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1.  Design, Synthesis, Mechanisms of Action, and Toxicity of Novel 20(S)-Sulfonylamidine Derivatives of Camptothecin as Potent Antitumor Agents 
Journal of Medicinal Chemistry  2014;57(14):6008-6018.
Twelve novel 20-sulfonylamidine derivatives (9a–9l) of camptothecin (1) were synthesized via a Cu-catalyzed three-component reaction. They showed similar or superior cytotoxicity compared with that of irinotecan (3) against A-549, DU-145, KB, and multidrug-resistant (MDR) KBvin tumor cell lines. Compound 9a demonstrated better cytotoxicity against MDR cells compared with that of 1 and 3. Mechanistically, 9a induced significant DNA damage by selectively inhibiting Topoisomerase (Topo) I and activating the ATM/Chk related DNA damage-response pathway. In xenograft models, 9a demonstrated significant activity without overt adverse effects at 5 and 10 mg/kg, comparable to 3 at 100 mg/kg. Notably, 9a at 300 mg/kg (i.p.) showed no overt toxicity in contrast to 1 (LD50 56.2 mg/kg, i.p.) and 3 (LD50 177.5 mg/kg, i.p.). Intact 9a inhibited Topo I activity in a cell-free assay in a manner similar to that of 1, confirming that 9a is a new class of Topo I inhibitor. 20-Sulfonylamidine 1-derivative 9a merits development as an anticancer clinical trial candidate.
PMCID: PMC4111373  PMID: 25003995
2.  Interception of the endotoxin-induced arterial hyporeactivity to vasoconstrictors 
Vascular pharmacology  2014;62(1):15-23.
Septic shock is a severe pathophysiologic condition characterized by vasodilation, hypotension, hypoperfusion, tissue hypoxia, multiple organ failure and death. It is unclear what causes the septic vasodilation that may result from general dysfunction of vascular smooth muscles (VSMs) or selective disruption of vasomotor balances in VSMs. The latter could be due to enhanced vasorelaxation and/or depressed vasoconstriction. Understanding these may lead to pharmacological interventions to septic vasodilation. Therefore, we performed studies in isolated and perfused mesenteric arterial rings. A 20-h exposure of the rings to lipopolysaccharide (LPS, 1μg/ml) led to hyporeactivity to phenylephrine (PE). However, the responses of the LPS-treated rings to high concentrations of KCl (60mM) and ATP remained comparable to control rings, suggesting that contractility of VSMs is retained. The hyporeactivity was marginally affected by atropine, indomethacin and L-NAME, suggesting that endothelium-dependent vasorelaxation does not play a major role. In addition to PE, the LPS-treated rings were hyporeactive to dopamine, histamine and angiotensin II. They showed intermediate hyporeactivity to the thromboxane-A2 receptor agonist U46619. Little hyporeactivity to endothelin-1 (ET-1), serotonin (5-HT) and vasopressin was found. ET-1-induced vasoconstriction occurred without endothelium, whereas the effect of serotonin was endothelium dependent. Although rings were hyporeactive to some of the vasopressors, their vasoconstriction effects were significantly potentiated by PE co-application. Taken together, these data suggest that the endotoxin-induced vasodilation may not result from general dysfunction of VSMs, neither from the endothelium-dependent vasorelaxation. The promising vascular response to various vasoconstrictors found in this study warrants further investigations of therapeutic potentials of these agents.
PMCID: PMC4374743  PMID: 24792896
Cardiovascular; endotoxemia; sepsis; septic shock; vascular tones; vasoconstrictor
3.  New Scalarane Sesterterpenoids from the Formosan Sponge Ircinia felix 
Marine Drugs  2015;13(7):4296-4309.
Five new scalarane sesterterpenoids, felixins A–E (1–5), were isolated from the Formosan sponge Ircinia felix. The structures of scalaranes 1–5 were elucidated on the basis of spectroscopic analysis. Cytotoxicity of scalaranes 1–5 against the proliferation of a limited panel of tumor cell lines was evaluated.
PMCID: PMC4515618  PMID: 26184237
Ircinia felix; sponge; scalarane; sesterterpenoid; cytotoxicity
4.  Outcomes and Treatment of Lumbosacral Spinal Tuberculosis: A Retrospective Study of 53 Patients 
PLoS ONE  2015;10(6):e0130185.
Study Strategy
A retrospective clinic study.
To evaluate the efficacy of conservative and surgical treatment for lumbosacral tuberculosis.
