These data demonstrate that fetuin-A, OPG, and MGP play an important role in the pathogenesis of uremic vascular calcification.

We have previously found that uremic human serum upregulates RUNX2 in vascular smooth muscle cells (VSMCs), and that RUNX2 is upregulated in areas of vascular calcification in vivo. To confirm the role of RUNX2, we transiently transfected a dominant-negative RUNX2 (DeltaRUNX2) construct in bovine vascular smooth muscle cells (BVSMCs). Blocking RUNX2 transcriptional activity significantly decreased uremic serum induced alkaline phosphatase (ALP) activity (268+/-34 vs 188+/-9.5 U/g protein, P<0.05) and osteocalcin expression (172+/-17 vs 125+/-9 ODU, P<0.05). To determine the mechanism by which uremic serum upregulates RUNX2, we examined cell signaling pathways. BVSMCs were incubated in the presence or absence of inhibitors and RUNX2 expression and ALP activity were determined. The results demonstrate that the cyclic AMP (cAMP)/protein kinase A (PKA), but not protein kinase C, signaling pathway is involved in uremic serum-induced RUNX2 expression and ALP activity in BVSMCs. To examine potential uremic 'toxins', we measured bone morphogenetic protein (BMP)-2 concentration and found that uremic serum contained increased BMP-2 (uremic serum=169+/-33 pg/ml, normal serum=117+/-15 pg/ml, P<0.05). The incubation of BVSMCs with noggin, an inhibitor of BMP, decreased RUNX2 expression. In addition, BMP-2 secretion progressively increased during calcification and uremic serum enhanced its secretion compared to normal serum. In conclusion, this study demonstrates that RUNX2 transcriptional activity is critical in uremic serum-induced bone matrix protein expression in BVSMCs and that the cAMP/PKA pathway is involved. BMP-2 is also increased in uremic serum and can upregulate RUNX2 and calcification in vitro in VSMCs.

In our Midwest retrospective case series of biopsy proven neuro-ophthalmic sarcoidosis, patients were predominately white females with a wide age range. Consideration for the diagnosis of neurosarcoidosis should therefore not be limited by age, gender, or race. Optic neuropathy was the most common manifestation, typically presenting with optic disc edema and severe visual loss. No light perception vision was relatively common and should be considered a "red flag" for the diagnosis. Contrast cranial MRI frequently shows pathologic enhancement of the visual pathway. Serum angiotensin converting enzyme and chest radiography had relatively poor sensitivity for detecting biopsy proven disease in our study and therefore additional testing for tissue diagnosis might still be necessary for extrapulmonary neuro-ophthalmic sarcoidosis. Corticosteroids are the mainstay of therapy but some patients may require additional immunosuppressive therapy.

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