TLR4-dependent upregulation of the platelet NLRP3 inflammasome promotes platelet aggregation in a murine model of hindlimb ischemia

Sebastian Vogel, Pranav Murthy, Xiangdong Cui, Michael T. Lotze, Herbert J. Zeh, Ulka Sachdev

Research output: Contribution to journalArticlepeer-review

24 Scopus citations

Abstract

Platelets play a critical role in the pathophysiology of peripheral arterial disease (PAD). The mechanisms by which muscle ischemia regulates aggregation of platelets are poorly understood. We have recently identified the Nod-like receptor nucleotide-binding domain leucine rich repeat containing protein 3 (NLRP3) expressed by platelets as a critical regulator of platelet activation and aggregation, which may be triggered by activation of toll-like receptor 4 (TLR4). In this study, we performed femoral artery ligation (FAL) in transgenic mice with platelet-specific ablation of TLR4 (TLR4 PF4) and in NLRP3 knockout (NLRP3−/−) mice. NLRP3 inflammasome activity of circulating platelets, as monitored by activation of caspase-1 and cleavage of interleukin-1β (IL-1β), was upregulated in mice subjected to FAL. Genetic ablation of TLR4 in platelets led to decreased platelet caspase 1 activation and platelet aggregation, which was reversed by the NLRP3 activator Nigericin. Two weeks after the induction of FAL, ischemic limb perfusion was increased in TLR4 PF4 and NLRP3−/− mice as compared to control mice. Hence, activation of platelet TLR4/NLRP3 signaling plays a critical role in upregulating platelet aggregation and interfering with perfusion recovery in muscle ischemia and may represent a therapeutic target to improve limb salvage.

Original languageEnglish (US)
Pages (from-to)614-619
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume508
Issue number2
DOIs
StatePublished - Jan 8 2019
Externally publishedYes

Keywords

  • Hindlimb ischemia
  • NLRP3
  • Peripheral arterial disease
  • Platelets

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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