[Apoptosis--molecular basis in pathogenesis of selected chronic inflammatory and neoplastic diseases]

Bartlomiej Kopaczewski1, Magda Kopaczewska, Stanisław Nowak

  • 1Katedra i Klinika Neurochirurgii i Neurotraumatologii Akademii Medycznej w Poznaniu. mkopa6@wp.pl

Insights

Programmed cell death, or apoptosis, is complex and its dysregulation causes diseases. Understanding apoptosis regulatory proteins like Bcl-2/Bax may lead to new diagnostics and therapies.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Apoptosis is a fundamental physiological process of programmed cell death.
  • The intricate molecular mechanisms governing apoptosis are not fully understood.
  • Dysregulation of apoptotic pathways is implicated in various diseases, including cancer and inflammatory conditions.

Purpose of the Study:

  • To explore the complex molecular regulation of programmed cell death (apoptosis).
  • To investigate the role of specific genetic mutations and protein imbalances in disease pathogenesis.
  • To identify potential diagnostic and therapeutic strategies by studying apoptotic protein interactions.

Main Methods:

  • Analysis of gene mutations, such as in the p53 gene.
  • Assessment of receptor expression levels, like that of receptor Fas.
  • Evaluation of the balance between apoptosis regulatory proteins, including Bcl-2 and Bax.

Main Results:

  • Mutations in the p53 gene are linked to cancerous transformation.
  • Elevated expression of receptor Fas is associated with increased cell elimination in chronic inflammation.
  • An imbalance in the Bcl-2/Bax protein ratio contributes to reduced cell death, radioresistance, and chemoresistance.

Conclusions:

  • Understanding the molecular regulation of apoptosis is crucial for disease intervention.
  • Targeting the interactions of apoptotic proteins offers promising avenues for novel diagnostic and therapeutic approaches.
  • Further research into apoptosis mechanisms can elucidate disease pathways and inform treatment development.

Related Concept Videos

The Intrinsic Apoptotic Pathway01:31

The 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...
Apoptosis01:30

Apoptosis

Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.
The Extrinsic Apoptotic Pathway01:17

The 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...
Phagocytosis of Apoptotic Cells01:17

Phagocytosis 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.
Cellular Injury V: Apoptosis and Autophagy01:22

Cellular 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...
Overview of Cell Death01:30

Overview 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...