Publications by authors named "Margaret Dah-Tsyr Chang"

78 Publications

Synthesis of α-1,2- and α-1,3-linked di-rhamnolipids for biological studies.

Carbohydr Res 2020 Oct 25;496:108102. Epub 2020 Jul 25.

Department of Pharmaceutical Chemistry, University of Debrecen, H-4032, Debrecen, Egyetem tér 1, Hungary. Electronic address:

For a detailed examination of the interaction of rhamnose containing derivatives with recombinant horseshoe crab plasma lectin (rHPL), two di-rhamno-di-lipids (an α-1,2- and an α-1,3-linked) were synthesized via a new simple method. The N-iodosuccinimide/triflic acid mediated glycosylation of the methyl (R)-3-hydroxydecanoate with phenyl-1-thio-rhamnobioside donors afforded the mono-lipid disaccharides. Removal of the methyl ester group followed by esterification of the mono-lipids with a second (R)-3-hydroxydecanoate unit resulted in fully protected di-lipid derivatives, transformation of which into the target compounds was accomplished in two steps. This method allows the synthesis of both regioisomers in only 6 steps starting from the corresponding free disaccharides. Both synthetic di-rhamnolipids were biologically active for lectin binding differential binding preference between two isomeric di-rhamno-di-lipids. The rHPL lectin favours the α-1,3-linked di-rhamno-di-lipids over its α-1,2-linked regioisomer.
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http://dx.doi.org/10.1016/j.carres.2020.108102DOI Listing
October 2020

Heparan sulfate targeting strategy for enhancing liposomal drug accumulation and facilitating deep distribution in tumors.

Drug Deliv 2020 Dec;27(1):542-555

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.

Nanoparticles (NPs), such as liposomes, effectively evade the severe toxicity of unexpected accumulation and passively shuttle drugs into tumor tissues by enhanced permeability and retention. In the case of non-small cell lung cancer and pancreatic ductal adenocarcinoma, cancer-associated fibroblasts promote the aggregation of a gel-like extracellular matrix that forms a physical barrier in the desmoplastic stroma of the tumor. These stroma are composed of protein networks and glycosaminoglycans (GAGs) that greatly compromise tumor-penetrating performance, leading to insufficient extravasation and tissue penetration of NPs. Moreover, the presence of heparan sulfate (HS) and related proteoglycans on the cell surface and tumor extracellular matrix may serve as molecular targets for NP-mediated drug delivery. Here, a GAG-binding peptide (GBP) with high affinity for HS and high cell-penetrating activity was used to develop an HS-targeting delivery system. Specifically, liposomal doxorubicin (L-DOX) was modified by post-insertion with the GBP. We show that the uptake of L-DOX in A549 lung adenocarcinoma cells increased by GBP modification. Cellular uptake of GBP-modified L-DOX (L-DOX-GBP) was diminished in the presence of extracellular HS but not in the presence of other GAGs, indicating that the interaction with HS is critical for the cell surface binding of L-DOX-GBP. The cytotoxicity of doxorubicin positively correlated with the molecular composition of GBP. Moreover, GBP modification improved the distribution and anticancer efficiency of L-DOX, with enhanced desmoplastic targeting and extensive distribution. Taken together, GBP modification may greatly improve the tissue distribution and delivery efficiency of NPs against HS-abundant desmoplastic stroma-associated neoplasm.
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http://dx.doi.org/10.1080/10717544.2020.1745326DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170378PMC
December 2020

Cell Penetrating Peptide as a High Safety Anti-Inflammation Ingredient for Cosmetic Applications.

Biomolecules 2020 01 7;10(1). Epub 2020 Jan 7.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan.

Cosmeceutical peptides have become an important topic in recent decades in both academic and industrial fields. Many natural or synthetic peptides with different biological functions including anti-ageing, anti-oxidation, anti-infection and anti-pigmentation have been developed and commercialized. Current cosmeceutical peptides have already satisfied most market demand, remaining: "cargos carrying skin penetrating peptide with high safety" still an un-met need. To this aim, a cell-penetrating peptide, CPP, which efficiently transported cargos into epithelial cells was exanimated. CPP was evaluated with cell model and 3D skin model following OECD guidelines without using animal models. As a highly stable peptide, CPP neither irritated nor sensitized skin, also did not disrupt skin barrier. In addition, such high safety peptide had anti-inflammation activity without allergic effect. Moreover, cargo carrying activity of CPP was assayed using HaCaT cell model and rapid CPP penetration was observed within 30 min. Finally, CPP possessed transepidermal activity in water in oil formulation without disruption of skin barrier. All evidences indicated that CPP was an ideal choice for skin penetrating and its anti-inflammatory activity could improve skin condition, which made CPP suitable and attractive for novel cosmeceutical product development.
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http://dx.doi.org/10.3390/biom10010101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023394PMC
January 2020

Rhamnose Binding Protein as an Anti-Bacterial Agent-Targeting Biofilm of .

Mar Drugs 2019 Jun 14;17(6). Epub 2019 Jun 14.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan.

More than 80% of infectious bacteria form biofilm, which is a bacterial cell community surrounded by secreted polysaccharides, proteins and glycolipids. Such bacterial superstructure increases resistance to antimicrobials and host defenses. Thus, to control these biofilm-forming pathogenic bacteria requires antimicrobial agents with novel mechanisms or properties. , a Gram-negative opportunistic nosocomial pathogen, is a model strain to study biofilm development and correlation between biofilm formation and infection. In this study, a recombinant hemolymph plasma lectin (rHPL) cloned from Taiwanese was expressed in an system. This rHPL was shown to have the following properties: (1) Binding to PA14 biofilm through a unique molecular interaction with rhamnose-containing moieties on bacteria, leading to reduction of extracellular di-rhamnolipid (a biofilm regulator); (2) decreasing downstream quorum sensing factors, and inhibiting biofilm formation; (3) dispersing the mature biofilm of PA14 to improve the efficacies of antibiotics; (4) reducing PA14 cytotoxicity to human lung epithelial cells in vitro and (5) inhibiting PA14 infection of zebrafish embryos in vivo. Taken together, rHPL serves as an anti-biofilm agent with a novel mechanism of recognizing rhamnose moieties in lipopolysaccharides, di-rhamnolipid and structural polysaccharides (Psl) in biofilms. Thus rHPL links glycan-recognition to novel anti-biofilm strategies against pathogenic bacteria.
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http://dx.doi.org/10.3390/md17060355DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6628293PMC
June 2019

Sialylation of vasorin by ST3Gal1 facilitates TGF-β1-mediated tumor angiogenesis and progression.

