scholarly journals Impact ofItga2-Gp6-double collagen receptor deficient mice for bone marrow megakaryocytes and platelets

2019 ◽  
Author(s):  
Daniela Semeniak ◽  
Kristina Faber ◽  
Patricia Öftering ◽  
Georgi Manukjan ◽  
Harald Schulze
Keyword(s):  
Bone Marrow ◽  
Collagen Type ◽  
Thrombus Formation ◽  
Collagen Type I ◽  
Type I ◽  
Marrow Cavity ◽  
Type Iv ◽  
Collagen Receptors ◽  
Flow Cytometric ◽  
Vessel Injury

ABSTRACTThe two main collagen receptors on platelets, GPVI and integrin α2β1, play an important role for the recognition of exposed collagen at sites of vessel injury, which leads to platelet activation and subsequently stable thrombus formation. Both receptors are already expressed on megakaryocytes, the platelet forming cells within the bone marrow. Megakaryocytes are in permanent contact with collagen filaments in the marrow cavity and at the basal lamina of sinusoids without obvious preactivation. The role of both collagen receptors for megakaryocyte maturation and thrombopoiesis is still poorly understood. To investigate the function of both collagen receptors, we generated mice that are double deficient forGp6andItga2. Flow cytometric analyses revealed that the deficiency of both receptors had no impact on platelet number and the expected lack in GPVI responsiveness. Integrin activation and degranulation ability was comparable to wildtype mice. By immunofluorescence microscopy, we could demonstrate that double-deficient megakaryocytes were overall normally distributed within the bone marrow. We found megakaryocyte count and size to be normal, the localization within the bone marrow, the degree of maturation, as well as their association to sinusoids were also unaltered. However, the contact of megakaryocytes to collagen type I filaments was decreased at sinusoids compared to wildtype mice, while the interaction to type IV collagen was unaffected. Our results imply that GPVI and α2β1 have no influence on the localization of megakaryocytes within the bone marrow, their association to the sinusoids or their maturation. The decreased contact of megakaryocytes to collagen type I might at least partially explain the unaltered platelet phenotype in these mice, since proplatelet formation is mediated by these receptors and their interaction to collagen. It is rather likely that other compensatory signaling pathways and receptors play a role that needs to be elucidated.

scholarly journals Confocal Blood Flow Videomicroscopy of Thrombus Formation over Human Arteries and Local Targeting of P2X7

2021 ◽  
Vol 22 (8) ◽  
pp. 4066
Author(s):  
Patrizia Marchese ◽  
Maria Lombardi ◽  
Maria Elena Mantione ◽  
Domenico Baccellieri ◽  
David Ferrara ◽  
...  
Keyword(s):  
Blood Flow ◽  
Vascular Function ◽  
Collagen Type ◽  
Thrombus Formation ◽  
Collagen Type I ◽  
Type I ◽  
Prevention Therapy ◽  
Healthy Donors ◽  
Internal Mammary ◽  
Human Arteries

Atherothrombosis exposes vascular components to blood. Currently, new antithrombotic therapies are emerging. Herein we investigated thrombogenesis of human arteries with/without atherosclerosis, and the interaction of coagulation and vascular components, we and explored the anti-thrombogenic efficacy of blockade of the P2X purinoceptor 7 (P2X7). A confocal blood flow videomicroscopy system was performed on cryosections of internal mammary artery (IMA) or carotid plaque (CPL) determining/localizing platelets and fibrin. Blood from healthy donors elicited thrombi over arterial layers. Confocal microscopy associated thrombus with tissue presence of collagen type I, laminin, fibrin(ogen) and tissue factor (TF). The addition of antibodies blocking TF (aTF) or factor XI (aFXI) to blood significantly reduced fibrin deposition, variable platelet aggregation and aTF + aFXI almost abolished thrombus formation, showing synergy between coagulation pathways. A scarce effect of aTF over sub-endothelial regions, more abundant in tissue TF and bundles of laminin and collagen type I than deep intima, may suggest tissue thrombogenicity as molecular structure-related. Consistently with TF-related vascular function and expression of P2X7, the sections from CPL but not IMA tissue cultures pre-treated with the P2X7 antagonist A740003 demonstrated poor thrombogenesis in flow experiments. These data hint to local targeting studies on P2X7 modulation for atherothrombosis prevention/therapy.

