Contrasting patterns of c-myc and N-myc expression in proliferating, quiescent, and differentiating cells of the embryonic chicken lens

Development ◽  
1992 ◽  
Vol 115 (3) ◽  
pp. 813-820
Author(s):  
L.L. Harris ◽  
J.C. Talian ◽  
P.S. Zelenka
Keyword(s):  
Cell Proliferation ◽  
Protein Product ◽  
Mrna Levels ◽  
Lens Fiber ◽  
Proliferating Cells ◽  
Fiber Cells ◽  
Embryonic Chicken ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation

The present study uses the polymerase chain reaction and in situ hybridization to examine c-myc and N-myc mRNA in the embryonic chicken lens at 6, 10, 14 and 19 days of development and compares the pattern of expression obtained with the developmental pattern of cell proliferation and differentiation. In the central epithelium, c-myc mRNA levels were proportional to the percentage of proliferating cells throughout development. N-myc mRNA expression in this region was relatively low and showed no correlation with cell proliferation. The ratio of N-myc to c-myc mRNA increased markedly with the onset of epithelial cell elongation and terminal fiber cell differentiation, although both c-myc and N-myc mRNAs continued to be expressed in postmitotic, elongating cells of the equatorial epithelium and in terminally differentiating lens fiber cells. Thus, increased expression of N-myc, a gene whose protein product may compete with c-myc protein for dimerization partners, accompanies the dissociation of c-myc expression and cell proliferation during terminal differentiation of lens fiber cells.

scholarly journals The influence of direct and indirect fibroblast cell contact on human myogenic cell behavior and gene expression in vitro

2019 ◽  
Vol 127 (2) ◽  
pp. 342-355 ◽  
Author(s):  
Cecilie J. L. Bechshøft ◽  
Peter Schjerling ◽  
Michael Kjaer ◽  
Abigail L. Mackey
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Myogenic Cell ◽  
Mrna Levels ◽  
Indirect Contact ◽  
Permeable Membrane ◽  
Primary Myoblasts ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation

Underpinning skeletal muscle plasticity is the interplay between many cell types, of which fibroblasts are emerging as potent players, both negatively in the development of fibrosis but also positively in stimulating muscle repair through enhancing myogenesis. The mechanisms behind this interaction however remain unknown. To investigate this, waste hamstring muscle tissue was obtained from eight healthy young men undergoing reconstructive anterior cruciate ligament surgery and primary myoblasts and fibroblasts were isolated. Myoblasts were cultured alone or with fibroblasts, either in direct or indirect contact (separated by an insert with a permeable membrane). The myogenesis parameters proliferation, differentiation, and fusion were determined from immunostained cells, while, in replicate samples, gene expression levels of GAPDH, Ki67, Pax7, MyoD, myogenin, myomaker, MHC-Iβ, TCF7L2, COL1A1, and p16 were determined by RT-PCR. We found only trends for an influence of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. While greater mRNA levels of GAPDH, Pax7, MyoD, myogenin, and MHC-Iβ were observed in myogenic cells in indirect contact with fibroblasts (insert) when compared with cells cultured alone, a similar effect of an empty insert was also observed. In conclusion we find very little influence of skeletal muscle fibroblasts on myoblasts derived from the same tissue, although it cannot be excluded that a different outcome would be seen under less optimal myogenic growth conditions. NEW & NOTEWORTHY Using passage one primary myoblasts and fibroblasts isolated from human skeletal muscle, we found only a trend for an effect of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. This is contrary to previous reports and raises the possibility that fibroblasts of different tissue origins exert distinct roles.

scholarly journals Use of a double-label method to detect rapid changes in the rate of cell proliferation.

