TGFbeta3 promotes transformation of chicken palate medial edge epithelium to mesenchyme in vitro

Development ◽  
1998 ◽  
Vol 125 (1) ◽  
pp. 95-105
Author(s):  
D. Sun ◽  
C.R. Vanderburg ◽  
G.S. Odierna ◽  
E.D. Hay

Epithelial-mesenchymal transformation plays an important role in the disappearance of the midline line epithelial seam in rodent palate, leading to confluence of the palate. The aim of this study was to test the potential of the naturally cleft chicken palate to become confluent under the influence of growth factors, such as TGFbeta3, which are known to promote epithelial-mesenchymal transformation. After labeling medial edge epithelia with carboxyfluorescein, palatal shelves (E8-9) with or without beak were dissected and cultured on agar gels. TGFbeta1, TGFbeta2 or TGFbeta3 was added to the chemically defined medium. By 24 hours in culture, medial edge epithelia form adherent midline seams in all paired groups without intact beaks. After 72 hours, seams in the TGFbeta3 groups disappear and palates become confluent due to epithelial-mesenchymal transformation, while seams remain mainly epithelial in control, TGFbeta1 and TGFbeta2 groups. Epithelium-derived mesenchymal cells are identified by carboxyfluorescein fluorescence with confocal microscopy and by membrane-bound carboxyfluorescein isolation bodies with electron microscopy. Labeled fibroblasts completely replace the labeled epithelia of origin in TGFbeta3-treated palates without beaks. Single palates are unable to undergo transformation, and paired palatal shelves with intact beaks do not adhere or undergo transformation, even when treated with TGFbeta3. Thus, physical contact of medial edge epithelia and formation of the midline seam are necessary for epithelial-mesenchymal transformation to be triggered. We conclude that there may be no fundamental difference in developmental potential of the medial edge epithelium for transformation to mesenchyme among reptiles, birds and mammals. The bird differs from other amniotes in having developed a beak and associated craniofacial structures that seemingly keep palatal processes separated in vivo. Even control medial edge epithelia partly transform to mesenchyme if placed in close contact. However, exogenous TGFbeta3 is required to achieve complete confluence of the chicken palate.

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 379-388 ◽  
Author(s):  
M.J. Carette ◽  
M.W. Ferguson

Fusion of bilateral shelves, to form the definitive mammalian secondary palate, is critically dependent on removal of the medial edge cells that constitute the midline epithelial seam. Conflicting views suggest that programmed apoptotic death or epithelial-mesenchymal transformation of these cells is predominantly involved. Due in part to the potentially ambiguous interpretation of static images and the notable absence of fate mapping studies, the process by which this is achieved has, however, remained mechanistically equivocal. Using an in vitro mouse model, we have selectively labelled palatal epithelia with DiI and examined the fate of medial edge epithelial (MEE) cells during palatal fusion by localisation using a combination of conventional histology and confocal laser scanning microscopy (CLSM). In dynamic studies using CLSM, we have made repetitive observations of the same palatal cultures in time-course investigations. Our results concurred with the established morphological criteria of seam degeneration; however, they provided no evidence of MEE cell death or transformation. Instead we report that MEE cells migrate nasally and orally out of the seam and are recruited into, and constitute, epithelial triangles on both the oral and nasal aspects of the palate. Subsequently these cells become incorporated into the oral and nasal epithelia on the surface of the palate. We hypothesize an alternative method of seam degeneration in vivo which largely conserves the MEE population by recruiting it into the nasal and oral epithelia.


Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 1087-1099 ◽  
Author(s):  
C.M. Griffith ◽  
E.D. Hay

During the fusion of rodent embryo palatal shelves, the cells of the outer epithelial layer slough off, allowing the cells of the medial edge basal layer to form a midline seam that undergoes epithelial-mesenchymal transformation, as judged by electron microscopy and immunohistochemistry. In this study, we analyze the fate of the transformed cells using a lipid soluble dye to label the medial edge epithelium in situ. Prefusion E14 mouse palates were exposed in vitro or in vivo to a fluoresceinated lipid soluble marker, carboxydichlorofluorescein diacetate succinimidyl ester (CCFSE), which localizes in epithelia as a lipid insoluble compound that does not pass into the connective tissue compartment. The midline seam that formed after 24 hours contained labelled epithelial cells that were replaced by individually labelled mesenchymal cells where the seam transformed. By light microscopy, the labelled cells were seen to contain intensely fluorescent bodies that do not react for acid phosphatase. We were able for the first time to identify these structures by electron microscopy as CCFSE isolation bodies. The cells with isolation bodies are clearly healthy and able to participate in subsequent development of the palate. At 4 days after labelling, individual CCFSE containing cells present in the palate mesenchyme occupy both midline and lateral areas and can clearly be classified as fibroblasts by electron microscopy. CCFSE is a far more useful marker than another lipid soluble marker, DiI, for following cells, because the cells can be fixed and identified both at the light and electron microscope levels. Interestingly, if labelled palatal shelves are not allowed to fuse in vitro, the basal epithelial cells do not form mesenchyme after sloughing, indicating that formation of the epithelial midline seam is necessary to trigger its epithelial-mesenchymal transformation.


