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A novel GTP-binding inhibitor, FX2149, attenuates LRRK2 toxicity in Parkinson's disease models.

Li T, He X, Thomas JM, Yang D, Zhong S, Xue F, Smith WW - PLoS ONE (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.

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.

No MeSH data available.


Related in: MedlinePlus

A. Chemical structures of 68 and FX2149; B. Synthesis of FX2149.
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pone.0122461.g001: A. Chemical structures of 68 and FX2149; B. Synthesis of FX2149.

Mentions: Given that 68 potently inhibits LRRK2 GTP binding and kinase activity in vitro [13], we kept its scaffold structure to retain the inhibition of GTP binding and kinase activity. A compound with good BBB permeability requires a Log P value between 1.0 and 3.0 and a Log BB value between -2.0 and 1.0 [17]. To optimize the BBB permeability of 68, we used a pyridine-3-sulfonamide group to replace the phenyl-sulfonamide head of 68 (Fig. 1A). Weakly basic groups, such as the pyridinyl group, are commonly present in therapeutic agents targeting the central nervous system [18]. Moreover, the 2-methoxy-ethyl tail of 68 was substituted by a propyl group to reduce the number of H-bond acceptors to fit the binding site of the LRRK2 GTPase domain. Compound FX2149 was calculated to have increased hydrophilicity (LogP = 1.38 vs 2.05 for 68) and enhanced BBB permeability (LogBB = -0.21 vs -0.27 for 68, calculated by using ACD/Labs Suite 5.0).


A novel GTP-binding inhibitor, FX2149, attenuates LRRK2 toxicity in Parkinson's disease models.

Li T, He X, Thomas JM, Yang D, Zhong S, Xue F, Smith WW - PLoS ONE (2015)

A. Chemical structures of 68 and FX2149; B. Synthesis of FX2149.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4376719&req=5

pone.0122461.g001: A. Chemical structures of 68 and FX2149; B. Synthesis of FX2149.
Mentions: Given that 68 potently inhibits LRRK2 GTP binding and kinase activity in vitro [13], we kept its scaffold structure to retain the inhibition of GTP binding and kinase activity. A compound with good BBB permeability requires a Log P value between 1.0 and 3.0 and a Log BB value between -2.0 and 1.0 [17]. To optimize the BBB permeability of 68, we used a pyridine-3-sulfonamide group to replace the phenyl-sulfonamide head of 68 (Fig. 1A). Weakly basic groups, such as the pyridinyl group, are commonly present in therapeutic agents targeting the central nervous system [18]. Moreover, the 2-methoxy-ethyl tail of 68 was substituted by a propyl group to reduce the number of H-bond acceptors to fit the binding site of the LRRK2 GTPase domain. Compound FX2149 was calculated to have increased hydrophilicity (LogP = 1.38 vs 2.05 for 68) and enhanced BBB permeability (LogBB = -0.21 vs -0.27 for 68, calculated by using ACD/Labs Suite 5.0).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, United States of America.

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.

No MeSH data available.


Related in: MedlinePlus