Contralateral S1 nerve root transfer for motor function recovery in the lower extremity among patients with central nervous system injury: study protocol for a randomized controlled trial.

BACKGROUND: Central nervous system injury (CNSI) comprises a series of common diseases that severely affect patients' motor function and quality of life and is associated with high disability and mortality rates. Previous studies have shown that contralateral lumbosacral nerve root transfer significantly improved the function of the paralyzed limb in rat models of CNSI. These studies showed that severing the sacral 1 nerve root (S1) did not damage the function of the ipsilateral lower extremity. Thus, we speculate that contralateral S1 nerve root transfer can improve the recovery of a paralyzed limb. Because no associated rigorously designed randomized controlled trial has evaluated the effectiveness of contralateral S1 nerve transfer thus far, we designed this clinical trial to compare the effects of this new treatment approach with those of traditional treatments in paralyzed patients after chronic CNSI. METHODS: This is a single-center, prospective, randomized controlled trial. Forty patients, who meet the inclusion criteria and have hemiplegia caused by chronic CNSI, will be randomly divided into the surgical or non-surgical group. The treatment effect in the 2 groups will be assessed before and 3, 6, 9, 12, 18, and 24 months after intervention by using numerous scales and resting-state functional magnetic resonance imaging. The primary outcome will be the Fugl-Meyer score for the lower limbs 24 months after treatment. The secondary outcomes include the modified Ashworth spasm scale, the modified Barthel scale, 10-m walking speed measurement results, three-dimensional gait analysis, muscle strength testing, electromyography, and resting-state functional magnetic resonance imaging findings. Safety outcomes and adverse events will be observed simultaneously. DISCUSSION: We expect that the surgery will improve the sensorimotor functions of the paralyzed limb, and the results of this trial will provide high-quality clinical evidence for a new efficient treatment strategy for disability after CNSI. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR1800014414, registration date: 12 January 2018.

Effect of exosomes from adipose-derived stem cells on the apoptosis of Schwann cells in peripheral nerve injury.

AIMS: Recovery after peripheral nerve injury (PNI) is often difficult, and there is no optimal treatment. Schwann cells (SCs) are important for peripheral nerve regeneration, so SC-targeting treatments have gained importance. Adipose-derived stem cells (ADSCs) and their exosomes can promote peripheral nerve repair, but their interactions with SCs are unclear. METHODS: Purified SCs from sciatic nerve injury sites were harvested, and apoptosis and proliferation of SCs at post-PNI 24 hours were analyzed. The effects of coculture with ADSCs and different concentrations of ADSC-derived exosomes (ADSC-Exo) were studied through in vitro experiments by flow cytometry, CCK8 assay, immunofluorescence staining, and histological analysis. The expression of the apoptosis-related genes Bcl-2 and Bax was also analyzed by qRT-PCR. RESULTS: ADSC-Exo reduced the apoptosis of SCs after PNI by upregulating the anti-apoptotic Bcl-2 mRNA expression and downregulating the pro-apoptotic Bax mRNA expression. Further, it also improved the proliferation rate of SCs. This effect was confirmed by the morphological and histological findings in PNI model rats. CONCLUSION: Our results present a novel exosome-mediated mechanism for ADSC-SC cross talk that reduces the apoptosis and promotes the proliferation of SCs and may have therapeutic potential in the future.

Differential gene and protein expression between rat tibial nerve and common peroneal nerve during Wallerian degeneration.

Wallerian degeneration and nerve regeneration after injury are complex processes involving many genes, proteins and cytokines. After different peripheral nerve injuries the regeneration rate can differ. Whether this is caused by differential expression of genes and proteins during Wallerian degeneration remains unclear. The right tibial nerve and the common peroneal nerve of the same rat were exposed and completely cut through and then sutured in the same horizontal plane. On days 1, 7, 14, and 21 after surgery, 1-2 cm of nerve tissue distal to the suture site was dissected out from the tibial and common peroneal nerves. The differences in gene and protein expression during Wallerian degeneration of the injured nerves were then studied by RNA sequencing and proteomic techniques. In the tibial and common peroneal nerves, there were 1718, 1374, 1187, and 2195 differentially expressed genes, and 477, 447, 619, and 495 differentially expressed proteins on days 1, 7, 14, and 21 after surgery, respectively. Forty-seven pathways were activated during Wallerian degeneration. Three genes showing significant differential expression by RNA sequencing (Hoxd4, Lpcat4 and Tbx1) were assayed by real-time quantitative polymerase chain reaction. RNA sequencing and real-time quantitative polymerase chain reaction results were consistent. Our findings showed that expression of genes and proteins in injured tibial and the common peroneal nerves were significantly different during Wallerian degeneration at different time points. This suggests that the biological processes during Wallerian degeneration are different in different peripheral nerves after injury. The procedure was approved by the Animal Experimental Ethics Committee of the Second Military Medical University, China (approval No. CZ20160218) on February 18, 2016.

Effect of exogenous spastin combined with polyethylene glycol on sciatic nerve injury.

