Publications by authors named "Joanne M Buxton"

Objective: The liver is a central regulator of energy metabolism exerting its influence both through intrinsic processing of substrates such as glucose and fatty acid as well as by secreting endocrine factors, known as hepatokines, which influence metabolism in peripheral tissues. Human genome wide association studies indicate that a predicted loss-of-function variant in the Inhibin βE gene (INHBE), encoding the putative hepatokine Activin E, is associated with reduced abdominal fat mass and cardiometabolic disease risk. However, the regulation of hepatic Activin E and the influence of Activin E on adiposity and metabolic disease are not well understood.

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Genetic ablation of the voltage-gated potassium channel Kv1.3 improves insulin sensitivity and increases metabolic rate in mice. Inhibition of Kv1.

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A PEGylated glucagon-like peptide-1 (GLP-1) agonist and glucagon antagonist hybrid peptide was engineered as a potential treatment for type 2 diabetes. To support preclinical development of this PEGylated dual-acting peptide for diabetes (DAPD), we developed a reproducible method for PEGylation, purification, and analysis. Optimal conditions for site-specific PEGylation with 22 and 43 kDa maleimide-polyethylene glycol (maleimide-PEG) polymers were identified by evaluating pH, reaction time, and reactant molar ratio parameters.

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Type 2 diabetes is characterized by reduced insulin secretion from the pancreas and overproduction of glucose by the liver. Glucagon-like peptide-1 (GLP-1) promotes glucose-dependent insulin secretion from the pancreas, while glucagon promotes glucose output from the liver. Taking advantage of the homology between GLP-1 and glucagon, a GLP-1/glucagon hybrid peptide, dual-acting peptide for diabetes (DAPD), was identified with combined GLP-1 receptor agonist and glucagon receptor antagonist activity.

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VPAC2P-PEG is a VPAC2 receptor agonist peptide that acts as a glucose-dependent insulin secretagogue. Proteolysis by DPPIV may contribute to the in vivo clearance of VPAC2P-PEG. Here, the N-terminus of VPAC2P-PEG is modified by N-terminal acetylation to impart DPPIV resistance.

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The closely related peptides glucagon-like peptide (GLP-1) and glucagon have opposing effects on blood glucose. GLP-1 induces glucose-dependent insulin secretion in the pancreas, whereas glucagon stimulates gluconeogenesis and glycogenolysis in the liver. The identification of a hybrid peptide acting as both a GLP-1 agonist and a glucagon antagonist would provide a novel approach for the treatment of type 2 diabetes.

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