RESUMEN
Type 2 diabetes (T2D) is associated with defective insulin secretion and reduced ß cell mass. Available treatments provide a temporary reprieve, but secondary failure rates are high, making insulin supplementation necessary. Reversibility of ß cell failure is a key translational question. Here, we reverse engineered and interrogated pancreatic islet-specific regulatory networks to discover T2D-specific subpopulations characterized by metabolic inflexibility and endocrine progenitor/stem cell features. Single-cell gain- and loss-of-function and glucose-induced Ca2+ flux analyses of top candidate master regulatory (MR) proteins in islet cells validated transcription factor BACH2 and associated epigenetic effectors as key drivers of T2D cell states. BACH2 knockout in T2D islets reversed cellular features of the disease, restoring a nondiabetic phenotype. BACH2-immunoreactive islet cells increased approximately 4-fold in diabetic patients, confirming the algorithmic prediction of clinically relevant subpopulations. Treatment with a BACH inhibitor lowered glycemia and increased plasma insulin levels in diabetic mice, and restored insulin secretion in diabetic mice and human islets. The findings suggest that T2D-specific populations of failing ß cells can be reversed and indicate pathways for pharmacological intervention, including via BACH2 inhibition.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/antagonistas & inhibidores , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Señalización del Calcio , Diabetes Mellitus Tipo 2/metabolismo , Epigénesis Genética , Células Secretoras de Insulina/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Células HEK293 , HumanosRESUMEN
Phenotypic screening is a neoclassical approach for drug discovery. We conducted phenotypic screening for insulin secretion enhancing agents using INS-1E insulinoma cells as a model system for pancreatic beta-cells. A principal regulator of insulin secretion in beta-cells is the metabolically regulated potassium channel Kir6.2/SUR1 complex. To characterize hit compounds, we developed an assay to quantify endogenous potassium channel activity in INS-1E cells. We quantified ligand-regulated potassium channel activity in INS-1E cells using fluorescence imaging and thallium flux. Potassium channel activity was metabolically regulated and coupled to insulin secretion. The pharmacology of channel opening agents (diazoxide) and closing agents (sulfonylureas) was used to validate the applicability of the assay. A precise high-throughput assay was enabled, and phenotypic screening hits were triaged to enable a higher likelihood of discovering chemical matter with novel and useful mechanisms of action.
Asunto(s)
Diazóxido/farmacología , Células Secretoras de Insulina/efectos de los fármacos , Canales de Potasio de Rectificación Interna/metabolismo , Secretagogos/farmacología , Compuestos de Sulfonilurea/farmacología , Receptores de Sulfonilureas/metabolismo , Células Cultivadas , Evaluación Preclínica de Medicamentos , Ensayos Analíticos de Alto Rendimiento , Humanos , Secreción de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Imagen Óptica , FenotipoRESUMEN
The discovery and optimization of a novel series of GPR142 agonists are described. These led to the identification of compound 21 (LY3325656), which demonstrated anti-diabetic benefits in pre-clinical studies and ADME/PK properties suitable for human dosing. Compound 21 is the first GPR142 agonist molecule advancing to phase 1 clinic trials for the treatment of Type 2 diabetes.