Understanding mechanisms underlying apoptotic destruction of insulin-secreting cells is critical to validate therapeutic targets for type 1 diabetes mellitus. We recently reported insulin-like growth factor binding protein-3 (IGFBP-3) as a novel mediator of apoptosis in insulin-secreting cells. In light of emerging IGF-independent roles for IGFBP-3, we investigated the mechanisms underlying actions of the novel, recombinant human mutant G(56)G(80)G(81)-IGFBP-3, which lacks intrinsic IGF binding affinity. Using the rat insulinoma RINm5F cell line, we report the first studies in insulin-secreting cells that IGFBP-3 selectively suppresses multiple, key intracellular phosphorelays. By immunoblot, we demonstrate that G(56)G(80)G(81)-IGFBP-3 suppresses phosphorylation of c-raf-MEK-ERK pathway and p38 kinase in time-dependent and dose-dependent manners. SAPK/JNK signaling was unaffected. These data delineate several novel intracellular sites of action for IGFBP-3 in insulin-secreting cells.
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http://dx.doi.org/10.1016/j.ghir.2005.09.003 | DOI Listing |
Artif Organs
January 2025
Laboratory of Tissue Engineering and Organ Regeneration, Department of Surgery, University of Geneva, Geneva, Switzerland.
Intrahepatic islet transplantation is a promising strategy for β-cell replacement therapy in the treatment of Type 1 Diabetes. However, several obstacles hinder the long-term efficacy of this therapy. A major challenge is the scarcity of donor organs.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
UR Diabète et Thérapeutiques, Centre européen d'étude du Diabète, Université de Strasbourg, Strasbourg, France.
Aim: Pancreatic β-cells are susceptible to inflammation, leading to decreased insulin production/secretion and cell death. Previously, we have identified a novel triceps-derived myokine, DECORIN, which plays a pivotal role in skeletal muscle-to-pancreas interorgan communication. However, whether DECORIN can directly impact β-cell function and susceptibility to inflammation remains unexplored.
View Article and Find Full Text PDFCell Mol Life Sci
January 2025
Department of Clinical and Molecular Medicine (IKOM), Norwegian University of Science and Technology, Trondheim, 7028, Norway.
Enteroviruses can infect various human organs, causing diseases such as meningitis, the common cold, hand-foot-and-mouth disease, myocarditis, pancreatitis, hepatitis, poliomyelitis, sepsis, and type 1 diabetes. Currently, there are no approved treatments for enterovirus infections. In this study, we identified a synergistic combination of orally available, safe-in-man pleconaril, AG7404, and mindeudesivir, that at non-toxic concentrations effectively inhibited enterovirus replication in human cell and organoid cultures.
View Article and Find Full Text PDFJ Diabetes
January 2025
State Key Laboratory of Female Fertility Promotion, Department of Obstetrics and Gynecology, Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China.
Pancreatic islet transplantation is a crucial treatment for managing type 1 diabetes (T1D) in clinical settings. However, the limited availability of human cadaveric islet donors and the need for ongoing administration of immunosuppressive agents post-transplantation hinder the widespread use of this treatment. Stem cell-derived islet organoids have emerged as an effective alternative to primary human islets.
View Article and Find Full Text PDFDiabetes Metab J
January 2025
Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
Type 2 diabetes mellitus (T2DM) is marked by chronic hyperglycemia, gradually worsening β-cell failure, and insulin resistance. Glucotoxicity and oxidative stress cause β-cell failure by increasing reactive oxygen species (ROS) production, impairing insulin secretion, and disrupting transcription factors such as pancreatic and duodenal homeobox 1 (PDX-1) and musculoaponeurotic fibrosarcoma oncogene family A (MafA). Cluster determinant 36 (CD36), an essential glycoprotein responsible for fatty acid uptake, exacerbates oxidative stress and induces the apoptosis of β-cells under hyperglycemic conditions through pathways involving ceramide, thioredoxin-interacting protein (TXNIP), and Rac1-nicotinamide adenine dinucleotide phosphate oxidase (NOX)-mediated redoxosome formation.
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