1
|
Vilar A, Hodgson-Garms M, Kusuma GD, Donderwinkel I, Carthew J, Tan JL, Lim R, Frith JE. Substrate mechanical properties bias MSC paracrine activity and therapeutic potential. Acta Biomater 2023; 168:144-158. [PMID: 37422008 DOI: 10.1016/j.actbio.2023.06.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 06/14/2023] [Accepted: 06/27/2023] [Indexed: 07/10/2023]
Abstract
Mesenchymal stromal cells (MSCs) have significant therapeutic potential due to their ability to differentiate into musculoskeletal lineages suitable for tissue-engineering, as well as the immunomodulatory and pro-regenerative effects of the paracrine factors that these cells secrete. Cues from the extracellular environment, including physical stimuli such as substrate stiffness, are strong drivers of MSC differentiation, but their effects upon MSC paracrine activity are not well understood. This study, therefore sought to determine the impact of substrate stiffness on the paracrine activity of MSCs, analysing both effects on MSC fate and their effect on T-cell and macrophage activity and angiogenesis. The data show that conditioned medium (CM) from MSCs cultured on 0.2 kPa (soft) and 100 kPa (stiff) polyacrylamide hydrogels have differing effects on MSC proliferation and differentiation, with stiff CM promoting proliferation whilst soft CM promoted differentiation. There were also differences in the effects upon macrophage phagocytosis and angiogenesis, with the most beneficial effects from soft CM. Analysis of the media composition identified differences in the levels of proteins including IL-6, OPG, and TIMP-2. Using recombinant proteins and blocking antibodies, we confirmed a role for OPG in modulating MSC proliferation with a complex combination of factors involved in the regulation of MSC differentiation. Together the data confirm that the physical microenvironment has an important influence on the MSC secretome and that this can alter the differentiation and regenerative potential of the cells. These findings can be used to tailor the culture environment for manufacturing potent MSCs for specific clinical applications or to inform the design of biomaterials that enable the retention of MSC activity after delivery into the body. STATEMENT OF SIGNIFICANCE: • MSCs cultured on 100 kPa matrices produce a secretome that boosts MSC proliferation • MSCs cultured on 0.2 kPa matrices produce a secretome that promotes MSC osteogenesis and adipogenesis, as well as angiogenesis and macrophage phagocytosis • IL-6 secretion is elevated in MSCs on 0.2 kPa substrates • OPG, TIMP-2, MCP-1, and sTNFR1 secretion are elevated in MSCs on 100 kPa substrates.
Collapse
Affiliation(s)
- Aeolus Vilar
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia; ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, Victoria 3800, Australia
| | - Margeaux Hodgson-Garms
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Gina D Kusuma
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Ilze Donderwinkel
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - James Carthew
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jean L Tan
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria 3800, Australia; Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria 3800, Australia
| | - Rebecca Lim
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria 3800, Australia; Department of Obstetrics and Gynecology, Monash University, Clayton, Victoria 3800, Australia; Australian Regenerative Medicine Institute, Monash University, Clayton, Australia
| | - Jessica E Frith
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia; Australian Regenerative Medicine Institute, Monash University, Clayton, Australia; ARC Training Centre for Cell and Tissue Engineering Technologies, Monash University, Clayton, Victoria 3800, Australia.
| |
Collapse
|
2
|
Brandão AS, Bensimon-Brito A, Lourenço R, Borbinha J, Soares AR, Mateus R, Jacinto A. Yap induces osteoblast differentiation by modulating Bmp signalling during zebrafish caudal fin regeneration. J Cell Sci 2019; 132:jcs.231993. [PMID: 31636113 DOI: 10.1242/jcs.231993] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 10/14/2019] [Indexed: 12/11/2022] Open
Abstract
Osteoblast differentiation is a key process for bone homeostasis and repair. Multiple signalling pathways have been associated with osteoblast differentiation, yet much remains unknown on how this process is regulated in vivo Previous studies have proposed that the Hippo pathway transcriptional co-activators YAP and TAZ (also known as YAP1 and WWTR1, respectively) maintain progenitor stemness and inhibit terminal differentiation of osteoblasts, whereas others suggest they potentiate osteoblast differentiation and bone formation. Here, we use zebrafish caudal fin regeneration as a model to clarify how the Hippo pathway regulates de novo bone formation and osteoblast differentiation. We demonstrate that Yap inhibition leads to accumulation of osteoprogenitors and prevents osteoblast differentiation in a cell non-autonomous manner. This effect correlates with a severe impairment of Bmp signalling in osteoblasts, likely by suppressing the expression of the ligand bmp2a in the surrounding mesenchymal cells. Overall, our findings provide a new mechanism of bone formation through the Hippo-Yap pathway, integrating Yap in the signalling cascade that governs osteoprogenitor maintenance and subsequent differentiation during zebrafish caudal fin regeneration.
