Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Mol Ecol ; 32(17): 4829-4843, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37448145

RESUMO

The impact of post-divergence gene flow in speciation has been documented across a range of taxa in recent years, and may have been especially widespread in highly mobile, wide-ranging marine species, such as cetaceans. Here, we studied individual genomes from nine species across the three families of the toothed whale superfamily Delphinoidea (Delphinidae, Phocoenidae and Monodontidae). To investigate the role of post-divergence gene flow in the speciation process, we used a multifaceted approach, including (i) phylogenomics, (ii) the distribution of shared derived alleles and (iii) demographic inference. We found the divergence of lineages within Delphinoidea did not follow a process of pure bifurcation, but was much more complex. Sliding-window phylogenomics reveal a high prevalence of discordant topologies within the superfamily, with further analyses indicating these discordances arose due to both incomplete lineage sorting and gene flow. D-statistics and f-branch analyses supported gene flow between members of Delphinoidea, with the vast majority of gene flow occurring as ancient interfamilial events. Demographic analyses provided evidence that introgressive gene flow has likely ceased between all species pairs tested, despite reports of contemporary interspecific hybrids. Our study provides the first steps towards resolving the large complexity of speciation within Delphinoidea; we reveal the prevalence of ancient interfamilial gene flow events prior to the diversification of each family, and suggest that contemporary hybridisation events may be disadvantageous, as hybrid individuals do not appear to contribute to the parental species' gene pools.


Assuntos
Genoma , Genômica , Animais , Genoma/genética , Filogenia , Fluxo Gênico , Hibridização Genética , Baleias/genética , Especiação Genética
2.
J Pathol ; 257(3): 314-326, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35239183

RESUMO

Age-related macular degeneration (AMD) is the leading cause of blindness in the aging population. Yet no therapies exist for ~85% of all AMD patients who have the dry form that is marked by degeneration of the retinal pigmented epithelium (RPE) and underlying choroidal vasculature. As the choroidal vessels are crucial for RPE development and maintenance, understanding how they degenerate may lead to effective therapies for dry AMD. One likely causative factor for choroidal vascular loss is the cytolytic membrane attack complex (MAC) of the complement pathway that is abundant on choroidal vessels of humans with early dry AMD. To examine this possibility, we studied the effect of complement activation on choroidal endothelial cells (ECs) isolated from a rhesus monkey model of early AMD that, we report, exhibits MAC deposition and choriocapillaris endothelial loss similar to that seen in human early AMD. Treatment of choroidal ECs from AMD eyes with complement-competent normal human serum caused extensive actin cytoskeletal injury that was significantly less pronounced in choroidal ECs from young normal monkey eyes. We further show that ECs from AMD eyes are significantly stiffer than their younger counterparts and exhibit peripheral actin organization that is distinct from the longitudinal stress fibers in young ECs. Finally, these differences in complement susceptibility and mechanostructural properties were found to be regulated by the differential activity of the small GTPases Rac and Rho, because Rac inhibition in AMD cells led to simultaneous reduction in stiffness and complement susceptibility, while Rho inhibition in young cells exacerbated complement injury. Thus, by identifying cell stiffness and cytoskeletal regulators Rac and Rho as important determinants of complement susceptibility, the current findings offer a new mechanistic insight into choroidal vascular loss in early AMD that warrants further investigation for assessment of translational potential. © 2022 The Pathological Society of Great Britain and Ireland.


Assuntos
Células Endoteliais , Degeneração Macular , Actinas/metabolismo , Idoso , Corioide/metabolismo , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Células Endoteliais/metabolismo , Humanos , Degeneração Macular/patologia
3.
Molecules ; 29(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38202786

