Publications by authors named "Jennifer L R Freeman"

Aims: To determine the effect of TTP399, a hepatoselective glucokinase activator, on the risk of ketoacidosis during insulin withdrawal in individuals with type 1 diabetes (T1D).

Materials And Methods: Twenty-three participants with T1D using insulin pump therapy were randomized to 800 mg TTP399 (n = 12) or placebo (n = 11) for 7 to 10 days. After the treatment period, an insulin withdrawal test (IWT) was performed, during which insulin pumps were removed to induce ketogenesis.

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Objective: Despite advances in exogenous insulin therapy, many patients with type 1 diabetes do not achieve acceptable glycemic control and remain at risk for ketosis and insulin-induced hypoglycemia. We conducted a randomized controlled trial to determine whether TTP399, a novel hepatoselective glucokinase activator, improved glycemic control in people with type 1 diabetes without increasing hypoglycemia or ketosis.

Research Design And Methods: SimpliciT1 was a phase 1b/2 adaptive study.

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The therapeutic success of interventions targeting glucokinase (GK) activation for the treatment of type 2 diabetes has been limited by hypoglycemia, steatohepatitis, and loss of efficacy over time. The clinical characteristics of patients with GK-activating mutations or GK regulatory protein (GKRP) loss-of-function mutations suggest that a hepatoselective GK activator (GKA) that does not activate GK in β cells or affect the GK-GKRP interaction may reduce hyperglycemia in patients with type 2 diabetes while limiting hypoglycemia and liver-associated adverse effects. Here, we review the rationale for TTP399, an oral hepatoselective GKA, and its progression from preclinical to clinical development, with an emphasis on the results of a randomized, double-blind, placebo- and active-controlled phase 2 study of TTP399 in patients with type 2 diabetes.

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1,5-Anhydroglucitol (1,5-AG), the 1-deoxy form of glucose, has been measured and used clinically in Japan for over a decade to monitor short-term glycemic control. Evaluation of glucose control otherwise requires measuring plasma glucose or glycated proteins whose levels reflect average glucose concentration over the half-life of the protein analyzed. Hemoglobin A1c measurements reflect blood glucose levels over that past 2-3 months, while fructosamine can be used to evaluate glycemic control over 10-14 days.

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G protein-coupled receptor kinases are well characterized for their ability to phosphorylate and desensitize G protein-coupled receptors (GPCRs). In addition to phosphorylating the beta2-adrenergic receptor (beta2AR) and other receptors, G protein-coupled receptor kinase 2 (GRK2) can also phosphorylate tubulin, a nonreceptor substrate. To identify novel nonreceptor substrates of GRK2, we used two-dimensional gel electrophoresis to find cellular proteins that were phosphorylated upon agonist-stimulation of the beta2AR in a GRK2-dependent manner.

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