scholarly journals Tyrosine-Derived Polycarbonate Nerve Guidance Tubes Elicit Pro-Regenerative Extracellular Matrix Deposition When Used to Bridge Segmental Nerve Defects in Swine

2020 ◽  
Author(s):  
JC Burrell ◽  
D Bhatnagar ◽  
DP Brown ◽  
NS Murthy ◽  
J Dutton ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Schwann Cell ◽  
Cell Infiltration ◽  
Large Animal ◽  
Matrix Deposition ◽  
Regenerative Response ◽  
Large Animal Models ◽  
Segmental Nerve ◽  
Collagen Iii ◽  
Wide Range

AbstractPromising biomaterials should be tested in appropriate large animal models that recapitulate human inflammatory and regenerative responses. Previous studies have shown tyrosine-derived polycarbonates (TyrPC) are versatile biomaterials with a wide range of applications across multiple disciplines. The library of TyrPC has been well studied and consists of thousands of polymer compositions with tunable mechanical characteristics and degradation and resorption rates that are useful for nerve guidance tubes (NGTs). NGTs made of different TyrPCs have been used in segmental nerve defect models in small animals. The current study is an extension of this work and evaluates NGTs made using two different TyrPC compositions in a 1 cm porcine peripheral nerve repair model. We first evaluated a nondegradable TyrPC formulation, demonstrating proof-of-concept chronic regenerative efficacy up to 6 months with similar nerve/muscle electrophysiology and morphometry to the autograft repair control. Next, we characterized the acute regenerative response using a degradable TyrPC formulation. After 2 weeks in vivo, TyrPC NGT promoted greater deposition of pro-regenerative extracellular matrix (ECM) constituents (in particular collagen I, collagen III, collagen IV, laminin and fibronectin) compared to commercially available collagen-based NGTs. This corresponded with dense Schwann cell infiltration and axon extension across the lumen. These findings confirmed results reported previously in a mouse model and reveal that TyrPC NGTs were well tolerated in swine and facilitated host axon regeneration and Schwann cell infiltration in the acute phase across segmental defects - likely by eliciting a favorable neurotrophic ECM milieu. This regenerative response ultimately can contribute to functional recovery.

scholarly journals Molecular Mechanisms of Fetal Tendon Regeneration Versus Adult Fibrous Repair

2021 ◽  
Vol 22 (11) ◽  
pp. 5619
Author(s):  
Iris Ribitsch ◽  
Andrea Bileck ◽  
Alexander D. Aldoshin ◽  
Maciej M. Kańduła ◽  
Rupert L. Mayer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Molecular Mechanisms ◽  
Unmet Need ◽  
Tendon Healing ◽  
Tendon Injury ◽  
Inflammatory Factors ◽  
Large Animal ◽  
Post Injury ◽  
Tendon Regeneration ◽  
Large Animal Models

Tendinopathies are painful, disabling conditions that afflict 25% of the adult human population. Filling an unmet need for realistic large-animal models, we here present an ovine model of tendon injury for the comparative study of adult scarring repair and fetal regeneration. Complete regeneration of the fetal tendon within 28 days is demonstrated, while adult tendon defects remained macroscopically and histologically evident five months post-injury. In addition to a comprehensive histological assessment, proteome analyses of secretomes were performed. Confirming histological data, a specific and pronounced inflammation accompanied by activation of neutrophils in adult tendon defects was observed, corroborated by the significant up-regulation of pro-inflammatory factors, neutrophil attracting chemokines, the release of potentially tissue-damaging antimicrobial and extracellular matrix-degrading enzymes, and a response to oxidative stress. In contrast, secreted proteins of injured fetal tendons included proteins initiating the resolution of inflammation or promoting functional extracellular matrix production. These results demonstrate the power and relevance of our novel ovine fetal tendon regeneration model, which thus promises to accelerate research in the field. First insights from the model already support our molecular understanding of successful fetal tendon healing processes and may guide improved therapeutic strategies.

scholarly journals Fabrication and Modeling of Dynamic Multipolymer Nanofibrous Scaffolds

2009 ◽  
Vol 131 (10) ◽  
Author(s):  
Brendon M. Baker ◽  
Nandan L. Nerurkar ◽  
Jason A. Burdick ◽  
Dawn M. Elliott ◽  
Robert L. Mauck
Keyword(s):  
Mechanical Properties ◽  
Rational Design ◽  
Cell Infiltration ◽  
Tissue Properties ◽  
Matrix Deposition ◽  
Native Tissue ◽  
Nanofibrous Scaffolds ◽  
Wide Range ◽  
Anisotropic Mechanical Properties

