APOD (Apolipoprotein D) is a lipocalin-family protein primarily associated with lipid metabolism and transport. Initially identified as a component of high-density lipoprotein (HDL), APOD binds small hydrophobic molecules such as cholesterol, arachidonic acid, and progesterone, facilitating their distribution and cellular uptake. Unlike other apolipoproteins, APOD is not liver-derived but is expressed in various tissues, including the brain, adrenal glands, and adipose tissue, suggesting diverse physiological roles beyond lipid transport.
Research highlights APOD's involvement in neuroprotection, aging, and stress response. In neurodegenerative diseases like Alzheimer’s and Parkinson’s, APOD levels increase, potentially mitigating oxidative stress and inflammation by regulating lipid peroxidation and stabilizing cell membranes. It also interacts with amyloid-beta peptides, implicating it in Alzheimer’s pathology. Additionally, APOD is overexpressed in certain cancers, where it may influence tumor progression, drug resistance, and metastasis through lipid signaling pathways.
Antibodies targeting APOD are critical tools for studying its expression, localization, and function. They enable detection in biological samples via techniques like Western blot, immunohistochemistry, and ELISA. Such antibodies aid in exploring APOD’s dual roles in neuroprotection and disease pathogenesis, as well as its potential as a biomarker or therapeutic target. However, challenges remain in standardizing antibodies due to APOD’s structural variability across species and isoforms. Ongoing research aims to refine antibody specificity to advance understanding of APOD’s complex roles in health and disease.