Transplacental exposure to AZT induces adverse neurochemical and behavioral effects in a mouse model: protection by L-acetylcarnitine

Predicting neurodevelopmental risk in children born to mothers living with HIV in Kenya: protocol for a prospective cohort study (Tabiri Study)

INTRODUCTION

For the growing number of children with in utero and postpartum exposure to HIV and/or antiretrovirals, it is unclear which exposures or risk factors play a significant role in predicting worse neurodevelopmental outcomes. This protocol describes a prospective longitudinal cohort study of infants born to mothers living with HIV and those born to mothers without HIV. We will determine which risk factors are most predictive of child neurodevelopment at 24 months. We aim to create a risk assessment tool to help predict which children are at risk for worse neurodevelopment outcomes.

METHODS AND ANALYSIS

This study leverages an existing Kenyan cohort to prospectively enrol 500 children born to mothers living with HIV and 500 to those without HIV (n=1000 total) and follow them from birth to age 24 months. The following factors will be measured every 6 months: infectious morbidity and biological/sociodemographic/psychosocial risk factors. We will compare these factors between the two groups. We will then measure and compare neurodevelopment within children in both groups at 24 months of age using the Child Behaviour Checklist and the Bayley Scales of Infant and Toddler Development, third edition. Finally, we will use generalised linear mixed modelling to quantify associations with neurodevelopment and create a risk assessment tool for children ≤24 months.

ETHICS AND DISSEMINATION

The study is approved by the Moi University's Institutional Research and Ethics Committee (IREC/2021/55; Approval #0003892), Kenya's National Commission for Science, Technology and Innovation (NACOSTI, Reference #700244) and Indiana University's Institutional Review Board (IRB Protocol #110990). This study carries minimal risk to the children and their mothers, and all mothers will provide written consent for participation in the study. Results will be disseminated to maternal child health clinics within Uasin Gishu County, Kenya and via papers submitted to peer-reviewed journals and presentation at international conferences.

Effects of combination antiretroviral drugs (cART) on hippocampal neuroplasticity in female mice

The incidence of HIV-associated neurocognitive disorder (HAND) continues despite the introduction of combination antiretroviral drugs (cART). Several studies have reported the neurotoxicity of individual antiretroviral drugs (monotherapy), while the common approach for HIV treatment is through cART. Hence, the current study investigated the effects of long-term exposure to cART on cognitive function, oxidative damage, autophagy, and neuroplasticity in the hippocampus of mice. Female Balb/c mice received a once-a-day oral dose of cART composed of emtricitabine + tenofovir disoproxil fumarate or vehicle for 8 weeks. On week 7 of drug administration, all mice were assessed for spatial learning in the Morris water maze (MWM), and then on week 8, mice were sacrificed, and hippocampal tissue dissected from the brain. For biochemical analyses, we measured the concentration of 4-hydroxynonenal, and the expression of autophagic marker LC3B, synaptophysin, and brain-derived neurotrophic factor (BDNF) in the hippocampus. Our results showed that cART exposure increased escape latency in the MWM test. The cART-treated mice also showed increased 4-hydroxynonenal concentration and expression of LC3B. Furthermore, cART treatment decreased the expression of synaptophysin and BDNF. These findings further support the evidence that cART may be neurotoxic and therefore may play a role in the neuropathogenesis of HAND.

Anti-HIV drugs promote β-amyloid deposition and impair learning and memory in BALB/c mice

OBJECTIVES

Growing evidence suggested that antiretroviral (ARV) drugs may promote amyloid beta (Aβ) accumulation in HIV-1-infected brain and the persistence of HIV-associated neurocognitive disorders (HANDs). It has also been shown that lipid peroxidation upregulates β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) expression and subsequently promotes Aβ peptide production. In the present study, we examined whether chronic exposure to the anti-HIV drugs tenofovir disoproxil fumarate (TDF) and nevirapine induces lipid peroxidation thereby promoting BACE1 and Aβ generation and consequently impair cognitive function in mice.

