Method for selective quantification of adipose-derived stromal/stem cells in tissue.

Current fat graft systems lack reliable methods to predict graft retention. Adipose-derived stromal/stem cells (ASCs) are critical for graft success, but measuring their concentration in tissue remains challenging. Traditional cell quantification techniques are not suitable for adipose tissue. This gap motivated the search for a more accurate and selective method. DNA methylation patterns have been explored as potential markers for cell types. Prior research has shown that CD31 is a marker for ASCs, but its use in quantification is limited. A specific methylated site in the CD31 promoter was identified as a potential ASC marker. This site is not methylated in other adipose cell types. This distinction suggests a novel approach to ASC quantification.

The aim of this research is to develop a selective method for quantifying adipose-derived stromal/stem cells (ASCs) in tissue. Fat graft systems require better prediction of ASC concentration to improve graft retention. Current techniques fail to provide accurate ASC counts in adipose tissue. This study addresses the need for a reliable quantification tool. The researchers focused on DNA methylation patterns unique to ASCs. A methylated site in the CD31 promoter was identified as a potential marker. This site is not methylated in other adipose cell types. The goal is to validate this methylation as a basis for ASC quantification.

The method involves identifying a methylated site in the CD31 promoter specific to ASCs. DNA methylation at this site was analyzed using quantitative polymerase chain reaction. Methylation-sensitive HapII-treated DNA was used as the template. The SQAT method was validated using CD31-/CD34+-based flow cytometry. This comparison confirmed the accuracy of SQAT. The methylation levels were measured in isolated ASCs from suctioned fat. The standard protocol included collagenase treatment for ASC isolation. SQAT results were compared to flow cytometry counts to ensure reliability.

SQAT results correlated perfectly with ASC counts determined by flow cytometry. The methylation at the CD31 promoter was specific to ASCs and absent in other cell types. ASCs isolated from suctioned fat yielded 59% ± 21% using SQAT. This suggests that current ASC isolation techniques need improvement. The methylation-based quantification method is highly selective. DNA extraction from tissue is straightforward, making SQAT practical. The method is suitable for arbitrary samples, including tissue. SQAT could enhance ASC isolation technologies and fat graft systems.

SQAT is a useful tool for quantifying ASCs in tissue based on DNA methylation. The method's accuracy was validated using flow cytometry. ASC isolation techniques require further refinement to improve yield. The CD31 promoter methylation is specific to ASCs and not found in other cells. SQAT's reliability was confirmed through correlation with established methods. The method facilitates better prediction of graft retention in fat graft systems. ASC isolation could benefit from this selective quantification approach. SQAT has the potential to improve ASC isolation technologies significantly.