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Seminars in Diagnostic Pathology Feb 2008Among benign primary cardiac tumors, myxomas and papillary fibroelastomas are the most common. Cardiac myxomas arise from pluripotent mesenchymal cells and are seen as... (Review)
Review
Among benign primary cardiac tumors, myxomas and papillary fibroelastomas are the most common. Cardiac myxomas arise from pluripotent mesenchymal cells and are seen as intracardiac, glistening polypoid masses arising most frequently from the interatrial septum in the left atrium. They are composed of stellate to polygonal myxoma cells in a mucopolysaccharide-rich matrix. These tumors can be sporadic or familial. On the other hand, papillary fibroelastomas are sporadic, seen as a mass of delicate papillary fronds ("sea anemone"-like) arising from a slender stalk, commonly located on diseased left-sided valves. They are lined by plump endothelial cells, which rest on stalks composed of mucopolysaccharides enclosing a collagen- and elastin-rich core. Embolism is often the mode of presentation for both of the tumors; myxomas are also associated with obstructive and constitutional symptoms. In contrast, neurogenic tumors (paraganglia or nerve sheath tumors) are exceedingly rare and occur as epicardial and infrequently as intracatdiac masses. The tumors are often incidentally diagnosed by the usual echocardiography, but magnetic resonance imaging is useful for further characterization of the tumors. The tumors are, in general, treated by surgical resection, but may require a little or at times more significant reconstruction. Among these tumors, the myxomas are associated with a higher rate of recurrences.
Topics: Heart Neoplasms; Humans; Mesoderm; Myxoma; Neoplasms, Fibroepithelial; Pluripotent Stem Cells
PubMed: 18350919
DOI: 10.1053/j.semdp.2007.10.005 -
Scientific Reports Nov 2016Pancreas development requires restrained Hedgehog (Hh) signaling activation. While deregulated Hh signaling in the pancreatic mesenchyme has been long suggested to be...
Pancreas development requires restrained Hedgehog (Hh) signaling activation. While deregulated Hh signaling in the pancreatic mesenchyme has been long suggested to be detrimental for proper organogenesis, this association was not directly shown. Here, we analyzed the contribution of mesenchymal Hh signaling to pancreas development. To increase Hh signaling in the pancreatic mesenchyme of mouse embryos, we deleted Patched1 (Ptch1) in these cells. Our findings indicate that deregulated Hh signaling in mesenchymal cells was sufficient to impair pancreas development, affecting both endocrine and exocrine cells. Notably, transgenic embryos displayed disrupted islet cellular composition and morphology, with a reduced β-cell portion. Our results indicate that the cell-specific growth rates of α- and β-cell populations, found during normal development, require regulated mesenchymal Hh signaling. In addition, we detected hyperplasia of mesenchymal cells upon elevated Hh signaling, accompanied by them acquiring smooth-muscle like phenotype. By specifically manipulating mesenchymal cells, our findings provide direct evidence for the non-autonomous roles of the Hh pathway in pancreatic epithelium development. To conclude, we directly show that regulated mesenchymal Hh signaling is required for pancreas organogenesis and establishment of its proper cellular composition.
Topics: Animals; Cell Proliferation; Epithelial Cells; Gene Expression Regulation, Developmental; Hedgehog Proteins; Homeodomain Proteins; Islets of Langerhans; Mesoderm; Mice, Transgenic; Pancreas; Patched-1 Receptor; Signal Transduction; Transcription Factors
PubMed: 27892540
DOI: 10.1038/srep38008 -
Wound Repair and Regeneration :... 1998A fundamental process in limb bud development is the formation of position-dependent cartilage pattern. Cells of the distal mesenchyme maintain positional values as the... (Review)
Review
A fundamental process in limb bud development is the formation of position-dependent cartilage pattern. Cells of the distal mesenchyme maintain positional values as the expression pattern of transcription factors, for example, hox genes, which induce position-related cell differentiation and cell surface differences. Cultured, dissociated limb bud mesenchymal cells segregate from each other, and eventually form cartilage nodules. This sorting out is position-dependent, not cell-type dependent, suggesting that the positional values may be involved. Positional valves were found to be retained in limb bud recombinants. In the chick system, the expression of HoxA13 and HoxD12 was present in the distal half of stage 20 recombinants, whereas these markers were expressed throughout the stages 25 recombinants. In the Xenopus system, multiple digit formation was introduced in limb recombinants, and a position-related relationship between regeneration potency and the multiple digit formation could be established. This determination of multiple digit formation with different stages of limb mesenchyme may be useful in understanding mechanisms of the loss of vertebrate limb regeneration potency.