RESUMO

Increasing rates of bacterial resistance to antibiotics are a growing concern worldwide. The search for potential new antibiotics has included several natural products such as anthraquinones. However, comparatively less attention has been given to anthraquinones that exhibit functional groups that are uncommon in nature. In this work, 114 anthraquinones were evaluated using in silico methods to identify inhibitors of the enzyme phosphopantetheine adenylyltransferase (PPAT) of Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. Virtual screenings based on molecular docking and the pharmacophore model, molecular dynamics simulations, and free energy calculations pointed to 1,8-dihydroxy-4,5-dinitroanthraquinone (DHDNA) as the most promising inhibitor. In addition, these analyses highlighted the contribution of the nitro group to the affinity of this anthraquinone for the nucleotide-binding site of PPAT. Furthermore, DHDNA was active in vitro towards Gram-positive bacteria with minimum inhibitory concentration (MIC) values of 31.25 µg/mL for S. aureus and 62.5 µg/mL for E. faecalis against both antibiotic-resistant isolates and reference strains but was ineffective against E. coli. Experiments on kill-time kinetics indicated that, at the tested concentrations, DHDNA produced bacteriostatic effects on both Gram-positive bacteria. Overall, our results present DHDNA as a potential PPAT inhibitor, showing antibacterial activity against antibiotic-resistant isolates of S. aureus and E. faecalis, findings that point to nitro groups as key to explaining these results.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Enterococcus faecalis , Escherichia coli , Simulação de Acoplamento Molecular , Antraquinonas/farmacologia , Antibacterianos/farmacologia
4.
Glob Chang Biol ; 28(8): 2657-2677, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35106859

RESUMO

Global warming is affecting the population dynamics and trophic interactions across a wide range of ecosystems and habitats. Translating these real-time effects into their long-term consequences remains a challenge. The rapid and extreme warming period that occurred after the Last Glacial Maximum (LGM) during the Pleistocene-Holocene transition (7-12 thousand years ago) provides an opportunity to gain insights into the long-term responses of natural populations to periods with global warming. The effects of this post-LGM warming period have been assessed in many terrestrial taxa, whereas insights into the impacts of rapid global warming on marine taxa remain limited, especially for megafauna. In order to understand how large-scale climate fluctuations during the post-LGM affected baleen whales and their prey, we conducted an extensive, large-scale analysis of the long-term effects of the post-LGM warming on abundance and inter-ocean connectivity in eight baleen whale and seven prey (fish and invertebrates) species across the Southern and the North Atlantic Ocean; two ocean basins that differ in key oceanographic features. The analysis was based upon 7032 mitochondrial DNA sequences as well as genome-wide DNA sequence variation in 100 individuals. The estimated temporal changes in genetic diversity during the last 30,000 years indicated that most baleen whale populations underwent post-LGM expansions in both ocean basins. The increase in baleen whale abundance during the Holocene was associated with simultaneous changes in their prey and climate. Highly correlated, synchronized and exponential increases in abundance in both baleen whales and their prey in the Southern Ocean were indicative of a dramatic increase in ocean productivity. In contrast, the demographic fluctuations observed in baleen whales and their prey in the North Atlantic Ocean were subtle, varying across taxa and time. Perhaps most important was the observation that the ocean-wide expansions and decreases in abundance that were initiated by the post-LGM global warming, continued for millennia after global temperatures stabilized, reflecting persistent, long-lasting impacts of global warming on marine fauna.


Assuntos
Ecossistema , Aquecimento Global , Animais , Oceano Atlântico , Dinâmica Populacional , Baleias/fisiologia
5.
Exp Eye Res ; 195: 108043, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376470

