54 research outputs found
Smart Moves: Effects of Relative Brain Size on Establishment Success of Invasive Amphibians and Reptiles
Brain size relative to body size varies considerably among animals, but the
ecological consequences of that variation remain poorly understood. Plausibly,
larger brains confer increased behavioural flexibility, and an ability to
respond to novel challenges. In keeping with that hypothesis, successful
invasive species of birds and mammals that flourish after translocation to a new
area tend to have larger brains than do unsuccessful invaders. We found the same
pattern in ectothermic terrestrial vertebrates. Brain size relative to body size
was larger in species of amphibians and reptiles reported to be successful
invaders, compared to species that failed to thrive after translocation to new
sites. This pattern was found in six of seven global biogeographic realms; the
exception (where relatively larger brains did not facilitate invasion success)
was Australasia. Establishment success was also higher in amphibian and reptile
families with larger relative brain sizes. Future work could usefully explore
whether invasion success is differentially associated with enlargement of
specific parts of the brain (as predicted by the functional role of the
forebrain in promoting behavioural flexibility), or with a general size increase
(suggesting that invasion success is facilitated by enhanced perceptual and
motor skills, as well as cognitive ability)
Alterations of renal phenotype and gene expression profiles due to protein overload in NOD-related mouse strains
BACKGROUND: Despite multiple causes, Chronic Kidney Disease is commonly associated with proteinuria. A previous study on Non Obese Diabetic mice (NOD), which spontaneously develop type 1 diabetes, described histological and gene expression changes incurred by diabetes in the kidney. Because proteinuria is coincident to diabetes, the effects of proteinuria are difficult to distinguish from those of other factors such as hyperglycemia. Proteinuria can nevertheless be induced in mice by peritoneal injection of Bovine Serum Albumin (BSA). To gain more information on the specific effects of proteinuria, this study addresses renal changes in diabetes resistant NOD-related mouse strains (NON and NOD.B10) that were made to develop proteinuria by BSA overload. METHODS: Proteinuria was induced by protein overload on NON and NOD.B10 mouse strains and histology and microarray technology were used to follow the kidney response. The effects of proteinuria were assessed and subsequently compared to changes that were observed in a prior study on NOD diabetic nephropathy. RESULTS: Overload treatment significantly modified the renal phenotype and out of 5760 clones screened, 21 and 7 kidney transcripts were respectively altered in the NON and NOD.B10. Upregulated transcripts encoded signal transduction genes, as well as markers for inflammation (Calmodulin kinase beta). Down-regulated transcripts included FKBP52 which was also down-regulated in diabetic NOD kidney. Comparison of transcripts altered by proteinuria to those altered by diabetes identified mannosidase 2 alpha 1 as being more specifically induced by proteinuria. CONCLUSION: By simulating a component of diabetes, and looking at the global response on mice resistant to the disease, by virtue of a small genetic difference, we were able to identify key factors in disease progression. This suggests the power of this approach in unraveling multifactorial disease processes
Structural, Stability, Dynamic and Binding Properties of the ALS-Causing T46I Mutant of the hVAPB MSP Domain as Revealed by NMR and MD Simulations
T46I is the second mutation on the hVAPB MSP domain which was recently identified from non-Brazilian kindred to cause a familial amyotrophic lateral sclerosis (ALS). Here using CD, NMR and molecular dynamics (MD) simulations, we characterized the structure, stability, dynamics and binding capacity of the T46I-MSP domain. The results reveal: 1) unlike P56S which we previously showed to completely eliminate the native MSP structure, T46I leads to no significant disruption of the native secondary and tertiary structures, as evidenced from its far-UV CD spectrum, as well as Cα and Cβ NMR chemical shifts. 2) Nevertheless, T46I does result in a reduced thermodynamic stability and loss of the cooperative urea-unfolding transition. As such, the T46I-MSP domain is more prone to aggregation than WT at high protein concentrations and temperatures in vitro, which may become more severe in the crowded cellular environments. 3) T46I only causes a 3-fold affinity reduction to the Nir2 peptide, but a significant elimination of its binding to EphA4. 4) EphA4 and Nir2 peptide appear to have overlapped binding interfaces on the MSP domain, which strongly implies that two signaling networks may have a functional interplay in vivo. 5) As explored by both H/D exchange and MD simulations, the MSP domain is very dynamic, with most loop residues and many residues on secondary structures highly fluctuated or/and exposed to bulk solvent. Although T46I does not alter overall dynamics, it does trigger increased dynamics of several local regions of the MSP domain which are implicated in binding to EphA4 and Nir2 peptide. Our study provides the structural and dynamic understanding of the T46I-causing ALS; and strongly highlights the possibility that the interplay of two signaling networks mediated by the FFAT-containing proteins and Eph receptors may play a key role in ALS pathogenesis
y Integrated analysis of 8-week glecaprevir/pibrentasvir in Japanese and overseas patients without cirrhosis and with hepatitis C virus genotype 1 or 2 infection
AbbVi
Analysis of the key elements of FFAT-like motifs identifies new proteins that potentially bind VAP on the ER, including two AKAPs and FAPP2.
Two phenylalanines (FF) in an acidic tract (FFAT)-motifs were originally described as having seven elements: an acidic flanking region followed by 6 residues (EFFDA-E). Such motifs are found in several lipid transfer protein (LTP) families, and they interact with a protein on the cytosolic face of the ER called vesicle-associated membrane protein-associated protein (VAP). Mutation of which causes ER stress and motor neuron disease, making it important to determine which proteins bind VAP. Among other proteins that bind VAP, some contain FFAT-like motifs that are missing one or more of the seven elements. Defining how much variation is tolerated in FFAT-like motifs is a preliminary step prior to the identification of the full range of VAP interactors
Efficacy and safety of ledipasvir/sofosbuvir with and without ribavirin in patients with chronic HCV genotype 1 infection receiving opioid substitution therapy: Analysis of phase 3 ION trials
Background. Interferon-based hepatitis C virus (HCV) therapy is safe and effective among people receiving opioid substitution therapy (OST), but treatment uptake remains low. Our aim was to evaluate the impact of OST and drug use during therapy on completion, adherence, sustained virologic response (SVR12), and safety of ledipasvir/sofosbuvir ± ribavirin. Methods. The phase 3 ION studies evaluated a fixed-dose combination of ledipasvir/sofosbuvir ± ribavirin administered for 8, 12, or 24 weeks in patients with chronic HCV genotype 1. People with clinically significant drug use ( prior 12 months) or noncannabinoids detected at screening by urine drug tests (not explained by prescriptions) were ineligible. Stored samples were available from ION-1 for retrospective testing for illicit drugs by enzyme-linked immunosorbent assay. Results. Among 1952 patients enrolled in the ION studies, 4% (n = 70) were receiving OST. Among those receiving (n = 70) and not receiving OST (n = 1882), there was no difference in treatment completion (97% vs 98%; P =.40), ≥80% adherence (93% vs 92%; P = 1.00), SVR12 (94% vs 97%; P = .28), and serious adverse events (4% vs 3%; P = .43), respectively. Among participants in the ION-1 trial, 23% (n = 196) used illicit drugs during therapy (15% cannabinoids alone; 8% other illicit drugs ± cannabinoids). There was no difference in treatment completion, ≥80% adherence, SVR12, or serious AEs in those with no drug use during treatment compared with those who used cannabinoids and/or other illicit drugs. No cases of HCV reinfection were observed in the 24 weeks following treatment. Conclusions. OST and drug use during HCV therapy did not impact treatment completion, adherence, SVR12, or safety
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