Spatiotemporal Characterization of Extracellular Matrix Microstructures in Engineered Tissue: A Whole-Field Spectroscopic Imaging Approach

Quality and functionality of engineered tissues are closely related to the microstructures and integrity of their extracellular matrix (ECM). However, currently available methods for characterizing ECM structures are often labor-intensive, destructive, and limited to a small fraction of the total area. These methods are also inappropriate for assessing temporal variations in ECM structures. In this study, to overcome these limitations and challenges, we propose an elastic light scattering approach to spatiotemporally assess ECM microstructures in a relatively large area in a nondestructive manner. To demonstrate its feasibility, we analyze spectroscopic imaging data obtained from acellular collagen scaffolds and dermal equivalents as model ECM structures. For spatial characterization, acellular scaffolds are examined after a freeze/thaw process mimicking a cryopreservation procedure to quantify freezing-induced structural changes in the collagen matrix. We further analyze spatial and temporal changes in ECM structures during cell-driven compaction in dermal equivalents. The results show that spectral dependence of light elastically backscattered from engineered tissue is sensitively associated with alterations in ECM microstructures. In particular, a spectral decay rate over the wavelength can serve as an indicator for the pore size changes in ECM structures, which are at nanometer scale. A decrease in the spectral decay rate suggests enlarged pore sizes of ECM structures. The combination of this approach with a whole-field imaging platform further allows visualization of spatial heterogeneity of EMC microstructures in engineered tissues. This demonstrates the feasibility of the proposed method that nano- and micrometer scale alteration of the ECM structure can be detected and visualized at a whole-field level. Thus, we envision that this spectroscopic imaging approach could potentially serve as an effective characterization tool to nondestructively, accurately, and rapidly quantify ECM microstructures in engineered tissue in a large area.

Download Full-text

Freezing-Induced Cell-Fluid-Matrix Interaction in Engineered Tissue

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192208 ◽

2008 ◽

Author(s):

Junkyu Jung ◽

Ka Yaw Teo ◽

J. Craig Dutton ◽

Bumsoo Han

Keyword(s):

Extracellular Matrix ◽

Biological Tissues ◽

Tissue Level ◽

Cellular Level ◽

Tissue Type ◽

Freezing And Thawing ◽

Matrix Interaction ◽

Engineered Tissues ◽

Quantitative Understanding ◽

Engineered Tissue

Freezing of biological tissues occurs in cryomedicine applications such as cryosurgery and cryopreservation. Although cellular level biophysics during freezing and thawing (F/T) has been extensively studied, tissue level biophysics is not fully understood yet. Especially, the effects of F/T on the functionalities of tissue are not well understood so that the outcomes of cryomedicine applications are highly tissue-type dependent [1]. Although many of the functionalities are associated with the extracellular matrix (ECM), the effect of F/T on ECM microstructure has been overlooked. Quantitative understanding on the post-thaw ECM structure is rarely available, but it is essential to design and improve cryopresevation and cryotherapy protocols for a wide variety of native and engineered tissues.

Download Full-text

THU0319 DEVELOPMENT AND OUTCOME OF AORTIC COMPLICATIONS DURING TOCILIZUMAB TREATMENT OF GCA AND HISTOPATHOLOGIC EVIDENCE OF RESIDUAL INFLAMMATION-A CASE SERIES.

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2020-eular.4660 ◽

2020 ◽

Vol 79 (Suppl 1) ◽

pp. 388.2-389

Author(s):

A. Rubbert-Roth ◽

P. K. Bode ◽

T. Langenegger ◽

C. Pfofe ◽

T. Neumann ◽

...

Keyword(s):

Structural Changes ◽

Case Series ◽

Aortic Aneurysms ◽

Imaging Data ◽

Limited Data ◽

Retrospective Case ◽

Pet Ct ◽

Fdg Pet Ct ◽

Pet Ct Scan

Background:Giant cell arteritis (GCA) may affect the aorta and the large aortic branches and lead to dissections and aortic aneurysms. Tocilizumab (TCZ) treatment has the capacity to control aortic inflammation as has been demonstrated by CRP normalization and imaging data. However, limited data are available on the histopathological findings obtained from patients who underwent surgery because of aortic complications during TCZ treatment.Objectives:We report on 5 patients with aortitis who were treated with TCZ and developed aortic complications.Methods:We describe a retrospective case series of patients with GCA treated with TCZ, who presented in our clinic between 2011 and 2019. Three patients underwent surgery. Histopathologic examination was performed in specimen from all of them.Results:Five female patients were diagnosed with GCA (4/5) or Takaysu arteritis (1/5) involving the aorta, all them diagnosed by MR angiography and/or FDG PET CT scan. Three patients (one with aortic aneurysm, one with dissection) underwent surgery after having been treated with TCZ for seven weeks, nine months and four years, respectively. Imaging before surgery showed remission on MRI and/or PET-CT in all cases. At the time of surgery, all patients showed normalized CRP and ESR values. Histopathological evaluation of the aortic wall revealed infiltrates, consisting predominantly of CD3+CD4+ T cells. Enlargement of pre-existing aneuryms was observed in the other two patients 10 weeks and 4 months after discontinuation of TCZ, respectively. Both patients were not eligible for surgical intervention and died during follow-up.Conclusion:Our case series suggests that during treatment with TCZ, regular imaging is necessary in this patient population to detect development of structural changes such as aneurysms or dissections. Despite treatment, residual inflammation might persist which could contribute to eventual aortic complications.Disclosure of Interests:Andrea Rubbert-Roth Consultant of: Abbvie, BMS, Chugai, Pfizer, Roche, Janssen, Lilly, Sanofi, Amgen, Novartis, Peter Karl Bode: None declared, Thomas Langenegger: None declared, Claudia Pfofe: None declared, Thomas Neumann: None declared, Olaf Chan-Hi Kim: None declared, Johannes von Kempis Consultant of: Roche

