33 research outputs found
Improved lung preservation relates to an increase in tubular myelin-associated surfactant protein A
BACKGROUND: Declining levels of surfactant protein A (SP-A) after lung transplantation are suggested to indicate progression of ischemia/reperfusion (IR) injury. We hypothesized that the previously described preservation-dependent improvement of alveolar surfactant integrity after IR was associated with alterations in intraalveolar SP-A levels. METHODS: Using immuno electron microscopy and design-based stereology, amount and distribution of SP-A, and of intracellular surfactant phospholipids (lamellar bodies) as well as infiltration by polymorphonuclear leukocytes (PMNs) and alveolar macrophages were evaluated in rat lungs after IR and preservation with EuroCollins or Celsior. RESULTS: After IR, labelling of tubular myelin for intraalveolar SP-A was significantly increased. In lungs preserved with EuroCollins, the total amount of intracellular surfactant phospholipid was reduced, and infiltration by PMNs and alveolar macrophages was significantly increased. With Celsior no changes in infiltration or intracellular surfactant phospholipid amount occurred. Here, an increase in the number of lamellar bodies per cell was associated with a shift towards smaller lamellar bodies. This accounts for preservation-dependent changes in the balance between surfactant phospholipid secretion and synthesis as well as in inflammatory cell infiltration. CONCLUSION: We suggest that enhanced release of surfactant phospholipids and SP-A represents an early protective response that compensates in part for the inactivation of intraalveolar surfactant in the early phase of IR injury. This beneficial effect can be supported by adequate lung preservation, as e.g. with Celsior, maintaining surfactant integrity and reducing inflammation, either directly (via antioxidants) or indirectly (via improved surfactant integrity)
Wnt5a Regulates Midbrain Dopaminergic Axon Growth and Guidance
During development, precise temporal and spatial gradients are responsible for
guiding axons to their appropriate targets. Within the developing ventral
midbrain (VM) the cues that guide dopaminergic (DA) axons to their forebrain
targets remain to be fully elucidated. Wnts are morphogens that have been
identified as axon guidance molecules. Several Wnts are expressed in the VM
where they regulate the birth of DA neurons. Here, we describe that a precise
temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal
projections by VM DA neurons. In mice at E11.5, Wnt5a is
expressed in the VM where it was found to promote DA neurite and axonal growth
in VM primary cultures. By E14.5, when DA axons are approaching their striatal
target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM
explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is
capable of repelling DA neurites. Antagonism experiments revealed that the
effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase,
Rac1 (a component of the non-canonical Wnt planar cell polarity pathway).
Moreover, the effects were specific as they could be blocked by Wnt5a antibody,
sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further
verified in Wnt5a−/− mice, where
fasciculation of the medial forebrain bundle (MFB) as well as the density of DA
neurites in the MFB and striatal terminals were disrupted. Thus, our results
identify a novel role of Wnt5a in DA axon growth and guidance
Syndromics: A Bioinformatics Approach for Neurotrauma Research
Substantial scientific progress has been made in the past 50 years in delineating many of the biological mechanisms involved in the primary and secondary injuries following trauma to the spinal cord and brain. These advances have highlighted numerous potential therapeutic approaches that may help restore function after injury. Despite these advances, bench-to-bedside translation has remained elusive. Translational testing of novel therapies requires standardized measures of function for comparison across different laboratories, paradigms, and species. Although numerous functional assessments have been developed in animal models, it remains unclear how to best integrate this information to describe the complete translational “syndrome” produced by neurotrauma. The present paper describes a multivariate statistical framework for integrating diverse neurotrauma data and reviews the few papers to date that have taken an information-intensive approach for basic neurotrauma research. We argue that these papers can be described as the seminal works of a new field that we call “syndromics”, which aim to apply informatics tools to disease models to characterize the full set of mechanistic inter-relationships from multi-scale data. In the future, centralized databases of raw neurotrauma data will enable better syndromic approaches and aid future translational research, leading to more efficient testing regimens and more clinically relevant findings
Corticobasal and ataxia syndromes widen the spectrum of C9ORF72 hexanucleotide expansion disease
Recently, a hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72 was reported as the cause of chromosome 9p21-linked frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS). We here report the prevalence of the expansion in a hospital-based cohort and associated clinical features indicating a wider clinical spectrum of C9ORF72 disease than previously described. We studied 280 patients previously screened for mutations in genes involved in early onset autosomal dominant inherited dementia disorders. A repeat-primed polymerase chain reaction amplification assay was used to identify pathogenic GGGGCC expansions. As a potential modifier, confirmed cases were further investigated for abnormal CAG expansions in ATXN2. A pathogenic GGGGCC expansion was identified in a total of 14 probands. Three of these presented with atypical clinical features and were previously diagnosed with clinical olivopontocerebellar degeneration (OPCD), atypical Parkinsonian syndrome (APS) and a corticobasal syndrome (CBS). Further, the pathogenic expansion was identified in six FTD patients, four patients with FTD-ALS and one ALS patient. All confirmed cases had normal ATXN2 repeat sizes. Our study widens the clinical spectrum of C9ORF72related disease and confirms the hexanucleotide expansion as a prevalent cause of FTD-ALS disorders. There was no indication of a modifying effect of the ATXN2 gene
The size distribution of neurons in the motor cortex in amyotrophic lateral sclerosis
The motor cortex of eight patients with amyotrophic lateral sclerosis (ALS) and nine control subjects was used in the study. Recent stereological tools, the disector and the rotator method, were applied to the motor cortex of patients with ALS and control subjects to obtain estimates of mean perikaryon volume, mean neuronal nuclear volume, total perikaryon volume and total neuronal nuclear volume. No significant differences were found in any of the estimates. In vivo proton magnetic resonance spectroscopy studies show a decrease in the concentration of neuronal markers. We expected to find changes in perikaryon and/or nuclei neuronal volume because the total neuron number is unchanged in ALS compared with control subjects. However, this was not the case; our results suggest that metabolic changes take place in the motor cortex of ALS patients without these concomitant anatomical changes
The impact of passive immunisation against BMPRIB and BMP4 on follicle development and ovulation in mice
The primordial follicle reserve is the corner stone of female fertility and determines the longevity and quality of reproduction. Complete depletion of this reserve will lead to primary infertility, and the key-limiting step of follicle depletion is the transition from primordial to primary follicles. It has been reported that this process is gonadotrophin-independent, but other conflicting reports are indicated otherwise and this discrepancy needs to be unequivocally clarified. The aim of this study was to investigate the role of bone morphogenetic proteins (BMPs) in the regulation of folliculogenesis in mice passively immunised against BMP receptor 1B (BMPRIB) and BMP4. While a stereological study revealed that the numbers of primordial follicles in immunised mice were significantly higher when compared with control animals, treatment with equine chorionic gonadotrophin showed no effect. In parallel, immunofluorescence microscopy revealed the presence of BMPRIB but not FSH receptor in primordial follicles. The number of primary follicles in immunised mice were also significantly increased when compared with control animals. After puberty, the rates of depletion of primordial and primary follicles were increased with age, particularly in treated animals; however, there was no significant difference between the treatment groups of the same age. Based on these results together with our previous reports in sheep and mice, we confirm that the attenuation of BMP signalling system can be an effective approach to sustain the primordial follicle reserve while promoting the development of growing follicles, ovulation and consequently overall female fertility