title: Hypoxia-like effect of cobalt chromium alloy micro particles on fibroblasts in vitro.
abstract: Periprosthetic osteolysis leading to asceptic loosening remains the primary cause of failure of joint replacement. Although many inflammatory cell types have been implicated, the exact pathomechanisms of asceptic loosening have not been delineated. In the present study we have adopted a proteomic approach to elucidate the initial signals that are expressed to particulate material, using an in vitro cell culture system. Human lung fibroblasts MRC-5 were cultured with Cobalt Chromium (CoCr ASTM F-75, 1-7 µm) particles. Cells were harvested after 72 h incubation and total cellular proteins extracted for downstream analysis via 2D Gel Electrophoresis and tandem mass spectrometry using MALDI-TOF-TOF-MS. Thirteen protein spots showed greater than twofold increase, following 72 h incubation of fibroblast with CoCr particles. Four of these proteins were identified by tandem mass spectrometry. These were Annexin II, Pyruvate kinase, Triose phosphate isomerase, and N-myc downstream regulated gene 1 protein. Cobalt is a hypoxia mimicking agent and N-myc downstream regulated gene 1 protein, Triose phosphate isomerase, Pyruvate kinase, and Annexin II are important hypoxia regulated gene products that are found to be over expressed in cellular oxidative stress response. Our data indicates that exposure of fibroblast to CoCr alloy induces the transition of these cells into a hypoxia like state and oxidative stress even in normoxic culture conditions. The study reflects the possibility of the presence of a hypoxic environment in the periprosthetic tissue surrounding metallic implants.
authors.affiliation: Histopathology Laboratory, Division of Implant Biology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Trivandrum 695012, Kerala, India.
authors.forename: Bernadette K
authors.initials: BK
authors.lastname: Madathil
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Lin
authors.forename: Choy-Leong
authors.initials: CL
authors.lastname: Hew
authors.forename: Mira
authors.initials: M
authors.lastname: Mohanty
mesh_terms: D000497:Alloys / Q000009:adverse effects*; D017306:Annexin A2 / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D015687:Cell Hypoxia / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology; D002858:Chromium Alloys / Q000009:adverse effects*; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D010316:Particle Size; D052638:Particulate Matter; D040901:Proteomics; D011770:Pyruvate Kinase / Q000378:metabolism; D014305:Triose-Phosphate Isomerase / Q000378:metabolism; D000099259:N-myc Downstream-Regulated Gene 1 Protein
chemical_list: D000497:Alloys; D017306:Annexin A2; D018797:Cell Cycle Proteins; D002858:Chromium Alloys; D047908:Intracellular Signaling Peptides and Proteins; D052638:Particulate Matter; D011770:Pyruvate Kinase; D014305:Triose-Phosphate Isomerase; D000099259:N-myc Downstream-Regulated Gene 1 Protein; C105750:ASTM F-75 implant alloy