This study retrospectively reviewed 53 patients with lumbosacral tuberculosis who were treated in our institution between January 2005 and January 2011. There were 29 males and 24 females with average ages of 37.53 ± 17.28 years (range 6–72 years). 11 patients were given only anti-TB drugs; the remainder underwent anterior debridement, interbody fusion with and without instrumentation, or one-stage anterior debridement combined with posterior instrumentation. Outcome data for these patients included neurologic status, lumbosacral angle, erythrocyte sedimentation rate value(ESR) and C-reactive protein value(CRP) were assessed before and after treatment.
The mean lumbosacral angles were 23.00°± 2.90°in the conservatively treated patients and 22.36°± 3.92o in the surgically treated patients. At the final follow-up, this had improved to 24.10o ± 2.96°in the conservatively treated patients and 28.13° ± 1.93°in the surgically treated patients (all P < 0.05). There were statistically significant differences before and after treatment in terms of ESR and CRP (all P < 0.05). All patients achieved bone fusion. The mean follow-up period was 32.34 ± 8.13 months (range 18 to 55 months). The neurological deficit did not worsen in any of the patients.
It has been proven that conservative and surgical treatments are safe and effective and produce good clinical outcomes for patients with lumbosacral tuberculosis. The advantages of operation include thoroughness of debridement, decompression of the spinal cord, and adequate spinal stabilization.
PMCID: PMC4485466  PMID: 26121685
5.  Subsecond Analyses of G Protein Couple Receptor Ternary Complex Dynamics by Rapid Mix Flow Cytometry 
Methods in enzymology  2009;461:227-247.
The binding of full and partial agonist ligands (L) to G protein coupled receptors (GPCRs) initiates the formation of ternary complexes with G proteins (LRG complexes). We describe the assembly of detergent solubilized LRG complexes on beads. Rapid mix flow cytometry is used to analyze the subsecond dynamics of guanine nucleotide-mediated ternary complex disassembly. Ternary complexes were assembled using three formyl peptide receptor constructs (wild type, FPR-Gαi2 fusion, and FPR-GFP fusion) and two isotypes of the α subunit (αi2 and αi3) and βγ dimer (β1γ2 and β4γ2). Experimental evidence suggests that thermodynamic stability of ternary complexes is dependent on subunit isotype. Comparison of assemblies derived from the three constructs of FPR and G protein heterotrimers composed of the available subunit isotypes demonstrate that the fast step is associated with the separation of receptor and G protein and that the dissociation of the ligand or of the α and βγ subunits was slower. These results are compatible with a cell activation model involving G protein conformational changes rather than disassembly of Gαβγ heterotrimer.
PMCID: PMC4476792  PMID: 19480922
6.  Mannan-modified adenovirus targeting TERT and VEGFR-2: A universal tumour vaccine 
Scientific Reports  2015;5:11275.
Antigen-presenting cells including dendritic cells (DCs) express mannan receptors (MR) on their surface, which can be exploited in cancer therapy by designing immune-stimulatory viruses coated with mannan-modified capsids that then bind to DCs and initiate a potent immune response. Although the combination of anti-angiogenesis and cancer immunotherapy agents has a synergistic antitumor effect, more effective strategies for delivering such combinations are still required. Here we report the design and application of mannan-modified adenovirus that expresses both telomerase reverse transcriptase (TERT) and vascular endothelial growth factor receptor-2 (VEGFR-2). Cytotoxic T lymphocytes that are reactive to TERT and VEGFR-2 are capable of mounting an anti-tumour response in murine breast and colon tumour models and in a lung metastatic model. Compared with mannan-modified TERT adenovirus vaccine or mannan-modified VEGFR-2 adenovirus vaccine alone, the combined vaccine showed remarkably synergistic anti-tumour immunity in these models. Both TERT- and VEGFR-2-specific cytotoxic T lymphocytes (CTL) were identified in an in vitro cytotoxicity assay, and the CTL activity against tumour cells was significantly elevated in the combined vaccine group. Furthermore, CTL-mediated toxicity was blocked by anti-CD8 monoclonal antibodies. Thus, the combined mannan-modified TERT and VEGFR-2 adenovirus confers potent anti-tumour immunity by targeting both tumour cells and intratumoural angiogenesis.
