The localization of laminin mRNA and protein in the postimplantation embryo and placenta of the mouse: an in situ hybridization and immunocytochemical study (original) (raw)
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Tissue distribution of the laminin β1 and β2 chain during embryonic and fetal human development
Journal of Molecular Histology, 2010
Laminins are the major glycoproteins present in all basement membranes. Previously, we showed that perlecan is present during human development. Although an overview of mRNA-expression of the laminin b1 and b2 chains in various developing fetal organs is already available, a systematic localization of the laminin b1 and b2 chains on the protein level during embryonic and fetal human development is missing. Therefore, we studied the immunohistochemical expression and tissue distribution of the laminin b1 and b2 chains in various developing embryonic and fetal human organs between gestational weeks 8 and 12. The laminin b1 chain was ubiquitously expressed in the basement membrane zones of the brain, ganglia, blood vessels, liver, kidney, skin, pancreas, intestine, heart and skeletal system. Furthermore, the laminin b2 chain was present in the basement membrane zones of the brain, ganglia, skin, heart and skeletal system. The findings of this study support and expand upon the theory that these two laminin chains are important during human development.
Regional differences in the expression of laminin isoforms during mouse neural tube development
Matrix Biology, 2011
Many significant human birth defects originate around the time of neural tube closure or early during post-closure nervous system development. For example, failure of the neural tube to close generates anencephaly and spina bifida, faulty cell cycle progression is implicated in primary microcephaly, while defective migration of neuroblasts can lead to neuronal migration disorders such as lissencephaly. At the stage of neural tube closure, basement membranes are becoming organised around the neuroepithelium, and beneath the adjacent non-neural surface ectoderm. While there is circumstantial evidence to implicate basement membrane dynamics in neural tube and surface ectodermal development, we have an incomplete understanding of the molecular composition of basement membranes at this stage. In the present study, we examined the developing basement membranes of the mouse embryo at mid-gestation (embryonic day 9.5), with particular reference to laminin composition. We performed in situ hybridization to detect the mRNAs of all eleven individual laminin chains, and immunohistochemistry to identify which laminin chains are present in the basement membranes. From this information, we inferred the likely laminin variants and their tissues of origin: that is, whether a given basement membrane laminin is contributed by epithelium, mesenchyme, or both. Our findings reveal major differences in basement composition along the body axis, with the rostral neural tube (at mandibular arch and heart levels) exhibiting many distinct laminin variants, while the lumbar level where the neural tube is just closing shows a much simpler laminin profile. Moreover, there appears to be a marked difference in the extent to which the mesenchyme contributes laminin variants to the basement membrane, with potential contribution of several laminins rostrally, but no contribution caudally. This information paves the way towards a mechanistic analysis of basement membrane laminin function during early neural tube development in mammals.
Experimental Cell Research, 2002
Protein levels, mRNA expression, and localization of laminin ␣1 and ␣2 chains in development and in adult mice were examined. Recombinant fragments were used to obtain high-titer-specific polyclonal antibodies for establishing quantitative radioimmunoinhibition assays. This often demonstrated an abundance of ␣2 chain, but also distinct amounts of ␣1 chain for adult tissues. The highest amounts of ␣1 were found in placenta, kidney, testis, and liver and exceeded those of ␣2. All other tissue extracts showed a higher content of ␣2, which was particularly high in heart and muscle when compared to ␣1. Content of ␥1 chain, shared by most laminins, was also analyzed. This demonstrated ␥1 chain levels being equal to or moderately exceeding the sum of ␣1 and ␣2 chains, indicating that these isoforms represent the major known laminin isoforms in most adult mouse tissues so far examined. Moreover, we found good correlation between radioimmuno-inhibition data and mRNA levels of adult tissues as measured by quantitative real-time reverse transcriptase-PCR. Embryonic tissues were also analyzed by radioimmuno-inhibition assays. This demonstrated for day 11 embryos comparable amounts of ␣1 and ␥1 and a more than 25-fold lower content of ␣2. This content increased to about 10% of ␣1 in day 13 embryos. The day 18 embryo showed in heart, kidney, and liver, but not yet in brain and lung, ␣1/␣2 chain ratios comparable to those in adult tissues. Immunostaining demonstrated ␣1 in Reichert's membrane (day 7.5), while ␣2 could not be detected before day 11.5. These data were compared with immunohistochemical localization results on several more embryonic and adult tissue sections. Our results regarding localization are consistent with those of earlier work with some notable exceptions. This was in part due to epitope masking for monoclonal antibodies commonly used in previous studies in esophagus, intestine, stomach, liver, kidney, and spleen.
