Monitoring Tumorigenesis and Senescence In Vivo with a p16INK4a-Luciferase Model

Monitoring cancer and aging in vivo remains experimentally challenging. Here, we describe a luciferase knockin mouse (p16LUC), which faithfully reports expression of p16INK4a, a tumor suppressor and aging biomarker. Lifelong assessment of luminescence in p16+/LUC mice revealed an exponential increase with aging, which was highly variable in a cohort of contemporaneously housed, syngeneic mice. Expression of p16INK4a with aging did not predict cancer development, suggesting that the accumulation of senescent cells is not a principal determinant of cancer-related death. In 14 of 14 tested tumor models, expression of p16LUC was focally activated by early neoplastic events, enabling visualization of tumors with sensitivity exceeding other imaging modalities. Activation of p16INK4a was noted in the emerging neoplasm and surrounding stromal cells. This work suggests that p16INK4a activation is a characteristic of all emerging cancers, making the p16LUC allele a sensitive, unbiased reporter of neoplastic transformation

Monitoring Tumorigenesis and Senescence In Vivo with a p16INK4a-Luciferase Model

Monitoring cancer and aging in vivo remains experimentally challenging. Here, we describe a luciferase knockin mouse (p16LUC), which faithfully reports expression of p16INK4a, a tumor suppressor and aging biomarker. Lifelong assessment of luminescence in p16+/LUC mice revealed an exponential increase with aging, which was highly variable in a cohort of contemporaneously housed, syngeneic mice. Expression of p16INK4a with aging did not predict cancer development, suggesting that the accumulation of senescent cells is not a principal determinant of cancer-related death. In 14 of 14 tested tumor models, expression of p16LUC was focally activated by early neoplastic events, enabling visualization of tumors with sensitivity exceeding other imaging modalities. Activation of p16INK4a was noted in the emerging neoplasm and surrounding stromal cells. This work suggests that p16INK4a activation is a characteristic of all emerging cancers, making the p16LUC allele a sensitive, unbiased reporter of neoplastic transformation

Citizen science reveals widespread negative effects of roads on amphibian distributions

Landscape structure is important for shaping the abundance and distribution of amphibians, but prior studies of landscape effects have been species or ecosystem-specific. Using a large-scale, citizen science-generated database, we examined the effects of habitat composition, road disturbance, and habitat split (i.e. the isolation of wetland from forest by intervening land use) on the distribution and richness of frogs and toads in the eastern and central United States. Undergraduates from nine biology and environmental science courses collated occupancy data and characterized landscape structure at 1617 sampling locations from the North American Amphibian Monitoring Program. Our analysis revealed that anuran species richness and individual species distributions were consistently constrained by both road density and traffic volume. In contrast, developed land around wetlands had small, or even positive effects on anuran species richness and distributions after controlling for road effects. Effects of upland habitat composition varied among species, and habitat split had only weak effects on species richness or individual species distributions. Mechanisms underlying road effects on amphibians involve direct mortality, behavioral barriers to movement, and reduction in the quality of roadside habitats. Our results suggest that the negative effects of roads on amphibians occur across broad geographic regions, affecting even common species, and they underscore the importance of developing effective strategies to mitigate the impacts of roads on amphibian populations

CD4+ Regulatory and Effector/Memory T Cell Subsets Profile Motor Dysfunction in Parkinson’s Disease

Animal models and clinical studies have linked the innate and adaptive immune system to the pathology of Parkinson’s disease (PD). Despite such progress, the specific immune responses that influence disease progression have eluded investigators. Herein, we assessed relationships between T cell phenotype and function with PD progression. Peripheral blood lymphocytes from two separate cohorts, a discovery cohort and a validation cohort, totaling 113 PD patients and 96 age- and environment-matched caregivers were examined by flow cytometric analysis and T cell proliferation assays. Increased effector/memory T cells (Tem), defined as CD45RO+ and FAS+ CD4+ T cells and decreased CD31+ and α4β7+ CD4+ T cells were associated with progressive Unified Parkinson’s Disease Rating Scale III scores. However, no associations were seen between immune biomarkers and increased age or disease duration. Impaired abilities of regulatory T cells (Treg) from PD patients to suppress effector T cell function was observed. These data support the concept that chronic immune stimulation, notably Tem activation and Treg dysfunction is linked to PD pathobiology and disease severity, but not disease duration. The association of T cell phenotypes with motor symptoms provides fresh avenues for novel biomarkers and therapeutic designs

Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis

Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR, and SPINK1 variants were associated with pancreatitis risk. We now report two significant genome-wide associations identified and replicated at PRSS1-PRSS2 (1×10-12) and x-linked CLDN2 (p < 1×10-21) through a two-stage genome-wide study (Stage 1, 676 cases and 4507 controls; Stage 2, 910 cases and 4170 controls). The PRSS1 variant affects susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous (or hemizygous male) CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men – male hemizygous frequency is 0.26, female homozygote is 0.07

