Development of <i>N</i>‑Hydroxycinnamamide-Based Histone Deacetylase Inhibitors with an Indole-Containing Cap Group

A novel series of histone deacetylase inhibitors combining <i>N</i>-hydroxycinnamamide bioactive fragment and indole bioactive fragment was designed and synthesized. Several compounds (<b>17c</b>, <b>17g</b>, <b>17h</b>, <b>17j</b>, and <b>17k</b>) exhibited comparable, even superior, total HDACs inhibitory activity and in vitro antiproliferative activities relative to the approved drug SAHA. A representative compound <b>17a</b> with moderate HDACs inhibition was progressed to isoform selectivity profile, Western blot analysis, and in vivo antitumor assay. Although HDACs isoform selectivity of <b>17a</b> was similar to that of SAHA, our Western blot results indicated that intracellular effects of <b>17a</b> at 1 μM were class I selective. It was noteworthy that the effect on histone H4 acetylation of SAHA decreased with time, while the effect on histone H4 acetylation of <b>17a</b> was maintained and even increased. Most importantly, compound <b>17a</b> exhibited promising in vivo antitumor activity in a U937 xenograft model

Additional file 1 of Serum levels of PDGF-CC as a potential biomarker for the diagnosis of Kawasaki disease

Supplementary Material

Optical study on the effects of the hydrogen injection timing on lean combustion characteristics using a natural gas/hydrogen dual-fuel injected spark-ignition engine

Lean combustion has the potential to achieve higher thermal efficiency for internal combustion (IC) engines. However, natural gas engines often suffer from slow burning rate and large cyclic variations when adopting lean combustion. In this study, using a dual-fuel optical engine with a high compression ratio, the effects of direct-injected hydrogen on lean combustion characteristics of natural gas engines was investigated, emphasizing the role of hydrogen injection timing. Synchronization measurement of in-cylinder pressure and high-speed photography was performed for combustion analysis. The results show that the direct-injected hydrogen exhibits great improvement in lean combustion instability and power capability of natural gas engines. Visual images and combustion phasing analysis indicate that the underlying reasons are ascribed to the fast flame propagation with hydrogen addition. Regarding the direct injection timings, it is found that late injection of direct-injected hydrogen can achieve higher thermal efficiency, manifesting advanced combustion phasing, and increased heat release rate. Specifically, the flame propagation speed is elevated by approximately 50% at −100 CAD than that of −250 CAD. Further analysis indicates that the improvement of engine performance is ascribed to the increased volumetric efficiency and in-cylinder turbulence intensity, manifesting distinct flame centroid pathways at different injection timings. The current study provides insights into the combustion optimization of natural gas engines under lean burning conditions

Primer pairs used for real-time PCR.

<p>Primer pairs of human <i>FGFR1</i>, <i>FGFR2</i>, <i>FGFR3</i>, <i>FGFR4</i>, influenza virus <i>M1</i>, and <i>GAPDH</i> were designed using Primer 5.0 and presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0124651#pone.0124651.t001" target="_blank">Table 1</a>.</p><p>Primer pairs used for real-time PCR.</p

Lentivirus-mediated FGFR1 overexpression in A549 cells significantly decreased influenza A virus replication.

<p>A549 cells were infected with recombinant lentivirus expressing FGFR1, FGFR4, or GFP (as a control). After 48 h, A549 cells were infected with PR8 virus (MOI = 1). The supernatants and lysates of A549 cells were harvested after 24 h virus infection. (<b>A</b>, <b>B</b>) Influenza M1 mRNA levels in A549 cells with PR8 and H5N1 were detected using real-time PCR. (<b>C</b>, <b>D</b>) Progeny virus titers of PR8 and H5N1 were determined as described previously. (<b>E</b>, <b>F</b>) FGFR1 and FGFR4 expression efficiencies were detected using real-time PCR and Western blotting. All graphs present the means ± s.e.m. (n = 3). Values of P<0.05 * were considered statistically significant and P<0.001 *** statistically highly significant.</p

FGFR1 silencing by RNAi increased influenza A/PR8 and H5N1 virus replication.

<p>(<b>A</b>-<b>D</b>) A549 cells were transiently transfected with specific siRNA targeting FGFR1, FGFR4, or negative control siRNA. Forty-eight hours later, A549 cells were infected with PR8 virus at an MOI of 1. The cell culture supernatants and cell lysates were obtained at 24 hpi. Influenza virus M1 mRNA expression in A549 cells with PR8 (<b>A</b>) or H5N1 (<b>B</b>) infection was detected using real-time PCR. Progeny virus titers of PR8 (<b>C</b>) or H5N1 (<b>D</b>) were determined using MDCK cells with the TCID₅₀ assay. (<b>E</b>) The knockdown efficiencies of FGFR1 and FGFR4 by target siRNA were tested using real-time PCR. (<b>F</b>) Protein expressions of FGFR1 and FGFR4 were detected using specific antibodies by Western blotting assay. All graphs represent the means ± s.e.m. (n = 3). Values of P<0.01 **and P<0.001 *** were considered statistically highly significant.</p

Specific siRNA target FGFR1 markedly increased PR8 virus entry at an early stage of the viral life cycle.

<p>(<b>A</b>-<b>C</b>) A549 cells were transfected with FGFR1 siRNA#1, FGFR4 siRNA#1, and negative control siRNA. After 48 h of transduction, A549 cells were incubated with PR8 virus at an MOI of 0.01 for 4 h, followed by indirect immunofluorescence assays. A549 cells were stained with anti-influenza A virus NP antibodies (green) and Hoechst 33342 (nucleus, blue). (<b>D</b>) The data of PR8-infected cells were presented as the percentages of NP-positive cells to the total number of cells. The bars represent the means ± s.e.m. (n = 3). P<0.001 *** were considered statistically highly significant.</p

Analysis of IFN-γ and IL-4 by ELISPOT assays.

<p>On day 14 following the second immunization, mice were sacrificed and single-cell suspensions were prepared from the spleen, cultured for 48 h, and stimulated with 5 μg/mL purified Ah01/AA viral antigen. IFN-γ (A) and IL-4 (B) secretion by splenocytes was determined by ELISPOT in triplicate wells. Values and bars represent means ± SD. ** <i>p</i><0.001 compared to the PBS group.</p

Protective efficacy of Ah01/AA ca vaccine immunized mice against a lethal challenge with live influenza Ah01/H7N9 virus.

<p>Two weeks after boost, vaccinated mice were i.n infected with Ah01/H7N9 (50LD₅₀) and monitored daily for 2 weeks post challenge. (A) Body weight change (%) of the mice. (B) Survival rate (%). Points represent means ± SD.</p

Live attenuated monovalent influenza A (H7N9) vaccines induce antibody responses in mice.

<p>Groups of mice were i.n. immunized at weeks 0 and 2 with various doses of 10⁴ CCID₅₀, 10⁵ CCID₅₀, and 10⁶ CCID₅₀ of the Ah01/AA ca vaccine or mock-infected with PBS. Levels of HI (A) and NT (B) antibodies against wt Influenza H7N9 virus in sera 2 weeks after prime and boost. Error bars indicate SDs (n = 8).</p