Plasma desmoplakin I biomarker of vascular recurrence after ischemic stroke

Stroke patients have a high risk of vascular recurrence. Biomarkers related to vascular recurrence, however, remain to be identified. The aim of the study was to identify, through proteomic analysis, plasma biomarkers associated with vascular recurrence within one year after the first ischemic stroke. This is a substudy (n = 134) of a large prospective multicenter study of post-stroke patients with an ischemic stroke. Plasma samples were obtained at inclusion. Among the identified proteins, only plasma levels of desmoplakin I were associated with protection against a new vascular event (Odds ratio: 0.64; 95% CI: 0.46-0.89; p = 0.009) after adjustment for hypercholesterolemia, statins and previous atherothrombotic stroke subtype. A greater number of patients without vascular recurrence had been treated with statins within three months of the recent ischemic stroke. Only patients who had been taking statins for 3 months after the ischemic stroke and did not suffer vascular recurrence over a follow-up year, have higher levels of desmoplakin I at the time of inclusion (Odds ratio 0.49; 95% CI: 0.28-0.86; p = 0.013). Increased desmoplakin I levels, determined within 1-3 months of the first ischemic stroke, could be a biomarker for statin responsiveness against a new vascular event in post-ischemic stroke patients taking statins early (1-3 months) after the ischemic stroke.     

Large-scale growth of the Plasmodium falciparum malaria parasite in a wave bioreactor

We describe methods for the large-scale in vitro culturing of synchronous and asynchronous blood-stage Plasmodium falciparum parasites in sterile disposable plastic bioreactors controlled by wave-induced motion (wave bioreactor). These cultures perform better than static flask cultures in terms of preserving parasite cell cycle synchronicity and reducing the number of multiple-infected erythrocytes. The straight-forward methods described here will facilitate the large scale production of malaria parasites for antigen and organelle isolation and characterisation, for the high throughput screening of compound libraries with whole cells or extracts, and the development of live- or whole-cell malaria vaccines under good manufacturing practice compliant standards.     

Excision of Trpv6 gene leads to severe defects in epididymal Ca2+ absorption and male fertility much like single D541A pore mutation

Replacement of aspartate residue 541 by alanine (D541A) in the pore of TRPV6 channels in mice disrupts Ca(2+) absorption by the epididymal epithelium, resulting in abnormally high Ca(2+) concentrations in epididymal luminal fluid and in a dramatic but incomplete loss of sperm motility and fertilization capacity, raising the possibility of residual activity of channels formed by TRPV6(D541A) proteins (Weissgerber, P., Kriebs, U., Tsvilovskyy, V., Olausson, J., Kretz, O., Stoerger, C., Vennekens, R., Wissenbach, U., Middendorff, R., Flockerzi, V., and Freichel, M. (2011) Sci. Signal. 4, ra27). It is known from other cation channels that introducing pore mutations even if they largely affect their conductivity and permeability can evoke considerably different phenotypes compared with the deletion of the corresponding protein. Therefore, we generated TRPV6-deficient mice (Trpv6(-/-)) by deleting exons encoding transmembrane domains with the pore-forming region and the complete cytosolic C terminus harboring binding sites for TRPV6-associated proteins that regulate its activity and plasma membrane anchoring. Using this strategy, we aimed to determine whether the TRPV6(D541A) pore mutant still contributes to residual channel activity and/or channel-independent functions in vivo. Trpv6(-/-) males reveal severe defects in fertility and motility and viability of sperm and a significant increase in epididymal luminal Ca(2+) concentration that is mirrored by a lack of Ca(2+) uptake by the epididymal epithelium. Therewith, Trpv6 excision affects epididymal Ca(2+) handling and male fertility to the same extent as the introduction of the D541A pore mutation, arguing against residual functions of the TRPV6(D541A) pore mutant in epididymal epithelial cells.     

