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Significant Differential Expression (significant + differential_expression)
Selected AbstractsVariation in Galr1 expression determines susceptibility to excitotoxin-induced cell death in miceGENES, BRAIN AND BEHAVIOR, Issue 5 2008S. Kong Inbred strains of mice differ in their susceptibility to excitotoxin-induced cell death, but the genetic basis of individual variation in differential susceptibility is unknown. Previously, we identified a highly significant quantitative trait locus (QTL) on chromosome 18 that influenced susceptibility to kainic acid-induced cell death (Sicd1). Comparison of susceptibility to seizure-induced cell death between reciprocal congenic lines for Sicd1 and parental background mice indicates that genes influencing this trait were captured in both strains. Two positional gene candidates, Galr1 and Mbp, map to 55 cM, where the Sicd1 QTL had been previously mapped. Thus, this study was undertaken to determine if Galr1 and/or Mbp could be considered as candidate genes. Genomic sequence comparison of these two functional candidate genes from the C57BL/6J (resistant at Sicd1) and the FVB/NJ (susceptible at Sicd1) strains showed no single-nucleotide polymorphisms. However, expression studies confirmed that Galr1 shows significant differential expression in the congenic and parental inbred strains. Galr1 expression was downregulated in the hippocampus of C57BL/6J mice and FVB.B6- Sicd1 congenic mice when compared with FVB/NJ or B6.FVB- Sicd1 congenic mice. A survey of Galr1 expression among other inbred strains showed a significant effect such that ,susceptible' strains showed a reduction in Galr1 expression as compared with ,resistant' strains. In contrast, no differences in Mbp expression were observed. In summary, these results suggest that differential expression of Galr1 may contribute to the differences in susceptibility to seizure-induced cell death between cell death-resistant and cell death-susceptible strains. [source] Increased tumor necrosis factor ,,converting enzyme activity induces insulin resistance and hepatosteatosis in mice,HEPATOLOGY, Issue 1 2010Loredana Fiorentino Tumor necrosis factor ,,converting enzyme (TACE, also known as ADAM17) was recently involved in the pathogenesis of insulin resistance. We observed that TACE activity was significantly higher in livers of mice fed a high-fat diet (HFD) for 1 month, and this activity was increased in liver > white adipose tissue > muscle after 5 months compared with chow control. In mouse hepatocytes, C2C12 myocytes, and 3T3F442A adipocytes, TACE activity was triggered by palmitic acid, lipolysaccharide, high glucose, and high insulin. TACE overexpression significantly impaired insulin-dependent phosphorylation of AKT, GSK3, and FoxO1 in mouse hepatocytes. To test the role of TACE activation in vivo, we used tissue inhibitor of metalloproteinase 3 (Timp3) null mice, because Timp3 is the specific inhibitor of TACE and Timp3,/, mice have higher TACE activity compared with wild-type (WT) mice. Timp3,/, mice fed a HFD for 5 months are glucose-intolerant and insulin-resistant; they showed macrovesicular steatosis and ballooning degeneration compared with WT mice, which presented only microvesicular steatosis. Shotgun proteomics analysis revealed that Timp3,/, liver showed a significant differential expression of 38 proteins, including lower levels of adenosine kinase, methionine adenosysltransferase I/III, and glycine N -methyltransferase and higher levels of liver fatty acid-binding protein 1. These changes in protein levels were also observed in hepatocytes infected with adenovirus encoding TACE. All these proteins play a role in fatty acid uptake, triglyceride synthesis, and methionine metabolism, providing a molecular explanation for the increased hepatosteatosis observed in Timp3,/, compared with WT mice. Conclusion: We have identified novel mechanisms, governed by the TACE,Timp3 interaction, involved in the determination of insulin resistance and liver steatosis during overfeeding in mice. (HEPATOLOGY 2009.) [source] Skeletal muscle fiber type conversion during the repair of mouse soleus: Potential implications for muscle healing after injuryJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 11 2007Tetsuya Matsuura Abstract We used a mouse model of cardiotoxin injury to examine fiber type conversion during muscle repair. We evaluated the soleus muscles of 37 wild-type mice at 2, 4, 8, and 12 weeks after injury. We also used antibodies (fMHC and sMHC) against fast and slow myosin heavy chain to classify the myofibers into three categories: fast-, slow-, and mixed (hybrid)-type myofibers (myofibers expressing both fMHC and sMHC). Our results revealed an increase in the percentage of slow-type myofibers