PMCID: PMC4471666  PMID: 26085010
7.  Purple Sweet Potato Leaf Extract Induces Apoptosis and Reduces Inflammatory Adipokine Expression in 3T3-L1 Differentiated Adipocytes 
Background. Purple sweet potato leaves (PSPL) are widely grown and are considered a healthy vegetable in Taiwan. PSPL contain a high content of flavonoids, and the boiling water-extracted PSPL (PSPLE) is believed to prevent metabolic syndrome. However, its efficacy has not yet been verified. Therefore, we investigated the effect of PSPLE on adipocytes. Methods. The differentiated 3T3-L1 cells used in this study were derived from preadipocytes that were differentiated into adipocytes using an adipogenic agent (insulin, dexamethasone, and 3-isobutyl-1-methylxanthine); approximately 90% of the cells were differentiated using this method. Results. Treating the differentiated 3T3-L1 cells with PSPLE caused a dose-dependent decrease in the number of adipocytes rather than preadipocytes. In addition, treatment with PSPLE resulted in apoptosis of the differentiated 3T3-L1 cells as determined by DAPI analysis and flow cytometry. PSPLE also increased the expression of cleaved caspase-3 and poly ADP-ribose polymerase (PARP). Furthermore, PSPLE induced downregulation of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) gene expression in the differentiated 3T3-L1 cells. Conclusions. These results suggest that PSPLE not only induced apoptosis but also downregulated inflammation-associated genes in the differentiated 3T3-L1 cells.
PMCID: PMC4480248  PMID: 26170870
8.  New Anti-Inflammatory Cembranes from the Cultured Soft Coral Nephthea columnaris 
Marine Drugs  2015;13(6):3443-3453.
Two new cembranes, columnariols A (1) and B (2), were isolated from the cultured soft coral Nephthea columnaris. The structures of cembranes 1 and 2 were elucidated by spectroscopic methods. In the anti-inflammatory effects test, cembranes 1 and 2 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 protein of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Compound 1 exhibited moderate cytotoxicity toward LNCaP cells with an IC50 value of 9.80 μg/mL.
PMCID: PMC4483638  PMID: 26035022
Nephthea columnaris; cembrane; octocoral; antiinflammatory; iNOS; COX-2; cytotoxicity
9.  Effect of Childhood Obesity Prevention Programs on Blood Pressure: A Systematic Review and Meta-Analysis 
Circulation  2014;129(18):1832-1839.
Childhood overweight and obesity are associated with elevated blood pressure (BP). However, little is known about how childhood obesity lifestyle prevention programs affect BP. We assessed the effects of childhood obesity prevention programs on BP in children in developed countries.
Methods and Results
We searched databases up to April 22, 2013 for relevant randomized controlled trials, quasi-experimental studies, and natural experiments. Studies were included if they applied a diet and/or physical activity intervention(s) and were followed for ≥1 year (or ≥ 6 months for school-based intervention studies); they were excluded if they targeted only overweight/obese subjects or those with a medical condition. In our meta-analysis, intervention effects were calculated for systolic blood pressure (SBP) and diastolic blood pressure (DBP) using weighted random effects models. Of the 23 included intervention studies (involving 18,925 participants), 21 involved a school setting. Our meta-analysis included 19 studies reporting on SBP and 18 on DBP. The pooled intervention effect was −1.64 mmHg (95% CI: -2.56, −0.71; P=0.001) for SBP and -1.44 mmHg (95% CI: −2.28, −0.60; P=0.001) for DBP. The combined diet and physical activity interventions led to a significantly greater reduction in both SBP and DBP than the diet-only or physical activity-only intervention. Thirteen interventions (46%) had a similar effect on both adiposity-related outcomes and BP; while 11 interventions (39%) showed a significant desirable effect on BP, but not on adiposity-related outcomes.
Obesity prevention programs have a moderate effect on reducing BP and those targeting at both diet and physical activity seem to be more effective.
PMCID: PMC4346224  PMID: 24552832
child; obesity; prevention; blood pressure; intervention
10.  Polydatin Restores Endothelium-Dependent Relaxation in Rat Aorta Rings Impaired by High Glucose: A Novel Insight into the PPARβ-NO Signaling Pathway 
PLoS ONE  2015;10(5):e0126249.
