scholarly journals Elastin synthesis by ligamentum nuchae fibroblasts: effects of culture conditions and extracellular matrix on elastin production.

1981 ◽  
Vol 90 (2) ◽  
pp. 332-338 ◽  
Author(s):  
R P Mecham ◽  
G Lange ◽  
J Madaras ◽  
B Starcher

Fetal bovine ligamentum nuchae fibroblasts maintained in culture synthesized soluble elastin but were unable to form the insoluble elastic fiber. Secreted elastin precursors accumulated in culture medium and were measured using a radioimmunoassay for elastin. When elastin production was examined in ligament tissue from fetal calves of various gestational ages, cells from tissue taken during the last trimester of development produced significantly more elastin than did cells from younger fetal tissue, with maximal elastin synthesis occurring shortly before birth. Soluble elastin was detected in ligament cells plated at low density until proliferation began to be density inhibited and the cells became quiescent. Also, soluble elastin production per cell declined with increasing population doubling or with age in culture. Cells grown in the presence of 5% fetal calf serum produced approximately four times as much soluble elastin as cells grown in serum-free medium. The addition of dexamethasone (0.1 microM) and bleomycin (1 microgram/ml) increased soluble elastin production by cultured cells 180% and 50%, respectively, whereas theophylline (5 micrograms/ml) depressed production 50% and antagonized stimulation by dexamethasone. Ascorbate (50 micrograms/ml), soybean trypsin inhibitor (1 mg/ml), insulin (100 microunits/ml), and aminoacetonitrile (50 micrograms/ml) had no effect, but cycloheximide at 10(-4) M completely inhibited soluble elastin production. In contrast to cells in culture, ligament tissue minces (ligament cells surrounded by in vivo extracellular matrix) efficiently incorporated soluble elastin precursors into insoluble, cross-linked elastin. In addition, soluble elastin production per cell (per microgram of DNA) was higher in tissue minces than elastin production by cells maintained on plastic. These results suggest a role for extracellular matrix in formation of the elastic fiber and in stabilizing elastin phenotypic expression by ligament fibroblasts. Fibroblasts from the bovine ligamentum nuchae present an excellent model for in vitro studies of elastin biosynthesis.

2009 ◽  
Vol 10 (6) ◽  
pp. 513-521 ◽  
Author(s):  
W. Mark Erwin ◽  
Facundo Las Heras ◽  
Diana Islam ◽  
Michael G. Fehlings ◽  
Robert D. Inman

Object The intervertebral disc (IVD) is a highly avascular structure that is occupied by highly specialized cells (nucleus pulposus [NP] cells) that have adapted to survive within an O2 concentration of 2–5%. The object of this study was to investigate the effects of long-term hypoxic and normoxic tissue cultures of nonchondrodystrophic canine notochordal cells—cells that appear to protect the disc NP from degenerative change. Methods The authors obtained notochordal cells from nonchondrodystrophic canines according to their established methods and placed them into monolayer and 3D culture using sodium alginate globules under either hypoxic (3.5% O2) or normoxic (21% O2) conditions. Histological, immunohistochemical, scanning electron microscopy, and histomorphometric methods were used to evaluate the cells within the globules after 5 months in culture. Results Notochordal cells under in vitro hypoxic tissue culture conditions produced a highly complex, organized, 3D cellular construct that was strikingly similar to that observed in vivo. In contrast, traditional normoxic tissue culture conditions resulted in notochordal cells that failed to produce an organized matrix. Hypoxia resulted in a matrix rich in aggrecan and collagen II, whereas normoxic cultured cells did not produce any observable aggrecan or collagen II after 5 months of culture. Conclusions Hypoxia induces notochordal cells to organize a complex 3D cellular/extracellular matrix without an external scaffold other than suspension within sodium alginate. These cells produce an extracellular matrix and large construct that shares exactly the same characteristics as the in vivo condition—robust aggrecan, and type II collagen production. Normoxic tissue culture conditions, however, lead to a failure of these cells to thrive and a lack of extracellular matrix production and significantly smaller cells. The authors suggest that future studies of NP cells and, in particular, notochordal cells should utilize hypoxic tissue culture conditions to derive meaningful, biologically relevant conclusions concerning possible biological/molecular interventions.


2010 ◽  
Vol 22 (1) ◽  
pp. 233
Author(s):  
L. V. M. Gulart ◽  
L. Gabriel ◽  
L. P. Salles ◽  
G. R. Gamas ◽  
D. K. Souza ◽  
...  

