Amino Acid Biosignature in Plasma among Ischemic Stroke Subtypes

Figure 5

Metabolic pathways activated in chronic ischemic stroke. (a) The increase of proline is promoted by activation of extracellular matrix degradation. High levels of proline can inhibit ALT enzyme and cause alanine concentration reduction. The reduction in alanine concentration can also be related to donation of this amino group for glutamine synthesis, which can be converted to glutamic acid in the neurons and, then, it can be used to increase the levels of leucine. (b) Decrease of methionine concentration due to its conversion to homocysteine; homocysteine increases as a result of the cofactor pyridoxal 5′-phosphate inhibition by inflammatory mediators (C-reactive protein); decrease of pyridoxal 5′-phosphate due to its migration to inflammatory sites. Blue arrows: activated pathways. ECM: extracellular matrix. MMPs: matrix metalloproteinases.

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