Long Coding RNA XIST Contributes to Neuronal Apoptosis through the Downregulation of AKT Phosphorylation and Is Negatively Regulated by miR-494 in Rat Spinal Cord Injury.

Recent evidence has suggested that long non-coding RNAs (lncRNAs) may play a significant role in the pathogenesis of several neurological diseases, including spinal cord injury (SCI). However, little is known about the role of lncRNAs in SCI. The aim of the present study was to evaluate the potential functions of lncRNAs in SCI and to identify the underlying mechanisms of action. We firstly analyzed Gene Expression Omnibus (GEO) datasets to investigate aberrantly-expressed lncRNAs which might be involved in the pathogenesis of SCI. The long non-coding RNA X-inactive specific transcript (XIST) was found to be one of the most significantly upregulated lncRNAs in the GEO dataset analysis, and is associated with apoptosis. We, therefore, selected this as a candidate lncRNA and investigated its function. We found that knockdown of lncRNA-XIST by Lv-shRNA had a prominent protective effect on SCI recovery by suppressing apoptosis through reactivation of the PI3K/AKT signaling pathway in rat spinal cord tissue. In particular, our results suggested that lncRNA-XIST may act as a competitive endogenous RNA, effectively becoming a sink for miR-494, leading to derepression of its target gene, phosphatase and tensin homolog deleted on chromosome ten (PTEN). In addition, an inverse relationship between lncRNA-XIST and miR-494 was observed in spinal cord tissues of SCI rats. Further study demonstrated that antagomiR-494 could reverse the protective effects of lncRNA-XIST knockdown on SCI rats through blocking the PTEN/PI3K/AKT signaling pathway. These results suggested that lncRNA-XIST knockdown may play an important role in limiting neuronal apoptosis in rats following SCI, and that the observed protective effects of lncRNA-XIST knockdown might have been mediated by its regulation on the phosphorylation of AKT by competitively binding miR-494. These findings have revealed, for the first time, the importance of the XIST/miR-494/PTEN/AKT signaling axis in the pathogenesis of SCI and suggest that lncRNA-XIST may be a promising molecular target for SCI therapy.

Identifying hedgehog signaling specific microRNAs in glioblastomas.

Aberrant activation of hedgehog (Hh) signaling pathway plays an important role in the development and proliferation of glioblastoma (GBM) cells. However, its mechanism remains unknown. MicroRNAs (miRNAs) are short non-coding RNA molecules which are involved in the post-transcriptional regulation of genes, and enrolled in signaling transduction network in tumors. This study was designed to investigate the role of miRNAs targeting the Hh signaling pathway in GBMs. According to the expression level of Gli1 mRNA measured by real time PCR, GBM samples were assigned to Gli1 high or low expression group. MiRNA microarray was applied to screen the dysregulated miRNA. As a result, 17 miRNAs were differentially expressed between Gli1 high expression and low expression groups (p < 0.005). Thirteen miRNAs including miR-125b-1 were downregulated, while only 4 miRNAs including miR-144 were upregulated in Gli1 high expression group. In summary, our study presents a subset of miRNAs which target the Hh signaling pathway in GBMs, and throws some light on the aberrant activation mechanism.

Anatomical study of suboccipital vertebral arteries and surrounding bony structures using virtual reality technology.

BACKGROUND: This work aimed to evaluate the efficacy of virtual reality (VR) technology in neurosurgical anatomy through a comparison of the virtual 3D microanatomy of the suboccipital vertebral arteries and their bony structures as part of the resection of tumors in the craniovertebral junction (CVJ) of 20 patients compared to the actual microanatomy of the vertebral arteries of 15 cadaveric headsets. MATERIAL AND METHODS: The study was conducted with 2 groups of data: a VR group composed of 20 clinical cases and a physical body group (PB group) composed of 15 cadaveric headsets. In the VR group, the dissection and measurements of the vertebral arteries were simulated on a Dextroscope. In the PB group, the vertebral arteries in the cadaver heads were examined under a microscope and anatomical measurements of VA and bony structures were performed. The length and course of the vertebral arteries and its surrounding bony structures in each group were compared. RESULTS: The distances from the inferior part of the transverse process foramen (TPF) of C1 to the inferior part of TPF of C2 were 17.68±2.86 mm and 18.4±1.82 mm in the PB and VR groups, respectively. The distances between the middle point of the posterior arch of the atlas and the medial intersection of VA on the groove were 17.35±2.23 mm in the PB group and 18.13±2.58 mm in the VR group. The distances between the middle line and the entrance of VA to the lower rim of TPF of Atlas were 28.64±2.67 mm in PB group and 29.23±2.89 mm in VR group. The diameters of the vertebral artery (VA) at the end of the groove and foramen of C2 transverse process were 4.02±046 mm and 4.25±0.51 mm, respectively, in the PB group and 3.54±0.44 mm and 4.47±0.62 mm, respectively, in VR group. The distances between the VA lumen center and midline of the foramen magnum at the level of dural penetration was 10.4±1.13 mm in the PB group and 11.5±1.34 mm in the VR group (P>0.05). CONCLUSIONS: VR technology can accurately simulate the anatomical features of the suboccipital vertebral arteries and their bony structures, which facilitates the planning of individual surgeries in the CVJ.

