Folia neuropathologica最新文献

The neuroinflammation is a crucial component of virtually all neurodegenerative disorders, including Alzheimer's disease (AD). The bacterial lipopolysaccharide (LPS), a potent activator of the innate immune system, was suggested to influence or even trigger the neuropathological alterations in AD. LPS-induced neuroinflammation involves changes in transcription of several genes, thus controlling these molecular processes may be a potentially efficient strategy to attenuate the progression of AD. Since genome-wide association studies showed that the majority of AD-related genetic risk factors (AD-GRF) are connected to the immune system, our aim was to identify AD-GRF affected in the hippocampus by LPS-induced systemic inflammatory response (SIR). Moreover, we analysed the role of bromodomain and extraterminal domain (BET) proteins, the readers of the acetylation code, in controlling the transcription of selected AD-GRF in the brain during neuroinflammation. In our study, we used a mouse model of LPS-induced SIR and mouse microglial BV2 cells. JQ1 was used as an inhibitor of BET proteins. The level of mRNA was analysed using microarrays and qPCR. Our data demonstrated that among the established AD-GRF, only the expression of Cd33 was significantly upregulated in the hippocampus during SIR. In parallel, we observed an increase in the expression of Brd4, a BET family member. JQ1 prevented an LPS-evoked increase in Cd33 expression in the hippocampus of mice. Moreover, JQ1 reduced Cd33 expression in BV2 microglial cells stimulated with blood serum from LPS-treated mice. Our study suggests that LPS-evoked SIR may increase Cd33 gene expression in the brain, and inhibition of BET proteins through suppression of Cd33 expression could be a promising strategy in prevention or in slowing down the progression of neuroinflammation and may potentially affect the pathomechanism of AD.

Introduction: Ischemic stroke (IS) is a prevalent disease that poses a significant threat to human life and is responsible for a substantial financial burden. Research has established the crucial role of the miR-17-92 cluster in lung cancer, cardiovascular diseases, and traumatic brain injury. Despite this, few research studies had fully detected the potential of the miR-17-92 cluster as a novel circulating marker for diagnosing IS.

Material and methods: miR-17-92 cluster expression in IS was investigated using GSE117064 dataset via bioinformatics analysis. Moreover, qRT-PCR was conducted to further verify miR-17-92 cluster expression in 58 IS individuals and 50 healthy controls (HCs). These cluster members were examined regarding their potential for detecting and diagnosing IS using the ROC method.

Results: The expression level of serum miR-20a-5p, miR-19a-3p, miR-18a-5p, and miR-19b-3p was considerably lowered in IS in contrast with HC in both the GSE117064 cohort and clinical cohort. Moreover, these four miRNAs had a fair performance in IS detection. Thereafter, a diagnostic model based on these aforementioned four miRNAs was developed by logistic regression, which had an AUC of 0.974 in the ROC curve. This diagnostic module was verified using the GSE117064 dataset. Further analysis demonstrated an increasing level of the aforementioned miRNAs in day-7 IS patients compared with day-1 IS patients.

Conclusions: This research verified the downregulation of the miR-17-92 cluster in IS. This diagnostic model enrolling four cluster members may be a promising biomarker for IS detection.

Cytidine-5'-diphosphocholine (CDP-choline) is a key precursor for the intracellular synthesis of phosphatidylcholine and other phospholipids. Following either intravenous or oral application citicoline (CDP-choline of exogenous origin) undergoes quick decomposition to cytidine and choline, and for this reason it is frequently considered a prodrug. However, upon acute intravenous application in mice citicoline is, on a molar basis, 20 times less toxic than choline. To find out whether cytidine may attenuate toxicity of choline, in the present experiments we compared maximum tolerated doses of single intravenous injections of choline and equimolar mixture of choline and cytidine. We assumed that, if after oral intake a substantial part of citicoline is catabolised already in the intestine and its catabolites enter blood separately, intravenously applied equimolar mixture of cytidine and choline will be markedly less toxic than an equivalent molar dose of choline. However, the maximum tolerated single doses determined in our experiment for choline and equimolar mixture of choline and cytidine were similar. These data suggest that citicoline taken orally is not significantly decomposed in the intestinal lumen, but absorbed to blood as the intact molecule.

