title: Increased ERK and JNK activities correlate with disease activity in patients with systemic lupus erythematosus.
abstract: BACKGROUND
  Aberrant signalling along the p21ras/MAP kinase pathway has been demonstrated in systemic lupus erythematosus (SLE).
  
  
  OBJECTIVE
  To determine whether expression and activity of the MAP kinases ERK and JNK reflect disease activity in patients with SLE.
  
  
  METHODS
  Blood samples of 42 outpatients with SLE were prospectively collected during four consecutive visits. The control group included 20 healthy subjects. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Expression of total ERK and JNK kinases and their active forms (pERK and pJNK) was determined in whole protein lysates of peripheral blood mononuclear cells.
  
  
  RESULTS
  The mean levels of the active kinases pERK and pJNK were significantly increased in patients with active disease (SLEDAI 4-20) as compared with patients with inactive disease (SLEDAI 0-3), p = 0.04, as well as with healthy controls, p = 0.03 and p = 0.003 for pERK and pJNK, respectively. The percentage of activated forms of ERK and JNK of the total expression of these MAP kinases was also gradually increased, reaching 50% for pERK and >40% for pJNK in patients with SLE with moderate-to-severe disease (SLEDAI 7-20), p = 0.005, p = 0.005 and p = 0.02, p = 0.05 as compared with controls and inactive patients, respectively. A decrease of more than three SLEDAI points was associated with a significant reduction in the expression of both total and activated forms of ERK and JNK, p = 0.03, p = 0.01, respectively.
  
  
  CONCLUSIONS
  The results show that ERK and JNK activity reflects disease activity in patients with SLE. These MAP kinases may serve as additional tools for the evaluation of disease activity and management of these patients.
authors.affiliation: Rheumatology Unit, Beilinson Hospital, Rabin Medical Centre, Petah Tikva, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Molad
authors.forename: M
authors.initials: M
authors.lastname: Amit-Vasina
authors.forename: O
authors.initials: O
authors.lastname: Bloch
authors.forename: E
authors.initials: E
authors.lastname: Yona
authors.forename: M J
authors.initials: MJ
authors.lastname: Rapoport
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D048049:Extracellular Signal-Regulated MAP Kinases / Q000097:blood*; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000201:enzymology*; D048670:MAP Kinase Kinase 4 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4