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1.
Int J Parasitol Drugs Drug Resist ; 24: 100529, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38461700

RESUMO

Earlier evidences showed that diglycosyl diselenides are active against the infective stage of African trypanosomes (top hits IC50 0.5 and 1.5 µM) but poorly selective (selectivity index <10). Here we extended the study to 33 new seleno-glycoconjugates with the aim to improve potency and selectivity. Three selenoglycosides and three glycosyl selenenylsulfides displayed IC50 against bloodstream Trypanosoma brucei in the sub-µM range (IC50 0.35-0.77 µM) and four of them showed an improved selectivity (selectivity index >38-folds vs. murine and human macrohages). For the glycosyl selenylsulfides, the anti-trypanosomal activity was not significantly influenced by the nature of the moiety attached to the sulfur atom. Except for a quinoline-, and to a minor extent a nitro-derivative, the most selective hits induced a rapid (within 60 min) and marked perturbation of the LMWT-redox homeostasis. The formation of selenenylsulfide glycoconjugates with free thiols has been identified as a potential mechanism involved in this process.


Assuntos
Tripanossomicidas , Trypanosoma brucei brucei , Trypanosoma , Tripanossomíase Africana , Animais , Camundongos , Humanos , Homeostase , Oxirredução , Tripanossomíase Africana/tratamento farmacológico , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico
2.
Neurotherapeutics ; : e00340, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38472048

RESUMO

Amyotrophic lateral sclerosis (ALS) is a rare neuromuscular disease characterized by severe muscle weakness mainly due to degeneration and death of motor neurons. A peculiarity of the neurodegenerative processes is the variable susceptibility among distinct neuronal populations, exemplified by the contrasting resilience of motor neurons innervating the ocular motor system and the more vulnerable facial and hypoglossal motor neurons. The crucial role of vascular endothelial growth factor (VEGF) as a neuroprotective factor in the nervous system is well-established since a deficit of VEGF has been related to motoneuronal degeneration. In this study, we investigated the survival of ocular, facial, and hypoglossal motor neurons utilizing the murine SOD1G93A ALS model at various stages of the disease. Our primary objective was to determine whether the survival of the different brainstem motor neurons was linked to disparate VEGF expression levels in resilient and susceptible motor neurons throughout neurodegeneration. Our findings revealed a selective loss of motor neurons exclusively within the vulnerable nuclei. Furthermore, a significantly higher level of VEGF was detected in the more resistant motor neurons, the extraocular ones. We also examined whether TDP-43 dynamics in the brainstem motor neuron of SOD mice was altered. Our data suggests that the increased VEGF levels observed in extraocular motor neurons may potentially underlie their resistance during the neurodegenerative processes in ALS in a TDP-43-independent manner. Our work might help to better understand the underlying mechanisms of selective vulnerability of motor neurons in ALS.

3.
Biol Sex Differ ; 14(1): 59, 2023 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-37716988

RESUMO

BACKGROUND: The amyloid-ß (Aß) cascade is one of the most studied theories linked to AD. In multiple models, Aß accumulation and dyshomeostasis have shown a key role in AD onset, leading to excitatory/inhibitory imbalance, the impairments of synaptic plasticity and oscillatory activity, and memory deficits. Despite the higher prevalence of Alzheimer's disease (AD) in women compared to men, the possible sex difference is scarcely explored and the information from amyloidosis transgenic mice models is contradictory. Thus, given the lack of data regarding the early stages of amyloidosis in female mice, the aim of this study was to systematically characterize the effect of an intracerebroventricular (icv.) injection of Aß1-42 on hippocampal-dependent memory, and on associated activity-dependent synaptic plasticity in the hippocampal CA1-CA3 synapse, in both male and female mice. METHODS: To do so, we evaluated long term potentiation (LTP) with ex vivo electrophysiological recordings as well as encoding and retrieval of spatial (working, short- and long-term) and exploratory habituation memories using Barnes maze and object location, or open field habituation tasks, respectively. RESULTS: Aß1-42 administration impaired all forms of memory evaluated in this work, regardless of sex. This effect was displayed in a long-lasting manner (up to 17 days post-injection). LTP was inhibited at a postsynaptic level, both in males and females, and a long-term depression (LTD) was induced for the same prolonged period, which could underlie memory deficits. CONCLUSIONS: In conclusion, our results provide further evidence on the shifting of LTP/LTD threshold due to a single icv. Aß1-42 injection, which underly cognitive deficits in the early stages of AD. These long-lasting cognitive and functional alterations in males and females validate this model for the study of early amyloidosis in both sexes, thus offering a solid alternative to the inconsistence of amyloidosis transgenic mice models.


