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

Intervalo de ano de publicação
1.
Trop Anim Health Prod ; 56(2): 78, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38351405

RESUMO

This study evaluated the economic impacts caused by mastitis in a small dairy farm with similar characteristics and production to most dairy farms in southern Brazil and investigated if climatic variations influenced mastitis occurrence in the region. A farm with, on average, 45 lactating Holstein cattle was monitored from November 2021 to October 2022, and data on mastitis cases, bulk tank milk somatic cell count, animal treatment costs, milk production, animal disposal costs, and production losses were collected. Monthly averages of temperature, relative humidity (RH), and rainfall in the region were obtained. The greatest loss was related to the drop in milk production, resulting in 63.8% of total losses, followed by animal disposal (29.5%), milk disposal (4.6%), and treating animals with mastitis (2.0%), totaling a 10.6% reduction in the annual gross income. There were negative correlations between the clinical mastitis rate and monthly RH and between subclinical mastitis and temperature; the occurrence of subclinical mastitis and average RH were positively correlated. Our findings showed that mastitis negatively impacted the economy and that climate influenced mastitis occurrence.


Assuntos
Doenças dos Bovinos , Mastite Bovina , Bovinos , Animais , Feminino , Lactação , Fazendas , Brasil/epidemiologia , Mastite Bovina/epidemiologia , Mastite Bovina/tratamento farmacológico , Indústria de Laticínios , Leite , Contagem de Células/veterinária , Doenças dos Bovinos/epidemiologia
2.
Behav Genet ; 53(5-6): 404-415, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37713023

RESUMO

Proprietary genetic datasets are valuable for boosting the statistical power of genome-wide association studies (GWASs), but their use can restrict investigators from publicly sharing the resulting summary statistics. Although researchers can resort to sharing down-sampled versions that exclude restricted data, down-sampling reduces power and might change the genetic etiology of the phenotype being studied. These problems are further complicated when using multivariate GWAS methods, such as genomic structural equation modeling (Genomic SEM), that model genetic correlations across multiple traits. Here, we propose a systematic approach to assess the comparability of GWAS summary statistics that include versus exclude restricted data. Illustrating this approach with a multivariate GWAS of an externalizing factor, we assessed the impact of down-sampling on (1) the strength of the genetic signal in univariate GWASs, (2) the factor loadings and model fit in multivariate Genomic SEM, (3) the strength of the genetic signal at the factor level, (4) insights from gene-property analyses, (5) the pattern of genetic correlations with other traits, and (6) polygenic score analyses in independent samples. For the externalizing GWAS, although down-sampling resulted in a loss of genetic signal and fewer genome-wide significant loci; the factor loadings and model fit, gene-property analyses, genetic correlations, and polygenic score analyses were found robust. Given the importance of data sharing for the advancement of open science, we recommend that investigators who generate and share down-sampled summary statistics report these analyses as accompanying documentation to support other researchers' use of the summary statistics.


Assuntos
Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único/genética , Fenótipo , Genômica/métodos , Herança Multifatorial
3.
Cytotherapy ; 24(2): 124-136, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34465515

RESUMO

BACKGROUND AIMS: The human endometrium has emerged as an attractive source of endometrial-derived mesenchymal stem/stromal cells (eMSCs) that can be easily isolated by non-invasive procedures. The prominent capacity of the endometrium for efficient and scarless regeneration each menstrual cycle indicates the increased eMSC immunomodulatory and pro-angiogenic properties. Herein the authors investigated the molecular responses of eMSCs to an inflammatory environment and whether those intrinsic responses affected their functional attributes. METHODS: Human eMSCs immunophenotypic, transcriptional and secretory profiles were evaluated at passage three (P3) and passage eight (P8) to determine culture effects. Functionally, P3 and P8 non-induced and TNF-α/IFN-γ-induced eMSCs were interrogated for their capacity to suppress stimulated peripheral blood mononuclear cell (PBMC) proliferation, whereas non-induced eMSCs were assessed for their support to vascular network formation in co-cultures with human umbilical vein endothelial cells in vitro. RESULTS: Non-induced P3 and P8 eMSCs exhibited similar spindle-shaped morphology and clonogenic capacity. Nevertheless, P8 eMSCs showed reduced growth rate capacity and telomere length. The eMSCs displayed the typical MSC-related immunophenotypic profile, with P3 and P8 eMSCs expressing high levels (>98%) of CD140ß, intermediate levels (35-60%) of CD146 and SUSD2 and low levels (∼8%) of NG2 pericytic markers. Non-induced P3 and P8 showed similar transcriptional and secretory profiles, though the expression of immunomodulatory HLA-G and IL-8 genes was significantly downregulated in P8 compared with P3 eMSCs. Upon TNF-α/IFN-γ induction, eMSCs showed an immunophenotypic profile similar to that of non-induced eMSCs, except for significant upregulation of HLA-DR protein expression in both induced P3 and P8 eMSCs. However, induced P3 and P8 eMSCs showed significant upregulation of CD10, HLA-G, IDO, IL-6, IL-8, LIF and TSG gene expression compared with non-induced cultures. TNF-α/IFN-γ induction strongly increased the secretion of inflammatory-/angiogenesis-related molecules, whereas growth factor secretion was similar to the non-induced eMSCs. Functionally, P3 and P8 eMSCs showed a strong inhibitory effect on stimulated PBMC proliferation and the capacity to support neovascularization in vitro. CONCLUSIONS: The authors' study suggests that serial expansion does not affect eMSC immunophenotypic, transcriptional and secretory profiles. This is directly reflected by the functional immunomodulatory and pro-angiogenic properties of eMSCs, which remain unaltered until P8 in vitro. However, exposure of eMSCs to inflammatory environments enhances their immunomodulatory transcriptional and inflammatory-/angiogenesis-related secretory profiles. Therefore, the resulting evidence of eMSCs serial expansion and exposure to inflammation could serve as a foundation for improved eMSCs manufacturing and potential clinical translation efforts.


