[Show abstract][Hide abstract]ABSTRACT: Acrolein is an alpha, beta-unsaturated aldehyde present in cigarette smoke, and is also a product of lipid peroxidation. Heme
oxygenase-1 (HO-1) plays critical roles in preventing oxidative stress and other cellular functions, and induces viability
and proliferation of tumor cells. Acrolein is well-known to induce HO-1, although the signal pathway has not been fully elucidated.
This study elucidated the involved signaling and acrolein’s cytoprotective effects in human hepatocellular carcinoma (HepG2)
cells. Cells were treated with acrolein to induce HO-1, whose expression was measured by Western blot, RT-PCR and immunofluorescence
staining analyses. Low concentrations of acrolein remarkably increased HO-1 mRNA and protein levels. Acrolein-mediated HO-1
induction was notably decreased by rottlerin and SB203580, selective inhibitors of PKC-δ and p38 MAPK, respectively. Furthermore,
the cells displayed an increased arrest at the G0/G1 phase of the cell-cycle. The data indicates that acrolein enhances HO-1 expression via PKC-δ and p38 MAPK signaling. Acrolein
may provide a cytoprotective effect via the expression of HO-1 in HepG2 cells.
KeywordsAcrolein-Heme oxygenase-1-Human hepatocellular carcinoma-Cytoprotective
Preview · Article · Jun 2010 · Molecular and Cellular Toxicology
[Show abstract][Hide abstract]ABSTRACT: Uncaria rhynchophylla (UR) is an herbal plant that has been used widely to treat stroke, hypertension and atherosclerosis. Upregulated heme oxygenase-1
(HO-1) plays a crucial role in cytoprotection and anti-inflammatory responses in a variety of pathological models. In this
study, we investigated upregulation of HO-1 by UR, which is inducible and cytoprotective enzyme in RAW 264.7 macrophages.
Upregulation of HO-1 and signal pathways were examined by western blots, RT-PCR and immunofluorescence staining. Treatment
of UR induced HO-1 protein expression and Nrf2 nuclear translocation in RAW 264.7 macrophages. HO-1 induction was strongly
inhibited by the suppression of p38 MAPK and ERK activity. Additionally, rottlerin, an inhibitor of protein kinase C δ (PKC
δ), abolished the upregulation of HO-1 protein levels. From the above results, it is suggested that UR may exert a cytoprotective
effect via the upregulation of HO-1 in RAW 264.7 macrophages.
-Heme oxygenase 1-Macrophage-Nrf2
Preview · Article · Mar 2010 · Molecular and Cellular Toxicology
[Show abstract][Hide abstract]ABSTRACT: Acrolein, a known toxin in cigarette smoke, is the most abundant electrophilic alpha, beta-unsaturated aldehyde to which humans are exposed in a variety of environmental pollutants, and is also product of lipid peroxidation. Increased unsaturated aldehyde levels and reduced antioxidant status plays a major role in the pathogenesis of various diseases such as diabetes, Alzheimer's and atherosclerosis. The findings reported here show that low concentrations of acrolein induce heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophages. HO-1 induction by acrolein and signal pathways was measured using reverse transcription-polymerase chain reaction, Western blot and immunofluorescence staining analyses. Inhibition of extracellular signal-regulated kinase activity significantly attenuated the induction of HO-1 protein by acrolein, while suppression of Jun N-terminal kinase and p38 activity did not affect induction of HO-1 expression. Moreover, rottlerin, an inhibitor of protein kinase delta, suppressed the upregulation of HO-1 protein production, possibly involving the interaction of NF-E2-related factor 2 (Nrf2), which has a key role as a HO-1 transcription factor. Acrolein elevated the nuclear translocation of Nrf2 in nuclear extraction. The results suggest that RAW 264.7 may protect against acrolein-mediated cellular damage via the upregulation of HO-1 which is an adaptive response to oxidative stress.
No preview · Article · Sep 2009 · Molecular and Cellular Toxicology
[Show abstract][Hide abstract]ABSTRACT: Give me some feedback: In vitro selection of aptamers against the H3 peptide provided specific hairpin RNAs that possess high homology with histone H3 mRNA. The identified H3 hairpin RNA binds specifically to the H3 peptide with micromolar affinity and dose-dependently inhibits in vitro translation of the H3 protein. Consequently, the hairpin RNA and H3 peptide are one of the rare cis- and trans-elements on coding regions found among housekeeping proteins in higher eukaryotes.
[Show abstract][Hide abstract]ABSTRACT: Primary liposarcoma of the liver is extremely rare. We report here on a case of primary well-differentiated liposarcoma in the left hepatic lobe of a 63-year-old woman. Abdominal ultrasonography showed a well-defined, echogenic, round mass. Abdominal computed tomography (CT) and magnetic resonance (MR) images showed an almost fatty, lobulated mass with a few, random distributed vascular structures and a small area of nodular enhancement. The resected tumor appeared as a well-defined, round, tan-yellow mass. Histological analysis showed a well-differentiated liposarcoma.
No preview · Article · Jan 2008 · Acta Radiologica
[Show abstract][Hide abstract]ABSTRACT: The combinatorial introduction of N,N-dimethyl-Lys groups into Lys-rich α-helical peptides and measuring affinities against RRE RNA were carried out. Peptide-g, in which two Lys were replaced by N,N-dimethyl-Lys at 3 and 9 positions, showed low-nanomolar affinity, which is almost the same value as Rev peptide, the natural RRE ligand. Moreover, peptide-g displays a compatible binding specificity as Rev peptide. The effects of the positions of Lys N,N-dimethylation on the specificity of RNA binding could serve as the basis of a new strategy for the design of novel agents against RNAs. The results support that nature may use N-methylation as a post-translational modification to enhance specific peptide−RNA interactions.
No preview · Article · May 2007 · Journal of the American Chemical Society