http://dx.doi.org/10.1002/jcp.29326DOI Listing
May 2020

Quaternary structures of Vac8 differentially regulate the Cvt and PMN pathways.

Autophagy 2020 06 12;16(6):991-1006. Epub 2019 Sep 12.

Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology , Ulsan, Republic of Korea.

Armadillo (ARM) repeat proteins constitute a large protein family with diverse and fundamental functions in all organisms, and armadillo repeat domains share high structural similarity. However, exactly how these structurally similar proteins can mediate diverse functions remains a long-standing question. Vac8 (vacuole related 8) is a multifunctional protein that plays pivotal roles in various autophagic pathways, including piecemeal microautophagy of the nucleus (PMN) and cytoplasm-to-vacuole targeting (Cvt) pathways in the budding yeast . Vac8 comprises an H1 helix at the N terminus, followed by 12 armadillo repeats. Herein, we report the crystal structure of Vac8 bound to Atg13, a key component of autophagic machinery. The 70-Å extended loop of Atg13 binds to the ARM domain of Vac8 in an antiparallel manner. Structural, biochemical, and experiments demonstrated that the H1 helix of Vac8 intramolecularly associates with the first ARM and regulates its self-association, which is crucial for Cvt and PMN pathways. The structure of H1 helix-deleted Vac8 complexed with Atg13 reveals that Vac8[Δ19-33]-Atg13 forms a heterotetramer and adopts an extended superhelical structure exclusively employed in the Cvt pathway. Most importantly, comparison of Vac8-Nvj1 and Vac8-Atg13 provides a molecular understanding of how a single ARM domain protein adopts different quaternary structures depending on its associated proteins to differentially regulate 2 closely related but distinct cellular pathways.

Abbreviations: Ape1: aminopeptidase I; ARM: armadillo repeat; Atg: autophagy-related; AUC: analytical ultracentrifugation; Cvt: cytoplasm-to-vacuole targeting; DIC: differential interference contrast; GFP: green fluorescent protein; GST: glutathione-S-transferase; ITC: isothermal titration calorimetry; NVJ: nucleus-vacuole junction; PDB: protein data bank; PMN: piecemeal microautophagy of the nucleus; prApe1: precursor Ape1; RMSD: root-mean-square deviation; SAXS: small-angle X-ray scattering; SD-N: nitrogen starvation medium; SEC: size-exclusion chromatography; tAtg13: Atg13 construct comprising residues 567-695; tNvj1: Nvj1 construct comprising residues 229-321; tVac8: Vac8 construct comprising residues 10-515; Vac8: vacuole related 8.
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http://dx.doi.org/10.1080/15548627.2019.1659615DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7469494PMC
June 2020

A significantly enhanced antibacterial spectrum of D-enantiomeric lipopeptide bactenecin.

Biochem Biophys Res Commun 2019 06 2;514(2):497-502. Epub 2019 May 2.

School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju, 61005, Republic of Korea. Electronic address:

Cationic antimicrobial peptides (CAMPs) are important antibiotics because they possess a broad spectrum of activity against both Gram-positive and Gram-negative bacteria, including those resistant to traditional antibiotics. The cyclic peptide bactenecin is a 12-amino acid CAMP that contains one intramolecular disulfide bond. To improve the antibacterial activity of bactenecin, we designed and synthesized several bactenecin analogs by applying multiple approaches, including amino acid substitution, use of the d-enantiomeric form, and lipidation. Among the synthetic analogs, d-enantiomeric bactenecin conjugated to capric acid, which we named dBacK-(cap), exhibited a significantly enhanced antibacterial spectrum with MIC values ranging from 1 to 8 μM against both Gram-positive and Gram-negative bacteria, including some drug-resistant bacteria. Upon exposure to dBacK-(cap), S. aureus cells were killed within 1 h at the MIC value, but full inactivation of E. coli required over 2 h. These results indicate that covalent addition of a d-amino acid and a fatty acid to bactenecin is the most effective approach for enhancing its antibacterial activity.
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http://dx.doi.org/10.1016/j.bbrc.2019.04.153DOI Listing
June 2019

Ets1 suppresses atopic dermatitis by suppressing pathogenic T cell responses.

JCI Insight 2019 03 7;4(5). Epub 2019 Mar 7.

Academy of Immunology and Microbiology (AIM), Institute for Basic Science (IBS), Pohang, South Korea.

