Cell proliferation and early differentiation during embryonic development and metamorphosis of Hydractinia echinata

Development ◽  
1988 ◽  
Vol 103 (4) ◽  
pp. 795-803 ◽  
Author(s):  
G. Plickert ◽  
M. Kroiher ◽  
A. Munck
Keyword(s):  
Cell Proliferation ◽  
Embryonic Development ◽  
Proliferative Activity ◽  
Longitudinal Axis ◽  
S Phase ◽  
Embryonic Cells ◽  
Proliferation Activity ◽  
Typical Distribution ◽  
Planula Larva ◽  
Induction Of Metamorphosis

The early embryonic development of Hydractinia lasts about 2.5 days until the developing planula larva acquires competence for metamorphosis. Most embryonic cells stop cycling on reaching the larval stage. In older larvae of Hydractinia, cells that are still proliferating occur exclusively in the endoderm in a typical distribution along the longitudinal axis. During metamorphosis, proliferation activity begins again. The number of S-phase cells has increased by the 9th hour after induction of metamorphosis. Proliferative activity starts in the middle gastric region and in basal parts of primary polyps. Tentacles and stolon tips are always free of replicating cells.

scholarly journals BrdU Pulse LabellingIn Vivoto Characterise Cell Proliferation during Regeneration and Repair following Injury to the Airway Wall in Sheep

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
B. Yahaya ◽  
G. McLachlan ◽  
D. D. S. Collie
Keyword(s):  
Cell Proliferation ◽  
Proliferative Activity ◽  
Histological Analysis ◽  
S Phase ◽  
Pulse Labelling ◽  
Airway Wall ◽  
Brush Biopsy ◽  
Cell Proliferative Activity ◽  
Airway Tree

The response of S-phase cells labelled with bromodeoxyuridine (BrdU) in sheep airways undergoing repair in response to endobronchial brush biopsy was investigated in this study. Separate sites within the airway tree of anaesthetised sheep were biopsied at intervals prior to pulse labelling with BrdU, which was administered one hour prior to euthanasia. Both brushed and spatially disparate unbrushed (control) sites were carefully mapped, dissected, and processed to facilitate histological analysis of BrdU labelling. Our study indicated that the number and location of BrdU-labelled cells varied according to the age of the repairing injury. There was little evidence of cell proliferation in either control airway tissues or airway tissues examined six hours after injury. However, by days 1 and 3, BrdU-labelled cells were increased in number in the airway wall, both at the damaged site and in the regions flanking either side of the injury. Thereafter, cell proliferative activity largely declined by day 7 after injury, when consistent evidence of remodelling in the airway wall could be appreciated. This study successfully demonstrated the effectiveness ofin vivopulse labelling in tracking cell proliferation during repair which has a potential value in exploring the therapeutic utility of stem cell approaches in relevant lung disease models.

185 PREVALENCE AND PROLIFERATIVE ACTIVITY OF MULTIOOCYTE FOLLICLES IN BITCHES: PRELIMINARY RESULTS

2015 ◽  
Vol 27 (1) ◽  
pp. 183
Author(s):  
R. C. Justino ◽  
N. T. Lunardon ◽  
K. C. Silva-Santos ◽  
R. L. Oliveira ◽  
M. M. Seneda ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Granulosa Cells ◽  
Proliferative Activity ◽  
Nuclear Antigen ◽  
Oocyte Nucleus ◽  
Follicular Growth ◽  
Stage Of Development ◽  
Secondary Stage ◽  
Cell Proliferation Activity ◽  
Proliferation Activity

