Tat-SynGAP improves angiogenesis and post-stroke recovery by inhibiting MST1/JNK signaling.

Small G protein Ras induces the activation of apoptosis-related molecule mammalian Ste20-like kinase1 (MST1)/JNK signal pathway, which is involved in the regulation of tissue damage under pathological conditions such as ischemic stroke. Our previous study indicated that GTPase-activating protein for Ras (SynGAP), a negative regulator of Ras, could bind with postsynaptic density protein-93 (PSD-93) and Tat-SynGAP (670-685aa) small peptide to exhibit neuroprotective role. Here, we report that Tat-SynGAP (670-685aa) reduced cerebral edema at acute cerebral ischemia/reperfusion (I/R), improved integrity of blood-brain barrier, and decreased cortical and striatum neuronal injury. Mechanistically, Tat-SynGAP (670-685aa) not only inhibited the phosphorylation of MST1 and JNK and the cleavage of caspase-3, but also facilitated the expression of angiogenesis related molecules VEGF and Ang-1. In conclusion, Tat-SynGAP (670-685aa) reduces neuronal apoptosis and cerebral infarction volume and maintains vascular stability and blood-brain barrier integrity by inhibiting MST1/JNK signaling pathway.