First, the NF ��B translocation inhibitor SN50 free overnight delivery fully blocked the decreased saquinavir accumulation mediated by LPS. No effect was observed with an inactive SN50 control peptide, SN50I. SN50 also significantly lowered levels of TNF and nitrite release in response to LPS, confirming a generalized decrease in microglial activation. Second, the MEK12 inhibitor U0126 also fully blocked the LPS mediated effects on saquinavir accumulation by the cells and nitrite release. Conclusions Here, we investigated how LPS induced inflammation al ters the function of drug transporters in microglia, the primary CNS target of HIV, using a clinically relevant concentration of the antiretroviral medication saquinavir as a prototypical probe substrate and the fol lowing model systems a rat microglia cell line, HAPI, and primary cultures of rat and mouse microglia.

Fur thermore, we examined at a molecular level, what mech anisms may drive the observed changes in saquinavir accumulation and retention by microglia following an inflammatory LPS challenge. Inhibitors,Modulators,Libraries As noted in another rat microglia cell line, accumulation of saquinavir into HAPI microglia cells was rapid, reached a plateau by one hour, and was increased significantly by a potent P glycoprotein inhibitor PSC833. In this model, an in crease in saquinavir accumulation in the presence of PSC833 provides an indirect measure of compound ef flux by the transporter. Following both short and long term LPS exposure in microglia, the overall accumulation of saquinavir decreased in a dose Inhibitors,Modulators,Libraries dependent manner, with significant decreases observed at 24 hours at doses greater than 2.

5 ngml LPS. Using LPS in the presence and absence of the P glycoprotein inhibitor PSC833, the decrease in saquinavir accumula tion Inhibitors,Modulators,Libraries was only partially explained by increases Inhibitors,Modulators,Libraries in P glyco protein function, that is, by increased P glycoprotein mediated efflux of compound from the intracellular compartment to the outside of the cell. The remainder of the unaccounted saquinavir transport surprisingly could not be explained by increases in efflux or protein expression Inhibitors,Modulators,Libraries of Mrp1, a transporter known to handle sa quinavir efficiently. Although less likely, a decrease in potential uptake of saquinavir into the cells via de creased SLC uptake transporter expressionfunction was also considered.

Transcripts of seven well characterized SLC transporters, some already well known to interact with ARs, were examined in the presence and absence of LPS. With the exception www.selleckchem.com/products/CP-690550.html of Slc22a2, none of these trans porters were expressed sig nificantly in HAPI microglia. Furthermore, Slc22a2 transcript levels in HAPI microglia were unchanged fol lowing LPS exposure. Therefore, it is unlikely that a change in SLC uptake transporters explains the reduced accumulation of saquinavir following LPS treatment.