title: Using next-generation RNA sequencing to examine ischemic changes induced by cold blood cardioplegia on the human left ventricular myocardium transcriptome.
abstract: BACKGROUND
  The exact mechanisms that underlie the pathological processes of myocardial ischemia in humans are unclear. Cardiopulmonary bypass with cardioplegic arrest allows the authors to examine the whole transcriptional profile of human left ventricular myocardium at baseline and after exposure to cold cardioplegia-induced ischemia as a human ischemia model.
  
  
  METHODS
  The authors obtained biopsies from 45 patients undergoing aortic valve replacement surgery at baseline and after an average of 79 min of cold cardioplegic arrest. Samples were RNA sequenced and analyzed with the Partek Genomics Suite (Partek Inc., St. Louis, MO) for differential expression. Ingenuity Pathway Analysis (Ingenuity Systems, Redwood City, CA) and Biobase ExPlain (Biobase GmbH, Wolfenbuettel, Germany) systems were used for functional and pathway analyses.
  
  
  RESULTS
  Of the 4,098 genes with a mean expression value greater than 5, 90% were down-regulated and 9.1% were up-regulated. Of those, 1,241 were significantly differentially expressed. Gene ontology analysis revealed significant down-regulation in immune inflammatory response and complement activation categories and highly consistent was the down-regulation of intelectin 1, proteoglycan, and secretory leukocyte peptidase inhibitor. Up-regulated genes of interest were FBJ murine osteosarcoma viral oncogene homolog and the hemoglobin genes hemoglobin α1 (HBA1) and hemoglobin β. In addition, analysis of transcription factor-binding sites revealed interesting targets in factors regulating reactive oxygen species production, apoptosis, immunity, cytokine production, and inflammatory response.
  
  
  CONCLUSIONS
  The authors have shown that the human left ventricle exhibits significant changes in gene expression in response to cold cardioplegia-induced ischemia during cardiopulmonary bypass, which provides great insight into the pathophysiology of ventricular ischemia, and thus, may help guide efforts to reduce myocardial damage during surgery.
authors.affiliation: From the Brigham and Women's Hospital, Department of Anesthesiology, Perioperative and Pain Medicine, Harvard Medical School, Boston, Massachusetts (J.D.M., M.H., S.K.S., S.C.B.); Department of Genetics, Harvard Medical School, Boston, Massachusetts (D.C.C., D.M., J.G., E.M., S.R.D., J.G.S.); Harvard Medical School, Boston, Massachusetts (G.L.); Northwest Anesthesia, Abbott Northwestern Hospital and Minneapolis Heart Institute, Minneapolis, Minnesota (T.E.P.); Department of Anesthesiology, University of Texas Southwestern Medical Center, Dallas, Texas (A.A.F.); Howard Hughes Medical Institute, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts (C.E.S.); and Brigham and Women's Hospital, Division of Cardiac Surgery, Department of Surgery, Harvard Medical School, Boston, Massachusetts (S.F.A.).
authors.forename: Jochen D
authors.initials: JD
authors.lastname: Muehlschlegel
authors.forename: Danos C
authors.initials: DC
authors.lastname: Christodoulou
authors.forename: David
authors.initials: D
authors.lastname: McKean
authors.forename: Joshua
authors.initials: J
authors.lastname: Gorham
authors.forename: Erica
authors.initials: E
authors.lastname: Mazaika
authors.forename: Mahyar
authors.initials: M
authors.lastname: Heydarpour
authors.forename: Grace
authors.initials: G
authors.lastname: Lee
authors.forename: Steven R
authors.initials: SR
authors.lastname: DePalma
authors.forename: Tjorvi E
authors.initials: TE
authors.lastname: Perry
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Fox
authors.forename: Stanton K
authors.initials: SK
authors.lastname: Shernan
authors.forename: Christine E
authors.initials: CE
authors.lastname: Seidman
authors.forename: Sary F
authors.initials: SF
authors.lastname: Aranki
authors.forename: Jon G
authors.initials: JG
authors.lastname: Seidman
authors.forename: Simon C
authors.initials: SC
authors.lastname: Body
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003080:Cold Temperature; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000235:genetics*; D009206:Myocardium / Q000473:pathology; D017423:Sequence Analysis, RNA / Q000379:methods*; D059467:Transcriptome / Q000235:genetics*