131 research outputs found
Computational costs comparison between our protocol and others.
<p>Computational costs comparison between our protocol and others.</p
Communication costs and storage overhead comparison between our protocol and others.
<p>Communication costs and storage overhead comparison between our protocol and others.</p
Comparison of the key length between RSA and ECC on the same security level.
<p>Comparison of the key length between RSA and ECC on the same security level.</p
Myostatin Suppression of Akirin1 Mediates Glucocorticoid-Induced Satellite Cell Dysfunction
<div><p>Glucocorticoids production is increased in many pathological conditions that are associated with muscle loss, but their role in causing muscle wasting is not fully understood. We have demonstrated a new mechanism of glucocorticoid-induced muscle atrophy: Dexamethasone (Dex) suppresses satellite cell function contributing to the development of muscle atrophy. Specifically, we found that Dex decreases satellite cell proliferation and differentiation <i>in vitro</i> and <i>in vivo</i>. The mechanism involved Dex-induced upregulation of myostatin and suppression of Akirin1, a promyogenic gene. When myostatin was inhibited in Dex-treated mice, Akirin1 expression increased as did satellite cell activity, muscle regeneration and muscle growth. In addition, silencing myostatin in myoblasts or satellite cells prevented Dex from suppressing Akirin1 expression and cellular proliferation and differentiation. Finally, overexpression of Akirin1 in myoblasts increased their expression of MyoD and myogenin and improved cellular proliferation and differentiation, theses improvements were no longer suppressed by Dex. We conclude that glucocorticoids stimulate myostatin which inhibits Akirin1 expression and the reparative functions of satellite cells. These responses attribute to muscle atrophy. Thus, inhibition of myostatin or increasing Akirin1 expression could lead to therapeutic strategies for improving satellite cell activation and enhancing muscle growth in diseases associated with increased glucocorticoid production.</p> </div
Dex suppresses satellite cell activation <i>in vivo</i>.
<p>C57/BL6 control mice were treated with Dex and TA muscles were injured. A. At 1.5 day following injury, the cryo-cross-section of injured muscle were co-immunostained with anti-Pax7 (green) and Ki-67 (red); in the merged (right) column, dual positive (proliferating) cells are indicated by yellow color. *indicates injured myofibers. The proliferation rate was shown in the right column. B. The mRNAs of Myf5, MyoD and Myogenin in non-injured (designated as 0 injury days) or injured muscles (at different time points) were assessed by RT-PCR (*p<0.05; Dex <i>vs.</i> non-Dex-treated CTRL mice; n = 3 mice for each group). C. H/E staining of the cross-section of injured muscles (bar = 50 µm). D. At 7 days after injury, the newly formed myofiber sizes were measured and the myofiber size distribution was presented.</p
Extraction, identification and antioxidant activity of proanthocyanidins from <i>Larix gmelinii</i> Bark
<div><p>This study was intended to extract and identify the proanthocyanidins from <i>Larix gmelinii</i> bark. Different extraction methods and degreasing methods were investigated. The content of proanthocyanidins, antioxidant activities and FT-IR analysis were used to evaluate and identify these extracts. The ultrasonic-assisted extracts displayed a higher content of proanthocyanidins and antioxidant activity than supercritical carbon dioxide extracts. The defatted extracts displayed a higher content of proanthocyanidins and antioxidant activity than un-defatted extracts. DPPH radical-scavenging capacity of extracts (29.88 μg mL<sup>− 1</sup>) was higher than <i>V</i><sub>C</sub> (36.04 μg mL<sup>− 1</sup>), and the inhibition effect of lipid peroxidation of extracts (15%) was higher than <i>V</i><sub>C</sub> (13%) and <i>V</i><sub>E</sub> (11%). The FT-IR analysis revealed that the main phenolic compounds were almost the same as proanthocyanidin standards.</p></div
Dex increases myostatin expression and impairs satellite cell activation <i>in vivo</i>.
<p>A. Representative western blots of myostatin in gastrocnemius muscles of mice treated with Dex for different days. B. Representative western blots of indicated proteins from muscles of control or mice treated with Dex for 14 days. C. mRNA expression of myostatin was measured by RT-PCR in muscles of mice treated with or without Dex and injured with CTX (*p<0.05 <i>vs.</i> CTRL; n = 3 mice in each group). D. At 4 days after injury, cross-sections of muscle were immunostained with anti-myogenin (left panel) and the ratio of myogenin positive cells to DAPI expressed as a percentage is shown in right panel (*p<0.05 <i>vs.</i> Dex plus PBS). E. Cross-sections of injured TA muscles from mice injected with Dex plus PBS or Dex plus myostatin inhibitor were immunostained with anti-eMyHC (green). F. Sections in Fig. 7E were immunostained with laminin and DAPI to show the newly formed myofibers (left panel). The average number of central nuclei myofibers was calculated from 10 areas counted (*p<0.05 <i>vs.</i> Dex plus PBS, right panel). G. at 14 days after injury, newly formed myofiber cross-sectional areas were measured and the distribution is shown.</p
Overexpression of Akirin1 blocked Dex-induced suppression of myogenic gene expression and myoblast proliferation and differentiation.
<p>A. C2C12 myoblasts were transfected with Akirin-1 or cDNA3 (control). After 24 h, cells were treated with 10 µM Dex in 2% horse serum for 24 h. Representative western blots of measured proteins are shown (upper panel) and band density corrected for GAPDH is shown in lower panel. (*p<0.05 <i>vs.</i> cells transfected with cDNA3 without Dex treatment; n = 3 repeats). B. Transfected cells were treated with 10 µM Dex and immunostained with anti-Ki67 (red). The percentage of Ki67 positive cells to the total number of cells in 10 areas was examined (lower panel) (*p<0.05 <i>vs.</i> cells transfected with cDNA3 without Dex treatment). C. Transfected cells were incubated in 2% horse serum with or without 20 µM Dex for 96 h to stimulate differentiation. Cells were immunostained with anti-eMyHC (green, left panel). The differentiation index is shown in right panel (*p<0.05 <i>vs.</i> cells transfected with cDNA3 without Dex treatment; n = 3 repeats).</p
Dex stimulates myostatin expression in satellite cells suppressing their activation <i>in vitro</i>.
<p>A. satellite cells were treated with different concentrations of Dex for 24 h. Myostatin mRNA was evaluated by RT-PCR (*p<0.05 <i>vs.</i> non-Dex; n = 3 independent experiments). B. Satellite cells were treated with different concentrations of Dex for 36 h; a representative western blot of myostatin is shown. C. Satellite cells were transducted with shRNA-myostatin or shRNA-control lentivirus and treated with/without Dex or myostatin for 24 h. The percentage of Ki67 and Pax7 dual positive cells (indicated by yellow color in the merged column) to total Pax7 positive cells (green) is shown in right panel. (*p<0.05 <i>vs.</i> shRNA-control bar = 50 µm). D. Satellite cells were transducted with shRNA-myostatin or shRNA-control lentivirus then exposed to differentiation media with/without Dex or myostatin for 96 h. The fixed cells were immunostained with anti-eMyHC (left panel). The differentiation index is shown in the right panel (*p<0.05 <i>vs.</i> shRNA-control bar = 50 µm).</p
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