253. Toxic effects of hyperglycaemia arise from induced O-linked glycosylation in early mouse embryos

2008 ◽  
Vol 20 (9) ◽  
pp. 53
Author(s):  
M. Pantaleon ◽  
H. Tan ◽  
P. L. Kaye
Keyword(s):  
Cell Proliferation ◽  
Negative Impact ◽  
Cell Number ◽  
Signalling Pathway ◽  
Blastocyst Formation ◽  
Hexosamine Biosynthetic Pathway ◽  
Sense And Respond ◽  
Pathway Inhibition ◽  
Early Mouse ◽  
Glcnac Transferase

Glucose flux through the hexosamine biosynthetic pathway (HBP) which is essential for preimplantation development (1) produces uridine 5′-diphospho-N-acetylglucosamine, a donor substrate for multiple glycosylation reactions including O-linked glycosylation. This novel signalling arm of the HBP, known as the hexosamine signalling pathway (HSP) operates via reversible addition of an O-linked β-N-acetylglucosamine (O-GlcNAc) unit to serine and threonine residues of proteins including transcription factors, cytoskeletal components, metabolic enzymes and cellular signalling components. O-linked glycosylation is functionally reciprocal to phosphorylation at the same residues, altering the activity and/or stability of targeted proteins, thus providing a mechanism for modulating cellular physiology in response to glucose availability. The enzymes regulating this O-GlcNAcylation are the β-linked-O-GlcNAc transferase (OGT) and an O-GlcNAc-selective β-N-acetylglucosaminidase (O-GlcNAcase). We hypothesised that the toxicity of hyperglycemia on early embryos arises from increased flux through HBP and increased O-GlcNAcylation of key proteins. Mouse zygotes (18 h post hCG) were cultured under conditions of modified flux through the HSP including hypoglycemia, hyperglycemia or supplemented with glucosamine which feeds exclusively into the HBP to increase downstream O-GlcNAcylation. BADGP was used to inhibit OGT and O-GlcNAcylation. Blastocyst formation, cell proliferation and apoptosis were assessed. Treatments that perturb levels of intracellular protein O-GlcNAcylation inhibited embryo development. Whilst some flux through HBP is required to activate embryonic differentiation (1), excess flux arising from a hyperglycemic environment or glucosamine supplementation reduced cell proliferation and blastocyst formation, confirming the criticality of this novel post-translational signalling pathway. Inhibition of OGT using 2 mM BADGP blocked the negative impact of hyperglycemia on blastocyst formation, cell number and apoptosis supporting our hypothesis that O-GlcNAcylation is a key mechanism used by the embryo to sense and respond to perturbations of glucose in its environment. (1) Pantaleon M, Scott J and Kaye PL (2008) Biol Reprod, 78(4):595–600

scholarly journals Müllerian Inhibiting Substance Is Required for Germ Cell Proliferation during Early Gonadal Differentiation in Medaka (Oryzias latipes)

Endocrinology ◽  
2007 ◽  
Vol 149 (4) ◽  
pp. 1813-1819 ◽  
Author(s):  
Eri Shiraishi ◽  
Norifumi Yoshinaga ◽  
Takeshi Miura ◽  
Hayato Yokoi ◽  
Yuko Wakamatsu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Germ Cell ◽  
Germ Cells ◽  
Sex Differentiation ◽  
Somatic Cells ◽  
Oryzias Latipes ◽  
Cell Number ◽  
Gonadal Differentiation ◽  
Loss Of Function ◽  
Germ Cell Proliferation

Müllerian inhibiting substance (MIS) is a glycoprotein belonging to the TGF-β superfamily. In mammals, MIS is responsible for the regression of Müllerian ducts in the male fetus. However, the role of MIS in gonadal sex differentiation of teleost fish, which have no Müllerian ducts, has yet to be clarified. In the present study, we examined the expression pattern of mis and mis type 2 receptor (misr2) mRNAs and the function of MIS signaling in early gonadal differentiation in medaka (teleost, Oryzias latipes). In situ hybridization showed that both mis and misr2 mRNAs were expressed in the somatic cells surrounding the germ cells of both sexes during early sex differentiation. Loss-of-function of either MIS or MIS type II receptor (MISRII) in medaka resulted in suppression of germ cell proliferation during sex differentiation. These results were supported by cell proliferation assay using 5-bromo-2′-deoxyuridine labeling analysis. Treatment of tissue fragments containing germ cells with recombinant eel MIS significantly induced germ cell proliferation in both sexes compared with the untreated control. On the other hand, culture of tissue fragments from the MIS- or MISRII-defective embryos inhibited proliferation of germ cells in both sexes. Moreover, treatment with recombinant eel MIS in the MIS-defective embryos dose-dependently increased germ cell number in both sexes, whereas in the MISRII-defective embryos, it did not permit proliferation of germ cells. These results suggest that in medaka, MIS indirectly stimulates germ cell proliferation through MISRII, expressed in the somatic cells immediately after they reach the gonadal primordium.

