BACKGROUND Despite the high cost and widespread prevalence of alcohol use disorders, treatment options are limited, underscoring the need for new, effective medications. Previous results using protein kinase C epsilon (PKCε) knockout mice, RNA interference against PKCε, and peptide inhibitors of PKCε predict that small-molecule inhibitors of PKCε should reduce alcohol consumption in humans. METHODS We designed a new class of PKCε inhibitors based on the Rho-associated protein kinase (ROCK) inhibitor Y-27632. In vitro kinase and binding assays were used to identify the most potent compounds. Their effects on ethanol-stimulated synaptic transmission; ethanol, sucrose, and quinine consumption; ethanol-induced loss of righting; and ethanol clearance were studied in mice. RESULTS We identified two compounds that inhibited PKCε with Ki <20 nM, showed selectivity for PKCε over other kinases, crossed the blood-brain barrier, achieved effective concentrations in mouse brain, prevented ethanol-stimulated gamma-aminobutyric acid release in the central amygdala, and reduced ethanol consumption when administered intraperitoneally at 40 mg/kg in wild-type but not in Prkce-/- mice. One compound also reduced sucrose and saccharin consumption, while the other was selective for ethanol. Both transiently impaired locomotion through an off-target effect that did not interfere with their ability to reduce ethanol intake. One compound prolonged recovery from ethanol-induced loss of righting but this was also due to an off-target effect since it was present in Prkce-/- mice. Neither altered ethanol clearance. CONCLUSIONS These results identify lead compounds for development of PKCε inhibitors that reduce alcohol consumption.

中文翻译：

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蛋白质激酶 C Epsilon 的新型小分子抑制剂可减少小鼠的乙醇消耗

背景尽管酒精使用障碍的成本高且普遍流行，但治疗选择是有限的，这突显了对新的有效药物的需求。先前使用蛋白激酶 C epsilon (PKCε) 敲除小鼠、针对 PKCε 的 RNA 干扰和 PKCε 的肽抑制剂的结果预测，PKCε 的小分子抑制剂应减少人类的酒精消耗。方法 我们设计了一类基于 Rho 相关蛋白激酶 (ROCK) 抑制剂 Y-27632 的新型 PKCε 抑制剂。体外激酶和结合试验用于鉴定最有效的化合物。它们对乙醇刺激的突触传递的影响；乙醇、蔗糖和奎宁的消耗量；乙醇引起的扶正损失；并在小鼠中研究了乙醇清除率。结果 我们鉴定了两种抑制 PKCε 的化合物，Ki <20 nM，PKCε 对其他激酶的选择性，穿过血脑屏障，在小鼠脑中达到有效浓度，防止乙醇刺激的中央杏仁核释放 γ-氨基丁酸，并在野生环境中以 40 mg/kg 腹膜内给药时减少乙醇消耗-type 但不是在 Prkce-/- 小鼠中。一种化合物还减少了蔗糖和糖精的消耗，而另一种则对乙醇有选择性。两者都通过脱靶效应暂时损害运动，这不会干扰它们减少乙醇摄入量的能力。一种化合物延长了从乙醇引起的翻正损失中恢复的时间，但这也是由于脱靶效应，因为它存在于 Prkce-/- 小鼠中。两者都没有改变乙醇清除率。