Neuroinflammatory Interactions in Neurodegenerative Diseases

Neuroinflammation has emerged as a central feature in the pathogenesis of many neurodegenerative disorders, including Parkinson’s disease, Alzheimer’s disease and amyotrophic lateral sclerosis. The interplay between central and peripheral immune responses contributes to neuronal dysfunction through activation of resident glial cells, recruitment of peripheral immune cells and disruption of the blood–brain barrier. Key molecular mediators such as pro-inflammatory cytokines, chemokines and complement components drive a chronic inflammatory milieu that exacerbates protein misfolding, mitochondrial stress and synaptic loss. Conversely, misfolded proteins including α-synuclein and amyloid-β can themselves trigger innate immune activation, establishing a self-propagating cycle. Recent advances have highlighted the importance of gut-brain communication in this context, with alterations in the intestinal microbiota and gut barrier function influencing systemic inflammation and trafficking of immune cells to the brain. Understanding these bidirectional pathways is crucial for the development of therapies that not only target aggregation of pathogenic proteins but also modulate neuroimmune mechanisms to slow or halt disease progression.

Research from Nature Portfolio

Recent studies have delineated how genetic risk factors interact with early inflammatory insults to precipitate neurodegenerative traits. Work in rodent models carrying the human LRRK2 G2019S mutation demonstrates that even subclinical intestinal inflammation accelerates α-synuclein accumulation in enteric and central myeloid cells, promotes dopaminergic neuron loss and induces motor deficits in a sex-dependent manner. These findings reveal that peripheral immune activation can prime microglia and amplify central neurodegeneration in genetically susceptible individuals. Importantly, the study identifies myeloid-cell pathways and sex chromosome complement as determinants of disease severity, pointing to novel targets for immunomodulatory intervention in early prodromal stages of Parkinsonian disorders.

Neuroinflammatory Interactions in Neurodegenerative Diseases publication trend

The graph below shows the total number of articles in neuroinflammatory interactions in neurodegenerative diseases across all publications each year (not limited to Nature Index journals).

Technical terms

Microglia: Resident immune cells of the central nervous system that detect and respond to injury or pathogens.

Astrocytes: Star-shaped glial cells that support neuronal function, maintain blood–brain barrier integrity and modulate inflammation.

α-Synuclein: A neuronal protein whose misfolding and aggregation are hallmarks of Parkinson’s disease pathology.

Cytokines: Small proteins released by immune cells that regulate inflammation and cell signalling.

LRRK2: Leucine-rich repeat kinase 2, a gene implicated in familial and sporadic forms of Parkinson’s disease.

Blood–brain barrier: A specialised endothelial interface that regulates exchange between the bloodstream and the brain.

CD8+ T-cells: A subset of T lymphocytes that can mediate cytotoxic responses and contribute to neuroinflammatory damage.

References

1. The landscape of rare genetic variation associated with inflammatory bowel disease and Parkinson’s disease comorbidity. Genome Medicine (2024).
2. The association between Parkinson’s disease and autoimmune diseases: A systematic review and meta-analysis. Frontiers in Immunology (2023).
3. Sex-dependent interactions between prodromal intestinal inflammation and LRRK2 G2019S in mice promote endophenotypes of Parkinson’s disease. Communications Biology (2024).
4. Experimental colitis promotes sustained, sex-dependent, T-cell-associated neuroinflammation and parkinsonian neuropathology. Acta Neuropathologica Communications (2021).