HIV infection and drugs of abuse: role of acute phase proteins.

BACKGROUND: HIV infection and drugs of abuse such as methamphetamine (METH), cocaine, and alcohol use have been identified as risk factors for triggering inflammation. Acute phase proteins such as C-reactive protein (CRP) and serum amyloid A (SAA) are the biomarkers of inflammation. Hence, the interactive effect of drugs of abuse with acute phase proteins in HIV-positive subjects was investigated. METHODS: Plasma samples were utilized from 75 subjects with METH use, cocaine use, alcohol use, and HIV-positive alone and HIV-positive METH, cocaine, and alcohol users, and age-matched control subjects. The plasma CRP and SAA levels were measured by ELISA and western blot respectively and the CD4 counts were also measured. RESULTS: Observed results indicated that the CRP and SAA levels in HIV-positive subjects who are METH, cocaine and alcohol users were significantly higher when compared with either drugs of abuse or HIV-positive alone. The CD4 counts were also dramatically reduced in HIV-positive with drugs of abuse subjects compared with only HIV-positive subjects. CONCLUSIONS: These results suggest that, in HIV-positive subjects, drugs of abuse increase the levels of CRP and SAA, which may impact on the HIV infection and disease progression.

Combinatorial cytotoxic effects of Curcuma longa and Zingiber officinale on the PC-3M prostate cancer cell line.

BACKGROUND: Many plant-derived products exhibit potent chemopreventive activity against animal tumor models as well as rodent and human cancer cell lines. They have low side effects and toxicity and presumably modulate the factors that are critical for cell proliferation, differentiation, senescence and apoptosis. The present study investigates the effects of some medicinal plant extracts from generally recognized as safe plants that may be useful in the prevention and treatment of cancer. METHODS: Clonogenic assays using logarithmically-growing cells were performed to test the effect. The cytotoxic effects of Curcuma longa and Zingiber officinale were studied using sulforhodamine B assay, tetrazolium dye assay, colony morphology and microscopic analysis. RESULTS: Out of the 13 lyophilized plant-derived extracts evaluated for growth-inhibitory effects on the PC-3M prostate cancer cell line, two extracts derived from C. longa and Z. officinale showed significant inhibitory effects on colony-forming ability. The individual and augmentative effects of these two extracts were tested for their narrow range effective lower concentration on PC-3M in clonogenic assays. At relatively lower concentrations, C. longa showed significant inhibition of colony formation in clonogenic assays; whereas at same concentrations Z. officinale showed only moderate inhibitory effects. However, when both the agents were tested together at the same concentrations, the combined effects were much more significant than their individual ones. On normal prostate epithelial cells both C. longa and Z. officinale had similar effects but at a lower magnitude. These observations were confirmed by several cytotoxicity assays involving the morphological appearance of the colonies, microscopic observations, per cent inhibition in comparison to control by sulforhodamine B and tetrazolium dye assay. CONCLUSIONS: From these observations, it was concluded that the combined effects of C. longa and Z. officinale are much greater than their individual effects, suggesting the role of multiple components and their synergistic mode of actions to elicit stronger beneficial effects.

MicroRNA: implications in HIV, a brief overview.

MicroRNAs (miRNAs) are 20-22 nucleotide length noncoding RNA molecules that represent key regulators of many normal cellular functions. miRNAs undergo two processing steps which transform a long primary transcript into the mature miRNA. Available literatures demonstrate the association between alterations in the expression of miRNAs and the progression of numerous human disorders. Even though significant advances have been made, many fundamental questions about their expression and function still remain unanswered. Identifying factors that block the negative action of drugs of abuse on the miRNAs could help in identifying new therapeutic strategies. In this review, we briefly discuss the importance of miRNAs on HIV, strategies used by virus to avoid the cells' antiviral miRNA defenses, and how HIV might control and regulate host cell genes by encoding viral miRNAs.

Human immunodeficiency virus type 1 clade B and C gp120 differentially induce neurotoxin arachidonic acid in human astrocytes: implications for neuroAIDS.

