Biochemical and Mechanical Signal Differentially Contribute to Survival in Surface-Modified Cell Model.

Abstract

Background: Regenerative cell sources such as bone marrow-multipotent stem cells (BM-MSCs) face poor survival after transplantation due to shear stress and anoikis in attachment-deprived conditions. Cell surface modification with type I collagen (Col I) may enhance cell survival in anoikis-inducing environment by mimicking cell-ECM interactions and activating Akt signaling. However, the relative contributions of biochemical versus mechanical signalling remain unclear.

Methods: BM-MSCs were surface-modified with 2, 4, or 8 layers (L) of Col I and cultured on poly-2-hydroxyethyl methacrylate-coated vessels for 3 days. Col I retention, Akt activation, and cytoskeletal changes were analyzed by immunofluorescence. YAP nuclear translocation was measured to assess mechanotransduction.

Results: Col I persisted up to 10 h in 4L and 8L groups but not in 2L. All surface-modified groups showed membrane-localized Akt phosphorylation, while controls did not. Only the 8L group demonstrated significant anoikis resistance from day 1, exhibiting distinct ring-like actin arrangement within 2 h and enhanced YAP nuclear localization, indicating activation of mechanotransduction-associated responses.

Conclusions: All surface-modified groups showed Akt phosphorylation, indicating biochemical signaling. The 4L group exhibited significantly higher survival by day 2, suggesting sustained biochemical signaling promotes survival. The 8L group showed superior survival from day 1 with increased YAP translocation and actin reorganization, demonstrating that mechanotransduction may contribute to an early survival advantage. This cell model enables differential investigation of biochemical and mechanical effects on cell survival.