RESUMO
The contribution of microRNAs (miRNAs) to mRNA post-transcriptional regulation has often been explored by the post hoc selection of downregulated genes and determining whether they harbor binding sites for miRNAs of interest. This approach, however, does not discriminate whether these mRNAs are also downregulated at the transcriptional level. Here, we have characterized the transcriptional and post-transcriptional changes in mRNA expression in two porcine tissues: gluteus medius muscle of fasted and fed Duroc gilts and adipose tissue of lean and obese Duroc-Göttingen minipigs. Exon-intron split analysis of RNA-seq data allowed us to identify downregulated mRNAs with high post-transcriptional signals in fed or obese states, and we assessed whether they harbor binding sites for upregulated miRNAs in any of these two physiological states. We found 26 downregulated mRNAs with high post-transcriptional signals in the muscle of fed gilts and 21 of these were predicted targets of miRNAs upregulated in fed pigs. For adipose tissue, 44 downregulated mRNAs in obese minipigs displayed high post-transcriptional signals, and 25 of these were predicted targets of miRNAs upregulated in the obese state. These results suggest that the contribution of miRNAs to mRNA repression is more prominent in the skeletal muscle system. Finally, we identified several genes that may play relevant roles in the energy homeostasis of the pig skeletal muscle (DKK2 and PDK4) and adipose (SESN3 and ESRRG) tissues. By differentiating transcriptional from post-transcriptional changes in mRNA expression, exon-intron split analysis provides a valuable view of the regulation of gene expression, complementary to canonical differential expression analyses.
Assuntos
MicroRNAs , Doenças dos Suínos , Animais , Éxons , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Íntrons , MicroRNAs/genética , MicroRNAs/metabolismo , Músculo Esquelético/metabolismo , Obesidade/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Suínos/genética , Doenças dos Suínos/genética , Porco Miniatura/genética , Porco Miniatura/metabolismoRESUMO
Aim: This study investigates the non-medical public health and surveillance policies and actions for tackling the community spread of COVID-19 pandemic in Denmark, Serbia and Sweden during the first five months of the pandemic in 2020. Method: The study is inspired by a process-tracing design for case study with a focus on the non-medical measures and surveillance strategies implemented by the three countries. The comprehensive collection and study of national documents formed the basis of the document analysis. Results: The Danish strategy was to prolong the transmission period, preventing high numbers of infected cases from impacting their healthcare capacity. The government's strategy was characterized by strict governance elements, health guidelines and behavioural recommendations. In Serbia, the main strategy was to prevent the spread and control of the infectious disease by shifting all human and material resources towards the function of controlling the spread. Serbia applied the strictest measures in the fight against coronavirus in relation to other countries in the region and in Europe. The Swedish strategy focused more on recommendations than requirements to motivate the public to modify their behaviours voluntarily. Sweden's loose pandemic strategy implementation focused on voluntary and stepwise action rather than legislation and compulsory measures. Conclusions: The public health policies and actions implemented to prevent community spread of COVID-19 in Denmark, Serbia and Sweden varied during the first five months of the pandemic. The differences in their response were due to delays in implementation, inconsistencies in perspectives towards the outbreak and the capacity of each country in terms of their pandemic preparedness and response.
Assuntos
COVID-19 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Dinamarca/epidemiologia , Política de Saúde , Humanos , Pandemias/prevenção & controle , Saúde Pública , SARS-CoV-2 , Sérvia , Suécia/epidemiologiaRESUMO
The aim of this study was to elucidate the relative impact of three phenotypes often used to characterize obesity on perturbation of molecular pathways involved in obesity. The three obesity-related phenotypes are (1) body mass index (BMI), (2) amount of subcutaneous adipose tissue (SATa), and (3) amount of retroperitoneal adipose tissue (RPATa). Although it is generally accepted that increasing amount of RPATa is 'unhealthy', a direct comparison of the relative impact of the three obesity-related phenotypes on gene expression has, to our knowledge, not been performed previously. We have used multiple linear models to analyze altered gene expression of selected obesity-related genes in tissues collected from 19 female pigs phenotypically characterized with respect to the obesity-related phenotypes. Gene expression was assessed by high-throughput qPCR in RNA from liver, skeletal muscle and abdominal adipose tissue. The stringent statistical approach used in the study has increased the power of the analysis compared to the classical approach of analysis in divergent groups of individuals. Our approach led to the identification of key components of cellular pathways that are modulated in the three tissues in association with changes in the three obesity-relevant phenotypes (BMI, SATa and RPATa). The deregulated pathways are involved in biosynthesis and transcript regulation in adipocytes, in lipid transport, lipolysis and metabolism, and in inflammatory responses. Deregulation seemed more comprehensive in liver (23 genes) compared to abdominal adipose tissue (10 genes) and muscle (3 genes). Notably, the study supports the notion that excess amount of intra-abdominal adipose tissue is associated with a greater metabolic disease risk. Our results provide molecular support for this notion by demonstrating that increasing amount of RPATa has a higher impact on perturbation of cellular pathways influencing obesity and obesity-related metabolic traits compared to increase in BMI and amount of SATa.