HIV-1 clades (subtypes) differentially contribute to the neuropathogenesis of HIV-associated dementia (HAD) in neuroAIDS. HIV-1 envelop protein, gp120, plays a major role in neuronal function. It is not well understood how these HIV-1 clades exert these neuropathogenic differences. The N-methyl-D: -aspartate (NMDA) receptor-reduced glutamine synthesis could lead to secretion of neurotoxins such as arachidonic acid (AA) which plays a significant role in the neuropathogenic mechanisms in neuroAIDS. We hypothesize that clade B and C gp120 proteins exert differential effects on human primary astrocytes by production of the neurotoxin arachidonic acid. Our results indicate that clade B gp120 significantly downregulated NMDA receptor gene and protein expression, and level of glutamine while increasing expression of prostaglandin E2 (PGE(2)) and thromboxane A2 receptor (TBXA(2) R) compared to HIV-1 clade C gp120 protein. Thus, our studies for the first time demonstrate that HIV-1 clade B-gp120 protein appears to induce higher levels of expression of the neuropathogenic molecule cyclooxygenase-2 (COX-2)-mediated arachidonic acid by-products, PGE(2), and TBXA(2) R compared to HIV-1 clade C gp120 protein. These studies suggest that HIV-1 clade B and C gp120 proteins may play a differential role in the neuropathogenesis of HAD in neuroAIDS.

Human immunodeficiency virus type 1 clade B and C Tat differentially induce indoleamine 2,3-dioxygenase and serotonin in immature dendritic cells: Implications for neuroAIDS.

Human immunodeficiency virus type 1 (HIV-1) is commonly associated with immune dysfunctions and the suppression of antigen-presenting cells. This results in immune alterations, which could lead to impaired neuronal functions, such as neuroAIDS. The neurotoxic factor kynurenine (KYN), the rate-limiting enzyme indoleamine 2,3-dioxygenase (IDO), serotonin (5-HT), and serotonin transporter (5-HTT) may play a role in tryptophan deficiency and serotogenic dysfunction in neuroAIDS. HIV-1 transactivator regulatory protein (Tat) is known to play a major role in immune dysfunction. Previous studies suggest that HIV-1 B and C clades differentially manifest neuronal dysfunctions in the infected host. In the present study we examine the effect of HIV-1 B and C clade-derived Tat on IDO and 5-HTT gene and protein expressions by dendritic cells as studied by quantitative polymerase chain reaction (qPCR) and Western blot. In addition, the intracellular IDO expression, IDO enzyme activity, and the levels of 5-HT and KYN were also measured. Results indicate that HIV-1 clade B Tat up-regulates IDO and down-regulates 5-HTT gene and protein expressions. Further, HIV-1 clade B Tat caused a reduction of 5-HT with simultaneous increase in KYN levels as compared to HIV-1 clade C Tat. These studies suggest that HIV-1 clade B and C Tat proteins may play a differential role in the neuropathogenesis of HIV-associated dementia (HAD) or HIV-associated neurocognitive disorder (HAND).

Interactive role of human immunodeficiency virus type 1 (HIV-1) clade-specific Tat protein and cocaine in blood-brain barrier dysfunction: implications for HIV-1-associated neurocognitive disorder.

In recent years, increasing interest has emerged to assess the human immunodeficiency virus type 1 (HIV-1) clade C viral pathogenesis due to its anticipated spread in the United States and other western countries. Previous studies suggest that clade C is less neuropathogenic than clade B; however, the underlying mechanism is poorly understood. Additionally, the interactive role of drugs of abuse such as cocaine on clade C-associated neuropathogenesis has not been reported. In the current study, we hypothesize that HIV-1 clade-specific Tat proteins exert differential effects on blood-brain barrier (BBB) integrity and cocaine further differentially aggravates the BBB dysfunction. We evaluated the effect of Tat B and Tat C and/or cocaine on the BBB integrity using an in vitro model constructed with primary human brain microvascular endothelial cells (HBMECs) and astrocytes. The BBB membrane integrity was measured by transendothelial electrical resistance (TEER) and paracellular permeability was measured by fluorescein isothiocyanate (FITC)-dextran transport assay and monocytes transmigration across the BBB. Results indicate that Tat B disrupts BBB integrity to a greater extent compared to Tat C and cocaine further differentially exacerbates the BBB dysfunction. This BBB dysfunction was associated with altered expression of tight junction proteins zona occuldens (ZO-1) and junctional adhesion molecule (JAM)-2. Thus, these results for the first time delineate the differential role of Tat B and Tat C and/or cocaine in BBB dysfunction, which may be correlated with the clade-specific differences observed in HIV-1-associated neurological disorders.

