Cloning and expression of the human single copy homologue of the mouse zinc finger protein zfr

A human homologue of the murine zinc finger protein zfr is transcriptionally induced in the Epstein-Barr virus-positive Burkitt lymphoma cell line Raji upon treatment with the granulocyte/macrophage lineage ganglioside IV(3)NeuAc-nLcOse(4)Cer. The gene was cloned by a rapid amplification of cDNA ends approach based on a cDNA clone. The resulting hzfr sequence is 3393 base pairs in length coding for a protein of 1057 amino acids. Sequence alignments between hzfr and zfr reveal an identity of 92% on the nucleotide level and an identity of 96.4% on the amino acid level, respectively. Based on Southern blot data hzfr can be addressed as a single copy gene. Tissue-specific expression was determined by semi-quantitative PCR of normalized cDNA populations from various human tissues with glyceraldehyde-3-phosphate dehydrogenase as an internal control. Highest levels of transcripts were found in brain. hzfr transcripts could not be detected in skeletal muscle.

[Experiences with calcitonin treatment of patients with type I complex regional pain syndrome (CRPS I--Sudeck disease)]

PURPOSE/METHODS/PATIENTS: Calcitonin is a common treatment in patients suffering from Complex Regional Pain Syndrome Type 1 (CRPS I), although its effects are being controversially discussed. In a prospective study of 24 patients with CRPS I of the upper limb, we examined the tolerance of daily doses of 0.5 mg human calcitonin administered subcutaneously over 8 weeks. To assess the benefit of this therapy, the patients were clinically examined every second week. The results were compared to a consecutive group of 25 CRPS 1 patients who received only analgetics and physiotherapy.

RESULTS

With regard to all examined parameters (spontaneous pain, grip strength, edema, hand function, systematic temperature difference), the patients treated with calcitonin showed an improvement during the observation time. However, a statistically significant difference to the control group was calculated only for the reduction of the edema (P < 0.01). 83% (20/24 patients) of the calcitonin-treated patients suffered from severe, mostly gastroenterological side-effects. Hence therapy had to be discontinued in 3 cases (13%).

CONCLUSION

The therapy with calcitonin has the burden of numerous unpleasant side-effects and causes only a slight therapeutic improvement. Thus, calcitonin must only be prescribed with reservations for patients suffering from CRPS I.

Early steps in termination of the immortalization state in Burkitt lymphoma: induction of genes involved in signal transduction, transcription, and trafficking by the ganglioside IV(3)NeuAc-nLcOse(4)Cer

Stimulation by the ganglioside IV(3)NeuAc-nLcOse(4)Cer leads to growth arrest in the Burkitt lymphoma cell line Raji. In order to analyze the primary response of Raji cells to that stimulus, a cDNA array screen and a suppression subtractive hybridization-PCR approach were performed. Twenty-four genes with assigned functions were confirmed to be induced by the ganglioside in reverse Northern blot experiments covering e.g. protein kinase B, phospholipase C, the MAP-kinase ERK3, the transcription factors YY1, DR1 and NSEP, the membrane traffic protein TAP, and the nuclear export protein CRM1. Most of the genes identified are involved in signal transduction, transcription, and cell trafficking. For selected genes, the induction of expression was quantified by semiquantitative RT-PCR.

Ultrastructural identification of storage compartments and localization of activity-dependent secretion of neurotrophin 6 in hippocampal neurons

A modulatory role of neurotrophins (NTs) in activity-dependent neuronal plasticity by pre- and postsynaptic mechanisms is now well established. In this context, it is important to identify the storage compartments and to localize the precise site(s) and mechanism of NT secretion in order to deduce the spatial and temporal availability of NTs. We approached these questions at the ultrastructural level, exploiting the unique property of NT6 to bind tightly to heparan sulfate proteoglycans at the neuronal surface (R. Götz et al., 1994, Nature 372, 266-269), permitting the localization of secretion sites excluding diffusion artifacts. The myc tagging of NT6 permitted glutaraldehyde fixation and hence good preservation of the membrane structure, permitting immunogold labeling of NT6myc at the neuronal surface. NT6myc is preferentially secreted from neurites compared to neuronal cell bodies. In agreement with light-microscopic observations, the ultrastructural localization of NT6myc by postembedding procedures showed a predominant localization in ER-like membrane-confined compartments, partially associated with microtubules.

