First insight into the proteome landscape of the porcine short posterior ciliary arteries: Key signalling pathways maintaining physiologic functions.

Short posterior ciliary arteries (sPCA) provide the major blood supply to the optic nerve head. Emerging evidence has linked structural and functional anomalies of sPCA to the pathogenesis of several ocular disorders that cause varying degrees of visual loss, particularly anterior ischaemic optic neuropathy and glaucoma. Although the functional relevance of this vascular bed is well-recognized, the proteome of sPCA remains uncharacterized. Since the porcine ocular system closely resembles that of the human's and is increasingly employed in translational ophthalmic research, this study characterized the proteome of porcine sPCA employing the mass spectrometry-based proteomics strategy. A total of 1742 proteins and 10527 peptides were identified in the porcine sPCA. The major biological processes involved in the maintenance of physiological functions of the sPCA included redox and metabolic processes, and cytoskeleton organization. These proteins were further clustered into diverse signalling pathways that regulate vasoactivity of sPCA, namely the tight junction, α- and ß-adrenoceptor, 14-3-3, nitric oxide synthase and endothelin-1 -mediated signalling pathways. This study provides the first insight into the complex mechanisms dictating the vast protein repertoire in normal vascular physiology of the porcine sPCA. It is envisioned that our findings will serve as important benchmarks for future studies of sPCA.

Actinically degenerate elastic tissue: the prime antigen in the giant cell (temporal) arteritis syndrome? New data from the posterior ciliary arteries.

OBJECTIVE: To search for evidence of actinic elastotic degeneration (actinic arteriopathy) and giant cell arteritis (GCA) in the posterior ciliary arteries of eyes from aged white Australians. METHODS: Three hundred donor eyes were given to us by the Lions Eye Bank of New South Wales at Sydney Hospital. Of these, 146 formed the basis of this study. Portions of the posterior ciliary arteries located in relation to the optic nerve heads were processed in paraffin and were then stained by a sensitive haematoxylin and eosin stain that had been especially developed to display actinic elastotic degeneration of elastic tissue. RESULTS: Among 60 "aged" subjects (70-90 yrs.), a total of 41 (approximately 68%) showed definite changes of actinic elastotic degeneration in their laminae, a condition called actinic arteriopathy. One of these subjects revealed giant cells on degenerate lamina, giving a picture regarded as early (pre-clinical) GCA. A young "control" group of 60 subjects 17-59 years of age revealed only one subject with a similar degree of actinic arteriopathy. CONCLUSIONS: Actinic arteriopathy of the posterior ciliary arteries was more frequent and advanced in the "aged", over-70 group as compared with changes in the "young" group < 60 years of age. One aged subject without a history of eye disease showed giant cells associated with elastotically degenerate internal elastic lamina. Her fortuitous lesions are regarded as indicative of how GCA is likely to begin in the damaged arteries.