title: The Opening of ATP-Sensitive K+ Channels Protects H9c2 Cardiac Cells Against the High Glucose-Induced Injury and Inflammation by Inhibiting the ROS-TLR4-Necroptosis Pathway.
abstract: OBJECTIVE
  Hyperglycemia activates multiple signaling molecules, including reactive oxygen species (ROS), toll-like receptor 4 (TLR4), receptor-interacting protein 3 (RIP3, a kinase promoting necroptosis), which mediate hyperglycemia-induced cardiac injury. This study explored whether inhibition of ROS-TLR4-necroptosis pathway contributed to the protection of ATP-sensitive K+ (KATP) channel opening against high glucose-induced cardiac injury and inflammation.
  
  
  METHODS
  H9c2 cardiac cells were treated with 35 mM glucose (HG) to establish a model of HG-induced insults. The expression of RIP3 and TLR4 were tested by western blot. Generation of ROS, cell viability, mitochondrial membrane potential (MMP) and secretion of inflammatory cytokines were measured as injury indexes.
  
  
  RESULTS
  HG increased the expression of TLR4 and RIP3. Necrostatin-1 (Nec-1, an inhibitor of necroptosis) or TAK-242 (an inhibitor of TLR4) co-treatment attenuated HG-induced up-regulation of RIP3. Diazoxide (DZ, a mitochondrial KATP channel opener) or pinacidil (Pin, a non-selective KATP channel opener) or N-acetyl-L-cysteine (NAC, a ROS scavenger) pre-treatment blocked the up-regulation of TLR4 and RIP3. Furthermore, pre-treatment with DZ or Pin or NAC, or co-treatment with TAK-242 or Nec-1 attenuated HG-induced a decrease in cell viability, and increases in ROS generation, MMP loss and inflammatory cytokines secretion. However, 5-hydroxy decanoic acid (5-HD, a mitochondrial KATP channel blocker) or glibenclamide (Gli, a non-selective KATP channel blocker) pre-treatment did not aggravate HG-induced injury and inflammation.
  
  
  CONCLUSIONS
  KATP channel opening protects H9c2 cells against HG-induced injury and inflammation by inhibiting ROS-TLR4-necroptosis pathway.
authors.forename: Weijie
authors.initials: W
authors.lastname: Liang
authors.forename: Meiji
authors.initials: M
authors.lastname: Chen
authors.forename: Dongdan
authors.initials: D
authors.lastname: Zheng
authors.forename: Jianhao
authors.initials: J
authors.lastname: Li
authors.forename: Mingcai
authors.initials: M
authors.lastname: Song
authors.forename: Wenzhu
authors.initials: W
authors.lastname: Zhang
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Feng
authors.forename: Jun
authors.initials: J
authors.lastname: Lan
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D003652:Decanoic Acids / Q000494:pharmacology; D003981:Diazoxide / Q000494:pharmacology; D005786:Gene Expression Regulation; D005947:Glucose / Q000633:toxicity*; D005905:Glyburide / Q000494:pharmacology; D006880:Hydroxy Acids / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009336:Necrosis / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control; D018384:Oxidative Stress; D020110:Pinacidil / Q000494:pharmacology; D015221:Potassium Channels / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013449:Sulfonamides / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
chemical_list: D003652:Decanoic Acids; D006880:Hydroxy Acids; D007093:Imidazoles; D007211:Indoles; D015221:Potassium Channels; D017382:Reactive Oxygen Species; D013449:Sulfonamides; C495347:Tlr4 protein, rat; D051197:Toll-Like Receptor 4; C507035:ethyl 6-(N-(2-chloro-4-fluorophenyl)sulfamoyl)cyclohex-1-ene-1-carboxylate; C117780:mitochondrial K(ATP) channel; C507699:necrostatin-1; C052853:5-hydroxydecanoic acid; D020110:Pinacidil; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; C582791:Ripk3 protein, rat; D005947:Glucose; D003981:Diazoxide; D005905:Glyburide; D000111:Acetylcysteine
keywords: ATP-sensitive K+ channel; H9c2 cardiac cells; High glucose; Necroptosis; Reactive oxygen species; Toll-like receptor 4