Mannosylphosphodolichol synthase overexpression supports angiogenesis

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• Mannosylphosphodolichol synthase (DPMS) is crucial for lipid-linked oligosaccharide (LLO) biosynthesis, a key step in N-linked protein glycosylation.
• Phosphorylation of DPMS enhances its catalytic activity, increasing LLO biosynthesis and protein N-glycosylation, which promotes angiogenesis.

Purpose of the Study:

• To investigate whether DPMS phosphorylation or overexpression drives angiogenesis.
• To determine the role of DPMS in regulating angiogenesis in capillary endothelial cells.

Main Methods:

• Quantitative reverse transcription PCR (QRT-PCR) to assess DPMS mRNA levels.
• Western blotting to quantify DPMS protein expression.
• Enzyme activity assays to measure DPMS catalytic function.
• Immunofluorescence microscopy to detect cell surface glycans.
• Cell proliferation and wound healing assays to evaluate angiogenesis.

Main Results:

• DPMS overexpression in capillary endothelial cells led to significantly higher DPMS mRNA and protein levels compared to controls.
• DPMS activity was approximately 108% higher in overexpressing cells.
• Increased expression of specific glycans (GlcNAc-beta-(1,4)-GlcNAc)1-4-beta-GlcNAc-NeuAc) was observed on the cell surface.
• DPMS overexpressing cells exhibited enhanced proliferation and accelerated wound healing.

Conclusions:

• DPMS overexpression, independent of phosphorylation, is sufficient to up-regulate angiogenesis.
• Increased DPMS activity and subsequent alterations in cell surface glycosylation contribute to enhanced endothelial cell proliferation and angiogenesis.
• DPMS is a key regulator of angiogenesis and a potential therapeutic target.