Reducing Neuron Apoptosis in the Pontine Micturition Center by Nerve Root Transfer for Restoration of Micturition Function after Spinal Cord Injury

Objective. The rate of neuronal apoptosis increases after spinal cord injury (SCI). Anastomosing the normal nerve roots above the SCI level to the injured sacral nerve roots can enhance the functional recovery of neurons. Therefore, we evaluated the effect of sacral nerve root transfer after SCI on pontine neuronal survival. Methods. Sprague–Dawley rats were randomly divided into three groups: Group A, reconstruction of afferent and efferent nerve pathways of the bladder after SCI; Group B, SCI only; and Group C, control group. We examined pontine neuronal morphology using hematoxylin and eosin (H&E) staining after SCI and nerve transfer. Bcl-2 and Bax protein expression changes in the pontine micturition center were quantified by immunohistochemistry. The number of apoptotic neurons was determined by TUNEL staining. We examined pontine neuronal apoptosis by transmission electron microscopy (TEM) at different time points. Results. H&E staining demonstrated that the number of neurons had increased in Group A, but more cells in Group B displayed nuclear pyknosis, with the disappearance of the nucleus. Compared with Group B, Group A had significantly higher Bcl-2 expression, significantly lower Bax expression, and a significantly higher Bcl-2/Bax ratio. The number of apoptotic neurons and neuron bodies in Group A was significantly lower than that in Group B, as indicated by TUNEL staining and TEM. Conclusions. These findings demonstrate that lumbosacral nerve transfer can reduce neuronal apoptosis in the pontine micturition center and enhance functional recovery of neurons. This result further suggests that lumbosacral nerve transfer can be used as a new approach for reconstructing bladder function after spinal cord injury.

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Reducing neuronal apoptosis in pontine micturition center by nerve root transfer to reconstruct bladder function after spinal cord injury

10.21203/rs.2.17382/v1 ◽

2019 ◽

Author(s):

Ronghua Yu ◽

Gang Yin ◽

Jianguo Zhao ◽

Huihao Chen ◽

Depeng Meng ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Nerve Root ◽

Neuronal Apoptosis ◽

Nerve Transfer ◽

Bladder Function ◽

Sprague Dawley ◽

Nerve Roots ◽

Sprague Dawley Rats ◽

Cord Injury

Abstract Background: The neuronal apoptosis is increased after spinal cord injury (SCI), but anastomosing the normal nerve roots above SCI level to the injury sacral nerve roots can enhance functional recovery of neurons. Therefore, we evaluated the effect of sacral nerve root transfer after SCI on pontine neuronal survival and restoration of bladder function. Methods: Adult female Sprague Dawley rats (N = 90, 9–10 weeks old, 240-260 grams weight) were randomly divided into three groups (N = 30). We anastomosed the dorsal and ventral roots of proximal L4 and distal S2 to reconstruct the rat bladder–spinal cord–cerebral nerve afferent and efferent pathways in Sprague Dawley rats after spinal cord transection. We examined pontine neuronal morphology and apoptosis using hematoxylin and eosin (H&E) staining and transmission electron microscopy (TEM) at different time points (1 day, 1 week, and 1, 3, or 6 months) after SCI and nerve transfer. Bcl-2 and Bax protein expression changes in the pontine micturition center were quantified by immunohistochemistry. Results: After nerve roots reconstruction, Group A compared with Group B, Bcl-2 expression increased significantly, Bax expression decreased significantly, Bcl-2/Bax ratio increased, the number of apoptotic neurons decreased, and the number of apoptotic bodies within neurons decreased significantly as observed by TEM.Conclusion: These findings demonstrate that lumbosacral nerve transfer can reduce neuronal apoptosis in the pontine micturition center and enhance functional recovery of neurons. This method can be used as a new approach for reconstructing bladder function after spinal cord injury.