Topics: Animals; Cells, Cultured; Hindlimb; In Vitro Techniques; Limb Buds; Mesoderm; Regeneration; Xenopus
PubMed: 9824559
DOI: 10.1046/j.1524-475x.1998.60416.x -
Results and Problems in Cell... 2024Many organs are composed of epithelial and mesenchymal tissue components. These two tissue component types develop via reciprocal interactions. However, for historical...
Many organs are composed of epithelial and mesenchymal tissue components. These two tissue component types develop via reciprocal interactions. However, for historical and technical reasons, the effects of the mesenchymal components on the epithelium have been emphasized. Well-documented examples are the regionally specific differentiation of the endoderm-derived primitive gut tube under the influence of surrounding mesenchyme. In contrast to a pile of reports on mesenchyme-derived signaling mechanisms, few studies have depicted the epithelial action in depth. This chapter highlights an example of an opposite action from the epithelial side, which was found in esophagus development.
Topics: Epithelium; Organogenesis; Signal Transduction; Mesoderm; Cell Differentiation
PubMed: 38509255
DOI: 10.1007/978-3-031-39027-2_7 -
Development, Growth & Differentiation Feb 1997Epithelial tissues in various organ rudiments undergo extensive shape changes during their development. The processes of epithelial shape change are controlled by tissue... (Review)
Review
Epithelial tissues in various organ rudiments undergo extensive shape changes during their development. The processes of epithelial shape change are controlled by tissue interactions with the surrounding mesenchyme which is kept in direct contact with the epithelium. One of the organs which has been extensively studied is the mouse embryonic submandibular gland, whose epithelium shows the characteristic branching morphogenesis beginning with the formation of narrow and deep clefts as well as changes in tissue organization. Various molecules in the mesenchyme, including growth factors and extracellular matrix components, affect changes of epithelial shape and tissue organization. Also, mesenchymal tissue exhibits dynamic properties such as directional movements in groups and rearrangement of collagen fibers coupled with force-generation by mesenchymal cells. The epithelium, during early branching morphogenesis, makes a cell mass where cell-cell adhesion systems are less developed. Such properties of both the mesenchyme and epithelium are significant for considering how clefts, which first appear as unstable tiny indentations on epithelial surfaces, are formed and stabilized.
Topics: Animals; Basement Membrane; Cell Adhesion; Collagen; Collagenases; Epithelium; Gestational Age; Matrix Metalloproteinase Inhibitors; Mesoderm; Mice; Submandibular Gland
PubMed: 9079029
DOI: 10.1046/j.1440-169x.1997.00001.x -
Developmental Biology Mar 2018The murine pancreas buds from the ventral embryonic endoderm at approximately 8.75 dpc and a second pancreas bud emerges from the dorsal endoderm by 9.0 dpc. Although it...
