Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles

Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles

Bibliographic Details
Main Author: Fort, Brian P.
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2020
Subjects:
Pathology
Inflammasome
Cathepsins
IL-1B
Aseptic loosening
Gasdermin D
ATP
Purinergic signaling
P2X7R
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1601395412505158
id ndltd-OhioLink-oai-etd.ohiolink.edu-case1601395412505158
record_format oai_dc
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case16013954125051582021-08-03T07:16:22Z Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles Fort, Brian P. Pathology Inflammasome Cathepsins IL-1B Aseptic loosening Gasdermin D ATP Purinergic signaling P2X7R Total joint replacements are the standard of care treatment for severe cases of anumber of conditions, including primary osteoarthritis, osteonecrosis, ankylosingspondylitis and rheumatoid arthritis. Wear particles from orthopaedic implants are amajor driver of aseptic loosening, a predominant cause of orthopaedic implant failure.The particles are phagocytosed by macrophages leading to activation of the NLRP3inflammasome and release of IL-1β, which then contributes to osteoclast differentiationand implant loosening.The goal of the first part of this thesis was to determine the role of lysosomalcathepsins in macrophages’ response to orthopaedic wear particles. Here, wedemonstrate that lysosome membrane disruption causes cathepsin release into thecytoplasm that drives both inflammasome activation and cell death, but that theseprocesses occur independently. Using wild-type and genetically-manipulatedimmortalized murine macrophages and pharmacologic inhibitors, we found that NLRP3and gasdermin D are required for particle-induced IL-1β release but not for particle-induced cell death. In contrast, phagocytosis and lysosomal cathepsin release are criticalfor both IL-1β release and cell death. Collectively, our findings identify the pancathepsin inhibitor Ca-074Me and the NLRP3 inflammasome inhibitor MCC950 astherapeutic interventions worth exploring in aseptic loosening.The goal of the second part of this thesis was to determine whether the deathinduced in response to titanium particles was immunogenic in nearby unstimulated cellsand whether purinergic signaling was involved. This study provides evidence thattitanium particles can induce death in macrophages and release of extracellular ATPcapable of activating the inflammasome in naive macrophages. First, using immortalizedmurine bone marrow-derived macrophages, we found that titanium particles induce therelease of a soluble factor able to activate the NLRP3 inflammasome. Second, we foundthat titanium particles induce the release of adenine nucleotides in a manner consistentwith release from pores formed during lysosomal cell death. Third, titanium particleinduced IL-1β release was attenuated in the presence of exogenous apyrase orhexokinase, which dephosphorylate extracellular ATP. Despite the dependence onextracellular ATP, knockout or inhibition of the ionotropic P2X7R in macrophages didnot reduce particle-induced IL-1β release, suggesting complex regulation by multiplepurinergic receptor subtypes. 2020 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1601395412505158 http://rave.ohiolink.edu/etdc/view?acc_num=case1601395412505158 restricted--full text unavailable until 2023-01-15 This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Pathology
Inflammasome
Cathepsins
IL-1B
Aseptic loosening
Gasdermin D
ATP
Purinergic signaling
P2X7R
spellingShingle Pathology
Inflammasome
Cathepsins
IL-1B
Aseptic loosening
Gasdermin D
ATP
Purinergic signaling
P2X7R
Fort, Brian P.
Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
author Fort, Brian P.
author_facet Fort, Brian P.
author_sort Fort, Brian P.
title Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
title_short Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
title_full Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
title_fullStr Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
title_full_unstemmed Inflammatory Pathways in the Macrophage Response to Orthopaedic Wear Particles
title_sort inflammatory pathways in the macrophage response to orthopaedic wear particles
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2020
url http://rave.ohiolink.edu/etdc/view?acc_num=case1601395412505158
work_keys_str_mv AT fortbrianp inflammatorypathwaysinthemacrophageresponsetoorthopaedicwearparticles
_version_ 1719457888798244864

Similar Items