Assuntos
Regulação da Expressão Gênica/genética , Gordura Intra-Abdominal/metabolismo , Obesidade/genética , Gordura Subcutânea/metabolismo , Adipócitos/metabolismo , Adipócitos/patologia , Animais , Índice de Massa Corporal , Feminino , Humanos , Gordura Intra-Abdominal/crescimento & desenvolvimento , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Obesidade/patologia , Biossíntese de Proteínas/genética , Gordura Subcutânea/crescimento & desenvolvimento , Suínos/genética , Suínos/crescimento & desenvolvimento , Suínos/metabolismoRESUMO
Candida albicans is a major fungal pathogen of humans. This yeast is carried by many individuals as a harmless commensal, but when immune defences are perturbed it causes mucosal infections (thrush). Additionally, when the immune system becomes severely compromised, C. albicans often causes life-threatening systemic infections. A battery of virulence factors and fitness attributes promote the pathogenicity of C. albicans. Fitness attributes include robust responses to local environmental stresses, the inactivation of which attenuates virulence. Stress signalling pathways in C. albicans include evolutionarily conserved modules. However, there has been rewiring of some stress regulatory circuitry such that the roles of a number of regulators in C. albicans have diverged relative to the benign model yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. This reflects the specific evolution of C. albicans as an opportunistic pathogen obligately associated with warm-blooded animals, compared with other yeasts that are found across diverse environmental niches. Our understanding of C. albicans stress signalling is based primarily on the in vitro responses of glucose-grown cells to individual stresses. However, in vivo this pathogen occupies complex and dynamic host niches characterised by alternative carbon sources and simultaneous exposure to combinations of stresses (rather than individual stresses). It has become apparent that changes in carbon source strongly influence stress resistance, and that some combinatorial stresses exert non-additive effects upon C. albicans. These effects, which are relevant to fungus-host interactions during disease progression, are mediated by multiple mechanisms that include signalling and chemical crosstalk, stress pathway interference and a biological transistor.
Assuntos
Candida albicans/patogenicidade , Glucose/metabolismo , Resposta ao Choque Térmico/fisiologia , Pressão Osmótica/fisiologia , Estresse Oxidativo/fisiologia , Adaptação Fisiológica , Candida albicans/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Saccharomyces cerevisiae/metabolismo , Schizosaccharomyces/metabolismo , Transdução de SinaisRESUMO
Candida albicans cells with increased cell wall chitin have reduced echinocandin susceptibility in vitro. The aim of this study was to investigate whether C. albicans cells with elevated chitin levels have reduced echinocandin susceptibility in vivo. BALB/c mice were infected with C. albicans cells with normal chitin levels and compared to mice infected with high-chitin cells. Caspofungin therapy was initiated at 24 h postinfection. Mice infected with chitin-normal cells were successfully treated with caspofungin, as indicated by reduced kidney fungal burdens, reduced weight loss, and decreased C. albicans density in kidney lesions. In contrast, mice infected with high-chitin C. albicans cells were less susceptible to caspofungin, as they had higher kidney fungal burdens and greater weight loss during early infection. Cells recovered from mouse kidneys at 24 h postinfection with high-chitin cells had 1.6-fold higher chitin levels than cells from mice infected with chitin-normal cells and maintained a significantly reduced susceptibility to caspofungin when tested in vitro. At 48 h postinfection, caspofungin treatment induced a further increase in chitin content of C. albicans cells harvested from kidneys compared to saline treatment. Some of the recovered clones had acquired, at a low frequency, a point mutation in FKS1 resulting in a S645Y amino acid substitution, a mutation known to confer echinocandin resistance. This occurred even in cells that had not been exposed to caspofungin. Our results suggest that the efficacy of caspofungin against C. albicans was reduced in vivo due to either elevation of chitin levels in the cell wall or acquisition of FKS1 point mutations.