Assuntos
Leucócitos Mononucleares , Células-Tronco Mesenquimais , Diferenciação Celular , Endométrio , Células Endoteliais , Feminino , Humanos
4.
J Neurophysiol ; 125(4): 1164-1179, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33502943

RESUMO

Modern neurophysiology research requires the interrogation of high-dimensionality data sets. Machine learning and artificial intelligence (ML/AI) workflows have permeated into nearly all aspects of daily life in the developed world but have not been implemented routinely in neurophysiological analyses. The power of these workflows includes the speed at which they can be deployed, their availability of open-source programming languages, and the objectivity permitted in their data analysis. We used classification-based algorithms, including random forest, gradient boosted machines, support vector machines, and neural networks, to test the hypothesis that the animal genotypes could be separated into their genotype based on interpretation of neurophysiological recordings. We then interrogate the models to identify what were the major features utilized by the algorithms to designate genotype classification. By using raw EEG and respiratory plethysmography data, we were able to predict which recordings came from genotype class with accuracies that were significantly improved relative to the no information rate, although EEG analyses showed more overlap between groups than respiratory plethysmography. In comparison, conventional methods where single features between animal classes were analyzed, differences between the genotypes tested using baseline neurophysiology measurements showed no statistical difference. However, ML/AI workflows successfully were capable of providing successful classification, indicating that interactions between features were different in these genotypes. ML/AI workflows provide new methodologies to interrogate neurophysiology data. However, their implementation must be done with care so as to provide high rigor and reproducibility between laboratories. We provide a series of recommendations on how to report the utilization of ML/AI workflows for the neurophysiology community.NEW & NOTEWORTHY ML/AI classification workflows are capable of providing insight into differences between genotypes for neurophysiology research. Analytical techniques utilized in the neurophysiology community can be augmented by implementing ML/AI workflows. Random forest is a robust classification algorithm for respiratory plethysmography data. Utilization of ML/AI workflows in neurophysiology research requires heightened transparency and improved community research standards.


Assuntos
Eletroencefalografia , Perfilação da Expressão Gênica , Aprendizado de Máquina , Neurofisiologia/métodos , Pletismografia , Respiração , Sono/fisiologia , Animais , Astrócitos , Eletroencefalografia/métodos , Perfilação da Expressão Gênica/métodos , Genótipo , Proteínas de Homeodomínio , Camundongos , Pletismografia/métodos , Fatores de Transcrição , Fluxo de Trabalho
5.
Stem Cells ; 38(8): 1034-1049, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32379908