Multioocyte follicles (MOF) are follicles that enclose two or more oocytes. They have been described in many mammalian species, but there is no evidence about their activity in the ovaries. The aim was to estimate the prevalence of MOF and to compare the cell proliferation activity between follicles containing one or more oocytes in the ovaries of prepubertal and adult bitches. Eighty ovaries from prepubertal (n = 20) and adult bitches (n = 20) were obtained by elective ovariohysterectomy (OHE). Immediately after OHE, ovaries were immersed in Bouin's fixative for histological processing. 5 µm thick sections were mounted on histological slides and stained with periodic acid-Schiff (PAS) and hematoxylin. Cell proliferation was evaluated by immunohistochemistry using the proliferating cell nuclear antigen (PCNA). Monoclonal antibody PCNA (clone PC1O, 1 : 200 dilution, Biocare, Concord, CA, USA) was used according to manufacturer's instructions and an antibody diluent was used as a negative control. Slides were counterstained with hematoxylin and examined at 200× to 400× magnification under light microscope. Only cells showing PCNA signal exclusively in the nucleus were considered positive. The prevalence of MOF in the ovaries was compared using a Fisher's exact test (P < 0.05). In all females, the prevalence of MOF was 55% (22/40). MOF containing two or three oocytes were more abundant; however, multioocyte follicles with up to 12 oocytes were observed. The prevalence of MOF at the primordial stage was higher for prepubertal bitches (47 v. 28%) but adult bitches exhibited a higher frequency of secondary MOF (49 v. 25%; P < 0.05). There was no difference in the prevalence of MOF at primary stage between prepubertal and adult bitches (28 v. 23%; P > 0.05). Regarding the cell proliferation activity, PCNA immunoreactivity was detected in oocyte nucleus and granulosa cells of multioocyte follicles at different stages of development. Similarly to what was observed for follicles containing only one oocyte, all nuclei of oocytes within multioocyte follicles exhibited PCNA immunoreactivity and there was a gradual increasing of immunoreactivity in granulosa cells according to the stage of follicular growth. Expression of PCNA by granulosa cells of multioocyte follicles was higher in the secondary and antral stage of development; however, some primordial and primary follicles also exhibited some PCNA-positive cells. In conclusion, the prevalence of MOF at the primordial stage of development was higher in prepubertal bitches, whereas MOF at the secondary stage were more frequent in adult bitches. The PCNA expression pattern by the oocyte nucleus of multioocyte follicles was similar to that observed in follicles containing only one oocyte, which is suggestive of similar activity between these follicles. Furthermore, the presence of proliferative activity in granulosa cells of multioocyte follicles suggests an association of the PCNA expression with more advanced stages of follicular growth.

scholarly journals Increased Cell Proliferation in ChronicHelicobacter pyloriPositive Gastritis and Gastric Carcinoma – Correlation between Immuno-Histochemistry and Tv Image Cytometry

2000 ◽  
Vol 20 (2-3) ◽  
pp. 131-139 ◽  
Author(s):  
Erika Szaleczky ◽  
László Prónai ◽  
Béla Molnár ◽  
Lajos Berczi ◽  
János Fehér ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Gastric Carcinoma ◽  
Chronic Gastritis ◽  
Image Cytometry ◽  
S Phase ◽  
Epithelial Cell Proliferation ◽  
Cell Proliferation Activity ◽  
Proliferation Activity ◽  
H Pylori

Backgound: Epithelial cell proliferation activity has been reported both to be unaltered and increased inHelicobacter pylori(H. pylori) associated chronic gastritis. The proliferation rate decreased followingH. pylorieradication, but results are controversial whether this change is dependent on the success of eradication. We compared the cell proliferation activity ofH. pyloripositive and negative gastric epithelial biopsies in chronic gastritis with and without intestinal metaplasia (IM) and gastric cancer by the expression of proliferation cell nuclear antigen (PCNA) and Tv image cytometry, and assessed the effect ofH. pylorieradication on the cell proliferation rate in the gastric epithelium.Methods: Brush smears and antral biopsies were taken from 70 patients (42 men, 28 women, mean age 58 ± 15 y.o.) on routine endoscopy. Patients were divided into four groups according to the histology; normal epithelia (n=10), chronic gastritis without IM (n=24), chronic gastritis with IM (n=20), and gastric carcinoma (n=16). Thirty‐three patients wereH. pyloripositive, and success of eradication was controlled in 24 cases. Cell proliferation was measured by immunohistochemistry using PCNA labeling index (LI) and by Tv image cytometry evaluating 12 morpho‐ and densitometric parameters of each nuclei and 6 additional parameters of each smear.Results: PCNA LI, DNA index and S + G2 ratio were all higher in chronic gastritis than in the normal epithelium, and were further increased in carcinoma. The lower PCNA LI observed in chronic gastritis with IM corresponds to the lower S phase ratio determined by Tv image analysis. InH. pyloripositive cases, the proliferation activity was 69.3 ± 13.05% prior to the eradication and it decreased to 55.8 ± 23.31% after the successful eradication therapy. When immunohistochemistry was compared with Tv image cytometry, PCNA LI significantly correlated with the percentage of cells in G1 phase (r=−0.415) and S phase (r=0.385), Integrated Optical Density mean (r=0.598), density maximum (r=0.608), surface (r=0.670), layers (r=0.638), diameter minimum (r=0.619), diameter maximum (r=0.730) and perimeter (r=0.501), respectively (p< 0.05).Conclusions: Epithelial cell turnover is increased in chronic gastritis with or without IM, and in gastric carcinoma. The lower PCNA LI observed in chronic gastritis with IM corresponds to the lower S phase ratio determined by Tv image analysis. Cell proliferation decreases after successfulH. pylorieradication. Both methods proved to be reliable for the determination of epithelial cell proliferation.

