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The effects of 16 lectins isolated from foodstuff on the transport system across human intestinal Caco-2 cell monolayers were investigated by using four fluorescent markers: lucifer yellow (LY) for the paracellular pathway, fluorescein (FL) for the monocarboxylic acid transporter-mediated pathway, rhodamine 123 for the P-glycoprotein-mediated efflux pathway, and calcein for the multidrug resistance associated protein-related efflux pathway. The transepithelial electrical resistance (TER) values for the monolayers were also measured. WGA from wheat germ, ABA from white mushroom, AOL from Aspergillus oryzae, and CSL3 from chum salmon eggs (each at 100 µg/mL) decreased the TER value by 20-40% which resulted in increased LY transport. These lectins, as well as such other lectins as SBA from soybean, RBA from rice bran, and Con A from jack bean, affected other transport pathways too. These results indicate that the lectins modulated the transepithelial transport system in different ways, probably because of their specific binding characteristics toward Caco-2 cell monolayers.

We consider the initial value problem to the Isobe-Kakinuma model for water waves and the structure of the model. The Isobe-Kakinuma model is the Euler-Lagrange equations for an approximate Lagrangian which is derived from Luke's Lagrangian for water waves by approximating the velocity potential in the Lagrangian. The Isobe-Kakinuma model is a system of second order partial differential equations and is classified into a system of nonlinear dispersive equations. Since the hypersurface t = 0 is characteristic for the IsobeKakinuma model, the initial data have to be restricted in an infinite dimensional manifold for the existence of the solution. Under this necessary condition and a sign condition, which corresponds to a generalized Rayleigh-Taylor sign condition for water waves, on the initial data, we show that the initial value problem is solvable locally in time in Sobolev spaces. We also discuss the linear dispersion relation to the model.

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Abstract:The effect of a chum salmon egg lectin (CSL3) on tight junction (TJ) of Caco-2 cell monolayers was investigated. The lectin opened TJ as indicated by the decrease of the transepithelial electrical resistance (TER) value and the increase of the permeation of lucifer yellow, which is transported via the TJ-mediated paracellular pathway. The effects of CSL3 were inhibited by the addition of 10 mM L-rhamnose or D-galactose which were specific sugars for CSL3. The lectin increased the intracellular Ca 2+ of Caco-2 cell monolayers, that could be inhibited by the addition of L-rhamnose. The fluorescence immunostaining of β-actin in Caco-2 cell monolayers revealed that the cytoskeleton was changed by the CSL3 treatment, suggesting that CSL3 depolymerized β-actin to cause reversible TJ structural and functional disruption. Although Japanese jack bean lectin and wheat germ lectin showed similar effects in the decrease of the TER values and the increase of the intracellular Ca 2+ , they could not be inhibited by the same concentrations of simple sugars, such as D-glucose and N-acetyl-D-glucosamine.