RESUMO

CD146+ bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs) play key roles in the perivascular niche, skeletogenesis, and hematopoietic support; however, comprehensive evaluation of therapeutic potency has yet to be determined. In this study, in vitro inflammatory priming to crude human BM-MSCs (n = 8) captured a baseline of signature responses, including enriched CD146+ with coexpression of CD107aHigh , CXCR4High , and LepRHigh , transcriptional profile, enhanced secretory capacity, and robust immunomodulatory secretome and function, including immunopotency assays (IPAs) with stimulated immune cells. These signatures were significantly more pronounced in CD146+ (POS)-sorted subpopulation than in the CD146- (NEG). Mechanistically, POS BM-MSCs showed a markedly higher secretory capacity with significantly greater immunomodulatory and anti-inflammatory protein production upon inflammatory priming compared with the NEG BM-MSCs. Moreover, IPAs with stimulated peripheral blood mononuclear cells and T lymphocytes demonstrated robust immunosuppression mediated by POS BM-MSC while inducing significant frequencies of regulatory T cells. in vivo evidence showed that POS BM-MSC treatment promoted pronounced M1-to-M2 macrophage polarization, ameliorating inflammation/fibrosis of knee synovium and fat pad, unlike treatment with NEG BM-MSCs. These data correlate the expression of CD146 with innately higher immunomodulatory and secretory capacity, and thus therapeutic potency. This high-content, reproducible evidence suggests that the CD146+ (POS) MSC subpopulation are the mediators of the beneficial effects achieved using crude BM-MSCs, leading to translational implications for improving cell therapy and manufacturing.


Assuntos
Células-Tronco Mesenquimais/metabolismo , Adulto , Antígeno CD146/metabolismo , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Humanos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia
6.
Chaos Solitons Fractals ; 142: 110388, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33162689

RESUMO

The coronavirus disease 2019 (Covid-19) outbreak led the world to an unprecedented health and economic crisis. In an attempt to respond to this emergency, researchers worldwide are intensively studying the dynamics of the Covid-19 pandemic. In this study, a Susceptible - Infected - Removed - Sick (SIRSi) compartmental model is proposed, which is a modification of the classical Susceptible - Infected - Removed (SIR) model. The proposed model considers the possibility of unreported or asymptomatic cases, and differences in the immunity within a population, i.e., the possibility that the acquired immunity may be temporary, which occurs when adopting one of the parameters ( γ ) other than zero. Local asymptotic stability and endemic equilibrium conditions are proved for the proposed model. The model is adjusted to the data from three major cities of the state of São Paulo in Brazil, namely, São Paulo, Santos, and Campinas, providing estimations of duration and peaks related to the disease propagation. This study reveals that temporary immunity favors a second wave of infection and it depends on the time interval for a recovered person to be susceptible again. It also indicates the possibility that a greater number of patients would get infected with decreased time for reinfection.

7.
Curr Sports Med Rep ; 20(11): 617-623, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34752437

RESUMO

ABSTRACT: The past two decades have built on the successes of the Human Genome Project identifying the impact of genetics and genomics on human traits. Given the importance of exercise in the physical and psychological health of individuals across the lifespan, using genomics to understand the impact of genes in the sports medicine field is an emerging field. Given the complexity of the systems involved, high-throughput genomics is required to understand genetic variants, their functions, and ultimately their effect on the body. Consequently, genomic studies have been performed across several domains of sports medicine with varying degrees of success. While the breadth of these is great, they focus largely on the following three areas: 1) performance; 2) injury susceptibility; and 3) sports associated chronic conditions, such as osteoarthritis. Herein, we review literature on genetics and genomics in sports medicine, offer suggestions to bolster existing studies, and suggest ways to ideally impact clinical care.


Assuntos
Medicina Esportiva , Esportes , Exercício Físico , Previsões , Genômica , Humanos
8.
Cytotherapy ; 22(11): 677-689, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723596