Polydatin, a natural component from Polygonum Cuspidatum, has important therapeutic effects on metabolic syndrome. A novel therapeutic strategy using polydatin to improve vascular function has recently been proposed to treat diabetes-related cardiovascular complications. However, the biological role and molecular basis of polydatin’s action on vascular endothelial cells (VECs)-mediated vasodilatation under diabetes-related hyperglycemia condition remain elusive. The present study aimed to assess the contribution of polydatin in restoring endothelium-dependent relaxation and to determine the details of its underlying mechanism. By measuring endothelium-dependent relaxation, we found that acetylcholine-induced vasodilation was impaired by elevated glucose (55 mmol/L); however, polydatin (1, 3, 10 μmol/L) could restore the relaxation in a dose-dependent manner. Polydatin could also improve the histological damage to endothelial cells in the thoracic aorta. Polydatin’s effects were mediated via promoting the expression of endothelial NO synthase (eNOS), enhancing eNOS activity and decreasing the inducible NOS (iNOS) level, finally resulting in a beneficial increase in NO release, which probably, at least in part, through activation of the PPARβ signaling pathway. The results provided a novel insight into polydatin action, via PPARβ-NO signaling pathways, in restoring endothelial function in high glucose conditions. The results also indicated the potential utility of polydatin to treat diabetes related cardiovascular diseases.
PMCID: PMC4420467  PMID: 25941823
11.  Tackling the Cytotoxic Effect of a Marine Polycyclic Quinone-Type Metabolite: Halenaquinone Induces Molt 4 Cells Apoptosis via Oxidative Stress Combined with the Inhibition of HDAC and Topoisomerase Activities 
Marine Drugs  2015;13(5):3132-3153.
A marine polycyclic quinone-type metabolite, halenaquinone (HQ), was found to inhibit the proliferation of Molt 4, K562, MDA-MB-231 and DLD-1 cancer cell lines, with IC50 of 0.48, 0.18, 8.0 and 6.76 μg/mL, respectively. It exhibited the most potent activity against leukemia Molt 4 cells. Accumulating evidence showed that HQ may act as a potent protein kinase inhibitor in cancer therapy. To fully understand the mechanism of HQ, we further explored the precise molecular targets in leukemia Molt 4 cells. We found that the use of HQ increased apoptosis by 26.23%–70.27% and caused disruption of mitochondrial membrane potential (MMP) by 17.15%–53.25% in a dose-dependent manner, as demonstrated by Annexin-V/PI and JC-1 staining assays, respectively. Moreover, our findings indicated that the pretreatment of Molt 4 cells with N-acetyl-l-cysteine (NAC), a reactive oxygen species (ROS) scavenger, diminished MMP disruption and apoptosis induced by HQ, suggesting that ROS overproduction plays a crucial rule in the cytotoxic activity of HQ. The results of a cell-free system assay indicated that HQ could act as an HDAC and topoisomerase catalytic inhibitor through the inhibition of pan-HDAC and topoisomerase IIα expression, respectively. On the protein level, the expression of the anti-apoptotic proteins p-Akt, NFκB, HDAC and Bcl-2, as well as hexokinase II was inhibited by the use of HQ. On the other hand, the expression of the pro-apoptotic protein Bax, PARP cleavage, caspase activation and cytochrome c release were increased after HQ treatment. Taken together, our results suggested that the antileukemic effect of HQ is ROS-mediated mitochondrial apoptosis combined with the inhibitory effect on HDAC and topoisomerase activities.
PMCID: PMC4446623  PMID: 26006712
halenaquinone; histone deacetylase (HDAC); mitochondria; reactive oxygen species (ROS); topoisomerase
12.  An updated meta-analysis of laparoscopic versus open pyeloplasty for ureteropelvic junction obstruction in children 
Purpose: To further explore the feasibility and safety of laparoscopic pyeloplasty (LP) in children with ureteropelvic junction obstruction compared with open pyeloplasty (OP). Methods: PUBMED, Web of science and Cochrane library were searched until Oct. 2014 to find eligible studies. WMD, OR, RD and their 95% CIs were used to estimate the difference. Baseline such as age, gender and crossing vessel, perioperative outcomes such as length of stay, operative time, overall complications, and success rate were compared. All the meta-analyses were performed in Revman 5.2. Results: 15 comparative studies and one RCT were eligible and included in the meta-analysis. Compared with OP, LP groups might be associated with shorted length of hospital stay (WMD: -1.92, 95% CI: -2.45--1.39), reduced complications (OR: 0.71, 95% CI: 0.49-1.01) and equal success rate (RD: 0.01, 95% CI: -0.02-0.04), but prolonged operative time (WMD: 48.64, 95% CI: 31.16-66.12). Conclusion: Our findings supported that laparoscopic pyeloplasty is feasibility and safety in the treatment of UPJ obstruction in children, especially in high-volume centers with experienced experts. Considering the select bias and recall bias, more RCTs are required to further explore the efficiencies of LP.
