scholarly journals Gene expression during osteogenic differentiation in mandibular condyles in vitro.

1990 ◽  
Vol 110 (4) ◽  
pp. 1369-1378 ◽  
Author(s):  
P G Strauss ◽  
E I Closs ◽  
J Schmidt ◽  
V Erfle

The cartilagenous tissue of mandibular condyles of newborn mice contains progenitor cells as well as young and mature chondrogenic cells. During in vitro cultivation of the tissue, progenitor cells undergo osteogenic differentiation and form new bone (Silbermann, M., D. Lewinson, H. Gonen, M. A. Lizarbe, and K. von der Mark. 1983. Anat. Rec. 206:373-383). We have studied the expression of genes that typify osteogenic differentiation in mandibular condyles during in vitro cultivation. RNAs of the genes for collagen type I, osteonectin, alkaline phosphatase, and bone gla protein were sequentially expressed in progenitor cells and hypertrophic chondrocytes during culture. Osteopontin expression peaked in both the early and the late phase of the differentiation process. The data indicate a distinct sequence of expression of osteoblast-specific genes during osteogenic differentiation and new bone formation in mandibular condyles.

Author(s):  
Hebe Agustina Mena ◽  
Paula Romina Zubiry ◽  
Blandine Dizier ◽  
Virginie Mignon ◽  
Fernanda Parborell ◽  
...  

Objective: Ceramide 1-phosphate (C1P) is a bioactive sphingolipid highly augmented in damaged tissues. Because of its abilities to stimulate migration of murine bone marrow–derived progenitor cells, it has been suggested that C1P might be involved in tissue regeneration. In the present study, we aimed to investigate whether C1P regulates survival and angiogenic activity of human progenitor cells with great therapeutic potential in regenerative medicine such as endothelial colony–orming cells (ECFCs). Approach and Results: C1P protected ECFC from TNFα (tumor necrosis factor-α)-induced and monosodium urate crystal–induced death and acted as a potent chemoattractant factor through the activation of ERK1/2 (extracellular signal-regulated kinases 1 and 2) and AKT pathways. C1P treatment enhanced ECFC adhesion to collagen type I, an effect that was prevented by β1 integrin blockade, and to mature endothelial cells, which was mediated by the E-selectin/CD44 axis. ECFC proliferation and cord-like structure formation were also increased by C1P, as well as vascularization of gel plug implants loaded or not with ECFC. In a murine model of hindlimb ischemia, local administration of C1P alone promoted blood perfusion and reduced necrosis in the ischemic muscle. Additionally, the beneficial effects of ECFC infusion after ischemia were amplified by C1P pretreatment, resulting in a further and significant enhancement of leg reperfusion and muscle repair. Conclusions: Our findings suggest that C1P may have therapeutic relevance in ischemic disorders, improving tissue repair by itself, or priming ECFC angiogenic responses such as chemotaxis, adhesion, proliferation, and tubule formation, which result in a better outcome of ECFC-based therapy.


Blood ◽  
2012 ◽  
Vol 119 (25) ◽  
pp. 6162-6171 ◽  
Author(s):  
Nicolas Ricard ◽  
Delphine Ciais ◽  
Sandrine Levet ◽  
Mariela Subileau ◽  
Christine Mallet ◽  
...  

Abstract ALK1 is a type I receptor of the TGF-β family that is involved in angiogenesis. Circulating BMP9 was identified as a specific ligand for ALK1 inducing vascular quiescence. In this work, we found that blocking BMP9 with a neutralizing antibody in newborn mice significantly increased retinal vascular density. Surprisingly, Bmp9-KO mice did not show any defect in retinal vascularization. However, injection of the extracellular domain of ALK1 impaired retinal vascularization in Bmp9-KO mice, implicating another ligand for ALK1. Interestingly, we detected a high level of circulating BMP10 in WT and Bmp9-KO pups. Further, we found that injection of a neutralizing anti-BMP10 antibody to Bmp9-KO pups reduced retinal vascular expansion and increased vascular density, whereas injection of this antibody to WT pups did not affect the retinal vasculature. These data suggested that BMP9 and BMP10 are important in postnatal vascular remodeling of the retina and that BMP10 can substitute for BMP9. In vitro stimulation of endothelial cells by BMP9 and BMP10 increased the expression of genes involved in the Notch signaling pathway (Jagged1, Dll4, Hey1, Hey2, Hes1) and decreased apelin expression, suggesting a possible cross-talk between these pathways and the BMP pathway.


1990 ◽  
Vol 111 (3) ◽  
pp. 1313-1323 ◽  
Author(s):  
E I Closs ◽  
A B Murray ◽  
J Schmidt ◽  
A Schön ◽  
V Erfle ◽  
...  