[Prognostic analyses of intramedullary high grade astrocytomas].

OBJECTIVE: To explore the prognostic factors of intramedullary high grade astrocytomas. METHODS: Retrospective analyses were conducted for 21 surgical patients with high grade astrocytoma in spinal cord during 2008 to 2012 at our hospital. Their preoperative and postoperative profiles were recorded and evaluated by modified McCormick classification scheme. RESULTS: Their median age was 32.5 years. There were anaplastic astrocytoma (n = 14) and glioblastoma (n = 7). The prognoses of high grade astrocytomas were correlated with pathology grade and MIB-1 index. No statistic significance existed in age, gender, McCormick score, extent of resection, radiotherapy or chemotherapy. CONCLUSION: Intramedullary high grade astrocytoma has a low incidence, but its outcome is poor. Once definitely diagnosed, operation is recommended as early as possible. Frozen pathology should be performed to determine the extent of resection. After operation, chemotherapy and radiotherapy are also suggested.

The surgical strategy "CSF decompression" facilitates outcomes of adults with Chiari malformation type I: An observational, real-world, single center study of 528 patients.

OBJECTIVES: We designed this study to introduce the surgical strategy "CSF decompression" in treating Chiari malformation type I (CMI), and compared the "CSF decompression" strategy with other surgical strategies to provide a solid basis for patient counseling. METHODS: A total of 528 consecutive CMI patients who underwent surgical interventions from 2012 to 2022 were enrolled. The surgical strategy for these patients was bony and dural decompression (BDD), anatomical reduction of herniated tonsils (AR) or CSF decompression (CSFD). Short-term results were determined after 3 months; long-term outcomes were evaluated at last follow-up and at least 18 months. RESULTS: The CSFD strategy was independently associated with better long- or short-term primary outcomes than AR or BDD (P < 0.001). Compared with short-term, the long-term outcomes were better in CSFD patients (P = 0.035), but were worse in BDD patients (P = 0.03). Specific surgical techniques cannot affect the long- and short-term outcomes of CMI patients. CSFD provided better long-term syringomyelia improvement than short-term (181/218, 83% vs 169/218, 77.5%; P < 0.001). CONCLUSION: The "CSF decompression" surgical strategy, but not a specific surgical technique or operative method, was associated with favorable neurological outcomes in adult CMI patients. The surgical technique and operative method should be selected according to the characteristics of each patient and the intraoperative condition to normalized CSF circulation at CVJ. The intraoperative target maybe smoothly CSF flow, out from the fourth ventricle and in to the bilateral Luschka foramina, could be observed.

Aberrant activation of Hedgehog/Gli1 pathway on angiogenesis in gliomas.