scholarly journals STUDIES IN THE BIOLOGY OF METALS

1928 ◽  
Vol 48 (5) ◽  
pp. 659-665 ◽  
Author(s):  
Frederick S. Hammett ◽  
Vilma L. Wallace
Keyword(s):  
Cell Proliferation ◽  
Chick Embryo ◽  
Body Length ◽  
Rapid Growth ◽  
Cell Number ◽  
Point Of View ◽  
Lead Ion ◽  
Head Region ◽  
Differential Development

Our study of the effect of the lead ion on the development of the chick embryo has brought out the following facts: 1. Gross growth is retarded. 2. Somite growth is retarded to a degree greater than that exhibited by body length and width. 3. The head and optic anlagen are regions of particular sensitivity. Their differential development is markedly inhibited. From the purely biological point of view these results are in line with the findings of Child (10) and his school as to the sensitivity of the head end of rapidly growing organisms to harmful influences, and with those of Stockard (11) as to the peculiar sensitivity of the optic anlagen. It is almost too well known to need repetition that the head region and the somites of embryos are specific areas of intense growth by increase in cell number. Therefore, turning from the general to the particular, the differential retardation of these regions which is caused by lead, is evidence justifying the conclusion that it is areas of rapid growth by cell proliferation which are selectively inhibited by this metallic ion.

Cell signalling pathway involved in PACAP-induced AR4-2J cell proliferation

1995 ◽  
Vol 7 (3) ◽  
pp. 195-205 ◽  
Author(s):  
Jean Morisset ◽  
Nadine Douziech ◽  
Grazyna Rydzewska ◽  
Louis Buscail ◽  
Nathalie Rivard
Keyword(s):  
Cell Proliferation ◽  
Cell Signalling ◽  
Signalling Pathway ◽  
Cell Signalling Pathway

scholarly journals si-SNHG5-FOXF2 inhibits TGF-β1-induced fibrosis in human primary endometrial stromal cells by the Wnt/β-catenin signalling pathway

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Limin Liu ◽  
Guobin Chen ◽  
Taoliang Chen ◽  
Wenjuan Shi ◽  
Haiyan Hu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Stromal Cells ◽  
Target Genes ◽  
Cell Model ◽  
Ex Vivo ◽  
Signalling Pathway ◽  
Endometrial Stromal Cells ◽  
Downstream Target ◽  
Related Proteins ◽  
Tgf Β1

Abstract Background Intrauterine adhesions (IUAs) are manifestations of endometrial fibrosis characterized by inflammation and fibrinogen aggregation in the extracellular matrix (ECM). The available therapeutic interventions for IUA are insufficiently effective in the clinical setting for postoperative adhesion recurrence and infertility problems. In this study, we investigated whether si-SNHG5-FOXF2 can serve as a molecular mechanism for the inhibition of IUA fibrosis ex vivo. Methods FOXF2, TGF-β1 and collagen expression levels were measured by microarray sequencing analysis in three normal endometrium groups and six IUA patients. We induced primary human endometrial stromal cells (HESCs) into myofibroblasts (MFs) to develop an IUA cell model with various concentrations of TGF-β1 at various times. Downstream target genes of FOXF2 were screened by chromatin immunoprecipitation combined with whole-genome high-throughput sequencing (ChIP-seq). We investigated ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs with FOXF2 downregulation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blotting (WB), immunohistochemistry (IHC), flow cytometry, ethylenediurea (EdU) and CCK8 assays. We identified long noncoding RNAs (lncRNA) SNHG5 as the upstream regulatory gene of FOXF2 through RNA immunoprecipitation (RIP), RNA pulldown and fluorescence in situ hybridization (FISH). Finally, we examined FOXF2 expression, ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs upon FOXF2 downregulation. Results FOXF2 was highly expressed in the endometrium of patients with IUA. Treatment of primary HESCs with 10 ng/ml TGF-β1 for 72 h was found to be most effective for developing an IUA cell model. FOXF2 regulated multiple downstream target genes, including collagen, vimentin (VIM) and cyclin D2/DK4, by ChIP-seq and ChIP-PCR. FOXF2 downregulation inhibited TGF-β1-mediated primary HESC fibrosis, including ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related protein expression. We identified lncRNA SNHG5 as an upstream gene that directly regulates FOXF2 by RIP-seq, qRT-PCR, WB and FISH. SNHG5 downregulation suppressed FOXF2 expression in the IUA cell model, resulting in synergistic repression of the Wnt/β-catenin pathway, thereby altering TGF-β1-mediated ECM aggregation in endometrial stromal cells ex vivo. Conclusions Regulation of the Wnt/β-catenin signalling pathway and ECM formation by si-SNHG5-FOXF2 effectively inhibited the profibrotic effect of TGF-β1 on primary HESCs. This finding can provide a molecular basis for antagonizing TGF-β1-mediated fibrosis in primary HESCs.

