The effect of 5-bromodeoxyuridine on limb regeneration in the newt Notophthalmus viridescens

1982 ◽  
Vol 60 (4) ◽  
pp. 580-585
Author(s):  
Steven R. Scadding
Keyword(s):  
Cell Differentiation ◽  
Cultured Cells ◽  
Limb Regeneration ◽  
Specific Effect ◽  
Size Reduction ◽  
Complete Inhibition ◽  
Notophthalmus Viridescens ◽  
Epidermal Thickness ◽  
Partial Inhibition ◽  
Dose Levels

The effect of the thymidine analogue 5-bromodeoxyuridine (BrdU) on limb regeneration in the newt was studied at three different dose levels. At 50 μg per day, there was no effect on regeneration in most cases. However, in about 20% of the cases there was a slight retardation of regeneration. At 250 μg per day, there was a partial inhibition of regeneration including reduction in blastema size, reduction in epidermal thickness, and less extensive muscle dedifferentiation. At 1 mg per day, there was a complete inhibition of limb regeneration; however, this dosage was also lethal to the newts. No specific effect of BrdU on cell differentiation was observed. The differences and similarities to BrdU effects on various cultured cells are discussed.

Vitamin A inhibits amphibian tail regeneration

1987 ◽  
Vol 65 (2) ◽  
pp. 457-459 ◽  
Author(s):  
Steven R. Scadding
Keyword(s):  
Retinoic Acid ◽  
Vitamin A ◽  
Xenopus Laevis ◽  
Ambystoma Mexicanum ◽  
Complete Inhibition ◽  
Notophthalmus Viridescens ◽  
Tail Regeneration ◽  
Dose Levels ◽  
Dose Dependent

The objective of this investigation was to determine what effect vitamin A had on tail regeneration in Notophthalmus viridescens adults, in Ambystoma mexicanum larvae, and in Xenopus laevis tadpoles. Notophthalmus viridescens and Ambystoma mexicanum had their tails amputated and then were treated with retinol palmitate by immersion in concentrations known to cause proximodistal duplications in regenerating limbs. Xenopus laevis tadpoles had their tails amputated and then were treated with either retinol palmitate by immersion, or with retinoic acid administered by implantation of silastin blocks containing retinoic acid. The results ranged from no effect at all at the lower dose levels used, to complete inhibition of tail regeneration at higher dose levels. The degree of inhibition of tail regeneration appeared to be dose dependent. In no case were any duplicated or accessory structures formed analogous to those observed in regenerating limbs. This result suggests that the morphogenetic processes involved in tail regeneration are at least in some ways different from those occurring in limbs, where a similar vitamin A treatment would cause proximodistal duplication or production of accessory limb structures.

Macrophage Inhibition of Collagen-Induced Platelet Aggregation

1979 ◽  
Vol 42 (04) ◽  
pp. 1207-1216 ◽  
Author(s):  
Berit Mørland
Keyword(s):  
Enzyme Activity ◽  
Platelet Aggregation ◽  
Peritoneal Macrophage ◽  
Cultured Cells ◽  
Culture Media ◽  
Human Platelets ◽  
Mouse Peritoneal Macrophage ◽  
Collagenase Activity ◽  
Partial Inhibition ◽  
Macrophage Phagocytosis

SummaryCollagen was incubated with cells or media fractions of mouse peritoneal macrophage cultures, and its aggregating effect on human platelets was tested. Incubation with lysates of cultured cells completely abolished the normal collagen-induced platelet aggregation, while incubation with media fractions only caused partial inhibition. The latter inhibition was more pronounced after macrophage phagocytosis of latex particles, while endocytosis of endotoxin had no effect.Corresponding macrophage cultures were also tested for specific collagenase activity, using 14C-glycine labelled collagen as substrate. Collagenase activity was found in the culture media fractions only, and the enzyme activity could be enhanced by endocytosis of latex as well as endotoxin.It appears that the effect of macrophage lysates and media on collagen-platelet interaction cannot be ascribed only to secretion of collagenase from macrophages.

scholarly journals Osteocalcin Production in Primary Osteoblast Cultures Derived from Normal and Hyp Mice

Endocrinology ◽  
1998 ◽  
Vol 139 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Thomas O. Carpenter ◽  
Kathleen C. Moltz ◽  
Bruce Ellis ◽  
Monica Andreoli ◽  
Thomas L. McCarthy ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Cultured Cells ◽  
Primary Cultures ◽  
Specific Effect ◽  
Continuous Exposure ◽  
Primary Osteoblast ◽  
Characteristic Features ◽  
Species Specific ◽  
Osteocalcin Production

