title: Stem cell therapies in preclinical models of stroke associated with aging.
abstract: Stroke has limited treatment options, demanding a vigorous search for new therapeutic strategies. Initial enthusiasm to stimulate restorative processes in the ischemic brain by means of cell-based therapies has meanwhile converted into a more balanced view recognizing impediments related to unfavorable environments that are in part related to aging processes. Since stroke afflicts mostly the elderly, it is highly desirable and clinically important to test the efficacy of cell therapies in aged brain microenvironments. Although widely believed to be refractory to regeneration, recent studies using both neural precursor cells and bone marrow-derived mesenchymal stem cells for stroke therapy suggest that the aged rat brain is not refractory to cell-based therapy, and that it also supports plasticity and remodeling. Yet, important differences exist in the aged compared with young brain, i.e., the accelerated progression of ischemic injury to brain infarction, the reduced rate of endogenous neurogenesis and the delayed initiation of neurological recovery. Pitfalls in the development of cell-based therapies may also be related to age-associated comorbidities, e.g., diabetes or hyperlipidemia, which may result in maladaptive or compromised brain remodeling, respectively. These age-related aspects should be carefully considered in the clinical translation of restorative therapies.
authors.affiliation: Department of Psychiatry, Aging and Brain Disorders, University of Medicine Rostock Rostock, Germany ; Department of Functional Sciences, Center of Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova Craiova, Romania.
authors.forename: Aurel
authors.initials: A
authors.lastname: Popa-Wagner
authors.affiliation: Department of Psychiatry, Aging and Brain Disorders, University of Medicine Rostock Rostock, Germany ; Department of Functional Sciences, Center of Clinical and Experimental Medicine, University of Medicine and Pharmacy of Craiova Craiova, Romania.
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Buga
authors.affiliation: Department of Neurology, University Hospital Essen Essen, Germany.
authors.forename: Thorsten R
authors.initials: TR
authors.lastname: Doeppner
authors.affiliation: Department of Neurology, University Hospital Essen Essen, Germany.
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Hermann
keywords: aging; cell therapy; comorbidities; neurogenesis; stroke