This study focuses on investigating how amyloid-ß (Aß), a key toxic protein in Alzheimer's disease (AD), impacts memory and functioning of the synapses in both male and female mice.Our primary objective was to comprehensively understand the impact of Aß1­42, a specific form of Aß, when introduced into the brain's ventricles, focusing on memory processes associated with the hippocampus, a brain region vital for learning and memory.Prior research established Aß's significance in AD and memory decline. However, despite the higher prevalence of AD in females, the connection between Aß, memory, and sex differences required further exploration. Furthermore, findings from experiments utilizing Aß transgenic mice have offered conflicting outcomes. Here, by administering Aß1­42 to male and female mice, we systematically assessed memory using cognitive tasks. Results were consistent: memory deficits were evident in both sexes, persisting for up to 17 days post-injection.Delving deeper, we explored alterations in synaptic plasticity, a cornerstone of learning and memory. Our investigations unveiled disruptions in long-term potentiation (LTP) and long-term depression (LTD)­essential synaptic processes­in both male and female mice subjected to Aß1­42 injection.These intriguing findings underscore Aß1­42's lasting influence on memory and synaptic function, emphasizing its role in early AD-related cognitive decline. Additionally, our study highlights the potential of this experimental model to investigate early AD across sex differences, offering a promising alternative to the existing array Aß transgenic mouse models and addressing the need for a more consistent investigative framework.


Assuntos
Doença de Alzheimer , Amiloidose , Feminino , Masculino , Humanos , Camundongos , Animais , Plasticidade Neuronal , Camundongos Transgênicos , Transtornos da Memória
4.
Proc Natl Acad Sci U S A ; 120(28): e2302143120, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37399380

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease affecting motor neurons and characterized by microglia-mediated neurotoxic inflammation whose underlying mechanisms remain incompletely understood. In this work, we reveal that MAPK/MAK/MRK overlapping kinase (MOK), with an unknown physiological substrate, displays an immune function by controlling inflammatory and type-I interferon (IFN) responses in microglia which are detrimental to primary motor neurons. Moreover, we uncover the epigenetic reader bromodomain-containing protein 4 (Brd4) as an effector protein regulated by MOK, by promoting Ser492-phospho-Brd4 levels. We further demonstrate that MOK regulates Brd4 functions by supporting its binding to cytokine gene promoters, therefore enabling innate immune responses. Remarkably, we show that MOK levels are increased in the ALS spinal cord, particularly in microglial cells, and that administration of a chemical MOK inhibitor to ALS model mice can modulate Ser492-phospho-Brd4 levels, suppress microglial activation, and modify the disease course, indicating a pathophysiological role of MOK kinase in ALS and neuroinflammation.


Assuntos
Esclerose Amiotrófica Lateral , Proteínas que Contêm Bromodomínio , Proteínas Quinases Ativadas por Mitógeno , Doenças Neurodegenerativas , Animais , Camundongos , Esclerose Amiotrófica Lateral/metabolismo , Modelos Animais de Doenças , Microglia/metabolismo , Doenças Neurodegenerativas/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas que Contêm Bromodomínio/genética , Proteínas que Contêm Bromodomínio/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo
5.
Rev. colomb. biotecnol ; 25(1)jun. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1535725

RESUMO

A medida que como sociedad vamos dando más importancia a lograr una economía circular, se hace importante encontrar fuentes renovables aptas para la producción de biocombustibles y bioquímicos. En los últimos años, diversas fuentes de biomasa lignocelulósica han sido estudiadas para estos propósitos. Dentro de estas fuentes de biomasa se encuentra el cáñamo (Cannabis sativa L.), siendo parte de una industria que ha crecido a pasos agigantados en las últimas décadas, en Colombia, desde su legalización. Específicamente, la industria del cannabis medicinal es responsable de generar una enorme cantidad de residuos en forma de los tallos de la planta, considerados un subproducto de bajo valor. En esta revisión se compila la información de diferentes estudios sobre el aprovechamiento de la fracción de polisacáridos de biomasa cáñamo, mediante transformaciones químicas y bioquímicas, para la obtención de productos de valor agregado. Se encontró que la mayoría de estudios están enfocados en la obtención de bioetanol o biogás; se encontraron también reportes de otras moléculas como ácido succínico, ácido láctico, furfural, polihidroxialcanoatos y bisaboleno. La viabilidad a nivel industrial de todos estos procesos permanece siendo una incógnita, pues los pasos de pretratamiento, hidrólisis y de conversión final utilizados suelen ser costosos. Es necesario que los estudios que realicen en el futuro se enfoquen en optimizar las condiciones de estos procesos y hacerlos verdes y así asegurar que puedan ser escalados.