Abstract Rickets and osteomalacia are characteristic features of the Hyp mouse model of human X-linked hypophosphatemia. Hyp mice demonstrate elevated circulating osteocalcin levels, as well as altered regulation of osteocalcin by 1,25(OH)2D3. Whether this osteocalcin abnormality is intrinsic to the osteoblast, or mediated by the in vivo milieu, has not been established. We therefore characterized osteocalcin production and its regulation by 1,25(OH)2D3 in primary cultures of murine osteoblasts and examined osteocalcin and its messenger RNA in response to 1,25(OH)2D3 in cultures of Hyp mouse-derived osteoblasts. Cell viability and osteocalcin production are optimal when murine cells are harvested within 36 h of age. Murine primary osteoblast cultures mineralize and produce osteocalcin in a maturation-dependent fashion (as demonstrated in other species), and continuous exposure to 1,25(OH)2D3, beginning at day 9 of culture, inhibits osteoblast differentiation and osteocalcin production and prevents mineralization of the culture. However, in contrast to other species, exposure to 1,25(OH)2D3, added later (days 17–25) in culture, does not stimulate osteocalcin but arrests osteocalcin production at current levels. Ambient media levels of osteocalcin were no different in cultures from Hyp mice and their normal litter mates, and the down-regulatory response to 1,25(OH)2D3 was comparable in cultures from normal and Hyp mice. Furthermore, expression of osteocalcin messenger RNA in murine cultures is reduced with exposure to 1,25(OH)2D3, and there is no difference between normal and Hyp cultures in this response. Thus, primary murine osteoblasts manifest a species-specific effect of 1,25(OH)2D3 on osteocalcin production. Furthermore, the increased serum osteocalcin production seen in intact Hyp mice, and the altered response to 1,25(OH)2D3 in Hyp mice, are not observed in osteoblast cultures derived from the mutant strain. These data indicate that abnormalities of osteocalcin described in intact Hyp mice require factors other than those present in cultured cells.

scholarly journals Cellular maturation in human preleukemia

Blood ◽  
1978 ◽  
Vol 52 (2) ◽  
pp. 355-361
Author(s):  
HP Koeffler ◽  
DW Golde
Keyword(s):  
Bone Marrow ◽  
Cell Differentiation ◽  
Liquid Culture ◽  
Cultured Cells ◽  
Bone Marrow Cells ◽  
Myelogenous Leukemia ◽  
Bone Marrow Cultures ◽  
Acute Myelogenous ◽  
Marrow Cultures

Bone marrow cells from three preleukemic patients with prominent marrow karyotypic abnormalities were studied in liquid culture to determine if the neoplastic clones were capable of maturation. Parallel cytogenetic and cytologic studies were performed in sequentially harvested bone marrow cultures. Maturation, albeit delayed, occurred in cultures from all three patients. By 14 days of culture in vitro, morphologic, cytochemical, and functional evidence of maturation was observed in about 70% of the cells. By day 21, 85% of the cells were mature by these criteria. All but 2 of 249 metaphases from the cultured cells contained the cytogenetic abnormality of the neoplastic clone. We conclude that some preleukemic cells identified by a chromosomal abnormality can mature in vitro. Preleukemia may be viewed as a syndrome of “early leukemia” in which the neoplastic clone is established and manifested functionally as ineffective hematopoiesis. Hematopoietic cell differentiation becomes progressively abnormal with termination in the nearly complete maturational block characteristic of acute myelogenous leukemia.

Role of prostaglandins in amphibian limb regeneration

1981 ◽  
Vol 59 (1) ◽  
pp. 136-137
Author(s):  
Steven R. Scadding
Keyword(s):  
Wound Healing ◽  
Acetylsalicylic Acid ◽  
Limb Regeneration ◽  
Limb Amputation ◽  
Prostaglandin E ◽  
Notophthalmus Viridescens ◽  
Bufo Americanus ◽  
Histological Appearance

Following limb amputation in the newt (Notophthalmus viridescens), the animals were given daily intraperitoneal injections of 0.1 or 1.0 mg of either indomethacin or acetylsalicylic acid. This had no observable influence on the rate or extent of limb regeneration or the histological appearance of the regenerating limb when compared with controls. Following limb amputation in toads (Bufo americanus), the limb stumps were injected daily for the first 15 days after amputation with 5 μg of either prostaglandin E1 or prostaglandin E2. Neither of these treatments had any observed effect on subsequent wound healing of the limbs when compared with controls. These observations suggest that prostaglandins do not play a major role in control of amphibian limb regeneration.

scholarly journals Regulatory Potential of bHLH-Type Transcription Factors on the Road to Rubber Biosynthesis in Hevea brasiliensis

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 674
Author(s):  
Tomoko Yamaguchi ◽  
Yukio Kurihara ◽  
Yuko Makita ◽  
Emiko Okubo-Kurihara ◽  
Ami Kageyama ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Early Stage ◽  
Rubber Biosynthesis ◽  
On The Road

