Accelerated brain aging with opioid misuse and HIV: New insights on the role of glially derived pro-inflammation mediators and neuronal chloride homeostasis

Detection of Trace Elements Se, Cu, and Zn Levels in Biological Samples of Drug Abusers: Halani Sindh, Pakistan

Illicit drug use has become a global issue, posing significant health, socioeconomic, and cultural risks. The study examined essential trace metals: selenium, zinc, and copper in blood concentrations, as well as in serum and scalp hair samples, from 240 male drug-abuse subjects/patients aged 18-45, categorized into three age groups. The study compared 45 healthy subjects of the same age group using an acid digestion method supported by a microwave oven during sample preparation. The technique of atomic absorption spectrometry was employed to identify essential and toxic elements, utilizing certified reference materials for accuracy. According to a recent study, plasma zinc and selenium concentrations in drug abusers are lower than those in referent subjects, potentially increasing vulnerability to infection due to poor nutritional status or other contaminants.

The effects of chronic morphine administration on spatial memory and microtubule dynamicity in male mice's brain

The examination of the influence of morphine on behavioral processes, specifically learning and memory, holds significant importance. Additionally, microtubule proteins play a pivotal role in cellular functions, and the dynamics of microtubules contribute to neural network connectivity, information processing, and memory storage. however, the molecular mechanism of morphine on microtubule dynamics, learning, and memory remains uncovered. In the present study, we examined the effects of chronic morphine administration on memory formation impairment and the kinetic alterations in microtubule proteins induced by morphine in mice. Chronic morphine administration at doses of 5 and 10 mg/kg dose-dependently decreased subjects' performance in spatial memory tasks, such as the Morris Water Maze and Y-maze spontaneous alternation behavior. Furthermore, morphine was found to stabilize microtubule structure, and increase polymerization, and total polymer mass. However, it simultaneously impaired microtubule dynamicity, stemming from structural changes in tubulin dimer structure. These findings emphasize the need for careful consideration of different doses when using morphine, urging a more cautious approach in the administration of this opioid medication.

HIV-1 Tat and morphine interactions dynamically shift striatal monoamine levels and exploratory behaviors over time

Despite the advent of combination anti-retroviral therapy (cART), nearly half of people infected with HIV treated with cART still exhibit HIV-associated neurocognitive disorders (HAND). HAND can be worsened by co-morbid opioid use disorder. The basal ganglia are particularly vulnerable to HIV-1 and exhibit higher viral loads and more severe pathology, which can be exacerbated by co-exposure to opioids. Evidence suggests that dopaminergic neurotransmission is disrupted by HIV exposure, however, little is known about whether co-exposure to opioids may alter neurotransmitter levels in the striatum and if this in turn influences behavior. Therefore, we assayed motor, anxiety-like, novelty-seeking, exploratory, and social behaviors, and levels of monoamines and their metabolites following 2 weeks and 2 months of Tat and/or morphine exposure in transgenic mice. Morphine decreased dopamine levels, but significantly elevated norepinephrine, the dopamine metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), and the serotonin metabolite 5-hydroxyindoleacetic acid, which typically correlated with increased locomotor behavior. The combination of Tat and morphine altered dopamine, DOPAC, and HVA concentrations differently depending on the neurotransmitter/metabolite and duration of exposure but did not affect the numbers of tyrosine hydroxylase-positive neurons in the mesencephalon. Tat exposure increased the latency to interact with novel conspecifics, but not other novel objects, suggesting the viral protein inhibits exploratory behavior initiation in a context-dependent manner. By contrast, and consistent with prior findings that opioid misuse can increase novelty-seeking behavior, morphine exposure increased the time spent exploring a novel environment. Finally, Tat and morphine interacted to affect locomotor activity in a time-dependent manner, while grip strength and rotarod performance were unaffected. Together, our results provide novel insight into the unique effects of HIV-1 Tat and morphine on monoamine neurochemistry that may underlie their divergent effects on motor and exploratory behavior.

Is the Central Nervous System Reservoir a Hurdle for an HIV Cure?

There is currently no cure for HIV infection although adherence to effective antiretroviral therapy (ART) suppresses replication of the virus in blood, increases CD4+ T-cell counts, reverses immunodeficiency, and increases life expectancy. Despite these substantial advances, ART is a lifelong treatment for people with HIV (PWH) and upon cessation or interruption, the virus quickly rebounds in plasma and anatomic sites, including the central nervous system (CNS), resulting in disease progression. With recent advances in quantifying viral burden, detection of genetically intact viral genomes, and isolation of replication-competent virus from brain tissues of PWH receiving ART, it has become apparent that the CNS viral reservoir (largely comprised of macrophage type cells) poses a substantial challenge for HIV cure strategies. Other obstacles impacting the curing of HIV include ageing populations, substance use, comorbidities, limited antiretroviral drug efficacy in CNS cells, and ART-associated neurotoxicity. Herein, we review recent findings, including studies of the proviral integration sites, reservoir decay rates, and new treatment/prevention strategies in the context of the CNS, together with highlighting the next steps for investigations of the CNS as a viral reservoir.