Hypoxia and Trypsin enhance the Proangiogenic Properties of human Adipose-derived Stem Cells

Riis, Simone

4. term

Medicine with Industrial Specialisation, Master

2012

2012-06-01

55

Diabetiske fodsår heler ofte dårligt på grund af nedsat blodtilførsel. Stamceller fra fedtvæv, såkaldte adipose-afledte stamceller (ASCs), kan muligvis hjælpe ved at fremme dannelsen af nye blodkar. Dette studie testede, om en forbehandling af ASCs med lavt iltindhold (hypoksi) og med trypsin, et enzym der ofte bruges til at håndtere celler, kan forstærke denne pro-angiogene effekt. Vi sammenlignede ubehandlede ASCs med celler udsat for hypoksi, trypsin eller en kombination af begge. Vi vurderede cellernes evne til at støtte blodkardannelse ved at måle vaskulær endotelial vækstfaktor (VEGF), et nøglesignal der fremmer nye blodkar: Vi målte både VEGF-genaktivitet i cellerne og den mængde VEGF, de udskilte, ved hjælp af standard laboratorietests. Vi forsøgte også at undersøge, om de behandlede ASCs påvirkede endothelcellers migration, et tidligt trin i kardanndelse. Både hypoksi og trypsin øgede VEGF-genudtryk og VEGF-sekretion sammenlignet med ubehandlede celler. Kombinationen af hypoksi og trypsin gav en endnu større, additiv stigning. Derimod gav migrationsforsøget med endothelceller ingen brugbare resultater, så ASCs’ indflydelse på denne proces er fortsat uklar. Samlet set øgede forbehandling af ASCs med både lavt iltindhold og trypsin deres produktion af VEGF på additiv vis. Denne tilgang kan undersøges nærmere som en måde at styrke ASCs’ pro-angiogene potentiale med henblik på fremtidige kliniske anvendelser. ASCs’ rolle i endothelmigration kræver stadig afklaring.

Diabetic foot ulcers often heal poorly because of limited blood flow. Stem cells taken from fat tissue, called adipose-derived stem cells (ASCs), may help by encouraging new blood vessels to form. This study tested whether preconditioning ASCs with low oxygen (hypoxia) and with trypsin, an enzyme commonly used to handle cells, could enhance this pro-angiogenic effect. We compared untreated ASCs with cells exposed to hypoxia, trypsin, or both. We assessed their potential to support blood vessel growth by measuring vascular endothelial growth factor (VEGF), a key signal that promotes new vessels: we measured VEGF gene activity inside the cells and the amount of VEGF they secreted using standard laboratory assays. We also attempted to evaluate whether the treated ASCs affected endothelial cell migration, an early step in vessel formation. Both hypoxia and trypsin increased VEGF gene expression and VEGF secretion compared with untreated cells. The combination of hypoxia and trypsin produced an even larger, additive increase. In contrast, the endothelial migration test did not yield usable results, so the influence of ASCs on this process remains unclear. Overall, preconditioning ASCs with both low oxygen and trypsin boosted their production of VEGF in an additive manner. This approach could be explored further as a way to enhance the pro-angiogenic potential of ASCs for future clinical applications. The role of ASCs in endothelial cell migration still needs clarification.

[This abstract was generated with the help of AI]

ASC ; Wound healing ; VEGF ; Hypoxia ; Trypsin

Download
View record in AAU Student Projects