Prolonged and Substantial Discordance in Prevalence of Raltegravir-Resistant HIV-1 in Plasma Versus PBMC Samples Revealed by 454 “Deep” Sequencing.
Prolonged and Substantial Discordance in Prevalence of Raltegravir-Resistant HIV-1 in Plasma versus PBMC Samples Revealed by 454 “Deep” Sequencing.
Filed under: Drug and Alcohol Rehabilitation
PLoS One. 2012; 7(9): e46181
Lee GQ, Swenson LC, Poon AF, Martin JN, Hatano H, Deeks SG, Harrigan PR
The evolution of drug resistance mutations in plasma samples is relatively well-characterized. However, the viral population and diversity in other body compartments such as peripheral blood mononuclear cells (PBMC) remains poorly understood. Previous studies have mostly focused on protease and reverse transcriptase drug resistance mutations (DRMs). In this study, we used 454 “deep” sequencing technology to observe and quantify longitudinally the prevalence of resistance mutations associated with the integrase inhibitor, raltegravir, in plasma versus PBMC samples from a San Francisco-based cohort. Four heavily treatment-experienced subjects were monitored in this study over a median of 1.2 years since the initiation of raltegravir-containing regimens. We observed a consistent discordance in the prevalence of DRMs, but not resistance pathway(s), in the plasma versus PBMC viral populations. In the final paired samples that were tested while the subjects were on a raltegravir-containing regimen, DRM prevalence reached 100% in plasma but remained 1% in PBMC on day 177 post-therapy in Subject 3180 (Q148H/G140S), 100% in plasma and 36% in PBMC on day 224 in Subject 3242 (N155H), 78% in plasma and 11-12% in PBMC on day 338 in Subject 3501 (Q148H/G140S), and 100% in plasma and 0% in PBMC on day 197 in Subject 3508 (Y143R). Furthermore, absolute sequence homology comparison between the two compartments revealed that 21% – 99% of PBMC sequences had no match in plasma, whereas 14% – 100% of plasma sequences had no match in PBMC. Overall, our observations suggested that plasma and PBMC hosted drastically different HIV-1 populations even after a prolonged exposure to raltegravir selection pressure.
HubMed – drug
Inhibition of Doxorubicin-Induced Senescence by PPAR? Activation Agonists in Cardiac Muscle Cells: Cooperation between PPAR? and Bcl6.
Filed under: Drug and Alcohol Rehabilitation
PLoS One. 2012; 7(9): e46126
Altieri P, Spallarossa P, Barisione C, Garibaldi S, Garuti A, Fabbi P, Ghigliotti G, Brunelli C
Senescence and apoptosis are two distinct cellular programs that are activated in response to a variety of stresses. Low or high doses of the same stressor, i.e., the anticancer drug doxorubicin, may either induce apoptosis or senescence, respectively, in cardiac muscle cells. We have demonstrated that PPAR?, a ligand-activated transcriptional factor that controls lipid metabolism, insulin sensitivity and inflammation, is also involved in the doxorubicin-induced senescence program. This occurs through its interference with the transcriptional repressor protein B cell lymphoma-6 (Bcl6). Low doses of doxorubicin increase the expression of PPAR? that sequesters Bcl6, thus preventing it from exerting its anti-senescent effects. We also found that L-165041, a specific PPAR? activator, is highly effective in protecting cardiomyocytes from doxorubicin-induced senescence through a Bcl6 related mechanism. In fact, L-165041 increases Bcl6 expression via p38, JNK and Akt activation, and at the same time it induces the release of Bcl6 from PPAR?, thereby enabling Bcl6 to bind to its target genes. L-165041 also prevented apoptosis induced by higher doses of doxorubicin. However, while experiments performed with siRNA analysis techniques very clearly showed the weight of Bcl6 in the cellular senescence program, no role was found for Bcl6 in the anti-apoptotic effects of L-165041, thus confirming that senescence and apoptosis are two very distinct stress response cellular programs. This study increases our understanding of the molecular mechanism of anthracycline cardiotoxicity and suggests a potential role for PPAR? agonists as cardioprotective agents.
HubMed – drug
Proteome Analysis Identified the PPAR? Ligand 15d-PGJ2 as a Novel Drug Inhibiting Melanoma Progression and Interfering with Tumor-Stroma Interaction.
