Heme oxygenase-1 promoter region (GT)n polymorphism associates with increased neuroimmune activation and risk for encephalitis in HIV infection.

TitleHeme oxygenase-1 promoter region (GT)n polymorphism associates with increased neuroimmune activation and risk for encephalitis in HIV infection.
Publication TypeJournal Article
Year of Publication2018
AuthorsGill, AJ, Garza, R, Ambegaokar, SS, Gelman, BB, Kolson, DL
JournalJ Neuroinflammation
Date Published2018 Mar 06
KeywordsAdult, Aged, Antigens, CD, Brain, Cohort Studies, Dinucleotide Repeats, Encephalitis, Viral, Female, Genetic Association Studies, Heme Oxygenase-1, HIV Infections, Humans, Male, Middle Aged, Polymorphism, Genetic, Promoter Regions, Genetic, RNA, Messenger

BACKGROUND: Heme oxygenase-1 (HO-1) is a critical cytoprotective enzyme that limits oxidative stress, inflammation, and cellular injury within the central nervous system (CNS) and other tissues. We previously demonstrated that HO-1 protein expression is decreased within the brains of HIV+ subjects and that this HO-1 reduction correlates with CNS immune activation and neurocognitive dysfunction. To define a potential CNS protective role for HO-1 against HIV, we analyzed a well-characterized HIV autopsy cohort for two common HO-1 promoter region polymorphisms that are implicated in regulating HO-1 promoter transcriptional activity, a (GT)n dinucleotide repeat polymorphism and a single nucleotide polymorphism (A(-413)T). Shorter HO-1 (GT)n repeats and the 'A' SNP allele associate with higher HO-1 promoter activity.METHODS: Brain dorsolateral prefrontal cortex tissue samples from an autopsy cohort of HIV-, HIV+, and HIV encephalitis (HIVE) subjects (nā€‰=ā€‰554) were analyzed as follows: HO-1 (GT)n polymorphism allele lengths were determined by PCR and capillary electrophoresis, A(-413)T SNP alleles were determined by PCR with allele specific probes, and RNA expression of selected neuroimmune markers was analyzed by quantitative PCR.RESULTS: HIV+ subjects with shorter HO-1 (GT)n alleles had a significantly lower risk of HIVE; however, shorter HO-1 (GT)n alleles did not correlate with CNS or peripheral viral loads. In HIV+ subjects without HIVE, shorter HO-1 (GT)n alleles associated significantly with lower expression of brain type I interferon response markers (MX1, ISG15, and IRF1) and T-lymphocyte activation markers (CD38 and GZMB). No significant correlations were found between the HO-1 (GT)n repeat length and brain expression of macrophage markers (CD163, CD68), endothelial markers (PECAM1, VWF), the T-lymphocyte marker CD8A, or the B-lymphocyte maker CD19. Finally, we found no significant associations between the A(-413)T SNP and HIVE diagnosis, HIV viral loads, or any neuroimmune markers.CONCLUSION: Our data suggest that an individual's HO-1 promoter region (GT)n polymorphism allele repeat length exerts unique modifying risk effects on HIV-induced CNS neuroinflammation and associated neuropathogenesis. Shorter HO-1 (GT)n alleles increase HO-1 promoter activity, which could provide neuroprotection through decreased neuroimmune activation. Therapeutic strategies that induce HO-1 expression could decrease HIV-associated CNS neuroinflammation and decrease the risk for development of HIV neurological disease.

Alternate JournalJ Neuroinflammation
PubMed ID29510721
PubMed Central IDPMC5838989
Grant ListF30 MH102120 / MH / NIMH NIH HHS / United States
U24 MH100929 / MH / NIMH NIH HHS / United States
R01MH095671 / / National Institute of Mental Health /
R01MH104134 / / National Institute of Mental Health /
T32 NS007180 / NS / NINDS NIH HHS / United States
F30MH102120 / / National Institute of Mental Health /
R01 MH104134 / MH / NIMH NIH HHS / United States
R01MH101017 / / National Institute of Mental Health /
U24 MH100930 / MH / NIMH NIH HHS / United States
R01 MH111389 / MH / NIMH NIH HHS / United States
T32NS007180 / / National Institute of Neurological Disorders and Stroke /