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Karkhaneh Yousefi AA, Petit C, Ben Hassine A, Avril S. Stiffness sensing by smooth muscle cells: Continuum mechanics modeling of the acto-myosin role. J Mech Behav Biomed Mater 2023; 144:105990. [PMID: 37385127 DOI: 10.1016/j.jmbbm.2023.105990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/30/2023] [Accepted: 06/23/2023] [Indexed: 07/01/2023]
Abstract
Aortic smooth muscle cells (SMCs) play a vital role in maintaining homeostasis in the aorta by sensing and responding to mechanical stimuli. However, the mechanisms that underlie the ability of SMCs to sense and respond to stiffness change in their environment are still partially unclear. In this study, we focus on the role of acto-myosin contractility in stiffness sensing and introduce a novel continuum mechanics approach based on the principles of thermal strains. Each stress fiber satisfies a universal stress-strain relationship driven by a Young's modulus, a contraction coefficient scaling the fictitious thermal strain, a maximum contraction stress and a softening parameter describing the sliding effects between actin and myosin filaments. To account for the inherent variability of cellular responses, large populations of SMCs are modeled with the finite-element method, each cell having a random number and a random arrangement of stress fibers. Moreover, the level of myosin activation in each stress fiber satisfies a Weibull probability density function. Model predictions are compared to traction force measurements on different SMC lineages. It is demonstrated that the model not only predicts well the effects of substrate stiffness on cellular traction, but it can also successfully approximate the statistical variations of cellular tractions induced by intercellular variability. Finally, stresses in the nuclear envelope and in the nucleus are computed with the model, showing that the variations of cytoskeletal forces induced by substrate stiffness directly induce deformations of the nucleus which can potentially alter gene expression. The predictability of the model combined to its relative simplicity are promising assets for further investigation of stiffness sensing in 3D environments. Eventually, this could contribute to decipher the effects of mechanosensitivity impairment, which are known to be at the root of aortic aneurysms.
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Affiliation(s)
| | - Claudie Petit
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 SAINBIOSE, 42023, Saint-Etienne, France
| | - Amira Ben Hassine
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 SAINBIOSE, 42023, Saint-Etienne, France
| | - Stéphane Avril
- Mines Saint-Etienne, Université Jean Monnet, INSERM, U1059 SAINBIOSE, 42023, Saint-Etienne, France.
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Bidone TC, Odde DJ. Multiscale models of integrins and cellular adhesions. Curr Opin Struct Biol 2023; 80:102576. [PMID: 36947952 PMCID: PMC10238663 DOI: 10.1016/j.sbi.2023.102576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 03/24/2023]
Abstract
Computational models of integrin-based adhesion complexes have revealed important insights into the mechanisms by which cells establish connections with their external environment. However, how changes in conformation and function of individual adhesion proteins regulate the dynamics of whole adhesion complexes remains largely elusive. This is because of the large separation in time and length scales between the dynamics of individual adhesion proteins (nanoseconds and nanometers) and the emergent dynamics of the whole adhesion complex (seconds and micrometers), and the limitations of molecular simulation approaches in extracting accurate free energies, conformational transitions, reaction mechanisms, and kinetic rates, that can inform mechanisms at the larger scales. In this review, we discuss models of integrin-based adhesion complexes and highlight their main findings regarding: (i) the conformational transitions of integrins at the molecular and macromolecular scales and (ii) the molecular clutch mechanism at the mesoscale. Lastly, we present unanswered questions in the field of modeling adhesions and propose new ideas for future exciting modeling opportunities.
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Affiliation(s)
- Tamara C Bidone
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA; Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA.
| | - David J Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA. https://twitter.com/davidodde
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Engineering Smooth Muscle to Understand Extracellular Matrix Remodeling and Vascular Disease. Bioengineering (Basel) 2022; 9:bioengineering9090449. [PMID: 36134994 PMCID: PMC9495899 DOI: 10.3390/bioengineering9090449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
The vascular smooth muscle is vital for regulating blood pressure and maintaining cardiovascular health, and the resident smooth muscle cells (SMCs) in blood vessel walls rely on specific mechanical and biochemical signals to carry out these functions. Any slight change in their surrounding environment causes swift changes in their phenotype and secretory profile, leading to changes in the structure and functionality of vessel walls that cause pathological conditions. To adequately treat vascular diseases, it is essential to understand how SMCs crosstalk with their surrounding extracellular matrix (ECM). Here, we summarize in vivo and traditional in vitro studies of pathological vessel wall remodeling due to the SMC phenotype and, conversely, the SMC behavior in response to key ECM properties. We then analyze how three-dimensional tissue engineering approaches provide opportunities to model SMCs’ response to specific stimuli in the human body. Additionally, we review how applying biomechanical forces and biochemical stimulation, such as pulsatile fluid flow and secreted factors from other cell types, allows us to study disease mechanisms. Overall, we propose that in vitro tissue engineering of human vascular smooth muscle can facilitate a better understanding of relevant cardiovascular diseases using high throughput experiments, thus potentially leading to therapeutics or treatments to be tested in the future.
