Effects of corn supplementation on serum and muscle microRNA profiles in horses

Laminitis associated with equine metabolic syndrome causes significant economic losses in the equine industry. Diets high in non-structural carbohydrates (NSC) have been linked to insulin resistance and laminitis in horses. Nutrigenomic studies analyzing the interaction of diets high in NSCs and gene expression regulating endogenous microRNAs (miRNA) are rare. This study\u27s objectives were to determine whether miRNAs from dietary corn can be detected in equine serum and muscle and its impacts on endogenous miRNA. Twelve mares were blocked by age, body condition score, and weight and assigned to a control (mixed legume grass hay diet) and a mixed legume hay diet supplemented with corn. Muscle biopsies and serum were collected on Days 0 and 28. Transcript abundances were analyzed using qRT-PCR for three plant-specific and 277 endogenous equine miRNAs. Plant miRNAs were found in serum and skeletal muscle samples with a treatment effect (p \u3c .05) with corn-specific miRNA being higher than control in serum after feeding. Endogenous miRNAs showed 12 different (p \u3c .05) miRNAs in equine serum after corn supplementation, six (eca-mir16, -4863p, -4865p, -126- 3p, -296, and -192) previously linked to obesity or metabolic disease. The results of our study indicate that dietary plant miRNAs can appear in circulation and tissues and may regulate endogenous genes

Microstructural and microchemical mechanisms controlling intergranular stress corrosion cracking in light-water-reactor systems

This review paper examines mechanisms controlling IGSCC in selected LWR components. Emphasis is placed on identifying material microstructures and microchemistries which promote susceptibility to premature failure. Two important examples are evaluated in some detail: stainless steel pipe cracking and primary-side SCC of alloy 600 steam generator tubing. In each case, grain boundary segregation and precipitation phenomena in these materials are reviewed and assessed relative to the mechanisms of IGSCC. This paper summarizes materials presented at the 1993 International Summer School on the Fundamentals of Radiation Damage held at the University of Illinois. A more comprehensive overview of SCC mechanisms and LWR examples was provided at the school, but will not be included in this article. Microstructural and microchemical aspects controlling IGSCC described here serve as a lead-in to the following paper focussing on how irradiation influences SCC resistance of reactor core components.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31289/1/0000195.pd

Non-Coding RNA Sequencing of Equine Endometrium During Maternal Recognition of Pregnancy.

Maternal recognition of pregnancy (MRP) in the mare is not well defined. In a non-pregnant mare, prostaglandin F2α (PGF) is released on day 14 post-ovulation (PO) to cause luteal regression, resulting in loss of progesterone production. Equine MRP occurs prior to day 14 to halt PGF production. Studies have failed to identify a gene candidate for MRP, so attention has turned to small, non-coding RNAs. The objective of this study was to evaluate small RNA (<200 nucleotides) content in endometrium during MRP. Mares were used in a cross-over design with each having a pregnant and non-mated cycle. Each mare was randomly assigned to collection day 11 or 13 PO (n = 3/day) and endometrial biopsies were obtained. Total RNA was isolated and sequencing libraries were prepared using a small RNA library preparation kit and sequenced on a HiSeq 2000. EquCab3 was used as the reference genome and DESeq2 was used for statistical analysis. On day 11, 419 ncRNAs, representing miRNA, snRNA, snoRNA, scaRNA, and vaultRNA, were different between pregnancy statuses, but none on day 13. Equine endometrial ncRNAs with unknown structure and function were also identified. This study is the first to describe ncRNA transcriptome in equine endometrium. Identifying targets of these ncRNAs could lead to determining MRP

Comparison of an Antioxidant Source and Antioxidant Plus BCAA on Athletic Performance and Post Exercise Recovery of Horses

Antioxidant supplementation decreases postexercise oxidative stress but could also decrease muscle pro- tein synthesis. This study compared the effects of three diets: low antioxidant (control, CON), high an- tioxidant (AO), and branched-chain amino acid high antioxidant (BCAO) supplementation on postexercise protein synthesis and oxidative stress. We hypothesized that supplementing antioxidants with branched- chain amino acids(BCAA) would reduce oxidative stress without hindering muscle protein synthesis. Eigh- teen mixed-breed polo horses (11 mares and 7 geldings, with age range between 5 and 18 years, were on CON diet for 30 days (from day -45 until day 0) and then were assigned to one of the treatments after the first lactate threshold test (day 0, LT). LT were also conducted on days 15 and 30 of supplemenation. Ox- idative stress was assessed by measuring blood glutathione peroxidase, superoxide dismutase, and mal- ondialdehyde concentrations before 2 and 4 hours after each LT. Muscle biopsies were taken before and 4 hours after each LT and analyzed for gene expression of protein synthesis by RTqPCR. Data were analyzed by ANOVA and compared by least-square means. A reduction in oxidative stress occurred over time ( P \u3c .05), from day 0 to day 30. An up-regulation in the abundance of muscle protein mRNA transcripts was found for CD36, CPT1, PDK4, MYF5, and MYOG ( P \u3c .05) after all lactate threshold tests, without a treat- ment effect. A treatment-by-exercise effect was observed for MYOD1 ( P = .0041). Transcript abundance was upregulated in AO samples post exercise compared to other treatments. MYF6 exhibited a time-by- treatment effect ( P = .045), where abundance increased more in AO samples from day 0 to day 15 and 30 compared to other treatments. Transcript abundance for metabolic and myogenic genes was upreg- ulated in post exercise muscle samples with no advantage from supplementation of antioxidants with branched-chain amino acids compared to antioxidants alone