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1.
Nat Commun ; 15(1): 2714, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548766

RESUMO

Anaerobic gut fungi (AGF, Neocallimastigomycota) reside in the alimentary tract of herbivores. While their presence in mammals is well documented, evidence for their occurrence in non-mammalian hosts is currently sparse. Culture-independent surveys of AGF in tortoises identified a unique community, with three novel deep-branching genera representing >90% of sequences in most samples. Representatives of all genera were successfully isolated under strict anaerobic conditions. Transcriptomics-enabled phylogenomic and molecular dating analyses indicated an ancient, deep-branching position in the AGF tree for these genera, with an evolutionary divergence time estimate of 104-112 million years ago (Mya). Such estimates push the establishment of animal-Neocallimastigomycota symbiosis from the late to the early Cretaceous. Further, tortoise-associated isolates (T-AGF) exhibited limited capacity for plant polysaccharides metabolism and lacked genes encoding several carbohydrate-active enzyme (CAZyme) families. Finally, we demonstrate that the observed curtailed degradation capacities and reduced CAZyme repertoire is driven by the paucity of horizontal gene transfer (HGT) in T-AGF genomes, compared to their mammalian counterparts. This reduced capacity was reflected in an altered cellulosomal production capacity in T-AGF. Our findings provide insights into the phylogenetic diversity, ecological distribution, evolutionary history, evolution of fungal-host nutritional symbiosis, and dynamics of genes acquisition in Neocallimastigomycota.


Assuntos
Neocallimastigomycota , Tartarugas , Humanos , Animais , Neocallimastigomycota/genética , Neocallimastigomycota/metabolismo , Tartarugas/genética , Filogenia , Anaerobiose , Simbiose/genética , Mamíferos , Fungos/genética
2.
J Fungi (Basel) ; 10(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38392793

RESUMO

The analysis of the secretome allows us to identify the proteins, especially carbohydrate-active enzymes (CAZymes), secreted by different microorganisms cultivated under different conditions. The CAZymes are divided into five classes containing different protein families. Thermothelomyces thermophilus is a thermophilic ascomycete, a source of many glycoside hydrolases and oxidative enzymes that aid in the breakdown of lignocellulosic materials. The secretome analysis of T. thermophilus LMBC 162 cultivated with submerged fermentation using tamarind seeds as a carbon source revealed 79 proteins distributed between the five diverse classes of CAZymes: 5.55% auxiliary activity (AAs); 2.58% carbohydrate esterases (CEs); 20.58% polysaccharide lyases (PLs); and 71.29% glycoside hydrolases (GHs). In the identified GH families, 54.97% are cellulolytic, 16.27% are hemicellulolytic, and 0.05 are classified as other. Furthermore, 48.74% of CAZymes have carbohydrate-binding modules (CBMs). Observing the relative abundance, it is possible to state that only thirteen proteins comprise 92.19% of the identified proteins secreted and are probably the main proteins responsible for the efficient degradation of the bulk of the biomass: cellulose, hemicellulose, and pectin.

3.
Proteomics ; : e2300332, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238893

RESUMO

Nontuberculous Mycobacteria (NTM) are a group of emerging bacterial pathogens that have been identified in cystic fibrosis (CF) patients with microbial lung infections. The treatment of NTM infection in CF patients is challenging due to the natural resistance of NTM species to many antibiotics. Mycobacterium abscessus is one of the most common NTM species found in the airways of CF patients. In this study, we characterized the extracellular vesicles (EVs) released by drug-sensitive M. abscessus untreated or treated with clarithromycin (CLR), one of the frontline anti-NTM drugs. Our data show that exposure to CLR increases mycobacterial protein trafficking into EVs as well as the secretion of EVs in culture. Additionally, EVs released by CLR-treated M. abscessus increase M. abscessus resistance to CLR when compared to EVs from untreated M. abscessus. Proteomic analysis further indicates that EVs released by CLR-treated M. abscessus carry an increased level of 50S ribosomal subunits, the target of CLR. Taken together, our results suggest that EVs play an important role in M. abscessus resistance to CLR treatment.