RESUMO

BACKGROUND AIMS: Mesenchymal stem/stromal cell (MSC)-based therapies have gained attention as potential alternatives for multiple musculoskeletal indications based on their trophic and immunomodulatory properties. The infrapatellar fat pad (IFP) serves as a reservoir of MSCs, which play crucial roles modulating inflammatory and fibrotic events at the IFP and its neighboring tissue, the synovium. In an effort to comply with the existing regulatory framework regarding cell-based product manufacturing, we interrogated the in vitro immunomodulatory capacity of human-derived IFP-MSCs processed under different conditions, including a regulatory-compliant protocol, in addition to their response to the inflammatory and fibrotic environments often present in joint disease. METHODS: Immunophenotype, telomere length, transcriptional and secretory immunomodulatory profiles and functional immunopotency assay were assessed in IFP-MSCs expanded in regular fetal bovine serum (FBS)-supplemented medium and side-by-side compared with same-donor cells processed with two media alternatives (i.e., regulatory-compliant pooled human platelet lysate [hPL] and a chemically reinforced/serum-reduced [Ch-R] formulation). Finally, to assess the effects of such formulations on the ability of the cells to respond to pro-inflammatory and pro-fibrotic conditions, all three groups were stimulated ex vivo (i.e., cell priming) with a cocktail containing TNFα, IFNγ and connective tissue growth factor (tumor-initiating cells) and compared with non-induced cohorts assessing the same outcomes. RESULTS: Non-induced and primed IFP-MSCs expanded in either hPL or Ch-R showed distinct morphology in vitro, similar telomere dynamics and distinct phenotypical and molecular profiles when compared with cohorts grown in FBS. Gene expression of IL-8, CD10 and granulocyte colony-stimulating factor was highly enriched in similarly processed IFP-MSCs. Cell surface markers related to the immunomodulatory capacity, including CD146 and CD10, were highly expressed, and secretion of immunomodulatory and pro-angiogenic factors was significantly enhanced with both hPL and Ch-R formulations. Upon priming, the immunomodulatory phenotype was enhanced, resulting in further increase in CD146 and CD10, significant CXCR4 presence and reduction in TLR3. Similarly, transcriptional and secretory profiles were enriched and more pronounced in IFP-MSCs expanded in either hPL or Ch-R, suggesting a synergistic effect between these formulations and inflammatory/fibrotic priming conditions. Collectively, increased indoleamine-2,3-dioxygenase activity and prostaglandin E2 secretion for hPL- and Ch-R-expanded IFP-MSCs were functionally reflected by their robust T-cell proliferation suppression capacity in vitro compared with IFP-MSCs expanded in FBS, even after priming. CONCLUSIONS: Compared with processing using an FBS-supplemented medium, processing IFP-MSCs with either hPL or Ch-R similarly enhances their immunomodulatory properties, which are further increased after exposure to an inflammatory/fibrotic priming environment. This evidence supports the adoption of regulatory-compliant practices during the manufacturing of a cell-based product based on IFP-MSCs and anticipates a further enhanced response once the cells face the pathological environment after intra-articular administration. Mechanistically, the resulting functionally enhanced cell-based product has potential utilization as a novel, minimally invasive cell therapy for joint disease through modulation of local immune and inflammatory events.


Assuntos
Tecido Adiposo/citologia , Imunomodulação , Células-Tronco Mesenquimais/citologia , Patela/anatomia & histologia , Controle Social Formal , Adulto , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Meios de Cultura/farmacologia , Citocinas/metabolismo , Feminino , Humanos , Imunomodulação/efeitos dos fármacos , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Soro , Transcrição Gênica/efeitos dos fármacos
9.
Gynecol Endocrinol ; 36(1): 24-29, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31464148

RESUMO

Congenital adrenal hyperplasia (CAH) is a group of rare orphan disorders caused by mutations in seven different enzymes that impair cortisol biosynthesis. The 17α-hydroxylase deficiency (17OHD) is one of the less common forms of CAH, corresponding to approximately 1% of the cases, with an estimated annual incidence of 1 in 50,000 newborns. Cases description - two phenotypically female Ecuadorian sisters, both with primary amenorrhea, absence of secondary sexual characteristics, and osteoporosis. High blood pressure was present in the older sister. Hypergonadotropic hypogonadism profile was observed: decreased cortisol and dehydroepiandrosterone sulfate (DHEAS), increased adrenocorticotropic hormone (ACTH) and normal levels of 17-hydroxyprogesterone, extremely high deoxycorticosterone (DOC) levels, and a tomography showed bilateral adrenal hyperplasia in both sisters. Consanguinity was evident in their ancestors. Furthermore, in the exon 7, the variant c.1216T > C, p.Trp406Arg was detected in homozygosis in the CYP17A1 gene of both sisters. We report a homozygous missense mutation in the CYP17A1 gene causing 17OHD in two sisters from Loja, Ecuador. According to the authors, this is the first time such deficiency and mutation are described in two members of the same family in Ecuador.


Assuntos
Hiperplasia Suprarrenal Congênita/genética , Irmãos , Esteroide 17-alfa-Hidroxilase/genética , 17-alfa-Hidroxiprogesterona/metabolismo , Hiperplasia Suprarrenal Congênita/complicações , Hiperplasia Suprarrenal Congênita/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Amenorreia/etiologia , Consanguinidade , Sulfato de Desidroepiandrosterona/metabolismo , Desoxicorticosterona/metabolismo , Erros de Diagnóstico , Equador , Feminino , Homozigoto , Humanos , Hidrocortisona/metabolismo , Hipertensão/etiologia , Hipogonadismo/etiologia , Hipogonadismo/metabolismo , Hipopotassemia/etiologia , Mosaicismo , Osteoporose/etiologia , Síndrome de Turner/diagnóstico , Adulto Jovem
10.
Semin Cell Dev Biol ; 62: 67-77, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27422331

