Efficient stem cell isolation from under vacuum preserved tissue samples

Different approaches for the isolation of stem/progenitor cells have been reported, including stem cell selection in stringent culture conditions. We evaluated the possibility of isolating human progenitor cells from surgical specimens preserved by under vacuum sealing and cooling, a clinical practice approached by several hospitals as alternative to formalin. Renal tissue samples (n = 20) maintained under vacuum from 6 to 48 h at 4°C were used to isolate human renal CD133⁺ progenitor cells. We obtained CD133⁺ progenitors from unsorted cells derived from disaggregated tissues from each sample. Phenotypic characterization as well as in vitro and in vivo differentiation of the obtained CD133⁺ lines showed results comparable with sorted CD133⁺ cells obtained from fresh tissue. These results indicate that the process of sealing under vacuum and cooling appears as a suitable tissue treatment to isolate hypoxia resistant cells, such as human stem/progenitor cells, and that this procedure can be exploited to render the extraction of stem cells from human samples more practical and feasible.     

Synergistic interaction between the type III secretion system of the endophytic bacterium Pantoea agglomerans DAPP-PG 734 and the virulence of the causal agent of olive knot Pseudomonas savastanoi pv. savastanoi DAPP-PG 722

The endophytic bacterium Pantoea agglomerans DAPP-PG 734 was previously isolated from olive knots caused by infection with Pseudomonas savastanoi pv. savastanoi DAPP-PG 722. Whole-genome analysis of this P. agglomerans strain revealed the presence of a Hypersensitive response and pathogenicity (Hrp) type III secretion system (T3SS). To assess the role of the P. agglomerans T3SS in the interaction with P. savastanoi pv. savastanoi, we generated independent knockout mutants in three Hrp genes of the P. agglomerans DAPP-PG 734 T3SS (hrpJ, hrpN, and hrpY). In contrast to the wildtype control, all three mutants failed to cause a hypersensitive response when infiltrated in tobacco leaves, suggesting that P. agglomerans T3SS is functional and injects effector proteins in plant cells. In contrast to P. savastanoi pv. savastanoi DAPP-PG 722, the wildtype strain P. agglomerans DAPP-PG 734 and its Hrp T3SS mutants did not cause olive knot disease in 1-year-old olive plants. Coinoculation of P. savastanoi pv. savastanoi with P. agglomerans wildtype strains did not significantly change the knot size, while the DAPP-PG 734 hrpY mutant induced a significant decrease in knot size, which could be complemented by providing hrpY on a plasmid. By epifluorescence microscopy and confocal laser scanning microscopy, we found that the localization patterns in knots were nonoverlapping for P. savastanoi pv. savastanoi and P. agglomerans when coinoculated. Our results suggest that suppression of olive plant defences mediated by the Hrp T3SS of P. agglomerans DAPP-PG 734 positively impacts the virulence of P. savastanoi pv. savastanoi DAPP-PG 722.     

Procoagulant activity of mouse transformed cells: Different expression in freshly isolated or cultured cells

The online version of the original article can be found at     

Washingtonia filifera seed extracts inhibit the islet amyloid polypeptide fibrils formations and α-amylase and α-glucosidase activity

Washingtonia filifera seeds have revealed to possess antioxidant properties, butyrylcholinesterase and xanthine oxidase inhibition activities. The literature has indicated a relationship between Alzheimer’s disease (AD) and type-2 diabetes (T2D). Keeping this in mind, we have now evaluated the inhibitory properties of W. filifera seed extracts on α-amylase, α-glucosidase enzyme activity and the Islet Amyloid Polypeptide (IAPP) fibrils formation.Three extracts from seeds of W. filifera were evaluated for their enzyme inhibitory effect and IC₅₀ values were calculated for all the extracts. The inhibition mode was investigated by Lineweaver-Burk plot analysis and the inhibition of IAPP aggregate formation was monitored.W. filifera methanol seed extract appears as the most potent inhibitor of α-amylase, α-glucosidase, and for the IAPP fibril formation.Current findings indicate new potential of this extract that could be used for the identification or development of novel potential agents for T2D and AD.     

Intra- and inter-cores fungal diversity suggests interconnection of different habitats in an Antarctic frozen lake (Boulder Clay,Northern Victoria Land)

A perennially frozen lake at Boulder Clay site (Victoria Land, Antarctica), characterized by the presence of frost mounds, have been selected as an in situ model for ecological studies. Different samples of permafrost, glacier ice and brines have been studied as a unique habitat system. An additional sample of brines (collected in another frozen lake close to the previous one) was also considered. Alpha- and beta-diversity of fungal communities showed both intra- and inter-cores significant (p < 0.05) differences, which suggest the presence of interconnection among the habitats. Therefore, the layers of frost mound and the deep glacier could be interconnected while the brines could probably be considered as an open habitat system not interconnected with each other. Moreover, the absence of similarity between the lake ice and the underlying permafrost suggested that the lake is perennially frozen based. The predominance of positive significant (p < 0.05) co-occurrences among some fungal taxa allowed to postulate the existence of an ecological equilibrium in the habitats systems. The positive significant (p < 0.05) correlation between salt concentration, total organic carbon and pH, and some fungal taxa suggests that a few abiotic parameters could drive fungal diversity inside these ecological niches.