scholarly journals Tenascin in bone morphogenesis: expression by osteoblasts and cell type-specific expression of splice variants

1992 ◽  
Vol 103 (3) ◽  
pp. 765-771 ◽  
Author(s):  
E.J. Mackie ◽  
R.P. Tucker
Keyword(s):  
In Situ Hybridization ◽  
Splice Variants ◽  
Cdna Probe ◽  
Cell Type ◽  
Specific Expression ◽  
Primary Osteoblast ◽  
Cell Type Specific ◽  
Enriched Cultures

The extracellular matrix glycoprotein, tenascin, is associated in vivo with mesenchyme undergoing osteogenesis and chondrogenesis, but is absent from mature bone and cartilage matrix. The expression of tenascin by osteoblastic cells in vitro has been investigated by immunoblotting and immunocytochemistry. Tenascin was secreted into the medium and deposited in the matrix by human and rat osteoblast-like cell lines, as well as by primary osteoblast-enriched cultures from chick embryo calvarial bones. In primary osteoblast-enriched cultures, extracellular tenascin was found only in cell aggregates expressing the osteoblast marker alkaline phosphatase. Chicken osteoblast cultures synthesized almost exclusively the largest tenascin subunit, whereas fibroblast cultures from periostea of chicken calvariae synthesized approximately equal amounts of all three subunits. In situ hybridization studies of developing chicken bones, using a cDNA probe that hybridizes to all chicken tenascin splice variants, showed specific labelling of both osteogenic and chondrogenic regions of developing endochondral bones. In contrast, a cDNA probe specific for the large tenascin splice variant showed specific hybridization in osteogenic but not chondrogenic regions. Within osteogenic regions, tenascin mRNA was expressed by osteoblasts. A comparison of in situ hybridization and immunohistochemical studies demonstrated that tenascin mRNA and protein were codistributed in osteogenic regions of endochondral and membrane bones, whereas protein was retained in regions of differentiating cartilage where mRNA was no longer detectable. The results presented here demonstrate that tenascin is synthesized by osteoblasts. Moreover, within developing bones, there are at least three different cell type-specific patterns of expression of tenascin splice variants.

scholarly journals Combination of in situ hybridization and immunocytochemistry to detect messenger RNAs in identified CNS neurons and glia in tissue culture.

1991 ◽  
Vol 39 (7) ◽  
pp. 891-898 ◽  
Author(s):  
P A Trimmer ◽  
L L Phillips ◽  
O Steward
Keyword(s):  
In Situ Hybridization ◽  
Cdna Probe ◽  
Cell Types ◽  
Intermediate Filament Protein ◽  
Messenger Rnas ◽  
Cell Type ◽  
Protein Subunit ◽  
The Central Nervous System ◽  
Cell Type Specific

We have developed a technique in which immunofluorescence is combined with in situ hybridization using cDNA and RNA probes to assess the expression and distribution of messenger RNAs (mRNA) by neurons and neuroglia in tissue cultures of the rat dentate gyrus. The probes used in this study include a cDNA probe for ribosomal RNA (rRNA) and an RNA probe (cRNA) for glial fibrillary acidic protein (GEAP), an intermediate filament protein subunit expressed by astrocytes in the central nervous system. Both ubiquitous (tubulin) and cell type-specific (MAP-2 and GEAP) antibodies were used to identify neurons and neuroglia in culture. Using this procedure, the mRNA for rRNA was found in the cell bodies and large processes of MAP-2-positive neurons and throughout the cytoplasm of GEAP-positive flat astrocytes. In process-bearing astrocytes, GEAP mRNA is concentrated in the cell body, although some hybridization also occurred in astrocyte cell processes. With this combined in situ hybridization-immunofluorescence technique, the expression and distribution of an mRNA can be examined in different immunocytochemically identified cell types under identical culture and hybridization conditions. It is also possible to determine if there is a differential subcellular distribution of an mRNA in a single cell and if the distribution of the mRNA reflects the distribution of the protein itself. Finally, this technique can be utilized to verify the specificity of probes for cell type-specific mRNAs and to determine appropriate hybridization conditions to produce a specific signal.

scholarly journals Changing Patterns of Gene Expression in Dictyostelium Prestalk Cell Subtypes Recognized by In Situ Hybridization with Genes from Microarray Analyses

2003 ◽  
Vol 2 (3) ◽  
pp. 627-637 ◽  
Author(s):  
Mineko Maeda ◽  
Haruyo Sakamoto ◽  
Negin Iranfar ◽  
Danny Fuller ◽  
Toshinari Maruo ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Cell Types ◽  
Cell Type ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Changing Patterns ◽  
Cell Type Specific

