The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
R. L. Carlone - One of the best experts on this subject based on the ideXlab platform.
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MicroRNA dysregulation in response to RARβ2 inhibition reveals a negative feedback loop between MicroRNAs 1, 133a, and RARβ2 during tail and spinal cord regeneration in the Adult newt.
Developmental Dynamics, 2015Co-Authors: A. C. Lepp, R. L. CarloneAbstract:Background: The molecular events underlying epimorphic regeneration of the Adult Urodele amphibian tail and caudal spinal cord are undetermined. Given the dynamic nature of gene expression control by retinoic acid (RA) signaling and the pleiotropic effects of microRNAs (miRNAs) on multiple mRNA targets in this complex system, we examined whether RA signaling through a specific receptor, RARβ2, alters expression of select miRNAs during spinal cord regeneration. Results: An initial screen identified 18 highly conserved miRNAs dysregulated in regenerating tail and spinal cord tissues after inhibition of RARβ2 signaling with a selective antagonist, LE135. miRNAs let-7c, miR-1, and miR-223 were expressed within the ependymoglial cells, coincident spatially with the expression of RARβ2. Altering the expression pattern of these three miRNAs led to a significant inhibition of caudal ependymal tube outgrowth by 21 days post tail amputation. We demonstrated that miR-1 targets the 3′-untranslated region of RARβ2 mRNA in vitro; and in vivo, up-regulation of miR-1 led to a significant decrease in RARβ2 protein. Conclusions: These and previous data suggest that miR-1 and miR-133a, both members of the same miRNA gene cluster, may participate with RARβ2 in a negative feedback loop contributing to the regulation of the ependymal response after tail amputation. Developmental Dynamics, 2015. © 2015 Wiley Periodicals, Inc.
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RARβ2 expression is induced by the down-regulation of microRNA 133a during caudal spinal cord regeneration in the Adult newt.
Developmental Dynamics, 2014Co-Authors: A. C. Lepp, R. L. CarloneAbstract:Background: Adult Urodele amphibians represent unique model organisms to study spinal cord regeneration. Trauma to the spinal cord induces an ependymal response, activating multipotent neural stem cells that contribute to the redifferentiation of both glia and neurons in the regenerate. The molecular events underlying this ependymal response are not completely understood, but likely involve coordinated global changes in gene expression. MicroRNAs and retinoid signaling are postulated to orchestrate these patterns of gene expression in response to trauma. Our objectives were to determine the roles played by some miRNAs as potential regulators of retinoid signaling in this process. Results: We found that the expression levels of miRNAs 133a, 203, and 124a are dysregulated during the first 21 days post amputation (dpa). Interestingly, these miRNAs are expressed primarily within the ependymoglia. We have shown in vitro that a miR-133a mimic targets the 3' UTR of the newt RARβ2 transcript. Importantly, upregulation of this mimic in vivo led to a significant decline in RARβ2 protein at 14 dpa and inhibited regeneration. Conclusions: These data are the first to link miRNAs and retinoid signaling during spinal cord regeneration and provide support for miR-133a as an upstream regulator of RARβ2 expression in this process. Developmental Dynamics 243:1581–1590, 2014. © 2014 Wiley Periodicals, Inc.
A. C. Lepp - One of the best experts on this subject based on the ideXlab platform.
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MicroRNA dysregulation in response to RARβ2 inhibition reveals a negative feedback loop between MicroRNAs 1, 133a, and RARβ2 during tail and spinal cord regeneration in the Adult newt.
