scholarly journals Abundance of Nef and p-Tau217 in Brains of Individuals Diagnosed with HIV-Associated Neurocognitive Disorders Correlate with Disease Severance

Author(s):  
Tatiana Pushkarsky ◽  
Adam Ward ◽  
Andrey Ivanov ◽  
Xionghao Lin ◽  
Dmitri Sviridov ◽  
...  

AbstractHIV-associated neurocognitive disorders (HAND) is a term used to describe a variety of neurological impairments observed in HIV-infected individuals. The pathogenic mechanisms of HAND and of its connection to HIV infection remain unknown, but one of the considered hypotheses suggests that HIV infection accelerates the development of Alzheimer’s disease. Previous studies suggested that HIV-1 Nef may contribute to HAND by inhibiting cholesterol efflux, increasing the abundance of lipid rafts, and affecting their functionality. Our comparative analysis of postmortem brain samples demonstrated a trend toward the decreased abundance of cholesterol transporter ABCA1 in samples from HIV-infected ART-treated individuals relative to samples from uninfected controls, and a reverse correlation between ABCA1 and flotillin 1, a marker for lipid rafts, in all analyzed samples. The brain samples from HIV-infected individuals, both with and without HAND, were characterized by the increased abundance of p-Tau217 peptide, which correlated with the abundance of flotillin 1. HIV-1 Nef was analyzed in samples from HAND-affected individuals by Western blot with 4 different antibodies and by LC–MS/MS, producing a Nef-positivity score. A significant correlation was found between this score and the abundance of flotillin 1, the abundance of p-Tau217, and the severity of HAND. These results highlight the contribution of Nef and Nef-dependent impairment of cholesterol efflux to HAND pathogenesis and support a connection between the pathogenesis of HAND and Alzheimer’s disease.

2021 ◽  
Author(s):  
Tatiana Pushkarsky ◽  
Adam I Ward ◽  
Dmitri Sviridov ◽  
Michael Ilya Bukrinsky

HIV-associated neurological disorders (HAND) is a term used to describe a variety of neurological impairments observed in HIV-infected individuals. The pathogenic mechanisms of HAND and of its connection to HIV infection remain unknown. Previous studies suggested that HIV-1 Nef may contribute to HAND by impairing cholesterol metabolism, increasing abundance of lipid rafts and affecting their functionality. Our comparative analysis of post-mortem brain samples demonstrated a trend towards decreased abundance of cholesterol transporter ABCA1 in samples from HIV-infected ART-treated individuals relative to samples from uninfected controls, and a reverse correlation between ABCA1 and flotillin 1, a marker for lipid rafts, in all analyzed samples. The brain samples from HIV-infected individuals, both with and without HAND, were characterized by increased abundance of p-Tau217 peptide, which correlated with the abundance of flotillin 1. HIV-1 Nef was detected in some, but not all, samples from HAND-affected individuals. Samples positive for Nef had lower abundance of ABCA1, higher abundance of flotillin 1 and p-Tau217, and were obtained from individuals with higher severity of HAND relative to Nef-negative samples. These results highlight the contribution of Nef and Nef-dependent impairment of cholesterol metabolism to the pathogenesis of HAND and support a connection between pathogenesis of HAND and Alzheimer disease.


2021 ◽  
Vol 26 (1) ◽  
pp. 40-46
Author(s):  
S.S. Ostrovska ◽  
V.F. Shatorna ◽  
E.O. Liholetov

The concept of the viral etiology of Alzheimer's disease (AD) was first proposed in 1982. Its author MJ Ball suggested that the herpes simplex virus (HSV1) may be involved in the pathogenesis of AD, finding that the areas of the brain damaged in acute herpetic encephalitis are the same as those that are affected in AD, and those who survived usually suffer from memory loss and other cognitive impairment typical of AD. Subsequently, in all postmortem brain samples (temporal, frontal, and hippocampal) viral sequences of the viral thymidinekinase gene were found in a high proportion (70-100%) both in AD and in elderly people without it, while in young people and children the virus was found in very low proportions, so it was suggested that HSV1 comes from the peripheral ganglia, where the virus can remain inactive for many years, then enters the brain at an older age due to a decrease in the activity of the immune system. The increased risk of AD is associated with the presence of HSV1 in the brain and the carriage of a specific genetic factor – allele-ε4 of the apolipoprotein E4 gene (APOE-ε4). By themselves, neither HSV1 nor the APOE-ɛ4 allele were found as risk factors for the development of AD but their combination increased the risk of AD development by 12 times and made up 60% in patients with AD. The phenomena involved in the pathophysiology of AD are neurodegenerative changes that occur as a result of fibrillation and deposition of amyloid-β-peptide (Aβ) and neurofibrillary tangles – accumulations of aggregated phosphorylated tau-proteins (P-tau), leading to brain atrophy due to neuronal death. Traditionally, Aβ has been characterized as a catabolic by-product. However, it has recently been shown that Aβ-peptide has antiviral activity and protective effects against HSV infections in the brain. А 16-year study in Thailand with more than 33,000 patients showed that long-term use of antiherpetic drugs reduces the risk of dementia, including AD patients infected with HSV1. Patients with HSV1 infection who received antiherpetic drugs showed a lower risk of all types of dementia compared with the group without these drugs. Their positive effect on stopping the accumulation of amyloid beta and tau protein in the body has been confirmed. In this regard, it is assumed that vaccination against HSV1 may be useful not only for treatment, but also for the prevention of AD.


2019 ◽  
Author(s):  
Lenora Higginbotham ◽  
Lingyan Ping ◽  
Eric B. Dammer ◽  
Duc M. Duong ◽  
Maotian Zhou ◽  
...  

AbstractAlzheimer’s disease (AD) features a complex web of pathological processes beyond amyloid accumulation and tau-mediated neuronal death. To meaningfully advance AD therapeutics, there is an urgent need for novel biomarkers that comprehensively reflect these disease mechanisms. Here we applied an integrative proteomics approach to identify cerebrospinal fluid (CSF) biomarkers linked to a diverse set of pathophysiological processes in the diseased brain. Using multiplex proteomics, we identified >3,500 proteins across 40 CSF samples from control and AD patients and >12,000 proteins across 48 postmortem brain tissues from control, asymptomatic AD (AsymAD), AD, and other neurodegenerative cases. Co-expression network analysis of the brain tissues resolved 44 protein modules, nearly half of which significantly correlated with AD neuropathology. Fifteen modules robustly overlapped with proteins quantified in the CSF, including 271 CSF markers highly altered in AD. These 15 overlapping modules were collapsed into five panels of brain-linked fluid markers representing a variety of cortical functions. Neuron-enriched synaptic and metabolic panels demonstrated decreased levels in the AD brain but increased levels in diseased CSF. Conversely, glial-enriched myelination and immunity panels were highly increased in both the brain and CSF. Using high-throughput proteomic analysis, proteins from these panels were validated in an independent CSF cohort of control, AsymAD, and AD samples. Remarkably, several validated markers were significantly altered in AsymAD CSF and appeared to stratify subpopulations within this cohort. Overall, these brain-linked CSF biomarker panels represent a promising step toward a physiologically comprehensive tool that could meaningfully enhance the prognostic and therapeutic management of AD.


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