Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
1.
Proc Natl Acad Sci U S A ; 116(49): 24819-24829, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31740620

RESUMO

Chronic gut inflammatory diseases are associated with disruption of intestinal epithelial barriers and impaired mucosal immunity. HIV-1 (HIV) causes depletion of mucosal CD4+ T cells early in infection and disruption of gut epithelium, resulting in chronic inflammation and immunodeficiency. Although antiretroviral therapy (ART) is effective in suppressing viral replication, it is incapable of restoring the "leaky gut," which poses an impediment for HIV cure efforts. Strategies are needed for rapid repair of the epithelium to protect intestinal microenvironments and immunity in inflamed gut. Using an in vivo nonhuman primate intestinal loop model of HIV/AIDS, we identified the pathogenic mechanism underlying sustained disruption of gut epithelium and explored rapid repair of gut epithelium at the intersection of microbial metabolism. Molecular, immunological, and metabolomic analyses revealed marked loss of peroxisomal proliferator-activated receptor-α (PPARα) signaling, predominant impairment of mitochondrial function, and epithelial disruption both in vivo and in vitro. To elucidate pathways regulating intestinal epithelial integrity, we introduced probiotic Lactobacillus plantarum into Simian immunodeficiency virus (SIV)-inflamed intestinal lumen. Rapid recovery of the epithelium occurred within 5 h of L. plantarum administration, independent of mucosal CD4+ T cell recovery, and in the absence of ART. This intestinal barrier repair was driven by L. plantarum-induced PPARα activation and restoration of mitochondrial structure and fatty acid ß-oxidation. Our data highlight the critical role of PPARα at the intersection between microbial metabolism and epithelial repair in virally inflamed gut and as a potential mitochondrial target for restoring gut barriers in other infectious or gut inflammatory diseases.


Assuntos
Metabolismo Energético/fisiologia , Microbioma Gastrointestinal/fisiologia , Intestinos/imunologia , Intestinos/microbiologia , Mitocôndrias/metabolismo , PPAR alfa/metabolismo , Animais , Terapia Antirretroviral de Alta Atividade , Linfócitos T CD4-Positivos/imunologia , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Epitélio/imunologia , Infecções por HIV , Humanos , Imunidade nas Mucosas , Interleucina-1beta/metabolismo , Intestinos/patologia , Lactobacillus plantarum/fisiologia , Macaca mulatta , Masculino , Metabolômica , Mitocôndrias/efeitos dos fármacos , Probióticos/administração & dosagem , Probióticos/uso terapêutico , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia
2.
Hum Mol Genet ; 24(13): 3608-22, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25792727

RESUMO

The heart is a muscle with high energy demands. Hence, most patients with mitochondrial disease produced by defects in the oxidative phosphorylation (OXPHOS) system are susceptible to cardiac involvement. The presentation of mitochondrial cardiomyopathy includes hypertrophic, dilated and left ventricular noncompaction, but the molecular mechanisms involved in cardiac impairment are unknown. One of the most frequent OXPHOS defects in humans frequently associated with cardiomyopathy is cytochrome c oxidase (COX) deficiency caused by mutations in COX assembly factors such as Sco1 and Sco2. To investigate the molecular mechanisms that underlie the cardiomyopathy associated with Sco deficiency, we have heart specifically interfered scox expression, the single Drosophila Sco orthologue. Cardiac-specific knockdown of scox reduces fly lifespan, and it severely compromises heart function and structure, producing dilated cardiomyopathy. Cardiomyocytes with low levels of scox have a significant reduction in COX activity and they undergo a metabolic switch from OXPHOS to glycolysis, mimicking the clinical features found in patients harbouring Sco mutations. The major cardiac defects observed are produced by a significant increase in apoptosis, which is dp53-dependent. Genetic and molecular evidence strongly suggest that dp53 is directly involved in the development of the cardiomyopathy induced by scox deficiency. Remarkably, apoptosis is enhanced in the muscle and liver of Sco2 knock-out mice, clearly suggesting that cell death is a key feature of the COX deficiencies produced by mutations in Sco genes in humans.