1992 ◽  
Vol 40 (5) ◽  
pp. 619-627 ◽  
Author(s):  
G A Hyatt ◽  
D C Beebe
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Short Pulse ◽  
S Phase ◽  
Fiber Cells ◽  
Label Method ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Double Label ◽  
Lens Cell

We developed a double-label method to directly measure the rate at which cells enter S-phase of the cell cycle. All cells in S-phase were first labeled with a short pulse of [3H]-thymidine. This was followed by a longer incubation in bromodeoxyuridine (BrdU), a thymidine analogue. Nuclei labeled with [3H]-thymidine were detected by autoradiography and those labeled with BrdU by immunocytochemistry. Cells labeled only with BrdU must have entered S-phase at some time after the end of the [3H]-thymidine pulse. Thus, the rate of entry of cells into S-phase could be determined. This method was shown to be more accurate and more sensitive than determining changes in the rate at which cells entered S-phase with a continuous labeling protocol. It was possible to detect changes in proliferative activity that occurred in less than 1 hr. We used this double-label technique to study changes in the cell cycle during the terminal differentiation of chicken embryo lens fiber cells. These studies revealed differences in the effects of several treatments known to stimulate fiber cell differentiation. They also demonstrated the presence in the embryonic eye of factors that stimulate and prevent lens cell proliferation and differentiation.

Functionalized nanoprobes for in situ detection of telomerase

2021 ◽  
Vol 57 (31) ◽  
pp. 3736-3748
Author(s):  
Zhengze Yu ◽  
Fan Jiang ◽  
Chenchen Hu ◽  
Bo Tang
Keyword(s):  
Cell Proliferation ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
In Situ Detection

Telomerase can maintain the length and stability of telomeres and plays an important role in cell proliferation and differentiation. Based on different materials, various functionalized nanoprobes were developed for in situ telomerase detection.

Complexity of the early genetic response to growth factors in mouse fibroblasts

1988 ◽  
Vol 8 (5) ◽  
pp. 2140-2148
Author(s):  
J M Almendral ◽  
D Sommer ◽  
H Macdonald-Bravo ◽  
J Burckhardt ◽  
J Perera ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mrna Levels ◽  
Genetic Response ◽  
3T3 Cells ◽  
Recombinant Phage ◽  
Cross Hybridization ◽  
Serum Stimulation ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Nih 3T3

Genes whose expression is growth factor regulated are likely to be important components in the mechanisms controlling cell proliferation and differentiation. With the aim of identifying some of those genes, a lambda cDNA library was prepared with poly(A)+ RNA from quiescent NIH 3T3 cells stimulated with serum for 4 h in the presence of cycloheximide. Differential screening of approximately 200,000 recombinant phage plaques revealed 2,540 clones that cross hybridized preferentially with [32P]cDNA derived from RNA of stimulated cells rather than with cDNA derived from nonstimulated cells. Cross hybridization of these clones identified 82 independent sequences, including c-fos and c-myc. Seventy-one clones were further studied. Analysis of the changes in transcription and mRNA levels after serum stimulation demonstrated that the kinetics and extent of the induction vary dramatically between the different genes. Cycloheximide in all cases superinduced the mRNA levels by two mechanisms, inhibiting the shutoff of transcription and prolonging the half-lives of the mRNAs. Our results showed that induction of proliferation is accompanied by the onset of a complex genetic program.

Polypyrrole-coated poly(l-lactic acid-co-ε-caprolactone)/silk fibroin nanofibrous membranes promoting neural cell proliferation and differentiation with electrical stimulation

2016 ◽  
Vol 4 (41) ◽  
pp. 6670-6679 ◽  
Author(s):  
Binbin Sun ◽  
Tong Wu ◽  
Juan Wang ◽  
Dawei Li ◽  
Jing Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Electrical Stimulation ◽  
Lactic Acid ◽  
Silk Fibroin ◽  
Oxidative Polymerization ◽  
Neural Cell ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Nanofiber Membranes

Conductive nanofiber membranes were developed by coating Ppy on PLCL/SF nanofibers via in situ oxidative polymerization.

scholarly journals Complexity of the early genetic response to growth factors in mouse fibroblasts.

1988 ◽  
Vol 8 (5) ◽  
pp. 2140-2148 ◽  
Author(s):  
J M Almendral ◽  
D Sommer ◽  
H Macdonald-Bravo ◽  
J Burckhardt ◽  
J Perera ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Mrna Levels ◽  
Genetic Response ◽  
3T3 Cells ◽  
Recombinant Phage ◽  
Cross Hybridization ◽  
Serum Stimulation ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Nih 3T3