Natural rubber is the main component of latex obtained from laticifer cells of Hevea brasiliensis. For improving rubber yield, it is essential to understand the genetic molecular mechanisms responsible for laticifer differentiation and rubber biosynthesis. Jasmonate enhances both secondary laticifer differentiation and rubber biosynthesis. Here, we carried out time-course RNA-seq analysis in suspension-cultured cells treated with methyljasmonic acid (MeJA) to characterize the gene expression profile. Gene Ontology (GO) analysis showed that the term “cell differentiation” was enriched in upregulated genes at 24 h after treatment, but inversely, the term was enriched in downregulated genes at 5 days, indicating that MeJA could induce cell differentiation at an early stage of the response. Jasmonate signaling is activated by MYC2, a basic helix–loop–helix (bHLH)-type transcription factor (TF). The aim of this work was to find any links between transcriptomic changes after MeJA application and regulation by TFs. Using an in vitro binding assay, we traced candidate genes throughout the whole genome that were targeted by four bHLH TFs: Hb_MYC2-1, Hb_MYC2-2, Hb_bHLH1, and Hb_bHLH2. The latter two are highly expressed in laticifer cells. Their physical binding sites were found in the promoter regions of a variety of other TF genes, which are differentially expressed upon MeJA exposure, and rubber biogenesis-related genes including SRPP1 and REF3. These studies suggest the possibilities that Hb_MYC2-1 and Hb_MYC2-2 regulate cell differentiation and that Hb_bHLH1 and Hb_bHLH2 promote rubber biosynthesis. We expect that our findings will help to increase natural rubber yield through genetic control in the future.

Specific effect of oestrone sulphate on protein synthesis and secretion by cultured epithelial cells from guinea-pig endometrium

1989 ◽  
Vol 123 (2) ◽  
pp. 233-NP ◽  
Author(s):  
G. Chaminadas ◽  
M. Alkhalaf ◽  
J. P. Rémy-Martin ◽  
A. Y. Propper ◽  
G. L. Adessi
Keyword(s):  
Protein Synthesis ◽  
Epithelial Cells ◽  
Progesterone Receptor ◽  
Guinea Pig ◽  
Cultured Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Specific Effect ◽  
Cellular Proteins ◽  
Oestrone Sulphate ◽  
In Cells

ABSTRACT Patterns of induced protein synthesis and secretion in guinea-pig endometrial epithelial cell cultures in response to oestrone sulphate alone and oestrone sulphate plus progesterone were investigated. Epithelial cells were cultured for 3 days in growth medium, then washed three times in a steroid-free medium. For each experiment, anticytokeratin immunostaining was used to discriminate the epithelial cells from the stromal cells. Only experiments in which the control dishes displayed more than 80% of anticytokeratinimmunostained cells were further processed. After this period oestradiol-17β (20 nmol/l; control), oestradiol-17β (20 nmol/l) plus progesterone (0·5 μmol/l), oestrone sulphate (1 μmol/l) or oestrone sulphate (1 μmol/l) plus progesterone (0·5 μmol/l) were added to the medium for 48 h. An immunocytochemical progesterone receptor assay showed that oestradiol-17β increased the progesterone receptor content of cells, and progesterone added to cultured cells in the presence of oestradiol-17β induced a significant increase in oestrogen sulphotransferase activity assessing the hormone responsiveness of the cultured cells. In these culture conditions and after 16 h of incubation, oestradiol-17β induced a 1·7-fold increase in [3H]thymidine incorporation into DNA, and [35S]methionine incorporation into cellular proteins was linearly increased up to 8 h. Biochemical changes induced by the different hormone treatments were studied by labelling the proteins with a 6-h pulse of [35S]methionine. The proteins present in the medium and in cells were analysed by two-dimensional polyacrylamide gel electrophoresis, followed by fluorography. Addition of oestrone sulphate alone or with progesterone produced a change in the patterns of cellular and secreted proteins compared with those in cells cultured with either oestradiol-17β or oestradiol-17β plus progesterone. Three cellular proteins (Mr < 14 000, isoelectric point (pI) 5·2 and 5·3; Mr 75 000, pI 4·9) and one secreted protein (Mr 155 000, pI 5·6–5·9) were specifically induced and could serve as markers of oestrone sulphate action. Journal of Endocrinology (1989) 123, 233–241

scholarly journals Collapse of Ribosome Biogenesis Induces Rapid Erythroblast Differentiation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2671-2671
Author(s):  
Anna Raimbault ◽  
Celia Floquet ◽  
Boris Guyot ◽  
Ulku Cuhadar ◽  
Olivier Kosmider ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Differentiation ◽  
Cell Growth ◽  
Cell Size ◽  
Ribosome Biogenesis ◽  
Size Reduction ◽  
Erythroid Cell ◽  
Specific Chemical ◽  
Final Maturation ◽  
Erythroid Cell Differentiation