RESUMO

Articular cartilage is a highly specialized tissue whose remarkable properties of deformability, resistance to mechanical loading, and low-friction gliding are essential to joint function. Due to its role as a cushion in bone articulation, articular cartilage is subject to many types of damaging insults, including decades of wear and tear, and acute joint injuries. However, this built-for-life tissue has a very poor intrinsic ability in adulthood to durably heal defects created by damaging insults. Consequently, articular cartilage progressively deteriorates and is eventually eroded, exposing the subchondral bone to the joint space, triggering inflammation and osteophyte development, and generating severe pain and joint incapacitation. The disease is called osteoarthritis (OA) and is today the leading cause of pain and disability in the human population. Researchers and clinicians have worked for decades to develop strategies to treat OA and restore joint function, but they are still far from being able to offer patients effective preventive or restorative treatments. Novel ideas, knowledge and technologies that nurture hope for major new breakthroughs are therefore sought. In this review, we first outline the composition, structure, and functional properties of normal human adult articular cartilage, as a reference for tissue conservation and regenerative strategies. We then describe current options that have been used clinically and in pre-clinical trials to treat osteoarthritic patients, and we discuss the benefits and inadequacies of these treatment options. Next, we review research efforts that are currently ongoing to try and achieve durable repair of functional cartilage tissue. Methods include engineering of tissue implants and we discuss the needs and options for tissue scaffolds, cell sources, and growth and differentiation factors to generate de novo or repair bona fide articular cartilage.


Assuntos
Cartilagem Articular/fisiologia , Regeneração , Medicina Regenerativa/métodos , Animais , Humanos , Próteses e Implantes , Engenharia Tecidual , Alicerces Teciduais/química
11.
Cytotherapy ; 21(12): 1179-1197, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31784241

RESUMO

Osteoarthritis (OA) is a debilitating, degenerative joint disease characterized by progressive destruction of articular cartilage. Given the poor repair capacity of articular cartilage and the associated local destructive immune/inflammatory responses involving all joint structures, OA frequently ends up as a "whole joint failure" requiring prosthetic replacement. Current pharmacological efforts, belatedly started, mainly aim at symptomatic pain relief, underscoring the need for novel therapeutic schemes designed to modify the course of the disease. Mesenchymal stem cell (MSC)-based therapy has gained significant interest, sparking the design of multiple trials proving safety while providing promising preliminary efficacy results. MSCs possess 'medicinal signaling cell' properties related to their immunomodulatory and anti-inflammatory effects, which induce the establishment of a pro-regenerative microenvironment at the injured tissue. Those trophic effects are paralleled by the long-established chondroprogenitor capacity that can be harnessed to ex vivo fabricate engineered constructs to repair damaged articular cartilage. The present review focuses on these two aspects of the use of MSCs for articular cartilage damage, namely, cell therapy and tissue engineering, providing information on their use criteria, advancements, challenges and strategies to overcome them.


Assuntos
Cartilagem Articular/fisiologia , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Osteoartrite/terapia , Engenharia Tecidual/tendências , Animais , Regeneração Óssea/fisiologia , Cartilagem Articular/fisiopatologia , Humanos , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Osteoartrite/fisiopatologia , Regeneração/fisiologia , Medicina Regenerativa/métodos , Medicina Regenerativa/tendências , Engenharia Tecidual/métodos
12.
Learn Mem ; 25(5): 214-229, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29661834

RESUMO

The microRNA miR-132 serves as a key regulator of a wide range of plasticity-associated processes in the central nervous system. Interestingly, miR-132 expression has also been shown to be under the control of the circadian timing system. This finding, coupled with work showing that miR-132 is expressed in the hippocampus, where it influences neuronal morphology and memory, led us to test the idea that daily rhythms in miR-132 within the forebrain modulate cognition as a function of circadian time. Here, we show that hippocampal miR-132 expression is gated by the time-of-day, with peak levels occurring during the circadian night. Further, in miR-132 knockout mice and in transgenic mice, where miR-132 is constitutively expressed under the control of the tetracycline regulator system, we found that time-of-day dependent memory recall (as assessed via novel object location and contextual fear conditioning paradigms) was suppressed. Given that miRNAs exert their functional effects via the suppression of target gene expression, we examined the effects that transgenic miR-132 manipulations have on MeCP2 and Sirt1-two miR-132 targets that are associated with neuronal plasticity and cognition. In mice where miR-132 was either knocked out, or transgenically expressed, rhythmic expression of MeCP2 and Sirt1 was suppressed. Taken together, these results raise the prospect that miR-132 serves as a key route through which the circadian timing system imparts a daily rhythm on cognitive capacity.


