What does glutamine do for cartilage cells?
Glutamine is the cell's main source of glutamate, the first building block of glutathione. In growth-plate cartilage, the identity switch SOX9 raised glutamine use, and glutathione made from glutamine kept reactive oxygen species down so the cells could survive without a blood supply (Stegen 2020). In rabbit cartilage cells, glutamine protected against heat stress and nitric oxide (Tonomura 2006).
Fuel, identity and defence
A 2020 study of growth-plate cartilage found that cartilage cell identity and glutamine metabolism are linked in a feed-forward loop. SOX9, the master cartilage switch, increased glutamine consumption and the enzyme glutaminase 1. Glutamine then supported cartilage gene expression, matrix production and, through glutathione synthesis, protection from reactive oxygen species in the avascular growth plate (Stegen 2020).
Protection under stress
Rabbit cartilage cells treated with glutamine were almost completely protected from the cell damage caused by heat stress or nitric oxide, alongside a rise in the protective heat shock protein HSP70 (Tonomura 2006).
Where it fits
Glutamate joins cysteine in the first, rate-controlling step of glutathione synthesis (Lu 2013). L-glutamine is one of the four parts of Gluthanol™.
Other questions people ask
Is glutamine the same as glutamate?
No. Glutamine carries an extra nitrogen group; cells remove it to make glutamate.
Sources
- Stegen S, Rinaldi G, Loopmans S et al. Glutamine Metabolism Controls Chondrocyte Identity and Function. Dev Cell 2020.
- Tonomura H, Takahashi KA, Mazda O et al. Glutamine protects articular chondrocytes from heat stress and NO-induced apoptosis with HSP70 expression. Osteoarthritis Cartilage 2006.
- Lu SC. Glutathione synthesis. Biochim Biophys Acta 2013.
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