title: Leptin regulates amyloid β production via the γ-secretase complex.
abstract: Alzheimer's disease (AD) is the most common age-related neurodegenerative disease, affecting an estimated 5.3million people in the United States. While many factors likely contribute to AD progression, it is widely accepted that AD is driven by the accumulation of β-amyloid (Aβ), a small, fibrillogenic peptide generated by the sequential proteolysis of the amyloid precursor protein by the β- and γ-secretases. Though the underlying causes of Aβ accumulation in sporadic AD are myriad, it is clear that lifestyle and overall health play a significant role. The adipocyte-derived hormone leptin has varied systemic affects, including neuropeptide release and neuroprotection. A recent study by Lieb et al. (2009) showed that individuals with low plasma leptin levels are at greater risk of developing AD, through unknown mechanisms. In this report, we show that plasma leptin is a strong negative predictor of Aβ levels in the mouse brain, supporting a protective role for the hormone in AD onset. We also show that the inhibition of Aβ accumulation is due to the downregulation of transcription of the γ-secretase components. On the other hand, β-secretase expression is either unchanged (BACE1) or increased (BACE2). Finally, we show that only presenilin 1 (PS1) is negatively correlated with plasma leptin at the protein level (p<0.0001). These data are intriguing and may highlight a role for leptin in regulating the onset of amyloid pathology and AD.
authors.affiliation: University of Kentucky, Lexington, KY 40536-0230, USA.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Niedowicz
authors.forename: Christa M
authors.initials: CM
authors.lastname: Studzinski
authors.forename: Adam M
authors.initials: AM
authors.lastname: Weidner
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Platt
authors.forename: Kristen N
authors.initials: KN
authors.lastname: Kingry
authors.forename: Tina L
authors.initials: TL
authors.lastname: Beckett
authors.forename: Annadora J
authors.initials: AJ
authors.lastname: Bruce-Keller
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Keller
authors.forename: M Paul
authors.initials: MP
authors.lastname: Murphy
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000096:biosynthesis / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D020738:Leptin / Q000097:blood* / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D053764:Presenilin-1 / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016229:Amyloid beta-Peptides; D020738:Leptin; D008562:Membrane Glycoproteins; D053764:Presenilin-1; C413604:nicastrin protein; D053829:Amyloid Precursor Protein Secretases