IU Indianapolis ScholarWorks :: Browsing by Subject "Extracellular matrix"

Browsing by Subject "Extracellular matrix"

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3D Mapping Reveals a Complex and Transient Interstitial Matrix During Murine Kidney Development
(Wolters Kluwer, 2021) Lipp, Sarah N.; Jacobson, Kathryn R.; Hains, David S.; Schwarderer, Andrew L.; Calve, Sarah; Pediatrics, School of Medicine
ESKD is increasing in incidence and a limited number of organs are available for transplantation. Therefore, researchers have focused on understanding how cellular signaling influences kidney development to expand strategies to rebuild a kidney. However, the extracellular matrix (ECM), another critical component that biomechanically regulates nephrogenesis, has been largely neglected. Proteomics and 3D imaging of the murine kidney resolved previously undescribed dynamics of the interstitial matrix in the cortex and corticomedullary junction during development. Combined with cells and growth factors, scaffolds modeled after the composition and organization of the developmental ECM have the potential to improve engineered models of the kidney.
Aged Breast Extracellular Matrix Drives Mammary Epithelial Cells to an Invasive and Cancer-Like Phenotype
(Wiley, 2021-11) Bahcecioglu, Gokhan; Yue, Xiaoshan; Howe, Erin; Guldner, Ian; Stack, M. Sharon; Nakshatri, Harikrishna; Zhang, Siyuan; Zorlutuna, Pinar; Surgery, School of Medicine
Age is a major risk factor for cancer. While the importance of age related genetic alterations in cells on cancer progression is well documented, the effect of aging extracellular matrix (ECM) has been overlooked. This study shows that the aging breast ECM alone is sufficient to drive normal human mammary epithelial cells (KTB21) to a more invasive and cancer‐like phenotype, while promoting motility and invasiveness in MDA‐MB‐231 cells. Decellularized breast matrix from aged mice leads to loss of E‐cadherin membrane localization in KTB21 cells, increased cell motility and invasion, and increased production of inflammatory cytokines and cancer‐related proteins. The aged matrix upregulates cancer‐related genes in KTB21 cells and enriches a cell subpopulation highly expressing epithelial‐mesenchymal transition‐related genes. Lysyl oxidase knockdown reverts the aged matrix‐induced changes to the young levels; it relocalizes E‐cadherin to cell membrane, and reduces cell motility, invasion, and cytokine production. These results show for the first time that the aging ECM harbors key biochemical, physical, and mechanical cues contributing to invasive and cancer‐like behavior in healthy and cancer mammary cells. Differential response of cells to young and aged ECMs can lead to identification of new targets for cancer treatment and prevention.
Cathepsin K Regulates Intraocular Pressure by Modulating Extracellular Matrix Remodeling and Actin-Bundling in the Trabecular Meshwork Outflow Pathway
(MDPI, 2021-10-24) Soundararajan, Avinash; Ghag, Sachin Anil; Vuda, Sai Supriya; Wang, Ting; Pattabiraman, Padmanabhan Paranji; Ophthalmology, School of Medicine
The homeostasis of extracellular matrix (ECM) and actin dynamics in the trabecular meshwork (TM) outflow pathway plays a critical role in intraocular pressure (IOP) regulation. We studied the role of cathepsin K (CTSK), a lysosomal cysteine protease and a potent collagenase, on ECM modulation and actin cytoskeleton rearrangements in the TM outflow pathway and the regulation of IOP. Initially, we found that CTSK was negatively regulated by pathological stressors known to elevate IOP. Further, inactivating CTSK using balicatib, a pharmacological cell-permeable inhibitor of CTSK, resulted in IOP elevation due to increased levels and excessive deposition of ECM-like collagen-1A in the TM outflow pathway. The loss of CTSK activity resulted in actin-bundling via fascin and vinculin reorganization and by inhibiting actin depolymerization via phospho-cofilin. Contrarily, constitutive expression of CTSK decreased ECM and increased actin depolymerization by decreasing phospho-cofilin, negatively regulated the availability of active TGFβ2, and reduced the levels of alpha-smooth muscle actin (αSMA), indicating an antifibrotic action of CTSK. In conclusion, these observations, for the first time, demonstrate the significance of CTSK in IOP regulation by maintaining the ECM homeostasis and actin cytoskeleton-mediated contractile properties of the TM outflow pathway.
