Expression and localization of prostaglandin transporter in Alzheimer disease brains and age-matched controls

Neuroinflammation, a major contributor to neurodegenerative diseases, involves the contribution of activated microglia, reactive astrocytes, and infiltrating inflammatory cells. Stress and various acute or chronic brain injuries stimulate the generation of free radicals and glutamate, triggering inflammatory pathways that lead to increases in chemokines, cytokines, and prostaglandins. Prostaglandins are lipid mediators of inflammation that are produced from arachidonic acid by cyclooxygenase enzymes. They are generally believed to be in all tissues and organs. Their transport through the lipid bilayers of the cell membranes/organelles is facilitated by the prostaglandin transporter (PGT). In this study, middle frontal gyrus brain tissue from patients diagnosed with Alzheimer disease (AD) and that of age-matched control brains were examined to determine the protein expression pattern of PGT and its possible role in modulating neuroinflammation associated with AD. Immunohistochemical and immunofluorescent studies showed that PGT protein was expressed in all the brain tissues examined and was localized in neurons, microglia, and astrocytes. Interestingly, Western blot analysis revealed that the PGT level was significantly less in AD than in age-matched control brain homogenates. Further work is warranted to address the possibility and implications that prostaglandins might not be cleared at a proper rate in AD brains.