scholarly journals Multiscale molecular profiling of pathological bone resolves sexually dimorphic control of extracellular matrix composition

2021 ◽  
Vol 14 (3) ◽  
pp. dmm048116 ◽  
Author(s):  
Aikta Sharma ◽  
Alice Goring ◽  
Peter B. Johnson ◽  
Roger J. H. Emery ◽  
Eric Hesse ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Collagen Fibre ◽  
Matrix Composition ◽  
Label Free ◽  
Fibre Number ◽  
Backscattered Electron ◽  
Matrix Mineralisation

ABSTRACTCollagen assembly during development is essential for successful matrix mineralisation, which determines bone quality and mechanocompetence. However, the biochemical and structural perturbations that drive pathological skeletal collagen configuration remain unclear. Deletion of vascular endothelial growth factor (VEGF; also known as VEGFA) in bone-forming osteoblasts (OBs) induces sex-specific alterations in extracellular matrix (ECM) conformation and mineralisation coupled to vascular changes, which are augmented in males. Whether this phenotypic dimorphism arises as a result of the divergent control of ECM composition and its subsequent arrangement is unknown and is the focus of this study. Herein, we used murine osteocalcin-specific Vegf knockout (OcnVEGFKO) and performed ex vivo multiscale analysis at the tibiofibular junction of both sexes. Label-free and non-destructive polarisation-resolved second-harmonic generation (p-SHG) microscopy revealed a reduction in collagen fibre number in males following the loss of VEGF, complemented by observable defects in matrix organisation by backscattered electron scanning electron microscopy. This was accompanied by localised divergence in collagen orientation, determined by p-SHG anisotropy measurements, as a result of OcnVEGFKO. Raman spectroscopy confirmed that the effect on collagen was linked to molecular dimorphic VEGF effects on collagen-specific proline and hydroxyproline, and collagen intra-strand stability, in addition to matrix carbonation and mineralisation. Vegf deletion in male and female murine OB cultures in vitro further highlighted divergence in genes regulating local ECM structure, including Adamts2, Spp1, Mmp9 and Lama1. Our results demonstrate the utility of macromolecular imaging and spectroscopic modalities for the detection of collagen arrangement and ECM composition in pathological bone. Linking the sex-specific genetic regulators to matrix signatures could be important for treatment of dimorphic bone disorders that clinically manifest in pathological nano- and macro-level disorganisation.This article has an associated First Person interview with the first author of the paper.

scholarly journals Multiomic and quantitative label-free microscopy-based analysis of ex vivo culture and TGFbeta1 stimulation of human precision-cut lung slices

2019 ◽  
Author(s):  
Muzamil Majid Khan ◽  
Daniel Poeckel ◽  
Aliaksandr Halavatyi ◽  
Frank Stein ◽  
Johanna Vappiani ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Integrated Approach ◽  
Imaging Method ◽  
Fibrillar Collagen ◽  
Label Free ◽  
Ex Vivo Culture ◽  
And Function ◽  
Precision Cut Lung Slices

AbstractFibrosis can affect any organ resulting in the loss of tissue architecture and function with often life-threatening consequences. Pathologically, fibrosis is characterised by expansion of connective tissue due to excessive deposition of extracellular matrix proteins (ECM), including the fibrillar forms of collagen. A significant hurdle for discovering cures for fibrosis is the lack of suitable models and techniques to quantify mature collagen deposition in tissues. Here we have extensively characterized an ex-vivo cultured human lung derived, precision-cut lung slices model (hPCLS) using live fluorescence light microscopy as well as mass spectrometry-based techniques to obtain a proteomic and metabolomic fingerprint. Using an integrated approach of multiple readouts such as quantitative label-free Second Harmonic Generation (SHG) imaging to measure fibrillar collagen in the extracellular matrix and ELISA-based methods to measure soluble ECM biomarkers, we investigated TGFbeta1-mediated pro-fibrotic signalling in hPCLS. We demonstrate that hPCLS are viable and metabolically active with mesenchymal, epithelial, endothelial, and immune cells surviving for at least two weeks in ex vivo culture. Analysis of hPCLS-conditioned supernatants showed strong induction of ECM synthesis proteins P1NP and fibronectin upon TGFb stimulation. Importantly, this effect translated into an increased deposition of fibrillar collagen in ECM of cultured hPCLS as measured by a novel quantitative SHG-based imaging method only following addition of a metalloproteinase inhibitor (GM6001). Together the data show that an integrated approach of measuring soluble pro-fibrotic markers and quantitative SHG-based analysis of fibrillar collagen is a valuable tool for studying pro-fibrotic signalling and testing anti-fibrotic agents.

