scholarly journals Pex mRNA Is Localized in Developing Mouse Osteoblasts and Odontoblasts

1998 ◽  
Vol 46 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Andréa Frota Ruchon ◽  
Mieczyslaw Marcinkiewicz ◽  
Géraldine Siegfried ◽  
Harriet S. Tenenhouse ◽  
Luc DesGroseillers ◽  
...  

Mutations in PEX, a phosphate-regulating gene with homology to endopeptidase on the X chromosome, were recently identified in patients with X-linked hypophosphatemia (XLH), an inherited disorder of phosphate homeostasis characterized by growth retardation and rachitic and osteomalacic bone disease. To understand the mechanism by which loss of PEX function elicits the mutant phenotype, a study of its mRNA localization and ontogenesis was undertaken. Using the reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) with polyA+ RNA purified from mouse testis, a 337-bp Pex cDNA fragment was generated and cloned in the pCRII plasmid. The cDNA was used to generate sense and anti-sense Pex riboprobes for in situ hybridization (ISH) and Northern analysis. To survey a large number of different tissues, sagittal sections of embryos and newborn mice were examined. ISH showed the presence of Pex mRNA in osteoblasts and odontoblasts. Pex gene expression was detectable on Day 15 of embryonic development, which coincides with the beginning of intercellular matrix deposition in bones. Finally, Northern analysis of total RNA from calvariae and teeth of 3-day-old and adult mice showed that the abundance of the 7-kb Pex transcript is decreased in adult bones and in nongrowing teeth. The present study demonstrates that Pex mRNA is expressed in bones and teeth and suggests that this putative endopeptidase plays an important role in the development of these tissues.

2001 ◽  
Vol 22 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Mario Menschikowski ◽  
Margot Vogel ◽  
Rolf Eckey ◽  
Gerd Dinnebier ◽  
Werner Jaross

In the present study a protocol of in situ reverse transcriptase‐nested polymerase chain reaction (in situ RT‐nested PCR) was examined based on the following modifications. (i) To exclude false positive signals caused by “DNA repair mechanisms” and “endogenous priming”, a two‐step PCR was applied after reverse transcription. The first step was performed in the presence of extrinsic primers and unlabeled nucleotides with a maximum of PCR cycles possible without destroying the cell morphology. The second step consisted of only one annealing/elongation reaction, the target sequence marked by addition of digoxigenin‐labeled nucleotides and intrinsic primers. (ii) In order to prevent amplifications of genomic DNA nested primer pairs were applied crossing intron sequences. (iii) To minimize the diffusion of PCR products in cells, the extrinsic primers were extended with complementary 5′‐tails. This approach results in the generation of high molecular weight concatamers during PCR cycles. By applying this protocol, immunostainings specific for phospholipase A2 of type IIA mRNA were exclusively detectable in the cytoplasm of HepG2 hepatoma cells, which were used as a model system, whereas the nuclei were unstained. Multiple control experiments yielded completely negative results. These data suggest that the in situ RT‐nested PCR, which in comparison to the method of in situ RT‐PCR‐in situ‐hybridisation is simpler and less time‐consuming, can be used as an alternative approach to identify intracellular nucleic acids.


2000 ◽  
Vol 84 (1) ◽  
pp. 65-75 ◽  
Author(s):  
Chung-Hsiung Wang ◽  
Hsi-Nan Yang ◽  
Hwei-Chung Liu ◽  
Guang-Hsung Kou ◽  
Chu-Fang Lo

1998 ◽  
Vol 274 (1) ◽  
pp. G122-G130 ◽  
Author(s):  
Naibedya Chattopadhyay ◽  
Ivan Cheng ◽  
Kimberly Rogers ◽  
Daniela Riccardi ◽  
Amy Hall ◽  
...  

