MicroRNA transcriptome profiles during swine skeletal muscle development

<p>Abstract</p> <p>Background</p> <p>MicroRNA (miR) are a class of small RNAs that regulate gene expression by inhibiting translation of protein encoding transcripts. To evaluate the role of miR in skeletal muscle of swine, global microRNA abundance was measured at specific developmental stages including proliferating satellite cells, three stages of fetal growth, day-old neonate, and the adult.</p> <p>Results</p> <p>Twelve potential novel miR were detected that did not match previously reported sequences. In addition, a number of miR previously reported to be expressed in mammalian muscle were detected, having a variety of abundance patterns through muscle development. Muscle-specific miR-206 was nearly absent in proliferating satellite cells in culture, but was the highest abundant miR at other time points evaluated. In addition, miR-1 was moderately abundant throughout developmental stages with highest abundance in the adult. In contrast, miR-133 was moderately abundant in adult muscle and either not detectable or lowly abundant throughout fetal and neonate development. Changes in abundance of ubiquitously expressed miR were also observed. MiR-432 abundance was highest at the earliest stage of fetal development tested (60 day-old fetus) and decreased throughout development to the adult. Conversely, miR-24 and miR-27 exhibited greatest abundance in proliferating satellite cells and the adult, while abundance of miR-368, miR-376, and miR-423-5p was greatest in the neonate.</p> <p>Conclusion</p> <p>These data present a complete set of transcriptome profiles to evaluate miR abundance at specific stages of skeletal muscle growth in swine. Identification of these miR provides an initial group of miR that may play a vital role in muscle development and growth.</p

Retail Display Properties and Consumer Perception of Extended Aged Beef Topically Treated with Ascorbic Acid and Rosemary Extract

Extended aging increases browning and decreases redness in fresh beef. The goal of this study was to test an already proven combination of antioxidants (0.05% ascorbic acid + 0.1% rosemary extract) using a method that could be applied at the retail level to simply and effectively extend the shelf-life of extended aged beef. The specific objective was to analyze the effect of topical application of ascorbic acid and rosemary extract on color, lipid oxidation, microbial growth, and sensory perception of beef longissimus lumborum (LL; n = 12) and semimembranosus (SM; n = 12) muscles wet aged at 0°C for 14, 28, and 42 (extended aging period) days. After aging, steaks were cut, sprayed with 2 mL of a 0.05% ascorbic acid + 0.1% rosemary extract solution (treated) or untreated (control), and subjected to retail display. Antioxidant treated LL steaks had greater (P < 0.05) L* (lightness) values, but lower (P < 0.05) a* (redness) and b* (yellowness) values than control steaks. Furthermore, antioxidant treatment decreased (P < 0.05) browning on d 4 of retail display compared to control steaks. Consumers scored antioxidant treated SM steaks as less tender on d 28, more juicy on d 14 but less juicy on d 18 and 42. Antioxidant treatment did not affect lipid oxidation, microbial growth, or sensory flavor scores. As expected, longer aging periods resulted in less color stability of LL and SM steaks. Although the antioxidant treatment resulted in measurable subjective color improvements, these improvements are likely not detectable by the consumer

Models of care for musculoskeletal health: A cross-sectional qualitative study of Australian stakeholders' perspectives on relevance and standardised evaluation

Background: The prevalence and impact of musculoskeletal conditions are predicted to rapidly escalate in the coming decades. Effective strategies are required to minimise 'evidence-practice', 'burden-policy' and 'burden-service' gaps and optimise health system responsiveness for sustainable, best-practice healthcare. One mechanism by which evidence can be translated into practice and policy is through Models of Care (MoCs), which provide a blueprint for health services planning and delivery. While evidence supports the effectiveness of musculoskeletal MoCs for improving health outcomes and system efficiencies, no standardised national approach to evaluation in terms of their 'readiness' for implementation and 'success' after implementation, is yet available. Further, the value assigned to MoCs by end users is uncertain. This qualitative study aimed to explore end users' views on the relevance of musculoskeletal MoCs to their work and value of a standardised evaluation approach. Methods: A cross-sectional qualitative study was undertaken. Subject matter experts (SMEs) with health, policy and administration and consumer backgrounds were drawn from three Australian states. A semi-structured interview schedule was developed and piloted to explore perceptions about musculoskeletal MoCs including: i) aspects important to their work (or life, for consumers) ii) usefulness of standardised evaluation frameworks to judge 'readiness' and 'success' and iii) challenges associated with standardised evaluation. Verbatim transcripts were analysed by two researchers using a grounded theory approach to derive key themes. Results: Twenty-seven SMEs (n = 19; 70.4 % female) including five (18.5 %) consumers participated in the study. MoCs were perceived as critical for influencing and initiating changes to best-practice healthcare planning and delivery and providing practical guidance on how to implement and evaluate services. A 'readiness' evaluation framework assessing whether critical components across the health system had been considered prior to implementation was strongly supported, while 'success' was perceived as an already familiar evaluation concept. Perceived challenges associated with standardised evaluation included identifying, defining and measuring key 'readiness' and 'success' indicators; impacts of systems and context changes; cost; meaningful stakeholder consultation and developing a widely applicable framework. Conclusions: A standardised evaluation framework that includes a strong focus on 'readiness' is important to ensure successful and sustainable implementation of musculoskeletal MoCs