scholarly journals Doxorubicin treatment modulates chemoresistance and affects the cell cycle in two canine mammary tumour cell lines

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Michela Levi ◽  
Roberta Salaroli ◽  
Federico Parenti ◽  
Raffaella De Maria ◽  
Augusta Zannoni ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Lines ◽  
Tumour Cell ◽  
S Phase ◽  
Mammary Tumour ◽  
Cancer Resistance ◽  
Neoplastic Cells ◽  
Canine Mammary Tumour ◽  
Tumour Cell Lines

Abstract Background Doxorubicin (DOX) is widely used in both human and veterinary oncology although the onset of multidrug resistance (MDR) in neoplastic cells often leads to chemotherapy failure. Better understanding of the cellular mechanisms that circumvent chemotherapy efficacy is paramount. The aim of this study was to investigate the response of two canine mammary tumour cell lines, CIPp from a primary tumour and CIPm, from its lymph node metastasis, to exposure to EC50(20h) DOX at 12, 24 and 48 h of treatment. We assessed the uptake and subcellular distribution of DOX, the expression and function of P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP), two important MDR mediators. To better understand this phenomenon the effects of DOX on the cell cycle and Ki67 cell proliferation index and the expression of p53 and telomerase reverse transcriptase (TERT) were also evaluated by immunocytochemistry (ICC). Results Both cell lines were able to uptake DOX within the nucleus at 3 h treatment while at 48 h DOX was absent from the intracellular compartment (assessed by fluorescence microscope) in all the surviving cells. CIPm, originated from the metastatic tumour, were more efficient in extruding P-gp substrates. By ICC and qRT-PCR an overall increase in both P-gp and BCRP were observed at 48 h of EC50(20h) DOX treatment in both cell lines and were associated with a striking increase in the percentage of p53 and TERT expressing cells by ICC. The cell proliferation fraction was decreased at 48 h in both cell lines and cell cycle analysis showed a DOX-induced arrest in the S phase for CIPp, while CIPm had an increase in cellular death without arrest. Both cells lines were therefore composed by a fraction of cells sensible to DOX that underwent apoptosis/necrosis. Conclusions DOX administration results in interlinked modifications in the cellular population including a substantial effect on the cell cycle, in particular arrest in the S phase for CIPp and the selection of a subpopulation of neoplastic cells bearing MDR phenotype characterized by P-gp and BCRP expression, TERT activation, p53 accumulation and decrease in the proliferating fraction. Important information is given for understanding the dynamic and mechanisms of the onset of drug resistance in a neoplastic cell population.

Cyclin D1 expression in astrocytomas is associated with cell proliferation activity and patient prognosis

1999 ◽  
Vol 188 (3) ◽  
pp. 289-293 ◽  
Author(s):  
Satu-Leena Sallinen ◽  
Pauli K. Sallinen ◽  
Juha T. Kononen ◽  
Kirsi M. Syrj�koski ◽  
Nina N. Nupponen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cyclin D1 ◽  
Cell Proliferation Activity ◽  
Proliferation Activity ◽  
Patient Prognosis

scholarly journals A MYBL2 complex for RRM2 transactivation and the synthetic effect of MYBL2 knockdown with WEE1 inhibition against colorectal cancer

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Qian Liu ◽  
Lijuan Guo ◽  
Hongyan Qi ◽  
Meng Lou ◽  
Rui Wang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Dna Synthesis ◽  
Ectopic Expression ◽  
Building Blocks ◽  
Small Subunit ◽  
S Phase ◽  
Clinical Samples ◽  
Dependent Manner

