Effect evaluation of methylprednisolone plus mitochondrial division inhibitor-1 on spinal cord injury rats

Melatonin Protects Injured Spinal Cord Neurons From Apoptosis by Inhibiting Mitochondrial Damage via the SIRT1/Drp1 Signaling Pathway

Spinal cord injuries (SCIs) often result in limited prospects for recovery and a high incidence of disability. Melatonin (Mel), a hormone, is acknowledged for its neuroprotective attributes. Mel was examined in this study to discover if it alleviates SCIs via the sirtuin1/dynamin-related protein1 (SIRT1/Drp1) signaling pathway. SCIs were simulated in mice by inducing cord contusion at the T9-T10 vertebrae and causing inflammation in primary spinal neurons using lipopolysaccharide (LPS). The findings of our study demonstrated that Mel treatment effectively promoted neuromotor recovery through multiple mechanisms, including the reduction of neuronal death, suppression of astrocyte and microglia activation, and attenuation of neuroinflammation. Moreover, Mel therapy significantly upregulated the expression of SIRT1 in both spinal cord tissues and spinal neurons of mice. Additionally, Mel exhibited the potential to mitigate neuronal mitochondrial dysfunction by modulating the levels of Drp1 and TOMM20, thereby addressing the underlying factors contributing to this dysfunction. Furthermore, when SIRT1 was downregulated, it reversed the positive effects of Mel. Overall, our present study suggests that Mel has the capacity to modulate the SIRT1/Drp1 pathway, thereby ameliorating mitochondrial dysfunction, attenuating inflammation and apoptosis, and enhancing neural function subsequent to SCIs.

Effects of methylprednisolone and treadmill training on spinal cord injury in experimental rats

Methylprednisolone (MP) is widely used to treat clinical spinal cord injury (SCI). Treadmill training is also considered an important treatment after SCI to improve motor function in patients, resulting in an evident improvement. Therefore, the present study was designed to evaluate and contrast the effects of MP and treadmill training administered in combination or alone after SCI in adult rats. A rat spinal cord T10 contusion model was induced in Sprague-Dawley rats using an impact device. A total of 40 rats were divided into four groups (n=10 rats/group): the MP, MP + treadmill training, SCI and sham group. At 30 min after injury, MP sodium succinate was injected into the rats of the MP and MP + treadmill training groups. Treadmill training began on the second week post-trauma and was performed for 8 weeks. The results showed that MP therapy combined with treadmill training significantly ameliorated several parameters of hind limb function compared with those by MP treatment alone (all P<0.05). A significantly reduced immunopositive area of Nogo receptor and chondroitin sulfate proteoglycans and reduced relative expression of these mRNAs were found in the MP + treadmill training group (P<0.05) compared with the findings in the MP group. In conclusion, the present study indicated that combined MP and treadmill training treatment improved the recovery of hind limb function in rats with SCI, thus potentially representing a promising strategy to cure SCI.

Total flavonoids of hawthorn leaves promote motor function recovery via inhibition of apoptosis after spinal cord injury

Flavonoids have been reported to have therapeutic potential for spinal cord injury. Hawthorn leaves have abundant content and species of total flavonoids, and studies of the effects of the total flavonoids of hawthorn leaves on spinal cord injury have not been published in or outside China. Therefore, Sprague-Dawley rats were used to establish a spinal cord injury model by Allen’s method. Rats were intraperitoneally injected with 0.2 mL of different concentrations of total flavonoids of hawthorn leaves (5, 10, and 20 mg/kg) after spinal cord injury. Injections were administered once every 6 hours, three times a day, for 14 days. After treatment with various concentrations of total flavonoids of hawthorn leaves, the Basso, Beattie, and Bresnahan scores and histological staining indicated decreases in the lesion cavity and number of apoptotic cells of the injured spinal cord tissue; the morphological arrangement of the myelin sheath and nerve cells tended to be regular; and the Nissl bodies in neurons increased. The Basso, Beattie, and Bresnahan scores of treated spinal cord injury rats were increased. Western blot assays showed that the expression levels of pro-apoptotic Bax and cleaved caspase-3 were decreased, but the expression level of the anti-apoptotic Bcl-2 protein was increased. The improvement of the above physiological indicators showed a dose-dependent relationship with the concentration of total flavonoids of hawthorn leaves. The above findings confirm that total flavonoids of hawthorn leaves can reduce apoptosis and exert neuroprotective effects to promote the recovery of the motor function of rats with spinal cord injury. This study was approved by the Ethics Committee of the Guangxi Medical University of China (approval No. 201810042) in October 2018.

Mitochondrial dynamics and their potential as a therapeutic target

Mitochondrial dynamics shape the mitochondrial network and contribute to mitochondrial function and quality control. Mitochondrial fusion and division are integrated into diverse cellular functions and respond to changes in cell physiology. Imbalanced mitochondrial dynamics are associated with a range of diseases that are broadly characterized by impaired mitochondrial function and increased cell death. In various disease models, modulating mitochondrial fusion and division with either small molecules or genetic approaches has improved function. Although additional mechanistic understanding of mitochondrial fusion and division will be critical to inform further therapeutic approaches, mitochondrial dynamics represent a powerful therapeutic target in a wide range of human diseases.