45 research outputs found
Involvement of Skeletal Muscle Protein, Glycogen, and Fat Metabolism in the Adaptation on Early Lactation of Dairy Cows
During early lactation, high-yielding dairy cows cannot consume enough feed to meet nutrient requirements. As a consequence, animals drop into negative energy balance and mobilize body reserves including muscle protein and glycogen for milk production, direct oxidation, and hepatic gluconeogenesis. To examine which muscle metabolic processes contribute to the adaptation during early lactation, six German Holstein cows were blood sampled and muscle biopsied throughout the periparturient period. From pregnancy to lactation, the free plasma amino acid pattern imbalanced and plasma glucose decreased. Several muscle amino acids, as well as total muscle protein, fat, and glycogen, and the expression of glucose transporter-4 were reduced within the first 4 weeks of lactation. The 2-DE and MALDI-TOF-MS analysis identified 43 differentially expressed muscle protein spots throughout the periparturient period. In early lactation, expression of cytoskeletal proteins and enzymes involved in glycogen synthesis and in the TCA cycle was decreased, whereas proteins related to glycolysis, fatty acid degradation, lactate, and ATP production were increased. On the basis of these results, we propose a model in which the muscle breakdown in early lactation provides substrates for milk production by a decoupled Cori cycle favoring hepatic gluconeogenesis and by interfering with feed intake signaling
Involvement of Skeletal Muscle Protein, Glycogen, and Fat Metabolism in the Adaptation on Early Lactation of Dairy Cows
During early lactation, high-yielding dairy cows cannot consume enough feed to meet nutrient requirements. As a consequence, animals drop into negative energy balance and mobilize body reserves including muscle protein and glycogen for milk production, direct oxidation, and hepatic gluconeogenesis. To examine which muscle metabolic processes contribute to the adaptation during early lactation, six German Holstein cows were blood sampled and muscle biopsied throughout the periparturient period. From pregnancy to lactation, the free plasma amino acid pattern imbalanced and plasma glucose decreased. Several muscle amino acids, as well as total muscle protein, fat, and glycogen, and the expression of glucose transporter-4 were reduced within the first 4 weeks of lactation. The 2-DE and MALDI-TOF-MS analysis identified 43 differentially expressed muscle protein spots throughout the periparturient period. In early lactation, expression of cytoskeletal proteins and enzymes involved in glycogen synthesis and in the TCA cycle was decreased, whereas proteins related to glycolysis, fatty acid degradation, lactate, and ATP production were increased. On the basis of these results, we propose a model in which the muscle breakdown in early lactation provides substrates for milk production by a decoupled Cori cycle favoring hepatic gluconeogenesis and by interfering with feed intake signaling
Increased Anaplerosis, TCA Cycling, and Oxidative Phosphorylation in the Liver of Dairy Cows with Intensive Body Fat Mobilization during Early Lactation
The onset of milk production lets mammals experience
an enormous
energy and nutrient demand. To meet these requirements, high-yielding
dairy cows mobilize body fat resulting in an augmented hepatic oxidative
metabolism, which has been suggested to signal for depressing hunger
after calving. To examine how the extent of fat mobilization influences
hepatic oxidative metabolism and thus potentially feed intake, blood
and liver samples of 19 Holstein cows were taken throughout the periparturient
period. Retrospectively grouped according to high (H) and low (L)
liver fat content, H cows showed higher fatty acid but lower amino
acid plasma concentrations and lower feed intake than L cows. The
hepatic phospho-AMPK/total AMP ratio was not different between groups
but decreased after parturition. A 2-DE coupled MALDI-TOF-TOF analysis
and qRT-PCR studies revealed H cows having lower expressions of major
enzymes involved in mitochondrial β-oxidation, urea cycling,
and the pentose phosphate pathway but higher expressions of enzymes
participating in peroxisomal and endoplasmic fatty acid degradation,
pyruvate and TCA cycling, amino acid catabolism, oxidative phosphorylation,
and oxidative stress defense. These data indicate that increasing
lipolysis leads to augmenting nutrient catabolism for anaplerosis
and mitochondrial respiration, providing a molecular link between
hepatic oxidative processes and feed intake
of Bacillus pumilus KatX2 confers enhanced hydrogen peroxide resistance to a Bacillus subtilis PkatA::katX2 mutant strain
of
Bacillus pumilus KatX2 confers enhanced hydrogen peroxide resistance to a Bacillus subtilis PkatA::katX2 mutant strai
Table_5_Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach.xlsx
