Cell experiment:

Cell proliferation are examined using MTT assay. The 5×103 cells grown in a 96-well plate for 24 h are partially starved in DMEM/F12 supplemented with 1% FBS for 12 h, and then stimulated with various concentrations of TCS-401 for an additional 24 h. MTT are added to the culture medium, and the cells are incubated for an additional 4 h. The formazan crystals formed are then dissolved by adding dimethyl sulfoxide (100 μL per well). Absorbance at 490 nm are measured using a microplate reader.

TCS 401 is a selective inhibitor of protein tyrosine phosphatase 1B (PTP1B).

TCS-401 (0.5, 1, 2 μM) significantly increases the proliferation of RPE cells. TCS-401 significantly increases the expression of cyclin A and cyclin D1 at the concentrations of 1 and 2 μM in a concentration-dependent manner. TCS-401 at concentrations of 0.5, 1, and 2 μM significantly increases phosphorylation of Erk and Akt compared to the control group. The activation of Erk and Akt by TCS-401 is blocked by pretreatment with PD98059 and LY294002, respectively. CS-401 treatment activates the MEK/Erk and PI3K/Akt signaling pathways and induces proliferation, differentiation, and migration in RPE cells[1]. CS-401 dose dependently inhibits the RPTC-Sup-induced reduction of fibronectin and α-SMA. At 1 μM, TCS-401 reverses the levels of fibronectin and α-SMA about onefold and at a dose of 2 μM, TCS-401 brings back fibronectin and α-SMA expression to near normal levels[2].

References:
[1]. Du ZD, et al. Protein tyrosine phosphatase 1B regulates the activity of retinal pigment epithelial cells. Mol Vis. 2015 May 1;21:523-31.
[2]. Ponnusamy M, et al. Necrotic renal epithelial cell inhibits renal interstitial fibroblast activation: role of protein tyrosine phosphatase 1B. Am J Physiol Renal Physiol. 2013 Mar 15;304(6):F698-709.