Implications of ER stress, the unfolded protein response, and pro- and anti-apoptotic protein fingerprints in human monocyte-derived dendritic cells treated with alcohol.

BACKGROUND: Dendritic cells (DCs) are responsible for the activation of T cells and B cells. There is accumulating evidence that psychoactive substances such as alcohol can affect immune responses. We hypothesize that this occurs by modulating changes in proteins triggering a process known as unfolded protein response (UPR). This process protects cells from the toxic effects of misfolded proteins responsible for causing endoplasmic reticulum (ER) stress. Although much is known about ER stress, little is understood about the consequences of ethanol use on DC's protein expression. METHODS: In this study, we investigated alterations in the proteins of human monocyte-derived dendritic cells (MDDC) treated with 0.1% of alcohol by two-dimensional (2D) gel electrophoresis followed by liquid chromatography-tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT-PCR. RESULTS: Proteomes of related samples demonstrated 32 differentially expressed proteins that had a 2-fold or greater change in expression (18 spots were up-regulated and 14 were down-regulated), compared to the control cultures (untreated cells). Alcohol significantly changed the expression of several components of the UPR stress-induced pathways that include chaperones, ER stress, antioxidant enzymes, proteases, alcohol dehydrogenase, cytoskeletal and apoptosis-regulating proteins. qRT-PCR analyses highlighted the enhanced expression of UPR and antioxidant genes that increased (18 hours) with alcohol treatment. CONCLUSION: Results of these analyses provide insights into alcohol mechanisms of regulating DC and suggest that alcohol induced specifically the UPR in DC. We speculate that activation of a UPR by alcohol may protect the DC from oxidant injury but may lead to the development of alcohol-related diseases.

AZT 5'-triphosphate nanoformulation suppresses human immunodeficiency virus type 1 replication in peripheral blood mononuclear cells.

Inefficient cellular phosphorylation of nucleoside and nucleotide analog reverse transcriptase inhibitors (NRTIs) to their active nucleoside 5'-triphosphate (NTPs) form is one of the limitations for human immunodeficiency virus (HIV) therapy. We report herein direct binding of 3'-azido-3'-deoxythymidine-5'-triphosphate (AZTTP) onto magnetic nanoparticles (Fe(3)O(4); magnetite) due to ionic interaction. This magnetic nanoparticle bound AZTTP (MP-AZTTP) completely retained its biological activity as assessed by suppression of HIV-1 replication in peripheral blood mononuclear cells. The developed MP-AZTTP nanoformulation can be used for targeting active NRTIs to the brain by application of an external magnetic force and thereby eliminate the brain HIV reservoir and help to treat NeuroAIDS.

Upregulation of serotonin transporter by alcohol in human dendritic cells: possible implication in neuroimmune deregulation.

BACKGROUND: Alcohol is the most widely abused substance and its chronic consumption causes neurobehavioral disorders. It has been shown that alcohol affects the function of immune cells. Dendritic cells (DC) serve as the first line of defense against infections and are known to accumulate neurotransmitters such as 5-hydroxytryptamine (5-HT). The enzyme monoamine oxidase-A (MAO-A) degrades 5-HT that is associated with clinical depression and other neurological disorders. 5-HT is selectively transported into neurons through the serotonin transporter (SERT), which is a member of the sodium- and chloride-dependent neurotransmitter transporter (SLC6) family. SERT also serves as a receptor for psychostimulant recreational drugs. It has been demonstrated that several drugs of abuse such as amphetamine and cocaine inhibit the SERT expression; however, the role of alcohol is yet to be elucidated. We hypothesize that alcohol can modulate SERT and MAO-A expression in DC, leading to reciprocal downregulation of 5-HT in extracellular medium. METHODS: Dendritic cells were treated with different concentrations (0.05% to 0.2%v/v) of alcohol for 24-72 hours and processed for SERT and MAO-A expression using Q-PCR and Western blots analysis. In addition, SERT function in DC treated with alcohol both in the presence and absence of imipramine, a SERT inhibitor was measured using 4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide uptake assay. 5-HT levels in culture supernatant and intracellular 5-hydroxy indole acetic acid (5-HIAA) and cyclic AMP were also quantitated using ELISA. RESULTS: Dendritic cells treated with 0.1% alcohol for 24 hours showed significant upregulation of SERT and MAO-A expression compared with untreated DC. We also observed that 0.1% alcohol enhanced the function of SERT and decreased extracellular 5-HT levels compared with untreated DC cultures, and this was associated with the elevation of intracellular 5-HIAA and cyclic AMP levels. CONCLUSIONS: Our study suggests that alcohol upregulates SERT and MAO-A by elevating cyclic AMP, which may lead to decreased concentration of 5-HT in the extracellular medium. As 5-HT is a major neurotransmitter and an inflammatory mediator, its alcohol-mediated depletion may cause both neurological and immunological deregulation.

