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1.
PLoS Genet ; 18(11): e1010506, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36441670

RESUMO

Short telomeres induce a DNA damage response (DDR) that evokes apoptosis and senescence in human cells. An extant question is the contribution of telomere dysfunction-induced DDR to the phenotypes observed in aging and telomere biology disorders. One candidate is RAP1, a telomere-associated protein that also controls transcription at extratelomeric regions. To distinguish these roles, we generated a knockin mouse carrying a mutated Rap1, which was incapable of binding telomeres and did not result in eroded telomeres or a DDR. Primary Rap1 knockin embryonic fibroblasts showed decreased RAP1 expression and re-localization away from telomeres, with an increased cytosolic distribution akin to that observed in human fibroblasts undergoing telomere erosion. Rap1 knockin mice were viable, but exhibited transcriptomic alterations, proinflammatory cytokine/chemokine signaling, reduced lifespan, and decreased healthspan with increased body weight/fasting blood glucose levels, spontaneous tumor incidence, and behavioral deficits. Taken together, our data present mechanisms distinct from telomere-induced DDR that underlie age-related phenotypes.


Assuntos
Complexo Shelterina , Telômero , Animais , Humanos , Camundongos , Longevidade , Fenótipo , Telômero/genética , Encurtamento do Telômero
2.
EMBO J ; 39(21): e103420, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-32935380

RESUMO

Short telomeres are a principal defining feature of telomere biology disorders, such as dyskeratosis congenita (DC), for which there are no effective treatments. Here, we report that primary fibroblasts from DC patients and late generation telomerase knockout mice display lower nicotinamide adenine dinucleotide (NAD) levels, and an imbalance in the NAD metabolome that includes elevated CD38 NADase and reduced poly(ADP-ribose) polymerase and SIRT1 activities, respectively, affecting many associated biological pathways. Supplementation with the NAD precursor, nicotinamide riboside, and CD38 inhibition improved NAD homeostasis, thereby alleviating telomere damage, defective mitochondrial biosynthesis and clearance, cell growth retardation, and cellular senescence of DC fibroblasts. These findings reveal a direct, underlying role of NAD dysregulation when telomeres are short and underscore its relevance to the pathophysiology and interventions of human telomere-driven diseases.


Assuntos
Disceratose Congênita/genética , Disceratose Congênita/metabolismo , Fibroblastos/metabolismo , NAD/metabolismo , Telomerase/genética , Telômero/metabolismo , ADP-Ribosil Ciclase 1/genética , Animais , Encéfalo/patologia , Linhagem Celular , Senescência Celular , Disceratose Congênita/patologia , Feminino , Homeostase , Humanos , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Niacinamida/análogos & derivados , Niacinamida/metabolismo , Fenótipo , Poli(ADP-Ribose) Polimerase-1/metabolismo , Compostos de Piridínio/metabolismo , Telomerase/metabolismo
3.
J Pediatr ; 209: 160-167.e4, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31047650

RESUMO

OBJECTIVE: To assess the efficacy and safety of a virtual reality distraction for needle pain in 2 common hospital settings: the emergency department (ED) and outpatient pathology (ie, outpatient laboratory). The control was standard of care (SOC) practice. STUDY DESIGN: In 2 clinical trials, we randomized children aged 4-11 years undergoing venous needle procedures to virtual reality or SOC at 2 tertiary Australian hospitals. In the first study, we enrolled children in the ED requiring intravenous cannulation or venipuncture. In the second, we enrolled children in outpatient pathology requiring venipuncture. In the ED, 64 children were assigned to virtual reality and 59 to SOC. In pathology, 63 children were assigned to virtual reality and 68 to SOC; 2 children withdrew assent in the SOC arm, leaving 66. The primary endpoint was change from baseline pain between virtual reality and SOC on child-rated Faces Pain Scale-Revised. RESULTS: In the ED, there was no change in pain from baseline with SOC, whereas virtual reality produced a significant reduction in pain (between-group difference, -1.78; 95% CI, -3.24 to -0.317; P = .018). In pathology, both groups experienced an increase in pain from baseline, but this was significantly less in the virtual reality group (between-group difference, -1.39; 95% CI, -2.68 to -0.11; P = .034). Across both studies, 10 participants experienced minor adverse events, equally distributed between virtual reality/SOC; none required pharmacotherapy. CONCLUSIONS: In children aged 4-11 years of age undergoing intravenous cannulation or venipuncture, virtual reality was efficacious in decreasing pain and was safe. TRIAL REGISTRATION: Australia and New Zealand Clinical Trial Registry: ACTRN12617000285358p.