Abstract Genetic insults of ribosomal protein (RP) genes including heterozygous mutations in Diamond Blackfan Anemia (DBA) or RPS14 haploinsufficiency in acquired 5q- syndrome selectively impair erythropoiesis suggesting that the integrity of ribosome biogenesis (RB) is fully required for the production of 10e11erythrocytes per day in humans. Defective RB consecutive to RPL5, RPL11 mutation or RPS14 deletion is thought to induce cell cycle arrest and a various degree of apoptosis in erythroblasts (EB). However, recent data showed that, loss of RPL5/RPL11neither induces apoptosis nor arrests cell cycle, but hampers the progression through the G1 phase, in primary fibroblasts. Furthermore, RB coordinates cell cycle to cell growth for the maintenance of constant cell size. In this work, we investigate the role of RB in erythroid cell differentiation and cell size regulation. We first analyzed the renewal of ribosome during in vitro differentiation of human EB derived from cytapheresis CD34+ cells and mouse erythroblasts derived from mouse fetal liver by a pulsed SILAC (Stable Isotopic Labeling by Amino acids in Culture cell) riboproteomic assay. Ribosome biogenesis dramatically decreases with the disappearance of proEB and basophilic EB and the onset of poly- and ortho-chromatophilic EB. Importantly, inhibition of RNA polI by CX-5461 in proEB forced them to enter the final maturation steps with an increase of glycophorin A (GPA) expression. To study the effect of RPS14 heterozygous deletion on RB, UT7/EPO cell line was infected by a lentivirus containing an inducible GFP-shRNA RPS14. After a 48-h treatment with doxycyclin, Rps14 protein expression was reduced by half and sorted GFP-positive cells had an altered ribosome profile devoid of 40S small subunit or 80S entire particle. Consistently, RB inhibition induced a cell size reduction. Second, we compared RB level in cells responsive to SCF+EPO or EPO alone. RB was optimal when EB responded to SCF+EPO and this was correlated with cell size being higher in SCF+EPO-responsive cells compared to EPO-responsive cells. Both cytokines additively activate the cell growth regulator, p70S6K1. Third, inhibition of p70S6K1 by rapamycin, or a specific chemical S6K1 inhibitor significantly reduced RB as shown by a 50% decrease of ribosome renewal in pulsed-SILAC. Inhibition of RB by rapamycin led to a size reduction and to GPA acquisition, which are the features of erythroid cell differentiation. Our data shows that the collapse of RB due to the loss of c-Kit and reduced activation of p70S6K1 is a key step for cell growth inhibition and induction of terminal differentiation in human or mouse erythroblasts. Disclosures No relevant conflicts of interest to declare.

Combinatorial control of cell differentiation by cAMP and DIF-1 during development of Dictyostelium discoideum

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 977-984 ◽  
Author(s):  
M. Berks ◽  
R.R. Kay
Keyword(s):  
Cell Differentiation ◽  
Normal Development ◽  
Specific Effect ◽  
Cell Types ◽  
Signal Molecules ◽  
Stage Of Development ◽  
Combinatorial Control ◽  
Cell Type Specific ◽  
Significant Pathway ◽  
Mrna Markers

At least three distinct types of cell arise from a population of similar amoebae during Dictyostelium development: prespore, prestalk A and prestalk B cells. We report evidence suggesting that this cellular diversification can be brought about by the combinatorial action of two diffusible signals, cAMP and DIF-1. Cells at different stages of normal development were transferred to shaken suspension, challenged with various combinations of signal molecules and the expression of cell-type-specific mRNA markers measured 1–2 h later. pDd63, pDd56 and D19 mRNAs were used for prestalk A, prestalk B and prespore cells respectively. We find the following results. (1) Cells first become responsive to DIF-1 for prestalk A differentiation and to cAMP for prespore differentiation at the end of aggregation, about 2 h before these cell types normally appear. (2) At the first finger stage of development, when the rate of accumulation of the markers is maximal, the expression of each is favoured by a unique combination of effectors: prespore differentiation is stimulated by cAMP and inhibited by DIF-1; prestalk A differentiation is stimulated by both cAMP and DIF-1 and prestalk B differentiation is stimulated by DIF-1 and inhibited by cAMP. (3) Half-maximal effects are produced by 10–70 nM DIF-1, which is in the physiological range. (4) Ammonia and adenosine, which can affect cell differentiation in other circumstances, have no significant pathway-specific effect in our conditions. These results suggest that cell differentiation could be brought about in normal development by the localized action of cAMP and DIF-1.

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