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Jimenez Y, Paulsen C, Turner E, Iturra S, Cuevas O, Lay-son G, Repetto GM, Rojas M, Calderon JF. Exome Sequencing Identifies Genetic Variants Associated with Extreme Manifestations of the Cardiovascular Phenotype in Marfan Syndrome. Genes (Basel) 2022; 13:genes13061027. [PMID: 35741789 PMCID: PMC9223058 DOI: 10.3390/genes13061027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/06/2022] [Accepted: 06/02/2022] [Indexed: 11/26/2022] Open
Abstract
Marfan Syndrome (MFS) is an autosomal dominant condition caused by variants in the fibrillin-1 (FBN1) gene. Cardinal features of MFS include ectopia lentis (EL), musculoskeletal features and aortic root aneurysm and dissection. Although dissection of the ascending aorta is the main cause of mortality in MFS, the clinical course differs considerably in age of onset and severity, even among individuals who share the same causative variant, suggesting the existence of additional genetic variants that modify the severity of the cardiovascular phenotype in MFS. We recruited MFS patients and classified them into severe (n = 8) or mild aortic phenotype (n = 14) according to age of presentation of the first aorta-related incident. We used Exome Sequencing to identify the genetic variants associated with the severity of aortic manifestations and we performed linkage analysis where suitable. We found five genes associated with severe aortic phenotype and three genes that could be protective for this phenotype in MFS. These genes regulate components of the extracellular matrix, TGFβ pathway and other signaling pathways that are involved in the maintenance of the ECM or angiogenesis. Further studies will be required to understand the functional effect of these variants and explore novel, personalized risk management and, potentially, therapies for these patients.
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Affiliation(s)
- Yanireth Jimenez
- Doctorado en Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 8320000, Chile; (Y.J.); (M.R.)
| | - Cesar Paulsen
- Servicio de Cirugía Cardiovascular, Instituto Nacional del Tórax, Santiago 7500808, Chile; (C.P.); (E.T.); (S.I.); (O.C.)
| | - Eduardo Turner
- Servicio de Cirugía Cardiovascular, Instituto Nacional del Tórax, Santiago 7500808, Chile; (C.P.); (E.T.); (S.I.); (O.C.)
| | - Sebastian Iturra
- Servicio de Cirugía Cardiovascular, Instituto Nacional del Tórax, Santiago 7500808, Chile; (C.P.); (E.T.); (S.I.); (O.C.)
| | - Oscar Cuevas
- Servicio de Cirugía Cardiovascular, Instituto Nacional del Tórax, Santiago 7500808, Chile; (C.P.); (E.T.); (S.I.); (O.C.)
- Departamento de Cirugía Cardiovascular, Clínica Alemana, Universidad del Desarrollo, Santiago 8320000, Chile
| | - Guillermo Lay-son
- Unidad de Genética, División de Pediatría, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile;
| | - Gabriela M. Repetto
- Programa de Enfermedades Poco Frecuentes, Centro de Genética y Genómica, Instituto de Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 8320000, Chile;
| | - Marcelo Rojas
- Doctorado en Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 8320000, Chile; (Y.J.); (M.R.)
| | - Juan F. Calderon
- Centro de Genética y Genómica, Instituto de Ciencias e Innovación en Medicina, Facultad de Medicina Clínica Alemana Universidad del Desarrollo, Santiago 8320000, Chile
- Research Center for the Development of Novel Therapeutic Alternatives for Alcohol Use Disorders, Santiago 8320000, Chile
- Correspondence: ; Tel.: +56-22-578-5778
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Petit C, Karkhaneh Yousefi AA, Guilbot M, Barnier V, Avril S. AFM Stiffness Mapping in Human Aortic Smooth Muscle Cells. J Biomech Eng 2022; 144:1133331. [DOI: 10.1115/1.4053657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Indexed: 11/08/2022]
Abstract
Abstract
Aortic Smooth Muscle Cells (SMCs) play a vital role in maintaining mechanical homeostasis in the aorta. We recently found that SMCs of aneurysmal aortas apply larger traction forces than SMCs of healthy aortas. This result was explained by the significant increase of hypertrophic SMCs abundance in aneurysms. In the present study, we investigate whether the cytoskeleton stiffness of SMCs may also be altered in aneurysmal aortas. For that, we use Atomic Force Microscopy (AFM) nanoindentation with a specific mode that allows subcellular-resolution mapping of the local stiffness across a specified region of interest of the cell. Aortic SMCs from a commercial human lineage (AoSMCs, Lonza) and primary aneurysmal SMCs (AnevSMCs) are cultured in conditions promoting the development of their contractile apparatus, and seeded on hydrogels with stiffness properties of 12kPa and 25kPa. Results show that all SMC exhibit globally a lognormal stiffness distribution, with medians in the range 10-30 kPa. The mean of stiffness distributions is slightly higher in aneurysmal SMCs than in healthy cells (16 kPa versus 12 kPa) but the differences are not statistically significant due to the large dispersion of AFM nanoindentation stiffness. We conclude that the possible alterations previously found in aneurysmal SMCs do not affect significantly the AFM nanoindentation stiffness of their cytoskeleton.
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Affiliation(s)
- Claudie Petit
- Mines Saint-Etienne, Université de Lyon, INSERM, U 1059 SAINBIOSE, F - 42023 Saint-Etienne France
| | | | - Marine Guilbot
- Mines Saint-Etienne, Université de Lyon, INSERM, U 1059 SAINBIOSE, F - 42023 Saint-Etienne France
| | - Vincent Barnier
- Mines Saint-Etienne, Université de Lyon, CNRS, UMR 5307 LGF, F - 42023 Saint-Etienne France
| | - Stephane Avril
- Mines Saint-Etienne, Université de Lyon, INSERM, U 1059 SAINBIOSE, F - 42023 Saint-Etienne France
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