Assuntos
Apoptose , Cardiomiopatias/enzimologia , Modelos Animais de Doenças , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Miocárdio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Cardiomiopatias/genética , Cardiomiopatias/metabolismo , Cardiomiopatias/fisiopatologia , Drosophila/enzimologia , Drosophila/genética , Proteínas de Drosophila/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Proteína Supressora de Tumor p53/genética
3.
Am J Med Genet A ; 173(8): 2240-2245, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28544784

RESUMO

Defects in genes encoding the isoforms of the laminin alpha subunit have been linked to various phenotypic manifestations, including brain malformations, muscular dystrophy, ocular defects, cardiomyopathy, and skin abnormalities. We report here a severe defect of neuromuscular transmission in a consanguineous patient with a homozygous variant in the laminin alpha-5 subunit gene (LAMA5). The variant c.8046C>T (p.Arg2659Trp) is rare and has a predicted deleterious effect. The affected individual, who also carries a rare homozygous sequence variant in LAMA1, had muscle weakness, myopia, and facial tics. Magnetic resonance imaging of brain showed mild volume loss and periventricular T2 prolongation. Repetitive nerve stimulation revealed 50% decrement of compound muscle action potential amplitudes and 250% facilitation immediately after exercise, Endplate studies identified a profound reduction of the endplate potential quantal content and endplates with normal postsynaptic folding that were denuded or partially occupied by small nerve terminals. Expression studies revealed that p.Arg2659Trp caused decreased binding of laminin alpha-5 to SV2A and impaired laminin-521 cell-adhesion and cell projection support in primary neuronal cultures. In summary, this report describing severe neuromuscular transmission failure in a patient with a LAMA5 mutation expands the list of phenotypes associated with defects in genes encoding alpha-laminins.


Assuntos
Laminina/genética , Síndromes Miastênicas Congênitas/genética , Doenças da Junção Neuromuscular/genética , Adulto , Face/diagnóstico por imagem , Face/fisiopatologia , Feminino , Homozigoto , Humanos , Síndromes Miastênicas Congênitas/complicações , Síndromes Miastênicas Congênitas/diagnóstico por imagem , Síndromes Miastênicas Congênitas/fisiopatologia , Miopia/complicações , Miopia/diagnóstico por imagem , Miopia/genética , Miopia/fisiopatologia , Doenças da Junção Neuromuscular/complicações , Doenças da Junção Neuromuscular/diagnóstico por imagem , Doenças da Junção Neuromuscular/fisiopatologia , Tiques/complicações , Tiques/diagnóstico por imagem , Tiques/genética , Tiques/fisiopatologia , Adulto Jovem
4.
Hum Mutat ; 36(9): 881-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26080897

RESUMO

Choline acetyltransferase catalyzes the synthesis of acetylcholine at cholinergic nerves. Mutations in human CHAT cause a congenital myasthenic syndrome due to impaired synthesis of ACh; this severe variant of the disease is frequently associated with unexpected episodes of potentially fatal apnea. The severity of this condition varies remarkably, and the molecular factors determining this variability are poorly understood. Furthermore, genotype-phenotype correlations have been difficult to establish in patients with biallelic mutations. We analyzed the protein expression of phosphorylated ChAT of seven CHAT mutations, p.Val136Met, p.Arg207His, p.Arg186Trp, p.Val194Leu, p.Pro211Ala, p.Arg566Cys, and p.Ser694Cys, in HEK-293 cells to phosphorylated ChAT, determined their enzyme kinetics and thermal stability, and examined their structural changes. Three mutations, p.Arg207His, p.Arg186Trp, and p.Arg566Cys, are novel, and p.Val136Met and p.Arg207His are homozygous in three families and associated with severe disease. The characterization of mutants showed a decrease in the overall catalytic efficiency of ChAT; in particular, those located near the active-site tunnel produced the most seriously disruptive phenotypic effects. On the other hand, p.Val136Met, which is located far from both active and substrate-binding sites, produced the most drastic reduction of ChAT expression. Overall, CHAT mutations producing low enzyme expression and severe kinetic effects are associated with the most severe phenotypes.


Assuntos
Colina O-Acetiltransferase/genética , Estudos de Associação Genética , Mutação , Síndromes Miastênicas Congênitas/genética , Adolescente , Alelos , Substituição de Aminoácidos , Sítios de Ligação , Domínio Catalítico , Pré-Escolar , Colina O-Acetiltransferase/química , Colina O-Acetiltransferase/metabolismo , Análise Mutacional de DNA , Ativação Enzimática , Feminino , Expressão Gênica , Genótipo , Células HEK293 , Humanos , Ligação de Hidrogênio , Masculino , Modelos Moleculares , Síndromes Miastênicas Congênitas/diagnóstico , Fosforilação , Conformação Proteica , Especificidade por Substrato
5.
Genesis ; 52(9): 793-808, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24895317