4.
Geroscience ; 46(2): 2739-2754, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38159133

RESUMO

Aging has a significant impact on the immune system, leading to a gradual decline in immune function and changes in the body's ability to respond to bacterial infections. Non-tuberculous mycobacteria (NTM), also known as atypical mycobacteria or environmental mycobacteria, are commonly found in soil, water, and various environmental sources. While many NTM species are considered opportunistic pathogens, some can cause significant infections, particularly in individuals with compromised immune systems, such as older individuals. When mycobacteria enter the body, macrophages are among the first immune cells to encounter them and attempt to engulf mycobacteria through a process called phagocytosis. Some NTM species, including Mycobacterium avium (M. avium) can survive and replicate within macrophages. However, little is known about the interaction between NTM and macrophages in older individuals. In this study, we investigated the response of bone marrow-derived macrophage (BMMs) isolated from young (5 months) and old (25 months) mice to M. avium serotype 4, one of the main NTM species in patients with pulmonary NTM diseases. Our results demonstrated that BMMs from old mice have an increased level of intracellular iron and are more susceptible to M. avium serotype 4 infection compared to BMMs from young mice. The whole-cell proteomic analysis indicated a dysregulated expression of iron homeostasis-associated proteins in old BMMs regardless of mycobacterial infection. Deferoxamine, an iron chelator, significantly rescued mycobacterial killing and phagolysosome maturation in BMMs from old mice. Therefore, our data for the first time indicate that an intracellular iron accumulation improves NTM survival within macrophages from old mice and suggest a potential application of iron-chelating drugs as a host-directed therapy for pulmonary NTM infection in older individuals.


Assuntos
Infecções por Mycobacterium não Tuberculosas , Proteômica , Humanos , Animais , Camundongos , Idoso , Infecções por Mycobacterium não Tuberculosas/microbiologia , Micobactérias não Tuberculosas/fisiologia , Macrófagos , Fagocitose
5.
mSphere ; 8(2): e0057322, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-36749044

RESUMO

Mycobacterium tuberculosis (Mtb) is transmitted through aerosols and primarily colonizes within the lung. The World Health Organization estimates that Mtb kills ~1.4 million people every year. A key aspect that makes Mtb such a successful pathogen is its ability to overcome iron limitation mounted by the host immune response. In our previous studies, we have shown that Mtb can utilize iron from heme, the largest source of iron in the human host, and that it uses two redundant heme utilization pathways. In this study, we show that the ESX-4 type VII secretion system (T7SS) is necessary for extracellular heme uptake into the Mtb cell through both heme utilization pathways. ESX-4 influences the secretion of the culture filtrate proteins Rv0125 and Rv1085c, which are also necessary for efficient heme utilization. We also discovered that deletion of the alternative sigma factor SigM significantly reduced Mtb heme utilization through both pathways and predict that SigM is a global positive regulator of core heme utilization genes of both pathways. Finally, we present the first direct evidence that some mycobacterial PPE (proline-proline-glutamate motif) proteins of the PPE protein family are pore-forming membrane proteins. Altogether, we identified core components of both Mtb Heme utilization pathways that were previously unknown and identified a novel channel-forming membrane protein of Mtb. IMPORTANCE M. tuberculosis (Mtb) is completely dependent on iron acquisition in the host to cause disease. The largest source of iron for Mtb in the human host is heme. Here, we show that the ancestral ESX-4 type VII secretion system is required for the efficient utilization of heme as a source of iron, which is an essential nutrient. This is another biological function identified for ESX-4 in Mtb, whose contribution to Mtb physiology is poorly understood. A most exciting finding is that some mycobacterial PPE (proline-proline-glutamate motif) proteins that have been implicated in the nutrient acquisition are membrane proteins that can form channels in a lipid bilayer. These observations have far-reaching implications because they support an emerging theme that PPE proteins can function as channel proteins in the outer mycomembrane for nutrient acquisition. Mtb has evolved a heme uptake system that is drastically different from all other known bacterial heme acquisition systems.


Assuntos
Mycobacterium tuberculosis , Sistemas de Secreção Tipo VII , Humanos , Sistemas de Secreção Tipo VII/genética , Sistemas de Secreção Tipo VII/metabolismo , Proteínas de Bactérias/metabolismo , Heme/metabolismo , Ferro/metabolismo , Proteínas de Membrana/metabolismo , Equipamento de Proteção Individual
6.
J Anim Sci ; 1012023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36638080

