Cerebrospinal Fluid Neurone-Specific Enolase in Mitochondrial Encephalomyopathies

Whether cerebrospinal fluid (CSF) neurone-specific enolase (NSE) contributes to the diagnosis of mitochondrial encephalomyopathies (MEMs) is unknown. Aim of the present study was thus to assess the validity of CSF-NSE in the diagnosis of MEM. CSF-NSE was determined in 24 controls, aged 28–88 years; and 23 MEM patients, aged 47–81 years. In controls, CSF-NSE was independent of sex (p = 0.849) and age (p = 0.346). Twenty-one MEM patients had clinical CNS involvement and two CNS abnormalities on imaging investigations exclusively. CSF cells were increased in 7, CSF protein in 17, CSF glucose in 1, and CSF lactate in 2 MEM patients. The upper reference limit of CSF-NSE was 14.66 ng/mL. CSF-NSE was elevated in 6 (26%) MEM patients. CSF-NSE was increased in a single MEM patient with subclinical CNS involvement. This study shows that CSF-NSE is elevated in only one quarter of the MEM patients. Determination of CSF-NSE appears to be of minor importance for the assessment of clinical or subclinical CNS involvement in MEM.     

Neuron-specific enolase reflects metabolic activity in mesencephalic neurons of the rat

Numerous studies on the local rate of energy metabolism of various brain regions during development and following experimental manipulation have been conducted using 2-deoxyglucose uptake and cytochrome oxidase (CO) histochemistry, both considered to be reliable indicators of long-term and short-term alterations in neuronal activity, respectively. Another method which has been related to neuronal activity is neuron-specific enolase (NSE) immunohistochemistry. An isoenzyme of enolase, a key element in the glycolytic pathway, NSE is present in neurons and neural-related cells e.g. neuroendocrine cells, pituicytes, and many tumor cells, but not in glia. The distribution on adjacent tissue sections of immunoreactive NSE and histochemically determined CO were mapped in the rat mesencephalon and adrenal medulla. Both methods showed highly restricted localization of staining which coincided with few exceptions in the most reactive areas, namely the superior colliculus, medial and lateral geniculate nuclei, red nucleus, lateral mammillary nucleus, interpeduncular nucleus and substantia nigra pars lateralis and pars reticulata. Immunoreactivity of varying intensity for NSE was also observed in perikarya and in processes of numerous scattered neurons throughout the mesencephalon, including the substantia nigra pars compacta, and reticular formation. The general correspondence in staining patterns between CO and NSE in the midbrain, supports the utility of NSE as a useful index of metabolic activity in neurons.     

Caloric restriction inhibits seizure susceptibility in epileptic EL mice by reducing blood glucose

PURPOSE: Caloric restriction (CR) involves underfeeding and has long been recognized as a dietary therapy that improves health and increases longevity. In contrast to severe fasting or starvation, CR reduces total food intake without causing nutritional deficiencies. Although fasting has been recognized as an effective antiseizure therapy since the time of the ancient Greeks, the mechanism by which fasting inhibits seizures remains obscure. The influence of CR on seizure susceptibility was investigated at both juvenile (30 days) and adult (70 days) ages in the EL mouse, a genetic model of multifactorial idiopathic epilepsy. METHODS: The juvenile EL mice were separated into two groups and fed standard lab chow either ad libitum (control, n=18) or with a 15% CR diet (treated, n=17). The adult EL mice were separated into three groups; control (n=15), 15% CR (n=6), and 30% CR (n=3). Body weights, seizure susceptibility, and the levels of blood glucose and ketones (beta-hydroxybutyrate) were measured over a 10-week treatment period. Simple linear regression and multiple logistic regression were used to analyze the relations among seizures, glucose, and ketones. RESULTS: CR delayed the onset and reduced the incidence of seizures at both juvenile and adult ages and was devoid of adverse side effects. Furthermore, mild CR (15%) had a greater antiepileptogenic effect than the well-established high-fat ketogenic diet in the juvenile mice. The CR-induced changes in blood glucose levels were predictive of both blood ketone levels and seizure susceptibility. CONCLUSIONS: We propose that CR may reduce seizure susceptibility in EL mice by reducing brain glycolytic energy. Our preclinical findings suggest that CR may be an effective antiseizure dietary therapy for human seizure disorders.     

糖酵解抑制剂2-DG改善大鼠偏头痛模型的偏头痛样症状

目的 探讨偏头痛实验模型中糖酵解的作用。方法 通过硬脑膜灌输炎性汤建立偏头痛实验模型; 2-脱氧-D-葡萄糖(2-Deoxy-D-glucose,2-DG)用于抑制糖酵解; 治疗效果通过挠头次数和机械痛阈评定; 通过动物行为学、蛋白免疫印迹、免疫荧光等方法检测糖酵解抑制剂2-DG对炎性汤诱导的机械异常性疼痛、降钙素基因相关肽(Calcitonin gene related peptide,CGRP)、即刻早期基因(c-Fos)和促炎因子表达水平的影响。结果 糖酵解抑制剂2-DG可改善偏头痛实验模型中的偏头痛样症状,减少促炎因子的释放,并降低CGRP和c-Fos的表达水平。结论 糖酵解抑制剂对c-Fos,CGRP、炎症因子释放和偏头痛样症状缓解的影响表明增强的糖酵解可能是实验性偏头痛的发病机制; 糖酵解抑制可能是偏头痛治疗的新靶点。     