Cerebral ischemia/reperfusion causes high disability, recurrence, and mortality. Ischemic stroke is a powerful stimulus that triggers significant microglia activation. Ginsenoside Rb1 (GS-Rb1) has been demonstrated to have neuroprotective effects in the central nervous system. In this study, the effects of GS-Rb1 against cerebral ischemia/reperfusion were explored. A mouse model of middle cerebral artery occlusion (MCAO) was used to mimic the cerebral ischemia/reperfusion. Mice in MCAO + GS-Rb1 groups received 5, 10, or 20 mg/kg GS-Rb1 through intraperitoneal injection. Modified neurological severity scoring (mNSS) showed neurological function, while the open field test tested the anxiety-like behaviors. Cognitive impairment was evaluated by Morris water maze. Protein levels were evaluated by ELISA and Western blot and mRNA levels were analyzed by qRT-PCR. When compared to the MCAO mice, mice in the MCAO + GS-Rb1 group had significantly lower mNSS scores and less brain water content. GS-Rb1 alleviated both cognitive impairment and anxiety and inhibited microglial activation in the cerebral ischemia/reperfusion model. GS-Rb1 enhanced M2-type microglia polarization while inhibiting M1-type microglia polarization. In summary, we observed that GS-Rb1 had neuro-protective effects in a cerebral ischemia/reperfusion mouse model through regulating the microglia polarization.

Lung adenocarcinoma remains one of the most frequent and deadly tumour entities. Early-stage lung adenocarcinoma is extremely difficult to detect and is also easy to recur or metastasize after treatment. Since the new adenocarcinoma classification was presented in 2011, several studies have shown that patients with solid and/or micropapillary (S/MP) predominant patterns showed a worse prognosis. Here we report the case of a 54-year-old woman who was diagnosed with stage Ib lung adenocarcinoma with S/MP components and developed an isolated brain oligometastasis after resection and adjuvant therapy. A craniocerebral operation was performed, combined with radiotherapy and targeted therapy, and the patient eventually achieved a good quality of life. Our work reviews the clinical features of lung cancer complicated with S/MP components, the relationship between MP and epidermal growth factor receptor (EGFR) mutation, as well as treatment strategies for such a patient with postoperative brain oligometastasis of lung adenocarcinoma complicated with EGFR Exon19del mutation.

Introduction: Glioma is one of the most commonly tumours which occurs in the central nervous system and accounts for nearly 80% of brain tumours, with a significantly high mortality and morbidity. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are used as EGFR targeted therapy in various types of solid tumours; however, effective treatment for glioma is still limited. Osimertinib is an irreversible, oral third-generation TKI that targets the mutation at T790M, which causes cancer cells to acquire resistance to drugs. Osimertinib could be effective in the treatment of EGFR mutations with minimal effects on the activity of wild-type EGFR. Absent in melanoma 2 (AIM2) is highly expressed in glioma cells, promoting the maturation of pro-cancer cytokines and contributing to progression of glioma. However, the secretion of pro-cancer cytokines of tumour cells has been regarded as the resistance mechanism to EGFR-TKIs, including osimertinib. A high level of these cytokines also indicates a shorter progression-free survival (PFS). As AIM2 regulates the secretion of pro-cancer cytokines, we thought inhibition of AIM2 may contribute to the therapeutic effect of EGFR-TKIs.

Material and methods: We first established AIM2 inhibition and overexpression in cells. Then, the viability rate of cells was calculated by cell counting kit-8 (CCK-8) method, and apoptotic ratio of cells were measured by flow cytometry. The expression of inflammatory-related genes was detected using quantitative polymerase chain reaction (qPCR), concentrations of inflammatory-related factors were measured using enzyme-linked immunosorbent assay (ELISA). The expression of Wnt/b-catenin and EGFR/Ras/Mitogen-activated protein kinase kinase 1 (MEK) signalling pathway components was detected using western blotting.