Assuntos
Candida albicans/genética , Candidíase/tratamento farmacológico , Parede Celular/química , Quitina/genética , Equinocandinas/administração & dosagem , Proteínas Fúngicas/genética , Glucosiltransferases/genética , Rim/efeitos dos fármacos , Substituição de Aminoácidos , Animais , Antifúngicos/administração & dosagem , Candida albicans/efeitos dos fármacos , Candida albicans/patogenicidade , Candida albicans/ultraestrutura , Candidíase/microbiologia , Candidíase/mortalidade , Candidíase/patologia , Caspofungina , Parede Celular/ultraestrutura , Análise Mutacional de DNA , Farmacorresistência Fúngica , Feminino , Rim/microbiologia , Rim/patologia , Lipopeptídeos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Mutação , Taxa de SobrevidaRESUMO
Pathogenic microbes exist in dynamic niches and have evolved robust adaptive responses to promote survival in their hosts. The major fungal pathogens of humans, Candida albicans and Candida glabrata, are exposed to a range of environmental stresses in their hosts including osmotic, oxidative and nitrosative stresses. Significant efforts have been devoted to the characterization of the adaptive responses to each of these stresses. In the wild, cells are frequently exposed simultaneously to combinations of these stresses and yet the effects of such combinatorial stresses have not been explored. We have developed a common experimental platform to facilitate the comparison of combinatorial stress responses in C. glabrata and C. albicans. This platform is based on the growth of cells in buffered rich medium at 30°C, and was used to define relatively low, medium and high doses of osmotic (NaCl), oxidative (H(2)O(2)) and nitrosative stresses (e.g., dipropylenetriamine (DPTA)-NONOate). The effects of combinatorial stresses were compared with the corresponding individual stresses under these growth conditions. We show for the first time that certain combinations of combinatorial stress are especially potent in terms of their ability to kill C. albicans and C. glabrata and/or inhibit their growth. This was the case for combinations of osmotic plus oxidative stress and for oxidative plus nitrosative stress. We predict that combinatorial stresses may be highly significant in host defences against these pathogenic yeasts.
Assuntos
Candida albicans/fisiologia , Candida glabrata/fisiologia , Viabilidade Microbiana/efeitos dos fármacos , Estresse Fisiológico , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Candida glabrata/efeitos dos fármacos , Candida glabrata/crescimento & desenvolvimento , Meios de Cultura/química , Humanos , Micologia/métodos , Compostos Nitrosos/toxicidade , Pressão Osmótica , Estresse Oxidativo , TemperaturaRESUMO
Enterotoxigenic Escherichia coli (ETEC) with fimbriae of the F4 family are one of the major causes of diarrhea and death among neonatal and young piglets. Bacteria use the F4 fimbriae to adhere to specific receptors expressed on the surface of the enterocytes. F4 fimbriae exist in three different antigenic variants, F4ab, F4ac, and F4ad, of which F4ac is the most common. Resistance to ETEC F4ab/F4ac adhesion in pigs has been shown to be inherited as an autosomal recessive trait. In previous studies the ETEC F4ab/F4ac receptor locus (F4bcR) was mapped to the q41 region on pig chromosome 13. A polymorphism within an intron of the mucin 4 (MUC4) gene, which is one of the possible candidate genes located in this region, was shown earlier to cosegregate with the F4bcR alleles. Recently, we discovered a Large White boar from a Swiss experimental herd with a recombination between F4bcR and MUC4. A three-generation pedigree including 45 offspring was generated with the aim to use this recombination event to refine the localization of the F4bcR locus. All pigs were phenotyped using the microscopic adhesion test and genotyped for a total of 59 markers. The recombination event was mapped to a 220-kb region between a newly detected SNP in the leishmanolysin-like gene (LMLN g.15920) and SNP ALGA0072075. In this study the six SNPs ALGA0072075, ALGA0106330, MUC13-226, MUC13-813, DIA0000584, and MARC0006918 were in complete linkage disequilibrium with F4bcR. Based on this finding and earlier investigations, we suggest that the locus for F4bcR is located between the LMLN locus and microsatellite S0283.
