Differential expression of neurotrophin receptors during renal development

Development ◽  
1993 ◽  
Vol 119 (4) ◽  
pp. 977-989 ◽  
Author(s):  
M. Durbeej ◽  
S. Soderstrom ◽  
T. Ebendal ◽  
C. Birchmeier ◽  
P. Ekblom
Keyword(s):  
Growth Factors ◽  
Antisense Oligonucleotides ◽  
Kidney Development ◽  
Developmental Stages ◽  
Current Data ◽  
Organ Cultures ◽  
Experimental Conditions ◽  
High Affinity ◽  
Epithelial Sheets

Early kidney differentiation is driven by local cell-cell interactions. The metanephrogenic mesenchyme stimulates the epithelial ureter bud to grow and branch, whereas the ureter bud stimulates the mesenchyme to convert into a new epithelium. These interactions may be dependent on local growth factors and their receptors. We studied the expression of receptors for nerve growth factors during kidney development. Expression of the low- and high-affinity receptors was cell-type specific. The low-affinity NGF receptor was found in the uninduced mesenchyme at early developmental stages, but in the glomerular podocytes at later developmental stages. In contrast, the high-affinity trkB receptor was found in the cortical mesenchyme cells that will differentiate into stroma. The trkC receptor was found only weakly expressed and in a few parts of the collecting ducts. The role of these receptors and c-ros, a receptor-type kinase expressed on the tip of the ureter bud, was studied by modified antisense oligonucleotides. However, we found that both sense, antisense and nonsense phosphorothioate oligonucleotides inhibited mouse and rat embryonic kidney development in vitro. The oligonucleotides appeared to be toxic for rodent embryonic kidneys in the experimental conditions that we used. Moreover, oligonucleotides did not penetrate well into the epithelial sheets in the organ cultures. We conclude that studies with phosphorothioate antisense oligonucleotides in organ cultures of embryonic kidneys should be interpreted with caution. Our current data do not allow us to not assign a function for the low- or high-affinity NGF receptors or c-ros in kidney development.

The Culture in vitro of Urogenital Organs of Pleurodeles waltlii

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 465-470
Author(s):  
Charles L. Foote ◽  
Florence M. Foote
Keyword(s):  
Organ Culture ◽  
Germ Cells ◽  
Culture Medium ◽  
Developmental Stages ◽  
Rana Catesbeiana ◽  
Sex Differentiation ◽  
Organ Cultures ◽  
Tissue And Organ Culture ◽  
Pleurodeles Waltlii

Earlier reports (Foote & Foote, 1958a, b, 1959) describe growth and maintenance in vitro of larval organs, particularly gonads, of Rana catesbeiana and Xenopus laevis. Immature germ cells of both testes and ovaries are well maintained in vitro, especially if the culture medium is supplemented with watersoluble sex-hormonal substances, although germ cells in process of maturation become necrotic. Recently some urogenital organs from the salamander, Pleurodeles waltlii, have been grown in vitro. Tissues and organs from this amphibian might prove to be more suitable for tissue and organ culture investigations than those of Anurans. Animals at three different ages were used in this study: recently hatched larvae, metamorphosing animals, and adults. To determine whether sex differentiation would occur in vitro, trunk portions of young larvae of Pleurodeles waltlii of developmental stages 37–38 (Gallien & Durocher, 1957) were placed in organ cultures.

scholarly journals Differentiation of Neural Stem Cells Into Cells of Oligodendroglial Lineage

2007 ◽  
Vol 50 (1) ◽  
pp. 35-41
Author(s):  
Jaroslav Mokrý ◽  
Jana Karbanová ◽  
Dana Čížková ◽  
Jan Pazour ◽  
Stanislav Filip ◽  
...  
Keyword(s):  
Stem Cells ◽  
Growth Factors ◽  
Cell Differentiation ◽  
Neural Stem Cells ◽  
Developmental Stages ◽  
Developmental Studies ◽  
Differentiation Markers ◽  
Lineage Differentiation ◽  
Massive Cell Death