BACKGROUND: Hedgehog/Gli1 (HH/Gli1) pathway plays an important role in the patterning and development of the central nervous system during embryogenesis. Recent data have shown its potential involvement in a subset of human gliomas and inhibition of the pathway resulted in tumor suppression in both in vitro and in vivo studies. The underlying mechanisms of tumor suppression, however, remain to be fully elucidated. MATERIALS AND METHODS: Gli1 expression was investigated in 60 surgically resected glioma tissues (World Health Organization (WHO) III-IV). RESULTS: Gli1 was expressed in 43 gliomas with high Gli1 expression in nine cases, moderate expression in 21 cases, and low expression in 13 cases. Additionally, microvessel counts were higher in Gli1 positive gliomas than those in Gli1 negative gliomas. Gli1 expression in gliomas was positively correlated with microvessel density (MVD). To explore the molecular mechanisms of the phenotypic changes, we performed quantitative real-time polymerase chain reaction (PCR) and Western blot analysis to monitor the changes of a series of genes, which play critical roles in the regulation of glioma angiogenesis. In conclusion, HH/Gli1 pathway inhibition resulted in down-regulation of vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP2), and matrix metalloproteinase 9 (MMP9) expressions, whereas this pathway activation led to up-regulation of VEGF, MMP2, and MMP9 expressions. These molecular changes of the HH/Gli1 pathway inhibited by indirect drug approach were consistent with Gli1 RNA-interference (RNAi) in glioma cell lines. CONCLUSION: Our findings demonstrated that the aberrantly active HH/Gli1 pathway contributed to angiogenesis in part through induction of VEGF, MMP2, and MMP9.

Establishment of SIAISi018-A, an induced pluripotent stem cell (iPSC) line from a healthy 45-year-old Chinese Han.

A 45-year-old Han Male from China contributed peripheral blood mononuclear cells induced by reprogramming human OKSM transcription factors (OCT3/4, KLF4 SOX2 and C-MYC) with a non-integrated additional vector system. Immunological markers confirmed the pluripotent nature of IPSC. Spontaneous tridermal differentiation confirmed the differentiation ability of IPSC with normal karyotype.

Establishment of SIAISi017-A, an induced pluripotent stem cell(iPSC)line from a healthy 25-year-old Chinese Hui.

With the development of cytology, the establishment of cell models in vitro has become a powerful means to study the mechanism and treatment of diseases. Here we successfully generated the IPSC-derived modeling system of a 25-year-old healthy male. His peripheral blood mononuclear cells (PBMC) were reprogrammed using human OKSM (SOX2, OCT3/4, KLF4, and C-MYC) transcription factors using a non-integrated additional vector system. Immunocytochemistry demonstrated that IPSCS expressed all the markers of pluripotency and demonstrated their ability to differentiate spontaneously from three hypoderms in vitro. Karyotype is normal.

Generation of a human induced pluripotent stem cell line (SIAISi010-A) from a 31-year-old healthy donor with Chinese Han genetic background.

A healthy 31-year-old Chinese Han female donated peripheral blood mononuclear cells (PBMC). Her PBMCs were reprogrammed with human OKSM (OCT3/4, KLF4 SOX2, and c-MYC) transcription factors by the non-integrating episomal vector system. Immunocytochemistry for pluripotency markers confirmed the pluripotency of transgene-free iPSCs. Their ability to differentiate spontaneously three germ layers in vitro is also confirmed. The iPSC line displayed a normal karyotype. This model can be used as a control in pathological mechanism studies.

[The diagnosis and surgical management for intramedullary spinal cord cavernous angioma].

OBJECTIVE: The clinical diagnosis and surgical management of intramedullary spinal cord cavernous angioma were discussed. METHOD: Total 19 patients with intramedullary cavernous angioma were analyzed retrospectively on the clinical manifestation, radiographic feature, diagnosis and differentiation, surgical technique and caution. Of all the 19 patients, averaging 38.7 years old, 14 were male and 5 were female. Nine patients were followed. RESULT: All the 19 patients pathologically diagnosed with spinal cord cavernous angioma got good surgical results, besides one patient showed loss of proprioception. Nine patients were followed up and all demonstrated improvement on neurological function. CONCLUSION: The clinical symptom of most of the patients with spinal cord cavernous angioma presented mildly at onset, but deteriorated gradually because of repeated prehemorrhage. Since the lesion showed some characteristic in MRI, MRI examination was regarded as an important diagnostic tool. Dissection should be done between the tumor and the gliosis during the surgical procedure, special attention should be paid to avoiding tumor residual. It was not necessary to aggressively evacuate the hematoma derived from tumor hemorrhage, which extended along the central canal up and down, except obvious occupied syndrome exited.

Surgical Outcomes of Spinal Cord Intramedullary Cavernous Malformation: A Retrospective Study of 83 Patients in a Single Center over a 12-Year Period.

