Abstract TP99: Human Lung Endothelial Cell Anti-Inflammatory and Regenerative Responses in Acute Ischemic Stroke

Abstract

Background: Inflammatory responses after stroke consists of central and peripheral immune responses. The role of the spleen after stroke is well-known, however the role of the lungs has not been studied in detail. We explored the relation between stroke severity and immunomodulatory changes in lung endothelial cells. Methods: Human pulmonary endothelial cells (hPECs, Cell Biologics) were cultured at passage 3. Serum from stroke patients with NIH Stroke Scale (NIHSS) severity ranging from 0 to 20 was collected at 24 hours after stroke. hPECs were exposed to media with 1) 10% FBS alone (N=6), 2) 10% serum from stroke patients (N=72), or 3) 10% serum from stroke mimic patients (N=6). After 3 hour of exposure, fresh media was added and secretomes from hPECs were measured after 24 hours. We isolated RNA from hPECs after 3 hour of serum exposure and measured gene expression (N=6 for each group). Secretome and gene changes in hPECs were analyzed based on stroke severity, tPA treatment, and co-morbidities. Results: Serum from stroke patients reduced the secretion of IL-8, MCP-1 and Fractalkine (p<0.01), and increased the secretion of VEGF and BDNF (p<0.01) from hPECs. These effects were more pronounced depending on stroke severity (Fig). There was no effect of tPA or T2DM on hPECs secretomes. There was significantly reduced gene expression of IL-6, IL-8, MCP-1 and IL-1β and significantly higher expression of ICAM1, IGF-1 and TGF-β1 as compared to stroke mimics. Conclusion: Exposure of hPECs to serum from stroke patients alters their immunomodulatory properties. Higher severity of stroke leads to more protective response from hPECs by reducing the secretion of pro-inflammatory factors, while increasing the secretion of anti-inflammatory factors.