PMCID: PMC4483847  PMID: 26131065
Laparoscopic pyeloplasty; ureteropelvic junction obstruction; children; meta-analysis
13.  Quantum Dots for quantitative flow cytometry 
In flow cytometry, the quantitation of fluorophore-tagged ligands and receptors on cells or at particulate surfaces is achieved by the use of standard beads of known calibration. To the best of our knowledge, only those calibration beads based on fluorescein, EGFP, phycoerythyrin and allophycocyanine are readily available from commercial sources. Because fluorophore based standards are specific to the selected fluorophore tag, their applicability is limited to the spectral region of resonance. Since quantum dots can be photo-excited over a continuous and broad spectral range governed by their size, it is possible to match the spectral range and width (absorbance and emission) of a wide range of fluorophores with appropriate quantum dots. Accordingly, quantitation of site coverage of the target fluorophores can be readily achieved using quantum dots whose emission spectra overlaps with the target fluorophore.
This chapter will focus on the relevant spectroscopic concepts and molecular assembly of quantum dot fluorescence calibration beads. We will first examine the measurement and applicability of spectroscopic parameters, ε, φ, and %T to fluorescence calibration standards. Where, ε is the absorption coefficient of the fluorophore, φ is the quantum yield of the fluorophore and %T is the percent fraction of emitted light that is transmitted by the bandpass filter at the detector PMT. The modular construction of beads decorated with discrete quantities of quantum dots with defined spectroscopic parameters is presented in the context of a generalizable approach to calibrated measurements of fluorescence in flow cytometry.
PMCID: PMC4388555  PMID: 21116979
Quantum dots; fluorescence calibration beads; flow cytometry; extinction coefficient; spectroscopy
14.  Cyclic [G(2′,5′)pA(3′,5′)p] Is the Metazoan Second Messenger Produced by DNA-Activated Cyclic GMP-AMP Synthase 
Cell  2013;153(5):1094-1107.
Recent studies identified cyclic GMP-AMP (cGAMP) as a metazoan second messenger triggering an interferon response. cGAMP is generated from GTP and ATP by cytoplasmic dsDNA sensor cGAMP synthase (cGAS). We combined structural, chemical, biochemical, and cellular assays to demonstrate that this second messenger contains G(2′,5′)pA and A(3′,5′)pG phosphodiester linkages, designated c[G(2′,5′) pA(3′,5′)p]. We show that, upon dsDNA binding, cGAS is activated through conformational transitions, resulting in formation of a catalytically competent and accessible nucleotide-binding pocket for generation of c[G(2′,5′)pA(3′,5′)p]. We demonstrate that cyclization occurs in a stepwise manner through initial generation of 5′-pppG(2′,5′)pA prior to cyclization to c[G(2′,5′)pA(3′,5′)p], with the latter positioned precisely in the catalytic pocket. Mutants of cGAS dsDNA-binding or catalytic pocket residues exhibit reduced or abrogated activity. Our studies have identified c[G(2′,5′)pA(3′,5′)p] as a founding member of a family of metazoan 2′,5′-containing cyclic heterodinucleotide second messengers distinct from bacterial 3′,5′ cyclic dinucleotides.
PMCID: PMC4382009  PMID: 23647843
15.  Briarenolides K and L, New Anti-Inflammatory Briarane Diterpenoids from an Octocoral Briareum sp. (Briareidae) 
Marine Drugs  2015;13(2):1037-1050.
Two new briarane-type diterpenoids, briarenolides K (1) and L (2), were isolated from an octocoral identified as Briareum sp. The structures of new briaranes 1 and 2 were elucidated by spectroscopic methods. In the in vitro anti-inflammatory effects test, briaranes 1 and 2 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS protein of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells.
PMCID: PMC4344617  PMID: 25689566
Briareum; briarane; octocoral; anti-inflammatory; iNOS
16.  Norcembranoidal Diterpenes from the Cultured-Type Octocoral Sinularia numerosa 
A known norcembranoidal diterpene, 5-episinuleptolide (1), along with a new analogue, 4α-hydroxy-5-episinuleptolide (2), were isolated from a cultured-type soft coral Sinularia numerosa. The structures of 1 and 2 were elucidated on the basis of spectroscopic methods and by comparison of the data with those of the related metabolites. Cytotoxicity of metabolites 1 and 2 against a panel of tumor cells is also described. Compound 2 exhibited moderate cytotoxicity toward CCRF-CEM cells with an IC50 value 4.21 μg/mL. Preliminary SAR (structure activity relationship) information was obtained from these two compounds.
