scholarly journals Superior Alignment of Human iPSC-Osteoblasts Associated with Focal Adhesion Formation Stimulated by Oriented Collagen Scaffold

2021 ◽  
Vol 22 (12) ◽  
pp. 6232
Author(s):  
Ryosuke Ozasa ◽  
Aira Matsugaki ◽  
Tadaaki Matsuzaka ◽  
Takuya Ishimoto ◽  
Hui-Suk Yun ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Structural Organization ◽  
Critical Role ◽  
Bone Matrix ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Collagen Scaffold ◽  
Patient Specific ◽  
Specific Cell ◽  
Adhesion Behavior

Human-induced pluripotent stem cells (hiPSCs) can be applied in patient-specific cell therapy to regenerate lost tissue or organ function. Anisotropic control of the structural organization in the newly generated bone matrix is pivotal for functional reconstruction during bone tissue regeneration. Recently, we revealed that hiPSC-derived osteoblasts (hiPSC-Obs) exhibit preferential alignment and organize in highly ordered bone matrices along a bone-mimetic collagen scaffold, indicating their critical role in regulating the unidirectional cellular arrangement, as well as the structural organization of regenerated bone tissue. However, it remains unclear how hiPSCs exhibit the cell properties required for oriented tissue construction. The present study aimed to characterize the properties of hiPSCs-Obs and those of their focal adhesions (FAs), which mediate the structural relationship between cells and the matrix. Our in vitro anisotropic cell culture system revealed the superior adhesion behavior of hiPSC-Obs, which exhibited accelerated cell proliferation and better cell alignment along the collagen axis compared to normal human osteoblasts. Notably, the oriented collagen scaffold stimulated FA formation along the scaffold collagen orientation. This is the first report of the superior cell adhesion behavior of hiPSC-Obs associated with the promotion of FA assembly along an anisotropic scaffold. These findings suggest a promising role for hiPSCs in enabling anisotropic bone microstructural regeneration.

scholarly journals Inverted formin 2 in focal adhesions promotes dorsal stress fiber and fibrillar adhesion formation to drive extracellular matrix assembly

2015 ◽  
Vol 112 (19) ◽  
pp. E2447-E2456 ◽  
Author(s):  
Colleen T. Skau ◽  
Sergey V. Plotnikov ◽  
Andrew D. Doyle ◽  
Clare M. Waterman
Keyword(s):  
Actin Polymerization ◽  
Critical Role ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Specific Class ◽  
Matrix Assembly ◽  
Dynamic Cell ◽  
Actin Structure ◽  
Actin Nucleator ◽  
Fibrillar Adhesion

Actin filaments and integrin-based focal adhesions (FAs) form integrated systems that mediate dynamic cell interactions with their environment or other cells during migration, the immune response, and tissue morphogenesis. How adhesion-associated actin structures obtain their functional specificity is unclear. Here we show that the formin-family actin nucleator, inverted formin 2 (INF2), localizes specifically to FAs and dorsal stress fibers (SFs) in fibroblasts. High-resolution fluorescence microscopy and manipulation of INF2 levels in cells indicate that INF2 plays a critical role at the SF–FA junction by promoting actin polymerization via free barbed end generation and centripetal elongation of an FA-associated actin bundle to form dorsal SF. INF2 assembles into FAs during maturation rather than during their initial generation, and once there, acts to promote rapid FA elongation and maturation into tensin-containing fibrillar FAs in the cell center. We show that INF2 is required for fibroblasts to organize fibronectin into matrix fibers and ultimately 3D matrices. Collectively our results indicate an important role for the formin INF2 in specifying the function of fibrillar FAs through its ability to generate dorsal SFs. Thus, dorsal SFs and fibrillar FAs form a specific class of integrated adhesion-associated actin structure in fibroblasts that mediates generation and remodeling of ECM.

Metabolic Regulation and Related Molecular Mechanisms in Various Stem Cell Functions

2020 ◽  
Vol 15 (6) ◽  
pp. 531-546 ◽  
Author(s):  
Hwa-Yong Lee ◽  
In-Sun Hong
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Oxidative Phosphorylation ◽  
Metabolic Pathways ◽  
Critical Role ◽  
The Self ◽  
Specific Cell ◽  
Differentiation Potential ◽  
Self Renewal ◽  
Cell Functions

