Proteomic analysis of tumor necrosis factor-alpha (TNF-α)-induced L6 myotube secretome reveals novel TNF-α-dependent myokines in diabetic skeletal muscle.
There is a strong possibility that skeletal muscle can respond to irregular metabolic states by secreting specific cytokines. Obesity-related chronic inflammation, mediated by pro-inflammatory cytokines, is believed to be one of the causes of insulin resistance that results in type 2 diabetes. Here, we attempted to identify and characterize the members of the skeletal muscle secretome in response to tumor necrosis factor-alpha (TNF-α)-induced insulin resistance. To conduct this study, we comparatively analyzed the media levels of proteins released from L6 skeletal muscle cells. We found 28 TNF-α modulated secretory proteins by using separate filtering methods: Gene Ontology, SignalP, and SecretomeP, as well as the normalized Spectral Index for label-free quantification. Ten of these secretory proteins were increased and 18 secretory proteins were decreased by TNF-α treatment. Using microarray analysis of Zuker diabetic rat skeletal muscle combined with bioinformatics and Q-PCR, we found a correlation between TNF-α-mediated insulin resistance and type 2 diabetes. This novel approach combining analysis of the conditioned secretome and transcriptome has identified several previously unknown, TNF-α-dependent secretory proteins, which establish a foothold for research on the different causes of insulin resistance and their relationships with each other.
Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk, Republic of Korea.
Jong Hyuk
JH
Yoon
Parkyong
P
Song
Jin-Hyeok
JH
Jang
Dae-Kyum
DK
Kim
Sunkyu
S
Choi
Jaeyoon
J
Kim
Jaewang
J
Ghim
Dayea
D
Kim
Sehoon
S
Park
Hyeongji
H
Lee
Dongoh
D
Kwak
Kyungmoo
K
Yea
Daehee
D
Hwang
Pann-Ghill
PG
Suh
Sung Ho
SH
Ryu
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D019295:Computational Biology; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000032:analysis / Q000378:metabolism*; D030562:Databases, Protein; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology; D007333:Insulin Resistance; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D018485:Muscle Fibers, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009124:Muscle Proteins / Q000032:analysis / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D040901:Proteomics / Q000379:methods*; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D059467:Transcriptome; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D017077:Culture Media, Conditioned; D016207:Cytokines; D051275:Glucose Transporter Type 4; D007328:Insulin; D009124:Muscle Proteins; C495694:Slc2a4 protein, rat; D014409:Tumor Necrosis Factor-alpha