Search results for " islets"
showing 10 items of 32 documents
Floristic and Vegetation Changes on a Small Mediterranean Island over the Last Century
2021
A synthetic and updated overview about the vascular flora and vegetation of the Island of Capo Passero (SE-Sicily) is provided. These data issue from two series of field surveys—the first carried out between 1997 and 2000, and the second between 2005 and 2019 and mostly focused on refining and implementing vegetation data. The current islet’s flora consists of 269 taxa, of which 149 (58%) are annual plants. The Mediterranean species are largely prevailing, 108 (40%) of which have a strictly Mediterranean biogeographical status. The comparison with a species list published in 1919 and updated in 1957 suggest that, despite the overall prevalence of anemochorous taxa, the vertebrate fauna repr…
Overexpression of glucose 6 phosphate dehydrogenase preserves mouse pancreatic beta cells function until late in life.
2021
NAD(P)H donates electrons for reductive biosynthesis and antioxidant defense across all forms of life. Glucose-6- phosphate dehydrogenase (G6PD) is a critical enzyme to provide NADPH. G6PD deficiency is present in more than 400 million people worldwide. This enzymopathy provides protection against malaria but sensitizes cells to oxidative stressors. Oxidative stress has been involved in the pathogenesis of the diabetic complications and several studies have provided evidences of a link between G6PD deficiency and type 2 diabetes (T2D). We hypothesized that a moderate overexpression of G6PD (G6PD-Tg) could protect β-cells from age-associated oxidative stress thus reducing the risk of develop…
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…
Atorvastatin but not pravastatin impairs mitochondrial function in human pancreatic islets and rat β-cells. Direct effect of oxidative stress
2017
AbstractStatins are a class of drugs widely prescribed as frontline therapy for lowering plasma LDL-cholesterol in cardiovascular risk prevention. Several clinical reports have recently suggested an increased risk of type 2 diabetes associated with chronic use of these drugs. The pathophysiology of this effect remains to be fully elucidated but impaired β-cell function constitutes a potential mechanism. The aim of this study was to explore the effect of a chronic treatment with lipophilic and hydrophilic statins on β-cell function, using human pancreatic islets and rat insulin-secreting INS-1 cells; we particularly focused on the role of mitochondria and oxidative stress. The present study …
The neuropeptide 26RFa in the human gut and pancreas: potential involvement in glucose homeostasis
2019
Objective Recent studies performed in mice revealed that the neuropeptide 26RFa regulates glucose homeostasis by acting as an incretin and by increasing insulin sensitivity. However, in humans, an association between 26RFa and the regulation of glucose homeostasis is poorly documented. In this study, we have thus investigated in detail the distribution of 26RFa and its receptor, GPR103, in the gut and the pancreas, and determined the response of this peptidergic system to an oral glucose challenge in obese patients. Design and methods Distribution of 26RFa and GPR103 was examined by immunohistochemistry using gut and pancreas tissue sections. Circulating 26RFa was determined using a specif…
CD40 activation in human pancreatic islets and ductal cells.
2008
Aims/hypothesis: CD40 expression on non-haematopoietic cells is linked to inflammation. We previously reported that CD40 is expressed on isolated human and non-human primate islets and its activation results in secretion of IL-8, macrophage inflammatory protein 1-beta (MIP-1β) and monocyte chemoattractant protein-1 (MCP-1) through nuclear factor-κB and extracellularly regulated kinases 1/2 pathways. The objective of this study was to identify the pattern of gene expression, and to study viability and functionality affected by CD40-CD40 ligand (CD40L) interaction in human islets. Furthermore, we have studied the CD40-mediated cytokine/chemokine profile in pancreatic ductal cells, as they are…
Autoimmune Diabetes Recurrence After Pancreas Transplantation: Diagnosis, Management, and Literature Review
2019
[EN] Background: Pancreas transplantation can be a viable treatment option for patients with type 1 diabetes mellitus (T1DM), especially for those who are candidates for kidney transplantation. T1DM may rarely recur after pancreas transplantation, causing the loss of pancreatic graft. The aim of this study was to describe the prevalence of T1DM recurrence after pancreas transplantation in our series. Material/Methods: Eighty-one patients transplanted from 2002 to 2015 were included. Autoantibody testing (GADA and IA-2) was performed before pancreas transplantation and during the follow-up. Results: The series includes 48 males and 33 females, mean age 37.4+5.7 years and mean duration of dia…
Evaluation of B-cell secretion and peripheral insulin resistance during pregnancy and after delivery in gestational diabetes mellitus with obesity
1988
Nine pregnant women with gestational diabetes mellitus (GDM) were studied. Six normal pregnant women and six normal nonpregnant women were evaluated as control groups. All the women underwent oral glucose tolerance test and glucose clamp during the third trimester of pregnancy and two months after delivery. During OGTT, glucose, C-peptide and insulin plasma levels were determined. C-peptide and insulin values in the late phase of OGTT were higher during pregnancy than after delivery in both groups. In gestational diabetic women, the M-value in the second steady-state during glucose clamp was lower than in controls, both during pregnancy and after delivery. Nevertheless, in both groups the M…
GLP-2 as Beneficial Factor in the Glucose Homeostasis in Mice Fed a High Fat Diet
2015
Glucagon like peptide-2 (GLP-2) is a gastrointestinal hormone released in response to dietary nutrients, which acts through a specific receptor, the GLP-2 receptor (GLP-2R). The physiological effects of GLP-2 are multiple, involving also the intestinal adaptation to high fat diet (HFD). In consideration of the well-known relationship between chronic HFD and impaired glucose metabolism, in the present study we examined if the blocking of the GLP-2 signaling by chronic treatment with the GLP-2R antagonist, GLP-2 (3-33), leads to functional consequences in the regulation of glucose metabolism in HFD-fed mice. Compared with animals fed standard diet (STD), mice at the 10th week of HFD showed hy…
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…