Proteomic analyses of methamphetamine (METH)-induced differential protein expression by immature dendritic cells (IDC).

In the US, the increase in methamphetamine (METH) use has been associated with increased human immunodeficiency virus (HIV-1) infection. Dendritic cells (DC) are the first line of defense against HIV-1. DC play a critical role in harboring HIV-1 and facilitate the infection of neighboring T cells. However, the role of METH on HIV-1 infectivity and the expression of the proteome of immature dendritic cells (IDC) has not been elucidated. We hypothesize that METH modulates the expression of a number of proteins by IDC that foster the immunopathogenesis of HIV-1 infection. We utilized LTR amplification, p24 antigen assay and the proteomic method of difference gel electrophoresis (DIGE) combined with protein identification through high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to analyze the effects of METH on HIV-1 infectivity (HIV-1 IIIB; CXCR4-tropic, X4 strain) and the proteomic profile of IDC. Our results demonstrate that METH potentiates HIV-1 replication in IDC. Furthermore, METH significantly differentially regulates the expression of several proteins including CXCR3, protein disulfide isomerase, procathepsin B, peroxiredoxin and galectin-1. Identification of unique, METH-induced proteins may help to develop novel markers for diagnostic, preventive and therapeutic targeting in METH using subjects.

Oxidative Stress in HIV Infection and Alcohol Use: Role of Redox Signals in Modulation of Lipid Rafts and ATP-Binding Cassette Transporters.

AIMS: Human immunodeficiency virus (HIV) infection induces oxidative stress and alcohol use accelerates disease progression, subsequently causing immune dysfunction. However, HIV and alcohol impact on lipid rafts-mediated immune dysfunction remains unknown. In this study, we investigate the modulation by which oxidative stress induces reactive oxygen species (ROS) affecting redox expression, lipid rafts caveiloin-1, ATP-binding cassette (ABC) transporters, and transcriptional sterol regulatory element-binding protein (SREBP) gene and protein modification and how these mechanisms are associated with arachidonic acid (AA) metabolites in HIV positive alcohol users, and how they escalate immune dysfunction. RESULTS: In both alcohol using HIV-positive human subjects and in vitro studies of alcohol with HIV-1 gp120 protein in peripheral blood mononuclear cells, increased ROS production significantly affected redox expression in glutathione synthetase (GSS), super oxide dismutase (SOD), and glutathione peroxidase (GPx), and subsequently impacted lipid rafts Cav-1, ABC transporters ABCA1, ABCG1, ABCB1, and ABCG4, and SREBP transcription. The increased level of rate-limiting enzyme 3-hydroxy-3-methylglutaryl HMG-CoA reductase (HMGCR), subsequently, inhibited 7-dehydrocholesterol reductase (DHCR-7). Moreover, the expression of cyclooxygenase-2 (COX-2) and lipoxygenase-5 (5-LOX) mRNA and protein modification tentatively increased the levels of prostaglandin E2 synthases (PGE2) in plasma when compared with either HIV or alcohol alone. INNOVATION: This article suggests for the first time that the redox inhibition affects lipid rafts, ABC-transporter, and SREBP transcription and modulates AA metabolites, serving as an important intermediate signaling network during immune cell dysfunction in HIV-positive alcohol users. CONCLUSION: These findings indicate that HIV infection induces oxidative stress and redox inhibition, affecting lipid rafts and ABC transports, subsequently upregulating AA metabolites and leading to immune toxicity, and further exacerbation with alcohol use. Antioxid. Redox Signal. 28, 324-337.

Proteomic analysis of the effects of cocaine on the enhancement of HIV-1 replication in normal human astrocytes (NHA).