RESUMO

Selective pericyte loss, the histological hallmark of early diabetic retinopathy (DR), enhances the breakdown of the blood-retinal barrier (BRB) in diabetes. However, the role of pericytes on BRB alteration in diabetes and the signaling pathways involved in their effects are currently unknown. To understand the role of diabetes-induced molecular alteration of pericytes, we performed transcriptomic analysis of sorted retinal pericytes from mice model of diabetes. Retinal tissue from non-diabetic and diabetic (duration 3 months) mouse eyes (n = 10 in each group) were used to isolate pericytes through fluorescent activated cell sorting (FACS) using pericyte specific fluorescent antibodies, PDGFRb-APC. For RNA sequencing and qPCR analysis, a cDNA library was generated using template switching oligo and the resulting libraries were sequenced using paired-end Illumina sequencing. Molecular functional pathways were analyzed using differentially expressed genes (DEGs). Differential expression analysis revealed 217 genes significantly upregulated and 495 genes downregulated, in pericytes isolated from diabetic animals. These analyses revealed a core set of differentially expressed genes that could potentially contribute to the pericyte dysfunction in diabetes and highlighted the pattern of functional connectivity between key candidate genes and blood retinal barrier alteration mechanisms. The top up-regulated gene list included: Ext2, B3gat3, Gpc6, Pip5k1c and Pten and down-regulated genes included: Notch3, Xbp1, Gpc4, Atp1a2 and AKT3. Out of these genes, we further validated one of the down regulated genes, Notch 3 and its role in BRB alteration in diabetic retinopathy. We confirmed the downregulation of Notch3 expression in human retinal pericytes exposed to Advanced Glycation End-products (AGEs) treatment mimicking the chronic hyperglycemia effect. Exploration of pericyte-conditioned media demonstrated that loss of NOTCH3 in pericyte led to increased permeability of endothelial cell monolayers. Collectively, we identify a role for NOTCH3 in pericyte dysfunction in diabetes. Further validation of other DEGs to identify cell specific molecular change through whole transcriptomic approach in diabetic retina will provide novel insight into the pathogenesis of DR and novel therapeutic targets.


Assuntos
Barreira Hematorretiniana/metabolismo , Diabetes Mellitus Experimental , Retinopatia Diabética/genética , Células Endoteliais/metabolismo , Retina/metabolismo , Transcriptoma/genética , Animais , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Células Endoteliais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Retina/patologia , Transdução de Sinais
6.
Ecotoxicol Environ Saf ; 191: 110163, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31951900

RESUMO

The purpose of the present work was to study the effect of the nitrogen source (NO3- vs NH4+) on cadmium (Cd) uptake, translocation and partition and its associated toxicity in hydroponically-grown Arabidopsis plants. After a short growth period on a complete Hoagland nutrient solution, Arabidopsis seedlings continued in the same growth medium (NA) or were switched to NO3- (N) or NH4+ (A) as sole N sources and supplied with 2.5 µM Cd. Unrelated to the nitrogen source, Cd reached higher levels in roots than in leaves. However, when ammonium was the source of nitrogen, Cd accumulation in roots was lower than in N or NA medium and the metal translocation to the aerial part was restricted, reaching values 25%-35% below the levels observed in plants grown with N or NA. Cadmium negatively affected chlorophyll content and PSII quantum yield, independently of the nitrogen source, with the highest decrease (35%) under NA treatment. Proline content increased, either with NA, N or A supplied in the presence of Cd, whereas a rise in total anthocyanin content was clearly favored when ammonium was the source of nitrogen, with or without Cd. In leaves, while NIA1 and NIA2 expression was markedly reduced by Cd in the presence of N or NA, ammonium source slightly reduced NIA1 expression but greatly upregulated NIA2 expression upon Cd exposure. The decay in NR activity was independent of the nitrogen source when Cd was applied and this decay was accompanied by a great increase in NH4+ levels either with nitrates or ammonium in the medium in the presence of Cd. Only NIA1 was detected in roots and its expression, together with NR activity and nitrates levels, was the highest in N medium devoid of Cd. The possibility of reducing Cd health risks through nitrogen fertilization practices is discussed.


Assuntos
Arabidopsis/metabolismo , Cádmio/toxicidade , Nitrogênio/metabolismo , Poluentes do Solo/toxicidade , Compostos de Amônio/metabolismo , Arabidopsis/efeitos dos fármacos , Transporte Biológico , Cádmio/metabolismo , Clorofila/metabolismo , Fertilizantes , Nitratos/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Poluentes do Solo/metabolismo
7.
Int J Mol Sci ; 21(8)2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32295293

