title: Targeting Ergosterol biosynthesis in Leishmania donovani: essentiality of sterol 14 alpha-demethylase.
abstract: Leishmania protozoan parasites (Trypanosomatidae family) are the causative agents of cutaneous, mucocutaneous and visceral leishmaniasis worldwide. While these diseases are associated with significant morbidity and mortality, there are few adequate treatments available. Sterol 14alpha-demethylase (CYP51) in the parasite sterol biosynthesis pathway has been the focus of considerable interest as a novel drug target in Leishmania. However, its essentiality in Leishmania donovani has yet to be determined. Here, we use a dual biological and pharmacological approach to demonstrate that CYP51 is indispensable in L. donovani. We show via a facilitated knockout approach that chromosomal CYP51 genes can only be knocked out in the presence of episomal complementation and that this episome cannot be lost from the parasite even under negative selection. In addition, we treated wild-type L. donovani and CYP51-deficient strains with 4-aminopyridyl-based inhibitors designed specifically for Trypanosoma cruzi CYP51. While potency was lower than in T. cruzi, these inhibitors had increased efficacy in parasites lacking a CYP51 allele compared to complemented parasites, indicating inhibition of parasite growth via a CYP51-specific mechanism and confirming essentiality of CYP51 in L. donovani. Overall, these results provide support for further development of CYP51 inhibitors for the treatment of visceral leishmaniasis.
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Laura-Isobel
authors.initials: LI
authors.lastname: McCall
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Amale
authors.initials: A
authors.lastname: El Aroussi
authors.affiliation: Department of Chemistry, Scripps Florida, Jupiter, Florida, United States of America.
authors.forename: Jun Yong
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Debora F
authors.initials: DF
authors.lastname: Vieira
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Geraldine
authors.initials: G
authors.lastname: De Muylder
authors.affiliation: Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Johnston
authors.affiliation: Small Molecule Discovery Center, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Steven
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Danielle
authors.initials: D
authors.lastname: Kellar
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Jair L
authors.initials: JL
authors.lastname: Siqueira-Neto
authors.affiliation: Department of Chemistry, Scripps Florida, Jupiter, Florida, United States of America.
authors.forename: William R
authors.initials: WR
authors.lastname: Roush
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Larissa M
authors.initials: LM
authors.lastname: Podust
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America.
authors.forename: James H
authors.initials: JH
authors.lastname: McKerrow
mesh_terms: D058888:14-alpha Demethylase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D002478:Cells, Cultured; D004875:Ergosterol / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007893:Leishmania donovani / Q000187:drug effects* / Q000378:metabolism; D007898:Leishmaniasis, Visceral / Q000188:drug therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D058886:Sterol 14-Demethylase / Q000032:analysis / Q000235:genetics / Q000502:physiology
chemical_list: D058888:14-alpha Demethylase Inhibitors; D058886:Sterol 14-Demethylase; D004875:Ergosterol