FSH at low concentrations affect embryo production. In vitro culture conditions also affect embryo production and embryonic expression of genes and alter oocyte competence to produce embryos. The search for better and less variable culture conditions simulating those in vivo has led to the development of several systems of oocyte in vitro maturation culture. To compare the efficiency of the systems of MIV we utilized 4 groups: (1) TCM-199 control; (2) α-minimal essential medium (MEM); 3) α-MEM + 1 ng of FSH; 4) α-MEM+ 10 ng of FSH. The medium of Group 1 is non-defined by the presence of fetal calf serum (10%). Groups 2, 3, and 4 are defined and polyvinyl alcohol (1%) was used as a macromolecule. Porcine FSH (1 IU mg-1) was used at 1 and 10 ng mL-1 and at 100 ng in defined and non-defined medium, respectively. Bovine ovaries were collected at an abbatoir. Oocytes (n = 1718) with homogeneous cytoplasm and with more than 3 layers of granulosa cells were used. Mature oocytes from the 4 treatments (11 replicates of each treatment) were inseminated with frozen-thawed, motile sperm separated by Percoll, using Sperm TALP HEPES medium. Presumptive zygotes with up to 2 or 3 layers of cumulus cells were cultured in 50-mL drops of SOF medium, supplemented with 10% FCS and 1 mg mL-1 BSA under mineral oil in a humid 5% CO2 atmosphere at 38.5°C after. Cleavage rate was evaluated 72 h post-insemination (hpi), and blastocyst rate was evaluated 168-192 hpi. Cleavage and blastocyst rates were calculated on the basis of number of presumptive zygotes. The expression of the following genes (Bax, Bcl-2, and conexin 43) was evaluated in blastocysts by RT-PCR. One-way ANOVA was used to compare blastocyst number. There was no difference in the proportion of embryos with more than 8 blastomeres in all groups tested, indicating that the rate of development during the first 72 hpi was similar for oocytes matured in chemically defined medium and for oocytes matured in medium containing serum. Bax is a pro-apoptotic marker and Bcl-2 an antiapoptotic marker. Connexin 43 (Cx43) may be a marker of embryo competence. Glyceraldehyde 3-phosphate dehydrogenase was used as internal control. The Bax gene was not expressed in any group. The Bcl-2 and Cx43 genes were expressed, mainly in the α-MEM 10. Although no differences were observed in blastocyst rate among the groups (30% to 40%), the strong expression of Bcl-2 and of Cx43 on the group containing 10 ng mL-1 of FSH may indicate that FSH could improve embryo quality under defined conditions. The authors thank FAP-DF, CNPq, FUNPE, FINATEC, CAPES, and Biovitro Tecnologia de Embrioes Ltda, for laboratory assistance and grants, and Frigorifico Ponte Alta, Brasília-DF, for supplying bovine ovaries.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Meifeng Zhu ◽  
Wen Li ◽  
Xianhao Dong ◽  
Xingyu Yuan ◽  
Adam C. Midgley ◽  
...  

Abstract Implanted scaffolds with inductive niches can facilitate the recruitment and differentiation of host cells, thereby enhancing endogenous tissue regeneration. Extracellular matrix (ECM) scaffolds derived from cultured cells or natural tissues exhibit superior biocompatibility and trigger favourable immune responses. However, the lack of hierarchical porous structure fails to provide cells with guidance cues for directional migration and spatial organization, and consequently limit the morpho-functional integration for oriented tissues. Here, we engineer ECM scaffolds with parallel microchannels (ECM-C) by subcutaneous implantation of sacrificial templates, followed by template removal and decellularization. The advantages of such ECM-C scaffolds are evidenced by close regulation of in vitro cell activities, and enhanced cell infiltration and vascularization upon in vivo implantation. We demonstrate the versatility and flexibility of these scaffolds by regenerating vascularized and innervated neo-muscle, vascularized neo-nerve and pulsatile neo-artery with functional integration. This strategy has potential to yield inducible biomaterials with applications across tissue engineering and regenerative medicine.


Cartilage ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 521-531 ◽  
Author(s):  
Nikolai P. Omelyanenko ◽  
Pavel A. Karalkin ◽  
Elena A. Bulanova ◽  
Elizaveta V. Koudan ◽  
Vladislav A. Parfenov ◽  
...  

Objective Chondrospheres represent a variant of tissue spheroids biofabricated from chondrocytes. They are already being used in clinical trials for cartilage repair; however, their biomechanical properties have not been systematically investigated yet. The aim of our study was to characterize chondrospheres in long-term in vitro culture conditions for morphometric changes, biomechanical integrity, and their fusion and spreading kinetics. Results It has been demonstrated that the increase in chondrospheres secant modulus of elasticity is strongly associated with the synthesis and accumulation of extracellular matrix. Additionally, significant interplay has been found between biomechanical properties of tissue spheroids and their fusion kinetics in contrast to their spreading kinetics. Conclusions Extracellular matrix is one of the main structural determinants of chondrospheres biomechanical properties during chondrogenic maturation in vitro. The estimation of tissue spheroids’ physical behavior in vitro prior to operative treatment can be used to predict and potentially control fusogenic self-assembly process after implantation in vivo.


Blood ◽  
2010 ◽  
Vol 115 (8) ◽  
pp. 1549-1553 ◽  
Author(s):  
Karin Tarte ◽  
Julien Gaillard ◽  
Jean-Jacques Lataillade ◽  
Loic Fouillard ◽  
Martine Becker ◽  
...  

