Characterization of HMBP-2, a DNA-Binding Protein That Binds to HIV-1 LTR When only One of the Three Sp1 Sites Is Methylated

Innate and adaptive factors regulating human immunodeficiency virus type 1 genomic activation

Over the past decade, antiretroviral therapy targeting the viral entry process, reverse transcriptase, integrase, and protease, has prolonged the lives of people infected with human immunodeficiency virus type 1 (HIV-1). However, despite the development of more effective therapeutic strategies, reservoirs of viral infection remain. This review discusses molecular mechanisms surrounding the development of latency from the site of integration to pre- and post-integration maintenance of latency, including epigenetic factors. In addition, an overview of innate and adaptive cells important to HIV-1 infection are examined from the viewpoint of cytokines released and cytokines that act on these cells to explore an overall understanding of HIV-1 proviral genome activation. Finally, this review is discussed from the viewpoint of how an understanding of the interplay of all of these factors will help guide the next generation of therapies.

Regulation of HIV-1 transcription in cells of the monocyte-macrophage lineage

Human immunodeficiency virus type 1 (HIV-1) has been shown to replicate productively in cells of the monocyte-macrophage lineage, although replication occurs to a lesser extent than in infected T cells. As cells of the monocyte-macrophage lineage become differentiated and activated and subsequently travel to a variety of end organs, they become a source of infectious virus and secreted viral proteins and cellular products that likely initiate pathological consequences in a number of organ systems. During this process, alterations in a number of signaling pathways, including the level and functional properties of many cellular transcription factors, alter the course of HIV-1 long terminal repeat (LTR)-directed gene expression. This process ultimately results in events that contribute to the pathogenesis of HIV-1 infection. First, increased transcription leads to the upregulation of infectious virus production, and the increased production of viral proteins (gp120, Tat, Nef, and Vpr), which have additional activities as extracellular proteins. Increased viral production and the presence of toxic proteins lead to enhanced deregulation of cellular functions increasing the production of toxic cellular proteins and metabolites and the resulting organ-specific pathologic consequences such as neuroAIDS. This article reviews the structural and functional features of the cis-acting elements upstream and downstream of the transcriptional start site in the retroviral LTR. It also includes a discussion of the regulation of the retroviral LTR in the monocyte-macrophage lineage during virus infection of the bone marrow, the peripheral blood, the lymphoid tissues, and end organs such as the brain. The impact of genetic variation on LTR-directed transcription during the course of retrovirus disease is also reviewed.

Guidelines for management of idiopathic normal pressure hydrocephalus

With the rapid aging of Japanese society, medical care of the elderly has become an important social issue. Among various disorders manifesting dementia, gait disturbance, and urinary incontinence in the elderly population, normal pressure hydrocephalus (NPH), especially of idiopathic type (iNPH), is becoming noteworthy. The Guidelines for management of iNPH in Japan are created in compliance with the evidence-based medicine methods and published in 2004. This English version is made to show the diagnosis and treatment of iNPH with reference to the socio-medical background in Japan and to promote the international research on iNPH. They propose three diagnostic levels; possible, probable, and definite. They indicate the diagnostic importance of high convexity tightness and dilated sylvian fissure with mild to moderate ventriculomegaly on coronal magnetic resonance imaging. The cerebrospinal fluid tap test is regarded as an important diagnostic test because of its simplicity to perform and high predictability of the shunt efficacy. The use of programmable valves at shunt surgeries is recommended. Flowcharts for diagnosis, preoperative assessment, and prevention for complications of shunt surgery are made to promote a wide use of them.

Validation of grading scale for evaluating symptoms of idiopathic normal-pressure hydrocephalus

BACKGROUND/AIMS

We developed an idiopathic normal-pressure hydrocephalus grading scale (iNPHGS) to classify a triad of disorders (cognitive impairment, gait disturbance and urinary disturbance) of iNPH with a wide range of severity. The purpose of this study was to assess the reliability and validity of this scale in 38 patients with iNPH.

RESULTS

The interrater reliability of this scale was high. The iNPHGS cognitive domain score significantly correlated with the cognitive test scores, including the Mini-Mental State Examination (MMSE), the gait domain score with the Up and Go Test and Gait Status Scale scores, and the urinary domain score with the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) score. The MMSE, Gait Status Scale and ICIQ-SF scores significantly improved in patients whose iNPHGS scores improved after CSF tapping but not in those whose iNPHGS scores did not improve after CSF tapping. Fourteen of the 38 patients received shunt operations. In these 14 patients, changes in the iNPHGS cognitive and urinary domains after CSF tapping were significantly associated with the changes after the shunt operation.

