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Immuno-neutralization of procalcitonin (ProCT) has been shown to ameliorate experimental sepsis as well as the renal complications of this disease. Accordingly, we investigated the direct effect of ProCT on mesangial cells (MCs). Primary culture of murine MCs. ProCT (0.5, 1.0, 2.5, 5.0 ng/ml) for 2, 4, 6 h. MCs were exposed in vitro to ProCT. Expression levels of IL-6, iNOS and TNF-α were determined by real time RT-PCR, Inflammatory pathways, and a panel of cytokines and chemokines involved in the process were investigated by PCR array; apoptosis/viability were evaluated in a multiplex assay and actin cytoskeleton alterations were examined by immunofluorescence (IF). ProCT caused an early elevation in both IL-6 and iNOS mRNA (2–4 h), and a later rise (6 h) in TNF-α mRNA. ProCT upregulated genes of proinflammatory pathways 5- to 24-fold compared to control. IF images revealed disruption of the actin cytoskeleton and retraction of cell bodies with loss of typical stellate or spindle shape phenotype. ProCT decreased MCs viability by 36 % compared to control cells and induced significant apoptosis. ProCT has direct cytotoxic properties and may play a role in septic acute kidney injury that is independent of endotoxemia or hemodynamic alterations.

Cone snails use venom containing a cocktail of peptides ('conopeptides') to capture their prey. Many of these peptides also target mammalian receptors, often with exquisite selectivity. Here we report the discovery of two new classes of conopeptides. One class targets alpha1-adrenoceptors (rho-TIA from the fish-hunting Conus tulipa), and the second class targets the neuronal noradrenaline transporter (chi-MrIA and chi-MrIB from the mollusk-hunting C. marmoreus). rho-TIA and chi-MrIA selectively modulate these important membrane-bound proteins. Both peptides act as reversible non-competitive inhibitors and provide alternative avenues for the identification of inhibitor drugs.

Protamine, a naturally occurring arginine-rich polycationic protein (pI 9.7 to 12), was tested in Necturus gallbladder using a transepithelial AC-impedance technique. Protamine sulfate or hydrochloride (100 micrograms/ml = 20 microM), dissolved in the mucosal bath, increased transepithelial resistance by 89% without affecting the resistance of subepithelial layers. At the same time, transepithelial voltage (psi ms) turned from slightly mucosa-positive values to mucosa-negative values of approximately +1 to -5 mV. The effect of protamine on transepithelial resistance was minimal at concentrations below 5 micrograms/ml but a maximum response was achieved between 10 and 20 micrograms/ml. Resistance started to increase within 1 min and was maximal after 10 min. These effects were not inhibited by serosal ouabain (5 X 10(-4) M) but could be readily reversed by mucosal heparin. The sequence of protamine effect and heparin reversal could be repeated several times in the same gallbladder. Mucosal heparin, a strong negatively charged mucopolysaccharide, or serosal protamine were without effect. Mucosal protamine reversibly decreased the partial ionic conductance of K and Na by a factor of 3, but did not affect Cl conductance. Net water transport from mucosa to serosa was reversibly increased by 60% by protamine. We conclude that protamine reversibly decreases the conductance of the cation-selective pathway through the tight junction. Although this effect is similar to that reported for 2,4,6-triamino-pyrimidinium (TAP), the mechanism of action may differ. We propose that protamine binds to the apical cell membrane and induces a series of intracellular events which leads to a conformational alteration of the tight junction structure resulting in decreased cationic permeability.

A number of 5- and 7-azaindolines were oxidized to the corresponding azaindoles by means of activated manganese dioxide. The dependence of the ease of dehydrogenation of 5- and 7-azaindolines by activated manganese dioxide on their oxidation potentials is demonstrated.