cellular response to caloric restriction

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 of caloric restriction, insufficient food energy intake. [GOC:dph, PMID:17914901]

Cellular response to caloric restriction is a complex and multifaceted process that involves numerous signaling pathways and cellular adaptations aimed at promoting survival and extending lifespan. It is characterized by a shift in metabolism, decreased energy expenditure, and an enhanced capacity for cellular repair and stress resistance. The process can be broken down into the following key steps:

1. **Nutrient Sensing and Signaling:**
* When caloric intake is reduced, cells sense this nutrient depletion through various mechanisms, including the mTOR (mammalian target of rapamycin) pathway. This pathway plays a crucial role in sensing cellular energy levels and promoting anabolic processes.
* Caloric restriction activates the AMPK (AMP-activated protein kinase) pathway, which promotes catabolic processes and energy production. AMPK is a key regulator of energy metabolism, promoting glucose uptake, fatty acid oxidation, and mitochondrial biogenesis.

2. **Metabolic Shift:**
* Caloric restriction induces a metabolic shift from glucose utilization to fatty acid oxidation as the primary energy source. This is achieved through increased expression of genes involved in fatty acid metabolism and reduced expression of genes involved in glucose metabolism.
* Insulin sensitivity is enhanced, allowing cells to utilize glucose more efficiently.

3. **Enhanced Stress Resistance:**
* Caloric restriction induces several cellular adaptations that enhance stress resistance. These include increased expression of antioxidant enzymes, which protect cells from damage caused by reactive oxygen species.
* The process also promotes autophagy, a cellular recycling process that clears damaged or unnecessary components, contributing to cell health and reducing oxidative stress.

4. **Cellular Repair and Maintenance:**
* Caloric restriction triggers increased expression of genes involved in DNA repair, protein synthesis, and cellular maintenance, promoting the removal of damaged molecules and preserving cellular integrity.

5. **Hormonal Changes:**
* Caloric restriction leads to changes in hormone levels, including an increase in growth hormone (GH) and a decrease in insulin-like growth factor 1 (IGF-1), which have been associated with longevity.

6. **Mitochondrial Biogenesis:**
* The process promotes mitochondrial biogenesis, increasing the number and function of mitochondria. This enhances energy production, reducing oxidative stress, and contributing to overall cell health.

7. **Epigenetic Modifications:**
* Caloric restriction can alter epigenetic modifications, such as DNA methylation and histone acetylation, affecting gene expression and contributing to longevity.

These complex processes collectively contribute to a state of increased resilience and longevity, highlighting the powerful effects of caloric restriction on cellular function.'"

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Compounds (34)