Aligned nanofibrous scaffolds hold tremendous potential for the engineering of dense connective tissues. These biomimetic micropatterns direct organized cell-mediated matrix deposition and can be tuned to possess nonlinear and anisotropic mechanical properties. For these scaffolds to function in vivo, however, they must either recapitulate the full dynamic mechanical range of the native tissue upon implantation or must foster cell infiltration and matrix deposition so as to enable construct maturation to meet these criteria. In our recent studies, we noted that cell infiltration into dense aligned structures is limited but could be expedited via the inclusion of a distinct rapidly eroding sacrificial component. In the present study, we sought to further the fabrication of dynamic nanofibrous constructs by combining multiple-fiber populations, each with distinct mechanical characteristics, into a single composite nanofibrous scaffold. Toward this goal, we developed a novel method for the generation of aligned electrospun composites containing rapidly eroding (PEO), moderately degradable (PLGA and PCL/PLGA), and slowly degrading (PCL) fiber populations. We evaluated the mechanical properties of these composites upon formation and with degradation in a physiologic environment. Furthermore, we employed a hyperelastic constrained-mixture model to capture the nonlinear and time-dependent properties of these scaffolds when formed as single-fiber populations or in multipolymer composites. After validating this model, we demonstrated that by carefully selecting fiber populations with differing mechanical properties and altering the relative fraction of each, a wide range of mechanical properties (and degradation characteristics) can be achieved. This advance allows for the rational design of nanofibrous scaffolds to match native tissue properties and will significantly enhance our ability to fabricate replacements for load-bearing tissues of the musculoskeletal system.

Schwann Cell Differentiation in vitro: Extracellular Matrix Deposition and Interaction

1986 ◽  
Vol 8 (3) ◽  
pp. 182-196 ◽  
Author(s):  
A. Baron-Van Evercooren ◽  
A. Gansmüller ◽  
M. Gumpel ◽  
N. Baumann ◽  
H.K. Kleinman
Keyword(s):  
Extracellular Matrix ◽  
Cell Differentiation ◽  
Schwann Cell ◽  
Matrix Deposition ◽  
Extracellular Matrix Deposition ◽  
Schwann Cell Differentiation

scholarly journals Cigarette smoke enhances proliferation and extracellular matrix deposition by human fetal airway smooth muscle

2014 ◽  
Vol 307 (12) ◽  
pp. L978-L986 ◽  
Author(s):  
Elizabeth R. Vogel ◽  
Sarah K. VanOosten ◽  
Michelle A. Holman ◽  
Danielle D. Hohbein ◽  
Michael A. Thompson ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Cell Proliferation ◽  
Smooth Muscle ◽  
Cigarette Smoke ◽  
Airway Smooth Muscle ◽  
Airway Hyperreactivity ◽  
Pediatric Airway ◽  
Matrix Deposition ◽  
Increased Risk ◽  
Collagen Iii

Cigarette smoke is a common environmental insult associated with increased risk of developing airway diseases such as wheezing and asthma in neonates and children. In adults, asthma involves airway remodeling characterized by increased airway smooth muscle (ASM) cell proliferation and increased extracellular matrix (ECM) deposition, as well as airway hyperreactivity. The effects of cigarette smoke on remodeling and contractility in the developing airway are not well-elucidated. In this study, we used canalicular-stage (18–20 wk gestational age) human fetal airway smooth muscle (fASM) cells as an in vitro model of the immature airway. fASM cells were exposed to cigarette smoke extract (CSE; 0.5–1.5% for 24–72 h), and cell proliferation, ECM deposition, and intracellular calcium ([Ca2+]i) responses to agonist (histamine 10 μM) were used to evaluate effects on remodeling and hyperreactivity. CSE significantly increased cell proliferation and deposition of ECM molecules collagen I, collagen III, and fibronectin. In contrast, [Ca2+]i responses were not significantly affected by CSE. Analysis of key signaling pathways demonstrated significant increase in extracellular signal-related kinase (ERK) and p38 activation with CSE. Inhibition of ERK or p38 signaling prevented CSE-mediated changes in proliferation, whereas only ERK inhibition attenuated the CSE-mediated increase in ECM deposition. Overall, these results demonstrate that cigarette smoke may enhance remodeling in developing human ASM through hyperplasia and ECM production, thus contributing to development of neonatal and pediatric airway disease.

scholarly journals The Extracellular Matrix in Pancreatic Cancer: Description of a Complex Network and Promising Therapeutic Options

Cancers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 4442
Author(s):  
Benedetta Ferrara ◽  
Cataldo Pignatelli ◽  
Mélissande Cossutta ◽  
Antonio Citro ◽  
José Courty ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Large Body ◽  
Blood Perfusion ◽  
Drug Carriers ◽  
Ductal Adenocarcinoma ◽  
Drug Penetration ◽  
Ecm Remodeling ◽  
Matrix Deposition ◽  
Wide Range ◽  
Current Therapies