As we as a society, give more importance to achieving a circular economy, it becomes important to find renewable sources suitable for the production of biofuels and biochemicals. In the last years, several different sources of lignocellulosic biomass have been studied for these purposes. One of these biomass sources is hemp (Cannabis sativa L), being part of an industry that has grown through giant steps in the last decades, in Colombia, since its legalization. Specifically, the industry of medicinal hemp is responsible for the generation of huge amounts of residues in the form of the plant stalks, considered a low value subproduct. This review compiles the information of several studies about the exploitation of the polysaccharide portion of hemp biomass through chemical and biochemical transformations, obtaining value-added products. It was found that most of these studies focus on the production of bioetanol or biogas; reports of other molecules such as succinic acid, furfural, polyhydroxyalkanoates and bisabolene were also found. Industrial viability of these processes remains a question, since pretreatment, hydrolysis and final conversion steps are usually expensive. It necessary that future studies focus on optimizing conditions of these processes as well as making them green, ensuring that they can be scaled.

6.
Sensors (Basel) ; 22(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36146348

RESUMO

Wearable sensors facilitate the evaluation of gait and balance impairment in the free-living environment, often with observation periods spanning weeks, months, and even years. Data supporting the minimal duration of sensor wear, which is necessary to capture representative variability in impairment measures, are needed to balance patient burden, data quality, and study cost. Prior investigations have examined the duration required for resolving a variety of movement variables (e.g., gait speed, sit-to-stand tests), but these studies use differing methodologies and have only examined a small subset of potential measures of gait and balance impairment. Notably, postural sway measures have not yet been considered in these analyses. Here, we propose a three-level framework for examining this problem. Difference testing and intra-class correlations (ICC) are used to examine the agreement in features computed from potential wear durations (levels one and two). The association between features and established patient reported outcomes at each wear duration is also considered (level three) for determining the necessary wear duration. Utilizing wearable accelerometer data continuously collected from 22 persons with multiple sclerosis (PwMS) for 6 weeks, this framework suggests that 2 to 3 days of monitoring may be sufficient to capture most of the variability in gait and sway; however, longer periods (e.g., 3 to 6 days) may be needed to establish strong correlations to patient-reported clinical measures. Regression analysis indicates that the required wear duration depends on both the observation frequency and variability of the measure being considered. This approach provides a framework for evaluating wear duration as one aspect of the comprehensive assessment, which is necessary to ensure that wearable sensor-based methods for capturing gait and balance impairment in the free-living environment are fit for purpose.


Assuntos
Esclerose Múltipla , Dispositivos Eletrônicos Vestíveis , Marcha , Humanos , Equilíbrio Postural , Velocidade de Caminhada
7.
J Enzyme Inhib Med Chem ; 37(1): 912-929, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35306933

RESUMO

Trypanothione synthetase (TryS) catalyses the synthesis of N1,N8-bis(glutathionyl)spermidine (trypanothione), which is the main low molecular mass thiol supporting several redox functions in trypanosomatids. TryS attracts attention as molecular target for drug development against pathogens causing severe and fatal diseases in mammals. A drug discovery campaign aimed to identify and characterise new inhibitors of TryS with promising biological activity was conducted. A large compound library (n = 51,624), most of them bearing drug-like properties, was primarily screened against TryS from Trypanosoma brucei (TbTryS). With a true-hit rate of 0.056%, several of the TbTryS hits (IC50 from 1.2 to 36 µM) also targeted the homologue enzyme from Leishmania infantum and Trypanosoma cruzi (IC50 values from 2.6 to 40 µM). Calmidazolium chloride and Ebselen stand out for their multi-species anti-TryS activity at low µM concentrations (IC50 from 2.6 to 13.8 µM). The moieties carboxy piperidine amide and amide methyl thiazole phenyl were identified as novel TbTryS inhibitor scaffolds. Several of the TryS hits presented one-digit µM EC50 against T. cruzi and L. donovani amastigotes but proved cytotoxic against the human osteosarcoma and macrophage host cells (selectivity index ≤ 3). In contrast, seven hits showed a significantly higher selectivity against T. b. brucei (selectivity index from 11 to 182). Non-invasive redox assays confirmed that Ebselen, a multi-TryS inhibitor, induces an intracellular oxidative milieu in bloodstream T. b. brucei. Kinetic and mass spectrometry analysis revealed that Ebselen is a slow-binding inhibitor that modifies irreversible a highly conserved cysteine residue from the TryS's synthetase domain. The most potent TbTryS inhibitor (a singleton containing an adamantine moiety) exerted a non-covalent, non-competitive (with any of the substrates) inhibition of the enzyme. These data feed the drug discovery pipeline for trypanosomatids with novel and valuable information on chemical entities with drug potential.


