Micromanaging the nuclear lamina

Main text

From the shear stress of arterial blood flow to the cyclic strain of lung expansion and the gradual stiffening of tumors during cancer progression, epithelia encounter and respond to a wide array of mechanical forces. These cues, perceived by transmembrane receptors and relayed through cytoskeletal linkages that indirectly tether the extracellular matrix (ECM) to the nucleus, modulate nuclear architecture and gene regulation. The physical coupling between the ECM and the nucleus plays a central role in regulating the genome and maintaining tissue homeostasis.

Mechanical forces transmitted to the nucleus can reorganize chromatin (1), modulate transcription factor accessibility (2), and alter histone modifications (3), thereby shaping the transcriptional programs that govern cell behavior. Lamin A/C, a core structural component of the nuclear lamina, is essential for maintaining nuclear integrity (4) and mediates force transmission to chromatin (5). While mechanical cues are known to regulate cytoskeletal organization and transcription, the role of microRNAs—noncoding RNAs that modulate gene expression by targeting specific mRNAs in the cytoplasm—remains underexplored in nuclear mechanics. Prior studies have identified stiffness-responsive microRNAs such as miR-21 and miR-143/145 that regulate actomyosin remodeling and focal adhesion dynamics (6,7).

In this issue, Lee et al. extend this paradigm by identifying miR-548t-3p as a modulator of nuclear mechanics (8). The authors demonstrate that miR-548t-3p reduces the transcript levels of LMNA, leading to decreased expression of Lamin A/C and reduced nuclear tension in cancer cells. Using FRET-based biosensors designed to report tension across the nuclear envelope (Nesprin-TS) or focal adhesion proteins (Lyn-FAK), the authors add to the growing body of evidence linking nuclear mechanics and cell-ECM interactions. These findings are complemented by traction force microscopy experiments, in which cells are cultured on hydrogels that contain fluorescent beads, and bead displacement data are then used to calculate the forces exerted by the cells. Using this approach, the authors reveal that miR-548t-3p-expressing cells generate weaker traction forces particularly on soft substrates, suggesting that microRNA-mediated regulation of the nuclear lamina can influence force transmission to the ECM. Altogether, these findings add to our understanding of posttranscriptional control in mechanobiology and invites further investigation into the broader relevance of microRNA-mediated regulation of cellular mechanics.

By integrating microRNA regulation into established biophysical assays, Lee et al. provide a sound framework for investigating how microRNAs shape the mechanical behavior of cells. Looking ahead, this study raises important questions about the role of miR-548t-3p in physiological and pathological contexts. For instance, does miR-548-3p regulate nuclear stiffness during normal tissue development or aging? Given that Lamin A/C mutations are associated with muscular dystrophies, cardiomyopathies, and progeroid syndromes (9), could miR-548t-3p or related microRNAs contribute to these conditions or be used to modulate nuclear mechanics? Exploring these questions could open new avenues for understanding the mechanical regulation of nuclear integrity and inspire novel therapeutic strategies. Future work in primary cells, tissue models, and in vivo systems will help define the broader relevance and potential translational impact of these findings.

Declaration of interests

The author declares no competing interests.

Editor: Guy Genin.