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SCAV-3 affects apoptotic cell degradation in Caenorhabditis elegans
Aiying Ma1,2,3, Qi Feng1, Peiyao Li1
1College of Life Sciences, Shaanxi Normal University, Xi'an, China.
FEBS Open Bio
|March 22, 2023
Summary
Loss of scav-3 in C. elegans impairs apoptotic cell clearance by affecting lysosome integrity and hydrolase activity, leading to cell corpse accumulation. This highlights scav-3
Area of Science:
- Cell Biology
- Apoptosis Research
- Molecular Genetics
Background:
- Apoptosis, or programmed cell death, requires efficient clearance of apoptotic cells (ACs) by phagocytes.
- Dysregulation of AC clearance is linked to various disorders.
- The role of scavenger receptor homologs in AC clearance is not fully understood.
Purpose of the Study:
- To investigate the function of Caenorhabditis elegans scavenger receptor homologs in apoptotic cell clearance.
- To elucidate the specific role of scav-3 in the process of AC removal.
Main Methods:
- Genetic screening in C. elegans to identify genes involved in AC clearance.
- Analysis of cell corpse accumulation in mutant strains.
- Localization studies of SCAV-3 protein.
- Phagosome maturation and lysosome recruitment assays.
- Assessment of hydrolytic enzyme activity in phagosomes.
Main Results:
- Loss of scav-3 function, the C. elegans homolog of human lysosomal integral membrane protein-2, resulted in significant accumulation of cell corpses.
- This accumulation was due to impaired degradation, not engulfment failure.
- SCAV-3 localizes to lysosomes and is crucial for maintaining lysosomal membrane integrity.
- Loss of scav-3 did not affect phagosome maturation or lysosome recruitment to phagosomes.
- Phagosomes in scav-3 mutants showed reduced hydrolytic enzyme content, suggesting leakage from damaged lysosomes.
Conclusions:
- SCAV-3 is essential for the degradation of apoptotic cells in C. elegans.
- Loss of scav-3 function compromises lysosomal integrity, leading to leakage of hydrolases and reduced digestive capacity within phagolysosomes.
- This mechanism directly impacts the efficiency of apoptotic cell elimination.
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