The role of Pax6 in restricting cell migration between developing cortex and basal ganglia

It is not clear to what extent restricted cell migration contributes to patterning of the developing telencephalon, since both restricted and widespread cell migration have been observed. Here, we have analysed dorso-ventral cell migration in the telencephalon of Pax6 mutant mice (Small Eye). The transcription factor Pax6 is expressed in the dorsal telencephalon, the cerebral cortex. Focal injections of adenoviral vectors containing the green fluorescent protein were used to follow and quantify cell movements between two adjacent regions in the developing telencephalon, the cerebral cortex and the ganglionic eminence (the prospective basal ganglia). The analysis in wild-type mice confirmed that the cortico-striatal boundary acts as a semipermeable filter and allows a proportion of cells from the ganglionic eminence to invade the cortex, but not vice versa. Ventro-dorsal cell migration was strongly enhanced in the Pax6 mutant. An essential function of Pax6 in the regionalisation of the telencephalon is then to limit the invasion of the cortex by cells originating in the ganglionic eminence. Cortical cells, however, remain confined to the cortex in the Pax6 mutant. Thus, dorsal and ventral cells are restricted to their respective territories by distinct mechanisms.

Are there differences between the secretion characteristics of NGF and BDNF? Implications for the modulatory role of neurotrophins in activity-dependent neuronal plasticity

In previous experiments the activity-dependent secretion of nerve growth factor (NGF) from native hippocampal slices and from NGF-cDNA transfected hippocampal neurons showed unusual characteristics [Blochl and Thoenen (1995) Eur J Neurosci 7:1220-1228; (1996) Mol Cell Neurosci 7:173-190]. In both hippocampal slices and cultured hippocampal neurons the activity-dependent secretion proved to be independent of extracellular calcium, but dependent on the release of calcium from intracellular stores. Under different experimental conditions, Goodman et al. [(1996) Mol Cell Neurosci 7:222-238] reported that the high potassium-mediated secretion of brain-derived neurotrophic factor (BDNF) from hippocampal cultures was dependent on extracellular calcium. Mowla et al. [(1997) Proc 27th Annu Meet Soc Neurosci New Orleans 875.10] reported on even further-reaching differences between NGF and BDNF secretion, namely, that in hippocampal neurons and in pituitary cell lines NGF was secreted exclusively according to the constitutive pathway, whereas BDNF was exclusively sorted according to the activity-dependent regulated pathway. In view of the crucial importance of such potential differences between the processing, sorting, and secretory mechanisms of different neurotrophins for their modulatory roles in activity-dependent neuronal plasticity, a thorough analysis under comparable experimental conditions was mandatory. We demonstrate that in native hippocampal slices and adenoviral-transduced hippocampal neurons there are no differences between NGF and BDNF with respect to the subcellular distribution and mechanism of secretion; that the activity-dependent secretion of both NGF and BDNF is dependent on intact intracellular calcium stores; and that the differences between our own observations and those of Goodman et al. (ibid.) regarding the dependence on extracellular calcium do not reflect differences between NGF and BDNF sorting and secretion, but reflect the differing experimental conditions used.

Myr 7 is a novel myosin IX-RhoGAP expressed in rat brain

Rho family GTPases are important regulators of neuronal morphology, but the proteins directly controlling their activity in neurons are still poorly defined. We report the identification of myr 7, a novel unconventional myosin IX-RhoGAP expressed in rat brain. Myr 7 is a multidomain protein related to myr 5, the first class IX myosin to be characterized. It exhibits a myosin head domain with an N-terminal extension and a large insertion at loop 2, an actin contact site and regulator of myosin ATPase rate. The myosin head domain is followed by a neck domain consisting of six unevenly spaced consecutive IQ motifs representing light chain binding sites. The tail domain contains a C6H2-zinc binding motif and a region that specifically stimulates the GTPase-activity of Rho followed by a short stretch predicted to adopt a coiled-coil structure. Five alternatively spliced regions, one in the 5′-noncoding region, two in the myosin head and two in the tail domain, were noted. Analysis of myr 7 and myr 5 expression in different tissues revealed that myr 7 is expressed at high levels in developing and adult brain tissue whereas myr 5 is expressed only at moderate levels in embryonic brain tissue and at even further reduced levels in adult brain tissue. Myr 5 is, however, highly expressed in lung, liver, spleen and testis. Myr 7 is expressed in all brain regions and is localized in the cytoplasm of cell bodies, dendrites and axons. Myr 5 exhibits an overlapping, but not identical cellular distribution. Finally, a myr 7 fusion protein encompassing the GAP domain specifically activates the GTPase-activity of Rho in vitro, and overexpression of myr 7 in HtTA1-HeLa cells leads to inactivation of Rho in vivo. These results are compatible with a role for myr 7 (and myr 5) in regulating Rho activity in neurons and hence in regulating neuronal morphology and function.