Assuntos
Relógios Circadianos , Ritmo Circadiano , Cognição/fisiologia , Hipocampo/metabolismo , MicroRNAs/metabolismo , Plasticidade Neuronal , Animais , Condicionamento Clássico , Medo , Feminino , Masculino , Rememoração Mental/fisiologia , Proteína 2 de Ligação a Metil-CpG/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , MicroRNAs/genética , Neurônios/metabolismo , Sirtuína 1/metabolismo
13.
Int J Cancer ; 138(2): 417-27, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26235173

RESUMO

Skeleton and liver are preferred organs for cancer dissemination in metastatic melanoma negatively impacting quality of life, therapeutic success and overall survival rates. At the target organ, the local microenvironment and cell-to-cell interactions between invading and resident stromal cells constitute critical components during the establishment and progression of metastasis. Mesenchymal stem cells (MSCs) possess, in addition to their cell progenitor function, a secretory capacity based on cooperativity with other cell types in injury sites including primary tumors (PT). However, their role at the target organ microenvironment during cancer dissemination is not known. We report that local MSCs, acting as pericytes, regulate the extravasation of melanoma cancer cells (MCC) specifically to murine bone marrow (BM) and liver. Intra-arterially injected wild-type MCC fail to invade those selective organs in a genetic model of perturbed pericyte coverage of the vasculature (PDGF-B(ret/ret)), similar to CD146-deficient MCC injected into wild type mice. Invading MCC interact with resident MSCs/pericytes at the perivascular space through co-expressed CD146 and Sdf-1/CXCL12-CXCR4 signaling. Implanted engineered bone structures with MSCs/pericytes deficient of either Sdf-1/CXCL12 or CD146 become resistant to invasion by circulating MCC. Collectively, the presence of MSCs/pericytes surrounding the target organ vasculature is required for efficient melanoma metastasis to BM and liver.


Assuntos
Melanoma/patologia , Células-Tronco Mesenquimais/patologia , Invasividade Neoplásica/patologia , Microambiente Tumoral/fisiologia , Animais , Neoplasias Ósseas/secundário , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/secundário , Camundongos , Camundongos Transgênicos , Pericitos/patologia
14.
Mol Ther ; 22(1): 160-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24067545

RESUMO

It has been hypothesized that mesenchymal stem cells (MSCs) home to sites of injury. Nevertheless, efficient delivery of MSCs to target organs and description of their ultimate fate remain major challenges. We provide evidence that intra-arterially (IA) injected MSCs selectively engraft from the circulation as perivascular cells in the bone marrow (BM) after a localized radiation injury. Luciferase-expressing MSCs, derived from a conditionally immortalized clone (BMC-9) representing a pure population of cells, were arterially delivered into mice irradiated in one leg. Cell distribution was measured by bioluminescent imaging and final destination assessed by luciferase immunolocalization. IA injections resulted in engraftment only in the irradiated leg where cells localize and proliferate abluminal to the BM vasculature, a phenomenon not replicated with intravenous injections or with IA injections of kidney cells harvested from the same donor used for MSCs. Furthermore, MSCs harvested from the engrafted marrow and serially transplanted retain the ability to selectively engraft at sites of injury. This study demonstrates that MSCs can serially engraft at sites of injury from the circulation, that they reside in the perivascular space, and that arterial delivery is more efficient than venous delivery for cell engraftment.


Assuntos
Medula Óssea/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Animais , Medula Óssea/patologia , Linhagem Celular , Sobrevivência de Enxerto , Camundongos , Modelos Animais , Irradiação Corporal Total
15.
J Neurosci ; 33(21): 9021-7, 2013 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-23699513

RESUMO

The CREB/CRE transcriptional pathway has been implicated in circadian clock timing and light-evoked clock resetting. To date, much of the work on CREB in circadian physiology has focused on how changes in the phosphorylation state of CREB regulate the timing processes. However, beyond changes in phosphorylation, CREB-dependent transcription can also be regulated by the CREB coactivator CRTC (CREB-regulated transcription coactivator), also known as TORC (transducer of regulated CREB). Here we profiled both the rhythmic and light-evoked regulation of CRTC1 and CRTC2 in the murine suprachiasmatic nucleus (SCN), the locus of the master mammalian clock. Immunohistochemical analysis revealed rhythmic expression of CRTC1 in the SCN. CRTC1 expression was detected throughout the dorsoventral extent of the SCN in the middle of the subjective day, with limited expression during early night, and late night expression levels intermediate between mid-day and early night levels. In contrast to CRTC1, robust expression of CRTC2 was detected during both the subjective day and night. During early and late subjective night, a brief light pulse induced strong nuclear accumulation of CRTC1 in the SCN. In contrast with CRTC1, photic stimulation did not affect the subcellular localization of CRTC2 in the SCN. Additionally, reporter gene profiling and chromatin immunoprecipitation analysis indicated that CRTC1 was associated with CREB in the 5' regulatory region of the period1 gene, and that overexpression of CRTC1 leads to a marked upregulation in period1 transcription. Together, these data raise the prospect that CRTC1 plays a role in fundamental aspects of SCN clock timing and entrainment.