Int J Cancer 2019 04 3;144(8):1996-2007. Epub 2019 Jan 3.

Institute of Stem Cell and Translational Cancer Research, Chang Gung Memorial Hospital at Linkou and Chang Gung University, Taoyuan, Taiwan.

ST3Gal1 is a key sialyltransferase which adds α2,3-linked sialic acid to substrates and generates core 1 O-glycan structure. Upregulation of ST3Gal1 has been associated with worse prognosis of breast cancer patients. However, the protein substrates of ST3Gal1 implicated in tumor progression remain elusive. In our study, we demonstrated that ST3GAL1-silencing significantly reduced tumor growth along with a notable decrease in vascularity of MCF7 xenograft tumors. We identified vasorin (VASN) which was shown to bind TGF-β1, as a potential candidate that links ST3Gal1 to angiogenesis. LC-MS/MS analysis of VASN secreted from MCF7, revealed that more than 80% of its O-glycans are sialyl-3T and disialyl-T. ST3GAL1-silencing or desialylation of VASN by neuraminidase enhanced its binding to TGF-β1 by 2- to 3-fold and thereby dampening TGF-β1 signaling and angiogenesis, as indicated by impaired tube formation of HUVECs, suppressed angiogenesis gene expression and reduced activation of Smad2 and Smad3 in HUVEC cells. Examination of 114 fresh primary breast cancer and their adjacent normal tissues showed that the expression levels of ST3Gal1 and TGFB1 were high in tumor part and the expression of two genes was positively correlated. Kaplan Meier survival analysis showed a significantly shorter relapse-free survival for those with lower expression VASN, notably, the combination of low VASN with high ST3GAL1 yielded even higher risk of recurrence (p = 0.025, HR = 2.967, 95% CI = 1.14-7.67). Since TGF-β1 is known to transcriptionally activate ST3Gal1, our findings illustrated a feedback regulatory loop in which TGF-β1 upregulates ST3Gal1 to circumvent the negative impact of VASN.
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http://dx.doi.org/10.1002/ijc.31891DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6590135PMC
April 2019

Intrahepatic hepatitis B virus large surface antigen induces hepatocyte hyperploidy via failure of cytokinesis.

J Pathol 2018 08 4;245(4):502-513. Epub 2018 Jul 4.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.

Hepatitis B virus (HBV) is an aetiological factor for liver cirrhosis and hepatocellular carcinoma (HCC). Despite current antiviral therapies that successfully reduce the viral load in patients with chronic hepatitis B, persistent hepatitis B surface antigen (HBsAg) remains a risk factor for HCC. To explore whether intrahepatic viral antigens contribute directly to hepatocarcinogenesis, we monitored the mitotic progression of HBV-positive cells. Cytokinesis failure was increased in HBV-positive HepG2.2.15 and 1.3ES2 cells, as well as in HuH-7 cells transfected with a wild-type or X-deficient HBV construct, but not in cells transfected with an HBsAg-deficient construct. We show that expression of viral large surface antigen (LHBS) was sufficient to induce cytokinesis failure of immortalized hepatocytes. Premitotic defects with DNA damage and G /M checkpoint attenuation preceded cytokinesis in LHBS-positive cells, and ultimately resulted in hyperploidy. Inhibition of polo-like kinase-1 (Plk1) not only restored the G /M checkpoint in these cells, but also suppressed LHBS-mediated in vivo tumourigenesis. Finally, a positive correlation between intrahepatic LHBS expression and hepatocyte hyperploidy was detected in >70% of patients with chronic hepatitis B. We conclude that HBV LHBS provokes hyperploidy by inducing DNA damage and upregulation of Plk1; the former results in atypical chromatin structures, and the latter attenuates the function of the G /M DNA damage checkpoint. Our data uncover a mechanism by which genomic integrity of hepatocytes is disrupted by viral LHBS. These findings highlight the role of intrahepatic surface antigen as an oncogenic risk factor in the development of HCC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/path.5102DOI Listing
August 2018

Cell Penetrating Peptide Derived from Human Eosinophil Cationic Protein Decreases Airway Allergic Inflammation.

Sci Rep 2017 09 27;7(1):12352. Epub 2017 Sep 27.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.

Cell penetrating peptide derived from human eosinophil cationic protein (CPPecp) is a 10-amino-acid peptide containing a core heparan sulfate (HS)-binding motif of human eosinophil cationic protein (ECP). It binds and penetrates bronchial epithelial cells without cytotoxic effects. Here we investigated airway-protective effects of CPPecp in BEAS-2B cell line and mite-induced airway allergic inflammation in BALB/c mice. In BEAS-2B cell, CPPecp decreases ECP-induced eotaxin mRNA expression. CPPecp also decreases eotaxin secretion and p-STAT6 activation induced by ECP, as well as by IL-4. In vivo studies showed CPPecp decreased mite-induced airway inflammation in terms of eosinophil and neutrophil count in broncho-alveolar lavage fluid, peri-bronchiolar and alveolar pathology scores, cytokine production in lung protein extract including interleukin (IL)-5, IL-13, IL-17A/F, eotaxin; and pause enhancement from methacholine stimulation. CPPecp treated groups also showed lower serum mite-specific IgE level. In this study, we have demonstrated the in vitro and in vivo anti-asthma effects of CPPecp.
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http://dx.doi.org/10.1038/s41598-017-12390-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5617860PMC
September 2017

Heparin-Promoted Cellular Uptake of the Cell-Penetrating Glycosaminoglycan Binding Peptide, GBP, Depends on a Single Tryptophan.

ACS Chem Biol 2017 02 21;12(2):398-406. Epub 2016 Dec 21.

