370 HISTONE PHOSPHORYLATION PATTERNS AND CHROMOSOMAL STABILITY OF CULTURED BOVINE FIBROBLASTS

2006 ◽  
Vol 18 (2) ◽  
pp. 290
Author(s):  
A. Giraldo ◽  
J. Lynn ◽  
R. Godke ◽  
J. Jenkins ◽  
K. Bondioli

The low percentage of cloned offspring produced by nuclear transfer has been attributed to a variety of factors, including aneuploidy of the donor cells. Previous reports indicate that cultured bovine fibroblasts have a significantly higher level of aneuploidy in late passages than in early passages (Giraldo et al. 2005 J. Reprod. Fert. Dev. 17, 167). Phosphorylation of histone H3 at Serine 10 (Ser10) has been shown to be involved in chromosome compaction during cell division.Abnormal phosphorylation of this histone residue during metaphase could lead to abnormal chromosome segregation and extensive chromosome loss during mitosis. Suboptimal culture conditions may lead to abnormal histone H3 phosphorylation (HP) patterns, ultimately inducing missegregation and loss of chromosomes. The objective of the present study was to determine if the high percentage of aneuploid bovine fibroblast cells observed after long-term culture is associated with an abnormal HP pattern. Four bovine fibroblast cell lines were established from 40- to 60-day fetuses. Cells were cultured in DMEM supplemented with 10% fetal bovine serum and 1% penicillin and streptomycin in 5% CO2 at 37°C and passaged at confluence. Relative levels of HP were determined in three different replicates at population doublings (PD) 2, 10, and 20. Cells were fixed and incubated with an anti-phosphorylated histone H3 (Ser10) antibody, labeled with a secondary antibody, counterstained with propidium iodide, and analyzed for HP fluorescence by flow cytometry. The number of chromosomes was also determined in counts of 800 metaphases. Differences in aneuploidy and HP fluorescence of cells in metaphase among PD were analyzed by χ2 two-way ANOVA, respectively (P < 0.05). The percentages of aneuploid cells in each of the cell lines increased progressively with duration of culture and were elevated from the start. Multinucleated cells were frequently observed after prolonged time in culture in all of the cell lines. The mean phosphorylated histone levels (relative fluorescence intensity) in cells during metaphase were 180.0, 131.5, 174.7, and 157.6 in PD 2; 170.4, 105.72, 145.8, and 152.7 in PD 10; and 274.0, 251.6, 191.4, and 308.3 in PD 20 for the four cell lines, respectively. No difference in HP levels was observed between PD 2 and PD 10. The average of HP during metaphase for the cell lines increased significantly from 160.9 at early passage to 256.3 at late passage (see Table 1). The increase in levels of HP occurred concurrently with the high percentage of aneuploid cells after extended time in culture. These data are consistent with the hypothesis that aneuploid cells observed after long in vitro culture are associated with abnormal HP patterns. Table 1. Relative HP fluorescence and aneuploidy at different PD of fetal bovine fibroblasts This study was supported by Grants in Aid of Research Program (GIAR) from Sigma Xi to A.G.

2005 ◽  
Vol 17 (2) ◽  
pp. 167 ◽  
Author(s):  
A.M. Giraldo ◽  
J.W. Lynn ◽  
C.E. Pope ◽  
R.A. Godke ◽  
K.R. Bondioli