scholarly journals TOB1 Deficiency Enhances the Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Tendon-Bone Healing in a Rat Rotator Cuff Repair Model

2016 ◽  
Vol 38 (1) ◽  
pp. 319-329 ◽  
Author(s):  
Yulei Gao ◽  
Yinquan Zhang ◽  
Yanghu Lu ◽  
Yi Wang ◽  
Xingrui Kou ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Rotator Cuff ◽  
Bone Healing ◽  
Rotator Cuff Repair ◽  
Collagen Type ◽  
Collagen Type I ◽  
Type I ◽  
Cuff Repair

Background/Aims: This study investigated the effect of silencing TOB1 (Transducer of ERBB2, 1) expression in bone marrow-derived mesenchymal stem cells (MSCs) on MSC-facilitated tendon-bone healing in a rat supraspinatus repair model. Methods: Rat MSCs were transduced with a recombinant lentivirus encoding short hairpin RNA (shRNA) against TOB1. MSC cell proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The effect of MSCs with TOB1 deficiency on tendon-bone healing in a rat rotator cuff repair model was evaluated by biomechanical testing, histological analysis and collagen type I and II gene expression. An upstream regulator (miR-218) of TOB1 was determined in MSCs. Results: We found that knockdown of TOB1 significantly increased the proliferative activity of rat MSCs in vitro. When MSCs with TOB1 deficiency were injected into injured rat supraspinatus tendon-bone junctions, the effect on tendon-bone healing was enhanced compared to treatment with control MSCs with normal TOB1 expression, as evidenced by elevated levels of ultimate load to failure and stiffness, increased amount of fibrocartilage and augmented expression of collagen type I and type II genes. In addition, we found that the TOB1 3′ untranslated region is a direct target of miR-218. Similar to the effect of TOB1 deficiency, overexpression of miR-218 effectively promoted tendon-bone healing in rat. Conclusion: These results suggest that TOB1 may play a negative role in the effect of MSCs on tendon-bone healing, and imply that expression of TOB1 may be regulated by miR-218.

Selective increase in the binding of the alpha 1 beta 1 integrin for collagen type IV during neurite outgrowth of human neuroblastoma TR 14 cells

1994 ◽  
Vol 107 (12) ◽  
pp. 3379-3392
Author(s):  
G. Carmeliet ◽  
B. Himpens ◽  
J.J. Cassiman
Keyword(s):  
Neurite Outgrowth ◽  
Collagen Type ◽  
Collagen Type I ◽  
Collagen Type Iv ◽  
Type I ◽  
Human Neuroblastoma ◽  
Specific Antibodies ◽  
Type Iv ◽  
Beta 1 Integrin ◽  
In Cells

Regulation of beta 1 integrins in neurite outgrowth following N6,2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate (dBcAMP) treatment was investigated using the human neuroblastoma cell line TR 14. Three beta 1 integrins were identified: the alpha 1 beta 1 receptor bound collagen type I, collagen type IV and probably laminin; the alpha 2 beta 1 integrin bound collagen type I; and the alpha v beta i receptor bound fibronectin. Neurite extension was detectable as early as 30 minutes following dBcAMP treatment, was maximal after 24 hours and remained constant during treatment for 4 days. Adhesion-perturbing beta 1 subunit-specific antibodies, added together with dBcAMP, prevented the outgrowth of new neurites. During the first 24 hours of neurite outgrowth, no change was observed in the amount of beta 1 integrins nor in their topographic distribution. However, dBcAMP treatment increased the binding of alpha 1 beta 1 receptors to collagen type IV-Sepharose by a factor 2.3 +/- 0.6 (P < 0.02), while no alteration in the binding to collagen type I was detected. Moreover, neurites and growth cones were immunoreactive for collagen type IV but not for collagen type I. Consistently dBcAMP-induced neurite outgrowth was inhibited by adhesion-perturbing alpha 1 subunit-specific antibodies. Following maximal neurite outgrowth, the amount of beta 1 integrins determined by immunoprecipitation and by confocal microscopy decreased to 58.3 +/- 11.2% (P < 0.001) and to 55.4 +/- 17.5% (P < 0.001) of untreated levels, respectively, without any change in the level of beta 1 mRNA or de novo synthesized beta 1 precursor. However, pulse-chase experiments showed an increased turnover of the beta 1 subunit: the amount of beta 1 precursor that was degraded after 1 hour chase was 50.5 +/- 8.4% in cells treated for 4 days and 34.2 +/- 3.9% in untreated cells (P < 0.02); the amount of mature beta 1 after 24 hours chase was smaller in cells treated for 4 days compared to untreated cells. In conclusion, during neurite outgrowth, alpha 1 beta 1 integrins are required and acquire an enhanced binding activity for collagen type IV; but following maximal neurite outgrowth, expression of beta 1 integrins is reduced.