Collapse
Affiliation(s)
- Ana S Brandão
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Campo Mártires da Pátria 130, Lisboa 1169-056, Portugal
| | - Anabela Bensimon-Brito
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Raquel Lourenço
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Campo Mártires da Pátria 130, Lisboa 1169-056, Portugal
| | - Jorge Borbinha
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Campo Mártires da Pátria 130, Lisboa 1169-056, Portugal
| | - Ana Rosa Soares
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Campo Mártires da Pátria 130, Lisboa 1169-056, Portugal
| | - Rita Mateus
- Department of Biochemistry, Sciences II, University of Geneva, Quai Ernest-Ansermet 30, 1211 Geneva 4, Switzerland
| | - António Jacinto
- CEDOC, NOVA Medical School, NOVA University of Lisbon, Campo Mártires da Pátria 130, Lisboa 1169-056, Portugal
| |
Collapse
|
3
|
Gerst F, Wagner R, Oquendo MB, Siegel-Axel D, Fritsche A, Heni M, Staiger H, Häring HU, Ullrich S. What role do fat cells play in pancreatic tissue? Mol Metab 2019; 25:1-10. [PMID: 31113756 PMCID: PMC6600604 DOI: 10.1016/j.molmet.2019.05.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/10/2019] [Accepted: 05/01/2019] [Indexed: 02/07/2023] Open
Abstract
Background It is now generally accepted that obesity is a major risk factor for type 2 diabetes mellitus (T2DM). Hepatic steatosis in particular, as well as visceral and ectopic fat accumulation within tissues, is associated with the development of the disease. We recently presented the first study on isolated human pancreatic adipocytes and their interaction with islets [Gerst, F., Wagner, R., Kaiser, G., Panse, M., Heni, M., Machann, J., et al., 2017. Metabolic crosstalk between fatty pancreas and fatty liver: effects on local inflammation and insulin secretion. Diabetologia 60(11):2240–2251.]. The results indicate that the function of adipocytes depends on the overall metabolic status in humans which, in turn, differentially affects islet hormone release. Scope of Review This review summarizes former and recent studies on factors derived from adipocytes and their effects on insulin-secreting β-cells, with particular emphasis on the human pancreas. The adipocyte secretome is discussed with a special focus on its influence on insulin secretion, β-cell survival and apoptotic β-cell death. Major Conclusions Human pancreatic adipocytes store lipids and release adipokines, metabolites, and pro-inflammatory molecules in response to the overall metabolic, humoral, and neuronal status. The differentially regulated adipocyte secretome impacts on endocrine function, i.e., insulin secretion, β-cell survival and death which interferes with glycemic control. This review attempts to explain why the extent of pancreatic steatosis is associated with reduced insulin secretion in some studies but not in others.
Collapse
Affiliation(s)
- Felicia Gerst
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Robert Wagner
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Morgana Barroso Oquendo
- German Center for Diabetes Research (DZD), Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Dorothea Siegel-Axel
- German Center for Diabetes Research (DZD), Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Andreas Fritsche
- German Center for Diabetes Research (DZD), Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Martin Heni
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Harald Staiger
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Institute of Pharmaceutical Sciences, Department of Pharmacy and Biochemistry, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Hans-Ulrich Häring
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany; Department of Internal Medicine IV, Division of Endocrinology, Diabetology, and Nephrology, University Hospital Tübingen, Tübingen, Germany
| | - Susanne Ullrich
- German Center for Diabetes Research (DZD), Tübingen, Germany; Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany.