Filed under: Drug and Alcohol Rehabilitation
PLoS One. 2012; 7(9): e46103
Paulitschke V, Gruber S, Hofstätter E, Haudek-Prinz V, Klepeisz P, Schicher N, Jonak C, Petzelbauer P, Pehamberger H, Gerner C, Kunstfeld R
Peroxisome proliferator-activated receptors (PPARs) have been originally thought to be restricted to lipid metabolism or glucose homeostasis. Recently, evidence is growing that PPAR? ligands have inhibitory effects on tumor growth. To shed light on the potential therapeutic effects on melanoma we tested a panel of PPAR agonists on their ability to block tumor proliferation in vitro. Whereas ciglitazone, troglitazone and WY14643 showed moderate effects on proliferation, 15d-PGJ2 displayed profound anti-tumor activity on four different melanoma cell lines tested. Additionally, 15d-PGJ2 inhibited proliferation of tumor-associated fibroblasts and tube formation of endothelial cells. 15d-PGJ2 induced the tumor suppressor gene p21, a G(2)/M arrest and inhibited tumor cell migration. Shot gun proteome analysis in addition to 2D-gel electrophoresis and immunoprecipitation of A375 melanoma cells suggested that 15d-PGJ2 might exert its effects via modification and/or downregulation of Hsp-90 (heat shock protein 90) and several chaperones. Applying the recently established CPL/MUW database with a panel of defined classification signatures, we demonstrated a regulation of proteins involved in metastasis, transport or protein synthesis including paxillin, angio-associated migratory cell protein or matrix metalloproteinase-2 as confirmed by zymography. Our data revealed for the first time a profound effect of the single compound 15d-PGJ2 on melanoma cells in addition to the tumor-associated microenvironment suggesting synergistic therapeutic efficiency.
HubMed – drug
The structural basis for the integrity of adenovirus ad3 dodecahedron.
Filed under: Drug and Alcohol Rehabilitation
PLoS One. 2012; 7(9): e46075
Szolajska E, Burmeister WP, Zochowska M, Nerlo B, Andreev I, Schoehn G, Andrieu JP, Fender P, Naskalska A, Zubieta C, Cusack S, Chroboczek J
During the viral life cycle adenoviruses produce excess capsid proteins. Human adenovirus serotype 3 (Ad3) synthesizes predominantly an excess of free pentons, the complexes of pentameric penton base and trimeric fiber proteins, which are responsible for virus penetration. In infected cells Ad3 pentons spontaneously assemble into dodecahedral virus-like nano-particles containing twelve pentons. They also form in insect cells during expression in the baculovirus system. Similarly, in the absence of fiber protein dodecahedric particles built of 12 penton base pentamers can be produced. Both kinds of dodecahedra show remarkable efficiency of intracellular penetration and can be engineered to deliver several millions of foreign cargo molecules to a single target cell. For this reason, they are of great interest as a delivery vector. In order to successfully manipulate this potential vector for drug and/or gene delivery, an understanding of the molecular basis of vector assembly and integrity is critical. Crystallographic data in conjunction with site-directed mutagenesis and biochemical analysis provide a model for the molecular determinants of dodecamer particle assembly and the requirements for stability. The 3.8 Å crystal structure of Ad3 penton base dodecamer (Dd) shows that the dodecahedric structure is stabilized by strand-swapping between neighboring penton base molecules. Such N-terminal strand-swapping does not occur for Dd of Ad2, a serotype which does not form Dd under physiological conditions. This unique stabilization of the Ad3 dodecamer is controlled by residues 59-61 located at the site of strand switching, the residues involved in putative salt bridges between pentamers and by the disordered N-terminus (residues 1-47), as confirmed by site directed mutagenesis and biochemical analysis of mutant and wild type protein. We also provide evidence that the distal N-terminal residues are externally exposed and available for attaching cargo.
HubMed – drug
Modeling of HIV-1 Infection: Insights to the Role of Monocytes/Macrophages, Latently Infected T4 Cells, and HAART Regimes.
Filed under: Drug and Alcohol Rehabilitation
PLoS One. 2012; 7(9): e46026
Li Q, Lu F, Wang K
A novel dynamic model covering five types of cells and three connected compartments, peripheral blood (PB), lymph nodes (LNs), and the central nervous system (CNS), is here proposed. It is based on assessment of the biological principles underlying the interactions between the human immunodeficiency virus type I (HIV-1) and the human immune system. The simulated results of this model matched the three well-documented phases of HIV-1 infection very closely and successfully described the three stages of LN destruction that occur during HIV-1 infection. The model also showed that LNs are the major location of viral replication, creating a pool of latently infected T4 cells during the latency period. A detailed discussion of the role of monocytes/macrophages is made, and the results indicated that infected monocytes/macrophages could determine the progression of HIV-1 infection. The effects of typical highly active antiretroviral therapy (HAART) drugs on HIV-1 infection were analyzed and the results showed that efficiency of each drug but not the time of the treatment start contributed to the change of the turnover of the disease greatly. An incremental count of latently infected T4 cells was made under therapeutic simulation, and patients were found to fail to respond to HAART therapy in the presence of certain stimuli, such as opportunistic infections. In general, the dynamics of the model qualitatively matched clinical observations very closely, indicating that the model may have benefits in evaluating the efficacy of different drug therapy regimens and in the discovery of new monitoring markers and therapeutic schemes for the treatment of HIV-1 infection.
HubMed – drug
More Drug And Alcohol Rehabilitation Information…