Biomedical subjects

M Wilda

Publications and source records attributed to M Wilda.

13 recordsLinked to original sources

PubMed2001

A high density of X-linked genes for general cognitive ability: a run-away process shaping human evolution?

The incidence of mental disability is 30% higher in males than in females. We have examined entries in the OMIM database that are associated with mental disability and for several other common defects. Our findings indicate that compared with the autosomes, the X chromosome contains a significantly higher number of genes that, when mutated, cause mental impairment. We propose that these genes are involved in the development of cognitive abilities and thus exert a large X-chromosome effect on general intelligence in humans. We discuss these conclusions with regard to the conservation of the vertebrate X-chromosomal linkage group and to human evolution.

Animals↗

PubMed2001

Protein kinase C isoenzyme: selective expression pattern of protein kinase C-θ during mouse development.

Protein kinase C (PKC)-θ, a serine/threonine protein kinase and novel PKC subfamily member, has been recently identified as an essential component of the T cell synapse which activates the NF-kB signaling cascade leading to expression of the IL-2 gene during T cell activation. By RNA in situ hybridization to whole-body embryo sections it is shown that the murine PKCθ is specifically expressed in tissues with hematopoietic and lymphopoietic activity. Expression is also evident in skeletal muscle. A further highly specific expression was observed in the peripheral and central nervous system which is described in detail. Expression in the brain persists up to adult stages.

Animals↗

PubMed2000

Identification of a novel putative Ran-binding protein and its close homologue.

In the process of cloning genes at the breakpoint of t(5;14) (q34;q11), a recurring translocation in acute lymphoblastic leukemia, we isolated and characterized a novel gene at 5q34, and a close human homologue (66% amino acid identity) located at 8p11-12. The presence of an importin-beta N-terminal domain at their N-terminus, their size of approximately 110 kD, their nuclear localization and the identity of the homologue to a gene of a recently submitted RanGTP binding protein (RanBP16), suggest that its protein is a novel member of the importin-beta superfamily of nuclear transport receptors, therefore called RanBP17. Northern blot analysis of human tissues revealed a ubiquitous expression pattern of the RanBP16 gene and a very restricted expression pattern of the RanBP17 gene, showing high expression in testis and pancreas. Both genes are evolutionary conserved and show a high (99 and 94%) amino acid conservation with their murine counterparts and a striking similarity (40%) to a protein product of Caenorhabditis elegans (C35A5.8).

Amino Acid Sequence↗

PubMed2000

Molecular cloning and characterization of the human protein kinase D2. A novel member of the protein kinase D family of serine threonine kinases.

We have isolated the full-length cDNA of a novel human serine threonine protein kinase gene. The deduced protein sequence contains two cysteine-rich motifs at the N terminus, a pleckstrin homology domain, and a catalytic domain containing all the characteristic sequence motifs of serine protein kinases. It exhibits the strongest homology to the serine threonine protein kinases PKD/PKCmicro and PKCnu, particularly in the duplex zinc finger-like cysteine-rich motif, in the pleckstrin homology domain and in the protein kinase domain. In contrast, it shows only a low degree of sequence similarity to other members of the PKC family. Therefore, the new protein has been termed protein kinase D2 (PKD2). The mRNA of PKD2 is widely expressed in human and murine tissues. It encodes a protein with a molecular mass of 105 kDa in SDS-polyacrylamide gel electrophoresis, which is expressed in various human cell lines, including HL60 cells, which do not express PKCmicro. In vivo phorbol ester binding studies demonstrated a concentration-dependent binding of [(3)H]phorbol 12,13-dibutyrate to PKD2. The addition of phorbol 12,13-dibutyrate in the presence of dioleoylphosphatidylserine stimulated the autophosphorylation of PKD2 in a synergistic fashion. Phorbol esters also stimulated autophosphorylation of PKD2 in intact cells. PKD2 activated by phorbol esters efficiently phosphorylated the exogenous substrate histone H1. In addition, we could identify the C-terminal Ser(876) residue as an in vivo phosphorylation site within PKD2. Phosphorylation of Ser(876) of PKD2 correlated with the activation status of the kinase. Finally, gastrin was found to be a physiological activator of PKD2 in human AGS-B cells stably transfected with the CCK(B)/gastrin receptor. Thus, PKD2 is a novel phorbol ester- and growth factor-stimulated protein kinase.

Amino Acid Sequence↗

PubMed2000

Expression pattern of the Nijmegen breakage syndrome gene, Nbs1, during murine development.