Assuntos
Amida Sintases/antagonistas & inibidores , Antineoplásicos/farmacologia , Antiprotozoários/farmacologia , Leishmania infantum/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos , Amida Sintases/metabolismo , Antineoplásicos/síntese química , Antineoplásicos/química , Antiprotozoários/síntese química , Antiprotozoários/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leishmania infantum/enzimologia , Macrófagos/efeitos dos fármacos , Estrutura Molecular , Relação Estrutura-Atividade , Trypanosoma cruzi/enzimologia
8.
Theranostics ; 11(14): 6983-7004, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093866

RESUMO

Rationale: We recently demonstrated that the 'Metabesity' factor HMG20A regulates islet beta-cell functional maturity and adaptation to physiological stress such as pregnancy and pre-diabetes. HMG20A also dictates central nervous system (CNS) development via inhibition of the LSD1-CoREST complex but its expression pattern and function in adult brain remains unknown. Herein we sought to determine whether HMG20A is expressed in the adult CNS, specifically in hypothalamic astrocytes that are key in glucose homeostasis and whether similar to islets, HMG20A potentiates astrocyte function in response to environmental cues. Methods: HMG20A expression profile was assessed by quantitative PCR (QT-PCR), Western blotting and/or immunofluorescence in: 1) the hypothalamus of mice exposed or not to either a high-fat diet or a high-fat high-sucrose regimen, 2) human blood leukocytes and adipose tissue obtained from healthy or diabetic individuals and 3) primary mouse hypothalamic astrocytes exposed to either high glucose or palmitate. RNA-seq and cell metabolic parameters were performed on astrocytes treated or not with a siHMG20A. Astrocyte-mediated neuronal survival was evaluated using conditioned media from siHMG20A-treated astrocytes. The impact of ORY1001, an inhibitor of the LSD1-CoREST complex, on HMG20A expression, reactive astrogliosis and glucose metabolism was evaluated in vitro and in vivo in high-fat high-sucrose fed mice. Results: We show that Hmg20a is predominantly expressed in hypothalamic astrocytes, the main nutrient-sensing cell type of the brain. HMG20A expression was upregulated in diet-induced obesity and glucose intolerant mice, correlating with increased transcript levels of Gfap and Il1b indicative of inflammation and reactive astrogliosis. Hmg20a transcript levels were also increased in adipose tissue of obese non-diabetic individuals as compared to obese diabetic patients. HMG20A silencing in astrocytes resulted in repression of inflammatory, cholesterol biogenesis and epithelial-to-mesenchymal transition pathways which are hallmarks of reactive astrogliosis. Accordingly, HMG20A depleted astrocytes exhibited reduced mitochondrial bioenergetics and increased susceptibility to apoptosis. Neuron viability was also hindered in HMG20A-depleted astrocyte-derived conditioned media. ORY1001 treatment rescued expression of reactive astrogliosis-linked genes in HMG20A ablated astrocytes while enhancing cell surface area, GFAP intensity and STAT3 expression in healthy astrocytes, mimicking the effect of HMG20A. Furthermore, ORY1001 treatment protected against obesity-associated glucose intolerance in mice correlating with a regression of hypothalamic HMG20A expression, indicative of reactive astrogliosis attenuation with improved health status. Conclusion: HMG20A coordinates the astrocyte polarization state. Under physiological pressure such as obesity and insulin resistance that induces low grade inflammation, HMG20A expression is increased to induce reactive astrogliosis in an attempt to preserve the neuronal network and re-establish glucose homeostasis. Nonetheless, a chronic metabesity state or functional mutations will result in lower levels of HMG20A, failure to promote reactive astrogliosis and increase susceptibility of neurons to stress-induced apoptosis. Such effects could be reversed by ORY1001 treatment both in vitro and in vivo, paving the way for a new therapeutic approach for Type 2 Diabetes Mellitus.


Assuntos
Astrócitos/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Gliose/metabolismo , Proteínas de Grupo de Alta Mobilidade/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Obesidade/metabolismo , Tecido Adiposo/metabolismo , Adulto , Animais , Sobrevivência Celular/efeitos dos fármacos , Proteínas Correpressoras/antagonistas & inibidores , Dieta Hiperlipídica , Proteína Glial Fibrilar Ácida/metabolismo , Glucose/metabolismo , Proteínas de Grupo de Alta Mobilidade/antagonistas & inibidores , Proteínas de Grupo de Alta Mobilidade/genética , Histona Desmetilases/antagonistas & inibidores , Humanos , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/antagonistas & inibidores , RNA Interferente Pequeno , RNA-Seq
9.
Eur J Med Chem ; 189: 112043, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31978782

RESUMO

Polyamides-based compounds related to the Streptomycetal distamycin and netropsin are potent cytostatic molecules that bind to AT-rich regions of the minor groove of the DNA, hence interfering with DNA replication and transcription. Recently, derivatives belonging to this scaffold have been reported to halt the proliferation of deadly African trypanosomes by different and unrelated mechanisms. Here we describe the synthesis and preliminary characterization of the anti-trypanosomal mode of action of new potent and selective distamycin analogues. Two tri-heterocyclic derivatives containing a central N-methyl pyrrole ring (16 and 17) displayed high activity (EC50 < 20 nM) and selectivity (selectivity index >5000 with respect to mammalian macrophages) against the infective form of T. brucei. Both compounds caused cell cycle arrest by blocking the replication of the mitochondrial DNA but without affecting its integrity. This mode of action clearly differs from that reported for classical minor groove binder (MGB) drugs, which induce the degradation of the mitochondrial DNA. In line with this, in vitro assays suggest that 16 and 17 have a comparatively lower affinity for different template DNAs than the MGB drug diminazene. Therapeutic efficacy studies and stability assays suggest that the pharmacological properties of the hits should be optimized. The compounds can be rated as excellent scaffolds for the design of highly potent and selective anti-T. brucei agents.