Polyethylene glycol can connect the distal and proximal ends of an injured nerve at the cellular level through axonal fusion to avoid Wallerian degeneration of the injured distal nerve and promote peripheral nerve regeneration. However, this method can only prevent Wallerian degeneration in 10% of axons because the cytoskeleton is not repaired in a timely fashion. Reconstruction of the cytoskeletal trunk and microtubule network has been suggested to be the key for improving the efficiency of axonal fusion. As a microtubule-severing protein, spastin has been used to enhance cytoskeletal reconstruction. Therefore, we hypothesized that spastin combined with polyethylene glycol can more effectively promote peripheral nerve regeneration. A total of 120 male Sprague-Dawley rats were randomly divided into sham, suture, polyethylene glycol, and polyethylene glycol + spastin groups. In suture group rats, only traditional nerve anastomosis of the end-to-end suture was performed after transection of the sciatic nerve. In polyethylene glycol and polyethylene glycol + spastin groups, 50 µL of polyethylene glycol or 25 µL of polyethylene glycol + 25 µL of spastin, respectively, were injected immediately under the epineurium of the distal suture. Sensory fiber regeneration distance, which was used to assess early nerve regeneration at 1 week after surgery, was shortest in the suture group, followed by polyethylene glycol group and greatest in the polyethylene glycol + spastin group. Behavioral assessment of motor function recovery in rats showed that limb function was restored in polyethylene glycol and polyethylene glycol + spastin groups at 8 weeks after surgery. At 1, 2, 4 and 8 weeks after surgery, sciatic functional index values and percentages of gastrocnemius muscle wet weight were highest in the sham group, followed by polyethylene glycol + spastin and polyethylene glycol groups, and lowest in the suture group. Masson staining was utilized to assess the morphology of muscle tissue. Morphological changes in skeletal muscle were detectable in suture, polyethylene glycol, and polyethylene glycol + spastin groups at 1, 2, 4, and 8 weeks after surgery. Among them, muscular atrophy of the suture group was most serious, followed by polyethylene glycol and polyethylene glycol + spastin groups. Ultrastructure of distal sciatic nerve tissue, as detected by transmission electron microscopy, showed a pattern of initial destruction, subsequent disintegration, and gradual repair in suture, polyethylene glycol, and polyethylene glycol + spastin groups at 1, 2, 4, and 8 weeks after surgery. As time proceeded, axonal ultrastructure gradually recovered. Indeed, the polyethylene glycol + spastin group was similar to the sham group at 8 weeks after surgery. Our findings indicate that the combination of polyethylene glycol and spastin can promote peripheral nerve regeneration. Moreover, the effect of this combination was better than that of polyethylene glycol alone, and both were superior to the traditional neurorrhaphy. This study was approved by the Animal Ethics Committee of the Second Military Medical University, China (approval No. CZ20170216) on March 16, 2017.

Accurate segmental motor innervation of human lower-extremity skeletal muscles.

BACKGROUND: There is limited knowledge about accurate segmental motor innervation of the human lower extremity skeletal muscles. The aim of the present study was to explore the truth of segmental motor innervation of the lower extremity. METHODS: Included in this study were 20 patients with unilateral fracture of the sacrum and sacral nerve injury, who underwent internal fixation and decompression of the sacral nerve in our hospital between June 2009 and January 2014. L4-S4 nerve roots of the uninjured side were stimulated during operation. Motor innervation was determined by stimulating the spinal nerves with supramaximal intensity. RESULTS: We found the gluteus medius and the gluteus maximus were both mainly innervated by L5 and S1. In addition, the nerve fibres that innervated the extensor digitorum brevis, the abductor hallucis and the flexor digitorum brevis were mainly from S2 to S3. CONCLUSIONS: Our study provides the electrophysiological mapping of the segmental anatomy of the human lower extremity muscles, which should be clinically useful in helping the diagnosis and treatment of nerve injury and neuropathies.

[Effect of extract of Ginkgo biloba leaves on expression of inducible nitric oxide synthase after sciatic nerve injury: experiment with rats].

OBJECTIVE: To investigate the effect of extract of Ginkgo biloba leaves (EGb50) on the expression of inducible nitric oxide synthase (iNOS) after sciatic nerve injury. METHODS: 156 male SD rats were randomly divided into 3 groups: experiment group (n=72), undergoing section and anastomosis of sciatic nerve and then gastric perfusion of EGb50 200 mg.kg-1.d-1; injury control group (n=72), undergoing section and anastomosis of sciatic nerve and then gastric perfusion of normal saline daily; and sham operation group (n=12), undergoing sham operation and gastric perfusion of normal saline daily. The rats were killed at different time points: 1, 3, 7, 14, 21, and 28 days after the operation. The sciatic nerve distant to the anastomotic sites with a length of 0.5 cm was cut out to undergo immunohistochemistry and RT-PCR to detect the protein and mRNA expression of iNOS. RESULTS: No obvious iNOS protein and mRNA expression was seen in the sham operation group. 3, 7, 14, and 21 days after operation the mean values of absorbance of iNOS in the sciatic nerve specimens of the experiment group were all significantly lower than those of the injury control group (P<0.05, P<0.01). High mRNA expression of iNOS began to be shown in the sciatic nerve specimens since 1day after the operation and remained at a high level till 7 days after and then began to decrease in the injury control group. The levels of mRNA expression of iNOS in the sciatic nerve specimens 1, 3, and 7 days after the operation of the experiment group were all significantly lower than those of the injury control group (all P<0.01), and there was no significant difference in the levels mRNA expression of iNOS 14, 21, and 28 days after the operation between the experiment group and injury control group (all>0.05). CONCLUSION: The extract of Gingko biloba promotes the regeneration of nervous tissues, probably by inhibiting the expression of iNOS.