Knock-down of PGM1 inhibits cell viability, glycolysis, and oxidative phosphorylation in glioma under low glucose condition via the Myc signaling pathway.

PGM1 is an essential enzyme for glucose metabolism and is involved in cell viability, proliferation, and metabolism. However, the regulatory role of PGMI in glioma progression and the relation between gliomas and PGM1 expression are still unclear. This study aimed to explore the role of PGM1 in glycolysis and oxidative phosphorylation in glioma. Correlation and enrichment analyses of PGM1 in glioma cells were explored in TCGA database and two hospital cohorts. The cell viability, glycolysis, and oxidative phosphorylation were investigated in PGM1 knock-down and overexpression situations. Higher PGM1 expression in glioma patients was associated with a poor survival rate. However, knock-down of PGM1 reduced glioma cell viability, glycolysis, and oxidative phosphorylation under low glucose condition. Moreover, it suppressed tumor growth in vivo. On the other hand, PGM1 overexpression promoted glioma cell viability, glycolysis, and oxidative phosphorylation under low glucose condition by a Myc positive feedback loop. Glioma patients with higher PGM1 expression were associated with poor survival rates. Additionally, PGM1 could promote glioma cell viability, glycolysis, and oxidative phosphorylation under low glucose condition via a myc-positive feedback loop, suggesting PGM1 could be a potential therapeutic target for gliomas.

Establishment and Validation of a Prognostic Immune Signature in Neuroblastoma.

BACKGROUND: Neuroblastoma (NBL) is the most common extracranial solid tumor in childhood, and patients with high-risk neuroblastoma had a relatively poor prognosis despite multimodal treatment. To improve immunotherapy efficacy in neuroblastoma, systematic profiling of the immune landscape in neuroblastoma is an urgent need. METHODS: RNA-seq and according clinical information of neuroblastoma were downloaded from the TARGET database and GEO database (GSE62564). With an immune-related-gene set obtained from the ImmPort database, Immune-related Prognostic Gene Pairs for Neuroblastoma (IPGPN) for overall survival (OS) were established with the TARGET-NBL cohort and then verified with the GEO-NBL cohort. Immune cell infiltration analysis was subsequently performed. The integrated model was established with IPGPN and clinicopathological parameters. Immune cell infiltration was analyzed with the XCELL algorithm. Functional enrichment analysis was performed with clusterProfiler package in R. RESULTS: Immune-related Prognostic Gene Pairs for Neuroblastoma was successfully established with seven immune-related gene pairs (IGPs) involving 13 unique genes in the training cohort. In the training cohort, IPGPN successfully stratified neuroblastoma patients into a high and low immune-risk groups with different OS (HR=3.92, P = 2 × 10-8) and event-free survival (HR=3.66, P=2 × 10-8). ROC curve analysis confirmed its predictive power. Consistently, high IPGPN also predicted worse OS (HR=1.84, P = .002) and EFS in validation cohort (HR=1.38, P = .06) Moreover, higher activated dendritic cells, M1 macrophage, Th1 CD4+, and Th2 CD4+ T cell enrichment were evident in low immune-risk group. Further integrating IPGPN with age and stage demonstrated improved predictive performance than IPGPN alone. CONCLUSION: Herein, we presented an immune landscape with IPGPN for prognosis prediction in neuroblastoma, which complements the present understanding of the immune signature in neuroblastoma.

Tripartite motif containing protein 37 involves in thrombin stimulated BV-2 microglial cell apoptosis and interleukin 1ß release.

