Matricellular proteins are a group of [[extracellular matrix]] proteins that play important roles in regulating cell behavior, including [[cell adhesion]], proliferation, differentiation, and survival. They do not serve a structural role in the extracellular matrix, but instead act as signaling molecules that modulate cell-matrix interactions and cell signaling pathways. Examples of matricellular proteins include thrombospondins, tenascins, and [[osteopontin]].
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[[Matricellular proteins]] have been implicated in pathologies after [[subarachnoid hemorrhage]] (SAH). To find a new therapeutic molecular target, a study aimed to clarify the relationships between serially measured plasma levels of a matricellular protein, secreted protein acidic and rich in cysteine (SPARC), and [[delayed cerebral ischemia]] (DCI) in 117 consecutive aneurysmal SAH patients with admission World Federation of Neurological Surgeons ([[WFNS]]) grades I-III. DCI developed in 25 patients with higher incidences of past history of hypertension and dyslipidemia, preoperative WFNS grade III, modified [[Fisher grade]] 4, spinal drainage, and [[angiographic vasospasm]]. Plasma SPARC levels were increased after SAH, and significantly higher in patients with than without DCI at days 7-9, and in patients with VASOGRADE-Yellow compared with [[VASOGRADE]]-Green at days 1-3 and 7-9. However, there were no relationships between plasma SPARC levels and angiographic vasospasm. Receiver-operating characteristic curves differentiating DCI from no DCI determined the cut-off value of plasma SPARC ≥ 82.1 ng/ml at days 7 - 9 (sensitivity, 0.800; specificity, 0.533; and area under the curve, 0.708), which was found to be an independent determinant of DCI development in multivariate analyses. This is the first study to show that [[SPARC]] is upregulated in peripheral blood after SAH, and that SPARC may be involved in the development of DCI without angiographic vasospasm in a clinical setting
((Nakajima H, Kawakita F, Oinaka H, Suzuki Y, Nampei M, Kitano Y, Nishikawa H, Fujimoto M, Miura Y, Yasuda R, Toma N, Suzuki H; pSEED group. Plasma SPARC Elevation in [[Delayed Cerebral Ischemia]] After Aneurysmal Subarachnoid Hemorrhage. Neurotherapeutics. 2023 Feb 13. doi: 10.1007/s13311-023-01351-x. Epub ahead of print. PMID: 36781745.)).