title: Effects of streptozotocin-induced diabetes and physical training on gene expression of titin-based stretch-sensing complexes in mouse striated muscle.
abstract: 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.
authors.affiliation: LIKES Research Center for Sport and Health Sciences, Rautpohjankatu 8, Viveca, FIN-40700 Jyväskylä, Finland. maarit.lehti@likes.fi
authors.forename: T Maarit
authors.initials: TM
authors.lastname: Lehti
authors.forename: Mika
authors.initials: M
authors.lastname: Silvennoinen
authors.forename: Riikka
authors.initials: R
authors.lastname: Kivelä
authors.forename: Heikki
authors.initials: H
authors.lastname: Kainulainen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Komulainen
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D002950:Citrate (si)-Synthase / Q000378:metabolism; D064211:Connectin; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism*; D060588:LIM Domain Proteins; D008297:Male; D040542:Mechanotransduction, Cellular; D051379:Mice; D008815:Mice, Inbred Strains; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism*; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000378:metabolism*; D055435:Myostatin; D009687:Nuclear Proteins / Q000378:metabolism; D010805:Physical Conditioning, Animal; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D013311:Streptozocin; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: C104844:Ankrd1 protein, mouse; C485877:Ankrd2 protein, mouse; D001786:Blood Glucose; D064211:Connectin; D060588:LIM Domain Proteins; C525912:Mstn protein, mouse; D009124:Muscle Proteins; D055435:Myostatin; D009687:Nuclear Proteins; D012097:Repressor Proteins; D016212:Transforming Growth Factor beta; C090114:cysteine and glycine-rich protein 3; D013311:Streptozocin; D002950:Citrate (si)-Synthase; D011494:Protein Kinases