Protein translocation as a tool: The current rapamycin story

In cell biology and pharmacology, small chemicals are mostly used as agonists and antagonists against receptors and enzymes. The immunosuppressant rapamycin can serve an entirely different purpose: if employed sensibly, it might function as an inducer of dimerization that is able to rapidly activate enzyme activity inside the intact cell. A number of very recent developments such as photoactivatable derivatives make rapamycin an even more attractive tool for basic science.     

Seasonal activity patterns of seven vespertilionid bat species in Polish lowlands

Data on seasonal dynamics of bat activity in central Europe are scarce, mostly restricted to either summer period or autumn swarming. Few studies provide extensive interspecific comparisons of temporal activity patterns. Through broadband ultrasound detection, temporal variation of flight activity was studied in seven insectivorous bat species in N Poland for the first time. Seasonal activity pattern ofMyotis daubentonii (Kuhl, 1817) was clearly bimodal with the higher peak of activity in April and the second, smaller peak in August–September. The first peak is possibly associated with post-hibernal restoration of fat reserves, while the second one might result either from pre-hibernal fat accumulation, increase in energy demands of males during spermatogenesis or from dispersal of newly weaned juveniles. The highest flight activity ofNyctalus, Eptesicus andPipistrellus bats was noted in summer months, reflecting mainly an increase in energy demands between pregnancy and lactation. However, a distinct, second peak in activity ofN. noctula appeared at the end of September, probably matching the late migration wave of individuals from E Europe. The cluster analysis of species’ activity patterns reflected division on different hunting tactics, but not migratory behaviour.     

Neuroprotective action of FK-506 (tacrolimus) after seizures induced with pilocarpine: quantitative and topographic elemental analysis of brain tissue

In the present work, X-ray fluorescence microscopy with a synchrotron source for the exciting radiation was applied for topographic and quantitative elemental analysis of rat brain tissue in pilocarpine-induced epilepsy and neuroprotection with FK-506. The mass per unit area of the elements P, S, Cl, K, Ca, Fe, Cu, Zn, Se, Br, and Rb was determined in four fields of the hippocampal formation (sectors 1 and 3 of Ammon’s horn–CA1, CA3; dentate gyrus; hilus of dentate gyrus) and the parietal cortex. The results obtained for epileptic rats treated with FK-506 (SNF) were compared with data obtained previously for epileptic rats (SNS) and a control group. Many statistically significant differences in elemental composition were observed between the SNF and SNS groups. Higher mass per unit area of P was noticed in CA1 and CA3 regions of the hippocampus of SNF rats in comparison with SNS rats. A similar relation was observed for K in all five brain areas analyzed. Also, Fe in CA3 and dentate gyrus, Cu in the parietal cortex, and Zn in CA3 and in the cortex were present at a higher level in the SNF group in comparison with the SNS group. The findings obtained in the present study suggest that the neuroprotective action of FK-506 in epileptic rat brain may involve not only the inhibition of calcineurin but also blockade of the K⁺ channels.     

Animals in Iodine Deficiency or Sulfadimethoxine Models of Thyroid Damage Are Differently Affected by the Consumption of Brassica Sprouts

Biological Trace Element Research - The study was primarily aimed at investigating the effect of brassica sprout consumption, namely rutabaga (Brassica napus L. var. napobrassica) sprouts (R)...     

Pannexin-1 channel “fuels” by releasing ATP from bone marrow cells a state of sterile inflammation required for optimal mobilization and homing of hematopoietic stem cells

