Related Experiment Video
Updated: Jun 17, 2026
05:30
Live-cell Imaging of Lysosomal Membrane Permeabilization During Necroptosis
Published on: November 14, 2025
Lipotoxicity-mediated cell dysfunction and death involve lysosomal membrane permeabilization and cathepsin L activity
Frankis G Almaguel1, Jo-Wen Liu, Fabio J Pacheco
1Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Mortensen Hall 142, 11085 Campus St., Loma Linda, CA 92350, USA.
Brain Research
|January 2, 2010
Summary
Palmitic acid-induced lipotoxicity in nerve cells involves early lysosomal membrane permeabilization (LMP). Docosahexanoic acid (DHA) inhibits this process, suggesting therapeutic potential for lipotoxicity-related diseases.
Area of Science:
- Cell Biology
- Neuroscience
- Biochemistry
Background:
- Lipotoxicity, driven by elevated free fatty acids, causes cell dysfunction and apoptosis, contributing to diabetes and central nervous system disorders.
- Palmitic acid-induced lipotoxicity (PA-LTx) in nerve growth factor-differentiated PC12 (NGFDPC12) cells is linked to oxidative stress and apoptosis.
- Previous studies indicated PA-LTx involves reactive oxygen species (ROS) generation, mitochondrial membrane permeabilization (MMP), and caspase activation.
Purpose of the Study:
- To investigate the early molecular mechanisms of palmitic acid-induced lipotoxicity in NGFDPC12 cells.
- To determine the role of lysosomal membrane permeabilization (LMP) in PA-LTx.
- To explore the protective effects of docosahexanoic acid (DHA) against PA-LTx.
Main Methods:
- Utilized nerve growth factor-differentiated PC12 (NGFDPC12) cells to model PA-induced lipotoxicity.
- Assessed lysosomal membrane permeabilization (LMP) as an early event.
- Investigated the role of cathepsin L and cathepsin B in PA-LTx and evaluated the effect of DHA co-treatment.
Main Results:
- Lysosomal membrane permeabilization (LMP) was identified as an early event in PA-induced lipotoxicity, preceding mitochondrial membrane permeabilization (MMP) and apoptosis.
- Pharmacological inhibition of cathepsin L, but not cathepsin B, significantly attenuated LMP, MMP, and apoptosis.
- Co-treatment with docosahexanoic acid (DHA) markedly reduced LMP, indicating DHA antagonizes upstream signals of lysosomal dysfunction.
Conclusions:
- Lysosomal membrane permeabilization (LMP) is a key early mediator in palmitic acid-induced lipotoxicity.
- Cathepsin L plays a critical role in mediating PA-LTx through lysosomal damage.
- Targeting upstream signals leading to LMP, potentially involving DHA, offers a promising therapeutic strategy for lipotoxicity-associated pathologies.
Related Concept Videos
01:18Autophagic Cell Death
Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...
01:16Necrosis
Necrosis is considered as an “accidental” or unexpected form of cell death that ends in cell lysis. The first noticeable mention of “necrosis” was in 1859 when Rudolf Virchow used this term to describe advanced tissue breakdown in his compilation titled “Cell Pathology”.
Morphological Manifestations of Necrosis
Necrotic cells show different types of morphological appearance depending on the type of tissue and infection. In coagulative necrosis, cells become anucleated and die, but their...
Morphological Manifestations of Necrosis
Necrotic cells show different types of morphological appearance depending on the type of tissue and infection. In coagulative necrosis, cells become anucleated and die, but their...
01:16Cellular Injury IV: Necrosis
Necrosis is a form of irreversible cell death caused by severe injury such as ischemia, toxins, or trauma. Unlike programmed cell death, it is an uncontrolled, pathological process that typically provokes inflammation in surrounding tissues.Pathophysiologic ChangesNecrosis begins when cells sustain critical damage, leading to swelling of organelles, particularly mitochondria, and rapid ATP depletion. As energy levels decline, membrane ion pumps fail, leading to calcium influx and eventually,...
01:11Cellular Injury IlI: Cellular Death
Cell death is the irreversible loss of cellular structure and function, representing the final stage of severe injury. It plays a key role in both normal physiology and disease.Types of Cell DeathThe two main types are necrosis and apoptosis, though others like necroptosis and pyroptosis also exist.Necrosis:Necrosis is an unregulated form of cell death caused by severe injury such as trauma, toxins, or ischemia. It is characterized by cell swelling, membrane loss, rupture, and leakage of...
01:22Lysosomal Hydrolases
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
01:30Overview of Cell Death
Cell death is an essential process where the body gets rid of old or damaged cells. Cell proliferation and death need to be balanced, as an imbalance between the two may lead to cancer or autoimmune diseases.
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...
Cell death was observed in the early 19th century, but there was no experimental evidence to prove it. In 1842, Carl Vogt first discovered cell death in a metamorphic toad; however, it was not termed ‘cell death.’ Scientists discovered different cell death pathways only in the 20th century...