ACTIVATED INTESTINAL MUSCLE CELLS PROMOTE PREADIPOCYTE MIGRATION: A NOVEL MECHANISM OF CREEPING FAT FORMATION IN CROHN’S DISEASE

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S34-S34
Author(s):  
Ren Mao ◽  
Genevieve Doyon ◽  
Ilyssa Gordon ◽  
Jiannan Li ◽  
Sinan Lin ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Ex Vivo ◽  
Muscularis Propria ◽  
Dominant Factor ◽  
Stricture Formation ◽  
Intestinal Tissue ◽  
Mesenteric Fat

Abstract Background and Aims Creeping fat, the wrapping of mesenteric fat around the bowel wall, is a typical feature of Crohn’s disease, and is associated with stricture formation and bowel obstruction. How creeping fat forms is unknown, and we interrogated potential mechanisms using novel intestinal tissue and cell interaction systems. Methods Tissues from normal, ulcerative colitis, non-strictured and strictured Crohn’s disease intestinal specimens were obtained. Fresh and decellularized tissue, mesenteric fat explants, primary human adipocytes, pre-adipocytes, muscularis propria cells, and native extracellular matrix were used in multiple ex vivo and in vitro systems involving cell growth, differentiation and migration, proteomics, and integrin expression. Results Crohn’s disease muscularis propria cells produced an extracellular matrix scaffold which is in direct spatial and functional contact with the immediately overlaid creeping fat. The scaffold contained multiple proteins, but only fibronectin production was singularly upregulated by TGF-b1. The muscle cell-derived matrix triggered migration of pre-adipocytes out of mesenteric fat, fibronectin being the dominant factor responsible for their migration. Blockade of α5β1 on the pre-adipocyte surface inhibited their migration out of mesenteric fat and on 3D decellularized intestinal tissue extracellular matrix. Conclusion Crohn’s disease creeping fat appears to result from the migration of pre-adipocytes out of mesenteric fat and differentiation into adipocytes in response to an increased production of fibronectin by activated muscularis propria cells. These new mechanistic insights may lead to novel approaches for prevention of creeping fat-associated stricture formation.

scholarly journals A decellularized human corneal scaffold for anterior corneal surface reconstruction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naresh Polisetti ◽  
Anke Schmid ◽  
Ursula Schlötzer-Schrehardt ◽  
Philip Maier ◽  
Stefan J. Lang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Ex Vivo ◽  
Sodium Deoxycholate ◽  
Nuclear Material ◽  
Biological Properties ◽  
Host Cells ◽  
Human Cornea ◽  
Human Donor ◽  
Short Period

AbstractAllogenic transplants of the cornea are prone to rejection, especially in repetitive transplantation and in scarred or highly vascularized recipient sites. Patients with these ailments would particularly benefit from the possibility to use non-immunogenic decellularized tissue scaffolds for transplantation, which may be repopulated by host cells in situ or in vitro. So, the aim of this study was to develop a fast and efficient decellularization method for creating a human corneal extracellular matrix scaffold suitable for repopulation with human cells from the corneal limbus. To decellularize human donor corneas, sodium deoxycholate, deoxyribonuclease I, and dextran were assessed to remove cells and nuclei and to control tissue swelling, respectively. We evaluated the decellularization effects on the ultrastructure, optical, mechanical, and biological properties of the human cornea. Scaffold recellularization was studied using primary human limbal epithelial cells, stromal cells, and melanocytes in vitro and a lamellar transplantation approach ex vivo. Our data strongly suggest that this approach allowed the effective removal of cellular and nuclear material in a very short period of time while preserving extracellular matrix proteins, glycosaminoglycans, tissue structure, and optical transmission properties. In vitro recellularization demonstrated good biocompatibility of the decellularized human cornea and ex vivo transplantation revealed complete epithelialization and stromal repopulation from the host tissue. Thus, the generated decellularized human corneal scaffold could be a promising biological material for anterior corneal reconstruction in the treatment of corneal defects.