AbstractRibonucleotide reductase (RR) is a unique enzyme for the reduction of NDPs to dNDPs, the building blocks for DNA synthesis and thus essential for cell proliferation. Pan-cancer profiling studies showed that RRM2, the small subunit M2 of RR, is abnormally overexpressed in multiple types of cancers; however, the underlying regulatory mechanisms in cancers are still unclear. In this study, through searching in cancer-omics databases and immunohistochemistry validation with clinical samples, we showed that the expression of MYBL2, a key oncogenic transcriptional factor, was significantly upregulated correlatively with RRM2 in colorectal cancer (CRC). Ectopic expression and knockdown experiments indicated that MYBL2 was essential for CRC cell proliferation, DNA synthesis, and cell cycle progression in an RRM2-dependent manner. Mechanistically, MYBL2 directly bound to the promoter of RRM2 gene and promoted its transcription during S-phase together with TAF15 and MuvB components. Notably, knockdown of MYBL2 sensitized CRC cells to treatment with MK-1775, a clinical trial drug for inhibition of WEE1, which is involved in a degradation pathway of RRM2. Finally, mouse xenograft experiments showed that the combined suppression of MYBL2 and WEE1 synergistically inhibited CRC growth with a low systemic toxicity in vivo. Therefore, we propose a new regulatory mechanism for RRM2 transcription for CRC proliferation, in which MYBL2 functions by constituting a dynamic S-phase transcription complex following the G1/early S-phase E2Fs complex. Doubly targeting the transcription and degradation machines of RRM2 could produce a synthetic inhibitory effect on RRM2 level with a novel potential for CRC treatment.

scholarly journals Inhibition of MCF-7 breast cancer cell proliferation by 5alpha-dihydrotestosterone; a role for p21(Cip1/Waf1)

2004 ◽  
Vol 32 (3) ◽  
pp. 793-810 ◽  
Author(s):  
MA Greeve ◽  
RK Allan ◽  
JM Harvey ◽  
JM Bentel
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
S Phase ◽  
Cyclin D3 ◽  
P27 Kip1 ◽  
Mcf 7

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.

scholarly journals MRG15 Regulates Embryonic Development and Cell Proliferation

2005 ◽  
Vol 25 (8) ◽  
pp. 2924-2937 ◽  
Author(s):  
Kaoru Tominaga ◽  
Bhakti Kirtane ◽  
James G. Jackson ◽  
Yuji Ikeno ◽  
Takayoshi Ikeda ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Embryonic Development ◽  
Chromatin Remodeling ◽  
Histone Deacetylases ◽  
Globin Gene ◽  
Immunohistochemical Analysis ◽  
Wild Type ◽  
Proliferating Cells ◽  
Globin Promoter

ABSTRACT MRG15 is a highly conserved protein, and orthologs exist in organisms from yeast to humans. MRG15 associates with at least two nucleoprotein complexes that include histone acetyltransferases and/or histone deacetylases, suggesting it is involved in chromatin remodeling. To study the role of MRG15 in vivo, we generated knockout mice and determined that the phenotype is embryonic lethal, with embryos and the few stillborn pups exhibiting developmental delay. Immunohistochemical analysis indicates that apoptosis in Mrg15 − / − embryos is not increased compared with wild-type littermates. However, the number of proliferating cells is significantly reduced in various tissues of the smaller null embryos compared with control littermates. Cell proliferation defects are also observed in Mrg15 − / − mouse embryonic fibroblasts. The hearts of the Mrg15 − / − embryos exhibit some features of hypertrophic cardiomyopathy. The increase in size of the cardiomyocytes is most likely a response to decreased growth of the cells. Mrg15 − / − embryos appeared pale, and microarray analysis revealed that α-globin gene expression was decreased in null versus wild-type embryos. We determined by chromatin immunoprecipitation that MRG15 was recruited to the α-globin promoter during dimethyl sulfoxide-induced mouse erythroleukemia cell differentiation. These findings demonstrate that MRG15 has an essential role in embryonic development via chromatin remodeling and transcriptional regulation.

scholarly journals Expression of 1N3R-Tau Isoform Inhibits Cell Proliferation by Inducing S Phase Arrest in N2a Cells

PLoS ONE ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. e0119865 ◽  
Author(s):  
Li Li ◽  
Zhi-Peng Xu ◽  
Gong-Ping Liu ◽  
Cheng Xu ◽  
Zhi-Hao Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
S Phase ◽  
Phase Arrest ◽  
N2a Cells ◽  
S Phase Arrest ◽  
Tau Isoform
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