Fig. 5.

Role of extra cellular regulated kinase1/2 (ERK1/2) in BK stimulated expression of COX-2 and PGE2 production. (a) BK stimulated ERK1/2 phosphorylation (pERK 1/2) in podocytes. Quiescent podocytes were stimulated with BK (10⁻⁷ M) for 5, 10, 30 min. pERK and total ERK levels were assessed by western blot. Bar graph represents the fold change in pERK relative to total ERK protein levels and is the sum of 3 separate experiments (*p = 0.016). (b) Quiescent podocytes were stimulated with BK (10⁻⁷ M) for 5 min (5 min) in the presence and absence of PD98059 (25 μM) or Ibuprofen (10⁻⁶ M). Bar graph represents the fold change in measured PGE₂ levels and is the sum of at least 3 separate experiments (*p-value = 0.004 BK 5 min vs Control; +p-value = 0.024 BK 5 min vs BK 5 min-IB; #p-value = 0.024 BK 5 min vs BK 5 min-PD). (c) Quiescent podocytes were stimulated with BK (10⁻⁷ M) for 6 h in the presence and absence of PD98059 (25 μM). Bar graph represents the fold change in measured PGE₂ levels and is the sum of at least 3 separate experiments (*p < 0.03 BK 6 h vs Control, +p < 0.05 BK 6 h vs. BK 6 h-PD). (d) Quiescent podocytes were stimulated with BK (10⁻⁷ M) for 6 h in the presence and absence of PD98059 (25 μM). COX-2 and actin protein levels were measured by western blot. Bar graph represents the fold change in COX-2 proteins levels relative to β-actin protein levels and is the average of 3 separate experiments (*p-value = 0.035, BK 6 h vs. control; +p-value = 0.01 BK 6 h vs PD).