Differential deposition of basement membrane components during formation of the caudal neural tube in the mouse embryo

Development ◽  
1987 ◽  
Vol 99 (4) ◽  
pp. 509-519
Author(s):  
K.S. O'Shea

The distribution of basement membrane and extracellular matrix components laminin, fibronectin, type IV collagen and heparan sulphate proteoglycan was examined during posterior neuropore closure and secondary neurulation in the mouse embryo. During posterior neuropore closure, these components were densely deposited in basement membranes of neuroepithelium, blood vessels, gut and notochord; although deposition was sparse in the midline of the regressing primitive streak. During secondary neurulation, mesenchymal cells formed an initial aggregate near the dorsal surface, which canalized and merged with the anterior neuroepithelium. With aggregation, fibronectin and heparan sulphate proteoglycan were first detected at the base of a 3- to 4-layer zone of radially organized cells. With formation of a lumen within the aggregate, laminin and type IV collagen were also deposited in the forming basement membrane. During both posterior neuropore closure and secondary neurulation, fibronectin and heparan sulphate proteoglycan were associated with the most caudal portion of the neuroepithelium, the region where newly formed epithelium merges with the consolidated neuroepithelium. In regions of neural crest migration, the deposition of basement membrane components was altered, lacking laminin and type IV collagen, with increased deposition of fibronectin and heparan sulphate proteoglycan.


Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 41-49 ◽  
Author(s):  
M. Solursh ◽  
K.L. Jensen

The study describes the distribution of several basement membrane molecules in the embryonic chick wing bud from stages 23 to 26, during the onset of myogenesis and chondrogenesis, and then later at stage 28. Laminin is localized as early as stage 23, prior to the onset of myogenesis, in regions corresponding to the position of the future dorsal and ventral myogenic areas. Other matrix components, including fibronectin, do not differentially accumulate in these same regions. Fibronectin, basement membrane heparan sulphate proteoglycan and type IV collagen are more widespread in their distribution than laminin, and are even present between mesenchymal cells. These results suggest a role for laminin in the initial differentiation of the muscle masses and emphasize that components of basement membrane can also be associated with mesenchymal cells.



1984 ◽  
Vol 99 (3) ◽  
pp. 861-869 ◽  
Author(s):  
J G Heathcote ◽  
R R Bruns ◽  
R W Orkin

Rabbit lens epithelial cells display a similar "cobblestone" morphology and produce the same complement of sulphated macromolecules (also see Heathcote, J.G., and R.W. Orkin, 1984, J. Cell Biol., 99:852-860) whether grown on plastic or glass, dried films of gelatin or type IV collagen with laminin, or on gels of type I collagen. There was no evidence of basement membrane formation by these cells when they were grown on plastic, glass, or dried films. In contrast, cultures that had been grown on gels deposited a discrete basement membrane that followed the contours of the basal surfaces of the cells and in addition, they secreted amorphous basement membrane-like material that diffused into the interstices of the gel and associated with the collagen fibrils of the gel. A significant proportion (approximately 70%) of the heparan sulphate proteoglycan fraction that was secreted into the culture medium (fraction MI) when the cells were grown on plastic became associated with the cell-gel layer in the gel cultures. Further, when basement membrane was isolated by detergent extraction, greater than 90% of the 35S-labeled material present was in this heparan sulphate proteoglycan.







1990 ◽  
Vol 259 (2) ◽  
pp. L47-L52
Author(s):  
D. G. Hoyt ◽  
J. S. Lazo

Constant 7-day subcutaneous infusion of bleomycin (100 mg/kg) induces pulmonary fibrosis in C57Bl/6N mice, whereas BALB/cN mice are relatively resistant. In contrast, cyclophosphamide (200 mg/kg, ip) induces fibrosis in BALB/cN mice, whereas C57Bl/6N mice are resistant. The effect of these drugs on the pulmonary levels of mRNA encoding the major basement membrane components, laminin and type IV collagen, relative to poly (A+)RNA was determined in both C57Bl/6N and BALB/cN mice. In the sensitive C57Bl/6N mice, bleomycin increased alpha 1IV and alpha 2IV procollagen mRNA/poly (A+)RNA twofold in the absence of increases in laminin A, B1, and B2 mRNA/poly (A+)RNA. In the relatively resistant BALB/cN mice, bleomycin did not alter alpha 1IV procollagen mRNA/poly (A+)RNA and only transiently increased laminin A, B1, B2, and alpha 2IV procollagen mRNA/poly (A+)RNA. Similarly, cyclophosphamide increased alpha 1IV and alpha 2IV procollagen mRNA/poly (A+)RNA twofold in the sensitive BALB/cN mice and not in C57Bl/6N mice. Laminin mRNAs/poly (A+)RNA were not increased by cyclophosphamide in either strain. Thus, in these models, pulmonary fibrosis is preceded by a coordinate increase in steady-state levels of mRNA encoding basement membrane procollagen but is not associated with an increase in laminin gene expression



1993 ◽  
Vol 79 (6) ◽  
pp. 427-432 ◽  
Author(s):  
Marcello Guarino

Aims To investigate the distribution of basement membrane components type IV collagen and laminin in synovial sarcomas. Methods Paraffin sections from four synovial sarcomas were studied by the peroxidase-antiperoxldase procedure using specific antibodies to type IV collagen and laminin. Results Type IV collagen and laminin immunoreactivity was confined around epithelial areas in biphasic tumors. Several interruptions and discontinuities of the linear basement membrane profile were seen in sites of transition between mesenchymal and epithelial tissue. Moreover, a spot-like immunoreactivity was often observed in the spindle cell component of biphasic tumors. Monophasic tumors were either negative or showed a pericellular staining for both type IV collagen and laminin. Conclusions The distribution of basement membrane components is clearly related to the formation of epithelial elements in biphasic synovial sarcoma. The spot-like immunoreactivity of the spindle cell component, and the basement membrane interruptions at the boundary between mesenchymal and epithelial tissue, are both consistent with early basement membrane formation by developing epithelium. These findings support the concept that synovial sarcomas are basically soft tissue carcinosarcomas and that the epithelial component of the tumors develops by conversion of mesenchyme to epithelium.



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