Minimal long-term neurobehavioral impairments after endovascular perforation subarachnoid hemorrhage in mice

AbstractCognitive deficits are among the most severe and pervasive consequences of aneurysmal subarachnoid hemorrhage (SAH). A critical step in developing therapies targeting such outcomes is the characterization of experimentally-tractable pre-clinical models that exhibit multi-domain neurobehavioral deficits similar to those afflicting humans. We therefore searched for neurobehavioral abnormalities following endovascular perforation induction of SAH in mice, a heavily-utilized model. We instituted a functional screen to manage variability in injury severity, then assessed acute functional deficits, as well as activity, anxiety-related behavior, learning and memory, socialization, and depressive-like behavior at sub-acute and chronic time points (up to 1 month post-injury). Animals in which SAH was induced exhibited reduced acute functional capacity and reduced general activity to 1 month post-injury. Tests of anxiety-related behavior including central area time in the elevated plus maze and thigmotaxis in the open field test revealed increased anxiety-like behavior at subacute and chronic time-points, respectively. Effect sizes for subacute and chronic neurobehavioral endpoints in other domains, however, were small. In combination with persistent variability, this led to non-significant effects of injury on all remaining neurobehavioral outcomes. These results suggest that, with the exception of anxiety-related behavior, alternate mouse models are required to effectively analyze cognitive outcomes after SAH.</jats:p

modCHIMERA: A novel murine closed-head model of moderate traumatic brain injury

AbstractTraumatic brain injury is a major source of global disability and mortality. Preclinical TBI models are a crucial component of therapeutic investigation. We report a tunable, monitored model of murine non-surgical, diffuse closed-head injury—modCHIMERA—characterized by impact as well as linear and rotational acceleration. modCHIMERA is based on the Closed-Head Impact Model of Engineered Rotational Acceleration (CHIMERA) platform. We tested this model at 2 energy levels: 1.7 and 2.1 Joules—substantially higher than previously reported for this system. Kinematic analysis demonstrated linear acceleration exceeding injury thresholds in humans, although outcome metrics tracked impact energy more closely than kinematic parameters. Acute severity metrics were consistent with a complicated-mild or moderate TBI, a clinical population characterized by high morbidity but potentially reversible pathology. Axonal injury was multifocal and bilateral, neuronal death was detected in the hippocampus, and microglial neuroinflammation was prominent. Acute functional analysis revealed prolonged post-injury unconsciousness, and decreased spontaneous behavior and stimulated neurological scores. Neurobehavioral deficits were demonstrated in spatial learning/memory and socialization at 1-month. The overall injury profile of modCHIMERA corresponds with the range responsible for a substantial portion of TBI-related disability in humans. modCHIMERA should provide a reliable platform for efficient analysis of TBI pathophysiology and testing of treatment modalities.</jats:p

Mitochondrial complex 1 activity measured by spectrophotometry is reduced across all brain regions in ageing and more specifically in neurodegeneration

Mitochondrial function, in particular complex 1 of the electron transport chain (ETC), has been shown to decrease during normal ageing and in neurodegenerative disease. However, there is some debate concerning which area of the brain has the greatest complex 1 activity. It is important to identify the pattern of activity in order to be able to gauge the effect of age or disease related changes. We determined complex 1 activity spectrophotometrically in the cortex, brainstem and cerebellum of middle aged mice (70–71 weeks), a cerebellar ataxic neurodegeneration model (pcd5J) and young wild type controls. We share our updated protocol on the measurements of complex1 activity and find that mitochondrial fractions isolated from frozen tissues can be measured for robust activity. We show that complex 1 activity is clearly highest in the cortex when compared with brainstem and cerebellum (p<0.003). Cerebellum and brainstem mitochondria exhibit similar levels of complex 1 activity in wild type brains. In the aged brain we see similar levels of complex 1 activity in all three-brain regions. The specific activity of complex 1 measured in the aged cortex is significantly decreased when compared with controls (p<0.0001). Both the cerebellum and brainstem mitochondria also show significantly reduced activity with ageing (p<0.05). The mouse model of ataxia predictably has a lower complex 1 activity in the cerebellum, and although reductions are measured in the cortex and brain stem, the remaining activity is higher than in the aged brains. We present clear evidence that complex 1 activity decreases across the brain with age and much more specifically in the cerebellum of the pcd5j mouse. Mitochondrial impairment can be a region specific phenomenon in disease, but in ageing appears to affect the entire brain, abolishing the pattern of higher activity in cortical regions

The transfer and fate of Pb from sewage sludge amended soil in a multi-trophic food chain: a comparison with the labile elements Cd and Zn