RESUMO

Although gene-environment interactions are known to play an important role in the inheritance of complex traits, it is still unknown how a genotype and the environmental factors result in an observable phenotype. Understanding this complex interaction in the pathogenesis of diabetic retinopathy (DR) remains a big challenge as DR appears to be a disease with heterogenous phenotypes with multifactorial influence. In this review, we examine the natural history and risk factors related to DR, emphasizing distinct clinical phenotypes and their natural course in retinopathy. Although there is strong evidence that duration of diabetes and metabolic factors play a key role in the pathogenesis of DR, accumulating new clinical studies reveal that this disease can develop independently of duration of diabetes and metabolic dysfunction. More recently, studies have emphasized the role of genetic factors in DR. However, linkage analyses, candidate gene studies, and genome-wide association studies (GWAS) have not produced any statistically significant results. Our recently initiated genomics study, the Diabetic Retinopathy Genomics (DRGen) Study, aims to examine the contribution of rare and common variants in the development DR, and how they can contribute to clinical phenotype, rate of progression, and response to available therapies. Our preliminary findings reveal a novel set of genetic variants associated with proangiogenic and inflammatory pathways that may contribute to DR pathogenesis. Further investigation of these variants is necessary and may lead to development of novel biomarkers and new therapeutic targets in DR.


Assuntos
Retinopatia Diabética/etiologia , Retinopatia Diabética/metabolismo , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Fenótipo , Animais , Variação Biológica da População , Mapeamento Cromossômico , Nefropatias Diabéticas/etiologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Retinopatia Diabética/diagnóstico , Progressão da Doença , Estudos de Associação Genética/métodos , Variação Genética , Genômica/métodos , Humanos , Herança Multifatorial , Índice de Gravidade de Doença
8.
Mol Phylogenet Evol ; 135: 86-97, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30771513

RESUMO

The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively "trivial" aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic.


Assuntos
Baleia Comum/classificação , Baleia Comum/genética , Genoma Mitocondrial , Filogenia , Animais , Sequência de Bases , Teorema de Bayes , DNA Mitocondrial/genética , Variação Genética , Genótipo , Geografia , Repetições de Microssatélites/genética
9.
J Psychosoc Nurs Ment Health Serv ; 57(7): 17-22, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30753733

RESUMO

Patients with autism spectrum disorder and/or intellectual disability (ASD/ID) face unique health care challenges. In addition to hospital experiences characterized by fear and insufficient staff training, these patients have 1.5-times longer lengths of stay (LOS) than patients without ASD/ID, and 3.4% of patients with ASD/ID have prolonged LOS (i.e., ≥30 days). Little research exists on factors related to prolonged LOS of patients with ASD/ID, hindering efforts to develop and implement evidence-based practices to improve care and reduce prolonged LOS. The purpose of the current study was to describe factors related to prolonged LOS of adult patients with ASD/ID in acute care settings using a retrospective chart review of 10 patients discharged from one academic medical center. Findings indicate that health care institutions should evaluate performance with this patient population and identify evidence-based strategies to provide a safe environment for care and reduce LOS that is due to non-health care needs. [Journal of Psychosocial Nursing and Mental Health Services, 57(7), 17-22.].


Assuntos
Transtorno do Espectro Autista/terapia , Deficiência Intelectual/terapia , Tempo de Internação/estatística & dados numéricos , Adulto , Atitude do Pessoal de Saúde , Feminino , Hospitalização , Humanos , Masculino , Unidade Hospitalar de Psiquiatria , Adulto Jovem
10.
FASEB J ; 30(2): 601-11, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26443820

