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J Nutr Hum Health 2017 Volume 1 Issue 2
Notes:
July 24-26, 2017 | Vancouver, Canada
International conference on
DIABETES, NUTRITION, METABOLISM & MEDICARE
O
besity has a tight association with type 2 diabetes
mellitus (T2DM) and elevated plasma free fatty acid level
induced insulin resistance is believed as the link between
obesity and T2DM. However, the detailed mechanism
of the changes in plasma free fatty acid level result in
insulin resistance remains to be elucidated. In this study,
insulin desensitization was induced in C2C12 myotubes via
palmitic acid treatment. To focus on the changes of nuclear
proteome, nuclei of C2C12 myotubes were isolated for two-
dimensional gel electrophoresis based proteomic study.
Result demonstrated that four nuclear proteins showed
changes in expression after palmitic acid treatment; nuclear
factor NF-kappa-B (NF-κB) p65 subunit and 60S acidic
ribosomal protein P0 were upregulated, while peroxisome
proliferator-activated receptor gamma coactivator 1-alpha
(PPARGC-1α) and cleavage and polyadenylation specificity
factor subunit 5 (CFIm25) were downregulated. Whereas,
inhibiting NF-κB p65 subunit nuclear translocation can
prevent the palmitic acid induced deleterious effect on
insulin sensitivity, implied that NF-κB p65 subunit play a key
role in palmitic acid induced insulin desensitization.
Methods:
A murine skeletal muscle cell line, C2C12
myotubes were established and exposed to first, palmitic
acid in order to induce insulin desensitization; and followed
by treatment with oleic acid to act as control. To focus on the
changes of nuclear proteome in comparing with that of the
cytosolic proteomic status, nuclear fractions were enriched
by centrifugation for two-dimensional gel electrophoresis (2-
DE) based proteomic study.
Results & Discussion:
The 2-DE result was confirmed by
western blotting analysis Five differentially expressed
proteins were found. After 24 h fatty acid treatment,
nuclear fractions were enriched and applied to 2-DE. Five
proteins demonstrated changes in expression after palmitic
acid treatment. Among these five proteins, nuclear factor-
kappa-B (NF-κB) p65 subunit and 60S acidic ribosomal
protein P0 were upregulated, after exposed to plamitic
acid; while peroxisome proliferator-activated receptor
gamma coactivator 1-alpha (PPARGC-1α), cleavage and
polyadenylation specificity factor subunit 5 (CFIm25) and
prohibitin were downregulated. Inhibiting NF-κB activation
could rescue C2C12 myotubes from palmitic acid induced
insulin desensitization. Inhibiting NF-κB activation by
parthenolide reversed the deleterious effects of palmitic acid
on Akt activation and insulin stimulated glucose uptake .These
results indicated that NF-κB p65 subunit was involved in
palmitic acid induced insulin desensitization.
Biography
Ngai Sai Ming is currently Director of The Chinese Medicinal Fungal Proteomics
Laboratory and Investigator of State Key Laboratory for Agrobiotechnology and
associate professsor in The School of Life Sciences, in The Chinese University of Hong
Kong, Hong Kong SAR, China. His research interest is bioinformatics, proteomics
and metabolomics, protein/peptide structural and functional studies, and Modern
Chinese Medicine. He has over 20 years experience in Protein/Peptide biochemistry,
proteomics and computational techniques and is the author of over 70 scientific
publications, 4 book chaperters and numerous conference papers.
smngai@cuhk.edu.hkProteome profiling of C2C12myotubes with alternated insulin sensitivity upon palmitic acid treatment
Ngai Sai Ming and Leung Chun Ning
The Chinese University of Hong Kong