| |
Collapse
|
4
|
Abstract
Cells of multicellular organisms are in continuous conversation with the neighbouring cells. The sender cells signal the receiver cells to influence their behaviour in transport, metabolism, motility, division, and growth. How cells communicate with each other can be categorized by biochemical signalling processes, which can be characterised by the distance between the sender cell and the receiver cell. Existing classifications describe autocrine signals as those where the sender cell is identical to the receiver cell. Complementary to this scenario, paracrine signalling describes signalling between a sender cell and a different receiver cell. Finally, juxtacrine signalling describes the exchange of information between adjacent cells by direct cell contact, whereas endocrine signalling describes the exchange of information, e.g., by hormones between distant cells or even organs through the bloodstream. In the last two decades, however, an unexpected communication mechanism has been identified which uses cell protrusions to exchange chemical signals by direct contact over long distances. These signalling protrusions can deliver signals in both ways, from sender to receiver and vice versa. We are starting to understand the morphology and function of these signalling protrusions in many tissues and this accumulation of findings forces us to revise our view of contact-dependent cell communication. In this review, we will focus on the two main categories of signalling protrusions, cytonemes and tunnelling nanotubes. These signalling protrusions emerge as essential structural components of a vibrant communication network in the development and tissue homeostasis of any multicellular organism.
Collapse
Affiliation(s)
- Benjamin Mattes
- Living Systems Institute, School of Biosciences, College of Life and Environmental Science, University of Exeter, Exeter, EX4 4QD, UK
| | - Steffen Scholpp
- Living Systems Institute, School of Biosciences, College of Life and Environmental Science, University of Exeter, Exeter, EX4 4QD, UK.
| |
Collapse
|
5
|
Apps JR, Carreno G, Gonzalez-Meljem JM, Haston S, Guiho R, Cooper JE, Manshaei S, Jani N, Hölsken A, Pettorini B, Beynon RJ, Simpson DM, Fraser HC, Hong Y, Hallang S, Stone TJ, Virasami A, Donson AM, Jones D, Aquilina K, Spoudeas H, Joshi AR, Grundy R, Storer LCD, Korbonits M, Hilton DA, Tossell K, Thavaraj S, Ungless MA, Gil J, Buslei R, Hankinson T, Hargrave D, Goding C, Andoniadou CL, Brogan P, Jacques TS, Williams HJ, Martinez-Barbera JP. Tumour compartment transcriptomics demonstrates the activation of inflammatory and odontogenic programmes in human adamantinomatous craniopharyngioma and identifies the MAPK/ERK pathway as a novel therapeutic target. Acta Neuropathol 2018. [PMID: 29541918 PMCID: PMC5904225 DOI: 10.1007/s00401-018-1830-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Adamantinomatous craniopharyngiomas (ACPs) are clinically challenging tumours, the majority of which have activating mutations in CTNNB1. They are histologically complex, showing cystic and solid components, the latter comprised of different morphological cell types (e.g. β-catenin-accumulating cluster cells and palisading epithelium), surrounded by a florid glial reaction with immune cells. Here, we have carried out RNA sequencing on 18 ACP samples and integrated these data with an existing ACP transcriptomic dataset. No studies so far have examined the patterns of gene expression within the different cellular compartments of the tumour. To achieve this goal, we have combined laser capture microdissection with computational analyses to reveal groups of genes that are associated with either epithelial tumour cells (clusters and palisading epithelium), glial tissue or immune infiltrate. We use these human ACP molecular signatures and RNA-Seq data from two ACP mouse models to reveal that cell clusters are molecularly analogous to the enamel knot, a critical signalling centre controlling normal tooth morphogenesis. Supporting this finding, we show that human cluster cells express high levels of several members of the FGF, TGFB and BMP families of secreted factors, which signal to neighbouring cells as evidenced by immunostaining against the phosphorylated proteins pERK1/2, pSMAD3 and pSMAD1/5/9 in both human and mouse ACP. We reveal that inhibiting the MAPK/ERK pathway with trametinib, a clinically approved MEK inhibitor, results in reduced proliferation and increased apoptosis in explant cultures of human and mouse ACP. Finally, we analyse a prominent molecular signature in the glial reactive tissue to characterise the inflammatory microenvironment and uncover the activation of inflammasomes in human ACP. We validate these results by immunostaining against immune cell markers, cytokine ELISA and proteome analysis in both solid tumour and cystic fluid from ACP patients. Our data support a new molecular paradigm for understanding ACP tumorigenesis as an aberrant mimic of natural tooth development and opens new therapeutic opportunities by revealing the activation of the MAPK/ERK and inflammasome pathways in human ACP.