Genes whose expression is growth factor regulated are likely to be important components in the mechanisms controlling cell proliferation and differentiation. With the aim of identifying some of those genes, a lambda cDNA library was prepared with poly(A)+ RNA from quiescent NIH 3T3 cells stimulated with serum for 4 h in the presence of cycloheximide. Differential screening of approximately 200,000 recombinant phage plaques revealed 2,540 clones that cross hybridized preferentially with [32P]cDNA derived from RNA of stimulated cells rather than with cDNA derived from nonstimulated cells. Cross hybridization of these clones identified 82 independent sequences, including c-fos and c-myc. Seventy-one clones were further studied. Analysis of the changes in transcription and mRNA levels after serum stimulation demonstrated that the kinetics and extent of the induction vary dramatically between the different genes. Cycloheximide in all cases superinduced the mRNA levels by two mechanisms, inhibiting the shutoff of transcription and prolonging the half-lives of the mRNAs. Our results showed that induction of proliferation is accompanied by the onset of a complex genetic program.

Icariin Stimulates hFOB 1.19 Osteoblast Proliferation and Differentiation via OPG/RANKL Mediated by the Estrogen Receptor

2020 ◽  
Vol 22 (1) ◽  
pp. 168-175 ◽  
Author(s):  
Lin-Jun Sun ◽  
Chong Li ◽  
Xiang-hao Wen ◽  
Lu Guo ◽  
Zi-Fen Guo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Estrogen Receptor ◽  
Protein Expression ◽  
Chinese Herb ◽  
Human Osteoblast ◽  
Osteoblast Cells ◽  
Expression Ratio ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Mrna And Protein Expression

Background:: Icariin (ICA), one of the main effective components isolated from the traditional Chinese herb Epimedium brevicornu Maxim., has been reported to possess extensive pharmacological actions, including enhanced sexual function, immune regulation, anti-inflammation, and antiosteoporosis. Methods:: Our study was designed to investigate the effect of ICA on cell proliferation and differentiation and the molecular mechanism of OPG/RANKL mediated by the Estrogen Receptor (ER) in hFOB1.19 human osteoblast cells. Results:: The experimental results show that ICA can stimulate cell proliferation and increase the activity of Alkaline Phosphatase (ALP), Osteocalcin (BGP) and I Collagen (Col I) and a number of calcified nodules. Furthermore, the mRNA and protein expression of OPG and RANKL and the OPG/ RANKL mRNA and protein expression ratios were upregulated by ICA. The above-mentioned results indicated that the optimal concentration of ICA for stimulating osteogenesis was 50ng/mL. Subsequent mechanistic studies comparing 50ng/mL ICA with an estrogen receptor antagonist demonstrated that the effect of the upregulated expression is connected with the estrogen receptor. In conclusion, ICA can regulate bone formation by promoting cell proliferation and differentiation and upregulating the OPG/RANKL expression ratio by the ER in hFOB1.19 human osteoblast cells.

scholarly journals Costimulation by B7 Modulates Specificity of Cytotoxic T Lymphocytes: A Missing Link That Explains Some Bystander T Cell Activation

1997 ◽  
Vol 186 (10) ◽  
pp. 1787-1791 ◽  
Author(s):  
Pan Zheng ◽  
Yang Liu
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
Target Cells ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation

It has been proposed that some bystander T cell activation may in fact be due to T cell antigen receptor (TCR) cross-reactivity that is too low to be detected by the effector cytotoxic T lymphocyte (CTL). However, this hypothesis is not supported by direct evidence since no TCR ligand is known to induce T cell proliferation and differentiation without being recognized by the effector CTL. Here we report that transgenic T cells expressing a T cell receptor to influenza virus A/NT/68 nucleoprotein (NP) 366-374:Db complexes clonally expand and become effector CTLs in response to homologous peptides from either A/PR8/34 (H1N1), A/AA/60 (H2N2), or A/NT/68 (H3N2). However, the effector T cells induced by each of the three peptides kill target cells pulsed with NP peptides from the H3N2 and H2N2 viruses, but not from the H1N1 virus. Thus, NP366–374 from influenza virus H1N1 is the first TCR ligand that can induce T cell proliferation and differentiation without being recognized by CTLs. Since induction of T cell proliferation was mediated by antigen-presenting cells that express costimulatory molecules such as B7, we investigated if cytolysis of H1N1 NP peptide–pulsed targets can be restored by expressing B7-1 on the target cells. Our results revealed that this is the case. These data demonstrated that costimulatory molecule B7 modulates antigen specificity of CTLs, and provides a missing link that explains some of the bystander T cell activation.

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