Extrinsic and intrinsic regulation of axon regeneration at a crossroads

Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need

The diverse roles of collapsin response mediator protein 4 in mitosis and nerve regeneration

Microtubule-actin interactions underlie a diverse number of biological processes including cell motility, neuronal outgrowth, cellular wound healing, cell division and cortical flow. CRMPs (Collapsin Response Mediator Proteins) are a family of cytosolic phosphoproteins that play roles in regulating both actin and microtubule dynamics. The roles of the CRMP family of proteins in regulating these cellular processes have only been partially described. Our lab has been particularly interested in the function of the CRMP4 isoform because of its unique ability to complex with RhoA, a master regulator of the actin cytoskeleton. In this thesis we explore the function of CRMP4 in two biological processes that are dependent on actin and microtubule dynamics: mitosis (Chapter 2) and axon regeneration (Chapter 3 and 4). In Chapter 2, we identify CRMP4 as an important regulator of mitotic chromosomal alignment. We show that CRMP4 localizes to spindle microtubules during mitosis and that loss of CRMP4 disrupts chromosomal alignment, mitotic progression and spindle morphology. Furthermore, we demonstrate that these processes are dependent on CRMP4 phosphorylation, which may be important for recruitment of additional proteins to the mitotic machinery. In Chapter 3, we investigate the ability of an adeno-associated virus (AAV) encoding a CRMP4 antagonist C4RIP (CRMP4-RhoA inhibitory peptide) to enhance adult retinal ganglion cell (RGC) axon regeneration in an in vivo preclinical optic nerve injury model. We describe the inability of AAV-C4RIP to promote RGC regeneration and discuss the likelihood that AAV-mediated expression levels of C4RIP may be insufficient to promote regeneration. In Chapter 4, we describe the development and validation of cell permeable recombinant C4RIP (TAT-C4RIP) and discuss our data testing the effects of TAT-C4RIP on regeneration in vitro and in vivo. Together, these studies identify CRMP4 as an important regulator of mitosis, and describe our ongoing studies testing the effects of a CRMP4 antagonist on nerve regeneration.Les interactions entre l'actine et les microtubules sont sous-jacentes à divers processus biologiques incluant la motilité cellulaire, le guidage neuronal, la cicatrisation cellulaire, la division cellulaire et la circulation corticale. Les protéines CRMPs (Collapsin Response Mediator Protein) sont une famille de phosphoprotéines cytosoliques jouant un rôle dans la régulation de la dynamique de l'actine et des microtubules. Cependant, cette régulation du cytosquelette par les CRMPs n'a été que partiellement décrite. Notre laboratoire s'intéresse à la fonction de l'isoforme CRMP4 en raison de sa capacité unique d'interagir avec RhoA, un régulateur important du cytosquelette d'actine. Dans cette thèse, nous explorons la fonction de CRMP4 dans deux processus biologiques qui dépendent de la dynamique de l'actine et des microtubules: la mitose (chapitre 2) et la régénération des axones (chapitre 3 et 4). Dans le chapitre 2 sera présentée notre identification de CRMP4 en tant que régulateur important de l'alignement chromosomique durant la mitose. Nous démontrons que, pendant la mitose, CRMP4 se situe sur les fuseaux mitotiques formés de microtubules et que la perte de CRMP4 perturbe l'alignement chromosomique, la progression de la mitose et la morphologie des fuseaux. En outre, nous démontrons que ces processus sont dépendants de la phosphorylation de CRMP4. Ceci pourrait être crucial pour le recrutement de protéines supplémentaires nécessaire pour la mitose. Dans le chapitre 3, nous étudions la capacité d'un virus adéno-associé (AAV) codant pour l'antagoniste de CRMP4, nommé C4RIP (CRMP4-RhoA inhibitory peptide), de favoriser la régénération de l'axone de cellules ganglionnaires de la rétine (RGC) chez l'adulte. Pour cela, nous utilisons un modèle in vivo de traumatismes du nerf optique chez le rat adulte. Nous décrivons l'incapacité des virus AAV-C4RIP de favoriser la régénération des RGCs et discutons de la probabilité que les niveaux de AAV-C4RIP exprimés puissent être insuffisants afin de favoriser la régénération. Le chapitre 4, quant à lui, est consacré à la description du développement et de la validation de la protéine recombinante TAT-C4RIP qui a le potentiel de traverser la membrane cellulaire. Nous y discutons les données concernant les effets de TAT-C4RIP sur la régénération in vitro et in vivo. Dans l'ensemble, ces études caractérisent CRMP4 comme important régulateur de la mitose et décrivent une nouvelle méthode de purification pour des protéines perméables à la membrane cellulaire