We have investigated the temporal pattern of expression of c-fos in cartilage cells in mouse mandibular condyles. During in vitro cultivation, the progenitor cells in this organ differentiate to osteoblasts, and hypertrophic chondrocytes start to show features indicative of osteogenic differentiation. Prior to these processes we observed two distinct patterns of c-fos expression. High, transient c-fos expression was found in the entire tissue within 30 min of culture. This type of c-fos expression appeared to result from mechanical forces applied during dissection. The second type of c-fos expression appeared in individual cells in the zone of hypertrophic chondrocytes. A varying number of formerly quiescent chondrocytes expressed high levels of c-fos mRNA after between 30 min and 10 d in culture, with a peak in the number of cells between days 1 and 3. c-fos expression in these cartilage cells was followed by DNA replication and expression of genes typifying osteoblastic differentiation. After 7 d in culture, groups of cells with the typical ultrastructural features of osteoblasts, and surrounded by an osteoid-like matrix, were observed in single chondrocyte-type lacunae, suggesting division of chondrocytes and differentiation to osteoblasts. The data suggest that c-fos may play a crucial role in the perturbation of determined pathways of skeletoblast differentiation and in the regulation of endochondral bone formation.


2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.


1991 ◽  
Vol 274 (2) ◽  
pp. 615-617 ◽  
Author(s):  
P Kern ◽  
M Menasche ◽  
L Robert

The biosynthesis of type I, type V and type VI collagens was studied by incubation of calf corneas in vitro with [3H]proline as a marker. Pepsin-solubilized collagen types were isolated by salt fractionation and quantified by SDS/PAGE. Expressed as proportions of the total hydroxyproline solubilized, corneal stroma comprised 75% type I, 8% type V and 17% type VI collagen. The rates of [3H]proline incorporation, linear up to 24 h for each collagen type, were highest for type VI collagen and lowest for type I collagen. From pulse-chase experiments, the calculated apparent half-lives for types I, V and VI collagens were 36 h, 10 h and 6 h respectively.


Author(s):  
Michel Haagdorens ◽  
Elle Edin ◽  
Per Fagerholm ◽  
Marc Groleau ◽  
Zvi Shtein ◽  
...  

Abstract Purpose To determine feasibility of plant-derived recombinant human collagen type I (RHCI) for use in corneal regenerative implants Methods RHCI was crosslinked with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) to form hydrogels. Application of shear force to liquid crystalline RHCI aligned the collagen fibrils. Both aligned and random hydrogels were evaluated for mechanical and optical properties, as well as in vitro biocompatibility. Further evaluation was performed in vivo by subcutaneous implantation in rats and corneal implantation in Göttingen minipigs. Results Spontaneous crosslinking of randomly aligned RHCI (rRHCI) formed robust, transparent hydrogels that were sufficient for implantation. Aligning the RHCI (aRHCI) resulted in thicker collagen fibrils forming an opaque hydrogel with insufficient transverse mechanical strength for surgical manipulation. rRHCI showed minimal inflammation when implanted subcutaneously in rats. The corneal implants in minipigs showed that rRHCI hydrogels promoted regeneration of corneal epithelium, stroma, and nerves; some myofibroblasts were seen in the regenerated neo-corneas. Conclusion Plant-derived RHCI was used to fabricate a hydrogel that is transparent, mechanically stable, and biocompatible when grafted as corneal implants in minipigs. Plant-derived collagen is determined to be a safe alternative to allografts, animal collagens, or yeast-derived recombinant human collagen for tissue engineering applications. The main advantage is that unlike donor corneas or yeast-produced collagen, the RHCI supply is potentially unlimited due to the high yields of this production method. Lay Summary A severe shortage of human-donor corneas for transplantation has led scientists to develop synthetic alternatives. Here, recombinant human collagen type I made of tobacco plants through genetic engineering was tested for use in making corneal implants. We made strong, transparent hydrogels that were tested by implanting subcutaneously in rats and in the corneas of minipigs. We showed that the plant collagen was biocompatible and was able to stably regenerate the corneas of minipigs comparable to yeast-produced recombinant collagen that we previously tested in clinical trials. The advantage of the plant collagen is that the supply is potentially limitless.


2017 ◽  
Vol 312 (3) ◽  
pp. G219-G227 ◽  
Author(s):  
Leonie Beljaars ◽  
Sara Daliri ◽  
Christa Dijkhuizen ◽  
Klaas Poelstra ◽  
Reinoud Gosens