Assuntos
Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/veterinária , Fímbrias Bacterianas/genética , Mucina-4/genética , Receptores de Superfície Celular/genética , Doenças dos Suínos/genética , Suínos/genética , Animais , Aderência Bacteriana , Sequência de Bases , Mapeamento Cromossômico , Escherichia coli Enterotoxigênica/genética , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Feminino , Fímbrias Bacterianas/imunologia , Desequilíbrio de Ligação , Masculino , Dados de Sequência Molecular , Mucina-4/imunologia , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/imunologia , Suínos/imunologia , Suínos/microbiologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologiaRESUMO
Principal mechanisms of resistance to azole antifungals include the upregulation of multidrug transporters and the modification of the target enzyme, a cytochrome P450 (Erg11) involved in the 14alpha-demethylation of ergosterol. These mechanisms are often combined in azole-resistant Candida albicans isolates recovered from patients. However, the precise contributions of individual mechanisms to C. albicans resistance to specific azoles have been difficult to establish because of the technical difficulties in the genetic manipulation of this diploid species. Recent advances have made genetic manipulations easier, and we therefore undertook the genetic dissection of resistance mechanisms in an azole-resistant clinical isolate. This isolate (DSY296) upregulates the multidrug transporter genes CDR1 and CDR2 and has acquired a G464S substitution in both ERG11 alleles. In DSY296, inactivation of TAC1, a transcription factor containing a gain-of-function mutation, followed by sequential replacement of ERG11 mutant alleles with wild-type alleles, restored azole susceptibility to the levels measured for a parent azole-susceptible isolate (DSY294). These sequential genetic manipulations not only demonstrated that these two resistance mechanisms were those responsible for the development of resistance in DSY296 but also indicated that the quantitative level of resistance as measured in vitro by MIC determinations was a function of the number of genetic resistance mechanisms operating in any strain. The engineered strains were also tested for their responses to fluconazole treatment in a novel 3-day model of invasive C. albicans infection of mice. Fifty percent effective doses (ED(50)s) of fluconazole were highest for DSY296 and decreased proportionally with the sequential removal of each resistance mechanism. However, while the fold differences in ED(50) were proportional to the fold differences in MICs, their magnitude was lower than that measured in vitro and depended on the specific resistance mechanism operating.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Farmacorresistência Fúngica/genética , Fluconazol/farmacologia , Animais , Sequência de Bases , Candida albicans/isolamento & purificação , Candida albicans/patogenicidade , Primers do DNA/genética , DNA Fúngico/genética , Modelos Animais de Doenças , Feminino , Proteínas Fúngicas/genética , Genes Fúngicos , Engenharia Genética , Humanos , Técnicas In Vitro , Proteínas de Membrana Transportadoras/genética , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , MutaçãoRESUMO
BACKGROUND: Model animals are valuable resources for dissecting basic aspects of the regulation of obesity and metabolism. The translatability of results relies on understanding comparative aspects of molecular pathophysiology. Several studies have shown that despite the presence of overt obesity and dyslipidemia in the pig key human pathological hepatic findings such as hepatocellular ballooning and abundant steatosis are lacking in the model. OBJECTIVES: The aim of this study was to elucidate why these histopathological characteristics did not occur in a high fat, fructose and cholesterol (FFC) diet-induced obese Göttingen Minipig model. METHODS: High-throughput expression profiling of more than 90 metabolically relevant genes was performed in liver, subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of male minipigs diet fed: standard chow (SD, n = 7); FFC diet (n = 14); FFC diet in streptozotocin-induced diabetic pigs (FFCDIA, n = 8). Moreover, histopathological assessment of SAT and VAT was performed. RESULTS: 12, 4 and 1 genes were highly significantly differentially expressed in liver, SAT and VAT when comparing the FFC and SD groups whereas the corresponding numbers were 15, 2, and 1 when comparing the FFCDIA and SD groups. Although the minipigs in both FFC groups developed sever obesity and dyslipidemia, the insulin-signaling pathways were not affected. Notably, four genes involved in lipid acquisition and removal, were highly deregulated in the liver: PPARG, LPL, CD36 and FABP4. These genes have been reported to play a major role in promoting hepatic steatosis in rodents and humans. Since very little macrophage-associated pro-inflammatory response was detected in the adipose tissues the expansion appears to have no adverse impact on adipose tissue metabolism. CONCLUSION: The study shows that morbidly obese Göttingen Minipigs are protected against many of the metabolic and hepatic abnormalities associated with obesity due to a remarkable ability to expand the adipose compartments to accommodate excess calories.