and a decrease in the percentage of fast-type myofibers during the repair process. The percentage of hybrid-type myofibers increased 2 weeks after injury, then gradually decreased over the following 6 weeks. Similarly, our analysis of centronucleated myofibers showed an increase in the percentage of slow-type myofibers and decreases in the percentages of fast- and hybrid-type myofibers. We also investigated the relationship between myofiber type conversion and peroxisome proliferator-activated receptor-, coactivator-1, (PGC-1,). The expression of both PGC-1, protein, which is expressed in both the nucleus and the cytoplasm of regenerating myofibers, and sMHC protein increased with time after cardiotoxin injection, but we observed no significant differential expression of fMHC protein in regenerating muscle fibers during muscle repair. PGC-1,-positive myofibers underwent fast to slow myofiber type conversion during the repair process. These results suggest that PGC-1, contributes to myofiber type conversion after muscle injury and that this phenomenon could influence the recovery of the injured muscle. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1534,1540, 2007 [source] Proteome analysis of hepatocellular carcinoma cell strains, MHCC97-H and MHCC97-L, with different metastasis potentialsPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2004Shi-Jian Ding Abstract To better understand the mechanism underlying hepatocellular carcinoma (HCC) metastasis and to search for potential markers for HCC prognosis, differential proteome analysis on two HCC cell strains with high and low metastatic potentials, MHCC97-H and MHCC97-L, was conducted using two-dimensional (2-D) gel electrophoresis followed by matrix-assisted laser desorption/time of flight mass spectrometry and liquid chromatography ion trap mass spectrometry. Image analysis of silver-stained 2-D gels revealed that 56 protein spots showed significant differential expression in MHCC97-H and MHCC97-L cells (Student's t -test, P < 0.05) and 4 protein spots were only detected in MHCC97-H cells. Fourteen protein spots were further identified using in-gel tryptic digestion, peptide mass fingerprinting and tandem mass spectrometry. The expressions of pyruvate kinase M2, ubiquitin carboxy-terminal hydrolase L1, laminin receptor 67 kDa, S100 calcium-binding protein A4, thioredoxin and cytokeratin 19 were elevated in MHCC97-H cells. However, manganese superoxide dismutase, calreticulin precursor, cathepsin D, lactate dehydrogenase B, non-metastatic cell protein 1, cofilin 1 and calumenin precursor were down-regulated in MHCC97-H cells. Intriguingly, most of these identified proteins have been reported to be associated with tumor metastasis. The functional implications of alterations in the levels of these proteins are discussed. [source] Determination of metastasis-associated proteins in non-small cell lung cancer by comparative proteomic analysisCANCER SCIENCE, Issue 8 2007Tian Tian The development of metastasis is the leading cause of death and an enormous therapeutic challenge in cases of non-small cell lung cancer. To better understand the molecular mechanisms underlying the metastasis process and to discover novel potential clinical markers for non-small cell lung cancer, comparative proteomic analysis of two non-small cell lung cancer cell lines with different metastatic potentials, the non-metastatic CL1-0 and highly metastatic CL1-5 cell lines, was carried out using two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization,time of flight mass spectrometry and tandem mass spectrometry. Thirty-three differentially expressed proteins were identified unambiguously, among which 16 proteins were significantly upregulated and 17 proteins were downregulated in highly metastatic CL1-5 cells compared with non-metastatic CL1-0 cells. Subsequently, 8 of 33 identified proteins were selected for further validation at the mRNA level using real-time quantitative polymerase chain reaction, and three identified proteins, S100A11, PGP 9.5 and HSP27, were confirmed by western blotting. The protein S100A11 displaying significant differential expression at both the protein and mRNA levels was further analyzed by immunohistochemical staining in 65 primary non-small cell lung cancer tissues and 10 matched local positive lymph node specimens to explore its relationship with metastasis. The results indicated that the upregulation of S100A11 expression in non-small cell lung cancer tissues was significantly associated with higher tumor,node,metastasis stage (P = 0.001) and positive lymph node status (P = 0.011), implying that S100A11 might be an important regulatory molecule in promoting invasion and metastasis of non-small cell lung cancer. (Cancer Sci 2007; 98: 1265,1274) [source] | |||||||||||||