cellular response to hydrogen peroxide

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a hydrogen peroxide (H2O2) stimulus. [CHEBI:16240, GOC:mah]

Cellular response to hydrogen peroxide is a complex and tightly regulated process that involves a cascade of signaling events aimed at mitigating the damaging effects of this reactive oxygen species (ROS). Hydrogen peroxide (H2O2) is a potent oxidant that can disrupt cellular homeostasis by damaging DNA, proteins, and lipids. To counteract these effects, cells have evolved sophisticated defense mechanisms that involve sensing, signaling, and detoxification pathways.

1. **Sensing H2O2:** The first step in cellular response to H2O2 is its detection by specialized sensor proteins. These proteins include the Peroxiredoxin (Prx) family, which directly interacts with H2O2 and undergoes redox changes in response to its presence. Other sensors, like the Keap1-Nrf2 pathway, indirectly detect H2O2-induced oxidative stress by sensing changes in the cellular redox state.

2. **Signaling Cascades:** Upon sensing H2O2, cells activate intricate signaling cascades to coordinate a coordinated response. Key signaling molecules involved include:

* **MAPK pathways:** H2O2 activates mitogen-activated protein kinases (MAPKs) such as ERK, JNK, and p38, triggering downstream gene expression and cellular processes.
* **PI3K/Akt pathway:** This pathway promotes cell survival and proliferation in response to H2O2, but can also contribute to oxidative stress-induced inflammation in certain contexts.
* **NF-κB pathway:** This pathway plays a crucial role in regulating inflammatory responses to H2O2 and is activated by oxidative stress-induced phosphorylation and degradation of the IκB inhibitor protein.

3. **Detoxification and Repair:** The ultimate goal of cellular response to H2O2 is to detoxify the reactive species and repair any damage caused. Cells employ various strategies for this purpose:

* **Catalase and Glutathione Peroxidase:** These enzymes catalyze the detoxification of H2O2 into water and oxygen, effectively reducing its levels.
* **Antioxidant Networks:** Cells rely on a network of antioxidants, including glutathione, vitamin C, and vitamin E, to neutralize ROS and protect against oxidative damage.
* **DNA Repair Mechanisms:** DNA repair pathways, such as base excision repair (BER), are activated to repair H2O2-induced DNA damage.
* **Protein Repair Mechanisms:** Cells possess mechanisms to repair oxidized proteins, including chaperone proteins and proteasome-mediated degradation.

4. **Adaptation and Tolerance:** Repeated exposure to H2O2 can lead to adaptive responses that enhance cellular tolerance to oxidative stress. This involves upregulation of antioxidant defense mechanisms, improved repair systems, and changes in gene expression that promote survival in the face of oxidative stress.

In summary, cellular response to hydrogen peroxide is a multifaceted and highly coordinated process that involves sensing, signaling, detoxification, repair, and adaptive mechanisms. These processes are crucial for maintaining cellular homeostasis and protecting cells from the damaging effects of oxidative stress.'
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Proteins (38)

Compounds (1,068)