Defects in TRPM7 channel function deregulate thrombopoiesis through altered cellular Mg(2+) homeostasis and cytoskeletal architecture

Nat Commun. 2016 Mar 29;7:11097. doi: 10.1038/ncomms11097.

Abstract

Mg(2+) plays a vital role in platelet function, but despite implications for life-threatening conditions such as stroke or myocardial infarction, the mechanisms controlling [Mg(2+)]i in megakaryocytes (MKs) and platelets are largely unknown. Transient receptor potential melastatin-like 7 channel (TRPM7) is a ubiquitous, constitutively active cation channel with a cytosolic α-kinase domain that is critical for embryonic development and cell survival. Here we report that impaired channel function of TRPM7 in MKs causes macrothrombocytopenia in mice (Trpm7(fl/fl-Pf4Cre)) and likely in several members of a human pedigree that, in addition, suffer from atrial fibrillation. The defect in platelet biogenesis is mainly caused by cytoskeletal alterations resulting in impaired proplatelet formation by Trpm7(fl/fl-Pf4Cre) MKs, which is rescued by Mg(2+) supplementation or chemical inhibition of non-muscle myosin IIA heavy chain activity. Collectively, our findings reveal that TRPM7 dysfunction may cause macrothrombocytopenia in humans and mice.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood Platelets / metabolism
  • Cytoskeleton / metabolism*
  • Homeostasis*
  • Humans
  • Magnesium / metabolism*
  • Megakaryocytes / metabolism
  • Mice
  • Mutant Proteins / metabolism
  • Nonmuscle Myosin Type IIA / metabolism
  • Protein-Serine-Threonine Kinases / deficiency
  • Protein-Serine-Threonine Kinases / metabolism*
  • TRPM Cation Channels / deficiency
  • TRPM Cation Channels / metabolism*
  • Thrombocytopenia / metabolism
  • Thrombocytopenia / pathology
  • Thrombopoiesis*

Substances

  • Mutant Proteins
  • TRPM Cation Channels
  • Trpm7 protein, mouse
  • Protein-Serine-Threonine Kinases
  • TRPM7 protein, human
  • Nonmuscle Myosin Type IIA
  • Magnesium