title: Minocycline and sulforaphane inhibited lipopolysaccharide-mediated retinal microglial activation.
abstract: OBJECTIVE
  To elucidate the inhibitory effect of minocycline and sulforaphane on lipopolysaccharide (LPS)-induced retinal microglial activation and the mechanisms through which they exerted their inhibitory effects.
  
  
  METHODS
  Primary retinal microglial cultures were exposed to LPS with or without minocycline and sulforaphane. The mRNA expression of monocyte chemotactic protein (MCP)-1, MCP-3, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, eotaxin, regulated upon activation normal T-cell expressed and secreted (RANTES) protein, and interleukin (IL)-10 were examined by reverse transcription polymerase chain reaction (RT-PCR) assay. The mRNA expression of inducible nitric oxide synthase (iNOS) and subsequent nitric oxide (NO) production were examined by RT-PCR assay and Griess reagent assay. Protein expression of the p65 subunit of nuclear factor-kappaB (NF-kappaB) and p-p38, p-p44/42 and p-JNK mitogen-activated protein kinases (MAPKs) were examined by Western blot and immunofluorescent analysis.
  
  
  RESULTS
  Cultured retinal microglial cells were activated following exposure to LPS. The mRNA expression and protein production of eotaxin, RANTES, and IL-10 and the mRNA expression of iNOS and subsequent NO production were upregulated. The protein expression of p-p38, p-JNK, and the p65 subunit of NF-kappaB were also upregulated. However, the protein expression of p-p44/42 was not significantly changed. Pretreatment with minocycline or sulforaphane for 1 h before LPS administration inhibited LPS-induced microglial morphological change and inhibited LPS-induced upregulation of p-p38, but had no effect on the expression of p-p44/42, p-JNK, and the p65 subunit of NF-kappaB.
  
  
  CONCLUSIONS
  Minocycline and sulforaphane inhibited LPS-induced retinal microglial activation, Western blot and immunofluorescent studies showed decreased p-p38 MAPK expression. We suggested that the inhibitory effect of minocycline and sulforaphane was partly through a p38 MAPK-dependent mechanism.
authors.affiliation: Peking University Eye Center, Peking University Third Hospital, Peking University, Beijing, PR China.
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Yang
authors.forename: Xiu-an
authors.initials: XA
authors.lastname: Zhu
authors.forename: Mark O M
authors.initials: MO
authors.lastname: Tso
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000235:genetics; D005455:Fluorescent Antibody Technique; D017879:Isothiocyanates; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D008911:Minocycline / Q000494:pharmacology*; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D012333:RNA, Messenger / Q000037:antagonists & inhibitors; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000166:cytology*; D013454:Sulfoxides; D013861:Thiocyanates / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D016207:Cytokines; D017879:Isothiocyanates; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D013454:Sulfoxides; D013861:Thiocyanates; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D048051:p38 Mitogen-Activated Protein Kinases; D008911:Minocycline; C016766:sulforaphane