Assuntos
Proteína de Ligação a CREB/metabolismo , Relógios Circadianos/fisiologia , Luz , Núcleo Supraquiasmático/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima/fisiologia , Animais , Proteína de Ligação a CREB/genética , Imunoprecipitação da Cromatina , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Circadianas Period/genética , Proteínas Circadianas Period/metabolismo , Fosfopiruvato Hidratase/metabolismo , Estimulação Luminosa , Fatores de Transcrição/genética , Transfecção , Regulação para Cima/efeitos da radiação
16.
Dev Neurosci ; 36(6): 520-31, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25342396

RESUMO

Hydrocephalus is a common neurological condition in children characterized by an imbalance between the production and absorption of cerebrospinal fluid (CSF), causing abnormal fluid accumulation in the brain cavities. Shunt systems have been used to drain excess CSF and to prevent progressive ventricular enlargement. However, despite improvements in these systems, neurological and structural changes cannot always be reversed. Our aim was to evaluate the magnetization transfer ratio as a biomarker for the effectiveness of a CSF shunt system to treat neurological and behavioral disorders observed in experimental hydrocephalus. Seven-day-old Wistar rats were used in this study. The pups were subjected to hydrocephalus induction via 20% kaolin intracisternal injection. After confirmation of ventriculomegaly by magnetic resonance imaging (MRI), a group of animals underwent placement of a ventriculosubcutaneous shunt (VSS). The reduction in ventricular size in hydrocephalic rats operated with functional VSS was observed as a decrease in ventricular ratio values and preservation of the corpus callosum thickness. Magnetization transfer values were significantly increased and matched to the recovery process of axonal myelination observed based on more-intense blue staining by solochrome cyanin. The histopathological analysis revealed a reduction in reactive astrocytes by means of GFAP immunostaining. The hydrocephalic rats operated with functional VSS also showed significant progress in motor and exploratory activities, similar to the control animals, at the end of the experiment. In conclusion, the VSS system employed 7 days after hydrocephalus induction was able to prevent structural damage and restore the axonal myelination process in periventricular structures by stabilizing and reducing the ventricular enlargement, and the results are in accordance with the magnetization transfer ratio in MRI.


Assuntos
Axônios/fisiologia , Comportamento Animal/fisiologia , Ventrículos Cerebrais/patologia , Derivações do Líquido Cefalorraquidiano/métodos , Hidrocefalia/cirurgia , Bainha de Mielina/fisiologia , Animais , Biomarcadores , Ventrículos Cerebrais/cirurgia , Modelos Animais de Doenças , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Wistar
17.
Childs Nerv Syst ; 30(4): 591-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24005799

RESUMO

PURPOSE: This study tested possible neuroprotective effects of Camellia sinensis-extracted polyphenols in experimental hydrocephalus in young rats. METHODS: Seven-day-old Wistar rats were used in this study. Pups were subjected to hydrocephalus induction by 20 % kaolin intracisternal injection. The polyphenol was administered intraperitoneally for 9 or 20 days from the induction of hydrocephalus. Clinical observations and behavioral tests were performed once a day. The animals, deeply anesthetized, were sacrificed by cardiac perfusion with saline 10 or 21 days after induction of hydrocephalus and their brains were removed. Preparations were made for histological analysis by hematoxylin and eosin, solochrome-cyanine, and immunohistochemistry for GFAP. RESULTS: Histopathological analysis showed that animals treated with the polyphenol for 9 consecutive days displayed reduction on astrocyte activity on the corpus callosum and external capsule, shown by GFAP immunostaining. They also displayed thicker and myelinated corpus callosum, exhibiting a more intense solochrome-cyanine blue staining. CONCLUSION: Although these results demonstrate a possible neuroprotective effect at the initial onset of the disease, additional studies should be performed to obtain an effective and safe therapy for deeper studies in clinical trials.


