Imperatorin Inhibits HIV-1 Replication through an Sp1-dependent Pathway

Abstract

Coumarins and structurally related compounds have been recently shown to present anti-human immunodeficiency virus, type 1 (HIV-1) activity. Among them, the dietary furanocoumarin imperatorin is present in citrus fruits, in culinary herbs, and in some medicinal plants. In this study we report that imperatorin inhibits either vesicular stomatitis virus-pseudotyped or gp160-enveloped recombinant HIV-1 infection in several T cell lines and in HeLa cells. These recombinant viruses express luciferase as a marker of viral replication. Imperatorin did not inhibit the reverse transcription nor the integration steps in the viral cell cycle. Using several 5 long terminal repeat-HIV-1 constructs where critical response elements were either deleted or mutated, we found that the transcription factor Sp1 is critical for the inhibitory activity of imperatorin induced by both phorbol 12-myristate 13-acetate and HIV-1 Tat. Moreover in transient transfections imperatorin specifically inhibited phorbol 12-myristate 13-acetate-induced transcriptional activity of the Gal4-Sp1 fusion protein. Since Sp1 is also implicated in cell cycle progression we further studied the effect of imperatorin on cyclin D1 gene transcription and protein expression and in HeLa cell cycle progression. We found that imperatorin strongly inhibited cyclin D1 expression and arrested the cells at the G 1 phase of the cell cycle. These results highlight the potential of Sp1 transcription factor as a target for natural anti-HIV-1 compounds such as furanocoumarins that might have a potential therapeutic role in the management of AIDS.

Development of a Fission Yeast-Based High-Throughput Screen to Identify Chemical Regulators of cAMP Phosphodiesterases

“…Members of these compound classes are known to have PDE-inhibitory properties, 37 including the furanocourmarin trioxsalen, furanochromones khellin, and visnagin, 38,39 although most of these compounds identified had not been shown to be PDE inhibitors. Interestingly, both rolipram and imperatorin had been previously shown to inhibit HIV replication, 40,41 although the mechanism of imperatorin action was unknown. We demonstrate here that imperatorin is an effective PDE4B inhibitor, although its effect on PDE4A is very modest (Fig.…”

Mechanisms of HIV-1 Inhibition by the Lipid Mediator N-Arachidonoyldopamine

“…PBMCs (2.5 ϫ 10 6 /ml) were treated with SEB (1 g/ml) for 72 h and then collected and used for recombinant virus infection assays. For cytotoxicity analysis, NADA-treated and untreated HIV-1-infected cells were incubated for 1 min at room temperature in the presence of propidium iodide (10 g/ml), as previously described (46). After incubation, cells were immediately analyzed by flow cytometry.…”

“…The detection of HIV-1-LTR integrated into the cell genome was performed, as previously described (46). The first PCR was conducted in hot start conditions by using primers Alu-LTR 5Ј (5Ј-TCCCAGCTACTCGGGAGGCTGAGG-3Ј) from conserved human Alu sequences and Alu-LTR 3Ј from conserved HIV-1-LTR sequences (5Ј-TTTCAGGTCCCTGTTCGGGCGCCA-3Ј).…”

Bioactive Chromone Derivatives – Structural Diversity

“…Numerous chromone-based phytochemicals have been purified from plant extracts or synthetised de novo, their properties being determined by the different substitution pattern of the chromone skeleton. In recent years, due to increasing public interest in healthy lifestyles and disease prevention and treatment, dietary supplements and nutraceuticals containing high doses of this type of phenolic derivatives have been introduced to the market [109][110][111]. In addition, some have even entered clinical trials, namely the synthetic flavone flavopiridol (5,7-dihydroxy-8-(4-N-methyl-2-hydroxypyridyl)-6-chloroflavone hydrochloride, Fig.…”