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Studies of ischemic brain injury in neonatal rodents have focused upon the pathophysiology of neuronal damage. Much less consideration has been given to white matter injury, even though it is a major contributor to chronic neurological dysfunction in children. In the human neonate, particularly in those born prematurely, periventricular white matter is highly susceptible to hypoxic--ischemic (H--I) injury. To understand the basis for this selective vulnerability, we examined myelin gene expression and cell death in the subventricular layer and the surrounding white matter of neonatal mice following H--I insult. Using an in situ hybridization technique that gives high resolution and is very sensitive, we examined myelin basic protein and proteolipid protein gene expression three and twenty-four hours after a H-I insult. To elicit unilateral forebrain hypoxic and ischemic injury, 9--10-day-old mice underwent right carotid artery ligation followed by timed (40--70 min) exposure to 10% oxygen. Twenty-four hours following H--I, myelin basic protein and proteolipid protein transcripts were markedly reduced in striatum, external capsule, fornix, and corpus callosum in the injured side. Three hours after lesioning (ligation+70 min hypoxic exposure) myelin basic protein gene transcripts were visibly reduced in the ipsilateral white matter tracts. Interestingly, some cells in the subventricular layer expressed proteolipid protein transcripts, and 3 h after a H--I insult they were degenerating in the injured but not contralateral side. TUNEL staining showed an increase in the number of positive cells in the injured subventricular layer and corpus callosum but the adjacent striatum did not show a corresponding change in the number of TUNEL labeled cells. Ultrastructural studies of the subventricular zone and corpus callosum 3 h after H--I revealed that many subventricular cells, glial cells in the corpus callosum, and callosal axons in the injured side had already degenerated. However, the subventricular cells, glia and axons in the contralateral corpus callosum were spared. Many cells in the injured corpus callosum exhibited a apoptotic morphology; yet more mature oligodendrocytes in this region appeared normal. Our results show that a H--I insult causes a surprisingly swift and dramatic degenerative response in the subventricular layer and adjacent white matter. Within 3 h after H--I, the programmed cell death cascade was initiated; internucleosomal DNA degradation took place in subventricular and glial cells; oligodendrocyte progenitors died and axonal degeneration in the ipsilateral corpus callosum was extensive. The swiftness of the subventricular and glial cell degeneration suggests the H--I insult directly targets glia, as well as neurons, and raises the provocative question of whether glia exert damaging effects upon neurons and axons. Since the severity of the H--I insult can be modulated by varying the duration of hypoxia, the model is ideal to study whether oligodendrocyte progenitors are more susceptible to death...

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A rapid loss of protein kinase C (PKC) activity is a prognostic feature of the lethal damage inflicted on neurons by cerebral ischemia in vivo and by hypoxic and excitotoxic insults in vitro. However, it is not known if this inactivation of PKC is incidental or is an essential part of the neurodegenerative process driven by such insults. To address this issue, the effects of glutamate on PKC activity and neurotoxicity were studied in immature [8 days in vitro (DIV)] and mature (15-20 DIV) embryonic day 18 rat cortical neuronal cultures. Exposing 16 DIV neurons to as little as 20-50 pM glutamate for 15 mm was neurotoxic and induced a rapid (.-~1-2h) Ca 2~-dependent inactivation of membrane PKC. By contrast, neurons 8 DIV were resistant to >800 pM glutamate, and no evidence of PKC inactivation was observed. Reverse transcriptionpolymerase chain reaction analysis of NMDA and AMPA receptor subtypes and fluorometric intracellular Ca2c oncentration measurements of the effects of NMDA, AMPA, kainate, and metabotropic glutamate receptor activation demonstrated that this striking difference in vulnerability was not due to an absence of functional glutamate receptors on neurons 8 DIV. However, 8 DIV neurons became highly vulnerable to low (<20 pM) concentrations of glutamate when PKC activity was inhibited by 50 nM staurosporine, 1 ,uM calphostin C, 5 pM chelerythrine, or chronic exposure to 100 nM PMA. A 15-mm coapplication of 50 nM staurosporine with glutamate,

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The clinical significance and essential role of long non-coding RNA colorectal neoplasia differentially expressed (lncRNA CRNDE) have been well illuminated in various cancers. However, the function of CRNDE in intrahepatic cholangiocarcinoma (IHCC) has not been reported at present. The aim of the present study was to investigate the role of CRNDE in IHCC. Firstly, the relative expression of CRNDE was observed to be upregulated in IHCC cell lines and tissues. And high CRNDE expression was statistically associated with IHCC differentiation grade, lymph node metastasis, tumor-nodes-metastasis (TNM) stage and size. Survival analysis identified that high CRNDE expression is a predictor of worse overall survival (OS) and progression-free survival (PFS) in patients with IHCC. Moreover, high CRNDE expression was identified as an independent risk factor of IHCC poor OS and PFS. Further studies of in vitro assays suggested that CRNDE silencing could suppress the proliferation of HuCCT1 cells following CCK-8 and colony formation assays, while CRNDE ectopic expression in HCCC9810 cells promoted proliferation. Moreover, the migration and invasion of HuCCT1 cells were greatly repressed with CRNDE deficiency following Transwell and Matrigel assays. Accordingly, the motility of HCCC9810 cells was notably accelerated with CRNDE overexpression. Mechanistically, CRNDE was revealed to facilitate the epithelial-mesenchymal transition (EMT) of IHCC cells. In conclusion, these observations indicated that CRNDE could promote the clinical progression and metastasis of IHCC by facilitating EMT. CRNDE may be a novel prognostic marker and therapeutic target in IHCC.