Assuntos
Cateterismo/efeitos adversos , Agulhas/efeitos adversos , Dor Processual/etiologia , Dor Processual/prevenção & controle , Flebotomia/efeitos adversos , Realidade Virtual , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Resultado do Tratamento
4.
J Neuroinflammation ; 15(1): 240, 2018 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-30149799

RESUMO

Neutrophils are the innate immune system's first line of defense. Neutrophils play a critical role in protecting the host against infectious pathogens, resolving sterile injuries, and mediating inflammatory responses. The granules of neutrophils and their constituent proteins are central to these functions. Although neutrophils may exert a protective role upon acute inflammatory conditions or insults, continued activity of neutrophils in chronic inflammatory diseases can contribute to tissue damage. Neutrophil granule proteins are involved in a number of chronic inflammatory conditions and diseases. However, the functions of these proteins in neuroinflammation and chronic neuroinflammatory diseases, including Alzheimer's disease (AD), remain to be elucidated. In this review, we discuss recent findings from our lab and others that suggest possible functions for neutrophils and the neutrophil granule proteins, CAP37, neutrophil elastase, and cathepsin G, in neuroinflammation, with an emphasis on AD. These findings reveal that neutrophil granule proteins may exert both neuroprotective and neurotoxic effects. Further research should determine whether neutrophil granule proteins are valid targets for therapeutic interventions in chronic neuroinflammatory diseases.


Assuntos
Doença de Alzheimer/patologia , Proteínas Granulares de Eosinófilos/metabolismo , Inflamação Neurogênica/patologia , Neutrófilos/metabolismo , Doença de Alzheimer/imunologia , Animais , Humanos , Inflamação Neurogênica/imunologia
5.
J Paediatr Child Health ; 58(6): 1104-1105, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34636110
6.
bioRxiv ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38328221

RESUMO

Type 1 diabetes (T1D) is an autoimmune disease in which pancreatic islet ß-cells are attacked by the immune system, resulting in insulin deficiency and hyperglycemia. One of the top non-synonymous single-nucleotide polymorphisms (SNP) associated with T1D is in the interferon-induced helicase C domain-containing protein 1 ( IFIH1 ), which encodes an anti-viral cytosolic RNA sensor. This SNP results in an alanine to threonine substitution at amino acid 946 (IFIH1 A946T ) and confers an increased risk for several autoimmune diseases, including T1D. We hypothesized that the IFIH1 A946T risk variant, ( IFIH1 R ) would promote T1D pathogenesis by stimulating type I interferon (IFN I) signaling leading to immune cell alterations. To test this, we developed Ifih1 R knock-in mice on the non-obese diabetic (NOD) mouse background, a spontaneous T1D model. Our results revealed a modest increase in diabetes incidence and insulitis in Ifih1 R compared to non-risk Ifih1 ( Ifih1 NR ) mice and a significant acceleration of diabetes onset in Ifih1 R females. Ifih1 R mice exhibited a significantly enhanced interferon stimulated gene (ISG) signature compared to Ifih1 NR , indicative of increased IFN I signaling. Ifih1 R mice exhibited an increased frequency of plasma cells as well as tissue-dependent changes in the frequency and activation of CD8 + T cells. Our results indicate that IFIH1 R may contribute to T1D pathogenesis by altering the frequency and activation of immune cells. These findings advance our knowledge on the connection between the rs1990760 variant and T1D. Further, these data are the first to demonstrate effects of Ifih1 R in NOD mice, which will be important to consider for the development of therapeutics for T1D.