The contamination of agroecosystems due to the presence of trace elements in commonly used agricultural materials is a serious issue. The most contaminated material is usually sewage sludge, and the sustainable use of this material within agriculture is a major concern. This study addresses a key issue in this respect, the fate of trace metals applied to soil in food chains. The work particularly addresses the transfer of Pb, which is an understudied element in this respect, and compares the transfer of Pb with two of the most labile metals, Cd and Zn. The transfer of these elements was determined from sludge-amended soils in a food chain consisting of Indian mustard (Brassica juncea), the mustard aphid (Lipaphis erysimi) and a predatory beetle (Coccinella septempunctata). The soil was amended with sludge at rates of 0, 5, 10 and 20 % (w/w). Results showed that Cd was readily transferred through the food chain until the predator trophic level. Zn was the most readily transferred element in the lower trophic levels, but transfer to aphids was effectively restricted by the plant regulating shoot concentration. Pb had the lowest level of transfer from soil to shoot and exhibited particular retention in the roots. Nevertheless, Pb concentrations were significantly increased by sludge amendment in aphids, and Pb was increasingly transferred to ladybirds as levels increased. The potential for Pb to cause secondary toxicity to organisms in higher trophic levels may have therefore been underestimated

PRIORITIZATION OF RESULTS FROM WHOLE EXOME SEQUENCING IN FAMILIAL INTRACRANIAL ANEURYSM

poster abstractWhole exome sequencing (WES) is an innovative approach to identifying rare variants associated with disease; however, reducing the large number of variants to a useful set of candidate genes is challenging. We developed a ranking system utilizing data from a previous genome-wide linkage analysis and various bioinformatics databases to prioritize the results of WES from families having multiple members with intracranial aneurysms. WES was performed in 35 affected individuals and 10 unaffected individ-uals across 7 families. All samples were genotyped (Illumina® OmniExpress) and sequenced (Agilent© SureSelect™ 50Mb Human All Exon Kit). Linkage analysis (Illumina 6K) was previously performed using autosomal domi-nant/recessive modes of inheritance. Application of quality filters resulted in 91,659 single nucleotide variants (SNVs). Nonsynonymous SNVs within an exon having an allele frequency of <3% were retained. Further filtering was performed based on Mendelian in-heritance (autosomal dominant or recessive). A ranking system prioritized retained variants based on the inheritance pattern specific to each family, occurrence in multiple families, relation to pathways and genes of interest, degree of penetrance, presence within a linkage peak, and whether the re-sultant proteins were predicted to be deleterious. Out of a 9-point score, 292 variants in 190 genes received scores of at least 5. Of these, 14 variants in 10 genes met the majority of prioritization criteria by achieving scores of over 7. While several WES studies have been successful at identifying genes im-portant to rare diseases, few have examined how to produce a list of candi-date genes contributing to a complex disease from WES data. We show that a ranking system that combines WES with bioinformatics resources and link-age data is a powerful approach to prioritize candidate genes for a complex disease like familial intracranial aneurysms. Subsequent studies are required to validate the utility of this approach

In Vivo Assessment of Neuroinflammation in 4-Repeat Tauopathies

Background: Neuroinflammation has received growing interest as a therapeutic target in neurodegenerative disorders, including 4-repeat tauopathies. Objectives: The aim of this cross-sectional study was to investigate 18 kDa translocator protein positron emission tomography (PET) as a biomarker for microglial activation in the 4-repeat tauopathies corticobasal degeneration and progressive supranuclear palsy. Methods Specific binding of the 18 kDa translocator protein tracer F-18-GE-180 was determined by serial PET during pharmacological depletion of microglia in a 4-repeat tau mouse model. The 18 kDa translocator protein PET was performed in 30 patients with corticobasal syndrome (68 +/- 9 years, 16 women) and 14 patients with progressive supranuclear palsy (69 +/- 9 years, 8 women), and 13 control subjects (70 +/- 7 years, 7 women). Group comparisons and associations with parameters of disease progression were assessed by region-based and voxel-wise analyses. Results Tracer binding was significantly reduced after pharmacological depletion of microglia in 4-repeat tau mice. Elevated 18 kDa translocator protein labeling was observed in the subcortical brain areas of patients with corticobasal syndrome and progressive supranuclear palsy when compared with controls and was most pronounced in the globus pallidus internus, whereas only patients with corticobasal syndrome showed additionally elevated tracer binding in motor and supplemental motor areas. The 18 kDa translocator protein labeling was not correlated with parameters of disease progression in corticobasal syndrome and progressive supranuclear palsy but allowed sensitive detection in patients with 4-repeat tauopathies by a multiregion classifier. Conclusions: Our data indicate that F-18-GE-180 PET detects microglial activation in the brain of patients with 4-repeat tauopathy, fitting to predilection sites of the phenotype. The 18 kDa translocator protein PET has a potential for monitoring neuroinflammation in 4-repeat tauopathies. (c) 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Societ

Potentially toxic metals in historic landfill sites: Implications for grazing animals

