Hertz L.,Shenyang University |
Chen Y.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc
Neuroscience and Biobehavioral Reviews | Year: 2016
Initial clearance of extracellular K+ ([K+]o) following neuronal excitation occurs by astrocytic uptake, because elevated [K+]o activates astrocytic but not neuronal Na+,K+-ATPases. Subsequently, astrocytic K+ is re-released via Kir4.1 channels after distribution in the astrocytic functional syncytium via gap junctions. The dispersal ensures widespread release, preventing renewed [K+]o increase and allowing neuronal Na+,K+-ATPase-mediated re-uptake. Na+,K+-ATPase operation creates extracellular hypertonicity and cell shrinkage which is reversed by the astrocytic cotransporter NKCC1. Inhibition of Kir channels by activation of specific PKC isotypes may decrease syncytial distribution and enable physiologically occurring [K+]o increases to open L-channels for Ca2+, activating [K+]o-stimulated gliotransmitter release and regulating gap junctions. Learning is impaired when [K+]o is decreased to levels mainly affecting astrocytic membrane potential or Na+,K+-ATPase or by abnormalities in its α2 subunit. It is enhanced by NKCC1-mediated ion and water uptake during the undershoot, reversing neuronal inactivity, but impaired in migraine with aura in which [K+]o is highly increased. Vasopressin augments NKCC1 effects and facilitates learning. Enhanced myelination, facilitated by astrocytic-oligodendrocytic gap junctions also promotes learning. © 2016 Elsevier Ltd
Hertz L.,Shenyang University |
Gibbs M.E.,Monash Institute of Pharmaceutical Sciences |
Dienel G.A.,University of Arkansas for Medical Sciences
Frontiers in Neuroscience | Year: 2014
Lactate is a versatile metabolite with important roles in modulation of brain glucose utilization rate (CMRglc), diagnosis of brain-injured patients, redox- and receptor-mediated signaling, memory, and alteration of gene transcription. Neurons and astrocytes release and accumulate lactate using equilibrative monocarboxylate transporters that carry out net transmembrane transport of lactate only until intra- and extracellular levels reach equilibrium. Astrocytes have much faster lactate uptake than neurons and shuttle more lactate among gap junction-coupled astrocytes than to nearby neurons. Lactate diffusion within syncytia can provide precursors for oxidative metabolism and glutamate synthesis and facilitate its release from endfeet to perivascular space to stimulate blood flow. Lactate efflux from brain during activation underlies the large underestimation of CMRglc with labeled glucose and fall in CMRO2/CMRglc ratio. Receptor-mediated effects of lactate on locus coeruleus neurons include noradrenaline release in cerebral cortex and c-AMP-mediated stimulation of astrocytic gap junctional coupling, thereby enhancing its dispersal and release from brain. Lactate transport is essential for its multifunctional roles. © 2014 Hertz, Gibbs and Dienel.
Guo M.,Shenyang University
Journal of Chemical and Pharmaceutical Research | Year: 2013
As photographing and video parsing techniques improved, it provides a boost for taekwondo technical researching. This paper make analysis of every stage features of back kick skills by using video parsing data, then based on analysis human gravity shifting features and relative features between hip angle and kick velocity in motion process, through analysis of each link of lower limbs' velocity status in five time phrases, get every links of lower limbs' velocity feature in 4 stages. With the analysis data of taekwondo back kick motions time consuming in 4 stages, get the order of time consuming proportion from biggest to smallest like: the 4th stage> the 1st stage>the 2nd stage>the 3rd stage; it provides theoretical basis to sports analyzing and data references to taekwondo training.
Luo X.-G.,Shenyang University |
Chen S.-D.,Shanghai JiaoTong University
Translational Neurodegeneration | Year: 2012
It has been nearly a century since the early description of microglia by Rio-Hortega; since then many more biological and pathological features of microglia have been recognized. Today, microglia are generally considered to be beneficial to homeostasis at the resting state through their abilities to survey the environment and phagocytose debris. However, when activated microglia assume diverse phenotypes ranging from fully inflamed, which involves the release of many pro-inflammatory cytokines, to alternatively activated, releasing anti-inflammatory cytokines or neurotrophins, the consequences to neurons can range from detrimental to supportive. Due to the different experimental sets and conditions, contradictory results have been obtained regarding the controversial question of whether microglia are " good" or " bad." While it is well understood that the dual roles of activated microglia depend on specific situations, the underlying mechanisms have remained largely unclear, and the interpretation of certain findings related to diverse microglial phenotypes continues to be problematic. In this review we discuss the functions of microglia in neuronal survival and neurogenesis, the crosstalk between microglia and surrounding cells, and the potential factors that could influence the eventual manifestation of microglia. © 2012 Luo and Chen; licensee BioMed Central Ltd.