Overexpression of Protein Phosphatase 2 Regulatory Subunit B″Alpha Promotes Glycolysis by Regulating Hexokinase 1 in Hepatocellular Carcinoma

ObjectiveTo investigate the regulatory relationship of Protein Phosphatase 2 Regulatory Subunit B″Alpha (PPP2R3A) and hexokinase 1 (HK1) in glycolysis of hepatocellular carcinoma (HCC).MethodsIn HepG2 and Huh7 cells, PPP2R3A expression was silenced by small interfering RNA (siRNA) and overexpression by plasmid transfection. The PPP2R3A-related genes were searched by RNA sequencing. Glycolysis levels were measured by glucose uptake and lactate production. QRT-PCR, ELISA, western blot and immunofluorescence assay were performed to detect the changes of PPP2R3A and HK1. Cell proliferation, migration and invasion assay were used to study the roles of HK1 regulation by PPP2R3A.ResultsRNA sequencing data revealed that PPP2R3A siRNA significantly downregulated the expression of HK1. PPP2R3A gene overexpression promotes, while gene silencing suppresses, the level of HK1 and glycolysis in HCC cells. In HCC tissue samples, PPP2R3A and HK1 were colocalized in the cytoplasm, and their expression showed a positive correlation. HK1 inhibition abrogated the promotion of glycolysis, proliferation, migration and invasion by PPP2R3A overexpression in liver cancer cells.ConclusionOur findings showed the correlation of PPP2R3A and HK1 in the glycolysis of HCC, which reveals a new mechanism for the oncogenic roles of PPP2R3A in cancer.     

Immunometabolic circuits in trained immunity

The classical view that only adaptive immunity can build immunological memory has recently been challenged. Both in organisms lacking adaptive immunity as well as in mammals, the innate immune system can adapt to mount an increased resistance to reinfection, a de facto innate immune memory termed trained immunity. Recent studies have revealed that rewiring of cellular metabolism induced by different immunological signals is a crucial step for determining the epigenetic changes underlying trained immunity. Processes such as a shift of glucose metabolism from oxidative phosphorylation to aerobic glycolysis, increased glutamine metabolism and cholesterol synthesis, play a crucial role in these processes. The discovery of trained immunity opens the door for the design of novel generations of vaccines, for new therapeutic strategies for the treatment of immune deficiency states, and for modulation of exaggerated inflammation in autoinflammatory diseases.     

Linc00460通过海绵吸附影响miR-320a对乳腺癌细胞的有氧糖酵解作用

目的 探讨Linc00460通过海绵吸附miR-320a对乳腺癌（BC）细胞有氧糖酵解作用的影响。方法 qRT-PCR法检测正常乳腺上皮细胞系MCF-10A及5种BC细胞系中Linc00460和miR-320a表达水平。qRT-PCR检测干扰Linc00460对miR-320a表达的影响,双荧光素酶报告基因实验检测miR-320a和Linc00460的靶向关系。将si-Linc00460和miR-320a inhibitor共转染至MDA-MB-231细胞,qRT-PCR检测细胞中miR-320a表达水平;MTT法检测细胞增殖能力;2-NBDG法检测细胞葡萄糖摄取率;比色法检测细胞上清液中乳酸含量;酶活性试剂盒检测糖酵解关键酶的活性;Western blot检测酵解途径中关键蛋白表达水平。结果 与MCF-10A细胞比较,5种BC细胞系中Linc00460高表达,而miR-320a低表达。干扰Linc00460后,MDA-MB-231细胞中miR-320a表达显著升高。双荧光素酶报告基因实验证实,miR-320a和Linc00460可靶向结合。干扰Linc00460表达后MDA-MB-231细胞增殖能力受到明显抑制（P=0.000）,细胞葡萄糖摄取率和细胞上清液中乳酸含量降低（均P=0.000）,PFK、PK和LDH酶活性受到抑制（均P=0.000）,PFKM、GLUT1和LDHA蛋白表达水平下调（均P=0.000）。抑制miR-320a可明显逆转si-Linc00460对MDA-MB-231细胞增殖和糖酵解的抑制作用（均P=0.000或0.001）。结论 Linc00460可能通过海绵吸附miR-320a,上调PFKM表达,从而促进BC细胞有氧糖酵解作用。     

肿瘤细胞的异常糖代谢

肿瘤细胞糖代谢异常与多种机制有关,如缺氧诱导因子（HIF）的参与可激活糖酵解相关酶类,有利于肿瘤细胞采取糖酵解方式获能;线粒体功能低下或数量减少可一定程度抑制葡萄糖氧化磷酸化途径;某些癌基因的激活及抑癌基因的失活也参与调节线粒体氧化呼吸链及糖酵解相关酶类,从而影响糖代谢过程;肿瘤细胞氧化磷酸化的相关酶类合成受到抑制等。此外,糖代谢异常对肿瘤细胞的生长、侵袭和转移具有重要作用。