Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Non-small cell lung cancer (NSCLC), which accounts for ~85% of lung cancer, is the major cause of malignancy mortality around the world. TP53 dysfunction and hypoxia are the typical biological features of the diverse solid tumors, including NSCLC. To develop an effective and low cytotoxic biological agent for targeted therapy, a p53 fusion protein, which was conjugated with the minimum motif of oxygen-dependent degradation domain (ODD) and the basic domain of TAT of HIV-1 named as TAT-ODD-p53, was evaluated for the treatment of NSCLC established by grafting H1299 cell line in which TP53 is homozygously deleted. We provide the evidence that this p53 fusion protein could significantly induce the cell-cycle arrest and/or apoptosis to inhibit H1299 cells' growth via p53-dependent pathways, including up-regulation of p21 expression and activation of pro-caspase-3, especially under hypoxia in vitro. The results in vivo indicated that this protein could selectively accumulate in the low oxygen tension areas of solid tumor tissues, inhibiting tumor growth via a similar mechanism to that in vitro. No obvious side effects were observed. Therefore, this recombinant p53 protein is likely to become a good candidate for targeted therapy of NSCLC.
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PMID:Introduction of hypoxia-targeting p53 fusion protein for the selective therapy of non-small cell lung cancer. 2118 50

Neuroinflammation is a key process in the neuropathogenesis of AIDS virus since as a result of the aberrant activation of the chemokine receptors (CXCR4, CX3CR1 and CR5) produces proinflammatory cytokine release by infected cells, increases microglial neurotoxicity and generates lipoperoxides and reactive oxygen species (ROS) that eventually damage the neuron. Moreover, the neurotoxin Tat produces dendritic loss by interacting with the low-density lipoprotein receptor (LRP) and also overstimulates N-methyl D-aspartate receptors (NMDA). Furthermore, the aberrant interaction of glycoprotein gp120 with the CXCR4 chemokine receptor causes caspase-3-dependent apoptosis (ceramide is also released) activating apoptotic proteins (p53 and retinoblastoma), which are part of the neurotoxic mechanisms associated to neuronal dysfunction in neuroAIDS. Similarly, gliosis/microglial activation and the release of neurotoxic factors by infected monocytes with elevated amounts of certain chemokines in the cerebrospinal fluid (MCP-1 and fractalkine, among others) contribute to the neuropathogenesis of HIV-1. Alpha-synuclein and beta amyloid deposits have also been detected in post mortem brains of seropositives patients. In addition, there are studies have detected several systemic markers related with the degenerative effects of the virus and its neurotoxins on the central nervous system; such as osteopontin, CD163 and fractalkine, among others. Lastly, clinical trials have been conducted using protective strategies related that attempt to inhibit apoptotic proteins (GSK-3 beta), microglial activation inhibitors (minocycline), antioxidants (selegiline) or trophic factors (IGF-1, growth hormone or erythropoietin). These trials have shown that their treatments are beneficial and complementary to treat complications of HIV/AIDS.
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PMID:[HIV-1 neuropathogenesis: therapeutic strategies against neuronal loss induced by gp120/Tat glycoprotein in the central nervous system]. 2127 50

Pituitary adenomas with local invasion and high secretory activity remain a therapeutic challenge. The HIV protease inhibitor nelfinavir is a radiosensitizer in multiple tumor models. We tested nelfinavir as a radiosensitizer in pituitary adenoma cells in vitro and in vivo. We examined the effect of nelfinavir with radiation on in vitro cell viability, clonogenic survival, apoptosis, prolactin secretion, cell cycle distribution, and the PI3K-AKT-mTOR pathway. We evaluated tumor growth delay and confirmed nelfinavir's effect on the PI3K-AKT-mTOR pathway in a hind-flank model. Nelfinavir sensitized pituitary adenoma cells to ionizing radiation as shown by viability assays and clonogenic assay with an enhancement ratio of 1.2 (p < 0.05). There is increased apoptotic cell death, as determined by annexin-V expression and cleaved caspase-3 levels. Nelfinavir does not affect prolactin secretion or cell cycle distribution. In vivo, untreated tumors reached 4-fold volume in 12 days, 17 days with nelfinavir treatment, 27 days with radiation 6 Gy, and 41 days with nelfinavir plus radiation (one-way ANOVA p < 0.001). Decreased phospho-S6 on Western blotting in vitro and immunohistochemistry in vivo demonstrated nelfinavir inhibition of the PI3K-AKT-mTOR pathway. Our data suggests a promising combination therapy with nelfinavir plus radiation in pituitary adenomas, which should be investigated in clinical studies.
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PMID:Nelfinavir induces radiation sensitization in pituitary adenoma cells. 2181 Oct 91

