Selective Cannabinoid 2 Receptor Stimulation Reduces Tubular Epithelial Cell Damage after Renal Ischemia-Reperfusion Injury
作者:Jeffrey D. Pressly、Suni M. Mustafa、Ammaar H. Adibi、Sahar Alghamdi、Pankaj Pandey、Kuldeep K. Roy、Robert J. Doerksen、Bob M. Moore、Frank Park
DOI:10.1124/jpet.117.245522
日期:2018.2
Ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI), which is an increasing problem in the clinic and has been associated with elevated rates of mortality. Therapies to treat AKI are currently not available, so identification of new targets that can be modulated to ameliorate renal damage upon diagnosis of AKI is essential. In this study, a novel cannabinoid receptor 2 (CB2) agonist, SMM-295 [3′-methyl-4-(2-(thiophen-2-yl)propan-2-yl)biphenyl-2,6-diol], was designed, synthesized, and tested in vitro and in silico. Molecular docking of SMM-295 into a CB2 active-state homology model showed that SMM-295 interacts well with key amino acids to stabilize the active state. In human embryonic kidney 293 cells, SMM-295 was capable of reducing cAMP production with 66-fold selectivity for CB2 versus cannabinoid receptor 1 and dose-dependently increased mitogen-activated protein kinase and Akt phosphorylation. In vivo testing of the CB2 agonist was performed using a mouse model of bilateral IRI, which is a common model to mimic human AKI, where SMM-295 was immediately administered upon reperfusion of the kidneys after the ischemia episode. Histologic damage assessment 48 hours after reperfusion demonstrated reduced tubular damage in the presence of SMM-295. This was consistent with reduced plasma markers of renal dysfunction (i.e., creatinine and neutrophil gelatinase–associated lipocalin) in SMM-295–treated mice. Mechanistically, kidneys treated with SMM-295 were shown to have elevated activation of Akt with reduced terminal deoxynucleotidyl transferase–mediated digoxigenin-deoxyuridine nick-end labeling (TUNEL)–positive cells compared with vehicle-treated kidneys after IRI. These data suggest that selective CB2 receptor activation could be a potential therapeutic target in the treatment of AKI.
缺血-再灌注损伤(IRI)是急性肾损伤(AKI)的常见原因,这是临床上日益严重的问题,与死亡率上升有关。目前还没有治疗AKI的疗法,因此,识别新的可调节靶点以在诊断出AKI后减轻肾脏损伤至关重要。在本研究中,设计、合成并测试了一种新型的大麻素受体2(CB2)激动剂SMM-295[3'-甲基-4-(2-(噻吩-2-基)丙-2-基)联苯-2,6-二醇],其在体外和计算机模拟中进行了测试。SMM-295与CB2活性状态的同源模型的分子对接显示,SMM-295与关键氨基酸很好地相互作用以稳定活性状态。在人胚胎肾293细胞中,SMM-295能够减少cAMP的产生,对CB2的选择性是对大麻素受体1的66倍,并能剂量依赖性地增加有丝分裂原激活的蛋白激酶和Akt的磷酸化。在体内测试CB2激动剂时,使用了模拟人类AKI的常见模型——双侧IRI小鼠模型,其中SMM-295在缺血发作后肾脏再灌注时立即给药。再灌注48小时后的组织学损伤评估显示,在SMM-295存在的情况下,小管损伤减少。这与SMM-295处理的小鼠中肾功能障碍(即肌酐和中性粒细胞明胶酶相关脂质运载蛋白)的减少的血浆标志物一致。机制上,与IRI后给予载体的肾脏相比,用SMM-295处理的肾脏显示出Akt激活增加,而末端脱氧核苷酸转移酶介导的二羟基尿苷缺口末端标记(TUNEL)阳性细胞减少。这些数据表明,选择性CB2受体激活可能是治疗AKI的一个潜在的治疗靶点。