Collagen in Wound Healing
(MDPI, 2021-05-11) Mathew-Steiner, Shomita S.; Roy, Sashwati; Sen, Chandan K.; Medicine, School of Medicine
Normal wound healing progresses through inflammatory, proliferative and remodeling phases in response to tissue injury. Collagen, a key component of the extracellular matrix, plays critical roles in the regulation of the phases of wound healing either in its native, fibrillar conformation or as soluble components in the wound milieu. Impairments in any of these phases stall the wound in a chronic, non-healing state that typically requires some form of intervention to guide the process back to completion. Key factors in the hostile environment of a chronic wound are persistent inflammation, increased destruction of ECM components caused by elevated metalloproteinases and other enzymes and improper activation of soluble mediators of the wound healing process. Collagen, being central in the regulation of several of these processes, has been utilized as an adjunct wound therapy to promote healing. In this work the significance of collagen in different biological processes relevant to wound healing are reviewed and a summary of the current literature on the use of collagen-based products in wound care is provided.
Comparison of porcine corneal decellularization methods and importance of preserving corneal limbus through decellularization
(PLOS, 2021-03-05) Isidan, Abdulkadir; Liu, Shaohui; Chen, Angela M.; Zhang, Wenjun; Li, Ping; Smith, Lester J.; Hara, Hidetaka; Cooper, David K. C.; Ekser, Burcin; Surgery, School of Medicine
Background: The aim of this study is to compare the three previously applied, conventional porcine corneal decellularization methods and to demonstrate the importance of preserving the corneal limbus through decellularization. Methods: Fresh, wild-type (with or without) limbus porcine corneas were decellularized using three different methods, including (i) sodium dodecyl sulfate (SDS), (ii) hypertonic saline (HS), and (iii) N2 gas (NG). Post-treatment evaluation was carried out using histological, residual nuclear material, and ultrastructural analyses. Glycerol was used to help reduce the adverse effects of decellularization. The corneas were preserved for two weeks in cornea storage medium. Results: All three decellularization methods reduced the number of keratocytes at different rates in the stromal tissue. However, all methods, except SDS, resulted in the retention of large numbers of cells and cell fragments. The SDS method (0.1% SDS, 48h) resulted in almost 100% decellularization in corneas without limbus. Low decellularization capacity of the NG method (<50%) could make it unfavorable. Although HS method had a more balanced damage-decellularization ratio, its decellularization capacity was lower than SDS method. Preservation of the corneoscleral limbus could partially prevent structural damage and edema, but it would reduce the decellularization capacity. Conclusion: Our results suggest that SDS is a very powerful decellularization method, but it damages the cornea irreversibly. Preserving the corneoscleral limbus reduces the efficiency of decellularization, but also reduces the damage.
Control of Bone Matrix Properties by Osteocytes
(Frontiers Media, 2021-01-18) Creecy, Amy; Damrath, John G.; Wallace, Joseph M.; Biomedical Engineering, School of Engineering and Technology
Osteocytes make up 90–95% of the cellular content of bone and form a rich dendritic network with a vastly greater surface area than either osteoblasts or osteoclasts. Osteocytes are well positioned to play a role in bone homeostasis by interacting directly with the matrix; however, the ability for these cells to modify bone matrix remains incompletely understood. With techniques for examining the nano- and microstructure of bone matrix components including hydroxyapatite and type I collagen becoming more widespread, there is great potential to uncover novel roles for the osteocyte in maintaining bone quality. In this review, we begin with an overview of osteocyte biology and the lacunar–canalicular system. Next, we describe recent findings from in vitro models of osteocytes, focusing on the transitions in cellular phenotype as they mature. Finally, we describe historical and current research on matrix alteration by osteocytes in vivo, focusing on the exciting potential for osteocytes to directly form, degrade, and modify the mineral and collagen in their surrounding matrix.
