Oct solution

After the reperfusion, fresh heart biopsies were fixed in 4% paraformaldehyde overnight at 4°C and embedded in paraffin. Sections into 5-μm slices were stained with hematoxylin-eosin (H&E) or Masson’s trichrome for assessment of fibrosis. Tissues for immunofluorescence were submerged in liquid nitrogen and then embedded in optimal cutting temperature (OCT) solution (Sakura Finetek, USA) on dry ice to be frozen completely. Cardiomyocyte hypertrophy was examined in the peri-infarct zone. Myocyte cross-sectional areas were measured using Image J software (National Institutes of Health) in frozen sections stained with 5 μg/ml wheat germ agglutinin (WGA-Alexa Fluor^® 488 conjugate, Invitrogen, USA). Five parts were chosen in the WGA images (200X) including left top, right top, middle, left bottom, and right bottom, and six cells were analyzed for each part. In other experiments, the hearts were excised for Masson staining to evaluate the cardiac remodeling. For inflammatory cell infiltration and PDGFR protein expression, immunofluorescence staining with anti-CD45 (Cell Signaling Technology, USA) and anti-PDGFRα (Cell Signaling Technology, USA) in frozen sections was conducted. Then the number of CD45+ cells/field were quantified by Image J software (National Institutes of Health, USA).

All human materials were used in accordance with the policies of the Institutional Review Board (IRB) at Wayne State University. Tumor tissues were obtained from patients with histologically-confirmed glioblastoma immediately after surgical resection, under a protocol approved by the IRB (#111610M1E). Depending on the amount of tumor tissue available, a part or whole of the tumor tissue was fixed with 4% paraformaldehyde, saturated with 30% sucrose and frozen in O.C.T. solution (Sakura Finetek USA, Torrance, CA) prior to sectioning for immunohistochemical analysis. The remaining portion was enzymatically digested to prepare single cell suspensions of primary glioma cells using the gentleMACS^® dissociator system with the Human Tumor Kit (Miltenyi Biotec, San Diego, CA) using the manufacturer's protocol. Some of the dissociated tumor cells were cultured in DMEM/F12 containing 10% FBS to derive primary glioma cell lines, while the bulk of patient-derived glioma cells were used in the studies described below. U87-MG cells were obtained from American Type Culture Collection (ATCC, Manassas, VA) and maintained in DMEM/F12 containing 10% FBS.