An efficient harvest of hematopoietic stem/progenitor cells (HSPCs) after pharmacological mobilization from the bone marrow (BM) into peripheral blood (PB) and subsequent proper homing and engraftment of these cells are crucial for clinical outcomes from hematopoietic transplants. Since extracellular adenosine triphosphate (eATP) plays an important role in both processes as an activator of sterile inflammation in the bone marrow microenvironment, we focused on the role of Pannexin-1 channel in the secretion of ATP to trigger both egress of HSPCs out of BM into PB as well as in reverse process that is their homing to BM niches after transplantation into myeloablated recipient. We employed a specific blocking peptide against Pannexin-1 channel and noticed decreased mobilization efficiency of HSPCs as well as other types of BM-residing stem cells including mesenchymal stroma cells (MSCs), endothelial progenitors (EPCs), and very small embryonic-like stem cells (VSELs). To explain better a role of Pannexin-1, we report that eATP activated Nlrp3 inflammasome in Gr-1⁺ and CD11b⁺ cells enriched for granulocytes and monocytes. This led to release of danger-associated molecular pattern molecules (DAMPs) and mitochondrial DNA (miDNA) that activate complement cascade (ComC) required for optimal egress of HSPCs from BM. On the other hand, Pannexin-1 channel blockage in transplant recipient mice leads to a defect in homing and engraftment of HSPCs. Based on this, Pannexin-1 channel as a source of eATP plays an important role in HSPCs trafficking.

     

Alleviation of Plant Stress Precedes Termination of Rich Fen Stages in Peat Profiles of Lowland Mires

Ecosystems - Mesotrophic rich fens, that is, groundwater-fed mires, may be long-lasting, as well as transient ecosystems, displaced in time by poor fens, bogs, forests or eutrophic reeds. We...     

GRSF1 Regulates RNA Processing in Mitochondrial RNA Granules

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Highlights? GRSF1 resides in the mitochondrial matrix and is required for mitochondrial function ? GRSF1 is required for the processing of tRNA-containing and tRNA-lacking precursors ? GRSF1, RNase P, and nascent RNA are part of “mitochondrial RNA granules” ? Mitochondrial RNA granules are functionally linked to RNA processing     

Gene Expression Profiling in Preterm Infants: New Aspects of Bronchopulmonary Dysplasia Development

Rationale

Bronchopulmonary dysplasia is one of the most serious complications observed in premature infants. Thanks to microarray technique, expression of nearly all human genes can be reliably evaluated.

Objective

To compare whole genome expression in the first month of life in groups of infants with and without bronchopulmonary dysplasia.

Methods

111 newborns were included in the study. The mean birth weight was 1029g (SD:290), and the mean gestational age was 27.8 weeks (SD:2.5). Blood samples were drawn from the study participants on the 5th, 14th and 28th day of life. The mRNA samples were evaluated for gene expression with the use of GeneChip® Human Gene 1.0 ST microarrays. The infants were divided into two groups: bronchopulmonary dysplasia (n=68) and control (n=43).

Results

Overall 2086 genes were differentially expressed on the day 5, only 324 on the day 14 and 3498 on the day 28. Based on pathway enrichment analysis we found that the cell cycle pathway was up-regulated in the bronchopulmonary dysplasia group. The activation of this pathway does not seem to be related with the maturity of the infant. Four pathways related to inflammatory response were continuously on the 5^th, 14^th and 28^th day of life down-regulated in the bronchopulmonary dysplasia group. However, the expression of genes depended on both factors: immaturity and disease severity. The most significantly down-regulated pathway was the T cell receptor signaling pathway.

Conclusion

The results of the whole genome expression study revealed alteration of the expression of nearly 10% of the genome in bronchopulmonary dysplasia patients.     

Unexpected bird-like features and high intraspecific variation in the braincase of the Triassic relative of dinosaurs

Abstract

Silesaurus opolensis Dzik, 2003 from the Late Triassic (late Carnian) of Poland is a key taxon for understanding the evolution of early dinosaurs. High intraspecific variation observed in the S. opolensis braincase brings caution in taxonomic and diversity studies of early dinosauromorphs. The external and internal osteology of three almost complete braincases of S. opolensis show that this taxon shares several similarities with other early dinosauriforms, which supports a close relationship among these forms. However, the paroccipital processes of S. opolensis are directed ventrally like in birds, reaching the level of the ventral margin of the basioccipital condyle. In dinosauromorphs, these processes usually have an almost horizontal orientation (presumed to be the plesiomorphic condition). Modifications observed in birds and S. opolensis have resulted in the dorsoventral expansion of M. complexus and M. depressor mandibulae, which occupy the dorsolateral part of the posterior side of the skull. In adult birds, these muscles act strongly on the initial upstroke of the head during drinking. Therefore, the inferred condition of these muscles in S. opolensis may imply that Silesauridae evolved toward bird-like feeding behaviour.