Calcium Deregulation in Neurodegeneration and Neuroinflammation in Parkinson's Disease: Role of Calcium-Storing Organelles and Sodium-Calcium Exchanger.

Parkinson's disease (PD) is a progressive neurodegenerative disorder that lacks effective treatment strategies to halt or delay its progression. The homeostasis of Ca ions is crucial for ensuring optimal cellular functions and survival, especially for neuronal cells. In the context of PD, the systems regulating cellular Ca are compromised, leading to Ca-dependent synaptic dysfunction, impaired neuronal plasticity, and ultimately, neuronal loss. Recent research efforts directed toward understanding the pathology of PD have yielded significant insights, particularly highlighting the close relationship between Ca dysregulation, neuroinflammation, and neurodegeneration. However, the precise mechanisms driving the selective loss of dopaminergic neurons in PD remain elusive. The disruption of Ca homeostasis is a key factor, engaging various neurodegenerative and neuroinflammatory pathways and affecting intracellular organelles that store Ca. Specifically, impaired functioning of mitochondria, lysosomes, and the endoplasmic reticulum (ER) in Ca metabolism is believed to contribute to the disease's pathophysiology. The Na+-Ca exchanger (NCX) is considered an important key regulator of Ca homeostasis in various cell types, including neurons, astrocytes, and microglia. Alterations in NCX activity are associated with neurodegenerative processes in different models of PD. In this review, we will explore the role of Ca dysregulation and neuroinflammation as primary drivers of PD-related neurodegeneration, with an emphasis on the pivotal role of NCX in the pathology of PD. Consequently, NCXs and their interplay with intracellular organelles may emerge as potentially pivotal players in the mechanisms underlying PD neurodegeneration, providing a promising avenue for therapeutic intervention aimed at halting neurodegeneration.