title: Neurorestoration after traumatic brain injury through angiotensin II receptor blockage.
abstract: See Moon (doi:10.1093/awv239) for a scientific commentary on this article.Traumatic brain injury frequently leads to long-term cognitive problems and physical disability yet remains without effective therapeutics. Traumatic brain injury results in neuronal injury and death, acute and prolonged inflammation and decreased blood flow. Drugs that block angiotensin II type 1 receptors (AT1R, encoded by AGTR1) (ARBs or sartans) are strongly neuroprotective, neurorestorative and anti-inflammatory. To test whether these drugs may be effective in treating traumatic brain injury, we selected two sartans, candesartan and telmisartan, of proven therapeutic efficacy in animal models of brain inflammation, neurodegenerative disorders and stroke. Using a validated mouse model of controlled cortical impact injury, we determined effective doses for candesartan and telmisartan, their therapeutic window, mechanisms of action and effect on cognition and motor performance. Both candesartan and telmisartan ameliorated controlled cortical impact-induced injury with a therapeutic window up to 6 h at doses that did not affect blood pressure. Both drugs decreased lesion volume, neuronal injury and apoptosis, astrogliosis, microglial activation, pro-inflammatory signalling, and protected cerebral blood flow, when determined 1 to 3 days post-injury. Controlled cortical impact-induced cognitive impairment was ameliorated 30 days after injury only by candesartan. The neurorestorative effects of candesartan and telmisartan were reduced by concomitant administration of the peroxisome proliferator-activated receptor gamma (PPARγ, encoded by PPARG) antagonist T0070907, showing the importance of PPARγ activation for the neurorestorative effect of these sartans. AT1R knockout mice were less vulnerable to controlled cortical impact-induced injury suggesting that the sartan's blockade of the AT1R also contributes to their efficacy. This study strongly suggests that sartans with dual AT1R blocking and PPARγ activating properties have therapeutic potential for traumatic brain injury.
authors.affiliation: 1 Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA *Present address: Georgetown University Medical Centre, Department of Neuroscience, Washington, DC, USA sonia.villapol@georgetown.edu.
authors.forename: Sonia
authors.initials: S
authors.lastname: Villapol
authors.affiliation: 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
authors.forename: María G
authors.initials: MG
authors.lastname: Balarezo
authors.affiliation: 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
authors.forename: Kwame
authors.initials: K
authors.lastname: Affram
authors.affiliation: 3 Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, USA.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Saavedra
authors.affiliation: 1 Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA 2 Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
authors.forename: Aviva J
authors.initials: AJ
authors.lastname: Symes
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001549:Benzamides / Q000494:pharmacology; D001562:Benzimidazoles / Q000494:pharmacology*; D001565:Benzoates / Q000494:pharmacology*; D001713:Biphenyl Compounds; D001930:Brain Injuries / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects; D005911:Gliosis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D007249:Inflammation; D051379:Mice; D018345:Mice, Knockout; D017628:Microglia / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D047495:PPAR gamma / Q000037:antagonists & inhibitors; D011725:Pyridines / Q000494:pharmacology; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D000077333:Telmisartan; D013777:Tetrazoles / Q000494:pharmacology*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001549:Benzamides; D001562:Benzimidazoles; D001565:Benzoates; D001713:Biphenyl Compounds; D018696:Neuroprotective Agents; D047495:PPAR gamma; D011725:Pyridines; D044140:Receptor, Angiotensin, Type 1; C458508:T 0070907; D013777:Tetrazoles; C081643:candesartan; D000077333:Telmisartan
keywords: apoptosis; candesartan; inflammation; recovery; telmisartan