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

Adrenomedullin (ADM), calcitonin receptor like receptor (CRLR), and eceptor activity modifying protein (RAMPs) needed for ADM signaling are expressed in the retina. A: Reverse transcriptase (RT)–PCR using ADM specific primers [23] showed a single band at the expected size of approximately 225 bp. Lane 1=ADM RT–PCR; Lane 2=no template control; Lane 3=NEB 50 bp ladder (New England BioLabs, Ipswich, MA), darkest band=200 bp. B: RT–PCR using primers described by Uzan et al. [23] confirmed the expression of CRLR (Lane 1, approximately 700 bp), RAMP3 (Lane 2, approximately 250 bp), and RAMP2 (Lane 3, approximately 190 bp). Lane 4=NEB 100 bp ladder.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: Adrenomedullin (ADM), calcitonin receptor like receptor (CRLR), and eceptor activity modifying protein (RAMPs) needed for ADM signaling are expressed in the retina. A: Reverse transcriptase (RT)–PCR using ADM specific primers [23] showed a single band at the expected size of approximately 225 bp. Lane 1=ADM RT–PCR; Lane 2=no template control; Lane 3=NEB 50 bp ladder (New England BioLabs, Ipswich, MA), darkest band=200 bp. B: RT–PCR using primers described by Uzan et al. [23] confirmed the expression of CRLR (Lane 1, approximately 700 bp), RAMP3 (Lane 2, approximately 250 bp), and RAMP2 (Lane 3, approximately 190 bp). Lane 4=NEB 100 bp ladder.

Mentions: We confirmed the expression of ADM in the retina using RT–PCR (Figure 1A). ADM-LI was detected weakly throughout the retina but was strongly localized near the photoreceptor outer segments, in elongated somata in the middle of the INL, and in some large somata in the GCL (Figure 2A) compared to an absorption control (Figure 2B) and a no primary control (not shown). We also observed faint ADM-LI in the cytoplasm of somata in the INL adjacent to the IPL.


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

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

Adrenomedullin (ADM), calcitonin receptor like receptor (CRLR), and eceptor activity modifying protein (RAMPs) needed for ADM signaling are expressed in the retina. A: Reverse transcriptase (RT)–PCR using ADM specific primers [23] showed a single band at the expected size of approximately 225 bp. Lane 1=ADM RT–PCR; Lane 2=no template control; Lane 3=NEB 50 bp ladder (New England BioLabs, Ipswich, MA), darkest band=200 bp. B: RT–PCR using primers described by Uzan et al. [23] confirmed the expression of CRLR (Lane 1, approximately 700 bp), RAMP3 (Lane 2, approximately 250 bp), and RAMP2 (Lane 3, approximately 190 bp). Lane 4=NEB 100 bp ladder.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: Adrenomedullin (ADM), calcitonin receptor like receptor (CRLR), and eceptor activity modifying protein (RAMPs) needed for ADM signaling are expressed in the retina. A: Reverse transcriptase (RT)–PCR using ADM specific primers [23] showed a single band at the expected size of approximately 225 bp. Lane 1=ADM RT–PCR; Lane 2=no template control; Lane 3=NEB 50 bp ladder (New England BioLabs, Ipswich, MA), darkest band=200 bp. B: RT–PCR using primers described by Uzan et al. [23] confirmed the expression of CRLR (Lane 1, approximately 700 bp), RAMP3 (Lane 2, approximately 250 bp), and RAMP2 (Lane 3, approximately 190 bp). Lane 4=NEB 100 bp ladder.
Mentions: We confirmed the expression of ADM in the retina using RT–PCR (Figure 1A). ADM-LI was detected weakly throughout the retina but was strongly localized near the photoreceptor outer segments, in elongated somata in the middle of the INL, and in some large somata in the GCL (Figure 2A) compared to an absorption control (Figure 2B) and a no primary control (not shown). We also observed faint ADM-LI in the cytoplasm of somata in the INL adjacent to the IPL.

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