Assuntos
Tecido Adiposo/metabolismo , Fígado/metabolismo , Obesidade Mórbida/metabolismo , Animais , Colesterol/administração & dosagem , Diabetes Mellitus Experimental/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Dislipidemias/metabolismo , Frutose/administração & dosagem , Humanos , Insulina/metabolismo , Gordura Intra-Abdominal/metabolismo , Masculino , Obesidade/genética , Obesidade/metabolismo , Obesidade Mórbida/genética , Fenótipo , Gordura Subcutânea/metabolismo , Suínos , Porco Miniatura/genética , Porco Miniatura/metabolismoRESUMO
The purpose was to compare the sella turcica morphology of individuals within pairs of monozygotic twins with normal karyotype and to analyze the similarity between the observed morphology and the morphology of non-twins at the same age with normal karyotype. Profile radiographs from 84 individuals of 42 twin pairs (18 male and 24 female pairs, aged 18-23 years) comprised the material. Sella turcica measurements from non-twins aged 6-21 years were used as normal reference. Length, depth and diameter of the sella turcica were measured and controlled by re-measurements. Pearson's correlation coefficient was used for comparison of individuals within twin pairs. For comparison of twins and non-twins, normal standard values for length, depth and diameter were subtracted from the twin values. For the mean values of these differences, confidence limits p values and t values were calculated. The study showed that the size of the sella turcica may be partly similar and partly dissimilar within the pair of monozygotic twins. Statistical evaluation of the data showed correlations between length, depth and diameter of the sella turcica between the two twin individuals in the same twin pair. Differences in sizes are observed between individuals in the twin material and individuals in the non-twin material. As a conclusion, the twin males were more similar within the twin pair, but deviated more from the non-twin material than the females. Female twins had more discrepancy within the twin pair, but deviated less from the non-twin material than the males.
Assuntos
Sela Túrcica/diagnóstico por imagem , Gêmeos Monozigóticos/genética , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Radiografia , Fatores SexuaisRESUMO
Reprogramming of adipocyte function in obesity is implicated in metabolic disorders like type 2 diabetes. Here, we used the pig, an animal model sharing many physiological and pathophysiological similarities with humans, to perform in-depth epigenomic and transcriptomic characterization of pure adipocyte fractions. Using a combined DNA methylation capture sequencing and Reduced Representation bisulfite sequencing (RRBS) strategy in 11 lean and 12 obese pigs, we identified in 3529 differentially methylated regions (DMRs) located at close proximity to-, or within genes in the adipocytes. By sequencing of the transcriptome from the same fraction of isolated adipocytes, we identified 276 differentially expressed transcripts with at least one or more DMR. These transcripts were over-represented in gene pathways related to MAPK, metabolic and insulin signaling. Using a candidate gene approach, we further characterized 13 genes potentially regulated by DNA methylation and identified putative transcription factor binding sites that could be affected by the differential methylation in obesity. Our data constitute a valuable resource for further investigations aiming to delineate the epigenetic etiology of metabolic disorders.
RESUMO
Multi-locus sequencing data for 242 different isolates of Candida tropicalis generated a dendrogram showing 235 strains assigned to a single large recently evolved group which contained several small clonal clusters. Haplotype analysis of a representative strain subset revealed a high level of recombination events in an otherwise clonal population. Pairs of isolates from single sources showed non-identity attributable to loss of heterozygosity in some genes in a manner similar to that established for C. albicans.