Developmental Dynamics, 2015Co-Authors: A. C. Lepp, R. L. CarloneAbstract:Background: The molecular events underlying epimorphic regeneration of the Adult Urodele amphibian tail and caudal spinal cord are undetermined. Given the dynamic nature of gene expression control by retinoic acid (RA) signaling and the pleiotropic effects of microRNAs (miRNAs) on multiple mRNA targets in this complex system, we examined whether RA signaling through a specific receptor, RARβ2, alters expression of select miRNAs during spinal cord regeneration. Results: An initial screen identified 18 highly conserved miRNAs dysregulated in regenerating tail and spinal cord tissues after inhibition of RARβ2 signaling with a selective antagonist, LE135. miRNAs let-7c, miR-1, and miR-223 were expressed within the ependymoglial cells, coincident spatially with the expression of RARβ2. Altering the expression pattern of these three miRNAs led to a significant inhibition of caudal ependymal tube outgrowth by 21 days post tail amputation. We demonstrated that miR-1 targets the 3′-untranslated region of RARβ2 mRNA in vitro; and in vivo, up-regulation of miR-1 led to a significant decrease in RARβ2 protein. Conclusions: These and previous data suggest that miR-1 and miR-133a, both members of the same miRNA gene cluster, may participate with RARβ2 in a negative feedback loop contributing to the regulation of the ependymal response after tail amputation. Developmental Dynamics, 2015. © 2015 Wiley Periodicals, Inc.
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RARβ2 expression is induced by the down-regulation of microRNA 133a during caudal spinal cord regeneration in the Adult newt.
Developmental Dynamics, 2014Co-Authors: A. C. Lepp, R. L. CarloneAbstract:Background: Adult Urodele amphibians represent unique model organisms to study spinal cord regeneration. Trauma to the spinal cord induces an ependymal response, activating multipotent neural stem cells that contribute to the redifferentiation of both glia and neurons in the regenerate. The molecular events underlying this ependymal response are not completely understood, but likely involve coordinated global changes in gene expression. MicroRNAs and retinoid signaling are postulated to orchestrate these patterns of gene expression in response to trauma. Our objectives were to determine the roles played by some miRNAs as potential regulators of retinoid signaling in this process. Results: We found that the expression levels of miRNAs 133a, 203, and 124a are dysregulated during the first 21 days post amputation (dpa). Interestingly, these miRNAs are expressed primarily within the ependymoglia. We have shown in vitro that a miR-133a mimic targets the 3' UTR of the newt RARβ2 transcript. Importantly, upregulation of this mimic in vivo led to a significant decline in RARβ2 protein at 14 dpa and inhibited regeneration. Conclusions: These data are the first to link miRNAs and retinoid signaling during spinal cord regeneration and provide support for miR-133a as an upstream regulator of RARβ2 expression in this process. Developmental Dynamics 243:1581–1590, 2014. © 2014 Wiley Periodicals, Inc.
Jeanmarie Cabelguen - One of the best experts on this subject based on the ideXlab platform.
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fictive rhythmic motor patterns induced by nmda in an in vitro brain stem spinal cord preparation from an Adult Urodele
Journal of Neurophysiology, 1999Co-Authors: Isabelle Delvolve, Pascal Branchereau, Rejean Dubuc, Jeanmarie CabelguenAbstract:An in vitro brain stem-spinal cord preparation from an Adult Urodele (PleUrodeles waltl) was developed in which two fictive rhythmic motor patterns were evoked by bath application of N-methyl-D-aspartate (NMDA; 2.5-10 microM) with D-serine (10 microM). Both motor patterns displayed left-right alternation. The first pattern was characterized by cycle periods ranging between 2.4 and 9. 0 s (4.9 +/- 1.2 s, mean +/- SD) and a rostrocaudal propagation of the activity in consecutive ventral roots. The second pattern displayed longer cycle periods (8.1-28.3 s; 14.2 +/- 3.6 s) with a caudorostral propagation. The two patterns were inducible after a spinal transection at the first segment. Preliminary experiments on small pieces of spinal cord further suggested that the ability for rhythm generation is distributed along the spinal cord of this preparation. This study shows that the in vitro brain stem-spinal cord preparation from PleUrodeles waltl may be a useful model to study the mechanisms underlying the different axial motor patterns and the flexibility of the neural networks involved.
Xavier Caubit - One of the best experts on this subject based on the ideXlab platform.
