In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Patients with diabetes are at increased risk of ischemic events. Suv39h1 is a histone methyltransferase that catalyzes the methylation of histone 3 lysine 9, which is associated with the suppression of inflammatory genes in diabetes. However, the role of Suv39h1 in myocardial ischemia/reperfusion (I/R) injury under diabetic condition has not been evaluated.', 'To generate diabetic model, male SD rats were fed with 60% fat diet followed by intraperitoneal injection with 40mg/kg streptozotocin. Adenovirus encoding Suv39h1 gene was used for Suv39h1 overexpression. Each rat received injections of adenovirus at five myocardial sites. Three days after gene transfection, each rat was subjected to left main coronary artery occlusion and reperfusion. After 30 min ischemia and reperfusion for 4 h, the rats were euthanized for real-time PCR, Western blot, immunohistochemical staining, and morphometric analysis.', 'Delivery of Ad-Suv39h1 into the hearts of diabetic rats could markedly increase Suv39h1 expression. Up-regulation of Suv39h1 significantly reduced infarct size and tissue damage after I/R injury, which was associated with protection from apoptosis of cardiac myocytes and reduction of inflammatory response. In addition, compared with injury group, Ad-Suv39h1 led to a decreased activity of mitogen-activated protein kinase family and its down-steam transcriptional factor NF-κB.\Question: Does suv39h1 protect from myocardial ischemia-reperfusion injury in diabetic rats?
Overexpression of Suv39h1 results in the de-activation of proinflammatory pathways and reduced apoptosis and myocardial injury. Therefore, Suv39h1 might represent a novel therapeutic strategy to reduce I/R injury under diabetic condition.

Context: Plasma high-density lipoprotein (HDL) level is inversely correlated with the risk of atherosclerosis. However, the cellular mechanism by which HDL exerts antiatherogenic actions is not well understood. In this study, we focus on the lipid components of HDL as mediators of the lipoprotein-induced antiatherogenic actions.', 'HDL and sphingosine 1-phosphate (S1P) stimulated the migration and survival of human umbilical vein endothelial cells. These responses to HDL and S1P were almost completely inhibited by pertussis toxin and other specific inhibitors for intracellular signaling pathways, although the inhibition profiles of migration and survival were different. The HDL-stimulated migration and survival of the cells were markedly inhibited by antisense oligonucleotides against the S1P receptors EDG-1/S1P1 and EDG-3/S1P3. Cell migration was sensitive to both receptors, but cell survival was exclusively sensitive to S1P1. The S1P-rich fraction and chromatographically purified S1P from HDL stimulated cell migration, but the rest of the fraction did not, as was the case of the cell survival.\Question: Does high-density lipoprotein stimulate endothelial cell migration and survival through sphingosine 1-phosphate and its receptors?
HDL-induced endothelial cell migration and survival may be mediated by the lipoprotein component S1P and the lipid receptors S1P1 and S1P3.

Context: Ephrin ligands and Eph receptors play important roles for cell behavior and movement by transducing bidirectional signaling into interacting cells. Since we found that the expression of ephrinB2 in the hematopoietic progenitor cell line was changed by coculture with stromal cells, we tried to examine the function of ephrinB2 in the hematopoietic microenvironment.', "Expression of ephrinB2 was measured by flow cytometry and reverse transcriptase polymerase chain reaction in the bone marrow (BM) hematopoietic cells and the stroma-dependent hematopoietic cell line (DFC-28) cocultured with stromal cells. Effect of ephrinB2 on the cells' behavior was monitored by overexpression of ephrinB2 cDNA in mouse pre-B-cell line (70z/3).", 'EphrinB2 expression in DFC-28 cells was modulated by two different stromal cells; ephrinB2 expression was high in DFC-28 cells when cocultured with MSS62 cells, whereas it was low when they were cocultured with TBR31-1 cells. Expression of EphB4, a receptor for ephrinB2, was detected in MSS62 cells but not in TBR31-1 cells. Similarly, BM hematopoietic cells did not express ephrinB2, but most of the BM cells expressed ephrinB2 after coculture with stromal cells. Ectopic expression of ephrinB2 in 70z/3 cells acquires specific binding to EphB4 and leads to significant decline in the locomotive activity underneath stromal cells.\Question: Do stromal cells modulate ephrinB2 expression and transmigration of hematopoietic cells?

These results indicate that expression of ephrinB2 in hematopoietic cells is regulated by interaction with particular stromal cells, and ephrinB2-EphB4 interaction modulates the migration and colonization of the hematopoietic cells in the local stromal microenvironment.