Effect of various factors on serotonin-induced Ca2+ response in human platelets

Serotonin (5-HT)-stimulated intracellular Ca2+ concentration change was studied in the platelets of healthy subjects, using fluorescent Ca indicator fura-2. 5-HT increased the Ca2+ response in a concentration-dependent manner. 10 microM of 5-HT induced the maximal response and its EC50 value was 0.4 microM. This response was potently inhibited by selective 5-HT2 antagonists, suggesting that 5-HT-induced Ca2+ mobilization in human platelets is mediated by 5-HT2 receptors. This 5-HT2-mediated Ca2+ response was not significantly affected by the time of blood sampling, gender, meal or exercise. However, this response declined with time after blood drawing, suggesting that it must be measured as soon as possible after sampling. These results indicate that 5-HT-stimulated Ca2+ response in human platelets is a stable parameter and that it will be suitable for assessing 5-HT2 receptor function in depressed patients.     

Aligned genetic linkage maps of apple rootstock cultivar ‘JM7’ and Malus sieboldii ‘Sanashi 63’ constructed with novel EST-SSRs

Identification of markers associated with genes of interest and quantitative trait loci (QTLs), combined with high-density genetic linkage maps, can help reduce labor and costs by enabling marker-assisted selection (MAS). In this study, a dwarfing apple rootstock cultivar ??JM7?? (Malus prunifolia × Malus pumila ??Malling 9??) and wild apple Malus sieboldii ??Sanashi 63?? (section Sorbomalus) were used for constructing genetic linkage maps. Here, a species from section Sorbomalus was used for the first time as a target species in a genome-wide mapping study. We also developed and mapped 137 novel-expressed sequence tag-simple sequence repeat (EST-SSR) markers. The genetic linkage maps of ??JM7?? and ??Sanashi 63?? consisted of 415 and 310 loci and spanned 998.0 and 981.8?cM, respectively, comparable to the reference map of Malus × domestica ??Discovery??. A BLASTN search revealed that all of the EST-SSR sequences used in this study exhibited very high homology to one or more previously characterized apple genome contigs. Although the most homologous contigs of 89 EST-SSRs were located within the same linkage groups (LGs) identified by mapping analysis, the other 48 EST-SSRs were aligned into contigs positioned in different LGs than those identified by mapping. When search criteria were expanded to include the five most homologous contigs of each EST-SSR, at least one of the top five contigs for 15 of these 48 EST-SSRs corresponded to the LG obtained by mapping. The maps of ??JM7?? and ??Sanashi 63?? may be useful for analyzing important rootstock characteristics and identifying markers for MAS.     

New insights on the roles of BMP signaling in bone-A review of recent mouse genetic studies

It is well known that Bone morphogenetic proteins (BMPs) induce bone formation and that some BMPs, including BMP2 and BMP7, are clinically used in orthopedics. Signaling by BMPs plays an important role in a variety of cell-types in bone such as osteoblasts, chondrocytes, and osteoclasts. It is recently reported using an osteoblast-targeted deletion of BMP signaling that BMP signaling in osteoblasts physiologically induces bone resorption by enhancing osteoclastogenesis via the RANKL-OPG pathway and reduces bone mass. In this review, the physiological function of BMP signaling in bone will be focused, and the current outcomes from mouse genetic studies will be discuss.     

Different Dicer-like protein components required for intracellular and systemic antiviral silencing in Arabidopsis thaliana

Eukaryotes employ RNA silencing as an innate defense system against invading viruses. Dicer proteins play the most crucial role in initiating this antiviral pathway as they recognize and process incoming viral nucleic acids into small interfering RNAs. Generally, 2 successive infection stages constitute viral infection in plants. First, the virus multiplies in initially infected cells or organs after viral transmission and then the virus subsequently spreads systemically through the vasculature to distal plant tissues or organs. Thus, antiviral silencing in plants must cope with both local and systemic invasion of viruses. In a recent study using 2 sets of different experiments, we clearly demonstrated the differential requirement for Dicer-like 4 (DCL4) and DCL2 proteins in the inhibition of intracellular and systemic infection by potato virus X in Arabidopsis thaliana. Taken together with the results of other studies, here we further discuss the functional specificity of DCL proteins in the antiviral silencing pathway.     

Ruptured renal arteriovenous malformation successfully treated by catheter embolization: a case report

Background

Fabry disease is an X-linked inherited metabolic condition where the deficit of the α-galactosidase A enzyme, encoded by the GLA gene, leads to glycosphingolipid storage, mainly globotriaosylceramide. To date, more than 600 mutations have been identified in human GLA gene that are responsible for FD, including missense and nonsense mutations, small and large deletions. Such mutations are usually inherited, and cases of de novo onset occur rarely.