WNT-5A is a secreted growth factor that belongs to the noncanonical members of the Wingless-related MMTV-integration family. Previous studies pointed to a connection between WNT-5A and the fibrogenic factor TGF-β warranting further studies into the functional role of WNT-5A in liver fibrosis. Therefore, we studied WNT-5A expressions in mouse and human fibrotic livers and examined the relation between WNT-5A and various fibrosis-associated growth factors, cytokines, and extracellular matrix proteins. WNT-5A gene and protein expressions were significantly increased in fibrotic mouse and human livers compared with healthy livers. Regression or therapeutic intervention in mice resulted in decreased hepatic WNT-5A levels paralleled by lower collagen levels. Immunohistochemical analysis showed WNT-5A staining in fibrotic septa colocalizing with desmin staining indicating WNT-5A expression in myofibroblasts. In vitro studies confirmed WNT-5A expression in this cell type and showed that TGF-β significantly enhanced WNT-5A expression in contrast to PDGF-BB and proinflammatory cytokines IL-1β and TNF-α. Additionally, TGF-β induces the expression of the WNT receptors FZD2 and FZD8. After silencing of WNT-5A, reduced levels of collagen type I, vimentin, and fibronectin in TGF-β-stimulated myofibroblasts were measured compared with nonsilencing siRNA-treated controls. Interestingly, the antifibrotic cytokine IFNγ suppressed WNT-5A in vitro and in vivo. IFNγ-treated fibrotic mice showed significantly less WNT-5A expression compared with untreated fibrotic mice. In conclusion, WNT-5A paralleled collagen I levels in fibrotic mouse and human livers. WNT-5A expression in myofibroblasts is induced by the profibrotic factor TGF-β and plays an important role in TGF-β-induced regulation of fibrotic matrix proteins, whereas its expression can be reversed upon treatment, both in vitro and in vivo. NEW & NOTEWORTHY This study describes the localization and functional role of WNT-5A in human and mouse fibrotic livers. Hepatic WNT-5A expression parallels collagen type I expression. In vivo and in vitro, the myofibroblasts were identified as the key hepatic cells producing WNT-5A. WNT-5A is under control of TGF-β and its activities are primarily profibrotic.


2010 ◽  
Vol 298 (2) ◽  
pp. H608-H613 ◽  
Author(s):  
Lavinia Tran ◽  
Andrew R. Kompa ◽  
Will Kemp ◽  
Arintaya Phrommintikul ◽  
Bing H. Wang ◽  
...  

The vasoactive peptide urotensin-II (U-II) is likely to play a key causal role in cardiac remodeling that ultimately leads to heart failure. Its contribution, specifically to the development of diastolic dysfunction and the downstream intracellular signaling, however, remains unresolved. This study interrogates the effect of chronic U-II infusion in normal rats on cardiac structure and function. The contribution of Rho kinase (ROCK) signaling to these pathophysiological changes is evaluated in cell culture studies. Chronic high-dose U-II infusion over 4 wk significantly impaired diastolic function in rats on echocardiography-derived Doppler indexes, including E-wave deceleration time (vehicle 56.7 ± 3.3 ms, U-II 118.0 ± 21.5 ms; P < 0.01) and mitral valve annulus peak early/late diastolic tissue velocity (vehicle 2.01 ± 0.19 ms, U-II 1.04 ± 0.25 ms; P < 0.01). A lower dose of U-II infusion (1 nmol·kg−1·h−1) yielded comparable changes. Diastolic dysfunction was accompanied by molecular [significant increases in procollagen-α1(I) gene expression on real-time PCR] and morphological (increases in total collagen, P < 0.05, and collagen type-I protein deposition, P < 0.001) evidence of left ventricular (LV) fibrosis following high-dose U-II infusion. The ROCK inhibitor GSK-576371 (10−7 to 10−5 M) elicited concentration-dependent inhibition of U-II (10−7 M)-stimulated cardiac fibroblast collagen synthesis and cardiac myocyte protein synthesis. Chronic U-II infusion causes diastolic dysfunction, caused by fibrosis of the LV. The in vitro data suggest that this may be in part occurring via a ROCK-dependent pathway.


2009 ◽  
Vol 423 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Sebastian Kalamajski ◽  
Anders Aspberg ◽  
Karin Lindblom ◽  
Dick Heinegård ◽  
Åke Oldberg

The interactions of the ECM (extracellular matrix) protein asporin with ECM components have previously not been investigated. Here, we show that asporin binds collagen type I. This binding is inhibited by recombinant asporin fragment LRR (leucine-rich repeat) 10–12 and by full-length decorin, but not by biglycan. We demonstrate that the polyaspartate domain binds calcium and regulates hydroxyapatite formation in vitro. In the presence of asporin, the number of collagen nodules, and mRNA of osteoblastic markers Osterix and Runx2, were increased. Moreover, decorin or the collagen-binding asporin fragment LRR 10–12 inhibited the pro-osteoblastic activity of full-length asporin. Our results suggest that asporin and decorin compete for binding to collagen and that the polyaspartate in asporin directly regulates collagen mineralization. Therefore asporin has a role in osteoblast-driven collagen biomineralization activity. We also show that asporin can be expressed in Escherichia coli (Rosetta-gami™) with correctly positioned cysteine bridges, and a similar system can possibly be used for the expression of other SLRPs (small LRR proteoglycans/proteins).


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