Recent studies on the mechanisms that link metabolic changes with stem cell fate have deepened our understanding of how specific metabolic pathways can regulate various stem cell functions during the development of an organism. Although it was originally thought to be merely a consequence of the specific cell state, metabolism is currently known to play a critical role in regulating the self-renewal capacity, differentiation potential, and quiescence of stem cells. Many studies in recent years have revealed that metabolic pathways regulate various stem cell behaviors (e.g., selfrenewal, migration, and differentiation) by modulating energy production through glycolysis or oxidative phosphorylation and by regulating the generation of metabolites, which can modulate multiple signaling pathways. Therefore, a more comprehensive understanding of stem cell metabolism could allow us to establish optimal culture conditions and differentiation methods that would increase stem cell expansion and function for cell-based therapies. However, little is known about how metabolic pathways regulate various stem cell functions. In this context, we review the current advances in metabolic research that have revealed functional roles for mitochondrial oxidative phosphorylation, anaerobic glycolysis, and oxidative stress during the self-renewal, differentiation and aging of various adult stem cell types. These approaches could provide novel strategies for the development of metabolic or pharmacological therapies to promote the regenerative potential of stem cells and subsequently promote their therapeutic utility.

scholarly journals Cardiomyocyte-Specific Circulating Cell-Free Methylated DNA in Esophageal Cancer Patients Treated with Chemoradiation

2021 ◽  
Vol 3 (3) ◽  
pp. 100-112
Author(s):  
Sarah Martinez Roth ◽  
Eveline E. Vietsch ◽  
Megan E. Barefoot ◽  
Marcel O. Schmidt ◽  
Matthew D. Park ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Cardiac Toxicity ◽  
Amplicon Sequencing ◽  
Neoadjuvant Chemoradiation ◽  
Patient Specific ◽  
High Dose ◽  
Specific Cell ◽  
Methylated Dna ◽  
Bisulfite Treatment ◽  
Dose Radiation

Thoracic high-dose radiation therapy (RT) for cancer has been associated with early and late cardiac toxicity. To assess altered rates of cardiomyocyte cell death due to RT we monitored changes in cardiomyocyte-specific, cell-free methylated DNA (cfDNA) shed into the circulation. Eleven patients with distal esophageal cancer treated with neoadjuvant chemoradiation to 50.4 Gy (RT) and concurrent carboplatin and paclitaxel were enrolled. Subjects underwent fasting blood draws prior to the initiation and after completion of RT as well as 4–6 months following RT. An island of six unmethylated CpGs in the FAM101A locus was used to identify cardiomyocyte-specific cfDNA in serum. After bisulfite treatment this specific cfDNA was quantified by amplicon sequencing at a depth of >35,000 reads/molecule. Cardiomyocyte-specific cfDNA was detectable before RT in the majority of patient samples and showed some distinct changes during the course of treatment and recovery. We propose that patient-specific cardiac damages in response to the treatment are indicated by these changes although co-morbidities may obscure treatment-specific events.

scholarly journals Phosphoproteins of chicken bone matrix. Proof of synthesis in bone tissue.

1984 ◽  
Vol 259 (1) ◽  
pp. 290-293
Author(s):  
M J Glimcher ◽  
D Kossiva ◽  
D Brickley-Parsons
Keyword(s):  
Bone Tissue ◽  
Bone Matrix ◽  
Chicken Bone

scholarly journals A novel gelatin/chitooligosaccharide/demineralized bone matrix composite scaffold and periosteum-derived mesenchymal stem cells for bone tissue engineering

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Thakoon Thitiset ◽  
Siriporn Damrongsakkul ◽  
Supansa Yodmuang ◽  
Wilairat Leeanansaksiri ◽  
Jirun Apinun ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Bone Formation ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Alp Activity

Abstract Background A novel biodegradable scaffold including gelatin (G), chitooligosaccharide (COS), and demineralized bone matrix (DBM) could play a significant part in bone tissue engineering. The present study aimed to investigate the biological characteristics of composite scaffolds in combination of G, COS, and DBM for in vitro cell culture and in vivo animal bioassays. Methods Three-dimensional scaffolds from the mixture of G, COS, and DBM were fabricated into 3 groups, namely, G, GC, and GCD using a lyophilization technique. The scaffolds were cultured with mesenchymal stem cells (MSCs) for 4 weeks to determine biological responses such as cell attachment and cell proliferation, alkaline phosphatase (ALP) activity, calcium deposition, cell morphology, and cell surface elemental composition. For the in vivo bioassay, G, GC, and GCD, acellular scaffolds were implanted subcutaneously in 8-week-old male Wistar rats for 4 weeks and 8 weeks. The explants were assessed for new bone formation using hematoxylin and eosin (H&E) staining and von Kossa staining. Results The MSCs could attach and proliferate on all three groups of scaffolds. Interestingly, the ALP activity of MSCs reached the greatest value on day 7 after cultured on the scaffolds, whereas the calcium assay displayed the highest level of calcium in MSCs on day 28. Furthermore, weight percentages of calcium and phosphorus on the surface of MSCs after cultivation on the GCD scaffolds increased when compared to those on other scaffolds. The scanning electron microscopy images showed that MSCs attached and proliferated on the scaffold surface thoroughly over the cultivation time. Mineral crystal aggregation was evident in GC and greatly in GCD scaffolds. H&E staining illustrated that G, GC, and GCD scaffolds displayed osteoid after 4 weeks of implantation and von Kossa staining confirmed the mineralization at 8 weeks in G, GC, and GCD scaffolds. Conclusion The MSCs cultured in GCD scaffolds revealed greater osteogenic differentiation than those cultured in G and GC scaffolds. Additionally, the G, GC, and GCD scaffolds could promote in vivo ectopic bone formation in rat model. The GCD scaffolds exhibited maximum osteoinductive capability compared with others and may be potentially used for bone regeneration.