Atopic dermatitis (AD) is a complex inflammatory skin disease mediated by immune cells of both adaptive and innate types. Among them, CD4+ Th cells are one of major players of AD pathogenesis. Although the pathogenic role of Th2 cells has been well characterized, Th17/Th22 cells are also implicated in the pathogenesis of AD. However, the molecular mechanisms underlying pathogenic immune responses in AD remain unclear. We sought to investigate how the defect in the AD susceptibility gene, Ets1, is involved in AD pathogenesis in human and mice and its clinical relevance in disease severity by identifying Ets1 target genes and binding partners. Consistent with the decrease in ETS1 levels in severe AD patients and the experimental AD-like skin inflammation model, T cell-specific Ets1-deficient mice (Ets1ΔdLck) developed severe AD-like symptoms with increased pathogenic Th cell responses. A T cell-intrinsic increase of gp130 expression upon Ets1 deficiency promotes the gp130-mediated IL-6 signaling pathway, thereby leading to the development of severe AD-like symptoms. Functional blocking of gp130 by selective inhibitor SC144 ameliorated the disease pathogenesis by reducing pathogenic Th cell responses. Our results reveal a protective role of Ets1 in restricting pathogenic Th cell responses and suggest a potential therapeutic target for AD treatment.
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http://dx.doi.org/10.1172/jci.insight.124202DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6483523PMC
March 2019

Role of SIRT1 in Modulating Acetylation of the Sarco-Endoplasmic Reticulum Ca-ATPase in Heart Failure.

Circ Res 2019 04;124(9):e63-e80

From the Cardiovascular Research Center, Icahn School of Medicine at Mount Sinai, New York (P.A.G., D.J., A.L., P.L., J.G.O., V.C., R.J.H., C.K.).

Rationale: SERCA2a, sarco-endoplasmic reticulum Ca-ATPase, is a critical determinant of cardiac function. Reduced level and activity of SERCA2a are major features of heart failure. Accordingly, intensive efforts have been made to develop efficient modalities for SERCA2a activation. We showed that the activity of SERCA2a is enhanced by post-translational modification with SUMO1 (small ubiquitin-like modifier 1). However, the roles of other post-translational modifications on SERCA2a are still unknown.

Objective: In this study, we aim to assess the role of lysine acetylation on SERCA2a function and determine whether inhibition of lysine acetylation can improve cardiac function in the setting of heart failure.

Methods And Results: The acetylation of SERCA2a was significantly increased in failing hearts of humans, mice, and pigs, which is associated with the reduced level of SIRT1 (sirtuin 1), a class III histone deacetylase. Downregulation of SIRT1 increased the SERCA2a acetylation, which in turn led to SERCA2a dysfunction and cardiac defects at baseline. In contrast, pharmacological activation of SIRT1 reduced the SERCA2a acetylation, which was accompanied by recovery of SERCA2a function and cardiac defects in failing hearts. Lysine 492 (K492) was of critical importance for the regulation of SERCA2a activity via acetylation. Acetylation at K492 significantly reduced the SERCA2a activity, presumably through interfering with the binding of ATP to SERCA2a. In failing hearts, acetylation at K492 appeared to be mediated by p300 (histone acetyltransferase p300), a histone acetyltransferase.

Conclusions: These results indicate that acetylation/deacetylation at K492, which is regulated by SIRT1 and p300, is critical for the regulation of SERCA2a activity in hearts. Pharmacological activation of SIRT1 can restore SERCA2a activity through deacetylation at K492. These findings might provide a novel strategy for the treatment of heart failure.
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http://dx.doi.org/10.1161/CIRCRESAHA.118.313865DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6483854PMC
April 2019

The CH25H-CYP7B1-RORα axis of cholesterol metabolism regulates osteoarthritis.

Nature 2019 02 6;566(7743):254-258. Epub 2019 Feb 6.

National Creative Research Initiatives Center for Osteoarthritis Pathogenesis and School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.

