Gene therapy in Aβ-induced cell and mouse models of Alzheimer's disease through compensating defective mitochondrial complex I function

From genetic roots to recent advancements in gene therapy targeting amyloid beta in Alzheimer's disease

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders. The pathological hallmarks of AD are amyloid-beta (Aβ) plaques and tau protein tangles, which cause neurodegeneration and lead to cognitive decline. The distinguished role of Aβ plaques in the onset of the disease, especially in familial AD, alongside the genetic complexity of AD, underscores the need for precise and targeted genetic interventions targeting Aβ. This review first highlights the amyloidogenic and non-amyloidogenic pathways and inflammatory mechanisms contributing to Aβ accumulation. It also introduces the role of genetic variants such as amyloid precursor protein (APP), presenilin (PSEN1), PSEN2, and Apolipoprotein E (APOE) alongside the molecular and cellular mechanisms involved in Aβ pathology. Then, gene therapy techniques are discussed for their potential to target Aβ either directly by inhibiting its production or enhancing its degradation or indirectly by targeting APOE, inflammatory pathways, and neurotrophic factors. While these approaches show significant preclinical promise, challenges such as timing, safety, and delivery across the blood-brain barrier persist and need further investigation.

Mitochondrial dysfunction in Alzheimer's disease: Guiding the path to targeted therapies

Alzheimer's disease (AD) is characterized by progressive neurodegeneration, marked by the accumulation of amyloid-β (Aβ) plaques and tau tangles. Emerging evidence suggests that mitochondrial dysfunction plays a pivotal role in AD pathogenesis, driven by impairments in mitochondrial quality control (MQC) mechanisms. MQC is crucial for maintaining mitochondrial integrity through processes such as proteostasis, mitochondrial dynamics, mitophagy, and precise communication with other subcellular organelles. In AD, disruptions in these processes lead to bioenergetic failure, gene dysregulation, the accumulation of damaged mitochondria, neuroinflammation, and lipid homeostasis impairment, further exacerbating neurodegeneration. This review elucidates the molecular pathways involved in MQC and their pathological relevance in AD, highlighting recent discoveries related to mitochondrial mechanisms underlying neurodegeneration. Furthermore, we explore potential therapeutic strategies targeting mitochondrial dysfunction, including gene therapy and pharmacological interventions, offering new avenues for slowing AD progression. The complex interplay between mitochondrial health and neurodegeneration underscores the need for innovative approaches to restore mitochondrial function and mitigate the onset and progression of AD.

Current Developments in Alzheimer's Disease

An increased understanding of the predisposing genetics and complex pathogenic mechanisms of Alzheimer's disease have facilitated delineation of the long preclinical course and re-invigorated the search for disease-modifying treatments. Establishment of accurate blood-based biomarkers has enabled preclinical identification of early disease and permits trials of preventative treatment and quantitative monitoring of therapeutic effects. The broad range of therapeutic possibilities encompasses gene editing, enzyme activators and inhibitors, antisense oligonucleotides, and antagonists of receptors for inflammatory mediators.