The stroma is a relevant player in driving and supporting the progression of pancreatic ductal adenocarcinoma (PDAC), and a large body of evidence highlights its role in hindering the efficacy of current therapies. In fact, the dense extracellular matrix (ECM) characterizing this tumor acts as a natural physical barrier, impairing drug penetration. Consequently, all of the approaches combining stroma-targeting and anticancer therapy constitute an appealing option for improving drug penetration. Several strategies have been adopted in order to target the PDAC stroma, such as the depletion of ECM components and the targeting of cancer-associated fibroblasts (CAFs), which are responsible for the increased matrix deposition in cancer. Additionally, the leaky and collapsing blood vessels characterizing the tumor might be normalized, thus restoring blood perfusion and allowing drug penetration. Even though many stroma-targeting strategies have reported disappointing results in clinical trials, the ECM offers a wide range of potential therapeutic targets that are now being investigated. The dense ECM might be bypassed by implementing nanoparticle-based systems or by using mesenchymal stem cells as drug carriers. The present review aims to provide an overview of the principal mechanisms involved in the ECM remodeling and of new promising therapeutic strategies for PDAC.

scholarly journals Differential Expression of Extracellular Matrix Components in Nasal Polyp Endotypes

2019 ◽  
Vol 33 (6) ◽  
pp. 665-670 ◽  
Author(s):  
Xin Feng ◽  
Spencer C. Payne ◽  
Larry Borish ◽  
John W. Steinke
Keyword(s):  
Extracellular Matrix ◽  
Nasal Polyp ◽  
Collagen Iv ◽  
Disease State ◽  
Collagen I ◽  
Cellular Infiltrate ◽  
Matrix Deposition ◽  
Total Collagen ◽  
Collagen Iii ◽  
Extracellular Matrix Components

Background Chronic rhinosinusitis is a difficult-to-treat disease that is often characterized by recurrent nasal polyp (NP) growth following surgical removal. The disease has been separated into distinct phenotypes based on cellular infiltrate or underlying physiological mechanisms. NPs are composed in part of an inflammatory cellular infiltrate, blood vessels, and a large amount of extracellular matrix (ECM). Despite the recognition of prominent ECM deposition, few studies have examined the components in detail and how they might differ with disease state. Objective The purpose of this study was to quantitate the expression of ECM components in NPs. Methods NPs were stained with pico-sirius red to determine total collagen content, and immunofluorescence was used to detect collagen I, collagen III, collagen IV, fibronectin, and laminin. Expression of each was quantitated and analyzed in relation to rhinosinusitis phenotype and separately as a function of polyp eosinophil number. Results When analyzed by phenotype, collagen I, collagen III, and fibronectin were expressed at the highest levels in noneosinophilic sinus disease. Collagen IV was not different among any groups, and its location was found predominately around vessels. When analyzed as a function of polyp eosinophil number, total collagen and collagen III showed a significant inverse correlation. Conclusions NP ECM composition differs with disease state with higher expression in cases where eosinophil levels are low. This suggests that in eosinophilic polyps there is a loss of matrix deposition either through break down or a failure to produce the essential components. Understanding these differences may identify new therapeutic targets.

scholarly journals A New Form of Decellularized Extracellular Matrix Hydrogel for Treating Ischemic Tissue via Intravascular Infusion

2020 ◽  
Author(s):  
Martin T. Spang ◽  
Tori S. Lazerson ◽  
Saumya Bhatia ◽  
James Corbitt ◽  
Gerardo Sandoval ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Left Ventricular ◽  
Large Animal Model ◽  
Left Ventricular Volumes ◽  
Large Animal ◽  
Proof Of Concept ◽  
Large Animal Models ◽  
Ischemic Tissue ◽  
New Form

AbstractExtracellular matrix (ECM) hydrogels have been widely used in preclinical studies as injectable materials for tissue engineering therapies. We have developed a new ECM therapy, the soluble fraction derived from decellularized, digested ECM, for intravascular infusion. This new form of ECM is capable of gelation in vivo and can be delivered acutely after an injury to promote cell survival and improve vascularization. In this study, we show proof-of-concept for the feasibility, safety, and efficacy of ECM infusions using small and large animal models of acute myocardial infarction (MI) and intracoronary infusion. Following infusion, the ECM material was retained in the heart, specifically in regions of ischemia, and colocalized with endothelial cells, coating the leaky microvasculature. Functional improvements, specifically reduced left ventricular volumes, were observed after ECM infusion post-MI. Genes associated with angiogenesis were upregulated, and genes associated with cell apoptosis/necrosis and fibrosis were downregulated. The ECM was also delivered using a clinically-relevant catheter in a large animal model of acute MI. This study shows proof-of-concept for a new intravascular delivery strategy for ECM biomaterial therapies with potential implications for a variety of pathologies with ischemic tissue or injured vasculature.