Assuntos
Ciclo Celular/efeitos dos fármacos , Distamicinas/química , Macrófagos/efeitos dos fármacos , Tiazóis/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Animais , Feminino , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Tiazóis/química , Tripanossomicidas/química , Trypanosoma/parasitologia , Tripanossomíase Africana/parasitologia
10.
Rev. colomb. biotecnol ; 21(2): 98-108, jul.-dic. 2019. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1058344

RESUMO

RESUMEN Las lipasas han sido usadas en las últimas décadas como catalizadores eficientes en la síntesis enzimática de polímeros y gracias a características como alta selectividad, reciclabilidad, inocuidad y fácil separación/purificación se han convertido en una herramienta importante en el campo de los polímeros. En este trabajo se recopilan los desarrollos más importantes en el área y a su vez se muestra la tendencia actual de este campo de investigación.


ABSTRACT Lipases have been used in last decades as efficient catalysts in enzimatic polymer chemistry, thanks to its high selectivity, recyclabil-ity, safety and easy recovery/ separation, lipases have become in an important tool in polymer field. In this paper we compile the most important achievements in the enzimatic polymer chemistry and, at the same, time we show the current trend in this field of research.

11.
Medchemcomm ; 10(8): 1481-1487, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31673311

RESUMO

1,4-Thiazepines derivatives are pharmacologically important heterocycles with different applications in medicinal chemistry. In the present work, we describe the preparation of new bicyclic thiazolidinyl-1,4-thiazepines 3 by reaction between azadithiane compounds and Michael acceptors. The reaction scope was explored and the yields were optimized. The activity of the new compounds was evaluated against Nippostrongylus brasiliensis and Caenorhabditis elegans as anthelmintic models and Trypanosoma brucei brucei. The most active compound was 3l, showing an EC50 = 2.8 ± 0.7 µM against T. b. brucei and a selectivity index >71.

12.
ACS Chem Neurosci ; 10(8): 3464-3478, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31313906

RESUMO

The formation of misfolded protein oligomers during early stages of amyloid aggregation and the activation of neuroinflammatory responses are two key events associated with neurodegenerative diseases. Although it has been established that misfolded oligomers are involved in the neuroinflammatory process, the links between their structural features and their functional effects on the immune response remain unknown. To explore such links, we took advantage of two structurally distinct soluble oligomers (type A and B) of protein HypF-N and compared the elicited microglial inflammatory responses. By using confocal microscopy, protein pull-down, and high-throughput mass spectrometry, we found that, even though both types bound to a common pool of microglial proteins, type B oligomers-with a lower solvent-exposed hydrophobicity-showed enhanced protein binding, correlating with the observed inflammatory response. Furthermore, the interactome associated with inflammatory-mediated neurodegeneration revealed previously unidentified receptors and signaling molecules likely to be involved in the oligomer-elicited innate immune response.


Assuntos
Carboxil e Carbamoil Transferases/imunologia , Proteínas de Escherichia coli/imunologia , Imunidade Inata/imunologia , Microglia/imunologia , Agregação Patológica de Proteínas/imunologia , Animais , Linhagem Celular , Cricetinae , Humanos , Camundongos , Microglia/patologia , Agregação Patológica de Proteínas/patologia , Ligação Proteica
13.
Nanomaterials (Basel) ; 9(2)2019 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-30781838

RESUMO

Progress in the field of biocompatible SERS nanoparticles has promising prospects for biomedical applications. In this work, we have developed a biocompatible Raman probe by combining anisotropic silver nanoparticles with the dye rhodamine 6G followed by subsequent coating with bovine serum albumin. This nanosystem presents strong SERS capabilities in the near infrared (NIR) with a very high (2.7 × 107) analytical enhancement factor. Theoretical calculations reveal the effects of the electromagnetic and chemical mechanisms in the observed SERS effect for this nanosystem. Finite element method (FEM) calculations showed a considerable near field enhancement in NIR. Using density functional quantum chemical calculations, the chemical enhancement mechanism of rhodamine 6G by interaction with the nanoparticles was probed, allowing us to calculate spectra that closely reproduce the experimental results. The nanosystem was tested in cell culture experiments, showing cell internalization and also proving to be completely biocompatible, as no cell death was observed. Using a NIR laser, SERS signals could be detected even from inside cells, proving the applicability of this nanosystem as a biocompatible SERS probe.

