The proglucagon gene encodes pancreatic glucagon and the glucagon-like peptides, which exert diverse effects on nutrient absorption and assimilation. The therapeutic potential of glucagon-like peptide-1 (GLP-1) has fostered interest in development of cellular engineering approaches to augment endogenous intestinal-derived GLP-1 for the treatment of type 2 diabetes. We have used adenovirus technology to examine the potential roles of the transcription factors Cdx-2/3 and Pax-6 as activators of endogenous proglucagon gene expression in enteroendocrine cell lines and in nontransformed rat intestinal cells. Adenoviral-expressed Cdx-2/3 and Pax-6 activated proglucagon promoter-luciferase activity in baby hamster kidney (BHK) fibroblasts, HEK 293 cells, and enteroendocrine cell lines. Pax-6, but not Cdx-2/3, induced expression of the endogenous proglucagon gene in enteroendocrine cell lines, but not in heterologous fibroblasts. Furthermore, transduction of primary rat intestinal cell cultures in vitro, or the rat colonic epithelium in vivo, with Ad-Pax-6 activated endogenous proglucagon gene expression. These data demonstrate that Pax-6, but not Cdx-2/3, is capable of activating the endogenous proglucagon gene in both immortalized enteroendocrine cells and the nontransformed intestinal epithelium in vivo.
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http://dx.doi.org/10.2337/diabetes.52.2.425 | DOI Listing |
Mol Cell Endocrinol
January 2025
Gastric Cancer Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China. Electronic address:
Objective: The gut-brain axis (GBA) is involved in the modulation of multiple physiological activities, and the vagus nerve plays an important role in this process. However, the association between vagus nerve function and nutritional regulation remains unclear. Here, we explored changes in the nutritional status of mice after vagotomy and investigated the underlying mechanisms responsible for these changes.
View Article and Find Full Text PDFCell Mol Life Sci
January 2025
Institute of Medicine, Chung Shan Medical University, No. 110, Sec. 1, Jianguo N. Rd, Taichung City, 402, Taiwan.
Background: Diabetes is a primary contributor to diabetic cardiomyopathy (DbCM), which is marked by metabolic imbalances such as elevated blood glucose and lipid levels, leading to significant structural and functional alterations in the myocardium. Elevated free fatty acids (FFAs) and hyperglycemia play critical roles in DbCM development, with FFAs inducing insulin resistance in cardiomyocytes and promoting lipid accumulation, resulting in oxidative stress and fibrosis. Current research suggests that glucagon-like peptide-1 (GLP-1) receptor agonists may effectively mitigate DbCM, although an effective treatment for this condition remains elusive, and the precise mechanisms of this protective effect are not fully understood.
View Article and Find Full Text PDFSci Transl Med
January 2025
Institute of Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Elevated glucagon concentrations have been reported in patients with type 2 diabetes (T2D). A critical role for α cell-intrinsic mechanisms in regulating glucagon secretion was previously established through genetic manipulation of the glycolytic enzyme glucokinase (GCK) in mice. Genetic variation at the glucose-6-phosphatase catalytic subunit 2 () locus, encoding an enzyme that opposes GCK, has been reproducibly associated with fasting blood glucose and hemoglobin A1c.
View Article and Find Full Text PDFJ Nanobiotechnology
December 2024
NHC Key Laboratory for Critical Care Medicine, School of Medicine, Tianjin First Central Hospital, Research Institute of Transplant Medicine, Organ Transplant Center, Nankai University, Tianjin, 300071, China.
Islet transplantation is a promising therapy for diabetes, yet the limited survival and functionality of transplanted islet grafts hinder optimal outcomes. Glucagon-like peptide-1 (GLP-1), an endogenous hormone, has shown potential to enhance islet survival and function; however, its systemic administration can result in poor localization and undesirable side effects. To address these challenges, we developed a novel peptide-based nanofiber hydrogel incorporating GLP-1 functionality for localized delivery.
View Article and Find Full Text PDFMol Metab
January 2025
Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan. Electronic address:
Objectives: Arginine vasopressin (AVP), known as an antidiuretic hormone, is also crucial in metabolic homeostasis. Although AVP receptor-deficient mice exhibit various abnormalities in glucose and lipid metabolism, the mechanism underlying these symptoms remains unclear. This study aimed to explore the involvement of the gut hormones including glucagon-like peptide-1 (GLP-1) and microbiota as essential mediators.
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