Intracranial pressure parameters in idiopathic normal pressure hydrocephalus patients with or without improvement of cognitive function after shunt treatment

BACKGROUND/AIMS

Previous research has shown improvements in the clinical triad (gait, incontinence and cognitive dysfunction) after shunt surgery in idiopathic normal pressure hydrocephalus (iNPH) patients with intracranial pulse pressure amplitudes >4-5 mm Hg, the pulse amplitudes being <4 mm Hg in the nonresponders. However, it is unknown whether similar differences exist regarding change in cognitive functioning after shunt surgery. The aim of this study was to compare preoperative intracranial pressure (ICP) parameters between iNPH that either improved or not improved in cognitive function after shunt treatment.

METHODS

Neuropsychological testing was performed before and after surgery in 27 consecutive iNPH patients treated with ventriculoperitoneal shunts. The ICP recordings were performed as part of routine preoperative assessment, stored as raw data files, and analyzed retrospectively. The mean ICP as well as single ICP wave amplitudes were computed and analyzed in consecutive 6-second time windows.

RESULTS

Significant improvement in neuropsychological tests, defined as a 4-point improvement in Folstein Mini-Mental State Examination or improvement by one standard deviation in 50% of subtests of Dementia Rating Scale, was found in 12 patients (44%; shunt responders). In these patients, mean ICP was similar though the mean ICP wave amplitude was significantly higher than in the shunt nonresponders.

CONCLUSIONS

While preoperative mean ICP was similar, the mean ICP wave amplitudes were considerably higher in iNPH patients with significant change in cognitive function following shunt surgery.

Cognitive impairment in patients with idiopathic normal pressure hydrocephalus

Cognitive impairment in patients with idiopathic normal pressure hydrocephalous (iNPH) has not been clearly documented. We performed standardized neuropsychological assessments of 21 patients with iNPH and of 42 patients with Alzheimer's disease (AD) matched to the patients with iNPH 2:1 by age, sex, and Mini-Mental State Examination score. Compared with the AD group, the iNPH group scored significantly higher on the orientation subtest of the Alzheimer's Disease Assessment Scale and on the general memory and delayed recall subtests of the Wechsler Memory Scale-Revised (WMS-R), and significantly lower on the attention/concentration subtest of the WMS-R and on the digit span, arithmetic, block design and digit symbol substitution subtests of the Wechsler Adult Intelligence Scale-Revised. The impairment of frontal lobe functions is disproportionately severe and memory impairment is disproportionately mild in patients with iNPH compared with AD. Recognition of these features contributes to an early diagnosis, which can lead to a better prognosis.

Transcriptional suppression of in vitro-integrated human immunodeficiency virus type 1 does not correlate with proviral DNA methylation

Persistence of human immunodeficiency virus type 1 (HIV-1) constitutes a major obstacle in the control of HIV-1 infection. Here we investigated whether the CpG methylation of the HIV-1 promoter can directly influence the expression of the HIV-1 genome and thereby contribute to the persistence and latency of HIV-1. The levels of CpG methylation in the promoter of HIV-1 were studied after bisulfite-induced modification of DNA in five Jurkat clonal cell lines transduced by an HIV-1 long terminal repeat (LTR)-driven retroviral vector and expressing enhanced green fluorescent protein (GFP) and in primary resting memory T cells challenged with HIV-1 or with an HIV-1-derived retroviral vector. Basal HIV-1 promoter activities were low or undetectable in three tested HIV-1 LTR-GFP clones, one of which encoded the Tat protein, and they reached medium or high levels in two other clones. The CpG dinucleotide that occurred in a latently infected clonal cell line 240 nucleotides upstream of the transcription start remained methylated after reactivation of HIV-1 transcription with 10 nM phorbol-12-myristate-13-acetate. In two clones showing a medium promoter activity and in resting memory T cells, the HIV-1 LTR was generally not methylated. Our results show that the methylation profiles of the HIV-1 LTR, including those present in latently infected cells, are low and do not correlate with the transcriptional activity. We suggest that, in a noncloned cellular population in which the HIV-1 proviruses are randomly integrated in the human genome, HIV-1 latency is imperfectly controlled by CpG methylation and is inherently accompanied by residual replication.