Ma L.H.,Shenyang University
Journal of neurosurgery | Year: 2012
This study was undertaken to analyze outcomes in patients with newly diagnosed brain metastases from non-small cell lung cancer (NSCLC) who were treated with hypofractionated stereotactic radiotherapy (HSRT) with or without whole-brain radiotherapy (WBRT). One hundred seventy-one patients comprised the study population. Fifty-four patients received HSRT alone, and 117 patients received both HSRT and WBRT. The median survival time (MST) was determined using the Kaplan-Meier method. Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) were also used to evaluate the results. Univariate and multivariate analyses were performed to determine significant prognostic factors for overall survival. Tumor control, radiation toxicity, and cause of death in the HSRT and HSRT+WBRT groups were evaluated. The MST for all patients was 13 months. According to the Kaplan-Meier method, the probability of survival at 1, 2, and 3 years was 51.2%, 21.7%, and 10.1%. The MSTs for RPA Classes I, II, and III were 19, 12, and 5 months, respectively; and the MSTs for GPA Scores 4, 3, 2, and 1 were 24, 14, 12, and 6 months, respectively. The MSTs in the HSRT+WBRT and HSRT groups were 13 and 9 months (p = 0.044), respectively, for all patients, 13 and 8 months (p = 0.031), respectively, for patients with multiple brain metastases, and 16 and 15 months (p = 0.261), respectively, for patients with a single brain metastasis. The multivariate analysis showed that HSRT+WBRT was a significant factor only for patients with multiple brain metastases (p = 0.010). The Kaplan-Meier-estimated tumor control rates at 3, 6, 9, and 12 months were 92.2%, 82.7%, 79.5%, and 68.3% in the HSRT+WBRT group and 73.5%, 58.4%, 51.0%, and 43.3% in the HSRT group, respectively, in all 165 patients (p = 0.001). The estimated tumor control rates at 3, 6, 9, and 12 months were 94.3%, 81.9%, 79.6%, and 76.7%, respectively, in the HSRT+WBRT group and 77.8%, 61.4%, 52.6%, and 48.2%, respectively, in the HSRT group in the 80 patients harboring a single metastasis (p = 0.009). The estimated tumor control rates at 3, 6, 9, and 12 months were 90.5%, 83.5%, 79.5%, and 60.9%, respectively, in the HSRT+WBRT group and 68.2%, 54.5%, 48.5%, and 36.4%, respectively, in the HSRT group in the 85 patients with multiple metastases (p = 0.010). The toxicity incidences of Grade 3 or worse were 6.0% (7 of 117 patients) in the HSRT+WBRT group and 1.9% (1 of 54 patients) in the HSRT group (p = 0.438). The differences in neurological death rates between the HSRT+WBRT group and the HSRT group were not statistically significant (34.4% vs 44.7%, p = 0.125, in all patients; 30.0% vs 52.0%, p = 0.114, in patients with a single metastasis; and 38.0% vs 36.4%, p = 0.397, in patients with multiple metastases). The overall survival results in the present study were similar to those in other studies. Hypofractionated stereotactic radiotherapy provides an alternative method to traditional stereotactic radiosurgery. We suggest that WBRT should be combined with HSRT in patients with single or multiple newly diagnosed brain metastases from NSCLC.
Guo P.,Shenyang University
PloS one | Year: 2013
Legumain, a novel asparaginyl endopeptidase, has been observed to be highly expressed in several types of tumors, which may play a vital role in carcinogenesis. However, there is no study investigating the relationship among Legumain expression, clinicopathologic, biological variables and patient prognosis in gastric carcinoma. In this study, a tissue microarray (TMA) containing 282 samples of primary gastric cancer was assessed for Legumain expression by immunohistochemistry. The TMA included 98 lymph node metastasis samples. The protein expression levels of Legumain were evaluated by Western blot analysis. Cytoplasmic immunoreactivity of Legumain was over-expressed in gastric cancer compared with paired normal gastric mucosa. Increased Legumain levels were significantly correlated with clinical stage, presence of distant metastasis. Legumain was significantly over-expressed in primary gastric cancer with metastasis than without metastasis. Patients with Legumain-positive localized tumors had lower 5-year overall survival (OS) than those with Legumain-negative tumors. Multivariate survival analysis showed that Legumain was an independent prognostic marker for OS (HR 1.459, 95% CI 1.251-1.703, P = 0.007). Legumain expression could serve as a prognostic biomarker in patients at risk of developing metastasis or recurrence with gastric carcinoma.
Wang D.,Shenyang University
European journal of medical research | Year: 2012
Accumulated evidence reveals that cyclooxygenase-2 (COX-2) was overexpressed in eutopic endometrium of endometriosis, which may play a critical role in the pathogenesis of endometriosis. However, few studies have been performed to explore the molecular mechanisms underlying the abnormal high expression of COX-2 in endometriosis. Considering the fact that a number of recent studies have shown DNA methylation affecting some genes in endometriosis, the present study was therefore aimed to determine whether the observed high expression COX-2 in endometriosis is caused by the hypomethylation of CpG island within the promoter of this gene. The endometrial tissues were collected from 60 women with endometriosis (endometriosis group) and 20 women without endometriosis (control group). The methylation status of COX-2 was examined by methylation specific PCR. Quantitative real-time RT-PCR was performed to measure COX-2 mRNA level in endometrial tissues. The frequency of promoter hypermethylation of COX-2 was lower in eutopic endometrium of the endometriosis group (41.7%) than that in the control group (75.0%), P < 0.05. COX-2 mRNA level in the eutopic endometrium of the endometriosis group was 2.61-fold higher than that in the control group (P < 0.01). COX-2 mRNA level in unmethylated endometrium of the endometriosis group or the control group was 2.39-fold and 2.66-fold, respectively, higher than that in the methylated endometrium of the same group (P < 0.01). The hypomethylation within the promoter of COX-2 may be responsible for the elevated gene expression in eutopic endometrium of endometriosis.