IntroductionThe environmental bacterium Burkholderia pseudomallei causes the often fatal and massively underreported infectious disease melioidosis. Antigens inducing protective immunity in experimental models have recently been identified and serodiagnostic tools have been improved. However, further elucidation of the antigenic repertoire of B. pseudomallei during human infection for diagnostic and vaccine purposes is required. The adaptation of B. pseudomallei to very different habitats is reflected by a huge genome and a selective transcriptional response to a variety of conditions. We, therefore, hypothesized that exposure of B. pseudomallei to culture conditions mimicking habitats encountered in the human host might unravel novel antigens that are recognized by melioidosis patients.Methods and resultsIn this study, B. pseudomallei was exposed to various stress and growth conditions, including anaerobiosis, acid stress, oxidative stress, iron starvation and osmotic stress. Immunogenic proteins were identified by probing two-dimensional Western blots of B. pseudomallei intracellular and extracellular protein extracts with sera from melioidosis patients and controls and subsequent MALDI-TOF MS. Among B. pseudomallei specific immunogenic signals, 90 % (55/61) of extracellular immunogenic proteins were identified by acid, osmotic or oxidative stress. A total of 84 % (44/52) of intracellular antigens originated from the stationary growth phase, acidic, oxidative and anaerobic conditions. The majority of the extracellular and intracellular protein antigens were identified in only one of the various stress conditions. Sixty-three immunoreactive proteins and an additional 38 candidates from a literature screening were heterologously expressed and subjected to dot blot analysis using melioidosis sera and controls. Our experiments confirmed melioidosis-specific signals in 58 of our immunoproteome candidates. These include 15 antigens with average signal ratios (melioidosis:controls) greater than 10 and another 26 with average ratios greater than 5, including new promising serodiagnostic candidates with a very high signal-to-noise ratio.ConclusionOur study shows that a comprehensive B. pseudomallei immunoproteomics approach, using conditions which are likely to be encountered during infection, can identify novel antibody targets previously unrecognized in human melioidosis.</p
Table_4_Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach.xlsx
IntroductionThe environmental bacterium Burkholderia pseudomallei causes the often fatal and massively underreported infectious disease melioidosis. Antigens inducing protective immunity in experimental models have recently been identified and serodiagnostic tools have been improved. However, further elucidation of the antigenic repertoire of B. pseudomallei during human infection for diagnostic and vaccine purposes is required. The adaptation of B. pseudomallei to very different habitats is reflected by a huge genome and a selective transcriptional response to a variety of conditions. We, therefore, hypothesized that exposure of B. pseudomallei to culture conditions mimicking habitats encountered in the human host might unravel novel antigens that are recognized by melioidosis patients.Methods and resultsIn this study, B. pseudomallei was exposed to various stress and growth conditions, including anaerobiosis, acid stress, oxidative stress, iron starvation and osmotic stress. Immunogenic proteins were identified by probing two-dimensional Western blots of B. pseudomallei intracellular and extracellular protein extracts with sera from melioidosis patients and controls and subsequent MALDI-TOF MS. Among B. pseudomallei specific immunogenic signals, 90 % (55/61) of extracellular immunogenic proteins were identified by acid, osmotic or oxidative stress. A total of 84 % (44/52) of intracellular antigens originated from the stationary growth phase, acidic, oxidative and anaerobic conditions. The majority of the extracellular and intracellular protein antigens were identified in only one of the various stress conditions. Sixty-three immunoreactive proteins and an additional 38 candidates from a literature screening were heterologously expressed and subjected to dot blot analysis using melioidosis sera and controls. Our experiments confirmed melioidosis-specific signals in 58 of our immunoproteome candidates. These include 15 antigens with average signal ratios (melioidosis:controls) greater than 10 and another 26 with average ratios greater than 5, including new promising serodiagnostic candidates with a very high signal-to-noise ratio.ConclusionOur study shows that a comprehensive B. pseudomallei immunoproteomics approach, using conditions which are likely to be encountered during infection, can identify novel antibody targets previously unrecognized in human melioidosis.</p
General aspects of <i>S. aureus</i> stress response.
<p>Inter-experimental analyses of stress induced protein synthesis patterns revealed general and specific effects on global protein synthesis. (<b>A</b>) The majority of the synthesis profiles showed a significant (ANOVA, α = 0.1, p-values based on 1000 permutations, absolute threshold of 2.5) induction or repression rate in response to one or two stimuli. (<b>B</b>) To identify more general effects a pairwise comparison of all experiments was performed using protein synthesis profiles significantly changed at least one time point following exposure to the different stimuli (t-test, α = 0.1; p-values based on all possible permutations, adjusted Bonferroni correction). The number of induced (orange) and repressed (blue) protein synthesis profiles shared by the respective stimuli is shown. The total number of synthesis profiles significantly induced or repressed by the respective stimulus are given on the right side. (<b>C</b>) Overlap of marker proteins induced in response to diamide, puromycin, and heat as well as to nitric oxide, fermentation, and nitrate respiration are shown.</p
Table_3_Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach.docx
IntroductionThe environmental bacterium Burkholderia pseudomallei causes the often fatal and massively underreported infectious disease melioidosis. Antigens inducing protective immunity in experimental models have recently been identified and serodiagnostic tools have been improved. However, further elucidation of the antigenic repertoire of B. pseudomallei during human infection for diagnostic and vaccine purposes is required. The adaptation of B. pseudomallei to very different habitats is reflected by a huge genome and a selective transcriptional response to a variety of conditions. We, therefore, hypothesized that exposure of B. pseudomallei to culture conditions mimicking habitats encountered in the human host might unravel novel antigens that are recognized by melioidosis patients.Methods and resultsIn this study, B. pseudomallei was exposed to various stress and growth conditions, including anaerobiosis, acid stress, oxidative stress, iron starvation and osmotic stress. Immunogenic proteins were identified by probing two-dimensional Western blots of B. pseudomallei intracellular and extracellular protein extracts with sera from melioidosis patients and controls and subsequent MALDI-TOF MS. Among B. pseudomallei specific immunogenic signals, 90 % (55/61) of extracellular immunogenic proteins were identified by acid, osmotic or oxidative stress. A total of 84 % (44/52) of intracellular antigens originated from the stationary growth phase, acidic, oxidative and anaerobic conditions. The majority of the extracellular and intracellular protein antigens were identified in only one of the various stress conditions. Sixty-three immunoreactive proteins and an additional 38 candidates from a literature screening were heterologously expressed and subjected to dot blot analysis using melioidosis sera and controls. Our experiments confirmed melioidosis-specific signals in 58 of our immunoproteome candidates. These include 15 antigens with average signal ratios (melioidosis:controls) greater than 10 and another 26 with average ratios greater than 5, including new promising serodiagnostic candidates with a very high signal-to-noise ratio.ConclusionOur study shows that a comprehensive B. pseudomallei immunoproteomics approach, using conditions which are likely to be encountered during infection, can identify novel antibody targets previously unrecognized in human melioidosis.</p
Table_2_Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach.docx
IntroductionThe environmental bacterium Burkholderia pseudomallei causes the often fatal and massively underreported infectious disease melioidosis. Antigens inducing protective immunity in experimental models have recently been identified and serodiagnostic tools have been improved. However, further elucidation of the antigenic repertoire of B. pseudomallei during human infection for diagnostic and vaccine purposes is required. The adaptation of B. pseudomallei to very different habitats is reflected by a huge genome and a selective transcriptional response to a variety of conditions. We, therefore, hypothesized that exposure of B. pseudomallei to culture conditions mimicking habitats encountered in the human host might unravel novel antigens that are recognized by melioidosis patients.Methods and resultsIn this study, B. pseudomallei was exposed to various stress and growth conditions, including anaerobiosis, acid stress, oxidative stress, iron starvation and osmotic stress. Immunogenic proteins were identified by probing two-dimensional Western blots of B. pseudomallei intracellular and extracellular protein extracts with sera from melioidosis patients and controls and subsequent MALDI-TOF MS. Among B. pseudomallei specific immunogenic signals, 90 % (55/61) of extracellular immunogenic proteins were identified by acid, osmotic or oxidative stress. A total of 84 % (44/52) of intracellular antigens originated from the stationary growth phase, acidic, oxidative and anaerobic conditions. The majority of the extracellular and intracellular protein antigens were identified in only one of the various stress conditions. Sixty-three immunoreactive proteins and an additional 38 candidates from a literature screening were heterologously expressed and subjected to dot blot analysis using melioidosis sera and controls. Our experiments confirmed melioidosis-specific signals in 58 of our immunoproteome candidates. These include 15 antigens with average signal ratios (melioidosis:controls) greater than 10 and another 26 with average ratios greater than 5, including new promising serodiagnostic candidates with a very high signal-to-noise ratio.ConclusionOur study shows that a comprehensive B. pseudomallei immunoproteomics approach, using conditions which are likely to be encountered during infection, can identify novel antibody targets previously unrecognized in human melioidosis.</p
Table_1_Deciphering the human antibody response against Burkholderia pseudomallei during melioidosis using a comprehensive immunoproteome approach.docx
IntroductionThe environmental bacterium Burkholderia pseudomallei causes the often fatal and massively underreported infectious disease melioidosis. Antigens inducing protective immunity in experimental models have recently been identified and serodiagnostic tools have been improved. However, further elucidation of the antigenic repertoire of B. pseudomallei during human infection for diagnostic and vaccine purposes is required. The adaptation of B. pseudomallei to very different habitats is reflected by a huge genome and a selective transcriptional response to a variety of conditions. We, therefore, hypothesized that exposure of B. pseudomallei to culture conditions mimicking habitats encountered in the human host might unravel novel antigens that are recognized by melioidosis patients.Methods and resultsIn this study, B. pseudomallei was exposed to various stress and growth conditions, including anaerobiosis, acid stress, oxidative stress, iron starvation and osmotic stress. Immunogenic proteins were identified by probing two-dimensional Western blots of B. pseudomallei intracellular and extracellular protein extracts with sera from melioidosis patients and controls and subsequent MALDI-TOF MS. Among B. pseudomallei specific immunogenic signals, 90 % (55/61) of extracellular immunogenic proteins were identified by acid, osmotic or oxidative stress. A total of 84 % (44/52) of intracellular antigens originated from the stationary growth phase, acidic, oxidative and anaerobic conditions. The majority of the extracellular and intracellular protein antigens were identified in only one of the various stress conditions. Sixty-three immunoreactive proteins and an additional 38 candidates from a literature screening were heterologously expressed and subjected to dot blot analysis using melioidosis sera and controls. Our experiments confirmed melioidosis-specific signals in 58 of our immunoproteome candidates. These include 15 antigens with average signal ratios (melioidosis:controls) greater than 10 and another 26 with average ratios greater than 5, including new promising serodiagnostic candidates with a very high signal-to-noise ratio.ConclusionOur study shows that a comprehensive B. pseudomallei immunoproteomics approach, using conditions which are likely to be encountered during infection, can identify novel antibody targets previously unrecognized in human melioidosis.</p