1. Attenuation of endothelial phosphatidylserine exposure decreases ischemia-reperfusion induced changes in microvascular permeability
- Author
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Strumwasser, Aaron, Bhargava, Aditi, and Victorino, Gregory P
- Subjects
Medical Physiology ,Biomedical and Clinical Sciences ,Cardiovascular ,5.1 Pharmaceuticals ,Aetiology ,2.1 Biological and endogenous factors ,Development of treatments and therapeutic interventions ,4 ,4'-Diisothiocyanostilbene-2 ,2'-Disulfonic Acid ,Animals ,Annexin A5 ,Capillary Permeability ,Dithioerythritol ,Endothelium ,Vascular ,Female ,Phosphatidylserines ,Rats ,Rats ,Sprague-Dawley ,Real-Time Polymerase Chain Reaction ,Reperfusion Injury ,Venules ,Scramblase ,ischemia-reperfusion ,endothelium ,hydraulic conductivity ,microvascular permeability ,Clinical sciences ,Nursing - Abstract
BACKGROUND:Translocation of phosphatidylserine from the inner leaflet to the outer leaflet of the endothelial membrane via phospholipid scramblase-1 (PLSCR1) is an apoptotic signal responsible for the loss of endothelial barrier integrity after ischemia-reperfusion injury (IRI). We hypothesized that inhibiting phosphatidylserine expression on endothelial cells would attenuate IRI induced increases in hydraulic permeability (Lp). METHODS:Mesenteric Lp was measured in rat post-capillary mesenteric venules subjected to IRI via superior mesenteric artery (SMA) occlusion (45 minutes) and release (300 minutes) in conjunction with several inhibitors of phosphatidylserine exposure as follows: (1) inhibition of PLSCR1 translocation (dithioerythritol, n = 3), (2) inhibition of PLSCR1 membrane trafficking (2-bromopalmitate [2-BP], n = 3), and (3) inhibition of ion exchange necessary for PLSCR1 function (4,4'-Diisothiocyano-2,2'-stilbenedisulfonic acid [DIDS], n = 3). Under the same IRI conditions, rats were also administered targeted inhibitors of phosphatidylserine exposure including knockdown of PLSCR1 (n = 3) using RNA interference (RNAi), and as a potential therapeutic tool Diannexin, a selective phosphatidylserine blocker (n = 3). RESULTS:During IRI net Lp increased by 80% (p < 0.01). Net reductions of Lp were accomplished by 2-BP (46% reduction, p = 0.005), combined DET + 2-BP + DIDS (32% reduction, p = 0.04), RNAi (55% reduction, p = 0.002), Diannexin administered pre-SMA artery occlusion (73% reduction, p = 0.001), and post-SMA occlusion (70% reduction, p = 0.002). CONCLUSION:Phosphatidylserine exposure is a key event in the pathogenesis of microvascular dysfunction during IRI. Clinically, inhibition of phosphatidylserine exposure is a promising strategy that may 1 day be used to mitigate the effects of IRI.
- Published
- 2018