The low efficiency of nuclear transfer (NT) has been related to factors such as mitochondria heteroplasmy, failure of genomic activation, and asynchrony between the donor karyoplast and recipient cytoplast. Few studies have characterized donor cell lines in terms of proliferative capacity and chromosomal stability. It is known that suboptimal culture conditions can induce chromosomal abnormalities, and the use of aneuploid donor cells during NT can lead to a high incidence of abnormal cloned embryos (Giraldo et al. 2004 Reprod. Fertil. Dev. 16, 124 abst). The purpose of this study was to determine the lifespan and chromosomal stability of bovine and porcine fetal cells. Four bovine and four porcine fibroblast cells lines were established from 50-day and 40-day fetuses, respectively. Cells were cultured in DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin and streptomycin at 37°C in 5% CO2. Each cell line was passaged to senescence. Total population doublings (PDs) and cell cycle duration were calculated. To determine the chromosome numbers at different PDs, cells were synchronized in metaphase, fixed, and stained. ANOVA and chi-square tests were used to analyze differences in PDs and proportion of aneuploid cells between cell lines, respectively (P < 0.05). The results show that proliferative capacity was not different between cell lines derived from the same species. Cell lines derived from bovine and porcine fetuses had different in vitro lifespans (33 PDs vs. 42 PDs, respectively; P < 0.05). The mean length of the cell cycles for both bovine and porcine fetal fibroblasts was ∼28 h. The percentage of aneupliod cells in both bovine and porcine fetal cell lines increased progressively with duration of culture (see Table) and was high throughout the study. The proliferative capacity of cultured cells was similar within individuals of the same species, but growth characteristics differed between fetal bovine and porcine cell lines. The progressive increase of aneuploid cells could be due to suboptimal culture conditions or unusual chromosome instability in the particular fetuses used. These data demonstrate the importance of determining chromosome content and the use of cells at early passages to decrease the percentage of aneuploid reconstructed embryos and increase the efficiency of NT.


2013 ◽  
Vol 25 (1) ◽  
pp. 172
Author(s):  
P. Pärn ◽  
M. Plaas ◽  
M. Nõmm ◽  
Ü. Jaakma ◽  
S. Kõks

Somatic cell nucleus transfer (SCNT) and in vitro culture of reconstructed embryos are the pivotal steps for successful cloning and generation of transgenic cattle. The aim of the study was to determine the influence of different cell fusion parameters, maturation, and culture conditions and the type of a cell line (bovine fetal fibroblast cell lines with or without gene transfection) on SCNT blastocyst development. Slaughterhouse-derived oocytes were matured for 17 h in TCM-199 (Sigma, St. Louis, MO, USA) supplemented with 0.05 µg mL–1 of epidermal growth factor (EGF) and 15 IU mL–1 of hCG/eCG (Intervet, PG600) or 10 µg mL–1 of FSH and 12.5 mU mL–1 of LH (Sioux Biochemical Inc., Sioux Center, IA, USA). Four fetal fibroblast cell lines (4 to 5 passages) and identical cell lines transfected with plasmid containing either human erythropoietin, FSH, growth hormone, or insulin-coding cDNA under β-casein promoter (7 to 9 passages) were used for SCNT. Cell fusion was induced by 2 direct-current pulses in 0.5 or 0.2 micro fusion chambers (Eppendorf Multiporator) using one of the following treatments: 100V for 15 µs (F1), 65V for 25 µs (F2), 65V for 20 µs (F3; all in a 0.5-mm chamber), or 36V for 25 µs (F4; 0.2-mm chamber). Fused complexes were activated with 4 µg mL–1 of Ca-ionophore for 4 min and then incubated for 5 h in 2 mM DMAP. The embryos were cultured in SOFaaci medium (Holm et al. 1999) or in commercial SOF medium (Minitüb GmbH, Tiefenbach, Germany) for 7 days. Data were analysed by ANOVA and the chi-square test. The results of the study showed that the cleavage rate of the reconstructed embryos was influenced by the fusion regimen (P < 0.05) but not by the donor cell type (P < 0.05). Treatments F2 and F3 resulted in cleavage rates higher (P < 0.05) than F1 and F4 (77.2, 82.0, 62.8, and 63.1%, respectively). Blastocyst yield was not significantly influenced by the different in vitro maturation (IVM) media – altogether, addition of FSH/LH resulted in 14.6% (158/1079) and EGF + hCG/eCG in 13.2% (73/554) of blastocysts (P < 0.05). The combination of TCM-199 + FSH/LH and SOFaaci resulted in 19.6% (79/403) blastocysts compared with 12.4% (74/596) when the same IVM medium and commercial SOF were used (P < 0.05). The use of transgenic cell lines for cloning led to a lower overall blastocyst rate (10.9%, 38/348) than use of non-transfected cell lines (17.7%, 115/651; P < 0.05), whereas the differences were 5.6 and 4.1 percentage points for SOF and SOFaaci, respectively. There were no significant differences between the individual cell lines within a cell line type. In conclusion, the optimization of the fusion parameters and in vitro culture (IVC) conditions led to improved blastocyst yields. In vivo development potential of the generated embryos still has to be evaluated in further studies. This study was supported by Project EU29023 of Enterprise Estonia, CCRMB, targeted grant SF1080045s07, and grant P8001 from the Estonian University of Life Sciences.


