In Situ Microparticles Loaded with S-Nitrosoglutathione Protect from Stroke

Abstract

Treatment of stroke, especially during the first hours or days, is still lacking. S-nitrosoglutathione (GSNO), a cerebroprotective agent with short life time, may help if administered early with a sustain delivery while avoiding intensive reduction in blood pressure. We developed in situ forming implants (biocompatible biodegradable copolymer) and microparticles (same polymer and solvent emulsified with an external oily phase) of GSNO to lengthen its effects and allow cerebroprotection after a single subcutaneous administration to Wistar rats. Arterial pressure was recorded for 3 days (telemetry, n = 14), whole-blood platelet aggregation up to 13 days (aggregometry, n = 58), and neurological score, cerebral infarct size and edema volume for 2 days after obstruction of the middle cerebral artery by autologous blood clots (n = 30). GSNO-loaded formulations (30 mg/kg) induced a slighter and longer hypotension (-10 vs. -56 ± 6 mmHg mean arterial pressure, 18 h vs. 40 min) than free GSNO at the same dose. The change in pulse pressure (-50%) lasted even up to 42 h for microparticles. GSNO-loaded formulations (30 mg/kg) prevented the transient 24 h hyper-aggregability observed with free GSNO and 7.5 mg/kg-loaded formulations. When injected 2 h after stroke, GSNO-loaded microparticles (30 mg/kg) reduced neurological score at 24 (-62%) and 48 h (-75%) vs. empty microparticles and free GSNO 7.5 mg/kg and, compared to free GSNO, divided infarct size by 10 and edema volume by 8 at 48 h. Corresponding implants reduced infarct size and edema volume by 2.5 to 3 times. The longer (at least 2 days) but slight effects on arterial pressures show sustained delivery of GSNO-loaded formulations (30 mg/kg), which prevent transient platelet hyper-responsiveness and afford cerebroprotection against the consequences of stroke. In conclusion, in situ GSNO-loaded formulations are promising candidates for the treatment of stroke.

Investigation of S-Nitrosoglutathione in stroke: A systematic review and meta-analysis of literature in pre-clinical and clinical research

“…Scoring item (Parent et al, 2015) (Khan et al, 2015c) (Khan et al, 2015b) (Sakakima et al, 2012) (Khan et al, 2006) (Khan et al, 2005) 1 Published in peer-reviewed journal 1 1 1 1 1 1 2 Statement confirming Compliance w/ animal welfare requirements 1 1 1 1 1 1 3 Avoided neuroprotective anesthetics 0 0 0 0 0 0 4 Control of temperature 1 1 1 1 1 1 5 Random treatment assignment 1 1 1 1 0 0 6 Allocation concealment 0 0 0 0 0 0 7 Conflict of interest statement 1 1 1 0 0 0 8 Blinded outcomes 1 1 1 1 1 1 9 Animals with comorbidities 0 0 0 0 0 0 10 Sample size calculation 1 0 0 0 0 0 Total Score 7 6 6 5 4 4…”

Targeting the Angiotensin II Type 1 Receptor in Cerebrovascular Diseases: Biased Signaling Raises New Hopes

“…We investigated the physiological consequences of this phenomenon by studying the effect of NO in an ex-vivo model: isolated and perfused middle cerebral arteries of normotensive rats [107]. S-nitrosation was induced by pretreatment with S-nitrosoglutathione (GSNO), an endogenous S-nitrosothiol previously shown as protective in different models of cerebral ischemia (MCAo) [108,109] and autologous blood clots injected through the internal carotid artery [110]). GSNO pretreatment of rat middle cerebral arteries specifically abolished the vasoconstriction induced by Ang II.…”

Regulation of protein function by S-nitrosation and S-glutathionylation: processes and targets in cardiovascular pathophysiology

“…These formulations for chronic oral treatments with GSNO showed a sustained in vitro release of GSNO (Wu et al, 2015b) and a storage of NO in the vascular wall 17 h after oral administration to wistar rats (Wu et al, 2016). Other formulations developed for subcutaneous long lasting delivery of GSNO also showed potential for stroke treatment (Parent et al, 2015). Even if the potential of GSNO for NO supplementation is limited by its poor stability and high hydrophilicity, causing NO release to not be sustained long enough for a chronic in vivo therapeutic effect, these studies however represent a starting point for the implementation of chronic oral treatments with GSNO, e.g.…”