PMCID: PMC4346896  PMID: 25654226
sinuleptolide; cembranoidal diterpene; Sinularia numerosa; cytotoxicity
17.  Isolation and Cytotoxicity Evaluation of the Chemical Constituents from Cephalantheropsis gracilis 
Cephalantheropsis gracilis afforded five new compounds: cephalanthrin-A (1), cephalanthrin-B (2), cephathrene-A (3), cephathrene-B (4), methyl 2-(aminocarbonyl)phenylcarbamate (5), and 52 known compounds. The structures of the new compounds were determined by spectroscopic analysis. Among the compounds isolated, tryptanthrin (6), phaitanthrin A (7), cephalinone D (19), and flavanthrin (30) showed significant cytotoxicity against MCF-7, NCI-H460, and SF-268 cell lines.
PMCID: PMC4346938  PMID: 25686035
Cephalantheropsis gracilis; Orchidaceae; quinazoline; tryptanthrin; indolotryptanthrin; dihydrophenanthrene; cytotoxicity
18.  Rapamycin inhibits mSin1 phosphorylation independently of mTORC1 and mTORC2 
Oncotarget  2015;6(6):4286-4298.
Current knowledge indicates that the mammalian target of rapamycin (mTOR) functions as two complexes, mTORC1 and mTORC2, regulating cell growth, proliferation, survival, differentiation, and motility. Recently mSin1 has been identified as a critical component of mTORC2, which is essential for phosphorylation of Akt and other signaling molecules. Studies have shown that rapamycin inhibits phosphorylation of mSin1. However, the underlying mechanism is unknown. Here we found that rapamycin inhibited phosphorylation of mSin1 potently and rapidly. Expression of rapamycin-resistant mutant of mTOR (mTOR-T), but not rapamycin-resistant and kinase dead mutant of mTOR (mTOR-TE), prevented rapamycin from inhibiting mSin1 phosphorylation, suggesting that rapamycin-induced dephosphorylation of mSin1 is mTOR-dependent. Surprisingly, ectopic expression of rapamycin-resistant and constitutively active p70 S6 kinase 1 (S6K1) did not confer resistance to rapamycin-induced dephosphorylation of mSin1. Furthermore, disruption of mTORC1 and mTORC2 by silencing raptor and rictor, respectively, or downregulation of S6K1 or Akt did not induce the dephosphorylation of mSin1 as rapamycin did. However, silencing mTOR or mLST8 mimicked the effect of rapamycin, inhibiting mSin1 phosphorylation. Our findings suggest that rapamycin inhibits mSin1 phosphorylation, which is independent of mTORC1 and mTORC2, but is possibly dependent on a new mTOR complex, which at least contains mTOR and mLST8.
PMCID: PMC4414190  PMID: 25738366
Rapamycin; mTOR; mSin1; raptor; rictor
19.  Real Time Detection of Protein Trafficking with High Throughput Flow Cytometry (HTFC) and Fluorogen Activating Protein (FAP) Base Biosensor 
We combined fluorogen activating protein (FAP) technology with high-throughput flow cytometry to detect real-time protein trafficking to and from the plasma membrane in living cells. The hybrid platform allows drug discovery for trafficking receptors, such as G-protein coupled receptors, receptor tyrosine kinases and ion channels, that were previously not suitable for high throughput screening by flow cytometry.. The system has been validated using the β2-adrenergic receptor (β2AR) system and extended to other GPCRs. When a chemical library containing ~1,200 off-patent drugs was screened against cells expressing FAP tagged β2AR, all known β2AR active ligands in the library were successfully identified, together with a few compounds that were later confirmed to regulate receptor internalization in a non-traditional manner. The unexpected discovery of new ligands by this approach indicates the potential of using this protocol for GPCR de-orphanization. In addition, screens of multiplexed targets promise improved efficiency with minor protocol modification.
PMCID: PMC3961059  PMID: 24510772
High throughput flow cytometer; Fluorogen activating protein; G protein coupled receptor; Receptor trafficking; Live cell assay
20.  Dihydroartemisinin inhibits the mammalian target of rapamycin-mediated signaling pathways in tumor cells 
Carcinogenesis  2013;35(1):192-200.