RESUMO

Previous studies investigated the biochemical basis of dark-cutting conditions at elevated muscle pH (above 6), but the molecular basis at slightly above normal pH (between 5.6 and 5.8) is still unclear. The objective was to determine protein and metabolite profiles to elucidate postmortem muscle darkening at slightly elevated pH. Loins were selected based on the criteria established in our laboratory before sample collections, such as pH less than 5.8, L* values (muscle lightness) less than 38, and not discounted by the grader (high-pH beef with dark color are discounted and not sold in retail stores). Six bright red loins (longissimus lumborum) at normal-pH (average pH = 5.57) and six dark-colored strip loins at slightly elevated pH (average pH = 5.70) from A maturity carcasses were obtained within 72-h postmortem from a commercial beef purveyor. Surface color, oxygen consumption, metmyoglobin reducing activity, protein, and metabolite profiles were determined on normal-pH and dark-colored steaks at slightly elevated pH. Enzymes related to glycogen metabolism and glycolytic pathways were more differently abundant than metabolites associated with these pathways. The results indicated that oxygen consumption and metmyoglobin reducing activity were greater (P < 0.05) in darker steaks than normal-pH steaks. Enzymes involved with glycogen catabolic pathways and glycogen storage disease showed lower abundance in dark beef. The tricarboxylic acid metabolite, aconitic acid, was overabundant in darker-colored beef than normal-pH beef, but glucose derivative metabolites were less abundant. The majority of glycogenolytic proteins and metabolites reported as overabundant in the previous dark-cutting studies at high pH (>6.4) also did not show significant differences in the current study. Therefore, our data suggest enzymes involved in glycogen metabolism, in part, create a threshold for muscle darkening than metabolites.


A bright cherry-red color beef is ideal during meat retail and carcass grading. Any deviation from a bright red color, such as dark red color, at the interface of the 12th and 13th rib-eye area leads to carcass discounts. Various studies have determined protein, metabolite, and mitochondrial profiles to understand the biochemical basis of dark-cutting beef (muscle pH greater than 6); however, limited knowledge is currently available on muscle darkening at a slightly elevated pH. Bright red loins at normal muscle pH and darker color loins at slightly elevated pH (not discounted by a grader) were collected 72-h postmortem from a commercial beef purveyor. Surface color, oxygen consumption, metmyoglobin reducing activity, protein, and metabolite profiles were determined on normal-pH and dark-colored steaks at slightly elevated pH. The results indicated that oxygen consumption and metmyoglobin reducing activity were greater in darker steaks than normal-pH steaks. Furthermore, the protein abundance profiles of enzymes related to glycogen metabolism and glycolytic pathways were more differently abundant than metabolites associated with these pathways. Understanding the factors involved in the occurrence of dark color steaks help to minimize losses due to discount carcasses.


Assuntos
Metamioglobina , Carne Vermelha , Bovinos , Animais , Metamioglobina/química , Músculo Esquelético/metabolismo , Carne Vermelha/análise , Proteômica , Cor , Glicogênio/metabolismo , Concentração de Íons de Hidrogênio , Carne
7.
J Proteomics ; 265: 104637, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35688335

RESUMO

Mitochondria remain active in postmortem muscles and can influence meat color via oxygen consumption. Previous studies have shown that dark-cutting compared with normal-pH beef has greater mitochondrial protein and DNA content per gram of muscle tissue. However, the mechanism regulating mitochondrial content in dark-cutting vs. normal-pH beef is still unknown. Therefore, the objective was to compare mitochondrial proteomes of dark-cutting vs. normal-pH beef using LC-MS/MS-based proteomics and mitochondrial respiratory capacity using a Clark oxygen electrode. Dark-cutting compared with normal-pH beef has up-regulation of proteins involved in mitochondrial biogenesis, oxidative phosphorylation, intracellular protein transport, and cellular calcium ion homeostasis. Mitochondria isolated from dark-cutting phenotypes showed greater mitochondrial complex II respiration and uncoupled oxidative phosphorylation. However, mitochondrial membrane integrity and respiration at complexes I and IV were not different between normal-pH and dark-cutting beef. These results indicate that dark-cutting beef has greater mitochondrial biogenesis proteins than normal-pH beef, increasing mitochondrial content and contributing to dark-cutting beef. SIGNIFICANCE: Defective glycogen metabolism resulting from chronic stress before slaughter coupled with the greater mitochondrial protein and DNA content per gram of muscle tissue promotes muscle darkening in dark-cutting phenotypes in beef. However, the mechanistic basis for this occurrence in dark-cutting phenotypes is still unknown. In this work, we show that dark-cutting beef phenotype is caused, in part, as a consequence of over-proliferation of mitochondria. This is supported by the up-regulation of proteins involved in mitochondrial biogenesis, mitochondrial electron transport, calcium homeostasis, and fatty acid metabolism. Hence, the study of mitochondrial proteome changes provides a set of mitochondrial biogenesis proteins that could be used as potential candidate markers for detecting changes in pre-slaughter developmental events contributing to dark-cutting phenotypes in beef.