The US is experiencing an epidemic of cocaine use entangled with HIV-1 infection. Normal human astrocytes (NHA) are susceptible to HIV-1 infection. We utilized LTR-R/U5 amplification, p24 antigen assay and the proteomic method of difference gel electrophoresis (DIGE) combined with protein identification through HPLC-MS/MS to investigate the effect of cocaine on HIV-1 infectivity and the proteomic profile of NHA, respectively. Data demonstrate that cocaine significantly upregulates HIV-1 infection in NHA as measured by LTR-R/U5 amplification and p24 antigen assay. Further, our results show for the first time that cocaine differentially regulates the expression of a number of proteins by NHA that may play a role in the neuropathogenesis of HIV-1 disease.

Gene expression of angiogenic factors correlates with metastatic potential of prostate cancer cells.

We hypothesize that expression of proangiogenic genes correlates with the metastatic potential of prostate cancer cells. LNCaP, DU-145, and PC-3 are prostate cancer cell lines with low, moderate, and high metastatic potential, respectively, as we demonstrated by their capacity to invade an extracellular matrix, an established tumor invasion assay. The constitutive gene expression of the proangiogenic factors, vascular endothelial growth factor, intercellular adhesion molecule-1, interleukin-8, and transforming growth factor-beta2, was significantly greater in the more metastatic DU-145 and PC-3 cells as compared with LNCaP cells. Matrix metalloproteinase (MMP)-9 is thought to contribute to the invasive phenotype of tumor cells. PC-3 cells showed increased expression of MMP-9 and membrane type 4-MMP as compared with LNCaP and DU-145. Tissue inhibitors of metalloproteinase 1 and 4 gene expression were elevated in DU-145 and PC-3 cells, but paradoxically, LNCaP cells had undetectable levels of these genes. We transfected and overexpressed MMP-9 in poorly metastatic LNCaP cells and measured their invasive activity. Transient expression of human MMP-9 in LNCaP cells produced a 3-5-fold increase in MMP-9 activity with a comparable increase in invasiveness. Antisense ablation of the expression of MMP-9 in DU-145 and PC-3 cells produced concomitant inhibition of the gene expression of the proangiogenic factors, vascular endothelial growth factor, and intercellular adhesion molecule-1 (ICAM-1). Treatment of DU-145 and PC-3 cells with a selective chemical inhibitor of MMP-9 proteinase activity also inhibited their invasive activity. These results support our hypothesis that metastatic potential of prostate cancer cells correlates with expression of proangiogenic factors.

HIV and Cocaine Impact Glial Metabolism: Energy Sensor AMP-activated protein kinase Role in Mitochondrial Biogenesis and Epigenetic Remodeling.

HIV infection and cocaine use have been identified as risk factors for triggering neuronal dysfunction. In the central nervous system (CNS), energy resource and metabolic function are regulated by astroglia. Glia is the major reservoir of HIV infection and disease progression in CNS. However, the role of cocaine in accelerating HIV associated energy deficit and its impact on neuronal dysfunction has not been elucidated yet. The aim of this study is to elucidate the molecular mechanism of HIV associated neuropathogenesis in cocaine abuse and how it accelerates the energy sensor AMPKs and its subsequent effect on mitochondrial oxidative phosphorylation (OXPHOS), BRSKs, CDC25B/C, MAP/Tau, Wee1 and epigenetics remodeling complex SWI/SNF. Results showed that cocaine exposure during HIV infection significantly increased the level of p24, reactive oxygen species (ROS), ATP-utilization and upregulated energy sensor AMPKs, CDC25B/C, MAP/Tau and Wee1 protein expression. Increased ROS production subsequently inhibits OCR/ECAR ratio and OXPHOS, and eventually upregulate epigenetics remodeling complex SWI/SNF in CHME-5 cells. These results suggest that HIV infection induced energy deficit and metabolic dysfunction is accelerated by cocaine inducing energy sensor AMPKs, mitochondrial biogenesis and chromatin remodeling complex SWI/SNF activation, which may lead to neuroAIDS disease progression.

Prostate-specific antigen modulates the expression of genes involved in prostate tumor growth.

