Dysregulation of lysosomal morphology by pathogenic LRRK2 is corrected by TPC2 inhibition

J Cell Sci. 2015 Jan 15;128(2):232-8. doi: 10.1242/jcs.164152. Epub 2014 Nov 21.

Abstract

Two-pore channels (TPCs) are endolysosomal ion channels implicated in Ca(2+) signalling from acidic organelles. The relevance of these ubiquitous proteins for human disease, however, is unclear. Here, we report that lysosomes are enlarged and aggregated in fibroblasts from Parkinson disease patients with the common G2019S mutation in LRRK2. Defects were corrected by molecular silencing of TPC2, pharmacological inhibition of TPC regulators [Rab7, NAADP and PtdIns(3,5)P2] and buffering local Ca(2+) increases. NAADP-evoked Ca(2+) signals were exaggerated in diseased cells. TPC2 is thus a potential drug target within a pathogenic LRRK2 cascade that disrupts Ca(2+)-dependent trafficking in Parkinson disease.

Keywords: Ca2+; LRRK2; Lysosomes; NAADP; Parkinson disease; TPCN2.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium / metabolism
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Calcium Signaling / genetics*
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • HEK293 Cells
  • Humans
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Lysosomes / metabolism
  • Lysosomes / pathology
  • NADP / analogs & derivatives
  • NADP / genetics
  • NADP / metabolism
  • Parkinson Disease / genetics*
  • Parkinson Disease / metabolism
  • Parkinson Disease / pathology
  • Primary Cell Culture
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*

Substances

  • Calcium Channels
  • TPCN2 protein, human
  • NADP
  • NAADP
  • LRRK2 protein, human
  • Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
  • Protein Serine-Threonine Kinases
  • Calcium