Impact of UGT1A1 gene polymorphisms on plasma dolutegravir trough concentrations and neuropsychiatric adverse events in Japanese individuals infected with HIV-1.

BACKGROUND: Dolutegravir (DTG) is metabolized mainly by uridine diphosphate (UDP)-glucuronosyltransferase 1A1 (UGT1A1), and partly by cytochrome P450 3A (CYP3A). Therefore, we focused on UGT1A1 gene polymorphisms (*6 and *28) in Japanese individuals infected with human immunodeficiency virus (HIV)-1 to examine the relationship between their plasma trough concentration of DTG and gene polymorphisms. Recently, neuropsychiatric adverse events (NP-AEs) after the use of DTG have become a concern, so the association between UGT1A1 gene polymorphisms and selected NP-AEs was also investigated. METHODS: The study subjects were 107 Japanese patients with HIV-1 infections who were receiving DTG. Five symptoms (dizziness, headache, insomnia, restlessness, and anxiety) were selected as NP-AEs. The subjects were classified by their UGT1A1 gene polymorphisms for the group comparison of DTG trough concentration and the presence or absence of NP-AEs. RESULTS: The subjects consisted of eight (7%) *6 homozygotes, three (3%) *28 homozygotes, four (4%) for *6/*28 compound heterozygotes, 23 (21%) *6 heterozygotes, 18 (17%) *28 heterozygotes, and 51 (48%) patients carrying the normal allele. The plasma DTG trough concentration of the *6 homozygous patients was significantly higher than that of the patients carrying the normal allele (median, 1.43 and 0.82 µg/mL, respectively, p = 0.0054). The *6 and *28 heterozygous patients also showed significantly higher values than those shown by patients with the normal allele. Multivariate analysis revealed that carrying one or two UGT1A1*6 gene polymorphisms, one UGT1A1*28 polymorphism, and age of < 40 years were independent factors associated with high DTG trough concentrations. The median DTG trough concentration was significantly higher in the patients with NP-AEs (1.31 µg/mL) than in those without NP-AEs (1.01 µg/mL). Consistent with these results, subjects carrying UGT1A1*6, UGT1A1*28, or both alleles showed a higher cumulative incidence of having selected NP-AEs than those carrying the normal alleles (p = 0.0454). CONCLUSION: In addition to younger age, carrying UGT1A1*6 and/or UGT1A1*28 was demonstrated to be a factor associated with high DTG trough concentrations. Our results also suggest a relationship between plasma DTG trough concentrations and NP-AEs, and that carrying UGT1A1*6 and/or UGT1A1*28 alleles might be a risk factor for NP-AEs.

Structure-activity relationship study of phenylpyrazole derivatives as a novel class of anti-HIV agents.

The structure-activity relationship of phenylpyrazole derivative 1 was investigated for the development of novel anti-HIV agents. Initial efforts revealed that the diazenyl group can be replaced by an aminomethylene group. In addition, we synthesized various derivatives by the reductive amination of benzaldehydes with 5-aminopyrazoles and carried out parallel structural optimization on the benzyl group and the pyrazole ring. This optimization led to a six-fold more potent derivative 32j than the lead compound 1, and this derivative has a 3',4'-dichloro-(1,1'-biphenyl)-3-yl group.

Comprehensive in vitro analysis of simian retrovirus type 4 susceptibility to antiretroviral agents.

