Proteomic study on X-irradiation-responsive proteins and ageing: search for responsible proteins for radiation adaptive response.

We investigated high- or low-dose irradiation-responsive proteins using proteomics on two-dimensional (2D) PAGE, and the effects of ageing on cell responses to radiation in variously aged rat astrocytes. After 5 Gy irradiation, the relative abundance of peroxiredoxin 2, an antioxidant enzyme, and latexin, an inhibitor of carboxypeptidase, increased. The induction of these proteins was suppressed by ageing, suggesting that the response to high-dose radiation decreased with ageing.

Phosphoproteomic profiling of human SH-SY5Y neuroblastoma cells during response to 6-hydroxydopamine-induced oxidative stress.

Dopaminergic neurons are known to be vulnerable to age-related neuronal disorders due to reactive oxygen species (ROS) generated during dopamine metabolism. However, it remains unclear what kinds of proteins are involved in the response to oxidative stress. We examined changes in whole proteins and phosphoproteins in the human dopaminergic neuroblastoma cell line SH-SY5Y under oxidative stress induced by the dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA).

Chromatin-related proteins in pluripotent mouse embryonic stem cells are downregulated after removal of leukemia inhibitory factor.

Embryonic stem (ES) cells have generated enormous interest due to their capacity to self-renew and the potential for growing many different cell types in vitro. Leukemia inhibitory factor (LIF), bone morphogenetic proteins, octamer-binding protein 3 or 4, and Nanog are important factors in the maintenance of pluripotency in mouse ES cells. However, the mechanisms by which these factors regulate the pluripotency remain poorly understood.

Performance of electrokinetic supercharging for high-sensitivity detection of DNA fragments in chip gel electrophoresis.

Chip gel electrophoresis was explored for high-sensitivity detection of DNA by combining electrokinetic injection with transient isotachophoresis preconcentration (here named electrokinetic supercharging (EKS)). Low concentrations (0.2 mg/L) of DNA sample could be detected without fluorescence labeling using a conventional UV detector (at 260 nm).

Electrokinetic supercharging preconcentration and microchip gel electrophoretic separation of sodium dodecyl sulfate-protein complexes.

A microchip gel electrophoresis (MCGE) method with electrokinetic supercharging (EKS, electrokinetic injection with transient isotachophoresis) on a single channel chip was developed for high-sensitive detection of a standard mixture of six proteins (phosphorylase b, albumin, ovalbumin, carbonic anhydrase, trypsin inhibitor, and alpha-lactalbumin) in the form of sodium dodecyl sulfate (SDS) complexes. An average lower limit of detectable concentration (LLDC) achieved using UV detection at 214 nm was 0.27 microg/mL that is 30 times lower than that of conventional MCGE on a cross geometry chip.