[Effect of cholestasis on Dynamin-Related Protein 1 [Drpl] gene expression in rat liver]

Background and Aim: Cholestasis is characterized by impaired bile flow, which can cause accumulation of bile acids in the liver and development of metabolic disorders, resulting in hepatocellular necrosis and apoptosis. Mitochondria are a critical cellular organelle that produces most of the cellular energy. Mitochondrial morphology varies from an interconnected filamentous network to isolated dots. This processes are called mitochondrial fission and fusion. Disrupted mitochondrial morphology has been observed in cholestatic liver disease. Dynamin related protein 1 is one of the genes involved in mitochondrial fission and plays a role in apoptosis. In this study we investigated Drpl gene expression in the liver of cholestatic rats

Materials and Methods: In this experimental study, male Wistar rats [290+/-25g] were divided into three groups of control [non-operated], sham [operated without common bile duct ligation] and BDL [operated with common bile duct ligation]. On the 28[th] day of BDL, rats were weighed and sacrificed. Biochemical assays for measurement of bilirubin level and liver enzymes, and also dissection of liver tissue for histopathological analysis were performed. Drpl gene expression was evaluated by semi-quantitative RT-PCR technique

Results: The results showed that serum levels of total bilirubin and liver enzymes [ALT, AST, ALK] were significantly increased in BDL group compared to those in the control and sham operation groups [P<0.0001 and P<0.001]. Histological examination revealed bile ductular hyperplasia, focal liver necrosis and fibrous tissue expansion in BDL group. The result of RT-PCR indicated significant increase of Drpl gene expression in the liver of the rats in BDL group compared to that in the other groups [P<0.001

Conclusion: In this study we found that liver cholestasis increased expression of Drpl gene which led to increased mitochondrial-mediated apoptotic effect with resultant liver cell death

Analysis of Spatial and Temporal Protein Expression in the Cerebral Cortex after Ischemia-Reperfusion Injury

BACKGROUND AND PURPOSE: Hypoxia, or ischemia, is a common cause of neurological deficits in the elderly. This study elucidated the mechanisms underlying ischemia-induced brain injury that results in neurological sequelae. METHODS: Cerebral ischemia was induced in male Sprague-Dawley rats by transient ligation of the left carotid artery followed by 60 min of hypoxia. A two-dimensional differential proteome analysis was performed using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry to compare changes in protein expression on the lesioned side of the cortex relative to that on the contralateral side at 0, 6, and 24 h after ischemia. RESULTS: The expressions of the following five proteins were up-regulated in the ipsilateral cortex at 24 h after ischemia-reperfusion injury compared to the contralateral (i.e., control) side: aconitase 2, neurotensin-related peptide, hypothetical protein XP-212759, 60-kDa heat-shock protein, and aldolase A. The expression of one protein, dynamin-1, was up-regulated only at the 6-h time point. The level of 78-kDa glucose-regulated protein precursor on the lesioned side of the cerebral cortex was found to be high initially, but then down-regulated by 24 h after the induction of ischemia-reperfusion injury. The expressions of several metabolic enzymes and translational factors were also perturbed soon after brain ischemia. CONCLUSIONS: These findings provide insights into the mechanisms underlying the neurodegenerative events that occur following cerebral ischemia.

Expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with mesial temporal lobe epilepsy / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To observe the expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with mesial temporal lobe epilepsy (MTLE) and to investigate the roles of dynamin-1 and phosphor-dynamin-1 in the development of MTLE.</p><p><b>METHODS</b>Male Sprague-Dawley rats (aged 25 days) were randomly divided into acute control (AC), acute seizure (AS), latent control (LC), latent seizure (LS), chronic control (CC) and chronic spontaneous seizure (CS) groups. Lithium chloride-pilocarpine was used to induce a rat model of MTLE. The hippocampus samples of 5 children with a pathologically confirmed hippocampal sclerosis who received surgical operation were collected as a human model (HM) group, and the hippocampus samples of 4 dead children (without organic lesion of the hippocampus) were collected by autopsy as a human control (HC) group. The expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with MTLE was measured by Western blot and immunohistochemistry.</p><p><b>RESULTS</b>The Western blot showed that the expression of phosphor-dynamin-1 was significantly lower in the AS and CS groups than in the corresponding control groups (AC and CC groups) (P<0.05). The expression of phosphor-dynamin-1 was significantly lower in the HM group than in the HC group (P<0.05). There were no significant differences in the expression of dynamin-1 among the AS, LS and CS groups and between the HM and HC groups (P>0.05). The immunohistochemical results showed that phosphor-dynamin-1 was highly expressed in the cytoplasm of hippocampal neurons of AC, CC and HC groups, but its expression was significantly reduced in the AS, CS and HM groups (P<0.05).</p><p><b>CONCLUSIONS</b>The expression of phosphor-dynamin-1, not dynamin-1, is downregulated in the hippocampus of children and rats with MTLE during seizures, which suggests that the phosphorylation/dephosphorylation of dynamin-1 may be involved in the development of MTLE.</p>

Comparative proteomic analysis of hippocampus between chronic cerebral ischemia rats and normal controls / 中南大学学报(医学版)

OBJECTIVE@#To explore the pathogenesis of brain damage after chronic cerebral ischemia through analysis of the differences in proteins expression in hippocampus between chronic cerebral ischemia rats and normal rats.@*METHODS@#The chronic cerebral ischemia model was established by ligating the bilateral common carotid arteries.Twenty rats were randomly divided into a model group (n=10)and a sham operation group(n=10). Four weeks later, the differences of proteins expression in hippocampus between model group and sham operation group were analyzed by two dimensional polyacryalmide gel electrophoresis and ultraflex TOF/TOF mass spectrograph.@*RESULTS@#Compared to the sham operation group, the expressions of 4 proteins were up-regulated and that of 2 proteins were down-regulated in the model group. Six proteins were identified by ultraflex TOF/TOF, which were ubiquitin carboxy-terminal hydrolase L1; Dynamin-1; TMF regulated nuclear protein-like, partial; ATP synthase; rCG50513, isoform CRA_a; and expressed sequence AU016693, isoform CRA_b.@*CONCLUSION@#Well-resolved and reproducible 2-DE patterns of chronic cerebral ischemia rats were established. Six proteins that correlate with nerve damage after chronic cerebral ischemia are identified.