scholarly journals Scaffolds for Growth Factor Delivery as Applied to Bone Tissue Engineering

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
Keith A. Blackwood ◽  
Nathalie Bock ◽  
Tim R. Dargaville ◽  
Maria Ann Woodruff
Keyword(s):  
Tissue Engineering ◽  
Growth Factors ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Donor Site ◽  
Structural Features ◽  
Donor Site Morbidity ◽  
Tissue Type ◽  
Specific Cell ◽  
Growth Factor Delivery

There remains a substantial shortfall in the treatment of severe skeletal injuries. The current gold standard of autologous bone grafting from the same patient has many undesirable side effects associated such as donor site morbidity. Tissue engineering seeks to offer a solution to this problem. The primary requirements for tissue-engineered scaffolds have already been well established, and many materials, such as polyesters, present themselves as potential candidates for bone defects; they have comparable structural features, but they often lack the required osteoconductivity to promote adequate bone regeneration. By combining these materials with biological growth factors, which promote the infiltration of cells into the scaffold as well as the differentiation into the specific cell and tissue type, it is possible to increase the formation of new bone. However due to the cost and potential complications associated with growth factors, controlling the rate of release is an important design consideration when developing new bone tissue engineering strategies. This paper will cover recent research in the area of encapsulation and release of growth factors within a variety of different polymeric scaffolds.

Abstract 14839: High-resolution Spatiotemporal Changes in Dominant Frequency and Structural Organization During Persistent Atrial Fibrillation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Terrence Pong ◽  
Joy Aparicio Valenzuela ◽  
Kevin J Cyr ◽  
Cody Carlton ◽  
Sasank Sakhamuri ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
High Resolution ◽  
Structural Organization ◽  
Porcine Model ◽  
Dominant Frequency ◽  
Patient Specific ◽  
Structural Remodeling ◽  
Atrial Activity ◽  
Spatiotemporal Changes ◽  
Mapping Arrays

Introduction: Spatiotemporal differences in atrial activity are thought to contribute to the maintenance of atrial fibrillation (AF). While recent evidence has identified changes in dominant frequency (DF) during the transition from paroxysmal to persistent AF, little is known about the frequency characteristics of the epicardium during this transition. The purpose of this study was to perform high-resolution mapping of the atrial epicardium and to characterize changes in frequency activity and structural organization during the transition from paroxysmal to persistent AF. Hypothesis: In a porcine model of persistent AF, we tested the hypothesis that the epicardium undergoes spatiotemporal changes in atrial activity and structural organization during persistent AF. Methods: Paroxysmal and persistent AF was induced in adult Yorkshire swine by atrial tachypacing. Atrial morphology was segmented from magnetic resonance imaging and high-resolution patient-specific flexible mapping arrays were 3D printed to match the epicardial contours of the atria. Epicardial activation and DF mapping was performed in four paroxysmal and four persistent AF animals using personalized mapping arrays. Histological analysis was performed to determine structural differences between paroxysmal and persistent AF. Results: The left atrial epicardium was associated with a significant increase in DF between paroxysmal and persistent AF (6.5 ± 0.2 vs. 7.4 ± 0.5 Hz, P = 0.03). High-resolution spatiotemporal mapping identified organized clusters of DF during paroxysmal AF which were lost during persistent AF. The development of persistent AF led to structural remodeling with increased atrial epicardial fibrosis. The organization index (OI) significantly decreased during persistent AF in both the left atria (0.3 ± 0.03 vs. 0.2 ± 0.03, P = 0.01) and right atria (0.33 ± 0.04 vs. 0.23 ± 0.02, P = 0.02). Conclusions: In the porcine model of persistent AF, the epicardium undergoes structural remodeling with increased epicardial fibrosis, reflected by changes in atrial organization index and dominant frequency.

