Comparing the effects of two neurotoxins in cortical astrocytes obtained from rats of different ages: involvement of oxidative damage

Abstract

Oxidative stress has been recognized as a potential mediator of cell death. Astrocytes play an active role in brain physiology responding to harmful stimuli by activating astrogliosis, which in turn has been associated either with survival or degenerative events. The characterization of the mechanistic actions exerted by different toxins in astrocytes is essential to understand the brain function and pathology. As age plays a critical role in degenerative processes, the aim of this study was to determine whether the administration of equimolar concentrations of two neurotoxins evoking different toxic patterns can induce differential effects on primary astrocytes obtained either from newborn or adult rats, with particular emphasis on those events linked to oxidative stress as a potential source of damage. Primary cortical astrocyte cultures derived from rat brains were exposed to 1-methyl-4-phenylpyridinium (MPP+) or beta-amyloid peptide (β-amyloid). Mitochondrial functionality and cell viability were determined as physiological parameters, whereas lipid and protein oxidation were used as markers of oxidative damage. The results of these experiments pointed towards a higher vulnerability to MPP + over β-amyloid, on most of the tested markers. Hence, in order to allow a comprehensive evaluation of astrocytic responses against MPP + intoxication, a third astrocyte group was included for dose-response experiments: astrocytes derived from aged rats. The present data indicate that the differences associated with age were mainly found in astrocytes exposed to MPP + (25 and 50 μM) at 1-h treatment. Results are discussed in terms of the differential mechanisms involved in each model.

Tert-buthylhydroquinone pre-conditioning exerts dual effects in old female rats exposed to 3-nitropropionic acid

“…In order to evaluate oxidative stress in the adult and senile brains from all experimental groups, protein oxidation was measured according to the Oxyblot protein oxidation detection kit (OxiBlot™; Millipore, Billerica, MA), as described by Alarcón-Aguilar et al [35]. Brain homogenates (20 μg protein) were derivatized to 2,4-dinitrophenylhydrazone (DNP) with 2,4-dinitrophenylhydrazine (DNPH).…”

t-BHQ Protects Against Oxidative Damage and Maintains the Antioxidant Response in Malnourished Rats

“…Lipid peroxidation (LPx) was assessed by the MDA formation, according to a previous report. 19 The optical density was determined at 532 nm. Protein concentration was determined using a commercial Bradford reagent (Bio-Rad, Hercules, California), and a 1.41 mg/mL standard of Bovine serum albumin (BSA).…”

Efecto del TBHQ sobre la capacidad antioxidante y el proceso inflamatorio en ratas lactantes desnutridas

“…Se ha propuesto que dosis altas de tBHQ pueden generar concentraciones mayores de ERO y provocar citotoxicidad [Alarcón-Aguilar et al, 2014]. Esto pudiera estar relacionado con lo observado en el presente estudio en donde el grupo BN (n=6), que recibió una dosis de tBHQ [100 mg/ kg de peso] presentó una mortalidad del 50%.…”

“…Sin embargo, se sabe que el preacondicionamiento de células con bajas concentraciones de tBHQ o H2O2, da como resultado una respuesta adaptativa que activa a Nrf2, protegiendo a las células de una citotoxicidad oxidativa adicional [Luna-López et al, 2010;Alarcón-Aguilar et al, 2014].…”