Download Full-text

Signaling Mechanisms in the Regulation of Renal Matrix Metabolism in Diabetes

Experimental Diabetes Research ◽

10.1155/2012/749812 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 23

Author(s):

Meenalakshmi M. Mariappan

Keyword(s):

Extracellular Matrix ◽

Signaling Pathways ◽

Matrix Protein ◽

Structural Changes ◽

Mammalian Target Of Rapamycin ◽

Adverse Outcomes ◽

Matrix Proteins ◽

Extracellular Matrix Protein ◽

Renal Hypertrophy ◽

Matrix Metabolism

Renal hypertrophy and accumulation of extracellular matrix proteins are among cardinal manifestations of diabetic nephropathy. TGF beta system has been implicated in the pathogenesis of these manifestations. Among signaling pathways activated in the kidney in diabetes, mTOR- (mammalian target of rapamycin-)regulated pathways are pivotal in orchestrating high glucose-induced production of ECM proteins leading to functional and structural changes in the kidney culminating in adverse outcomes. Understanding signaling pathways that influence individual matrix protein expression could lead to the development of new interventional strategies. This paper will highlight some of the diverse components of the signaling network stimulated by hyperglycemia with an emphasis on extracellular matrix protein metabolism in the kidney in diabetes.

Download Full-text

Analysis of Variance in Spectroscopic Imaging Data from Human Tissues

Analytical Chemistry ◽

10.1021/ac2026496 ◽

2011 ◽

Vol 84 (2) ◽

pp. 1063-1069 ◽

Cited By ~ 24

Author(s):

Jin Tae Kwak ◽

Rohith Reddy ◽

Saurabh Sinha ◽

Rohit Bhargava

Keyword(s):

Analysis Of Variance ◽

Spectroscopic Imaging ◽

Human Tissues ◽

Imaging Data

Download Full-text

Abstract 3863: Deletion Of Integrin Alpha7 Leads To Altered Cardiac Conduction And Sudden Death Associated With Connexin43 Downregulation

Circulation ◽

10.1161/circ.118.suppl_18.s_494-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Raja Nadif ◽

Michael Emerson ◽

Ulrike Mayer ◽

Ludwig Neyses ◽

Elizabeth Cartwright

Keyword(s):

Atrial Fibrillation ◽

Extracellular Matrix ◽

Ventricular Hypertrophy ◽

Structural Changes ◽

Cellular Adhesion ◽

Left Ventricular ◽

Cardiac Conduction ◽

Cardiac Phenotype ◽

One Year ◽

Deficient Mice

Effective propagation of the electrical impulse throughout the myocardium is highly dependent on cell-to-cell and cell-to-extracellular matrix interactions. Increasing evidence indicates that dysregulation of cellular adhesion is a critical determinant in the genesis of arrhythmia. Null mutations in the integrin α7 gene, an essential mediator of cellular adhesion in cardiac and skeletal muscles, have been linked to myopathy in humans, however, the in vivo role of the integrin α7 subunit in the heart is undefined. The mouse model of integrin α7 deletion dies prematurely at one year of age. We therefore analysed the cardiac phenotype in integrin α7 deficient mice (α7 −/− ) to determine whether their premature death was associated with altered cardiac conduction. One year old integrin α7 −/− mice exhibited altered cardiac conduction characterised by spontaneous atrial fibrillation and prolonged QTc duration (α7 −/− : 25.7±0.74ms, α7 +/+ : 19.5±0.61ms; n=6; p<0.001, QTc=QT/(RR/100) 1/2 ). The abnormal cardiac conduction was associated with downregulation of connexin43. However, no significant changes were observed in the expression of ion chanels that have been linked to long QT syndrome or atrial fibrillation (kv1.1, kv1.5, kcne1, kcnq1, erg1, Cav1.2 and Cav1.3). In addition, α7 −/− mice displayed increased susceptibility to drug-induced arrhythmias: treatment with ouabain (2mg/kg BW) in combination with isoprenaline (2.5mg/kg BW) induced atrial fibrillation and ventricular tachycardia and eventually death in 6 month-old integrin α7 −/− mice, but not in α7 +/+ mice. Interestingly, α7 −/− also displayed concentric ventricular hypertrophy with increased septal wall thickness and reduced left ventricular end-diastolic diameter starting from 6 months of age. These structural changes were accompanied by an increase in myocyte size and increased ERK1/2 phosphorylation. In conclusion, deletion of the integrin α7 gene in mice leads to ventricular hypertrophy and to abnormal cardiac conduction. The integrin α7 deficient mice have a marked propensity to lethal arrhythmias through alterations in gap junctions but not ion channels. The integrin α7 knockout model provides new insight into the link between the extracellular matrix and cardiac conduction.

