A 2 × 2 factorial design for the combination therapy of minocycline and remote ischemic perconditioning: efficacy in a preclinical trial in murine thromboembolic stroke model

Md Nasrul Hoda; Susan C Fagan; Mohammad B Khan; Kumar Vaibhav; Aizaz Chaudhary; Phillip Wang; Krishnan M Dhandapani; Jennifer L Waller; David C Hess

doi:10.1186/2040-7378-6-10

A 2 × 2 factorial design for the combination therapy of minocycline and remote ischemic perconditioning: efficacy in a preclinical trial in murine thromboembolic stroke model

Exp Transl Stroke Med. 2014 Oct 9:6:10. doi: 10.1186/2040-7378-6-10. eCollection 2014.

Authors

Md Nasrul Hoda¹, Susan C Fagan², Mohammad B Khan³, Kumar Vaibhav⁴, Aizaz Chaudhary⁵, Phillip Wang⁶, Krishnan M Dhandapani⁷, Jennifer L Waller⁸, David C Hess⁹

Affiliations

¹ Department of Neurology, Georgia Regents University, Augusta, GA 30912, USA ; Department of Medical Laboratory, Imaging and Radiologic Sciences, Georgia Regents University, Augusta, GA 30912, USA ; Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, USA ; Charlie Norwood VA Medical Centre, Augusta, USA.
² Department of Neurology, Georgia Regents University, Augusta, GA 30912, USA ; Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, USA ; Charlie Norwood VA Medical Centre, Augusta, USA.
³ Department of Neurology, Georgia Regents University, Augusta, GA 30912, USA ; Charlie Norwood VA Medical Centre, Augusta, USA.
⁴ Department of Medical Laboratory, Imaging and Radiologic Sciences, Georgia Regents University, Augusta, GA 30912, USA.
⁵ Department of Neurology, Georgia Regents University, Augusta, GA 30912, USA ; Department of Medical Laboratory, Imaging and Radiologic Sciences, Georgia Regents University, Augusta, GA 30912, USA.
⁶ Department of Psychiatry, Georgia Regents University, Augusta, GA 30912, USA.
⁷ Department of Neurosurgery, Georgia Regents University, Augusta, GA 30912, USA.
⁸ Department of Biostatistics and Epidemiology, Georgia Regents University, Augusta, GA 30912, USA.
⁹ Department of Neurology, Georgia Regents University, Augusta, GA 30912, USA ; Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, USA.

Abstract

Background: After the failure of so many drugs and therapies for acute ischemic stroke, innovative approaches are needed to develop new treatments. One promising strategy is to test combinations of agents in the pre-hospital setting prior to the administration of intravenous tissue plasminogen activator (IV-tPA) and/ or the use of mechanical reperfusion devices in the hospital.

Methods: We performed a 2 × 2 factorial design preclinical trial where we tested minocycline (MINO), remote ischemic perconditioning (RIPerC) and their combination treatment in a thromboembolic clot model of stroke in mice, without IV-tPA or later treated with IV-tPA at 4 hours post-stroke. Cerebral blood flow (CBF) was measured by laser speckle contrast imaging (LSCI), behavioral outcomes as neurological deficit score (NDS) and adhesive tape removal test, and infarct size measurement were performed at 48 hours post-stroke. Mice within the experimental sets were randomized for the different treatments, and all outcome measures were blinded.

Results: RIPerC significantly improved CBF as measured by LSCI in both with and without tPA treated mice (P < 0.001). MINO and RIPerC treatment were effective alone at reducing infarct size (p < 0.0001) and improving short-term functional outcomes (p < 0.001) in the tPA and non-tPA treated animals. The combination treatment of MINO and RIPerC significantly reduced the infarct size greater than either intervention alone (p < 0.05). There were trends in favor of improving functional outcomes after combination treatment of MINO and RIPerC; however combination treatment group was not significantly different than the individual treatments of MINO and RIPerC. There was no "statistical" interaction between minocycline and RIPerC treatments indicating that the effects of RIPerC and MINO were additive and not synergistic on the outcome measures.

Conclusion: In the future, combining these two safe and low cost interventions in the ambulance has the potential to "freeze" the penumbra and improve outcomes in stroke patients. This pre-clinical 2 × 2 design can be easily translated into a pre-hospital clinical trial.

Keywords: Intravenous tPA; Minocycline; Neurovascular protection; Remote ischemic perconditioning; Thromboembolic stroke.