The extracellular calcium ([Formula: see text])-sensing receptor (CaR) plays vital roles in [Formula: see text] homeostasis, but no data are available on its expression in small and large intestine. Polymerase chain reaction products amplified from reverse-transcribed duodenal RNA using CaR-specific primers showed >99% homology with the rat kidney CaR. Northern analysis with a CaR-specific cRNA probe demonstrated 4.1- and 7.5-kb transcripts in all intestinal segments. Immunohistochemistry with CaR-specific antisera showed clear basal staining of epithelial cells of small intestinal villi and crypts and modest apical staining of the former, whereas there was both basal and apical staining of colonic crypt epithelial cells. In situ hybridization and immunohistochemistry also demonstrated CaR expression in Auerbach’s myenteric plexus of small and large intestines and in the submucosa in the region of Meissner’s plexus. Our results reveal CaR expression in several cell types of small and large intestine, in which it may modulate absorptive and/or secretomotor functions.


1991 ◽  
Vol 130 (3) ◽  
pp. 443-NP ◽  
Author(s):  
T. J. Parkinson ◽  
H. J. Stewart ◽  
M. G. Hunter ◽  
D. S. C. Jones ◽  
D. C. Wathes ◽  
...  

ABSTRACT Analysis of ovine conceptus RNA by slot blotting, Northern analysis and nested polymerase chain reaction failed to detect oxytocin–neurophysin prohormone mRNA. Probes used hybridized with both the 3' end of the prohormone mRNA and the oxytocin-coding sequence. Northern analysis of bovine and porcine conceptus RNA was also negative, and polymerase chain reaction demonstrated oxytocin–neurophysin mRNA in ovine corpus luteum, but not in human corpus luteum or decidua, or in ovine endometrium. Infusion of oxytocin into the uterine lumen in cyclic ewes between days 9 and 19 or 20 after oestrus failed to prolong the luteal phase of the cycle and had no effect on endometrial oxytocin receptor concentrations or uterine prostaglandin F secretion. Oxytocin administered systematically prevented luteolysis and reduced uterine prostaglandin F secretion. Taken together, these data suggest that blastocyst-derived oxytocin is unlikely to contribute to corpus luteum maintenance in early pregnancy. They are inconsistent with a previous report that the ovine blastocyst synthesizes and secretes oxytocin. Journal of Endocrinology (1991) 130, 443–449


1995 ◽  
Vol 6 (7) ◽  
pp. 851-869 ◽  
Author(s):  
C L Wilson ◽  
K J Heppner ◽  
L A Rudolph ◽  
L M Matrisian

To explore the role of the matrix metalloproteinase matrilysin (MAT) in normal tissue remodeling, we cloned the murine homologue of MAT from postpartum uterus using RACE polymerase chain reaction and examined its pattern of expression in embryonic, neonatal, and adult mice. The murine coding sequence and the corresponding predicted protein sequence were found to be 75% and 70% identical to the human sequences, respectively, and organization of the six exons comprising the gene is similar to the human gene. Northern analysis and in situ hybridization revealed that MAT is expressed in the normal cycling, pregnant, and postpartum uterus, with levels of expression highest in the involuting uterus at early time points (6 h to 1.5 days postpartum). The mRNA was confined to epithelial cells lining the lumen and some glandular structures. High constitutive levels of MAT transcripts were also detected in the small intestine, where expression was localized to the epithelial Paneth cells at the base of the crypts. Similarly, MAT expression was found in epithelial cells of the efferent ducts, in the initial segment and cauda of the epididymis, and in an extra-hepatic branch of the bile duct. MAT transcripts were detectable only by reverse transcription-polymerase chain reaction in the colon, kidney, lung, skeletal muscle, skin, stomach, juvenile uterus, and normal, lactating, and involuting mammary gland, as was expression primarily late in embryogenesis. Analysis of MAT expression during postnatal development indicated that although MAT is expressed in the juvenile small intestine and reproductive organs, the accumulation of significant levels of MAT mRNA appears to correlate with organ maturation. These results show that MAT expression is restricted to specific organs in the mouse, where the mRNA is produced exclusively by epithelial cells, and suggest that in addition to matrix degradation and remodeling, MAT may play an important role in the differentiated function of these organs.