1977 ◽  
Vol 37 (01) ◽  
pp. 073-080 ◽  
Author(s):  
Knut Gjesdal ◽  
Duncan S. Pepper

SummaryHuman platelet factor 4 (PF-4) showed a reaction of complete identity with PF-4 from Macaca mulatta when tested against rabbit anti-human-PF-4. Such immunoglobulin was used for quantitative precipitation of in vivo labelled PF-4 in monkey serum. The results suggest that the active protein had an intra-platelet half-life of about 21 hours. In vitro 125I-labelled human PF-4 was injected intravenously into two monkeys and isolated by immuno-precipita-tion from platelet-poor plasma and from platelets disrupted after gel-filtration. Plasma PF-4 was found to have a half-life of 7 to 11 hours. Some of the labelled PF-4 was associated with platelets and this fraction had a rapid initial disappearance rate and a subsequent half-life close to that of plasma PF-4. The results are compatible with the hypothesis that granular PF-4 belongs to a separate compartment, whereas membrane-bound PF-4 and plasma PF-4 may interchange.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1414
Author(s):  
Josep M. Cambra ◽  
Emilio A. Martinez ◽  
Heriberto Rodriguez-Martinez ◽  
Maria A. Gil ◽  
Cristina Cuello

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1160
Author(s):  
Adrien Chastel ◽  
Delphine Vimont ◽  
Stephane Claverol ◽  
Marion Zerna ◽  
Sacha Bodin ◽  
...  

Background: [68Ga]Ga-RM2 is a potent Gastrin-Releasing Peptide-receptor (GRP-R) antagonist for imaging prostate cancer and breast cancer, currently under clinical evaluation in several specialized centers around the world. Targeted radionuclide therapy of GRP-R-expressing tumors is also being investigated. We here report the characteristics of a kit-based formulation of RM2 that should ease the development of GRP-R imaging and make it available to more institutions and patients. Methods: Stability of the investigated kits over one year was determined using LC/MS/MS and UV-HPLC. Direct 68Ga-radiolabeling was optimized with respect to buffer (pH), temperature, reaction time and shaking time. Conventionally prepared [68Ga]Ga-RM2 using an automated synthesizer was used as a comparator. Finally, the [68Ga]Ga-RM2 product was assessed with regards to hydrophilicity, affinity, internalization, membrane bound fraction, calcium mobilization assay and efflux, which is a valuable addition to the in vivo literature. Results: The kit-based formulation, kept between 2 °C and 8 °C, was stable for over one year. Using acetate buffer pH 3.0 in 2.5–5.1 mL total volume, heating at 100 °C during 10 min and cooling down for 5 min, the [68Ga]Ga-RM2 produced by kit complies with the requirements of the European Pharmacopoeia. Compared with the module production route, the [68Ga]Ga-RM2 produced by kit was faster, displayed higher yields, higher volumetric activity and was devoid of ethanol. In in vitro evaluations, the [68Ga]Ga-RM2 displayed sub-nanomolar affinity (Kd = 0.25 ± 0.19 nM), receptor specific and time dependent membrane-bound fraction of 42.0 ± 5.1% at 60 min and GRP-R mediated internalization of 24.4 ± 4.3% at 30 min. The [natGa]Ga-RM2 was ineffective in stimulating intracellular calcium mobilization. Finally, the efflux of the internalized activity was 64.3 ± 6.5% at 5 min. Conclusion: The kit-based formulation of RM2 is suitable to disseminate GRP-R imaging and therapy to distant hospitals without complex radiochemistry equipment.


Author(s):  
Liqing Jia ◽  
Xiaolu Ge ◽  
Chao Du ◽  
Linna Chen ◽  
Yanhong Zhou ◽  
...  

