The Efficacy and Mechanism of Autologous Fat Stem Cells Combined with Microcarrier 6 Transplantation for Anal Fistula Treatment

Background: Adipose-derived stem cells (ASCs) function in multi-directional differentiation, proliferation, and tissue regeneration. It is not clear whether microcarrier 6 can promote the migration, differentiation, and regeneration of fat stem cells, and improve therapeutic effects for the treatment of anal fistula.Methods: Japanese big ear rabbits were employed to establish an anal fistula model, and ASC-microcarrier 6 mixed transplantation was used as a treatment. HE staining, immunohistochemistry, and RNA sequencing were used to observe the effect of ASC-microcarrier 6 transplantation on anal fistula healing, in comparison with the ASC treatment group, rubber band operation group, and control group.Results: HE staining indicated scattered striated muscle cells and epithelial tissues in fistula tissues of the ASC-microcarrier 6 complex group and the ASC treatment group, while a small number of lymphocytes were clustered around the microcarrier 6, and fat cell aggregation was seen in the ASC treatment group. RNA sequence analysis showed that differential genes were mainly concentrated in striated muscle cells, vascular smooth muscle, and other tissues. PI3K/AKT signaling pathway molecules were significantly enriched, granulation tissue and lymphocyte infiltration were observed in the rubber band string operation group, and a large amount of necrotic tissue was seen in the control group.Conclusion: Microcarrier 6 is beneficial to the multi-directional differentiation of ASCs, which can provide a good environment for the survival of ASCs and promote fistula healing.