Assuntos
Encéfalo/patologia , Camellia sinensis , Hidrocefalia/patologia , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Animais , Modelos Animais de Doenças , Imuno-Histoquímica , Masculino , Ratos , Ratos Wistar
18.
Biomedicines ; 12(5)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38790957

RESUMO

Tendinopathies continue to be a challenge for both patients and the medical teams providing care as no universal clinical practice guidelines have been established. In general, tendinopathies are typically characterized by prolonged, localized, activity-related pain with abnormalities in tissue composition, cellularity, and microstructure that may be observed on imaging or histology. In the lower limb, tendinopathies affecting the Achilles and the patellar tendons are the most common, showing a high incidence in athletic populations. Consistent diagnosis and management have been challenged by a lack of universal consensus on the pathophysiology and clinical presentation. Current management is primarily based on symptom relief and often consists of medications such as non-steroidal anti-inflammatories, injectable therapies, and exercise regimens that typically emphasize progressive eccentric loading of the affected structures. Implementing the knowledge of tendon stem/progenitor cells (TSPCs) and assessing their potential in enhancing tendon repair could fill an important gap in this regard. In the present pilot in vivo study, we have characterized the structural and cellular alterations that occur soon after tendon insult in models of both Achilles and patellar tendinopathy. Upon injury, CD146+ TSPCs are recruited from the interfascicular tendon matrix to the vicinity of the paratenon, whereas the observed reduction in M1 macrophage polarization is related to a greater abundance of reparative CD146+ TSPCs in situ. The robust TSPCs' immunomodulatory effects on macrophages were also demonstrated in in vitro settings where TSPCs can effectively polarize M1 macrophages towards an anti-inflammatory therapeutic M2 phenotype. Although preliminary, our findings suggest CD146+ TSPCs as a key phenotype that could be explored in the development of targeted regenerative therapies for tendinopathies.

19.
J Biomed Mater Res B Appl Biomater ; 112(1): e35319, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37610175

RESUMO

Cobalt-doped monetite powders were synthesized by coprecipitation method under a cobalt nominal content between 2 and 20 mol % of total cation. Structural characterization of samples was performed by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. XRD results indicated that the Co-doped samples exhibited a monetite single-phase with the cell parameters and crystallite size dependent on the amount of substitutional element incorporated into the triclinic crystalline structure. Cell viability and adhesion assays using pre-osteoblastic cells showed there is no toxicity and the RTqPCR analysis showed significant differences in the expression for osteoblastic phenotype genes, showing a potential material for the bone regeneration.


Assuntos
Fosfatos de Cálcio , Cobalto , Cobalto/farmacologia , Cobalto/química , Regeneração Óssea , Difração de Raios X , Espectroscopia de Infravermelho com Transformada de Fourier
20.
ISA Trans ; 139: 391-405, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37217378

RESUMO

Covid-19, caused by severe acute respiratory syndrome coronavirus 2, broke out as a pandemic during the beginning of 2020. The rapid spread of the disease prompted an unprecedented global response involving academic institutions, regulatory agencies, and industries. Vaccination and nonpharmaceutical interventions including social distancing have proven to be the most effective strategies to combat the pandemic. In this context, it is crucial to understand the dynamic behavior of the Covid-19 spread together with possible vaccination strategies. In this study, a susceptible-infected-removed-sick model with vaccination (SIRSi-vaccine) was proposed, accounting for the unreported yet infectious. The model considered the possibility of temporary immunity following infection or vaccination. Both situations contribute toward the spread of diseases. The transcritical bifurcation diagram of alternating and mutually exclusive stabilities for both disease-free and endemic equilibria were determined in the parameter space of vaccination rate and isolation index. The existing equilibrium conditions for both points were determined in terms of the epidemiological parameters of the model. The bifurcation diagram allowed us to estimate the maximum number of confirmed cases expected for each set of parameters. The model was fitted with data from São Paulo, the state capital of SP, Brazil, which describes the number of confirmed infected cases and the isolation index for the considered data window. Furthermore, simulation results demonstrate the possibility of periodic undamped oscillatory behavior of the susceptible population and the number of confirmed cases forced by the periodic small-amplitude oscillations in the isolation index. The main contributions of the proposed model are as follows: A minimum effort was required when vaccination was combined with social isolation, while additionally ensuring the existence of equilibrium points. The model could provide valuable information for policymakers, helping define disease prevention mitigation strategies that combine vaccination and non-pharmaceutical interventions, such as social distancing and the use of masks. In addition, the SIRSi-vaccine model facilitated the qualitative assessment of information regarding the unreported infected yet infectious cases, while considering temporary immunity, vaccination, and social isolation index.


Assuntos
COVID-19 , Vacinas , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Brasil , SARS-CoV-2
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA