PDT-induced epigenetic changes in the mouse cerebral cortex: a protein microarray study

Area of Science:

• Neuroscience
• Oncology
• Epigenetics

Background:

• Photodynamic therapy (PDT) is a cancer treatment, but its effects on normal brain tissue epigenetics are unknown.
• Investigating epigenetic changes in normal brain tissue after PDT is crucial for understanding treatment side effects.

Purpose of the Study:

• To investigate the role of epigenetic processes in photodynamic injury of normal brain tissue.
• To identify epigenetic markers of photo-oxidative injury in the mouse cerebral cortex following ALA-PDT.

Main Methods:

• 5-Aminolevulinic acid (ALA) was used to photosensitize mouse cerebral cortex, followed by spectrofluorometric PpIX measurement.
• Histological staining and proteomic antibody microarrays were employed to assess morphological and epigenetic changes.
• Expression of proteins involved in epigenetic regulation, DNA repair, and transcription was evaluated.

Main Results:

• ALA-PDT induced PpIX accumulation, neuronal injury, and microvascular alterations in the mouse cerebral cortex.
• Epigenetic changes included histone H3 dimethylation, upregulation of HDAC-1/HDAC-11, and altered DNA methylation (Kaiso).
• Modifications in DNA repair proteins (H2AX, MTA1/MTA1L1, PML) and transcription factors (FOXC2, E2F4) were observed.

Conclusions:

• ALA-PDT causes neuronal and microvascular injury in the normal mouse cerebral cortex.
• Epigenetic regulation of transcription, histone modification, DNA repair, and protein import is altered by ALA-PDT.
• Specific epigenetic alterations serve as markers for photo-oxidative injury in normal brain tissue.