High-glucose Induced Mitochondrial Dynamics Disorder of Spinal Cord Neurons in Diabetic Rats and its Effect on Mitochondrial Spatial Distribution.

STUDY DESIGN

A randomized, double-blind, controlled trial.

OBJECTIVE

Few studies have investigated the changes in mitochondrial dynamics in spinal cord neurons. Meanwhile, the distribution of mitochondria in axons remains unclear. In the present study, the investigators attempted to clarify these questions and focused in observing the changes in mitochondrial spatial distribution under a high-glucose environment.

SUMMARY OF BACKGROUND DATA

Mitochondrial dynamics disorder is one of the main mechanisms that lead to nervous system diseases due to its adverse effects on mitochondrial morphology, function, and axon distribution. High-glucose stress can promote the increase in mitochondrial fission of various types of cells.

METHODS

The lumbar spinal cord of type 1 diabetic Sprague-Dawley rats at 4 weeks was observed. VSC4.1 cells were cultured and divided into three groups: normal control group, high-glucose intervention group, and high-glucose intervention combined with mitochondrial fission inhibitor Mdivi-1 intervention group. Immunohistochemistry and immunofluorescence methods were used to detect the expression of mitochondrial marker VDAC-1 in the spinal cord. An electron microscope was used to observe the number, structure, and distribution of mitochondria. Western blot was used to detect VDAC-1, fusion protein MFN1, MFN2, and OPA1, and fission protein FIS1 and DRP1. Living cell mitochondrial staining was performed using MitoTracker. Laser confocal microscopy and an Olympus live cell workstation were used to observe the mitochondrial changes.

RESULTS

The mitochondrial dynamics of spinal cord related neurons under an acute high-glucose environment were significantly unbalanced, including a reduction of fusion and increase of fission. Hence, mitochondrial fission has the absolute advantage. The total number of mitochondria in neuronal axons significantly decreased.

CONCLUSION

Increased mitochondrial fission and abnormal distribution occurred in spinal cord related neurons in a high-glucose environment. Mdivi-1 could significantly improve these disorders of mitochondria in VSC4.1 cells. Mitochondrial division inhibitors had a positive significance on diabetic neuropathy.

LEVEL OF EVIDENCE

N/A.