Randomised controlled single-blind study of conventional versus depot mydriatic drug delivery prior to cataract surgery

BACKGROUND: A prerequisite for safe cataract surgery is an adequately dilated pupil. The authors conducted a trial to assess the efficacy (in terms of pupil diameter) of a depot method of pre-operative pupil dilatation, as compared with repeated instillations of drops (which is time-consuming for the nursing staff and uncomfortable for the patient). METHODS: A prospective randomised masked trial was conducted comprising 130 patients with no significant ocular history undergoing elective clear corneal phacoemulsification. 65 patients had mydriatic drops (Tropicamide 1%, Phenylephrine 2.5%, Diclofenac sodium 0.1%) instilled prior to surgery, 65 had a wick soaked in the same drop mixture placed in the inferior fornix. Horizontal pupil diameters were recorded on a millimetre scale immediately prior to surgery. RESULTS: There was no significant difference in pupil size between the two groups (p = 0.255, Student's t-test). CONCLUSION: There was no significant difference between the mydriasis obtained with the depot system compared with conventional drop application. Use of a depot mydriatic delivery system appears to be a safe and efficient method of drug delivery. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number Register ISRCTN7804776

Variation in Prices Charged to Patients for Specialty Intraocular Lenses Inserted during Universally Covered Cataract Surgery

Patients often pay for specialty intraocular lenses (IOLs) for cataract surgery covered by universal insurance. This practice creates the potential for inequitable pricing where the medical service provider is also the retailer. We measured the variation in prices between cataract surgeons for the same IOL and associated testing.We telephoned every cataract surgeon in Ontario, Canada, and asked their price for the most common type of specialty IOL as a prospective patient. We measured the total prices quoted and variation between providers.We contacted 404 ophthalmologists. There were 256 that performed cataract surgery but 127 offered the most commonly employed specialty IOL and would provide a price to patients over the telephone. We obtained prices from all 127 ophthalmologists. Prices for the same lens and associated testing varied substantially between ophthalmologists from $358 to$2790 (median $615, interquartile range$528-$915). There was variation in all components of the total out-of-pocket price, including the price for the IOL itself, charges for uninsured eye measurements, and non-specific supplemental fees.Although cataract surgery is covered by public health insurance, some ophthalmologists charge much more than others for the same specialty IOL and associated testing. Greater access to price information and better regulatory control could help ensure patients receive fair value for out-of-pocket health expenses

Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC

Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin

Global, regional, and national disability-adjusted life-years (DALYs) for 359 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.