Osteoarthritis-the most common form of age-related degenerative whole-joint disease-is primarily characterized by cartilage destruction, as well as by synovial inflammation, osteophyte formation and subchondral bone remodelling. However, the molecular mechanisms that underlie the pathogenesis of osteoarthritis are largely unknown. Although osteoarthritis is currently considered to be associated with metabolic disorders, direct evidence for this is lacking, and the role of cholesterol metabolism in the pathogenesis of osteoarthritis has not been fully investigated. Various types of cholesterol hydroxylases contribute to cholesterol metabolism in extrahepatic tissues by converting cellular cholesterol to circulating oxysterols, which regulate diverse biological processes. Here we show that the CH25H-CYP7B1-RORα axis of cholesterol metabolism in chondrocytes is a crucial catabolic regulator of the pathogenesis of osteoarthritis. Osteoarthritic chondrocytes had increased levels of cholesterol because of enhanced uptake, upregulation of cholesterol hydroxylases (CH25H and CYP7B1) and increased production of oxysterol metabolites. Adenoviral overexpression of CH25H or CYP7B1 in mouse joint tissues caused experimental osteoarthritis, whereas knockout or knockdown of these hydroxylases abrogated the pathogenesis of osteoarthritis. Moreover, retinoic acid-related orphan receptor alpha (RORα) was found to mediate the induction of osteoarthritis by alterations in cholesterol metabolism. These results indicate that osteoarthritis is a disease associated with metabolic disorders and suggest that targeting the CH25H-CYP7B1-RORα axis of cholesterol metabolism may provide a therapeutic avenue for treating osteoarthritis.
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http://dx.doi.org/10.1038/s41586-019-0920-1DOI Listing
February 2019

A potent antibacterial activity of new short d-enantiomeric lipopeptide against multi drug resistant bacteria.

Biochim Biophys Acta Biomembr 2019 01 26;1861(1):34-42. Epub 2018 Oct 26.

School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea. Electronic address:

The emergence of drug-resistant pathogenic bacteria threatens human health. Resistance to existing antibiotics is increasing, while the emergence of new antibiotics is slowing. Cationic antimicrobial peptides (CAMPs) are fascinating alternative antibiotics because they possess a broad spectrum of activity, being active against both Gram-positive and Gram-negative bacteria including those resistant to traditional antibiotics. However, low bioavailability resulting from enzymatic degradation and attenuation by divalent cations like Mg and Ca limits their use as antibiotic agents. Here, we report the design of new CAMPs showing both high antibacterial activity and serum stability under physiological ion concentrations. The peptides were designed by applying two approaches, the use of d-enantiomer and lipidation. Based on the sequence of the CopW (LLWIALRKK-NH), a nonapeptide derived from coprisin, a series of novel d-form CopW lipopeptides with different acyl chain lengths (C6, C8, C10, C12, C14, and C16) were synthesized and evaluated with respect to their activity and salt sensitivity. Among the analogs, the d-form lipopeptide dCopW3 exhibited MIC values ranging from 1.25 to 5 μM against multidrug-resistant bacteria. Significantly, this compound did not induce bacterial resistance and was highly stable in human serum proteases. The results emphasize the potential of cationic d-form lipopeptide as therapeutically valuable antibiotics for treating drug-resistant bacterial infections.
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http://dx.doi.org/10.1016/j.bbamem.2018.10.014DOI Listing
January 2019

Comparative proteomic analysis of mouse models of pathological and physiological cardiac hypertrophy, with selection of biomarkers of pathological hypertrophy by integrative Proteogenomics.

Biochim Biophys Acta Proteins Proteom 2018 Jul 23. Epub 2018 Jul 23.

School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea. Electronic address:

To determine fundamental characteristics of pathological cardiac hypertrophy, protein expression profiles in two widely accepted models of cardiac hypertrophy (swimming-trained mouse for physiological hypertrophy and pressure-overload-induced mouse for pathological hypertrophy) were compared using a label-free quantitative proteomics approach. Among 3955 proteins (19,235 peptides, false-discovery rate < 0.01) identified in these models, 486 were differentially expressed with a log fold difference ≥ 0.58, or were detected in only one hypertrophy model (each protein from 4 technical replicates, p < .05). Analysis of gene ontology biological processes and KEGG pathways identified cellular processes enriched in one or both hypertrophy models. Processes unique to pathological hypertrophy were compared with processes previously identified in cardiac-hypertrophy models. Individual proteins with differential expression in processes unique to pathological hypertrophy were further confirmed using the results of previous targeted functional analysis studies. Using a proteogenomic approach combining transcriptomic and proteomic analyses, similar patterns of differential expression were observed for 23 proteins and corresponding genes associated with pathological hypertrophy. A total of 11 proteins were selected as early-stage pathological-hypertrophy biomarker candidates, and the results of western blotting for five of these proteins in independent samples confirmed the patterns of differential expression in mouse models of pathological and physiological cardiac hypertrophy.
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http://dx.doi.org/10.1016/j.bbapap.2018.07.006DOI Listing
July 2018

SPATC1L maintains the integrity of the sperm head-tail junction.