RESUMO

Fast and slow TnI are co-expressed in E11.5 embryos, and fast TnI is present from the very beginning of myogenesis. A novel green fluorescent protein (GFP) reporter mouse lines (FastTnI/GFP lines) that carry the primary and secondary enhancer elements of the mouse fast troponin I (fast TnI), in which reporter expression correlates precisely with distribution of the endogenous fTnI protein was generated. Using the FastTnI/GFP mouse model, we characterized the early myogenic events in mice, analyzing the migration of GFP+ myoblasts, and the formation of primary and secondary myotubes in transgenic embryos. Interestingly, we found that the two contractile fast and slow isoforms of TnI are expressed during the migration of myoblasts from the somites to the limbs and body wall, suggesting that both participate in these events. Since no sarcomeres are present in myoblasts, we speculate that the function of fast TnI in early myogenesis is, like Myosin and Tropomyosin, to participate in cell movement during the initial myogenic stages. genesis


Assuntos
Rastreamento de Células/métodos , Regulação da Expressão Gênica no Desenvolvimento , Mioblastos/metabolismo , Troponina I/genética , Animais , Extremidades/embriologia , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Camundongos Transgênicos , Modelos Animais , Desenvolvimento Muscular/genética , Miosinas/genética , Miosinas/metabolismo , Isoformas de Proteínas , Tropomiosina/genética , Tropomiosina/metabolismo , Troponina I/metabolismo
6.
Hum Genet ; 133(5): 599-616, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24281389

RESUMO

Collagen Q (ColQ) is a key multidomain functional protein of the neuromuscular junction (NMJ), crucial for anchoring acetylcholinesterase (AChE) to the basal lamina (BL) and accumulating AChE at the NMJ. The attachment of AChE to the BL is primarily accomplished by the binding of the ColQ collagen domain to the heparan sulfate proteoglycan perlecan and the COOH-terminus to the muscle-specific receptor tyrosine kinase (MuSK), which in turn plays a fundamental role in the development and maintenance of the NMJ. Yet, the precise mechanism by which ColQ anchors AChE at the NMJ remains unknown. We identified five novel mutations at the COOH-terminus of ColQ in seven patients from five families affected with endplate (EP) AChE deficiency. We found that the mutations do not affect the assembly of ColQ with AChE to form asymmetric forms of AChE or impair the interaction of ColQ with perlecan. By contrast, all mutations impair in varied degree the interaction of ColQ with MuSK as well as basement membrane extract (BME) that have no detectable MuSK. Our data confirm that the interaction of ColQ to perlecan and MuSK is crucial for anchoring AChE to the NMJ. In addition, the identified COOH-terminal mutants not only reduce the interaction of ColQ with MuSK, but also diminish the interaction of ColQ with BME. These findings suggest that the impaired attachment of COOH-terminal mutants causing EP AChE deficiency is in part independent of MuSK, and that the COOH-terminus of ColQ may interact with other proteins at the BL.


Assuntos
Acetilcolinesterase/genética , Membrana Basal/metabolismo , Colágeno/genética , Proteínas de Membrana/metabolismo , Proteínas Musculares/genética , Mutação , Síndromes Miastênicas Congênitas/genética , Acetilcolinesterase/metabolismo , Animais , Sequência de Bases , Células COS , Chlorocebus aethiops , Cromatografia Líquida , Colágeno/metabolismo , Primers do DNA , Células HEK293 , Humanos , Proteínas Musculares/metabolismo , Ligação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas em Tandem
7.
Zootaxa ; 3785: 469-80, 2014 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-24872238

RESUMO

We describe a new species of Philodryas from the highlands of southern Ecuador. The new species is distinguished from all known species of Philodryas by a unique combination of coloration, scalation, and hemipenial characters. The new species resembles Philodryas simonsii in color pattern. However, they differ notoriously by their hemipenial morphology. The three other trans-Andean members of the genus (Philodryas simonsii, Philodryas chamissonis, and Philodryas tachymenoides), along with the new species, compose a probably monophyletic group that may be characterized by the presence of ungrooved postdiastemal teeth in the maxilla. Unlike most species of the genus Philodryas, the new species shows a restricted distribution, being apparently endemic to a small region of high-altitude (3150-4450m) grasslands in the southern Andes of Ecuador.


Assuntos
Serpentes/anatomia & histologia , Serpentes/classificação , Animais , Demografia , Equador , Feminino , Masculino
8.
FEBS Open Bio ; 14(2): 276-289, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38013241

RESUMO

Mitochondrial carrier homologs 1 (MTCH1) and 2 (MTCH2) are orphan members of the mitochondrial transporter family SLC25. Human MTCH1 is also known as presenilin 1-associated protein, PSAP. MTCH2 is a receptor for tBid and is related to lipid metabolism. Both proteins have been recently described as protein insertases of the outer mitochondrial membrane. We have depleted Mtch in Drosophila and show here that mutant flies are unable to complete development, showing an excess of apoptosis during pupation; this observation was confirmed by RNAi in Schneider cells. These findings are contrary to what has been described in humans. We discuss the implications in view of recent reports concerning the function of these proteins.


