Intermittent glucose stimulation impairs proliferation and differentiation of C2C12 myoblasts

Intermittent glucose stimulation impairs proliferation and differentiation of C2C12 myoblasts

Shunichi Nakamura, Shinichi Yonekura, Tomohide Takaya.

Faculty of Agriculture, Shinshu University, Nagano, Japan.

2018 International Symposium on Animal Science and Technology (Ina, Japan), 2018/08/10 (Poster).

Abstract

Summary: Glucose spike is a set of acute increase and decrease in blood glucose level which occurs within 2 hours after meal. Recent studies revealed that glucose spike is a risk factor for diabetes, dementia, and myocardial and cerebral infarctions. However, the impact of glucose spike on skeletal muscle myoblasts has not been reported. In this study, we investigated proliferation and differentiation of the murine C2C12 myoblast cell line intermittently stimulated with high-concentrated glucose.

Materials & Methods: C2C12 cells were cultured in growth medium (GM) with normal glucose concentration (NG, 5.6 mM), high glucose concentration (HG, 25 mM), or oscillated glucose concentration (OG) which is a repeat of NG and HG every 24 hours. The numbers of the cells were counted every 2 days. After 4 days of culture in GM, the cells were differentiated in differentiation medium (DM) with NG, HG, or OG for 4 days. Myogenic differentiation was measured by immunostaining for myosin heavy chain (MHC). Gene expression was quantified by qPCR.

Results & Discussion: At day 4 in GM, the numbers of C2C12 cells were significantly decreased in HG and OG groups compared with NG group. At day 4 in DM, MHC-positive cells and multinuclear myotubes were markedly reduced in HG and OG groups. qPCR results indicated that HG or OG do not affect MyoD expression but suppressed myogenin expression. Expression of myostatin, a repressor for myogenic differentiation, tended to be induced by HG or OG. These data suggest that intermittent glucose stimulation such as OG or glucose spike possibly impairs proliferation and differentiation of myoblasts by altering gene expression pattern.