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

Area of Science:

• Biomaterials Science
• Cell Biology
• Regenerative Medicine

Background:

• Bone marrow-multipotent stem cells (BM-MSCs) exhibit poor survival post-transplantation due to shear stress and anoikis.
• Type I collagen (Col I) surface modification may improve BM-MSC survival by mimicking extracellular matrix interactions and activating Akt signaling.
• The distinct roles of biochemical versus mechanical signaling in Col I-mediated cell survival remain unclear.

Purpose of the Study:

• To investigate the impact of type I collagen (Col I) surface modification on bone marrow-multipotent stem cell (BM-MSC) survival under anoikis-inducing conditions.
• To differentiate the contributions of biochemical (Akt signaling) and mechanical (mechanotransduction) pathways to enhanced cell survival.
• To establish a cell model for studying the interplay between biochemical and mechanical cues in cell survival.

Main Methods:

• BM-MSCs were surface-modified with varying layers (2, 4, 8) of Col I.
• Cells were cultured on non-adherent surfaces for 3 days to induce anoikis.
• Analysis included Col I retention, Akt phosphorylation, cytoskeletal organization (actin), and YAP nuclear translocation to assess mechanotransduction.

Main Results:

• Col I coating was retained for up to 10 hours in 4 and 8-layer groups.
• All Col I-modified BM-MSCs showed Akt phosphorylation, indicating activation of biochemical signaling.
• The 8-layer group exhibited significant anoikis resistance from day 1, with actin reorganization and increased YAP nuclear localization, suggesting early mechanotransduction activation.

Conclusions:

• Surface modification with Col I activates Akt phosphorylation, a biochemical signaling pathway, in BM-MSCs.
• Sustained biochemical signaling, as seen in the 4-layer group, promotes cell survival by day 2.
• Early survival advantage in the 8-layer group is attributed to activated mechanotransduction, indicated by YAP translocation and actin remodeling, highlighting the combined role of biochemical and mechanical cues.