Assuntos
Carne Vermelha , Animais , Cálcio/metabolismo , Bovinos , Cromatografia Líquida , Cor , DNA/metabolismo , Metabolismo Energético , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Músculo Esquelético/metabolismo , Proteômica , Carne Vermelha/análise , Espectrometria de Massas em Tandem
8.
Adv Simul (Lond) ; 6(1): 43, 2021 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-34863312

RESUMO

BACKGROUND: Health professionals who have experienced ill-health appear to demonstrate greater empathy towards their patients. Simulation can afford learners opportunities to experience aspects of illness, but to date, there has been no overarching review of the extent of this practice or the impact on empathic skills. OBJECTIVE: To determine from the evidence-what is known about simulation-based learning methods of creating illness experiences for health professions and the impact on their empathic skills. STUDY SELECTION: Arksey and O'Malley's methodological framework informed our scoping review of articles relevant to our research question. Three databases (MEDLINE, Embase and Web of Science) were searched, and a sample of 516 citations was screened. Following review and application of our exclusion criteria, 77 articles were selected to be included in this review. FINDINGS: Of the 77 articles, 52 (68%) originated from the USA, 37 (48%) of studies were qualitative based and 17 (22%) used a mixed-methods model. Of all the articles in our scope, the majority (87%) reported a positive impact and range of emotions evoked on learners. However, some studies observed more negative effects and additional debriefing was required post-simulation. Learners were noted to internalise perceived experiences of illness and to critically reflect on their empathic role as healthcare providers. CONCLUSIONS: A diverse range of simulation methods and techniques, evoking an emotional and embodied experience, appear to have a positive impact on empathy and could be argued as offering a complementary approach in healthcare education; however, the long-term impact remains largely unknown.

9.
Exp Eye Res ; 213: 108846, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34801534

RESUMO

PURPOSE: Diabetic retinopathy is a vision-threatening complication of diabetes characterized by endothelial injury and vascular dysfunction. The loss of the endothelial glycocalyx, a dynamic layer lining all endothelial cells, contributes to several microvascular pathologies, including an increase in vascular permeability, leukocyte plugging, and capillary occlusion, and may drive the progression of retinopathy. Previously, a significant decrease in glycocalyx thickness has been observed in diabetic retinas. However, the effects of diabetes on specific components of the retinal glycocalyx have not yet been studied. Therefore, the aim of our study was to investigate changes in synthesis, expression, and shedding of retinal glycocalyx components induced by hyperglycemia, which could provide a novel therapeutic target for diabetic retinopathy. METHODS: Primary rat retinal microvascular endothelial cells (RRMECs) were grown under normal glucose (5 mM) or high-glucose (25 mM) conditions for 6 days. The mRNA and protein levels of the glycocalyx components were examined using qRT-PCR and Western blot analysis, respectively. Further, mass spectrometry was used to analyze protein intensities of core proteins. In addition, the streptozotocin-induced Type 1 diabetic rat model was used to study changes in the expression of the retinal glycocalyx in vivo. The shedding of the glycocalyx was studied in both culture medium and in plasma using Western blot analysis. RESULTS: A significant increase in the shedding of syndecan-1 and CD44 was observed both in vitro and in vivo under high-glucose conditions. The mRNA levels of syndecan-3 were significantly lower in the RRMECs grown under high glucose conditions, whereas those of syndecan-1, syndecan-2, syndecan-4, glypican-1, glypican-3, and CD44 were significantly higher. The protein expression of syndecan-3 and glypican-1 in RRMECs was reduced considerably following exposure to high glucose, whereas that of syndecan-1 and CD44 increased significantly. In addition, mass spectrometry data also suggests a significant increase in syndecan-4 and a significant decrease in glypican-3 protein levels with high glucose stimulation. In vivo, our data also suggest a significant decrease in the mRNA transcripts of syndecan-3 and an increase in mRNA levels of glypican-1 and CD44 in the retinas of diabetic rats. The diabetic rats exhibited a significant reduction in the retinal expression of syndecan-3 and CD44. However, the expression of syndecan-1 and glypican-1 increased significantly in the diabetic retina. CONCLUSIONS: One of the main findings of our study was the considerable diversity of glucose-induced changes in expression and shedding of various components of endothelial glycocalyx, for example, increased endothelial and retinal syndecan-1, but decreased endothelial and retinal syndecan-3. This indicates that the reported decrease in the retinal glycocalyx in diabetes in not a result of a non-specific shedding mechanism. Moreover, mRNA measurements indicated a similar diversity, with increases in endothelial and/or retinal levels of syndecan-1, glypican-1, and CD44, but a decrease for syndecan-3, with these increases in mRNA potentially a compensatory reaction to the overall loss of glycocalyx.


