Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 Jun;250(6):839-48.
doi: 10.1007/s00417-012-1969-9. Epub 2012 Mar 14.

Co-expression of endothelial and neuronal nitric oxide synthases in the developing vasculatures of the human fetal eye

D Scott McLeod  1 , Takayuki Baba, Imran A Bhutto, Gerard A Lutty
Affiliations

Co-expression of endothelial and neuronal nitric oxide synthases in the developing vasculatures of the human fetal eye

D Scott McLeod et al. Graefes Arch Clin Exp Ophthalmol. 2012 Jun.

Abstract

Background: Nitric oxide (NO) is a multifunctional gaseous molecule that regulates various physiological functions in both neuronal and non-neuronal cells. NO is synthesized by nitric oxide synthases (NOSs), of which three isoforms have been identified. Neuronal NOS (nNOS) and endothelial NOS (eNOS) constitutively produce low levels of NO as a cell-signaling molecule in response to an increase in intracellular calcium concentration. Recent data have revealed a predominant role of eNOS in both angiogenesis and vasculogenesis.

Methods: The immunohistochemical localization of nNOS and eNOS was investigated during embryonic and fetal ocular vascular development from 7 to 21 weeks gestation (WG) on sections of cryopreserved tissue.

Results: eNOS was confined to endothelial cells of developing vessels at all ages studied. nNOS was prominent in nuclei of vascular endothelial and smooth muscle cells in the fetal vasculature of vitreous and choriocapillaris. nNOS was also prominent in the nuclei of CXCR4(+) progenitors in the inner retina and inner neuroblastic layer.

Conclusions: These findings demonstrate co-expression of n- and eNOS isoforms in different compartments of vasoformative cells during development. Nuclear nNOS was present in vascular and nonvascular progenitors as well as endothelial cells and pericytes. This suggests that nNOS may play a role in the transcription regulatory systems in endothelial cells and pericytes during ocular hemo-vasculogenesis, vasculogenesis, and angiogenesis.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: none.

Figures

Figure 1
Figure 1
APase immunostaining for eNOS and nNOS in fetal vasculature of vitreous in human fetal eyes from 9 WG to 14 WG. H&E staining (a-c) shows morphological features of the vasculature in vitreous, which is intensely labeled for CD31 (d-f). Note that eNOS is prominently localized diffusely in endothelial cells (g-i), whereas nNOS is present in endothelial cell (EC) nuclei of the vasculature (j-l). Arrow indicates a blood vessel in each set of micrographs. Scale bar in “a” = 10 μm
Figure 2
Figure 2
Fetal vasculature of vitreous at 12 WG double-labeled with vWf (red fluorescence) and nNOS (green fluorescence). Endothelial cells (ECs) are positive for vWf (c). nNOS immunofluorescence is seen in EC nuclei (paired arrow) (d). Nuclei were counter stained with DAPI (blue fluorescence)(a). The merged images (a-b) demonstrate nNOS within endothelial cell nuclei Scale bar “a” = 10 μm
Figure 3
Figure 3
Fetal vasculature of vitreous at 12 WG double-labeled for SMA (red)(c) and nNOS (green)(d) shows nuclear nNOS expression in SMA+ cells (paired arrow)(merged in a-b). Nuclei were counter stained with DAPI (blue fluorescence)(a). Scale bar “a” = 10 μm
Figure 4
Figure 4
Fetal vasculature of vitreous at 12 WG double-labeled for eNOS (red)(c) and nNOS (green)(d) shows eNOS in the cytoplasm and nNOS in nuclei of both endothelial cells (paired arrows) and pericytes (arrow)(merged images a-b). Scale bar “a” = 10 μm
Figure 5
Figure 5
APase immunostaining for eNOS and nNOS in choroid of human fetal eyes from 7 WG to 21 WG. H&E staining (a-c) shows morphological features of developing choroid. Choriocapillaris (arrow in all) and deeper choroidal vessels (arrowhead in 14 & 21 WG) are labeled for CD31 (d-f). eNOS is prominently localized to the ECs of all choroidal vessels, whereas nNOS is present in mesenchymal precursor cells of stroma (bottom), in RPE nuclei and EC’s of blood vessels. Scale bar in “a” = 10 μm
Figure 6
Figure 6
Choroid at 17 WG double-labeled for vWf (red fluorescence)(c) and nNOS (green fluorescence)(d). Nuclear nNOS expression is seen in RPE (arrowhead), ECs of CC (arrow), and large choroidal vessels (paired arrow)(merged a-b). Nuclei were counter stained with DAPI (blue fluorescence)(a). Scale bar in “a” = 10 μm
Figure 7
Figure 7
Choroid at 17 WG double-labeled for SMA (red)(c) and nNOS (green)(d) shows nuclear nNOS expression in aSMA+ cells in large choroidal vessel (paired arrow)(merged a-b). Nuclei were counter stained with DAPI (blue fluorescence)(a). Scale bar in “a” = 10 μm
Figure 8
Figure 8
APase immunostaining for eNOS and nNOS in developing retina of human fetal eyes from 12 WG to 21 WG. H&E staining shows morphological features of developing retina (a-c). Developing retinal blood vessels (present after 12 WG), are intensely labeled for CD31 (e-f). eNOS is prominently localized to the ECs of retinal developing vessels (arrow h-i), whereas nNOS is present in progenitors (arrowhead in “j) in neuroblastic layer, migrating angioblasts in nerve fiber and ganglion cell layer, as well as ECs of developing retinal blood vessels. Arrow indicates developing retinal blood vessels. Scale bar in “a” = 10 μm
Figure 9
Figure 9
Seventeen WG retina double-labeled for vWf (red fluorescence)(c) and nNOS (green fluorescence)(d). Nuclear nNOS expression is seen in retinal vessel (arrow)(merged a-b). Nuclei were counter stained with DAPI (blue fluorescence)(a). Scale bar in “a” = 10 μM
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Moncada S, Palmer RM, Higgs EA. Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev. 1991;43:109–142. - PubMed
    1. Moncada S. Nitric oxide: discovery and impact on clinicaql medicine. J R Soc Med. 1999;92:164–169. - PMC - PubMed
    1. Bhutto IA, Baba T, Merges C, McLeod DS, Lutty GA. Low nitric oxide synthases (NOS) in eyes with age-related macular degeneration (AMD) Exp Eye Res 2009 - PMC - PubMed
    1. Neufeld AH, Shareef S, Pena J. Cellular localization of neuronal nitric oxide synthase (NOS-1) in the human and rat retina. J Comp Neurol. 2000;416:269–275. - PubMed
    1. Giove TJ, Deshpande MM, Eldred WD. Identification of alternate transcripts of neuronal nitric oxide synthase in the mouse retina. J Neurosci Res. 2009;87:3134–3142. - PubMed

Publication types

MeSH terms

Substances