METHODS

TDF or nevirapine was orally administered to female BALB/c mice once a day for 8 weeks. On the 7th week of treatment, spatial learning and memory were assessed using the Morris water maze test. The levels of lipid peroxidation, BACE1, amyloid β 1-42 (Aβ1-42) and Aβ deposits were measured in the hippocampal tissue upon completion of treatment.

RESULTS

Chronic administration of nevirapine induced spatial learning and memory impairment in the Morris water maze test, whereas TDF did not have an effect. TDF and nevirapine administration increased hippocampal lipid peroxidation and Aβ1-42 concentration. Nevirapine further upregulated BACE1 expression and Aβ deposits.

CONCLUSION

Our results suggest that chronic exposure to TDF and nevirapine contributes to hippocampal lipid peroxidation and Aβ accumulation, respectively, as well as spatial learning and memory deficits in mice even in the absence of HIV infection. These findings further support a possible link between ARV drug toxicity, Aβ accumulation and the persistence of HANDs.

Mitochondrial Toxicogenomics for Antiretroviral Management: HIV Post-exposure Prophylaxis in Uninfected Patients

Background: Mitochondrial genome has been used across multiple fields in research, diagnosis, and toxicogenomics. Several compounds damage mitochondrial DNA (mtDNA), including biological and therapeutic agents like the human immunodeficiency virus (HIV) but also its antiretroviral treatment, leading to adverse clinical manifestations. HIV-infected and treated patients may show impaired mitochondrial and metabolic profile, but specific contribution of viral or treatment toxicity remains elusive. The evaluation of HIV consequences without treatment interference has been performed in naïve (non-treated) patients, but assessment of treatment toxicity without viral interference is usually restricted to in vitro assays.

Objective: The objective of the present study is to determine whether antiretroviral treatment without HIV interference can lead to mtDNA disturbances. We studied clinical, mitochondrial, and metabolic toxicity in non-infected healthy patients who received HIV post-exposure prophylaxis (PEP) to prevent further infection. We assessed two different PEP regimens according to their composition to ascertain if they were the cause of tolerability issues and derived toxicity.

Methods: We analyzed reasons for PEP discontinuation and main secondary effects of treatment withdrawal, mtDNA content from peripheral blood mononuclear cells and metabolic profile, before and after 28 days of PEP, in 23 patients classified depending on PEP composition: one protease inhibitor (PI) plus Zidovudine/Lamivudine (PI plus AZT + 3TC; n = 9) or PI plus Tenofovir/Emtricitabine (PI plus TDF + FTC; n = 14).

Results: Zidovudine-containing-regimens showed an increased risk for drug discontinuation (RR = 9.33; 95% CI = 1.34–65.23) due to adverse effects of medication related to gastrointestinal complications. In the absence of metabolic disturbances, 4-week PEP containing PI plus AZT + 3TC led to higher mitochondrial toxicity (−17.9 ± 25.8 decrease in mtDNA/nDNA levels) than PI plus TDF + FTC (which increased by 43.2 ± 24.3 units mtDNA/nDNA; p < 0.05 between groups). MtDNA changes showed a significant and negative correlation with baseline alanine transaminase levels (p < 0.05), suggesting that a proper hepatic function may protect from antiretroviral toxicity.

Conclusions: In absence of HIV infection, preventive short antiretroviral treatment can cause secondary effects responsible for treatment discontinuation and subclinical mitochondrial damage, especially pyrimidine analogs such as AZT, which still rank as the alternative option and first choice in certain cohorts for PEP. Forthcoming efforts should be focused on launching new strategies with safer clinical and mitotoxic profile.

In utero exposure to HIV and/or antiretroviral therapy: a systematic review of preclinical and clinical evidence of cognitive outcomes

INTRODUCION

With the increasing number of children exposed to HIV or antiretroviral therapy in utero, there are concerns that this population may have worse neurodevelopmental outcomes compared to those who are unexposed. The objective of this study was to systematically review the clinical and preclinical literature on the effects of in utero exposure to HIV and/or antiretroviral therapy (ART) on neurodevelopment.

METHODS

We systematically searched OVID Medline, PsycINFO and Embase, as well as the Cochrane Collaborative Database, Google Scholar and bibliographies of pertinent articles. Titles, abstracts, and full texts were assessed independently by two reviewers. Data from included studies were extracted. Results are summarized qualitatively.

