Development of NLRP3 inhibitors for HIV-associated neuroinflammation in cocaine use.

ABSTRACT Despite the advances in antiretroviral therapy (ART) and its widespread use, cognitive impairment is commonly seen in HIV-1-infected patients. A salient feature of the HIV-1 infection is the initiation and maintenance of chronic inflammation which underlies a number of co-morbidities. HIV-associated neurocognitive disorders (HAND) represent a most common comorbidity in HIV patients and involves a spectrum of cognitive, motor, and/or neurological issues. Substances of abuse, such as cocaine, aggravate the CNS pathogenesis even in patients receiving ART, with neuroinflammation playing the central role in this comorbidity. Given the widespread occurrence of substance abuse in HIV patients, therapies that specifically target neuroinflammation in this patient population remains an urgent and unmet challenge. Nucleotide binding domain of the leucine rich repeat pyrin domain containing protein-3 (NLRP3) inflammasome has emerged as a druggable target for the management of HIV-1-associated neuropathologies, but optimal drug candidates have not been designed yet. The NLRP3 inflammasome is shown to be activated in response to a wide array of pathogen- and danger-associated molecular patterns (PAMPs and DAMPs respectively). Activation of the NLRP3 inflammasome in turn, stimulates the activity of caspase-1 and results in the release of pro- inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18, ultimately causing neuronal pyroptosis and death. Disruption of NLRP3 signaling was reported to display beneficial effects in the transgenic mouse models of neuroinflammation. Our recent studies identified a small molecule, AMS-17, that thwarted the NLRP3 activation in N9 microglia both in vitro and in vivo. AMS-17 was well-tolerated by the microglial cells and did not adversely affect microglial viability. This proposal is focused on developing computationally-guided structural changes in AMS-17 to improve its biological activity and maintain low toxicity. Aim 1 described in this proposal is focused on the computer-assisted design, synthesis and chemical characterization of AMS-17 analogues. Aim 2 will involve in vitro and in vivo screening of the novel analogues developed in Aim 1. The in vivo studies will be performed in HIV-infected humanized mice treated with cocaine, thus modeling the disease in people. The proposed studies are highly significant since they will provide new therapeutic options to minimize HIV- associated neurocognitive dysfunction in substance abuse. The proposal incorporates expertise in the area of synthetic medicinal chemistry (Dr. Kulkarni), computational chemistry (Dr. Hevener) and biological screening (Dr. Bukrinsky). Additionally, Dr. Mocchetti will provide his expertise in the area of animal models of cocaine in HIV. The proposal builds on our previous research and is fully consistent with the goals of this RFA.