Abstract Clinical-grade human mesenchymal stromal cells (MSCs) have been expanded in vitro for tissue engineering or immunoregulatory purposes without standardized culture conditions or release criteria. Although human MSCs show poor susceptibility for oncogenic transformation, 2 recent studies described their capacity to accumulate chromosomal instability and to give rise to carcinoma in immunocompromised mice after long-term culture. We thus investigated the immunologic and genetic features of MSCs expanded with fetal calf serum and fibroblast growth factor or with platelet lysate in 4 cell-therapy facilities during 2 multicenter clinical trials. Cultured MSCs showed a moderate expression of human leukocyte antigen-DR without alteration of their low immunogenicity or their immunomodulatory capacity. Moreover, some transient and donor-dependent recurring aneuploidy was detected in vitro, independently of the culture process. However, MSCs with or without chromosomal alterations showed progressive growth arrest and entered senescence without evidence of transformation either in vitro or in vivo.


1990 ◽  
Vol 95 (1) ◽  
pp. 97-107
Author(s):  
A.M. Mackay ◽  
R.P. Tracy ◽  
J.E. Craighead

Rat mesothelial cells co-express vimentin and the simple epithelial cytokeratins. While cytokeratins predominate in situ, under most culture conditions vimentin is the major intermediate filament protein of the cells. This loss of cytokeratin production upon culture can be partly prevented by growing mesothelial cells on a basement membrane matrix. However, the basement membrane-promoted persistence of cytokeratin synthesis is not accompanied by expression of cytokeratin G (no. 19), the major acidic cytokeratin of mesothelium in vivo. While cells grown on plastic establish a prominent juxtanuclear assemblage of tonofilaments, those cultured on basement membrane exhibit cytokeratin filaments which are distributed throughout the cytoplasm and attach to neighboring cells at the plasma membrane. This latter pattern resembles that seen in the intact mesothelium. Intermediate filaments are markers of cellular differentiation, but their roles are obscure. The response of cultured mesothelial cells to different growth substrata supports the hypothesis that intermediate filament synthesis is influenced by cellular contact with the extracellular matrix.


1995 ◽  
Vol 74 (04) ◽  
pp. 1096-1102 ◽  
Author(s):  
Hence J M Verhagen ◽  
Glenda J Heijnen-Snyder ◽  
Tom Vink ◽  
Apollo Pronk ◽  
Theo J M V van Vroonhoven ◽  
...  

SummaryLining the luminal surface of prosthetic small diameter bypasses with endothelial cells (EC) will lower its thrombogenicity. Unfortunately, human EC are only scarcely available. Mesotheliai cells (MC) have antithrombotic properties in vivo and can be harvested in large numbers, from the omentum. Recent work demonstrated that the expression of tissue factor (TF) is induced in MC after isolation and culture. Different culture conditions were studied to suppress TF-expression.MC grown in pooled human serum (HS) are procoagulant (717 ± 119 pM factor Xa/min.105 cells). Replacing HS for fetal calf serum, precoating the surface with extracellular matrix and the addition of the xanthine-oxidase inhibitor allopurinol, inhibited TF expression by 90% (p <0.001). Allopurinol clearly reduced TF-mRNA levels.TF expression on cultured MC is an in-vitro effect due to culture conditions and the formation of oxygen free radicals. By reducing TF expression by 90%, we have established conditions in which MC are a good alternative for EC for seeding on synthetic grafts.


2022 ◽  
Author(s):  
You Chen ◽  
Langtao Xu ◽  
Weilin Li ◽  
Wanqi Chen ◽  
Qiubei He ◽  
...  

Abstract The traditional evaluation of nanoparticles (NPs) is mainly based on 2D cell culture and animal models. However, these models are difficult to accurately represent human tumor microenvironment (TME) and fail to systematically study the complex transportation of NPs, thus limiting the translation of nano-drug formulations to clinical studies. This study reports a tumor model fabricated via 3D bioprinting with decellularized extracellular matrix (adECM) enhanced hybrid bioink. Compared with 2D cultured cells, the 3D printed tumor models with multicellular spheroids formation are closer to real tumor in protein, gene expression and tumorigenicity both in vitro and in vivo. Two characteristics of TME, ECM remodeling and epithelial-mesenchymal transition (EMT), are tracked simultaneously under 3D conditions. Furthermore, the cellular uptake efficiency of two different NPs is significantly lower in the printed 3D tumor model than the 2D individual cells, and higher drug resistance is observed in 3D group, which suggest the ECM barrier of tumor can significantly affect the permeability of NPs. These results suggest that this 3D printed tumor model is capable of mimicking the multiple TME, potentially providing a more accurate platform for the design and development of NPs before moving into animal and clinical trials.


Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.


Author(s):  
J. Roemer ◽  
S.R. Simon

We are developing an in vitro interstitial extracellular matrix (ECM) system for study of inflammatory cell migration. Falcon brand Cyclopore membrane inserts of various pore sizes are used as a support substrate for production of ECM by R22 rat aortic smooth muscle cells. Under specific culture conditions these cells produce a highly insoluble matrix consisting of typical interstitial ECM components, i.e.: types I and III collagen, elastin, proteoglycans and fibronectin.


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