Optimization of Mechanosensitive Cross-talk between Matrix Stiffness and Protein Density: Independent Matrix Properties Regulate Spreading Dynamics of Myocytes
J. Brock, J. Erhardt, S.A. Eisler, and M. Hörning
Cells, 11, 2122, 2022
- doi : 10.3390/cells11132122

Brief Summary: ''... Here, C2C12 myocytes were monitored on L-DOPA functionalized hydrogels of 22 different elasticity and fibronectin density compositions. We observed a fibronectin density independent increase of the projected cell area until 12 kPa and an optimal fibronectin density at about 2.6 μg/cm² with a maximum actin filament to cell area ratio of 7.5%. The proliferation evaluation of cells showed an opposite correlation between cell spreading duration and speed to the matrix elasticity and protein density, which did not affect the cell cycle duration.''

Correlation of mitochondrial TOM core complex stop-and-go and open-closed
S. Wang, L. Findeisen, S. Leptihn, M.I. Wallace, M. Hörning and S. Nussberger
Communications Biology, 5, 471, 2022
- doi : 10.1038/s42003-022-03419-4

Brief Summary: ''... Here we show the correlation between lateral protein diffusion and channel activity of the general protein import pore of mitochondria (TOM-CC) in membranes resting on ultrathin hydrogel films. We find that TOM-CC switches reversibly between three states of ion permeability associated with protein diffusion. We explain this behavior by the mechanical interaction between the hydrogel and the two β-barrel pores of TOM-CC.''

Local membrane curvature pins and guides excitable membrane waves in chemotactic and macropinocytic cells - biomedical insights from an innovative simple model
M. Hörning, T. Bullmann and T. Shibata
Frontiers in Cell and Developmental Biology, 9, 2467, 2021
- doi : 10.3389/fcell.2021.670943

Brief Summary: ''... Here, using 3D spatial fluctuation and phase map analysis on actin polymerization inhibited Dictyostelium cells, we reveal a spatial asymmetry of PIP3 signaling on the membrane that is mediated by the contact perimeter of the plasma membrane. We show that the contact perimeter guides PIP3 waves and acts as a pinning site of PIP3 phase singularities. The contact perimeter serves as a diffusion influencing boundary that is regulated by a cell size- and shape-dependent curvature.''

Circulating re-entrant waves promote maturation of hiPSC-derived cardiomyocytes in self-organized tissue ring
J. Li, L. Zhang, L. Yu, I. Minami, S. Miyagawa, M. Hörning, J. Dong, J. Qiao, X. Qu, Y. Hua, Fujimoto, Y. Shiba, Y. Zhao, F. Tang, S. Miyagawa, Y. Chen, Y. Sawa, C. Tang, L. Liu
Comunications Biology, 3, 122, 2020
- doi : 10.1038/s42003-020-0853-0

Brief Summary: ''HiPSC-derived cardiomyocytes can form three-dimensional self-organized tissue rings... the trained tissue show matured features including increased cardiac-specific gene expression, enhanced Ca²⁺-handling properties, an increased oxygen-consumption rate, and enhanced contractile force. A mathematical model interprets the origination, propagation, and long-term behavior of the findings.''

Three-dimensional cell geometry controls excitable membrane signaling in Dictyostelium cells 
M. Hörning and T. Shibata
Biophysical Journal 116(2), 372-382, 2019
 - doi : 10.1016/j.bpj.2018.12.012

Brief Summary: ''Using a novel method of three-dimensional analysis of the entire cell membrane of Dictyostelium cells, we found that PtdInsP3 domains can propagate persistently in any direction on the entire plasma membrane, while their propagation direction and speed are governed by the geometry of the cell.''

Brief Summary: ''A new class of reversible rigidity switching hydrogels to actively control cells is used. Actin depolarization dynamics as well as cellular responses are tracked over time.''