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Biology subjects

Mahan, T. E.

Publications and source records attributed to Mahan, T. E..

2 recordsLinked to original sources

Sulfonylureas target the neurovascular response to decrease Alzheimer's pathology

Hyperexcitability is a defining feature of Alzheimers disease (AD), where aberrant neuronal activity is both a cause and consequence of AD. Therefore, identifying novel targets that modulate cellular excitability is an important strategy for treating AD. ATP-sensitive potassium (KATP) channels are metabolic sensors that modulate cellular excitability. Sulfonylureas are KATP channel antagonists traditionally used to combat hyperglycemia in diabetic patients by inhibiting pancreatic KATP channels, thereby stimulating insulin release. However, KATP channels are not limited to the pancreas and systemic modulation of KATP channels has pleotropic physiological effects, including profound effects on vascular function. Here, we demonstrate that human AD patients have higher cortical expression of vascular KATP channels, important modulators of vasoreactivity. We demonstrate that peripheral treatment with the sulfonylurea and KATP channel inhibitor, glyburide, reduced the aggregation and activity-dependent production of amyloid-beta (A{beta}), a hallmark of AD, in mice. Since glyburide does not readily cross the blood brain barrier, our data suggests that glyburide targets vascular KATP channel activity to reduce arterial stiffness, improve vasoreactivity, and normalize pericyte-endothelial cell morphology, offering a novel therapeutic target for AD. Graphical abstractTargeting vascular KATP channel activity for the treatment of Alzheimers disease pathology. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

neuroscience↗

High affinity interactions and signal transduction between Aβ oligomers and TREM2

Rare coding variant in the Triggering receptor expressed on myeloid cells 2 (TREM2) are associated with increased risk for Alzheimers disease (AD), but how they confer this risk remains uncertain. We assessed binding of TREM2, AD associated TREM2 variants to various forms of A{beta} and APOE in multiple assays. TREM2 interacts directly with various forms of A{beta}, with highest affinity interactions observed between TREM2 and soluble A{beta}42 oligomers. We confirm the previous interaction between APOE3 and APOE4 and TREM2. High affinity binding of TREM2 to A{beta} oligomers is characterized by very slow dissociation. Pre-incubation with A{beta} is shown to block the interaction of APOE. In cellular assays, AD-associated variants of TREM2 reduced the amount of A{beta}42 internalized, and in NFAT assay the R47H variant decreased NFAT signaling activity in response to A{beta}42. These studies demonstrate i) a high affinity interaction between TREM2 and A{beta} oligomers that can block interaction with another ligand and ii) that AD-associated TREM2 variants bind A{beta} with equivalent affinity but show loss of function in terms of signaling and A{beta} internalization.

cell biology↗