NLRP3 inflammasome has recently emerged as an attractive drug target for neurodegenerative disorders. In our continuing studies, a new chemical scaffold was designed as selective inhibitors of NLRP3 inflammasome. Initial characterization of the lead HL16 demonstrated improved however non-selective inhibition on the NLRP3 inflammasome. Structure-activity relationship studies of HL16 identified a new lead, 17 (YQ128), with an IC 50 of 0.30 ± 0.01 μM. Further studies from in vitro and in vivo models confirmed its selective inhibition on the NLRP3 inflammaome and its brain penetration. Furthermore, pharmacokinetic studies in rats at 20 mg/kg indicated extensive systemic clearance and tissue distribution, leading to a half-life of 6.6 hours. However, the oral bioavailability is estimated to be only 10%, which may reflect limited GI permeability and possibly high first-pass effects. Collectively, these findings strongly encourage development of more potent analogs with improved pharmacokinetic properties from this new chemical scaffold.

Human immunodeficiency (HIV) infection results in neurocognitive deficits in about one half of infected individuals. Despite systemic effectiveness, restricted antiretroviral penetration across the blood-brain barrier (BBB) is a major limitation in fighting central nervous system (CNS)-localized infection. Drug abuse exacerbates HIV-induced cognitive and pathological CNS changes. This study's purpose was to investigate the effects of the HIV-1 protein Tat and methamphetamine on factors affecting drug penetration across an in vitro BBB model. Factors affecting paracellular and transcellular flux in the presence of Tat and methamphetamine were examined. Transendothelial electrical resistance, ZO-1 expression, and lucifer yellow (a paracellular tracer) flux were aspects of paracellular processes that were examined. Additionally, effects on P-glycoprotein (P-gp) and multidrug resistance protein 1 (MRP-1) mRNA (via quantitative PCR [qPCR]) and protein (via immunoblotting) expression were measured; Pgp and MRP-1 are drug efflux proteins. Transporter function was examined after exposure of Tat with or without methamphetamine using the P-gp substrate rhodamine 123 and also using the dual P-gp/MRP-1 substrate and protease inhibitor atazanavir. Tat and methamphetamine elicit complex changes affecting transcellular and paracellular transport processes. Neither Tat nor methamphetamine significantly altered P-gp expression. However, Tat plus methamphetamine exposure significantly increased rhodamine 123 accumulation within brain endothelial cells, suggesting that treatment inhibited or impaired P-gp function. Intracellular accumulation of atazanavir was not significantly altered after Tat or methamphetamine exposure. Atazanavir accumulation was, however, significantly increased by simultaneous inhibition of P-gp and MRP. Collectively, our investigations indicate that Tat and methamphetamine alter aspects of BBB integrity without affecting net flux of paracellular compounds. Tat and methamphetamine may also affect several aspects of transcellular transport.

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There are several new mechanisms of action being represented within clinical development, including histone deacetylase (HDAC) inhibitors, gene therapies, broadly neutralizing anti-HIV antibodies, immune modulation, and drugs with new mechanisms to block HIV entry. The new therapies are being developed for both as add-on therapy to existing combination antiretroviral therapy and as agents to be used during treatment interruption. The current drugs in development have had varying degrees of success in the early trials. Each of these new drugs may potentially fill a void in current antiretroviral therapy (ART) therapies, which will ultimately lead to improved outcomes in HIV-infected individuals.

Combination antiretroviral therapy (cART) regimens are recommended for HIV patients to better achieve and maintain plasma viral suppression. Despite adequate plasma viral suppression, HIV persists inside the brain, which is, in part thought to result from poor brain penetration of antiretroviral drugs. In this study, a simple and ultra-sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of tenofovir, emtricitabine, and dolutegravir in cell lysates of an immortalized human brain microvascular endothelial cell line (hCMEC/D3) was developed and validated. Analytes were separated on a reverse phase C 18 column using water and 0.1% formic acid in acetonitrile as mobile phases. The analytes were detected using positive electrospray ionization mode with multiple reaction monitoring (MRM). The assay was linear in the concentration range of 0.1-100 ng mL −1 for all analytes. Intra-and inter-assay precision and accuracy were within ± 13.33% and ± 10.53%, respectively. This approach described herein was used to determine the intracellular accumulation of tenofovir, emtricitabine, dolutegravir simultaneously in hCMEC/D3 cells samples.