Uterine leiomyomata and sterility: therapy with gonadotropin-releasing hormone agonists and leiomyomectomy

The aim of this study was to obtain data about the pregnancy rate in patients with uterine leiomyomata after treatment with gonadotropin-releasing hormone (GnRH) agonists followed by myomectomy. Between 1987 and 1993, 61 patients with uterine leiomyomata and sterility underwent 6 months' GnRH agonist treatment, in part with a surgical intervention. Sixty-two per cent of the patients suffered from concomitant endometriosis. After hormonal therapy 41 patients underwent a myomectomy. According to sonographic and clinical criteria, there was no indication for the enucleation of the leiomyomata for the remaining 20 patients. Owing to the combined therapy, consisting of primary treatment of uterine leiomyomata with GnRH agonists, followed by surgical intervention, 25 patients (41%) suffering from long-term sterility (average 4 years) became pregnant. An early abortion occurred in only three cases (12%). No patient who underwent a myomectomy developed new myomata during the following pregnancy. Four patients suffering from a single leiomyoma became pregnant within the first 3 months after myomectomy, all of them conceiving spontaneously. Considering the high rate of spontaneous conceptions and the low abortion and complication rates during pregnancy, the combined therapy of GnRH agonists followed by myomectomy represents a major step forwards in the effective treatment of sterility in patients with uterine leiomyomata.

Copper dependent control of the enzymic and phagocyte induced degradation of some biopolymers, a possible link to systemic inflammation

The role of copper during inflammation is unknown. An attempt was made to examine the reactivity of copper on the oxygen free radical induced depolymerization of hyaluronic acid and synovial fluid. Thionein-copper and CuSO4 at 2 mumol/l concentrations inhibited the degradation of this biopolymer successfully. Translation of the enzymically generated excited oxygen species onto a cellular level was performed. Activated PMN cells were used to decompose hyaluronic acid in the presence of CuSO4, Cu-thionein and ceruloplasmin not exceeding physiological levels. All employed copper compounds inhibited the depolymerizing process. Furthermore, PMN cell induced bleaching of cytochrome c was also affected in the presence of both CuSO4 and thionein-copper.

Extracellular carbonic anhydrase of skeletal muscle associated with the sarcolemma

We report here 1) the synthesis and properties of a new macromolecular carbonic anhydrase inhibitor, Prontosil-dextran, 2) its application to determine the localization of a previously described extracellular carbonic anhydrase in skeletal muscle, and 3) the application of a recently published histochemical technique using dansylsulfonamide to the same problem. Stable macromolecular inhibitors of molecular weights of 5,000, 100,000 and 1,000,000 were produced by covalently coupling the sulfonamide Prontosil to dextrans. Their inhibition constants towards bovine carbonic anhydrase II are 1-2 X 10(-7) M. The Prontosil-dextrans, PD 5,000, PD 100,000, and PD 1,000,000, were used in studies of the washout of H14CO3-) from the perfused rabbit hindlimb. This washout is slow due to the presence of an extracellular carbonic anhydrase and can be markedly accelerated by PD 5,000 but not by PD 100,000 and PD 1,000,000. Since PD 5,000 is accessible to the entire extracellular space and PD 100,000 and PD 1,000,000 are confined to the intravascular space, we conclude that the extracellular carbonic anhydrase of skeletal muscle is located in the interstitium. The histochemical studies show a strong staining of the sarcolemma of the muscle fibers with high oxidative capacity. It appears likely, therefore, that the extracellular carbonic anhydrase of skeletal muscle is associated with muscle plasma membranes with its active site directed toward the interstitial space.