RESUMO

Endothelial activation is a hallmark of the high-glucose (HG)-induced retinal inflammation associated with diabetic retinopathy (DR). However, precisely how HG induces retinal endothelial activation is not fully understood. We hypothesized that HG-induced up-regulation of lysyl oxidase (LOX), a collagen-cross-linking enzyme, in retinal capillary endothelial cells (ECs) enhances subendothelial basement membrane (BM) stiffness, which, in turn, promotes retinal EC activation. Diabetic C57BL/6 mice exhibiting a 70 and 50% increase in retinal intercellular adhesion molecule (ICAM)-1 expression and leukocyte accumulation, respectively, demonstrated a 2-fold increase in the levels of BM collagen IV and LOX, key determinants of capillary BM stiffness. Using atomic force microscopy, we confirmed that HG significantly enhances LOX-dependent subendothelial matrix stiffness in vitro, which correlated with an ∼2.5-fold increase in endothelial ICAM-1 expression, a 4-fold greater monocyte-EC adhesion, and an ∼2-fold alteration in endothelial NO (decrease) and NF-κB activation (increase). Inhibition of LOX-dependent subendothelial matrix stiffening alone suppressed HG-induced retinal EC activation. Finally, using synthetic matrices of tunable stiffness, we demonstrated that subendothelial matrix stiffening is necessary and sufficient to promote EC activation. These findings implicate BM stiffening as a critical determinant of HG-induced retinal EC activation and provide a rationale for examining BM stiffness and underlying mechanotransduction pathways as therapeutic targets for diabetic retinopathy.


Assuntos
Membrana Basal/patologia , Diabetes Mellitus Experimental/complicações , Retinopatia Diabética/induzido quimicamente , Endotélio/patologia , Retina/patologia , Animais , Linhagem Celular , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/fisiologia , Haplorrinos , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Monócitos , Proteína-Lisina 6-Oxidase/antagonistas & inibidores , Proteína-Lisina 6-Oxidase/genética , Proteína-Lisina 6-Oxidase/metabolismo
11.
Mol Vis ; 22: 1280-1290, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27829783

RESUMO

PURPOSE: To redesign a complement-inhibiting peptide with the potential to become a therapeutic for dry and wet age-related macular degeneration (AMD). METHODS: We present a new potent peptide (Peptide 2) of the compstatin family. The peptide is developed by rational design, based on a mechanistic binding hypothesis, and structural and physicochemical properties derived from molecular dynamics (MD) simulation. The inhibitory activity, efficacy, and solubility of Peptide 2 are evaluated using a hemolytic assay, a human RPE cell-based assay, and ultraviolet (UV) absorption properties, respectively, and compared to the respective properties of its parent peptide (Peptide 1). RESULTS: The sequence of Peptide 2 contains an arginine-serine N-terminal extension (a characteristic of parent Peptide 1) and a novel 8-polyethylene glycol (PEG) block C-terminal extension. Peptide 2 has significantly improved aqueous solubility compared to Peptide 1 and comparable complement inhibitory activity. In addition, Peptide 2 is more efficacious in inhibiting complement activation in a cell-based model that mimics the pathobiology of dry AMD. CONCLUSIONS: We have designed a new peptide analog of compstatin that combines N-terminal polar amino acid extensions and C-terminal PEGylation extensions. This peptide demonstrates significantly improved aqueous solubility and complement inhibitory efficacy, compared to the parent peptide. The new peptide overcomes the aggregation limitation for clinical translation of previous compstatin analogs and is a candidate to become a therapeutic for the treatment of AMD.


Assuntos
Proteínas do Sistema Complemento/metabolismo , Degeneração Macular/tratamento farmacológico , Peptídeos/uso terapêutico , Sequência de Aminoácidos , Animais , Linhagem Celular , Hemólise/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Peptídeos/síntese química , Peptídeos/química , Peptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Peptídeos Cíclicos/uso terapêutico , Coelhos , Solubilidade
12.
J Biomater Appl ; 39(1): 66-79, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38646887

