Objective: The present abstract aims to investigate the impact of viral infections and microgravity exposure in the context of Parkinson’s disease (PD).
Background: PD is a neurodegenerative disorder characterized by the loss of dopaminergic neurons and pathological α-synuclein aggregation. Recent evidence implicates latent retroviral elements, particularly HERVs, and active viral infections such as Herpes Simplex Virus 1 (HSV-1), in modulating neurodegenerative diseases’ onset and progression. Astrocytes appear critically involved in PD, with altered HERV-K expression patterns observed in patient-derived astrocytes.
Method: We analyzed peripheral blood mononuclear cells (PBMCs) from PD patients and matched healthy controls, assessing microRNA expression profiles, HERV-K gene expression (gag, env, pol), and circulating autoantibody levels against HERV-K. Additionally, in vitro experiments were performed using U-87 MG astrocytic cells infected with wild-type HSV-1 and mutant strains lacking viral immune-evasion proteins (VP22, viral-dUTPase), under simulated microgravity conditions. Differential expression analyses of PD-associated genes, such as SNCA, LRRK2, PINK1, and inflammatory mediators, such as IL-1β, IL-18, TNF-α, were conducted.
Results: PD patient PBMCs exhibited significant upregulation of specific microRNAs and related downregulation of HERV-K expression. Reduced levels of anti-HERV-K autoantibodies were observed in PD patients compared to controls. In vitro, HSV-1 infection and microgravity independently and synergistically enhanced neuroinflammatory responses and HERV expression in U-87 MG cells.
Conclusion: We have observed a microRNA-mediated suppression of HERV-K in PD patients and the potential reactivation of endogenous retroviral elements triggered by viral infections and microgravity, highlighting novel and clinically relevant mechanisms in PD pathogenesis.
To cite this abstract in AMA style:
ER. Simula, S. Jasemi, D. Cossu, I. Cossu, M. Fais, M. Noli, LA. Sechi. The Impact of Microgravity and Herpes Simplex Virus 1 on Parkinson’s Neurodegeneration and HERV Expression [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/the-impact-of-microgravity-and-herpes-simplex-virus-1-on-parkinsons-neurodegeneration-and-herv-expression/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/the-impact-of-microgravity-and-herpes-simplex-virus-1-on-parkinsons-neurodegeneration-and-herv-expression/