Maslinic acid is a triterpenoid compound present in plants of Olea europaea. This compound has been reported to have potent antioxidant, anti-cancer, anti-HIV and anti-inflammatory activities. In this study, we investigated the neuroprotective effect of maslinic acid and its mechanism of action. With presence or absence of maslinic acid, cortical neurons were subjected to 1h of oxygen-glucose deprivation and 24h of reoxygenation. Cell injury was determined by lactate dehydrogenase (LDH) measurement and 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Neuronal apoptosis was evaluated by flow cytometry assay, caspase-3 expression/activity, caspase-9 activity and Bcl-2/Bax ratio. Nitric Oxide (NO) production and inducible nitric oxide synthase (iNOS) expression were also detected. Results showed that maslinic acid dose-dependently ameliorated neuron injury and apoptosis. Maslinic acid treatment normalized the caspase expression/activation and increased the Bcl-2/Bax ratio. In addition, maslinic acid inhibited oxygen-glucose deprivation-induced NO production and iNOS expression. These results indicated that maslinic acid has beneficial effects on hypoxic neurons by suppressing iNOS activation, which may, in turn, provide neuroprotection.
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PMID:Maslinic acid, a natural triterpenoid compound from Olea europaea, protects cortical neurons against oxygen-glucose deprivation-induced injury. 2183 77

HIV-1 infections lead to a progressive depletion of CD4 cells culminating in AIDS. The coreceptor usage by HIV varies from CCR5 (R5) tropic early in infection to CXCR4 (X4) tropic in later infections. Although the coreceptor switch from R5 to X4 tropic HIV is well associated with progression to AIDS, the role of CCR5 in disease progression especially in patients infected exclusively with R5 isolates throughout the disease remains enigmatic. To better understand the role of CCR5 and R5 tropic HIV envelope in AIDS pathogenesis, we asked whether the levels of CCR5 and/or HIV Env-mediated fusion determine apoptosis of bystander cells. We generated CD4(+) T cell lines expressing varying levels of CCR5 on the cell surface to show that CCR5 expression levels correlate with bystander apoptosis induction. The mechanism of apoptosis involved caspase-3 activation and mitochondrial depolarization and was dependent on gp41 fusion activity as confirmed by fusion-restricted gp41 point mutants and use of the fusion inhibitor T20. Interestingly, lower levels of CCR5 were able to support virus replication in the absence of bystander apoptosis. Our findings suggest that R5 HIV-1-mediated bystander apoptosis is dependent on both CCR5 expression levels as well as fusogenic activity of the Env glycoprotein.
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PMID:HIV ENV glycoprotein-mediated bystander apoptosis depends on expression of the CCR5 co-receptor at the cell surface and ENV fusogenic activity. 2185 12

The replication of viruses involves control of some aspects of host cell homeostasis by modification of target cell metabolism and regulation of the apoptotic machinery. It is not well known whether molecules involved in apoptotic pathways affect human immunodeficiency virus type 1 (HIV-1) replication and regulate viral yields. Using the susceptible Jurkat cell line, we studied the relationship of apoptosis-associated molecules with HIV-1 virus production using a sensitive real-time RT-PCR assay. Here, we found that expression of proapoptotic proteins, including Fas ligand (FasL), FADD, or p53 significantly increased HIV-1 virus production. In contrast, the expression of antiapoptotic molecules, such as FLIP, Bcl-X(L), and XIAP, decreased HIV-1 virus production. Knockdown of Bax with siRNA and FADD with expression of its antisense mRNA also inhibited viral replication and the caspase-3 inhibitor, Z-DEVD, and decreased virus production. These data indicate that HIV-1 infection regulates the apoptosis process to facilitate viral replication and inhibition of apoptosis may inhibit HIV-1 replication and cytopathogenesis. We also discuss the effects of MAPK signaling pathways and apoptosis on HIV-1 replication.
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PMID:Molecules from apoptotic pathways modulate HIV-1 replication in Jurkat cells. 2194 13

Chronic use of efavirenz (EFV) has been linked to incidences of hepatotoxicity in patients receiving EFV to treat HIV-1. While recent studies have demonstrated that EFV stimulates hepatic cell death a role for the metabolites of efavirenz in this process has yet to be examined. In the present study, incubation of primary human hepatocytes with synthetic 8-hydroxyEFV (8-OHEFV), which is the primary metabolite of EFV, resulted in cell death, caspase-3 activation and reactive oxygen species formation. The metabolite exerted these effects at earlier time points and using lower concentrations than were required for the parent compound. In addition, pharmacological inhibition of cytochrome P450-dependent metabolism of EFV using 1-aminobenzotriazole markedly decreased reactive oxygen species formation and cell death. Treatment of primary human hepatocytes with EFV and 8-OHEFV also stimulated phosphorylation of c-Jun N-terminal kinase (JNK) as well as phosphorylation of the JNK substrate c-Jun. Further, the mRNA and protein expression of an isoform of Bim (Bcl-2 interacting mediator of cell death) denoted as BimEL, which is proapoptotic and has been shown to be modulated by JNK, was increased. Inhibition of JNK using SP600125 prevented the EFV- and 8-OHEFV-mediated cell death. Silencing of Bim using siRNA transfected into hepatocytes also prevented cell death resulting from 8-OHEFV-treatment. These data suggest that the oxidative metabolite 8-OHEFV is a more potent inducer of hepatic cell death than the parent compound EFV. Further, activation of the JNK signaling pathway and BimEL mRNA expression appear to be required for EFV- and 8-OHEFV-mediated hepatocyte death.
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PMID:Efavirenz and 8-hydroxyefavirenz induce cell death via a JNK- and BimEL-dependent mechanism in primary human hepatocytes. 2195 19

