Role of Adipose Tissue-Derived Stem Cells versus Differentiated Schwann-like cells Transplantation on the Regeneration of Crushed Sciatic Nerve in Rats. A Histological Study

Abstract

Background & objectives: Despite surgical advances, recovery of peripheral nerve injuries has often been poor, leading to irreversible impairment. This study aimed to differentiate adipose-derived stem cells (ASCs) into Schwann-like cells (SCs) in vitro and assess their role versus the undifferentiated ASCs in the regeneration of crushed sciatic nerves in adult male albino rats. Materials & Methods: We performed a simple and less costly method to differentiate ASCs into SCs. Forty rats, weighing 200-250 g, were randomly divided to 4 equal groups. Group I (control) subjected to sham operation. Group II subjected to crush injury of the sciatic nerve. Group III subjected to crush injury with local transplantation of ASCs. Group IV subjected to crush injury with local transplantation of differentiated Schwannlike cells. The rats were sacrificed 4 weeks later. We studied the nerves using H&E and Masson’s Trichrome stain. Immuno-histochemical studies using S-100 and neurofilament-H (NF-H), together with morphometric and statistical studies were done. Results: Differentiated Schwann-like cells adopted a spindle-like morphology and 87.9% of the cells became GFAP positive and 90.4% were positive to S-100. Group II showed thin discontinuous nerve fibers with proliferation of SCs. Significant increase in collagen area percentage, and significant decrease in S-100 & NF-H immune reaction was noted as well. Group IV revealed better regeneration of axons, and higher intensity of immune reaction by S-100& NF-H, than Group III. Meanwhile, both Groups III & IV showed thicker, more packed nerve fibers with significant decrease in collagen area percentage compared to Group II. Conclusion: Our results suggested that differentiated Schwann-like cells might have a more beneficial role than ASCs, for treatment of peripheral nerve injuries. Keywords: ASCs; Schwann cell differentiation; Sciatic nerve crush injury; S-100; NF-H.