A simple, rapid and efficient isolation of erythrocyte Cu2Zn2-superoxide dismutase

On the basis of the thermal stability of erythrocuprein (Cu2Zn2-superoxide dismutase) a rapid preparation technique was devised and successfully employed to isolate this protein. Partial heat-deterioration of the haemolysate and subsequent chromatography of the supernatant on DEAE-Sephacel and Sephadex G-75 yielded an electrophoretically homogeneous protein within a few days. The physicochemical properties and biochemical function were identical with those reported for Cu2Zn2-superoxide dismutases prepared by established methods.

Oxidation of Cu(I)-Thionein by Enzymically Generated H2O2

Very little is known of the metabolism of copper on a molecular level. For example, there is no evidence of an oxidative breakdown of Cu(I)-thionein leading to Cu(II). Thus it was of interest to use L- and D-amino-acid oxidases, amino oxidase and galactose oxidase to control the oxidation of Cu(I)-thionein by enzymically generated H2O2. In the presence of these enzymes Cu(II) was generated in each case. In a more detailed study the Cu(I)-thiolate chromophores of Cu-thionein were oxidized in the presence of xanthine oxidase as deduced from spectrometrical measurements using EPR and circular dichroism. Unlike Cu2Zn2-superoxide dismutase catalase inhibited the oxidative cleavage, suggesting peroxide as the actual oxidizing agent. Possibly there is an enzymic oxidative pathway for the generation of biologically important Cu(II).

The use of prontosil for the visualization of carbonic anhydrase bands in polyacrylamide gels. Application to the carbonic anhydrase isozymes of erythrocytes and white skeletal muscle of the rabbit

Prontosil, a carbonic anhydrase inhibitor of orange-red colour, is used to visualize carbonic anhydrase bands during isoelectric focusing in polyacrylamide gels. 5-60 ng of the sulfonamide Prontosil are added to the 100-200 microliters samples before application to the gels. Bound Prontosil moves into the gel together with carbonic anhydrase and stains the enzyme bands formed there, while unbound Prontosil remains on top of the gels. The method is specific, no proteins other than carbonic anhydrase were observed to be stained, and it requires no special equipment. It was applied to chloroform/ethanol extracts of erythrolysates and white muscle homogenates from rabbits. Densitometric evaluation of the Prontosil-stained bands obtained with these extracts showed that rabbit red cells contain roughly equal amounts of carbonic anhydrase isoenzymes B and C while in rabbit white skeletal muscle isoenzyme C is predominant and little B enzyme occurs. These results confirm previous findings obtained by affinity chromatography of erythrolysates and muscle homogenates.

Erythrocuprein (Cu2Zn2 superoxide dismutase) is the major copper protein of the red blood cell

The copper balance in the red blood cell deserved special attention as the exact amount of copper being bound in erythrocuprein (Cu2Zn2 superoxide dismutase) is poorly understood. An improved aqueous isolation of erythrocuprein revealed that essentially all erythrocyte copper is found in this protein. This fact is supported by both superoxide dismutase activity measurements of the haemolysate and EPR-quantification studies throughout the course of the isolation.

Molecular aspects of bovine erythrocyte bis[(heme b)copper] protein

An erythrocyte Cu2(heme b)2 protein of Mr 400000 was successfully isolated. Incubating the protein in sodium dodecyl sulfate prior to polyacrylamide gel electrophoresis caused the splitting into Mr 70000, 120000, and 200000 units. The copper was fully electron paramagnetic resonance detectable of the type II (g perpendicular = 2.0309, g parallel = 2.2122, A parallel = 175 G). The high-spin (d55/2) iron(III) showed a g value of 6.05. No magnetic interaction between copper and heme iron was detected. In a comparison of more than ten different enzymatic oxidase activities, not a single one could be assigned to the Cu2(heme b)2 protein. Azide, CO, cyanide, fluoride, and imidazole were bound to the heme iron. The binding of imidazolate suggests the accessibility of the sixth coordination site of the heme b group to fairly large ligands. Removal of the copper by ethylenediaminetetraacetic acid or cyanide resulted in an irreversible precipitation of the protein. This supports the structural contribution of the copper.

Immunohistochemical demonstration of chorionic gonadotrophin in trophoblastic tumors

Chorionic gonadotrophin has immunohistochemically been localized to trophoblastic tissue. In normal placenta immunoreactivity was found in syncytiotrophoblastic cells. However, in trophoblastic neoplasms, chorioadenoma destruens and choriocarcinoma, the hormone was also found in cytotrophoblastic cells. The tumor cells showing immunoreactivity appeared to have distinct light microscopic features.