Proceedings of the National Academy of Sciences, 1980
The glycoprotein laminin is found exclusively in the basement membranes of adult tissues, not in the mesenchymal stroma. We studied the appearance and distribution of laminin during the early formation of kidney tubules in mouse embryos and in an in vitro transfilter model system. In immunofluorescence using affinity-purified antibodies, the distribution of laminin showed a clear correlation, both spatially and temporally, to the early stages of tubule formation. In vivo, laminin was first detected in a punctate pattern in areas where the pretubular aggregates form; later, it became confined to the basement membranes of the tubules. In experiments in vitro, the nephrogenic mesenchyme was found to form tubules after 12-24 hr of transfilter contact with the inductor. The first laminin spots were found after 12 hr of culture, 24 hr before overt morphogenesis. As the mesenchymal cells began to aggregate and elongate (at 36 hr), laminin was detected in those cells destined to become epithelial, and at 48 hr it was not found in cells remaining in the stroma. In more mature tubules (at 72 hr), laminin was seen as a sharp band in the basement membranes.
Expression of laminin α1, α5 and β2 chains during embryogenesis of the kidney and vasculature
Matrix Biology, 1996
Laminins, found predominantly in basement membranes, are large glycoproteins consisting of different subsets of ix, 13 and y chain subunits. To resolve conflicting data in the literature concerning coexpression of ctl and 132 chains, expression of ixl chain was studied with two different antisera against the E3 fragment of laminin ix1 chain. Expression of the (xl chain was seen in several types of epithelial basement membranes throughout development, but its expression in rat glomerular basement membranes and some other types of epithelial basement membranes occurred only during early stages of development. By contrast, 132 chains were detected by immunofluorescence only during advanced stages of glomerulogenesis and vascular development. By Northern and Western blots, 132 chains were detected somewhat earlier, but in situ hybridization revealed that 132 chain was also confined to vasculature during the earlier stages. It thus seems that, in the tissues studied here, the expression of ix1 and 132 chains was mutually exclusive. To explore whether the newly described 0d chain is expressed in locations lacking ix1 chain, expression of ~5 chain was studied by Northern blots and in situ hybridization. The ct5 chain was not uniformly expressed in all embryonic epithelial cell types but was present mainly in epithelial sheets which produce very little ix1 chain. There also appeared to be a developmental trend, with ix1 chain appearing early and ix5 later, in maturing epithelial sheets. The 0d chain could be a major ix chain of the adult glomerular basement membrane.
2000
Two monoclonal antibodiesraisedagainstlamininisolatedfrom a mouse parietal yolksaccelllinewere used forimmunohistochemical studiesofbasement membranes ofthe mouse embryo and variousfetaland adulttissues.No immunoreactivitywitheitherofthetwo monoclonal antibodiescould be detected inthe preimplantation-stageembryos, although it has been shown thattheseembryos containextracellular lamininreactivewith the conven- tionalpolyclonalantilamininantibodies.Reichert'smembrane inearlypostimplantationstages ofdevelopment reactedwith themonoclonal antibody LAM-I butnotwiththeantibody LAM- II.However, from day 8 of pregnancy onward the Reichert'smembrane reactedwith both antibodies.Basement membranes of the embryo proper
Primary Structure, Developmental Expression, and Immunolocalization of the Murine Laminin α4 Chain
Journal of Biological Chemistry, 1997
The complete primary structure of the mouse laminin ␣4 chain was derived from cDNA clones. The translation product contains a 24-residue signal peptide preceding the mature ␣4 chain of 1,792 residues. Northern analysis on whole mouse embryos revealed that the expression was weak at day 7, but it later increased and peaked at day 15. In adult tissues the strongest expression was observed in lung and cardiac and skeletal muscles. Weak expression was also seen in other adult tissues such as brain, spleen, liver, kidney, and testis. By in situ hybridization of fetal and newborn tissues, expression of the laminin ␣4 chain was mainly localized to mesenchymal cells. Strong expression was seen in the villi and submucosa of the developing intestine, the mesenchymal stroma surrounding the branching lung epithelia, and the external root sheath of vibrissae follicles, as well as in cardiac and skeletal muscle fibers. In the developing kidney, intense but transient expression was associated with the differentiation of epithelial kidney tubules from the nephrogenic mesenchyme. Immunohistologic staining with affinity-purified IgG localized the laminin ␣4 chain primarily to lung septa, heart, and skeletal muscle, capillaries, and perineurium.
