Dalcetrapib (RO4607381), a rhCETP inhibitor (IC50=0.2 μM), increases the plasma HDL cholesterol.

CETP (recombinant human):0.2 μM

Dalcetrapib 通过调节 CETP 活性发挥作用。当加入人类血浆中时，Dalcetrapib 诱导 CETP 发生构象变化。在 Dalcetrapib ≤3 μM 的条件下，CETP 诱导的人类血浆中 pre-β-HDL 形成保持不变，而在 10 μM 时增加。Dalcetrapib 统计学上显著增加 pre-β-HDL 形成。[1] 在人类血浆中，Dalcetrapib 以 9 μM 的浓度实现对 CETP 活性的 50% 抑制。[2] Dalcetrapib 以剂量依赖性方式抑制 HepG2 中介质的 CETP 活性。[3]

Dalcetrapib处理显著提高了HDL-C水平。在注射了[3H]胆固醇标记的自体巨噬细胞的仓鼠体内，Dalcetrapib显著增加了[3H]中性甾醇和[3H]胆汁酸的粪便排泄。Dalcetrapib提高了血浆中HDL-[3H]胆固醇水平。[1] 在口服剂量为30 mg/kg时，Dalcetrapib在日本白兔雄性动物身上抑制CETP活性达到95%。Dalcetrapib通过每天一次，连续3天口服30 mg/kg或100 mg/kg的剂量，分别将血浆HDL胆固醇水平提高了27%和54%。[2] Dalcetrapib处理显著提升了血清HDL-C水平。在5个月和7个月时，接受Dalcetrapib处理的兔子与对照组兔子相比，HDL2-C与HDL3-C的比率显著更高，表明Dalcetrapib通过抑制CETP活性改变了HDL亚类分布，并优先提高了HDL2-C水平。Dalcetrapib治疗增加了血清中的多巴酚醌酶活性和与HDL相关的血小板活化因子乙酰水解酶活性，但降低了血浆中的溶血磷脂酰胆碱浓度。[4]

Inhibition of rhCETP and C13S CETP-mediated transfer of CE from HDL to LDL: The inhibitory potency (IC50) of Dalcetrapib to decrease CE transfer from HDL to LDL by rhCETP and C13S CETP is measured using a scintillation proximity assay kit. Briefly, [3H]CE-labeled HDL donor particles are incubated in the presence of purified CETP proteins (final concentration 0.5 μg/mL) and biotinylated LDL acceptor particles for 3 hours at 37 °C. Subsequently, streptavidin-coupled polyvinyltoluene beads containing liquid scintillation cocktail binding selectively to biotinylated LDL are added, and the amount of [3H]CE molecules transferred to LDL is measured by β counting.

The HepG2 cells are seeded in 6-well plates and cultured to 70–80% confluence. After being washed with PBS, the cells are incubated with growth medium and a different concentration (0 μM–30 μM) of chemical inhibitor Dalcetrapib and dissolved in 2% DMSO for 24 hours. Total RNA is used for RT-PCR.(Only for Reference)