response to nitrosative stress

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a nitrosative stress stimulus. Nitrosative stress is a state often resulting from exposure to high levels of nitric oxide (NO) or the highly reactive oxidant peroxynitrite, which is produced following interaction of NO with superoxide anions. [PMID:15925705]

Nitrosative stress refers to the disruption of cellular function caused by the accumulation of reactive nitrogen species (RNS), particularly nitric oxide (NO) and its derivatives. This stress can arise from various sources, including inflammation, environmental pollutants, and even normal metabolic processes.

The response to nitrosative stress involves a complex interplay of cellular signaling pathways and defense mechanisms. Here's a detailed breakdown:

**1. Detection and Signaling:**
* **NO sensing:** Cells possess various mechanisms to detect NO, including heme-containing proteins like soluble guanylyl cyclase (sGC) and redox-sensitive transcription factors like nuclear factor kappa B (NF-κB).
* **Signal transduction:** Once NO is detected, a cascade of signaling events is initiated, often involving phosphorylation of proteins and changes in gene expression.

**2. Antioxidant Defense:**
* **Enzymes:** Cells employ enzymes like superoxide dismutase (SOD), catalase, and glutathione peroxidase to detoxify reactive nitrogen species.
* **Antioxidant molecules:** Glutathione (GSH) and other antioxidants directly scavenge reactive species, preventing their damaging effects.

**3. Repair Mechanisms:**
* **DNA repair:** NO can damage DNA, leading to mutations. Cells activate DNA repair mechanisms to correct these lesions.
* **Protein repair:** RNS can modify proteins, altering their function. Cells possess mechanisms to repair damaged proteins or degrade them.

**4. Adaptive Responses:**
* **Transcriptional regulation:** Nitrosative stress triggers changes in gene expression, leading to the upregulation of stress-responsive genes.
* **Cellular adaptation:** Cells can adapt to nitrosative stress by altering their metabolism, increasing antioxidant defenses, or promoting cell survival pathways.

**5. Apoptosis and Cell Death:**
* **Caspase activation:** If nitrosative stress is overwhelming, cells can undergo programmed cell death (apoptosis) to prevent further damage to the organism.

**6. Pathological Consequences:**
* **Inflammation:** Nitrosative stress plays a significant role in chronic inflammatory diseases like rheumatoid arthritis and inflammatory bowel disease.
* **Cardiovascular disease:** NO dysregulation contributes to the development of cardiovascular disorders, including hypertension and atherosclerosis.
* **Neurodegenerative diseases:** Nitrosative stress is linked to the pathogenesis of neurodegenerative diseases like Alzheimer's and Parkinson's.

**In summary, the response to nitrosative stress involves a multifaceted cellular response aimed at detecting, neutralizing, and repairing the damage caused by reactive nitrogen species. This complex interplay of signaling pathways, antioxidant defenses, and adaptive mechanisms is essential for maintaining cellular homeostasis and protecting the organism from disease.**'
"

Proteins (1)

Compounds (3)