Characterization of serum lipoproteins from Suncus: a candidate animal model for abetalipoproteinemia
Related Experiment Videos
1Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo.
Abstract:
We have previously reported that fatty liver was induced in a novel experimental animal, Suncus murinus (suncus), by 24-h fasting and that apolipoprotein B (apo B) was not actively synthesized in the liver. However, a faint signal of apo B mRNA was detected in the liver, suggesting possible synthesis of apo B. Small amounts of VLDL and LDL have been separated from suncus serum by ultracentrifugation. Electron microscopic study of the lipoproteins revealed the existence of small particles in VLDL. High performance liquid chromatographic analysis of the lipoproteins showed that the peaks of TG and cholesterol were mainly at the HDL fraction. These results indicate the existence of lipoproteins as small as HDL which were rich in TG and floated at the density of VLDL upon ultracentrifugation. Apolipoprotein analysis showed two bands of 500- and 200-kDa proteins in VLDL and LDL. Western blot analysis using antibody against the 500-kDa protein revealed reaction not only with suncus 500- and 200-kDa proteins but also with human apo B-100. In conclusion, a small amount of apo B is transported in the suncus serum as VLDL and LDL, although almost all lipid is packed in HDL-size particles.
Insights
Suncus murinus, a novel animal model, shows limited apolipoprotein B (apo B) synthesis but transports it in VLDL and LDL. Most lipids are packaged in HDL-size particles, despite apo B presence in VLDL/LDL.
Area of Science:
- Biochemistry
- Animal Models
- Lipid Metabolism
Background:
- Fatty liver induced in Suncus murinus by fasting.
- Previous findings suggested limited apolipoprotein B (apo B) synthesis in the liver.
Purpose of the Study:
- Investigate the presence and characteristics of apolipoprotein B (apo B) in Suncus murinus serum.
- Clarify the lipoprotein profile and lipid packaging in this animal model.
Main Methods:
- Ultracentrifugation to separate VLDL and LDL from serum.
- Electron microscopy for lipoprotein particle visualization.
- High-performance liquid chromatography (HPLC) for lipid analysis.
- Western blot analysis for apolipoprotein identification.
Main Results:
- Small amounts of VLDL and LDL were detected in suncus serum.
- Lipoprotein analysis revealed TG and cholesterol peaks mainly in the HDL fraction.
- Apolipoprotein analysis identified 500- and 200-kDa proteins in VLDL/LDL, reacting with anti-human apo B-100 antibody.
Conclusions:
- Suncus murinus transports a small quantity of apolipoprotein B (apo B) within VLDL and LDL fractions.
- Lipids are predominantly packaged into HDL-sized particles, despite their density characteristics.
- This suggests a unique lipid transport mechanism in Suncus murinus.