7.
Front Immunol ; 15: 1349601, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487540

RESUMO

Type 1 diabetes (T1D) is an autoimmune disease in which pancreatic islet ß-cells are attacked by the immune system, resulting in insulin deficiency and hyperglycemia. One of the top non-synonymous single-nucleotide polymorphisms (SNP) associated with T1D is in the interferon-induced helicase C domain-containing protein 1 (IFIH1), which encodes an anti-viral cytosolic RNA sensor. This SNP results in an alanine to threonine substitution at amino acid 946 (IFIH1A946T) and confers an increased risk for several autoimmune diseases, including T1D. We hypothesized that the IFIH1A946T risk variant, (IFIH1R) would promote T1D pathogenesis by stimulating type I interferon (IFN I) signaling leading to immune cell alterations. To test this, we developed Ifih1R knock-in mice on the non-obese diabetic (NOD) mouse background, a spontaneous T1D model. Our results revealed a modest increase in diabetes incidence and insulitis in Ifih1R compared to non-risk Ifih1 (Ifih1NR) mice and a significant acceleration of diabetes onset in Ifih1R females. Ifih1R mice exhibited a significantly enhanced interferon stimulated gene (ISG) signature compared to Ifih1NR, indicative of increased IFN I signaling. Ifih1R mice exhibited an increased frequency of plasma cells as well as tissue-dependent changes in the frequency and activation of CD8+ T cells. Our results indicate that IFIH1R may contribute to T1D pathogenesis by altering the frequency and activation of immune cells. These findings advance our knowledge on the connection between the rs1990760 variant and T1D. Further, these data are the first to demonstrate effects of Ifih1R in NOD mice, which will be important to consider for the development of therapeutics for T1D.


Assuntos
Doenças Autoimunes , Diabetes Mellitus Tipo 1 , Feminino , Animais , Camundongos , Helicase IFIH1 Induzida por Interferon/genética , RNA Helicases DEAD-box/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Predisposição Genética para Doença , Camundongos Endogâmicos NOD , Doenças Autoimunes/genética , Interferons/genética
8.
Pediatrics ; 152(1)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37259203

RESUMO

CONTEXT: Distraction therapies are widely used in emergency departments to manage pediatric pain and distress. Little is known about which distraction techniques would translate best into the prehospital environment. OBJECTIVE: To identify emergency department-based distraction techniques for managing pain and/or distress in pediatric patients who may be suitable for the prehospital environment. DATA SOURCES: Ovid Medline, Embase, CINAHL, Cochrane library, World Health Organization Clinical Trials Registry and Google Scholar were searched from their beginning to May 2022. STUDY SELECTION: Studies were included if they reported on: (1) distraction techniques, (2) pediatric ED patients, (3) with pain and/or distress, and (4) used interventional or observational study designs. Studies utilizing interventions not feasible in the prehospital setting were excluded. DATA EXTRACTION: Three authors independently assessed eligibility and completed data extraction. RESULTS: The search yielded 4516 records, and 29 studies were included. Risk of bias across all studies was moderate to high. Children were 3 months to 18 years old. Digital, nondigital, and environmental distractors were tested using 12 pain and 15 distress measurement tools. No significant negative outcomes were reported. Fifteen studies reported reductions in self-reported pain and/or distress. Active, nondigital distractors most consistently reduced pain. There was insufficient evidence to support a distraction type for distress. LIMITATIONS: The heterogeneity in study design, distractors, measurement tools, and reporting restricted statistical analysis. CONCLUSIONS: Distraction tools that effectively reduce pediatric pain and/or distress in the ED exist and could be adapted to the prehospital environment. Further research is required to determine feasibility and effectiveness.