2018 ◽  
Vol 18 (2) ◽  
pp. 295-301 ◽  
Author(s):  
Shabnam Farzaneh ◽  
Elnaz Zeinalzadeh ◽  
Bahram Daraei ◽  
Soraya Shahhosseini ◽  
Afshin Zarghi

Background: Due to the astonishing properties of ferrocene and its derivatives, it has a broad application in diverse areas. Numerous ferrocene derivatives demonstrated anti-proliferative activity. Also COX-2, as a key isoenzyme for production of prostaglandins, is frequently overexpressed in various cancers. It is now recognized that COX-2 over expression promotes tumorigenic functions which can be suppressed by COX-2 inhibitors, a phenomenon useful for the preventing of tumor progression. The combination of COX-2 inhibitors with other anti-cancer or cancer prevention drugs may reduce their side effects in future cancer prevention and treatment. Objective: Owing to high anticancer potential of ferrocene derivatives and considerable COX-2 inhibitory and cytotoxicity effects of our previously synthesized chalcones, we decided to incorporate the ferrocenyl moiety into appropriate COX-2 inhibitor chalcone based scaffold, to evaluate COX-2 inhibitory activity as well as anticancer activities. Methods: Chalcones were synthesized via clasien-schmidt condensation of methylsulfonyl aldehyde and acetyl ferrocene. Further different amines with solvent free and ultra sound condition were reacted with chalcones to have different 1-ferrocenyl-3-amino carbonyl compounds. Docking study was carried out with Auto Dock vina software. All the newly-synthesized compounds were evaluated for their cyclooxygenase-2 (COX-2) inhibitory activity using chemiluminescent enzyme assays as well as cytotoxicity activity against MCF-7 and T47D and fibroblast cell lines by MTT assay. Results: In vitro COX-1/COX-2 inhibition studies demonstrated that all compounds were selective inhibitors of the COX-2 isozyme with IC50 values in the highly potent 0.05-0.12 µM range, and COX-2 selectivity indexes (SI) in the 148.3-313.7 range. These results indicated that either potency or selectivity of COX-2 inhibitory activity was affected by the nature and size of the substituents on C-3 of propane-1-one. Also anti-proliferative and toxicity activities of synthesized compounds against breast cancer cell lines MCF-7 and T47D and fibroblast cell lines showed that the synthesized compounds had mild to moderate cytotoxicity against MCT7 and T47D breast cancer cell lines at 10 µM concentration. In vitro COX-1/COX-2 inhibition studies and anticancer activity against MCF-7, identified 1-ferrocenyl-3-(4-methylsulfonylphenyl) propen-1-one as a potent compound (IC50 COX-2 = 0.05 µM, MCF-7: % inhibition (at concentration of 10 µM) = 32.7%), and also 1-ferrocenyl-3- (propan-1-amine)-3-(4-methylsulfonylphenyl) propan-1-one showed the most selectivity on COX-2 inhibition (selectivity index= 313.7). Conclusion: A novel group of ferrocene compounds, possessing a methyl sulfonyl COX-2 pharmacophore were synthesized to investigate the effect of different substituents on selectivity and potency of COX-2 inhibitory activity and their cytotoxicity effects. This study indicates that 1-ferrocenyl-3-amino carbonyl compounds having ferrocene motif and methyl sulfonyl COX-2 pharmacophore is a suitable scaffold to design COX-2 inhibitors and anti-cancer agents.