14.
Front Med (Lausanne) ; 6: 292, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32039212

RESUMO

Myasis is the infestation by fly larvae (Diptera) in live vertebrates including humans. Myasis has been reported most commonly in tropical and subtropical areas around the world with poor sanitation and presence of cattle. Neonatal umbilical myiasis is an important cause of death in bovines and produces major economic losses in the livestock industry. However, its presentation in humans is rare, with a few cases reported worldwide. Moreover, umbilical myasis can be life-treating due to the risk of larvae migration to deeper tissues of the abdomen, omphalitis, and sepsis. We describe the case of a 7-day-old infant admitted to the hospital due to umbilical cord myiasis. In total, 55 larvae were removed from the wound and identified as Cochliomyia hominivorax. The patient recovered satisfactorily after treatment with ivermectin and amoxicillin. A literature search was performed in Pubmed, Medline, Lilacs and Google Scholar, with 64 cases of myasis by C. hominivorax being reviewed. Oral cavity, wounds, scalp and natural orifices are the main affected anatomical areas. Risk factors include the extremes of age, male sex, poor hygiene, alcohol and drug use, cancer, and mental disability. Programs for human myiasis prevention and surveillance are needed in neotropical areas where living conditions make it difficult to implement control strategies.

15.
J Cell Physiol ; 233(10): 6317-6328, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29319169

RESUMO

Adipose tissue is an important source of adipose derived stem cells (ADSCs). These cells have the potential of being used for certain therapies, in which the main objective is to recover the function of a tissue/organ affected by a disease. In order to contribute to repair of the tissue, these cells should be able to survive and carry out their functions in unfavorable conditions after being transplanted. This process requires a better understanding of the biology involved: such as the time cells remain in the implant site, how long they stay there, and whether or not they differentiate into host tissue cells. This report focuses on these questions. ADSC were injected into three different tissues (substantia nigra, ventricle, liver) and they were tracked in vivo with a dual GFP-Luc reporter system. The results show that ADSCs were able to survive up to 4 months after the engraftment and some of them started showing resident cell tissue phenotype. These results demonstrate their long-term capacity of survival and differentiation when injected in vivo.


Assuntos
Sobrevivência Celular/fisiologia , Rastreamento de Células/normas , Transplante de Células-Tronco/normas , Células-Tronco/citologia , Adipócitos/citologia , Tecido Adiposo/citologia , Animais , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Humanos , Fígado/fisiologia , Fígado/cirurgia , Ratos , Ratos Wistar , Células-Tronco/fisiologia , Substância Negra/fisiologia , Substância Negra/cirurgia , Função Ventricular/fisiologia
16.
Glia ; 66(1): 191-205, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29024008

RESUMO

Neuroinflammation mediated by chronically activated microglia, largely caused by abnormal accumulation of misfolded α-synuclein (αSyn) protein, is known to contribute to the pathophysiology of Parkinson's disease (PD). In this work, based on the immunomodulatory activities displayed by particular heat-shock proteins (HSPs), we tested a novel vaccination strategy that used a combination of αSyn and Grp94 (HSPC4 or Gp96) chaperone and a murine PD model. We used two different procedures, first, the adoptive transfer of splenocytes from αSyn/Grp94-immunized mice to recipient animals, and second, direct immunization with αSyn/Grp94, to study the effects in a chronic mouse MPTP-model of parkinsonism. We found that both approaches promoted a distinct profile in the peripheral system-supported by humoral and cellular immunity-consisting of a Th1-shifted αSyn-specific response accompanied by an immune-regulatory/Th2-skewed general phenotype. Remarkably, this mixed profile sustained by αSyn/Grp94 immunization led to strong suppression of microglial activation in the substantia nigra and striatum, pointing to a newly described positive effect of anti-αSyn Th1-responses in the context of PD. This strategy is the first to target αSyn and report the suppression of PD-associated microgliosis. Overall, we show that the αSyn/Grp94 combination supports a distinct and long-lasting immune profile in the peripheral system, which has an impact at the CNS level by suppressing chronic microglial activation in an MPTP model of PD. Furthermore, our study demonstrates that reshaping peripheral immunity by vaccination with appropriate misfolding protein/HSP combinations could be highly beneficial as a treatment for neurodegenerative misfolding diseases.


