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Osteopontin Affects Insulin Vesicle Localization and Ca2+ Homeostasis in Pancreatic Beta Cells from Female Mice
- Source :
- PLoS ONE, PLoS ONE, Vol 12, Iss 1, p e0170498 (2017)
- Publication Year :
- 2016
-
Abstract
- Type 2 diabetic patients suffer from insulin resistance and reduced insulin secretion. Osteopontin (OPN), a versatile protein expressed in several tissues throughout the body including the islets of Langerhans, has previously been implicated in the development of insulin resistance. Here we have investigated the role of OPN in insulin secretion using an OPN knock out mouse model (OPN-/-). Ultra-structural analyzes of islets from OPN-/- and WT mice indicated weaker cell-cell connections between the islet cells in the OPN-/- mouse compared to WT. Analysis of the insulin granule distribution in the beta cells showed that although OPN-/- and WT beta cells have the same number of insulin granules OPN-/- beta cells have significantly fewer docked granules. Both OPN-/- and WT islets displayed synchronized Ca2+ oscillations indicative of an intact beta cell communication. OPN-/- islets displayed higher intracellular Ca2+ concentrations when stimulated with 16.7 mM glucose than WT islets and the initial dip upon elevated glucose concentrations (which is associated with Ca2+ uptake into ER) was significantly lower in these islets. Glucose-induced insulin secretion was similar in OPN-/- and WT islets. Likewise, non-fasted blood glucose levels were the same in both groups. In summary, deletion of OPN results in several minor beta-cell defects that can be compensated for in a healthy system.
- Subjects :
- 0301 basic medicine
Physiology
medicine.medical_treatment
Peptide Hormones
Cell Membranes
lcsh:Medicine
Biochemistry
Mice
Endocrinology
Insulin-Secreting Cells
Insulin Secretion
Medicine and Health Sciences
Group-Specific Staining
Homeostasis
Insulin
Osteopontin
lcsh:Science
Mice, Knockout
Staining
Multidisciplinary
biology
Organic Compounds
Monosaccharides
Inulin
Hematology
Blood Sugar
Insulin oscillation
Body Fluids
Chemistry
Blood
Physical Sciences
Female
Beta cell
Cellular Structures and Organelles
Anatomy
Vesicle localization
Research Article
medicine.medical_specialty
endocrine system
Carbohydrates
Gastric Inhibitory Polypeptide
Real-Time Polymerase Chain Reaction
Research and Analysis Methods
03 medical and health sciences
Insulin resistance
stomatognathic system
Microscopy, Electron, Transmission
Internal medicine
medicine
Animals
Vesicles
Diabetic Endocrinology
Endocrine Physiology
Secretory Vesicles
lcsh:R
Organic Chemistry
Hematoxylin Staining
Chemical Compounds
Biology and Life Sciences
Cell Biology
medicine.disease
Hormones
030104 developmental biology
Glucose
Specimen Preparation and Treatment
biology.protein
Blood sugar regulation
lcsh:Q
Calcium
Subjects
Details
- ISSN :
- 19326203
- Volume :
- 12
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- PloS one
- Accession number :
- edsair.doi.dedup.....e62d6acd56a13d9538e91915e72abdb0