KIAA0753 promotes glucose and energy metabolism in osteoblasts inhibited by diabetes

Abstract

Objective To explore the effect of KIAA0753 on glucose and energy metabolism in mouse embryonic osteoblast precursor cell line MC3T3-E1. Methods The GSE182286 datasets of patients with Joubert syndrome acquired from the Gene Expression Comprehensive database were analyzed for the levels of gene expression. After the cells with KIAA0753 overexpression were constructed and the experiment were divided into the control group, the high glucose group and the high glucose+overexpression KIAA0753 group, Western blotting was used to determine the effect of KIAA0753 on MC3T3-E1 cells under high glucose condition by detecting the expression of the glucose metabolism-related proteins, such as glycogen synthase 1 (GYS1), glycogen phosphorylase L (PYGL), glucose transporter type 4(GluT4), phosphofructokinase muscle (PFKM), pyruvate dehydrogenase phosphatase 1 (PDP1), and acetyl-CoA carboxylase α (ACACA), as well as the mitochondria function-associated proteins, including peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (TFAM). The effect of KIAA0753 on the intermediates of glucose metabolism was analyzed by determining the contents of glycogen, glucose and lactic acid in the cell culture medium. Cellular immunofluorescence assay and adenosine triphosphate (ATP) assay were employed to measure the mitochondrial activity and function impacted by KIAA0753 in the cells under high glucose condition. The effect of KIAA0753 on the proliferation of MC3T3-E1 cells under high glucose was detected by EdU staining. Results The expression of KIAA0753 protein was downregulated in patients with Joubert syndrome and in MC3T3-E1 cells under high glucose conditions (P < 0.05). High glucose resulted in inhibited protein expression of GYS1, ACACA, PFKM, GluT4, PGC-1α, TFAM and NRF1, enhanced protein levels of PDP1 and PYGL, reduced glycogen generation and consumption of extracellular glucose, and promoted production of lactic acid (P < 0.05). While, overexpression of KIAA0753 could attenuate the effect of high glucose, that is, up-regulating the protein expression levels of GYS1, ACACA, PFKM, GluT4, PGC-1α, TFAM and NRF1, suppressing those of PDP1 and PYGL, enhancing glycogen generation and consumption of extracellular glucose, and inhibiting production of lactic acid (P < 0.05). What's more, the overexpression also could elevate the activity and membrane potential of mitochondria, and promote the ATP synthesis (P < 0.05) and cell proliferation (P < 0.05) in MC3T3-E1 cells under high glucose. Conclusion KIAA0753 can promote glucose metabolism and improve mitochondrial activity and function in osteoblasts, consequently providing more energy to the body.

Keywords

• joubert syndrome
• osteoblasts
• kiaa0753
• glucose metabolism
• mitochondria
• atp