RTP801/REDD1: a stress coping regulator that turns into a troublemaker in neurodegenerative disorders

Area of Science:

• Cellular Biology
• Neuroscience
• Molecular Biology

Background:

• The mechanistic target of Rapamycin (mTOR) pathway is vital for cellular homeostasis, regulating growth, proliferation, and survival.
• Deregulation of the mTOR pathway is implicated in various diseases, particularly neurodegenerative disorders, where neuron function and survival depend on its precise regulation.
• RTP801/REDD1/Dig2 is a complex regulator of mTOR, known to inactivate mTOR and Akt via the tuberous sclerosis complex (TSC1/TSC2).

Purpose of the Study:

• To review the role of RTP801 deregulation in the mechanistic target of Rapamycin (mTOR) pathway within the context of Parkinson's disease (PD) and other neurodegenerative disorders.
• To elucidate the dual role of RTP801 in cell survival and death based on cellular context and stress levels.

Main Methods:

• Review of existing literature and experimental models of Parkinson's disease.
• Analysis of RTP801's mechanism of action on mTOR and Akt pathways.
• Examination of RTP801's differential effects on dividing versus differentiated cells under stress.

Main Results:

• Stress-induced upregulation of RTP801 may initially protect neurons by repressing mTOR in early PD stages.
• Sustained elevation of RTP801 can lead to neuron cell death through sequential inhibition of mTOR and Akt.
• RTP801 exhibits context-dependent effects, protecting dividing cells but sensitizing differentiated cells to apoptosis.

Conclusions:

• RTP801 plays a critical, albeit complex, role in neurodegeneration by modulating the mTOR pathway.
• Understanding RTP801's dual function is crucial for developing therapeutic strategies for Parkinson's disease and related disorders.
• Further research is needed to fully comprehend the intricate mechanisms of RTP801 in neuronal health and disease.