OBJECTIVE: Spinal cord intramedullary cavernous malformation (SICM) is kind of rare vascular disease, and the therapeutic strategy is still under debate. The purpose of this article is to analyze outcome of SICM surgical resection and to find the possible factors indicating a better outcome. METHODS: A retrospective analysis of 83 patients with SICM in a single center from 2005 to 2017 was performed. Neurologic status was assessed using the McCormick Scale. Clinical information was collected and analyzed using multivariate logistic regression analysis. RESULTS: Eighty patients with SICM were included, 48% of whom were male (n = 40). The mean age was 39.0 years; 7% of patients (n = 6) had a family history and 4% of patients (n = 3) had multiple lesions; and 41% (n = 34) were found with definite hemorrhage. Before surgery, neurologic status of the patients was 43.4%, 31.3%, 13.3%, and 12.0% in grades I (n = 36), II (n = 26), III (n = 11), and IV (n = 10), respectively. Sixty-three patients received long-term follow-up, of whom 19 improved, 39 remained in stable condition, and 5 deteriorated. Patients with duration of symptoms less than 3 months showed a higher improved outcome rate than those with duration longer than 3 months. CONCLUSIONS: The finding suggests that if total resection of SICM is achievable, surgical therapy could be considered to avoid risks of severe complications followed by lesion bleeding. Early microsurgical resection (usually within 3 months) for patients with SICM can lead to better clinical outcomes.

A novel functional polymorphism of GFAP decrease glioblastoma susceptibility through inhibiting the binding of miR-139.

Glioblastoma (GBM) is the most commonly diagnosed solid tumor outside the central nervous system. However, genetic factors underlying GBM remain largely unclear. Previous studies indicated that Glial fibrillary acidic protein (GFAP) might play an important role in the aggressiveness of GBM and also contributed to its poor overall survival. The present study aims to test (1) the associations between GFAP single nucleotide polymorphisms (SNPs) and GBM cells chemoresistance and metastasis, and (2) the molecular mechanism accounting for their effects. Four tagging SNPs of GFAP were initially genotyped in 667 subjects and the significant SNP was further analyzed via online bioinformatical tools. SNP rs11558961 was found to be significantly associated with GBM susceptibility. It was predicted to influence microRNA(miR)-139 binding to 3'UTR of GFAP gene. In functional experiments, we found that cells transfected with rs11558961 G-allele constructs had lower baseline luciferase activities and were more responsive to miR-139 changes, compared to C-allele constructs. Moreover, rs11558961 C>G variant reduced the chemoresistance of GBM cells and migration capability. In conclusion, rs11558961 might influence the chemoresistance and progression of GBM cells via promoting the binding of miR-139, ultimately decrease the susceptibility of GBM. This investigation will shed light on the optimizing for clinical trial design and individualizing of therapeutic plans.

[Diagnosis and treatment of spinal cord hemangioblastoma].

OBJECTIVE: To study the diagnosis and treatment of spinal cord hemangioblastoma. METHOD: The clinical data of 42 patients with spinal cord hemangioblastoma who were operated on between 1997 and 2005 were analyzed. RESULT: Spinal cord hemangioblastoma mostly showed space occupying lesions with clear boundary and Dd-DTPA homogenous enhancement by MRI. All the 42 patients underwent complete excision. 27 patients showed improvement of their symptoms, the 6 patients failed to show any change, and neurological deficits were aggravated in the 5 patients. CONCLUSION: MRI and DSA are helpful in qualitative and localized diagnoses of the spinal cord hemangioblastoma. Surgical outcomes are favorable.

[Comparison of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle puncture: in vitro experiment on a cadaveric lumbar trunk specimen].

OBJECTIVE: To compare the accuracy and operating features of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle punctures. METHODS: A specimen of cadaveric lumbar trunk underwent lumbar pedicle punctures at the levels of L3, L4, and L5 under the guidance of the 3D C-arm fluoroscopy-based and CT-based navigation systems. During the procedure C-arm fluoroscopy was used to monitor the accuracy of the puncture. Generally, in comparison with the 3D C-arm fluoroscopy-based navigation system, the best operation route and protocol could be drawn up pre-operatively, matched registration needed to be renewed for each vertebra, and the images thus obtained were of high quality in CT-based navigation. RESULTS: Both navigation systems had excellent accuracy in the guidance of lumbar pedicle punctures, and had different operating features. CONCLUSION: Both navigation systems had its special advantages. The operating process of the 3D C-arm fluoroscopy-based navigation system was more convenient and rapid, and suitable for percutaneous vertebral puncture. CT based navigation system had clearer pictures, especially for the osteoporotic vertebral bodies, and it had less requirements for the equipments.