Assuntos
Serviços Médicos de Emergência , Dor , Criança , Humanos , Manejo da Dor/métodos , Viés , Autorrelato , Estudos Observacionais como Assunto
9.
Geroscience ; 45(4): 2213-2228, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36826621

RESUMO

Short telomeres are a defining feature of telomere biology disorders (TBDs), including dyskeratosis congenita (DC), for which there is no effective general cure. Patients with TBDs often experience bone marrow failure. NAD, an essential metabolic coenzyme, is decreased in models of DC. Herein, using telomerase reverse transcriptase null (Tert-/-) mice with critically short telomeres, we investigated the effect of NAD supplementation with the NAD precursor, nicotinamide riboside (NR), on features of health span disrupted by telomere impairment. Our results revealed that NR ameliorated body weight loss in Tert-/- mice and improved telomere integrity and telomere dysfunction-induced systemic inflammation. NR supplementation also mitigated myeloid skewing of Tert-/- hematopoietic stem cells. Furthermore, NR alleviated villous atrophy and inflammation in the small intestine of Tert-/- transplant recipient mice. Altogether, our findings support NAD intervention as a potential therapeutic strategy to enhance aspects of health span compromised by telomere attrition.


Assuntos
Disceratose Congênita , Transplante de Células-Tronco Hematopoéticas , Humanos , Animais , Camundongos , NAD , Telômero/metabolismo , Disceratose Congênita/genética , Disceratose Congênita/metabolismo , Inflamação
10.
BMC Pediatr ; 12: 135, 2012 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-22928654

RESUMO

BACKGROUND: Infant colic, characterised by excessive crying/fussing for no apparent cause, affects up to 20% of infants under three months of age and is a great burden to families, health professionals and the health system. One promising approach to improving its management is the use of oral probiotics. The Baby Biotics trial aims to determine whether the probiotic Lactobacillus reuteri DSM 17938 is effective in reducing crying in infants less than three months old (<13.0 weeks) with infant colic when compared to placebo. DESIGN: Double-blind, placebo-controlled randomised trial in Melbourne, Australia. PARTICIPANTS: 160 breast and formula fed infants less than three months old who present either to clinical or community services and meet Wessel's criteria of crying and/or fussing. INTERVENTION: Oral once-daily Lactobacillus reuteri (1x108 cfu) versus placebo for one month. PRIMARY OUTCOME: Infant crying/fussing time per 24 hours at one month. SECONDARY OUTCOMES: i) number of episodes of infant crying/fussing per 24 hours and ii) infant sleep duration per 24 hours (at 7, 14, 21, 28 days and 6 months); iii) maternal mental health scores, iv) family functioning scores, v) parent quality adjusted life years scores, and vi) intervention cost-effectiveness (at one and six months); and vii) infant faecal microbiota diversity, viii) infant faecal calprotectin levels and ix) Eschericia coli load (at one month only). ANALYSIS: Primary and secondary outcomes for the intervention versus control groups will be compared with t tests and non-parametric tests for continuous data and chi squared tests for dichotomous data. Regression models will be used to adjust for potential confounding factors. Intention-to-treat analysis will be applied. DISCUSSION: An effective, practical and acceptable intervention for infant colic would represent a major clinical advance. Because our trial includes breast and formula-fed babies, our results should generalise to most babies with colic. If cost-effective, the intervention's simplicity is such that it could be widely taken up as a new standard of care in the primary and secondary care sectors. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95287767.


Assuntos
Cólica/dietoterapia , Probióticos/uso terapêutico , Método Duplo-Cego , Humanos , Lactente , Resultado do Tratamento
11.
Front Aging ; 2: 785171, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35822010

RESUMO

Telomeres are specialized nucleoprotein structures that form protective caps at the ends of chromosomes. Short telomeres are a hallmark of aging and a principal defining feature of short telomere syndromes, including dyskeratosis congenita (DC). Emerging evidence suggests a crucial role for critically short telomere-induced DNA damage signaling and mitochondrial dysfunction in cellular dysfunction in DC. A prominent factor linking nuclear DNA damage and mitochondrial homeostasis is the nicotinamide adenine dinucleotide (NAD) metabolite. Recent studies have demonstrated that patients with DC and murine models with critically short telomeres exhibit lower NAD levels, and an imbalance in the NAD metabolome, including elevated CD38 NADase and reduced poly (ADP-ribose) polymerase and SIRT1 activities. CD38 inhibition and/or supplementation with NAD precursors reequilibrate imbalanced NAD metabolism and alleviate mitochondrial impairment, telomere DNA damage, telomere dysfunction-induced DNA damage signaling, and cellular growth retardation in primary fibroblasts derived from DC patients. Boosting NAD levels also ameliorate chemical-induced liver fibrosis in murine models of telomere dysfunction. These findings underscore the relevance of NAD dysregulation to telomeropathies and demonstrate how NAD interventions may prove to be effective in combating cellular and organismal defects that occur in short telomere syndromes.