Download Full-text

Extracellular matrix‐based combination scaffold for guided regeneration of large‐area full‐thickness rabbit burn wounds upon a single application

Journal of Biomedical Materials Research Part B Applied Biomaterials ◽

10.1002/jbm.b.34965 ◽

2021 ◽

Author(s):

Rashmi Ramakrishnan ◽

Vijayakumar Sreelatha Harikrishnan ◽

Arya Anil ◽

Sabareeswaran Arumugham ◽

Lissy Kalliyana Krishnan

Keyword(s):

Extracellular Matrix ◽

Full Thickness ◽

Single Application ◽

Large Area ◽

Burn Wounds

Download Full-text

Tracking Extracellular Matrix Remodeling in Lungs Induced by Breast Cancer Metastasis. Fourier Transform Infrared Spectroscopic Studies

Molecules ◽

10.3390/molecules25010236 ◽

2020 ◽

Vol 25 (1) ◽

pp. 236 ◽

Cited By ~ 3

Author(s):

Karolina Chrabaszcz ◽

Katarzyna Kaminska ◽

Karolina Augustyniak ◽

Monika Kujdowicz ◽

Marta Smeda ◽

...

Keyword(s):

Breast Cancer ◽

Extracellular Matrix ◽

Fourier Transform ◽

Cancer Metastasis ◽

Fourier Transform Infrared ◽

Muscle Cells ◽

Breast Cancer Metastasis ◽

Extracellular Matrix Remodeling ◽

Matrix Remodeling ◽

Large Area

This work focused on a detailed assessment of lung tissue affected by metastasis of breast cancer. We used large-area chemical scanning implemented in Fourier transform infrared (FTIR) spectroscopic imaging supported with classical histological and morphological characterization. For the first time, we differentiated and defined biochemical changes due to metastasis observed in the lung parenchyma, atelectasis, fibrous, and muscle cells, as well as bronchi ciliate cells, in a qualitative and semi-quantitative manner based on spectral features. The results suggested that systematic extracellular matrix remodeling with the progress of the metastasis process evoked a decrease in the fraction of the total protein in atelectasis, fibrous, and muscle cells, as well as an increase of fibrillar proteins in the parenchyma. We also detected alterations in the secondary conformations of proteins in parenchyma and atelectasis and changes in the level of hydroxyproline residues and carbohydrate moieties in the parenchyma. The results indicate the usability of FTIR spectroscopy as a tool for the detection of extracellular matrix remodeling, thereby enabling the prediction of pre-metastatic niche formation.

Download Full-text

Trypanosoma congolense in the Microvasculature of the Pituitary Gland of Experimentally Infected Boran Cattle (Bos indicus)

Veterinary Pathology ◽

10.1177/030098589303000501 ◽

1993 ◽

Vol 30 (5) ◽

pp. 401-409 ◽

Cited By ~ 12

Author(s):

G. Abebe ◽

M. K. Shaw ◽

R. M. Eley

Keyword(s):

Electron Microscopy ◽

Extracellular Matrix ◽

Structural Changes ◽

Bos Indicus ◽

Light And Electron Microscopy ◽

Trypanosoma Congolense ◽

Glossina Morsitans ◽

Glossina Morsitans Centralis ◽

Pituitary Glands ◽

Female Control

The pituitary glands of seven Boran cattle ( Bos indicus), five infected with a clone of Trypanosoma congolense IL 1180 (ILNat 3.1) transmitted by Glossina morsitans centralis and two uninfected controls, were examined by light and electron microscopy 43 (experiment 2) or 56 (experiment 1) days after fly challenge. The three cattle used in the first experiment included a 15-month-old female (No. 1), a 24–month-old female (No. 2), and a 21–month-old male (No. 3) as a control. In the second experiment, four cattle were used: two females (Nos. 4, 5) and one male (No. 6), all between 15 and 24 months of age, and one female control (No. 7) of similar age. In all the infected animals, dilation of both the sinusoids and microvasculature was apparent, as was an increase in the thickness of the extracellular matrix between the pituitary lobules. Trypanosomes were found in the microvasculature of the adenohypophysis and neurohypophysis in all the infected animals. Focal degenerative changes were seen in the adenohypophyseal section of glands from the infected animals euthanatized 56 days post-infection. These degenerative structural changes were confined to the somatotrophs cells. The possible role that trypanosomes in the microvasculature may play in inducing pituitary damage and dysfunction is discussed.

Download Full-text