We described three different conditions that induce differentiation of dissociated neural stem cells derived from mouse embryonic CNS. In the first set of experiments, where the cell differentiation was triggered by cell adhesion, removal of growth factors and serum-supplemented medium, only sporadic neuronal and astroglial cells survived longer than two weeks and the latter formed a monolayer. When differentiation was induced in serum-free medium supplemented with retinoic acid, rapid and massive cell death occurred. A prolonged survival was observed in cultivation medium supplemented with serum and growth factors EGF plus FGF-2. One third of the cells did not express cell differentiation markers and were responsible for an increase in cell numbers. The remaining cells differentiated and formed the astrocytic monolayer on which occasional neuronal cells grew. One third of the differentiated phenotypes were represented by cells of oligodendroglial lineage. Differentiation of oligodendroglial cells occurred in a stepwise mechanism because the culture contained all successive developmental stages, including oligodendrocyte progenitors, preoligodendrocytes and immature and mature oligodendrocytes. Maturing oligodendrocytes displayed immunocytochemical and morphological features characteristic of cells that undergo physiological development. The cultivation conditions that supported growth and differentiation of neural stem cells were optimal for in vitro developmental studies and the production of oligodendroglial cells.

scholarly journals Cd44 Enhances Neuregulin Signaling by Schwann Cells

2000 ◽  
Vol 150 (5) ◽  
pp. 1071-1084 ◽  
Author(s):  
Larry S. Sherman ◽  
Tilat A. Rizvi ◽  
Saikumar Karyala ◽  
Nancy Ratner
Keyword(s):  
Growth Factors ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Cd44 Expression ◽  
High Affinity ◽  
Transmembrane Glycoprotein ◽  
Low Expression

We describe a key role for the CD44 transmembrane glycoprotein in Schwann cell–neuron interactions. CD44 proteins have been implicated in cell adhesion and in the presentation of growth factors to high affinity receptors. We observed high CD44 expression in early rat neonatal nerves at times when Schwann cells proliferate but low expression in adult nerves, where CD44 was found in some nonmyelinating Schwann cells and to varying extents in some myelinating fibers. CD44 constitutively associated with erbB2 and erbB3, receptor tyrosine kinases that heterodimerize and signal in Schwann cells in response to neuregulins. Moreover, CD44 significantly enhanced neuregulin-induced erbB2 phosphorylation and erbB2–erbB3 heterodimerization. Reduction of CD44 expression in vitro resulted in loss of Schwann cell–neurite adhesion and Schwann cell apoptosis. CD44 is therefore crucial for maintaining neuron–Schwann cell interactions at least partly by facilitating neuregulin-induced erbB2–erbB3 activation.

Selective PF4 Release In Vitro Induced by Heparin and Related Glycosaminoglycans (GAGs) - Correlation with β-TG Release and Platelet Aggregation

1984 ◽  
Vol 51 (01) ◽  
pp. 105-107 ◽  
Author(s):  
E Cofrancesco ◽  
M Colombi ◽  
G Cristoforetti ◽  
E M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Activation Process ◽  
Experimental Conditions ◽  
High Affinity ◽  
Human Platelet Aggregation ◽  
Release In Vitro ◽  
Heparin Preparation

SummaryWe studied human platelet aggregation and β-TG/PF4 release induced by heparin and related GAGs in vitro both in normal PRP and in PRP after aspirin. In our experimental conditions, heparin and related GAGs always caused PF4 release in vitro from normal platelets, whether or not there was measurable platelet aggregation in the aggregometer. Significant β-TG release was induced only by the mucosal heparin preparation (which also induced platelet aggregation in some citrated PRP). Therefore, while β-TG release in vitro seems to correlate with platelet aggregating activity of heparin, the selective PF4 release, caused by heparin and related GAGs also in conditions in which neither platelet aggregation nor β-TG are measurable, is probably associated with the high affinity of PF4 for heparin. The degree of affinity of GAGs for PF4 (heparin > DeS > HS) seems to correlate with PF4 release. Moreover, the significant reduction in PF4 release in vitro after aspirin suggests that GAGs-induced PF4 release is related to a cyclooxygenase-dependent activation process.

