title: A novel ligand of calcitonin receptor reveals a potential new sensor that modulates programmed cell death.
abstract: We have discovered that the accumulation of an anti-calcitonin receptor (anti-CTR) antibody conjugated to a fluorophore (mAb2C4:AF568) provides a robust signal for cells undergoing apoptotic programmed cell death (PCD). PCD is an absolute requirement for normal development of metazoan organisms. PCD is a hallmark of common diseases such as cardiovascular disease and tissue rejection in graftversushost pathologies, and chemotherapeutics work by increasing PCD. This robust signal or high fluorescent events were verified by confocal microscopy and flow cytometry in several cell lines and a primary culture in which PCD had been induced. In Jurkat cells, GBM-L2 and MG63 cells, the percentage undergoing PCD that were positive for both mAb2C4:AF568 and annexin V ranged between 70 and >90%. In MG63 cells induced for the preapoptotic cell stress response (PACSR), the normal expression ofα-tubulin, a key structural component of the cytoskeleton, and accumulation of mAb2C4:AF568 were mutually exclusive. Our data support a model in which CTR is upregulated during PACSR and recycles to the plasma membrane with apoptosis. In cells committed to apoptosis (α-tubulin negative), there is accumulation of the CTR-ligand mAb2C4:AF568 generating a high fluorescent event. The reagent mAb2C4:AF568 effectively identifies a novel event linked to apoptosis.
authors: Drug Discovery Biology Laboratory, Monash Institute of Pharmaceutical Science, 381 Royal Parade, Parkville, Victoria 3052, Australia; Department of Pharmacology, Monash University, Wellington Road, Clayton, Parkville, Victoria 3800, Australia.
authors: Sgb
authors: S
authors: Furness
authors: Department of Medicine, University of Melbourne, Austin Health , Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia.
authors: D L
authors: DL
authors: Hare
authors: Department of Medicine, University of Melbourne, Austin Health , Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia.
authors: A
authors: A
authors: Kourakis
authors: Department of Anatomy and Neuroscience, Melbourne Brain Centre, University of Melbourne , Royal Parade, Parkville, Victoria 3010, Australia.
authors: A M
authors: AM
authors: Turnley
authors: Department of Medicine, University of Melbourne, Austin Health , Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia.
authors: P J
authors: PJ
authors: Wookey