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1.
Inflammatory responses mediated by activated microglia play a pivotal role in the pathogenesis of human immunodeficiency virus type 1 (HIV-1)-associated neurocognitive disorders. Studies on identification of specific targets to control microglia activation and resultant neurotoxic activity are imperative. Increasing evidence indicate that voltage-gated K+ (Kv) channels are involved in the regulation of microglia functionality. In this study, we investigated Kv1.3 channels in the regulation of neurotoxic activity mediated by HIV-1 glycoprotein 120 (gp120)-stimulated rat microglia. Our results showed treatment of microglia with gp120 increased the expression levels of Kv1.3 mRNA and protein. In parallel, whole-cell patch-clamp studies revealed that gp120 enhanced microglia Kv1.3 current, which was blocked by margatoxin, a Kv1.3 blocker. The association of gp120 enhancement of Kv1.3 current with microglia neurotoxicity was demonstrated by experimental results that blocking microglia Kv1.3 attenuated gp120-associated microglia production of neurotoxins and neurotoxicity. Knockdown of Kv1.3 gene by transfection of microglia with Kv1.3-siRNA abrogated gp120-associated microglia neurotoxic activity. Further investigation unraveled an involvement of p38 MAPK in gp120 enhancement of microglia Kv1.3 expression and resultant neurotoxic activity. These results suggest not only a role Kv1.3 may have in gp120-associated microglia neurotoxic activity, but also a potential target for the development of therapeutic strategies. 相似文献
2.
The 231-residue capsid (CA) protein of human immunodeficiency virus type 1 (HIV-1) spontaneously self-assembles into tubes with a hexagonal lattice that is believed to mimic the surface lattice of conical capsid cores within intact virions. We report the results of solid-state nuclear magnetic resonance (NMR) measurements on HIV-1 CA tubes that provide new information regarding changes in molecular structure that accompany CA self-assembly, local dynamics within CA tubes, and possible mechanisms for the generation of lattice curvature. This information is contained in site-specific assignments of signals in two- and three-dimensional solid-state NMR spectra, conformation-dependent 15N and 13C NMR chemical shifts, detection of highly dynamic residues under solution NMR conditions, measurements of local variations in transverse spin relaxation rates of amide 1H nuclei, and quantitative measurements of site-specific 15N–15N dipole–dipole couplings. Our data show that most of the CA sequence is conformationally ordered and relatively rigid in tubular assemblies and that structures of the N-terminal domain (NTD) and the C-terminal domain (CTD) observed in solution are largely retained. However, specific segments, including the N-terminal β-hairpin, the cyclophilin A binding loop, the inter-domain linker, segments involved in intermolecular NTD–CTD interactions, and the C-terminal tail, have substantial static or dynamical disorder in tubular assemblies. Other segments, including the 310-helical segment in CTD, undergo clear conformational changes. Structural variations associated with curvature of the CA lattice appear to be localized in the inter-domain linker and intermolecular NTD–CTD interface, while structural variations within NTD hexamers, around local 3-fold symmetry axes, and in CTD–CTD dimerization interfaces are less significant. 相似文献
3.
《Bioorganic & medicinal chemistry》2016,24(8):1653-1657
The antiretroviral activity of azulene derivatives was detected for the first time. A series of eighteen diversely substituted azulenes was synthesized and tested in vitro using HIV-1 based virus-like particles (VLPs) and infectious HIV-1 virus in U2OS and TZM-bl cell lines. Among the compounds tested, the 2-hydroxyazulenes demonstrated the most significant activity by inhibiting HIV-1 replication with IC50 of 2–10 and 8–20 μM for the VLPs and the infectious virus, respectively. These results indicate that azulene derivatives may be potentially useful candidates for the development of antiretroviral agents. 相似文献
4.
Human immunodeficiency virus type-1 (HIV-1) Rev acts by inducing the specific nucleocytoplasmic transport of a class of incompletely spliced RNAs that encodes the viral structural proteins. The transfection of HeLA cells with a rev-defective HIV-1 expression plasmid, however, resulted in the export of overexpressed, intron-containing species of viral RNAs, possibly through a default process of nuclear retention. Thus, this system enabled us to directly compare Rev+ and Rev− cells as to the usage of RRE-containing mRNAs by the cellular translational machinery. Biochemical examination of the transfected cells revealed that although significant levels of gag and env mRNAs were detected in both the presence and absence of Rev, efficient production of viral proteins was strictly dependent on the presence of Rev. A fluoroscence in situ hybridisation assay confirmed these findings and provided further evidence that even in the presence of Rev, not all of the viral mRNA was equally translated. At the early phase of RNA export in Rev+ cells, gag mRNA was observed throughout both the cytoplasm and nucleoplasm as uniform fine stippling. In addition, the mRNA formed clusters mainly in the perinuclear region, which were not observed in Rev− cells. In the presence of Rev, expression of the gag protein was limited to these perinuclear sites where the mRNA accumulated. Subsequent staining of the cytoskeletal proteins demonstrated that in Rev+ cells gag mRNA is colocalized with β-actin in the sites where the RNA formed clusters. In the absence of Rev, in contrast, the gag mRNA failed to associate with the cytoskeletal proteins. These results suggest that in addition to promoting the emergence of intron-containing RNA from the nucleus, Rev plays an important role in the compartmentation of translation by directing RRE-containing mRNAs to the β-actin to form the perinuclear clusters at which the synthesis of viral structural proteins begins. 相似文献
5.