Analysis of shared heritability in common disorders of the brain

ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders

Multi-ancestry genome-wide association meta-analysis of Parkinson?s disease

Although over 90 independent risk variants have been identified for Parkinson’s disease using genome-wide association studies, most studies have been performed in just one population at a time. Here we performed a large-scale multi-ancestry meta-analysis of Parkinson’s disease with 49,049 cases, 18,785 proxy cases and 2,458,063 controls including individuals of European, East Asian, Latin American and African ancestry. In a meta-analysis, we identified 78 independent genome-wide significant loci, including 12 potentially novel loci (MTF2, PIK3CA, ADD1, SYBU, IRS2, USP8, PIGL, FASN, MYLK2, USP25, EP300 and PPP6R2) and fine-mapped 6 putative causal variants at 6 known PD loci. By combining our results with publicly available eQTL data, we identified 25 putative risk genes in these novel loci whose expression is associated with PD risk. This work lays the groundwork for future efforts aimed at identifying PD loci in non-European populations

Roles of Infectious Diseases Consultant Pharmacists and Antimicrobial Stewardship Pharmacists: A Survey of Canadian Tertiary Care Academic Hospitals

ABSTRACTBackground: Infectious diseases consultant (IDC) pharmacists work within an IDC service to care for inpatients with complex infections. With Accreditation Canada’s new Required Organizational Practice promoting the establishment of antimicrobial stewardship (AMS) programs, AMS pharmacists are being employed in acute care hospitals. There is potential for overlap in responsibilities between IDC and AMS pharmacists, but there is no literature outlining the current duties for each group in Canada.Objective: To describe the demographic characteristics and roles of IDC and AMS pharmacists in Canadian tertiary care academic hospitals.Methods: A survey of IDC and AMS pharmacists at Canadian tertiary care academic hospitals was conducted between February and April 2015. The questionnaire included questions about the pharmacist’s experience, education, and training; the institution where the pharmacist was practising; the IDC or AMS team characteristics; and the pharmacist’s roles in clinical, educational, administrative, and research sectors.Results: The survey response rate was 77% (68/88). The 68 respondents self-identified as IDC pharmacists (14 [21%]), AMS pharmacists (34 [50%]), or dual-role IDC and AMS pharmacists (20 [29%]). Compared with AMS pharmacists, IDC pharmacists reported more of the following unique clinical activities: directly communicating with patients, attending rounds, involving patients in decision-making, and providing patient education. The 3 groups of pharmacists described similar educational responsibilities. The AMS pharmacists performed more of the following administrative and research duties: development of antibiograms and preprinted orders, collection of antimicrobial metrics, and drug-use evaluations for antimicrobials. Dual-role IDC and AMS pharmacists were involved in fewer of the unique activities described by those who practised within a single subspecialty.Conclusions: Self-identified IDC and AMS pharmacists in Canadian tertiary care academic hospitals were performing many similar roles; however, distinct differences within the clinical, administrative, and research domains were identified among IDC pharmacists, AMS pharmacists, and those who identified as dual-role IDC and AMS pharmacists.RÉSUMÉContexte : Les pharmaciens consultants en maladies infectieuses travaillent au sein d’un service de consultants en maladies infectieuses afin de prodiguer des soins aux patients hospitalisés atteints d’infections complexes. Or, en raison de la nouvelle Pratique organisationnelle requise d’Agrément Canada qui encourage la mise en oeuvre de programmes de gérance des antimicrobiens, des pharmaciens sont affectés à cette fonction dans les hôpitaux de soins de courte durée. On distingue un possible chevauchement des responsabilités entre les pharmaciens consultants en maladies infectieuses et ceux chargés de la gérance des antimicrobiens, mais il n’y a aucun document qui définit les responsabilités actuelles pour chacun de ces groupes au Canada.Objectif : Décrire les caractéristiques démographiques et les rôles des pharmaciens consultants en maladies infectieuses et de ceux chargés de la gérance des antimicrobiens dans les hôpitaux universitaires de soins tertiaires au Canada.Méthodes : Entre février et avril 2015, on a mené un sondage auprès des pharmaciens consultants en maladies infectieuses et de ceux chargés de la gérance des antimicrobiens travaillant dans les hôpitaux universitaires de soins tertiaires au Canada. Les questions portaient, entre autres, sur l’expérience du pharmacien, ses études et sa formation, l’établissement où il travaillait, les caractéristiques des équipes de consultants en maladies infectieuses et de gérance des antimicrobiens ainsi que sur ses rôles dans les secteurs cliniques et administratifs et dans les secteurs de la formation et de la recherche.Résultats : Le taux de réponse au sondage était de 77 % (68/88). Les 68 répondants s’identifiaient comme des pharmaciens consultants en maladies infectieuses (14 [21 %]), des pharmaciens chargés de la gérance des antimicrobiens (34 [50 %]) ou des pharmaciens occupant les deux rôles (20 [29 %]). Comparativement à leur collègues chargés de la gérance des antimicrobiens, les pharmaciens consultants en maladies infectieuses ont davantage indiqué accomplir les activités cliniques uniques suivantes : communiquer directement avec les patients, participer aux tournées médicales, amener les patients à participer aux prises de décisions et offrir des conseils aux patients. Les trois groupes de pharmaciens ont évoqué des responsabilités éducatives similaires. Les pharmaciens chargés de la gérance des antimicrobiens accomplissaient davantage les tâches administratives et de recherche suivantes : élaboration d’antibiogrammes et d’ordonnances préimprimées, cueillette de mesures sur les antimicrobienset évaluation de l’utilisation des antimicrobiens. Les pharmaciens qui cumulaient les deux rôles participaient à un moins grand nombre des activités uniques décrites par ceux qui exerçaient une seule sous-spécialité.Conclusions : Les pharmaciens des hôpitaux universitaires de soins tertiaires au Canada qui s’identifiaient eux-mêmes comme des pharmaciens consultants en maladies infectieuses ou des pharmaciens chargés de la gérance des antimicrobiens exécutaient bon nombre de tâches similaires. Cependant, des différences marquées en ce qui touche aux domaines clinique et administratif et à celui de la recherche ont été repérées entre les pharmaciens consultants en maladies infectieuses, ceux chargés de la gérance des antimicrobiens et ceux occupant les deux rôles