Institute of Bioinformatics and Structural Biology, National Tsing Hua University , Hsinchu 30013, Taiwan.

A 10-residue, glycosaminoglycan-binding peptide, GBP, derived from human eosinophil cationic protein has been recently designated as a potent cell-penetrating peptide. A model system containing peptide, glycan, and lipid was monitored by nuclear magnetic resonance (NMR) spectroscopy to determine the cell-penetrating mechanism. Heparin octasaccharide with dodecylphosphocholine (DPC) lipid micelle was titrated into the GBP solution. Our data revealed substantial roles for the charged residues Arg5 and Lys7 in recognizing heparin, whereas Arg3 had less effect. The aromatic residue Trp4 acted as an irreplaceable moiety for membrane insertion, as the replacement of Trp4 with Arg4 abolished cell penetration, although it significantly improved the heparin-binding ability. GBP bound either heparin or lipid in the presence or absence of the other ligand indicating that the peptide has two alternative binding sites: Trp4 is responsible for lipid insertion, and Arg5 and Lys7 are for GAG binding. We developed a molecular model showing that the two effects synergistically promote the penetration. The loss of either effect would abolish the penetration. GBP has been proven to enter cells through macropinocytosis. The GBP treatment inhibited A549 lung cancer cell migration and invasion, implying that the cellular microenvironment would be modulated by GBP internalization. The intracellular penetration of GBP leading to inhibition of epithelial cell migration and invasion depends on the presence of the tryptophan residue in its sequence compared with similar derivative peptides. Therefore, GBP shows substantial potential as a novel delivery therapeutic through rapid and effective internalization and interference with cell mobility.
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http://dx.doi.org/10.1021/acschembio.6b00864DOI Listing
February 2017

Inhibitory Effect of Multivalent Rhamnobiosides on Recombinant Horseshoe Crab Plasma Lectin Interactions with Pseudomonas aeruginosa PAO1.

Chem Asian J 2016 Dec 3;11(23):3398-3413. Epub 2016 Nov 3.

Department of Pharmaceutical Chemistry, University of Debrecen, H-4032, Debrecen, Egyetem tér 1, Hungary.

To evaluate the molecular interaction of recombinant horseshoe crab plasma lectin (rHPL) with Pseudomonas aeruginosa PAO1, multivalent rhamnobioside derivatives were designed. Eight rhamnoclusters with three or four α(1-3)-rhamnobiosides attached to different central cores, such as methyl gallate, pentaerythritol, and N-Boc Tris, through either an ethylene glycol or a tetraethylene glycol linker, were assembled in two consecutive azide-alkyne cycloaddition click reactions. The synthetic method embraced the preparation of two α(1-3)-rhamnobiosides with different linker arms and their conjugation, in stoichiometric or substoichiometric amounts, to propargyl ether-functionalized tri- or tetravalent scaffolds. A divalent derivative and two self-assembling rhamnobiosides were also prepared. The different architectures and valences of the rhamnoclusters provided an opportunity to evaluate the impact of topology and valency on the binding properties toward rHPL. Inhibitory ELISA data showed that all covalently linked rhamnoclusters could inhibit P. aeruginosa PAO1 recognition activity of rHPL with high efficacy. Trivalent rhamnobiosides showed a stronger inhibitory effect on P. aeruginosa PAO1 binding, and the more flexible clusters on a pentaerythritol or a Tris core were superior to the less flexible methyl gallate-based clusters. Interestingly, the length of the linker arms had a very low impact on the binding ability of the rhamnoclusters. Herein, the two trivalent derivatives on an N-Boc protected Tris central core were the best inhibitors. The self-assembling amphiphilic rhamnobioside derivatives were found to display no multivalent effect.
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http://dx.doi.org/10.1002/asia.201601162DOI Listing
December 2016

Hepatitis B virus PreS2-mutant large surface antigen activates store-operated calcium entry and promotes chromosome instability.

Oncotarget 2016 Apr;7(17):23346-60

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 300, Taiwan.

Hepatitis B virus (HBV) is a driver of hepatocellular carcinoma, and two viral products, X and large surface antigen (LHBS), are viral oncoproteins. During chronic viral infection, immune-escape mutants on the preS2 region of LHBS (preS2-LHBS) are gain-of-function mutations that are linked to preneoplastic ground glass hepatocytes (GGHs) and early disease onset of hepatocellular carcinoma. Here, we show that preS2-LHBS provoked calcium release from the endoplasmic reticulum (ER) and triggered stored-operated calcium entry (SOCE). The activation of SOCE increased ER and plasma membrane (PM) connections, which was linked by ER- resident stromal interaction molecule-1 (STIM1) protein and PM-resident calcium release- activated calcium modulator 1 (Orai1). Persistent activation of SOCE induced centrosome overduplication, aberrant multipolar division, chromosome aneuploidy, anchorage-independent growth, and xenograft tumorigenesis in hepatocytes expressing preS2- LHBS. Chemical inhibitions of SOCE machinery and silencing of STIM1 significantly reduced centrosome numbers, multipolar division, and xenograft tumorigenesis induced by preS2-LHBS. These results provide the first mechanistic link between calcium homeostasis and chromosome instability in hepatocytes carrying preS2-LHBS. Therefore, persistent activation of SOCE represents a novel pathological mechanism in HBV-mediated hepatocarcinogenesis.
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http://dx.doi.org/10.18632/oncotarget.8109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5029631PMC
April 2016

MMP-13 is involved in oral cancer cell metastasis.

Oncotarget 2016 03;7(13):17144-61

Department of Medical Sciences and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.