12.
Curr Opin Genet Dev ; 60: 48-55, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32155570

RESUMO

The discovery that rare POT1 variants are associated with extremely long telomeres and increased cancer predisposition has provided a framework to revisit the relationship between telomere length and cancer development. Telomere shortening is linked with increased risk for cancer. However, over the past decade, there is increasing evidence to show that extremely long telomeres caused by mutations in shelterin components (POT1, TPP1, and RAP1) also display an increased risk of cancer. Here, we will review current knowledge on germline mutations of POT1 identified from cancer-prone families. In particular, we will discuss some common features presented by the mutations through structure-function studies. We will further provide an overview of how POT1 mutations affect telomere length regulation and tumorigenesis.


Assuntos
Transformação Celular Neoplásica/patologia , Mutação em Linhagem Germinativa , Neoplasias/genética , Neoplasias/patologia , Homeostase do Telômero , Proteínas de Ligação a Telômeros/genética , Telômero , Transformação Celular Neoplásica/genética , Humanos , Complexo Shelterina
13.
Invest Ophthalmol Vis Sci ; 61(4): 16, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32298435

RESUMO

Purpose: Corneal abrasion is a common eye injury, and its resolution can be seriously complicated by bacterial infection. We showed that topical application of the cationic antimicrobial protein of 37 kDa (CAP37) promotes corneal re-epithelialization in mice, and peptides derived from CAP37 can recapitulate the antibacterial and wound-healing effects of the full-length protein. The current study was designed to identify the molecular mechanisms mediating the wound-healing effect of CAP37 and derived bioactive peptides. Methods: We used a TriCEPS-based, ligand-receptor glycocapture method to identify the binding partners of CAP37 on live human corneal epithelial cells using the hTCEpi cell line. We used an ELISA method to confirm binding with identified partners and test the binding with CAP37-derived peptides. We used a reporter cell line to measure activation of the identified membrane receptor by CAP37 and derived peptides. Results: We pulled down S100 calcium-binding protein A9 (S100A9) as a binding partner of CAP37 and found that CAP37 and four derived peptides encompassing two regions of CAP37 bind S100A9 with high affinities. We found that CAP37 and the S100A9-binding peptides could also directly interact with the Toll-like receptor 4 (TLR4), a known receptor for S100A9. CAP37 and one peptide partially activated TLR4. The other three peptides did not activate TLR4. Finally, we found that CAP37 and all four peptides could inhibit the activation of TLR4 by S100A9. Conclusions: This study identifies a mechanism of action for CAP37 and derived antimicrobial peptides that may restrain inflammatory responses to corneal injury and favor corneal re-epithelialization.


Assuntos
Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Proteínas Sanguíneas/uso terapêutico , Calgranulina B/farmacologia , Lesões da Córnea/tratamento farmacológico , Epitélio Corneano/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , Cicatrização/efeitos dos fármacos , Administração Oftálmica , Animais , Calgranulina B/metabolismo , Linhagem Celular , Cromatografia Líquida , Lesões da Córnea/metabolismo , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Epitélio Corneano/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Soluções Oftálmicas , Espectrometria de Massas em Tandem
14.
Pediatr Emerg Care ; 24(12): 805-9, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19050661

