[Effects of MD2 gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes]

Zhongguo Ying Yong Sheng Li Xue Za Zhi. 2019 May 28;35(3):273-278. doi: 10.12047/j.cjap.5834.2019.057.
[Article in Chinese]

Abstract

Objective: To investigate the effects of myeloid differentiation-2 (MD2) gene silencing on high glucose-induced proliferation inhibition, apoptosis and inflammation in rat cardiomyocytes.

Methods: The immortalized rat cardiomyocyte cell line H9C2 were transfected with MD2 small interfering RNA (si-MD2) and negative control for 24 h, then stimulated with high glucose (HG) for 48 h. RT-qPCR was performed to detect the mRNA levels of MD2 and inflammatory factors TNF-α, IL-1β and IL-6. MTS and flow cytometry were used to evaluate cell proliferation, cell cycle and apoptosis rate. Western blot was used to detect protein expression levels and phosphorylation levels.

Results: The mRNA and protein levels of MD2 in H9C2 cells were dramatically decreased after transfected with si-MD2 (P<0.01). After stimulation of high glucose, the mRNA levels of inflammatory factors, the cells in G0/G1 phase , the cell apoptosis rate and the protein level of cleaved Caspase-3 were significantly increased, while the cell proliferation ability was decreased (P<0.01). MD2 gene silencing antagonized the effects of high glucose on cell proliferation, cell cycle, cell apoptosis and the mRNA levels of TNF-α, IL-1β , IL-6(P<0.05). Western blot analysis showed that the phosphorylation levels of extracellular signal-regulated kinase(ERK1/2), P38 mitogen-activated protein kinase(P38 MAPK) and C-Jun N-terminal kinase(JNK) protein were increased significantly in H9C2 cells treated with high glucose, which could be reversed by silencing of MD2 (P<0.01).

Conclusion: This study demonstrates that MD2 gene silencing reverses high glucose-induced myocardial inflammation, apoptosis and proliferation inhibition via the mechanisms involving suppression of ERK, P38 MAPK, JNK signaling pathway.

MeSH terms

  • Animals
  • Apoptosis*
  • Cell Proliferation*
  • Cells, Cultured
  • Cytokines / metabolism
  • Gene Silencing*
  • Glucose
  • Inflammation
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Lymphocyte Antigen 96 / genetics*
  • Myocytes, Cardiac / cytology*
  • Rats
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Cytokines
  • Lymphocyte Antigen 96
  • JNK Mitogen-Activated Protein Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Glucose