کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10759520 | 1050425 | 2013 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Cessation of cyclic stretch induces atrophy of C2C12 myotubes
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
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چکیده انگلیسی
Cyclic stretch of differentiated myotubes mimics the loading pattern of mature skeletal muscle. We tested a cell culture model of disuse atrophy by the cessation of repetitive bouts of cyclic stretch in differentiated C2C12 myotubes. Myotubes were subjected to cyclic strain (12%, 0.7 Hz, 1 h/d) on collagen-I-coated Bioflex plates using a computer-controlled vacuum stretch apparatus (Flexcell Int.) for 2 (2dSTR) or 5 (5dSTR) consecutive days. Control cultures were maintained in the Bioflex plates without cyclic stretch for 2 d or 5 d. Additionally, some cultures were stretched for 2 d followed by cessation of stretch for 3 d (2dSTR3dCES). Cyclic stretching (5dSTR) increased myotube diameter and overall myotube area by â¼2-fold (P < 0.05) compared to non-stretched controls, while cessation of stretch (2dSTR3dCES) resulted in â¼80% smaller myotubes than 5dSTR cells, and 40-50% smaller than non-stretched controls (P < 0.05). Further, the calpain-dependent cleavage products of αII-spectrin (150 kDa) and talin increased (3.5-fold and 2.2-fold, respectively; P < 0.05) in 2dSTR3dCES myotubes, compared to non-stretched controls. The 1 h cyclic stretching protocol acutely increased the phosphorylation of Akt (+4.5-fold; P < 0.05) and its downstream targets, FOXO3a (+4.2-fold; P < 0.05) and GSK-3β (+1.8-fold; P < 0.05), which returned to baseline by 48 h after cessation of stretch. Additionally, nitric oxide production increased during stretch and co-treatment with the NOS inhibitor, l-NAME, inhibited the effects of stretch and cessation of stretch. We conclude that cessation of cyclic stretching causes myotube atrophy by activating calpains and decreasing activation of Akt. Stretch-induced myotube growth, as well as activation of atrophy signaling with cessation of stretch, are dependent on NOS activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 434, Issue 2, 3 May 2013, Pages 316-321
Journal: Biochemical and Biophysical Research Communications - Volume 434, Issue 2, 3 May 2013, Pages 316-321
نویسندگان
Quinlyn A. Soltow, Elizabeth H. Zeanah, Vitor A. Lira, David S. Criswell,