RESUMO

Three-dimensional (3D) structures are actually the state-of-the-art technique to create porous scaffolds for tissue engineering. Since regeneration in cartilage tissue is limited due to intrinsic cellular properties this study aims to develop and characterize three-dimensional porous scaffolds of poly (L-co-D, L lactide-co-trimethylene carbonate), PLDLA-TMC, obtained by 3D fiber deposition technique. The PLDLA-TMC terpolymer scaffolds (70:30), were obtained and characterized by scanning electron microscopy, gel permeation chromatography, differential scanning calorimetry, thermal gravimetric analysis, compression mechanical testing and study on in vitro degradation, which showed its amorphous characteristics, cylindrical geometry, and interconnected pores. The in vitro degradation study showed significant loss of mechanical properties compatible with a decrease in molar mass, accompanied by changes in morphology. The histocompatibility association of mesenchymal stem cells from rabbit's bone marrow, and PLDLA-TMC scaffolds, were evaluated in the meniscus regeneration, proving the potential of cell culture at in vivo tissue regeneration. Nine New Zealand rabbits underwent total medial meniscectomy, yielding three treatments: implantation of the seeded PLDLA-TMC scaffold, implantation of the unseeded PLDLA-TMC and negative control (defect without any implant). After 24 weeks, the results revealed the presence of fibrocartilage in the animals treated with polymer. However, the regeneration obtained with the seeded PLDLA-TMC scaffolds with mesenchymal stem cells had become intimal to mature fibrocartilaginous tissue of normal meniscus both macroscopically and histologically. This study demonstrated the effectiveness of the PLDLA-TMC scaffold in meniscus regeneration and the potential of mesenchymal stem cells in tissue engineering, without the use of growth factors. It is concluded that bioresorbable polymers represent a promising alternative for tissue regeneration.


Assuntos
Dioxanos , Células-Tronco Mesenquimais , Poliésteres , Impressão Tridimensional , Engenharia Tecidual , Alicerces Teciduais , Animais , Coelhos , Alicerces Teciduais/química , Células-Tronco Mesenquimais/citologia , Dioxanos/química , Poliésteres/química , Engenharia Tecidual/métodos , Materiais Biocompatíveis/química , Menisco/citologia , Regeneração , Transplante de Células-Tronco Mesenquimais/métodos , Porosidade , Teste de Materiais , Implantes Absorvíveis , Células Cultivadas , Polímeros/química
13.
Diabetes ; 72(6): 781-794, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36930735

RESUMO

Inflammation plays an important role in the pathogenesis of diabetic retinopathy (DR). To precisely define the inflammatory mediators, we examined the transcriptomic profile of human retinal endothelial cells exposed to advanced glycation end products, which revealed the neutrophil chemoattractant chemokine CXCL1 as one of the top genes upregulated. The effect of neutrophils in the alteration of the blood-retinal barrier (BRB) was further assessed in wild-type C57BL/6J mice intravitreally injected with recombinant CXCL1 as well as in streptozotocin-induced diabetic mice. Both intravitreally CXCL1-injected and diabetic animals showed significantly increased retinal vascular permeability, with significant increase in infiltration of neutrophils and monocytes in retinas and increased expression of chemokines and their receptors, proteases, and adhesion molecules. Treatment with Ly6G antibody for neutrophil depletion in both diabetic mice as well as CXCL1-injected animals showed significantly decreased retinal vascular permeability accompanied by decreased infiltration of neutrophils and monocytes and decreased expression of cytokines and proteases. CXCL1 level was significantly increased in the serum samples of patients with DR compared with samples of those without diabetes. These data reveal a novel mechanism by which the chemokine CXCL1, through neutrophil recruitment, alters the BRB in DR and, thus, serves as a potential novel therapeutic target. ARTICLE HIGHLIGHTS: Intravitreal CXCL1 injection and diabetes result in increased retinal vascular permeability with neutrophil and monocyte recruitment. Ly6G antibody treatment for neutrophil depletion in both animal models showed decreased retinal permeability and decreased cytokine expression. CXCL1 is produced by retinal endothelial cells, pericytes, and astrocytes. CXCL1 level is significantly increased in serum samples of patients with diabetic retinopathy. CXCL1, through neutrophil recruitment, alters the blood-retinal barrier in diabetic retinopathy and, thus, may be used as a therapeutic target.


