Autotaxin-lysophosphatidic acid receptor 5 axis evokes endothelial dysfunction via reactive oxygen species signaling

Lysophosphatidylcholine (LPC) is a bioactive lipid that has been shown to attenuate endothelium-dependent vasorelaxation contributing to endothelial dysfunction; however, the underlying mechanisms are not well understood. In this study, we investigated the molecular mechanisms involved in the development of LPC-evoked impairment of endothelium-dependent vasorelaxation. In aortic rings isolated from wild-type (WT) mice, a 20-min exposure to LPC significantly reduced the acetylcholine chloride (ACh)-induced vasorelaxation indicating the impairment of normal endothelial function. Interestingly, pharmacological inhibition of autotaxin (ATX) by GLPG1690 partially reversed the endothelial dysfunction, suggesting that lysophosphatidic acid (LPA) derived from LPC may be involved in the effect. Therefore, the effect of LPC was also tested in aortic rings isolated from different LPA receptor knock-out (KO) mice. LPC evoked a marked reduction in ACh-dependent vasorelaxation in Lpar1, Lpar2, and Lpar4 KO, but its effect was significantly attenuated in Lpar5 KO vessels. Furthermore, addition of superoxide dismutase reduced the LPC-induced endothelial dysfunction in WT but not in the Lpar5 KO mice. In addition, LPC increased H2O2 release from WT vessels, which was significantly reduced in Lpar5 KO vessels. Our findings indicate that the ATX-LPA-LPA5 receptor axis is involved in the development of LPC-induced impairment of endothelium-dependent vasorelaxation via LPA5 receptor-mediated reactive oxygen species production. Taken together, in this study, we identified a new pathway contributing to the development of LPC-induced endothelial dysfunction.

Cell Attachment Capacity and Compounds of Fibrin Membranes Isolated from Fresh Frozen Plasma and Cryoprecipitate

Fibrin membranes are widely used in regenerative medicine because they are biocompatible, biodegradable, contain growth factors, and support cell attachment. Most commonly they are produced from serum, but they can also be isolated from activated plasma. To increase the fibrinogen concentration of plasma, cryoprecipitate isolation is a possible solution. In this work, cryoprecipitate was prepared from fresh frozen plasma, isolated by plasmapheresis. The concentration of cellular elements, fibrinogen, total protein, and immunoglobulins among others was measured in different concentrations of cryoprecipitates. After activation with Ca-gluconate, fibrin membranes were produced in different thicknesses, and human mesenchymal stem cells were seeded onto the membranes. They were visualized by live-dead staining and their viability was determined by XTT. The platelet-derived growth factor AB content was quantified by ELISA. Our results showed that fibrinogen and platelet concentration can be multiplied in plasma by cryoprecipitate isolation, which affects the thickness and slightly the growth factor content of the membranes. According to live-dead staining, the thickness of the membranes does not influence cell attachment, and XTT measurement did not reveal a significant difference in cell attachment capacity either; however, a growing trend could be observed in the case of some membranes.

[The association of unwanted drug effects and increased psychovegetative lability]

OBJECTIVE

Based on a history of unwanted drug effects, patients had to undergo a series of exposure tests to identify alternative non-invasive drugs. In our study we examined if psychosomatic factors (in the sense of psychovegetative lability) occurred more frequently in patients with unwanted drug effects.

METHODS

For this purpose, 91 patients filled out a series of questionnaires for the assessment of mental factors. The questionnaires used were the BEB (a questionnaire for the assessment of psychosomatic complaints), the TICS questionnaire (Trierer questionnaire of chronic stress), the scale "critical life events" of LRF-LE and the anxiety questionnaire "STAI".

RESULTS

All scales which were used for the assessment of the psychosomatic complaint status (BEB) showed increased values. Chronic stress factors (TICS) and anxiety (STAI) did not play a role. Critical life events occurred more often.

CONCLUSION

The occurrence of unwanted drug effects is associated with psychosomatic complaints and acute critical life events. This enables the patient to get a complex understanding for the explanation of the complaints.

First Report of Hop stunt viroid Infecting Hop in Slovenia

Hop (Humulus lupulus), of the Cannabaceae family, is a dioecious perennial climbing plant that is native to Asia, North America, and Europe and is commercially grown in many countries for its use in brewing and the pharmaceutical industry. Slovenia has a more than 100-year-old hop-growing tradition and it is an important national agricultural business, with 90% of production exported to foreign markets. Since 2007, symptoms similar to Hop stunt viroid (HSVd) infection have been observed in several hop gardens with cvs. Celeia, Bobek, and Aurora in the Savinja Valley and Koroška Region. Symptoms include stunting, leaf curl, small cone formation, and dry root rot. In the first year of finding the disease, the incidence varied from 1 to 30% and increased rapidly (by as much as 10%) each subsequent year, predominantly along plant rows. For molecular identification of the pathogen, RNA was extracted from leaves and cones of symptomatic and asymptomatic plants from two different hop gardens with cv. Celeia using Tri Reagent (T9424; Sigma-Aldrich, St Louis, MO). Reverse transcription-PCR was carried out using two pairs of specific HSVd primers, HSVdI/HSVdII and HSVdeI/HSVdeII (3,4). Both primer pairs gave a single PCR product from tissue from symptomatic plants, with expected lengths of ~300 bp, but no amplicons were produced using samples from asymptomatic plants. PCR products from HSVdI/HSVdII were subjected to direct sequencing and HSVdeI/HSVdeII products were cloned in PCR Script SK (+) (Stratagene, La Jolla, CA) vector and sequenced. Five sequences (EMBL Accession Nos. HE575344, HE575345, HE575346, HE575347, and HE575348) were obtained, which revealed 96 to 99% sequence identity with various HSVd variants (grapevine, citrus, and cucumber) reported in GenBank of the National Centre for Biotechnology Information (NCBI). HSVd belonging to the Hostuviroid genus, Pospiviroidae family, has been previously reported in hop in Japan, South Korea, North America, and China (1,2). To our knowledge, this is the first report of the detection of HSVd on hop in Europe. Strict phytosanitary measures have been taken to prevent further spread and to eradicate HSVd infections. References: (1) K. C. Eastwell and T. Sano. Hop Stunt. Page 48 in: Compendium of Hop Diseases and Pests. W. F. Mahaffee et al., eds. The American Phytopathological Society, St. Paul, MN, 2009. (2) L. Guo et al. Plant Pathol. 57:764, 2008. (3) J. Matoušek et al. Plant Soil Environ. 49:168, 2003. (4) J. Matoušek et al. J. Virol. Methods 122:153, 2004.