Regulation of Adipogenesis and Key Adipogenic Gene Expression by 1, 25-Dihydroxyvitamin D in 3T3-L1 Cells

<div><p>The functions of 1, 25-dihydroxyvitamin D (1, 25-(OH)₂D₃) in regulating adipogenesis, adipocyte differentiation and key adipogenic gene expression were studied in 3T3-L1 preadipocytes. Five concentrations (0.01, 0.1, 1, 10, 100nM) of 1, 25-(OH)₂D₃ were studied and lipid accumulation measured by Oil Red O staining and expression of adipogenic genes quantified using quantitative real-time PCR. Adipogenic responses to 1, 25-(OH)₂D₃ were determined on 6, and 12 h, and days 1-10 after induction of adipogenesis by a hormonal cocktail with or without 1, 25-(OH)₂D₃. In response to 1, 25-(OH)₂D₃ (1, 10, and 100 nM), lipid accumulation and the expression of <i>PPARγ</i>, <i>C/EBPα</i>, <i>FABP4</i> and <i>SCD-1</i> were inhibited through day 10, and vitamin D receptor expression was inhibited in the early time points. The greatest inhibitory effect was upon expression of <i>FABP4</i>. Expression of <i>SREBP-1c</i> was only affected on day 2. The lowest concentrations of 1, 25-(OH)₂D₃ tested did not affect adipocyte differentiation or adipogenic gene expression. The <i>C/EBPα</i> promoter activity response to 1, 25-(OH)₂D₃ was also tested, with no effect detected. These results indicate that 1, 25-(OH)₂D₃ inhibited adipogenesis via suppressing adipogenic-specific genes, and is invoked either during PPARγ activation or immediately up-stream thereof. Gene expression down-stream of PPARγ especially <i>FABP4</i> was strongly inhibited, and we suggest that the role of 1, 25-(OH)₂D₃ in regulating adipogenesis will be informed by further studies of adipogenic-specific gene promoter activity.</p></div

Real-time PCR quantification of <i>SREBP-1c</i> gene expression in 3T3-L1 cells (A): in the positive control treatment (DM) on days 0, 1, 2, 4, 6, 8, and 10 (B to F).

<p>Cells were treated with DM in the presence or absence of 0.01, 0.1, 1, 10, and 100 nM 1, 25 - (OH)₂D₃ and <i>EEF2</i> was used as endogenous control (∆Ct). Data were normalized to <i>SREBP-1c</i> gene expression of the positive control (DM) at the corresponding time point (∆∆Ct). (B) day 2, (C) day 4 (D) day 6, (E) day 8 and (F) day 10. Data are means ± SE (n = 3). Different letters represent treatment effects that were significantly different (<i>P</i> < 0.05).</p

Real-time PCR quantification of <i>PPARγ</i> gene expression in 3T3-L1 cells on days 2 (A), 4 (B), 6 (C), 8 (D) and 10 (E).

<p>Cells were treated with DM in the presence or absence of 0.01, 0.1, 1, 10, and 100 nM 1, 25 - (OH)₂D₃ and <i>EEF2</i> was used as endogenous control (∆Ct). Data were normalized to <i>PPARγ</i> gene expression of the positive control (DM) at the corresponding time point (∆∆Ct). Data are means ± SE (n = 3). Different letters represent treatment effects that were significantly different (<i>P</i> < 0.05).</p

Oil Red O staining in 3T3-L1 cells.

<p>Cells were treated with basal growth medium (GM) (A) or differentiation medium plus different concentrations of 1, 25 - (OH)₂D₃, 100 nM (B), 10 nM (C), 1 nM (D), 0.1 nM (E) or 0.01 nM (F) or differentiation medium (DM) (G). Oil Red O staining was performed on days 2, 4, 6, 8 and 10. Representative day 10 images are shown. Images were collected at 400x magnification. (H): Quantification of lipid accumulation in 3T3-L1 cells. Lipid accumulation was quantified using MetaMorph Image analysis software. Area fractions were collected for each treatment and normalized to control of corresponding time point. Data are means ± SE (n = 3). Different letters represent treatment effects that were significantly different (<i>P</i> < 0.05). The dose-response effect of 1, 25 - (OH)₂D₃ treatment on lipid accumulation is illustrated.</p