Assuntos
Drosophila , Proteínas Mitocondriais , Animais , Humanos , Apoptose/genética , Drosophila/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Mitocondriais/metabolismo
9.
Bioeng Transl Med ; 8(3): e10508, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37206248

RESUMO

We have developed a serology test platform for identifying individuals with prior exposure to specific viral infections and provide data to help reduce public health risks. The serology test composed of a pair of cell lines engineered to express either a viral envelop protein (Target Cell) or a receptor to recognize the Fc region of an antibody (Reporter Cell), that is, Diagnostic-Cell-Complex (DxCell-Complex). The formation of an immune synapse, facilitated by the analyte antibody, resulted into a dual-reporter protein expression by the Reporter Cell. We validated it with human serum with confirmed history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. No signal amplification steps were necessary. The DxCell-Complex quantitatively detected the target-specific immunoglobulin G (IgG) within 1 h. Validation with clinical human serum containing SARS-CoV-2 IgG antibodies confirmed 97.04% sensitivity and 93.33% specificity. The platform can be redirected against other antibodies. Self-replication and activation-induced cell signaling, two attributes of the cell, will enable rapid and cost-effective manufacturing and its operation in healthcare facilities without requiring time-consuming signal amplification steps.

10.
Hum Mol Genet ; 19(12): 2370-9, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20371544

RESUMO

We describe a severe congenital myasthenic syndrome (CMS) caused by two missense mutations in the gene encoding the muscle specific receptor tyrosine kinase (MUSK). The identified MUSK mutations M605I and A727V are both located in the kinase domain of MuSK. Intracellular microelectrode recordings and microscopy studies of the neuromuscular junction conducted in an anconeus muscle biopsy revealed decreased miniature endplate potential amplitudes, reduced endplate size and simplification of secondary synaptic folds, which were consistent with postsynaptic deficit. The study also showed a striking reduction of the endplate potential quantal content, consistent with additional presynaptic failure. Expression studies in MuSK deficient myotubes revealed that A727V, which is located within the catalytic loop of the enzyme, caused severe impairment of agrin-dependent MuSK phosphorylation, aggregation of acetylcholine receptors (AChRs) and interaction of MuSK with Dok-7, an essential intracellular binding protein of MuSK. In contrast, M605I, resulted in only moderate impairment of agrin-dependent MuSK phosphorylation, aggregation of AChRs and interaction of MuSK with Dok-7. There was no impairment of interaction of mutants with either the low-density lipoprotein receptor-related protein, Lrp4 (a co-receptor of agrin) or with the mammalian homolog of the Drosophila tumorous imaginal discs (Tid1). Our findings demonstrate that missense mutations in MUSK can result in a severe form of CMS and indicate that the inability of MuSK mutants to interact with Dok-7, but not with Lrp4 or Tid1, is a major determinant of the pathogenesis of the CMS caused by MUSK mutations.


Assuntos
Proteínas Musculares/metabolismo , Síndromes Miastênicas Congênitas/genética , Receptores Proteína Tirosina Quinases/genética , Receptores Colinérgicos/genética , Agrina/metabolismo , Animais , Linhagem Celular , Feminino , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Camundongos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia , Mutação de Sentido Incorreto , Síndromes Miastênicas Congênitas/metabolismo , Síndromes Miastênicas Congênitas/patologia , Junção Neuromuscular/metabolismo , Junção Neuromuscular/ultraestrutura , Estrutura Secundária de Proteína , Receptores Proteína Tirosina Quinases/química , Receptores Proteína Tirosina Quinases/metabolismo , Receptores Colinérgicos/química , Receptores Colinérgicos/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Adulto Jovem
11.
Hum Genet ; 131(7): 1123-35, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22205389