scholarly journals Murine Metatarsus Bone and Joint Collagen-I Fiber Morphologies and Networks Studied With SHG Multiphoton Imaging

2021 ◽  
Vol 9 ◽  
Author(s):  
Martin Vielreicher ◽  
Aline Bozec ◽  
Georg Schett ◽  
Oliver Friedrich
Keyword(s):  
Rheumatoid Arthritis ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Chronic Inflammatory Disease ◽  
Collagen I ◽  
Bone Architecture ◽  
Fiber Types ◽  
Label Free ◽  
Fiber Morphology ◽  
Collagen Network

Chronic inflammatory disease of bones and joints (e.g., rheumatoid arthritis, gout, etc.), but also acute bone injury and healing, or degenerative resorptive processes inducing osteoporosis, are associated with structural remodeling that ultimately have impact on function. For instance, bone stability is predominantly orchestrated by the structural arrangement of extracellular matrix fibrillar networks, i.e., collagen-I, -IV, elastin, and other proteins. These components may undergo distinct network density and orientation alterations that may be causative for decreased toughness, resilience and load bearing capacity or even increased brittleness. Diagnostic approaches are usually confined to coarse imaging modalities of X-ray or computer tomography that only provide limited optical resolution and lack specificity to visualize the fibrillary collagen network. However, studying collagen structure at the microscopic scale is of considerable interest to understand the mechanisms of tissue pathologies. Multiphoton Second Harmonic Generation (SHG) microscopy, is able to visualize the sterical topology of the collagen-I fibrillar network in 3D, in a minimally invasive and label-free manner. Penetration depths exceed those of conventional visible light imaging and can be further optimized through employing decalcification or optical clearing processing ex vivo. The goal of this proof-of-concept study was to use SHG and two-photon excited fluorescence (2-PEF) imaging to mainly characterize the fibrillary collagen organization within ex vivo decalcified normal mouse metatarsus bone and joint. The results show that the technique resolved the fibrillar collagen network of complete bones and joints with almost no artifacts and enabled to study the complex collagen-I networks with various fiber types (straight, crimped) and network arrangements of mature and woven bone with high degree of detail. Our imaging approach enabled to identify cavities within both cortical and trabecular bone architecture as well as interfaces with sharply changing fiber morphology and network structure both within bone, in tendon and ligament and within joint areas. These possibilities are highly advantageous since the technology can easily be applied to animal models, e.g., of rheumatoid arthritis to study structural effects of chronic joint inflammation, and to many others and to compare to the structure of human bone.

scholarly journals Introduction to Infrared and Raman-Based Biomedical Molecular Imaging and Comparison with Other Modalities

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5547
Author(s):  
Carlos F. G. C. Geraldes
Keyword(s):  
Computed Tomography ◽  
Molecular Imaging ◽  
Single Photon ◽  
Ex Vivo ◽  
Photon Emission ◽  
Raman Imaging ◽  
Emission Computed Tomography ◽  
Label Free ◽  
Advantages And Disadvantages

Molecular imaging has rapidly developed to answer the need of image contrast in medical diagnostic imaging to go beyond morphological information to include functional differences in imaged tissues at the cellular and molecular levels. Vibrational (infrared (IR) and Raman) imaging has rapidly emerged among the molecular imaging modalities available, due to its label-free combination of high spatial resolution with chemical specificity. This article presents the physical basis of vibrational spectroscopy and imaging, followed by illustration of their preclinical in vitro applications in body fluids and cells, ex vivo tissues and in vivo small animals and ending with a brief discussion of their clinical translation. After comparing the advantages and disadvantages of IR/Raman imaging with the other main modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), positron emission tomography/single-photon emission-computed tomography (PET/SPECT), ultrasound (US) and photoacoustic imaging (PAI), the design of multimodal probes combining vibrational imaging with other modalities is discussed, illustrated by some preclinical proof-of-concept examples.

