Effect of mitofusin 2 overexpression on the proliferation and apoptosis of high-glucose-induced rat glomerular mesangial cells.

BACKGROUND: Mitofusin 2 (Mfn2) regulates mitochondrial morphology and associated signaling pathways. However, the role of Mfn2 in kidney disease is not fully understood. The present study aimed to investigate the effects of Mfn2 overexpression on high-glucose-induced cell proliferation and apoptosis. Another objective was to explore the possible underlying signal transduction mechanisms in a rat glomerular mesangial cell (GMC) line.

METHODS: After adenovirus-mediated Mfn2 gene transfection, Mfn2 expression was detected by real-time PCR. Time-dependent concentration changes in Mfn2 and relevant proteins induced by high glucose were investigated to define the optimal time for research. The protein expression levels of Mfn2, proliferating cell nuclear antigen (PCNA), p-Akt, p-ERK1/2 and Bcl-2 were examined on Western blots. Cell proliferation was detected by the CCK-8 method. Apoptosis was analyzed by flow cytometry.

RESULTS: Mfn2 gene expression was successfully increased via adenovirus mediation. The correlation of Mfn2 expression with p-ERK1/2 and phosphorylated Akt was significant 48 hours after high-glucose stimulation. p-ERK1/2 was increased by high glucose, but was inhibited by overexpressed Mfn2. Changes in the PCNA and GMC proliferative level coincided with p-ERK1/2. Overexpressed Mfn2 significantly inhibited Akt phosphorylation and Bcl-2 expression. The apoptosis rate increased in the AdMfn2 group.

CONCLUSIONS: Overexpressed Mfn2 could alleviate GMC proliferation and increase apoptosis. Subsequently, cellular quantity is maintained, which may contribute to reversing early diabetic nephropathy pathological changes. Mfn2 may perform its activities through the MAPK/ERK and PI3K/Akt signal pathways in correlation with proliferation and apoptosis.