Assuntos
Retinopatia Diabética/metabolismo , Glicocálix/metabolismo , Hiperglicemia/metabolismo , Retina/metabolismo , Animais , Glicemia/metabolismo , Western Blotting , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Ensaio de Imunoadsorção Enzimática , Glucose/farmacologia , Glipicanas/metabolismo , Receptores de Hialuronatos/metabolismo , Insulina/sangue , Masculino , Espectrometria de Massas , RNA Mensageiro/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Vasos Retinianos/citologia , Sindecanas/metabolismo
10.
BMJ Simul Technol Enhanc Learn ; 7(4): 207-215, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35516833

RESUMO

Introduction: Hearing impairment is a common condition that can have a significant impact on an individual. Ineffective communication between such individuals and doctors remains an important barrier. There is a need to provide medical students with a deeper understanding of such challenges. Increasingly, simulation is being used to develop empathy skills. In this study, we aimed to seek a deep understanding of medical students' experiences of being placed in the role of a hearing-impaired patient by means of a virtual reality (VR) simulation. Methods: A multidisciplinary group developed a 360° VR video-learning experience. This experience portrayed a consultation with a doctor from a hearing-impaired individual's perspective. A qualitative study approach, using hermeneutic phenomenology, was conducted. Following the VR experience, students were interviewed, and transcripts of interviews were analysed using a Template Analysis approach. Results: Analysis yielded four main themes: (1) 'much more than just watching a video': a VR experience of hearing impairment; (2) 'hearing through their ears': experiencing a person's world with hearing impairment; (3) 'not just what you can't hear…but how it makes you feel': reactions evoked by a VR hearing impairment experience and (4) redirecting my future professional self? Discussion: This study provides an insight into medical students' experiences of a novel VR hearing impairment simulation. VR simulation has the potential to provide a novel complementary training method for medical students. By providing an immersive learning experience, VR can offer an empathic stepping into the ears of those that live with hearing impairment.

11.
J Proteomics ; 232: 104016, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-33059087

RESUMO

Dark-cutting beef is a condition in which beef fails to have a characteristic bright-red color when the cut surface is exposed to oxygen. However, the mechanistic basis for this occurrence is not clear. Protein expression profiles were compared between dark-cutting and normal-pH beef using LC-MS/MS-based proteomics. Mass spectrometry analysis identified 1162 proteins in the proteomes of dark-cutting and normal-pH beef. Of these, 92 proteins had significant changes in protein abundance between dark-cutting versus normal-pH beef. In dark-cutting beef, 25 proteins were down-regulated, including enzymes related to glycogen metabolism, glucose homeostasis, denovo synthesis of adenosine monophosphate (AMP), and glycogen phosphorylase activity. In comparison, 27 proteins were up-regulated in dark-cutting beef related to oxidation-reduction processes, muscle contraction, and oxidative phosphorylation. Down-regulation of glycogenolytic proteins suggests decreased glycogen mobilization and utilization, while the up-regulation of mitochondrial transport chain proteins indicates a greater capacity to support mitochondrial respiration in dark-cutting beef. These results showed that changes in proteins involved in glycogenolysis and mitochondrial electron transport would promote the development of high-pH and greater oxygen consumption, respectively; thus limiting myoglobin oxygenation in dark-cutting beef. SIGNIFICANCE: The current understanding indicates that defective glycolysis causes less carbon flow, leading to less postmortem lactic acid formation and elevated muscle pH in dark-cutting beef. However, to the best of our knowledge, limited research has evaluated how changes in glycolytic and mitochondrial protein abundance regulate postmortem muscle acidification and oxygen consumption in dark-cutting beef. We utilized a shotgun proteomics approach to elucidate potential differences in protein profiles between dark-cutting versus normal-pH beef that may influence differences in postmortem metabolism and muscle surface color characteristics. Our study shows that down-regulation of glycolgenolytic and IMP/AMP biosynthetic proteins results in elevated postmortem muscle pH in dark-cutting beef. In addition, the up-regulation of mitochondrial protein content coupled with the higher muscle pH are conducive factors for enhanced oxygen consumption and less myoglobin oxygenation, contributing to a dark meat color typically associated with dark-cutting beef.


