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Biermann N, Eigenberger A, Felthaus O, Brébant V, Heine N, Brix E, Spoerl S, Prantl L, Gurtner G, Anker AM. Breast Lipofilling: Is the Bra Really Full? Clinical Bra Pressure Measurement and In Vitro Testing of Processed and Unprocessed Fat Cells. Aesthetic Plast Surg 2024:10.1007/s00266-024-04116-9. [PMID: 38814346 DOI: 10.1007/s00266-024-04116-9] [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: 03/12/2024] [Accepted: 04/25/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND Breast lipofilling, a popular cosmetic and reconstructive procedure, involves the transplantation of autologous fat to enhance breast volume and contour. Despite its widespread use, cell processing and the aftertreatment remain controversial. This study investigates the pressure applied by a compression bra and reports in vitro stress tests of processed and unprocessed fat cells. METHODS Clinical bra pressure measurements were conducted on a cohort of 45 patients following lipofilling, reduction mammoplasties and DIEP flaps. Laboratory analysis included cell vitality testing using Resazurin assays of processed and unprocessed fat cells after exposure to mechanical or hyperbaric pressure. RESULTS Our findings show a mean overall pressure value of the compression bra for all patients of 6.7 ± 5.7 mmHg (range 0-35). Cell processing is superior to sedimentation only regarding fat cell vitality. However, neither mechanical pressure within the specified range nor hyperbaric oxygen exposure significantly affected fat graft survival as measured by Resazurin assays. CONCLUSION The in vitro measurements showed that it was impossible to harm fat cells with external pressure during lipofilling procedures, regardless of their processing. In the clinical context, the compression bra applied pressure values deceeding the perfusion pressure and may therefore not diminish oxygen supply nor harm the transplanted cells. Therefore, we recommend the use of a compression bra for all lipofilling procedures around the breast. LEVEL OF EVIDENCE III This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266.
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Affiliation(s)
- Niklas Biermann
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany.
| | - Andreas Eigenberger
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
- Medical Device Lab, Regensburg Center of Biomedical Engineering (RCBE), Faculty of Mechanical Engineering, Ostbayerische Technische Hochschule Regensburg, Galgenbergstraße 30, 93053, Regensburg, Germany
| | - Oliver Felthaus
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Vanessa Brébant
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Norbert Heine
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Eva Brix
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Steffen Spoerl
- Clinic and Polyclinic for Oral and Maxillofacial Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Lukas Prantl
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
| | - Geoffrey Gurtner
- Department of Plastic and Reconstructive Surgery, Stanford University School Medicine, 291 Campus Drive, Stanford, CA, 94305, USA
| | - Alexandra M Anker
- Department of Plastic, Hand- and Reconstructive Surgery, University Hospital Regensburg, Franz-Josef-Strauß-Allee 11, D-93053, Regensburg, Germany
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Sakamoto N, Ito K, Ii S, Conway DE, Ueda Y, Nagatomi J. A homeostatic role of nucleus-actin filament coupling in the regulation of cellular traction forces in fibroblasts. Biomech Model Mechanobiol 2024:10.1007/s10237-024-01839-1. [PMID: 38502433 DOI: 10.1007/s10237-024-01839-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 03/21/2024]
Abstract
Cellular traction forces are contractile forces that depend on the material/substrate stiffness and play essential roles in sensing mechanical environments and regulating cell morphology and function. Traction forces are primarily generated by the actin cytoskeleton and transmitted to the substrate through focal adhesions. The cell nucleus is also believed to be involved in the regulation of this type of force; however, the role of the nucleus in cellular traction forces remains unclear. In this study, we explored the effects of nucleus-actin filament coupling on cellular traction forces in human dermal fibroblasts cultured on substrates with varying stiffness (5, 15, and 48 kPa). To investigate these effects, we transfected the cells with a dominant-negative Klarsicht/ANC-1/Syne homology (DN-KASH) protein that was designed to displace endogenous linker proteins and disrupt nucleus-actin cytoskeleton connections. The force that exists between the cytoskeleton and the nucleus (nuclear tension) was also evaluated with a fluorescence resonance energy transfer (FRET)-based tension sensor. We observed a biphasic change in cellular traction forces with a peak at 15 kPa, regardless of DN-KASH expression, that was inversely correlated with the nuclear tension. In addition, the relative magnitude and distribution of traction forces in nontreated wild-type cells were similar across different stiffness conditions, while DN-KASH-transfected cells exhibited a different distribution pattern that was impacted by the substrate stiffness. These results suggest that the nucleus-actin filament coupling play a homeostatic role by maintaining the relative magnitude of cellular traction forces in fibroblasts under different stiffness conditions.
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Affiliation(s)
- Naoya Sakamoto
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, Minami- Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan.