scholarly journals BM-MSCs differentiated to chondrocytes for treatment of full-thickness cartilage defect of the knee

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Rodrigo Mardones ◽  
Alessio Giai Via ◽  
Gennaro Pipino ◽  
Claudio M. Jofre ◽  
Sara Muñoz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Articular Cartilage ◽  
Cartilage Defect ◽  
Collagen Type ◽  
Oxford Knee Score ◽  
Collagen Type I ◽  
Type I ◽  
Knee Score ◽  
Full Thickness

Abstract Background Full-thickness articular cartilage injury of the knee is a major cause of disability. The aim of this study is to assess the outcome of patients treated with differentiated to chondrocytes bone marrow mesenchymal stem cells (BM-MSCs) cultured on a collagen type I/III (Chondro-Gide®) scaffold. The secondary aim was to confirm the absence of adverse events. Methods Fifteen patients (19 knees) with symptomatic full-thickness cartilage defects of the knee were enrolled. Bone marrow was harvested from the iliac crest, BM-MSCs were prepared, and expanded cells were grown in a standard medium or in a standard culture medium containing TGF-β. BM-MSCs differentiated to chondrocytes were seeded in a porcine collagen type I/III scaffold (Chondro-Gide®) and cultured in TGF-β containing media. After 4 weeks, the membrane was sutured on the cartilage defect. All patients underwent plain radiographs (antero-posterior, lateral, and axial view of the patella) and MRI of the affected knee. The Oxford knee score, the Lyhsolm scale, and the VAS score were administered to all patients. At final follow-up a MRI for the study of articular cartilage was undertaken. Results The mean size of the cartilage lesions was 20 × 17 mm (range, 15 × 10 mm–30 × 30 mm). At final follow-up, the median Oxford knee score and Lyhsolm scale scores significantly improved from 29 (range 12–39; SD 7.39) to 45 (range 24–48; SD 5.6) and from 55.5 (range 25–81; SD 17.7) to 94.5 (58–100; SD 10.8), respectively. Pain, according to the VAS score, significantly improved. Sixty percent of patients reported their satisfaction as excellent, 20% as good, 14% as fair, and 1 patient as poor. Conclusion The treatment of full-thickness chondral injuries of the knee with differentiated to chondrocytes BM-MSCs and Chondro-Gide® scaffold showed encouraging outcomes. Further studies involving more patients, and with longer follow-up, are required to evaluate the effectiveness of the treatment and the long-term results.

scholarly journals Biological Characteristics and Osteogenic Differentiation of Ovine Bone Marrow Derived Mesenchymal Stem Cells Stimulated with FGF-2 and BMP-2

2020 ◽  
Vol 21 (24) ◽  
pp. 9726
Author(s):  
Sandra Gromolak ◽  
Agnieszka Krawczenko ◽  
Agnieszka Antończyk ◽  
Krzysztof Buczak ◽  
Zdzisław Kiełbowicz ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Collagen Type ◽  
Collagen Type I ◽  
Biological Characteristics ◽  
Immunofluorescent Staining ◽  
Type I ◽  
Differentiation Potential