How long one lives, how many years of life are spent in good and poor health, and how the population's state of health and leading causes of disability change over time all have implications for policy, planning, and provision of services. We comparatively assessed the patterns and trends of healthy life expectancy (HALE), which quantifies the number of years of life expected to be lived in good health, and the complementary measure of disability-adjusted life-years (DALYs), a composite measure of disease burden capturing both premature mortality and prevalence and severity of ill health, for 359 diseases and injuries for 195 countries and territories over the past 28 years. Methods We used data for age-specific mortality rates, years of life lost (YLLs) due to premature mortality, and years lived with disability (YLDs) from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 to calculate HALE and DALYs from 1990 to 2017. We calculated HALE using age-specific mortality rates and YLDs per capita for each location, age, sex, and year. We calculated DALYs for 359 causes as the sum of YLLs and YLDs. We assessed how observed HALE and DALYs differed by country and sex from expected trends based on Socio-demographic Index (SDI). We also analysed HALE by decomposing years of life gained into years spent in good health and in poor health, between 1990 and 2017, and extra years lived by females compared with males. Findings Globally, from 1990 to 2017, life expectancy at birth increased by 7·4 years (95% uncertainty interval 7·1-7·8), from 65·6 years (65·3-65·8) in 1990 to 73·0 years (72·7-73·3) in 2017. The increase in years of life varied from 5·1 years (5·0-5·3) in high SDI countries to 12·0 years (11·3-12·8) in low SDI countries. Of the additional years of life expected at birth, 26·3% (20·1-33·1) were expected to be spent in poor health in high SDI countries compared with 11·7% (8·8-15·1) in low-middle SDI countries. HALE at birth increased by 6·3 years (5·9-6·7), from 57·0 years (54·6-59·1) in 1990 to 63·3 years (60·5-65·7) in 2017. The increase varied from 3·8 years (3·4-4·1) in high SDI countries to 10·5 years (9·8-11·2) in low SDI countries. Even larger variations in HALE than these were observed between countries, ranging from 1·0 year (0·4-1·7) in Saint Vincent and the Grenadines (62·4 years [59·9-64·7] in 1990 to 63·5 years [60·9-65·8] in 2017) to 23·7 years (21·9-25·6) in Eritrea (30·7 years [28·9-32·2] in 1990 to 54·4 years [51·5-57·1] in 2017). In most countries, the increase in HALE was smaller than the increase in overall life expectancy, indicating more years lived in poor health. In 180 of 195 countries and territories, females were expected to live longer than males in 2017, with extra years lived varying from 1·4 years (0·6-2·3) in Algeria to 11·9 years (10·9-12·9) in Ukraine. Of the extra years gained, the proportion spent in poor health varied largely across countries, with less than 20% of additional years spent in poor health in Bosnia and Herzegovina, Burundi, and Slovakia, whereas in Bahrain all the extra years were spent in poor health. In 2017, the highest estimate of HALE at birth was in Singapore for both females (75·8 years [72·4-78·7]) and males (72·6 years [69·8-75·0]) and the lowest estimates were in Central African Republic (47·0 years [43·7-50·2] for females and 42·8 years [40·1-45·6] for males). Globally, in 2017, the five leading causes of DALYs were neonatal disorders, ischaemic heart disease, stroke, lower respiratory infections, and chronic obstructive pulmonary disease. Between 1990 and 2017, age-standardised DALY rates decreased by 41·3% (38·8-43·5) for communicable diseases and by 49·8% (47·9-51·6) for neonatal disorders. For non-communicable diseases, global DALYs increased by 40·1% (36·8-43·0), although age-standardised DALY rates decreased by 18·1% (16·0-20·2)

The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019

Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

Erratum: Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017

Interpretation: By quantifying levels and trends in exposures to risk factors and the resulting disease burden, this assessment offers insight into where past policy and programme efforts might have been successful and highlights current priorities for public health action. Decreases in behavioural, environmental, and occupational risks have largely offset the effects of population growth and ageing, in relation to trends in absolute burden. Conversely, the combination of increasing metabolic risks and population ageing will probably continue to drive the increasing trends in non-communicable diseases at the global level, which presents both a public health challenge and opportunity. We see considerable spatiotemporal heterogeneity in levels of risk exposure and risk-attributable burden. Although levels of development underlie some of this heterogeneity, O/E ratios show risks for which countries are overperforming or underperforming relative to their level of development. As such, these ratios provide a benchmarking tool to help to focus local decision making. Our findings reinforce the importance of both risk exposure monitoring and epidemiological research to assess causal connections between risks and health outcomes, and they highlight the usefulness of the GBD study in synthesising data to draw comprehensive and robust conclusions that help to inform good policy and strategic health planning