Intracerebral hemorrhage (ICH) is the most common of stroke with high mortality and severe morbidity. Peroxisome proliferator-activated receptor gamma (PPARγ) plays a neuronprotective role in ICH. In the current study, TRIM37 mRNA expression in peripheral blood mononuclear cells (PBMCs) was found to be increased in ICH patients compared to that in healthy controls (n = 15). TRIM37 bound to PPARγ and enhanced its ubiquitination in mouse microglial BV-2 cell line. According to previous studies, thrombin is produced in the brain instantaneously after ICH and triggers the activation of microglia. Here, thrombin induced TRIM37 expression, cell apoptosis and interleukin-1ß (IL-1ß) release in BV-2 cells, while TRIM37 knockdown partially reversed the effects of thrombin on BV-2 cells. TRIM37 overexpression showed similar effects as thrombin on BV-2 cells, and PPARγ agonist rosiglitazone abolished the effects of TRIM37. In summary, TRIM37 involved in apoptosis and IL-1ß release in BV-2 microglia by regulating PPARγ ubiquitination. The present data established a potential biological role of TRIM37 in ICH-induced brain damage and may provide insight into the development of therapy strategies for ICH.

GDF15 regulated by HDAC2 exerts suppressive effects on oxygen-glucose deprivation/reoxygenation-induced neuronal cell pyroptosis via the NLRP3 inflammasome.

Background: Pyroptosis, inflammation-related programed cell death mediated by NLRP3 inflammasome, is involved in the pathogenesis of cerebral hypoxic-ischemic injury. Our study aims to explore the biological role of growth differentiation factor (GDF)15 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced neuronal pyroptosis. Methods: HT22 neurons were subjected to OGD/R to simulate cerebral hypoxic-ischemic injury. Cells were transfected with plasmids to overexpress GDF15, or lentiviral-based shRNAs constructs to silence GDF15. ELISA assay was used to detect GDF15, IL-1ß, IL-18, and neuron specific enolase (NSE) levels. Cell pyroptosis was measured by flow cytometery. Chromatin immunoprecipitation assay was used to detect interaction of H3K27ac with GDF15 promoter. GDF15, NLRP3, Caspase-1 p20 and GSDMD-N expressions were measured by Western blotting. Results: Patients with malignant middle cerebral artery infarction showed decreased GDF15, but increased IL-1ß, IL-18, and NSE levels in serum compared to healthy controls. OGD/R treatment caused significant increases in the levels of IL-1ß, IL-18 and NSE, percentages of pyroptotic cells, and expressions of NLRP3, Caspase-1 p20, and GSDMD in HT22 cells, which were markedly reversed by GDF15 overexpression. However, GDF15 knockdown resulted in neuronal injury similar to those observed in OGD/R treatment. The GDF15 knockdown-induced effects were counteracted by treatment with NLRP3 inhibitor. OGD/R decreased the enrichment of H3K27ac in the promoter of GDF15 to down-regulate GDF15, but was compromised by co-treatment with HDAC2 inhibitor. Conclusion: Our data demonstrates that GDF15 attenuates OGD/R-induced pyroptosis through NLRP3 inflammasome. HDAC2 is involved in mediating OGD-induced GDF15 down-regulation via H3K27ac modification. GDF15 overexpression and HDAC2 inhibition hold potential as useful therapeutic strategies for neuroprotection.

Network pharmacology and molecular-docking-based strategy to explore the potential mechanism of salidroside-inhibited oxidative stress in retinal ganglion cell.

