Evaluation of the Leishmania Inositol Phosphorylceramide Synthase as a Drug Target Using a Chemical and Genetic Approach

ACS Infect Dis. 2024 Aug 9;10(8):2913-2928. doi: 10.1021/acsinfecdis.4c00284. Epub 2024 Jul 18.

Abstract

The lack of effective vaccines and the development of resistance to the current treatments highlight the urgent need for new anti-leishmanials. Sphingolipid metabolism has been proposed as a promising source of Leishmania-specific targets as these lipids are key structural components of the eukaryotic plasma membrane and are involved in distinct cellular events. Inositol phosphorylceramide (IPC) is the primary sphingolipid in the Leishmania species and is the product of a reaction mediated by IPC synthase (IPCS). The antihistamine clemastine fumarate has been identified as an inhibitor of IPCS in L. major and a potent anti-leishmanial in vivo. Here we sought to further examine the target of this compound in the more tractable species L. mexicana, using an approach combining genomic, proteomic, metabolomic and lipidomic technologies, with molecular and biochemical studies. While the data demonstrated that the response to clemastine fumarate was largely conserved, unexpected disturbances beyond sphingolipid metabolism were identified. Furthermore, while deletion of the gene encoding LmxIPCS had little impact in vitro, it did influence clemastine fumarate efficacy and, importantly, in vivo pathogenicity. Together, these data demonstrate that clemastine does inhibit LmxIPCS and cause associated metabolic disturbances, but its primary target may lie elsewhere.

Keywords: CRISPR-Cas9; Leishmania; clemastine fumarate; inositol phosphorylceramide synthase; polyomics; thermal proteomic profiling.

MeSH terms

  • Animals
  • Antiprotozoal Agents* / chemistry
  • Antiprotozoal Agents* / pharmacology
  • Glycosphingolipids / metabolism
  • Hexosyltransferases / antagonists & inhibitors
  • Hexosyltransferases / genetics
  • Hexosyltransferases / metabolism
  • Leishmania / drug effects
  • Leishmania / enzymology
  • Leishmania / genetics
  • Leishmania mexicana / drug effects
  • Leishmania mexicana / enzymology
  • Leishmania mexicana / genetics
  • Sphingolipids / metabolism
  • Transferases (Other Substituted Phosphate Groups) / genetics
  • Transferases (Other Substituted Phosphate Groups) / metabolism

Substances

  • Antiprotozoal Agents
  • Sphingolipids
  • Hexosyltransferases
  • phosphatidylinositol-ceramide phosphoinositol transferase
  • inositolphosphorylceramide
  • Glycosphingolipids
  • Transferases (Other Substituted Phosphate Groups)