1998 ◽  
Vol 35 (3) ◽  
pp. 209-217 ◽  
Author(s):  
C. Schulze ◽  
W. Baumgärtner

The usefulness of two nucleic acid detection systems in suspected cases of spontaneous canine herpesvirus (CHV) infection in puppies was evaluated. Formalin-fixed, paraffin-embedded tissues from seven 1–3-week-old naturally infected puppies with lesions characteristic of CHV infection were investigated in a retrospective study. Nested polymerase chain reaction (PCR) and nonradioactive in situ hybridization (ISH) were used to detect nucleotide sequences of the CHV thymidine kinase (TK) gene. According to the original necropsy reports, CHV was isolated in four of the seven puppies using primary canine lung and/or kidney cells. In all seven puppies, gross and histologic lesions consisted of disseminated focal necroses and hemorrhages predominantly in kidneys, lung, liver, and spleen. In addition, few small amphophilic intranuclear inclusion bodies were detected by light microscopy mainly in epithelial cells of kidney, lung, and liver. ISH was performed with a 111-base-pair (bp) digoxigenin-labeled double-stranded DNA probe. Viral DNA was detected in the nuclei of cells near and within lesions. Various cell types, including bronchiolar and alveolar epithelial cells, hepatocytes, renal tubular epithelial cells, neurons, fibrocytes, cardiac myocytes, and endothelial cells, were positive for viral DNA. PCR amplification products of the expected length of 168 bp containing the expected cleavage site for the restriction enzyme EcoRI, derived from paraffin blocks containing lung, kidney, and liver tissues, were detected in all seven puppies. The specificity of the obtained amplicon was further confirmed by Southern blot analysis. ISH and PCR are both useful methods for diagnosing CHV infection in formalin-fixed, paraffin-embedded tissues and are highly specific and sensitive methods for further investigations of the pathogenesis of CHV-induced lesions.


1995 ◽  
Vol 268 (6) ◽  
pp. F1038-F1045 ◽  
Author(s):  
S. S. Chong ◽  
C. A. Kozak ◽  
L. Liu ◽  
K. Kristjansson ◽  
S. T. Dunn ◽  
...  

Renal tubular reabsorption of phosphate is critical to the maintenance of phosphate homeostasis in mammals, and the brush-border membrane Na-P(i) cotransport systems in proximal tubules play a major role in this process. We have isolated a cDNA encoding a mouse sodium-dependent phosphate transport protein (Npt1), which is expressed primarily in the kidney. This protein is highly similar to its human and rabbit homologues, based on nucleotide and amino acid comparisons. The presence of potential Asn-linked glycosylation and protein kinase C phosphorylation sites that are conserved among all three homologues suggests that these sites may be important in the function and regulation of this protein. The Npt1 gene was mapped to mouse chromosome 13, close to the Tcrg locus. By both in situ hybridization and reverse transcription-polymerase chain reaction, Npt1 mRNA was localized predominantly to the proximal tubule.


1997 ◽  
Vol 273 (5) ◽  
pp. L1073-L1081 ◽  
Author(s):  
Cheryl R. Killingsworth ◽  
Stephanie A. Shore ◽  
Francesca Alessandrini ◽  
Richard D. Dey ◽  
Joseph D. Paulauskis

Although the tachykinins substance P (SP) and neurokinin A have been largely localized to neurons, eosinophils have also been shown to express these peptides. Our aim was to determine whether rat alveolar macrophages (AM) express preprotachykinin gene-I (PPT-I) mRNA that encodes these tachykinins and to examine expression during inflammation. PPT-I mRNA was detected by reverse transcription (RT)-polymerase chain reaction (PCR) in AM and brain (control) but not in peritoneal macrophages. Northern analysis showed that PPT-I mRNA was induced two- to fourfold by in vivo treatment of rats with intratracheal lipopolysaccharide (LPS) and in vitro after 4 h of exposure to LPS. This increase was inhibited by dexamethasone. In situ RT-PCR and immunocytochemistry further confirmed that AM express PPT-I mRNA and SP-like immunoreactivity, respectively, which was enhanced by LPS treatment. A 1.3-kb transcript consistent with PPT-I mRNA was detected by Northern analysis of bronchoalveolar lavage neutrophils. Therefore, rat AM express PPT-I mRNA that is upregulated in AM by LPS and is attenuated by dexamethasone. PPT-I mRNA was also detected in lung neutrophils.


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