Impaired hepatic amyloid-beta degradation in Alzheimer's disease.

Extensive research strongly suggests that amyloid beta (Aβ) aggregates in the brain have a central role in Alzheimer's disease (AD) pathogenesis. Pathological Aβ deposition is likely due to an altered balance between overproduction and elimination. Rodent studies have suggested that the liver has a major role in Aβ degradation. It is possible alterations of liver function could affect brain Aβ levels through changes in blood Aβ concentration. In this study, we hypothesized hepatic Aβ degradation to be impaired in AD subjects. To test our hypothesis, an Aβ degradation assay was developed using synthetic fluorescein-labeled Aβ40 and Aβ42 spiked into human liver homogenates. Aβ degradation rates were lower in AD-derived homogenates as compared with those from non-demented (ND) control subjects, even after accounting for such covariates as age, sex, and APOE genotype. The protein expression of potential Aβ-degrading enzymes were also examined. Neprilysin levels were not different in AD liver samples, while cathepsin D and insulin-degrading enzyme were significantly altered in AD subjects. The results support the possibility that impaired hepatic Aβ degradation could be a factor contributing to increased brain Aβ accumulation and AD

A role for α-Synuclein in axon growth and its implications in corticostriatal glutamatergic plasticity in Parkinson’s disease

Background α-Synuclein (α-Syn) is a protein implicated in the pathogenesis of Parkinson’s disease (PD). α-Syn has been shown to associate with membranes and bind acidic phospholipids. However, the physiological importance of these associations to the integrity of axons is not fully clear. Methods Biochemical, immunohistochemical and ultrastructural analyses in cultured neurons, transgenic mouse brains, PD and control human brains. Results We analyzed the ultrastructure of cross-sectioned axons localized to white matter tracts (WMTs), within the dorsal striatum of old and symptomatic α-Syn transgenic mouse brains. The analysis indicated a higher density of axons of thinner diameter. Our findings in cultured cortical neurons indicate a role for α-Syn in elongation of the main axon and its collaterals, resulting in enhanced axonal arborization. We show that α-Syn effect to enhance axonal outgrowth is mediated through its activity to regulate membrane levels of the acidic phosphatidylinositol 4,5-bisphosphate (PI4,5P2). Moreover, our findings link α-Syn- enhanced axonal growth with evidence for axonal injury. In relevance to disease mechanisms, we detect in human brains evidence for a higher degree of corticostriatal glutamatergic plasticity within WMTs at early stages of PD. However, at later PD stages, the respective WMTs in the caudate are degenerated with accumulation of Lewy pathology. Conclusions Our results show that through regulating PI4,5P2 levels, α-Syn acts to elongate the main axon and collaterals, resulting in a higher density of axons in the striatal WMTs. Based on these results we suggest a role for α-Syn in compensating mechanisms, involving corticostriatal glutamatergic plasticity, taking place early in PD