The neuropathology of Parkinson's disease (PD) is characterized by the presence of a-synuclein (a-syn) inclusions. In affected neurons, the inclusions appear as thread-like Lewy neurites or globular Lewy bodies. Vulnerable neurons with Lewy pathology all belong to the class of projection neurons with long unmyelinated or poorly myelinated neurites (Braak et al. 2006).The degeneration of neuromelanin-containing dopaminergic neurons in the substantia nigra is regarded as the most important hallmark of PD and to be the primary cause of the motor deficits in PD (Dauer and Przedborski 2003). However, the neuropathology is not restricted to the substantia nigra and includes various specific, extra-nigral brain regions such as the dorsal IX/X motor nucleus, the reticulate zone, subnuclei of the Raphe system, the thalamus or amygdala and the cortex (Braak et al. 1998(Braak et al. , 2003aBraak and Braak 2000). The temporal and topographical order of the histopathological lesions in sporadic PD has been described in detail (Braak et al. 2003a,b). Braak et al. suggested a gradually progressing, ascending course with little interindividual deviation in the development of the PD neuropathology. According to this hypothesis it is conceivable that after an initial event, the disease pathology progresses without remission until reaching a terminal phase (Braak et al. 2003a(Braak et al. , 2006. Recent studies have highlighted the possibility that a seeding-nucleation mechanism may exist by studying the fate of neurons grafted into the brains of patients with PD. In these studies, grafted healthy neurons gradually developed the same pathology as the host neurons in the diseased brains (Kordower et al. 2008;Li et al. 2008; Received July 18, 2009; accepted July 28, 2009 AbstractLewy bodies, a-synuclein (a-syn) immunopositive intracellular deposits, are the pathological hallmark of Parkinson's disease (PD). Interestingly, Lewybody-like structures have been identified in fetal tissue grafts about one decade after transplantation into the striatum of PD patients. One possible explanation for the accelerated deposition of a-syn in the graft is that the aggregation of a-syn from the host tissue to the graft is spread by a prion disease-like mechanism. We discuss here an in vitro model which might recapitulate some aspects of disease propagation in PD. We found here that in vitro-generated a-syn oligomers induce transmembrane seeding of a-syn aggregation in a dose-and time-dependent manner. This effect was observed in primary neuronal cultures as well as in neuronal cell lines. The seeding oligomers were characterized by a distinctive lithium dodecyl sulfate-stable oligomer pattern and could be generated in a dynamic process out of pore-forming oligomers. We propose that a-syn oligomers form as a dynamic mixture of oligomer types with different properties and that a-syn oligomers can be converted into different types depending on the brain milieu conditions. Our data indicate that extracellular a-syn oligomers can induce intracellular...

Non-alcoholic fatty liver disease (NAFLD) and the progressive form of non-alcoholic steatohepatitis (NASH) are diseases of major importance with a high unmet medical need. Efficacy studies on novel compounds to treat NAFLD/NASH using disease models are frequently evaluated using established histological feature scores on ballooning, inflammation, steatosis and fibrosis. These features are assessed by a trained pathologist using microscopy and assigned discrete scores. We demonstrate how to automate these scores with convolutional neural networks (CNNs). Whole slide images of stained liver sections are analyzed using two different scales with four CNNs, each specialized for one of four histopathological features. A continuous value is obtained to quantify the extent of each feature, which can be used directly to provide a high resolution readout. In addition, the continuous values can be mapped to obtain the established discrete pathologist-like scores. The automated deep learning-based scores show good agreement with the trainer - a human pathologist.

It has repeatedly been shown that uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists can mimic certain aspects of positive and negative symptoms of schizophrenia in human volunteers and laboratory animals. The purpose of the present study was to expand these findings and to determine whether the selective metabotropic glutamate receptor subtype 5 (mGluR5) antagonist, MTEP (3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine), could induce similar effects in Wistar rats. First, MTEP (1.0-10.0 mg/kg; intraperitoneally) after acute and subchronic (daily for 5 days) administration as well as the uncompetitive antagonists of the NMDA receptor of either high affinity, phencyclidine (0.5-4.0 mg/kg; subcutaneously (s.c.)) and ( + )-MK-801 (0.03-0.25 mg/kg; s.c.), or low-moderate affinity, ketamine (2.0-16.0 mg/kg; s.c.) and memantine (0.15-20.0 mg/kg; s.c.), following daily administration for 3 days were tested in the social interaction test to determine their ability to reproduce the negative and positive symptoms measured by social isolation and stereotyped behavior, respectively. Second, the compounds were tested in the motility test following acute administration to determine their ability to induce locomotor hyperactivity reflecting the positive symptoms. In line with previous findings, all examined NMDA receptor antagonists produced social interaction deficits, locomotor hyperactivity, and stereotypy except memantine. Notably, this study found that MTEP following both acute and subchronic administration dose-dependently induced social isolation, but did not cause either locomotor hyperactivity or stereotypy. These data demonstrate that social behavior deficits in rats can be caused by both the blockade of the NMDA receptor and the inhibition of mGluR5, whereas mGluR5 antagonists may not independently be able to mimic the positive symptoms.