RESUMO

OBJECTIVE: The aim of this study was to determine whether pH testing is an accurate method of confirming nasogastric tube (NGT) position in children with and without gastroenteritis in the emergency department. METHODOLOGY: A prospective observational study of NGT insertions was conducted at a tertiary pediatric emergency department, during a 9-month period in 2006. We evaluated methods of NGT position confirmation, pH of nasogastric aspirates from patients with and without gastroenteritis, and adverse events. RESULTS: A total of 404 patients were enrolled. For 393 patients (97.3%), NGT aspirates could be obtained to assess pH. Of these patients, 294 (74.8%) had a diagnosis of gastroenteritis and 99 (25.2%) did not. There was no difference in median pH between the patients with gastroenteritis (pH, 2; interquartile range, 2-4) and those without gastroenteritis (pH, 2; interquartile range, 2-4; P = 0.09). Overall, 341 patients (86.8%) had a pH of 4 or lower. The patients with gastroenteritis were more likely to have a pH of 4 or lower than the patients without gastroenteritis (P = 0.018). Tube position was confirmed by pH alone in 332 patients (84.5%). Nine (2.6%) of the 341 patients with a pH of 4 or lower also had radiography (7 for causes other than confirmation of NGT position) indicating correct placement of all NGTs. Fifty-two patients (13.2%) had a pH higher than 4, and 18 (34%) of these had the tube position confirmed by radiography, of which 3 had tubes misplaced in the distal esophagus. Irrespective of pH level, there were no respiratory placements clinically or by radiography. Overall, 22 patients (5.6% 95% CI 3.5%-8.3%) required more than 1 attempt for NGT insertion. There were 13 minor adverse events (3.3% 95% CI 1.8%-5.6%) and no major adverse events. CONCLUSIONS: Testing of gastric pH is a reliable way of confirming NGT position when the pH is 4 or lower. When the pH is higher than 4, a radiograph may be necessary.


Assuntos
Desidratação/terapia , Serviço Hospitalar de Emergência , Hidratação/instrumentação , Determinação da Acidez Gástrica , Gastroenterite/complicações , Concentração de Íons de Hidrogênio , Intubação Gastrointestinal , Adolescente , Criança , Pré-Escolar , Desidratação/etiologia , Remoção de Dispositivo , Emergências , Serviço Hospitalar de Emergência/estatística & dados numéricos , Falha de Equipamento , Esôfago , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Hospitais Urbanos/estatística & dados numéricos , Humanos , Lactente , Intubação Gastrointestinal/métodos , Intubação Gastrointestinal/enfermagem , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes
15.
Emerg Med Australas ; 28(5): 600-2, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27215918

RESUMO

Diagnosis of low incidence neurological conditions can be a challenge in paediatric emergency medicine. Neurological examination in young children can be very difficult, and medical staff may not previously have encountered conditions like acute demyelinating encephalomyelitis. We propose that the simple process of walking a child (provided they were previously ambulant) is the crucial step in the neurological examination. We present three cases to demonstrate this important part of the examination.


Assuntos
Medicina de Emergência , Doenças do Sistema Nervoso/diagnóstico , Exame Neurológico , Caminhada , Diagnóstico Tardio , Humanos , Lactente , Triagem
16.
PLoS One ; 11(9): e0163330, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27676391

RESUMO

We previously showed an elevated expression of the neutrophil protein, cationic antimicrobial protein of 37kDa (CAP37), in brains of patients with Alzheimer's disease (AD), suggesting that CAP37 could be involved in AD pathogenesis. The first step in determining how CAP37 might contribute to AD pathogenesis was to identify the receptor through which it induces cell responses. To identify a putative receptor, we performed GAMMA analysis to determine genes that positively correlated with CAP37 in terms of expression. Positive correlations with ligands for the receptor for advanced glycation end products (RAGE) were observed. Additionally, CAP37 expression positively correlated with two other neutrophil proteins, neutrophil elastase and cathepsin G. Enzyme-linked immunosorbent assays (ELISAs) demonstrated an interaction between CAP37, neutrophil elastase, and cathepsin G with RAGE. Amyloid beta 1-42 (Aß1-42), a known RAGE ligand, accumulates in AD brains and interacts with RAGE, contributing to Aß1-42 neurotoxicity. We questioned whether the binding of CAP37, neutrophil elastase and/or cathepsin G to RAGE could interfere with Aß1-42 binding to RAGE. Using ELISAs, we determined that CAP37 and neutrophil elastase inhibited binding of Aß1-42 to RAGE, and this effect was reversed by protease inhibitors in the case of neutrophil elastase. Since neutrophil elastase and cathepsin G have enzymatic activity, mass spectrometry was performed to determine the proteolytic activity of all three neutrophil proteins on Aß1-42. All three neutrophil proteins bound to Aß1-42 with different affinities and cleaved Aß1-42 with different kinetics and substrate specificities. We posit that these neutrophil proteins could modulate neurotoxicity in AD by cleaving Aß1-42 and influencing the Aß1-42 -RAGE interaction. Further studies will be required to determine the biological significance of these effects and their relevance in neurodegenerative diseases such as AD. Our findings identify a novel area of study that underscores the importance of neutrophils and neutrophil proteins in neuroinflammatory diseases such as AD.