30 Antisense oligonucleotides against the urokinase receptor inhibit both urokinase-dependent and growth factors-dependent angiogenesis in vitro

1997 ◽  
Vol 11 ◽  
pp. 9
Author(s):  
Mario Del Rosso ◽  
Gabriella Fibbi ◽  
Marco Pucci ◽  
Enrica Anichini ◽  
Alessandra Zamperini ◽  
...  
Keyword(s):  
Growth Factors ◽  
Antisense Oligonucleotides ◽  
Urokinase Receptor

Chromosomal mosaicism in human blastocysts: the ultimate diagnostic dilemma

2020 ◽  
Vol 26 (3) ◽  
pp. 313-334 ◽  
Author(s):  
Mina Popovic ◽  
Lien Dhaenens ◽  
Annekatrien Boel ◽  
Björn Menten ◽  
Björn Heindryckx
Keyword(s):  
Next Generation Sequencing ◽  
Developmental Stages ◽  
Outcome Data ◽  
Current Data ◽  
Chromosomal Mosaicism ◽  
Next Generation ◽  
Diagnostic Dilemma ◽  
Preimplantation Genetic Testing ◽  
Generation Sequencing

Abstract BACKGROUND Trophectoderm (TE) biopsy and next generation sequencing (NGS) are currently the preferred techniques for preimplantation genetic testing for aneuploidies (PGT-A). Although this approach delivered important improvements over previous testing strategies, increased sensitivity has also prompted a rise in diagnoses of uncertain clinical significance. This includes reports of chromosomal mosaicism, suggesting the presence of karyotypically distinct cells within a single TE biopsy. Given that PGT-A relies on the chromosomal constitution of the biopsied cells being representative of the entire embryo, the prevalence and clinical implications of blastocyst mosaicism continue to generate considerable controversy. OBJECTIVE AND RATIONALE The objective of this review was to evaluate existing scientific evidence regarding the prevalence and impact of chromosomal mosaicism in human blastocysts. We discuss insights from a biological, technical and clinical perspective to examine the implications of this diagnostic dilemma for PGT-A. SEARCH METHODS The PubMed and Google Scholar databases were used to search peer-reviewed publications using the following terms: ‘chromosomal mosaicism’, ‘human’, ‘embryo’, ‘blastocyst’, ‘implantation’, ‘next generation sequencing’ and ‘clinical management’ in combination with other keywords related to the subject area. Relevant articles in the English language, published until October 2019 were critically discussed. OUTCOMES Chromosomal mosaicism predominately results from errors in mitosis following fertilization. Although it appears to be less pervasive at later developmental stages, establishing the true prevalence of mosaicism in human blastocysts remains exceedingly challenging. In a clinical context, blastocyst mosaicism can only be reported based on a single TE biopsy and has been ascribed to 2–13% of embryos tested using NGS. Conversely, data from NGS studies disaggregating whole embryos suggests that mosaicism may be present in up to ~50% of blastocysts. However, differences in testing and reporting strategies, analysis platforms and the number of cells sampled inherently overshadow current data, while added uncertainties emanate from technical artefacts. Moreover, laboratory factors and aspects of in vitro culture generate further variability. Outcome data following the transfer of blastocysts diagnosed as mosaic remain limited. Current studies suggest that the transfer of putative mosaic embryos may lead to healthy live births, but also results in significantly reduced ongoing pregnancy rates compared to the transfer of euploid blastocysts. Observations that a subset of mosaic blastocysts has the capacity to develop normally have sparked discussions regarding the ability of embryos to self-correct. However, there is currently no direct evidence to support this assumption. Nevertheless, the exclusion of mosaic blastocysts results in fewer embryos available for transfer, which may inevitably compromise treatment outcomes. WIDER IMPLICATIONS Chromosomal mosaicism in human blastocysts remains a perpetual diagnostic and clinical dilemma in the context of PGT-A. This review offers an important scientific resource, informing about the challenges, risks and value of diagnosing mosaicism. Elucidating these uncertainties will ultimately pave the way towards improved clinical and patient management.

