Total and phospho specific antibodies

Phorbol-12-myristate-13 acetate (PMA) and (3-4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide (MTT) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). The luciferase construct harboring AP-1 and collagen (Col)1A1 promoter binding sites was used as reported earlier [16] (link), [17] (link). TRIzol reagent was purchased from Molecular Research Center (Montgomery, OH, USA). Fetal bovine serum and Dulbecco's modified Eagle's medium (DMEM) were purchased from Gibco (Grand Island, NY, USA). The cell lines used in the present experiments (NIH3T3, HEK293, and B16F10 cells) were obtained from American Type Culture Collection (Rockville, MD, USA). All other chemicals were obtained from Sigma Chemical Co. Total and phosphospecific antibodies were purchased from Cell Signaling Technology (Beverly, MA, USA). Plasmid constructs driving the expression of Smad3 (mothers against decapentaplegic homolog 3) were used as reported previously [18] (link).

(3-4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide (MTT) was obtained from AMRESCO (Solon, OH, USA). Compound K (purity: > 96%), L-3,4-dihydroxyphenylalanine (L-DOPA), α-melanocyte-stimulating hormone (α-MSH), arbutin, and mushroom tyrosinase were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Fetal bovine serum (FBS) and Dulbecco's modified Eagle's medium (DMEM) were purchased from Gibco (Grand Island, NY, USA). Inhibitors (SB203583, SP600125, and U0126) were purchased from Millipore (Billerica, MA, USA). Total and phospho-specific antibodies were purchased from Cell Signaling Technology (Beverly, MA, USA). Phospho- and total antibodies against p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK), inhibitor of κBα (IκBα), and β-actin were purchased from Cell Signaling (Beverly, MA, USA).