17.
PeerJ ; 3: e898, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25909038

RESUMO

Flowering is one of the most influential events in the life history of a plant and one of the main determinants of reproductive investment and lifetime fitness. It is also a highly complex trait controlled by dozens of genes. Understanding the selective pressures influencing time to flowering, and being able to reliably predict how it will evolve in novel environments, are unsolved challenges for plant evolutionary geneticists. Using the model plant species, Arabidopsis thaliana, we examined the impact of simulated high and low winter precipitation levels on the flowering time of naturalized lines from across the eastern portion of the introduced North American range, and the fitness consequences of early versus late flowering. Flowering time order was significantly correlated across two environments-in a previous common garden experiment and in environmental chambers set to mimic mid-range photoperiod and temperature conditions. Plants in low water flowered earlier, had fewer basal branches and produced fewer fruits. Selection in both treatments favored earlier flowering and more basal branches. Our analyses revealed an interaction between flowering time and water treatment for fitness, where flowering later was more deleterious for fitness in the low water treatment. Our results are consistent with the hypothesis that differences in winter precipitation levels are one of the selective agents underlying a flowering time cline in introduced A. thaliana populations.

18.
Philos Trans R Soc Lond B Biol Sci ; 369(1649): 20130259, 2014 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-25002704

RESUMO

Clinal variation is commonly interpreted as evidence of adaptive differentiation, although clines can also be produced by stochastic forces. Understanding whether clines are adaptive therefore requires comparing clinal variation to background patterns of genetic differentiation at presumably neutral markers. Although this approach has frequently been applied to single traits at a time, we have comparatively fewer examples of how multiple correlated traits vary clinally. Here, we characterize multivariate clines in the Ivyleaf morning glory, examining how suites of traits vary with latitude, with the goal of testing for divergence in trait means that would indicate past evolutionary responses. We couple this with analysis of genetic variance in clinally varying traits in 20 populations to test whether past evolutionary responses have depleted genetic variance, or whether genetic variance declines approaching the range margin. We find evidence of clinal differentiation in five quantitative traits, with little evidence of isolation by distance at neutral loci that would suggest non-adaptive or stochastic mechanisms. Within and across populations, the traits that contribute most to population differentiation and clinal trends in the multivariate phenotype are genetically variable as well, suggesting that a lack of genetic variance will not cause absolute evolutionary constraints. Our data are broadly consistent theoretical predictions of polygenic clines in response to shallow environmental gradients. Ecologically, our results are consistent with past findings of natural selection on flowering phenology, presumably due to season-length variation across the range.


Assuntos
Adaptação Biológica/genética , Variação Genética/genética , Ipomoea/genética , Fenótipo , Característica Quantitativa Herdável , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Genética Populacional , Geografia , Folhas de Planta/anatomia & histologia , Especificidade da Espécie , Estados Unidos
19.
BMJ ; 348: g2107, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24690625

