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This Article Full Text Full Text (PDF) All Versions of this Article: 292/2/E533    most recent 00229.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lehti, T. M. Articles by Komulainen, J. Search for Related Content PubMed PubMed Citation Articles by Lehti, T. M. Articles by Komulainen, J.

Effects of streptozotocin-induced diabetes and physical training on gene expression of titin-based stretch-sensing complexes in mouse striated muscle

¹LIKES Research Center for Sport and Health Sciences; and ²Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland

Submitted 16 May 2006 ; accepted in final form 21 September 2006

In striated muscle, a sarcomeric noncontractile protein, titin, is proposed to form the backbone of the stress- and strain-sensing structures. We investigated the effects of diabetes, physical training, and their combination on the gene expression of proteins of putative titin stretch-sensing complexes in skeletal and cardiac muscle. Mice were divided into control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups performed for 1, 3, or 5 wk of endurance training on a motor-driven treadmill. Muscle samples from T and DT groups together with respective controls were collected 24 h after the last training session. Gene expression of calf muscles (soleus, gastrocnemius, and plantaris) and cardiac muscle were analyzed using microarray and quantitative PCR. Diabetes induced changes in mRNA expression of the proteins of titin stretch-sensing complexes in Z-disc (MLP, myostatin), I-band (CARP, Ankrd2), and M-line (titin kinase signaling). Training alleviated diabetes-induced changes in most affected mRNA levels in skeletal muscle but only one change in cardiac muscle. In conclusion, we showed diabetes-induced changes in mRNA levels of several fiber-type-biased proteins (MLP, myostatin, Ankrd2) in skeletal muscle. These results are consistent with previous observations of diabetes-induced atrophy leading to slower fiber type composition. The ability of exercise to alleviate diabetes-induced changes may indicate slower transition of fiber type.

skeletal muscle; cardiac muscle; microarray; muscle LIM protein; myostatin