Results: We found that inhibition of AIM2 enlarged the effect of osimertinib on the upregulation of inflammatory gene expression and secretion of these genes, increasing apoptosis. In addition, we also found that AIM2 could enhance the effect of osimertinib on reducing the expression of the Wnt/b-catenin and EGFR/Ras/MEK signalling pathways, resulting in the inhibition of cellular proliferation, and exerting an anti-tumour effect. These effects were also observed using in vivo experiments.

Conclusions: AIM2 presents a potential therapeutic target in treatment of glioma.

Alzheimer's disease (AD), the most common contributor to dementia, is a growing global health problem. This study aimed to investigate the role of lemur tyrosine kinase 2 (LMTK2) in AD as well as its relevant mechanism. To establish an in vitro cell model, PC12 cells were challenged with 20 µmol/l Ab 25-35 for 24 h. RT-qPCR and western blot examined LMTK2 mRNA and protein expressions. With the application of CCK-8, TUNEL, iron colorimetric assay kit and DCFH-DA, the viability, apoptosis, Fe 2+ and ROS content in PC12 cells were assessed. Besides, the expressions of oxidative stress-, apoptosis-, ferroptosis- and Nrf2/ARE signalling-related proteins were evaluated with western blot. Moreover, commercial kits examined SOD, MDA and CAT contents. The results manifested that LMTK2 expression was noticeably downregulated in Ab 25-35 -treated PC12 cells. Notably, LMTK2 overexpression exhibited inhibitory effects on oxidative stress, apoptosis and ferroptosis in PC12 cells exposed to Ab 25-35 . The upregulated Nrf2, NQO1 and HO-1 expressions in LMTK2 overexpressed-PC12 cells with Ab 25-35 induction revealed that LMTK2 overexpression could activate the Nrf2/ARE signalling pathway. What is more, a series of cellular experiments further testified that ML385, a specific Nrf2 inhibitor, partly hindered the protective role of LMTK2 overexpression against Ab 25-35 -triggered oxidative stress, apoptosis and ferroptosis in PC12 cells. In conclusion, LMTK2 overexpression alleviated the ferroptosis, oxidant damage and apoptosis in PC12 cells exposed to Ab 25-35 through the activation of the Nrf2/ARE signalling pathway, indicating the potential target of LMTK2 in the treatment of AD.

Introduction: This research hoped to explore the molecular mechanism of neutrophil extracellular traps (NETs) on glioblastoma multiforme (GBM) progression, and develop a promising prognostic signature for GBM based on NETs-related genes (NETGs).

Material and methods: Gene expression data and clinical data of GBM tumour samples were downloaded from TCGA and CGGA databases. NETs-related molecular subtypes were explored by using ConsensusClusterPlus. The NETGs with a prognostic value were identified, and then a prognostic model was constructed using LASSO Cox regression. The predicted performance of the prognostic model was evaluated using TCGA training and CGGA validation cohorts. Moreover, independent prognostic indicators were identified by univariate and multivariate analysis to generate the nomogram model. The sensitivities for antitumor drugs and immunotherapy were predicted. Finally, hub genes in the prognostic model were validated using qPCR analysis.

Results: GBM patients were divided into two molecular subtypes with significant differences in tumour microenvironment (TME) score, survival, and immune infiltration. A NETGs signature was constructed based on seven genes (CPPED1, F3, G0S2, MME, MMP9, MAPK1, and MPO), which had a high value for predicting prognosis. A nomogram was constructed by two independent prognostic factors (age and risk score), which could be used to predict 1-, 2-, and 3-year survival probability of GBM. Patients in the high-risk group were more sensitive to bicalutamide, gefitinib, and dasatinib; patients in the low-risk group were associated with poor response to immunotherapy. The validation of the six genes in the prognostic model was consistent with the results of bioinformatics analysis.

Conclusions: The NETs-based prognostic model and nomogram proposed in this study are promising prognostic prediction tools for GBM, which may provide new ideas for the development of precise tumour targeted therapy.