Prostate-specific antigen (PSA) is a serine protease that is widely used as a surrogate marker in the early diagnosis and management of prostate cancer. The physiological relevance of tissue PSA levels and their role in prostate tumor growth and metastasis are not known. Free-PSA (f-PSA) was purified to homogeneity from human seminal plasma by column chromatography, eliminating hk2 and all known PSA complexes and retaining its protease activity. Confluent monolayers of prostate cancer cell lines, PC-3M and LNCaP, were treated with f-PSA in a series of in vitro experiments to determine the changes in expression of various genes that are known to regulate tumor growth and metastasis. Gene array, quantitative polymerase chain reaction (QPCR), and enzyme-linked immunosorbent assay (ELISA) results show significant changes in the expression of various cancer-related genes in PC-3M and LNCaP cells treated with f-PSA. In a gene array analysis of PC-3M cells treated with 10 muM f-PSA, 136 genes were upregulated and 137 genes were downregulated. In LNCaP cells treated with an identical concentration of f-PSA, a total of 793 genes was regulated. QPCR analysis reveals that the genes for urokinase-type plasminogen activator (uPA), VEGF, and Pim-1 oncogene, known to promote tumor growth, were significantly downregulated, whereas IFN-gamma, known to be a tumor-suppressor gene, was significantly upregulated in f-PSA-treated PC-3M cells. The effect of f-PSA on VEGF and IFN-gamma gene expression and on protein release in PC-3M cells was distinctly dose-dependent. In vivo studies showed a significant reduction (P = .03) in tumor load when f-PSA was administered in the tumor vicinity of PC-3M tumor-bearing BALB/c nude mice. Our data support the hypothesis that f-PSA plays a significant role in prostate tumor growth by regulating various proangiogenic and antiangiogenic growth factors.

The flavonoid, quercetin, differentially regulates Th-1 (IFNgamma) and Th-2 (IL4) cytokine gene expression by normal peripheral blood mononuclear cells.

Flavonoids are plant metabolites that are dietary antioxidants and exert significant anti-tumor, anti-allergic, anti-inflammatory and anti-viral effects. It is generally accepted that Th-1 derived cytokines such as IL-2, IFNgamma and IL-12 promote cellular immunity while Th-2 derived cytokines such as IL-4, IL-5, IL-6 exert negative immunoregulatory effects on cellular immunity while upregulating humoral immunity. The molecular mechanisms underlying the biological activities of flavonoids have not been elucidated. We hypothesize that the flavonoid, quercetin, exert significant anti-viral and anti-tumor effects possibly by modulating the production of Th-1 and Th-2 derived cytokines. Peripheral blood mononuclear cells (PBMC, 1 x 10(6) cells/ml) from normal subjects were cultured with different concentrations of quercetin (0.5-50 microM) for 24-72 h and supernates were quantitated for IFN-gamma and IL-4 by ELISA and antiviral activity of IFNgamma by bioassay. FACS analysis was done to determine the number of IFN-gamma and IL-4 positive cells and RT-PCR was done to quantitate gene expression. Quercetin significantly induces the gene expression as well as the production of Th-1 derived IFNgamma and the downregulates Th-2 derived IL-4 by normal PBMC. Further, quercetin treatment increased the phenotypic expression of IFNgamma cells and decreased IL-4 positive cells by FACS analysis, which corroborate with protein secretion and gene expression studies. These results suggest that the beneficial immuno-stimulatory effects of quercetin may be mediated through the induction of Th-1 derived cytokine, IFNgamma, and inhibition of Th-2 derived cytokine, IL-4.

Morphine exacerbates HIV-1 viral protein gp120 induced modulation of chemokine gene expression in U373 astrocytoma cells.

HIV-1 affects microglia and astroglia, which subsequently contributes to the neurodegenerative changes. Viral proteins cause neurotoxicity by direct action on the CNS cells or by activating glial cells to cause the release of cytokines, chemokines or neurotoxic substances. Opioid abuse has been postulated as a cofactor in the immunopathogenesis of human immunodeficiency virus (HIV) infection and AIDS. HIV-induced pathogenesis is exacerbated by opiate abuse and that the synergistic neurotoxicity is a direct effect of opiates on the CNS. Chemokines and their receptors have been implicated in the pathogenesis of neuroAIDS. Herein we describe the effects of morphine and/or gp120 on the expression of the genes for the beta-chemokine MIP-1beta and its receptors CCR3 and CCR5 by the U373 cells which are a human brain-derived astrocytoma/glioblastoma cell line. Our results indicate that treatment of U373 cells with morphine significantly downregulated the gene expression of the beta chemokine, MIP-1 beta, while reciprocally upregulating the expression of its specific receptors, CCR3 and CCR5 suggesting that the capacity of mu-opioids to increase HIV-1 co-receptor expression may promote viral binding, trafficking of HIV-1-infected cells, and enhanced disease progression. Additionally, opiates can enhance the cytotoxicity of HIV-1 viral protein gp120 via mechanisms that involve intracellular calcium modulation resulting in direct actions on astroglia, making them an important cellular target for HIV-opiate interactions.