The Nijmegen breakage syndrome (NBS; MIM 251260), is an autosomal recessive disease characterized by microcephaly, growth retardation, immuno-deficiency and cancer predisposition. NBS cells show spontaneous chromosomal instability and hypersensitivity to ionizing radiation in combination with radioresistant DNA synthesis. At the cellular level, NBS has some features in common with ataxia teleangiectasia. In this study the murine Nbs1 gene was used for an expression study in mouse embryos at different developmental stages as well as in adult mice. A low level of expression is observed in all tissues. Highly specific expression was observed in organs with physiologic DNA double strand breakage (DSB), such as testis, thymus and spleen. Enhanced expression is also found at sites of high proliferative activity. These are the subventricular layer of the telencephalon and the diencephalon, the liver, lung, kidney and gut, as well as striated and smooth muscle cells in various organs. In the adult cerebellum the postmitotic Purkinje cells are marked specifically. These expression patterns suggest that in addition to the role of the Nbs1 gene product as part of a DNA DSB repair complex, the Nbs1 gene product may serve further functions during development.

Abnormalities, Multiple↗

PubMed2000

Role of MT-MMPs and MMP-2 in pancreatic cancer progression.

Activation of matrix metalloproteinase-2 (MMP-2) by the membrane-type matrix metalloproteinases (MT-MMPs) has been associated with tumor progression. In the present study, we examined the role of MMP-2 and its activators MT1-MMP, MT2-MMP and MT3-MMP in pancreatic tumor cell invasion and the development of the desmoplastic reaction characteristic of pancreatic cancer tissues. Northern blot analyses revealed that transcript levels of MT1-MMP and MT2-MMP, but not MT3-MMP, were enhanced in pancreatic cancer tissues (n = 18) compared with both chronic pancreatitis (n = 9) and healthy pancreas (n = 9). A good correlation was found between MT1-MMP and both MMP-2 expression (p < 0.01) and activity in pancreatic cancer tissues. In addition, expression and activation of MMP-2 were strongly associated with the extent of the desmoplastic reaction in pancreatic cancer tissues. Invasion assays showed a good correlation between MMP-2 expression and activity and the invasive potential of pancreatic cancer cell lines. In cell lines with high levels of MMP-2 expression and activity, the MMP inhibitor Batimastat led to significant reduction of the number of invading cells. Our results suggest that MT1-MMP is involved in the progression of pancreatic cancer via activation of MMP-2. MMP-2 itself plays an important role in tumor cell invasion and appears to be associated with the development of the characteristic desmoplastic reaction in pancreatic cancer.

Adenocarcinoma↗

PubMed2000

T cell expressed PKCtheta demonstrates cell-type selective function.

T lymphocyte stimulation leading to interleukin-2 (IL-2) expression requires activation of protein kinase C (PKC); however, the relevant PKC isoform(s) have not yet been systematically defined. Here we examine seven major T cell expressed PKC isoforms (PKCalpha, delta, epsilon, zeta, nu, theta and iota) and identify PKCtheta to be essential for IL-2 expression (via the critical NF-AT and NF-kappaB enhancer) in Jurkat T cells. Employing a conditionally activated PKCtheta estrogen-receptor fusion mutant, a de novo synthesis-independent transactivation of JNK2 was established. Based on mRNA in situ hybridization to mouse whole body sections, PKCtheta was found to be highly expressed in lymphoid organs but also skeletal muscle and the nervous system. PKCtheta function appears to be cell-type specific, since its isoenzyme-selective function was not observed in ectopic expression studies, employing COS-1 or NIH3T3 cells. These results confirm PKCtheta to be the prime target for the activating effect of phorbol ester in T cell signaling and suggest that gene expression as well as gene function of PKCtheta is strictly controlled by the cell type.

3T3 Cells↗

PubMed2000

Do the constraints of human speciation cause expression of the same set of genes in brain, testis, and placenta?

Evolution appears to be especially rapid during speciation, and the genes involved in speciation should be evident in species such as humans that have recently speciated or are presently in the process of speciation. Haldane's rule is that when one sex is sterile or inviable in interspecific F(1) hybrids, it is usually the heterogametic sex. For mammals, this implicates genes on the X chromosome as those particularly responsible for speciation. A preponderance of sex- and reproduction-related genes on the X chromosome has been shown repeatedly, but also mental retardation genes are more frequent on the X chromosome. We argue that brain, testis, and placenta are those organs most responsible for human speciation. Furthermore, the high degree of complexity of the vertebrate genome demands coordinate evolution of new characters. This coordination is best attained when the same set of genes is redeployed for these new characters in the brain, testis, and placenta.

Biological Evolution↗

PubMed2000

A comparison of the expression pattern of five genes of the family of small leucine-rich proteoglycans during mouse development.

