Unique Transcriptional Profile of Sustained Ligand-Activated Preconditioning in Pre- and Post-Ischemic Myocardium

Abstract

BackgroundOpioidergic SLP (sustained ligand-activated preconditioning) induced by 3–5 days of opioid receptor (OR) agonism induces persistent protection against ischemia-reperfusion (I-R) injury in young and aged hearts, and is mechanistically distinct from conventional preconditioning responses. We thus applied unbiased gene-array interrogation to identify molecular effects of SLP in pre- and post-ischemic myocardium.Methodology/Principal FindingsMale C57Bl/6 mice were implanted with 75 mg morphine or placebo pellets for 5 days. Resultant SLP did not modify cardiac function, and markedly reduced dysfunction and injury in perfused hearts subjected to 25 min ischemia/45 min reperfusion. Microarray analysis identified 14 up- and 86 down-regulated genes in normoxic hearts from SLP mice (≥1.3-fold change, FDR≤5%). Induced genes encoded sarcomeric/contractile proteins (Myh7, Mybpc3,Myom2,Des), natriuretic peptides (Nppa,Nppb) and stress-signaling elements (Csda,Ptgds). Highly repressed genes primarily encoded chemokines (Ccl2,Ccl4,Ccl7,Ccl9,Ccl13,Ccl3l3,Cxcl3), cytokines (Il1b,Il6,Tnf) and other proteins involved in inflammation/immunity (C3,Cd74,Cd83, Cd86,Hla-dbq1,Hla-drb1,Saa1,Selp,Serpina3), together with endoplasmic stress proteins (known: Dnajb1,Herpud1,Socs3; putative: Il6, Gadd45g,Rcan1) and transcriptional controllers (Egr2,Egr3, Fos,Hmox1,Nfkbid). Biological themes modified thus related to inflammation/immunity, together with cellular/cardiovascular movement and development. SLP also modified the transcriptional response to I-R (46 genes uniquely altered post-ischemia), which may influence later infarction/remodeling. This included up-regulated determinants of cellular resistance to oxidant (Mgst3,Gstm1,Gstm2) and other forms of stress (Xirp1,Ankrd1,Clu), and repression of stress-response genes (Hspa1a,Hspd1,Hsp90aa,Hsph1,Serpinh1) and Txnip.ConclusionsProtection via SLP is associated with transcriptional repression of inflammation/immunity, up-regulation of sarcomeric elements and natriuretic peptides, and modulation of cell stress, growth and development, while conventional protective molecules are unaltered.

Synthetic CpG oligonucleotides induce a genetic profile ameliorating murine myocardial I/R injury

“…and CXCL10, and the protective effect of their selective suppression, respectively, have been demonstrated in a number of publications. [57][58][59][60] This also applies for the transcriptional controllers FOS and HMOX1. 57 Several other studies have shown a protective effect of CpG…”

Chronically elevated bilirubin protects from cardiac reperfusion injury in the male Gunn rat

“…Tissues were stored at −80 °C in RNAlater (Qiagen, Melbourne, Vic, Australia) immediately following collection, to measure nitric oxide‐regulating genes, Nos1 and Noa1 . RNA extraction, cDNA synthesis and two‐step quantitative real‐time PCR on these tissues were performed as previously described . Quantitative PCR data were normalized to RPL13A (ribosomal protein L13A) and expressed relative to wild‐type controls.…”

Hyperbilirubinemia modulates myocardial function, aortic ejection, and ischemic stress resistance in the Gunn rat

“…Transcript levels for antioxidant enzymes and determinants of Ca 2ϩ handling and contraction were assessed. RNA extraction, cDNA synthesis, and two-step quantitative real-time PCR was performed as previously described (2) in LV myocardial samples from Gunn and control hearts. Hearts were excised, and LVs were removed, placed in RNAlater solution (Qiagen, Melbourne, VIC, Australia), and frozen at Ϫ80°C.…”