Assuntos
Candida tropicalis/classificação , Candida tropicalis/genética , Técnicas de Tipagem Micológica , Filogenia , Candida albicans/genética , Candida tropicalis/isolamento & purificação , Candidíase/microbiologia , Haplótipos , Humanos , Polimorfismo de Nucleotídeo Único , Recombinação GenéticaRESUMO
Multi-locus sequence typing data for 217 Candida albicans isolates cultured since 1990 from blood and vaginal samples in Japan, England/Wales and the USA were analysed for geographically related variations. While no significant differences were found between distributions of diploid sequence types (DSTs) in blood vs. vaginal isolates, there were highly significant differences in the clade distributions of isolates from the three geographical sources. Clade 2 strains were predominantly isolates from England/Wales, while clade 3 strains came mainly from the USA. The isolates from Japan were highly prevalent among strains in clades 5-17, and provided the first example seen so far in C. albicans of an amino acid encoded by three separate codons. Within clade 1, the most commonly encountered clade for isolates from all three regions, 15 Japanese isolates and 1 English isolate formed a separate clonal cluster in eBURST analysis. A similarly well demarcated clonal cluster rich in isolates from Japan was also found among the clade 4 strains. The data suggest C. albicans undergoes localized evolution, but human movements and person-to-person spread considerably blur the boundaries of such evolution.
Assuntos
Candida albicans/classificação , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Sangue/microbiologia , Análise por Conglomerados , Impressões Digitais de DNA , DNA Fúngico/química , DNA Fúngico/genética , Feminino , Genótipo , Humanos , Japão , Epidemiologia Molecular , Análise de Sequência de DNA/métodos , Homologia de Sequência , Reino Unido , Estados Unidos , Vagina/microbiologiaRESUMO
Multilocus sequencing strain types of a panel of 43 Candida albicans isolates from animals, including mammals and avian species, were compared with strain types for human isolates. The clade distribution of the animal isolates was significantly different from that of the human isolates, in both a comparison involving a total of 1580 isolates from multiple geographical sources and a comparison restricted to 675 human isolates from the same geographical regions as the animal isolates. A nearest-neighbour analysis involving the 43 animal isolates and 67 human isolates, randomly selected to give a proportionate distribution of geographical sources, showed a strong statistical trend towards genetic selection of different C. albicans strain types adapted to non-human animal hosts, but without complete genetic separation.
Assuntos
Candida albicans/classificação , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Candidíase/veterinária , Técnicas de Tipagem Micológica/métodos , Animais , Candida albicans/genética , Geografia , Humanos , FilogeniaRESUMO
Stress adaptation is critical for the survival of microbes in dynamic environments, and in particular, for fungal pathogens to survive in and colonise host niches. Proteomic analyses have the potential to significantly enhance our understanding of these adaptive responses by providing insight into post-transcriptional regulatory mechanisms that contribute to the outputs, as well as testing presumptions about the regulation of protein levels based on transcript profiling. Here, we used label-free, quantitative mass spectrometry to re-examine the response of the major fungal pathogen of humans, Candida albicans, to osmotic stress. Of the 1,262 proteins that were identified, 84 were down-regulated in response to 1M NaCl, reflecting the decrease in ribosome biogenesis and translation that often accompanies stress. The 64 up-regulated proteins included central metabolic enzymes required for glycerol synthesis, a key osmolyte for this yeast, as well as proteins with functions during stress. These data reinforce the view that adaptation to salt stress involves a transient reduction in ribosome biogenesis and translation together with the accumulation of the osmolyte, glycerol. The specificity of the response to salt stress is highlighted by the small proportion of quantified C. albicans proteins (5%) whose relative elevated abundances were statistically significant.
