66 research outputs found
Proteolytic processing of chromogranin A in purified insulin granules. Formation of a 20 kDa N-terminal fragment (betagranin) by the concerted action of a Ca2+-dependent endopeptidase and carboxypeptidase H (EC 3.4.17.10)
Physiologic and Pharmacologic Modulation of Glucose-Dependent Insulinotropic Polypeptide (GIP) Receptor Expression in β-Cells by Peroxisome Proliferator–Activated Receptor (PPAR)-γ Signaling: Possible Mechanism for the GIP Resistance in Type 2 Diabetes
β-Cell Proliferation, but Not Neogenesis, Following 60% Partial Pancreatectomy Is Impaired in the Absence of FoxM1
OBJECTIVE—This study was designed to determine whether the transcription factor FoxM1 was required for regeneration of β-cell mass via proliferation and/or neogenesis in the adult after 60% partial pancreatectomy (PPx)
Blood Glucose Levels Regulate Pancreatic β-Cell Proliferation during Experimentally-Induced and Spontaneous Autoimmune Diabetes in Mice
Type 1 diabetes mellitus is caused by immune-mediated destruction of pancreatic beta-cells leading to insulin deficiency, impaired intermediary metabolism, and elevated blood glucose concentrations. While at autoimmune diabetes onset a limited number of beta-cells persist, the cells' regenerative potential and its regulation have remained largely unexplored. Using two mouse autoimmune diabetes models, this study examined the proliferation of pancreatic islet ss-cells and other endocrine and non-endocrine subsets, and the factors regulating that proliferation.We adapted multi-parameter flow cytometry techniques (including DNA-content measurements and 5'-bromo-2'-deoxyuridine [BrdU] incorporation) to study pancreatic islet single cell suspensions. These studies demonstrate that beta-cell proliferation rapidly increases at diabetes onset, and that this proliferation is closely correlated with the diabetic animals' elevated blood glucose levels. For instance, we show that when normoglycemia is restored by exogenous insulin or islet transplantation, the beta-cell proliferation rate returns towards low levels found in control animals, yet surges when hyperglycemia recurs. In contrast, other-than-ss endocrine islet cells did not exhibit the same glucose-dependent proliferative responses. Rather, disease-associated alterations of BrdU-incorporation rates of delta-cells (minor decrease), and non-endocrine islet cells (slight increase) were not affected by blood glucose levels, or were inversely related to glycemia control after diabetes onset (alpha-cells).We conclude that murine beta-cells' ability to proliferate in response to metabolic need (i.e. rising blood glucose concentrations) is remarkably well preserved during severe, chronic beta-cell autoimmunity. These data suggest that timely control of the destructive immune response after disease manifestation could allow spontaneous regeneration of sufficient beta-cell mass to restore normal glucose homeostasis
Structure and regulation of the human muscle-specific enolase
SIGLEAvailable from British Library Document Supply Centre-DSC:DX189938 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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