The oral cancer cell line OC3-I5 with a highly invasive ability was selected and derived from an established OSCC line OC3. In this study, we demonstrated that matrix metalloproteinases protein MMP-13 was up-regulated in OC3-I5 than in OC3 cells. We also observed that expression of epithelial-mesenchymal transition (EMT) markers including Twist, p-Src, Snail1, SIP1, JAM-A, and vinculin were increased in OC3-I5 compared to OC3 cells, whereas E-cadherin expression was decreased in the OC3-I5 cells. Using siMMP-13 knockdown techniques, we showed that siMMP-13 not only reduced the invasion and migration, but also the adhesion abilities of oral cancer cells. In support of the role of MMP-13 in metastasis, we used MMP-13 expressing plasmid-transfected 293T cells to enhance MMP-13 expression in the OC3 cells, transplanting the MMP-13 over expressing OC3 cells into nude mice led to enhanced lung metastasis. In summary, our findings show that MMP-13 promotes invasion and metastasis in oral cancer cells, suggesting altered expression of MMP-13 may be utilized to impede the process of metastasis.
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http://dx.doi.org/10.18632/oncotarget.7942DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4941377PMC
March 2016

A Heparan Sulfate-Binding Cell Penetrating Peptide for Tumor Targeting and Migration Inhibition.

Biomed Res Int 2015 3;2015:237969. Epub 2015 May 3.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 30013, Taiwan ; Department of Medical Science, National Tsing Hua University, Hsinchu 30013, Taiwan.

As heparan sulfate proteoglycans (HSPGs) are known as co-receptors to interact with numerous growth factors and then modulate downstream biological activities, overexpression of HS/HSPG on cell surface acts as an increasingly reliable prognostic factor in tumor progression. Cell penetrating peptides (CPPs) are short-chain peptides developed as functionalized vectors for delivery approaches of impermeable agents. On cell surface negatively charged HS provides the initial attachment of basic CPPs by electrostatic interaction, leading to multiple cellular effects. Here a functional peptide (CPPecp) has been identified from critical HS binding region in hRNase3, a unique RNase family member with in vitro antitumor activity. In this study we analyze a set of HS-binding CPPs derived from natural proteins including CPPecp. In addition to cellular binding and internalization, CPPecp demonstrated multiple functions including strong binding activity to tumor cell surface with higher HS expression, significant inhibitory effects on cancer cell migration, and suppression of angiogenesis in vitro and in vivo. Moreover, different from conventional highly basic CPPs, CPPecp facilitated magnetic nanoparticle to selectively target tumor site in vivo. Therefore, CPPecp could engage its capacity to be developed as biomaterials for diagnostic imaging agent, therapeutic supplement, or functionalized vector for drug delivery.
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http://dx.doi.org/10.1155/2015/237969DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4433633PMC
March 2016

A recombinant horseshoe crab plasma lectin recognizes specific pathogen-associated molecular patterns of bacteria through rhamnose.

PLoS One 2014 26;9(12):e115296. Epub 2014 Dec 26.

Institute of Molecular and Cellular Biology & Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

Horseshoe crab is an ancient marine arthropod that, in the absence of a vertebrate-like immune system, relies solely on innate immune responses by defense molecules found in hemolymph plasma and granular hemocytes for host defense. A plasma lectin isolated from the hemolymph of Taiwanese Tachypleus tridentatus recognizes bacteria and lipopolysaccharides (LPSs), yet its structure and mechanism of action remain unclear, largely because of limited availability of horseshoe crabs and the lack of a heterogeneous expression system. In this study, we have successfully expressed and purified a soluble and functional recombinant horseshoe crab plasma lectin (rHPL) in an Escherichia coli system. Interestingly, rHPL bound not only to bacteria and LPSs like the native HPL but also to selective medically important pathogens isolated from clinical specimens, such as Gram-negative Pseudomonas aeruginosa and Klebsiella pneumoniae and Gram-positive Streptococcus pneumoniae serotypes. The binding was demonstrated to occur through a specific molecular interaction with rhamnose in pathogen-associated molecular patterns (PAMPs) on the bacterial surface. Additionally, rHPL inhibited the growth of P. aeruginosa PAO1 in a concentration-dependent manner. The results suggest that a specific protein-glycan interaction between rHPL and rhamnosyl residue may further facilitate development of novel diagnostic and therapeutic strategies for microbial pathogens.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0115296PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4277298PMC
August 2015

A biologically inspired lung-on-a-chip device for the study of protein-induced lung inflammation.

Integr Biol (Camb) 2015 Feb;7(2):162-9

Institute of NanoEngineering and MicroSystems, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

This study reports a biomimetic microsystem that reconstitutes the lung microenvironment for monitoring the role of eosinophil cationic protein (ECP) in lung inflammation. ECP induces the airway epithelial cell expression of CXCL-12, which in turn stimulates the migration of fibrocytes towards the epithelium. This two-layered microfluidic system provides a feasible platform for perfusion culture, and was used in this study to reveal that the CXCL12-CXCR4 axis mediates ECP induced fibrocyte extravasation in lung inflammation. This 'lung-on-a-chip' microdevice serves as a dynamic transwell system by introducing a flow that can reconstitute the blood vessel-tissue interface for in vitro assays, enhancing pre-clinical studies. We made an attempt to develop a new microfluidic model which could not only simulate the transwell for studying cell migration, but could also study the migration in the presence of a flow mimicking the physiological conditions in the body. As blood vessels are the integral part of our body, this model gives an opportunity to study more realistic in vitro models of organs where the blood vessel i.e. flow based migration is involved.
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http://dx.doi.org/10.1039/c4ib00239cDOI Listing
February 2015

Low-molecular-weight heparin and unfractionated heparin decrease Th-1, 2, and 17 expressions.

PLoS One 2014 3;9(11):e109996. Epub 2014 Nov 3.

Pediatric Department, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China.

Background: We evaluated the effects of T helper cell differentiation in a mite-allergic animal model treated with inhaled heparins of different molecular weight.

Method: BALB/c mice were divided into four groups: 1. Control, 2. Mite intratracheal (mIT), 3. Inhaled heparin (hIN), 4. Inhaled low-molecular-weight heparin (lmwhIN). Groups 2, 3, and 4 were sensitized twice with Der p allergen subcutaneously on day 1 and day 8. Der p allergen was administered intratracheally on day 15. Groups 3 and 4 were treated with heparin or low-molecular-weight (lmw) heparin intranasally from day 1 to 22. Splenocytes from sacrificed mice stimulated with 16 µg/ml of Der p were cultured for 72 hours. Supernatants of splenocyte were collected to analyze the effect of Interleukin (IL)17-A/F, Interferon(IFN)-γ, IL-4, IL-13, and IL-10. Serum was also collected for Der P-specific IgE level on day 23. Total RNA was extracted from spleen tissue for mRNA expression. Gene expression of Foxp3, IL-10 IFN-γ, GATA3, IL-5, and RORγt were analyzed.

Results: Both hIN and lmwhIN groups had lower serum IgE level than that of the mIT group (both p<0.0001). Both hIN and lmwhIN groups showed significantly decreased transcripts of GATA-3, IFN-γ, IL-5, and RORγt mRNA in their spleen. Regarding the supernatant of splenocyte culture stimulated with Der p, compared with the mIT group, there were significant decreases in IL-17A/F, IFN-γ, IL-4, IL-13, and IL-10 secretion in inhaled hIN and lmwhIN groups.

Conclusions: From this balb/c mice study, the analyses of mRNA and cytokines revealed that both intranasal heparin and lmw heparin treatment decreased the expression of Th1, Th2, and Th17 in spleen. The underlying mechanism(s) warrant further studies.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0109996PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4217718PMC
August 2015

The effect of catalase on migration and invasion of lung cancer cells by regulating the activities of cathepsin S, L, and K.

Exp Cell Res 2014 Apr 26;323(1):28-40. Epub 2014 Feb 26.

Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan. Electronic address:

Abundant clinical evidences indicate that up-regulation of several cathepsins in many human cancers is correlated with malignant progression and poor patient prognosis. In addition, a decrease in catalase activity or accumulation of hydrogen peroxide correlates with cancer metastasis. Recent studies indicate that cathepsin activation and expression can be modulated via H2O2 treatment. However, the actual relationship between catalase and cathepsins is not yet fully understood. In the present study, we found that catalase expression (or activity) was higher, while intracellular and extracellular Cat S, Cat L, and Cat K activities were lower in the non-invasive CL1-0 cells compared to the highly invasive CL1-5 cells. After CL1-0 cells were transfected with catalase-shRNA, the corresponding ROS (H2O2) level and Cat S, Cat L, or Cat K expression (or activity) was up-regulated, accompanied by an increase in cell migration and invasion. On the other hand, ROS (H2O2) level, cathepsin S, L, and K activities, cell migration and invasion were decreased in catalase-overexpressed CL1-5 cells. It is suggested that catalase may regulate cathepsin activity by controlling the production of ROS (H2O2), leading to variation in migration and invasion ability of lung cancer cells.
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http://dx.doi.org/10.1016/j.yexcr.2014.02.014DOI Listing
April 2014

Functional characterization of ECP-heparin interaction: a novel molecular model.

PLoS One 2013 11;8(12):e82585. Epub 2013 Dec 11.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China ; Department of Medical Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

Human eosinophil cationic protein (ECP) and eosinophil derived neurotoxin (EDN) are two ribonuclease A (RNaseA) family members secreted by activated eosinophils. They share conserved catalytic triad and similar three dimensional structures. ECP and EDN are heparin binding proteins with diverse biological functions. We predicted a novel molecular model for ECP binding of heparin hexasaccharide (Hep6), [GlcNS(6S)-IdoA(2S)]3, and residues Gln(40), His(64) and Arg(105) were indicated as major contributions for the interaction. Interestingly, Gln(40) and His(64) on ECP formed a clamp-like structure to stabilize Hep6 in our model, which was not observed in the corresponding residues on EDN. To validate our prediction, mutant ECPs including ECP Q40A, H64A, R105A, and double mutant ECP Q40A/H64A were generated, and their binding affinity for heparins were measured by isothermal titration calorimetry (ITC). Weaker binding of ECP Q40A/H64A of all heparin variants suggested that Gln(40)-His(64) clamp contributed to ECP-heparin interaction significantly. Our in silico and in vitro data together demonstrate that ECP uses not only major heparin binding region but also use other surrounding residues to interact with heparin. Such correlation in sequence, structure, and function is a unique feature of only higher primate ECP, but not EDN.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082585PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3859622PMC
October 2014

Crystal structures of starch binding domain from Rhizopus oryzae glucoamylase in complex with isomaltooligosaccharide: insights into polysaccharide binding mechanism of CBM21 family.

Proteins 2014 Jun 22;82(6):1079-85. Epub 2013 Nov 22.

Department of Life Science and Institute of Bioinformatics and Structural Biology, College of Life Science, National Tsing Hua University, Hsin Chu, 30013, Taiwan, Republic of China.

Glucoamylases are responsible for hydrolysis of starch and polysaccharides to yield β-D-glucose. Rhizopus oryzae glucoamylase (RoGA) is composed of an N-terminal starch binding domain (SBD) and a C-terminal catalytic domain connected by an O-glycosylated linker. Two carbohydrate binding sites in RoSBD have been identified, site I is created by three highly conserved aromatic residues, Trp47, Tyr83, and Tyr94, and site II is built up by Tyr32 and Phe58. Here, the two crystal structures of RoSBD in complex with only α-(1,6)-linked isomaltotriose (RoSBD-isoG3) and isomaltotetraose (RoSBD-isoG4) have been determined at 1.2 and 1.3 Å, respectively. Interestingly, site II binding is observed in both complexes, while site I binding is only found in the RoSBD-isoG4 complex. Hence, site II acts as the recognition binding site for carbohydrate and site I accommodates site II to bind isoG4. Site I participates in sugar binding only when the number of glucosyl units of oligosaccharides is more than three. Taken together, two carbohydrate binding sites in RoSBD cooperate to reinforce binding mode of glucoamylase with polysaccharides as well as the starch.
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http://dx.doi.org/10.1002/prot.24446DOI Listing
June 2014

Effects of novel human cathepsin S inhibitors on cell migration in human cancer cells.

J Enzyme Inhib Med Chem 2014 Aug 1;29(4):538-46. Epub 2013 Oct 1.

Department of Life Science, Institute of Biotechnology, National Tsing Hua University , Hsinchu , Taiwan .