scholarly journals MT1-MMP–dependent neovessel formation within the confines of the three-dimensional extracellular matrix

2004 ◽  
Vol 167 (4) ◽  
pp. 757-767 ◽  
Author(s):  
Tae-Hwa Chun ◽  
Farideh Sabeh ◽  
Ichiro Ota ◽  
Hedwig Murphy ◽  
Kevin T. McDonagh ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Surface ◽  
Type I Collagen ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Collagenolytic Activity ◽  
Type I ◽  
Ex Vivo Model

During angiogenesis, endothelial cells initiate a tissue-invasive program within an interstitial matrix comprised largely of type I collagen. Extracellular matrix–degradative enzymes, including the matrix metalloproteinases (MMPs) MMP-2 and MMP-9, are thought to play key roles in angiogenesis by binding to docking sites on the cell surface after activation by plasmin- and/or membrane-type (MT) 1-MMP–dependent processes. To identify proteinases critical to neovessel formation, an ex vivo model of angiogenesis has been established wherein tissue explants from gene-targeted mice are embedded within a three-dimensional, type I collagen matrix. Unexpectedly, neither MMP-2, MMP-9, their cognate cell-surface receptors (i.e., β3 integrin and CD44), nor plasminogen are essential for collagenolytic activity, endothelial cell invasion, or neovessel formation. Instead, the membrane-anchored MMP, MT1-MMP, confers endothelial cells with the ability to express invasive and tubulogenic activity in a collagen-rich milieu, in vitro or in vivo, where it plays an indispensable role in driving neovessel formation.

scholarly journals Alternative Splicing of FN (Fibronectin) Regulates the Composition of the Arterial Wall Under Low Flow

2020 ◽  
Author(s):  
Patrick A. Murphy ◽  
Noor Jailkhani ◽  
Sarah-Anne Nicholas ◽  
Amanda M. Del Rosario ◽  
Jeremy L. Balsbaugh ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Alternative Splicing ◽  
Low Flow ◽  
Matrix Composition ◽  
Splice Isoforms ◽  
Vitro Assay ◽  
Disturbed Flow ◽  
The Impact

Objective: Exposure of the arterial endothelium to low and disturbed flow is a risk factor for the erosion and rupture of atherosclerotic plaques and aneurysms. Circulating and locally produced proteins are known to contribute to an altered composition of the extracellular matrix at the site of lesions, and to contribute to inflammatory processes within the lesions. We have previously shown that alternative splicing of FN (fibronectin) protects against flow-induced hemorrhage. However, the impact of alternative splicing of FN on extracellular matrix composition remains unknown. Approach and Results: Here, we perform quantitative proteomic analysis of the matrisome of murine carotid arteries in mice deficient in the production of FN splice isoforms containing alternative exons EIIIA and EIIIB (FN-EIIIAB null) after exposure to low and disturbed flow in vivo. We also examine serum-derived and endothelial-cell contributions to the matrisome in a simplified in vitro system. We found flow-induced differences in the carotid artery matrisome that were impaired in FN-EIIIAB null mice. One of the most interesting differences was reduced recruitment of FBLN1 (fibulin-1), abundant in blood and not locally produced in the intima. This defect was validated in our in vitro assay, where FBLN1 recruitment from serum was impaired by the absence of these alternatively spliced segments. Conclusions: Our results reveal the extent of the dynamic alterations in the matrisome in the acute response to low and disturbed flow and show how changes in the splicing of FN, a common response in vascular inflammation and remodeling, can affect matrix composition.

scholarly journals An integrated multiomic and quantitative label-free microscopy-based approach to study pro-fibrotic signalling in ex vivo human precision-cut lung slices

