Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during ?-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature ?-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn ?-cells, suggesting that they contribute to the limited proliferative capacity of adult ?-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation. Islets from 10-day-old rats (P10) (n=5) or 3-month-old male rat (n=6) were taken. Total RNA was extracted and microRNA profiling was performed using the Illumina TruSeq small RNA kit and single-end sequencing.
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation. Islets from 10-day-old rats (P10) (n=3) or 3-month-old male rat (n=3) were taken. Total RNA was extracted and mRNA profiling via Illumina single-end sequencing of mRNA-seq libraries was performed.
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation.
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation.
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation. Islets from 10-day-old rats (P10) were taken, dispersed and transfected with control miRNA mimic or miR-17-5p. Total RNA was extracted and mRNA profiling via Illumina single-end sequencing of mRNA-seq libraries was performed. In parallel, Ago2 immunoprecipitation with RNA recovery and mRNA-seq was performed (RISC-seq).
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fule supply and to maintain glucose homeostasis by regulating insulin release and proliferation.
Project description:To elucidate the mechanisms involved in the acquisition of a fully differentiated beta-cell phenotype, we compared by microarray the mRNAs and the long non-coding RNAs expressed in newborn and adult rat islets.
Project description:During pancreas development, endocrine progenitors differentiate into the islet-cell subtypes, which undergo further functional maturation in postnatal islet development. In islet b-cells, genes involved in glucose-stimulated insulin secretion are activated and glucose exposure increases the insulin response as b-cells mature. Here, we investigated the role of H3K4 trimethylation in endocrine cell differentiation and functional maturation by disrupting TrxG complex histone methyltransferase activity in mouse endocrine progenitors. In the embryo, genetic inactivation of TrxG component Dpy30 in NEUROG3+ cells did not affect the number of endocrine progenitors or endocrine cell differentiation. H3K4 trimethylation was progressively lost in postnatal islets and the mice displayed elevated non-fasting and fasting glycemia, as well as impaired glucose tolerance by postnatal day 24. Although postnatal endocrine cell proportions were equivalent to controls, islet RNA-sequencing revealed a downregulation of genes involved in glucose-stimulated insulin secretion and an upregulation of immature b-cell genes. Comparison of histone modification enrichment profiles in NEUROG3+ endocrine progenitors and mature islets suggested that genes downregulated by loss of H3K4 trimethylation more frequently acquire active histone modifications during maturation. Taken together, these findings suggest that H3K4 trimethylation is required for the activation of genes involved in the functional maturation of pancreatic islet endocrine cells.
Project description:We found that in rodents, postnatal beta-cell maturation is associated with changes in the expression of several islet microRNAs and discovered that these modifications are driven by changes in the nutrient supply. Mimicking the microRNA changes observed during β-cell maturation in newborn rat islet cells was sufficient to promote glucose-induced insulin release and to achieve a mature β-cell secretory phenotype. Moreover, the modifications in the level of some of these microRNAs reduced the proliferation of newborn β-cells, suggesting that they contribute to the limited proliferative capacity of adult β-cells. These findings demonstrated that miRNAs contribute to postnatal beta-cell maturation and development. Their role is likely to promote beta-cell adaptation to fuel supply and to maintain glucose homeostasis by regulating insulin release and proliferation. Islets from 10-day-old rats (P10) (n=4) or 3-month-old male rat (n=4) were taken. Total RNA was extracted and microRNA profiling was performed with miRNA Agilent arrays.