Neuroprotective Effect of IND1316, an Indole-Based AMPK Activator, in Animal Models of Huntington Disease.

HHS Public Access Author manuscript Author Manuscript ACS Chem Neurosci. Author manuscript; available in PMC 2022 February 08. Published in final edited form as: ACS Chem Neurosci. 2022 January 19; 13(2): 275–287. doi:10.1021/acschemneuro.1c00758. Neuroprotective effect of IND1316, an indole-based AMPK activator, in animal models of Huntington disease Marta Vela†,#, M Adelaida García-Gimeno‡,#, Ana Sanchis§,#, José Bono-Yagüe§, José Cumella†, Laura Lagartera†, Concepción Pérez†, Eva Ma Priego†, Angela Campos$, Pascual Sanz$,*, Rafael P. Vázquez-Manrique&,*, Ana Castro†,* †Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, 28006-Madrid, Spain. Author Manuscript ‡Department of Biotechnology, Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural (ETSIAMN), Universitat Politécnica de València, 46022-Valencia, Spain. §Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026-Valencia, Spain and Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012-Valencia, Spain &Grupo de Investigación en Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe (IIS La Fe), 46026-Valencia, Spain; Joint Unit for Rare Diseases IIS La Fe-CIPF, 46012-Valencia, Spain and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER)-ISCIII, 28029-Madrid, Spain. $Instituto de Biomedicina de Valencia, IBV-CSIC, 46010-Valencia, Spain and Centro de Author Manuscript Investigación Biomédica en Red de Enfermedades Raras (CIBERER)-ISCIII, 28029-Madrid, Spain. Abstract Aggregation of mutant huntingtin, due to an expanded polyglutamine track, underlies the cause of neurodegeneration in Huntington disease (HD). However, it remains unclear how some alterations at the cellular level lead to specific structural changes in HD brains. In this context, the neuroprotective effect of the activation of AMP-activated protein kinase (AMPK) appears to be a determinant factor in several neurodegenerative diseases, including HD. In the present work, we describe a series of indole-derived compounds able to activate AMPK at the cellular level. By using animal models of HD (both worms and mice), we demonstrate the in vivo efficacy of one Author Manuscript * Corresponding Authors: Phone: +34915622900. Phone: +34961246678, Phone: +34963391779. #These authors contributed equally to this work. *These three Co-corresponding authors contributed equally to this work. Author Contributions M.V., M.A.G-G, and A.S. contributed equally. A.C., P.S., and R.V-M. designed the project. M.V. and J.C. carried out the synthesis and analyzed the compounds. L.L. and C.P. performed the SPR analyses and the in vitro activation of AMPK experiments. E.P. performed ADME in silico studies. M.A.G-G carried out in cell experiments. A.S achieved in vivo experiments with mice. JB-Y performed the test on worms. A.C., P.S., and R.V-M. wrote the manuscript. All authors have read and agreed to the published version of the manuscript. The authors declare no competing financial interest. SUPPORTING INFORMATION: The supplementary material file contains supplementary Figures S1 and S2. Supplementary Figure S1 contains the whole information regarding Figure 4, in the main manuscript, for the sake of transparency. Figure S2 contains immunostaining of mHtt and inflammatory biomarkers, which did not yield positive results. Vela et al. Page 2 Author Manuscript of these compounds (IND1316), confirming that it can reduce neuropathological symptoms of this disease. Taken together, in vivo results and in silico studies of druggability, allow us to suggest that IND1316 could be considered as a promising new lead compound for the treatment of HD and other central nervous system diseases in which activation of AMPK results in neuroprotection. Graphical Abstract Author Manuscript Keywords indole derivatives; AMPK; neuroprotection; ADME in silico; C. elegans models; polyQ toxicity; Huntington disease mouse models INTRODUCTION Author Manuscript Huntington disease (HD) is a progressive, autosomal dominant neurodegenerative disorder that causes alterations in motor coordination together with symptoms characterized by involuntary movements, cognitive impairment, and mental deterioration. The disease is caused by an abnormally long expansion of trinucleotide CAG in the HTT gene, leading to the production of a cytosolic protein, of yet unclear function,1 called huntingtin (Htt). Carriers of an expansion of 36 or more CAG trinucleotides express a mutant version of Htt (mHtt), which contains a tandem of glutamines (polyQ) that makes the protein unstable and prone to aggregation. The process of aggregation produces toxic species of mHtt, both soluble and in form of aggregates,2,3 that disrupt key cellular processes (e.g. autophagic flow, axonal transport, transcription of some genes, synaptic function, etc.) which in turn induces neuronal degeneration. Author Manuscript AMP-activated protein kinase (AMPK) acts as a key player in regulating energy metabolism. This enzyme is a heterotrimer (AMPKα is the catalytic and AMPKβ and AMPKγ are regulatory subunits) that is activated when there is a drop in the levels of ATP. Activation of AMPK inhibits anabolic pathways and activates catabolic pathways to restore energy levels. AMPK plays a very important role in brain physiology as a metabolic sensor of the central nervous system, ensuring the maintenance of energy homeostasis.4 In particular, it has been described that drugs that activate AMPK lead to a neuroprotective effect in several neurodegenerative diseases.4,5,6 The most representative example is metformin, which has demonstrated its therapeutic potential for the treatment of Alzheimer’s disease,7 Parkinson’s disease,8 and HD.9,10 ACS Chem Neurosci. Author manuscript; available in PMC 2022 February 08. Vela et al. Page 3 Author Manuscript Related to the role of AMPK as a therapeutic target in HD, several groups have reported that AMPK activation prevents the toxic effects induced by mHtt species, based on both invertebrate models of polyQ toxicity (C. elegans)10,11,12 and mouse models of HD.9,10 These results, together with the improvement in cognitive function after metformin administration in HD patients, who also have type 2 diabetes,13 indicate that the pharmacological activation of AMPK might be a potential strategy to address HD. To reinforce this hypothesis and following with our AMPK drug discovery programs,14 we performed a screening of our in-house chemical library. As result, we report herein the therapeutic potential of new AMPK activators as neuroprotective agents by describing the synthesis, the in silico ADME properties prediction, and AMPK activation studies of three new aryl indole derivatives (Figure 1). In addition, one of these compounds, IND1316, has been evaluated for its neuroprotective activity in animal models of HD. Author Manuscript RESUL (...truncated)