RESUMO

OBJECTIVE: To determine whether the probiotic Lactobacillus reuteri DSM 17938 reduces crying or fussing in a broad community based sample of breastfed infants and formula fed infants with colic aged less than 3 months. DESIGN: Double blind, placebo controlled randomised trial. SETTING: Community based sample (primary and secondary level care centres) in Melbourne, Australia. PARTICIPANTS: 167 breastfed infants or formula fed infants aged less than 3 months meeting Wessel's criteria for crying or fussing: 85 were randomised to receive probiotic and 82 to receive placebo. INTERVENTIONS: Oral daily L reuteri (1 × 10(8) colony forming units) versus placebo for one month. MAIN OUTCOMES MEASURES: The primary outcome was daily duration of cry or fuss at 1 month. Secondary outcomes were duration of cry or fuss; number of cry or fuss episodes; sleep duration of infant at 7, 14, and 21 days, and 1 and 6 months; maternal mental health (Edinburgh postnatal depression subscale); family functioning (paediatric quality of life inventory), parent quality adjusted life years (assessment of quality of life) at 1 and 6 months; infant functioning (paediatric quality of life inventory) at 6 months; infant faecal microbiota (microbial diversity, colonisation with Escherichia coli), and calprotectin levels at 1 month. In intention to treat analyses the two groups were compared using regression models adjusted for potential confounders. RESULTS: Of 167 infants randomised from August 2011 to August 2012, 127 (76%) were retained to primary outcome; of these, a subset was analysed for faecal microbial diversity, E coli colonisation, and calprotectin levels. Adherence was high. Mean daily cry or fuss time fell steadily in both groups. At 1 month, the probiotic group cried or fussed 49 minutes more than the placebo group (95% confidence interval 8 to 90 minutes, P=0.02); this mainly reflected more fussing, especially for formula fed infants. The groups were similar on all secondary outcomes. No study related adverse events occurred. CONCLUSIONS: L reuteri DSM 17938 did not benefit a community sample of breastfed infants and formula fed infants with colic. These findings differ from previous smaller trials of selected populations and do not support a general recommendation for the use of probiotics to treat colic in infants. TRIAL REGISTRATION: Current Controlled Trials ISRCTN95287767.


Assuntos
Cólica/terapia , Limosilactobacillus reuteri/metabolismo , Probióticos/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Lactente , Comportamento do Lactente , Masculino , Probióticos/efeitos adversos , Resultado do Tratamento
20.
Arch Dis Child ; 98(1): 36-40, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23148311

RESUMO

OBJECTIVE: To determine the prevalence of postnatal depression (PND) in mothers of young infants presenting to the emergency department (ED). DESIGN, SETTING AND PARTICIPANTS: Prospective observational study of the prevalence of PND in mothers of infants aged 14 days to 6 months presenting with non-time-critical conditions to the ED of a large tertiary paediatric hospital. MAIN OUTCOME MEASURES: We assessed PND by applying a self-administered validated screening tool, the Edinburgh Postnatal Depression Scale (EPDS). Mothers of patients were approached before clinician consultation when a social worker was available on site. EPDS scores of 13 and above were considered 'positive'. Univariate analysis was used to determine associations with demographic, maternal and child factors. RESULTS: 236 mothers were approached; 200 consented to participate in the study. Thirty-two mothers screened positively, with a prevalence rate of 16% (95% CI 11.2% to 21.8%). A positive screen was most strongly associated with history of depression (relative risk (RR) 4.8, 95% CI 2.3 to 10.1). Other associations were with single-parent status (RR 2.5, 95% CI 1.1 to 5.4), Indigenous status (4.4, 95% CI 1.8 to 10.4) and 'crying baby' as the presenting problem (RR 2.9, 95% CI 1.4 to 6.2). Fifty-three per cent of mothers had not completed a PND screen before coming to the ED. CONCLUSIONS: Mothers of young infants coming to the ED regardless of infant's presenting complaint have a high prevalence of PND determined using the EPDS. Many mothers were not screened for PND before coming to the ED. Clinical staff need to be aware of the condition, incorporate appropriate questioning into the consultation, and refer mothers to support services if necessary.


Assuntos
Depressão Pós-Parto/epidemiologia , Mães/psicologia , Adolescente , Adulto , Serviço Hospitalar de Emergência , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prevalência , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários , Adulto Jovem
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