Assuntos
Gliose/etiologia , Gliose/terapia , Imunização/métodos , Intoxicação por MPTP , Glicoproteínas de Membrana/imunologia , alfa-Sinucleína/imunologia , Transferência Adotiva , Análise de Variância , Animais , Antígenos CD4/metabolismo , Doença Crônica , Citocinas/metabolismo , Modelos Animais de Doenças , Intoxicação por MPTP/induzido quimicamente , Intoxicação por MPTP/complicações , Intoxicação por MPTP/imunologia , Intoxicação por MPTP/terapia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/patologia , Substância Negra/metabolismo , Substância Negra/patologia , Linfócitos T Reguladores/metabolismo
17.
Rev. colomb. cardiol ; 24(5): 496-504, sep.-oct. 2017. tab, graf
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-900569

RESUMO

Resumen La miocarditis es una enfermedad inflamatoria del músculo cardiaco no asociada a anormalidades valvulares y en ausencia de enfermedad isquémica. Su prevalencia e incidencia se desconocen, ya que se presenta de manera subaguda o con síntomas iniciales inespecíficos. Su fisiopatología consta de tres fases: aguda (< 3 días-daño miocárdico mediado por acción directa del virus), subaguda (4-14 días-el daño miocárdico resulta de una disregulación de la respuesta autoinmune del huésped) y crónica (> 15 días-aclaramiento viral insuficiente y perpetuación del proceso inflamatorio, que conduce a remodelamiento cardiaco y falla cardiaca). Como agente etiológico más frecuente se describe el Parvovirus B19 y el herpes virus humano 6. Entre las manifestaciones clínicas: dolor torácico, arritmias, en lactantes (letargo, taquipnea, dificultad respiratoria leve, etc.), puede iniciar con pródromo viral, disfunción ventricular o muerte súbita. Tiene cuatro posibles presentaciones clínicas: asintomático, miocarditis aguda, fulminante o miocardiopatía crónica dilatada. El electrocardiograma detecta anormalidades entre el 93 al 100%; la resonancia magnética nuclear cardiovascular con gadolinio es de mayor uso, principalmente en la biopsia endomiocárdica. El tratamiento se basa en la monitorización hemodinámica del paciente, la evaluación de la necesidad de diuréticos, inhibidores de la enzima convertidora de angiotensina, betabloqueadores no selectivos, soporte inotrópico, antiarrítmicos o, en casos severos, el requerimiento de soporte mecánico cardiovascular. Se evalúa el uso de inmunoglobulina y, de manera controversial, el de inmunosupresor y antiviral. El pronóstico es variable y depende de factores inherentes al ambiente y al huésped. Se realizó una revisión actualizada de la literatura.


Abstract Myocarditis is an inflammatory disease of the heart muscle unrelated to valvular abnormalities and ischaemic disease. The prevalence and incidence are unknown since it is presented sub-acutely or with non-specific initial symptoms. Its pathophysiology consists of three phases: acute <3 days-myocardial damage mediated by direct action a virus), sub-acute (4-14 days-the myocardial damage is due to a dysregulation of an autoimmune host response), and chronic (>15 days - insufficient viral clearance and perpetuation of the inflammatory process, which leads to cardiac remodelling and heart failure). Parvovirus B19 and human herpesvirus 6 have been described as the most common aetiological agents. The clinical signs include, chest pain, arrhythmias, and in infants (lethargy, tachypnoea, mild shortness of breath, etc.) It can start with a viral prodrome, ventricular dysfunction, or sudden death. There are four possibilities of clinical presentation: asymptomatic, acute myocarditis, fulminant or dilated chronic cardiomyopathy. The electrocardiogram detects between 93%-100% of abnormalities. Cardiovascular nuclear magnetic resonance with gadolinium is the most used, mainly in endomyocardial biopsy. Treatment is based on the haemodynamic monitoring of the patient, the evaluation of the need for diuretics, angiotensin converting enzyme inhibitors, non-selective beta-blockers, inotropic support, anti-arrhythmic drugs or, in severe cases, and the need for mechanical cardiovascular support. The use of immunoglobulin has been evaluated, and there is controversy over the use of immunosuppressives and antivirals. The prognosis is variable and depends on factors inherent to the environment and the host. An updated review of the literature is presented.


Assuntos
Humanos , Miocardite , Biópsia , Cardiomiopatias , Pediatria , Vírus
18.
Int J Parasitol Drugs Drug Resist ; 7(3): 303-313, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28826037

RESUMO

With the aim to develop compounds able to target multiple metabolic pathways and, thus, to lower the chances of drug resistance, we investigated the anti-trypanosomal activity and selectivity of a series of symmetric diglycosyl diselenides and disulfides. Of 18 compounds tested the fully acetylated forms of di-ß-D-glucopyranosyl and di-ß-D-galactopyranosyl diselenides (13 and 15, respectively) displayed strong growth inhibition against the bloodstream stage of African trypanosomes (EC50 0.54 µM for 13 and 1.49 µM for 15) although with rather low selectivity (SI < 10 assayed with murine macrophages). Nonacetylated versions of the same sugar diselenides proved to be, however, much less efficient or completely inactive to suppress trypanosome growth. Significantly, the galactosyl (15), and to a minor extent the glucosyl (13), derivative inhibited glucose catabolism but not its uptake. Both compounds induced redox unbalance in the pathogen. In vitro NMR analysis indicated that diglycosyl diselenides react with glutathione, under physiological conditions, via formation of selenenylsulfide bonds. Our results suggest that non-specific cellular targets as well as actors of the glucose and the redox metabolism of the parasite may be affected. These molecules are therefore promising leads for the development of novel multitarget antitrypanosomal agents.