Elevated cathepsin S (Cat S) level is correlated with higher migration ability in tumor cells. This study investigates the inhibitory effect of novel synthetic α-ketoamide compounds on cathepsin activity and cancer cell migration. The effect of several α-ketoamide compounds on the activity of recombinant cathepsins (Cat S, Cat L and Cat K) was examined. Two highly metastatic cancer cell lines were incubated with three Cat S-specific compounds (6n, 6 w and 6r) to analyze their effect on cellular Cat S activity and cell migration. At a 100 nM concentration, compounds 6n, 6r and 6 w effectively inhibited Cat S activity. Cat S activity and cell migration were significantly reduced in CL1-3 cells after treatment with either 6n or 6 w at 5 μM. Similar results were also obtained when A2058 cells were treated with 6n. These results highlight the therapeutic potential of α-ketoamide compounds, especially 6n and 6 w, to prevent or delay cancer metastasis.
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http://dx.doi.org/10.3109/14756366.2013.823957DOI Listing
August 2014

Gene expression rate comparison for multiple high-throughput datasets.

IET Syst Biol 2013 Oct;7(5):135-42

Microarray provides genome-wide transcript profiles, whereas RNA-seq is an alternative approach applied for transcript discovery and genome annotation. Both high-throughput techniques show quantitative measurement of gene expression. To explore differential gene expression rates and understand biological functions, the authors designed a system which utilises annotations from Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathways and Gene Ontology (GO) associations for integrating multiple RNA-seq or microarray datasets. The developed system is initiated by either estimating gene expression levels from mapping next generation sequencing short reads onto reference genomes or performing intensity analysis from microarray raw images. Normalisation procedures on expression levels are evaluated and compared through different approaches including Reads Per Kilobase per Million mapped reads (RPKM) and housekeeping gene selection. Such gene expression levels are shown in different colour shades and graphically displayed in designed temporal pathways. To enhance importance of functional relationships of clustered genes, representative GO terms associated with differentially expressed gene cluster are visually illustrated in a tag cloud representation.
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http://dx.doi.org/10.1049/iet-syb.2012.0060DOI Listing
October 2013

Basic amino acid residues of human eosinophil derived neurotoxin essential for glycosaminoglycan binding.

Int J Mol Sci 2013 Sep 16;14(9):19067-85. Epub 2013 Sep 16.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu 300, Taiwan.

Human eosinophil derived neurotoxin (EDN), a granule protein secreted by activated eosinophils, is a biomarker for asthma in children. EDN belongs to the human RNase A superfamily possessing both ribonucleolytic and antiviral activities. EDN interacts with heparin oligosaccharides and heparin sulfate proteoglycans on bronchial epithelial Beas-2B cells. In this study, we demonstrate that the binding of EDN to cells requires cell surface glycosaminoglycans (GAGs), and the binding strength between EDN and GAGs depends on the sulfation levels of GAGs. Furthermore, in silico computer modeling and in vitro binding assays suggest critical roles for the following basic amino acids located within heparin binding regions (HBRs) of EDN 34QRRCKN39 (HBR1), 65NKTRKN70 (HBR2), and 113NRDQRRD119 (HBR3) and in particular Arg35, Arg36, and Arg38 within HBR1, and Arg114 and Arg117 within HBR3. Our data suggest that sulfated GAGs play a major role in EDN binding, which in turn may be related to the cellular effects of EDN.
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http://dx.doi.org/10.3390/ijms140919067DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3794821PMC
September 2013

Mechanical regulation of cancer cell apoptosis and autophagy: roles of bone morphogenetic protein receptor, Smad1/5, and p38 MAPK.

Biochim Biophys Acta 2013 Dec 8;1833(12):3124-3133. Epub 2013 Sep 8.

Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli, Taiwan. Electronic address:

Mechanical forces induced by interstitial fluid flow in and surrounding tissues and by blood/lymphatic flow in vessels may modulate cancer cell invasion and metastasis and anticancer drug delivery. Our previous study demonstrated that laminar flow-induced shear stress induces G2/M arrest in tumor cells. However, whether shear stress modulates final cell fate remains unclear. In this study, we investigated the role of flow-induced shear stress in modulating the survival of four human tumor cell lines, i.e., Hep3B hepatocarcinoma cells, MG63 osteosarcoma cells, SCC25 oral squamous carcinoma cells, and A549 carcinomic alveolar basal epithelial cells. Laminar shear stress (LSS) ranging from 0.5 to 12dyn/cm(2) induced death of these four tumor cell lines. In contrast to LSS at 0.5dyn/cm(2), oscillatory shear stress (OSS) at 0.5±4dyn/cm(2) cannot induce cancer cell death. Both LSS and OSS had no effect on human normal hepatocyte, lung epithelial, and endothelial cells. Application of LSS to these four cell lines increased the percentage of cells stained positively for annexin V-FITC, with up-regulations of cleaved caspase-8, -9, and -3, and PARP. In addition, LSS also induced Hep3B cell autophagy, as detected by acidic vesicular organelle formation, LC3B transformation, and p62/SQSTM1 degradation. By transfecting with small interfering RNA, we found that the shear-induced apoptosis and autophagy are mediated by bone morphogenetic protein receptor type (BMPR)-IB, BMPR-specific Smad1 and Smad5, and p38 mitogen-activated protein kinase in Hep3B cells. Our findings provide insights into the molecular mechanisms by which shear stress induces apoptosis and autophagy in tumor cells.
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http://dx.doi.org/10.1016/j.bbamcr.2013.08.023DOI Listing
December 2013

Elevated serum autoantibody against high mobility group box 1 as a potent surrogate biomarker for amyotrophic lateral sclerosis.