The murine pancreas buds from the ventral embryonic endoderm at approximately 8.75 dpc and a second pancreas bud emerges from the dorsal endoderm by 9.0 dpc. Although it is clear that secreted signals from adjacent mesoderm-derived sources are required for both the appropriate emergence and further refinement of the pancreatic endoderm, neither the exact signals nor the requisite tissue sources have been defined in mammalian systems. Herein we use DiI fate mapping of cultured murine embryos to identify the embryonic sources of both the early inductive and later condensed pancreatic mesenchyme. Despite being capable of supporting pancreas induction from dorsal endoderm in co-culture experiments, we find that in the context of the developing embryo, the dorsal aortae as well as the paraxial, intermediate, and lateral mesoderm derivatives only transiently associate with the dorsal pancreas bud, producing descendants that are decidedly anterior to the pancreas bud. Unlike these other mesoderm derivatives, the axial (notochord) descendants maintain association with the dorsal pre-pancreatic endoderm and early pancreas bud. This fate mapping data points to the notochord as the likely inductive source in vivo while also revealing dynamic morphogenetic movements displayed by individual mesodermal subtypes. Because none of the mesoderm examined above produced the pancreatic mesenchyme that condenses around the induced bud to support exocrine and endocrine differentiation, we also sought to identify the mesodermal origins of this mesenchyme. We identify a portion of the coelomic mesoderm that contributes to the condensed pancreatic mesenchyme. In conclusion, we identify a portion of the notochord as a likely source of the signals required to induce and maintain the early dorsal pancreas bud, demonstrate that the coelomic mesothelium contributes to the dorsal and ventral pancreatic mesenchyme, and provide insight into the dynamic morphological rearrangements of mesoderm-derived tissues during early organogenesis stages of mammalian development.
Topics: Animals; Embryo, Mammalian; Mesoderm; Mice; Organogenesis; Pancreas
PubMed: 29329912
DOI: 10.1016/j.ydbio.2018.01.003 -
The Journal of Investigative... Dec 1999The formation of skin appendages represents a morphogenetic process through which a homogeneous system is converted into a patterned system. We have pursued molecules... (Review)
Review
The formation of skin appendages represents a morphogenetic process through which a homogeneous system is converted into a patterned system. We have pursued molecules involved in the early placode induction and mesenchymal condensation stages of this process. We found that intracellular and extracellular signaling molecules collaborate to position the location of feather primordia and initiate mesenchymal condensations mediated by adhesion molecules. During the inductive stage, cells interact in a fashion best described by a reaction-diffusion mechanism. Thus in early feather morphogenesis, low level adhesion molecules drive cell interactions. The interactions were modulated by extracellular signaling molecules, which eventually increase the level of signaling molecules at sites of feather initiation and subsequently the level of adhesion molecules (Jiang et al, 1999a). These physico-chemical events lead to the formation of dermal condensations and epithelial placodes at sites of feather primordia, thus achieving the earliest and most fundamental events of skin appendage formation: induction.
Topics: Animals; Cell Adhesion Molecules; Cell Differentiation; Hair; Humans; Mesoderm; Signal Transduction; Skin; Skin Physiological Phenomena
PubMed: 10674386
DOI: 10.1038/sj.jidsp.5640234 -
Biology of Reproduction Dec 2022Morphogenesis of the female reproductive tract is regulated by the mesenchyme. However, the identity of the mesenchymal lineage that directs the morphogenesis of the...
Morphogenesis of the female reproductive tract is regulated by the mesenchyme. However, the identity of the mesenchymal lineage that directs the morphogenesis of the female reproductive tract has not been determined. Using in vivo genetic cell ablation, we identified Amhr2+ mesenchyme as an essential mesenchymal population in patterning the female reproductive tract. After partial ablation of Amhr2+ mesenchymal cells, the oviduct failed to develop its characteristic coiling due to decreased epithelial proliferation and tubule elongation during development. The uterus displayed a reduction in size and showed decreased cellular proliferation in both epithelial and mesenchymal compartments. More importantly, in the uterus, partial ablation of Amhr2+ mesenchyme caused abnormal lumen shape and altered the direction of its long axis from the dorsal-ventral axis to the left-right axis (i.e., perpendicular to the dorsal-ventral axis). Despite these morphological defects, epithelia underwent normal differentiation into secretory and ciliated cells in the oviduct and glandular epithelial cells in the uterus. These results demonstrated that Amhr2+ mesenchyme can direct female reproductive tract morphogenesis by regulating epithelial proliferation and lumen shape without affecting the differentiation of epithelial cell types.