Effects of Collagen Gel Stiffness on Cdc42 Activities of Endothelial Colony Forming Cells during Early Vacuole Formation
(2013-08-14) Kim, Seung Joon; Na, Sungsoo; Xie, Dong; Li, Jiliang
Recent preclinical reports have provided evidence that endothelial colony forming cells (ECFCs), a subset of endothelial progenitor cells, significantly improve vessel formation, largely due to their robust vasculogenic potential. While it has been known that the Rho family GTPase Cdc42 is involved in this ECFC-driven vessel formation process, the effect of extracellular matrix (ECM) stiffness on its activity during vessel formation is largely unknown. Using a fluorescence resonance energy transfer (FRET)-based Cdc42 biosensor, we examined the spatio-temporal activity of Cdc42 of ECFCs in three-dimensional (3D) collagen matrices with varying stiffness. The result revealed that ECFCs exhibited an increase in Cdc42 activity in a soft (150 Pa) matrix, while they were much less responsive in a rigid (1 kPa) matrix. In both soft and rigid matrices, Cdc42 was highly activated near vacuoles. However, its activity is higher in a soft matrix than that in a rigid matrix. The observed Cdc42 activity was closely associated with vacuole formation. Soft matrices induced higher Cdc42 activity and faster vacuole formation than rigid matrices. However, vacuole area is not dependent on the stiffness of matrices. Time courses of Cdc42 activity and vacuole formation data revealed that Cdc42 activity proceeds vacuole formation. Collectively, these results suggest that matrix stiffness is critical in regulating Cdc42 activity in ECFCs and its activation is an important step in early vacuole formation.
Evaluation of variable flip angle, MOLLI, SASHA, and IR-SNAPSHOT pulse sequences for T1 relaxometry and extracellular volume imaging of the pancreas and liver
(Elsevier, 2019-06-04) Tirkes, Temel; Zhao, Xuandong; Lin, Chen; Stuckey, Alex Jordan; Li, Liang; Giri, Shivriman; Nickel, Dominik; Radiology and Imaging Sciences, School of Medicine
Purpose Compare four T1 mapping pulse sequences for T1 relaxometry and extracellular volume (ECV) fraction of the pancreas and liver Materials and Methods In vitro phase of this prospective study was performed on a T1 phantom, followed by imaging twenty-two patients. Variable flip angle (VFA), modified Look-Locker inversion recovery (MOLLI), prototype saturation recovery single-shot acquisition (SASHA), and prototype inversion recovery (IR-SNAPSHOT) pulse sequences were used to obtain T1 and ECV maps on the same 1.5T MR scanner using the same imaging protocol. Results In vitro tests showed almost perfect precision of MOLLI (ρc=0.9998), SASHA (ρc=0.9985) and IR-SNAPSHOT (ρc=0.9976) while VFA showed relatively less, however substantial precision (ρc=0.9862). Results of patient scans showed similar ECV fraction of the liver (p=0.08), pancreas (p=0.43), and T1 of the liver (p=0.08) with all pulse sequences. T1 of the pancreas with MOLLI, SASHA and IR-SNAPSHOT were statistically similar (p>0.05). Conclusion MOLLI, SASHA and IR-SNAPSHOT provided almost perfect in vitro precision and similar T1 during in vivo scans. Similar ECV fractions of the liver and pancreas were obtained with all sequences. More refinement of pulse sequences to provide sufficient spatial coverage in one breath hold together with high precision would be desirable in abdominal imaging.