RESUMO

We describe a severe form of congenital myasthenic syndrome (CMS) caused by two heteroallelic mutations: a nonsense and a missense mutation in the gene encoding agrin (AGRN). The identified mutations, Q353X and V1727F, are located at the N-terminal and at the second laminin G-like (LG2) domain of agrin, respectively. A motor-point muscle biopsy demonstrated severe disruption of the architecture of the neuromuscular junction (NMJ), including: dispersion and fragmentation of endplate areas with normal expression of acetylcholinesterase; simplification of postsynaptic membranes; pronounced reduction of the axon terminal size; widening of the primary synaptic cleft; and, collection of membranous debris material in the primary synaptic cleft and in the subsynaptic cytoplasm. Expression studies in heterologous cells revealed that the Q353X mutation abolished expression of full-length agrin. Moreover, the V1727F mutation decreased agrin-induced clustering of the acetylcholine receptor (AChR) in cultured C2 muscle cells by >100-fold, and phosphorylation of the MuSK receptor and AChR beta subunit by ~tenfold. Surprisingly, the V1727F mutant also displayed increased binding to α-dystroglycan but decreased binding to a neural (z+) agrin-specific antibody. Our findings demonstrate that agrin mutations can associate with a severe form of CMS and cause profound distortion of the architecture and function of the NMJ. The impaired ability of V1727F agrin to activate MuSK and cluster AChRs, together with its increased affinity to α-dystroglycan, mimics non-neural (z-) agrin and are important determinants of the pathogenesis of the disease.


Assuntos
Agrina/genética , Códon sem Sentido , Mutação de Sentido Incorreto , Síndromes Miastênicas Congênitas/genética , Acetilcolinesterase/metabolismo , Adulto , Agrina/química , Agrina/metabolismo , Sequência de Bases , Linhagem Celular , Distroglicanas/metabolismo , Feminino , Células HEK293 , Humanos , Masculino , Modelos Moleculares , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Síndromes Miastênicas Congênitas/metabolismo , Junção Neuromuscular/metabolismo , Junção Neuromuscular/patologia , Linhagem , Receptores Colinérgicos/genética , Receptores Colinérgicos/metabolismo , Análise de Sequência de DNA
12.
Front Microbiol ; 13: 879152, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35495669

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of the COVID-19 pandemic, is initiated by its binding to the ACE2 receptor and other co-receptors on mucosal epithelial cells. Variable outcomes of the infection and disease severity can be influenced by pre-existing risk factors. Human immunodeficiency virus (HIV), the cause of AIDS, targets the gut mucosal immune system and impairs epithelial barriers and mucosal immunity. We sought to determine the impact and mechanisms of pre-existing HIV infection increasing mucosal vulnerability to SARS-CoV-2 infection and disease. We investigated changes in the expression of ACE2 and other SARS-CoV-2 receptors and related pathways in virally inflamed gut by using the SIV infected rhesus macaque model of HIV/AIDS. Immunohistochemical analysis showed sustained/enhanced ACE2 expression in the gut epithelium of SIV infected animals compared to uninfected controls. Gut mucosal transcriptomic analysis demonstrated enhanced expression of host factors that support SARS-CoV-2 entry, replication, and infection. Metabolomic analysis of gut luminal contents revealed the impact of SIV infection as demonstrated by impaired mitochondrial function and decreased immune response, which render the host more vulnerable to other pathogens. In summary, SIV infection resulted in sustained or increased ACE2 expression in an inflamed and immune-impaired gut mucosal microenvironment. Collectively, these mucosal changes increase the susceptibility to SARS-CoV-2 infection and disease severity and result in ineffective viral clearance. Our study highlights the use of the SIV model of AIDS to fill the knowledge gap of the enteric mechanisms of co-infections as risk factors for poor disease outcomes, generation of new viral variants and immune escape in COVID-19.

13.
Microbiol Spectr ; 10(4): e0073122, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35852348

RESUMO

We have engineered a cell that can be used for diagnosing active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Isolation of individuals with active infections offers an effective solution for mitigating pandemics. However, the implementation of this practice requires robust infrastructure for rapid and intuitive testing, which is currently missing in our communities. To address this need, we engineered a fast-growing cell line into a cell-based antigen test platform for emerging viruses, i.e., DxCell, that can be rapidly deployed in decentralized health care facilities for continuous testing. The technology was characterized using cells engineered to present spike glycoprotein of SARS-CoV-2 (SARS-CoV-2-Sgp-cells) and Calu-3 host cells infected with competent SARS-CoV-2. Preclinical validation was conducted by directly incubating the DxCell with oropharyngeal swabs from mice infected with SARS-CoV-2. No sample preparation steps are necessary. The DxCell quantitatively detected the SARS-CoV-2-Sgp-cells within 1 h (P < 0.02). Reporter signal was proportional to the number of SARS-CoV-2-Sgp-cells, which represents the infection burden. The SARS-CoV-2 DxCell antigen test was benchmarked against quantitative PCR (qPCR) test and accurately differentiated between infected (n = 8) and control samples (n = 3) (P < 0.05). To demonstrate the broad applicability of the platform, we successfully redirected its specificity and tested its sensing function with cells engineered to present antigens from other viruses. In conclusion, we have developed an antigen test platform that capitalizes on the two innate functions of the cell, self-replication and activation-induced cell signaling. These provide the DxCell key advantages over existing technologies, e.g., label-free testing without sample processing, and will facilitate its implementation in decentralized health care facilities. IMPORTANCE Pandemic mitigation requires continuous testing of symptomatic or asymptomatic individuals with rapid turnaround time, and lack of this capability in our community has prolonged pandemic duration leading to obliteration of world economies. The DxCell platform is a cell-based self-replicative antigen test that detects molecular signatures of the target pathogen and can be distributed in small quantities to testing facilities for expansion on site to the desired volume. In this work, we directed this platform to target SARS-CoV-2. Unlike the PCR detection of viral mRNA that requires trained personnel, the DxCell does not require any sample preparation or signal amplification step and introduces an opportunity for a decentralized testing network.


