Immune-directed gene therapeutic development for Alzheimer's, prion, and Parkinson's diseases

Exploring the association between interleukin-1β and its interacting proteins in Alzheimer's disease

Alzheimer’s disease (AD) is an age-associated progressive neurodegenerative disorder which is of clinical concern. The association between the nervous and immune system is defined as an neuroimmunological theory that supports a model of pathology or treatment for AD. Interleukin (IL)-1β has a pro-inflammatory function in AD; however, the mechanism of its dysregulation in AD remains unknown. It is therefore of significance to understand the molecular mechanisms of IL-1β and how it may regulate AD. Proteins, which have been previously reported to be associated with IL-1β in AD, have been used in the present study as nodes to illustrate a net of protein interaction in Cytoscape. The Kyoto Encyclopedia of Genes and Genomes was used to further analyze the association of these proteins with the pathology of AD. The present study identified and subsequently compared two AD and six IL-1β pathways with the network produced in Cytoscape. The present study identified important mechanisms in the pathology of AD and constructed two novel networks using Cytoscape.

Eph receptors: new players in Alzheimer's disease pathogenesis

Alzheimer's disease (AD) is devastating and leads to permanent losses of memory and other cognitive functions. Although recent genetic evidences strongly argue for a causative role of Aβ in AD onset and progression (Jonsson et al., 2012), its role in AD etiology remains a matter of debate. However, even if not the sole culprit or pathological trigger, genetic and anatomical evidences in conjunction with numerous pharmacological studies, suggest that Aβ peptides, at least contribute to the disease. How Aβ contributes to memory loss remains largely unknown. Soluble Aβ species referred to as Aβ oligomers have been shown to be neurotoxic and induce network failure and cognitive deficits in animal models of the disease. In recent years, several proteins were described as potential Aβ oligomers receptors, amongst which are the receptor tyrosine kinases of Eph family. These receptors together with their natural ligands referred to as ephrins have been involved in a plethora of physiological and pathological processes, including embryonic neurogenesis, learning and memory, diabetes, cancers and anxiety. Here we review recent discoveries on Eph receptors-mediated protection against Aβ oligomers neurotoxicity as well as their potential as therapeutic targets in AD pathogenesis.

Parkinson's disease

Parkinson's disease (PD) is the most common age-related motoric neurodegenerative disease initially described in the 1800's by James Parkinson as the 'Shaking Palsy'. Loss of the neurotransmitter dopamine was recognized as underlying the pathophysiology of the motor dysfunction; subsequently discovery of dopamine replacement therapies brought substantial symptomatic benefit to PD patients. However, these therapies do not fully treat the clinical syndrome nor do they alter the natural history of this disorder motivating clinicians and researchers to further investigate the clinical phenotype, pathophysiology/pathobiology and etiology of this devastating disease. Although the exact cause of sporadic PD remains enigmatic studies of familial and rare toxicant forms of this disorder have laid the foundation for genome wide explorations and environmental studies. The combination of methodical clinical evaluation, systematic pathological studies and detailed genetic analyses have revealed that PD is a multifaceted disorder with a wide-range of clinical symptoms and pathology that include regions outside the dopamine system. One common thread in PD is the presence of intracytoplasmic inclusions that contain the protein, α-synuclein. The presence of toxic aggregated forms of α-synuclein (e.g., amyloid structures) are purported to be a harbinger of subsequent pathology. In fact, PD is both a cerebral amyloid disease and the most common synucleinopathy, that is, diseases that display accumulations of α-synuclein. Here we present our current understanding of PD etiology, pathology, clinical symptoms and therapeutic approaches with an emphasis on misfolded α-synuclein.

Future directions for immune modulation in neurodegenerative disorders: focus on Parkinson's disease

One common feature of neurodegenerative diseases is neuroinflammation. In the case of Parkinson's disease (PD), neuroinflammation appears early and persists throughout the disease course. The principal cellular mediator of brain inflammation is the resident microglia which share many features with related hematopoietically derived macrophages. Microglia can become activated by misfolded proteins including the PD relevant example, alpha-synuclein, a presynaptic protein. When activated, microglia release pro-inflammatory diffusible mediators that promote dysfunction and contribute to the death of the PD vulnerable dopaminergic neurons in the midbrain. Recently, the orphan nuclear receptor Nurr1, well known as a critical determinant in dopaminergic neuron maturation, has been ascribed two new properties. First, it promotes the production and release of the neuropeptide vasoactive intestinal peptide that functions both to stimulate dopaminergic neuron survival and inhibit neuroinflammation. Second, Nurr1 suppresses the expression and release of pro-inflammatory cytokines in glial cells. Herein, we discuss these new findings in context of strategies to attenuate neuroinflammation in PD.