Migration of cells treated with Gal-3, Gal-3C and LNnT.

<p>Cells were treated for 21 h with buffer control, Cytochalasin D (197 nM), Gal-3 (50 μg mL^-1), Gal-3C (50 μg mL^-1), and LNnT (100 mM). Migration was normalized and compared to buffer control; *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.005; ****, p ≤ 0.0001.</p

Viability of cells under cell migration conditions.

<p>Viability of cells under cell migration conditions.</p

Clustering of integrins is increased on Gal-3 treated cells.

<p>Cells were stained using the same anti-α5-Cy5 conjugate employed for tracking experiments. Ten fields of stained cells were analyzed using ImageJ to identify clusters and measure their size. Treatment with Gal-3 resulted in an increase in the size of integrin clusters. See Table B and Figure A in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.s001" target="_blank">S1 File</a>. Data were compared to a PBS control, or PBS containing BME (control) using a student’s t-test to determine p values; *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.005; ****, p ≤ 0.0001.</p

Model of Gal-3 interactions with integrin.

<p>(<b>a.</b>) Glycosylated receptors, such as the integrins, will have reduced binding sites for Gal-3 if they are heavily sialylated. (<b>b.</b>) Removal of sialic acids by neuraminidase enzymes (or decreased SiaT activity) will increase the number of Gal-3 binding sites present, and should increase oligomerization (only a dimer is shown for clarity). Oligomers likely interact with cytoskeletal regulators, including talin,[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.ref089" target="_blank">89</a>] which lead to increased mobility through active processes. (<b>c.</b>) Addition of exogenous Gal-3C or a competitive binder (e.g. LNnT) will disrupt the formation of oligomers. This will occur either by (<b>d.</b>) competition for dimerization sites or (<b>e.</b>) blocking dimer binding sites.</p

Viability of cells treated with LNnT, Gal-3C, and Gal-3.

<p>Cells were treated for 21 h with buffer control, Gal-3 (50 μg mL^-1), Gal-3C (50 μg mL^-1), and LNnT (100 mM). Viability of each condition were measured using MTS assay.[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.ref088" target="_blank">88</a>] Viability for each condition was normalized and compared to buffer control; *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.005; ****, p ≤ 0.0001.</p

Lateral mobility of integrins.

<p>Lateral mobility of integrins.</p

Lateral mobility of integrins is modulated by the presence of saccharides and lectins.

<p>The lateral mobility of integrins were determined using SPT, and the data from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.t001" target="_blank">Table 1</a> are shown. Each sample population is shown as a bean plot,[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.ref087" target="_blank">87</a>] with the logarithmic median of the diffusion coefficients indicated by a solid line for each population.[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0184378#pone.0184378.ref087" target="_blank">87</a>] Each population is shown with a density estimate and horizontal lines indicate individual diffusion coefficient measurements. Gal-3C and Gal-3 treatments are shown for 50 μg mL^-1 concentrations. Diffusion coefficients are given as log(D), where D is in units of x 10⁻¹⁰ [cm²s^-1] or x 10⁻² [μm²s^-1]. Data were compared to a PBS control using a student’s t-test to determine p values; *, p ≤ 0.05; **, p ≤ 0.01; ***, p ≤ 0.005; ****, p ≤ 0.0001.</p

Selective Inhibitors of Human Neuraminidase 3

Human neuraminidases (NEU) are associated with human diseases including cancer, atherosclerosis, and diabetes. To obtain small molecule inhibitors as research tools for the study of their biological functions, we designed a library of 2-deoxy-2,3-didehydro-<i>N</i>-acetylneuraminic acid (DANA) analogues with modifications at C4 and C9 positions. This library allowed us to discover selective inhibitors targeting the human NEU3 isoenzyme. Our most selective inhibitor for NEU3 has a <i>K</i>_i of 320 ± 40 nM and a 15-fold selectivity over other human neuraminidase isoenzymes. This inhibitor blocks glycolipid processing by NEU3 in vitro. To improve their pharmacokinetic properties, various esters of the best inhibitors were synthesized and evaluated. Finally, we confirmed that our best compounds exhibited selective inhibition of NEU orthologues from murine brain

Selective Inhibitors of Human Neuraminidase 3

Human neuraminidases (NEU) are associated with human diseases including cancer, atherosclerosis, and diabetes. To obtain small molecule inhibitors as research tools for the study of their biological functions, we designed a library of 2-deoxy-2,3-didehydro-<i>N</i>-acetylneuraminic acid (DANA) analogues with modifications at C4 and C9 positions. This library allowed us to discover selective inhibitors targeting the human NEU3 isoenzyme. Our most selective inhibitor for NEU3 has a <i>K</i>_i of 320 ± 40 nM and a 15-fold selectivity over other human neuraminidase isoenzymes. This inhibitor blocks glycolipid processing by NEU3 in vitro. To improve their pharmacokinetic properties, various esters of the best inhibitors were synthesized and evaluated. Finally, we confirmed that our best compounds exhibited selective inhibition of NEU orthologues from murine brain