Dihydroartemisinin (DHA), an antimalarial drug, has previously unrecognized anticancer activity, and is in clinical trials as a new anticancer agent for skin, lung, colon and breast cancer treatment. However, the anticancer mechanism is not well understood. Here, we show that DHA inhibited proliferation and induced apoptosis in rhabdomyosarcoma (Rh30 and RD) cells, and concurrently inhibited the signaling pathways mediated by the mammalian target of rapamycin (mTOR), a central controller for cell proliferation and survival, at concentrations (<3 μM) that are pharmacologically achievable. Of interest, in contrast to the effects of conventional mTOR inhibitors (rapalogs), DHA potently inhibited mTORC1-mediated phosphorylation of p70 S6 kinase 1 and eukaryotic initiation factor 4E binding protein 1 but did not obviously affect mTORC2-mediated phosphorylation of Akt. The results suggest that DHA may represent a novel class of mTORC1 inhibitor and may execute its anticancer activity primarily by blocking mTORC1-mediated signaling pathways in the tumor cells.
PMCID: PMC3871936  PMID: 23929438
21.  Correlation and prognostic significance of MMP-2 and TFPI-2 differential expression in pancreatic carcinoma 
Aberrant expression of matrix metalloproteinase (MMP)-2 and tissue factor pathway inhibitor (TFPI)-2 not only correlate with tumorigenesis, but also with tumor invasion and metastasis. This study aims to investigate the correlation and prognostic significance of MMP-2 and TFPI-2 differential expression in pancreatic carcinoma. Immunohistochemistry was used to evaluate MMP-2 and TFPI-2 expression in tumor tissues and corresponding non-tumor tissues from 122 patients with pancreatic carcinoma. The results showed that the expression of MMP-2 was significantly (P < 0.05) higher in tumor tissues (78.7%) than in adjacent non-tumor tissues (27.9%), whereas the expression of TFPI-2 was significantly (P < 0.001) lower in tumor tissues (27.9%) than in adjacent non-tumor tissues (79.5%). Spearman’s rank correlation test showed a negative correlation between MMP-2 and TFPI-2 expression (r = -0.346, P < 0.001). Kaplan-Meier survival analysis showed that high MMP-2 expression was significantly correlated with decreased disease-free survival (DFS) (P < 0.001) and overall survival (OS) (P < 0.001), while high TFPI-2 expression was significantly associated with increased DFS (P < 0.001) and OS (P < 0.001) of the patients. Multivariate analysis showed that high MMP-2 expression can act as an independent predictive factor for poor DFS (P = 0.01); and low TFPI-2 expression as an independent prognostic factor for poor DFS (P < 0.001) and OS (P < 0.001). In conclusion, our findings suggested that the differential expression of MMP-2 and TFPI-2 have a negative correlation in pancreatic carcinoma tissues; they may be considered as valuable biomarkers for prognosis of pancreatic carcinoma.
PMCID: PMC4348899  PMID: 25755762
Pancreatic carcinoma; MMP-2; TFPI-2; biomarkers; prognosis
22.  Rumphellaoic Acid A, a Novel Sesquiterpenoid from the Formosan Gorgonian Coral Rumphella antipathies 
Marine Drugs  2014;12(12):5856-5863.
A novel sesquiterpenoid, rumphellaoic acid A (1), was isolated from the gorgonian coral Rumphella antipathies, and was found to possess a carbon skeleton that was obtained for the first time from a natural sources. The structure of 1 was elucidated by spectroscopic methods and this compound and was found to exert a moderate inhibitory effect on the release of elastase by human neutrophils.
PMCID: PMC4278205  PMID: 25486110
Rumphella antipathies; gorgonian; rumphellaoic acid; sesquiterpenoid; elastase
23.  Effect of Platelet-Rich Plasma and Bioactive Glass Powder for the Improvement of Rotator Cuff Tendon-to-Bone Healing in a Rabbit Model 
To test the hypothesis that a platelet-rich plasma (PRP) plus bioactive glass (BG) mixture could shorten the tendon-bone healing process in rotator cuff tendon repair, thirty mature male New Zealand white rabbits were randomly divided into three groups, Control, PRP, and PRP + BG. All groups underwent a surgical procedure to establish a rotator cuff tendon healing model. Mechanical examinations and histological assays were taken to verify the adhesion of the tendon-bone. Real-time PCR was adopted to analyze Bone Morphogenetic Protein-2 (BMP-2). The maximum load-to-failure value in mechanical examinations was significantly higher in the PRP + BG group than that in the control group after six weeks (Control 38.73 ± 8.58, PRP 54.49 ± 8.72, PRP + BG 79.15 ± 7.62, p < 0.001), but it was not significantly different at 12 weeks (PRP 74.27 ± 7.74, PRP + BG 82.57 ± 6.63, p = 0.145). In histological assays, H&E (hematoxylin-eosin) staining showed that the interface between the tendon-bone integration was much sturdier in the PRP + BG group compared to the other two groups at each time point, and more ordered arranged tendon fibers can be seen at 12 weeks. At six weeks, the mRNA expression levels of BMP-2 in the PRP + BG group were higher than those in the other groups (PRP + BG 0.65 ± 0.11, PRP 2.284 ± 0.07, Control 0.12 ± 0.05, p < 0.05). However, there was no significant difference in the mRNA expression levels of BMP-2 among the three groups at 12 weeks (p = 0.922, 0.067, 0.056). BMP-2 levels in PRP and PRP+BG groups were significantly lower at 12 weeks compared to six weeks (p = 0.006, <0.001).We found that the PRP + BG mixture could enhance tendon-bone healing in rotator cuff tendon repair.
