ABSTRACT
Nuclear clearance and cytoplasmic aggregation of TDP-43 in neurons, initially identified in ALS-FTD, are hallmark pathological features observed across a spectrum of neurodegenerative diseases. We previously found that TDP-43 loss-of-function leads to the transcriptome-wide inclusion of deleterious cryptic exons in brains and biofluids post-mortem as well as during the presymptomatic stage of ALS-FTD, but upstream mechanisms that lead to TDP-43 dysregulation remain unclear. Here, we developed a web-based resource (SnapMine) to determine the levels of TDP-43 cryptic exon inclusion across hundreds of thousands of publicly available RNA sequencing datasets. We established cryptic exon inclusion across a variety of human cells and tissues to provide ground truth references for future studies on TDP-43 dysregulation. We then explored studies that were entirely unrelated to TDP-43 or neurodegeneration and found that ciclopirox olamine (CPX), an FDA-approved antifungal, can trigger the inclusion of TDP-43-associated cryptic exons in a variety of mouse and human primary cells. CPX induction of cryptic exon occurs via heavy metal toxicity and oxidative stress, suggesting that similar vulnerabilities could play a role in neurodegeneration. Our work demonstrates how diverse datasets can be linked through common biological features and underscores that public archives of sequencing data represent a vastly underutilized resource with tremendous potential for uncovering novel insights into complex biological mechanisms and diseases.
ABSTRACT
Although loss of TAR DNA-binding protein 43 kDa (TDP-43) splicing repression is well documented in postmortem tissues of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), whether this abnormality occurs during early-stage disease remains unresolved. Cryptic exon inclusion reflects loss of function of TDP-43, and thus detection of proteins containing cryptic exon-encoded neoepitopes in cerebrospinal fluid (CSF) or blood could reveal the earliest stages of TDP-43 dysregulation in patients. Here we use a newly characterized monoclonal antibody specific to a TDP-43-dependent cryptic epitope (encoded by the cryptic exon found in HDGFL2) to show that loss of TDP-43 splicing repression occurs in ALS-FTD, including in presymptomatic C9orf72 mutation carriers. Cryptic hepatoma-derived growth factor-like protein 2 (HDGFL2) accumulates in CSF at significantly higher levels in familial ALS-FTD and sporadic ALS compared with controls and is elevated earlier than neurofilament light and phosphorylated neurofilament heavy chain protein levels in familial disease. Cryptic HDGFL2 can also be detected in blood of individuals with ALS-FTD, including in presymptomatic C9orf72 mutation carriers, and accumulates at levels highly correlated with those in CSF. Our findings indicate that loss of TDP-43 cryptic splicing repression occurs early in disease progression, even presymptomatically, and that detection of the HDGFL2 cryptic neoepitope serves as a potential diagnostic biomarker for ALS, which should facilitate patient recruitment and measurement of target engagement in clinical trials.
Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Humans , Frontotemporal Dementia/genetics , Amyotrophic Lateral Sclerosis/genetics , C9orf72 Protein/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Biomarkers/cerebrospinal fluidABSTRACT
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of upper and lower motor neurons. Presently, three FDA-approved drugs are available to help slow functional decline for patients with ALS, but no cure yet exists. With an average life expectancy of only two to five years after diagnosis, there is a clear need for biomarkers to improve the care of patients with ALS and to expedite ALS treatment development. Here, we provide a review of the efforts made towards identifying diagnostic, prognostic, susceptibility/risk, and response fluid biomarkers with the intent to facilitate a more rapid and accurate ALS diagnosis, to better predict prognosis, to improve clinical trial design, and to inform interpretation of clinical trial results. Over the course of 20 + years, several promising fluid biomarker candidates for ALS have emerged. These will be discussed, as will the exciting new strategies being explored for ALS biomarker discovery and development.
