Pre-treatment of rapamycin transformed M2 microglia alleviates traumatic cervical spinal cord injury via AIM2 signaling pathway in vitro and in vivo.

BACKGROUND: Traumatic spinal cord injury (SCI) is still devastating. It was suggested that the inhibition of mTOR may alleviate neuronal inflammatory injury but its underlying mechanism remained to be elucidated. AIM2 (absent in melanoma 2) recruits ASC (apoptosis-associated speck-like protein containing a CARD) and caspase-1 to form the AIM2 inflammasome, activate caspase-1, and elicit inflammatory responses. We designed this study to elucidate whether pre-treatments of rapamycin could suppress SCI induced neuronal inflammatory injury via AIM2 signaling pathway in vitro and in vivo. METHODS: We performed oxygen and glucose deprivation / re-oxygenation (OGD) treatment and rats clipping model to mimic neuronal injury after SCI in vitro and in vivo. Morphologic changes of injured spinal cord were detected by hematoxylin and eosin staining. The expression of mTOR, p-mTOR, AIM2, ASC, Caspase-1 and et al were analyzed by fluorescent staining, western blotting or qPCR. The polarization phenotype of microglia was identified by flow cytometry or fluorescent staining. RESULTS: We found BV-2 microglia without any pre-treatment cannot alleviate primary cultured neuronal OGD injury. However, pre-treated rapamycin in BV-2 cells could transform microglia to M2 phenotype and protects against neuronal OGD injury via AIM2 signaling pathway. Similarly, pre-treatment of rapamycin could improve the outcome of cervical SCI rats through AIM2 signaling pathway. CONCLUSIONS: It was suggested that resting state microglia pre-treated by rapamycin could protect against neuronal injury via AIM2 signaling pathway in vitro and in vivo. Pre-inhibition of mTOR pathway may improve neuronal protection after SCI.

Surgical outcomes of basilar invagination type B without atlantoaxial dislocation through simple posterior fossa decompression: a retrospective study of 18 cases.

BACKGROUND: Basilar invagination (BI) is a common disease in the craniocervical junction (CVJ) area. Posterior fossa decompression with/without fixation is a controversial surgical strategy for BI type B. This study aimed to evaluate the efficacy of simple posterior fossa decompression in treating BI type B. METHODS: This study retrospectively enrolled BI type B patients who underwent simple posterior fossa decompression at Huashan Hospital, Fudan University between 2014.12 and 2021.12. Patient data and images were recorded pre- and postoperatively (at the last follow-up) to evaluate the surgical outcomes and craniocervical stability. RESULTS: A total of 18 BI type B patients (13 females), with a mean age of 44.2±7.9 years (range 37-62 years), were enrolled. The mean follow-up period was 47.7±20.6 months (range 10-81 months). All patients received simple posterior fossa decompression without any fixation. At the last follow-up, compared with preoperation, the JOA scores were significantly higher (14.2±1.5 vs. 9.9±2.0, p = 0.001); the CCA was improved (128.7±9.6° vs. 121.5±8.1° p = 0.001), and the DOCL was reduced (7.9±1.5 mm vs. 9.9±2.5 mm, p = 0.001). However, the follow-up and preoperative ADI, BAI, PR, and D/L ratio were similar. No patients had an unstable condition between the C1-2 facet joints that was observed in the follow-up CT and dynamic X-ray. CONCLUSIONS: In BI type B patients, simple posterior fossa decompression could improve neurological function and will not induce CVJ instability in BI type B patients. Simple posterior fossa decompression could be a satisfactory surgical strategy for BI type B patients, but preoperative CVJ stability assessment is crucial.

Blood Pressure Variability Associates with Six-Month Outcomes in Acute Cervical Spinal Cord Injury: An Analysis of 105 Patients.

OBJECTIVE: Blood pressure variability (BPV) has been shown to correlate with poor outcomes in patients with intracerebral hemorrhage (ICH) and traumatic brain injury. However, this association has not been elucidated in patients with traumatic cervical spinal cord injury (cSCI). We hypothesized that 24-hour BPV from time of admission is associated with worse outcomes in patients with cSCI. METHODS: We performed a retrospective chart review analysis of adult patients at Huashan Hospital Fudan University between January 2006 and September 2022. We included isolated patients with traumatic cSCI within 6 hours of injury. Outcomes of patients with cSCI were assessed using 6-month American Spinal Injury Association (ASIA) impairment scale grade, and were dichotomized into poor (ASIA grade A-C, or decreasing ASIA grade compared with baseline) and good (ASIA grade D and E, or increasing ASIA grade compared with baseline) outcome groups. Blood pressures (BPs) were recorded during the first 24 hours of hospital course. BP was analyzed in the hyperacute period, from 0 to 4-5 hours; and in the acute period, from 4-5 to 24-25 hours after admission. BPV was analyzed by standard deviation (SD), coefficient of variation (CV), and successive variation (SV) of systolic BP (SBP). RESULTS: We analyzed 105 patients' charts. The first BP assessment, on emergency department arrival, at median 267 minutes (interquartile range, 152-312 minutes) after onset of injury was mean 152.2 mm Hg (SD, 51.8 mm Hg). The second BP assessment, on neurosurgical intensive care unit arrival, was mean 148.1 mm Hg (53.2 mm Hg). Poor outcomes occurred in 63 patients (60%). In univariate analysis, univariate quintile analysis or multivariate analysis, SBPSD, SBPCV, and SBPSV were associated with poor outcomes in both the hyperacute and the acute period. CONCLUSIONS: BPV during the first 24 hours after injury in patients with traumatic cSCI was independently associated with poor functional outcome at 3 months. Stabilization of BPV during the hyperacute and acute period may be a therapeutic target to improve functional outcomes of these patients.