Interaction of drugs of abuse and microRNA with HIV: a brief review.

MicroRNAs (miRNAs), the post-transcriptional regulators of gene expression, play key roles in modulating many cellular processes. The changes in the expression profiles of several specific miRNAs affect the interactions between miRNA and their targets in various illnesses, including addiction, HIV, cancer etc. The presence of anti-HIV-1 microRNAs (which regulate the level of infectivity of HIV-1) have been validated in the cells which are the primary targets of HIV infection. Drugs of abuse impair the intracellular innate anti-HIV mechanism(s) in monocytes, contributing to cell susceptibility to HIV infection. Emerging evidence has implicated miRNAs are differentially expressed in response to chronic morphine treatment. Activation of mu opioid receptors (MOR) by morphine is shown to down regulate the expression of anti-HIV miRNAs. In this review, we summarize the results which demonstrate that several drugs of abuse related miRNAs have roles in the mechanisms that define addiction, and how they interact with HIV.

Interactive effects of cocaine on HIV infection: implication in HIV-associated neurocognitive disorder and neuroAIDS.

Substantial epidemiological studies suggest that not only, being one of the reasons for the transmission of the human immunodeficiency virus (HIV), but drug abuse also serves its role in determining the disease progression and severity among the HIV infected population. This article focuses on the drug cocaine, and its role in facilitating entry of HIV into the CNS and mechanisms of development of neurologic complications in infected individuals. Cocaine is a powerfully addictive central nervous system stimulating drug, which increases the level of neurotransmitter dopamine (DA) in the brain, by blocking the dopamine transporters (DAT) which is critical for DA homeostasis and neurocognitive function. Tat protein of HIV acts as an allosteric modulator of DAT, where as cocaine acts as reuptake inhibitor. When macrophages in the CNS are exposed to DA, their number increases. These macrophages release inflammatory mediators and neurotoxins, causing chronic neuroinflammation. Cocaine abuse during HIV infection enhances the production of platelet monocyte complexes (PMCs), which may cross transendothelial barrier, and result in HIV-associated neurocognitive disorder (HAND). HAND is characterized by neuroinflammation, including astrogliosis, multinucleated giant cells, and neuronal apoptosis that is linked to progressive virus infection and immune deterioration. Cocaine and viral proteins are capable of eliciting signaling transduction pathways in neurons, involving in mitochondrial membrane potential loss, oxidative stress, activation of JNK, p38, and ERK/MAPK pathways, and results in downstream activation of NF-κB that leads to HAND. Tat-induced inflammation provokes permeability of the blood brain barrier (BBB) in the platelet dependent manner, which can potentially be the reason for progression to HAND during HIV infection. A better understanding on the role of cocaine in HIV infection can give a clue in developing novel therapeutic strategies against HIV-1 infection in cocaine using HIV infected population.

Cell cycle checkpoints and pathogenesis of HIV-1 infection: a brief overview.

To understand HIV pathogenesis or development is no simple undertaking and neither is the cell cycle which is highly complex that requires the coordination of multiple events and machinery. It is interesting that these two processes are interrelated, intersect and interact as HIV-1 infection results in cell cycle arrest at the G2 phase which is accompanied by massive CD4+ T cell death. For its own benefit, in an impressive manner and with the overabundance of tactics, HIV maneuvers DNA damage responses and cell cycle check points for viral replication at different stages from infection, to latency and to pathogenesis. Although the cell cycle is the most critical aspect involved in both viral and cellular replication, in this review, our main focus is on recent developments, including our own observations in the field of cell cycle proteins, checkpoints and strategies utilized by the viruses to manipulate these pathways to promote their own replication and survival. We will also discuss the emerging concept of targeting the replication initiation machinery for HIV therapy.