RESULTS

The search yielded 3027 unique titles. Of the 255 critically reviewed full-text articles, 25 met inclusion criteria for the systematic review. Five articles studied human subjects and looked at brain structure and function. The remaining 20 articles were preclinical studies that mostly focused on behavioural assessments in animal models. The few clinical studies had mixed results. Some clinical studies found no difference in white matter while others noted higher fractional anisotropy and lower mean diffusivity in the brains of HIV-exposed uninfected children compared to HIV-unexposed uninfected children, correlating with abnormal neurobehavioral scores. Preclinical studies focused primarily on neurobehavioral changes resulting from monotherapy with either zidovudine or lamivudine. Various developmental and behavioural changes were noted in preclinical studies with ART exposure, including decreased grooming, decreased attention, memory deficits and fewer behaviours associated with appropriate social interaction.

CONCLUSIONS

While the existing literature suggests that there may be some neurobehavioral differences associated with HIV and ART exposure, limited data are available to substantially support these claims. More research is needed comparing neurobiological factors between HIV-exposed uninfected and HIV-unexposed uninfected children and using exposures consistent with current clinical care.

High-throughput chinmedomics-based prediction of effective components and targets from herbal medicine AS1350

This work was designed to explore the effective components and targets of herbal medicine AS1350 and its effect on “Kidney-Yang Deficiency Syndrome” (KYDS) based on a chinmedomics strategy which is capable of directly discovering and predicting the effective components, and potential targets, of herbal medicine. Serum samples were analysed by UPLC-MS combined with pattern recognition analysis to identify the biomarkers related to the therapeutic effects. Interestingly, the effectiveness of AS1350 against KYDS was proved by the chinmedomics method and regulated the biomarkers and targeting of metabolic disorders. Some 48 marker metabolites associated with alpha-linolenic acid metabolism, fatty acid metabolism, sphingolipids metabolism, phospholipid metabolism, steroid hormone biosynthesis, and amino acid metabolism were identified. The correlation coefficient between the constituents in vivo and the changes of marker metabolites were calculated by PCMS software and the potential effective constituents of AS1350 were also confirmed. By using chinmedomics technology, the components in AS1350 protecting against KYDS by re-balancing metabolic disorders of fatty acid metabolism, lipid metabolism, steroid hormone biosynthesis, etc. were deduced. These data indicated that the phenotypic characterisations of AS1350 altering the metabolic signatures of KYDS were multi-component, multi-pathway, multi-target, and overall regulation in nature.

The PHACS SMARTT Study: Assessment of the Safety of In Utero Exposure to Antiretroviral Drugs

The Surveillance Monitoring for ART Toxicities (SMARTT) cohort of the Pediatric HIV/AIDS Cohort Study includes over 3,500 HIV-exposed but uninfected infants and children at 22 sites in the US, including Puerto Rico. The goal of the study is to determine the safety of in utero exposure to antiretrovirals (ARVs) and to estimate the incidence of adverse events. Domains being assessed include metabolic, growth and development, cardiac, neurological, neurodevelopmental (ND), behavior, language, and hearing. SMARTT employs an innovative trigger-based design as an efficient means to identify and evaluate adverse events. Participants who met a predefined clinical or laboratory threshold (trigger) undergo additional evaluations to define their case status. After adjusting for birth cohort and other factors, there was no significant increase in the likelihood of meeting overall case status (case in any domain) with exposure to combination ARVs (cARVs), any ARV class, or any specific ARV. However, several individual ARVs were significantly associated with case status in individual domains, including zidovudine for a metabolic case, first trimester stavudine for a language case, and didanosine plus stavudine for a ND case. We found an increased rate of preterm birth with first trimester exposure to protease inhibitor-based cARV. Although there was no overall increase in congenital anomalies with first trimester cARV, a significant increase was seen with exposure to atazanavir, ritonavir, and didanosine plus stavudine. Tenofovir exposure was associated with significantly lower mean whole-body bone mineral content in the newborn period and a lower length and head circumference at 1 year of age. With ND testing at 1 year of age, specific ARVs (atazanavir, ritonavir-boosted lopinavir, nelfinavir, and tenofovir) were associated with lower performance, although all groups were within the normal range. No ARVs or classes were associated with lower performance between 5 and 13 years of age. Atazanavir and saquinavir exposure were associated with late language emergence at 1 year, but not at 2 years of age. The results of the SMARTT study are generally reassuring, with little evidence for serious adverse events resulting from in utero ARV exposure. However, several findings of concern warrant further evaluation, and new ARVs used in pregnancy need to be evaluated.