Assuntos
COVID-19 , Animais , COVID-19/diagnóstico , Teste para COVID-19 , Camundongos , Pandemias , SARS-CoV-2/genética , Manejo de Espécimes
14.
Rev Cient Odontol (Lima) ; 10(1): e093, 2022.
Artigo em Espanhol | MEDLINE | ID: mdl-38389917

RESUMO

Objective: The purpose of this study was to determine in vitro the inhibitory activity of the ethanolic extract of Cyperus rotundus (Cajamarca - Contumazá) against a standardize strain of Streptococcus mutans (ATCC®25175™). Materials and methods: This study was an experimental in vitro study, which consisted of determining the inhibitory effect of three concentrations of the ethanolic extract of Cyperus rotundus: 250 mg/ml, 500 mg/ml, and 1000 mg/ml against a strains of Streptococcus mutans (ATCC®25175™). Ten tests were performed for each concentration, having 0.12% chlorhexidine as a positive control for Streptococcus mutans plates and 10% DMSO as a negative control. To evaluate the inhibitory effect, the disk diffusion method or Kirby-Bauer test was used, reading the results at 48 hours after initial sowing. Results: None of the three concentrations of the ethanolic extract of Cyperus rotundus demosntrated inhibitory effects on the Streptococcus mutans strain; however, the positive control, chlorhexidine, clearly showed inhibition halos of 14.43 mm ± 1.23 mm after 48 hours of incubation. Conclusions: The ethanolic extract of Cyperus rotundus did not inhibit the growth of Streptococcus mutans. It is recommended to deepen the chemical analysis of the components of this plant and explore other extraction methods to verify its bacteriostatic action versus other oral and non-oral microorganisms.

15.
Dev Biol ; 337(1): 16-28, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19835855

RESUMO

Although tight quantitative control of gene expression is required to ensure that organs and tissues function correctly, the transcriptional mechanisms underlying this process still remain poorly understood. Here, we describe novel and evolutionary conserved secondary enhancers that are needed for the regulation of the expression of Troponin I genes. Secondary enhancers are silent when tested individually in electroporated muscles but interact with the primary enhancers and are required to precisely control the appropriate timing, the tissue and fibre specificity, and the quantitative expression of these genes during muscle differentiation. Synergism is completely dependent of the fully conserved MEF2 site present on the primary enhancers core of skeletal muscle Troponin I genes. Thus, while each of these paired enhancers has a different function, the concerted action of both is crucial to recapitulate endogenous gene expression. Through comparative genomics, we predict that this mechanism has also arisen in other mammalian muscle genes. Our results reveal the existence of a novel mechanism, conserved from flies to mammals, to fine-tune gene expression in each muscle and probably other tissues.


Assuntos
Elementos Facilitadores Genéticos/fisiologia , Regulação da Expressão Gênica , Músculo Esquelético/metabolismo , Miócitos Cardíacos/metabolismo , Troponina I/genética , Animais , Sítios de Ligação , Células Cultivadas , Sequência Conservada , Óperon Lac , Fatores de Transcrição MEF2 , Masculino , Camundongos , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Fatores de Regulação Miogênica/metabolismo , Ratos , Ratos Wistar
16.
J Biol Chem ; 285(6): 3695-3704, 2010 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-20007702