Assuntos
Antiprotozoários/farmacologia , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Trypanosoma/efeitos dos fármacos , Trypanosoma/metabolismo , Animais , Glicosilação , Homeostase/fisiologia , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Redes e Vias Metabólicas/efeitos dos fármacos , Camundongos , Oxirredução/efeitos dos fármacos , Selênio/química , Selênio/farmacologia
19.
Adv Exp Med Biol ; 978: 255-275, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28523551

RESUMO

Despite being clinically described 150 years ago, the mechanisms underlying amyotrophic lateral sclerosis (ALS) pathogenesis have not yet been fully understood. Studies in both animal models of ALS and human patients reveal a plethora of alterations such as increased glutamate-mediated excitotoxicity, redox stress, increased apoptosis, defective axonal transport, protein-misfolding events, mitochondrial impairment and sustained unregulated immune responses. Regardless of being sporadic or familiar ALS, the final outcome at the cellular level is the death of upper and lower motor neurons, and once diagnosed, ALS is typically lethal within the next 5 years. There are neither clear biomarkers nor therapeutic or disease-modifying treatments for ALS.Accumulating evidence supports the concept that epigenetic-driven modifications, including altered chromatin remodelling events, RNA editing and non-coding RNA molecules, might shed light into the pathogenic mechanisms underlying sporadic/familiar ALS onset and/or severity to facilitate the identification of effective therapies, early diagnosis and potentially early-stage therapeutic interventions to increase the survival outcome of ALS patients.


Assuntos
Esclerose Amiotrófica Lateral/genética , Epigênese Genética/genética , Regulação da Expressão Gênica/genética , Acetilação , Esclerose Amiotrófica Lateral/tratamento farmacológico , Esclerose Amiotrófica Lateral/metabolismo , Esclerose Amiotrófica Lateral/patologia , Animais , Metilação de DNA/genética , Modelos Animais de Doenças , Exposição Ambiental , Interação Gene-Ambiente , Código das Histonas/genética , Inibidores de Histona Desacetilases/uso terapêutico , Histona Desacetilases/fisiologia , Humanos , MicroRNAs/genética , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Mutação , Estresse Oxidativo , Processamento de Proteína Pós-Traducional , Riluzol/uso terapêutico , Superóxido Dismutase-1/deficiência , Superóxido Dismutase-1/genética
20.
FASEB J ; 31(7): 2797-2816, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28336525

RESUMO

Dysregulated microglial responses are central in neurodegenerative proteinopathies, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar disease (FTLD). Pathologic TDP-43, which is typically found in intracellular inclusions, is a misfolding protein with emerging roles in ALS and FTLD. Recently, TDP-43 species have been found in extracellular fluids of patients; however, the overall implications of TDP-43-mediated signaling linked to neuroinflammation are poorly understood. Our work-the first, to our knowledge, to focus on innate immunity responses to TDP-43 aggregates-shows that such species are internalized by microglia and cause abnormal mobilization of endogenous TDP-43. Exposure to TDP-43 aggregates elicited not only IL-1ß, but also NLRP3-dependent and noncanonical IL-18 processing. Moreover, we report a link between TDP-43 and neuronal loss via the apoptosis-independent emerging roles of caspase-3 in neurotoxic inflammation. Our results further support the view of noncell autonomous neurodegenerative mechanisms in ALS. Remarkably, we demonstrate that TDP-43 aggregates bind to and colocalize with MAPK/MAK/MRK overlapping kinase (MOK) and show that its phosphorylation status is disrupted. Finally, we show that this TDP-43-caused activation state can be altered by exogenous Hsp27 and Hsp70 chaperones. Our study provides new insight into the immune phenotype, mechanisms, and signaling pathways that operate in microglial neurotoxic activation in ALS.-Leal-Lasarte, M. M., Franco, J. M., Labrador-Garrido, A., Pozo, D., Roodveldt, C. Extracellular TDP-43 aggregates target MAPK/MAK/MRK overlapping kinase (MOK) and trigger caspase-3/IL-18 signaling in microglia.


Assuntos
Caspase 3/metabolismo , Proteínas de Ligação a DNA/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Interleucina-18/metabolismo , Microglia/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Animais , Caspase 3/genética , Sobrevivência Celular , Células Cultivadas , Proteínas de Ligação a DNA/administração & dosagem , Regulação Enzimológica da Expressão Gênica/fisiologia , Inflamassomos/metabolismo , Inflamação/metabolismo , Interleucina-18/genética , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/genética
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