The maintenance of cellular homeostasis involves the participation of multiple organelles. These organelles are associated in space and time, and either cooperate or antagonize each other with regards to cell function. Crosstalk between organelles has become a significant topic in research over recent decades. We believe that signal transduction between organelles, especially the endoplasmic reticulum (ER) and mitochondria, is a factor that can influence the cell fate. As the cellular center for protein folding and modification, the endoplasmic reticulum can influence a range of physiological processes by regulating the quantity and quality of proteins. Mitochondria, as the cellular “energy factory,” are also involved in cell death processes. Some researchers regard the ER as the sensor of cellular stress and the mitochondria as an important actuator of the stress response. The scientific community now believe that bidirectional communication between the ER and the mitochondria can influence cell death. Recent studies revealed that the death signals can shuttle between the two organelles. Mitochondria-associated membranes (MAMs) play a vital role in the complex crosstalk between the ER and mitochondria. MAMs are known to play an important role in lipid synthesis, the regulation of Ca2+ homeostasis, the coordination of ER-mitochondrial function, and the transduction of death signals between the ER and the mitochondria. Clarifying the structure and function of MAMs will provide new concepts for studying the pathological mechanisms associated with neurodegenerative diseases, aging, and cancers. Here, we review the recent studies of the structure and function of MAMs and its roles involved in cell death, especially in apoptosis.
Meningeal carcinomatosis (MC) is characterized by diffuse infiltration of tumor cells in meninges. There is no tumor mass in the brain and parenchyma of the spinal cord. MC is divided into primary and metastatic types. MC cases were previously diagnosed postoperatively or at autopsy. Recent advances in spinal abbreviation cytology and imaging have led to increase in number of reported cases. In this study, we discuss the manifestations of MC patients based on magnetic resonance imaging (MRI) findings, as well as the correlation between the manifestations and pathology. MC was confirmed in all three cases by lumbar puncture and gadopentetate dimeglumine-enhanced magnetic resonance imaging. Due to different primary diseases, the patients had specific imaging manifestations. Enhanced MRI examination is extremely sensitive for detecting abnormalities in meninges, which plays a very important role in the diagnosis of MC. Since meninges of some MC patients cannot be enhanced, the enhanced MRI examination cannot be replaced by conventional cerebrospinal abbreviation examination. Attribute to the diversity of MR contrast agents, which could provide higher lesion conspicuity and enhances lesion detection, there may be some more choices to improve the detection rate of MC patients and prolong their survival lifetime.
In this paper we try to find out the importance of legitimacy across different stages of corporate life cycles. We introduce the concept of ties intensity and develop a conceptual framework showing that at the enterprise's different development stages, how the two different kinds of ties intensity will affect the legitimacy types. Our research is devoted to find out what kind of effect will different development stages have on legitimacy. We find that in enterprise creation period, the strength of market ties has positive effect on the legitimacy, but the strength of government ties has no significant effect on it; In the early growth period of enterprises, the strength of market ties has no significant effect on the legitimacy, but the strength of government ties has positive effect it; In the mature period of the enterprise, the strength of market ties has positive effect on the legitimacy, the strength of government ties has no significant effect on it.
Ataxia telangiectasia mutated (ATM) gene is critical in the process of recognizing and repairing DNA lesions and is related to invasion and metastasis of malignancy. The incidence rate of papillary thyroid cancer (PTC) has increased for several decades and is higher in females than males. In this study, we want to investigate whether ATM polymorphisms are associated with gender-specific metastasis of PTC. 358 PTC patients in Northern China, including 109 males and 249 females, were included in our study. Four ATM single nucleotide polymorphisms (SNPs) were genotyped using Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS). Association between genotypes and the gender-specific risk of metastasis was assessed by odds ratios (OR) and 95% confidence intervals (CI) under the unconditional logistic regression analysis. Significant associations were observed between rs189037 and metastasis of PTC in females under different models of inheritance (codominant model:OR=0.15, 95% CI 0.04–0.56,P=0.01for GA versus GG andOR=0.08, 95% CI 0.01–0.74,P=0.03for AA versus GG, resp.; dominant model:OR=0.49, 95% CI 0.25–0.98,P=0.04; overdominant model:OR=0.47, 95% CI 0.25–0.89,P=0.02). However, no association remained significant after Bonferroni correction. Our findings suggest a possible association between ATM rs189037 polymorphisms and metastasis in female PTCs.
