Combination Therapy With Hyperbaric Oxygen and Erythropoietin Inhibits Neuronal Apoptosis and Improves Recovery in Rats With Spinal Cord Injury

Abstract Background Apoptosis plays an important role in various diseases, including spinal cord injury (SCI). Hyperbaric oxygen (HBO) and erythropoietin (EPO) promote the recovery from SCI, but the relationship between apoptosis and the combination therapeutic effect is not completely clear. Objective The purpose of this study was to investigate the effects of HBO and EPO on SCI and the mechanisms that underlie their therapeutic benefits. Design The study was designed to explore the effects of HBO and EPO on SCI through a randomized controlled trial. Methods Sixty young developing female Sprague-Dawley rats were randomly divided into groups of 12 rats receiving sham, SCI, HBO, EPO, or HBO plus EPO. The SCI model was modified with the Allen method to better control consistency. HBO was performed for 1 hour per day for a total of 21 days, and EPO was given once per week for a total of 3 weeks. Both methods were performed 2 hours after SCI. Locomotor function was evaluated with the 21-point Basso-Beattie-Bresnahan Locomotor Rating Scale, an inclined-plane test, and a footprint analysis. All genes were detected by Western blotting and immunohistochemistry. The level of cell apoptosis was determined by Hoechst staining. Results The results showed that HBO and EPO promoted the recovery of locomotor function in the hind limbs of rats by inhibiting the apoptosis of neurons. During this period, the expression of B-cell lymphoma/leukemia 2 protein (Bcl-2) increased significantly, whereas the expression of Bcl-2–associated X protein (Bax) and cleaved caspase 3 decreased significantly, indicating the inhibition of apoptosis. Meanwhile, the expression of G protein–coupled receptor 17 decreased, and that of myelin basic protein increased, suggesting that there may be a potential connection between demyelination and neuronal apoptosis. Limitations The limitations of the study include deviations in the preparation of SCI models; lack of reverse validation of molecular mechanisms; absence of in vitro cell experiments; and only one time point after SCI was studied. Conclusions HBO and EPO treatments are beneficial for SCI, especially when the 2 therapies are combined.

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Activation of SIRT1 by Hyperbaric Oxygenation Promotes Recovery of Motor Dysfunction in Spinal Cord Injury Rats

10.21203/rs.2.23545/v1 ◽

2020 ◽

Author(s):

Huiqiang Chen ◽

Mengyu Yao ◽

Zhibo Li ◽

Ranran Xing ◽

Cheng Zhang ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Molecular Mechanisms ◽

Hyperbaric Oxygenation ◽

Rating Scale ◽

Motor Dysfunction ◽

Sprague Dawley ◽

Inflammatory Cascade ◽

Locomotor Function ◽

Cord Injury

Abstract Background: Emerging evidence demonstrated that hyperbaric oxygenation (HBO) therapy improved the locomotor dysfunction following spinal cord injury (SCI). Sirtuin1(SIRT1) has been characterized as neuroprotection in nerve system. However, whether SIRT1 is involved in alleviation of locomotor function by HBO therapy is unclear. Methods: The Basso, Beattie Bresnahan (BBB) locomotor rating scale was used to evaluate the open-field locomotor function. Western blot, real-time quantitative reverse transcription polymerase chain reaction, SIRT1 activity assay and enzyme-linked immunosorbent assays were performed to explore the molecular mechanisms in adult Sprague-Dawley rats. Results: We found that series HBO therapy significantly improved the locomotor dysfunction and ameliorated the decrease mRNA, protein and activity of spinal cord SIRT1 induced by traumatic SCI injury in rats. In addition, intraperitoneal injection SIRT1 antagonist EX-527 abolished the beneficial effects of series HBO treatment on locomotor deficits and SIRT1 activity loss caused by traumatic SCI injury. However, the rats undergone both series HBO therapy and SIRT1 agonist SRT1720 got the higher BBB score than that undergone series HBO treatment only. Importantly, series HBO treatment following the traumatic SCI injury inhibited the inflammatory cascade and apoptosis-related protein, which was retained by EX-527 and enhanced by SRT1720. Furthermore, EX-527 blocked the enhanced induction of autophagy series with HBO application. Conclusion: These findings demonstrated a new mechanism for series HBO therapy involving activation of SIRT1 and subsequent modulation of inflammatory cascade, apoptosis and autophagy, which contributed to the recovery of motor dysfunction. Key words: HBO, SIRT1, motor dysfunction, inflammation, autophagy, apoptosis

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Inhibition of x-irradiation–enhanced locomotor recovery after spinal cord injury by hyperbaric oxygen or the antioxidant nitroxide tempol

Journal of Neurosurgery Spine ◽

10.3171/spi.2007.6.4.9 ◽

2007 ◽

Vol 6 (4) ◽

pp. 337-343 ◽

Cited By ~ 7

Author(s):

Virany H. Hillard ◽

Hong Peng ◽

Kaushik Das ◽

Raj Murali ◽

Chitti R. Moorthy ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Hyperbaric Oxygen ◽