The in Vitro Activity of Two Urinary Polypeptides Respect to G- and GM-CSF and IL3 on the Peripheral CFU of Normal and Leukemic Subjects

1995 ◽  
Vol 8 (3) ◽  
pp. 173-184
Author(s):  
A. Notario ◽  
I. Mazzucchelli ◽  
M. L. Rolandi ◽  
G. Fossati
Keyword(s):  
Growth Factors ◽  
Normal Subjects ◽  
Colony Growth ◽  
Experimental Conditions ◽  
Gm Csf ◽  
Pathological Conditions ◽  
Trans Retinoic Acid ◽  
Cellular Markers ◽  
Important Marker

We isolated two polypeptides on HPLC from the acetonic precipitate of the urine of normal subjects and of patients with untreated AML, APL and AMML. Before separation the quantity of the total urinary factor from leukemic patients was 50±10 mg/24h and from normal subjects was 10±5 mg. We tested the total polypeptidic extract and the two main fractions obtained on liquid cultures of the peripheral CFU of normal and leukemic subjects (AML, APL, CML and CMmL). Colony growth, cell morphology changes and the main cellular markers were examined at the beginning and at the 5th and 10th days of incubation in RPMI 1640 medium. Testing conditions were basal and as determined by the addition of the polypeptidic fractions, both alone and in association with trans-retinoic acid (t-RA) or thioproline (T). Simultaneously and under the same experimental conditions, we tested the activity of G- and GM-CSF and IL3. The results obtained prove the colony stimulating activity of the two fractions and of crude extract; they also prove the ability of such agents to modify the behavior in vitro of peripheral CFU. The urinary extracts are also able to stimulate a moderate differentiation of the elements and an increase both in fibroblasts and in adhesion molecules. We conclude that the dosage of growth factors in urine may be usefull as important marker in several hemopoietic pathological conditions or as a possible source of growth factors.

Calcium/calmodulin-dependent protein kinase II controls alpha5beta1 integrin-mediated inside-out signaling

1998 ◽  
Vol 111 (5) ◽  
pp. 657-665 ◽  
Author(s):  
D. Bouvard ◽  
A. Molla ◽  
M.R. Block
Keyword(s):  
Cell Adhesion ◽  
Specific Inhibitor ◽  
Cell Surface Expression ◽  
Scatchard Analysis ◽  
Experimental Conditions ◽  
Vitro Assay ◽  
High Affinity ◽  
Calcium Calmodulin Dependent ◽  
Fibronectin Binding

Fibronectin binding on alpha5beta1 integrin is strictly dependent on intracellular calcium. Using an in vitro assay, we previously found that either calcineurin inhibitors or a blocking calcineurin monoclonal antibody added to cell lysates completely abolished the fibronectin/integrin interaction, which suggested that the activity of calcineurin, a calcium/calmodulin-dependent phosphatase, was required to counteract some kinase activity and maintain the high affinity state of alpha5beta1. In this paper, we show that blocking of the calcium/calmodulin kinase II (CaMKII) activity with the specific inhibitor KN-62 or with its pseudosubtrate Autocamtide-2 preserved the high affinity state of the integrin even under experimental conditions that inhibit calcineurin. Conversely, the addition of purified CaMKII to the cell lysate inhibited alpha5beta1 binding to fibronectin in vitro. Consistent with these results, cell adhesion on fibronectin was stimulated by KN-62. Moreover, Scatchard analysis of fibronectin binding on CHO cells revealed that KN-62 decreased the Kd value from 0.3 to 0.05 microM. Finally the expression of exogenous constitutively active CaMKII resulted in a dramatic defect in cell adhesion with no significant modification in alpha5beta1 cell surface expression. In summary our results demonstrate that CaMKII controls the affinity state of the integrin alpha5beta1 in vitro and in living cells.

scholarly journals Insulin-like growth factors I and II are produced in the metanephros and are required for growth and development in vitro.

