Reis, Roberta S.
(2021)
Understanding HIV-1- Neuropathogenesis Using 3D Brain Organoids: Role of Host and Viral Factors in Neuronal Dysregulation.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Dendritic pruning and synapses loss are the major pathological hallmarks of HIV-1 associated neurocognitive disorders (HAND). However, the underlying mechanisms remain elusive mainly because of the lack of human representative in vitro models. Neurogranin (Nrgn) is a post-synaptic protein that is enriched in dendritic spines of neurons in healthy cortex and hippocampus. Interestingly, our group has identified that Nrgn expression is altered in postmortem tissue from HIV-1 positive individuals cognitively impaired, suggesting a role for this protein in the development of HAND. We hypothesized that HIV-1 induced inflammatory factors and/or viral proteins differentially regulate Nrgn levels in HIV-1, resulting in synaptic dysfunction and cognitive impairment. To address this hypothesis, we firstly developed a brain organoid as a more physiologically relevant tool to further HIV-1 neuropathogenesis studies in vitro. The incorporation of HIV-1 infected microglia to brain organoids resulted in a tri-culture that recapitulated the pathological hallmarks of HIV-1 neuropathogenesis as neuroinflammation, astrogliosis, synaptodendritic damage and neurodegeneration. Secondly, we showed that Nrgn is dysregulated in frontal cortex tissue from HIV-1 positive individuals at mRNA and protein levels before the emergence of cognitive symptoms. Further studies demonstrated that HIV-1 infection of macrophages/microglia alters the inflammatory milieu, leading to a transient downregulation of Nrgn mRNA in neurons, which in turn might disrupts the synaptic integrity. Lastly, we have identified a long noncoding RNA transcript (RP11-677M14.2) from the antisense strand of NRGN locus which is up-regulated in postmortem tissue from HIV-1 positive individuals. Our in vitro results pointed out to a plausible role for RP11-677M14.2 in modulating Nrgn expression, and the lncRNA dysregulation may be mechanistic link between Nrgn loss and early stages of HAND.
This study contributes to public health because it describes a new brain-representative in vitro model with improved physiological relevance over standard 2D experimental models for investigating host-viral interactions. Our findings also shed new light on the molecular mechanism(s) underlying the dysregulation of synaptodendritic integrity, in particular those involved in decreased levels of neurogranin observed in HAND. Restoring neurogranin levels in neurons can potentially prevent or revert the synaptic injury alleviating the cognitive deficits in patients with HAND.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
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| ETD Committee: |
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| Date: |
12 May 2021 |
| Date Type: |
Publication |
| Defense Date: |
21 January 2021 |
| Approval Date: |
12 May 2021 |
| Submission Date: |
28 April 2021 |
| Access Restriction: |
2 year -- Restrict access to University of Pittsburgh for a period of 2 years. |
| Number of Pages: |
142 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Public Health > Infectious Diseases and Microbiology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
HIV-1 Neuropathogenesis, 3D Brain organoids, Virology, Neuroinflammation |
| Date Deposited: |
12 May 2021 19:38 |
| Last Modified: |
12 May 2023 05:15 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/40846 |
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