RESUMO

A loss of epidermal cohesion in pemphigus vulgaris (PV) results from autoantibody action on keratinocytes (KCs) activating the signaling kinases and executioner caspases that damage KCs, causing their shrinkage, detachment from neighboring cells, and rounding up (apoptolysis). In this study, we found that PV antibody binding leads to activation of epidermal growth factor receptor kinase, Src, p38 MAPK, and JNK in KCs with time pattern variations from patient to patient. Both extrinsic and intrinsic apoptotic pathways were also activated. Although Fas ligand neutralizing antibody could inhibit the former pathway, the mechanism of activation of the latter remained unknown. PV antibodies increased cytochrome c release, suggesting damage to mitochondria. The immunoblotting experiments revealed penetration of PVIgG into the subcellular mitochondrial fraction. The antimitochondrial antibodies from different PV patients recognized distinct combinations of antigens with apparent molecular sizes of 25, 30, 35, 57, 60, and 100 kDa. Antimitochondrial antibodies were pathogenic because their absorption abolished the ability of PVIgG to cause keratinocyte detachment both in vitro and in vivo. The downstream signaling of antimitochondrial antibodies involved JNK and late p38 MAPK activation, whereas the signaling of anti-desmoglein 3 (Dsg3) antibody involved JNK and biphasic p38 MAPK activation. Using KCs grown from Dsg3(-/-) mice, we determined that Dsg3 did not serve as a surrogate antigen allowing antimitochondrial antibodies to enter KCs. The PVIgG-induced activation of epidermal growth factor receptor and Src was affected neither in Dsg3(-/-) KCs nor due to absorption of antimitochondrial antibodies. These results demonstrated that apoptolysis in PV is a complex process initiated by at least three classes of autoantibodies directed against desmosomal, mitochondrial, and other keratinocyte self-antigens. These autoantibodies synergize with the proapoptotic serum and tissue factors to trigger both extrinsic and intrinsic pathways of cell death and break the epidermal cohesion, leading to blisters. Further elucidation of the primary signaling events downstream of PV autoantigens will be crucial for the development of a more successful therapy for PV patients.


Assuntos
Autoanticorpos/imunologia , Mitocôndrias/imunologia , Pênfigo/imunologia , Animais , Apoptose/efeitos dos fármacos , Autoanticorpos/farmacologia , Caspases/metabolismo , Células Cultivadas , Citocromos c/metabolismo , Desmogleína 3/genética , Desmogleína 3/metabolismo , Receptores ErbB/metabolismo , Feminino , Humanos , Immunoblotting , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Pênfigo/fisiopatologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Quinases da Família src/metabolismo
17.
Cir Cir ; 89(4): 547-552, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34352863

RESUMO

En México, la presión coloidosmótica del plasma ha sido un tema clave del estudio de la mujer embarazada por más de dos décadas. Las investigaciones clínicas han permitido conocer sus valores en población abierta, mujeres con embarazo normal, puerperio fisiológico, preeclampsia severa, síndrome HELLP y eclampsia. También se ha reportado la relación de la presión coloidosmótica del plasma con la presión sanguínea (índice de Briones), síndrome de fuga capilar y la acumulación de líquido en cavidades serosas (derrame pleural, ascitis). Revisamos la base de datos PubMed, The Cochrane Library, OVID, Science Direct, Google Scholar, Artemisa, LILACS e IMBIOMED de 1997 a 2018 con las siguientes palabras clave: albúmina sérica, presión coloidosmótica del plasma, síndrome de fuga capilar, índice de Briones, derrame pleural, ascitis, preeclampsia severa, síndrome HELLP, eclampsia y cuidados críticos en obstetricia. Los criterios de inclusión fueron revisiones sistemáticas, meta-análisis, ensayos clínicos controlados y artículos con metodología de medicina basada en evidencia con recomendaciones sólidas. Incluimos 12 artículos mexicanos. Los objetivos de la presente investigación fueron: revisar la literatura médica de la presión coloidosmótica del plasma en preeclampsia reportada de 1997 a 2018, describir el tratamiento con albúmina humana y las perspectivas de la investigación en los siguientes años.In Mexico, plasma colloid osmotic pressure has been a key issue in the study of pregnant women for more than two decades. Clinical investigations have allowed to know their values in the open population, as well as in women with normal pregnancy, physiological puerperium, severe preeclampsia, HELLP syndrome, and eclampsia. The relationship of plasma colloid osmotic pressure with mean arterial pressure (Briones index), capillary leak syndrome and the accumulation of fluid in serous cavities (pleural effusion, and ascites) have also been reported. We reviewed the database of PubMed, The Cochrane Library, OVID, Science Direct, Google Scholar, Artemisa, LILACS, and IMBIOMED from 1997 to 2018 with the following keywords: serum albumin, plasma colloid osmotic pressure, capillary leak syndrome, Briones index, pleural effusion, ascites, severe preeclampsia, HELLP syndrome, eclampsia, and obstetrics critical care. Inclusion criteria were systematic reviews, meta-analysis, clinical controlled trials, and articles with evidence-based medicine methodology with strong recommendations. We included 12 Mexican articles. The objectives of the present investigation were to review the medical literature on plasma colloid osmotic pressure in preeclampsia reported from 1997 to 2018, describe the treatment with human albumin and the perspectives of the research in the following years.