EMBO Rep 2018 09 19;19(9). Epub 2018 Jul 19.

School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea

Spermatogenesis is a tightly regulated process involving germ cell-specific and germ cell-predominant genes. Here we investigate a novel germ cell-specific gene, Spatc1l (spermatogenesis and centriole associated 1 like). Expression analyses show that SPATC1L is expressed in mouse and human testes. We find that mouse SPATC1L localizes to the neck region in testicular sperm. Moreover, SPATC1L associates with the regulatory subunit of protein kinase A (PKA). Using CRISPR/Cas9-mediated genome engineering, we generate mice lacking SPATC1L. Disruption of Spatc1l in mice leads to male sterility owing to separation of sperm heads from tails. The lack of SPATC1L is associated with a reduction in PKA activity in testicular sperm, and we identify capping protein muscle Z-line beta as a candidate target of phosphorylation by PKA in testis. Taken together, our results implicate the SPATC1L-PKA complex in maintaining the stability of the sperm head-tail junction, thereby revealing a new molecular basis for sperm head-tail integrity.
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http://dx.doi.org/10.15252/embr.201845991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6123647PMC
September 2018

Structural and Biochemical Study of the Mono-ADP-Ribosyltransferase Domain of SdeA, a Ubiquitylating/Deubiquitylating Enzyme from Legionella pneumophila.

J Mol Biol 2018 08 2;430(17):2843-2856. Epub 2018 Jun 2.

Department of Life Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea. Electronic address:

Conventional ubiquitylation occurs through an ATP-dependent three-enzyme cascade (E1, E2, and E3) that mediates the covalent conjugation of the C-terminus of ubiquitin to a lysine on the substrate. SdeA, which belongs to the SidE effector family of Legionella pneumophila, can transfer ubiquitin to endoplasmic reticulum-associated Rab-family GTPases in a manner independent of E1 and E2 enzymes. The novel ubiquitin-modifying enzyme SdeA utilizes NAD as a cofactor to attach ubiquitin to a serine residue of the substrate. Here, to elucidate the coupled enzymatic reaction of NAD+ hydrolysis and ADP-ribosylation of ubiquitin in SdeA, we characterized the mono-ADP-ribosyltransferase domain of SdeA and show that it consists of two sub-domains termed mART-N and mART-C. The crystal structure of the mART-C domain of SdeA was also determined in free form and in complex with NAD at high resolution. Furthermore, the spatial orientations of the N-terminal deubiquitylase, phosphodiesterase, mono-ADP-ribosyltransferase, and C-terminal coiled-coil domains within the 180-kDa full-length SdeA were determined. These results provide insight into the unusual ubiquitylation mechanism of SdeA and expand our knowledge on the structure-function of mono-ADP-ribosyltransferases.
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http://dx.doi.org/10.1016/j.jmb.2018.05.043DOI Listing
August 2018

Replacement of the C-terminal Trp-cage of exendin-4 with a fatty acid improves therapeutic utility.

Biochem Pharmacol 2018 05 6;151:59-68. Epub 2018 Mar 6.

School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdangwagiro, Buk-gu, Gwangju 500-712, South Korea; Rm. 206, Pilot Plant, Anygen, Gwangju Technopark, Cheomdankwagiro 333, Buk-gu, Gwangju 61008, South Korea. Electronic address:

Exendin-4, a 39 amino acid peptide isolated from the saliva of the Gila monster, plays an important role in regulating glucose homeostasis, and is used clinically for the treatment of type 2 diabetes. Exendin-4 shares 53% sequence identity with the incretin hormone glucagon-like peptide 1 (GLP-1) but, unlike GLP-1, is highly resistant to proteolytic enzymes such as dipeptidyl peptidase IV (DPP-IV) and neutral endopeptidase 24.11 (NEP 24.11). Herein, we focused on the structure and function of the C-terminal Trp-cage of exendin-4, and suggest that it may be structurally required for resistance to proteolysis by NEP 24.11. Using a series of substitutions and truncations of the C-terminal Trp-cage, we found that residues 1-33, including the N-terminal and helical regions of wild-type (WT) exendin-4, is the minimum motif required for both high peptidase resistance and potent activity toward the GLP-1 receptor comparable to WT exendin-4. To improve the therapeutic utility of C-terminally truncated exendin-4, we incorporated various fatty acids into exendin-4(1-33) in which Ser was substituted with Lys for acylation. Exendin-4(1-32)K-capric acid exhibited the most well balanced activity, with much improved therapeutic utility for regulating blood glucose and body weight relative to WT exendin-4.
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http://dx.doi.org/10.1016/j.bcp.2018.03.004DOI Listing
May 2018

Locus-Specific Reversible DNA Methylation Regulates Transient IL-10 Expression in Th1 Cells.

J Immunol 2018 03 26;200(5):1865-1875. Epub 2018 Jan 26.

Academy of Immunology and Microbiology, Institute for Basic Science, Pohang 37673, Republic of Korea;

IL-10 is a pleiotropic cytokine with multifaceted functions in establishing immune homeostasis. Although expressed by Th1 and Th2 cells, conventional Th1 cells produce marginal levels of IL-10 compared with their Th2 counterparts. In this study, we investigated the epigenetic mechanisms of gene expression in Th1 cells. Bioinformatics EMBOSS CpG plot analysis and bisulfite pyrosequencing revealed three CpG DNA methylation sites in the gene locus. Progressive DNA methylation at all of the CpG regions of interest (ROIs) established a repressive program of gene expression in Th1 cells. Interestingly, Th1 cells treated with IL-12 and IL-27 cytokines, thereby mimicking a chronic inflammatory condition in vivo, displayed a significant increase in IL-10 production that was accompanied by selective DNA demethylation at ROI 3 located in intron 3. IL-10-producing T cells isolated from lymphocytic choriomeningitis virus-infected mice also showed enhanced DNA demethylation at ROI 3. Binding of STAT1 and STAT3 to demethylated ROI 3 enhanced IL-10 expression in an IL-12/IL-27-dependent manner. Accordingly, CD4 T cells isolated from STAT1- or STAT3-knockout mice were significantly defective in IL-10 production. Our data suggest that, although stably maintained DNA methylation at the promoter may repress IL-10 expression in Th1 cells, locus-specific reversible DNA demethylation may serve as a threshold platform to control transient gene expression.
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http://dx.doi.org/10.4049/jimmunol.1701162DOI Listing
March 2018

SAMHD1 acetylation enhances its deoxynucleotide triphosphohydrolase activity and promotes cancer cell proliferation.

Oncotarget 2017 Sep 31;8(40):68517-68529. Epub 2017 Jul 31.

SNU-Harvard NeuroVascular Protection Research Center, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Korea.

SAM domain and HD domain containing protein 1 (SAMHD1) is a deoxynucleotide triphosphohydrolase (dNTPase) that inhibits retroviruses by depleting intracellular deoxynucleotide triphosphates (dNTPs) in non-cycling myeloid cells. Although SAMHD1 is expressed ubiquitously throughout the human body, the molecular mechanisms regulating its enzymatic activity and function in non-immune cells are relatively unexplored. Here, we demonstrate that the dNTPase activity of SAMHD1 is regulated by acetylation, which promotes cell cycle progression in cancer cells. SAMHD1 is acetylated at residue lysine 405 (K405) and by an acetylatransferase, arrest defective protein 1 (ARD1). Acetylated SAMHD1 wildtype proteins have enhanced dNTPase activity , whereas non-acetylated arginine substituted mutants (K405R) do not. K405R mutant expressing cancer cells have reduced G1/S transition and slower proliferation compared to wildtype. SAMHD1 acetylation levels are strongest during the G1 phase, indicating a role during G1 phase. Collectively, these findings suggest that SAMHD1 acetylation enhances its dNTPase activity and promotes cancer cell proliferation. Therefore, SAMHD1 acetylation may be a potent therapeutic target for cancer treatment.
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http://dx.doi.org/10.18632/oncotarget.19704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620274PMC
September 2017

PKCθ-Mediated PDK1 Phosphorylation Enhances T Cell Activation by Increasing PDK1 Stability.

Mol Cells 2017 Jan 26;40(1):37-44. Epub 2017 Jan 26.

School of Life Sciences and Cell Logistics Research Center, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea.

PDK1 is essential for T cell receptor (TCR)-mediated activation of NF-κB, and PDK1-induced phosphorylation of PKCθ is important for TCR-induced NF-κB activation. However, inverse regulation of PDK1 by PKCθ during T cell activation has not been investigated. In this study, we found that PKCθ is involved in human PDK1 phosphorylation and that its kinase activity is crucial for human PDK1 phosphorylation. Mass spectrometry analysis of wild-type PKCθ or of kinase-inactive form of PKCθ revealed that PKCθ induced phosphorylation of human PDK1 at Ser-64. This PKCθ-induced PDK1 phosphorylation positively regulated T cell activation and TCR-induced NF-κB activation. Moreover, phosphorylation of human PDK1 at Ser-64 increased the stability of human PDK1 protein. These results suggest that Ser-64 is an important phosphorylation site that is part of a positive feedback loop for human PDK1-PKCθ-mediated T cell activation.
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http://dx.doi.org/10.14348/molcells.2017.2236DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5303887PMC
January 2017

Characterization of MAGEG2 with testis-specific expression in mice.