Case presentation

In this article we report an interesting case of a 44-year-old male patient suffering from a severe form of Fabry disease, with negative family history. The patient showed signs such as cornea verticillata, angiokeratomas, cardiac and neurological manifestations, an end-stage renal disease and he had low α-galactosidase A activity. We detected, in this subject, the mutation c.493 G?>?C in the third exon of the GLA gene which causes the amino acid substitution D165H in the protein. This mutation affects the amino acid - belonging to the group of buried residues - involved, probably, in the preservation of the protein folding. Moreover, studies of multiple sequence alignment indicate that this amino acid is highly conserved, thus strengthening the hypothesis that it is a key amino acid to the enzyme functionality. The study of the relatives of the patient showed that, surprisingly, none of the members of his family of origin had this genetic alteration, suggesting a de novo mutation. Only his 11-year-old daughter - showing acroparaesthesias and heat intolerance with reduced enzymatic activity - had the same mutation.

Conclusions

We suggest that a non-inherited mutation of the α-galactosidase A gene is responsible for Fabry disease in the patient who had reduced enzyme activity and classical clinical manifestations of the disease. In a family, it is rare to find only one Fabry disease affected subject with a de novo mutation. These findings emphasize the importance of early diagnosis, genetic counselling, studying the genealogical tree of the patients and starting enzyme replacement therapy to prevent irreversible vital organ damage that occurs during the course of the disease.     

Differential susceptibility to hydrogen sulfide-induced apoptosis between PHLDA1-overexpressing oral cancer cell lines and oral keratinocytes: Role of PHLDA1 as an apoptosis suppressor

Hydrogen sulfide (H₂S) is a novel gasotransmitter that plays multiple biological roles in various body systems. In addition to its endogenous production, H₂S is produced by bacteria colonizing digestive organs, including the oral cavity. H₂S was previously shown to enhance pro-apoptotic effects in cancer cell lines, although the mechanisms involved remain unclear. To properly assess the anti-cancer effects of H₂S, however, investigations of apoptotic effects in normal cells are also necessary. The aims of this study were (1) to compare the susceptibility to H₂S-induced apoptosis between the oral cancer cell line Ca9-22 and oral keratinocytes that were derived from healthy gingiva, and (2) to identify candidate genes involved in the induction of apoptosis by H₂S. The susceptibility to H₂S-induced apoptosis in Ca9-22 cells was significantly higher than that in keratinocytes. H₂S exposure in Ca9-22 cells, but not keratinocytes, enhanced the expression of pleckstrin homology-like domain, family A, member 1 (PHLDA1), which was identified through a differential display method. In addition, PHLDA1 expression increased during actinomycin D-induced apoptosis in Ca9-22 cells. Knockdown of PHLDA1 expression by small interfering RNA in Ca9-22 cells led to expression of active caspase 3, thus indicating apoptosis induction. The tongue cancer cell line SCC-25, which expresses PHLDA1 at a high level, showed similar effects. Our data indicate that H₂S is an anti-cancer compound that may contribute to the low incidence of oral cancer. Furthermore, we demonstrated the role of PHLDA1 as an apoptosis suppressor.     

Accelerated polymer-polymer click conjugation by freeze-thaw treatment

Herein, we report a unique technique to accelerate polymer-SNA conjugation based on copper-free click chemistry: gradual freeze-thawing of the reaction solution substantially increases the conjugation rate possibly because of the reactant concentration at the microenvironment scale. This technique was applied to the conjugation between a small interfering RNA (siRNA) and PEG in an aqueous buffer at/below room temperature.     

Strain difference in expression of the adult-type polycystic kidney disease gene, pcy, in the mouse

DBA/2FG-pcy and C57BL/6FG-pcy congenic strains were established by transferring the polycystic kidney disease gene, pcy, to DBA/2 and C57BL/6 mice. We carried out pathological and hematological examinations of these strains at 4, 8, 16 and 30 weeks of age. In DBA/2FG-pcy mice more than 8 weeks of age, macroscopic renal cysts were observed on the surface of both kidneys. Their kidneys weight was significantly greater than in DBA/2 mice at all ages examined. Microscopic renal cysts were evenly distributed at 4, 8 and 16 weeks of age. At 30 weeks of age, the kidneys were filled with numerous polycysts. In C57BL/6FG-pcy mice, no macroscopic renal cysts were found until the animals were 30 weeks old, and the weight of their kidneys was greater than in B6 mice of the same age. From 8 weeks of age on, a limited number of microscopic renal cysts was observed, and many renal cysts were found adjacent to the enlarged Bowman's capsules. With age, the red blood cell count and hematocrit level decreased while the platelet count increased in both strains, with greater changes occurring in DBA/2FG-pcy mice than in C57 BL/6FG-pcy mice. These findings demonstrate that polycystic kidney disease exhibits strain differences in animals with a DBA/2 and C57BL/6 background. Our results suggest that phenotypic expression of the pcy gene in the mouse depends on genetic background, and that variations in the severity of human polycystic kidney disease may be explained, at least in part, by individual differences in genetic background.