TY - JOUR
T1 - Antisense miR-7 impairs insulin expression in developing pancreas and in cultured pancreatic buds
AU - Nieto, Margarita
AU - Hevia, Pedro
AU - Garcia, Enrique
AU - Klein, Dagmar
AU - Alvarez-Cubela, Silvia
AU - Bravo-Egana, Valia
AU - Rosero, Samuel
AU - Damaris Molano, R.
AU - Vargas, Nancy
AU - Ricordi, Camillo
AU - Pileggi, Antonello
AU - Diez, Juan
AU - Domínguez-Bendala, Juan
AU - Pastori, Ricardo L.
PY - 2012
Y1 - 2012
N2 - MicroRNAs regulate gene expression by inhibiting translation or inducing target mRNA degradation. MicroRNAs regulate organ differentiation and embryonic development, including pancreatic specification and islet function. We showed previously that miR-7 is highly expressed in human pancreatic fetal and adult endocrine cells. Here we determined the expression profile of miR-7 in the mouse-developing pancreas by RT-PCR and in situ hybridization. MiR-7 expression was low between embryonic days e10.5 and e11.5, then began to increase at e13.5 through e14.5, and eventually decreased by e18. In situ hybridization and immunostaining analysis showed that miR-7 colocalizes with endocrine marker Isl1, suggesting that miR-7 is expressed preferentially in endocrine cells. Whole-mount in situ hybridization shows miR-7 highly expressed in the embryonic neural tube. To investigate the role of miR-7 in development of the mouse endocrine pancreas, antisense miR 7 morpholinos (MO) were delivered to the embryo at an early developmental stage (e10.5 days) via intrauterine fetal heart injection. Inhibition of miR-7 during early embryonic life results in an overall downregulation of insulin production, decreased β-cell numbers, and glucose intolerance in the postnatal period. This phenomenon is specific for miR-7 and possibly due to a systemic effect on pancreatic development. On the other hand, the in vitro inhibition of miR-7 in explanted pancreatic buds leads to β-cell death and generation of β-cells expressing less insulin than those in MO control. Therefore, in addition to the potential indirect effects on pancreatic differentiation derived from its systemic downregulation, the knockdown of miR-7 appears to have a β-cell-specific effect as well. These findings suggest that modulation of miR-7 expression could be utilized in the development of stem cell therapies to cure diabetes.
AB - MicroRNAs regulate gene expression by inhibiting translation or inducing target mRNA degradation. MicroRNAs regulate organ differentiation and embryonic development, including pancreatic specification and islet function. We showed previously that miR-7 is highly expressed in human pancreatic fetal and adult endocrine cells. Here we determined the expression profile of miR-7 in the mouse-developing pancreas by RT-PCR and in situ hybridization. MiR-7 expression was low between embryonic days e10.5 and e11.5, then began to increase at e13.5 through e14.5, and eventually decreased by e18. In situ hybridization and immunostaining analysis showed that miR-7 colocalizes with endocrine marker Isl1, suggesting that miR-7 is expressed preferentially in endocrine cells. Whole-mount in situ hybridization shows miR-7 highly expressed in the embryonic neural tube. To investigate the role of miR-7 in development of the mouse endocrine pancreas, antisense miR 7 morpholinos (MO) were delivered to the embryo at an early developmental stage (e10.5 days) via intrauterine fetal heart injection. Inhibition of miR-7 during early embryonic life results in an overall downregulation of insulin production, decreased β-cell numbers, and glucose intolerance in the postnatal period. This phenomenon is specific for miR-7 and possibly due to a systemic effect on pancreatic development. On the other hand, the in vitro inhibition of miR-7 in explanted pancreatic buds leads to β-cell death and generation of β-cells expressing less insulin than those in MO control. Therefore, in addition to the potential indirect effects on pancreatic differentiation derived from its systemic downregulation, the knockdown of miR-7 appears to have a β-cell-specific effect as well. These findings suggest that modulation of miR-7 expression could be utilized in the development of stem cell therapies to cure diabetes.
KW - Antisense microRNA
KW - In vivo delivery
KW - Islets
KW - MicroRNA
KW - β-Cells
UR - http://www.scopus.com/inward/record.url?scp=84868132259&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84868132259&partnerID=8YFLogxK
U2 - 10.3727/096368911X612521
DO - 10.3727/096368911X612521
M3 - Article
C2 - 22186137
AN - SCOPUS:84868132259
SN - 0963-6897
VL - 21
SP - 1761
EP - 1774
JO - Cell Transplantation
JF - Cell Transplantation
IS - 8
ER -