Nanodelivery of Cerebrolysin and Rearing in Enriched Environment Induce Neuroprotective Effects in a Preclinical Rat Model of Parkinson’s Disease

Abstract

Rearing in enriched environment (EE) improves the recuperation in animal models of Parkinson's disease (PD). Administration of TiO-nanowired cerebrolysin (CBL) could represent an additional strategy to protect or repair the nigrostriatal system. This study aims to explore morphofunctional and biochemical changes in a preclinical stage of PD testing the synergistic efficiency of combining both strategies, housing in EE, and nanodelivery of CBL. Sprague-Dawley male rats receiving intrastriatally 6-hydroxydopamine after a short evolution time were segregated into CBL group (rats receiving nanowired CBL), EE group (rats housed in EE), CBL + EE group (rats housed in EE and receiving nanowired CBL), and control group (rats without additional treatment). Prodromic stage and treatment effects were characterized by the presence of motor symptoms (amphetamine-induced rotational behavior test). Tyrosine hydroxylase (TH) immunohistochemistry and Western blot (p-Akt/Akt and p-ERK/ERK 1/2 as survival markers and caspase-3 as apoptotic marker) were performed in striatum and SN. A decrease in motor symptoms was shown by rats receiving CBL. EE monitoring cages revealed that rats from CBL + EE group showed more significant number of laps in the wheel than EE group. In SN, CBL + EE group also presented the highest neuronal density. Moreover, p-Akt/Akt and p-ERK/ERK 1/2 ratio was significant higher and caspase-3 expression was lower in CBL + EE group. In conclusion, the combination of CBL and EE provided evidence of neuoprotective-neurorestorative mechanisms by which this combined strategy promoted morphofunctional improvement by activation of survival pathways after dopamine depletion in a preclinical model of PD.

Changes in Day/Night Activity in the 6-OHDA-Induced Experimental Model of Parkinson’s Disease: Exploring Prodromal Biomarkers

“…Rats were lesioned as we previously described ( Requejo et al, 2018a , b ). Briefly, thirty minutes before surgery, rats were pre-treated with desipramine (25 mg/kg, i.p., Sigma, St. Louis, United States) and pargyline (50 mg/kg, i.p., Sigma, St. Louis, United States) in order to preserve the noradrenergic system and the degradation of the toxin, respectively.…”

“…Morphological evaluation was performed as we previously described ( Requejo et al, 2015 , 2018a , b ).…”

“…The unbiased stereological analysis was performed as previously described ( Requejo et al, 2015 , 2017 , 2018a , b ) by using a computerized image analysis system (Mercator Image Analysis system, Explora Nova, La Rochelle, France) connected to an Olympus BX-50 photomicroscope. For this purpose, a total of 7–8 sections in a 1: 8 series were analyzed to cover the entire striatum and SN for each animal.…”

“…In brief, in order to evaluate the TH-immunoreactivity (ir) in the IL striatum, the volume of the preserved striatum was calculated using the Cavalieri method ( Howard and Reed, 2004 ) available on Mercator image analysis system by delimiting the negative areas and the entire striatum at 4x magnification, and multiplying these measurements by the thickness of the slices and the intersectional distance ( Requejo et al, 2015 , 2018a , b ). Values were expressed as the percentage of TH-ir volume of the IL striatum respect to the total volume of the IL one.…”

“…In this model, the site of administration and time elapsed after the injection are critical for determining the extent and time course of the lesion ( Kirik et al, 2000 ; Deumens et al, 2002 ). In our hands, this model is also useful for studying the preclinical phase of PD, as intrastriatal injection of 6-OHDA in adult male rats induced an early degeneration of the nigrostriatal system without any gross motor impairment as well as upregulation of caspase-3 and downregulation of survival signaling pathways ( Requejo et al, 2018a , b ).…”