Limits...
Evidence for a functional adrenomedullin signaling pathway in the mouse retina.

Blom J, Giove TJ, Pong WW, Blute TA, Eldred WD - Mol. Vis. (2012)

Bottom Line: We found that calcitonin-receptor-like receptor and receptor activity modifying protein 2 had localization patterns similar to ADM, especially in somata in the inner nuclear and ganglion cell layers.These results are the first to show that ADM and functional ADM receptors are present in the retina.Since ADM is increased in eyes with ocular pathologies such as diabetic retinopathy, glaucoma, retinitis pigmentosa, and uveitis, the ADM signaling pathway may provide a new target for ameliorating these retinal pathologies.

View Article: PubMed Central - PubMed

Affiliation: Boston University, Laboratory of Visual Neurobiology, Department of Biology, Boston, MA 02215, USA.

ABSTRACT

Purpose: Adrenomedullin (ADM) is a small, secreted peptide often associated with vasodilation. However, ADM can also function as a neurotransmitter/neuromodulator, and studies suggest ADM is upregulated in the eye in several ocular diseases. However, no studies to date have described an ADM signaling pathway in the retina.

Methods: PCR, immunocytochemistry, nitric oxide imaging, western blots, and a nitrite assay were used to determine the localization of the components of the ADM signaling pathway in the mouse retina.

Results: We used reverse-transcriptase polymerase chain reaction to show that ADM and its primary receptor, calcitonin-receptor-like receptor, along with its associated receptor activity modifying proteins 2 and 3 are expressed in the retina. Using immunocytochemistry, we detected ADM staining throughout the retina in the photoreceptor outer segments, the outer nuclear layer, Müller and amacrine cell somata in the inner nuclear layer, and some somata in the ganglion cell layer. We found that calcitonin-receptor-like receptor and receptor activity modifying protein 2 had localization patterns similar to ADM, especially in somata in the inner nuclear and ganglion cell layers. Finally, we showed that the ADM receptor was functional in the retina. Stimulation of isolated retinas with ADM increased cyclic adenosine monophosphate- and cyclic guanosine monophosphate-like immunoreactivity, as well as nitric oxide production.

Conclusions: These results are the first to show that ADM and functional ADM receptors are present in the retina. Since ADM is increased in eyes with ocular pathologies such as diabetic retinopathy, glaucoma, retinitis pigmentosa, and uveitis, the ADM signaling pathway may provide a new target for ameliorating these retinal pathologies.

Show MeSH

Related in: MedlinePlus

Stimulation with adrenomedullin (ADM) increases nitric oxide (NO) production. In isolated retinas stimulated with ADM (200 nM), there was a statistically significant increase in nitrite (i.e., NO) production. There was a statistically significant decrease in nitrite production when the isolated retinas were stimulated with ADM in the presence of the nNOS inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME). Asterisks denote p<0.001 (two way ANOVA n=6; error bars represent the standard deviation).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3369892&req=5

f7: Stimulation with adrenomedullin (ADM) increases nitric oxide (NO) production. In isolated retinas stimulated with ADM (200 nM), there was a statistically significant increase in nitrite (i.e., NO) production. There was a statistically significant decrease in nitrite production when the isolated retinas were stimulated with ADM in the presence of the nNOS inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME). Asterisks denote p<0.001 (two way ANOVA n=6; error bars represent the standard deviation).

Mentions: Nitrite analysis was used as a measure of NO production in isolated retinas stimulated with ADM. There was a statistically significant increase (p<0.001) in NO production in retinas that were stimulated with ADM (200 nM), and a statistically significant decrease (p<0.001) in NO production when the isolated retinas were stimulated with ADM in the presence of the NOS inhibitor L-NAME (1 mM; Figure 7). The decrease in nitrite to below control levels seen with L-NAME indicated that basal levels of NOS activity were inhibited as well.


Evidence for a functional adrenomedullin signaling pathway in the mouse retina.

Blom J, Giove TJ, Pong WW, Blute TA, Eldred WD - Mol. Vis. (2012)

Stimulation with adrenomedullin (ADM) increases nitric oxide (NO) production. In isolated retinas stimulated with ADM (200 nM), there was a statistically significant increase in nitrite (i.e., NO) production. There was a statistically significant decrease in nitrite production when the isolated retinas were stimulated with ADM in the presence of the nNOS inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME). Asterisks denote p<0.001 (two way ANOVA n=6; error bars represent the standard deviation).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369892&req=5

f7: Stimulation with adrenomedullin (ADM) increases nitric oxide (NO) production. In isolated retinas stimulated with ADM (200 nM), there was a statistically significant increase in nitrite (i.e., NO) production. There was a statistically significant decrease in nitrite production when the isolated retinas were stimulated with ADM in the presence of the nNOS inhibitor Nω-Nitro-L-arginine methyl ester (L-NAME). Asterisks denote p<0.001 (two way ANOVA n=6; error bars represent the standard deviation).
Mentions: Nitrite analysis was used as a measure of NO production in isolated retinas stimulated with ADM. There was a statistically significant increase (p<0.001) in NO production in retinas that were stimulated with ADM (200 nM), and a statistically significant decrease (p<0.001) in NO production when the isolated retinas were stimulated with ADM in the presence of the NOS inhibitor L-NAME (1 mM; Figure 7). The decrease in nitrite to below control levels seen with L-NAME indicated that basal levels of NOS activity were inhibited as well.

Bottom Line: We found that calcitonin-receptor-like receptor and receptor activity modifying protein 2 had localization patterns similar to ADM, especially in somata in the inner nuclear and ganglion cell layers.These results are the first to show that ADM and functional ADM receptors are present in the retina.Since ADM is increased in eyes with ocular pathologies such as diabetic retinopathy, glaucoma, retinitis pigmentosa, and uveitis, the ADM signaling pathway may provide a new target for ameliorating these retinal pathologies.

View Article: PubMed Central - PubMed

Affiliation: Boston University, Laboratory of Visual Neurobiology, Department of Biology, Boston, MA 02215, USA.

ABSTRACT

Purpose: Adrenomedullin (ADM) is a small, secreted peptide often associated with vasodilation. However, ADM can also function as a neurotransmitter/neuromodulator, and studies suggest ADM is upregulated in the eye in several ocular diseases. However, no studies to date have described an ADM signaling pathway in the retina.

Methods: PCR, immunocytochemistry, nitric oxide imaging, western blots, and a nitrite assay were used to determine the localization of the components of the ADM signaling pathway in the mouse retina.

Results: We used reverse-transcriptase polymerase chain reaction to show that ADM and its primary receptor, calcitonin-receptor-like receptor, along with its associated receptor activity modifying proteins 2 and 3 are expressed in the retina. Using immunocytochemistry, we detected ADM staining throughout the retina in the photoreceptor outer segments, the outer nuclear layer, Müller and amacrine cell somata in the inner nuclear layer, and some somata in the ganglion cell layer. We found that calcitonin-receptor-like receptor and receptor activity modifying protein 2 had localization patterns similar to ADM, especially in somata in the inner nuclear and ganglion cell layers. Finally, we showed that the ADM receptor was functional in the retina. Stimulation of isolated retinas with ADM increased cyclic adenosine monophosphate- and cyclic guanosine monophosphate-like immunoreactivity, as well as nitric oxide production.

Conclusions: These results are the first to show that ADM and functional ADM receptors are present in the retina. Since ADM is increased in eyes with ocular pathologies such as diabetic retinopathy, glaucoma, retinitis pigmentosa, and uveitis, the ADM signaling pathway may provide a new target for ameliorating these retinal pathologies.

Show MeSH
Related in: MedlinePlus