CFTRinh-172 was identified as a potent and selective blocker of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. CFTRinh-172 inhibits Cl- current in wild-type, G551D, and G1349D CFTR with Ki value of 0.5μM[1]. 1 and 10µM CFTRinh-172 caused 50% and 90% reduction of the original current in chinese hamster ovary (CHO) cells within 1-2s respectively with IC50 value of 1.1μM, and this inhibition is reversible[2].
In vitro, CFTR-expressing fischer rat thyroid cells incubated with CFTRinh-172 rapid and dose-dependently inhibited short-circuit current with CFTRinh-172 added to the solution bathing the apical cell surface. The average dose inhibition relationships of CFTRinh-172 is with Kd value of 300nM[3]. Human glioblastoma cell line U87 cells pretreated with CFTRinh-172 (5μM) for 30min, and then exposed to Forskolin (50μM) for additional 48h. CFTRinh-172 significantly increased cell viability and cell density, while partially restored inhibitory effects of Forskolin on U87 cell viability and cell density. CFTRinh-172 pretreatment partially attenuated the effects of Forskolin on Ki67 positive rate and significantly increased cell colony formation number[4]. CCRF-CEM, Jurkat and MOLT-4 T-ALL cell line were treated with CFTRinh-172 (5 to 40μM) for 24h or 48h. CFTRinh-172 concentration-dependently inhibited the growth of all three T-ALL cell lines and blocked the cell cycle. CCRF-CEM, JURKAT and MOLT-4 cells treated with 20μM CFTRinh-172 for 24h significantly changed the gene expression involved in various signaling pathways, including the Wnt/TGF-beta signaling pathway, the cell cycle, apoptotic process, cell proliferation, programmed cell death, etc[5].
In vivo, CFTRinh-172 (3mg/kg) was intraperitoneal administrated in E. coli-induced acute lung inflammation mouse models. Inhibition of CFTR by CFTRinh-172 deteriorated E. coli-induced acute lung inflammation. CFTRinh-172 induced deficiency of CFTR promotes migration of monocytes and neutrophils in E. coli pneumonia and peritonitis mouse models[6]. LPS-Induced Acute Lung Injury rat models were administrated with lipoxin A4 (2µM/kg; iv) following CFTRinh-172 treatment. 1.5mL (5mL/kg) of the instillate solution with CFTRinh-172 (1µM) was instilled at a rate of 0.08mL/min via tracheal instillation using a syringe pump. Lipoxin A4 significantly improved histology of rat lungs and inhibited IL-6 and TNF-α in LPS-induced lung injury. CFTRinh-172 abolished the effect of lipoxin A4 on alveolar fluid clearance (AFC)[7].
References:
[1] Taddei A, Folli C, Moran O G, et al. Altered channel gating mechanism for CFTR inhibition by a high-affinity thiazolidinone blocker. FEBS Lett. 2004 Jan 30;558(1-3):52-6.
[2] Kopeikin Z, Sohma Y, Li M, Hwang T C.On the mechanism of CFTR inhibition by a thiazolidinone derivative. J Gen Physiol. 2010 Dec;136(6):659-71.
[3] Ma T, Thiagarajah J R, Yang H, et al. Thiazolidinone CFTR inhibitor identified by high-throughput screening blocks cholera toxin-induced intestinal fluid secretion. J Clin Invest. 2002 Dec;110(11):1651-8.
[4] Zhong X, Chen H Q, Yang X L, et al. CFTR activation suppresses glioblastoma cell proliferation, migration and invasion. Biochem Biophys Res Commun. 2019 Jan 22;508(4):1279-1285
[5] Liu M F, Liao H J, Chen Y, et al. Treatment of human T-cell acute lymphoblastic leukemia cells with CFTR inhibitor CFTRinh-172. Leuk Res. 2019 Nov:86:106225.
[6] Gao Z, Su X. CFTR regulates acute inflammatory responses in macrophages. QJM. 2015 Dec;108(12):951-8.
[7] Yang Y, Cheng Y, Lian Q Q, et al. Contribution of CFTR to alveolar fluid clearance by lipoxin A4 via PI3K/Akt pathway in LPS-induced acute lung injury. Mediators Inflamm. 2013:2013:862628.