Neurobiol Dis 2013 Oct 29;58:13-8. Epub 2013 Apr 29.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

Amyotrophic lateral sclerosis (ALS) is a complicate and progressive onset devastating neurodegenerative disease. Its pathogenic mechanisms remain unclear and there is no specific test for diagnosis. For years, researchers have been vigorously searching for biomarkers associated with ALS to assist clinical diagnosis and monitor disease progression. Some specific inflammatory processes in the central nervous system have been reported to participate in the pathogenesis of ALS. As high mobility group box 1 (HMGB1) is elevated in spinal cord tissues of patients with ALS, we hypothesized, therefore, that serum autoantibody against HMGB1 (HMGB1 autoAb) might represent an effective biomarker for ALS. Patients with ALS, Alzheimer's disease, Parkinson's disease, and healthy age-matched control subjects were recruited for this study. ALS group consisted of 61 subjects, the other groups each consisted of forty subjects. We generated a polyclonal antibody against HMGB1 and developed an ELISA-based methodology for screening serum samples of these subjects. All samples were coded for masked comparison. For statistic analyses, two-tailed Student's t-test, ANOVA, Bonferroni multiple comparison test, Spearman correlation, and receiver operating characteristic curve were applied. We discovered that the level of HMGB1 autoAb significantly increased in patients with ALS as compared with that of patients with Alzheimer's disease, Parkinson's disease, and healthy control subjects. The differences between all groups were robust even at the early stages of ALS progression. More importantly, higher HMGB1 autoAb level was found in more severe disease status with significant correlation. Our study demonstrates that serum HMGB1 autoAb may serve as a biomarker for the diagnosis of ALS and can be used to monitor disease progression.
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http://dx.doi.org/10.1016/j.nbd.2013.04.013DOI Listing
October 2013

Molecular imaging of heparan sulfate expression with radiolabeled recombinant eosinophil cationic protein predicts allergic lung inflammation in a mouse model for asthma.

J Nucl Med 2013 May 21;54(5):793-800. Epub 2013 Mar 21.

Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan.

Unlabelled: Heparan sulfate proteoglycans (HSPGs) are glycoproteins consisting of a core protein to which linear heparan sulfate (HS) side chains are covalently attached. These HS side chains mediate a variety of biologic functions involved in inflammation. Radionuclide imaging of HS side chains in tissues with inflammation may be used for the stratification of patients who would most likely benefit from HSPG-targeting therapy. The goal of this study was to evaluate the feasibility of in vivo radionuclide imaging of HS side chain expression in a mouse model of asthma using the recombinant eosinophil cationic protein (rECP).

Methods: rECP was radioiodinated with (125)I or (123)I using the Chloramine-T method. The 50% inhibitory concentration value for (125)I-labeled rECP was determined in a competitive cell-binding assay using Beas-2B cells. The binding of radiolabeled rECP to HS side chains was evaluated both in vitro and in vivo. The biodistribution of radiolabeled rECP was assessed in asthma mice or in control mice using SPECT imaging, ex vivo biodistribution measurements, and microautoradiography.

Results: The 50% inhibitory concentration value for (125)I-rECP was 7.4 ± 0.1 nM. The loss of HS side chains substantially inhibited the cellular and tissue uptake of (125)I- or (123)I-rECP, indicating that HS side chains of HSPGs are required for (125)I- or (123)I-eosinophil cationic protein binding and uptake both in vitro and in vivo. SPECT imaging demonstrated an appreciably higher accumulation of radioactivity in the lungs of asthma mice than in those of control mice. Ex vivo biodistribution studies also confirmed that there was at least a 4-fold increase in the lung-to-muscle ratio of asthma mice, compared with control mice. The accumulation of radiolabeled rECP was linearly correlated with leukocyte infiltration.

Conclusion: This study illustrates the feasibility of using radiolabeled rECP for the visualization of HS side chains of HSPGs and the evaluation of allergic lung inflammation in living subjects. Our data indicate that radiolabeled rECP is a novel imaging agent for HS side chains of HSPGs in predicting allergic lung inflammation in living mice.
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http://dx.doi.org/10.2967/jnumed.112.111393DOI Listing
May 2013

In silico prediction and in vitro characterization of multifunctional human RNase3.

Biomed Res Int 2013 17;2013:170398. Epub 2013 Jan 17.

Institute of Molecular and Cellular Biology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan.

Human ribonucleases A (hRNaseA) superfamily consists of thirteen members with high-structure similarities but exhibits divergent physiological functions other than RNase activity. Evolution of hRNaseA superfamily has gained novel functions which may be preserved in a unique region or domain to account for additional molecular interactions. hRNase3 has multiple functions including ribonucleolytic, heparan sulfate (HS) binding, cellular binding, endocytic, lipid destabilization, cytotoxic, and antimicrobial activities. In this study, three putative multifunctional regions, (34)RWRCK(38) (HBR1), (75)RSRFR(79) (HBR2), and (101)RPGRR(105) (HBR3), of hRNase3 have been identified employing in silico sequence analysis and validated employing in vitro activity assays. A heparin binding peptide containing HBR1 is characterized to act as a key element associated with HS binding, cellular binding, and lipid binding activities. In this study, we provide novel insights to identify functional regions of hRNase3 that may have implications for all hRNaseA superfamily members.
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http://dx.doi.org/10.1155/2013/170398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3581242PMC
September 2013

A novel cell-penetrating peptide derived from human eosinophil cationic protein.

PLoS One 2013 4;8(3):e57318. Epub 2013 Mar 4.

Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.

Cell-penetrating peptides (CPPs) are short peptides which can carry various types of molecules into cells; however, although most CPPs rapidly penetrate cells in vitro, their in vivo tissue-targeting specificities are low. Herein, we describe cell-binding, internalization, and targeting characteristics of a newly identified 10-residue CPP, denoted ECP(32-41), derived from the core heparin-binding motif of human eosinophil cationic protein (ECP). Besides traditional emphasis on positively charged residues, the presence of cysteine and tryptophan residues was demonstrated to be essential for internalization. ECP(32-41) entered Beas-2B and wild-type CHO-K1 cells, but not CHO cells lacking of cell-surface glycosaminoglycans (GAGs), indicating that binding of ECP(32-41) to cell-surface GAGs was required for internalization. When cells were cultured with GAGs or pre-treated with GAG-digesting enzymes, significant decreases in ECP(32-41) internalization were observed, suggesting that cell-surface GAGs, especially heparan sulfate proteoglycans were necessary for ECP(32-41) attachment and penetration. Furthermore, treatment with pharmacological agents identified two forms of energy-dependent endocytosis, lipid-raft endocytosis and macropinocytosis, as the major ECP(32-41) internalization routes. ECP(32-41) was demonstrated to transport various cargoes including fluorescent chemical, fluorescent protein, and peptidomimetic drug into cultured Beas-2B cells in vitro, and targeted broncho-epithelial and intestinal villi tissues in vivo. Hence this CPP has the potential to serve as a novel vehicle for intracellular delivery of biomolecules or medicines, especially for the treatment of pulmonary or gastrointestinal diseases.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057318PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587609PMC
August 2013

Redox-proteomic analysis of doxorubicin resistance-induced altered thiol activity in uterine carcinoma.

