Spread the love

Cellular Mechanisms for Repairing Oxidative Damage

Oxidative damage refers to the harmful effects caused by reactive oxygen species (ROS) in cells. These ROS are generated as byproducts of normal cellular metabolism and can cause damage to various cellular components, including DNA, proteins, and lipids. To counteract this damage, cells have evolved several mechanisms for repairing oxidative damage and maintaining cellular homeostasis.

Base Excision Repair (BER)

Base excision repair is a cellular mechanism that repairs oxidative damage to DNA. It involves the removal of damaged or modified bases from the DNA strand and their subsequent replacement with the correct bases. This repair pathway is initiated by DNA glycosylases, which recognize and remove the damaged bases. The resulting abasic site is then processed by other enzymes, such as AP endonucleases and DNA polymerases, to complete the repair process.

See also What ethical challenges arise when considering the potential strain on healthcare systems due to increased longevity?

Nucleotide Excision Repair (NER)

Nucleotide excision repair is another cellular mechanism that repairs oxidative damage to DNA. It primarily targets bulky DNA lesions, such as those caused by UV radiation or certain chemical agents. NER involves the recognition and removal of the damaged DNA segment, followed by the synthesis and ligation of a new DNA strand to restore the integrity of the DNA molecule. This repair pathway is carried out by a complex set of proteins, including XPC, XPA, and XPG.

Protein Quality Control

Proteins are also susceptible to oxidative damage, which can lead to their misfolding or aggregation. To prevent the accumulation of damaged proteins, cells employ protein quality control mechanisms. These mechanisms involve chaperone proteins, such as heat shock proteins, that assist in the correct folding of newly synthesized proteins and the refolding of damaged proteins. Additionally, cells have proteolytic systems, such as the ubiquitin-proteasome system and autophagy, which selectively degrade damaged or misfolded proteins.

See also What is tau pathology?

Antioxidant Defense Systems

Cells have evolved antioxidant defense systems to counteract the harmful effects of ROS and prevent oxidative damage. These defense systems include enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, which neutralize ROS and convert them into less harmful molecules. Additionally, cells produce small antioxidant molecules, such as glutathione and vitamin C, which can directly scavenge ROS and protect cellular components from oxidative damage.

Conclusion

The cellular mechanisms for repairing oxidative damage play a crucial role in maintaining cellular homeostasis and preventing the accumulation of oxidative damage. These mechanisms, including base excision repair, nucleotide excision repair, protein quality control, and antioxidant defense systems, work together to ensure the integrity and functionality of cellular components. Understanding these mechanisms can provide insights into the processes underlying longevity and age-related diseases.

See also Why are collagen and bone broth recommended for individuals with osteoporosis?

Keywords: damage, cellular, oxidative, proteins, repair, mechanisms, excision, damaged, systems