The Molecular Feature of HOX Gene Family in the Intramedullary Spinal Tumors.

STUDY DESIGN: The expression of HOXB13 and HOXA9 proteins was detected. OBJECTIVE: The purpose of this study was to investigate the molecular signature of spinal ependymoma (EPN) and astrocytoma, 2 most common types of intramedullary spinal tumor. SUMMARY OF BACKGROUND DATA: Intramedullary spinal tumor is unusual. It leads to high neurological morbidity and mortality without treatment. Till now, its molecular feature has been elucidated up to a little extent. METHODS: A total of 37 cases of spinal EPN, including 12 myxopapillary EPNs (MEPNs), 18 classic EPNs, and 7 anaplastic EPNs, and another 12 cases of astrocytoma were selected for this study. Immunohistochemical analysis of a large cohort of patients providing clinical tumor samples was performed to compare the expression of HOXB13 and HOXA9 not only between spinal EPN and astrocytoma but also among all 3 World Health Organization grades of spinal EPN. RESULTS: The results showed that HOXB13 and HOXA9 were selectively expressed in spinal EPN instead of astrocytoma. Furthermore, we found the strongest positive response of HOXB13 in MEPN whereas that of HOXA9 was ubiquitously detected in all subgroups of EPN. CONCLUSION: Both specificity and sensitivity of HOXB13 in MEPN indicated that HOXB13 might be a diagnostic marker to distinguish MEPN from other 2 types of EPN and a promising therapeutic target for MEPN. The strong immunoreactivity of HOXA9 in spinal EPN suggested an indispensable role in the progression of spinal EPN, and further research on its molecular function will provide new clues for the development of treatment options. LEVEL OF EVIDENCE: N /A.

MicroRNA-494 improves functional recovery and inhibits apoptosis by modulating PTEN/AKT/mTOR pathway in rats after spinal cord injury.

Multiple cellular, molecular, and biochemical changes contribute to the etiology and treatment outcome of contusion spinal cord injury (SCI). MicroRNAs (miRNAs) aberrant expression have been found after SCI in recent studies. However, little is known about the functional significance of the unique role of miRNAs in SCI. Here, we established a rat SCI model and performed the miRNA microarray to analyze miRNAs expression at different times post-SCI. Microarray data revealed that 14 miRNAs were upregulated and 46 miRNAs were downregulated by 2 times compared with sham rat spinal cords, and miR-494 was one of the miRNAs being most significantly downregulated. Subsequently, we investigated miR-494 function and found that upregulation of miR-494 by agomir-494 improves functional recovery, reduces lesion size and inhibits apoptotic cell in rats following SCI. Moreover, our data showed that miR-494 suppresses phosphatase and tensin homolog (PTEN), a negative regulator of AKT/mTOR pathway, through directly targeting its 3'-UTR in BV-2 cells. Most importantly, we demonstrated that overexpression of miR-494 activates AKT/mTOR signaling pathway via inhibiting PTEN expression in rat SCI model. These findings suggested that miR-494 harbored the protective effect after SCI by modulating PTEN/AKT/mTOR pathway in rats and it is a potential candidate for SCI therapeutics.

[Choice of the surgical approach to petroclival tumor].

OBJECTIVE: To discuss the reasonable choice of the surgical approach to petroclvial tumors. METHODS: The clinical data of consecutive 53 patients with the petroclival tumors, treated from June 2002 to June 2004, were reviewed to compare the different surgical approaches to pertroclival region. RESULT: Subtemporal transtentorial approach were used in 11 patients, suboccipital retrosigmoid approach in 12 patients, (transzygomatic or orbitozygomatic) frontotemporal (pterional) approach in 12 patients, presigmoid sinus approach in 2 patients, subtemporal and retrosigmoid sinus combined approach in 7 patients, subtemporal anterior petrosal extradural approach in 7 patients and extended transfrontal base extradural approach in 2 patients. Of all patients in this group, total tumor removal was achieved in 32 patients, subtotal in 9, largely partial in 12. The new cranial nerve deficit took place in 16 patients postoperatively, two patients died from coma and serious pneumonia. CONCLUSIONS: Using perfect microsurgical technique, conventional surgical approaches on petroclival region such as suboccipital retrosigmoid approach, subtemporal transtentorial approach can be suitable for most petroclival tumor with the help of neuro-navigation and neuro-endoscopy. To the epidural tumor on petroclival region, the epidural approach should be used with less invasion to the brain tissue. And to the giant petroclival tumor, the combined-tentorial approach can provide an excellent access and exposure to the tumor.