ABSTRACT We used microarrays carrying most of the genes that are developmentally regulated in Dictyostelium to discover those that are preferentially expressed in prestalk cells. Prestalk cells are localized at the front of slugs and play crucial roles in morphogenesis and slug migration. Using whole-mount in situ hybridization, we were able to verify 104 prestalk genes. Three of these were found to be expressed only in cells at the very front of slugs, the PstA cell type. Another 10 genes were found to be expressed in the small number of cells that form a central core at the anterior, the PstAB cell type. The rest of the prestalk-specific genes are expressed in PstO cells, which are found immediately posterior to PstA cells but anterior to 80% of the slug that consists of prespore cells. Half of these are also expressed in PstA cells. At later stages of development, the patterns of expression of a considerable number of these prestalk genes changes significantly, allowing us to further subdivide them. Some are expressed at much higher levels during culmination, while others are repressed. These results demonstrate the extremely dynamic nature of cell-type-specific expression in Dictyostelium and further define the changing physiology of the cell types. One of the signals that affect gene expression in PstO cells is the hexaphenone DIF-1. We found that expression of about half of the PstO-specific genes were affected in a mutant that is unable to synthesize DIF-1, while the rest appeared to be DIF independent. These results indicate that differentiation of some aspects of PstO cells can occur in the absence of DIF-1.

scholarly journals Control of Cell Type Proportioning in Dictyostelium discoideum by Differentiation-Inducing Factor as Determined by In Situ Hybridization

2004 ◽  
Vol 3 (5) ◽  
pp. 1241-1248 ◽  
Author(s):  
Toshinari Maruo ◽  
Haruyo Sakamoto ◽  
Negin Iranfar ◽  
Danny Fuller ◽  
Takahiro Morio ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Dictyostelium Discoideum ◽  
Wild Type ◽  
Cell Type ◽  
Type Conversion ◽  
New Genes ◽  
A Cell ◽  
Cell Type Specific ◽  
Cell Type Conversion

ABSTRACT We have determined the proportions of the prespore and prestalk regions in Dictyostelium discoideum slugs by in situ hybridization with a large number of prespore- and prestalk-specific genes. Microarrays were used to discover genes expressed in a cell type-specific manner. Fifty-four prespore-specific genes were verified by in situ hybridization, including 18 that had been previously shown to be cell type specific. The 36 new genes more than doubles the number of available prespore markers. At the slug stage, the prespore genes hybridized to cells uniformly in the posterior 80% of wild-type slugs but hybridized to the posterior 90% of slugs lacking the secreted alkylphenone differentiation-inducing factor 1 (DIF-1). There was a compensatory twofold decrease in prestalk cells in DIF-less slugs. Removal of prespore cells resulted in cell type conversion in both wild-type and DIF-less anterior fragments. Thus, DIF-1 appears to act in concert with other processes to establish cell type proportions.

scholarly journals Induction of Golli-MBP Expression in CNS Macrophages During Acute LPS-Induced CNS Inflammation and Experimental Autoimmune Encephalomyelitis (EAE)

2007 ◽  
Vol 7 ◽  
pp. 112-120 ◽  
Author(s):  
Tracey L. Papenfuss ◽  
J. Cameron Thrash ◽  
Patricia E. Danielson ◽  
Pamela E. Foye ◽  
Brian S. Hllbrush ◽  
...  
Keyword(s):  
Experimental Autoimmune Encephalomyelitis ◽  
Cell Type ◽  
Autoimmune Encephalomyelitis ◽  
Cns Inflammation ◽  
Cell Type Specific ◽  
Candidate Molecule ◽  
Experimental Autoimmune

Microglia are the tissue macrophages of the CNS. Microglial activation coupled with macrophage infiltration is a common feature of many classic neurodegenerative disorders. The absence of cell-type specific markers has confounded and complicated the analysis of cell-type specific contributions toward the onset, progression, and remission of neurodegeneration. Molecular screens comparing gene expression in cultured microglia and macrophages identified Golli-myelin basic protein (MBP) as a candidate molecule enriched in peripheral macrophages.In situhybridization analysis of LPS/IFNg and experimental autoimmune encephalomyelitis (EAE)–induced CNS inflammation revealed that only a subset of CNS macrophages express Golli-MBP. Interestingly, the location and morphology of Golli-MBP+ CNS macrophages differs between these two models of CNS inflammation. These data demonstrate the difficulties of extendingin vitroobservations toin vivobiology and concretely illustrate the complex heterogeneity of macrophage activation states present in region- and stage-specific phases of CNS inflammation. Taken altogether, these are consistent with the emerging picture that the phenotype of CNS macrophages is actively defined by their molecular interactions with the CNS microenvironment.

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