Collapse
Affiliation(s)
- John R Apps
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK.
| | - Gabriela Carreno
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Jose Mario Gonzalez-Meljem
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Basic Research Department, National Institute of Geriatrics, Mexico City, Mexico
| | - Scott Haston
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Romain Guiho
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Julie E Cooper
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Saba Manshaei
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Nital Jani
- Centre for Translational Omics-GOSgene, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, University College London, London, UK
| | - Annett Hölsken
- Department of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | | | - Robert J Beynon
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Deborah M Simpson
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Helen C Fraser
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Ying Hong
- Infection, Immunity and Inflammation Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Shirleen Hallang
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | - Thomas J Stone
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Alex Virasami
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Andrew M Donson
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - David Jones
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kristian Aquilina
- Neurosurgery Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Helen Spoudeas
- Endocrinology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Abhijit R Joshi
- Laboratory Medicine, Royal Victoria Infirmary, Newcastle, UK
| | - Richard Grundy
- Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, UK
| | - Lisa C D Storer
- Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, UK
| | - Márta Korbonits
- William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University, London, UK
| | - David A Hilton
- Pathology Department, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Kyoko Tossell
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Selvam Thavaraj
- Head and Neck Pathology, Dental Institute, King's College London, London, UK
| | - Mark A Ungless
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Jesus Gil
- MRC London Institute of Medical Sciences, Imperial College London, London, UK
| | - Rolf Buslei
- Department of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany
- Institute of Pathology, Klinikum Sozialstiftung Bamberg, Bamberg, Germany
| | - Todd Hankinson
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Darren Hargrave
- Haematology and Oncology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Colin Goding
- Ludwig Institute for Cancer Research, Oxford University, Old Road Campus, Headington, Oxford, UK
| | - Cynthia L Andoniadou
- Centre for Craniofacial and Regenerative Biology, King's College London, Guy's Hospital, Floor 27 Tower Wing, London, UK
- Department of Internal Medicine III, Technische Universität Dresden, Fetscherstaße 74, 01307, Dresden, Germany
| | - Paul Brogan
- Infection, Immunity and Inflammation Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Rheumatology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Thomas S Jacques
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
- Histopathology Department, Great Ormond Street Hospital NHS Trust, London, UK
| | - Hywel J Williams
- Centre for Translational Omics-GOSgene, Genetics and Genomic Medicine Programme, UCL Institute of Child Health, University College London, London, UK
| | - Juan Pedro Martinez-Barbera
- Developmental Biology and Cancer Programme, Birth Defects Research Centre, UCL Great Ormond Street Institute of Child Health, University College London, London, UK.
| |
Collapse
|
6
|
Narayanan S, Loganathan G, Dhanasekaran M, Tucker W, Patel A, Subhashree V, Mokshagundam S, Hughes MG, Williams SK, Balamurugan AN. Intra-islet endothelial cell and β-cell crosstalk: Implication for islet cell transplantation. World J Transplant 2017; 7:117-128. [PMID: 28507914 PMCID: PMC5409911 DOI: 10.5500/wjt.v7.i2.117] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/28/2017] [Accepted: 03/24/2017] [Indexed: 02/05/2023] Open
Abstract
The intra-islet microvasculature is a critical interface between the blood and islet endocrine cells governing a number of cellular and pathophysiological processes associated with the pancreatic tissue. A growing body of evidence indicates a strong functional and physical interdependency of β-cells with endothelial cells (ECs), the building blocks of islet microvasculature. Intra-islet ECs, actively regulate vascular permeability and appear to play a role in fine-tuning blood glucose sensing and regulation. These cells also tend to behave as “guardians”, controlling the expression and movement of a number of important immune mediators, thereby strongly contributing to the physiology of islets. This review will focus on the molecular signalling and crosstalk between the intra-islet ECs and β-cells and how their relationship can be a potential target for intervention strategies in islet pathology and islet transplantation.