Assuntos
Carne Vermelha , Animais , Bovinos , Cromatografia Líquida , Cor , Glicólise , Homeostase , Concentração de Íons de Hidrogênio , Carne/análise , Proteínas Mitocondriais/metabolismo , Músculo Esquelético/metabolismo , Consumo de Oxigênio , Mudanças Depois da Morte , Carne Vermelha/análise , Espectrometria de Massas em Tandem
12.
Insect Biochem Mol Biol ; 127: 103489, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33096211

RESUMO

The tobacco hornworm, Manduca sexta, is a lepidopteran model species widely used to study insect biochemical processes. Some of its larval hemolymph proteins are well studied, and a detailed proteomic analysis of larval plasma proteins became available in 2016, revealing features such as correlation with transcriptome data, formation of immune complexes, and constitution of an immune signaling system in hemolymph. It is unclear how the composition of these proteins may change in other developmental stages. In this paper, we report the proteomes of cell-free hemolymph from prepupae, pupae on day 4 and day 13, and young adults. Of the 1824 proteins identified, 907 have a signal peptide and 410 are related to immunity. Drastic changes in abundance of the storage proteins, lipophorins and vitellogenin, for instance, reflect physiological differences among prepupae, pupae, and adults. Considerably more proteins lacking signal peptide are present in the late pupae, suggesting that plasma contains relatively low concentrations of intracellular components released from remodeling tissues during metamorphosis. The defense proteins detected include 43 serine proteases and 11 serine protease homologs. Some of these proteins are members of the extracellular immune signaling network found in feeding larvae, and others may play additional roles and hence confer new features in the later life stages. In summary, the proteins and their levels revealed in this study, together with their transcriptome data, are expected to stimulate focused explorations of humoral immunity and other physiological systems in wandering larvae, pupae, and adults of M. sexta and shed light upon functional and comparative genomic research in other holometabolous insects.


Assuntos
Hemolinfa/química , Proteínas de Insetos/genética , Manduca/química , Metamorfose Biológica , Proteoma/genética , Animais , Proteínas de Insetos/metabolismo , Larva/química , Larva/genética , Larva/crescimento & desenvolvimento , Manduca/genética , Manduca/crescimento & desenvolvimento , Proteoma/metabolismo , Pupa/química , Pupa/genética , Pupa/crescimento & desenvolvimento
13.
Antibiotics (Basel) ; 8(4)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31816949

RESUMO

Tea tree oil (TTO) is hypothesized to kill bacteria by indiscriminately denaturing membrane and protein structures. A Staphylococcus aureus small colony variant (SCV) selected with TTO (SH1000-TTORS-1) demonstrated slowed growth, reduced susceptibility to TTO, a diminutive cell size, and a thinned cell wall. Utilizing a proteomics and metabolomics approach, we have now revealed that the TTO-selected SCV mutant demonstrated defective fatty acid synthesis, an alteration in the expression of genes and metabolites associated with central metabolism, the induction of a general stress response, and a reduction of proteins critical for active growth and translation. SH1000-TTORS-1 also demonstrated an increase in amino acid accumulation and a decrease in sugar content. The reduction in glycolytic pathway proteins and sugar levels indicated that carbon flow through glycolysis and gluconeogenesis is reduced in SH1000-TTORS-1. The increase in amino acid accumulation coincides with the reduced production of translation-specific proteins and the induction of proteins associated with the stringent response. The decrease in sugar content likely deactivates catabolite repression and the increased amino acid pool observed in SH1000-TTORS-1 represents a potential energy and carbon source which could maintain carbon flow though the tricarboxylic acid (TCA) cycle. It is noteworthy that processes that contribute to the production of the TTO targets (proteins and membrane) are reduced in SH1000-TTORS-1. This is one of a few studies describing a mechanism that bacteria utilize to withstand the action of an antiseptic which is thought to inactivate multiple cellular targets.

14.
Methods Mol Biol ; 1709: 139-162, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29177657

RESUMO

Mass spectrometry assays demonstrate that Hsp90 inhibitors alter the expression of approximately one-quarter of the assayable proteome in mammalian cells. These changes are extraordinarily robust and reproducible, making "proteomics profiling" the gold standard for validating the effects of new Hsp90 inhibitors on cultured cells. Proteomics assays can also suggest novel hypotheses regarding drug mechanisms. To assist investigators in adopting this approach, this Chapter provides detailed protocols for conducting simple proteomics assays of Hsp90 inhibition. The protocols present a robust label-free approach that utilizes pre-fractionation of protein samples by SDS-PAGE, thereby providing reasonably good penetration into the proteome while addressing common issues with sample quality. The actual programming and operation of liquid chromatography-tandem mass spectrometers is not covered, but expectations for achievable performance are discussed, as are alternative approaches, common challenges, and software for data analysis.