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Local Delivery of β-Elemene Improves Locomotor Functional Recovery by Alleviating Endoplasmic Reticulum Stress and Reducing Neuronal Apoptosis in Rats with Spinal Cord Injury

Cellular Physiology and Biochemistry ◽

10.1159/000492996 ◽

2018 ◽

Vol 49 (2) ◽

pp. 595-609 ◽

Cited By ~ 8

Author(s):

Jingyu Wang ◽

Heyangzi Li ◽

Yucheng Ren ◽

Ying Yao ◽

Jue Hu ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Endoplasmic Reticulum ◽

Endoplasmic Reticulum Stress ◽

Rat Model ◽

Neuronal Apoptosis ◽

Ventral Horn ◽

Tunel Staining ◽

Cord Injury

Background/Aims: Spinal cord injury (SCI) is a serious global problem that leads to permanent motor and sensory deficits. This study explores the anti-apoptotic and neuroprotective effects of the natural extract β-elemene in vitro and in a rat model of SCI. Methods: CCK-8 assay was used to evaluate cell viability and lactate dehydrogenase assay was used to evaluate cytotoxicity. A model of cell injury was established using cobalt chloride. Apoptosis was evaluated using a fluorescence-activated cell sorting assay of annexin V-FITC and propidium iodide staining. A rat SCI model was created via the modified Allen’s method and Basso, Beattie, and Bresnahan (BBB) scores were used to assess locomotor function. Inflammatory responses were assessed via enzyme-linked immunosorbent assay (ELISA). Apoptotic and surviving neurons in the ventral horn were respectively observed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Nissl staining. Western blotting was used to measure protein expression. Results: β-elemene (20 μg/ml) promoted cell viability by activating phosphorylation of the PI3K-AKT-mTOR pathway. β-elemene reduced CoCl2-induced cellular death and apoptosis by suppressing the expression levels of CHOP, cleaved-caspase 12, 78-kilodalton glucose-regulated protein, cleaved-caspase 3, and the Bax/Bcl-2 ratio. In the rat model of SCI, Nissl and TUNEL staining showed that β-elemene promoted motor neuron survival and reduced neuronal apoptosis in the spinal cord ventral horn. BBB scores showed that β-elemene significantly promoted locomotor behavioral recovery after SCI. In addition, β-elemene reduced the ELISA-detected secretion of interleukin (IL)-6 and IL-1β. Conclusion: β-elemene reduces neuronal apoptosis by alleviating endoplasmic reticulum stress in vitro and in vivo. In addition, β-elemene promotes locomotor function recovery and tissue repair in SCI rats. Thus, our study provides a novel encouraging strategy for the potential treatment of β-elemene in SCI patients.

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MCC950 reduces neuronal apoptosis in spinal cord injury in mice.

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527319666201005170659 ◽

2020 ◽

Vol 19 ◽

Author(s):

Ning He ◽

Xiaohe Zheng ◽

Teng He ◽

Gerong Shen ◽

Kunyu Wang ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Nlrp3 Inflammasome ◽

Cortical Neurons ◽

Neuronal Apoptosis ◽

Specific Inhibitor ◽

Tunel Staining ◽

Tail Flick ◽

Severe Condition ◽

Cord Injury

Background: Traumatic spinal cord injury (SCI) is a severe condition usually accompanied by an inflammatory process that gives rise to uncontrolled local apoptosis and a subsequent unfavorable prognosis. One reason for this unfavorable outcome could be the activation of the NLRP3 inflammasome. Objective: MCC950 is a specific inhibitor of NLRP3 that further inhibits the formation of the NLRP3 inflammasome. The purpose of this study was to determine whether the NLRP3 inflammasome was associated with the severity of local apoptosis and whether MCC950 could prevent neuronal apoptosis following SCI. Methods: In this study, primary cortical neurons were cultured in vitro. With or without pretreatment/posttreatment with MCC950, neurons were subjected to oxygen-glucose deprivation (OGD) for 2 h and then reperfusion for 20 h. Immunofluorescence was used to determine the expression of NLRP3, ASC and cleaved caspase-1 in neurons. In vivo, SCI model mice were established with a 5 g weight-drop method. MCC950 was intraperitoneally injected at 0, 2, 4, 6, 8, 10, and 12 days after SCI. Basso Mouse Scale (BMS) scores and footprint assays were used to assess motor function. Paw withdrawal threshold and tail flick latency were used to assess somatosensory function. H&E, Nissl and TUNEL staining were used to measure histological changes and apoptosis at 3 days after SCI, and scar formation was observed by Masson staining and GFAP immunohistochemical analysis at 28 days after SCI. Results: Immunofluorescence analysis confirmed that MCC950 inhibited OGD-induced activation of the NLRP3 inflammasome in neurons.

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