Asian J Androl 2017 Nov-Dec;19(6):659-665

School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea.

Male germ cell development is a well-defined process occurring in numerous seminiferous tubules of the testis. Uncovering testicular novel genes related to intrinsic regulation of spermatogenesis is essential for the understanding of spermatogenesis. In the present study, we investigated mouse Mageg2, which belongs to a group of melanoma-associated antigens (MAGEs). Mageg2 is transcribed in the testis specifically, and its expression level is increased at the pachytene spermatocyte stage, indicating that Mageg2 is expressed predominantly in germ cells. We generated an antibody against mouse MAGEG2 for further characterization at the protein level. Immunoblot analysis suggested that MAGEG2 has specific testicular expression and the expression primarily occurred in pachytene spermatocytes. Proteomic analyses demonstrated that mouse MAGEG2 binded to testicular germ cell-specific serine/threonine-protein kinase 31 (STK31) and heat shock protein 9 (HSPA9). Direct binding with both interaction partners was confirmed by co-immunoprecipitation. We found that STK31 and HSPA9 bind MAGEG2 directly but not with each other. Interestingly, MAGEG2 reduced the kinase activity of STK31. Our study suggests that mouse MAGEG2 has at least two functions, including chaperone activity related to HSPA9 and regulation of pachytene spermatocyte-specific kinase, STK31. Altogether, our results provide the first information about MAGEG2 at the transcript and protein levels and suggest its potential molecular functions.
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http://dx.doi.org/10.4103/1008-682X.192033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5676425PMC
June 2018

Structure-activity relationships of ω-Agatoxin IVA in lipid membranes.

Biochem Biophys Res Commun 2017 Jan 9;482(1):170-175. Epub 2016 Nov 9.

School of Life Sciences, Gwangju Institute of Science and Technology, 123, Cheomdangwagi-ro, Buk-gu, Gwangju, Republic of Korea. Electronic address:

To analyze structural features of ω-Aga IVA, a gating modifier toxin from spider venom, we here investigated the NMR solution structure of ω-Aga IVA within DPC micelles. Under those conditions, the Cys-rich central region of ω-Aga IVA still retains the inhibitor Cys knot motif with three short antiparallel β-strands seen in water. However, N HSQC spectra of ω-Aga IVA within micelles revealed that there are radical changes to the toxin's C-terminal tail and several loops upon binding to micelles. The C-terminal tail of ω-Aga IVA appears to assume a β-turn like conformation within micelles, though it is disordered in water. Whole-cell patch clamp studies with several ω-Aga IVA analogs indicate that both the hydrophobic C-terminal tail and an Arg patch in the core region of ω-Aga IVA are critical for Cav2.1 blockade. These results suggest that the membrane environment stabilizes the structure of the toxin, enabling it to act in a manner similar to other gating modifier toxins, though its mode of interaction with the membrane and the channel is unique.
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http://dx.doi.org/10.1016/j.bbrc.2016.11.025DOI Listing
January 2017

ARD1-mediated Hsp70 acetylation balances stress-induced protein refolding and degradation.

Nat Commun 2016 10 6;7:12882. Epub 2016 Oct 6.

SNU-Harvard NeuroVascular Protection Research Center, College of Pharmacy, Seoul National University, Seoul 08826, Korea.

Heat shock protein (Hsp)70 is a molecular chaperone that maintains protein homoeostasis during cellular stress through two opposing mechanisms: protein refolding and degradation. However, the mechanisms by which Hsp70 balances these opposing functions under stress conditions remain unknown. Here, we demonstrate that Hsp70 preferentially facilitates protein refolding after stress, gradually switching to protein degradation via a mechanism dependent on ARD1-mediated Hsp70 acetylation. During the early stress response, Hsp70 is immediately acetylated by ARD1 at K77, and the acetylated Hsp70 binds to the co-chaperone Hop to allow protein refolding. Thereafter, Hsp70 is deacetylated and binds to the ubiquitin ligase protein CHIP to complete protein degradation during later stages. This switch is required for the maintenance of protein homoeostasis and ultimately rescues cells from stress-induced cell death in vitro and in vivo. Therefore, ARD1-mediated Hsp70 acetylation is a regulatory mechanism that temporally balances protein refolding/degradation in response to stress.
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http://dx.doi.org/10.1038/ncomms12882DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5059642PMC
October 2016

Pyrazolodiazepine derivatives with agonist activity toward Drosophila RYamide receptor.