Song L.,Shenyang University
PloS one | Year: 2012
Silicosis is an occupational lung disease caused by inhalation of silica dust and characterized by lung inflammation and fibrosis. Previous study showed that Tregs regulate the process of silicosis by modulating the maintenance of immune homeostasis in the lung. Th17 cells share reciprocal developmental pathway with Tregs and play a pivotal role in the immunopathogenesis of many lung diseases by recruiting and activating neutrophils, but the regulatory function of Tregs on Th17 response in silica induced lung fibrosis remains to be explored. To evaluate the role of Th17 and IL-17 in the development of silicosis and their interaction with Tregs, Treg-depleted mice model was generated and exposed to silica to establish experimental model of silica-induced lung fibrosis. Here we showed that silica increased Th17 response in lung fibrosis. Tregs depletion enhanced the neutrophils accumulation and attenuated Th17 response in silica induced lung fibrosis. Both mRNA and protein results showed that Tregs exerted its modulatory function on Th17 cells and IL-17 by regulating TGF-β1 and IL-1β. Our study suggested that Tregs could promote Th17 cells differentiation by regulating TGF-β1 and IL-1β in silica induced lung fibrosis of mice, which further the understanding of the progress of silicosis and provide a new insight in the regulatory mechanism of Th17 by Tregs in lung inflammation.
Wang M.,Shenyang University
BMC cancer | Year: 2011
δ-Catenin (CTNND2), which encodes a scaffold protein in humans, has been found in a few malignancies. However, the expression pattern and contribution of δ-catenin to astrocytoma progression are unclear. We investigated δ-catenin expression in human astrocytoma samples and its function in astrocytoma cell lines using immunohistochemistry, siRNA knockdown, transfection, MTT, transwell migration and Rac1 pulldown techniques. δ-Catenin protein expression was detected in cytoplasm of astrocytoma cells by immunohistochemistry. Analysis showed that grade I astrocytoma (0%, 0/11) and glial cells from normal brain tissue exhibited negative staining. δ-Catenin expression was significantly higher in grade III-IV (35%, 29/84) compared to grade II astrocytoma cells (18%, 11/61); p < 0.01). In addition, CTNND2 overexpression promoted proliferation, invasion and Rac1 activity of U251 astrocytoma cells. Treatment of δ-catenin-transfected cells with a Rac1 inhibitor decreased Rac1 activity and invasion. δ-Catenin knockdown in U87 glioblastoma cell decreased cell proliferation, invasion and Rac1 activity. The results suggest that δ-catenin expression is associated with the malignant progression of astrocytoma and promotes astrocytoma cell invasion through upregulation of Rac1 activity. δ-Catenin expression levels may serve as a useful marker of the biological behavior of astrocytoma cells.
Hertz L.,Shenyang University
Frontiers in Endocrinology | Year: 2013
The gold standard for studies of glutamate-glutamine (GABA) cycling and its connections to brain biosynthesis from glucose of glutamate and GABA and their subsequent metabolism are the elegant in vivo studies by 13C magnetic resonance spectroscopy (NMR), showing the large fluxes in the cycle. However, simpler experiments in intact brain tissue (e.g., immunohistochemistry), brain slices, cultured brain cells, and mitochondria have also made important contributions to the understanding of details, mechanisms, and functional consequences of glutamate/GABA biosynthesis and degradation. The purpose of this review is to attempt to integrate evidence from different sources regarding (i) the enzyme(s) responsible for the initial conversion of α-ketoglutarate to glutamate; (ii) the possibility that especially glutamate oxidation is essentially confined to astrocytes; and (iii) the ontogenetically very late onset and maturation of glutamine-glutamate (GABA) cycle function. Pathway models based on the functional importance of aspartate for glutamate synthesis suggest the possibility of interacting pathways for biosynthesis and degradation of glutamate and GABA and the use of transamination as the default mechanism for initiation of glutamate oxidation. The late development and maturation are related to the late cortical gliogenesis and convert brain cortical function from being purely neuronal to becoming neuronal-astrocytic. This conversion is associated with huge increases in energy demand and production, and the character of potentially incurred gains of function are discussed. These may include alterations in learning mechanisms, in mice indicated by lack of pairing of odor learning with aversive stimuli in newborn animals but the development of such an association 10-12 days later. The possibility is suggested that analogous maturational changes may contribute to differences in the way learning is accomplished in the newborn human brain and during later development. © 2013 Hertz. This is an open-access article.