Assuntos
Candida albicans/metabolismo , Proteínas Fúngicas/biossíntese , Regulação Fúngica da Expressão Gênica , Pressão Osmótica , Proteômica , Candida albicans/genética , Proteínas Fúngicas/genética , HumanosRESUMO
A 12 month survey of candidaemia in Scotland, UK, in which every Scottish hospital laboratory submitted all blood isolates of yeasts for identification, strain typing and susceptibility testing, provided 300 isolates from 242 patients, generating incidence data of 4.8 cases per 100,000 population per year and 5.9 cases per 100,000 acute occupied bed days; 27.9 % of cases occurred in intensive care units. More than half the patients with candidaemia had an underlying disease involving the abdomen, 78 % had an indwelling intravenous catheter, 62 % had suffered a bacterial infection within the 2 weeks prior to candidaemia and 37 % had undergone a laparotomy. Candida albicans was the infecting species in 50 % of cases, followed by Candida glabrata (21 %) and Candida parapsilosis (12 %). Seven cases of candidaemia were caused by Candida dubliniensis, which was more prevalent even than Candida lusitaniae and Candida tropicalis (six cases each). Among C. glabrata isolates, 55 % showed reduced susceptibility to fluconazole, but azole resistance among other species was extremely low. Multilocus sequence typing showed isolates with high similarity came from different hospitals across the country, and many different types came from the hospitals that submitted the most isolates, indicating no tendency towards hospital-specific endemic strains. Multiple isolates of C. albicans and C. glabrata from individual patients were of the same strain type with single exceptions for each species. The high prevalence of candidaemia in Scotland, relative to other population-based European studies, and the high level of reduced fluconazole susceptibility of Scottish C. glabrata isolates warrant continued future surveillance of invasive Candida infections.
Assuntos
Candida , Candidíase/epidemiologia , Fungemia/epidemiologia , Adolescente , Adulto , Idoso , Antifúngicos/farmacologia , Infecções Bacterianas , Candida/classificação , Candida/efeitos dos fármacos , Candida/genética , Cateteres de Demora , Criança , Pré-Escolar , Feminino , Fluconazol/farmacologia , Inquéritos Epidemiológicos , Humanos , Incidência , Lactente , Laparotomia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica , Estudos Prospectivos , Fatores de Risco , Escócia/epidemiologiaRESUMO
Obesity and its comorbidities are an increasing challenge for both affected individuals and health care systems, worldwide. In obese individuals, perturbation of expression of both protein-coding genes and microRNAs (miRNA) are seen in obesity-relevant tissues (i.e. adipose tissue, liver and skeletal muscle). miRNAs are small non-coding RNA molecules which have important regulatory roles in a wide range of biological processes, including obesity. Rodents are widely used animal models for human diseases including obesity. However, not all research is applicable for human health or diseases. In contrast, pigs are emerging as an excellent animal model for obesity studies, due to their similarities in their metabolism, their digestive tract and their genetics, when compared to humans. The Göttingen minipig is a small sized easy-to-handle pig breed which has been extensively used for modeling human obesity, due to its capacity to develop severe obesity when fed ad libitum. The aim of this study was to identify differentially expressed of protein-coding genes and miRNAs in a Göttingen minipig obesity model. Liver, skeletal muscle and abdominal adipose tissue were sampled from 7 lean and 7 obese minipigs. Differential gene expression was investigated using high-throughput quantitative real-time PCR (qPCR) on 90 mRNAs and 72 miRNAs. The results revealed de-regulation of several obesity and inflammation-relevant protein-coding genes and miRNAs in all tissues examined. Many genes that are known to be de-regulated in obese humans were confirmed in the obese minipigs and several of these genes have target sites for miRNAs expressed in the opposing direction of the gene, confirming miRNA-mediated regulation in obesity. These results confirm the translational value of the pig for human obesity studies.
Assuntos
Perfilação da Expressão Gênica , MicroRNAs/genética , Obesidade/genética , Porco Miniatura , Animais , Modelos Animais de Doenças , Feminino , Especificidade de Órgãos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , SuínosRESUMO
Obesity is associated with immunological perturbations that contribute to insulin resistance. Epigenetic mechanisms can control immune functions and have been linked to metabolic complications, although their contribution to insulin resistance still remains unclear. In this study, we investigated the link between metabolic dysfunction and immune alterations with the epigenetic signature in leukocytes in a porcine model of obesity. Global DNA methylation of circulating leukocytes, adipose tissue leukocyte trafficking, and macrophage polarisation were established by flow cytometry. Adipose tissue inflammation and metabolic function were further characterised by quantification of metabolites and expression levels of genes associated with obesity and inflammation. Here we show that obese pigs showed bigger visceral fat pads, higher levels of circulating LDL cholesterol, and impaired glucose tolerance. These changes coincided with impaired metabolism, sustained macrophages infiltration, and increased inflammation in the adipose tissue. Those immune alterations were linked to global DNA hypermethylation in both B-cells and T-cells. Our results provide novel insight into the possible contribution of immune cell epigenetics into the immunological disturbances observed in obesity. The dramatic changes in the transcriptomic and epigenetic signature of circulating lymphocytes reinforce the concept that epigenetic processes participate in the increased immune cell activation and impaired metabolic functions in obesity.
