The effect of rapamycin treatment on cerebral ischemia: A systematic review and meta-analysis of animal model studies

<strong>Background</strong> Amplifying endogenous neuroprotective mechanisms is a promising avenue for stroke therapy. One target is mammalian target of rapamycin (mTOR), a serine/threonine kinase regulating cell proliferation, cell survival, protein synthesis, and autophagy. Animal stud...

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Bibliographic Details
Main Authors: Beard, D, Hadley, G, Thurley, N, Howells, D, Sutherland, B, Buchan, A
Format: Journal article
Published: Sage Publications 2018
Description
Summary:<strong>Background</strong> Amplifying endogenous neuroprotective mechanisms is a promising avenue for stroke therapy. One target is mammalian target of rapamycin (mTOR), a serine/threonine kinase regulating cell proliferation, cell survival, protein synthesis, and autophagy. Animal studies investigating the effect of rapamycin on mTOR inhibition following cerebral ischemia have shown conflicting results. <strong>Aim</strong> To conduct a systematic review and meta-analysis evaluating the effectiveness of rapamycin in reducing infarct volume in animal models of ischemic stroke. <strong>Summary of review</strong> Our search identified 328 publications. Seventeen publications met inclusion criteria (52 comparisons: 30 reported infarct size and 22 reported neurobehavioral score). Study quality was modest (median 4 of 9) with no evidence of publication bias. The point estimate for the effect of rapamycin was a 21.6% (95% CI, 7.6%–35.7% p &lt; 0.01) improvement in infarct volume and 30.5% (95% CI 17.2%–43.8%, p &lt; 0.0001) improvement in neuroscores. Effect sizes were greatest in studies using lower doses of rapamycin. <strong>Conclusion</strong> Low-dose rapamycin treatment may be an effective therapeutic option for stroke. Modest study quality means there is a potential risk of bias. We recommend further high-quality preclinical studies on rapamycin in stroke before progressing to clinical trials.