Municipal waste disposal is an increasing global problem, frequently solved by the use of landfill sites. Following closure, such sites contain a legacy of pollutants and must be managed to provide a safe and useful end life. The soils and vegetation from four historic landfill sites were analysed to determine the extent of pollution by potentially toxic metals (PTMs). Data were subsequently assessed to determine if post closure uses involving grazing were safe for the animals. The heaviest and widest spread soil contamination was due to Ni. Concentrations at all sites exceeded the 95th percentile value for rural soils, in one case by a factor of 30. Cu and Pb contamination was identified at some sites, but no evidence of Al or Zn contamination was found. Oral bioaccessibility testing showed that the availability of Ni in soil was exceedingly low, whilst that of Cu and Pb was high. Concentrations in plant shoots differed significantly amongst the sites, but interspecific differences in shoot concentration were only significant in the case of Cu. The results indicated that exposure levels to grazers would be at or below tolerable levels, indicating that it is generally safe to graze historic landfill. However, animals could be exposed to higher levels of PTMs than would be expected from rural locations, and grazing under conditions where soil consumption may be high could result in levels of exposure to Al, Ni and Pb exceeding tolerable levels. © Springer International Publishing 2014

Genome screen in familial intracranial aneurysm

Research articl

Comparison of Therapeutic Effects between Pulsed and Continuous Wave 810-nm Wavelength Laser Irradiation for Traumatic Brain Injury in Mice

Background and Objective Transcranial low-level laser therapy (LLLT) using near-infrared light can efficiently penetrate through the scalp and skull and could allow non-invasive treatment for traumatic brain injury (TBI). In the present study, we compared the therapeutic effect using 810-nm wavelength laser light in continuous and pulsed wave modes in a mouse model of TBI. Study Design/Materials and Methods TBI was induced by a controlled cortical-impact device and 4-hours post-TBI 1-group received a sham treatment and 3-groups received a single exposure to transcranial LLLT, either continuous wave or pulsed at 10-Hz or 100-Hz with a 50% duty cycle. An 810-nm Ga-Al-As diode laser delivered a spot with diameter of 1-cm onto the injured head with a power density of 50-mW/cm2 for 12-minutes giving a fluence of 36-J/cm2. Neurological severity score (NSS) and body weight were measured up to 4 weeks. Mice were sacrificed at 2, 15 and 28 days post-TBI and the lesion size was histologically analyzed. The quantity of ATP production in the brain tissue was determined immediately after laser irradiation. We examined the role of LLLT on the psychological state of the mice at 1 day and 4 weeks after TBI using tail suspension test and forced swim test. Results The 810-nm laser pulsed at 10-Hz was the most effective judged by improvement in NSS and body weight although the other laser regimens were also effective. The brain lesion volume of mice treated with 10-Hz pulsed-laser irradiation was significantly lower than control group at 15-days and 4-weeks post-TBI. Moreover, we found an antidepressant effect of LLLT at 4-weeks as shown by forced swim and tail suspension tests. Conclusion The therapeutic effect of LLLT for TBI with an 810-nm laser was more effective at 10-Hz pulse frequency than at CW and 100-Hz. This finding may provide a new insight into biological mechanisms of LLLT.National Institutes of Health (U.S.) (NIH grant R01AI050875)Center for Integration of Medicine and Innovative Technology (DAMD17-02-2-0006)United States. Dept. of Defense. Congressionally Directed Medical Research Programs (W81XWH-09-1-0514)United States. Air Force Office of Scientific Research (Military Photomedicine Program (FA9950-04-1-0079))Japan. Ministry of Education, Culture, Sports, Science and TechnologyJapan Society for the Promotion of Scienc

Learning from Fifteen Years of Genome-Wide Association Studies in Age-Related Macular Degeneration

Over the last 15 years, genome-wide association studies (GWAS) have greatly advanced our understanding of the genetic landscape of complex phenotypes. Nevertheless, causal interpretations of GWAS data are challenging but crucial to understand underlying mechanisms and pathologies. In this review, we explore to what extend the research community follows up on GWAS data. We have traced the scientific activities responding to the two largest GWAS conducted on age-related macular degeneration (AMD) so far. Altogether 703 articles were manually categorized according to their study type. This demonstrates that follow-up studies mainly involve "Review articles" (33%) or "Genetic association studies" (33%), while 19% of publications report on findings from experimental work. It is striking to note that only three of 16 AMD-associated loci described de novo in 2016 were examined in the four-year follow-up period after publication. A comparative analysis of five studies on gene expression regulation in AMD-associated loci revealed consistent gene candidates for 15 of these loci. Our random survey highlights the fact that functional follow-up studies on GWAS results are still in its early stages hampering a significant refinement of the vast association data and thus a more accurate insight into mechanisms and pathways