Glutamine as a Potential Neuroprotectant in Alzheimer's Disease

Glutamine is the most abundant amino acid in the human bloodstream. It is conditionally essential and critical for many cellular functions. In the brain, glutamine is mainly produced by astrocytes expressing glutamine synthetase. Many pathological factors known to contribute to Alzheimer's disease can directly reduce glutamine synthetase activity, including Aβ deposition, chronic inflammation, hypoxia, ischemia/reperfusion, and oxidative stress. Indeed, glutamine metabolism is compromised in patients with Alzheimer's disease. Importantly, glutamine deficiency hampers critical cellular functions such as mitochondria energy production, DNA damage response, apoptosis, and autophagy. Thus, glutamine supplementation may be of interest in preventing or delaying the degenerative diseases of aging, where loss of these functions is common.