Poster Presentation 25th Annual Lorne Proteomics Symposium 2020

New Stemsation: Proteomic Characterisation of Human Adipose Stem Cells (#109)

Naomi Koh Belic 1 , Jerran Santos 1 , Bruce Milthorpe 1 , Matthew Padula 1
  1. University of Technology Sydney, Broadway, NSW, Australia

Human adipose stem cells are widely used as treatments for a plethora of disorders, despite minimal scientific evidence of their safety let alone efficacy. These unproven stem cell treatments are being offered by predatory clinics around the globe, more than 60 of which are practicing in Australia. Our understanding of human adipose stem cells is limited, and this study is the first to characterise the proteome of freshly isolated human adipose stem cells.

Adipose stem cells were isolated from abdominal lipoaspirates of 8 healthy patients. Their proteome was characterised through a comprehensive analysis of the whole cell lysate, membrane bound fraction, extracellular vesicles and secreted cytokines.

An average of 4379 proteins were detected in the whole cell lysate of each patient, with 1854 of these proteins conserved across all 8 patients, demonstrating patient diversity. In addition, an average of 1583 proteins were detected in the membrane bound fraction of each patient with 577 proteins conserved across all patients, providing an extensive catalogue of cell surface markers that are useful for antibody-based assay development to address the paucity of reliable markers.

Stem cells secrete extracellular vesicles in substantial quantities, and they are known to play a significant role in cancer, injury healing and immune suppression. An average of 2582 proteins were detected in the extracellular vesicles of each patient, 1312 of which were conserved across all patients, 15.37% of these detected proteins were unique to the extracellular vesicles. An additional 27 cytokines were quantified and investigated through the utilisation of a multiplex immunoassay.

This study produced a comprehensive data set of human adipose stem cell proteins, which is a unique resource that ultimately investigates the biological phenotype of these cells. This is an invaluable tool as it will assist in developing much needed understanding of cells that are already being used in the clinic.