scholarly journals Hexosamine Biosynthetic Pathway Inhibition Leads to AML Cell Differentiation and Cell Death

2018 ◽  
Vol 17 (10) ◽  
pp. 2226-2237 ◽  
Author(s):  
Abhishek Asthana ◽  
Parameswaran Ramakrishnan ◽  
Yorleny Vicioso ◽  
Keman Zhang ◽  
Reshmi Parameswaran
Keyword(s):  
Cell Death ◽  
Cell Differentiation ◽  
Biosynthetic Pathway ◽  
Hexosamine Biosynthetic Pathway ◽  
Pathway Inhibition

Micromere fate maps in leech embryos: lineage-specific differences in rates of cell proliferation

Development ◽  
1994 ◽  
Vol 120 (12) ◽  
pp. 3427-3438 ◽  
Author(s):  
C. M. Smith ◽  
D. A. Weisblat
Keyword(s):  
Cell Proliferation ◽  
Late Stage ◽  
Squamous Epithelium ◽  
Cell Lineage ◽  
Cell Number ◽  
Animal Pole ◽  
Fluorescent Cell ◽  
Plate Formation

Stereotyped early cleavages in glossiphoniid leech embryos yield 25 micromeres, along with 3 macromeres and 10 teloblasts. The micromeres generate prostomial tissues and also give rise to most of the squamous epithelium of a provisional integument that spreads epibolically from the animal pole, covering the rest of the embryo during germinal plate formation. We systematically injected individual micromeres with fluorescent cell lineage tracers at the time of their birth and quantitatively mapped the contributions of all these cells to the late stage 7 embryo, a time in development that is early in the epibolic expansion. At this time, micromere derivatives comprise two types of cells: squamous epithelial (superficial) cells that cover the germinal bands and the region of the animal cap between the germinal bands; and underlying (deep) cells that are confined to the distal ends of the germinal bands and in the area between their distal ends. We find that individual micromeres contribute clones of deep and/or superficial progeny that are stereotyped with respect to both numbers and types of cells in the clone and the domains that they occupy. The N teloblasts also contribute cells to the squamous epithelium. We find significant differences in the rate of cell proliferation between different micromere clones. These differences appear to reflect lineage-specific traits, since there is little or no regulation of cell number after ablation of individual micromeres.

Heterogeneous differentiation of external cells in individual isolated early mouse inner cell masses in culture

Development ◽  
1984 ◽  
Vol 80 (1) ◽  
pp. 225-240
Author(s):  
J. Nichols ◽  
R. L. Gardner
Keyword(s):  
Mitotic Cycle ◽  
Giant Cells ◽  
Cell Number ◽  
Small Cells ◽  
External Layer ◽  
Tissue Heterogeneity ◽  
Dense Suspension ◽  
Early Mouse ◽  
Do So

