Expression of Collagen XIII in Tissues of the Thyroid and Orbit With Relevance to Thyroid-Associated Ophthalmopathy.

Purpose: Antibodies against collagen XIII have previously been identified in patients with active thyroid-associated ophthalmopathy (TAO). Although collagen XIII expression has been described in extraocular muscles and orbital fat, its detailed localization in extraocular and thyroid tissues and the connection to autoimmunity for collagen XIII remain unclear. Our objective was to map the potential targets for these antibodies in the tissues of the orbit and thyroid. Methods: We evaluated the expression of collagen XIII in human patient and mouse orbital and thyroid tissues with immunostainings and RT-qPCR using Col13a1-/- mice as negative controls. COL13A1 expression in Graves' disease and goiter thyroid samples was compared with TGF-ß1 and TNF, and these were also studied in human thyroid epithelial cells and fibroblasts. Results: Collagen XIII expression was found in the neuromuscular and myotendinous junctions of extraocular muscles, blood vessels of orbital connective tissue and fat and the thyroid, and in the thyroid epithelium. Thyroid expression was also seen in germinal centers in Graves' disease and in neoplastic epithelium. The expression of COL13A1 in goiter samples correlated with levels of TGF-B1. Upregulation of COL13A1 was reproduced in thyroid epithelial cells treated with TGF-ß1. Conclusions: We mapped the expression of collagen XIII to various locations in the orbit, demonstrated its expression in the pathologies of the Graves' disease thyroid and confirmed the relationship between collagen XIII and TGF-ß1. Altogether, these data add to our understanding of the targets of anti-collagen XIII autoantibodies in TAO.

Ang-2 upregulation correlates with increased levels of MMP-9, VEGF, EPO and TGFß1 in diabetic eyes undergoing vitrectomy.

PURPOSE: Angiogenesis in diabetic retinopathy (DR) is a multifactorial process regulated by hypoxia-induced growth factors and inflammatory cytokines. In addition to the angiogenic switch, the proteolytic processing and altered synthesis of the extracellular matrix are critical steps in this disease. This study was performed to evaluate the levels of matrix metalloproteinase-2 and matrix metalloproteinase-9 (MMP-2 and MMP-9), angiopoietin-1 and angiopoietin-2 (Ang-1 and Ang-2), vascular endothelial growth factor (VEGF), erythropoietin (EPO) and transforming growth factor-ß1 (totalTGFß1) in the vitreous of diabetic eyes undergoing vitrectomy compared with control eyes operated because of macular hole or pucker. METHODS: Prospective consecutive controlled observational study performed in the unit of vitreoretinal surgery in Finland during the years 2006-2008. Vitreous samples were collected before the start of the conventional 3-ppp vitrectomy. Vitreous MMP-2 and MMP-9, Ang-1 and Ang-2, VEGF, EPO and TGFß1 concentrations were measured from 69 patients with Type 1 or 2 diabetes and 40 controls. RESULTS: Comparison of eyes with DR with controls revealed that the mean vitreous concentrations of proMMP-2 (p = 0.0015), totalMMP-2 (p = 0.0011), proMMP-9 (p = 0.00001), totalMMP-9 (p < 0.00001), Ang-2 (p < 0.00001), VEGF (p < 0.00001), EPO (p < 0.00001) and totalTGFß1 (p = 0.000026) were significantly higher in the former group. A multivariate logistic regression analysis suggested intravitreal Ang-2 concentration being the key marker of PDR (p = 0.00025) (OR = 1507.9). CONCLUSION: The main new finding is that the intravitreal concentrations of Ang-2 correlated significantly with MMP-9, VEGF, EPO and TGFß1 levels in diabetic eyes undergoing vitrectomy. Thus, these factors could promote retinal angiogenesis synergistically.

Elevated messenger RNA expression and plasma protein levels of osteopontin and matrix metalloproteinase types 2 and 9 in patients with ascending aortic aneurysms.

OBJECTIVE: Ascending aortic aneurysms result from a degenerative process in the aortic wall, characterized by the loss of smooth muscle cells and elastic fibers. We hypothesized that there would be changes in plasma protein and aortic tissue messenger RNA levels of osteopontin, matrix metalloproteinase type 2, matrix metalloproteinase type 9, and tissue inhibitor of matrix metalloproteinases type 1 in ascending aortic aneurysm samples. METHODS: Plasma, aortic tissue, and aortic mRNA samples were collected from patients with an ascending aortic aneurysm or an abdominal aortic aneurysm and from control individuals. Plasma protein levels of osteopontin, matrix metalloproteinase (MMP) types 2 and 9, and tissue inhibitor of matrix metalloproteinases type 1 were determined by quantitative sandwich enzyme-linked immunosorbent assay. Aortic mRNA levels of these same proteins were analyzed with the quantitative real-time polymerase chain reaction (RT-PCR) method and protein levels from the aortic tissues were assayed by immunostaining. Quantitative RT-PCR results were estimated by the normalized expression method (ΔΔCt). RESULTS: Plasma protein levels were significantly elevated for osteopontin, MMP-2, and MMP-9 in the samples of ascending and abdominal aortic aneurysm group compared with controls. Plasma protein levels of MMP-9 were higher in the nonoperated compared with the operated ascending aortic aneurysm group. Aortic osteopontin, MMP-2, and MMP-9 mRNA levels were increased for ascending aortic aneurysm samples. CONCLUSIONS: This study reveals an important role of osteopontin, MMP-2 and MMP-9 in the development of ascending and abdominal aortic aneurysm.