Bioorg Med Chem Lett 2016 10 16;26(20):5116-5118. Epub 2016 Aug 16.

School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea. Electronic address:

The neuropeptide Y (NPY)-like signaling is conserved broadly in many animal species, and implicated in diverse biological functions, particularly those associated with feeding and metabolism. In Drosophila, three G protein coupled receptors (GPCRs) are closely related to the vertebrate NPY receptors: RYamide receptor (RYa-R) CG5811, neuropeptide F receptor (NPFR) CG1147 and short neuropeptide F receptor (sNPF-R) CG7395. Here, we screened 442 compounds of the pyrazolodiazepine analogs library, and identified four synthetic small compounds that activate the RYa-R, but not other two receptors. Their maximum activity is about 40% of the endogenous ligand, Drosophila RYamide-1, indicating they are partial agonists. Structural comparisons of these agonists identified an active core structure, characterized by phenylalanine and lysine fused pyrazolodiazepine skeletons, which can be utilized as a lead structure for further development of more potent drugs active on mammalian NPYRs. Identification of small compound agonists selective on RYa-R of the genetically amenable insect model will facilitate future efforts to understand biological functions of RYa-R, a GPCR conserved in many species.
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http://dx.doi.org/10.1016/j.bmcl.2016.08.039DOI Listing
October 2016

Effect of EF-2001 on experimentally induced atopic eczema in mice.

Food Sci Biotechnol 2016 31;25(4):1087-1093. Epub 2016 Aug 31.

5School of Life Sciences, Immune Synapse Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Gwangju, 61005 Korea.

Here, the effects of heat-killed Enterococcus faecalis EF-2001 (EF-2001) on atopic eczema (AE) were assessed. An AE model was established in vivo by repetitious topical exposure to 1-chloro-2,4-dinitrobenzene (CDNB) and dermatophagoidesfarinae extract (DFE) via application on each ear. Mice were administered EF-2001 orally for 4 weeks, dermal and epidermal ear thickness, mast cell infiltration of the ear tissue, and serum IgE and IgG2a levels were evaluated. Moreover, pathogenic cytokines levels of the ears, splenocytes, and cervical lymph nodes were determined. EF-2001 reduced AE symptoms grounded in the ear thickness, histopathological analysis, and serum IgE levels. Furthermore, EF-2001 attenuated mast cell infiltration in the ears and CDNB/DFE-induced various pathogenic cytokines levels of the ears, splenocytes and cervical lymph nodes. Thus, our data suggested that EF-2001 may have potential medicinal applications in the treatment of AE through its immunomodulatory properties.
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http://dx.doi.org/10.1007/s10068-016-0175-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049111PMC
August 2016

The positive duration of varicella zoster immunoglobulin M antibody test in herpes zoster.

Medicine (Baltimore) 2016 Aug;95(33):e4616

Department of Anesthesiology and Pain Medicine, Seoul Metropolitan Government Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul School of Life Science, Gwangju Institute of Science and Technology, Gwangju Department of Bioinformatics and Statistics, Korea National Open University Graduate School, Seoul, Korea.

Laboratory tests for herpes zoster (HZ) are required to confirm varicella zoster virus (VZV) infection, especially when a skin lesion is not typical or apparent. The serological test for VZV IgM antibody is simple and cost-effective; however, the change in the VZV IgM-positive rate over the time course of the disease has not been investigated. Therefore, we conducted an observational study to evaluate the positive rate of VZV IgM results during the time course of HZ and estimate the VZV IgM-positive period.After obtaining serum from patients with typical HZ, the VZV IgM titer was examined using enzyme-linked immunosorbent assay methods. After logarithmic transformation of the VZV IgM titer and the period after the onset of HZ, regression analysis was performed with the 2 transformed variables.A total of 62 patients were included in this study, and VZV IgM antibody was positive only in 23 patients (37%). The estimated antibody-positive period after HZ onset was 3.5 weeks (95% confidence interval 2.8-4.6 weeks).These findings suggest that the serological diagnosis of VZV IgM to confirm HZ is only useful within 3.5 weeks after the onset of symptoms.
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http://dx.doi.org/10.1097/MD.0000000000004616DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5370824PMC
August 2016

Chemical Composition and Inhibitory Effect of Lentinula edodes Ethanolic Extract on Experimentally Induced Atopic Dermatitis in Vitro and in Vivo.