scholarly journals Aging increases senescence, calcium signaling, and extracellular matrix deposition in human airway smooth muscle

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254710
Author(s):  
Sarah A. Wicher ◽  
Benjamin B. Roos ◽  
Jacob J. Teske ◽  
Yun Hua Fang ◽  
Christina Pabelick ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Smooth Muscle ◽  
Calcium Signaling ◽  
Intracellular Calcium ◽  
Airway Smooth Muscle ◽  
Human Airway Smooth Muscle ◽  
Matrix Deposition ◽  
Human Airway ◽  
Intracellular Calcium Signaling ◽  
Collagen Iii

Lung function declines as people age and their lungs become stiffer. With an increasing elderly population, understanding mechanisms that contribute to these structural and functional changes in the aging lung is important. Part of the aging process is characterized by thicker, more fibrotic airways, and senile emphysema caused by changes in lung parenchyma. There is also senescence, which occurs throughout the body with aging. Here, using human airway smooth muscle (ASM) cells from patients in different age groups, we explored senescence pathways and changes in intracellular calcium signaling and extracellular matrix (ECM) deposition to elucidate potential mechanisms by which aging leads to thicker and stiffer lungs. Senescent markers p21, γH2AX, and β-gal, and some senescence-associated secretory proteins (SASP) increased with aging, as shown by staining and biochemical analyses. Agonist-induced intracellular Ca2+ responses, measured using fura-2 loaded cells and fluorescence imaging, increased with age. However, biochemical analysis showed that expression of the following markers decreased with age: M3 muscarinic receptor, TRPC3, Orai1, STIM1, SERCA2, MMP2 and MMP9. In contrast, collagen III, and fibronectin deposition increased with age. These data show that senescence increases in the aging airways that is associated with a stiffer but surprisingly greater intracellular calcium signaling as a marker for contractility. ASM senescence may enhance fibrosis in a feed forward loop promoting remodeling and altered calcium storage and buffering.

scholarly journals 308 DEVELOPMENT OF TRANSGENIC LIVESTOCK WITH REDUCED MYOSTATIN EXPRESSION USING RNA INTERFERENCE

2009 ◽  
Vol 21 (1) ◽  
pp. 251
Author(s):  
K. Tessanne ◽  
T. Stroud ◽  
C. Long ◽  
G. Hannon ◽  
S. Sadeghieh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Interference ◽  
Lentiviral Vector ◽  
Muscle Growth ◽  
Negative Regulator ◽  
Large Animal ◽  
Large Animal Models ◽  
Transgenic Livestock ◽  
Fetal Fibroblasts ◽  
Wide Range

RNA interference (RNAi) is a means of regulating gene expression by targeting mRNA in a sequence-specific manner for degradation or translational inhibition. Short hairpin RNAs (shRNAs) and siRNAs have been extensively employed for manipulating gene expression in a wide range of species. However, the great majority of this work has involved in vitro studies with cells grown in culture. Our goal for this project is to produce transgenic livestock in which myostatin, a negative regulator of muscle growth, has been targeted for silencing by RNAi. In theory, livestock in which myostatin has been silenced should exhibit increased muscle growth and development. To that end, we designed shRNAs to target the bovine myostatin mRNA sequence. The shRNAs were cloned into a lentiviral vector that contains a cytomegalovirus promoter controlling green fluorescent protein and shRNA expression as well as neomycin resistance. Infective lentivirus was made in HEK293T cells through co-transfection of the lentiviral vector, a packaging plasmid, and a plasmid expressing the VSVG pseudotype. Bovine fetal fibroblasts were transduced, selected using Geneticin®, and nuclear transfer was utilized to produce cloned transgenic embryos. There were 186 fusion attempts resulting in 160 fused embryos (fusion rate = 86%). Of these, 54 reached the blastocyst stage (34%) and 10 embryos were transferred into 5 recipient females (2 embryos per recipient). At 40 days, ultrasound revealed 1 confirmed pregnancy. Current plans are to harvest this fetus at 90 days and analyze it for evidence of myostatin knockdown. The production of transgenic animals exhibiting myostatin knockdown through lentiviral-mediated RNAi will demonstrate the utility of RNAi in the study of gene function in large animal models without the need for homologous recombination techniques, which are currently inefficient in species other than mice.

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