Abstract P392: The Effect Of Cell Sex On Magnetic Nanoparticle Uptake Of Human Induced Pluripotent Stem Cell-derived Cardiomyocytes

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Morteza Mahmoudi ◽  
Vahid Serpooshan ◽  
Phillip C Yang ◽  
Mahyar Heydarpour
Keyword(s):  
Heart Failure ◽  
Actin Filaments ◽  
Electromechanical Coupling ◽  
Critical Role ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
P Value ◽  
Male And Female ◽  
Cell Therapies ◽  
Human Cardiomyocytes

Introduction: It is well understood that the occurrence, progress, and treatment of heart failure, which is a leading cause of death worldwide, is sex-specific. Over the past decade, the majority of efforts in myocardial regeneration have been centered on cell-based cardiac repair. A promising cell source for these efforts is patient-specific human cardiomyocytes (CMs) differentiated from human inducible pluripotent stem cells (hiPSCs). However, successful use of hiPSC-CMs faces a major limitation, the poor engraftment and electromechanical coupling of transplanted cells with the host myocardial tissue. Magnetic nanoparticles (NPs) demonstrate great potential to address this challenge for treating heart failure via cell therapies. In particular, superparamagnetic iron oxide NPs (SPIONs) have been used to label hiPSC-CMs and, with the aid of external magnetic field, improve their engraftment and electromechanical coupling in the heart tissue. However, the critical role of cell sex in the uptake and labeling efficacy of NPs has not been evaluated. Hypothesis: Significant differences in the molecular and structural (e.g., actin structures and distribution) characteristics of male and female hiPSC-CMs affect their labeling efficacy with SPIONs. Methods and Results: To test our hypothesis, we first performed RNA-Seq analysis on three male and three female (healthy) hiPSC-CM lines. The normalized outcomes were analyzed by edgeR package. We next calculated gene-expression differential between male and female CMs. The results revealed 58 genes with significant differences between the male and female cells (p-value < 0.01). The highest observed sex-specific variation in genes was related to tophit gene (MEG3: logFC = 7.32, P-value = 5.63e -06 ), which is the maternally expressed imprinted gene with a great role in cardiac angiogenesis. Among the identified genes, a number of those were related to the cellular cytoskeletal structures including actin. We probed possible structural differences between actin filaments organization and distribution of male and female hiPSC-CMs using the stochastic optical reconstruction microscopy (STORM) technique. The results demonstrated substantial differences in organization, distribution, and morphology of actin filaments between male and female CMs. Incubation of SPIONs with male and female hiPSC-CMs revealed higher uptake of NPs (~ 3 folds) in female cells as compared to the male cells. The significant differences in the uptake of SPIONs by male vs. female cells could be attributed to the distinct organization, distribution, and morphology of actin in male vs. female cells. Conclusions: Our results indicate that male and female hiPSCs-CMs respond differently to the labeling SPIONs.

Cell cycle regulatory proteins in renal disease: role in hypertrophy, proliferation, and apoptosis

2000 ◽  
Vol 278 (4) ◽  
pp. F515-F529 ◽  
Author(s):  
Stuart J. Shankland ◽  
Gunter Wolf
Keyword(s):  
Cell Cycle ◽  
Renal Function ◽  
Renal Disease ◽  
Cell Injury ◽  
Critical Role ◽  
Regulatory Proteins ◽  
Specific Cell ◽  
Cell Cycle Proteins ◽  
Proliferation And Apoptosis ◽  
Cell Cycle Regulatory Proteins

The response to glomerular and tubulointerstitial cell injury in most forms of renal disease includes changes in cell number (proliferation and apoptosis) and cell size (hyerptrophy). These events typically precede and may be reponsible for the accumulation of extracellular matrix proteins that leads to a decrease in renal function. There is increasing evidence showing that positive (cyclins and cyclin-dependent kinases) and negative (cyclin-dependent kinase inhibitors) cell cycle regulatory proteins have a critical role in regulating these fundamental cellular responses to immune and nonimmune forms of injury. Data now show that altering specific cell cycle proteins affects renal cell proliferation and improves renal function. Equally exciting is the expanding body of literature showing novel biological roles for cell cycle proteins in the regulation of cell hypertrophy and apoptosis. With increasing understanding of the role for cell cyle regulatory proteins in renal disease comes the hope for potential therapeutic inverventions.

scholarly journals Studying and modulating schizophrenia-associated dysfunctions of oligodendrocytes with patient-specific cell systems

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Florian J. Raabe ◽  
Sabrina Galinski ◽  
Sergi Papiol ◽  
Peter G. Falkai ◽  
Andrea Schmitt ◽  
...  
Keyword(s):  
Patient Specific ◽  
Specific Cell ◽  
Cell Systems
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