Asymmetric dimethylarginine (ADMA) regulates c-jun expression and phosphorylation. C-jun expression (A), c-jun phosphorylation (B), and connexin 43 (Cx43; C) expression in untreated human pulmonary artery endothelial cells (HPAECs) and HPAECs treated with ADMA, SP600125, mock transfected (OligofectAMINE only), transfected with nontargeting small interfering RNA (siRNA) or c-jun siRNA, or overexpressing DDAHI (AdDDAHI), as indicated. D, Representative Western blots corresponding to A–C. One asterisk: ; two asterisks: ; three asterisks: , comparisons with transfection controls.