Topics: Animals; Female; Mice; Genitalia, Female; Mesoderm; Morphogenesis; Oviducts; Protein Serine-Threonine Kinases; Uterus
PubMed: 36130202
DOI: 10.1093/biolre/ioac179 -
Scientific Reports Jun 2015Mesenchyme is an embryonic precursor tissue that generates a range of structures in vertebrates including cartilage, bone, muscle, kidney, and the erythropoietic system....
Mesenchyme is an embryonic precursor tissue that generates a range of structures in vertebrates including cartilage, bone, muscle, kidney, and the erythropoietic system. Mesenchyme originates from both mesoderm and the neural crest, an ectodermal cell population, via an epithelial to mesenchymal transition (EMT). Because ectodermal and mesodermal mesenchyme can form in close proximity and give rise to similar derivatives, the embryonic origin of many mesenchyme-derived tissues is still unclear. Recent work using genetic lineage tracing methods have upended classical ideas about the contributions of mesodermal mesenchyme and neural crest to particular structures. Using similar strategies in the Mexican axolotl (Ambystoma mexicanum), and the South African clawed toad (Xenopus laevis), we traced the origins of fin mesenchyme and tail muscle in amphibians. Here we present evidence that fin mesenchyme and striated tail muscle in both animals are derived solely from mesoderm and not from neural crest. In the context of recent work in zebrafish, our experiments suggest that trunk neural crest cells in the last common ancestor of tetrapods and ray-finned fish lacked the ability to form ectomesenchyme and its derivatives.
Topics: Amphibians; Animals; Biomarkers; Epidermis; Larva; Mesoderm; Muscles; Neural Crest; Tail
PubMed: 26086331
DOI: 10.1038/srep11428 -
Developmental Dynamics : An Official... Aug 1998Normal lung morphogenesis and cytodifferentiation require interactions between epithelium and mesenchyme. We have previously shown that distal lung mesenchyme (LgM) is...
Normal lung morphogenesis and cytodifferentiation require interactions between epithelium and mesenchyme. We have previously shown that distal lung mesenchyme (LgM) is capable of reprogramming tracheal epithelium (TrE) from day 13-14 rat fetuses to branch in a lung-like pattern and express a distal lung epithelial phenotype. In the present study, we have assessed the effects of tracheal mesenchyme (TrM) on branching and cytodifferentiation of distal lung epithelium (LgE). Tracheae and distal lung tips from day 13 rat fetuses were separated into purified epithelial and mesenchymal components, then recombined as homotypic (LgM + LgE or TrM + TrE) or heterotypic (LgM + TrE or TrM + LgE) recombinants and cultured for 5 days; unseparated lung tips and tracheae served as controls. Control lung tips, LgM + LgE, and LgM + TrE recombinants all branched in an identical pattern. Epithelial cells, including those from the induced TrE, contained abundant glycogen deposits and lamellar bodies, and expressed surfactant protein C (SP-C) mRNA. Trachea controls, and both TrM + TrE, and TrM + LgE recombinants did not branch, but instead formed cysts. The epithelium contained ciliated and mucous secretory cells; importantly, no cells containing lamellar bodies were observed, nor was SP-C mRNA detected. Mucin immunostaining showed copious production of mucous in both LgE and TrE when recombined with TrM. These results demonstrate that epithelial differentiation in the recombinants appears to be wholly dependent on the type of mesenchyme used, and that the entire respiratory epithelium has significant plasticity in eventual phenotype at this stage in development.
Topics: Animals; Cell Differentiation; Cells, Cultured; Epithelial Cells; Female; Lung; Mesoderm; Microscopy, Electron; Pregnancy; Rats; Rats, Sprague-Dawley; Subcellular Fractions; Trachea
PubMed: 9707322
DOI: 10.1002/(SICI)1097-0177(199808)212:4<482::AID-AJA2>3.0.CO;2-D