Assuntos
Cromatografia Líquida/métodos , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteoma/genética , Proteômica/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Células Cultivadas , Eletroforese em Gel de Poliacrilamida/métodos , Regulação da Expressão Gênica , Humanos , Proteoma/análise , Proteoma/efeitos dos fármacos
15.
Dev Comp Immunol ; 74: 110-124, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28431895

RESUMO

Anopheles gambiae is a major vector of human malaria and its immune system in part determines the fate of ingested parasites. Proteins, hemocytes and fat body in hemolymph are critical components of this system, mediating both humoral and cellular defenses. Here we assessed differences in the hemolymph proteomes of water- and E. coli-pricked mosquito larvae by a gel-LC-MS approach. Among the 1756 proteins identified, 603 contained a signal peptide but accounted for two-third of the total protein amount on the quantitative basis. The sequence homology search indicated that 233 of the 1756 may be related to defense. In general, we did not detect substantial differences between the control and induced plasma samples in terms of protein numbers or levels. Protein distributions in the gel slices suggested post-translational modifications (e.g. proteolysis) and formation of serpin-protease complexes and high Mr immune complexes. Based on the twenty-five most abundant proteins, we further suggest that major functions of the larval hemolymph are storage, transport, and immunity. In summary, this study provided first data on constitution, levels, and possible functions of hemolymph proteins in the mosquito larvae, reflecting complex changes occurring in the fight against E. coli infection.


Assuntos
Anopheles/imunologia , Vetores Aracnídeos/imunologia , Infecções por Escherichia coli/imunologia , Escherichia coli/imunologia , Hemócitos/metabolismo , Hemolinfa/metabolismo , Malária/imunologia , Animais , Anopheles/microbiologia , Complexo Antígeno-Anticorpo/metabolismo , Hemócitos/imunologia , Hemócitos/microbiologia , Hemolinfa/imunologia , Hemolinfa/microbiologia , Humanos , Imunidade , Larva , Plasmodium/fisiologia , Proteólise , Proteoma , Serpinas/metabolismo
16.
AMB Express ; 6(1): 103, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27807811

RESUMO

Biomass is abundant, renewable and useful for biofuel production as well as chemical priming for plastics and composites. Deconstruction of biomass by enzymes is perceived as recalcitrant while an inclusive breakdown mechanism remains to be discovered. Fungi such as Myceliophthora thermophila M77 appear to decompose natural biomass sources quite well. This work reports on this fungus fermentation property while producing cellulolytic enzymes using natural biomass substrates. Little hydrolytic activity was detected, insufficient to explain the large amount of biomass depleted in the process. Furthermore, this work makes a comprehensive account of extracellular proteins and describes how secretomes redirect their qualitative protein content based on the nature and chemistry of the nutritional source. Fungus grown on purified cellulose or on natural biomass produced secretomes constituted by: cellobiohydrolases, cellobiose dehydrogenase, ß-1,3 glucanase, ß-glucosidases, aldose epimerase, glyoxal oxidase, GH74 xyloglucanase, galactosidase, aldolactonase and polysaccharide monooxygenases. Fungus grown on a mixture of purified hemicellulose fractions (xylans, arabinans and arabinoxylans) produced many enzymes, some of which are listed here: xylosidase, mixed ß-1,3(4) glucanase, ß-1,3 glucanases, ß-glucosidases, ß-mannosidase, ß-glucosidases, galactosidase, chitinases, polysaccharide lyase, endo ß-1,6 galactanase and aldose epimerase. Secretomes produced on natural biomass displayed a comprehensive set of enzymes involved in hydrolysis and oxidation of cellulose, hemicellulose-pectin and lignin. The participation of oxidation reactions coupled to lignin decomposition in the breakdown of natural biomass may explain the discrepancy observed for cellulose decomposition in relation to natural biomass fermentation experiments.

17.
Mol Cell Proteomics ; 15(4): 1176-87, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26811355

RESUMO

Manduca sextais a lepidopteran model widely used to study insect physiological processes, including innate immunity. In this study, we explored the proteomes of cell-free hemolymph from larvae injected with a sterile buffer (C for control) or a mixture of bacteria (I for induced). Of the 654 proteins identified, 70 showed 1.67 to >200-fold abundance increases after the immune challenge; 51 decreased to 0-60% of the control levels. While there was no strong parallel between plasma protein levels and their transcript levels in hemocytes or fat body, the mRNA level changes (i.e.I/C ratios of normalized read numbers) in the tissues concurred with their protein level changes (i.e.I/C ratios of normalized spectral counts) with correlation coefficients of 0.44 and 0.57, respectively. Better correlations support that fat body contributes a more significant portion of the plasma proteins involved in various aspects of innate immunity. Consistently, ratios of mRNA and protein levels were better correlated for immunity-related proteins than unrelated ones. There is a set of proteins whose apparent molecular masses differ considerably from the calculatedMr's, suggestive of posttranslational modifications. In addition, some lowMrproteins were detected in the range of 80 to >300 kDa on a reducing SDS-polyacrylamide gel, indicating the existence of highMrcovalent complexes. We identified 30 serine proteases and their homologs, 11 of which are known members of an extracellular immune signaling network. Along with our quantitative transcriptome data, the protein identification, inducibility, and association provide leads toward a focused exploration of humoral immunity inM. sexta.


