Autoren:	Timaru-Kast, Ralph Gotthardt, Philipp Luh, Clara Huang, Changsheng Hummel, Regina Schäfer, Michael Thal, Serge
Titel:	Angiotensin II receptor 1 blockage limits brain damage and improves functional outcome after brain injury in aged animals despite age-dependent reduction in AT1 expression
Online-Publikationsdatum:	10-Jul-2019
Erscheinungsdatum:	2019
Sprache des Dokuments:	Englisch
Zusammenfassung/Abstract:	Traumatic brain injury (TBI) is a frequent pathology associated with poor neurological outcome in the aged population. We recently observed accelerated cerebral inflammation in aged mice in response to TBI. Candesartan is a potent specific inhibitor of angiotensin II receptor type 1 (AT1) which limits cerebral inflammation and brain damage in juvenile animals after experimental TBI. In the present study, we show significantly lower posttraumatic AT1 mRNA levels in aged (21 months) compared to young (2 months) mice. Despite low cerebral At1 expression, pharmacologic blockade by treatment with candesartan [daily, beginning 30 min after experimental TBI by controlled cortical impact (CCI)] was highly effective in both young and aged animals and reduced histological brain damage by −20% after 5 days. In young mice, neurological improvement was enhanced by AT1 inhibition 5 days after CCI. In older animals, candesartan treatment reduced functional impairment already on day 3 after TBI and post-traumatic body weight (BW) loss was attenuated. Candesartan reduced microglia activation (−40%) in young and aged animals, and neutrophil infiltration (−40% to 50%) in aged mice, whereas T-cell infiltration was not changed in either age group. In young animals, markers of anti-inflammatory microglia M2a polarization [arginase 1 (Arg1), chitinase3-like 3 (Ym1)] were increased by candesartan at days 1 and 5 after insult. In older mice 5 days after insult, expression of Arg1 was significantly higher independently of the treatment, whereas Ym1 gene expression was further enhanced by AT1 inhibition. Despite age-dependent posttraumatic differences in At1 expression levels, inhibition of AT1 was highly effective in a posttreatment paradigm. Targeting inflammation with candesartan is, therefore, a promising therapeutic strategy to limit secondary brain damage independent of the age.
DDC-Sachgruppe:	610 Medizin 610 Medical sciences
Veröffentlichende Institution:	Johannes Gutenberg-Universität Mainz
Organisationseinheit:	FB 04 Medizin
Veröffentlichungsort:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-173
URN:	urn:nbn:de:hebis:77-publ-591423
Version:	Published version
Publikationstyp:	Zeitschriftenaufsatz
Nutzungsrechte:	CC BY
Informationen zu den Nutzungsrechten:	https://creativecommons.org/licenses/by/4.0/
Zeitschrift:	Frontiers in aging neuroscience 11
Seitenzahl oder Artikelnummer:	Art. 63
Verlag:	Frontiers Research Foundation
Verlagsort:	Lausanne
Erscheinungsdatum:	2019
ISSN:	1663-4365
URL der Originalveröffentlichung:	http://dx.doi.org/10.3389/fnagi.2019.00063
DOI der Originalveröffentlichung:	10.3389/fnagi.2019.00063
Enthalten in den Sammlungen:	JGU-Publikationen