1993 ◽  
Vol 21 (2) ◽  
pp. 206-209
Author(s):  
Anders H. G. Andrén ◽  
Anders P. Wieslander

Cytotoxicity, measured as inhibition of cell growth of cultured cell lines, is a widely used method for testing the safety of biomaterials and chemicals. One major technical disadvantage with this method is the continuous routine maintenance of the cell lines. We decided to investigate the possibility of storing stock cultures of fibroblasts (L-929) in an ordinary refrigerator as a means of reducing the routine workload. Stock cultures of the mouse fibroblast cell line L-929 were prepared in plastic vials with Eagle's minimum essential medium. The vials were stored in a refrigerator at 4–10°C for periods of 7–31 days. The condition of the cells after storage was determined as cell viability, cell growth and the toxic response to acrylamide, measured as cell growth inhibition. We found that the L-929 cell line can be stored for 2–3, weeks with a viabilty > 90% and a cell growth of about 95%, compared to L-929 cells grown and subcultured in the normal manner. The results also show that the toxic response to acrylamide, using refrigerator stored L-929 cells, corresponds to that of control L-929 cells. We concluded that it is possible to store L-929 cells in a refrigerator for periods of up to 3 weeks and still use the cells for in vitro cytotoxic assays.


2013 ◽  
Vol 12 (12) ◽  
pp. 1629-1640 ◽  
Author(s):  
Riyad N. H. Seervai ◽  
Stephen K. Jones ◽  
Matthew P. Hirakawa ◽  
Allison M. Porman ◽  
Richard J. Bennett

ABSTRACTCandidaspecies exhibit a variety of ploidy states and modes of sexual reproduction. Most species possess the requisite genes for sexual reproduction, recombination, and meiosis, yet only a few have been reported to undergo a complete sexual cycle including mating and sporulation.Candida albicans, the most studiedCandidaspecies and a prevalent human fungal pathogen, completes its sexual cycle via a parasexual process of concerted chromosome loss rather than a conventional meiosis. In this study, we examine ploidy changes inCandida tropicalis, a closely related species toC. albicansthat was recently revealed to undergo sexual mating.C. tropicalisdiploid cells mate to form tetraploid cells, and we show that these can be induced to undergo chromosome loss to regenerate diploid forms by growth on sorbose medium. The diploid products are themselves mating competent, thereby establishing a parasexual cycle in this species for the first time. Extended incubation (>120 generations) ofC. tropicalistetraploid cells under rich culture conditions also resulted in instability of the tetraploid form and a gradual reduction in ploidy back to the diploid state. The fitness levels ofC. tropicalisdiploid and tetraploid cells were compared, and diploid cells exhibited increased fitness relative to tetraploid cellsin vitro, despite diploid and tetraploid cells having similar doubling times. Collectively, these experiments demonstrate distinct pathways by which a parasexual cycle can occur inC. tropicalisand indicate that nonmeiotic mechanisms drive ploidy changes in this prevalent human pathogen.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alexander P Browning ◽  
Jesse A Sharp ◽  
Ryan J Murphy ◽  
Gency Gunasingh ◽  
Brodie Lawson ◽  
...  

Tumour spheroids are common in vitro experimental models of avascular tumour growth. Compared with traditional two-dimensional culture, tumour spheroids more closely mimic the avascular tumour microenvironment where spatial differences in nutrient availability strongly influence growth. We show that spheroids initiated using significantly different numbers of cells grow to similar limiting sizes, suggesting that avascular tumours have a limiting structure; in agreement with untested predictions of classical mathematical models of tumour spheroids. We develop a novel mathematical and statistical framework to study the structure of tumour spheroids seeded from cells transduced with fluorescent cell cycle indicators, enabling us to discriminate between arrested and cycling cells and identify an arrested region. Our analysis shows that transient spheroid structure is independent of initial spheroid size, and the limiting structure can be independent of seeding density. Standard experimental protocols compare spheroid size as a function of time; however, our analysis suggests that comparing spheroid structure as a function of overall size produces results that are relatively insensitive to variability in spheroid size. Our experimental observations are made using two melanoma cell lines, but our modelling framework applies across a wide range of spheroid culture conditions and cell lines.


