Reports in North America suggest that up to 20% of young women (18-24 years) use cannabis during pregnancy. This is concerning given clinical studies indicate that maternal cannabis use is associated with fetal growth restriction and dysglycemia in the offspring. Preclinical studies demonstrated that prenatal exposure to Δ9-tetrahydrocannabinol, the main psychoactive component of cannabis, in rat dams led to female-specific deficits in β-cell mass and glucose intolerance/insulin resistance.
View Article and Find Full Text PDFObjectives: Administration of Δ-tetrahydrocannabinol (Δ-THC) to pregnant rats results in glucose intolerance, insulin resistance and reduced islet mass in female, but not male, offspring. The effects of Δ-THC on other islet hormones is not known. One downstream target of the cannabinoid receptor, stathmin-2 (Stmn2), has recently been shown to suppress glucagon secretion, thereby suggesting Δ-THC may also affect alpha-cell function.
View Article and Find Full Text PDFMaternal diabetes impairs fetal development and increases the risk of metabolic diseases in the offspring. Previously, we demonstrated that maternal dietary supplementation with 6% of olive oil prevents diabetes-induced embryo and fetal defects, in part, through the activation of peroxisome proliferator-activated receptors (PPARs). In this study, we examined the effects of this diet on neonatal and adult pancreatic development in male and female offspring of mothers affected with pre-gestational diabetes.
View Article and Find Full Text PDFCombination of ischemia and β-amyloid (Aβ) toxicity has been shown to simultaneously increase neuro-inflammation, endogenous Aβ deposition, and neurodegeneration. However, studies on the evolution of infarct and panorama of cellular degeneration as a synergistic or overlapping mechanism between ischemia and Aβ toxicity are lacking. Here, we compared fluorojade B (FJB) and hematoxylin and eosin (H&E) stains primarily to examine the chronology of infarct, and the viability and morphological changes in neuroglia and neurons located in different brain regions on d1, d7, and d28 post Aβ toxicity and endothelin-1 induced ischemia (ET1) in rats.
View Article and Find Full Text PDFThe original version of this article contained a random order of part labels for Fig. 4. The correct caption of Fig.
View Article and Find Full Text PDFBesides other causes, ischemia and Alzheimer's disease pathology is also linked to decreased cerebral blood flow (CBF). There is little or no consensus about the role of neuroglial cells in maintaining CBF in various neuropathologies. This consensus becomes scarcer when it comes to clinical and experimental cases of comorbid Abeta-amyloid (Aβ) toxicity and ischemia.
View Article and Find Full Text PDFLarge cerebral infarctions are major predictors of death and severe disability from stroke. Conversely, data concerning these types of infarctions and the affected adjacent brain circuits are scarce. It remains to be determined if the co-morbid concurrence of large infarct and β-amyloid (Aβ) toxicity can precipitate the early development of dementia.
View Article and Find Full Text PDFFibroblast growth factor receptor-1 (FGFR1) activity at the plasma membrane is tightly controlled by the availability of co-receptors and competing receptor isoforms. We have previously shown that FGFR1 activity in pancreatic beta-cells modulates a wide range of processes, including lipid metabolism, insulin processing, and cell survival. More recently, we have revealed that co-expression of FGFR5, a receptor isoform that lacks a tyrosine-kinase domain, influences FGFR1 responses.
View Article and Find Full Text PDFBoth bone marrow-derived hematopoietic stem cells (HSC) and mesenchymal stem cells (MSC) improve glycemic control in diabetic mice, but their kinetics and associated changes in pancreatic morphology have not been directly compared. Our goal was to examine the time course of improvements in glucose tolerance and associated changes in β-cell mass and proliferation following transplantation of equivalent numbers of HSC or MSC from the same bone marrow into diabetic non-obese diabetic severe combined immune deficiency (NOD.SCID) mice.
View Article and Find Full Text PDFThe hippocampus, a brain region vital for memory and learning, is sensitive to the damage caused by ischemic/hypoxic stroke and is one of the main regions affected by Alzheimer's disease. The pathological changes that might occur in the hippocampus and its connections, because of cerebral injury in a distant brain region, such as the striatum, have not been examined. Therefore, in the present study, we evaluated the combined effects of endothelin-1-induced ischemia (ET1) in the striatum and β-amyloid (Aβ) toxicity on hippocampal pathogenesis, dictated by the anatomical and functional intra- and inter-regional hippocampal connections to the striatum.
View Article and Find Full Text PDFIschemic stroke and diabetes are vascular risk factors for the development of impaired memory such as dementia and/or Alzheimer's disease. Clinical studies have demonstrated that minor striatal ischemic lesions in combination with β-amyloid (Aβ) load are critical in generating cognitive deficits. These cognitive deficits are likely to be associated with impaired insulin signaling.
View Article and Find Full Text PDFRegeneration of insulin-producing β-cells from resident pancreas progenitors requires an understanding of both progenitor identity and lineage plasticity. One model suggested that a rare β-cell sub-population within islets demonstrated multi-lineage plasticity. We hypothesized that β-cells from young mice (postnatal day 7, P7) exhibit such plasticity and used a model of islet dedifferentiation toward a ductal epithelial-cell phenotype to test this theory.
View Article and Find Full Text PDFLow birth weight and poor foetal growth following low protein (LP) exposure are associated with altered islet development and glucose intolerance in adulthood. Additionally, LP-fed offspring fail to regenerate their β-cells following depletion with streptozotocin (STZ) in contrast to control-fed offspring that restore β-cell mass. Our objective was to identify signalling pathways and cellular functions that may be critically altered in LP offspring rendering them susceptible to developing long-term glucose intolerance and decreased β-cell plasticity.
View Article and Find Full Text PDFNeonatal rats undergo considerable beta-cell regeneration after depletion with streptozotocin (STZ). Since the intraislet vasculature is necessary for both beta-cell growth and function, we examined changes in vascular morphology following STZ. Neonatal Wistar rats (4 days) were injected with 70 mg/kg STZ, or buffer, and were examined between days 4 and 40 postinjection.
View Article and Find Full Text PDFBeta cells are partially replaced in neonatal rodents after deletion with streptozotocin (STZ). Exposure of pregnant rats to a low protein (LP) diet impairs endocrine pancreas development in the offspring, leading to glucose intolerance in adulthood. Our objective was to determine whether protein restriction has a similar effect on the offspring in mice, and if this alters the capacity for beta cell regeneration after STZ.
View Article and Find Full Text PDFDietary insult in early life can affect the development and future function of the endocrine pancreas. We maintained pregnant non-obese diabetic (NOD) mice on a low protein (LP, 8% protein versus control, 20%) diet from conception until the weaning of pups at day 21. Serum insulin and pancreatic insulin content were reduced in LP-fed NOD offspring at 8 weeks, as were serum interferon gamma and pancreatic tumor necrosis factor alpha, while the number of pancreatic islets demonstrating peri-insulitis, and the degree of invasiveness were reduced.
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