Subject(s)
Amyotrophic Lateral Sclerosis , Neurodegenerative Diseases , Humans , Amyotrophic Lateral Sclerosis/diagnosis , Biomarkers , Motor NeuronsABSTRACT
LATE-NC, the neuropathologic changes of limbic-predominant age-related TAR DNA-binding protein 43 kDa (TDP-43) encephalopathy are frequently associated with Alzheimer's disease (AD) and cognitive impairment in older adults. The association of TDP-43 proteinopathy with AD neuropathologic changes (ADNC) and its impact on specific cognitive domains are not fully understood and whether loss of TDP-43 function occurs early in the aging brain remains unknown. Here, using a large set of autopsies from the Baltimore Longitudinal Study of Aging (BLSA) and another younger cohort, we were able to study brains from subjects 21-109 years of age. Examination of these brains show that loss of TDP-43 splicing repression, as judged by TDP-43 nuclear clearance and expression of a cryptic exon in HDGFL2, first occurs during the 6th decade, preceding by a decade the appearance of TDP-43+ neuronal cytoplasmic inclusions (NCIs). We corroborated this observation using a monoclonal antibody to demonstrate a cryptic exon-encoded neoepitope within HDGFL2 in neurons exhibiting nuclear clearance of TDP-43. TDP-43 nuclear clearance is associated with increased burden of tau pathology. Age at death, female sex, high CERAD neuritic plaque score, and high Braak neurofibrillary stage significantly increase the odds of LATE-NC. Faster rates of cognitive decline on verbal memory (California Verbal Learning Test immediate recall), visuospatial ability (Card Rotations Test), mental status (MMSE) and semantic fluency (Category Fluency Test) were associated with LATE-NC. Notably, the effects of LATE-NC on verbal memory and visuospatial ability are independent of ADNC. However, the effects of TDP-43 nuclear clearance in absence of NCI on the longitudinal trajectories and levels of cognitive measures are not significant. These results establish that loss of TDP-43 splicing repression is an early event occurring in the aging population during the development of TDP-43 proteinopathy and is associated with increased tau pathology. Furthermore, LATE-NC correlates with high levels of ADNC but also has an impact on specific memory and visuospatial functions in aging that is independent of AD.
Subject(s)
Alzheimer Disease , Cognitive Dysfunction , TDP-43 Proteinopathies , Humans , Female , Aged , Alzheimer Disease/pathology , Longitudinal Studies , TDP-43 Proteinopathies/pathology , Aging/genetics , Cognitive Dysfunction/genetics , Cognitive Dysfunction/complications , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolismABSTRACT
Loss of TAR DNA-binding protein 43 kDa (TDP-43) splicing repression is well-documented in postmortem tissues of amyotrophic lateral sclerosis (ALS), yet whether this abnormality occurs during early-stage disease remains unresolved. Cryptic exon inclusion reflects functional loss of TDP-43, and thus detection of cryptic exon-encoded peptides in cerebrospinal fluid (CSF) could reveal the earliest stages of TDP-43 dysregulation in patients. Here, we use a newly characterized monoclonal antibody specific to a TDP-43-dependent cryptic epitope (encoded by the cryptic exon found in HDGFL2) to show that loss of TDP-43 splicing repression occurs in C9ORF72-associated ALS, including pre-symptomatic mutation carriers. In contrast to neurofilament light and heavy chain proteins, cryptic HDGFL2 accumulates in CSF at higher levels during early stages of disease. Our findings indicate that loss of TDP-43 splicing repression occurs early in disease progression, even pre-symptomatically, and that detection of HDGFL2's cryptic neoepitope may serve as a prognostic test for ALS which should facilitate patient recruitment and measurement of target engagement in clinical trials.
ABSTRACT
BACKGROUND: Pronounced asymmetric changes in ocular globe size during eye development have been observed in a number of species ranging from humans to lizards. In contrast, largely symmetric changes in globe size have been described for other species like rodents. We propose that asymmetric changes in the three-dimensional structure of the developing eye correlate with the types of retinal remodeling needed to produce areas of high photoreceptor density. To test this idea, we systematically examined three-dimensional aspects of globe size as a function of eye development in the bifoveated brown anole, Anolis sagrei. RESULTS: During embryonic development, the anole eye undergoes dynamic changes in ocular shape. Initially spherical, the eye elongates in the presumptive foveal regions of the retina and then proceeds through a period of retraction that returns the eye to its spherical shape. During this period of retraction, pit formation and photoreceptor cell packing are observed. We found a similar pattern of elongation and retraction associated with the single fovea of the veiled chameleon, Chamaeleo calyptratus. CONCLUSIONS: These results, together with those reported for other foveated species, support the idea that areas of high photoreceptor packing occur in regions where the ocular globe asymmetrically elongates and retracts during development.
Subject(s)
Lizards , Animals , Embryonic Development , Lizards/physiology , RetinaABSTRACT
The emergence of methicillin-resistant Staphylococcus pseudintermedius has increased the interest in topical therapy for treating canine pyoderma. Shampooing with chlorhexidine followed by dilute bleach rinses are often recommended, but household bleach can dry the skin and is unpleasant to use. A shampoo formulated with sodium hypochlorite and salicylic acid was evaluated as sole therapy for dogs with superficial pyoderma associated with S. pseudintermedius, including methicillin-resistant strains. Client-owned dogs were recruited based on positive culture for methicillin-resistant staphylococci or prior failure of pyoderma to respond to antibiotics. This prospective, open-label pilot study assessed the efficacy of the shampoo when used three times weekly for 4 wk. Dogs were evaluated at baseline and at 2 and 4 wk by cytology, clinical examination, and owner assessment. Digital images were also obtained. Baseline bacterial counts, clinical assessments and owner scores were significantly improved at 2 and 4 wk. Clients completing the study reported excellent lathering and dispersion, reduction in odor, and brightening of white and light coats. No owners reported skin dryness or other adverse events during the study. We conclude that this shampoo containing sodium hypochlorite in a vehicle that avoids skin drying is an effective treatment for canine pyoderma.