Abstract Background Eukaryotic protein translation elongation factor 1α2 (EEF1A2) is an oncogene that promotes the progression of breast and pancreatic cancer. In this study, we aimed to elucidate the oncogenic function of EEF1A2 in the metastasis of lung adenocarcinoma (LUAD). Methods Immunohistochemistry and western blot were used to study EEF1A2 expression levels in LUAD tissues and cells, respectively. The role of EEF1A2 in LUAD progression were investigated in vitro and in vivo. We identified potential EEF1A2-binding proteins by liquid chromatography-electrospray mass spectrometry (LC-MS)/MS. Protein–protein interactions were determined by immunofluorescence and co-immunoprecipitation (Co-IP). Results In this study, we report that EEF1A2 mediates the epithelial–mesenchymal transformation (EMT), to promote the metastasis of LUAD cells in vitro and in vivo. Moreover, EEF1A2 interacts with HSP90AB1 to increase TGFβ Receptor (TβR)-I, and TβRII expression, followed by enhanced SMAD3 and pSMAD3 expression and nuclear localisation, which promotes the EMT of LUAD cells. Overexpression of EEF1A2 in cancer tissues is associated with poor prognosis and short survival of patients with LUAD. Conclusions These findings underscore the molecular functions of EEF1A2 in LUAD metastasis and indicate that EEF1A2 represents a promising target in the treatment of aggressive LUAD.


Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 293-302 ◽  
Author(s):  
E. A. MACINTYRE ◽  
C. G. EARNHART ◽  
S. L. KAATTARI

Perkinsus marinus is responsible for a chronic disease (Dermo) of the Eastern oyster, Crassostrea virginica. In order to simulate the in vivo environment more closely, a chemically defined medium (JL-ODRP-3) was supplemented with tissue homogenate extracts or plasma from oysters possessing varying degrees of susceptibility to P. marinus infection. In media supplemented with extracts from highly susceptible oysters (C. virginica), P. marinus cells secreted elevated amounts of a set of low molecular weight serine proteases (LMP: 30–45 kDa) as assessed by enhanced digestion within gelatin-substrate SDS–PAGE gels. Oyster species of low susceptibility (C. gigas and C. ariakensis) did not exhibit this ability to upregulate P. marinus LMP expression. Oyster extract supplementation also led to pronounced changes in P. marinus cellular morphology, such that the cells were comparable to those observed within naturally infected oysters.


1997 ◽  
Vol 110 (14) ◽  
pp. 1673-1682 ◽  
Author(s):  
J.G. Stone ◽  
L.I. Spirling ◽  
M.K. Richardson

The peptide endothelin 3 (EDN3) is essential for normal neural crest development in vivo, and is a potent mitogen for quail truncal crest cells in vitro. It is not known which subpopulations of crest cells are targets for this response, although it has been suggested that EDN3 is selective for melanoblasts. In the absence of cell markers for different precursor types in the quail crest, we have characterised EDN3-responsive cell types using in vitro colony assay and clonal analysis. Colonies were analysed for the presence of Schwann cells, melanocytes, adrenergic cells or sensory-like cells. We provide for the first time a description of the temporal pattern of lineage segregation in neural crest cultures. In the absence of exogenous EDN3, crest cells proliferate and then differentiate. Colony assay indicates that in these differentiated cultures few undifferentiated precursors remain and there is a low replating efficiency. By contrast, in the presence of 100 ng/ml EDN3 differentiation is inhibited and most of the cells maintain the ability to give rise to mixed colonies and clones containing neural crest derivatives. A high replating efficiency is maintained. In secondary culture there was a progressive decline in the number of cell types per colony in control medium. This loss of developmental potential was not seen when exogenous EDN3 was present. Cell type analysis suggests two novel cellular targets for EDN3 under these conditions. Contrary to expectations, one is a multipotent precursor whose descendants include melanocytes, adrenergic cells and sensory-like cells; the other can give rise to melanocytes and Schwann cells. Our data do not support previous claims that the action of EDN3 in neural crest culture is selective for cells in the melanocyte lineage.


1979 ◽  
Vol 34 (11) ◽  
pp. 948-950 ◽  
Author(s):  
Carl Fedtke ◽  
Robert R. Schmidt

Abstract The enzymatic activity from sugar beet leaves which is responsible for the detoxification of the herbicide metamitron (4-amino-4,5-dihydro-3-methyl-6-phenyl-1, 2, 4-triazin-5-one, trade name Goltix®) has been characterized in vitro. The detoxification occurs by rapid deamination in vivo as well as in vitro. However, the deamination in vitro is only maximal under reducing conditions, i. e. with an electron donor and in a nitrogen atmosphere. The electron donor may be cystein, glutathione, dithionite or ascorbate. The enzymatic deamination further requires the addition of cytochrome c and a “supernatant factor”, which may be replaced by FMN, FAD or DCPIP. However, in the presence of FMN or DCPIP cytochrome c is not essential but only stimulatory. The partic­ulate as well as the soluble metamitron deaminating enzyme preparations obtained take up oxygen when supplied with cysteine and FMN. The particulate enzyme appears in the peroxysome-fraction. It is therefore suggested, that the enzymatic deamination of metamitron in sugar beet leaves is mediated by a proxisomal membrane bound electron transport system which alternatively may reduce oxygen or metamitron (deaminating).


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