Fibrinogen in the glioblastoma microenvironment contributes to the invasiveness of brain tumor‐initiating cells
(Wiley, 2021-09) Dzikowski, Lauren; Mirzaei, Reza; Sarkar, Susobhan; Kumar, Mehul; Bose, Pinaki; Bellail, Anita; Hao, Chunhai; Yong, V. Wee; Pathology and Laboratory Medicine, School of Medicine
Glioblastomas (GBMs) are highly aggressive, recurrent, and lethal brain tumors that are maintained via brain tumor-initiating cells (BTICs). The aggressiveness of BTICs may be dependent on the extracellular matrix (ECM) molecules that are highly enriched within the GBM microenvironment. Here, we investigated the expression of ECM molecules in GBM patients by mining the transcriptomic databases and also staining human GBM specimens. RNA levels for fibronectin, brevican, versican, heparan sulfate proteoglycan 2 (HSPG2), and several laminins were high in GBMs compared to normal brain, and this was corroborated by immunohistochemistry. While fibrinogen transcript was at normal level in GBM, its protein immunoreactivity was prominent within GBM tissues. These ECM molecules in tumor specimens were in proximity to, and surrounding BTICs. In culture, fibronectin and pan-laminin induced the adhesion of BTICs onto the plastic substratum. However, fibrinogen increased the size of the BTIC spheres by facilitating the adhesive property, motility, and invasiveness of BTICs. These features of elevated invasiveness were corroborated in resected GBM specimens by the close proximity of fibrinogen with matrix metalloproteinase (MMP)-2 and-9, which are proteases implicated in metastasis. Moreover, the effect of fibrinogen-induced invasiveness was attenuated in BTICs where MMP-2 and -9 have been inhibited with siRNAs or pharmacological inhibitors. Our results implicate fibrinogen in GBM as a mediator of the invasive properties of BTICs, and as a target for therapy to reduce BTIC tumorigenecity.
Fluconazole impacts the extracellular matrix of fluconazole-susceptible and -resistant Candida albicans and Candida glabrata biofilms
(Taylor & Francis Open, 2018-06-04) Panariello, Beatriz Helena Dias; Klein, Marlise I.; Mima, Ewerton Garcia De Oliveira; Pavarina, Ana Cláudia; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
Background: Fluconazole (FLZ) is a drug commonly used for the treatment of Candida infections. However, β-glucans in the extracellular matrices (ECMs) hinder FLZ penetration into Candida biofilms, while extracellular DNA (eDNA) contributes to the biofilm architecture and resistance. Methods: This study characterized biofilms of FLZ-sensitive (S) and -resistant (R) Candida albicans and Candida glabrata in the presence or absence of FLZ focusing on the ECM traits. Biofilms of C. albicans American Type Culture Collection (ATCC) 90028 (CaS), C. albicans ATCC 96901 (CaR), C. glabrata ATCC 2001 (CgS), and C. glabrata ATCC 200918 (CgR) were grown in RPMI medium with or without FLZ at 5× the minimum inhibitory concentration (37°C/48 h). Biofilms were assessed by colony-forming unit (CFU)/mL, biomass, and ECM components (alkali-soluble polysaccharides [ASP], water-soluble polysaccharides [WSP], eDNA, and proteins). Scanning electron microscopy (SEM) was also performed. Data were analyzed by parametric and nonparametric tests (α = 0.05). Results: In biofilms, FLZ reduced the CFU/mL of all strains (p < 0.001), except for CaS (p = 0.937). However, the ASP quantity in CaS was significantly reduced by FLZ (p = 0.034), while the drug had no effect on the ASP levels in other strains (p > 0.05). Total biomasses and WSP were significantly reduced by FLZ in the ECM of all yeasts (p < 0.001), but levels of eDNA and proteins were unaffected (p > 0.05). FLZ affected the cell morphology and biofilm structure by hindering hyphae formation in CaS and CaR biofilms, by decreasing the number of cells in CgS and CgR biofilms, and by yielding sparsely spaced cell agglomerates on the substrate. Conclusion: FLZ impacts biofilms of C. albicans and C. glabrata as evident by reduced biomass. This reduced biomass coincided with lowered cell numbers and quantity of WSPs. Hyphal production by C. albicans was also reduced.

Browsing by Subject "Extracellular matrix"

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