J Pharm Biomed Anal 2013 May 31;78-79:1-8. Epub 2013 Jan 31.

Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, Taiwan.

Doxorubicin is an anticancer drug used in a wide range of cancer therapies; however, doxorubicin-induced drug resistance is one of the most serious obstacles of cancer chemotherapy. Recent studies have indicated that reduced oxidative stress levels in cancer cells induce drug resistance. However, the redox-modifications of resistance - associated cellular targets are largely unknown. Thus, the current study employed cysteine-labeling based two-dimensional differential gel electrophoresis (2D-DIGE) combined with MALDI-TOF mass spectrometry (MALDI-TOF MS) to analyze the effect of doxorubicin resistance on redox regulation in uterine cancer and showed 33 spots that were significantly changed in thiol reactivity. These proteins involve cytoskeleton regulation, signal transduction, redox-regulation, glycolysis, and cell-cycle regulation. The current work shows that the redox 2D-DIGE-based proteomic strategy provides a rapid method to study the molecular mechanisms of doxorubicin-induced drug resistance in uterine cancer. The identified targets may be used to further evaluate their roles in drug-resistance formation and for possible diagnostic or therapeutic applications.
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http://dx.doi.org/10.1016/j.jpba.2013.01.028DOI Listing
May 2013

Activation of PPAR-α induces cell cycle arrest and inhibits transforming growth factor-β1 induction of smooth muscle cell phenotype in 10T1/2 mesenchymal cells.

Cell Signal 2013 May 4;25(5):1252-63. Epub 2013 Feb 4.

Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli, Taiwan.

Transforming growth factor-β1 (TGF-β1) regulates the cell cycle and the differentiation of mesenchymal cells into smooth muscle cells (SMCs). However, the precise intracellular signaling pathways involved in these processes have not been fully clarified. It has also been shown that there is an increase in TGF-β1 expression in human atherosclerotic plaques. Furthermore, peroxisome proliferator-activated receptors (PPARs) and their agonists have recently gained more attention in the study of the pathogenesis of atherosclerosis. In this study, we examined the role of PPARs in the TGF-β1-mediated cell cycle control and SMC phenotypic modulation of C3H10T1/2 (10T1/2) mesenchymal cells. The results showed the following: (1) the PI3K/Akt/p70S6K signaling cascade is involved in TGF-β1-induced differentiation of 10T1/2 cells into cells with a SMC phenotype. (2) PPAR-α agonists (i.e., WY14,643 and clofibrate), but not a PPAR-δ/β agonist (GW501516) or PPAR-γ agonist (troglitazone), inhibit TGF-β1-induced SMC markers and the DNA binding activity of serum response factor (SRF) in 10T1/2 cells. (3) WY14,643 and clofibrate inhibit the TGF-β1 activation of the Smad3/Akt/P70S6K signaling cascade. (4) TGF-β1-induced cell cycle arrest at the G0/G1 phases is mediated by Smad3 in 10T1/2 cells. (5) The PPAR-α-mediated 10T1/2 cell cycle arrest at the G0/G1 phases is TGF-β receptor independent. These results suggest that PPAR-α mediates cell cycle control and TGF-β1-induced SMC phenotypic changes in 10T1/2 cells.
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http://dx.doi.org/10.1016/j.cellsig.2013.01.021DOI Listing
May 2013

Chemoattraction of macrophages by secretory molecules derived from cells expressing the signal peptide of eosinophil cationic protein.

BMC Syst Biol 2012 Aug 20;6:105. Epub 2012 Aug 20.

College of Medicine, China Medical University, Taichung, Taiwan.

Background: Eosinophil cationic protein is a clinical asthma biomarker that would be released into blood, especially gathered in bronchia. The signal peptide of eosinophil cationic protein (ECPsp) plays an important role in translocating ECP to the extracellular space. We previously reported that ECPsp inhibits microbial growth and regulates the expression of mammalian genes encoding tumor growth factor-α (TGF-α) and epidermal growth factor receptor (EGFR).

Results: In the present study, we first generated a DNA microarray dataset, which showed that ECPsp upregulated proinflammatory molecules, including chemokines, interferon-induced molecules, and Toll-like receptors. The levels of mRNAs encoding CCL5, CXCL10, CXCL11, CXCL16, STAT1, and STAT2 were increased in the presence of ECPsp by 2.07-, 4.21-, 7.52-, 2.6-, 3.58-, and 1.67-fold, respectively. We then constructed a functional linkage network by integrating the microarray dataset with the pathway database of Kyoto Encyclopedia of Genes and Genomes (KEGG). Follow-up analysis revealed that STAT1 and STAT2, important transcriptional factors that regulate cytokine expression and release, served as hubs to connect the pathways of cytokine stimulation (TGF-α and EGFR pathways) and inflammatory responses. Furthermore, integrating TGF-α and EGFR with the functional linkage network indicated that STAT1 and STAT2 served as hubs that connect two functional clusters, including (1) cell proliferation and survival, and (2) inflammation. Finally, we found that conditioned medium in which cells that express ECPsp had been cultured could chemoattract macrophages. Experimentally, we also demonstrated that the migration of macrophage could be inhibited by the individual treatment of siRNAs of STAT1 or STAT2. Therefore, we hypothesize that ECPsp may function as a regulator for enhancing the migration of macrophages through the upregulation of the transcriptional factors STAT1 and STAT2.

Conclusion: The increased expression and release of various cytokines triggered by ECPsp may attract macrophages to bronchia to purge damaged cells. Our approach, involving experimental and computational systems biology, predicts pathways and potential biological functions for further characterization of this novel function of ECPsp under inflammatory conditions.
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http://dx.doi.org/10.1186/1752-0509-6-105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3478170PMC
August 2012