Human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) usually occurs late in the course of HIV-1 infection and the mechanisms underlying HAD pathogenesis are not well understood. Accumulating evidence indicates that neuronal voltage-gated potassium (Kv) channels play an important role in memory processes and acquired neuronal channelopathies in HAD. To examine whether Kv channels are involved in HIV-1-associated neuronal injury, we studied the effects of HIV-1 glycoprotein 120 (gp120) on outward K+ currents in rat cortical neuronal cultures using whole-cell patch techniques. Exposure of cortical neurons to gp120 produced a dose-dependent enhancement of A-type transient outward K+ currents (IA). The gp120-induced increase of IA was attenuated by T140, a specific antagonist for chemokine receptor CXCR4, suggesting gp120 enhancement of neuronal IA via CXCR4. Pretreatment of neuronal cultures with a protein kinase C (PKC) inhibitor, GF109203X, inhibited the gp120-induced increase of IA. Biological significance of gp120 enhancement of IA was demonstrated by experimental results showing that gp120-induced neuronal apoptosis, as detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and caspase-3 staining, was attenuated by either an IA blocker 4-aminopyridine or a specific CXCR4 antagonist T140. Taken together, these results suggest that gp120 may induce caspase-3 dependent neuronal apoptosis by enhancing IA via CXCR4-PKC signaling.
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PMID:HIV-1gp120 induces neuronal apoptosis through enhancement of 4-aminopyridine-senstive outward K+ currents. 2201 98

The intestinal mucosa is an important target of human immunodeficiency virus (HIV) infection. HIV virus induces CD4+ T cell loss and epithelial damage which results in increased intestinal permeability. The mechanisms involved in nutrient malabsorption and alterations of intestinal mucosal architecture are unknown. We previously demonstrated that HIV-1 transactivator factor (Tat) induces an enterotoxic effect on intestinal epithelial cells that could be responsible for HIV-associated diarrhea. Since oxidative stress is implicated in the pathogenesis and morbidity of HIV infection, we evaluated whether Tat induces apoptosis of human enterocytes through oxidative stress, and whether the antioxidant N-acetylcysteine (NAC) could prevent it. Caco-2 and HT29 cells or human intestinal mucosa specimens were exposed to Tat alone or combined with NAC. In an in-vitro cell model, Tat increased the generation of reactive oxygen species and decreased antioxidant defenses as judged by a reduction in catalase activity and a reduced (GSH)/oxidized (GSSG) glutathione ratio. Tat also induced cytochrome c release from mitochondria to cytosol, and caspase-3 activation. Rectal dialysis samples from HIV-infected patients were positive for the oxidative stress marker 8-hydroxy-2'-deoxyguanosine. GSH/GSSG imbalance and apoptosis occurred in jejunal specimens from HIV-positive patients at baseline and from HIV-negative specimens exposed to Tat. Experiments with neutralizing anti-Tat antibodies showed that these effects were direct and specific. Pre-treatment with NAC prevented Tat-induced apoptosis and restored the glutathione balance in both the in-vitro and the ex-vivo model. These findings indicate that oxidative stress is one of the mechanism involved in HIV-intestinal disease.
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PMID:The HIV-1 transactivator factor (Tat) induces enterocyte apoptosis through a redox-mediated mechanism. 2221 81

Development of a therapeutic application of CASP3/caspase 3/CPP32, an executor of apoptosis, has been challenging because regulation of its activation is complicated. This study aimed to inhibit cancer cell growth and human immunodeficiency virus type 1 (HIV-1) propagation through a CASP3 mutant, CASP3*, activable by HIV-1-encoded aspartate protease. Active CASP3* was delivered to leukemic cells using a protein transduction vehicle, the lentivirus-like nanoparticle (LENA), which should contain thousands of CASP3*-Gag protein molecules and release the activated CASP3* into the target cell cytoplasm. CASP3*-LENA induced apoptosis in various types of leukemic cells. In addition to being effective against leukemic cells, constitutive expression of CASP3* restricted HIV-1 propagation in SUP-T1 cells. The attenuation of HIV-1 replication in SUP-T1/CASP3* cells was attributed to the elimination of HIV-1-infected cells by apoptosis. These data suggest that CASP3* has therapeutic potential against both lymphoid malignancies and HIV-1 infection.
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PMID:Therapeutic potential of HIV protease-activable CASP3. 2249 55


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