It is generally acknowledged that reactive oxygen species (ROS) play crucial roles in a variety of natural processes in cells. If increased to levels which cannot be neutralized by the defense mechanisms, they damage biological molecules, alter their functions, and also act as signaling molecules thus generating a spectrum of pathologies. In this review, we summarize current data on oxidative stress markers associated with human immunodeficiency virus type‐1 (HIV‐1) infection, analyze mechanisms by which this virus triggers massive ROS production, and describe the status of various defense mechanisms of the infected host cell. In addition, we have scrutinized scarce data on the effect of ROS on HIV‐1 replication. Finally, we present current state of knowledge on the redox alterations as crucial factors of HIV‐1 pathogenicity, such as neurotoxicity and dementia, exhaustion of CD4+/CD8+ T‐cells, predisposition to lung infections, and certain side effects of the antiretroviral therapy, and compare them to the pathologies associated with the nitrosative stress.
17 August 2011 in Bioorganic & Medicinal Chemistry
HIV-induced immune suppression results in the high prevalence of HIV/AIDS-associated malignancies including Kaposi sarcoma, non-Hodgkin lymphoma, and cervical cancer. HIV-infected people are also at an increased risk of “non-AIDS-defining” malignancies not directly linked to immune suppression but associated with viral infections. Their incidence is increasing despite successful antiretroviral therapy. The mechanism behind this phenomenon remains unclear. Here, we obtained daughter clones of murine mammary gland adenocarcinoma 4T1luc2 cells expressing consensus reverse transcriptase of HIV-1 subtype A FSU_A strain (RT_A) with and without primary mutations of drug resistance. Inin vitrotests, mutations of resistance to nucleoside inhibitors K65R/M184V reduced the polymerase, and to nonnucleoside inhibitors K103N/G190S, the RNase H activities of RT_A. Expression of these RT_A variants in 4T1luc2 cells led to increased production of the reactive oxygen species (ROS), lipid peroxidation, enhanced cell motility in the wound healing assay, and upregulation of expression ofVimentinandTwist. These properties, particularly, the expression ofTwist, correlated with the levels of expression RT_A and/or the production of ROS. When implanted into syngeneic BALB/C mice, 4T1luc2 cells expressing nonmutated RT_A demonstrated enhanced rate of tumor growth and increased metastatic activity, dependent on the level of expression of RT_A andTwist. No enhancement was observed for the clones expressing mutated RT_A variants. Plausible mechanisms are discussed involving differential interactions of mutated and nonmutated RTs with its cellular partners involved in the regulation of ROS. This study establishes links between the expression of HIV-1 RT, production of ROS, induction of EMT, and enhanced propagation of RT-expressing tumor cells. Such scenario can be proposed as one of the mechanisms of HIV-induced/enhanced carcinogenesis not associated with immune suppression.
A new series of potential nonnucleoside inhibitors of HIV-1 reverse transcriptase (NNRTIs) based on the carbocyclic 5′-nor-uracil scaffold were designed and synthesized. Three different aspects of the scaffold were investigated: the effects of adding a linker between the carbocyclic and phenyl fragments, introduction of different substituents on the benzoyl residue and replacing the central carbocyclic ring with a benzyl group. Analogues of 2′,3′-dideoxy-2′,3′-didehydro-5′-nor-uridine, bearing 3,5-dichloro- or 3,5-dimethylbenzoyl groups, showed inhibitory activity against HIV-RT wild-type (IC50 5–10 μM) and mutants L100I (IC50 1.2–2.1 μM) and K103N (IC50 8–17 μM).