Brain region‐specific immunolocalization of the lipolysis‐stimulated lipoprotein receptor (LSR) and altered cholesterol distribution in aged LSR^+/− mice

Abstract

Brain lipid homeostasis is important for maintenance of brain cell function and synaptic communications, and is intimately linked to age-related cognitive decline. Because of the bloodbrain barrier's limiting nature, this tissue relies on a complex system for the synthesis and receptor-mediated uptake of lipids between the different networks of neurons and glial cells. Using immunofluorescence, we describe the region-specific expression of the lipolysis-stimulated lipoprotein receptor (LSR), in the mouse hippocampus, cerebellum Purkinje cells, the ependymal cell interface between brain parenchyma and cerebrospinal fluid, and the choroid plexus. Colocalization with cell-specific markers revealed that LSR was expressed in neurons, but not astrocytes. Age-related cognitive decline associated with higher risk of neurodegenerative disorders has become an important public concern as life expectancy increases in industrially developed countries. Although the molecular mechanisms underlying the decrease in memory and other brain-related functions with age are under active investigation, the processes Address correspondence and reprint requests to Frances T. Yen, Lipidomix, Université de Lorraine, ENSAIA, 2 avenue de la Forêt de Haye, 54501 Vandoeuvre-lès-Nancy, France. E-mail: frances.yen-potin@univ-lorraine.fr 1 CS and AP contributed equally to this work.Abbreviations used: BBB, blood-brain barrier; FFA, free fatty acid; GFAP, glial fibrillary acidic protein; LDL-R, low-density lipoprotein receptor; LpL, lipoprotein lipase; LRP1, low-density lipoprotein receptor-related protein 1; LSR, lipolysis-stimulated lipoprotein receptor; NeuN, neuronal nuclei; PBS, phosphate-buffered saline; PFA, paraformaldehyde. Journal of Neurochemistry

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