2020 ◽  
pp. 2000221
Author(s):  
Muzamil Majid Khan ◽  
Daniel Poeckel ◽  
Aliaksandr Halavatyi ◽  
Joanna Zukowska-Kasprzyk ◽  
Frank Stein ◽  
...  
Keyword(s):  
Immune Cell ◽  
Ex Vivo ◽  
Second Harmonic ◽  
Integrated Approach ◽  
Fibrillar Collagen ◽  
Collagen Deposition ◽  
Label Free ◽  
Human Lung Tissue ◽  
Ecm Proteins ◽  
Precision Cut Lung Slices

Fibrosis can affect any organ resulting in the loss of tissue architecture and function with often life-threatening consequences. Pathologically, fibrosis is characterised by expansion of connective tissue due to excessive deposition of extracellular matrix proteins (ECM), including the fibrillar forms of collagen. A significant limitation for discovering cures for fibrosis is the availability of suitable human models and techniques to quantify mature fibrillar collagen deposition as close as possible to human physiological conditions. Here we have extensively characterised an ex vivo cultured human lung tissue-derived, precision-cut lung slices model (hPCLS) using label-free second harmonic (SHG) light microscopy to quantify fibrillar collagen deposition and mass spectrometry-based techniques to obtain a proteomic and metabolomic fingerprint of hPCLS in ex vivo culture.We demonstrate that hPCLS are viable and metabolically active with mesenchymal, epithelial, endothelial, and immune cell types surviving for at least 2 weeks in ex vivo culture. Analysis of hPCLS-conditioned supernatants showed a strong induction of pulmonary fibrosis-related ECM proteins upon TGFß1 stimulation. This upregulation of ECM proteins was not translated into an increased deposition of fibrillar collagen. In support of this observation, we revealed the presence of a pro-ECM degradation activity in our ex vivo cultures of hPCLS, inhibition of which by metalloproteinase inhibitor resulted in increased collagen deposition in response to TGFß1 stimulation. Together the data show that an integrated approach of measuring soluble pro-fibrotic markers alongside quantitative SHG-based analysis of fibrillar collagen is a valuable tool for studying pro-fibrotic signalling and testing antifibrotic agents.

scholarly journals A Decellularized Human Corneal Scaffold for Anterior Corneal Surface Reconstruction

2020 ◽  
Author(s):  
Naresh Polisetti ◽  
Anke Schmid ◽  
Ursula Schlötzer-Schrehardt ◽  
Philip Maier ◽  
Stefan Lang ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Ex Vivo ◽  
Sodium Deoxycholate ◽  
Nuclear Material ◽  
Biological Properties ◽  
Host Cells ◽  
Human Cornea ◽  
Human Donor ◽  
Short Period

Abstract Allogenic transplants of the cornea are prone to rejection, especially in repetitive transplantation and in scarred or highly vascularized recipient sites. Patients with these ailments would particularly benefit from the possibility to use non-immunogenic decellularized tissue scaffolds for transplantation, which may be repopulated by host cells in situ or in vitro. So, the aim of this study was to develop a fast and efficient decellularization method for creating a human corneal extracellular matrix scaffold suitable for repopulation with human cells from the corneal limbus. To decellularize human donor corneas, sodium deoxycholate, deoxyribonuclease I, and dextran were assessed to remove cells and nuclei and to control tissue swelling, respectively. We evaluated the decellularization effects on the ultrastructure, optical, mechanical, and biological properties of the human cornea. Scaffold recellularization was studied using primary human limbal epithelial cells, stromal cells, and melanocytes in vitro and a lamellar transplantation approach ex vivo. Our data strongly suggest that this approach allowed the effective removal of cellular and nuclear material in a very short period of time while preserving extracellular matrix proteins, glycosaminoglycans, tissue structure, and optical transmission properties. In vitro recellularization demonstrated good biocompatibility of the decellularized human cornea and ex vivo transplantation revealed complete epithelialization and stromal repopulation from the host tissue. Thus, the generated decellularized human corneal scaffold could be a promising biological material for anterior corneal reconstruction in the treatment of corneal defects.

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