Collapse
|
7
|
Brady RT, O'Brien FJ, Hoey DA. Mechanically stimulated bone cells secrete paracrine factors that regulate osteoprogenitor recruitment, proliferation, and differentiation. Biochem Biophys Res Commun 2015; 459:118-23. [PMID: 25721667 DOI: 10.1016/j.bbrc.2015.02.080] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 02/13/2015] [Indexed: 01/20/2023]
Abstract
Bone formation requires the recruitment, proliferation and osteogenic differentiation of mesenchymal progenitors. A potent stimulus driving this process is mechanical loading, yet the signalling mechanisms underpinning this are incompletely understood. The objective of this study was to investigate the role of the mechanically-stimulated osteocyte and osteoblast secretome in coordinating progenitor contributions to bone formation. Initially osteocytes (MLO-Y4) and osteoblasts (MC3T3) were mechanically stimulated for 24 hrs and secreted factors within the conditioned media were collected and used to evaluate mesenchymal stem cell (MSC) and osteoblast recruitment, proliferation and osteogenesis. Paracrine factors secreted by mechanically stimulated osteocytes significantly enhanced MSC migration, proliferation and osteogenesis and furthermore significantly increased osteoblast migration and proliferation when compared to factors secreted by statically cultured osteocytes. Secondly, paracrine factors secreted by mechanically stimulated osteoblasts significantly enhanced MSC migration but surprisingly, in contrast to the osteocyte secretome, inhibited MSC proliferation when compared to factors secreted by statically cultured osteoblasts. A similar trend was observed in osteoblasts. This study provides new information on mechanically driven signalling mechanisms in bone and highlights a contrasting secretome between cells at different stages in the bone lineage, furthering our understanding of loading-induced bone formation and indirect biophysical regulation of osteoprogenitors.
Collapse
|
8
|
Knútsdóttir H, Pálsson E, Edelstein-Keshet L. Mathematical model of macrophage-facilitated breast cancer cells invasion. J Theor Biol 2014; 357:184-99. [PMID: 24810842 DOI: 10.1016/j.jtbi.2014.04.031] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 02/24/2014] [Accepted: 04/24/2014] [Indexed: 11/25/2022]
Abstract
Mortality from breast cancer stems from its tendency to invade into surrounding tissues and organs. Experiments have shown that this metastatic process is facilitated by macrophages in a short-ranged chemical signalling loop. Macrophages secrete epidermal growth factor, EGF, and respond to the colony stimulating factor 1, CSF-1. Tumor cells secrete CSF-1 and respond to EGF. In this way, the cells coordinate aggregation and cooperative migration. Here we investigate this process in a model for in vitro interactions using two distinct but related mathematical approaches. In the first, we analyze and simulate a set of partial differential equations to determine conditions for aggregation. In the second, we use a cell-based discrete 3D simulation to follow the fates and motion of individual cells during aggregation. Linear stability analysis of the PDE model reveals that decreasing the chemical secretion, chemotaxis coefficients or density of cells or increasing the chemical degradation in the model could eliminate the spontaneous aggregation of cells. Simulations with the discrete model show that the ratio between tumor cells and macrophages in aggregates increases when the EGF secretion parameter is increased. The results also show how CSF-1/CSF-1R autocrine signalling in tumor cells affects the ratio between the two cell types. Comparing the continuum results with simulations of a discrete cell-based model, we find good qualitative agreement.
Collapse
Affiliation(s)
- Hildur Knútsdóttir
- Mathematics Department, University of British Columbia, Vancouver, BC, Canada V6T 1Z2.
| | - Eirikur Pálsson
- Biology Department, Simon Fraser University, Burnaby, BC, Canada V5A 1S6.
| | - Leah Edelstein-Keshet
- Mathematics Department, University of British Columbia, Vancouver, BC, Canada V6T 1Z2.
| |
Collapse
|