Related Experiment Video
Updated: May 7, 2026
10:49
An Injury Paradigm to Investigate Central Nervous System Repair in Drosophila
Published on: March 28, 2013
Neuronal repair: Apoptotic proteins make good
Christopher P Reina1, Monica Driscoll, Christopher V Gabel
1Department of Molecular Biology and Biochemistry; Rutgers University; Piscataway, NJ USA.
Worm
|September 24, 2013
Summary
Scientists discovered that core apoptotic proteins, CED-4 and CED-3, unexpectedly promote central nervous system (CNS) regeneration in C. elegans. These proteins activate via a novel calcium-dependent pathway, offering new therapeutic targets for CNS injury.
Area of Science:
- Neuroscience
- Cell Biology
- Developmental Biology
Background:
- Central nervous system (CNS) regeneration is limited by poorly understood intrinsic and extrinsic factors.
- Identifying factors that promote CNS repair is crucial for developing effective therapies for CNS injuries.
Purpose of the Study:
- To genetically identify novel factors that promote neuronal regeneration.
- To investigate the role of apoptosis-related proteins in CNS repair.
Main Methods:
- Utilized in vivo laser severing of single axons in C. elegans as a model system.
- Performed genetic screens to identify regeneration-promoting factors.
- Investigated the function of CED-4 and CED-3 in neuronal repair downstream of injury-induced calcium transients and the DLK-1 pathway.
Main Results:
- Unexpectedly identified core apoptotic proteins CED-4/Apaf-1 and executioner caspase CED-3 as promoters of early regeneration events in C. elegans.
- Found that other upstream regulators of apoptosis do not influence regeneration, suggesting a novel activation mechanism for CED-4 and CED-3.
- Demonstrated that CED-4 and CED-3 function downstream of injury-induced calcium transients and act via the DLK-1 pathway.
Conclusions:
- CED-4 and CED-3 play a novel role in promoting CNS regeneration, independent of canonical apoptosis pathways.
- Propose a model for calcium-dependent, localized activation of CED-4 and CED-3 caspases in neuronal repair.
- Further research is needed to elucidate mechanisms of CED-3 regulation and substrate cleavage in regeneration.
Related Concept Videos
01:15Neurogenesis and Regeneration of Nervous Tissue
In the CNS, neurogenesis, the birth of new neurons from stem cells, is limited to the hippocampus in adults. In other regions of the brain and spinal cord, neurogenesis is almost non-existent due to inhibitory influences from neuroglia, especially oligodendrocytes, and the absence of growth-stimulating cues. The myelin produced by oligodendrocytes in the CNS inhibits neuronal regeneration. Furthermore, astrocytes proliferate rapidly after neuronal damage, forming scar tissue that physically...
01:22Cellular Injury V: Apoptosis and Autophagy
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...
01:17Phagocytosis of Apoptotic Cells
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
Normal cells contain receptors that prevent them from being recognized by phagocytes.
01:17The Extrinsic Apoptotic Pathway
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
01:31The Intrinsic Apoptotic Pathway
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
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...