BACKGROUND: Salidroside (SAL), the main component of Rhodiola rosea extract, is a flavonoid with biological activities, such as antioxidative stress, anti-inflammatory, and hypolipidemic. In this study, the potential therapeutic targets and mechanisms of SAL against oxidative stress in retinal ganglion cells (RGCs) were investigated on the basis of in-vitro experiments, network pharmacology, and molecular docking techniques. METHODS: RGC oxidative stress models were constructed, and cell activity, reactive oxygen species (ROS), and apoptosis levels were examined for differences. The genes corresponding to rhodopsin, RGCs, and oxidative stress were screened from GeneCards, TCMSP database, and an analysis platform. The intersection of the three was taken, and a Venn diagram was drawn. Protein interactions, GO functional enrichment, and KEGG pathway enrichment data were analyzed by STRING database, Cytohubba plugin, and Metascape database. The key factors in the screening pathway were validated using qRT-PCR. Finally, molecular docking prediction was performed using MOE 2019 software, molecular dynamic simulations was performed using Gromacs 2018 software. RESULTS: In the RGC oxidative stress model in vitro, the cell activity was enhanced, ROS was reduced, and apoptosis was decreased after SAL treatment. A total of 16 potential targets of oxidative stress in SAL RGCs were obtained, and the top 10 core targets were screened by network topology analysis. GO analysis showed that SAL retinal oxidative stress treatment mainly involved cellular response to stress, transcriptional regulatory complexes, and DNA-binding transcription factor binding. KEGG analysis showed that most genes were mainly enriched in multiple cancer pathways and signaling pathways in diabetic complications, nonalcoholic fatty liver, and lipid and atherosclerosis. Validation by PCR, molecular docking and molecular dynamic simulations revealed that SAL may attenuate oxidative stress and reduce apoptosis in RGCs by regulating SIRT1, NRF2, and NOS3. CONCLUSION: This study initially revealed the antioxidant therapeutic effects and molecular mechanisms of SAL on RGCs, providing a theoretical basis for subsequent studies.

Exosomal LncRNA TM7SF3-AU1 Aggravates White Matter Injury via MiR-702-3p/SARM1 Signaling After Subarachnoid Hemorrhage in Rats.

Subarachnoid hemorrhage (SAH) is a devastating disease associated with a high mortality and morbidity. Exosomes have been considered as a potential therapeutic target for SAH. However, the effect of exosomes in SAH remains to be elucidated. In this study, we focused on investigating the effect of plasma exosomal lncRNA TM7SF3-AU1 in white matter injury after SAH. The SAH model was established by means of endovascular perforation. Exosomes were extracted from rat plasma samples. The expression of RNAs in the exosomes was detected by the transcriptomic microarray. Differentially expressed circRNA, lncRNA, and mRNA were obtained. The ceRNA network showed that the lncRNA TM7SF3-AU1 and miR-702-3p were closely associated with SARM1. Knocking down TM7SF3-AU1 promoted the expression of miR-702-3p and suppressed the expression of SARM1, and knocking down TM7SF3-AU1 also attenuated white matter injury after SAH. In addition, knocking down TM7SF3-AU1 improved the neurological deficits in locomotion, anxiety, learning, memory, and electrophysiological activity after SAH. Mechanistically, TM7SF3-AU1 was able to absorb miR-702-3p, which directly bind the SARM1 mRNA. Furthermore, the white matter injury attenuated by knockdown of TM7SF3-AU1 was partially reversed by the miR-702-3p antagomir in SAH rats. Taken together, this study showed that TM7SF3-AU1 acts as a sponge for miR-702-3p, reducing the inhibitory effect of miR-702-3p on SARM1, resulting in increased SARM1 expression and thus leading to white matter injury after SAH. Our study provides new insights into exosome-associated white matter injury. It also highlights TM7SF3-AU1 as a potential therapeutic target for white matter injury after SAH.

Relationship of uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide with acute cerebral infarction.

OBJECTIVE: The objective was to study the relationship of serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels with acute cerebral infarction. METHODS: A total of 96 acute cerebral infarction patients were divided into small, middle, and large infarct size groups based on the size of infarct focus and mild, moderate, and severe infarction groups based on the evaluation criteria of nerve defect degree. In addition, 75 healthy people were selected as the control group. The serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels of all subjects were detected. RESULTS: The serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels in the acute cerebral infarction group were significantly higher than the control group (p<0.05). Compared with the small infarct size group, each index in middle and large infarct size groups was significantly increased (p<0.05). Compared with the middle infarct size group, each index in the large infarct size group was significantly increased (p<0.05). The serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels in moderate and severe infarction groups were significantly higher than the mild infarction group (p<0.05). Compared with the moderate infarction group, each index in the severe infarction group was significantly increased (p<0.05). The serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels were positively correlated with the infarct size and nerve defect degree (p<0.05). CONCLUSIONS: The serum uric acid, C-reactive protein, and N-terminal pro-B-type natriuretic peptide levels are closely correlated with the occurrence and development of acute cerebral infarction. The detection of these indexes has significance for understanding the severity of acute cerebral infarction, guiding the individual treatment scheme, and evaluating the prognosis.