1991 ◽  
Vol 113 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
S A Rogers ◽  
G Ryan ◽  
M R Hammerman
Keyword(s):  
Growth Factors ◽  
Organ Culture ◽  
Growth And Development ◽  
Culture Media ◽  
Messenger Rnas ◽  
Organ Cultures ◽  
Igf I ◽  
Insulin Like Growth Factors

The role(s) of one family of polypeptide growth factors in a developing organ system was examined. Renal anlagen (metanephroi) were surgically removed from 13-d-old rat embryos and grown in organ culture for up to 6 d. Over this period of time when placed in serum-free defined media, the metanephroi increased in size and morphologic complexity. Messenger RNAs for both insulin-like growth factors (IGFs), IGF I and IGF II, were present in the metanephroi. Immunoreactive IGF I and IGF II were produced by the renal anlagen and released into culture media. Levels were relatively constant during the 6 d in culture and averaged 3.5 X 10(-9) M IGF I and 8.3 X 10(-9) M IGF II in media removed from metanephroi after contact for 24 h. IGF binding protein activity was not detected in culture media. Growth and development of metanephroi in vitro was prevented by the addition of anti-IGF I or anti-IGF II antibodies to organ cultures. IGF II produced by metanephroi was active in an IGF II biological assay system and addition of anti-IGF II receptor antibodies to organ cultures prevented growth and development, consistent with the action of IGF II in metanephroi being mediated via the IGF II receptor. The data demonstrate production of both IGF I and IGF II by developing rat metanephroi in organ culture. Each of these peptides is necessary for growth and development of the renal anlage to take place in vitro. Our findings suggest that both IGF I and IGF II are produced within the developing metanephros in vivo and promote renal organogenesis.

scholarly journals Toxicity of nanomaterials found in human environment

2017 ◽  
Vol 1 ◽  
pp. 239784731772635 ◽  
Author(s):  
Saura C Sahu ◽  
A Wallace Hayes
Keyword(s):  
Current Literature ◽  
General Information ◽  
Current Data ◽  
Consumer Products ◽  
Experimental Conditions ◽  
Human Environment ◽  
Toxicological Effects ◽  
Nanomaterial Characterization

The US National Nanotechnology Initiative (NNI) defines nanotechnology as “the understanding and control of matter at dimensions between approximately 1 and 100 nm, where unique phenomena enable novel applications.” Recent scientific reports available in the literature clearly demonstrate the potential benefits of nanotechnology in consumer and industrial products. More and more nanomaterials are expected to be used in consumer products. This is expected to lead to increased human exposure to nanomaterials in their daily lives. Therefore, the effect of nanomaterials present in human environment is an area of increasing scientific interest. The information presented in this review is obtained from the current literature. It indicates that nanomaterials found in human environment may have potential for toxicological effects. However, the current literature on toxicological effects of nanomaterials is diverse. The current data are presented from studies without harmonization. These studies have used different in vitro and in vivo test models, different sources of test nanomaterials, different methods for nanomaterial characterization, and different experimental conditions. Therefore, these data are hard to interpret. More research on nanomaterial characterization, biological interaction, toxicity, and health effects is needed. The test methods need to be validated. Positive and negative controls for nanotoxicity need to be identified. Toxicity data harmonization needs to be done. Therefore, general information is not currently available for risk evaluation of certain nanomaterials that might be present in consumer products or that may enter into the market in future. Standardized and validated methods are necessary for toxicity assessment of nanomaterials. Therefore, in the absence of standardized validated methods any specific regulatory testing requirements for nanomaterials are currently premature. We conclude that the benefits of nanomaterials found currently in human environment are many, but their overall adverse effects on human health are limited.

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