Spinal Cord Tissue ◽

Irradiation Site ◽

Injury Site ◽

Locomotor Recovery ◽

Locomotor Function ◽

Cord Injury ◽

X Irradiation

Object Hyperbaric oxygen (HBO), the nitroxide antioxidant tempol, and x-irradiation have been used to promote locomotor recovery in experimental models of spinal cord injury. The authors used x-irradiation of the injury site together with either HBO or tempol to determine whether combined therapy offers greater benefit to rats. Methods Contusion injury was produced with a weight-drop device in rats at the T-10 level, and recovery was determined using the 21-point Basso-Beattie-Bresnahan (BBB) locomotor scale. Locomotor function recovered progressively during the 6-week postinjury observation period and was significantly greater after x-irradiation (20 Gy) of the injury site or treatment with tempol (275 mg/kg intraperitoneally) than in untreated rats (final BBB Scores 10.6 [x-irradiation treated] and 9.1 [tempol treated] compared with 6.4 [untreated], p < 0.05). Recovery was not significantly improved by HBO (2 atm for 1 hour [BBB Score 8.2, p > 0.05]). Interestingly, the improved recovery of locomotor function after x-irradiation, in contrast with antiproliferative radiotherapy for neoplasia, was inhibited when used together with either HBO or tempol (BBB Scores 8.2 and 8.3, respectively). The ability of tempol to block enhanced locomotor recovery by x-irradiation was accompanied by prevention of alopecia at the irradiation site. The extent of locomotor recovery following treatment with tempol, HBO, and x-irradiation correlated with measurements of spared spinal cord tissue at the contusion epicenter. Conclusions These results suggest that these treatments, when used alone, can activate neuroprotective mechanisms but, in combination, may result in neurotoxicity.

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Electrical epidural stimulation of the cervical spinal cord: Implications for spinal respiratory neuroplasticity after spinal cord injury

Journal of Neurophysiology ◽

10.1152/jn.00625.2020 ◽

2021 ◽

Author(s):

Ian G Malone ◽

Rachel L Nosacka ◽

Marissa A Nash ◽

Kevin J Otto ◽

Erica A Dale

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Neural Plasticity ◽

Molecular Mechanisms ◽

Cervical Spinal Cord ◽

Motor Nucleus ◽

Epidural Stimulation ◽

Locomotor Function ◽

Lumbosacral Spinal Cord ◽

Cord Injury

Traumatic cervical spinal cord injury (cSCI) can lead to damage of bulbospinal pathways to the respiratory motor nuclei and consequent life-threatening respiratory insufficiency due to respiratory muscle paralysis/paresis. Reports of electrical epidural stimulation (EES) of the lumbosacral spinal cord to enable locomotor function after SCI are encouraging, with some evidence of facilitating neural plasticity. Here, we detail the development and success of EES in recovering locomotor function with consideration of stimulation parameters and safety measures to develop effective EES protocols. EES is just beginning to be applied in other motor, sensory, and autonomic systems; however, there has only been moderate success in preclinical studies aimed at improving breathing function after cSCI. Thus, we explore rationale for applying EES to the cervical spinal cord, targeting the phrenic motor nucleus for the restoration of breathing. We also suggest cellular/molecular mechanisms by which EES may induce respiratory plasticity including a brief examination of sex-related differences in these mechanisms. Finally, we suggest more attention be paid to the effects of specific electrical parameters that have been used in the development of EES protocols and how that can impact the safety and efficacy for those receiving this therapy. Ultimately, we aim to inform readers about the potential benefits of EES in the phrenic motor system and encourage future studies in this area.

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A simple and reliable behavioral analysis of locomotor function after spinal cord injury in mice

Journal of Neurosurgery Spine ◽

10.3171/spi.2002.97.1.0142 ◽

2002 ◽

Vol 97 (1) ◽

pp. 142-147 ◽

Cited By ~ 14

Author(s):

Yuji Mikami ◽

Masahiro Toda ◽

Masahiko Watanabe ◽

Masaya Nakamura ◽

Yoshiaki Toyama ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Rating Scale ◽

Animal Movement ◽

Vertical Movement ◽

Behavioral Analysis ◽

Content Type ◽

Locomotor Function ◽

Cord Injury ◽

Fine Print

✓ To establish a simple and reliable method to assess the behavioral function after spinal cord injury (SCI) in mice, the authors used an automated animal movement analysis system, SCANET. Two different SCI lesions were created in adult female BALB/c and C57BL/6 mice by transecting both the posterior columns and the left lateral and anterior funiculi or only the left lateral and anterior funiculi at T-8. Control mice underwent laminectomy only. The SCANET system consists of a cage equipped with two crossing sensor frames arranged at different heights, by which small (M1) and large (M2) horizontal movements and the vertical movement involved in rearing (RG) can be monitored. The authors assessed locomotor function by determining the M1, M2, and RG scores; to this end, they used the SCANET system and a previously established behavior test, the 21-point open-field Basso-Beattie-Bresnahan (BBB) Locomotor Rating Scale. The results indicated that the RG scores were significantly and consistently different between the spinal cord—injured and control mice, irrespective of the mouse strain or injury model, but that M1 and M2 scores were not. Moreover, there was a statistically positive correlation between the RG score and the BBB Scale score. For the assessment of locomotor function after SCI, use of the SCANET sytem in behavioral analysis is simple and the method is highly reproducible. The analysis of vertical movement is useful for assessing the recovery of limb function in mice following thoracic hemisection.

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