Assuntos
Imunidade Inata , Proteínas de Insetos/sangue , Manduca/microbiologia , Proteoma/metabolismo , Transcriptoma , Animais , Corpo Adiposo/fisiologia , Regulação da Expressão Gênica , Hemolinfa/metabolismo , Larva/imunologia , Larva/microbiologia , Manduca/crescimento & desenvolvimento , Manduca/imunologia
18.
Mol Microbiol ; 95(2): 352-64, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25425348

RESUMO

Bacterial persisters are rare, phenotypically distinct cells that survive exposure to multiple antibiotics. Previous studies indicated that formation and maintenance of the persister phenotype are regulated by suppressing translation. To examine the mechanism of this translational suppression, we developed novel methodology to rapidly purify ribosome complexes from persister cells. We purified His-tagged ribosomes from Escherichia coli cells that over-expressed HipA protein, which induces persister formation, and were treated with ampicillin to remove antibiotic-sensitive cells. We profiled ribosome complexes and analyzed the ribosomal RNA and protein components from these persister cells. Our results show that (i) ribosomes in persisters exist largely as inactive ribosomal subunits, (ii) rRNAs and tRNAs are mostly degraded and (iii) a small fraction of the ribosomes remain mostly intact, except for reduced amounts of seven ribosomal proteins. Our findings explain the basis for translational suppression in persisters and suggest how persisters survive exposure to multiple antibiotics.


Assuntos
Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismo , Ampicilina/farmacologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Proteínas de Escherichia coli/biossíntese , RNA Bacteriano/metabolismo , RNA Ribossômico/metabolismo , RNA de Transferência/metabolismo , Proteínas Ribossômicas/metabolismo
19.
J Proteome Res ; 12(8): 3697-706, 2013 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-23763277

RESUMO

AUY922 is a potent synthetic Hsp90 antagonist that is moving steadily through clinical trials against a small range of cancers. To identify protein markers that might measure the drug's effects, and to gain understanding of mechanisms by which AUY922 might inhibit the proliferation of leukemia cells, we characterized AUY922's impacts on the proteomes of cultured Jurkat cells. We describe a robust and readily assayed proteomics fingerprint that AUY922 shares with the flagship Hsp90 inhibitors 17-DMAG and radicicol. We also extend our proteomics findings, demonstrating that an unrelated antagonist of protein folding potentiates the antiproliferative effects of AUY922. Results provide a set of candidate biomarkers for responses to AUY922 in leukemia cells and suggest new modalities for enhancing AUY922's anticancer activities.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Isoxazóis/farmacologia , Proteoma/análise , Resorcinóis/farmacologia , Antineoplásicos/química , Benzoquinonas/química , Benzoquinonas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Isoxazóis/química , Células Jurkat , Lactamas Macrocíclicas/química , Lactamas Macrocíclicas/farmacologia , Macrolídeos/química , Macrolídeos/farmacologia , Dobramento de Proteína/efeitos dos fármacos , Resorcinóis/química , Espectrometria de Massas em Tandem
20.
Health Care Manag (Frederick) ; 29(1): 63-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20145469

RESUMO

Students of allied health who have positive clinical education experiences often accept employment offered by their clinical sites. Most allied health professionals are not trained to be educators; to improve student clinical experiences, students were surveyed regarding their learning experiences during clinical internships. This study examined the teaching abilities and professional development training needs of clinical supervisors as identified by student perceptions. Results were compared with the results of the clinical supervisors' perceptions of themselves. A survey addressed the students' perceptions of the clinical supervisors' teaching skills. Results revealed that both students and clinical supervisors identified similar professional development training needs as they related to the improvement of teaching skills. The identified needs were understanding different learning styles, planning learning experiences prior to students' arrival, giving feedback, and assessing student skills based on learning goals. Students and clinical supervisors agreed on the areas that need to be addressed to improve the learning experiences in clinical education. Continuing education courses should focus on clinical supervisors' teaching skills, especially teaching methodology that focuses on students' different learning styles, how to plan learning experiences, and how to assess students' skills based on set learning goals.


Assuntos
Ocupações Relacionadas com Saúde/educação , Comportamento do Consumidor , Estudantes/psicologia , Adulto , Coleta de Dados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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