Changes in HSP gene and protein expression in natural scrapie with brain damage

Abstract

Heat shock proteins (Hsp) perform cytoprotective functions such as apoptosis regulation and inflammatory response control. These proteins can also be secreted to the extracellular medium, acting as inflammatory mediators, and their chaperone activity permits correct folding of proteins and avoids the aggregation of anomalous isoforms. Several studies have proposed the implication of Hsp in prion diseases. We analysed the gene expression and protein distribution of different members of the Hsp27, Hsp70, and Hsp90 families in the central nervous system of sheep naturally infected with scrapie. Different expression profiles were observed in the areas analysed. Whereas changes in transcript levels were not observed in the cerebellum or medulla oblongata, a significant decrease in HSP27 and HSP90 was detected in the prefrontal cortex. In contrast, HSP73 was over-expressed in diencephalons of scrapie animals. Western blotting did not reveal significant differences in Hsp90 and Hsp70 protein expression between scrapie and control animals. Expression rates identified by real-time RT-PCR and western blotting were compared with the extent of classical scrapie lesions using stepwise regression. Changes in Hsp gene and protein expression were associated with prion protein deposition, gliosis and spongiosis rather than with apoptosis. Finally, immunohistochemistry revealed intense Hsp70 and Hsp90 immunolabelling in Purkinje cells of scrapie sheep. In contrast, controls displayed little or no staining in these cells. The observed differences in gene expression and protein distribution suggest that the heat shock proteins analysed play a role in the natural form of the disease.

Quercetin: A Phytoestrogen Attenuate GSK-3β Inhibitors Induced Delayed Cardioprotection in Diabetic Rat Heart

“…Further, Gross et al 11 reported that the administration of SB 216763, a selective GSK-3β inhibitor, 24 h before ischemia, produces cardioprotection through ATP sensitive potassium channels (K ATP ) and thereby inhibiting the opening of Mitochondrial Permeability Transition Pore (MPTP) during reperfusion phase. Moreover, opening of KATP 25 and inhibition of the opening of MPTP 26 is responsible for early phase of cardioprotection 3 and author suggested for further assessment of components regulated by GSK-3β inhibition to elucidate the mechanism involved in delayed cardioprotection.…”

“…Moreover, these results are supported by findings of our laboratory and of other published reports 5,[28][29][30] . "Heat Shock Protein" (HSP) are the group of proteins referred to as molecular chaperones 3,9 which are highly conserved proteins that utilize ATP for conformational changes to refold other proteins and also regulate the activity of other enzymes 26,31,32 . Brief ischemic episodes have been reported to trigger the synthesis of HSP-72 in the heart which increases the resistance against myocardial infarction after 24 h 33,34 .…”

Biomarcadores asociados con scrapie y otras encefalopatías espongiformes transmisibles

“…Los estudios del transcriptoma en muestras del SNC evidencian problemas de heterogeneidad de datos entre los resultados obtenidos en regiones específicas como médula oblongada, corteza cerebral o puente, y los detectados uti-lizando homogenizado de todo el encéfalo, donde los cambios específicos del área quedarían diluidos en el conjunto global. Estas diferencias entre áreas son manifiestas tanto a nivel genómico (Riemer et al, 2004), como cuando se analizan rutas moleculares específicas, por ejemplo en la activación de la apoptosis (Serrano et al, 2009;Hedman et al, 2012) o en la activa ción de chaperonas (Serrano et al, 2011). Este hecho podría ser consecuencia de que el cerebro está compuesto de distintos tipos de células, y es posible que cada tipo reaccione de forma variable a la infección por priones.…”

“…Asimismo, varios genes implicados en la respuesta celular al estrés y al plegamiento de proteínas, como el gen de la proteína de choque térmico 9 (Hspa9), Calr y peptidil-prolil cis-trans isomerasa (Fkbp), también se muestran alterados en células infectadas por priones (Greenwood et al, 2005). Además, en casos naturales de scrapie, se ha detectado una disminución en el nivel de expresión de HSPB1 y HSP90AA1 a nivel de corteza frontal del cerebro, y un aumento de la expresión de la HSP73 a nivel de diencéfalo (Serrano et al, 2011). Asimismo, la asociación estadística entre los niveles de expresión de las chaperonas y los valores semi-cuantitativos del depósito de la proteína prión, gliosis y espongiosis sugiere que las Hsp parecen estar implicadas en la gliosis, y no en reacciones anti-apoptóticas.…”

Effects of different ventilation strategies on lung injury in newborn rabbits

“…An immunohistochemical analysis of protein expression was performed on paraffin slides (middle lobus) using an anti-caspase-3 antibody (Thermo, Runcorn, UK), a Dako peroxidase kit (Dako, Carpinteria, CA) and a DAB reagent (DAKO, Glostrup, Denmark) as previously described. 18 The sections were lightly counterstained with hematoxylin, mounted and examined with a microscope (Nikon). Brown staining indicated positive apoptotic cells, whereas normal cells exhibited no staining (http://en.wikipedia.org/wiki/Immunohistochemistry).…”