Participation of caspase-3-like protease in oxidation-induced impairment of erythrocyte membrane properties

Erythrocytes are very susceptible to oxidative stress, having a high content of intracellular oxygen and hemoglobin. In the present study, exposure to oxidative stress resulted in a significant impairment of erythrocyte membrane functions, such as deformability and anion exchange. Band 3 protein, also known as anion exchanger-1, plays an important role in these two functions. We show that oxidative stress activated caspase-3 inside the erythrocytes, which resulted in band 3 protein cleavage. Interestingly, inhibition of the caspase-3 with its specific inhibitor not only suppressed the digestion of band 3 protein, but also blunted the functional damage to erythrocytes, such as deformability and anion exchange, without changing the level of peroxidation of membrane lipids. These results provide experimental evidence that activation of caspase-3 plays an important role in the oxidative stress-induced impairment of membrane functions of erythrocytes.     

Age-Associated Different Transcriptome Profiling in Zebrafish and Rats: an Insight into the Diversity of Vertebrate Aging

Marine Biotechnology - Most mammals, including humans, show obvious aging phenotypes, for example, loss of tissue plasticity and sarcopenia. In this regard, fish can be attractive models to study...     

Effects of a novel gaseous antioxidative system containing a rosemary extract on the oxidation induced by nitrogen dioxide and ultraviolet radiation

Rosemary is commonly used as a spice and a flavoring agent in food processing. Although the antioxidative properties of its extracts have been investigated, there have been few reports on the volatile components of rosemary. We designed a novel antioxidative system which can generate the volatile constituents in the gaseous phase from a rosemary extract and evaluated the gaseous antioxidative activities against both lipid peroxidation and cell death induced by nitrogen dioxide and ultraviolet radiation. The antioxidative effects of the major volatile components on the oxidation of linoleic acid induced by azo compounds were also investigated in a solution. The volatile components in the novel antioxidative system suppressed the Jurkat cell death induced by nitrogen dioxide and the intracellular formation of reactive oxygen species in fibroblast cells induced by ultraviolet radiation. 1,8-Cineole among the volatile components exerted an antioxidative effect against the oxidation of linoleic acid in a solution induced by azo compounds and ultraviolet radiation. These data suggest that the volatile constituents of a rosemary extract had antioxidative properties and that gaseous exposure antioxidant is a promising method for promoting health.     

Formation of N-(hexanoyl)ethanolamine, a novel phosphatidylethanolamine adduct, during the oxidation of erythrocyte membrane and low-density lipoprotein

The primary amino groups of biomolecules such as aminophospholipids, as well as proteins, are the potential targets of covalent modifications by lipid peroxidation products; however, little attention has been paid to the modification of aminophospholipids such as phosphatidylethanolamine (PE). The purpose of this study is to characterize the formation of a novel modified phospholipid, N-(hexanoyl)phosphatidylethanolamine (HEPE), in the reaction of PE with lipid hydroperoxides using mass spectrometric analyses. Upon reaction of egg PE with 13-hydroperoxyoctadecadienoic acid or other oxidized polyunsaturated fatty acids followed by phospholipase D-mediated hydrolysis, the formation of N-(hexanoyl)ethanolamine (HEEA), a head group of HEPE, was confirmed by isotope dilution liquid chromatography/tandem mass spectrometry. Moreover, increasing HEEA was detected in the hydrolysates of oxidized erythrocyte ghosts and low-density lipoprotein with their increasing lipid peroxidation levels. Collectively, these results suggest that the N-hexanoylated product of phospholipid, HEPE, can be generated during lipid peroxidation and may serve as one mechanism for the covalent modification of aminophospholipids in vivo.     

Oligoamine-acridine conjugates for promotion of gap-selective DNA hydrolysis by Ce(IV)/EDTA complex

Oligoamines (spermidine, dipropylenetriamine and propylenediamine) were covalently attached to acridine via a hexamethylene linker. These oligoamine–acridine conjugates were efficiently bound to gap sites in substrate DNA, and promoted the DNA hydrolysis by a homogeneous Ce(IV)/ethylenediamine-N,N,N′,N′-tetraacetate (EDTA) complex at these sites. In contrast, the hydrolysis of the double-stranded portion in the DNA was little affected by these conjugates, although they were strongly bound thereto by the intercalation of their acridine moieties. As a result, the gap site was selectively and efficiently hydrolyzed by combining the Ce(IV)/EDTA complex with the oligoamine– acridine conjugate. Either the oligoamine or the acridine was only poorly active for the purpose, substantiating the essential role of cooperation between them. The promotion of gap-selective DNA hydrolysis by the conjugates has been ascribed to electrostatic stabilization of a negatively charged transition state by their positive charges.     

Inducible liver injury in the transgenic rat by expressing liver-specific suicide gene

Suicide gene expression in specific tissue of transgenic animals has been used for cell-specific ablation. To examine the influence of hepatocyte removal, we produced the herpes simplex virus thymidine kinase (HSVtk) transgenic rat, whose gene was regulated by an albumin enhancer promoter. The liver presence of HSVtk was demonstrated in one line of the transgenic rats. We injected ganciclovir (GCV, 50mg/kg) into the rat on alternate days. After 28 days of GCV administration, liver tissues, and blood of the rats were collected. The histological investigation revealed infiltration of T cells, macrophages, granulocytes/neutrophils, and hepatocyte cell death. The biochemistry analysis demonstrated elevated levels of AST, ALT, and total bilirubin in transgenic rat. In conclusion, the transgenic rat with expressed albumin-specific HSVtk developed experimental hepatitis with administration of GCV, and will be a useful model to facilitate the evaluation of drug effects for clinical control of liver disease.     

Establishment of Alb-DsRed2 transgenic rat for liver regeneration research

Because serum albumin is specifically produced by mature hepatocytes, detection system of albumin producing cells could be a valuable tool to visualize liver regeneration or development. We have developed here an albumin enhancer/promoter-driven Alb-DsRed2 Tg rat that expresses DsRed2, having liver-specific reporter gene expression of red fluorescent protein. To study the transdifferentiation of bone marrow cells (BMCs) into albumin producing cells, BMCs from the Alb-DsRed2 Tg rat were injected into rats having acute liver damage caused by 2-acetylaminofluorene plus carbon tetrachloride and chronic liver damage by repeated administration of CCl(4). DsRed2-positive cells were generated in the recipient liver after BMC injection. The number of transdifferentiated DsRed2-positive cells in chronic liver injury model was increased comparing with that in acute injury model. We propose that the Alb-DsRed2 Tg rat is well suited to studying in vivo liver regeneration.