PMCID: PMC4284689  PMID: 25464384
rotator cuff tendon; platelet-rich plasma; bioactive glass
24.  Staphylococcus epidermidis SrrAB Regulates Bacterial Growth and Biofilm Formation Differently under Oxic and Microaerobic Conditions 
Journal of Bacteriology  2014;197(3):459-476.
SrrAB expression in Staphylococcus epidermidis strain 1457 (SE1457) was upregulated during a shift from oxic to microaerobic conditions. An srrA deletion (ΔsrrA) mutant was constructed for studying the regulatory function of SrrAB. The deletion resulted in retarded growth and abolished biofilm formation both in vitro and in vivo and under both oxic and microaerobic conditions. Associated with the reduced biofilm formation, the ΔsrrA mutant produced much less polysaccharide intercellular adhesion (PIA) and showed decreased initial adherence capacity. Microarray analysis showed that the srrA mutation affected transcription of 230 genes under microaerobic conditions, and 51 genes under oxic conditions. Quantitative real-time PCR confirmed this observation and showed downregulation of genes involved in maintaining the electron transport chain by supporting cytochrome and quinol-oxidase assembly (e.g., qoxB and ctaA) and in anaerobic metabolism (e.g., pflBA and nrdD). In the ΔsrrA mutant, the expression of the biofilm formation-related gene icaR was upregulated under oxic conditions and downregulated under microaerobic conditions, whereas icaA was downregulated under both conditions. An electrophoretic mobility shift assay further revealed that phosphorylated SrrA bound to the promoter regions of icaR, icaA, qoxB, and pflBA, as well as its own promoter region. These findings demonstrate that in S. epidermidis SrrAB is an autoregulator and regulates biofilm formation in an ica-dependent manner. Under oxic conditions, SrrAB modulates electron transport chain activity by positively regulating qoxBACD transcription. Under microaerobic conditions, it regulates fermentation processes and DNA synthesis by modulating the expression of both the pfl operon and nrdDG.
PMCID: PMC4285975  PMID: 25404696
25.  An Analysis of the Binding Characteristics of a Panel of Recently Selected ICAM-1 Binding Plasmodium falciparum Patient Isolates 
PLoS ONE  2014;9(10):e111518.
The basis of severe malaria pathogenesis in part includes sequestration of Plasmodium falciparum-infected erythrocytes (IE) from the peripheral circulation. This phenomenon is mediated by the interaction between several endothelial receptors and one of the main parasite-derived variant antigens (PfEMP1) expressed on the surface of the infected erythrocyte membrane. One of the commonly used host receptors is ICAM-1, and it has been suggested that ICAM-1 has a role in cerebral malaria pathology, although the evidence to support this is not conclusive. The current study examined the cytoadherence patterns of lab-adapted patient isolates after selecting on ICAM-1. We investigated the binding phenotypes using variant ICAM-1 proteins including ICAM-1Ref, ICAM-1Kilifi, ICAM-1S22/A, ICAM-1L42/A and ICAM-1L44/A using static assays. The study also examined ICAM-1 blocking by four anti-ICAM-1 monoclonal antibodies (mAb) under static conditions. We also characterised the binding phenotypes using Human Dermal Microvascular Endothelial Cells (HDMEC) under flow conditions. The results show that different isolates have variant-specific binding phenotypes under both static and flow conditions, extending our previous observations that this variation might be due to variable contact residues on ICAM-1 being used by different parasite PfEMP1 variants.
PMCID: PMC4216080  PMID: 25360558

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