The Journal of Cell Biology, 1989
The appearance of extracellular matrix molecules and their receptors represent key events in the differentiation of cells of the kidney. Steady-state mRNA levels for a laminin receptor, the laminin B1, B2, and A chains, and the ctl-chain of collagen IV (ctl[IV]), were examined in mouse kidneys at 16 d gestation and birth, when cell differentiation is active, and 1-3 wk after birth when this activity has subsided. Northern analysis revealed that mRNA expression of laminin receptor precedes the otl(IV) and laminin B chains whereas laminin A chain mRNA expression was very low. In situ hybridization reflected this pattern and revealed the cells responsible for expression. At 16 d gestation, laminin receptor mRNA was elevated in cells of newly forming glomeruli and proximal and distal tubules of the nephrogenic zone located in the kidney cortex. These cells also expressed mRNA for cd(IV) and laminin chains. At birth, mRNA expression of receptor and all chains remained high in glomeruli but was reduced in proximal and distal tubules. At 1 wk after birth, expression was located in the medulla over collecting ducts and loops of Henle. Little expression was detectable by 3 wk. These results suggest that cellular expression of steady-state mRNA for laminin receptor, laminin, and collagen IV is temporally linked, with laminin receptor expression proceeding first and thereafter subsiding.
Primary structure, developmental expression, and immunolocalization of the murine laminin ��4 chain
1997
The complete primary structure of the mouse laminin ␣4 chain was derived from cDNA clones. The translation product contains a 24-residue signal peptide preceding the mature ␣4 chain of 1,792 residues. Northern analysis on whole mouse embryos revealed that the expression was weak at day 7, but it later increased and peaked at day 15. In adult tissues the strongest expression was observed in lung and cardiac and skeletal muscles. Weak expression was also seen in other adult tissues such as brain, spleen, liver, kidney, and testis. By in situ hybridization of fetal and newborn tissues, expression of the laminin ␣4 chain was mainly localized to mesenchymal cells. Strong expression was seen in the villi and submucosa of the developing intestine, the mesenchymal stroma surrounding the branching lung epithelia, and the external root sheath of vibrissae follicles, as well as in cardiac and skeletal muscle fibers. In the developing kidney, intense but transient expression was associated with the differentiation of epithelial kidney tubules from the nephrogenic mesenchyme. Immunohistologic staining with affinity-purified IgG localized the laminin ␣4 chain primarily to lung septa, heart, and skeletal muscle, capillaries, and perineurium.
Developmental Expression and Cellular Origin of the Laminin α2, α4, and α5 Chains in the Intestine
Developmental Biology, 1999
Laminins are extracellular matrix glycoproteins that are involved in various cellular functions, including adhesion, proliferation, and differentiation. In this study, we examine the expression patterns and the cellular origins of the laminin ␣2, ␣4, and ␣5 chains in the developing mouse intestine and in in vitro mouse/chick or chick/mouse interspecies hybrid intestines. In situ hybridization and Northern blot analysis revealed that mRNA levels for all three laminin ␣ chains are highest in the fetal intestine undergoing intense morphogenetic movements. Laminin ␣4 mRNA and polypeptide are associated with mesenchyme-derived cell populations such as endothelium and smooth muscle. In contrast, laminin ␣2 and ␣5 chains participate in the structural organization of the subepithelial basement membrane and, in the mature intestine, show a complementary pattern of expression. All three laminin ␣ chains occur in the smooth muscle basement membrane, with a differential expression of laminin ␣5 chain in the circular and longitudinal smooth muscle layers. The cellular origin of laminin ␣2 and ␣5 chains found in the subepithelial cell basement membrane was studied by immunocytochemical analysis of mouse/chick or chick/mouse interspecies hybrid intestines at various stages of development using mousespecific antibodies. Laminin ␣2 was found to be deposited into the basement membrane exclusively by mesenchymal cells, while the laminin ␣5 chain was deposited by both epithelial and mesenchymal cells in an apparently developmentally regulated pattern. We conclude that (1) multiple laminin ␣ chains are expressed in the intestine, implying specific roles for individual laminin isoforms during intestinal development, and (2) reciprocal epithelial/mesenchymal interactions are essential for the formation of a structured subepithelial basement membrane.