Simian retrovirus type 4 (SRV-4), a simian type D retrovirus, naturally infects cynomolgus monkeys, usually without apparent symptoms. However, some infected monkeys presented with an immunosuppressive syndrome resembling that induced by simian immunodeficiency virus infection. Antiretrovirals with inhibitory activity against SRV-4 are considered to be promising agents to combat SRV-4 infection. However, although some antiretrovirals have been reported to have inhibitory activity against SRV-1 and SRV-2, inhibitors with anti-SRV-4 activity have not yet been studied. In this study, we identified antiretroviral agents with anti-SRV-4 activity from a panel of anti-human immunodeficiency virus (HIV) drugs using a robust in vitro luciferase reporter assay. Among these, two HIV reverse transcriptase inhibitors, zidovudine (AZT) and tenofovir disoproxil fumarate (TDF), potently inhibited SRV-4 infection within a submicromolar to nanomolar range, which was similar to or higher than the activities against HIV-1, Moloney murine leukemia virus, and feline immunodeficiency virus. In contrast, nonnucleoside reverse transcriptase inhibitors and protease inhibitors did not exhibit any activities against SRV-4. Although both AZT and TDF effectively inhibited cell-free SRV-4 transmission, they exhibited only partial inhibitory activities against cell-to-cell transmission. Importantly, one HIV integrase strand transfer inhibitor, raltegravir (RAL), potently inhibited single-round infection as well as cell-free and cell-to-cell SRV-4 transmission. These findings indicate that viral expansion routes impact the inhibitory activity of antiretrovirals against SRV-4, while only RAL is effective in suppressing both the initial SRV-4 infection and subsequent SRV-4 replication.

Novel histone deacetylase inhibitor NCH-51 activates latent HIV-1 gene expression.

Pharmacological manipulations to purge human immunodeficiency virus (HIV) from latent reservoirs have been considered as an adjuvant therapeutic approach to highly-active antiretroviral therapy for the eradication of HIV. Our novel histone deacetylase inhibitor NCH-51 induced expression of latent HIV-1 with minimal cytotoxicity. Using chromatin immunoprecipitation assays, we observed a reduction of HDAC1 occupancy, histone hyperacetylation and the recruitment of positive transcription factors at the HIV-1 promoter in latently infected-cells under the treatment with NCH-51. Mutation studies of the long terminal repeat (LTR) revealed NCH-51 mediated gene expression through the Sp1 sites. When Sp1 expression was knocked-down by small interfering RNA, the NCH-51-mediated activation of a stably integrated HIV-1 LTR was attenuated. Moreover, the Sp1 inhibitor mithramycin A abolished the effects of NCH-51.

Involvement of histone H3 lysine 9 (H3K9) methyltransferase G9a in the maintenance of HIV-1 latency and its reactivation by BIX01294.

Elucidating the mechanism of human immunodeficiency virus, type 1 (HIV-1) provirus transcriptional silencing in latently infected cells is crucial for understanding the pathophysiological process of HIV-1 infection. It is well established that hypoacetylation of histone proteins by histone deacetylases is involved in the maintenance of HIV-1 latency by repressing viral transcription. Although histone methylation is involved in the organization of chromatin domains and plays a central epigenetic role in gene expression, the role of histone methylation in the maintenance of HIV-1 latency has not been clarified. Here we present evidence that histone H3 Lys(9) (H3K9) methyltransferase G9a is responsible for transcriptional repression of HIV-1 by promoting repressive dimethylation at H3K9 and for the maintenance of viral latency. We observed that G9a significantly inhibited basal, as well as, the induced HIV-1 gene expression by tumor necrosis factor-alpha or Tat. Mutant G9a, however, lacking the SET domain responsible for the catalytic activity of histone methyltransferase, did not show such an effect. When G9a expression was knocked down by small interfering RNA, HIV-1 replication was augmented from cells transiently transfected with a full-length HIV-1 clone. Moreover, a specific inhibitor of G9a, BIX01294, could reactivate expression of HIV-1 from latently infected cells such as ACH-2 and OM10.1. Furthermore, chromatin immunoprecipitation assays revealed the presence of G9a and H3K9 dimethylation on nucleosome histones in the vicinity of the HIV-1 long terminal repeat promoter. These results suggest that G9a is responsible for the transcriptional quiescence of latent HIV-1 provirus and provide a molecular basis for understanding the mechanism by which HIV-1 latency is maintained.