Iron is a trace metal element that is essential for the survival of cells and parasites. The role of iron in cerebral toxoplasmosis (CT) is still unclear. Deferiprone (DFP) is the orally active iron chelator that binds iron in a molar ratio of 3:1 (ligand:iron) and promotes urinary iron excretion to remove excess iron from the body. The aims of this experiment were to observe the alterations in iron in brains with Toxoplasma gondii (T. gondii) acute infections and to investigate the mechanism of ferroptosis in CT using DFP. We established a cerebral toxoplasmosis model in vivo using TgCtwh3, the dominant strains of which are prevalent in China, and treated the mice with DFP at a dose of 75 mg/kg/d. Meanwhile, we treated the HT-22 cells with 100 μM DFP for half an hour and then infected cells with TgCtwh3 in vitro. A qRT-PCR assay of TgSAG1 levels showed a response to the T. gondii burden. We used inductively coupled plasma mass spectrometry, an iron ion assay kit, Western blot analysis, glutathione and glutathione disulfide assay kits, a malonaldehyde assay kit, and immunofluorescence to detect the ferroptosis-related indexes in the mouse hippocampus and HT-22 cells. The inflammatory factors interferon-γ, tumor necrosis factor-α, transforming growth factor-β, and arginase 1 in the hippocampus and cells were detected using the Western blot assay. Hematoxylin and eosin staining, electron microscopy, and the Morris water maze experiment were used to evaluate the brain injuries of the mice. The results showed that TgCtwh3 infection is followed by the activation of ferroptosis-related signaling pathways and hippocampal pathological damage in mice. The use of DFP led to ferroptosis resistance and attenuated pathological changes, inflammatory reactions and T. gondii burden of the mice, prolonging their survival time. The HT-22 cells with TgCtwh3 activated the ferroptosis pathway and was inhibit by DFP in vitro. In TgCtwh3-infected cells, inflammatory response and mitochondrial damage were severe, but these effects could be reduced by DFP. Our study elucidates the mechanism by which T. gondii interferes with the host's iron metabolism and activates ferroptosis, complementing the pathogenic mechanism of CT and further demonstrating the potential value of DFP for the treatment of CT.
Nucleotide-binding oligomerization domain protein 1 (NOD1) is one of the innate immune receptors that has been associated with tumorigenesis and abnormally expressed in various cancers. However, the role of NOD1 in Glioblastoma Multiforme (GBM) has not been investigated. We used the Tumor Immune Estimate Resource (TIMER) database to compare the differential expression of NOD1 in various tumors. NOD1 expression in GBM was further validated in the GEO database, and the survival of NOD1 was assessed by the Kaplan–Meier method. Clinical samples were collected to validate NOD1 expression. GSEA was carried out to expound on NOD1-related pathways involved in GBM. NOD1 co-expression and enrichment analysis were performed using the Linked Omics database and R software. The relationship between immune infiltrates and NOD1 expression was assessed by TIMER. Besides, the correlation between NOD1 and immune signatures (immunomodulators and chemokine) was evaluated by TISIDB. We found that NOD1 expression was significantly upregulated in GBM patients, and higher expression of NOD1 was associated with a poor prognosis. GSEA and enrichment analysis revealed that NOD1 might play a vital role in immune response and GBM progression. TIMER analysis showed a positive correlation between NOD1 expression and 17 types of tumor-infiltrating immune cells. Moreover, NOD1 expression was positively correlated with the expression of chemokine and immunomodulators in GBM. Overall, our findings suggest that NOD1 is a promising prognostic biomarker and is associated with immune cell infiltration in GBM, making it a potential diagnostic biomarker for this aggressive brain cancer.