Further Characterisation of the Molecular Signature of Quiescent and Activated Mouse Muscle Satellite Cells

Satellite cells are the resident stem cells of adult skeletal muscle. To date though, there is a paucity of native markers that can be used to easily identify quiescent satellite cells, with Pax7 probably being the best that is currently available. Here we have further characterized a number of recently described satellite cell markers, and also describe novel ones. Caveolin-1, integrin α7 and the calcitonin receptor proved reliable markers for quiescent satellite cells, being expressed by all satellite cells identified with Pax7. These three markers remained expressed as satellite cells were activated and underwent proliferation. The nuclear envelope proteins lamin A/C and emerin, mutations in which underlie Emery-Dreifuss muscular dystrophy, were also expressed in both quiescent and proliferating satellite cells. Conversely, Jagged-1, a Notch ligand, was not expressed in quiescent satellite cells but was induced upon activation. These findings further contribute to defining the molecular signature of muscle satellite cells

Reduced Satellite Cell Numbers and Myogenic Capacity in Aging Can Be Alleviated by Endurance Exercise

Background: Muscle regeneration depends on satellite cells, myogenic stem cells that reside on the myofiber surface. Reduced numbers and/or decreased myogenic aptitude of these cells may impede proper maintenance and contribute to the age-associated decline in muscle mass and repair capacity. Endurance exercise was shown to improve muscle performance; however, the direct impact on satellite cells in aging was not yet thoroughly determined. Here, we focused on characterizing the effect of moderate-intensity endurance exercise on satellite cell, as possible means to attenuate adverse effects of aging. Young and old rats of both genders underwent 13 weeks of treadmill-running or remained sedentary. Methodology: Gastrocnemius muscles were assessed for the effect of age, gender and exercise on satellite-cell numbers and myogenic capacity. Satellite cells were identified in freshly isolated myofibers based on Pax7 immunostaining (i.e., exvivo). The capacity of individual myofiber-associated cells to produce myogenic progeny was determined in clonal assays (in-vitro). We show an age-associated decrease in satellite-cell numbers and in the percent of myogenic clones in old sedentary rats. Upon exercise, there was an increase in myofibers that contain higher numbers of satellite cells in both young and old rats, and an increase in the percent of myogenic clones derived from old rats. Changes at the satellite cell level in old rats were accompanied with positive effects on the lean-to-fat Gast muscle composition and on spontaneous locomotion levels. The significance of these data is that they suggest that the endurance exercise-mediated boost in bot

Soil tillage as influenced by climate change

A long-term field trial was set up in order to define the effects of autumn or spring primary tillage upon the physical characteristics and yields of spring row crops – maize and soybean. The objectives were to assess and recommend the most effective tillage method. In the first trial year, the year factor had a stronger influence on maize yields compared to the tillage factor. In the second trial year, however, the situation was quite contrasted. The tillage factor had a stronger impact on soybean yields compared to the year factor. The twoyear investigation period was only allowed to draw some preliminary conclusions. For this reason the research will be continued

A note on the effect of dietary supplementation with herbal extracts on sow and litter performance

The aim of this study was to assess the efficacy of the phytogenic product, Ruchamax® (Ayurvet, India), on the productivity of sows and the performance of their first litters. Ruchamax® contains a blend of herbal extracts from Adrographis paniculata, Phyllanthus emblica, Curcuma longa, Zingiber officinale and Allium sativum. It was incorporated into a lactation concentrate mixture (E) at an inclusion rate of 1 kg per 1000 kg. A total of 40 primiparous sows (PIC) were allocated to two equal groups: untreated (control (C)) and herb-supplemented (E). Treatments were from day 1 to 28 of lactation. Nursing sows fed the herb-supplemented diet had significantly increased average daily feed intake (5.84 vs. 5.46 kg) and milk output (7.58 vs. 6.71 kg). The experimental factor had a positive effect on the condition of sows (lower reduction of thickness during lactation). Changes in backfat thickness (farrowing-weaning) were significantly different (−6.45 vs. −9.40 mm). There were no differences in initial litter size and litter birth weight (BW) between groups. The average BW of piglets was similar (ca. 1.6 kg) in both groups. The herb-supplemented diet affected 28-day litter weight (69.95 vs. 63.40 kg), average piglet body weight (7.27 vs. 6.74 kg) and daily litter growth rate (1.79 vs. 1.68 kg) significantly compared with the control. It can be concluded that the sows receiving an herb-supplemented diet were characterized by better productivity indices than the control group.Keywords: Herbal extract; primiparous sows; piglets; performanc

Standard lumbar discectomy versus microdiscectomy - Differences in clinical outcome and reoperation rate

Microdiscectomy (MD) is accepted nowadays as the operative method of choice for lumbar disc herniation, but it is not rare for neurosurgeons to opt for standard discectomy (SD), which does not entail the use of operating microscope. In our study, diff erences in disc herniation recurrence and clinical outcome of surgical treatment of lumbar disc herniation with and without the use of operating microscope were assessed. Our study included 167 patients undergoing lumbar disc surgery during a three-year period (SD, n=111 and MD, n=56). Clinical outcome assessments were recorded by patients via questionnaire forms filled out by patients at three time points. Operation duration, length of hospital stay and revision surgeries were also recorded. According to study results, after one-year follow up there was no statistically significant diff erence between the SD and MD groups in functional outcome. However, we recorded a statistically significant diff erence in leg pain reduction in favor of the MD group. According to the frequency of reoperations with the mean follow up period of 33.4 months, there was a statistically significant diff erence in favor of the MD group (SD 6.3% vs. MD 3.2%). There appears to be no particular advantage of either technique in terms of functional outcome since both result in good overall outcome. However, we choose MD over SD because it includes significantly lower recurrent disc herniation rate and higher reduction of leg pain

Structures of three MORN repeat proteins and a re-evaluation of the proposed lipid-binding properties of MORN repeats

UK Research and Innovation | Medical Research Council (MRC):Terry K. Smith MR/Mo20118/1.MORN (Membrane Occupation and Recognition Nexus) repeat proteins have a wide taxonomic distribution, being found in both prokaryotes and eukaryotes. Despite this ubiquity, they remain poorly characterised at both a structural and a functional level compared to other common repeats. In functional terms, they are often assumed to be lipid-binding modules that mediate membrane targeting. We addressed this putative activity by focusing on a protein composed solely of MORN repeats—Trypanosoma brucei MORN1. Surprisingly, no evidence for binding to membranes or lipid vesicles by TbMORN1 could be obtained either in vivo or in vitro. Conversely, TbMORN1 did interact with individual phospholipids. High- and low-resolution structures of the MORN1 protein from Trypanosoma brucei and homologous proteins from the parasites Toxoplasma gondii and Plasmodium falciparum were obtained using a combination of macromolecular crystallography, small-angle X-ray scattering, and electron microscopy. This enabled a first structure-based definition of the MORN repeat itself. Furthermore, all three structures dimerised via their C-termini in an antiparallel configuration. The dimers could form extended or V-shaped quaternary structures depending on the presence of specific interface residues. This work provides a new perspective on MORN repeats, showing that they are protein-protein interaction modules capable of mediating both dimerisation and oligomerisation.Publisher PDFPeer reviewe