Knocking down of Polo-like kinase 2 inhibits cell proliferation and induced cell apoptosis in human glioma cells.

AIMS: Polo-like kinase 2 (PLK2) belongs to a family of serine/threonine kinases, and it is involved in tumorigenesis. The present study aimed to explore the potential clinical significance of PLK2 in the development of gliomas. MAIN METHODS: Immunohistochemistry (IHC) was performed to detect the expression of PLK2 in glioma tissues. Cell proliferation and apoptosis were determined by Cell Counting Kit 8 (CCK8) and flow cytometry analysis, respectively. KEY FINDINGS: PLK2 expression gradually increased with the degree of glioma malignancy. High PLK2 expression was associated with a poor prognosis in glioma. Short hairpin RNAs targeting PLK2 (shPLK2) inhibited the viability and induced apoptosis of glioma cells, both in vitro and in vivo. Ring finger protein 180 (RNF180), an E3 ubiquitin ligase, interacted with PLK2 and induced the ubiquitination of PLK2. Overexpression of PLK2 in glioma cells significantly inhibited RNF180 upregulation-induced cell apoptosis. The expression level of RNF180 gradually decreased with the degree of glioma malignancy. SIGNIFICANCE: Knocking down of PLK2 may suppress the glioma development through cancer cell proliferation inhibition and cell apoptosis promotion. Furthermore, RNF180 may mediate the ubiquitination of PLK2. The present findings may help improve the clinical management of glioma in the future.

Low Expression of APOB mRNA or Its Hypermethylation Predicts Favorable Overall Survival in Patients with Low-Grade Glioma.

BACKGROUND: This study was performed to explore the clinical and prognostic significance of APOB mRNA expression, DNA methylation and APOB mutation in patients with low-grade glioma (LGG). METHODS: Bioinformatic analysis was conducted using genomic, clinical and survival data from The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) databases. Serum APOB protein levels were measured via immunoturbidimetry in 150 patients with LGG and 100 healthy controls from Hubei General Hospital. RESULTS: There was a negative association between the levels of APOB mRNA and DNA methylation (r=-0.355, P<0.0001) in patients with LGG from the TCGA database. Additionally, LGG patients with low levels of APOB mRNA exhibited better overall survival (OS) than those with high levels of APOB mRNA (HR=0.637, P=0.0085). The survival time of LGG patients with APOB hypermethylation was markedly longer than that of patients with APOB hypomethylation (HR=0.423, P=0.0185). The prognostic significance of APOB mRNA and DNA methylation was also validated with the CGGA cohort, and a similar conclusion was reached. APOB gene mutations were observed in 3% of patients with LGG from the TCGA database, and no association was detected between APOB mutations and OS (P=0.164). Furthermore, the levels of APOB protein were much lower in patients with LGG than in normal individuals (P=0.0022), and the expression of APOB protein was markedly different among groups when stratified by histological type (P<0.0001) and histological-molecular classification (P<0.0001). CONCLUSION: APOB mRNA expression is negatively regulated by DNA methylation in patients with LGG. Low expression or hypermethylation of APOB might predict relatively favorable survival in patients with LGG.

Low expression or hypermethylation of PLK2 might predict favorable prognosis for patients with glioblastoma multiforme.

