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 200 nM adrenomedullin (ADM) increases cyclic adenosine monophosphate (cAMP)-like immunoreactivity (LI) and cyclic guanosine monophosphate (cGMP)-LI. A: In the control retinas, cAMP-LI was in isolated somata in the outer nuclear layer (ONL; horizontal arrow), in faint staining in the outer plexiform layer (OPL; asterisk), in sparse somata in the inner nuclear layer (INL; diagonal arrow), in diffuse puncta in the inner plexiform layer (IPL), and in somata in the ganglion cell layer (GCL; down arrow). B: In retinas stimulated with ADM, there was an overall increase in cAMP-LI, with increased numbers of photoreceptor somata (horizontal arrow), puncta in the OPL (asterisk), and somata in the INL (diagonal arrow) and the GCL (down arrow). C: In the control retinas, faint cGMP-LI was in some photoreceptor outer segments (vertical arrow) and in somata in the inner (diagonal arrow) and outer (horizontal arrow) ONL. D: In retinas stimulated with ADM, there was an increase in the number and intensity of labeled photoreceptor outer segments (up arrow) and somata in the inner region of the ONL (diagonal arrow). There were also some faint somata in the INL (horizontal arrow). Scale bars=20 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Stimulation with 200 nM adrenomedullin (ADM) increases cyclic adenosine monophosphate (cAMP)-like immunoreactivity (LI) and cyclic guanosine monophosphate (cGMP)-LI. A: In the control retinas, cAMP-LI was in isolated somata in the outer nuclear layer (ONL; horizontal arrow), in faint staining in the outer plexiform layer (OPL; asterisk), in sparse somata in the inner nuclear layer (INL; diagonal arrow), in diffuse puncta in the inner plexiform layer (IPL), and in somata in the ganglion cell layer (GCL; down arrow). B: In retinas stimulated with ADM, there was an overall increase in cAMP-LI, with increased numbers of photoreceptor somata (horizontal arrow), puncta in the OPL (asterisk), and somata in the INL (diagonal arrow) and the GCL (down arrow). C: In the control retinas, faint cGMP-LI was in some photoreceptor outer segments (vertical arrow) and in somata in the inner (diagonal arrow) and outer (horizontal arrow) ONL. D: In retinas stimulated with ADM, there was an increase in the number and intensity of labeled photoreceptor outer segments (up arrow) and somata in the inner region of the ONL (diagonal arrow). There were also some faint somata in the INL (horizontal arrow). Scale bars=20 µm.

Mentions: Isolated retinas were stimulated with ADM (200 nM), and immunocytochemistry was then used to detect the downstream second messengers cAMP and cGMP (Figure 6). We found an increase in cAMP-LI and cGMP-LI when isolated retinas were stimulated with ADM.


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 200 nM adrenomedullin (ADM) increases cyclic adenosine monophosphate (cAMP)-like immunoreactivity (LI) and cyclic guanosine monophosphate (cGMP)-LI. A: In the control retinas, cAMP-LI was in isolated somata in the outer nuclear layer (ONL; horizontal arrow), in faint staining in the outer plexiform layer (OPL; asterisk), in sparse somata in the inner nuclear layer (INL; diagonal arrow), in diffuse puncta in the inner plexiform layer (IPL), and in somata in the ganglion cell layer (GCL; down arrow). B: In retinas stimulated with ADM, there was an overall increase in cAMP-LI, with increased numbers of photoreceptor somata (horizontal arrow), puncta in the OPL (asterisk), and somata in the INL (diagonal arrow) and the GCL (down arrow). C: In the control retinas, faint cGMP-LI was in some photoreceptor outer segments (vertical arrow) and in somata in the inner (diagonal arrow) and outer (horizontal arrow) ONL. D: In retinas stimulated with ADM, there was an increase in the number and intensity of labeled photoreceptor outer segments (up arrow) and somata in the inner region of the ONL (diagonal arrow). There were also some faint somata in the INL (horizontal arrow). Scale bars=20 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f6: Stimulation with 200 nM adrenomedullin (ADM) increases cyclic adenosine monophosphate (cAMP)-like immunoreactivity (LI) and cyclic guanosine monophosphate (cGMP)-LI. A: In the control retinas, cAMP-LI was in isolated somata in the outer nuclear layer (ONL; horizontal arrow), in faint staining in the outer plexiform layer (OPL; asterisk), in sparse somata in the inner nuclear layer (INL; diagonal arrow), in diffuse puncta in the inner plexiform layer (IPL), and in somata in the ganglion cell layer (GCL; down arrow). B: In retinas stimulated with ADM, there was an overall increase in cAMP-LI, with increased numbers of photoreceptor somata (horizontal arrow), puncta in the OPL (asterisk), and somata in the INL (diagonal arrow) and the GCL (down arrow). C: In the control retinas, faint cGMP-LI was in some photoreceptor outer segments (vertical arrow) and in somata in the inner (diagonal arrow) and outer (horizontal arrow) ONL. D: In retinas stimulated with ADM, there was an increase in the number and intensity of labeled photoreceptor outer segments (up arrow) and somata in the inner region of the ONL (diagonal arrow). There were also some faint somata in the INL (horizontal arrow). Scale bars=20 µm.
Mentions: Isolated retinas were stimulated with ADM (200 nM), and immunocytochemistry was then used to detect the downstream second messengers cAMP and cGMP (Figure 6). We found an increase in cAMP-LI and cGMP-LI when isolated retinas were stimulated with ADM.

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