Lactoferrin receptor (LfR)

Lactoferrin receptors, primarily comprising Low-density lipoprotein receptor-related protein 1 (LRP1) and Intelectin-1 (ITLN1), are cell-surface glycoproteins that mediate the diverse biological effects of lactoferrin, a multifunctional iron-binding protein. LRP1 is a large, multi-ligand endocytic and signaling receptor widely expressed in the brain, liver, and bone, where it facilitates the transport of lactoferrin across the blood-brain barrier and stimulates osteoblast proliferation. Intelectin-1, often referred to as the intestinal lactoferrin receptor, is predominantly expressed in the small intestine and is responsible for the uptake of dietary lactoferrin and iron. These receptors play critical roles in iron homeostasis, immune modulation, and neuroprotection, making them attractive targets for drug delivery and therapeutic intervention in neurodegenerative diseases, cancer, and osteoporosis. Drugs and delivery systems, such as lactoferrin-conjugated nanoparticles and recombinant human lactoferrin (e.g., talactoferrin), leverage these receptors to enhance tissue-specific targeting and modulate inflammatory or metabolic pathways.

Other names

Low-density lipoprotein receptor-related protein 1LRP1Intelectin-1ITLN1Omentin-1CD91Alpha-2-macroglobulin receptorA2MRLow-density lipoprotein receptor-related protein 2LRP2Megalin

Lactoferrin receptors mediate the cellular uptake of lactoferrin through receptor-mediated endocytosis and transcytosis, particularly across the blood-brain barrier and intestinal epithelium. Upon binding, these receptors activate intracellular signaling pathways, including the MAPK/ERK and PI3K/Akt cascades, which promote cell survival, proliferation, and anti-inflammatory responses. In the context of drug delivery, lactoferrin-modified carriers exploit these receptors for targeted transport into the central nervous system or tumor cells. Additionally, the receptors facilitate iron sequestration and modulate the innate immune response by interacting with Toll-like receptors and other signaling molecules.