Endotoxin Modulates the Expression of Renal Drug Transporters in HIV-1 Transgenic Rats

PURPUSE: Bacterial co-infections and low grade endotoxemia are common in HIV patients. Inflammation due to endotoxin or HIV may influence the expression and activity of transporters. Kidney transporters influence renal drug clearances including many antiretroviral agents. Our objective was to study the effect of endotoxin and HIV on the renal expression of drug transporters in an HIV-transgenic (HIV-Tg) rat model. These rats develop immune dysfunction and AIDS-associated conditions like humans. METHODS: Endotoxin or saline was administered intraperitoneally to HIV-Tg or wild type (WT) littermates and kidneys were collected 18 hours later. Expression of transporters and cytokines were measured by qRT-PCR and Western blots. Serum cytokine levels were measured by ELISA. RESULTS: Endotoxin induced serum levels of IL-6, TNF-alpha and IFN-gamma in both HIV-Tg and WT animals. The basal mRNA expression of Oct2, Oct3, Octn1, Mate 1, Uratl and Entlwas significantly lower (33-60%) and the expression of Ent2 and Pept2 was significantly higher (33-45%) in HIV-Tg as compared to WT. While endotoxin significantly downregulated the mRNA expression of Mdra1 and Pept2 in both HIV and WT groups (69-78%), it imposed a significant reduction on the mRNA expression of Oct2, Oct3, Octn1, Mate 1, Oat2, urat1, and Ent1 (54-83%) only in the WT group. Endotoxin significantly increased the mRNA expression of Pept1 (140%) in both WT and HIV groups. CONCLUSIONS: HIV and endotoxin each imposed alterations in the expression of many clinically important renal drug transporters although co-infection did not augment this effect. Viral and/or bacterial infections may impact the renal clearance of drug substrates in patients and could potentially be a source of drug-disease interactions.