For five members of the family of the small leucine-rich proteoglycans (SLRPs), the expression pattern during fetal development was analyzed. RNA in situ hybridization on whole body sections of mouse embryos was performed for biglycan (Bgn), decorin (Dcn), fibromodulin (Fmod), chondroadherin (Chad), and lumican (Lum). Special attention was given to the question of whether these patterns coincide only with sites of collagen secretion in connective tissue during tissue modeling or if expression can be observed at specific sites of organ differentiation also. In general, Fmod, Lum, and Bgn are expressed at sites of cartilage and bone formation and interstitial tissue deposition; Chad is expressed only at sites of cartilage; and Dcn is expressed only at sites of interstitial tissue deposition. However, there are some distinct developmental stages where no collagen secretion is known to occur. For example, this applies for the expression of Fmod in the forming somites of stage 9.5 postconception (p.c.), for Dcn and Lum in later stage embryos in the pituitary gland and dorsal root ganglia, and for Bgn and Dcn during differentiation in the kidney. These studies provide further evidence for a role of these molecules during connective tissue organization but also for an involvement at specific sites of organ differentiation.

Animals↗

PubMed1999

Expression and differential regulation of connective tissue growth factor in pancreatic cancer cells.

CTGF is an immediate early growth responsive gene that has been shown to be a downstream mediator of TGFbeta actions in fibroblasts and vascular endothelial cells. In the present study hCTGF was isolated as immediate early target gene of EGF/TGFalpha in human pancreatic cancer cells by suppression hybridization. CTGF transcripts were found in 13/15 pancreatic cancer cell lines incubated with 10% serum. In 3/7 pancreatic cancer cell lines EGF/TGFalpha induced a significant rise of CTGF transcript levels peaking 1-2 h after the start of treatment. TGFbeta increased CTGF transcript levels in 2/7 pancreatic cancer cell lines after 4 h of treatment and this elevation was sustained after 24 h. Only treatment with TGFbeta was accompanied by a parallel induction of collagen type I transcription. 15/19 human pancreatic cancer tissues were shown to overexpress high levels of CTGF transcripts. CTGF transcript levels in pancreatic cancer tissues and nude mouse xenograft tumors showed a good correlation to the degree of fibrosis. In situ hybridization and the nude mouse experiments revealed that in pancreatic cancer tissues, fibroblasts are the predominant site of CTGF transcription, whereas the tumor cells appear to contribute to a lesser extent. We conclude that CTGF may be of paramount importance for the development of the characteristic desmoplastic reaction in pancreatic cancer tissues.

Animals↗

PubMed1999

Expression of the highly conserved RNA binding protein KOC in embryogenesis.

The human KOC gene which is highly expressed in cancer shows typical structural features of an RNA binding protein. We analyzed the temporal and spatial expression pattern of KOC in mouse embryos at different gestational ages. The expression of KOC seems to be ubiquitous at early stages. During advanced gestation highest KOC expression occurs in the gut, pancreas, kidney, and in the developing brain. The expression pattern of KOC was compared to its Xenopus homologue Vg1-RBP during frog development. Similar expression was found in these organs suggesting an important functional role of the homologous proteins in embryonic development.

Amino Acid Sequence↗

PubMed1998

Characterization of the murine polycystic kidney disease (Pkd2) gene.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most frequent genetically transmitted disorders among Europeans with an attributed frequency of 0.1%. The two most common genetic determinants for ADPKD are the PKD1 and PKD2 genes. In this study we report the genomic structure and pattern of expression of the Pkd2 gene, the murine homolog of the human PKD2 gene. Pkd2 is localized on mouse Chromosome (Chr) 5 proximal to anchor marker D5Mit175, spans at least 35 kb of the mouse genome, and consists of 15 exons. Its translation product consists of 966 amino acids, and the peptide shows a 95% homology to human polycystin2. Functional domains are particularly well conserved in the mouse homolog. The expression of mouse polycystin2 in the developing embryo at day 12.5 post conception is localized in mesenchymally derived structures. In the adult mouse, the protein is mostly expressed in kidney, which suggests its functional relevance for this organ.

Animals↗

PubMed1998

The expression pattern of the Hmgic gene during development.

The technique of RNA in situ hybridization to mouse embryo sections from different developmental stages was used to perform a detailed analysis of the expression pattern of the gene for the architectural chromatin factor Hmgic. At early stages of fetal development (day 9.5 post conceptionem), Hmgic is expressed at a high rate throughout the whole embryo. In the second half of development, the pattern of expression becomes more restricted. Expression is found in mesenchymal derivatives, which differentiate into cartilage or muscle, in epithelial cell layers of the lung, pancreas, submandibular gland, and vibrissae, and in some special parts of the central nervous system. The expression pattern of Hmgic was compared with the previously reported studies of Hmgiy gene expression, another member of the Hmgic protein family, and with the expression of histone H4, Hist4, which is representative of cellular proliferation stages. In some tissues the pattern of expression for both factors coincides, but in others the expression is different. Hmgic expression correlates throughout fetal development with high proliferative activity. In contrast, Hmgiy is expressed also in tissues with no proliferative activity, such as the cortical plate of the telencephalon and the spinal cord at late gestational stages.

Animals↗