Assuntos
Pré-Eclâmpsia , Coloides , Feminino , Humanos , México/epidemiologia , Pressão Osmótica , Pré-Eclâmpsia/epidemiologia , Gravidez , Estudos Retrospectivos
18.
JCI Insight ; 6(12)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34014838

RESUMO

Although antiretroviral therapy suppresses HIV replication, it does not eliminate viral reservoirs or restore damaged lymphoid tissue, posing obstacles to HIV eradication. Using the SIV model of AIDS, we investigated the effect of mesenchymal stem/stromal cell (MSC) infusions on gut mucosal recovery, antiviral immunity, and viral suppression and determined associated molecular/metabolic signatures. MSC administration to SIV-infected macaques resulted in viral reduction and heightened virus-specific responses. Marked clearance of SIV-positive cells from gut mucosal effector sites was correlated with robust regeneration of germinal centers, restoration of follicular B cells and T follicular helper (Tfh) cells, and enhanced antigen presentation by viral trapping within the follicular DC network. Gut transcriptomic analyses showed increased antiviral response mediated by pathways of type I/II IFN signaling, viral restriction factors, innate immunity, and B cell proliferation and provided the molecular signature underlying enhanced host immunity. Metabolic analysis revealed strong correlations between B and Tfh cell activation, anti-SIV antibodies, and IL-7 expression with enriched retinol metabolism, which facilitates gut homing of antigen-activated lymphocytes. We identified potentially new MSC functions in modulating antiviral immunity for enhanced viral clearance predominantly through type I/II IFN signaling and B cell signature, providing a road map for multipronged HIV eradication strategies.


Assuntos
Centro Germinativo , Mucosa Intestinal/imunologia , Células-Tronco Mesenquimais , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Citocinas/metabolismo , Centro Germinativo/citologia , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Imunidade Humoral/imunologia , Macaca mulatta , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/imunologia
19.
J Breath Res ; 16(1)2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34852327

RESUMO

Exhaled breath condensate (EBC) is routinely collected and analyzed in breath research. Because it contains aerosol droplets, EBC samples from SARS-CoV-2 infected individuals harbor the virus and pose the threat of infectious exposure. We report for the first time a safe and consistent method to fully inactivate SARS-CoV-2 in EBC samples and make EBC samples safe for processing and analysis. EBC samples containing infectious SARS-CoV-2 were treated with several concentrations of acetonitrile. The most commonly used 10% acetonitrile treatment for EBC processing failed to completely inactivate the virus in samples and viable virus was detected by the assay of SARS-CoV-2 infection of Vero E6 cells in a biosafety level 3 laboratory. Treatment with either 50% or 90% acetonitrile was effective to completely inactivate the virus, resulting in safe, non-infectious EBC samples that can be used for metabolomic analysis. Our study provides SARS-CoV-2 inactivation protocol for the collection and processing of EBC samples in the clinical setting and for advancing to metabolic assessments in health and disease.


Assuntos
COVID-19 , SARS-CoV-2 , Testes Respiratórios , Expiração , Humanos , Metabolômica
20.
Toxicon ; 194: 11-16, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33524427

RESUMO

Spontaneous and experimental Stryphnodendron fissuratum poisoning in cattle have been documented in the scientific literature. However, clinical and anatomopathological aspects of such poisoning are not fully understood. Thus, the objective of this study was to describe the clinical, biochemical, gross and microscopic findings of spontaneous Stryphnodendron fissuratum poisoning in cattle as well the experimental poisoning by this plant in sheep. Three outbreaks in cattle from different farms were analyzed. From these farms, S. fissuratum fruit specimens were collected and subsequently administered to six sheep. Some cattle showed clinical signs of poisoning such as blindness, apathy, dysphagia, excessive drooling, weight loss and photodermatitis. In the experimental poisoning condition, one sheep received only the peel of the fruit, one received the seed, and the others received the whole fruit. The whole fruit caused fatal poisoning in one sheep, which showed anorexia, excessive drooling, nystagmus, and paddling. Necropsies and clinical, histopathological, and pathological examination of poisoned cattle and sheep showed that the plant may cause acute renal failure along with extrarenal uremic lesions.


Assuntos
Doenças dos Bovinos , Fabaceae , Intoxicação por Plantas , Doenças dos Ovinos , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Surtos de Doenças , Intoxicação por Plantas/epidemiologia , Intoxicação por Plantas/veterinária , Ovinos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA