Mechanotransduction and cell fate: from molecular sensors to multicellular self-organization.

Mechanical signals are now recognized as instructive cues that guide cell fate decisions with a precision comparable to classical morphogens. The identification of genetically encoded mechanosensors-including the PIEZO and TMC ion channel families, Transient Receptor Potential channels, and mechanosensitive adhesion complexes-has revealed how cells translate forces into transcriptional programs. In this review we integrate three levels of mechanotransduction biology: the molecular sensors that detect force, the intracellular signaling networks that convert sensing into gene expression, and the multicellular dynamics by which local mechanical interactions drive tissue self-organization. We discuss how substrate stiffness, applied tension, and cell-cell mechanical coupling regulates the differentiation of stem and progenitor cells across diverse lineages, with particular emphasis on the developing cardiovascular system as a paradigmatic mechanobiological organ: primitive blood flow instructs cardiac chamber morphogenesis, and mechanosensitive channels such as PIEZO1 are essential for vascular patterning. We also examine skeletal progenitor commitment and articulate an emerging conceptual distinction-the Regeneration-Specific Mechanosensor hypothesis-proposing that a defined subset of mechanosensors is dispensable during morphogenesis but becomes essential during tissue repair, with TRPA1 as the prototypical example. Structural and computational insights into channel gating, together with engineered mechanical environments for directing stem cell fate, provide a translational bridge toward regenerative therapeutics in cardiovascular and musculoskeletal medicine. Outstanding questions include the hierarchy of mechanosensors during lineage commitment, the mechanical logic of multicellular symmetry breaking, and the translational potential of regeneration-specific mechanosensitive drug targets. We propose that integrating molecular, cellular, and tissue-scale mechanobiology offers a unifying framework for understanding cell fate decisions in both development and regenerative medicine.