2008 ◽  
Vol 139 (6) ◽  
pp. 816-822 ◽  
Author(s):  
Susan L. Thibeault ◽  
Wenhua Li ◽  
Stephanie Bartley

Objective Vocal fold biology research is emerging as a vital area of study in laryngology. One impediment is the lack of both commercially available vocal fold lamina propria fibroblasts and a constitutively expressed specific marker for fibroblasts. We present an in vitro technique that allows for identification of fibroblasts by ruling out the possibility of the cells belonging to other lineages that are found in vocal fold tissue. Study Design An in vitro study. Methods Two primary vocal fold fibroblast cell lines and one immortalized vocal fold fibroblast cell line were cultured. Immunohistologic staining for α-actinin, cytokeratin 19, and von Willebrand factor was completed for the three fibroblast lines in addition to skeletal, endothelial, and epithelial cell lines. Cell type was differentiated by positive staining for α-actinin, cytokeratin 19, and von Willebrand factor. Results Fibroblast cultures did not express α-actinin, cytokeratin 19, and von Willebrand factor, whereas skeletal muscle, endothelial, and epithelial cultured cells expressed each respectively. Conclusions This simple rule-out methodology for fibroblast confirmation is an important step when establishing cell culture, and it establishes sound internal validity particularly in the early stages of this emerging area of study.


1993 ◽  
Vol 13 (10) ◽  
pp. 6036-6043
Author(s):  
T Ogata ◽  
D Ayusawa ◽  
M Namba ◽  
E Takahashi ◽  
M Oshimura ◽  
...  

Using nontumorigenic immortalized human cell lines KMST-6 (KMST) and SUSM-1 (SUSM), we attempted to identify the chromosome that carries a putative senescence-related gene(s). These cell lines are the only ones that have been established independently from normal human diploid fibroblasts following in vitro mutagenesis. We first examined restriction fragment length polymorphisms on each chromosome of these immortalized cell lines and their parental cell lines and found specific chromosomal alterations common to these cell lines (a loss of heterozygosity in KMST and a deletion in SUSM) on the long arm of chromosome 7. In addition to these, we also found that introduction of chromosome 7 into these cell lines by means of microcell fusion resulted in the cessation of cell division, giving rise to cells resembling cells in senescence. Introduction of other chromosomes, such as chromosomes 1 and 11, on which losses of heterozygosity were also detected in one of the cell lines (KMST), to either KMST or SUSM cells or of chromosome 7 to several tumor-derived cell lines had no effect on their division potential. These results strongly suggest that a gene(s) affecting limited-division potential or senescence of normal human fibroblasts is located on chromosome 7, probably at the long arm of the chromosome, representing the first case in which a specific chromosome reverses the immortal phenotype of otherwise normal human cell lines.


2020 ◽  
Vol 25 (01) ◽  
pp. 10-18
Author(s):  
Fatma Yurt ◽  
Ece Tugba Saka ◽  
Zekeriya Biyiklioglu ◽  
Ayça Tunçel ◽  
Derya Ozel ◽  
...  

In this study, two SiPcs have been selected and the photodynamic therapy potentials were evaluated of the Pcs. Synthesis of Axially 2-decyn-1-oxy disubstituted Es-SiPc-2 was newly synthesized by the reaction of SiPcCl2 with 2-decyn-1-ol in the presence of NaH in toluene. Furthermore, their nuclear imaging potentials were evaluated in human colon adenocarcinoma (HT-29) and human lung fibroblast cell (WI-38) cell lines. The uptake results have indicated that Es-SiPc labeled with [Formula: see text]I radionuclide ([Formula: see text]I-Es-SiPc) was approximately 2-fold higher in the HT-29 cell line than the WI-38 cell line. In other words, the target/non-target tissue ratio is defined as two in the HT-29/WI-38 cell lines. Besides, the uptake values of [Formula: see text]I-Es-SiPc were found to be higher than [Formula: see text]I-Es-SiPc-2. [Formula: see text]I-Es-SiPc and [Formula: see text]I-Es-SiPc-2 are promising for imaging or treating colon adenocarcinoma. In vitrophotodynamic therapy (PDT) studies have shown that both compounds are suitable and can be used in this field. Also, Es-SiPc has been shown to have higher phototoxicity than Es-SiPc-2.


Hernia ◽  
2016 ◽  
Vol 21 (3) ◽  
pp. 407-416 ◽  
Author(s):  
R. Wiessner ◽  
T. Kleber ◽  
N. Ekwelle ◽  
K. Ludwig ◽  
D.-U. Richter

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