Search results for "Mesoderm"
showing 10 items of 51 documents
Interaction between mesenchymal cells and the posterior iris epithelium in chicken embryos
1977
The iris anlage of 3--10 day old chicken embryos was studied by both light and electron microscopy. Serial semithin sections showed that some of the mesenchymal cells overlying the eye cup moved into the primitive eye cavity by the 3rd day of incubation. On the 4th day some of these cells came into close contact with the basement membrane of the dorsal iris epithelium. The bases of the epithelial cells were flat at this stage. Towards the 10th day they formed cytoplasmic processes which did not penetrate the basement membrane. Fine mesenchymal cytoplasmic processes and a large number of extracellular fibrils developed in the epithelial--mesenchymal interface. The fine mesenchymal processes …
Arsenic trioxide alters the differentiation of mouse embryonic stem cell into cardiomyocytes
2015
AbstractChronic arsenic exposure is associated with increased morbidity and mortality for cardiovascular diseases. Arsenic increases myocardial infarction mortality in young adulthood, suggesting that exposure during foetal life correlates with cardiac alterations emerging later. Here, we investigated the mechanisms of arsenic trioxide (ATO) cardiomyocytes disruption during their differentiation from mouse embryonic stem cells. Throughout 15 days of differentiation in the presence of ATO (0.1, 0.5, 1.0 μM) we analysed: the expression of i) marker genes of mesoderm (day 4), myofibrillogenic commitment (day 7) and post-natal-like cardiomyocytes (day 15); ii) sarcomeric proteins and their orga…
α5β1 integrin-mediated adhesion to fibronectin is required for axis elongation and somitogenesis in mice.
2011
The arginine-glycine-aspartate (RGD) motif in fibronectin (FN) represents the major binding site for α5β1 and αvβ3 integrins. Mice lacking a functional RGD motif in FN (FN(RGE/RGE)) or α5 integrin develop identical phenotypes characterized by embryonic lethality and a severely shortened posterior trunk with kinked neural tubes. Here we show that the FN(RGE/RGE) embryos arrest both segmentation and axis elongation. The arrest is evident at about E9.0, corresponding to a stage when gastrulation ceases and the tail bud-derived presomitic mesoderm (PSM) induces α5 integrin expression and assumes axis elongation. At this stage cells of the posterior part of the PSM in wild type embryos are tight…
JNK ‐dependent gene regulatory circuitry governs mesenchymal fate
2015
The epithelial to mesenchymal transition (EMT) is a biological process in which cells lose cell-cell contacts and become motile. EMT is used during development, for example, in triggering neural crest migration, and in cancer metastasis. Despite progress, the dynamics of JNK signaling, its role in genomewide transcriptional reprogramming, and involved downstream effectors during EMT remain largely unknown. Here, we show that JNK is not required for initiation, but progression of phenotypic changes associated with EMT. Such dependency resulted from JNK-driven transcriptional reprogramming of critical EMT genes and involved changes in their chromatin state. Furthermore, we identified eight no…
Bone morphogenetic protein-4 is required for mesoderm formation and patterning in the mouse.
1995
Bone morphogenetic protein-4 (BMP-4) is a member of the TGF-beta superfamily of polypeptide signaling molecules, closely related to BMP-2 and to Drosophila decapentaplegic (DPP). To elucidate the role of BMP-4 in mouse development the gene has been inactivated by homologous recombination in ES cells. Homozygous mutant Bmp-4tm1blh embryos die between 6.5 and 9.5 days p.c., with a variable phenotype. Most Bmp-4tm1blh embryos do not proceed beyond the egg cylinder stage, do not express the mesodermal marker T(Brachyury), and show little or no mesodermal differentiation. Some homozygous mutants develop to the head fold or beating heart/early somite stage or beyond. However, they are development…
Exclusion of the Sonic Hedgehog gene as responsible for Currarino syndrome and anorectal malformations with sacral hypodevelopment.
1999
Anorectal malformations (ARMs) are common congenital anomalies that account for 1:4 digestive malformations. ARM patients show different degrees of sacral hypodevelopment while the hemisacrum is characteristic of the Currarino syndrome (CS). Cases of CS present an association of ARM, hemisacrum and presacral mass. A gene responsible for CS has recently been mapped in 7q36. Among the genes localized in this critical region, sonic hedgehog (SHH) was thought to represent a candidate gene for CS as well as for ARM with different levels of sacral hypodevelopment according to its role in the differentiation of midline mesoderm. By linkage analysis we confirmed the critical region in one large fam…
Expression of KIT (CD117) in Biphasic Pulmonary Blastoma. Novel Data on Histogenesis
2003
Biphasic pulmonary blastoma (BPB) is a rare primary neoplasm of the lung and its histogenesis is still uncertain. It has been proposed that BPB is derived from mesoderm or endoderm. Others suggested an origin from a single pluripotential cell. We present a case of a BPB with emphasis on expression of the stem cell factor receptor KIT (CD117). We describe a 61-year-old male patient with a BPB of the upper right lobe. Immunohistochemical analysis was performed using a panel of several antibodies including anti-CD117. Strong cytoplasmic expression of CD117 was found in the epithelium (cytokeratin-positive) as well as in the spindle cells (cytokeratin-negative). Expression of CD117 in both mese…
The T-box transcription factor eomesodermin controls CD8 T cell activity and lymph node metastasis in human colorectal cancer.
2007
An efficient cytolytic T cell function is essential for immune mediated rejection of colorectal cancer. However, the molecular mechanisms driving T cell mediated cancer rejection are still poorly understood. Here, we assessed the relevance of the T-box transcription factor eomesodermin in colorectal cancer. METHODS/ RESULTS: By analysing tissue probes from 88 different colorectal tumours, a significant (p0.02) inverse correlation between eomesodermin expression in colorectal cancers and the presence of lymph node metastases could be shown, whereas no such correlation was noted for the master transcription factor of regulatory T cells, FoxP3 and CD8 alpha expression. To evaluate whether this…
Role of the Angiotensin Type 2 Receptor Gene in Congenital Anomalies of the Kidney and Urinary Tract, CAKUT, of Mice and Men
1999
Angiotensin type 2 receptor gene null mutant mice display congenital anomalies of the kidney and urinary tract (CAKUT). Various features of mouse CAKUT impressively mimic human CAKUT. Studies of the human type 2 receptor (AGTR2) gene in two independent cohorts found that a significant association exists between CAKUT and a nucleotide transition within the lariat branchpoint motif of intron 1, which perturbs AGTR2 mRNA splicing efficiency. AGTR2, therefore, has a significant ontogenic role for the kidney and urinary tract system. Studies revealed that the establishment of CAKUT is preceded by delayed apoptosis of undifferentiated mesenchymal cells surrounding the urinary tract during key ont…
Villification: How the Gut Gets Its Villi
2013
Intestinal Villus Formation The intestinal villi are essential elaborations of the lining of the gut that increase the epithelial surface area for nutrient absorption. Shyer et al. (p. 212 , published online 29 August; see the Perspective by Simons ) show that in both the developing human and chick gut, the villi are formed in a step-wise progression, involving the sequential folding of the endoderm into longitudinal ridges, via a zigzag pattern, to finally form individual villi. These changes are established through the differentiation of the smooth muscle layers of the gut, restricting the expansion of the adjacent proliferating and growing endoderm and mesenchyme, generating compressive …