When submitted to defined specific culture conditions, primary human fibroblasts cultivated in standard tissue culture treated plasticware undergo a phenotypic conversion during the next 10-15 days whereby cells gradually reorganize into aster-like structures, eventually growing into spheroids, forming preferentially cell-cell adherence and breaking off to float in the medium. Spheroid cells express stem cell markers as expected for partially dedifferentiated cells and may give rise to “rejuvenated “cells i.e with enhanced cytoskeletal gene expression, and actomyosin contractility.
In decellularized “conversion” vessels (i.e. where the cells were originally submitted to specific culture conditions) fresh batches of naive fibroblasts, seeded and kept under normal culture conditions, undergo a similar phenotypic conversion. Thus, the decellularized extra-cellular matrix (ECM) coating of the two-dimensional cell culture plasticware deposited by cells after their conversion is entirely sufficient to induce conversion in fresh batches of naive fibroblasts and maybe other differentiated cells, under “normal” tissue culture conditions. This “conversion” ECM has also special characteristics that maintain the phenotypic change of cells inside the “conversion vessel.”
Preliminary experiments of immunofluorescent labelling of decellularized ECM highlight differences in abundance and distribution of several ECM components. Parallel mass-spectrometry analysis of fibroblasts ECM and conversion ECM will be also performed. DI-2024-14