Inner cell masses (ICMs) were isolated from early blastocysts by immunosurgery and incubated in a dense suspension of melanin granules for 3h after 21 h in culture. The majority of such labelled ICMs subsequently formed outgrowths in vitro in which either giant cells or small solitary cells contained melanin granules. However, a substantial minority produced outgrowths in which both types of cell were unequivocally labelled. Labelled cells appeared from the results of control experiments to have originated within the external layer of the ICM. The giant cells were indistinguishable morphologically from those formed by authentic trophectodermal tissue. The small cells were identified as belonging to the extraembryonic endodermal lineage on the basis of their distribution in host conceptuses following injection into blastocysts. These findings support the conclusion reached in previous studies that early ICM cells can engage in trophectodermal differentiation under certain conditions. In addition, by providing evidence that both trophectoderm and endoderm cells can differentiate from the outer layer of the same ICM, they argue that loss of cellular lability is not coordinated throughout this tissue. Heterogeneity in the differentiation of external cells may depend on differences in both the stage of the mitotic cycle and the number of such cycles that they have completed since fertilization. Finally, cell number in isolated early ICMs was found to increase approximately two-fold during the first 24 h of culture in the present experiments. This contrasts with the results of previous experiments in which cell number either increased more modestly or failed to do so altogether.

scholarly journals Is resistant starch protective against colorectal cancer via modulation of the WNT signalling pathway?

2015 ◽  
Vol 74 (3) ◽  
pp. 282-291 ◽  
Author(s):  
Fiona C. Malcomson ◽  
Naomi D. Willis ◽  
John C. Mathers
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Resistant Starch ◽  
Wnt Pathway ◽  
Wnt Signalling ◽  
Signalling Pathway ◽  
Wnt Signalling Pathway ◽  
Crypt Cell Proliferation ◽  
And Migration ◽  
Epigenetic Modulation

Epidemiological and experimental evidence suggests that non-digestible carbohydrates (NDC) including resistant starch are protective against colorectal cancer. These anti-neoplastic effects are presumed to result from the production of the SCFA, butyrate, by colonic fermentation, which binds to the G-protein-coupled receptor GPR43 to regulate inflammation and other cancer-related processes. The WNT pathway is central to the maintenance of homeostasis within the large bowel through regulation of processes such as cell proliferation and migration and is frequently aberrantly hyperactivated in colorectal cancers. Abnormal WNT signalling can lead to irregular crypt cell proliferation that favours a hyperproliferative state. Butyrate has been shown to modulate the WNT pathway positively, affecting functional outcomes such as apoptosis and proliferation. Butyrate's ability to regulate gene expression results from epigenetic mechanisms, including its role as a histone deacetylase inhibitor and through modulating DNA methylation and the expression of microRNA. We conclude that genetic and epigenetic modulation of the WNT signalling pathway may be an important mechanism through which butyrate from fermentation of resistant starch and other NDC exert their chemoprotective effects.

Retinoic acid-induced proliferation of lung alveolar epithelial cells: relation with the IGF system

1998 ◽  
Vol 275 (1) ◽  
pp. L71-L79 ◽  
Author(s):  
Elodie Nabeyrat ◽  
Valérie Besnard ◽  
Sophie Corroyer ◽  
Véronique Cazals ◽  
Annick Clement
Keyword(s):  
Cell Proliferation ◽  
Retinoic Acid ◽  
Growth Factor ◽  
Alveolar Epithelium ◽  
Cell Number ◽  
Dependent Manner ◽  
Alveolar Epithelial ◽  
Igf System ◽  
Tgf Β1

Retinoids, including retinol and retinoic acid (RA) derivatives, are important molecules for lung growth and homeostasis. The presence of RA receptors and of RA-binding proteins in the alveolar epithelium led to suggest a role for RA on alveolar epithelial cell replication. In the present study, we examined the effects of RA on proliferation of the stem cells of the alveolar epithelium, the type 2 cells. We showed that treatment of serum-deprived type 2 cells with RA led to a stimulation of cell proliferation, with an increase in cell number in a dose-dependent manner. To gain some insights into the mechanisms involved, we studied the effects of RA on the expression of several components of the insulin-like growth factor (IGF) system that have been shown to be associated with the growth arrest of type 2 cells, mainly the IGF-binding protein-2 (IGFBP-2), IGF-II, and the type 2 IGF receptor. We documented a marked decrease in the expression of these components upon RA treatment. Using conditioned media from RA-treated cells, we provided evidence that the proliferative response of type 2 cells to RA was mediated through production of growth factor(s) distinct from IGF-I. We also showed that RA was able to reduce the decrease in cell number observed when type 2 cells were treated with transforming growth factor (TGF)-β1. These results together with the known stimulatory effect of TGF-β1 on IGFBP-2 expression led to suggest that RA may be associated with type 2 cell proliferation through mechanisms interfering with the TGF-β1 pathway.

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