《Bioorganic & medicinal chemistry》2019,27(17):3836-3845
A novel series of 3-hydroxyquinazoline-2,4(1H,3H)-diones derivatives has been designed and synthesized. Their biochemical characterization revealed that most of the compounds were effective inhibitors of HIV-1 RNase H activity at sub to low micromolar concentrations. Among them, II-4 was the most potent in enzymatic assays, showing an IC50 value of 0.41 ± 0.13 μM, almost five times lower than the IC50 obtained with β-thujaplicinol. In addition, II-4 was also effective in inhibiting HIV-1 IN strand transfer activity (IC50 = 0.85 ± 0.18 μM) but less potent than raltegravir (IC50 = 71 ± 14 nM). Despite its relatively low cytotoxicity, the efficiency of II-4 in cell culture was limited by its poor membrane permeability. Nevertheless, structure-activity relationships and molecular modeling studies confirmed the importance of tested 3-hydroxyquinazoline-2,4(1H,3H)-diones as useful leads for further optimization. 相似文献
6.
Algirdas Mikalkėnas Bazilė Ravoitytė Daiva Tauraitė Elena Servienė Rolandas Meškys 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):384-389
Small molecule inhibitors have a powerful blocking action on viral polymerases. The bioavailability of the inhibitor, nevertheless, often raise a significant selectivity constraint and may substantially limit the efficacy of therapy. Phosphonoacetic acid has long been known to possess a restricted potential to block DNA biosynthesis. In order to achieve a better affinity, this compound has been linked with natural nucleotide at different positions. The structural context of the resulted conjugates has been found to be crucial for the acquisition by DNA polymerases. We show that nucleobase-conjugated phosphonoacetic acid is being accepted, but this alters the processivity of DNA polymerases. The data presented here not only provide a mechanistic rationale for a switch in the mode of DNA synthesis, but also highlight the nucleobase-targeted nucleotide functionalization as a route for enhancing the specificity of small molecule inhibitors. 相似文献
7.
8.
A systemic oxidative stress of HIV (+) individuals has been recognized from a low glutathione level and a high level of inflammatory cytokines such as TNF. Previously, we demonstrated that the catalase enzyme activity in HIV (+) population is significantly altered depending on the cell types; the level was significantly high in red blood cells while the enzymes in white blood cells were remarkably low (Res Commun Subs Abuse 16: 161–176, 1995). In this study, we further characterized the difference in RBC catalase molecules between HIV (+) and control population. We have found that RBC from HIV (+) population, whether they were asymptomatic or symptomatic, contained a significantly elevated catalase protein accompanied by the enzyme activities, and that the majority of the elevated protein were acidic pl of the molecules with an identical subunit mass of approximately 60 KDa. These results suggest that catalase is induced prior to and/or during erythroid differentiation lineage in HIV (+) population as a somatic defense to respond and compensate for a systemic oxidative stress and for an anemic condition. (Mol Cell Biochem 165: 77–81, 1996) 相似文献
9.
Ulf Dittmer Wolfgang Lüke Christiane Stahl-Hennig Cheick Coulibaly Harald Petry Walter Bodemer Gerhard Hunsmann Gerald Voss 《Journal of medical primatology》1994,23(5):298-303
Both naive and vaccinated macaques acquired a virus-specific proliferative helper T-cell reactivity in response to infection with the nonpathogenic human immunodeficiency virus type 2 (HIV-2). In contrast, macaques infected with the pathogenic simian immunodeficiency virus of the macaque strain (SIVmac) did not develop a helper T-cell response. Furthermore, a vaccine-induced preexisting T-cell reactivity was abrogated after SIVmac infection in vaccine failures. These differences may reflect the different pathogenicity of the two closely related viruses. 相似文献
10.
Expression of human immunodeficiency virus-1 integrase in Escherichia coli, at levels that had no effect on bacterial cell growth, blocked plaque formation by bacteriophages having single-stranded genomic DNA (M13) or RNA (R17, Q, PRR1). Plaque formation by phages having double-stranded genomic DNA (T4, PR4) was unaffected. Integrase also inhibited infection by the phagemid M13KO7, but it had no effect on production of phage once infection by M13KO7 was established. This result indicated that integrase affects an early stage in infection. Integrase also inhibited phage production following transfection by either single-stranded or double-stranded (replicative form) M13 DNA, it blocked M13 DNA replication, as assayed by incorporation of radioactive nucleotides into DNA, and it failed to affect bacterial pilus function. These data suggest that integrase interacts in vivo with phage nucleic acid, a conclusion supported by studies in which integrase was shown to have a DNA-binding activity in its C-terminal portion. This portion of integrase was both necessary and sufficient for interference of plaque formation by M13 in the present study. Expression of the N-terminal portion of integrase at the same level as intact integrase had little effect on phage growth, indicating that expression of foreign protein in general was not responsible for the inhibitory effect. The simple bacteriophage assay described is potentially useful for identifying integrase mutants that lack single-stranded DNA binding activity. 相似文献