bims-lycede 2025-12-07 papers

J Vis Exp. 2025 Nov 14.

Live-cell Imaging of Lysosomal Membrane Permeabilization During Necroptosis.

Katia S G Andrade, John Mably, Da-Zhi Wang, Zhigao Wang.

Necroptosis, a form of regulated necrosis, culminates in cell membrane rupture. Our lab and others have discovered that lysosomal membrane permeabilization (LMP) is an early and crucial event in this process, preceding membrane rupture. Rapid LMP releases potent lysosomal enzymes, particularly proteases, into the cytosol, actively promoting cell death. Live-cell imaging provides an invaluable tool for detecting LMP during necroptosis in real-time. Several fluorescent dyes are highly effective: (1) pH-sensitive LysoTracker dyes track changes in lysosomal pH. A decrease in fluorescence signal indicates a loss of the lysosomal pH gradient, a primary sign of lysosomal dysfunction, which may be a precursor or direct consequence of LMP. (2) Fluorescein-labeled dextran beads are internalized and accumulate in lysosomes. Their release into the cytosol signals complete LMP and cargo leakage. Here, we observed a progressive loss of Lysotracker fluorescence, with diffusing Dextran fluorescence into the cytosol after necroptosis induction. Thus, the live-cell imaging methodology enables researchers to precisely track the timing and extent of lysosomal dysfunction, contributing to a more comprehensive understanding of necroptosis mechanisms and illuminating potential therapeutic interventions.

DOI: https://doi.org/10.3791/69495

J Cell Sci. 2025 Dec 01. pii: jcs264255. [Epub ahead of print]138(23):

Molecular mechanisms of the lysosomal damage response and its roles in aging and disease.

Shuhei Nakamura, Takayuki Shima, Tamotsu Yoshimori.

Lysosomes are the main digestive organelles and serve as a signaling hub linking environmental cues to cellular metabolism. Through these functions, lysosomes play a crucial role in maintaining cellular and organismal homeostasis. However, how lysosomal homeostasis itself is maintained is not well understood. Lysosomes are frequently damaged by a variety of substances, including crystals, silica, lipids, bacteria, toxins, amyloid proteins and reactive oxygen species. When lysosomes are damaged, their acidic contents leak out, leading to oxidative stress, inflammation and cell death. Damaged lysosomes are thus harmful to cells, and to restore lysosomal function after damage, cells have developed several defense mechanisms, collectively called the lysosomal damage response (or endo-lysosomal damage response). Recent studies have shown that this response is composed of three main pathways depending on the degree and duration of damage - repair, removal of the damaged lysosomes, and lysosomal biogenesis and regeneration. Growing evidence suggest that the failure and/or dysregulation of this response is implicated in aging and several diseases, including neurodegenerative diseases and kidney disease. In light of the rapid growth of this field, this Review summarizes our current knowledge of the lysosomal damage response, its significance in aging and diseases, and future perspectives.

Keywords: Aging; Autophagy; Disease; Lysosomal damage; Lysosome

DOI: https://doi.org/10.1242/jcs.264255

Mol Biol Rep. 2025 Dec 05. 53(1): 163

Mechanistic insights into the dynamics of plasma membrane repair in cancer.

Yufeng Huang, Asad Ullah, Muhammad Muddassir Ali.

Cancer cells are well equipped with plasma membrane repair to survive mechanical tension, chemical stress, immune assaults and therapeutic interventions. Maintaining plasma membrane integrity is quintessential for tumor cells as it plays a pivotal role in communication between the internal environment of the tumor cell and the extracellular surroundings. Therefore, tumor cells achieve plasma membrane repair by several dynamic repair pathways such as calcium (Ca2+) guided lysosomal exocytosis, annexins (ANXs) mediated membrane repair and shedding, damaged oriented membrane repair via endocytosis, ESCRT (Endosomal Sorting Complex Required for Transport) mediated plasma Membrane repair and LC-3 Associated Macropinocytosis (LAM) to survive persistent membrane damage inflicted by immune attack, mechanical stress especially during metastasis and chemotherapy induction. These processes rapidly restore membrane integrity, maintaining cellular homeostasis and conferring survival advantages during metastasis and immune evasion. Notably, key repair proteins such as ANXs, synaptotagmin VII (Syt VII), ESCRT components, and autophagy-related factors (ATGs, rubicon and LC-3) are often upregulated in various cancers including breast, pancreatic, bladder, liver, and aggressive solid tumors, highlighting their clinical relevance and potential as therapeutic targets. Moreover, an understanding of the mechanistic interplay among different pathways unveils a new therapeutic window to selectively disrupt these repair pathways, sensitizing cancer cells to persistent damage while sparing normal tissues. This review elucidates the mechanisms of plasma membrane repair in cancer, highlights the differential regulation of their key mediators across multiple tumor types, and briefly explores their therapeutic potential.

Keywords: Cancer; Membrane repair mechanisms; Molecular oncology and cell biology; Plasma membrane repair

DOI: https://doi.org/10.1007/s11033-025-11329-x