Effects of Zidovudine Treatment on Heart mRNA Expression and Mitochondrial DNA Copy Number Associated with Alterations in Deoxynucleoside Triphosphate Composition in a Neonatal Rat Model

The prevention of mother-to-child transmission (MTCT) of HIV is a crucial component in HIV therapy. Nucleoside reverse transcriptase inhibitors (NRTIs), primarily 3'-azido-3'-thymidine (AZT [zidovudine]), have been used to treat both mothers and neonates. While AZT is being replaced with less toxic drugs in treating mothers in MTCT prevention, it is still commonly used to treat neonates. Problems related to mitochondrial toxicity and potential mutagenesis associated with AZT treatment have been reported in treated cohorts. Yet little is known concerning the metabolism and potential toxicity of AZT on embryonic and neonatal tissues, especially considering that the enzymes of nucleoside metabolism change dramatically as many tissues convert from hyperplastic to hypertrophic growth during this period. AZT is known to inhibit thymidine phosphorylation and potentially alter deoxynucleoside triphosphate (dNTP) pools in adults. This study examines the effects of AZT on dNTP pools, mRNA expression of deoxynucleoside/deoxynucleotide metabolic enzymes, and mitochondrial DNA levels in a neonatal rat model. Results show that AZT treatment dramatically altered dNTP pools in the first 7 days of life after birth, which normalized to age-matched controls in the second and third weeks. Additionally, AZT treatment dramatically increased the mRNA levels of many enzymes involved in deoxynucleotide synthesis and mitochondrial biogenesis during the first week of life, which normalized to age-matched controls by the third week. These results were correlated with depletion of mitochondrial DNA noted in the second week. Taken together, results demonstrated that AZT treatment has a powerful effect on the deoxynucleotide synthesis pathways that may be associated with toxicity and mutagenesis.

Mitochondrial disturbances in HIV pregnancies

BACKGROUND

Mitochondrial consequences from foetal exposure to HIV infection and antiretrovirals could be further investigated.

OBJECTIVE

The main objective of this study was to evaluate maternofoetal mitochondrial disturbances in HIV infection and antiretroviral administration in human pregnancies as the aetiopathogenic basis of suboptimal perinatal-clinical features.

DESIGN

Cross-sectional, prospective, observational, exploratory and controlled study.

METHODS

Clinical/epidemiological data of 35 HIV-infected pregnant women and 17 controls were collected. Mitochondrial DNA (mtDNA) and RNA (mtRNA) content (real time-PCR), enzymatic activities and content (spectrophotometry) were measured in leucocytes. Genetic-functional, maternofoetal and molecular-clinical correlations were assessed.

RESULTS

Birth weight was lower in infants from HIV-infected mothers compared with controls. MtDNA values were slightly decreased in HIV cases, although not reaching statistical significance. MtRNA values were lower in HIV-infected mothers. Similarly, binary complex II+III enzymatic activity decreased to 50% in both HIV-infected mothers (44.45 ± 3.77%) and their infants (48.79 ± 3.41%) (P = 0.001 and P < 0.001). Global CI+III+IV enzymatic activity was lower in HIV-infected mothers and infants (90.43 ± 2.39% and 51.16 ± 9.30%) (P < 0.005 and P < 0.05). MtDNA content correlated with function in mothers and infants. Maternofoetal parameters correlated at genetic and functional levels.

CONCLUSION

HAART toxicity caused mitochondrial damage in HIV-infected pregnant women and their newborns, being present at a genetic and functional level with a maternofoetal correlation.