Cell-based therapies using mesenchymal stem cells (MSCs) are a promising tool in bone tissue engineering. Bone regeneration with MSCs involves a series of molecular processes leading to the activation of the osteoinductive cascade supported by bioactive factors, including fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 (BMP-2). In this study, we examined the biological characteristics and osteogenic differentiation potential of sheep bone marrow MSCs (BM-MSCs) treated with 20 ng/mL of FGF-2 and 100 ng/mL BMP-2 in vitro. The biological properties of osteogenic-induced BM-MSCs were investigated by assessing their morphology, proliferation, phenotype, and cytokine secretory profile. The osteogenic differentiation was characterized by Alizarin Red S staining, immunofluorescent staining of osteocalcin and collagen type I, and expression levels of genetic markers of osteogenesis. The results demonstrated that BM-MSCs treated with FGF-2 and BMP-2 maintained their primary MSC properties and improved their osteogenic differentiation capacity, as confirmed by increased expression of osteocalcin and collagen type I and upregulation of osteogenic-related gene markers BMP-2, Runx2, osterix, collagen type I, osteocalcin, and osteopontin. Furthermore, sheep BM-MSCs produced a variety of bioactive factors involved in osteogenesis, and supplementation of the culture medium with FGF-2 and BMP-2 affected the secretome profile of the cells. The results suggest that sheep osteogenic-induced BM-MSCs may be used as a cellular therapy to study bone repair in the preclinical large animal model.

Immunohistochemical Localization of Collagen Types I, III, and IV, Laminin, Fibronectin, and Keratin in the Endolymphatic Sac

2000 ◽  
Vol 109 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Teruhiko Harada ◽  
Youngki Kim ◽  
Steven K. Juhn ◽  
Yasuo Sakakura
Keyword(s):  
Collagen Type ◽  
Collagen Type I ◽  
Immunohistochemical Localization ◽  
Basement Membranes ◽  
Endolymphatic Sac ◽  
Type I ◽  
Collagen Types ◽  
Type Iv ◽  
Baseline Information ◽  
Subepithelial Layer

We have employed immunohistochemistry to obtain baseline information on the molecular constituents of the extracellular matrix (ECM) of the endolymphatic duct (ED) and endolymphatic sac (ES) of the chinchilla. The results demonstrated that collagen types I and III were distributed in the subepithelial layer in the ED and ES, type IV collagen and laminin in the basement membranes, and fibronectin in the subepithelial layer and partly in the conglomerated cells in the ES. Collagen type III was diffusely distributed in the whole subepithelial layer of the ES, whereas collagen type I was concentrated densely in the deep layer of the interstitium, although gradually, the cuboidal epithelium in the ES was transformed into a flatter type in the ED. The epithelial cells of the ED and ES were clearly positive for keratin. This study deals, in particular, with the normal distribution of ECM components of the ED and ES of the chinchilla.

Elevated Threshold Shear Rate for the Dependence of Glycoprotein Ibα-Mediated Platelet Thrombus Formation onto Immobilized von Willebrand Factor in Mouse Blood.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3662-3662
Author(s):  
Patrizia Marchese ◽  
Taisuke Kanaji ◽  
Denisa D. Wagner ◽  
Jerry Ware ◽  
Zaverio M. Ruggeri
Keyword(s):  
Shear Rate ◽  
Collagen Type ◽  
Thrombus Formation ◽  
Collagen Type I ◽  
Type I ◽  
Shear Rates ◽  
Normal Platelet ◽  
Platelet Thrombus ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The interaction between platelet glycoprotein (GP) Ibα and von Willebrand Factor (VWF) is essential to initiate platelet deposition at sites of vascular injury and sustain platelet thrombus formation when the shear rate exceeds a threshold value. With human blood, the dependence of normal platelet adhesion and aggregation on VWF-GP Ibα function becomes evident at shear rates above 1,000 s−1. In the last several years, mouse models have been increasingly used to study the mechanisms of thrombus formation in circulating blood, and mice deficient in both VWF and GP Ibα have been generated. These animals offer the opportunity to evaluate whether the pathways of platelet adhesion and aggregation mediated by VWF and GP Ibα are equally important in mouse and human blood as well as to define the threshold shear rate at which the function of these pathways may become essential in the mouse circulation. To address this issue, we used an ex vivo perfusion system using fibrillar collagen type I as the thrombogenic surface and a flow chamber in which the shear rate varied according to a predictable function from the inlet to the outlet in relation to the x,y position in the flow path. Thus, wall shear rates between 5,000 at the inlet and 0 s−1 at the outlet could be evaluated in a single experiment, allowing a precise definition of the threshold at which platelet deposition on the surface could initiate. In these studies we used wild type control animals (WT), mice deficient in VWF (VWF-KO) and mice in which most of the extracellular domain of GP Ibα was replaced by a domain of the human interleukin 4 receptor (GPIb-KO/IL-4R). In the latter case, the ligand binding function of GP Ibα was obliterated, but unlike in GP Ib-KO mice platelet morphology and count were essentially normal. Blood was obtained from the retroorbital vein plexus and contained 100 u/ml heparin as an anticoagulant. Experiments were recorded in real time for the visualization of platelet-surface contacts and confocal videomicroscopy was used for the direct measurement of platelet thrombus volume. With normal mouse blood, platelet formed large thrombi throughout the tested range of shear rates. In contrast, with VWF-KO and GPIb-KO/IL-4R blood, thrombus volume was less than 5% of normal at 5,000 s−1, approximately 50% of normal at 3,000 s−1, but entirely normal at 1,500 s−1. Essentially the same results were observed when the extracellular matrix of mouse fibroblasts, which may better represent the complex thrombogenic properties of the vascular wall, was used as a reactive substrate instead of isolated collagen type I. The different threshold shear rate at which VWF and GP Ibα function are essential for thrombus formation with human and mouse platelets may be explained by the smaller size of the latter, which consequently are subjected to a lower drag at equivalent shear rate levels. Moreover, the similar behavior of VWF-KO and GPIb-KO/IL-4R platelets suggests that, under the conditions of these studies, VWF binding is the predominant GP Ibα function required for normal platelet thrombus formation at high shear rates. The present results should allow a more critical evaluation of the findings derived from mouse models of hemostasis and thrombosis.