BACKGROUND: As the most aggressive brain tumor, patients with glioblastoma multiforme (GBM) have a poor prognosis. Our purpose was to explore prognostic value of Polo-like kinase 2 (PLK2) in GBM, a member of the PLKs family. METHODS: The expression profile of PLK2 in GBM was obtained from The Cancer Genome Atlas database. The PLK2 expression in GBM was tested. Kaplan-Meier curves were generated to assess the association between PLK2 expression and overall survival (OS) in patients with GBM. Furthermore, to assess its prognostic significance in patients with primary GBM, we constructed univariate and multivariate Cox regression models. The association between PLK2 expression and its methylation was then performed. Differentially expressed genes correlated with PLK2 were identified by Pearson test and functional enrichment analysis was performed. RESULTS: Overall survival results showed that low PLK2 expression had a favorable prognosis of patients with GBM (P-value = 0.0022). Furthermore, PLK2 (HR = 0.449, 95% CI [0.243-0.830], P-value = 0.011) was positively associated with OS by multivariate Cox regression analysis. In cluster 5, DNA methylated PLK2 had the lowest expression, which implied that PLK2 expression might be affected by its DNA methylation status in GBM. PLK2 in CpG island methylation phenotype (G-CIMP) had lower expression than non G-CIMP group (P = 0.0077). Regression analysis showed that PLK2 expression was negatively correlated with its DNA methylation (P = 0.0062, Pearson r = -0.3855). Among all differentially expressed genes of GBM, CYGB (r = 0.5551; P < 0.0001), ISLR2 (r = 0.5126; P < 0.0001), RPP25 (r = 0.5333; P < 0.0001) and SOX2 (r = -0.4838; P < 0.0001) were strongly correlated with PLK2. Functional enrichment analysis results showed that these genes were enriched several biological processes or pathways that were associated with GBM. CONCLUSION: Polo-like kinase 2 expression is regulated by DNA methylation in GBM, and its low expression or hypermethylation could be considered to predict a favorable prognosis for patients with GBM.

NLRP3 is Required for Complement-Mediated Caspase-1 and IL-1beta Activation in ICH.

Complement-mediated inflammation plays a vital role in intracerebral hemorrhage (ICH), implicating pro-inflammatory factor interleukin-1beta (IL-1ß) secretion. Brain samples and contralateral hemiencephalon were all collected and detected by Western blot. NLRP3 expression was located by dual immunofluorescence staining at 1, 3, and 5 days post-ICH. Brain water content was examined post-ICH. The neural deficit scores were evaluated by observers blindly. ILs were detected by ELISA. SiRNAs targeting NLRP3 (siNLRP3), siASC, and siControl were injected to inhibit NLRP3 function. To test the complement activation via Nod-like receptor (NLR) family pyrin domain-containing 3 (NLRP3), normal rabbit complement (NRC) was injected with lipopolysaccharide (LPS) to facilitate the complement function. As a result, complement 3a (C3a) and complement 5a (C5a) were upregulated during the ICH-induced neuroinflammation, and ablation of C3 attenuates ICH-induced IL-1ß release. Though the LPS rescues the neuroinflammation in the ICH model, C3 deficiency attenuates the LPS-induced inflammatory effect. The NLRP3 inflammasome was activated after ICH and was located in the microglial cell of the mouse brain, which exhibits a time-dependent manner. However, the number of NLRP3/Iba-1 dual-labeled cells in the C3-/- group is less than that in the WT group in each time course, respectively. IL-1ß and IL-18 released in perihematoma tissue, caspase-1-p20, brain water content, and behavioral outcomes were attenuated in the siNLRP3 and siASC groups than in the siControl and ICH groups. We also found that 5% of complement supplement enhances ICH-induced IL-1ß release, while NLRP3 and ASC inhibition attenuates it. In conclusion, complement-induced ICH neuroinflammation depended on NLRP3 activation, which facilities LPS- and ICH-induced neuroinflammation, and NLRP3 is required for ICH-induced inflammation.