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the spatial restrictions of 5 hoxc genes expression are maintained in Adult newt spinal cord
Biology of the Cell, 2003Co-Authors: S Nicolas, Daniel Papillon, Yvan Perez, Xavier Caubit, Le Y ParcoAbstract:Abstract Urodele amphibians are the only Adult vertebrates possessing the capacity to regenerate their limbs and tail after amputation. Epimorphic regeneration is characterized by the accumulation of undifferentiated and dividing mesenchymal cells originating from the tissues of the stump, which form a blastema. It has been proposed that the ability to regenerate precisely the amputated structures depends on a ‘positional memory’ of the cells at the level of amputation plane and that a continuum of positional value would be present in Adult Urodeles along the appendages able to regenerate. Hox genes are good candidates for playing a role in providing the capacity for regeneration and for carrying positional information. Here, we report the cloning of four AbdB -like genes ( Hoxa9, Hoxc10, Hoxc12 and Hoxc13 ) in the newt PleUrodeles waltl (Pw). To analyse their expression pattern along the antero-posterior (AP) axis of Adult Urodele central nervous system (CNS), we used the reverse transcription-polymerase chain reaction (RT-PCR) and showed that the 5’ HoxC genes expression pattern conforms to the usual spatial colinearity rule. In addition, the expression level in tail regenerates of PwHoxc13, PwHoxc12, and PwHoxc10 was respectively 20, 7 and 2 fold higher than in Adult tail. These last results suggest that 5' HoxC genes could specify positional memory in Adult spinal cord (SC) and could be involved in axial patterning of the tail during regeneration.
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reactivation and graded axial expression pattern of wnt 10a gene during early regeneration stages of Adult tail in amphibian Urodele pleUrodeles waltl
Developmental Dynamics, 1997Co-Authors: Xavier Caubit, Stephane Nicolas, Deli Shi, Yannick Le ParcoAbstract:Adult Urodele amphibians such as PleUrodeles waltl are able to regenerate their amputated limbs or tail. The mechanisms implicated in growth control and formation of the blastema are unknown but it has been proposed that regeneration in newts may proceed through reactivation of genes involved in embryonic development. Knowing the role of Wnt genes in the patterning of the primary and secondary axes of the vertebrate embryo, we suspected that some of these genes could be involved in axial pattern during newt tail regeneration. Pwnt-10a gene, cloned from a newt tail regenerate cDNA library, showed an expression pattern compatible with such a role in tail regenerates. Pwnt-10a, which is highly expressed during embryonic development (from gastrula to tailbud-stage) and weakly expressed in the Adult tail, is strongly re-expressed during tail regeneration. In the blastemal mesenchyme Pwnt-10a transcripts exhibited a graded distribution along the antero-posterior axis, the mRNA accumulation being maximal in the caudal most part corresponding to the growing zone. These findings strongly support the view that Pwnt-10a may act in cooperation with other factors to control growth and patterning in newt tail regeneration. Until now Wnt-10a was only known to be involved in central nervous system development; our results suggest that this gene may also play a role in other developmental processes. Dev. Dyn. 208:139–148, 1997. © 1997 Wiley-Liss, Inc.
Isabelle Delvolve - One of the best experts on this subject based on the ideXlab platform.
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fictive rhythmic motor patterns induced by nmda in an in vitro brain stem spinal cord preparation from an Adult Urodele
Journal of Neurophysiology, 1999Co-Authors: Isabelle Delvolve, Pascal Branchereau, Rejean Dubuc, Jeanmarie CabelguenAbstract:An in vitro brain stem-spinal cord preparation from an Adult Urodele (PleUrodeles waltl) was developed in which two fictive rhythmic motor patterns were evoked by bath application of N-methyl-D-aspartate (NMDA; 2.5-10 microM) with D-serine (10 microM). Both motor patterns displayed left-right alternation. The first pattern was characterized by cycle periods ranging between 2.4 and 9. 0 s (4.9 +/- 1.2 s, mean +/- SD) and a rostrocaudal propagation of the activity in consecutive ventral roots. The second pattern displayed longer cycle periods (8.1-28.3 s; 14.2 +/- 3.6 s) with a caudorostral propagation. The two patterns were inducible after a spinal transection at the first segment. Preliminary experiments on small pieces of spinal cord further suggested that the ability for rhythm generation is distributed along the spinal cord of this preparation. This study shows that the in vitro brain stem-spinal cord preparation from PleUrodeles waltl may be a useful model to study the mechanisms underlying the different axial motor patterns and the flexibility of the neural networks involved.