Molecules 2016 Jul 29;21(8). Epub 2016 Jul 29.

Division of Food Bioscience, College of Biomedical and Health Sciences, Konkuk University, Chungju 27478, Korea.

The ethanolic extract of Lentinula edodes was partially analyzed and then characterized for its efficacy in treating atopic dermatitis. Polyphenols were determined to be the major antioxidant component in the extract (6.12 mg/g), followed by flavonoids (1.76 mg/g), β-carotene (28.75 μg/g), and lycopene (5.25 μg/g). An atopic dermatitis (AD) model was established and epidermal and dermal ear thickness, mast cell infiltration, and serum immunoglobulin levels were measured after oral administration of the L. edodes extract for 4 weeks. L. edodes extract decreased Dermatophagoides farinae extract (DFE) and 4-dinitrochlorobenzene (DNCB)-induced expression of several inflammatory cytokines in the ears, cervical lymph nodes, and splenocytes. Consequently, L. edodes extract may have therapeutic potential in the treatment of AD attributable to its immunomodulatory effects.
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http://dx.doi.org/10.3390/molecules21080993DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6273379PMC
July 2016

A Pair of Oviduct-Born Pickpocket Neurons Important for Egg-Laying in Drosophila melanogaster.

Mol Cells 2016 Jul 24;39(7):573-9. Epub 2016 Jun 24.

School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.

During copulation, male Drosophila transfers Sex Peptide (SP) to females where it acts on internal sensory neurons expressing pickpocket (ppk). These neurons induce a post-mating response (PMR) that includes elevated egg-laying and refractoriness to re-mating. Exactly how ppk neurons regulate the different aspects of the PMR, however, remains unclear. Here, we identify a small subset of the ppk neurons which requires expression of a pre-mRNA splicing factor CG3542 for egg-laying, but not refractoriness to mating. We identify two CG3542-ppk expressing neurons that innervate the upper oviduct and appear to be responsible for normal egg-laying. Our results suggest specific subsets of the ppk neurons are responsible for each PMR component.
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http://dx.doi.org/10.14348/molcells.2016.0121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4959023PMC
July 2016

1,2,4,5-Tetramethoxybenzene Suppresses House Dust Mite-Induced Allergic Inflammation in BALB/c Mice.

Int Arch Allergy Immunol 2016 30;170(1):35-45. Epub 2016 Jun 30.

Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.

Background: Atopic dermatitis (AD) is the most common allergic inflammatory skin disease. The activation of innate immunity by house dust mite (Dermatophagoides farinae extract, DFE) allergen plays an important role in the pathogenesis of AD. We previously showed the inhibitory effect of an extract of Amomum xanthioides on allergic diseases, and isolated 1,2,4,5-tetramethoxybenzene (TMB) as a major active component. In this study, we investigated whether TMB relieves DFE-induced allergic inflammation symptoms.

Methods: We established a DFE-induced allergic inflammation model in BALB/c mice by repeated skin exposure to DFE. To define the underlying mechanisms of action, we used a tumor necrosis factor-α and interferon-x03B3;-activated human keratinocytes (HaCaT cell line) and mouse keratinocytes (3PC cell line) cell line model.

Results: Oral administration of TMB suppressed allergic inflammation symptoms, such as histopathological analysis and ear thickness, in addition to serum IgE, DFE-specific IgE and IgG2a levels. TMB decreased the serum histamine levels and tissue infiltration of inflammatory cells, including mast cells and eosinophils. TMB also inhibited CD4+IFN-x03B3;+, CD4+IL-4+, and CD4+IL-17A+ lymphocyte expansion in the draining lymph nodes and expression of the Th2 cytokines in the ear tissue. TMB significantly inhibited the expression of cytokines and chemokines by the downregulation of the mitogen-activated protein kinases and nuclear factor of activated cytoplasmic T cells in HaCaT cells.

Conclusions: TMB improved DFE-induced allergic inflammation by suppressing the production of proinflammatory cytokines and chemokines. Our results suggest that TMB might be a potential therapeutic agent for AD.
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http://dx.doi.org/10.1159/000446510DOI Listing
February 2017