Evaluation of a melanocortin-4 receptor (MC4R) agonist (Setmelanotide) in MC4R deficiency.

Objective: Pro-opiomelanocortin (POMC)-derived peptides act on neurons expressing the Melanocortin 4 receptor (MC4R) to reduce body weight. Setmelanotide is a highly potent MC4R agonist that leads to weight loss in diet-induced obese animals and in obese individuals with complete POMC deficiency. While POMC deficiency is very rare, 1-5% of severely obese individuals harbor heterozygous mutations in MC4R.

Plasmonic activation of gold nanorods for remote stimulation of calcium signaling and protein expression in HEK 293T cells.

Remote activation of specific cells of a heterogeneous population can provide a useful research tool for clinical and therapeutic applications. Here, we demonstrate that photostimulation of gold nanorods (AuNRs) using a tunable near-infrared (NIR) laser at specific longitudinal surface plasmon resonance wavelengths can induce the selective and temporal internalization of calcium in HEK 293T cells. Biotin-PEG-Au nanorods coated with streptavidin Alexa Fluor-633 and biotinylated anti-His antibodies were used to decorate cells genetically modified with His-tagged TRPV1 temperature-sensitive ion channel and AuNRs conjugated to biotinylated RGD peptide were used to decorate integrins in unmodified cells.

Intracerebral adeno-associated virus gene delivery of apolipoprotein E2 markedly reduces brain amyloid pathology in Alzheimer's disease mouse models.

The common apolipoprotein E alleles (ε4, ε3, and ε2) are important genetic risk factors for late-onset Alzheimer's disease, with the ε4 allele increasing risk and reducing the age of onset and the ε2 allele decreasing risk and markedly delaying the age of onset. Preclinical and clinical studies have shown that apolipoprotein E (APOE) genotype also predicts the timing and amount of brain amyloid-β (Aβ) peptide deposition and amyloid burden (ε4 >ε3 >ε2). Using several administration protocols, we now report that direct intracerebral adeno-associated virus (AAV)-mediated delivery of APOE2 markedly reduces brain soluble (including oligomeric) and insoluble Aβ levels as well as amyloid burden in 2 mouse models of brain amyloidosis whose pathology is dependent on either the expression of murine Apoe or more importantly on human APOE4.

Tau pathogenesis is promoted by Aβ1-42 but not Aβ1-40.

Background: The relationship between the pathogenic amyloid β-peptide species Aβ1-42 and tau pathology has been well studied and suggests that Aβ1-42 can accelerate tau pathology in vitro and in vivo. The manners if any in which Aβ1-40 interacts with tau remains poorly understood. In order to answer this question, we used cell-based system, transgenic fly and transgenic mice as models to study the interaction between Aβ1-42 and Aβ1-40.

Low-density lipoprotein receptor overexpression enhances the rate of brain-to-blood Aβ clearance in a mouse model of β-amyloidosis.

The apolipoprotein E (APOE)-ε4 allele is the strongest genetic risk factor for late-onset, sporadic Alzheimer's disease, likely increasing risk by altering amyloid-β (Aβ) accumulation. We recently demonstrated that the low-density lipoprotein receptor (LDLR) is a major apoE receptor in the brain that strongly regulates amyloid plaque deposition. In the current study, we sought to understand the mechanism by which LDLR regulates Aβ accumulation by altering Aβ clearance from brain interstitial fluid.