A novel serine protease highly expressed in the pancreas is expressed in various kinds of cancer cells

We have isolated a cDNA that encodes a novel serine protease, prosemin, from human brain. The cDNA of human prosemin is 1306 bp, encoding 317 amino acids. It showed significant homology with the sequence of a chromosome 16 cosmid clone (accession no. NT_037887.4). The prosemin gene contains six exons and five introns. The amino acid sequence of prosemin shows significant homology to prostasin, gamma-tryptase, and testisin (43%, 41%, and 38% identity, respectively), the genes of which are also located on chromosome 16. Northern hybridization showed that prosemin is expressed predominantly in the pancreas and weakly in the prostate and cerebellum. However, western blot and RT-PCR analyses showed that prosemin is expressed and secreted from various kinds of cancer cells, such as glioma, pancreas, prostate, and ovarian cell lines. Prosemin is secreted in the cystic fluid of clinical ovarian cancers. Furthermore, immunohistochemistry showed prosemin protein localized in the apical parts of ovarian carcinomas. Recombinant prosemin was expressed in COS cells and was purified by immunoaffinity chromatography. Recombinant prosemin preferentially cleaved benzyloxycarbonyl (Z)-His-Glu-Lys-methylcoumaryl amidide (MCA) and t-butyloxycarbonyl (Boc)-Gln-Ala-Arg-MCA. Our results suggest that prosemin is a novel serine protease of the chromosome 16 cluster that is highly expressed in the pancreas. The usefulness of this serine protease as a candidate tumor marker should be further examined.     

Octanuclear iron(III) complexes supported by Kemp’s tricarboxylate ligands

Reactions of FeCl₂·4H₂O and diimino ligand (L) with H₃kta (cis,cis-1,3,5-trimethylcyclohexane-1,3,5-tricarboxylic acid) in the presence of [ⁿBu₄N][OH] afforded a series of octanuclear iron(III) complexes formulated as [Fe₈O₅(kta)₂(Hkta)₄(L)₂] (L = bpy (1), 5,5′-Me₂bpy (2), 4,4′-Me₂bpy (3), phen (4), 4-Mephen (5), 4,7-Me₂phen (6), and 3,4,7,8-Me₄phen (7)). The structure of 4 was determined by X-ray crystallography to consist of a planar {Fe₈(μ₄-O)(μ₃-O)₄}¹⁴⁺ core supported by two kta³⁻ tricarboxylates, where the inner four Fe^III ions form a {Fe₄O₅} square plane, of which apex μ-oxo atoms are further connected to the outer four Fe^III ions. The peripheral part of the Fe₈ core is bridged by four Hkta²⁻ ligands and chelated by two phen ligands. ⁵⁷Fe Mössbauer spectra of 2 at 290 K and 77 K indicated the presence of high-spin octahedral Fe(III) ions, and the temperature dependent dc magnetic susceptibility data for 1, 2, and 4 showed strong antiferromagnetic exchange in the {Fe₈O₅} moiety.     

Spontaneous porphyria of the Long-evans cinnamon rat: an animal model of Wilson's disease

To confirm and extend our previous microspectrophotometric observations of 30-week-old male Long-Evans Cinnamon (LEC) rats, an animal model of human Wilson's disease, we analyzed the porphyrin patterns of the organs, urine, and plasma of LEC rats. Abnormal accumulation of porphyrins, especially highly carboxylated porphyrins (uro- and heptaporphyrin), in the kidneys and liver was seen in male and female LEC rats aged 30 weeks and also in 10-week-old rats, before the onset of spontaneous hepatic dysfunction. Accumulation of copper and iron in the kidneys was not observed in the 10-week-old rats. Massive accumulation of porphyrins was observed only in the kidneys of the 30-week-old male LEC rat, indicating that this symptom is related to sex and age. Renal accumulation of porphyrins was reflected in the rate of urinary porphyrin excretion. Hepatic accumulation of porphyrins appeared to be independent of sex and age. These results indicate that neither renal nor hepatic porphyrin accumulation is the result of renal deposition of metals or of spontaneous hepatic dysfunction and that porphyrinuria in the LEC rat is closely related to the renal accumulation of porphyrins. In contrast to these organs, a reduction in the porphyrin levels was observed in the brain of the LEC rat. This was independent of sex and age. The present work stresses the existence of an abnormal heme metabolism in the LEC rat, and thus, the necessity to study the heme metabolism in human Wilson's disease is strongly suggested.     

cDNA cloning and tissue-specific splicing variants of mouse hippostasin/TLSP (PRSS20)

Two splicing variants of mouse hippostasin/TLSP (PRSS20) were identified and termed brain-type and prostate-type, respectively. Mouse hippostasin/TLSP showed 76.8% identity to the human homologue. Transient expression showed that both translational products were secreted into the conditioned medium. Mouse hippostasin/TLSP was expressed preferentially in the fetal brain and the prostate, but not in the neonatal brain. The brain expressed only brain-type hippostasin/TLSP, while the prostate expressed both types.     

Detection of hypoxia in the pulmonary tissues of Xenopus laevis over repeated dives

The oxygen environment in African clawed frogs (Xenopus laevis) continuously changes during their development, which involves a rapid increase in the body size, metamorphosis, and transition to adulthood. Nevertheless, there are limited reports on experimental models that are available for studying fluctuations in the oxygen environment in X. laevis. Thus, this study aimed to develop an experimental model on intermittent hypoxia in X. laevis and evaluate hypoxia and oxidative stress in the same. X. laevis were submerged in water with a dissolved oxygen concentration of 2 mg/L for 30 min; they were then removed from the water and allowed to freely absorb oxygen for 5 min. Immunostaining of pimonidazole-containing frozen tissue sections of the lung and liver using anti-pimonidazole antibodies as the hypoxia probes revealed that more than 95% of the submerged X. laevis cells were pimonidazole positive, providing direct evidence of tissue hypoxia. When the amount of oxidative stress in the lungs and liver was evaluated in terms of the amount of lipid peroxides, the diving group showed a 2.08-fold and 3.20-fold increase over the normal group, respectively. Following hypoxia exposure, the dry-to-wet weight ratios of the lung tissues was 1.27 times higher (p < .05), while the liver tissues was 1.06 times higher (although not significant). Thus, the degree of damage depended on the tissues affected. In the future, we believe that this model will be a promising option for analyzing the physiological responses of X. laevis to hypoxia and oxidative stress.     

Promises and rules: The implications of rethinking the 14‐day rule for research on human embryos

Removing the 14‐day limit for research on human embryos without public deliberation could jeopardize public trust in and support of research on human development. Subject Categories: Development & Differentiation, S&S: Economics & Business, Molecular Biology of Disease

In On Revolution, Hannah Arendt, one of the great political thinkers of the 20^th century, stated that “promises and agreements deal with the future and provide stability in the ocean of future uncertainty where the unpredictable may break in from all sides” (Arendt, 1963). She cited the Mayflower Compact, which was “drawn up on the ship and signed upon landing” on the uncharted territory of the American continent, as such an example of promise in Western history. Human beings are born with the capacity to act freely amid the vast ocean of uncertainty, but this capacity also creates unpredictable and irreversible consequences. Thus, in society and in politics, moral virtues can only persist through “making promises and keeping them” (Arendt, 1959).