Lysosomal lumen

The lysosomal lumen is the acidic internal environment of the lysosome, a membrane-bound organelle essential for the degradation and recycling of macromolecules such as proteins, lipids, and polysaccharides. This compartment maintains a low pH (approximately 4.5–5.0) to optimize the activity of over 60 different acid hydrolases, which are critical for cellular waste management and homeostasis [1, 4]. Beyond degradation, the lysosomal lumen and its membrane serve as a signaling hub for nutrient sensing, particularly through the recruitment and activation of the mTORC1 complex [1]. Dysfunction in lysosomal processes is a hallmark of lysosomal storage diseases (LSDs), where the accumulation of undigested substrates leads to severe multi-systemic pathologies [2]. Furthermore, impaired lysosomal function is increasingly linked to neurodegenerative conditions like Parkinson's and Alzheimer's diseases, as well as cancer progression and drug resistance [2, 3]. Therapeutic strategies targeting the lysosomal lumen include lysosomotropic agents that alter pH, enzyme replacement therapies (ERT) to restore missing hydrolases, and small molecules designed to enhance lysosomal biogenesis or stability [3].

Other names

LysosomeLysosomal compartmentAcidic vacuoleLysosomal system

Modulation of lysosomal pH, inhibition of vacuolar-type H+-ATPase (V-ATPase), enzyme replacement therapy (ERT), or substrate reduction therapy (SRT).