- Research Center for Medicine-Engineering Collaboration, Tokyo Metropolitan University, Minami-Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan.
| | - Keisuke Ito
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, Minami- Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
| | - Satoshi Ii
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, Minami- Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
- Research Center for Medicine-Engineering Collaboration, Tokyo Metropolitan University, Minami-Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
| | - Daniel E Conway
- Department of Biomedical Engineering, The Ohio State University, 140W 19th Avenue, Columbus, OH, USA
| | - Yuki Ueda
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, Minami- Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
| | - Jiro Nagatomi
- Research Center for Medicine-Engineering Collaboration, Tokyo Metropolitan University, Minami-Osawa 1-1, Hachioji, Tokyo, 192-0397, Japan
- Department of Bioengineering, Clemson University, 301 Rhodes Research Center, Clemson, SC, 29634-0905, USA
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Calcagno G, Ouzren N, Kaminski S, Ghislin S, Frippiat JP. Chronic Hypergravity Induces a Modification of Histone H3 Lysine 27 Trimethylation at TCRβ Locus in Murine Thymocytes. Int J Mol Sci 2022; 23:ijms23137133. [PMID: 35806138 PMCID: PMC9267123 DOI: 10.3390/ijms23137133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/24/2022] [Accepted: 06/25/2022] [Indexed: 11/16/2022] Open
Abstract
Gravity changes are major stressors encountered during spaceflight that affect the immune system. We previously evidenced that hypergravity exposure during gestation affects the TCRβ repertoire of newborn pups. To identify the mechanisms underlying this observation, we studied post-translational histone modifications. We first showed that among the four studied post-translational histone H3 modifications, only lysine 27 trimethylation (H3K27me3) is downregulated in the thymus of mice exposed to 2× g for 21 days. We then asked whether the TCRβ locus chromatin structure is altered by hypergravity exposure. ChIP studies performed on four Vβ segments of the murine double-negative SCIET27 thymic cell line, which corresponds to the last maturation stage before V(D)J recombination, revealed increases in H3K27me3 after 2× g exposure. Finally, we evaluated the implication for the EZH2 methyltransferase in the regulation of the H3K27me3 level at these Vβ segments by treating SCIET27 cells with the GSK126-specific inhibitor. These experiments showed that the downregulation of H3K27me3 contributes to the regulation of the Vβ germline transcript expression that precedes V(D)J recombination. These data show that modifications of H3K27me3 at the TCRβ locus likely contribute to an explanation of why the TCR repertoire is affected by gravity changes and imply, for the first time, EZH2 in the regulation of the TCRβ locus chromatin structure.
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Ju Z, Thomas TN, Chiu YJ, Yamanouchi S, Yoshida Y, Abe JI, Takahashi A, Wang J, Fujiwara K, Hada M. Adaptation and Changes in Actin Dynamics and Cell Motility as Early Responses of Cultured Mammalian Cells to Altered Gravitational Vector. Int J Mol Sci 2022; 23:6127. [PMID: 35682810 PMCID: PMC9181735 DOI: 10.3390/ijms23116127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 02/05/2023] Open
Abstract
Cultured mammalian cells have been shown to respond to microgravity (μG), but the molecular mechanism is still unknown. The study we report here is focused on molecular and cellular events that occur within a short period of time, which may be related to gravity sensing by cells. Our assumption is that the gravity-sensing mechanism is activated as soon as cells are exposed to any new gravitational environment. To study the molecular events, we exposed cells to simulated μG (SμG) for 15 min, 30 min, 1 h, 2 h, 4 h, and 8 h using a three-dimensional clinostat and made cell lysates, which were then analyzed by reverse phase protein arrays (RPPAs) using a panel of 453 different antibodies. By comparing the RPPA data from cells cultured at 1G with those of cells under SμG, we identified a total of 35 proteomic changes in the SμG samples and found that 20 of these changes took place, mostly transiently, within 30 min. In the 4 h and 8 h samples, there were only two RPPA changes, suggesting that the physiology of these cells is practically indistinguishable from that of cells cultured at 1 G. Among the proteins involved in the early proteomic changes were those that regulate cell motility and cytoskeletal organization. To see whether changes in gravitational environment indeed activate cell motility, we flipped the culture dish upside down (directional change in gravity vector) and studied cell migration and actin cytoskeletal organization. We found that compared with cells grown right-side up, upside-down cells transiently lost stress fibers and rapidly developed lamellipodia, which was supported by increased activity of Ras-related C3 botulinum toxin substrate 1 (Rac1). The upside-down cells also increased their migratory activity. It is possible that these early molecular and cellular events play roles in gravity sensing by mammalian cells. Our study also indicated that these early responses are transient, suggesting that cells appear to adapt physiologically to a new gravitational environment.
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Affiliation(s)
- Zhenlin Ju
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Tamlyn N. Thomas
- Department of Cardiology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (T.N.T.); (J.-i.A.)
- Aab Cardiovascular Research Institute, University of Rochester Medical School, Rochester, NY 14642, USA;
| | - Yi-Jen Chiu
- Aab Cardiovascular Research Institute, University of Rochester Medical School, Rochester, NY 14642, USA;
| | - Sakuya Yamanouchi
- Gunma University Heavy Ion Medical Center, Maebashi 371-8511, Japan; (S.Y.); (Y.Y.); (A.T.)
| | - Yukari Yoshida
- Gunma University Heavy Ion Medical Center, Maebashi 371-8511, Japan; (S.Y.); (Y.Y.); (A.T.)
| | - Jun-ichi Abe
- Department of Cardiology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (T.N.T.); (J.-i.A.)
| | - Akihisa Takahashi
- Gunma University Heavy Ion Medical Center, Maebashi 371-8511, Japan; (S.Y.); (Y.Y.); (A.T.)
| | - Jing Wang
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Keigi Fujiwara
- Department of Cardiology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; (T.N.T.); (J.-i.A.)
| | - Megumi Hada
- Radiation Institute for Science & Engineering, Prairie View A&M University, Prairie View, TX 77446, USA;
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