Assuntos
Diabetes Mellitus Experimental , Retinopatia Diabética , Camundongos , Humanos , Animais , Barreira Hematorretiniana/metabolismo , Retinopatia Diabética/metabolismo , Quimiocina CXCL1/genética , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/farmacologia , Diabetes Mellitus Experimental/metabolismo , Transcriptoma , Células Endoteliais/metabolismo , Infiltração de Neutrófilos , Camundongos Endogâmicos C57BL , Permeabilidade Capilar , Anticorpos/farmacologia , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Peptídeo Hidrolases/farmacologia
14.
Ambio ; 52(4): 786-801, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36701114

RESUMO

In this paper, we developed an innovative and plural methodology for a socio-cultural assessment of ecosystem services (ES). This methodology was performed using diverse and interdependent tools applied within the framework of ethnoecology and post-normal science, with the aim of identifying ES from the perspective of local communities that inhabit different socio-ecosystems, highlighting the relevance of Indigenous and Local Knowledge (ILK). As examples of how this methodology works, we analyzed a multiple case study performed in three peasant communities of the Dry Chaco eco-region, Argentina. We identified ES in all the categories and their fundamental contributions to the particular way of life in this area. The method is flexible enough to be used in other socio-ecosystems with different environmental and social features.


Assuntos
Ecossistema , Conhecimento , Argentina , Conservação dos Recursos Naturais/métodos
15.
Sci Adv ; 9(45): eadf3326, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37939193

RESUMO

The Arctic is among the most climatically sensitive environments on Earth, and the disappearance of multiyear sea ice in the Arctic Ocean is predicted within decades. As apex predators, polar bears are sentinel species for addressing the impact of environmental variability on Arctic marine ecosystems. By integrating genomics, isotopic analysis, morphometrics, and ecological modeling, we investigate how Holocene environmental changes affected polar bears around Greenland. We uncover reductions in effective population size coinciding with increases in annual mean sea surface temperature, reduction in sea ice cover, declines in suitable habitat, and shifts in suitable habitat northward. Furthermore, we show that west and east Greenlandic polar bears are morphologically, and ecologically distinct, putatively driven by regional biotic and genetic differences. Together, we provide insights into the vulnerability of polar bears to environmental change and how the Arctic marine ecosystem plays a vital role in shaping the evolutionary and ecological trajectories of its inhabitants.


Assuntos
Ursidae , Animais , Ecossistema , Mudança Climática , Evolução Biológica , Regiões Árticas , Camada de Gelo
16.
Ecol Evol ; 12(8): e9185, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36035270

RESUMO

Accurate sex identification is crucial for elucidating the biology of a species. In the absence of directly observable sexual characteristics, sex identification of wild fauna can be challenging, if not impossible. Molecular sexing offers a powerful alternative to morphological sexing approaches. Here, we present SeXY, a novel sex-identification pipeline, for very low-coverage shotgun sequencing data from a single individual. SeXY was designed to utilize low-effort screening data for sex identification and does not require a conspecific sex-chromosome assembly as reference. We assess the accuracy of our pipeline to data quantity by downsampling sequencing data from 100,000 to 1000 mapped reads and to reference genome selection by mapping to a variety of reference genomes of various qualities and phylogenetic distance. We show that our method is 100% accurate when mapping to a high-quality (highly contiguous N50 > 30 Mb) conspecific genome, even down to 1000 mapped reads. For lower-quality reference assemblies (N50 < 30 Mb), our method is 100% accurate with 50,000 mapped reads, regardless of reference assembly quality or phylogenetic distance. The SeXY pipeline provides several advantages over previously implemented methods; SeXY (i) requires sequencing data from only a single individual, (ii) does not require assembled conspecific sex chromosomes, or even a conspecific reference assembly, (iii) takes into account variation in coverage across the genome, and (iv) is accurate with only 1000 mapped reads in many cases.