Subject(s)
Dog Diseases/drug therapy , Methicillin Resistance , Salicylic Acid/therapeutic use , Sodium Hypochlorite/therapeutic use , Staphylococcal Skin Infections/veterinary , Staphylococcus/drug effects , Animals , Anti-Infective Agents/therapeutic use , Dogs , Dosage Forms , Female , Male , Methicillin/pharmacology , Pilot Projects , Salicylic Acid/administration & dosage , Sodium Hypochlorite/administration & dosage , Staphylococcal Skin Infections/drug therapyABSTRACT
Continuity of care is generally considered beneficial in primary healthcare, and in this paper the evidence for such assumptions is examined. Studies and reviews showed that continuity of care is able to decrease unnecessary hospitalisation, length of hospital stay and attendance at Accident and Emergency departments, as well as improve patient and doctor experience. It has also been found that the continuity of care provided to patients varies greatly depending on patient demographic, GP surgery policy and size. As the evidence suggests that continuity of care has such great health benefits for the patient, addressing the deficit in continuity that some patients receive would be an effective way to improve quality of care.
Subject(s)
Hospitalization , Primary Health Care , Quality of Health Care , Continuity of Patient Care , Emergency Service, Hospital , HumansABSTRACT
BACKGROUND: Glucocorticoids as sole therapy for pemphigus foliaceus (PF) in cats are not always successful, and it is common to need additional immunomodulating agents to manage the disease. HYPOTHESIS/OBJECTIVES: This retrospective study evaluated the use of modified ciclosporin as an adjuvant or sole immunomodulating drug in cats with PF and compared their response to PF cats managed with chlorambucil. ANIMALS: Fifteen client-owned cats diagnosed with PF that received ciclosporin and/or chlorambucil as part of their treatment and had adequate follow-up to assess treatment response were evaluated. METHODS: Records were reviewed from feline PF patients presented between the years of 1999 and 2009. Cats were divided into two treatment groups: those treated with ciclosporin and those treated with chlorambucil. Most cats in both groups also received concurrent systemic glucocorticoids. Each group contained six patients. Three cats were treated with both medications and are discussed separately. Time to disease remission, remission-inducing glucocorticoid dose, maintenance or final glucocorticoid dose, disease response and adverse effects were assessed. RESULTS: There was no significant difference in remission times or disease response between groups. All six patients maintained with ciclosporin for PF management were weaned off systemic glucocorticoids, while glucocorticoid therapy was stopped in only one of the six cats receiving chlorambucil. CONCLUSIONS AND CLINICAL IMPORTANCE: Modified ciclosporin is effective in the management of feline pemphigus foliaceus and is glucocorticoid sparing.
Subject(s)
Cat Diseases/drug therapy , Cyclosporine/therapeutic use , Immunosuppressive Agents/therapeutic use , Pemphigus/veterinary , Animals , Cats , Chlorambucil/therapeutic use , Dose-Response Relationship, Drug , Female , Glucocorticoids/administration & dosage , Glucocorticoids/therapeutic use , Male , Pemphigus/drug therapy , Retrospective StudiesABSTRACT
BACKGROUND: Studies of youth violence have usually examined social capital using qualitative methods, but remain limited by small sample sizes. In addition, few studies examine violence among Asian/Pacific Islander (API) youth, even though they are one of the fastest-growing youth populations in the USA. AIMS: To contribute to a better understanding of culture and ethnicity in youth violence among Asian Americans and Pacific Islanders by quantifying ethnic forms of social capital. METHODS: We use an n = 326 sample of three API groups from Oahu, Hawaii. Defining social capital as ethnic practice, we test Filipino, Hawaiian and Samoan forms of youth social capital on intimate and non-intimate violence. RESULTS: Bivariate findings associate lower violence with language ability among Filipinos, coming-of-age practices among Hawaiians, and community leader engagement among Samoans. Multivariate tests showed language to be the strongest correlation. Bivariate tests also suggested potentially risky forms of social capital. CONCLUSIONS: results lead us to hypothesize that social capital that deliberately places individuals within their respective ethnic communities are risk-reducing, as are those that promote formal ethnic community structures. Those that formalize ethnic practice and social capital into commercial activities may be associated with higher risk of violence. Given the relatively small sample size and the exploratory approach for the present investigation, further research is needed to determine whether the findings can be replicated and to extend the findings of the present preliminary study.