Identification of dysregulated miRNAs and their regulatory signature in glioma patients using the partial least squares method.

Using microarray data, the present study identified differentially expressed microRNAs (miRNAs) and evaluated their regulatory characteristics in high-grade glioma patients, with the aim to further the understanding into the underlying etiology of the condition. Previously, studies have generally implemented regression or variance analysis, which ignores various background biological factors. However, in the present study, analysis was performed with microarray data collected from the Gene Expression Omnibus database using a partial least squares-based method, which is more sensitive in handling microarray data. Among the six identified differentially expressed miRNAs, hsa-miR-21 and hsa-miR-612 have been previously reported to be associated with glioma. In addition, the remaining miRNAs, hsa-miR-4680, hsa-miR-1908, hsa-miR-4656 and hsa-miR-4467, may also contribute to glioma progression since they are all associated with the tumorigenesis of other types of cancer. Moreover, the expression levels of hsa-miR-1908, hsa-miR-4656 and hsa-miR-4680 have been identified to significantly correlate with the survival rate. Enrichment analysis of the dysregulated target genes revealed that the selected miRNAs primarily affect biological processes in the nervous system and the protein phosphorylation process. Therefore, the results may offer a new understanding into the pathogenesis of high-grade glioma.

Knockdown of immature colon carcinoma transcript-1 inhibits proliferation of glioblastoma multiforme cells through Gap 2/mitotic phase arrest.

"Glioblastoma multiforme" (GBM) is the frequent form of malignant glioma. Immature colon carcinoma transcript-1 (ICT1) is essential for cell vitality and mitochondrial function and has been recognized in several human cancers. In the study reported here, we attempted to evaluate the functional role of ICT1 in GBM cells. Lentivirus-mediated RNA interference (RNAi) was applied to silence ICT1 expression in human GBM cell lines U251 and U87. Cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony-formation assays. Cell-cycle progression was determined by flow cytometry with propidium iodide staining. The results revealed that lentivirus-mediated short hairpin RNA (shRNA) can specifically suppress the expression of ICT1 in U251 and U87 cells. Functional investigations proved for the first time, as far as we are aware, that ICT1 knockdown significantly inhibited the proliferation of both cell lines. Moreover, the cell cycle of U251 cells was arrested at Gap 2 (G2)/mitotic (M) phase after ICT1 knockdown, with a concomitant accumulation of cells in the Sub-Gap 1 (G1) phase. This study highlights the crucial role of ICT1 in promoting GBM cell proliferation, and provides a foundation for further study into the clinical potential of lentivirus-mediated silencing of ICT1 for GBM therapy.

p53 inhibition provides a pivotal protective effect against ischemia-reperfusion injury in vitro via mTOR signaling.

Tumor suppressor p53 has recently been reported to have numerous functions independent of tumorigenesis, including neuronal survival during ischemia. The mammalian target of rapamycin (mTOR) signaling pathway plays a central role in the regulation of metabolism, cell growth, development, and cell survival. Our recent work has demonstrated the neuroprotective effects of the mTOR pathway. Considering that p53 is also an important regulator of mTOR, to further clarify the role of p53 and the mTOR signaling pathway in neuronal ischemic-reperfusion injury, we used mouse primary mixed cultured neurons with an oxygen glucose deprivation (OGD) model to mimic an ischemic-reperfusion injury in vitro. A lentiviral system was also used to inhibit or overexpress p53 to determine whether p53 alteration affects OGD and reperfusion injury. Our results show that activated p53 was induced and it suppressed mTOR expression in primary mixed cultured neurons after OGD and reperfusion. Inhibiting p53, using either a chemical inhibitor or lentiviral-mediated shRNA, exhibited neuroprotective effects in primary cultured neurons against OGD and reperfusion injury through the upregulation of mTOR activity. Such protective effects could be reversed by rapamycin, an mTOR inhibitor. Conversely, p53 overexpression tended to exacerbate the detrimental effects of OGD injury by downregulating mTOR activity. These results suggest that p53 inhibition has a pivotal protective effect against an in vitro ischemia-reperfusion injury via mTOR signaling and provides a potential and promising therapeutic target for stroke treatment.