KN-93 is a selective inhibitor of Ca2+/calmodulin-dependent kinase II (CaMKII), competitively blocking CaM binding to the kinase.

CaMK II:370 nM. (Ki)

经过2天的KN-93处理后，95%的细胞在G1期停滞。G1期的停滞是可逆的；释放KN-93一天后，有一个细胞高峰期进入S期和G2-M期。此外，KN-93还能阻断由基础成纤维细胞生长因子、血小板衍生生长因子-BB、表皮生长因子和胰岛素样生长因子-1在NIH 3T3成纤维细胞中刺激的细胞生长[1]。KN-93抑制H+、K+-ATP酶的活性，但显著地消散胃膜囊泡形成的质子梯度，并减少腔室空间的体积[2]。在动作电位延长和早期后去极化期间，KN-93（0.5 μM）能防止左室开发压力的增加。在早期后去极化期间，Ca2+-独立的CaM激酶活性增加，KN-93可阻止这种增加[3]。KN-93（10 μM）显著抑制由高糖诱导的CaMKII/NF-κB信号传导的激活，并随后降低Müller细胞中的VEGF、iNOS和ICAM-1的表达[4]。

KN-93（1 mg/kg/day，i.p.）能抑制糖尿病引起的视网膜血管渗漏，并在糖尿病视网膜中抑制CaMKII和NF-κB的磷酸化[4]。

Cells are grown on 12-mm diameter glass coverslips in DMEM 100% serum and various concentrations of KN-93 or KN-92. After 0, 1, 2, and 3 days of culture in the presence of drug, coverslips are removed from culture, rinsed once in PBS, and then submerged in 100% methanol at -20°C for 3 min. Fixed cells are stored in PBS until staining using the TUNEL assay. Cells are overlaid on 20 μL PBS/1 mg/mL BSA for 30 min, rinsed in PBS, and then overlaid on 20 μL containing 100 mM sodium cacodylate (pH 6.8), 1 mM CoCl2, 0.1 mM DTT, 0.1 mg/mL BSA, 20 μM fluorescein-12-dUTP, and 0.1 unit/μL terminal transferase at 37°C for 60 min. Coverslips are rinsed in PBS twice, mounted on slides, and photographed using an OLYMPUS BX5O epifluorescent microscope using a UPLAN APO 40X oil immersion objective.

KN-93 is dissolved in DMSO. Cell viability is assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay. Briefly, Müller cells are seeded at a density of 10×104 cells per well in 96-well plates and cultured until sub-confluence. Next, cells are treated with curcumin for 24 h before incubation with MTT (5 mg/mL) at 37°C in 5% CO2 atmosphere for 4 h. The culture medium is then removed, and the formazan formed in the reaction is dissolved in 150 μL DMSO. The optical density of the solution is measured at 490 nm using a multifunctional microplate reader. Cell viability in each well is presented as a percentage of the control (vehicle-treated group).