Epigenetic Mechanisms Shaping Spine Regulation: Unveiling the Role of Cytoskeletal Dynamics and Localized Protein Synthesis.

Spines, the anatomical specializations on nerve cells, undergo persistent remodeling that often drives synapse development and plasticity. This remodeling is primarily driven by cytoskeletal regulation and local protein synthesis, both of which shape spine morphology. The cytoskeleton, composed mainly of actin filaments and microtubules, provides structural integrity and plasticity to spines by tuning their dynamics. Complementing this, local protein synthesis supports spine growth and modification by enabling localized trafficking and translation of synaptic mRNAs. At a given time, stimuli elicit a cascade of synaptic events involving both cytoskeletal dynamics and localized translation that converge to orchestrate spine development. Importantly, these events are not governed solely by immediate cellular signaling; rather, it extends to include epigenetic modifiers that exert control over the spatial and temporal dynamics of spine development. Aberrant expression of such modifiers can disrupt spine development and contribute to synaptopathies-neurological disorders rooted from synaptic dysfunction. Previous research has cursorily examined how epigenetic regulation contributes to neurodegenerative diseases, lacking detailed exploration of epigenetics in individual synaptic events. However, understanding spine reprogramming and its epigenetic, underpinnings need to be deciphered. Emerging evidence suggests altered epigenetic profiles disturb the coordinated balance of synaptic machinery and its structural architecture. Here, we review the stochastic mechanisms influencing spine and synapse morphology, emphasizing cytoskeletal maintenance and local protein synthesis-and how these events are tuned in light of epigenetic regulation.