Assuntos
Linfócitos B/metabolismo , Metilação de DNA , Epigênese Genética , Mediadores da Inflamação/sangue , Gordura Intra-Abdominal/metabolismo , Lipídeos/sangue , Obesidade/genética , Paniculite/genética , Linfócitos T/metabolismo , Adiposidade , Animais , Linfócitos B/imunologia , Quimiotaxia de Leucócito , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Gordura Intra-Abdominal/imunologia , Masculino , Obesidade/sangue , Obesidade/imunologia , Paniculite/sangue , Paniculite/imunologia , Suínos , Linfócitos T/imunologia , Fatores de TempoRESUMO
Obesity is a complex condition that increases the risk of life threatening diseases such as cardiovascular disease and diabetes. Studying the gene regulation of obesity is important for understanding the molecular mechanisms behind the obesity derived diseases and may lead to better intervention and treatment plans. MicroRNAs (miRNAs) are short non-coding RNAs regulating target mRNA by binding to their 3'UTR. They are involved in numerous biological processes and diseases, including obesity. In this study we use a mixed breed pig model designed for obesity studies to investigate differentially expressed miRNAs in subcutaneous adipose tissue by RNA sequencing (RNAseq). Both male and female pigs are included to explore gender differences. The RNAseq study shows that the most highly expressed miRNAs are in accordance with comparable studies in pigs and humans. A total of six miRNAs are differentially expressed in subcutaneous adipose tissue between the lean and obese group of pigs, and in addition gender specific significant differential expression is observed for a number of miRNAs. The differentially expressed miRNAs have been verified using qPCR. The results of these studies in general confirm the trends found by RNAseq. Mir-9 and mir-124a are significantly differentially expressed with large fold changes in subcutaneous adipose tissue between lean and obese pigs. Mir-9 is more highly expressed in the obese pigs with a fold change of 10 and a p-value < 0.001. Mir-124a is more highly expressed in the obese pigs with a fold change of 114 and a p-value < 0.001. In addition, mir-124a is significantly higher expressed in abdominal adipose tissue in male pigs with a fold change of 119 and a p-value < 0.05. Both miRNAs are also significantly higher expressed in the liver of obese male pigs where mir-124a has a fold change of 12 and mir-9 has a fold change of 1.6, both with p-values < 0.05.
Assuntos
Regulação da Expressão Gênica , MicroRNAs/biossíntese , Obesidade/metabolismo , Caracteres Sexuais , Gordura Subcutânea Abdominal/metabolismo , Animais , Feminino , Masculino , MicroRNAs/genética , Obesidade/genética , SuínosRESUMO
The major fungal pathogen of humans, Candida albicans, mounts robust responses to oxidative stress that are critical for its virulence. These responses counteract the reactive oxygen species (ROS) that are generated by host immune cells in an attempt to kill the invading fungus. Knowledge of the dynamical processes that instigate C. albicans oxidative stress responses is required for a proper understanding of fungus-host interactions. Therefore, we have adopted an interdisciplinary approach to explore the dynamical responses of C. albicans to hydrogen peroxide (H2O2). Our deterministic mathematical model integrates two major oxidative stress signalling pathways (Cap1 and Hog1 pathways) with the three major antioxidant systems (catalase, glutathione and thioredoxin systems) and the pentose phosphate pathway, which provides reducing equivalents required for oxidative stress adaptation. The model encapsulates existing knowledge of these systems with new genomic, proteomic, transcriptomic, molecular and cellular datasets. Our integrative approach predicts the existence of alternative states for the key regulators Cap1 and Hog1, thereby suggesting novel regulatory behaviours during oxidative stress. The model reproduces both existing and new experimental observations under a variety of scenarios. Time- and dose-dependent predictions of the oxidative stress responses for both wild type and mutant cells have highlighted the different temporal contributions of the various antioxidant systems during oxidative stress adaptation, indicating that catalase plays a critical role immediately following stress imposition. This is the first model to encapsulate the dynamics of the transcriptional response alongside the redox kinetics of the major antioxidant systems during H2O2 stress in C. albicans.