Cigarette smoke (CS) is the leading risk factor to develop COPD. Therefore, the pathologic effects of whole CS on the differentiation of primary small airway epithelial cells (SAEC) were investigated, using cells from three healthy donors and three COPD patients, cultured under ALI (air-liquid interface) conditions. The analysis of the epithelial physiology demonstrated that CS impaired barrier formation and reduced cilia beat activity. Although, COPD-derived ALI cultures preserved some features known from COPD patients, CS-induced effects were similarly pronounced in ALI cultures from patients compared to healthy controls. RNA sequencing analyses revealed the deregulation of marker genes for basal and secretory cells upon CS exposure. The comparison between gene signatures obtained from the in vitro model (CS vs. air) with a published data set from human epithelial brushes (smoker vs. nonsmoker) revealed a high degree of similarity between deregulated genes and pathways induced by CS. Taken together, whole cigarette smoke alters the differentiation of small airway basal cells in vitro. the established model showed a good translatability to the situation in vivo. Thus, the model can help to identify and test novel therapeutic approaches to restore the impaired epithelial repair mechanisms in COPD, which is still a high medical need. Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and its prevalence continues to rise 1. The main risk factor to develop COPD is cigarette smoke 2,3. Smoking induces epithelial injury and this repeated injury of the epithelium triggers a pathophysiologic response, which leads to tissue remodeling of the airways that is characteristic for COPD 4,5. These changes of the small airway epithelium in COPD include: Goblet cell metaplasia 6-8 , reduced cilia function 9-13 , reduced club cell numbers 7,14,15 , basal membrane thickening 16,17 , epithelial barrier dysfunction 18-20 and squamous metaplasia 8,21-23. Furthermore, the epithelial defense mechanisms against inhaled particles and pathogens are impaired enabling sub-epithelial penetration of pathogens that increases the risk of COPD patients suffering from bacterial and viral infections and subsequent exacerbations 24-26. To address cigarette smoke (CS)-induced damage on epithelial cells in vitro, previous studies used primary epithelial cells or cell lines that were mostly exposed to cigarette smoke extract (CSE) or to whole CS. These studies demonstrate smoke effects e.g. on epithelial barrier integrity, mucus production and cilia toxicity 27-34. The majority of these studies focus on the pathophysiology of large airways, i.e. bronchial or tracheal epithelial cells.

Emphysema is a life-threatening pathology that causes irreversible destruction of alveolar walls. In vivo imaging techniques play a fundamental role in the early non-invasive pre-clinical and clinical detection and longitudinal follow-up of this pathology. In the present study, we aimed to evaluate the feasibility of using high resolution radial three-dimensional (3D) zero echo time (ZTE) and 3D ultra-short echo time (UTE) MRI to accurately detect lung pathomorphological changes in a rodent model of emphysema.Porcine pancreas elastase (PPE) was intratracheally administered to the rats to produce the emphysematous changes. 3D ZTE MRI, low and high definition 3D UTE MRI and micro-computed tomography images were acquired 4 weeks after the PPE challenge. Signal-to-noise ratios (SNRs) were measured in PPE-treated and control rats. T2* values were computed from low definition 3D UTE MRI. Histomorphometric measurements were made after euthanizing the animals. Both ZTE and UTE MR images showed a significant decrease in the SNR measured in PPE-treated lungs compared with controls, due to the pathomorphological changes taking place in the challenged lungs. A significant decrease in T2* values in PPE-challenged animals compared with controls was measured using UTE MRI. Histomorphometric measurements showed a significant increase in the mean linear intercept in PPE-treated lungs. UTE yielded significantly higher SNR compared with ZTE (14% and 30% higher in PPE-treated and non-PPE-treated lungs, respectively).This study showed that optimized 3D radial UTE and ZTE MRI can provide lung images of excellent quality, with high isotropic spatial resolution (400 µm) and SNR in parenchymal tissue (>25) and negligible motion artifacts in freely breathing animals. These techniques were shown to be useful non-invasive instruments to accurately and reliably detect the pathomorphological alterations taking place in emphysematous lungs, without incurring the risks of cumulative radiation exposure typical of micro-computed tomography.