title: A novel GTP-binding inhibitor, FX2149, attenuates LRRK2 toxicity in Parkinson's disease models.
abstract: Leucine-rich repeat kinase-2 (LRRK2), a cytoplasmic protein containing both GTP binding and kinase activities, has emerged as a highly promising drug target for Parkinson's disease (PD). The majority of PD-linked mutations in LRRK2 dysregulate its GTP binding and kinase activities, which may contribute to neurodegeneration. While most known LRRK2 inhibitors are developed to target the kinase domain, we have recently identified the first LRRK2 GTP binding inhibitor, 68, which not only inhibits LRRK2 GTP binding and kinase activities with high potency in vitro, but also reduces neurodegeneration. However, the in vivo effects of 68 are low due to its limited brain penetration. To address this problem, we reported herein the design and synthesis of a novel analog of 68, FX2149, aimed at increasing the in vivo efficacy. Pharmacological characterization of FX2149 exhibited inhibition of LRRK2 GTP binding activity by ~90% at a concentration of 10 nM using in vitro assays. Furthermore, FX2149 protected against mutant LRRK2-induced neurodegeneration in SH-SY5Y cells at 50-200 nM concentrations. Importantly, FX2149 at 10 mg/kg (i.p.) showed significant brain inhibition efficacy equivalent to that of 68 at 20 mg/kg (i.p.), determined by mouse brain LRRK2 GTP binding and phosphorylation assays. Furthermore, FX2149 at 10 mg/kg (i.p.) attenuated lipopolysaccharide (LPS)-induced microglia activation and LRRK2 upregulation in a mouse neuroinflammation model comparable to 68 at 20 mg/kg (i.p.). Our results highlight a novel GTP binding inhibitor with better brain efficacy, which represents a new lead compound for further understanding PD pathogenesis and therapeutic studies.
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.
authors: Tianxia
authors: T
authors: Li
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America; Beijing Institute of Pharmacology and Toxicology, Beijing, China.
authors: Xinhua
authors: X
authors: He
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.
authors: Joseph M
authors: JM
authors: Thomas
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.
authors: Dejun
authors: D
authors: Yang
authors: School of Life Science and Biotechnology, Dalian University of Technology, Liaoning, China.
authors: Shijun
authors: S
authors: Zhong
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.
authors: Fengtian
authors: F
authors: Xue
authors: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.
authors: Wanli W
authors: WW
authors: Smith
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects; D002460:Cell Line; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage* / Q000138:chemical synthesis* / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; D051379:Mice; D017628:Microglia / Q000187:drug effects; D010300:Parkinson Disease / Q000188:drug therapy* / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D004791:Enzyme Inhibitors; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; C495279:Lrrk2 protein, mouse; D017346:Protein Serine-Threonine Kinases