17.
J Imaging ; 8(12)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36547491

RESUMO

Advances in Artificial intelligence (AI) and embedded systems have resulted on a recent increase in use of image processing applications for smart cities' safety. This enables a cost-adequate scale of automated video surveillance, increasing the data available and releasing human intervention. At the same time, although deep learning is a very intensive task in terms of computing resources, hardware and software improvements have emerged, allowing embedded systems to implement sophisticated machine learning algorithms at the edge. Additionally, new lightweight open-source middleware for constrained resource devices, such as EdgeX Foundry, have appeared to facilitate the collection and processing of data at sensor level, with communication capabilities to exchange data with a cloud enterprise application. The objective of this work is to show and describe the development of two Edge Smart Camera Systems for safety of Smart cities within S4AllCities H2020 project. Hence, the work presents hardware and software modules developed within the project, including a custom hardware platform specifically developed for the deployment of deep learning models based on the I.MX8 Plus from NXP, which considerably reduces processing and inference times; a custom Video Analytics Edge Computing (VAEC) system deployed on a commercial NVIDIA Jetson TX2 platform, which provides high level results on person detection processes; and an edge computing framework for the management of those two edge devices, namely Distributed Edge Computing framework, DECIoT. To verify the utility and functionality of the systems, extended experiments were performed. The results highlight their potential to provide enhanced situational awareness and demonstrate the suitability for edge machine vision applications for safety in smart cities.

18.
Mitochondrial DNA B Resour ; 6(8): 2191-2193, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34263047

RESUMO

The endangered giant root-rat (Tachyoryctes macrocephalus, also known as giant mole rat) is a fossorial rodent endemic to the afro-alpine grasslands of the Bale Mountains in Ethiopia. The species is an important ecosystem engineer with the majority of the global population found within 1000 km2. Here, we present the first complete mitochondrial genome of the giant root-rat and the genus Tachyoryctes, recovered using shotgun sequencing and iterative mapping. A phylogenetic analysis including 15 other representatives of the family Spalacidae placed Tachyoryctes as sister genus to Rhizomys with high support. This position is in accordance with a recent study revealing the topology of the Spalacidae family. The full mitochondrial genome of the giant root-rat presents an important resource for further population genetic studies.

19.
Healthcare (Basel) ; 9(11)2021 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-34828594

RESUMO

Improved technology facilitates the acceptance of telemedicine. The aim was to analyze the effectiveness of telephone follow-up to detect severe SARS-CoV-2 cases that progressed to pneumonia. A prospective cohort study with 2-week telephone follow-up was carried out March 1 to May 4, 2020, in a primary healthcare center in Barcelona. Individuals aged ≥15 years with symptoms of SARS-CoV-2 were included. Outpatients with non-severe disease were called on days 2, 4, 7, 10 and 14 after diagnosis; patients with risk factors for pneumonia received daily calls through day 5 and then the regularly scheduled calls. Patients hospitalized due to pneumonia received calls on days 1, 3, 7 and 14 post-discharge. Of the 453 included patients, 435 (96%) were first attended to at a primary healthcare center. The 14-day follow-up was completed in 430 patients (99%), with 1798 calls performed. Of the 99 cases of pneumonia detected (incidence rate 20.8%), one-third appeared 7 to 10 days after onset of SARS-CoV-2 symptoms. Ten deaths due to pneumonia were recorded. Telephone follow-up by a primary healthcare center was effective to detect SARS-CoV-2 pneumonias and to monitor related complications. Thus, telephone appointments between a patient and their health care practitioner benefit both health outcomes and convenience.

20.
J Clin Med ; 9(1)2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31947513

RESUMO

Although there is strong clinical evidence that the control of blood glucose, blood pressure, and lipid level can prevent and slow down the progression of diabetic retinopathy (DR) as shown by landmark clinical trials, it has been shown that these factors only account for 10% of the risk for developing this disease. This suggests that other factors, such as genetics, may play a role in the development and progression of DR. Clinical evidence shows that some diabetics, despite the long duration of their diabetes (25 years or more) do not show any sign of DR or show minimal non-proliferative diabetic retinopathy (NPDR). Similarly, not all diabetics develop proliferative diabetic retinopathy (PDR). So far, linkage analysis, candidate gene studies, and genome-wide association studies (GWAS) have not produced any statistically significant results. We recently initiated a genomics study, the Diabetic Retinopathy Genetics (DRGen) Study, to examine the contribution of rare and common variants in the development of different phenotypes of DR, as well as their responsiveness to anti-VEGF treatment in diabetic macular edema (DME). Our preliminary findings reveal a novel set of genetic variants involved in the angiogenesis and inflammatory pathways that contribute to DR progression or protection. Further investigation of variants can help to develop novel biomarkers and lead to new therapeutic targets in DR.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa