Immune function, gene expression, blood indices and performance in transition dairy cows affected by diet and inflammation

The transition period is associated with the peak incidence of production problems, metabolic disorders and infectious diseases in dairy cows (Drackley, 1999). During this time the cow’s immune system seems to be weakened; it is apparent that metabolic challenges associated with the onset of lactation are factors capable of affecting immune function. However, the reasons for this state are not entirely clear (Goff, 2006). The negative energy balance associated with parturition leads to extensive mobilization of fatty acids stored in adipose tissue, thus, causing marked elevations in blood non-esterified fatty acids (NEFA) and B-hydroxybutyrate (BHBA) concentrations (Drackley et al., 2001). Prepartal level of dietary energy can potentially affect adipose tissue deposition and, thus, the amount of NEFA released into blood and available for metabolism in liver (Drackley et al., 2005). The current feeding practices for pregnant non-lactating cows has been called into question because increasing amounts of moderate-to-high energy diets (i.e. those more similar to lactation diets in the content of energy) during the last 3 wk postpartum have largely failed to overcome peripartal health problems, excessive body condition loss after calving, or declining fertility (Beever, 2006). Current prepartal feeding practices can lead to elevated intakes of energy, which can increase fat deposition in the viscera and upon parturition lead to compromised liver metabolism (Beever, 2006, Drackley et al., 2005). Our general hypothesis was that overfeeding dietary energy during the dry period, accompanied by the metabolic challenges associated with the onset of lactation would render the cow’s immune function less responsive early postpartum. The chapters in this dissertation evaluated neutrophil function, metabolic and inflammation indices and gene expression affected by the plane of dietary energy prepartum and an early post-partum inflammatory challenge in dairy cows. The diet effect in this experiment was transcendental during the transition period and potentially during the entire lactation. Changes in energy balance were observed and provided a good model to study the challenges associated with the onset of lactation. Overall the LPS model provided a consistent response representing an inflammation incident; however the changes in metabolic indices were sudden and hard to detect in most of the cases during the days following the challenge. In general overfeeding dietary energy during the dry period resulted in a less responsive immune function during the early postpartum. In other words, controlling the dietary energy prepartum has more benefits for the dairy cow during transition

Operation of a DNA-Based Autocatalytic Network in Serum

The potential for inferring the presence of cancer by the detection of miRNA in human blood has motivated research into the design and operation of DNA-based chemical amplifiers that can operate in bodily fluids. As a first step toward this goal, we have tested the operation of a DNA-based autocatalytic network in human serum and mouse serum. With the addition of sodium dodecyl sulfate to prevent degradation by nuclease activity, the network was found to operate successfully with both DNA and RNA catalysts

Improving the Relative Calculations of Volta Potential Differences Acquired from Scanning Kelvin Probe Force Microscopy (SKPFM) from Comparing an Inert Material to First-Principle Calculations

An improved relative scaling of Volta potential differences (VPD) acquired from scanning Kelvin probe force microscopy (SKPFM) was developed by quantifying the probe work function. In corrosion studies, SKPFM has been used to identify local nobility of complex metallic systems and provide theoretical corrosion initiation sites. However, large variability in measured VPD values for metallic phases has led to controversy in their interpretation. Tracking changes of the probe work function has been shown to decrease the variability seen in SKPFM results. To quantify the work function of SKPFM probes, the measured VPD of an inert gold standard was compared to the work function theoretically calculated by density functional theory (DFT) first-principles. For proof of concept, a stainless steel sample joined by a Cu-Ag-Ti brazing material was characterized by SKPFM with three different types of probes

Adipogenic and energy metabolism gene networks in longissimus lumborum during rapid post-weaning growth in Angus and Angus × Simmental cattle fed high-starch or low-starch diets

<p>Abstract</p> <p>Background</p> <p>Transcriptional networks coordinate adipocyte differentiation and energy metabolism in rodents. The level of fiber and starch in diets with adequate energy content fed to young cattle has the potential to alter intramuscular adipose tissue development in skeletal muscle. Post-weaning alterations in gene expression networks driving adipogenesis, lipid filling, and intracellular energy metabolism provide a means to evaluate long-term effects of nutrition on longissimus muscle development across cattle types.</p> <p>Results</p> <p><it>Longissimus lumborum </it>(LL) from Angus (n = 6) and Angus × Simmental (A × S; n = 6) steer calves (155 ± 10 days age) fed isonitrogenous high-starch (HiS; 1.43 Mcal/kg diet dry matter; n = 6) or low-starch (LoS; 1.19 Mcal/kg diet dry matter; n = 6) diets was biopsied at 0, 56, and 112 days of feeding for transcript profiling of 31 genes associated with aspects of adipogenesis and energy metabolism. Intake of dietary energy (9.44 ± 0.57 Mcal/d) across groups during the study did not differ but feed efficiency (weight gain/feed intake) during the first 56 days was greater for steers fed HiS. Expression of <it>PPARG </it>increased ca. 2-fold by day 56 primarily due to HiS in A × S steers. Several potential <it>PPARG</it>-target genes (e.g., <it>ACACA</it>, <it>FASN</it>, <it>FABP4</it>, <it>SCD</it>) increased 2.5-to-25-fold by day 56 across all groups, with responses (e.g., <it>FASN</it>, <it>FABP4</it>) being less pronounced in A × S steers fed LoS. This latter group of steers had markedly greater blood plasma glucose (0.99 vs. 0.79 g/L) and insulin (2.95 vs. 1.17 μg/L) by day 112, all of which were suggestive of insulin resistance. Interactions were observed for <it>FABP4</it>, <it>FASN</it>, <it>GPAM</it>, <it>SCD</it>, and <it>DGAT2</it>, such that feeding A × S steers high-starch and Angus steers low-starch resulted in greater fold-changes by day 56 or 112 (<it>GPAM</it>). Marked up-regulation of <it>INSIG1 </it>(4-to-8-fold) occurred throughout the study across all groups. <it>SREBF1 </it>expression, however, was only greater on day 112 namely due to LoS in A × S steers. The lipogenic transcription factor <it>THRSP </it>was 6-to-60-fold greater by day 56 primarily due to HiS in A × S steers, constituting the greatest response among all genes.</p> <p>Conclusion</p> <p>Results involving gene markers of mature adipocytes (e.g., <it>PPARG</it>, <it>THRSP</it>, <it>SCD</it>) provided evidence of intramuscular adipose tissue differentiation during the early portion of the growing phase. The resulting gene networks underscored a central role for <it>PPARG </it>in controlling transcription of genes which are known to co-ordinately regulate adipocyte differentiation and lipid filling in non-ruminants. Unlike rodents, <it>INSIG1 </it>appears to play an important role in cattle muscle adipogenesis. We propose that a network of transcription regulators and nuclear receptors including <it>PPARG</it>-target genes,<it> INSIG1</it>, and <it>THRSP</it>, coordinate activation of adipocyte differentiation and lipid filling at an early age.</p

Phase Separation in Ti-6Al-4V Alloys with Boron Additions for Biomedical Applications: Scanning Kelvin Probe Force Microscopy Investigation of Microgalvanic Couples and Corrosion Initiation

To investigate the effect of boron additions on the corrosion behavior of Ti-6Al-4V for potential use in biomedical implants and devices, cast samples of Ti-6Al-4V were alloyed with 0.01% to 1.09% boron by weight and subjected to hot isostatic pressing. Subsequent analysis via scanning Kelvin probe force microscopy and scanning electron microscopy/energy-dispersive spectroscopy revealed the presence of both alpha (α) and beta (β) phase titanium, enriched in aluminum and vanadium, respectively. At all concentrations, boron additions affected the grain structure and were dispersed throughout both phases, but above the solubility limit, needle-like TiB structures also formed. The TiB needles and β phase exhibited similar surface potentials, whereas that of the α phase was found to be significantly lower. Nevertheless, when subjected to high applied electrochemical potentials in saline solutions, corrosion initiation was observed exclusively within the more noble β phase

Internal controls for quantitative polymerase chain reaction of swine mammary glands during pregnancy and lactation.

High-throughput microarray analysis is an efficient means of obtaining a genome-wide view of transcript profiles across physiological states. However, quantitative PCR (qPCR) remains the chosen method for high-precision mRNA abundance analysis. Essential for reliability of qPCR data is normalization using appropriate internal control genes (ICG), which is now, more than ever before, a fundamental step for accurate gene expression profiling. We mined mammary tissue microarray data on >13,000 genes at -34, -14, 0, 7, 14, 21, and 28 d relative to parturition in 27 crossbred primiparous gilts to identify suitable ICG. Initial analysis revealed TBK1, PCSK2, PTBP1, API5, VAPB, QTRT1, TRIM41, TMEM24, PPP2R5B, and AP1S1 as the most stable genes (sample/reference = 1 +/- 0.2). We also included 9 genes previously identified as ICG in bovine mammary tissue. Gene network analysis of the 19 genes identified AP1S1, API5, MTG1, VAPB, TRIM41, MRPL39, and RPS15A as having no known co-regulation. In addition, UXT and ACTB were added to this list, and mRNA abundance of these 9 genes was measured by qPCR. Expression of all 9 of these genes was decreased markedly during lactation. In a previous study with bovine mammary tissue, mRNA of stably expressed genes decreased during lactation due to a dilution effect brought about by large increases in expression of highly abundant genes. To verify this effect, highly abundant mammary genes such as CSN1S2, SCD, FABP3, and LTF were evaluated by qPCR. The tested ICG had a negative correlation with these genes, demonstrating a dilution effect in the porcine mammary tissue. Gene stability analysis identified API5, VABP, and MRPL39 as the most stable ICG in porcine mammary tissue and indicated that the use of those 3 genes was most appropriate for calculating a normalization factor. Overall, results underscore the importance of proper validation of internal controls for qPCR and highlight the limitations of using absence of time effects as the criteria for selection of appropriate ICG. Further, we showed that use of the same ICG from one organism might not be suitable for qPCR normalization in other species

Availability: A Metric for Nucleic Acid Strand Displacement Systems

DNA strand displacement systems have transformative potential in synthetic biology. While powerful examples have been reported in DNA nanotechnology, such systems are plagued by leakage, which limits network stability, sensitivity, and scalability. An approach to mitigate leakage in DNA nanotechnology, which is applicable to synthetic biology, is to introduce mismatches to complementary fuel sequences at key locations. However, this method overlooks nuances in the secondary structure of the fuel and substrate that impact the leakage reaction kinetics in strand displacement systems. In an effort to quantify the impact of secondary structure on leakage, we introduce the concepts of availability and mutual availability and demonstrate their utility for network analysis. Our approach exposes vulnerable locations on the substrate and quantifies the secondary structure of fuel strands. Using these concepts, a 4-fold reduction in leakage has been achieved. The result is a rational design process that efficiently suppresses leakage and provides new insight into dynamic nucleic acid networks

Liver lipid content and inflammometabolic indices in peripartal dairy cows are altered in response to prepartal energy intake and postpartal intramammary inflammatory challenge.

This study evaluated the effect of feeding a control diet (CON) or a moderate energy diet (overfed, OVE) during the dry period (∼45d) and a postpartum intramammary lipopolysaccharide (LPS) challenge on blood metabolic and inflammatory indices, milk production, and hepatic gene expression. A subset of cows (n=9/diet) in CON (1.34 Mcal/kg of dry matter) and OVE (1.62 Mcal/kg of dry matter) received an intramammary LPS challenge (200 μg; CON-LPS, OVE-LPS, respectively). Liver biopsies were harvested at -14 d from calving, and postpartum at 2.5h post-LPS on d 7, 14, and 30. Prepartum, the OVE group was in more positive energy balance (EB) and had greater body condition score compared with CON. In contrast, during wk 1 postpartum and before the LPS challenge, the OVE group was in greater negative EB than CON. Prepartal diet did not affect postpartal milk production or dry matter intake. At 2h postchallenge on d 7, we observed an increase in serum nonesterified fatty acids (NEFA) and bilirubin and a decrease in hydroxybutyrate, regardless of diet. That was coupled with greater haptoglobin in OVE-LPS compared with CON-LPS. In addition, OVE-LPS cows versus CON nonchallenged, OVE nonchallenged, and CON-LPS had greater liver triacylglycerol (TAG) concentration 2.5h postchallenge on d 7. The concentration of TAG in liver of OVE-LPS remained elevated by 30d postpartum. The liver TAG concentration in OVE-LPS compared with CON-LPS cows was associated with greater serum concentration of NEFA and reactive oxygen metabolites on d 10 and 14 postpartum. Cows in OVE-LPS also had greater concentrations of ceruloplasmin, cholesterol, and vitamin E from d 10 through 21. Among 28 genes associated with fatty acid oxidation, inflammation, oxidative stress, and gluconeogenesis, only SAA3 (which encodes an acute phase protein) was greater in CON-LPS compared with OVE-LPS at 2.5h postchallenge. Expression of HP, which encodes another acute phase protein, was greater in OVE-LPS than in CON-LPS at 14 and 30 d postpartum. Several inflammation-related genes (TNF, IRAK1, NFKB1, ANGPTL4) showed markedly decreased expression between 7 and 14 d, after which expression remained unchanged. No differences were observed in several genes of the growth-hormone/insulin-like growth factor-1 axis, except for SOCS2, expression of which decreased markedly between 7 and 14 d in OVE-LPS but not in CON-LPS. These data suggest that overfeeding a moderate-energy diet prepartum alters the response of the cow to an intramammary challenge after calving and may predispose it to sustained liver lipidosis

Acute mammary and liver transcriptome responses after an intramammary Escherichia coli lipopolysaccharide challenge in postpartal dairy cows

The study investigated the effect of an intramammary lipopolysaccharide (LPS) challenge on the bovine mammary and liver transcriptome and its consequences on metabolic biomarkers and liver tissue composition. At 7 days of lactation, 7 cows served as controls (CTR) and 7 cows (LPS) received an intramammary Escherichia coli LPS challenge. The mammary and liver tissues for transcriptomic profiling were biopsied at 2.5 h from challenge. Liver composition was evaluated at 2.5 h and 7 days after challenge, and blood biomarkers were analyzed at 2, 3, 7 and 14 days from challenge. In mammary tissue, the LPS challenge resulted in 189 differentially expressed genes (DEG), with 20 down-regulated and 169 up-regulated. In liver tissue, there were 107 DEG in LPS compared with CTR with 42 down-regulated and 65 up-regulated. In mammary, bioinformatics analysis highlighted that LPS led to activation of NOD-like receptor signaling, Toll-like receptor signaling, RIG-I-like receptor signaling and apoptosis pathways. In liver, LPS resulted in an overall inhibition of fatty acid elongation in mitochondria and activation of the p53 signaling pathway. The LPS challenge induced changes in liver lipid composition, a systemic inflammation (rise of blood ceruloplasmin and bilirubin), and an increase in body fat mobilization. The data suggest that cells within the inflamed mammary gland respond by activating mechanisms of pathogen recognition. However, in the liver the response likely depends on mediators originating from the udder that affect liver functionality and specifically fatty acid metabolism (b-oxidation, ketogenesis, and lipoprotein synthesis).Fil: Minuti, Andrea. Universita Cattolica del Sacro Cuore; ItaliaFil: Zhou, Zheng. University Of Illinois At Urbana; Estados UnidosFil: Graugnard, Daniel E. University Of Illinois At Urbana; Estados UnidosFil: Rodriguez Zas, Sandra L.. University Of Illinois At Urbana; Estados UnidosFil: Palladino, Rafael Alejandro. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cardoso, Felipe C.. University Of Illinois At Urbana; Estados UnidosFil: Trevisi, Erminio. Universita Cattolica del Sacro Cuore; ItaliaFil: Loor, Juan J. University Of Illinois At Urbana; Estados Unido