Hyperplasia as a mechanism for rapid resealing urothelial injuries and maintaining high transepithelial resistance

When the urothelial barrier, i.e., the blood−urine barrier, is injured, rapid resealing of the injury is crucial for the normal functioning of the organism. In order to investigate the mechanisms required for rapid resealing of the barrier, we established in vitro models of hyperplastic and normoplastic urothelia. We found that hyperplastic urothelia achieve significantly higher transepithelial resistance (TER) than normoplastic urothelia. However, the expression of cell junctional (claudin-8, occludin, E-cadherin) and differentiation-related proteins (cytokeratin 20 and uroplakins) is weaker in hyperplastic urothelia. Further investigation of cell differentiation status at the ultrastructural level confirmed that superficial urothelial cells (UCs) in hyperplastic urothelial models achieve a lower differentiation stage than superficial UCs in normoplastic urothelial models. With the establishment of such in vitro models and the aid of TER measurements, flow cytometry, molecular and ultrastructural analysis, we here provide unequivocal evidence that the specific cell-cycle distribution and, consequently, the number of cell layers have a significant influence on the barrier function of urothelia. We demonstrate the importance of hyperplasia for the rapid restoration of the urothelial barrier and the maintenance of high TER until the UCs reach a highly differentiated stage and restoration of the urothelial barrier after injury is complete. The information that this approach provides is unique and we expect that further exploitation of hyperplastic and normoplastic urothelial models in future studies may advance our understanding of blood−urine barrier development and functionality.     

Trans fatty acids enhance amyloidogenic processing of the Alzheimer amyloid precursor protein (APP)

Hydrogenation of oils and diary products of ruminant animals leads to an increasing amount of trans fatty acids in the human diet. Trans fatty acids are incorporated in several lipids and accumulate in the membrane of cells. Here we systematically investigate whether the regulated intramembrane proteolysis of the amyloid precursor protein (APP) is affected by trans fatty acids compared to the cis conformation. Our experiments clearly show that trans fatty acids compared to cis fatty acids increase amyloidogenic and decrease nonamyloidogenic processing of APP, resulting in an increased production of amyloid beta (Aβ) peptides, main components of senile plaques, which are a characteristic neuropathological hallmark for Alzheimer's disease (AD). Moreover, our results show that oligomerization and aggregation of Aβ are increased by trans fatty acids. The mechanisms identified by this in vitro study suggest that the intake of trans fatty acids potentially increases the AD risk or causes an earlier onset of the disease.     

High altitude biodiversity of the Alps and the Himalayas: ethnobotany,plant distribution and conservation perspective

Historical evidences suggest that the Himalayas have some strong biogeographical links to the Alps. In view of this fact, the present study aims to understand the similarities in plant species distribution and their ethnobotanical uses in the Indian Himalayas and the Slovenian Alps. The plant species common in both the mountain systems and used by local inhabitants were compiled by extensive literature search and also by carrying out primary surveys. Ethnobotanical information was collected through personal interviews of villagers with the help of local assistants and also through direct and indirect observations made during the field surveys. A total of 59 ethnobotanical species representing 17 families common in both the Indian Himalayas and the Slovenian Alps were documented, of these 78% obtained medicinal properties and traditionally used by local people for curing diseases. Comparatively, people of the Indian Himalayas used plants for medicine in higher percentage (73%) than the people of Slovenia (42%). Of the total medicinal plants, only 7 plant species such as Acorus calamus, Capsella bursa-partoris, Hypericum perforatum, Origanum vulgare, Prunella vulgaris, Solanum nigrum and Urtica dioica had some common uses in both the Slovenian Alps and the Indian Himalayas. In the Slovenian Alps, the maximum ethnobotanical species (61%) had wide distribution range whereas maximum ethnobotanical species in the Indian Himalayas (62%) had localized distribution. Though, 27% of common ethnobotanical species belonged to different threat categories, only 2 species—Taxus baccata and Hippophae rhamnoides—are placed under similar threat category in these two different mountain areas. The study unfolds relationship in plant species distribution and their ethnobotanical uses along with offering an opportunity to provide information on uses of plant species though available but unknown to community.     

Selective hydroboration of dieneamines. Formation of hydroxyalkylphenothiazines as MDR modulators

N-dienylphenothiazines synthesized from tetrazolo[1,5-a]pyridinium salts by treatment with phenothiazine were subjected to catalytic hydrogenation to yield N-butylphenothiazines, whereas transformation of these dienes with borane dimethyl sulfide (BH(3) × Me(2)S) resulted in selective hydroboration of one double bond and full reduction of the other double bond to give 2-hydroxybutylphenothiazines. Position of the hydroxyl group was supported by NMR spectroscopy and verified by X-ray analysis. Comparison of MDR modulatory activity of the new derivatives revealed that the hydroxybutyl compounds are promising candidates for development of novel MDR inhibitors.