The in Vitro Characterization of Primary Human Rectus Sheath Fibroblasts

Each day, thousands of patients undergo surgical procedures which require an incision through the abdominal fascia. Failure of this connective tissue layer to heal properly can result in uncomfortable and unsightly incisional hernias. Rectus sheath fibroblasts (RSFs) have a key role to play in tissue healing – specifically wound contraction and laying down new collagen. Fibroblasts from the human rectus sheath have not previously been studied in vitro, and little is known about their capacity to survive in vitro culture, their gene expression, or their ability to contract a collagen matrix. Our study isolated primary human fibroblasts from the rectus sheaths of 3 human volunteer patients and assessed them for a number of factors including their morphology, metabolic activity, intracellular markers and their contractility. Cells from all three donors underwent an identical characterization process and were compared directly to a well-characterised, immortalised cell line of human dermal fibroblasts. Our work demonstrates that human rectus sheath fibroblasts can be cultured successfully in vitro following cryopreservation – albeit with differing levels of proliferation. In 2D, these cells express typical intracellular fibroblast markers including α-Smooth Muscle Actin and Vimentin. An MTT assay revealed comparable levels of metabolic activity between cells from all donors with slightly greater activity in collective RSF populations. All RSF cells contracted collagen matrix in vitro, albeit less so than dermal fibroblasts. Our work demonstrates the possibility of working with this cell type in vitro and introduces the possible development of an in vitro rectus sheath tissue model.

Keywords: Fibroblast, Characterization, Rectus Sheath, Hernia, 3D Models.