scholarly journals BM-MSCs differentiated to chondrocytes for treatment of full-thickness cartilage defect of the knee

2020 ◽  
Author(s):  
Rodrigo Mardones ◽  
Alessio Giai Via ◽  
Gennaro Pipino ◽  
Claudio Jofrè ◽  
Sara Muñoz ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Articular Cartilage ◽  
Cartilage Defect ◽  
Collagen Type ◽  
Oxford Knee Score ◽  
Collagen Type I ◽  
Type I ◽  
Knee Score ◽  
Full Thickness

Abstract Background Full-thickness articular cartilage injury of the knee is a major cause of disability. The aim of this study is to assess the results of patients treated with differentiated to chondrocytes bone marrow Mesenchymal Stem Cells (BM-MSCs) cultured on a collagen Type I/III (Chondro-Gide®) scaffold. The secondary aim was to confirm the absence of adverse events. Methods Fifteen patients (19 knees) with symptomatic full-thickness cartilage defects of the knee have been enrolled for the study. Bone marrow was harvested from the iliac crest, BM-MSCs were prepared, and expanded cells were grown in a standard medium or in a standard culture medium containing TGF-β. BM-MSCs differentiated to chondrocytes were seeded in a porcine collagen Type I/III scaffold (Chondro-Gide®), and cultured in TGF- β containing media. After 4 weeks, the membrane was sutured on the cartilage defect. All patients underwent plain radiographs of the knee (antero-posterior, lateral, and axial view of the patella), and MRI of the affected knee. The Oxford knee score, the Lyhsolm scale, and the VAS score were administered to all patients. At final follow-up a MRI for the study of articular cartilage was undertaken. Results The mean size of the cartilage lesions was 20 × 17 mm (range, 15 × 10 mm − 30 × 30 mm). At final follow-up, the median Oxford knee score and Lyhsolm scale scores significantly improved from 29 (range 12–39; SD 7,39) to 45 (range 24–48; SD 5,6) and from 55.5 (range 25–81; SD 17,7) to 94.5 (58–100; SD 10,8) respectively. Pain, according the VAS score, significantly improved. 60% of patients reported their satisfaction as excellent, 20% as good, 14% as fair, and 1 patient as poor. Conclusion The treatment of full-thickness chondral injuries of the knee with differentiated to chondrocytes BM-MSCs and Chondro-Gide® scaffold showed encouraging outcomes. Further studies involving more patients, and with longer follow-up, are required in order to evaluate the effectiveness of the treatment and the long-term results.

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