Modulation of brain cation-Cl− cotransport via the SPAK kinase inhibitor ZT-1a
Jinwei Zhang, Mohammad Iqbal H. Bhuiyan, Ting Zhang, Jason K. Karimy, Zhijuan Wu, Victoria M. Fiesler, Jingfang Zhang, Huachen Huang, Md Nabiul Hasan, Anna E. Skrzypiec, Mariusz Mucha, Daniel Durán, Wei Huang, Robert Pawlak, Lesley M. Foley, T. Kevin Hitchens, M. Beth Minnigh, Samuel M. Poloyac, Seth L. Alper, Bradley J. Molyneaux, Andrew J. Trevelyan, Kristopher T. Kahle, Dandan Sun, Xianming Deng
Abstract
cotransporters (CCC), including NKCC1 and the KCCs, are important determinants of brain ionic homeostasis. SPAK kinase (STK39) is the CCC master regulator, which stimulates NKCC1 ionic influx and inhibits KCC-mediated efflux via phosphorylation at conserved, shared motifs. Upregulation of SPAK-dependent CCC phosphorylation has been implicated in several neurological diseases. Using a scaffold-hybrid strategy, we develop a novel potent and selective SPAK inhibitor, 5-chloro-N-(5-chloro-4-((4-chlorophenyl)(cyano)methyl)-2-methylphenyl)-2-hydroxybenzamide ("ZT-1a"). ZT-1a inhibits NKCC1 and stimulates KCCs by decreasing their SPAK-dependent phosphorylation. Intracerebroventricular delivery of ZT-1a decreases inflammation-induced CCC phosphorylation in the choroid plexus and reduces cerebrospinal fluid (CSF) hypersecretion in a model of post-hemorrhagic hydrocephalus. Systemically administered ZT-1a reduces ischemia-induced CCC phosphorylation, attenuates cerebral edema, protects against brain damage, and improves outcomes in a model of stroke. These results suggest ZT-1a or related compounds may be effective CCC modulators with therapeutic potential for brain disorders associated with impaired ionic homeostasis.