Cellular apoptosis

Definition

Cellular apoptosis is a programmed cell death process that occurs in multicellular organisms, allowing cells to self-destruct in a controlled manner. This process is crucial for maintaining homeostasis, eliminating damaged or unneeded cells, and playing a role in immune responses. In the context of virus-induced cellular damage, apoptosis can be triggered as a defense mechanism to prevent the spread of infection.

5 Must Know Facts For Your Next Test

1. Apoptosis is characterized by specific morphological changes, including cell shrinkage, chromatin condensation, and the formation of apoptotic bodies.
2. Viruses can manipulate apoptosis pathways to either promote or inhibit cell death, affecting their ability to replicate and spread.
3. During viral infections, apoptosis serves as a mechanism to limit the virus's ability to propagate by eliminating infected cells.
4. Dysregulation of apoptosis can lead to diseases such as cancer, where cells evade normal apoptotic signals and continue to proliferate uncontrollably.
5. The extrinsic and intrinsic pathways are two main routes that trigger apoptosis, with distinct signaling mechanisms and regulatory factors.

Review Questions

• How does cellular apoptosis function as a defense mechanism against viral infections?
  • Cellular apoptosis acts as a defense mechanism by enabling infected cells to self-destruct, thereby limiting the spread of viruses. When a cell detects viral components, it can initiate the apoptotic process to eliminate itself before the virus replicates further. This helps to contain the infection and activate surrounding immune responses, as the dying cell can release signals that attract immune cells to the site of infection.
• Discuss how viruses can manipulate apoptosis pathways to their advantage.
  • Viruses can manipulate apoptosis pathways by either promoting or inhibiting the apoptotic process to enhance their survival and replication. Some viruses produce proteins that inhibit caspases, blocking the apoptotic pathway and allowing infected cells to survive longer than they normally would. Conversely, other viruses may induce apoptosis in immune cells to evade detection and destruction by the host's immune system, ultimately facilitating their spread.
• Evaluate the impact of dysregulated apoptosis on cancer development in the context of viral infections.
  • Dysregulated apoptosis can significantly impact cancer development, especially when linked with viral infections. Certain viruses are known to cause cancer by altering apoptotic pathways, enabling infected cells to avoid programmed death. This unchecked proliferation of potentially cancerous cells can lead to tumor formation. Understanding how viruses exploit these mechanisms not only sheds light on cancer biology but also informs therapeutic strategies aimed at restoring normal apoptotic processes in cancer treatment.

Related terms

Caspases: Caspases are a family of cysteine proteases that play essential roles in the initiation and execution phases of apoptosis.

Necrosis:

Necrosis is an uncontrolled form of cell death that results from acute cellular injury, leading to inflammation and damage to surrounding tissues.

Bcl-2 family proteins: These proteins regulate apoptosis by either promoting cell survival or facilitating cell death, influencing the decision of a cell to undergo apoptosis.