Molecular insights of peroxisome proliferator-activated receptor-γ signalling in amyotrophic lateral sclerosis and Huntington's disease.

Progressive neuronal loss is a hallmark of neurodegenerative diseases like Huntingtons disease (HD) and Amyotrophic lateral sclerosis (ALS) which are caused by convergent mechanisms such as oxidative stress, mitochondrial dysfunction, neuroinflammation, impaired autophagy and dysregulated cell death pathways. Both conditions share significant disruptions in metabolic and inflammatory signalling despite having different genetic origins and clinical manifestations; underscoring the necessity of pathway-oriented treatment approaches. In the central nervous system, peroxisome proliferator-activated receptor-γ (PPAR-γ), a ligand-activated nuclear receptor has become an important regulator of inflammation, redox homeostasis, mitochondrial biogenesis and cellular stress responses. After giving a thorough overview of PPAR-γ structure activation and transcriptional regulation and the PGC-1α-mediated mitochondrial biogenesis axis, this chapter delves deeply into its interactions with major signalling pathways such as NF-κB, Wnt/β-catenin Nrf2/ARE and the autophagy-apoptosis networks. With a focus on experimental data showing PPAR-γ signaling's neuroprotective, anti-inflammatory, antioxidant and metabolic regulatory roles the pathophysiology of ALS and HD is critically investigated. Lastly the need for improved biomarkers, tailored multi-target strategies and selective modulators is highlighted in the discussion of current therapeutic limitations and translational difficulties.