Search results for "Beta cell"
showing 10 items of 21 documents
Spatial learning and long-term memory impairments in RasGrf1 KO, Pttg1 KO, and double KO mice
2018
© 2018 The Authors.
Unexpected subcellular distribution of a specific isoform of the Coxsackie and adenovirus receptor, CAR-SIV, in human pancreatic beta cells
2018
Aims/hypothesis: The Coxsackie and adenovirus receptor (CAR) is a transmembrane cell-adhesion protein that serves as an entry receptor for enteroviruses and may be essential for their ability to infect cells. Since enteroviral infection of beta cells has been implicated as a factor that could contribute to the development of type 1 diabetes, it is often assumed that CAR is displayed on the surface of human beta cells. However, CAR exists as multiple isoforms and it is not known whether all isoforms subserve similar physiological functions. In the present study, we have determined the profile of CAR isoforms present in human beta cells and monitored the subcellular localisation of the princi…
Carnosine protects pancreatic beta cells and islets against oxidative stress damage
2018
Abstract Islet transplantation is a valid therapeutic option for type 1 diabetes treatment. However, in this procedure one of the major problems is the oxidative stress produced during pancreatic islet isolation. The aim of our study was to evaluate potential protective effects of L-carnosine and its isomer D-carnosine against oxidative stress. We evaluated the carnosine effect on cell growth, cell death, insulin production, and the main markers of oxidative stress in rat and murine stressed beta cell lines as well as in human pancreatic islets. Both isomers clearly inhibited hydrogen peroxide induced cytotoxicity, with a decrease in intracellular reactive oxygen and nitrogen species, preve…
The pancreatic beta-cell response to intravenous administration of glucose in elderly subjects.
1970
A study was made of the serum insulin level after the intravenous administration of glucose (0.33 gm/ kg) in two groups of normal subjects—18 in the 60–85 age bracket, and 16 in the 23–45 age bracket. All had a normal coefficient of glucose utilization and a normal blood glucose curve after intravenous administration of glucose. Serum insulin was assayed by the radio-immunological method, with use of an ion exchange resin. Blood samples were drawn at 2, 5, 10, 30, 45 and 60 minutes after the end of the glucose infusion. In the elderly subjects the maximal value was reached only after 5 minutes and the mean value was 39± 9 µU/ml (range, 27–50), whereas in the younger subjects the serum insul…
Autoimmune Diabetes Induced by the β-cell Toxin STZ: Immunity to the 60-kDa Heat Shock Protein and to Insulin
1994
Administered at a suitably low dose, the toxin streptozotocin (STZ) can trigger an autoimmune process leading to destruction of the beta-cells of the pancreatic islets. In this study, we examined specific immunological reactions in mice before and during the development of STZ-induced autoimmune diabetes. We now report that the development of spontaneous autoantibodies to insulin can serve as a marker of susceptibility to a low dose of STZ. Susceptible male mice of the C57BL/KsJ strain manifested such anti-insulin antibodies, and resistant female mice did not. Administration of a low dose of STZ (five daily doses each of 30 mg/kg) induced transient hyperglycemia approximately 20-30 days lat…
Recovery of endogenous beta cell function in non-human primates following chemical diabetes induction and islet transplantation
2009
Objectives: To describe the ability of non-human primate endocrine pancreata to re-establish endogenous insulin production after chemical beta cell destruction. Research Design and Methods: Eleven monkeys (macaca fascicularis) were rendered diabetic with streptozotocin. Eight diabetic monkeys received intraportal porcine islet transplantation. Results: Two monkeys transplanted after 75 days of insulin dependent diabetes, showed recovery of endogenous C-peptide production a few weeks after transplantation, concomitant with graft failure. Histological analysis of the pancreas of these monkeys showed insulin-positive cells, single or in small aggregates scattered in the pancreas and adjacent t…
Defective insulin secretory response to intravenous glucose in C57Bl/6J compared to C57Bl/6N mice
2014
Objective: The C57Bl/6J (Bl/6J) mouse is the most widely used strain in metabolic research. This strain carries a mutation in nicotinamide nucleotide transhydrogenase (Nnt), a mitochondrial enzyme involved in NADPH production, which has been suggested to lead to glucose intolerance and beta-cell dysfunction. However, recent reports comparing Bl/6J to Bl/6N (carrying the wild-type Nnt allele) under normal diet have led to conflicting results using glucose tolerance tests. Thus, we assessed glucose-stimulated insulin secretion (GSIS), insulin sensitivity, clearance and central glucose-induced insulin secretion in Bl/6J and N mice using gold-standard methodologies. Methods: GSIS was measured u…
Wharton’s Jelly Mesenchymal Stem Cells as Candidates for Beta Cells Regeneration: Extending the Differentiative and Immunomodulatory Benefits of Adul…
2010
Mesenchymal stem cells (MSC) are uniquely capable of crossing germinative layers borders (i.e. are able to differentiate towards ectoderm-, mesoderm- and endoderm-derived cytotypes) and are viewed as promising cells for regenerative medicine approaches in several diseases. Type I diabetes therapy should potentially benefit from such differentiated cells: the search for alternatives to organ/islet transplantation strategies via stem cells differentiation is an ongoing task, significant goals having been achieved in most experimental settings (e.g. insulin production and euglycaemia restoration), though caution is still needed to ensure safe and durable effects in vivo. MSC are obtainable in …
Transcriptional profiling reveals functional links between RasGrf1 and Pttg1 in pancreatic beta cells
2014
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License .
Estimated intake levels for Finnish children of methylmercury from fish
2013
Abstract Methylmercury (MeHg) is a well-known neurotoxic agent, and consumption of contaminated fish is the principal environmental source of MeHg exposure in humans. Children are more susceptible to adverse effects than adults. No previous specific data exist for intake by Finnish children of methylmercury from fish. We estimated fish consumption and MeHg intakes from species most commonly consumed by Finnish children aged 1–6 years. The total mercury concentrations were determined in fish species consumed, and age-specific methylmercury intakes were derived. We also examined safety margins and the proportion of children exceeding the tolerable daily intakes set by international expert bod…