Background Malignant ‘triton’ tumor is an extremely rare subtype of malignant periphery nerve sheath tumors. Clinical diagnosis of malignant triton tumor is difficult before surgery due to its low incidence and the lack of knowledge. Therefore, to describe and summarize the CT imaging characteristics of malignant triton tumor is of great assistance for early and preoperative diagnosis. Case presentation Two cases suspected of MTT by CT scan before operation were closely observed. The diagnosis of malignant triton tumor was eventually confirmed by immunochemical assay, which verified speculation of CT scans. Huge, irregular, well-circumscribed lobulated mass-like shadows can be observed from these patients by CT scans. Besides, heterogeneity of density within the body of tumor was well-established by CT scans, together with linear septum. Meanwhile, CT scans demonstrated that calcifications were remarkable at the margin of tumor body. Conclusions Some CT image features from two cases were presented as a reference for the preoperative consideration of MTT: (i) enormity of mass-like shadow; (ii) presence of well-circumscribed lobulated shape; (iii) septum within the well-defined mass accompanied with hemorrhage, necrosis and cystic changes as well as calcification, especially within neurofibromatosis type 1 patients.
Background Astrocytes mediate brain defense against oxidative stress-induced injury. Silent information regulator 1 (SIRT1) has anti-oxidative stress effects in many diseases and is highly expressed in astrocytes. However, the neuroprotective effects of SIRT1 on astrocytes after cerebral ischemia/reperfusion injury are unclear. Methods Here, we evaluated the effects of SIRT1 in astrocytes after cerebral ischemia/reperfusion injury using oxygen-glucose deprivation/recovery in astrocytes in vitro and middle cerebral artery occlusion in rats in vivo. Results SIRT1 knockdown reduced cell viability, increased oxidative stress, and decreased peroxisome proliferator activated receptor (PPAR)-γ coactivator (PGC)-1α, PPARγ, nuclear factor erythroid 2-related factor 2 (NRF2), heme oxygenase (HO)-1, and NAD(P)H:quinone oxidoreductase-1 (NQO1) expression. Moreover, SIRT1 knockdown also suppressed PGC-1α activity, the PGC-1α/PPARγ interaction, and the PPARγ/peroxisome proliferator-response element (PPRE) interaction. Similarly, in our in vivo experiments, SIRT1 overexpression and PGC-1α or PPARγ knockdown reduced PGC-1α, PPARγ, NRF2, HO-1, and NQO1 protein expression and blocked the PGC-1α/PPARγ interaction. SIRT1 overexpression plus PPARγ knockdown inhibited the interaction of PPARγ with PPRE. NRF2 knockdown blocked NRF2 expression and downstream proteins induced by SIRT1 overexpression. Conclusion Overall, our data indicated that SIRT1 directly mediated the PGC-1α/PPARγ pathway in response to focal cerebral ischemia/reperfusion-induced neurological deficit, providing insights into the treatment of focal cerebral ischemia/reperfusion injury.
The activation of the microglia plays an important role in the neuroinflammation induced by different stimulations associated with Alzheimer’s disease (AD). Different stimulations, such as pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs) and cytokines, trigger a consequence of activation in the microglia with diverse changes of the microglial cell type response in AD. The activation of the microglia is often accompanied by metabolic changes in response to PAMPs, DAMPs and cytokines in AD. Actually, we do not know the distinct differences on the energetic metabolism of microglia when subject to these stimuli. This research assessed the changes of the cell type response and energetic metabolism in mouse-derived immortalized cells (BV-2 cells) induced by a PAMP (LPS), DAMPs (Aβ and ATP) and a cytokine (IL-4) in mouse-derived immortalized cells (BV-2 cells) and whether the microglial cell type response was improved by targeting the metabolism. We uncovered that LPS, a proinflammatory stimulation of PAMPs, modified the morphology from irregular to fusiform, with stronger cell viability, fusion rates and phagocytosis in the microglia accompanied by a metabolic shift to the promotion of glycolysis and the inhibition of oxidative phosphorylation (OXPHOS). Aβ and ATP, which are two known kinds of DAMPs that trigger microglial sterile activation, induced the morphology from irregular to amoebic, and significantly decreased others in the microglia, accompanied by boosting or reducing both glycolysis and OXPHOS. Monotonous pathological changes and energetic metabolism of microglia were observed under IL-4 exposure. Further, the inhibition of glycolysis transformed the LPS-induced proinflammatory morphology and decreased the enhancement of LPS-induced cell viability, the fusion rate and phagocytosis. However, the promotion of glycolysis exerted a minimal effect on the changes of morphology, the fusion rate, cell viability and phagocytosis induced by ATP. Our study reveals that microglia induced diverse pathological changes accompanied by various changes in the energetic metabolism in response to PAMPs, DAMPs and cytokines, and it may be a potential application of targeting the cellular metabolism to interfere with the microglia-mediated pathological changes in AD.
Background: Acute inflammation developed by reactive astrocytes after cerebral ischemia/reperfusion (I/R) injury is important in protecting the resultant lesion. Our previous study demonstrated the abundant expression of DJ-1 in reactive astrocytes after cerebral I/R injury. Here, we show that DJ-1 negatively regulates the inflammatory response by facilitating the interaction between SHP-1 and TRAF6, thereby inducing NLRX1 dissociation from TRAF6. Methods: We used oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro in primary astrocyte cultures and transient middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo to mimic ischemic reperfusion insult. Results: The inhibition of DJ-1 expression increased the expression of the inflammatory cytokines TNF-α, IL-1β, and IL-6. DJ-1 knockdown facilitated the interaction of NLRX1 with TRAF6. However, the loss of DJ-1 attenuated the interaction of SHP-1 with TRAF6. In subsequent experiments, an SHP-1 inhibitor altered the interaction of SHP-1 with TRAF6 and facilitated the interaction of NLRX1 with TRAF6 in DJ-1-overexpressing astrocytes.. Conclusion: This finding suggests that DJ-1 exerts an SHP-1-dependent anti-inflammatory effect and induces the dissociation of NLRX1 and TRAF6 in cerebral I/R injury. Thus, DJ-1 may be an efficacious therapeutic target for the treatment of I/R injury.
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